Efrat Levy, Ph.D.

Cystatin C is released in association with exosomes: A new tool of neuronal communication which is unbalanced in Alzheimer's disease
Ghidoni, Roberta; Paterlini, Anna; Albertini, Valentina; Glionna, Michela; Monti, Eugenio; Schiaffonati, Luisa; Benussi, Luisa; Levy, Efrat; Binetti, Giuliano
2011 ;32(8):1435-1442, Neurobiology of aging
It has recently become clear that proteins associated with neurodegenerative disorders can be selectively incorporated into intraluminal vesicles of multivesicular bodies and subsequently released within exosomes. Multiple lines of research support a neuroprotective role for cystatin C in Alzheimer's disease (AD). Herein we demonstrate that cystatin C, a protein targeted to the classical secretory pathway by its signal peptide sequence, is also secreted by mouse primary neurons in association with exosomes. Immunoproteomic analysis using SELDI-TOF MS revealed the presence in exosomes of at least 9 different cystatin C glycoforms. Moreover, the over-expression of familial AD-associated presenilin 2 mutations (PS2 M239I and PS2 T122R) resulted in reduced levels of all cystatin C forms (native and glycosylated) and of amyloid-beta precursor protein (APP) metabolites within exosomes. A better understanding of the mechanisms involved in exosomal processing and release may have important implications for the fight against AD and other neurodegenerative diseases.
— id: 135643, year: 2011, vol: 32, page: 1435, stat: Journal Article,

Sensory Network Dysfunction, Behavioral Impairments, and Their Reversibility in an Alzheimer's beta-Amyloidosis Mouse Model
Wesson DW; Borkowski AH; Landreth GE; Nixon RA; Levy E; Wilson DA
2011 Nov 2;31(44):15962-15971, Journal of neuroscience
The unique vulnerability of the olfactory system to Alzheimer's disease (AD) provides a quintessential translational tool for understanding mechanisms of synaptic dysfunction and pathological progression in the disease. Using the Tg2576 mouse model of beta-amyloidosis, we show that aberrant, hyperactive olfactory network activity begins early in life, before detectable behavioral impairments or comparable hippocampal dysfunction and at a time when amyloid-beta (Abeta) deposition is restricted to the olfactory bulb (OB). Hyperactive odor-evoked activity in the piriform cortex (PCX) and increased OB-PCX functional connectivity emerged at a time coinciding with olfactory behavior impairments. This hyperactive activity persisted until later in life when the network converted to a hyporesponsive state. This conversion was Abeta-dependent, because liver-X receptor agonist treatment to promote Abeta degradation rescued the hyporesponsive state and olfactory behavior. These data lend evidence to a novel working model of olfactory dysfunction in AD and, complimentary to other recent works, suggest that disease-relevant network dysfunction is highly dynamic and region specific, yet with lasting effects on cognition and behavior
— id: 145504, year: 2011, vol: 31, page: 15962, stat: Journal Article,

Mechanisms of neural and behavioral dysfunction in Alzheimer's disease
Wesson, Daniel W; Nixon, Ralph A; Levy, Efrat; Wilson, Donald A
2011 Jun;43(3):163-179, Molecular neurobiology
This review critically examines progress in understanding the link between Alzheimer's disease (AD) molecular pathogenesis and behavior, with an emphasis on the impact of amyloid-beta. We present the argument that the AD research field requires more multifaceted analyses into the impacts of Alzheimer's pathogenesis which combine simultaneous molecular-, circuit-, and behavior-level approaches. Supporting this argument is a review of particular research utilizing similar, 'systems-level' methods in mouse models of AD. Related to this, a critique of common physiological and behavioral models is made-highlighting the likely usefulness of more refined and specific tools in understanding the relationship between candidate molecular pathologies and behavioral dysfunction. Finally, we propose challenges for future research which, if met, may greatly extend our current understanding of how AD molecular pathology impacts neural network function and behavior and possibly may lead to refinements in disease therapeutics
— id: 131960, year: 2011, vol: 43, page: 163, stat: Journal Article,

Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis
Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel W; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A
2011 Jul 1;7(7):788-789, Autophagy
The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-beta peptide (Abeta) accumulation, extracellular beta-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Abeta, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Abeta40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Abeta clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD
— id: 134440, year: 2011, vol: 7, page: 788, stat: Journal Article,

Reversal of autophagy dysfunction in the TgCRND8 mouse model of Alzheimer's disease ameliorates amyloid pathologies and memory deficits
Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A
2011 Jan;134(Pt 1):258-277, Brain
Autophagy, a major degradative pathway for proteins and organelles, is essential for survival of mature neurons. Extensive autophagic-lysosomal pathology in Alzheimer's disease brain contributes to Alzheimer's disease pathogenesis, although the underlying mechanisms are not well understood. Here, we identified and characterized marked intraneuronal amyloid-beta peptide/amyloid and lysosomal system pathology in the Alzheimer's disease mouse model TgCRND8 similar to that previously described in Alzheimer's disease brains. We further establish that the basis for these pathologies involves defective proteolytic clearance of neuronal autophagic substrates including amyloid-beta peptide. To establish the pathogenic significance of these abnormalities, we enhanced lysosomal cathepsin activities and rates of autophagic protein turnover in TgCRND8 mice by genetically deleting cystatin B, an endogenous inhibitor of lysosomal cysteine proteases. Cystatin B deletion rescued autophagic-lysosomal pathology, reduced abnormal accumulations of amyloid-beta peptide, ubiquitinated proteins and other autophagic substrates within autolysosomes/lysosomes and reduced intraneuronal amyloid-beta peptide. The amelioration of lysosomal function in TgCRND8 markedly decreased extracellular amyloid deposition and total brain amyloid-beta peptide 40 and 42 levels, and prevented the development of deficits of learning and memory in fear conditioning and olfactory habituation tests. Our findings support the pathogenic significance of autophagic-lysosomal dysfunction in Alzheimer's disease and indicate the potential value of restoring normal autophagy as an innovative therapeutic strategy for Alzheimer's disease
— id: 126481, year: 2011, vol: 134, page: 258, stat: Journal Article,

Days to criterion as an indicator of toxicity associated with human Alzheimer amyloid-beta oligomers
Gandy, Sam; Simon, Adam J; Steele, John W; Lublin, Alex L; Lah, James J; Walker, Lary C; Levey, Allan I; Krafft, Grant A; Levy, Efrat; Checler, Frederic; Glabe, Charles; Bilker, Warren B; Abel, Ted; Schmeidler, James; Ehrlich, Michelle E
2010 Aug;68(2):220-230, Annals of neurology
OBJECTIVE: Recent evidence suggests that high molecular weight soluble oligomeric Abeta (oAbeta) assemblies (also known as Abeta-derived diffusible ligands, or ADDLs) may represent a primary neurotoxic basis for cognitive failure in Alzheimer disease (AD). To date, most in vivo studies of oAbeta/ADDLs have involved injection of assemblies purified from the cerebrospinal fluid of human subjects with AD or from the conditioned media of Abeta-secreting cells into experimental animals. We sought to study the bioactivities of endogenously formed oAbeta/ADDLs generated in situ from the physiological processing of human amyloid precursor protein (APP) and presenitin1 (PS1) transgenes. METHODS: We produced and histologically characterized single transgenic mice overexpressing APP(E693Q) or APP(E693Q) X PS1DeltaE9 bigenic mice. APP(E693Q) mice were studied in the Morris water maze (MWM) task at 6 and 12 months of age. Following the second MWM evaluation, mice were sacrificed, and brains were assayed for Abetatotal, Abeta40, Abeta42, and oAbeta/ADDLs by enzyme-linked immunosorbent assay (ELISA) and were also histologically examined. Based on results from the oAbeta/ADDL ELISA, we assigned individual APP(E693Q) mice to either an undetectable oAbeta/ADDLs group or a readily detectable oAbeta/ADDLs group. A days to criterion (DTC) analysis was used to determine delays in acquisition of the MWM task. RESULTS: Both single transgenic and bigenic mice developed intraneuronal accumulation of APP/Abeta, although only APP(E693Q) X PS1Delta9 bigenic mice developed amyloid plaques. The APP(E693Q) mice did not develop amyloid plaques at any age studied, up to 30 months. APP(E693Q) mice were tested for spatial learning and memory, and only 12-month-old APP(E693Q) mice with readily detectable oAbeta/ADDLs displayed a significant delay in acquisition of the MWM task when compared to nontransgenic littermates. INTERPRETATION: These data suggest that cerebral oAbeta/ADDL assemblies generated in brain in situ from human APP transgenes may be associated with cognitive impairment. We propose that a DTC analysis may be a sensitive method for assessing the cognitive impact in mice of endogenously generated oligomeric human Abeta assemblies. ANN NEUROL 2010
— id: 139843, year: 2010, vol: 68, page: 220, stat: Journal Article,

Plasma cystatin C and risk of developing Alzheimer's disease in subjects with mild cognitive impairment
Ghidoni, Roberta; Benussi, Luisa; Glionna, Michela; Desenzani, Silvia; Albertini, Valentina; Levy, Efrat; Emanuele, Enzo; Binetti, Giuliano
2010 ;22(3):985-991, Journal of Alzheimer's Disease
Recent years have witnessed an increasing interest in mild cognitive impairment (MCI), particularly as a possible prodromal stage of Alzheimer's disease (AD). Experimental and clinical data have suggested that cystatin C (CysC) is protective against the development of AD. In this study, we sought to cross-sectionally and longitudinally investigate the changes in plasma CysC levels in patients with MCI and whether the levels of this molecule might serve as a biochemical predictor of cognitive decline in this patient group. Cross-sectional analysis of baseline data showed a borderline significant difference in plasma CysC levels among the three study groups (Controls, n=63; AD, n=63; MCI, n=59) (p =0.032) that disappeared after post hoc analysis. Plasma CysC levels did not differ at baseline (t1) and at follow-up (t2) both in MCI patients that converted to AD (n= 32) and those that did not convert (n=27). However, a significant independent association between CysC at t1 and CysC at t2 was found in non-converters but not in converters MCI subjects. Moreover, when disease onset was evaluated in patients groups stratified on the basis of their CysC plasma levels, a significant anticipation of the conversion to dementia in MCI subjects with CysC levels below the median (CysC < 1067 ng/ml) (p =0.0011) was observed. Altogether, this work adds to the growing body of literature suggesting that CysC modulates the clinical expression of cognitive decline, and opens a new area of investigation of CysC as a therapeutic target for neurodegenerative disorders
— id: 140041, year: 2010, vol: 22, page: 985, stat: Journal Article,

Cystatin C rescues degenerating neurons in a cystatin B-knockout mouse model of progressive myoclonus epilepsy
Kaur, Gurjinder; Mohan, Panaiyur; Pawlik, Monika; DeRosa, Steven; Fajiculay, Jay; Che, Shaoli; Grubb, Anders; Ginsberg, Stephen D; Nixon, Ralph A; Levy, Efrat
2010 Nov;177(5):2256-2267, American journal of pathology
In vitro studies have shown that cystatin C (CysC) is neuroprotective. Here we demonstrate that CysC is neuroprotective in vivo, in a mouse model of the inherited neurodegenerative disorder, progressive myoclonic epilepsy type 1 (EPM1). Loss-of-function mutations in the cystatin B (CysB) gene, an intracellular cysteine protease inhibitor, lead to this human disease. A CysB-knockout (CysBKO) mouse model develops symptoms that mimic EPM1. CysB deficiency in these mice results in enhanced cathepsin B and D activities, indicating lysosomal dysfunction. We show that expression of CysC is enhanced in the brains of CysBKO mice. Crossbreeding of CysBKO mice with either CysC-overexpressing transgenic mice or CysC-knockout mice demonstrates that clinical symptoms and neuropathologies, including motor coordination disorder, cerebellar atrophy, neuronal loss in the cerebellum and cerebral cortex, and gliosis caused by CysB deficiency, are rescued by CysC overexpression and exacerbated by CysC deficiency. Thus, CysC effectively rescues the CysB loss-of-function mutations, facilitating the reversal of pathophysiological changes and suggesting a novel therapeutic intervention for patients with EPM1 and other neurodegenerative disorders
— id: 126484, year: 2010, vol: 177, page: 2256, stat: Journal Article,

Novel phage peptides attenuate beta amyloid-42 catalysed hydrogen peroxide production and associated neurotoxicity
Taddei, K; Laws, S. M; Verdile, G; Munns, S; D'Costa, K; Harvey, A. R; Martins, I. J; Hill, F; Levy, E; Shaw, J. E; Martins, R. N
2010 ;31(2):203-214, Neurobiology of aging
Amyloid-beta (Abeta ) peptides play a central role in the pathogenesis of Alzheimer's disease. There is accumulating evidence that supports the notion that the toxicity associated with human Abeta (both 40 and 42) is dependent on its superoxide dismutase (SOD)-like activity. We developed a novel screening method involving phage display technology to identify novel peptides capable of inhibiting Abeta 's neurotoxicity. Two random peptide libraries containing 6-mer and 15-mer peptide inserts were used and resulted in the identification of 25 peptides that bound human Abeta (40 or 42). Here, we show that two of the three most enriched peptides obtained significantly reduced Abeta 42's SOD-like activity. A 15-mer peptide reduced Abeta 42 neurotoxicity in a dose-dependent manner as evidenced by a reduction in LDH release. These findings were confirmed in the independent MTT assay. Furthermore, comparative analysis of the 15-mer peptide with Clioquinol, a known inhibitor of Abeta 's metal-mediated redox activity, showed the 15-mer peptide to be equipotent to this metal chelator, under the same experimental conditions. These agents represent novel peptides that selectively target and neutralise Abeta -induced neurotoxicity and thus provide promising leads for rational drug development.
— id: 107649, year: 2010, vol: 31, page: 203, stat: Journal Article,

Cystatin C Protects Neuronal Cells from Amyloid-beta-induced Toxicity
Tizon, B; Ribe, EM; Mi, WQ; Troy, CM; Levy, E
2010 MAR ;19(3):885-894, Journal of Alzheimer's Disease
Multiple studies suggest that cystatin C (CysC) has a role in Alzheimer's disease (AD) and a decrease in CysC secretion is linked to the disease in patients with a polymorphism in the CysC gene. CysC binds amyloid-beta (A beta) and inhibits formation of A beta fibrils and oligomers both in vitro and in mouse models of amyloid deposition. Here we studied the effect of CysC on cultured primary hippocampal neurons and a neuronal cell line exposed to either oligomeric or fibrillar cytotoxic forms of A beta. The extracellular addition of the secreted human CysC together with preformed either oligomeric or fibrillar A beta increased cell survival. While CysC inhibits A beta aggregation, it does not dissolve preformed A beta fibrils or oligomers. Thus, CysC has multiple protective effects in AD, by preventing the formation of the toxic forms of A beta and by direct protection of neuronal cells from A beta toxicity. Therapeutic manipulation of CysC levels, resulting in slightly higher concentrations than physiological could protect neuronal cells from cell death in AD
— id: 109503, year: 2010, vol: 19, page: 885, stat: Journal Article,

Induction of autophagy by cystatin C: a mechanism that protects murine primary cortical neurons and neuronal cell lines
Tizon, Belen; Sahoo, Susmita; Yu, Haung; Gauthier, Sebastien; Kumar, Asok R; Mohan, Panaiyur; Figliola, Matthew; Pawlik, Monika; Grubb, Anders; Uchiyama, Yasuo; Bandyopadhyay, Urmi; Cuervo, Ana Maria; Nixon, Ralph A; Levy, Efrat
2010 ;5(3):e9819-e9819, PLoS ONE
Cystatin C (CysC) expression in the brain is elevated in human patients with epilepsy, in animal models of neurodegenerative conditions, and in response to injury, but whether up-regulated CysC expression is a manifestation of neurodegeneration or a cellular repair response is not understood. This study demonstrates that human CysC is neuroprotective in cultures exposed to cytotoxic challenges, including nutritional-deprivation, colchicine, staurosporine, and oxidative stress. While CysC is a cysteine protease inhibitor, cathepsin B inhibition was not required for the neuroprotective action of CysC. Cells responded to CysC by inducing fully functional autophagy via the mTOR pathway, leading to enhanced proteolytic clearance of autophagy substrates by lysosomes. Neuroprotective effects of CysC were prevented by inhibiting autophagy with beclin 1 siRNA or 3-methyladenine. Our findings show that CysC plays a protective role under conditions of neuronal challenge by inducing autophagy via mTOR inhibition and are consistent with CysC being neuroprotective in neurodegenerative diseases. Thus, modulation of CysC expression has therapeutic implications for stroke, Alzheimer's disease, and other neurodegenerative disorders
— id: 109506, year: 2010, vol: 5, page: e9819, stat: Journal Article,

Olfactory dysfunction correlates with amyloid-beta burden in an Alzheimer's disease mouse model
Wesson, Daniel W; Levy, Efrat; Nixon, Ralph A; Wilson, Donald A
2010 Jan 13;30(2):505-514, Journal of neuroscience
Alzheimer's disease often results in impaired olfactory perceptual acuity-a potential biomarker of the disorder. However, the usefulness of olfactory screens to serve as informative indicators of Alzheimer's is precluded by a lack of knowledge regarding why the disease impacts olfaction. We addressed this question by assaying olfactory perception and amyloid-beta (Abeta) deposition throughout the olfactory system in mice that overexpress a mutated form of the human amyloid-beta precursor protein. Such mice displayed progressive olfactory deficits that mimic those observed clinically-some evident at 3 months of age. Also, at 3 months of age, we observed nonfibrillar Abeta deposition within the olfactory bulb-earlier than deposition within any other brain region. There was also a correlation between olfactory deficits and the spatial-temporal pattern of Abeta deposition. Therefore, nonfibrillar, versus fibrillar, Abeta-related mechanisms likely contribute to early olfactory perceptual loss in Alzheimer's disease. Furthermore, these results present the odor cross-habituation test as a powerful behavioral assay, which reflects Abeta deposition and thus may serve to monitor the efficacy of therapies aimed at reducing Abeta
— id: 126491, year: 2010, vol: 30, page: 505, stat: Journal Article,

Age-dependent dysregulation of brain amyloid precursor protein in the Ts65Dn Down syndrome mouse model
Choi, Jennifer H K; Berger, Jason D; Mazzella, Matthew J; Morales-Corraliza, Jose; Cataldo, Anne M; Nixon, Ralph A; Ginsberg, Stephen D; Levy, Efrat; Mathews, Paul M
2009 Sep;110(6):1818-1827, Journal of neurochemistry
Individuals with Down syndrome develop beta-amyloid deposition characteristic of early-onset Alzheimer's disease (AD) in mid-life, presumably because of an extra copy of the chromosome 21-located amyloid precursor protein (App) gene. App mRNA and APP metabolite levels were assessed in the brains of Ts65Dn mice, a mouse model of Down syndrome, using quantitative PCR, western blot analysis, immunoprecipitation, and ELISAs. In spite of the additional App gene copy, App mRNA, APP holoprotein, and all APP metabolite levels in the brains of 4-month-old trisomic mice were not increased compared with the levels seen in diploid littermate controls. However starting at 10 months of age, brain APP levels were increased proportional to the App gene dosage imbalance reflecting increased App message levels in Ts65Dn mice. Similar to APP levels, soluble amino-terminal fragments of APP (sAPPalpha and sAPPbeta) were increased in Ts65Dn mice compared with diploid mice at 12 months but not at 4 months of age. Brain levels of both Abeta40 and Abeta42 were not increased in Ts65Dn mice compared with diploid mice at all ages examined. Therefore, multiple mechanisms contribute to the regulation towards diploid levels of APP metabolites in the Ts65Dn mouse brain
— id: 126493, year: 2009, vol: 110, page: 1818, stat: Journal Article,

A recessive mutation in the APP gene with dominant-negative effect on amyloidogenesis
Di Fede, Giuseppe; Catania, Marcella; Morbin, Michela; Rossi, Giacomina; Suardi, Silvia; Mazzoleni, Giulia; Merlin, Marco; Giovagnoli, Anna Rita; Prioni, Sara; Erbetta, Alessandra; Falcone, Chiara; Gobbi, Marco; Colombo, Laura; Bastone, Antonio; Beeg, Marten; Manzoni, Claudia; Francescucci, Bruna; Spagnoli, Alberto; Cantu, Laura; Del Favero, Elena; Levy, Efrat; Salmona, Mario; Tagliavini, Fabrizio
2009 Mar 13;323(5920):1473-1477, Science
beta-Amyloid precursor protein (APP) mutations cause familial Alzheimer's disease with nearly complete penetrance. We found an APP mutation [alanine-673-->valine-673 (A673V)] that causes disease only in the homozygous state, whereas heterozygous carriers were unaffected, consistent with a recessive Mendelian trait of inheritance. The A673V mutation affected APP processing, resulting in enhanced beta-amyloid (Abeta) production and formation of amyloid fibrils in vitro. Co-incubation of mutated and wild-type peptides conferred instability on Abeta aggregates and inhibited amyloidogenesis and neurotoxicity. The highly amyloidogenic effect of the A673V mutation in the homozygous state and its anti-amyloidogenic effect in the heterozygous state account for the autosomal recessive pattern of inheritance and have implications for genetic screening and the potential treatment of Alzheimer's disease
— id: 135217, year: 2009, vol: 323, page: 1473, stat: Journal Article,

Systemic pathology in aged mouse models of Down's syndrome and Alzheimer's disease
Levine, Seymour; Saltzman, Arthur; Levy, Efrat; Ginsberg, Stephen D
2009 Feb;86(1):18-22, Experimental & molecular pathology
Down's syndrome (DS) in humans is caused by trisomy of chromosome 21 (HSA 21). DS patients have a variety of pathologies, including mental retardation and an unusually high incidence of leukemia or lymphoma such as megakaryocytic leukemia. Individuals with DS develop the characteristic neuropathological hallmarks of Alzheimer's disease (AD) in early adulthood, generally by the fourth decade of life. There are several mouse models of DS that have a segmental trisomy of mouse chromosome 16 (MMU 16) with triplicated genes orthologous to HSA 21. These mice display neurodegeneration similar to DS. Although brain pathology in DS models is known, little information is available about other organs. We studied the extraneural pathology in aged DS mice (Ts65Dn, Ts2 and Ts1Cje aged 8 to 24 months) as well as other mouse models of neurodegeneration, including presenilin (PS), amyloid-beta precursor protein (APP), and tau (hTau and JNPL) transgenic mice. An increased incidence of peripheral amyloidosis, positive for amyloid A (AA) but not amyloid-beta peptide (A beta), was found in APP over-expressing and tauopathic mice as compared to non-transgenic (ntg) littermates or to DS mouse models. A higher incidence of lymphoma was found in the DS models, including Ts1Cje that is trisomic for a small segment of MMU 16 not including the App gene, but not in the APP over-expressing mice, suggesting that high APP expression is not the cause of lymphoma in DS. The occurrence of lymphomas in mouse DS models is of interest in relation to the increased incidence of malignant conditions in human DS
— id: 95847, year: 2009, vol: 86, page: 18, stat: Journal Article,

CYSTATIN C BINDS AMYLOID beta AND INHIBITS ITS OLIGOMERIZATION, FIBRIL FORMATION, AND DEPOSITION IN ALZHEIMER'S DISEASE MOUSE MODELS
Levy, E
2009 APR ;43(2):149-150, Neuropeptides
— id: 98842, year: 2009, vol: 43, page: 149, stat: Journal Article,

Complexes of amyloid-beta and cystatin C in the human central nervous system
Mi, Weiqian; Jung, Sonia S; Yu, Haung; Schmidt, Stephen D; Nixon, Ralph A; Mathews, Paul M; Tagliavini, Fabrizio; Levy, Efrat
2009 ;18(2):273-280, Journal of Alzheimer's Disease
A role for cystatin C (CysC) in the pathogenesis of Alzheimer's disease (AD) has been suggested by the genetic linkage of a CysC gene (CST3) polymorphism with late-onset AD, the co-localization of CysC with amyloid-beta (Abeta) in AD brains, and binding of CysC to soluble Abeta in vitro and in mouse models of AD. This study investigates the binding between Abeta and CysC in the human central nervous system. While CysC binding to soluble Abeta was observed in AD patients and controls, a SDS-resistant CysC/Abeta complex was detected exclusively in brains of neuropathologically normal controls, but not in AD cases. The association of CysC with Abeta in brain from control individuals and in cerebrospinal fluid reveals an interaction of these two polypeptides in their soluble form. The association between Abeta and CysC prevented Abeta accumulation and fibrillogenesis in experimental systems, arguing that CysC plays a protective role in the pathogenesis of AD in humans and explains why decreases in CysC concentration caused by the CST3 polymorphism or by specific presenilin 2 mutations can lead to the development of the disease. Thus, enhancing CysC expression or modulating CysC binding to Abeta have important disease-modifying effects, suggesting a novel therapeutic intervention for AD
— id: 126494, year: 2009, vol: 18, page: 273, stat: Journal Article,

In vivo turnover of tau and APP metabolites in the brains of wild-type and Tg2576 mice: greater stability of sAPP in the beta-amyloid depositing mice
Morales-Corraliza, Jose; Mazzella, Matthew J; Berger, Jason D; Diaz, Nicole S; Choi, Jennifer H K; Levy, Efrat; Matsuoka, Yasuji; Planel, Emmanuel; Mathews, Paul M
2009 ;4(9):e7134-e7134, PLoS ONE
The metabolism of the amyloid precursor protein (APP) and tau are central to the pathobiology of Alzheimer's disease (AD). We have examined the in vivo turnover of APP, secreted APP (sAPP), Abeta and tau in the wild-type and Tg2576 mouse brain using cycloheximide to block protein synthesis. In spite of overexpression of APP in the Tg2576 mouse, APP is rapidly degraded, similar to the rapid turnover of the endogenous protein in the wild-type mouse. sAPP is cleared from the brain more slowly, particularly in the Tg2576 model where the half-life of both the endogenous murine and transgene-derived human sAPP is nearly doubled compared to wild-type mice. The important Abeta degrading enzymes neprilysin and IDE were found to be highly stable in the brain, and soluble Abeta40 and Abeta42 levels in both wild-type and Tg2576 mice rapidly declined following the depletion of APP. The cytoskeletal-associated protein tau was found to be highly stable in both wild-type and Tg2576 mice. Our findings unexpectedly show that of these various AD-relevant protein metabolites, sAPP turnover in the brain is the most different when comparing a wild-type mouse and a beta-amyloid depositing, APP overexpressing transgenic model. Given the neurotrophic roles attributed to sAPP, the enhanced stability of sAPP in the beta-amyloid depositing Tg2576 mice may represent a neuroprotective response
— id: 106444, year: 2009, vol: 4, page: e7134, stat: Journal Article,

Olfactory Perceptual Correlates of b-Amyloid Plaque Burden in Alzheimer's Disease Mouse Models
Wesson, DW; Levy, E; Nixon, RA; Wilson, DA
2009 SEP ;34(7):A26-A27, Chemical Senses
— id: 101941, year: 2009, vol: 34, page: A26, stat: Journal Article,

Cystatin C: a potential target for Alzheimer's treatment
Levy, Efrat
2008 May;8(5):687-689, Expert review of neurotherapeutics
— id: 79424, year: 2008, vol: 8, page: 687, stat: Journal Article,

Neuronal apoptosis and autophagy cross talk in aging PS/APP mice, a model of Alzheimer's disease
Yang, Dun-Sheng; Kumar, Asok; Stavrides, Philip; Peterson, Jesse; Peterhoff, Corrine M; Pawlik, Monika; Levy, Efrat; Cataldo, Anne M; Nixon, Ralph A
2008 Sep;173(3):665-681, American journal of pathology
Mechanisms of neuronal loss in Alzheimer's disease (AD) are poorly understood. Here we show that apoptosis is a major form of neuronal cell death in PS/APP mice modeling AD-like neurodegeneration. Pyknotic neurons in adult PS/APP mice exhibited apoptotic changes, including DNA fragmentation, caspase-3 activation, and caspase-cleaved alpha-spectrin generation, identical to developmental neuronal apoptosis in wild-type mice. Ultrastructural examination using immunogold cytochemistry confirmed that activated caspase-3-positive neurons also exhibited chromatin margination and condensation, chromatin balls, and nuclear membrane fragmentation. Numbers of apoptotic profiles in both cortex and hippocampus of PS/APP mice compared with age-matched controls were twofold to threefold higher at 6 months of age and eightfold higher at 21 to 26 months of age. Additional neurons undergoing dark cell degeneration exhibited none of these apoptotic features. Activated caspase-3 and caspase-3-cleaved spectrin were abundant in autophagic vacuoles, accumulating in dystrophic neurites of PS/APP mice similar to AD brains. Administration of the cysteine protease inhibitor, leupeptin, promoted accumulation of autophagic vacuoles containing activated caspase-3 in axons of PS/APP mice and, to a lesser extent, in those of wild-type mice, implying that this pro-apoptotic factor is degraded by autophagy. Leupeptin-induced autophagic impairment increased the number of apoptotic neurons in PS/APP mice. Our findings establish apoptosis as a mode of neuronal cell death in aging PS/APP mice and identify the cross talk between autophagy and apoptosis, which influences neuronal survival in AD-related neurodegeneration
— id: 86556, year: 2008, vol: 173, page: 665, stat: Journal Article,

Dysregulation of brain APP in the Ts65Dn Down syndrome mouse
Choi, JH; Mazzella, MJ; Berger, JD; Cataldo, AM; Ginsberg, SD; Levy, E; Nixon, RA; Mathews, PM
2007 AUG ;102(3):131-131, Journal of neurochemistry
— id: 74183, year: 2007, vol: 102, page: 131, stat: Journal Article,

Alzheimer's presenilin 1 modulates sorting of APP and its carboxyl-terminal fragments in cerebral neurons in vivo (vol 102, pg 619, 2007)
Gandy, S; Zhang, YW; Ikin, A; Schmidt, SD; Bogush, A; Levy, E; Sheffield, R; Nixon, RA; Liao, FF; Mathews, PM; Xu, HX; Ehrlich, ME
2007 NOV ;103(3):1272-1272, Journal of neurochemistry
— id: 74687, year: 2007, vol: 103, page: 1272, stat: Journal Article,

Alzheimer's presenilin 1 modulates sorting of APP and its carboxyl-terminal fragments in cerebral neurons in vivo
Gandy, Sam; Zhang, Yun-wu; Ikin, Annat; Schmidt, Stephen D; Bogush, Alexey; Levy, Efrat; Sheffield, Roxanne; Nixon, Ralph A; Liao, Francesca-Fang; Mathews, Paul M; Xu, Huaxi; Ehrlich, Michelle E
2007 Aug;102(3):619-626, Journal of neurochemistry
Studies in continuously cultured cells have established that familial Alzheimer's disease (FAD) mutant presenilin 1 (PS1) delays exit of the amyloid precursor protein (APP) from the trans-Golgi network (TGN). Here we report the first description of PS1-regulated APP trafficking in cerebral neurons in culture and in vivo. Using neurons from transgenic mice or a cell-free APP transport vesicle biogenesis system derived from the TGN of those neurons, we demonstrated that knocking-in an FAD-associated mutant PS1 transgene was associated with delayed kinetics of APP arrival at the cell surface. Apparently, this delay was at least partially attributable to impaired exit of APP from the TGN, which was documented in the cell-free APP transport vesicle biogenesis assay. To extend the study to APP and carboxyl terminal fragment (CTF) trafficking to cerebral neurons in vivo, we performed subcellular fractionation of brains from APP transgenic mice, some of which carried a second transgene encoding an FAD-associated mutant form of PS1. The presence of the FAD mutant PS1 was associated with a slight shift in the subcellular localization of both holoAPP and APP CTFs toward iodixanol density gradient fractions that were enriched in a marker for the TGN. In a parallel set of experiments, we used an APP : furin chimeric protein strategy to test the effect of artificially forcing TGN concentration of an APP : furin chimera that could be a substrate for beta- and gamma-cleavage. This chimeric substrate generated excess Abeta42 when compared with wildtype APP. These data indicate that the presence of an FAD-associated mutant human PS1 transgene is associated with redistribution of the APP and APP CTFs in brain neurons toward TGN-enriched fractions. The chimera experiment suggests that TGN-enrichment of a beta-/gamma-secretase substrate may play an integral role in the action of mutant PS1 to elevate brain levels of Abeta42
— id: 95391, year: 2007, vol: 102, page: 619, stat: Journal Article,

Cystatin C modulates cerebral beta-amyloidosis
Kaeser, Stephan A; Herzig, Martin C; Coomaraswamy, Janaky; Kilger, Ellen; Selenica, Maj-Linda; Winkler, David T; Staufenbiel, Matthias; Levy, Efrat; Grubb, Anders; Jucker, Mathias
2007 Dec;39(12):1437-1439, Nature genetics
The CST3 Thr25 allele of CST3, which encodes cystatin C, leads to reduced cystatin C secretion and conveys susceptibility to Alzheimer's disease. Here we show that overexpression of human cystatin C in brains of APP-transgenic mice reduces cerebral amyloid-beta deposition and that cystatin C binds amyloid-beta and inhibits its fibril formation. Our results suggest that cystatin C concentrations modulate cerebral amyloidosis risk and provide an opportunity for genetic risk assessment and therapeutic interventions
— id: 95848, year: 2007, vol: 39, page: 1437, stat: Journal Article,

Cystatin C inhibits amyloid-beta deposition in Alzheimer's disease mouse models
Mi, Weiqian; Pawlik, Monika; Sastre, Magdalena; Jung, Sonia S; Radvinsky, David S; Klein, Andrew M; Sommer, John; Schmidt, Stephen D; Nixon, Ralph A; Mathews, Paul M; Levy, Efrat
2007 Dec;39(12):1440-1442, Nature genetics
Using transgenic mice expressing human cystatin C (encoded by CST3), we show that cystatin C binds soluble amyloid-beta peptide and inhibits cerebral amyloid deposition in amyloid-beta precursor protein (APP) transgenic mice. Cystatin C expression twice that of the endogenous mouse cystatin C was sufficient to substantially diminish amyloid-beta deposition. Thus, cystatin C has a protective role in Alzheimer's disease pathogenesis, and modulation of cystatin C concentrations may have therapeutic implications for the disease
— id: 95389, year: 2007, vol: 39, page: 1440, stat: Journal Article,

Proteins that bind to the RERMS region of beta amyloid precursor protein
Pawlik, Monika; Otero, Deborah A C; Park, Minkyu; Fischer, Wolfgang H; Levy, Efrat; Saitoh, Tsunao
2007 Apr 20;355(4):907-912, Biochemical & biophysical research communications
The main objective of this study was to investigate the biological function of beta amyloid precursor protein (APP), in particular its nerve growth factor-like activity. We hypothesize that the extracellular domain containing the sequence RERMS, amino acids 328-332 of APP(695), represents the active site for this function. Binding assays using peptide fragments of this domain have demonstrated specific and saturable binding to the cell surface with affinity in the low nanomolar range. This induced our quest for an APP-specific receptor. We chose different peptide fragments of the RERMS domain as ligands and displacing agents on affinity columns to purify APP-binding molecules. Amino acid microsequencing yielded partial sequences of serum albumin, actin, two novel proteins of 41 and 63kDa, and human Collapsin Response Mediator Protein-2 (hCRMP-2). Because both APP and hCRMP-2 promote neuronal outgrowth and use a common signaling pathway, APP could be acting through a semaphorin receptor as well
— id: 95849, year: 2007, vol: 355, page: 907, stat: Journal Article,

The role of cystatin C in cerebral amyloid angiopathy and stroke: cell biology and animal models
Levy, Efrat; Jaskolski, Mariusz; Grubb, Anders
2006 Jan;16(1):60-70, Brain pathology
A variant of the cysteine protease inhibitor, cystatin C, forms amyloid deposited in the cerebral vasculature of patients with hereditary cerebral hemorrhage with amyloidosis, Icelandic type (HCHWA-I), leading to cerebral hemorrhages early in life. However, cystatin C is also implicated in neuronal degenerative diseases in which it does not form the amyloid protein, such as Alzheimer disease (AD). Accumulating data suggest involvement of cystatin C in the pathogenic processes leading to amyloid deposition in cerebral vasculature and most significantly to cerebral hemorrhage in patients with cerebral amyloid angiopathy (CAA). This review focuses on cell culture and animal models used to study the role of cystatin C in these processes
— id: 64170, year: 2006, vol: 16, page: 60, stat: Journal Article,

Studies on the first described Alzheimer's disease amyloid beta mutant, the Dutch variant
Levy, Efrat; Prelli, Frances; Frangione, Blas
2006 ;9(3 Suppl):329-339, Journal of Alzheimer's Disease
Amyloid protein deposited in cerebral vessel walls and diffuse plaques of patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type (HCHWA-D), is similar to the 40-42 residues amyloid beta (Abeta) in vessel walls and senile plaques in brains of patients with Alzheimer's disease (AD), Down's syndrome, and familial and sporadic cerebral amyloid angiopathy (CAA). In 1990 we sequenced the amyloid beta-protein precursor (AbetaPP) gene from HCHWA-D patients revealing a single mutation that results in an amino acid substitution, Abeta E22Q. Subsequent identification of additional mutations in the AbetaPP gene in familial AD (FAD) pedigrees revealed that whereas substitutions in the middle of Abeta, residues Abeta21-23, are predominantly vasculotropic, those found amino- or carboxyl-terminal to the Abeta sequence within AbetaPP enhance amyloid parenchymal plaque deposition. Studies of transfected cells showed that substitutions amino- or carboxyl-terminal to Abeta lead to either greater Abeta production or to enhanced secretion of the more hydrophobic thus more fibrillogenic Abeta1-42. Substitutions in the center of Abeta facilitate rapid aggregation and fibrillization, slower clearance across the blood-brain barrier and perivascular drainage to the systemic circulation, possibly higher resistance to proteolysis, and enhanced toxicity towards endothelial and smooth muscle cells. However, most AD patients have no genetic defects in AbetaPP, indicating that other factors may alter Abeta production, conformation, and/or clearance initiating the disease process
— id: 68936, year: 2006, vol: 9, page: 329, stat: Journal Article,

Murine cerebrovascular cells as a cell culture model for cerebral amyloid angiopathy: isolation of smooth muscle and endothelial cells from mouse brain
Jung, Sonia S; Levy, Efrat
2005 ;299:211-219, Methods in molecular biology
The use of murine cerebrovascular cells, that is, endothelial and smooth muscle cells, has not been widely employed as a cell culture model for the investigation of cellular mechanisms involved in cerebral amyloid angiopathy (CAA). Difficulties in isolation and propagation of murine cerebrovascular cells and insufficient yields for molecular and cell culture studies have deterred investigators from using mice as a source for cerebrovascular cells in culture. To date, most of the literature has described isolation of smooth muscle cells or endothelial cells from human, canine, rat, guinea pig, or other large animals. In recent years, several transgenic mice have been established that show CAA pathology; therefore, it is necessary to re-examine the use of mouse cerebrovascular cells as an important model for cell culture studies. We have optimized the isolation procedure of (1) murine microvessels, (2) smooth muscle cells, and (3) endothelial cells to yield a sufficient population of cells for experimentation purposes. Comparisons with rat and human isolation procedures are also noted. Murine smooth muscle cells isolated using the methodology described herein exhibit the classic 'hill and valley' morphology and are immunoreactive for smooth muscle cell-specific alpha-actin, whereas endothelial cells demonstrate a more 'cobblestone' appearance and stain for von Willebrand factor or factor VIII-related antigen
— id: 60834, year: 2005, vol: 299, page: 211, stat: Journal Article,

Periprocedural morbidity and mortality associated with endovascular treatment of intracranial aneurysms
Park, Hae-Kwan; Horowitz, Michael; Jungreis, Charles; Genevro, Julie; Koebbe, Christopher; Levy, Elad; Kassam, Amin
2005 Mar;26(3):506-514, AJNR. American journal of neuroradiology
BACKGROUND AND PURPOSE: Despite experience and technological improvements, endovascular treatment of intracranial aneurysms still has inherent risks. We evaluated cerebral complications associated with this treatment. METHODS: From October 1998 to October 2002, 180 consecutive patients underwent 131 procedures for 118 ruptured aneurysms and 79 procedures for 72 unruptured aneurysms. We retrospectively reviewed their records and images to evaluate their morbidity and mortality. RESULTS: Thirty-seven (17.6%) procedure-related complications occurred: 27 and six with initial embolization of ruptured and unruptured aneurysms, respectively, and four with re-treatment. Complications included 22 cerebral thromboembolisms, nine intraprocedural aneurysm perforations, two coil migrations, two parent vessel injuries, one postprocedural aneurysm rupture, and one cranial nerve palsy. Fourteen complications had no neurologic consequence. Three caused transient neurologic morbidity; 10, persistent neurologic morbidity; and 10, death. Procedure-related neurologic morbidity and mortality rates, respectively, were as follows: overall, 4.8% and 4.8%; ruptured aneurysms, 5.9% and 7.6%; unruptured aneurysms, 1.4% and 1.4%; and re-treated aneurysms, 10% and 0%. Combined procedure-related morbidity and mortality rates for ruptured, unruptured, and re-treated aneurysms were 13.5%, 2.8%, and 10%, respectively. Nonprocedural complications attributable to subarachnoid hemorrhage in 118 patients with ruptured aneurysm were early rebleeding before coil placement (0.9%), symptomatic vasospasm (5.9%), and shunt-dependent hydrocephalus (5.9%); mortality from complications of subarachnoid hemorrhage itself was 11.9%. CONCLUSION: Procedural morbidity and mortality rates were highest in ruptured aneurysms and lowest in unruptured aneurysms. Morbidity rates were highest in re-treated aneurysms and lowest in unruptured aneurysms. No procedural mortality occurred with re-treated aneurysms. The main cause of morbidity and mortality was thromboembolism
— id: 146469, year: 2005, vol: 26, page: 506, stat: Journal Article,

Purification of human wild-type or variant cystatin C from conditioned media of transfected cells
Prelli, Frances; Pawlik, Monika; Frangione, Blas; Levy, Efrat
2005 ;299:221-226, Methods in molecular biology
The characterization of proteins in their native state is essential for the understanding of patho-genic isoforms. A variant of the cysteine protease inhibitor cystatin C is the major constituent of the amyloid deposited in the cerebral vasculature of patients with the Icelandic form of hereditary cerebral hemorrhage with amyloidosis (HCHWA-I). In order to study the nature of the bio-physical changes owing to the Leu68Gln substitution in cystatin C, we have developed a purification procedure of human cystatin C in its native state. The protein is isolated from media of stably transfected tissue culture cells using physiological conditions that preclude protein denaturation. The importance of mild purification conditions is underscored by the finding that denaturation of the wild-type and variant proteins facilitates a similar folding of both molecules, diminishing their differences in structure and biophysical properties. Following native purification conditions, variant cystatin C has a distinct structure compared to the wild-type protein
— id: 56366, year: 2005, vol: 299, page: 221, stat: Journal Article,

Axonal transport of British and Danish amyloid peptides via secretory vesicles
Choi, Seung-Il; Vidal, Ruben; Frangione, Blas; Levy, Efrat
2004 Feb;18(2):373-375, FASEB journal
The ABri and ADan amyloid peptides deposited in familial British and Danish neurodegenerative disorders are generated by processing mutant forms of the precursor protein BRI2. Although the pathogenic process that leads to deposition of amyloid in the brains of patients has been studied extensively, the cellular processes and normal function of the precursor protein did not receive much attention. We observed in a variety of transfected cell lines the presence of two independent proteolytic processing events. In addition to the previously described cleavage, which results in the production of carboxyl-terminal approximately 3 kDa wild-type peptide or approximately 4 kDa ABri or ADan peptides, we describe a novel amino-terminal cleavage site within BRI2. Both cleavages occur within the cis- or medial-Golgi. Following cleavage, the BRI2-derived carboxyl-terminal peptides are transported via a regulated secretory pathway into secretory vesicles in neuronal cells. Worth noting is that expression of wild-type British or Danish mutants of BRI2, in mouse neuroblastoma N2a cells that do not express endogenous BRI2, induces elongation of neurites, which suggests a role for this protein in differentiation of neuronal cells
— id: 42639, year: 2004, vol: 18, page: 373, stat: Journal Article,

Binding of cystatin C to amyloid beta inhibits amyloid fibril formation
Pawlik, M; Sastre, M; Calero, M; Mathews, PM; Kumar, A; Schmidt, SD; Nixon, RA; Levy, E
2004 JUL ;25(10):S241-S241, Neurobiology of aging
— id: 47728, year: 2004, vol: 25, page: S241, stat: Journal Article,

Overexpression of human cystatin C in transgenic mice does not affect levels of endogenous brain amyloid Beta Peptide
Pawlik, Monika; Sastre, Magdalena; Calero, Miguel; Mathews, Paul M; Schmidt, Stephen D; Nixon, Ralph A; Levy, Efrat
2004 ;22(1-2):13-18, Journal of molecular neuroscience
Cystatin C, an inhibitor of cysteine proteases, colocalizes with amyloid beta (Abeta) in parenchymal and vascular amyloid deposits in brains of Alzheimer's disease (AD) patients, suggesting that cystatin C has a role in AD. Cystatin C also colocalizes with beta amyloid precursor protein (betaAPP) in transfected cultured cells. In vitro analysis of the association between the two proteins revealed that binding of cystatin C to full-length betaAPP does not affect the level of Abeta secretion. Here we studied the effect of in vivo overexpression of cystatin C on the levels of endogenous brain Abeta. We have generated lines of transgenic mice expressing either wild-type human cystatin C or the Leu68Gln variant that forms amyloid deposits in the cerebral vessels of Icelandic patients with hereditary cerebral hemorrhage, under control sequences of the human cystatin C gene. Western blot analysis of brain homogenates was used to select lines of mice expressing various levels of the transgene. Analysis of Abeta40 and Abeta42 concentrations in the brain showed no difference between transgenic mice and their nontransgenic littermates. Thus, in vivo overexpression of human cystatin C does not affect Abeta levels in mice that do not deposit Abeta
— id: 42253, year: 2004, vol: 22, page: 13, stat: Journal Article,

Binding of cystatin C to Alzheimer's amyloid beta inhibits in vitro amyloid fibril formation
Sastre, Magdalena; Calero, Miguel; Pawlik, Monika; Mathews, Paul M; Kumar, Asok; Danilov, Vlatko; Schmidt, Stephen D; Nixon, Ralph A; Frangione, Blas; Levy, Efrat
2004 Oct;25(8):1033-1043, Neurobiology of aging
The colocalization of cystatin C, an inhibitor of cysteine proteases, with amyloid beta (Abeta) in parenchymal and vascular amyloid deposits in brains of Alzheimer's disease (AD) patients may reflect cystatin C involvement in amyloidogenesis. We therefore sought to determine the association of cystatin C with Abeta. Immunofluorescence analysis of transfected cultured cells demonstrated colocalization of cystatin C and beta amyloid precursor protein (betaAPP) intracellularly and on the cell surface. Western blot analysis of immunoprecipitated cell lysate or medium proteins revealed binding of cystatin C to full-length betaAPP and to secreted betaAPP (sbetaAPP). Deletion mutants of betaAPP localized the cystatin C binding site within betaAPP to the Abeta region. Cystatin C association with betaAPP resulted in increased sbetaAPP but did not affect levels of secreted Abeta. Analysis of the association of cystatin C and Abeta demonstrated a specific, saturable and high affinity binding between cystatin C and both Abeta(1-42) and Abeta(1-40). Notably, cystatin C association with Abeta results in a concentration-dependent inhibition of Abeta fibril formation
— id: 46126, year: 2004, vol: 25, page: 1033, stat: Journal Article,

Copy number and level of overexpression of human cystatin C in transgenic mice
Tizon, B; Pawlik, M; Levy, E
2004 JUL ;25(10):S238-S238, Neurobiology of aging
— id: 47727, year: 2004, vol: 25, page: S238, stat: Journal Article,

Axonal transport of British and Danish amyloid peptides via secretory vesicles
Choi, SI; Vidal, R; Frangione, B; Levy, E
2003 DEC ;17(15):275-281, FASEB journal
The ABri and ADan amyloid peptides deposited in familial British and Danish neurodegenerative disorders are generated by processing mutant forms of the precursor protein BRI2. Although the pathogenic process that leads to deposition of amyloid in the brains of patients has been studied extensively, the cellular processes and normal function of the precursor protein did not receive much attention. We observed in a variety of transfected cell lines the presence of two independent proteolytic processing events. In addition to the previously described cleavage, which results in the production of carb oxyl-terminal similar to3 kDa wild-type peptide or similar to4 kDa ABri or ADan peptides, we describe a novel amino-terminal cleavage site within BRI2. Both cleavages occur within the cis- or medial-Golgi. Following cleavage, the BRI2-derived carb oxyl-terminal peptides are transported via a regulated secretory pathway into secretory vesicles in neuronal cells. Worth noting is that expression of wild-type British or Danish mutants of BRI2, in mouse neuroblastoma N2a cells that do not express endogenous BRI2, induces elongation of neurites, which suggests a role for this protein in differentiation of neuronal cells
— id: 42536, year: 2003, vol: 17, page: 275, stat: Journal Article,

Alcohol embolization of carotid-cavernous indirect fistulae
Koebbe, Christopher J; Horowitz, Michael; Jungreis, Charles; Levy, Elad; Pless, Misha
2003 May;52(5):1111-1115, Neurosurgery
OBJECTIVE: Carotid-cavernous fistulae (CCFs) are abnormal communications between the carotid artery and cavernous sinus that may present with rapid visual deterioration and extraocular paresis as a result of increasing intraocular pressure requiring emergent treatment to preserve vision. We present a technique of balloon-assisted ethanol embolization of the cavernous carotid artery supply to indirect CCFs providing immediate reduction in intraocular pressure with symptomatic improvement. METHODS: We reviewed clinical and angiographic data and present a retrospective case series illustrating six patients who underwent endovascular embolization because of worsening visual acuity and extraocular motility disorder caused by CCFs. Cerebral angiography revealed significant blood supply from the cavernous carotid artery to these CCFs. We performed ethanol embolization of these branches with distal balloon protection. RESULTS: Five of the six patients experienced immediate and sustained (mean follow-up, 21 mo) decreases in intraocular pressure, with significant symptom improvement. One patient experienced cavernous sinus thrombosis after conclusion of embolization, which caused a temporary worsening of symptoms that improved gradually over time. CONCLUSION: Many surgical and endovascular options are available to treat indirect CCFs. Absolute ethanol is a liquid agent that causes immediate vessel sclerosis and occlusion, which makes it a dangerous but potent liquid embolic agent. With distal temporary balloon protection to prevent migration of ethanol, we achieved excellent clinical and angiographic results using absolute ethanol to embolize the cavernous carotid supply to indirect CCFs. This represents a safe and effective method of endovascular management of this complex vascular anomaly
— id: 146453, year: 2003, vol: 52, page: 1111, stat: Journal Article,

Overexpression of human cystatin C in transgenic mice does not affect levels of endogenous brain amyloid beta peptide
Pawlik, M; Sastre, M; Calero, M; Mathews, PM; Schmidt, SD; Nixon, RA; Levy, E
2003 FEB ;22(1-2):13-18, Journal of molecular neuroscience
Cystatin C, an inhibitor of cysteine proteases, colocalizes with amyloid beta (Abeta) in parenchymal and vascular amyloid deposits in brains of Alzheimer's disease (AD) patients, suggesting that cystatin C has a role in AD. Cystatin C also colocalizes with beta amyloid precursor protein (betaAPP) in transfected cultured cells. In vitro analysis of the association between the two proteins revealed that binding of cystatin C to full-length betaAPP does not affect the level of Abeta secretion. Here we studied the effect of in vivo overexpression of cystatin C on the levels of endogenous brain Abeta. We have generated lines of transgenic mice expressing either wild-type human cystatin C or the Leu68Gln variant that forms amyloid deposits in the cerebral vessels of Icelandic patients with hereditary cerebral hemorrhage, under control sequences of the human cystatin C gene. Western blot analysis of brain homogenates was used to select lines of mice expressing various levels of the transgene. Analysis of Abeta40 and Abeta42 concentrations in the brain showed no difference between transgenic mice and their nontransgenic littermates. Thus, in vivo overexpression of human cystatin C does not affect Abeta levels in mice that do not deposit Abeta
— id: 42508, year: 2003, vol: 22, page: 13, stat: Journal Article,

Transport of the precursor protein of familiar British and Danish dementias into secretory vesicles in neuronal cells
Choi, S; Ghiso, J; Frangione, B; Levy, E
2002 Jul-Aug;23(1):66-, Neurobiology of aging
— id: 32407, year: 2002, vol: 23, page: 66, stat: Journal Article,

Dural arteriovenous fistula after ventriculostomy. Case illustration
Field, Melvin; Branstetter, Barton F 4th; Levy, Elad; Yonas, Howard; Jungreis, Charles A
2002 Jul;97(1):227-227, Journal of neurosurgery
— id: 146375, year: 2002, vol: 97, page: 227, stat: Journal Article,

Temporary balloon occlusion and ethanol injection for preoperative embolization of carotid-body tumor
Horowitz, Michael; Whisnant, Richard E; Jungreis, Charles; Snyderman, Carl; Levy, Elad I; Kassam, Amin
2002 Aug;81(8):536-8, 540, 542 passim, Ear, nose & throat journal
We report on the preoperative embolization of a carotid-body paraganglioma by temporary balloon occlusion and ethanol injection. Complete devascularization was achieved without complication. Resection after a short postembolization interval required artery sacrifice. Histologic evaluation revealed that the tumor contained diffuse ethanol-induced microemboli. Compared with unembolized and polyvinyl-alcohol-embolized carotid-body paragangliomas, our technique resulted in no greater adverse effects on the tumor-vessel interface. This procedure is an effective and promising method of preoperative embolization of carotid-body tumors and warrants further experience and study. In this article, we also review the literature on carotid-body tumor embolization and ethanol embolization
— id: 146451, year: 2002, vol: 81, page: 536, stat: Journal Article,

Target-specific multimodality endovascular management of carotid artery blow-out syndrome
Levy, Elad I; Horowitz, Michael B; Koebbe, Christopher; Jungreis, Charles C
2002 Feb;81(2):115-118, Ear, nose & throat journal
We describe a novel multimodality endovascular approach to safely control hemorrhage from a carotid artery pseudoaneurysm and tumor vasculature associated with a squamous cell carcinoma. This approach was used in the case of a 68-year-old man who had previously undergone a laryngectomy, chemotherapy, and brachytherapy and who subsequently experienced acute oropharyngeal bleeding. Angiography detected a carotid artery pseudoaneurysm and significant tumor vascularity. A target-specific multimodality approach was taken to embolize the potential etiologies for both the current and any future hemorrhages. Stent-assisted coiling of the pseudoaneurysm was successful. The tumor blush was treated with polyvinyl alcohol particles and both retrievable and nonretrievable coils. Endovascular surgeons have become increasingly involved in the management of patients with carotid injuries and with neoplasms in and around the skull base. Current endovascular technology provides a rapid target-specific approach to the treatment of carotid artery blow-out syndrome and has a greater potential to lower morbidity than does carotid sacrifice
— id: 146447, year: 2002, vol: 81, page: 115, stat: Journal Article,

Hemorrhages caused by overexpression of cystatin C in transgenic mice
Pawlik, M; Danilov, V; Mancevska, K; Levy, E
2002 Jul-Aug;23(1):909-, Neurobiology of aging
— id: 32420, year: 2002, vol: 23, page: 909, stat: Journal Article,

Distinct properties of wild-type and the amyloidogenic human cystatin C variant of hereditary cerebral hemorrhage with amyloidosis, Icelandic type
Calero M; Pawlik M; Soto C; Castano EM; Sigurdsson EM; Kumar A; Gallo G; Frangione B; Levy E
2001 Apr;77(2):628-637, Journal of neurochemistry
Variant human cystatin C (L68Q) is an amyloidogenic protein. It deposits in the cerebral vasculature of Icelandic patients with cerebral amyloid angiopathy, leading to stroke. Wild-type and variant cystatin C are cysteine proteinase inhibitors which form concentration dependent inactive dimers; however, variant cystatin C dimerizes at lower concentrations and has an increased susceptibility to a serine protease. We studied the effect of the L68Q amino acid substitution on cystatin C properties, utilizing full length cystatin C purified in mild conditions from media of cells stably transfected with either the wild-type or variant cystatin C genes. The variant cystatin C forms fibrils in vitro detectable by electron microscopy in conditions in which the wild-type protein forms amorphous aggregates. We also show by circular dichroism, steady-state fluorescence and Fourier-transformed infrared spectroscopy that the amino acid substitution modifies cystatin C structure by destabilizing alpha-helical structures and exposing the tryptophan residue to a more polar environment, yielding a more unfolded molecule. These spectral changes demonstrate that variant cystatin C has a three-dimensional structure different from that of the wild-type protein. The structural differences between variant and wild-type cystatin C account for the susceptibility of the variant protein to unfolding, proteolysis and fibrillogenesis
— id: 20351, year: 2001, vol: 77, page: 628, stat: Journal Article,

Codeposition of cystatin C with amyloid-beta protein in the brain of Alzheimer disease patients
Levy E; Sastre M; Kumar A; Gallo G; Piccardo P; Ghetti B; Tagliavini F
2001 Jan;60(1):94-104, Journal of neuropathology & experimental neurology
Immunohistochemical analysis of brains of patients with Alzheimer disease (AD) revealed that the cysteine proteinase inhibitor cystatin C colocalizes with amyloid beta-protein (Abeta) in parenchymal and vascular amyloid deposits. No evidence of cerebral hemorrhage was observed in any of the brains studied. Immunoelectron microscopy demonstrated dual staining of amyloid fibrils with anti-Abeta and anti-cystatin C antibodies. Cystatin C immunoreactivity was also observed in amyloid deposits in the brain of transgenic mice overexpressing human beta amyloid precursor protein. Massive deposition of the variant cystatin C in the cerebral vessels of patients with the Icelandic form of hereditary cerebral hemorrhage with amyloidosis is thought to be responsible for the pathological processes leading to stroke. Anti-cystatin C antibodies strongly labeled pyramidal neurons within cortical layers most prone to amyloid deposition in the brains of AD patients. Immunohistochemistry with antibodies against the carboxyl-terminus of Abeta(x-42) showed intracellular immunoreactivity in the same neuronal subpopulation. It remains to be established whether the association of cystatin C to Abeta plays a primary role in amyloidogenesis of AD or is a late event in which the protein is bound to the previously formed Abeta amyloid fibrils
— id: 26817, year: 2001, vol: 60, page: 94, stat: Journal Article,

Rupture of intracranial aneurysms during endovascular coiling: management and outcomes
Levy, E; Koebbe, C J; Horowitz, M B; Jungreis, C A; Pride, G L; Dutton, K; Kassam, A; Purdy, P D
2001 Oct;49(4):807-811, Neurosurgery
OBJECTIVE: In this study, the incidence, etiologies, and management with respect to clinical outcome of patients with iatrogenic aneurysmal rupture during attempted coil embolization of intracranial aneurysms are reviewed. METHODS: A retrospective analysis was conducted of 274 patients with intracranial aneurysms treated with Guglielmi detachable coils over a 6-year period from 1994 to 2000. Patient medical records were examined for demographic data, aneurysm location, the number of coils deployed preceding and after aneurysmal rupture, the etiology of the rupture, and the clinical status on admission and at the time of discharge. RESULTS: Of 274 patients with intracranial aneurysms treated with coil embolization, six (2%) had an intraprocedural rupture. Of these six, two were women and four were men. The mean age was 67 years (range, 52-85 yr). Mean follow-up time was 8 months (range, 0-25 mo). Aneurysmal rupture resulted from detachment of the last coil in three patients, detachment of the third coil (of four) in one patient, and insertion of the first coil in another patient. In one patient, the aneurysmal rupture was a result of catheter advancement before detachment of the last coil. The Glasgow Outcome Scale score at last follow-up examination was 1 in two patients, 2 in two patients, and 5 in two patients. CONCLUSION: The rate of rupture of aneurysms during coil embolization is approximately 2 to 4%. The clinical outcome may be related to the timing of the rupture and the number of coils placed before rupture. If extravasation of contrast agent is seen, which suggests intraprocedural rupture, further coil deposition should be attempted if safely possible
— id: 146377, year: 2001, vol: 49, page: 807, stat: Journal Article,

Primate-like amyloid-beta sequence but no cerebral amyloidosis in aged tree shrews
Pawlik M; Fuchs E; Walker LC; Levy E
1999 Jan-Feb;20(1):47-51, Neurobiology of aging
A central pathological feature of Alzheimer's disease is the profuse deposition of amyloid-beta protein (Abeta) in the brain parenchyma and vessel walls. Abeta also forms deposits in the brains of a variety of mammals, including all aged non-human primates studied to date. The sequence of Abeta in these animals is identical to that in humans. No Abeta deposits have been found in the brains of wild-type rats and mice, suggesting that the three amino acid differences between their Abeta and that of amyloid-bearing mammals impedes the fibrillogenicity of Abeta. Analysis of the primary sequence of the beta-amyloid precursor protein in tree shrews revealed a 98% similarity and 97% identity with the human protein. Furthermore, the predicted amino acid sequence of Abeta in tree shrews is identical to that in humans. However, immunohistochemical analysis failed to reveal beta-amyloid deposits in the neural parenchyma or vasculature of eight aged (7-8 years) tree shrews (Tupaia belangeri). The lack of correlation between the Abeta sequence and amyloid formation suggests that other factors contribute to cerebral amyloid deposition in aged animals
— id: 6188, year: 1999, vol: 20, page: 47, stat: Journal Article,

No cerebral amyloidosis in aged tree shrews with primate-like amyloid-beta sequence
Pawlik, M; Fuchs, E; Walker, L C; Levy, E
1999 Oct 23-28;25(1-2):1859-1859, Abstracts (Society for Neuroscience)
— id: 15860, year: 1999, vol: 25, page: 1859, stat: Journal Article,

Primate-like amyloid-a sequence but no cerebral amyloidosis in aged tree shrews (vol 20, pg 47, 1999)
Pawlik, M; Fuchs, E; Walker, LC; Levy, E
1999 MAY-JUN ;20(3):361-361, Neurobiology of aging
— id: 53841, year: 1999, vol: 20, page: 361, stat: Journal Article,

Cell-lysate conversion of prion protein into its protease-resistant isoform suggests the participation of a cellular chaperone
Saborio GP; Soto C; Kascsak RJ; Levy E; Kascsak R; Harris DA; Frangione B
1999 May 10;258(2):470-475, Biochemical & biophysical research communications
A conformational transition between the normal cellular prion protein (PrPC) and the beta-sheet-rich pathological isoform (PrPSc) is a central event in the pathogenesis of spongiform encephalopathies. The prion infectious agent seems to contain mainly, if not exclusively, PrPSc, which has the ability to propagate its abnormal conformation by transforming the host PrPC into the pathological isoform. We have developed an in vitro system to induce the PrPC --> PrPSc conversion by incubating a cell-lysate containing mouse PrPC with partially purified mouse PrPSc. After 48 h of incubation with a 10-fold molar excess of PrPSc, the cellular protein acquired PK-resistance resembling a PrPSc-like state. Time course experiments suggest that the conversion follows a stepwise mechanism involving kinetic intermediates. The conversion was induced by PrPSc extracted from mice infected with two different prion strains, each propagating its characteristic Western blot profile. The latter results and the fact that all the cellular components are present in the conversion reaction suggest that PrPC-PrPSc interaction is highly specific and required for the conversion. No transformation was observed under the same conditions using purified proteins without cell-lysate. However, when PrPC-depleted cell-lysate was added to the purified proteins the conversion was recovered. These findings provide direct evidence for the participation of a chaperone-like activity involved in catalyzing the conversion of PrPC into PrPSc.
— id: 6115, year: 1999, vol: 258, page: 470, stat: Journal Article,

Cell-lysate conversion of prion protein into its protease-resistant isoform indicates the participation of a cellular chaperone
Saborio, G P; Soto, C; Kascsak, R J; Levy, E; Kascsak, R; Harris, D A; Frangione, B
1999 Oct 23-28;25(1-2):41-41, Abstracts (Society for Neuroscience)
— id: 15872, year: 1999, vol: 25, page: 41, stat: Journal Article,

Presenilin 1 Met146Leu variant due to an A --> T transversion in an early-onset familial Alzheimer's disease pedigree from Argentina
Morelli L; Prat MI; Levy E; Mangone CA; Castano EM
1998 Jun;53(6):469-473, Clinical genetics
Most of the cases of early-onset familial Alzheimer's disease (FAD) are related to missense mutations in the presenilin 1 (PS-1) gene on chromosome 14. Although PS-1 mutations are distributed throughout the entire open reading frame, most mutations are found in transmembrane region II and hydrophilic loop VI encoded by exons 5 and 8, respectively. These two groups of substitutions are associated with an age of onset of 40-43 years for exon 5 and 45-55 years for exon 8, respectively. We have previously described a South American pedigree from Argentina with early-onset FAD (mean age of onset 38.9 +/- 3.9 years) with no mutations in exons 16 and 17 of the beta-protein precursor gene (betaPP770 transcript). Here we report the identification of an A --> T transversion at the first position of codon 146 of PS-1 in these patients. This missense mutation results in a Met --> Leu substitution, as reported for the Italian pedigrees Tor1.1 and FAD4. The significant differences in ages of onset and death among members of generations II-III and IV suggest that other genetic and/or environmental factors may influence disease phenotype in this pedigree
— id: 57211, year: 1998, vol: 53, page: 469, stat: Journal Article,

X11 interaction with beta-amyloid precursor protein modulates its cellular stabilization and reduces amyloid beta-protein secretion
Sastre M; Turner RS; Levy E
1998 Aug 28;273(35):22351-22357, Journal of biological chemistry
The protein interaction domain of the neuronal protein X11 binds to the YENPTY motif within the cytoplasmic domain of beta-amyloid precursor protein (betaAPP). Amyloid-beta protein (Abeta), the major constituent of the amyloid deposited in brain of Alzheimer's disease patients, is generated by proteolytic processing of betaAPP, which occurs in part following betaAPP internalization. Because the YENPTY motif has a role in the internalization of betaAPP, the effect of X11 binding on betaAPP processing was studied in mouse neuroblastoma N2a, human embryonic kidney 293, monkey kidney COS-1, and human glial U251 cell lines transfected with wild type or mutated betaAPP cDNAs. Secretion of soluble betaAPP via alpha-secretase activity increased significantly in cells transfected with betaAPP variants containing mutations that impair interaction with X11 when compared with cells transfected with wild type cDNA. Cotransfection of betaAPP and X11 caused retention of cellular betaAPP, decreased secretion of sbetaAPPalpha, and decreased Abeta secretion. Thus, betaAPP interaction with the protein interaction domain of X11 stabilizes cellular betaAPP and thereby participates in the regulation of betaAPP processing pathways
— id: 7778, year: 1998, vol: 273, page: 22351, stat: Journal Article,

Instability of the amyloidogenic cystatin C variant of hereditary cerebral hemorrhage with amyloidosis, Icelandic type
Wei L; Berman Y; Castano EM; Cadene M; Beavis RC; Devi L; Levy E
1998 May 8;273(19):11806-11814, Journal of biological chemistry
A cystatin C variant with L68Q substitution and a truncation of 10 NH2-terminal residues is the major constituent of the amyloid deposited in the cerebral vasculature of patients with the Icelandic form of hereditary cerebral hemorrhage with amyloidosis (HCHWA-I). Variant and wild type cystatin C production, processing, secretion, and clearance were studied in human cell lines stably overexpressing the cystatin C genes. Immunoblot and mass spectrometry analyses demonstrated monomeric cystatin C in cell homogenates and culture media. While cystatin C formed concentration-dependent dimers, the HCHWA-I variant dimerized at lower concentrations than the wild type protein. Amino-terminal sequence analysis revealed that the variant and normal proteins produced and secreted are the full-length cystatin C. Pulse-chase experiments demonstrated similar levels of normal and variant cystatin C production and secretion. However, the secreted variant cystatin C exhibited an increased susceptibility to a serine protease in conditioned media and in human cerebrospinal fluid, explaining its depletion from the cerebrospinal fluid of HCHWA-I patients. Thus, the amino acid substitution may induce unstable cystatin C with intact inhibitory activity and predisposition to self-aggregation and amyloid fibril formation
— id: 7979, year: 1998, vol: 273, page: 11806, stat: Journal Article,

Carboxyl-terminal fragments of beta-amyloid precursor protein bind to microtubules and the associated protein tau
Islam K; Levy E
1997 Jul;151(1):265-271, American journal of pathology
Alzheimer's disease is a neurodegenerative disorder characterized by protein depositions in intracellular and extracellular spaces in the brain. The intraneuronal deposits are formed by neurofibrillary tangles composed mainly of abnormally phosphorylated tau, a microtubule-associated protein, whereas the major constituent of the amyloid deposited extracellularly in the brain parenchyma and vessel walls is amyloid beta-protein (A beta). The proteolytic processing of the beta-amyloid precursor protein (beta PP) results in the generation of a complex set of carboxyl-terminal peptides that contain A beta. In this study, we have used fusion proteins containing carboxyl-terminal fragments of beta PP to investigate the association of beta PP with cellular components. We demonstrate that specific domains within the carboxyl end of beta PP contain binding sites for cytoskeletal components; one, within residues 1 to 28 of A beta, binds directly to tubulin, and the second one, within sequences carboxyl-terminal to A beta, binds tau and tubulin. We propose that the two neuropathological hallmarks of Alzheimer's disease, A beta deposition and neurofibrillary tangles, represent the residual of a disrupted beta PP-tubulin-tau complex
— id: 7171, year: 1997, vol: 151, page: 265, stat: Journal Article,

C-terminal fragments of alpha- and beta-tubulin form amyloid fibrils in vitro and associate with amyloid deposits of familial cerebral amyloid angiopathy, British type
Baumann MH; Wisniewski T; Levy E; Plant GT; Ghiso J
1996 Feb 6;219(1):238-242, Biochemical & biophysical research communications
Familial amyloidosis, British type, is an autosomal dominant disease characterized by progressive dementia, spastic paralysis and ataxia. The identity of the accumulating amyloid is not known, thus preventing the definitive classification of the disease. Biochemical methods were used to characterize the nature of the amyloid deposits from the brain tissue of one individual who died with this disease. The purified tissue material was subjected to trypsin digestion and subsequent N-terminal sequence analysis. Major tryptic fragments yielded the sequences VGINYQPPTVVPGGDLAK, FDLMYAK, GLTVPEL and GYLTVAAVFR, which are all tryptic fragments of the C-termini of human tubulin subunits alpha and beta. Synthetic peptides based on the sequences of these fragments formed amyloid fibrils in vitro fitting the characteristic definition of amyloid. These findings suggest that the C-terminal fragments of both alpha- and beta-tubulin are closely associated to the amyloid deposits of familial amyloidosis, British type
— id: 6886, year: 1996, vol: 219, page: 238, stat: Journal Article,

The phosphotyrosine interaction domains of X11 and FE65 bind to distinct sites on the YENPTY motif of amyloid precursor protein
Borg JP; Ooi J; Levy E; Margolis B
1996 Nov;16(11):6229-6241, Molecular & cellular biology
The phosphotyrosine interaction (PI) domains (also known as the PTB, or phosphotyrosine binding, domains) of Shc and IRS-1 are recently described domains that bind peptides phosphorylated on tyrosine residues. The PI/PTB domains differ from Src homology 2 (SH2) domains in that their binding specificity is determined by residues that lie amino terminal and not carboxy terminal to the phosphotyrosine. Recently, it has been appreciated that other cytoplasmic proteins also contain PI domains. We now show that the PI domain of X11 and one of the PI domains of FE65, two neuronal proteins, bind to the cytoplasmic domain of the amyloid precursor protein ((beta)APP). (beta)APP is an integral transmembrane glycoprotein whose cellular function is unknown. One of the processing pathways of (beta)APP leads to the secretion of A(beta), the major constituent of the amyloid deposited in the brain parenchyma and vessel walls of Alzheimer's disease patients. We have found that the X11 PI domain binds a YENPTY motif in the intracellular domain of (beta)APP that is strikingly similar to the NPXY motifs that bind the Shc and IRS-1 PI/PTB domains. However, unlike the case for binding of the Shc PI/PTB domain, tyrosine phosphorylation of the YENPTY motif is not required for the binding of (beta)APP to X11 or FE65. The binding site of the FE65 PI domain appears to be different from that of X11, as mutations within the YENPTY motif differentially affect the binding of X11 and FE65. Using site-directed mutagenesis, we have identified a crucial residue within the PI domain involved in X11 and FE65 binding to (beta)APP. The binding of X11 or FE65 PI domains to residues of the YENPTY motif of (beta)APP identifies PI domains as general protein interaction domains and may have important implications for the processing of (beta)APP
— id: 18111, year: 1996, vol: 16, page: 6229, stat: Journal Article,

The PI domain of X11 binds to the YEN
Margolis, B; Ooi, J; Levy, E; Borg, JP
1996 SEP ;7(9):A0328-A0328, Journal of the American Society of Nephrology
— id: 52796, year: 1996, vol: 7, page: A0328, stat: Journal Article,

Cerebrovascular amyloidosis in squirrel monkeys and rhesus monkeys: apolipoprotein E genotype
Morelli L; Wei L; Amorim A; McDermid J; Abee CR; Frangione B; Walker LC; Levy E
1996 Jan 29;379(2):132-134, FEBS letters
Some neuropathological changes characteristic of aging and Alzheimer's disease (AD) in humans are present also in senescent non-human primates. The human apoE4 allele is associated with an increased risk of developing late-onset familial and sporadic AD. We found that rhesus monkeys and three subspecies of squirrel monkeys are homozygous for apoE phenotype with arginine at positions 112 and 158 as in human apoE4. However, in both species threonine replaces arginine at position 61 of human apoE. It was previously shown that arginine 61 was critical in determining apoE4 lipoprotein distribution in humans
— id: 56834, year: 1996, vol: 379, page: 132, stat: Journal Article,

Cystatin C. Icelandic-like mutation in an animal model of cerebrovascular beta-amyloidosis
Wei LH; Walker LC; Levy E
1996 Nov;27(11):2080-2085, Stroke
BACKGROUND AND PURPOSE: Cerebral amyloid angiopathy (CAA) occurs as a sporadic disorder in aged humans, as a frequent component of Alzheimer's disease, or in hereditary cerebral hemorrhage with amyloidosis (HCHWA). The primary histological locus of cerebral amyloid deposition varies in aged humans and in different species of nonhuman primates. In aged rhesus monkeys, amyloid deposition occurs most frequently in senile plaques, whereas in aged squirrel monkeys CAA is more common. We hypothesized that the preponderance of CAA in squirrel monkeys is related to a species-specific amino acid change in cystatin C, a cysteine protease inhibitor, similar to the Leu68Gln substitution found in the amyloid protein of Icelandic patients with HCHWA-I, also termed hereditary cystatin C amyloid angiopathy. METHODS: We performed immunohistochemical analyses of brain sections of aged squirrel and rhesus monkeys with anti-amyloid-beta and anti-cystatin C antibodies and sequenced the cystatin C cDNA of these monkeys. RESULTS: Cerebral amyloid in aged squirrel and rhesus monkeys, previously shown to be immunoreactive with anti-amyloid-beta anti-bodies, reacts also with antibodies to cystatin C. While the predicted amino acid sequence in rhesus monkeys differs from the human sequence by four residues, that of the squirrel monkeys has seven additional amino acid substitutions, one of which is Leu68Met. CONCLUSIONS: The presence of a mutation in squirrel monkeys similar to the one found in HCHWA-I suggests that alterations in cystatin C may influence the likelihood that amyloid will be deposited in the walls of cerebral blood vessels. These observations support the utilization of the monkeys as models to study CAA
— id: 12508, year: 1996, vol: 27, page: 2080, stat: Journal Article,

Mutational analysis of desmoglein binding domains of plakoglobin
Witcher, LL; Collins, R; Levy, E; Cowin, P
1996 DEC ;7(3):490-490, Molecular biology of the cell
— id: 53350, year: 1996, vol: 7, page: 490, stat: Journal Article,

CYSTATIN-C MUTATION IN AN ELDERLY MAN WITH SPORADIC AMYLOID ANGIOPATHY AND INTRACEREBRAL HEMORRHAGE
GRAFFAGNINO, C; HERBSTREITH, MH; SCHMECHEL, DE; LEVY, E; ROSES, AD; ALBERTS, MJ
1995 NOV ;26(11):2190-2193, Stroke
Background Cerebral amyloid angiopathy (CAA)with intracerebral hemorrhage (ICH) occurs both sporadically and as a result of mutations in either cystatin C or the amyloid precursor protein. ICH due to cystatin C mutations typically occurs in young people of Icelandic origin. Case Description We report a case of sporadic CAA with ICH in an elderly Croatian man with a mutation in cystatin C identical to that found in Icelandic hereditary cerebral hemorrhage with amyloidosis. Conclusions This is the first case report of sporadic CAA associated with the same mutation causing hereditary cerebral hemorrhage with amyloidosis of the Icelandic type. Sporadic CAA may thus be associated with genetic mutations in some patients. The frequency of these mutations is yet to be determined
— id: 86680, year: 1995, vol: 26, page: 2190, stat: Journal Article,

beta-Amyloid precursor protein gene in squirrel monkeys with cerebral amyloid angiopathy
Levy E; Amorim A; Frangione B; Walker LC
1995 Sep-Oct;16(5):805-808, Neurobiology of aging
Senescent nonhuman primates frequently develop cerebral beta-amyloidosis; for reasons that are not yet understood, the primary histological locus of beta-amyloid deposition varies in different species. In aged rhesus monkeys (Macaca mulatta), fibrillar (congophilic) beta-amyloid (A beta) occurs most frequently in senile plaques, whereas in aged squirrel monkeys (Saimiri sciureus) the cerebral blood vessels are most affected. To determine if cerebral beta-amyloid angiopathy (CAA) in squirrel monkeys is related to a species-specific amino acid change in A beta, as was shown in two hereditary human forms of CAA, the beta-amyloid precursor protein (beta PP) cDNA was sequenced. The predicted amino acid sequence of A beta in squirrel monkeys is identical to that in normal humans. Overall, beta PP751 in the squirrel monkey differs from the human sequence only by four amino acids near the N-terminus and in the KPI domain. These findings suggest that other factors most likely predispose aged squirrel monkeys to cerebral amyloid angiopathy. We propose the squirrel monkey as a useful model for studying the factors contributing to human CAA, and for testing diagnostic and therapeutic approaches to this disorder
— id: 6840, year: 1995, vol: 16, page: 805, stat: Journal Article,

Early onset Alzheimer's disease in a South American pedigree from Argentina
Mangone CA; Castano EM; Levy E; Abiusi G; Wisniewski T; Marques MR; Faccio E; Gorelick PB; Frangione B; Sica RE
1995 Jan;91(1):6-13, Acta neurologica Scandinavica
We report the clinical, SPET, immunohistochemical and DNA features of an early-onset familial Alzheimer's disease (FAD) in an Argentine pedigree of South American indian ethnic background. Pedigree spans 5 generations comprising more than 110 biological relatives. Clinical data supported the diagnosis of early onset FAD (mean age at onset 38.9 years) in 10 family members, including 3 with pathological confirmation (mean age at death 48.5). The pattern of transmission suggested autosomal dominant inheritance. Prominent features were mood changes, early language impairment, myoclonus, seizures and cerebellar signs. SPET displayed bilateral frontal, temporo-parietal and cerebellar hypoperfusion in early stages and in an asymptomatic member at risk, suggesting that SPET may have predictive value in this family. Immunohistochemistry showed beta amyloid deposits within neuritic plaques and vessel walls and no anti-PrP immunoreactivity. DNA analysis showed no abnormalities in the beta amyloid precursor protein gene. The identification of additional genetic defects in well characterized independent FAD pedigrees will contribute to the understanding of the pathogenesis of Alzheimer's disease
— id: 9521, year: 1995, vol: 91, page: 6, stat: Journal Article,

The influence of apolipoprotein E isotypes on Alzheimer's disease pathology in 40 cases of Down's syndrome
Wisniewski T; Morelli L; Wegiel J; Levy E; Wisniewski HM; Frangione B
1995 Jan;37(1):136-138, Annals of neurology
— id: 9519, year: 1995, vol: 37, page: 136, stat: Journal Article,

Chromosome 14-encoded Alzheimer's disease: genetic and clinicopathological description
Haltia M; Viitanen M; Sulkava R; Ala-Hurula V; Poyhonen M; Goldfarb L; Brown P; Levy E; Houlden H; Crook R; et al.
1994 Sep;36(3):362-367, Annals of neurology
A family of Finnish descent with very-early-onset Alzheimer's disease has been identified. Genetic analysis of this family eliminated the amyloid precursor protein gene as the pathogenic locus, but strongly implicated a locus on chromosome 14q23.4 between D14S52 and D14S55. The early age at onset of the disease (average, 36 years; range, 35-39 years), the rapid progression, and the early and prominent myoclonus, while they appear to be frequent findings in the chromosome 14-encoded form of Alzheimer's disease, raised the clinical suspicion of prion disease. However, sequencing the prion gene-coding region of 2 affected members of the pedigree failed to show any abnormality. Apart from the presence of modest cortical vacuolar change, the pathological features of our index patient appeared typical of Alzheimer's disease with abundant senile plaques immunoreactive with beta-amyloid, but not with prion protein antibodies
— id: 66414, year: 1994, vol: 36, page: 362, stat: Journal Article,

EXPRESSION OF APP MESSENGER-RNA LACKING EXON-15 IS LOWER IN THE BRAIN THAN IN NONNEURAL TISSUES
LEVY, E; DEAMORIM, AF
1994 JUL ;15(7):S61-S61, Neurobiology of aging
— id: 52405, year: 1994, vol: 15, page: S61, stat: Journal Article,

The amino acid sequence of neuritic plaque amyloid from a familial Alzheimer's disease patient
Wisniewski T; Lalowski M; Levy E; Marques MR; Frangione B
1994 Feb;35(2):245-246, Annals of neurology
— id: 9525, year: 1994, vol: 35, page: 245, stat: Journal Article,

Risk of another basal cell carcinoma developing after treatment of a basal cell carcinoma
Marghoob A; Kopf AW; Bart RS; Sanfilippo L; Silverman MK; Lee P; Levy E; Vossaert KA; Yadav S; Abadir M
1993 Jan;28(1):22-28, Journal of the American Academy of Dermatology
BACKGROUND: There is an increased risk of new basal cell carcinomas (BCCs) developing in a person who has had a BCC. OBJECTIVE: This study attempts to define the magnitude of this increased risk. METHODS: The charts of 260 white patients with a histologically proven BCC were reviewed for the occurrence of new BCCs. The cumulative 5-year incidence (modified life-table method) for new BCCs developing in these patients was compared with the 5-year incidence in the general white population of the United States. RESULTS: Of the 260 patients, new BCCs developed in 137 within an average of 38.3 months, a 5-year cumulative rate of one or more new BCCs of 45.2%. The yearly risk for new BCCs developing in the study population remained high during the 5-year interval. In the general white population of the United States, the maximal 5-year incidence was calculated to be 5% (p < 0.005, chi-square test). CONCLUSION: Patients with a history of BCC require life-long follow-up because of the high probability of new BCCs developing
— id: 13296, year: 1993, vol: 28, page: 22, stat: Journal Article,

Sequencing of the Alzheimer's APP gene Dutch variant (APP-D)
Vidal RG; Fernandez-Madrid I; Frangione B; Levy E
1993 ;2(6):496-497, Human mutation
— id: 9530, year: 1993, vol: 2, page: 496, stat: Journal Article,

Gelsolin gene mutation--at codon 187--in familial amyloidosis, Finnish: DNA-diagnostic assay
Haltia M; Levy E; Meretoja J; Fernandez-Madrid I; Koivunen O; Frangione B
1992 Feb 1;42(3):357-359, American journal of medical genetics
Familial amyloidosis, Finnish (FAF), is an autosomal dominant form of systemic amyloidosis with lattice corneal dystrophy and progressive cranial neuropathy as principal clinical manifestations. We have shown that the novel amyloid fibril protein found in these patients is an internal degradation fragment of gelsolin, an actin-binding protein, and that it contains an amino acid substitution, asparagine for aspartic acid at position 15, that is due to a guanine-to-adenine transversion corresponding to codon 187 of human plasma gelsolin cDNA. To test that this mutation cosegregates with the disease high-molecular-weight genomic DNA was isolated from autopsied tissues or lymphocytes of 23 patients, 6 healthy relatives and 20 unrelated healthy control persons. Specific fragments were amplified with the polymerase chain reaction for oligonucleotide hybridization analysis using the slot-blot technique. The guanine-to-adenine transversion was found in all FAF patients tested, but in none of the control subjects. Our results show that the mutation (G to A) cosegregates with the disease phenotype, and that the slot-blot analysis can be used as a diagnostic assay, including prenatal evaluation
— id: 9539, year: 1992, vol: 42, page: 357, stat: Journal Article,

Induction of B16 melanoma melanogenesis by a serum-free synthetic medium
Johnston D; Orlow SJ; Levy E; Bystryn JC
1992 Jul;201(1):91-98, Experimental cell research
Cultured murine B16 melanoma cells normally grow as spindle-shaped cells firmly attached to tissue culture flasks. Pellets obtained from harvested B16 melanoma cells are white to grey in color. When the same cells were grown in synthetic, serum-free AIM V medium, cellular morphology and pigmentation were radically altered. Within 3 days of subculture in AIM V, cells rounded up and grew in clusters in suspension. Melanin content increased to greater than 30 times and tyrosinase activity was found to be 10-50 times higher in cells grown in AIM V medium compared to those cultured in normal medium. A concomitant increase in the level of immunoreactive tyrosinase was also induced. The individual growth factors and hormones present in AIM V medium were examined to determine which component(s) stimulates melanogenesis. Only those cells grown in the presence of 2.5% human albumin were stimulated to synthesize melanin. These findings suggest that albumin, or a component associated with albumin, has a major effect upon the regulation of melanogenesis in these cells
— id: 13530, year: 1992, vol: 201, page: 91, stat: Journal Article,

DNA diagnosis for hereditary cerebral hemorrhage with amyloidosis (Dutch type) [see comments]
Bakker E; van Broeckhoven C; Haan J; Voorhoeve E; van Hul W; Levy E; Lieberburg I; Carman MD; van Ommen GJ; Frangione B; et al
1991 Sep;49(3):518-521, American journal of human genetics
Hereditary cerebral hemorrhage with amyloidosis of the Dutch type (HCHWA-D) is tightly linked to the Alzheimer amyloid precursor protein gene on chromosome 21, which codes for the amyloid beta-protein. A point mutation detected at position 1852 of the amyloid precursor protein gene in four HCHWA-D patients was hypothesized to be the basic defect. This study proves that 22 HCHWA-D patients from three pedigrees all carry this point mutation, whereas the mutation is absent in escapees from the HCHWA-D families as well as in randomly selected Dutch individuals. A mutation-specific oligonucleotide is now available for the confirmation of the HCHWA-D diagnosis. Therefore, presymptomatic testing and prenatal evaluation of individuals at risk in the HCHWA-D families is now feasible
— id: 9543, year: 1991, vol: 49, page: 518, stat: Journal Article,

Codon 618 variant of Alzheimer amyloid gene associated with inherited cerebral hemorrhage
Fernandez-Madrid I; Levy E; Marder K; Frangione B
1991 Nov;30(5):730-733, Annals of neurology
Hereditary cerebral hemorrhage with amyloidosis, Dutch type (HCHWA-D) is an autosomal dominant form of severe cerebrovascular amyloid angiopathy causing recurrent strokes during the fifth and sixth decades of life. The major constituent of the amyloid deposits in HCHWA-D is the amyloid beta-protein (A beta), also found in Alzheimer's disease. A point mutation in the DNA sequence encoding A beta has been found in 2 unrelated patients with HCHWA-D, and an assay detecting the single base change was developed for diagnostic purposes. We describe the detection of the point mutation in a patient living in the United States, suffering from recurring cerebral hemorrhages, who only recently was diagnosed with HCHWA-D. In addition, we tested a number of family members, and found the mutation in 2 additional individuals, one of them too young to exhibit clinical manifestations. This study combined with the study of two other families in Holland indicates that the codon 618 variant in the amyloid precursor protein gene segregates with HCHWA-D
— id: 57029, year: 1991, vol: 30, page: 730, stat: Journal Article,

Familial amyloidosis - Finish type - and its relationship to Lewy bodies in Parkinson's and Diffuse Lewy Body disease
Frangione B; Haltia M; Levy E; Ghiso J; Kiuru S; Prelli F; Wisniewski T
Proceedings of the XIth International Congress of Neuropathology, September 2-8, 1990, Kyoto, Japan [Tokyo] : Japanese Society of Neuropathology, 1991,
— id: 4980, year: 1991, vol: , page: 150, stat: Chapter,

Amyloidosis due to a mutation of the gelsolin gene in an American family with lattice corneal dystrophy type II [see comments]
Gorevic PD; Munoz PC; Gorgone G; Purcell JJ Jr; Rodrigues M; Ghiso J; Levy E; Haltia M; Frangione B
1991 Dec 19;325(25):1780-1785, New England journal of medicine
— id: 9416, year: 1991, vol: 325, page: 1780, stat: Journal Article,

LATTICE CORNEAL-DYSTROPHY (LCD) TYPE-II - GELSOLIN GENE MUTATION CODON 187 DEMONSTRATED IN AN AMERICAN FAMILY BY PCR AMPLIFICATION AND DNA SEQUENCING
GOREVIO, PD; MUNOZ, PC; GORGONE, G; PURCELL, F; RODRIGUES, M; LEVY, E; FRANGIONE, B
1991 APR ;39(2):A267-A267, Clinical research
— id: 51610, year: 1991, vol: 39, page: A267, stat: Journal Article,

Polymerization of gelsolin variant fragment in tissue causes familial amyloidosis, Finnish type (FAF)
Haltia M; Ghiso J; Prelli F; Levy E; Gallo G; Kiuru S; Somer H; Palo J; Frangione B
Amyloid and amyloidosis 1990 Boston : Kluwer, 1991,
— id: 5142, year: 1991, vol: , page: 409, stat: Chapter,

Late recurrence of malignant melanoma: a report of five cases, a review of the literature and a study of associated factors
Levy E; Silverman MK; Vossaert KA; Kopf AW; Bart RS; Golomb FM; Levenstein MJ
1991 Apr-May;1(1):63-67, Melanoma research
This is a study of factors associated with late recurrence (i.e. 10 or more years after definitive surgery) of cutaneous malignant melanoma (MM). Four factors were evaluated: Breslow thickness, site of the primary MM, age of the patient at initial treatment for MM, and gender. These factors were compared between two groups: (1) Stage I cases in the New York University Melanoma Cooperative Group (NYU-MCG) database that had 'early recurrence' (less than 10 years) of MM, and (2) cases in the literature with late recurrence of MM plus five new cases reported here. Compared to the group of patients with 'early recurrence' of MM, the group of patients who had late recurrence of MM were found more likely to have thinner primary melanomas (p less than 0.001), to be younger (p less than 0.001), to be female (p = 0.001), and, for females, to have the MM located on an extremity (p = 0.017). Because late recurrence does occur and because the risk of developing a new primary MM is increased in MM patients, any patient who has had a MM should be followed for life
— id: 14090, year: 1991, vol: 1, page: 63, stat: Journal Article,

Familial Alzheimer's disease
Levy, E; Frangione, B
1991 Oct;1(5):312-314, Current biology. CB
— id: 101675, year: 1991, vol: 1, page: 312, stat: Journal Article,

Mutation of the Alzheimer's disease amyloid gene in hereditary cerebral hemorrhage, Dutch type
Levy E; Carman MD; Fernandez-Madrid IJ; Power MD; Lieberburg I; van Duinen SG; Bots GT; Luyendijk W; Frangione B
1990 Jun 1;248(4959):1124-1126, Science
An amyloid protein that precipitates in the cerebral vessel walls of Dutch patients with hereditary cerebral hemorrhage with amyloidosis is similar to the amyloid protein in vessel walls and senile plaques in brains of patients with Alzheimer's disease, Down syndrome, and sporadic cerebral amyloid angiopathy. Cloning and sequencing of the two exons that encode the amyloid protein from two patients with this amyloidosis revealed a cytosine-to-guanine transversion, a mutation that caused a single amino acid substitution (glutamine instead of glutamic acid) at position 22 of the amyloid protein. The mutation may account for the deposition of this amyloid protein in the cerebral vessel walls of these patients, leading to cerebral hemorrhages and premature death
— id: 8382, year: 1990, vol: 248, page: 1124, stat: Journal Article,

Mutation in gelsolin gene in Finnish hereditary amyloidosis
Levy E; Haltia M; Fernandez-Madrid I; Koivunen O; Ghiso J; Prelli F; Frangione B
1990 Dec 1;172(6):1865-1867, Journal of experimental medicine
Familial amyloidosis, Finnish type (FAF), is an autosomal dominant form of familial amyloid polyneuropathy. The novel amyloid fibril protein found in these patients is a degradation fragment of gelsolin, an actin-binding protein. We found a mutation (adenine for guanine) at nucleotide 654 of the gelsolin gene in genomic DNA isolated from five FAF patients. This site is polymorphic since the normal allele was also present in all the patients tested. This mutation was not found in two unaffected family members and 11 normal controls. The A for G transition causes an amino acid substitution (asparagine for aspartic acid) that was found at position 15 of the amyloid protein. The mutation and consequent amino acid substitution may lead to the development of FAF
— id: 9427, year: 1990, vol: 172, page: 1865, stat: Journal Article,

MUTATION IN THE ALZHEIMERS-DISEASE AMYLOID GENE IN PATIENTS WITH HEREDITARY CEREBRAL-HEMORRHAGE WITH AMYLOIDOSIS - DUTCH TYPE
Levy, E; Carman, MD; Fernandezmadrid, IJ; Lieberburg, I; Power, MD; Vanduinen, SG; Bots, GTAM; Luyendijk, W; Frangione, B
1990 May-Jun;11(3):300-300, Neurobiology of aging
— id: 31941, year: 1990, vol: 11, page: 300, stat: Journal Article,

Expression of a normal and variant Alzheimer's beta-protein gene in amyloid of hereditary cerebral hemorrhage, Dutch type: DNA and protein diagnostic assays
Prelli F; Levy E; van Duinen SG; Bots GT; Luyendijk W; Frangione B
1990 Jul 16;170(1):301-307, Biochemical & biophysical research communications
Amyloid fibrils deposited in cerebral vessel walls in Dutch patients with hereditary cerebral hemorrhage with amyloidosis (HCHWA-D) are formed by polymerization of a 39-residue peptide similar to the beta-protein of Alzheimer's disease, Down syndrome, sporadic cerebral amyloid angiopathy and normal aging. Sequence analysis of genomic DNA in HCHWA-D patients demonstrated a point mutation, cytosine for guanine at position 1852 of the precursor beta-protein gene, which causes a single amino acid substitution (glutamine for glutamic acid) corresponding to position 22 of the amyloid protein. The normal allele was also present in these patients. To examine the expression of normal and variant beta-protein alleles in HCHWA-D we analyzed all the tryptic peptides obtained from several amyloid fractions from leptomeningeal vascular walls. Amino acid sequence of two peptides (T3a and T3b) with identical amino acid composition revealed that T3a had glutamine and T3b had glutamic acid at position 22. Thus both the normal and variant Alzheimer's beta-protein alleles are expressed in vascular amyloid in HCHWA-D and may be detected by tryptic peptide mapping. Moreover, we have developed a diagnostic assay for high risk populations and prenatal evaluation that is based on the existence of the mutation
— id: 9555, year: 1990, vol: 170, page: 301, stat: Journal Article,

Stroke in Icelandic patients with hereditary amyloid angiopathy is related to a mutation in the cystatin C gene, an inhibitor of cysteine proteases
Levy E; Lopez-Otin C; Ghiso J; Geltner D; Frangione B
1989 May 1;169(5):1771-1778, Journal of experimental medicine
Cystatin C is an inhibitor of lysosomal cysteine proteases and consists of 120 amino acids. A variant of cystatin C lacking the first NH2-terminal residues and having one amino acid substitution at position 68 forms amyloid deposits mainly in the walls of brain arteries, causing fatal strokes in Icelandic patients with familial cerebral hemorrhage secondary to a form of an autosomal dominant amyloidosis. To understand the molecular basis of the genetic defect, the gene encoding cystatin C was isolated from genomic DNA libraries made from normal tissue and the brain of an Icelandic patient with hereditary cerebral hemorrhage with amyloidosis (HCHWA-I). The data indicate that the cystatin C gene encodes a polypeptide of 146 amino acids, of which the first 26 correspond to a secretory peptide signal sequence. The gene contains two intervening sequences that interrupt the coding region at amino acids 55 and 93. Comparison with genes encoding salivary cystatins and kininogen proteins show sequence homology and conservation of exon-intron structure. Except for a mutation in the second exon (CAG instead of CTG in the normal gene, resulting in the substitution of glutamine for a leucine residue), the gene cloned from the brain of the Icelandic patient is identical to the normal cystatin C gene. Thus, HCHWA-I is the first familial type of amyloidosis related to a point mutation in a gene encoding for an inhibitor. The mutation in the structural gene encoding cystatin C appears to be the primary defect in this inherited disorder causing amyloid fibril formation and accumulation followed by cerebral hemorrhage
— id: 9435, year: 1989, vol: 169, page: 1771, stat: Journal Article,

HEREDITARY STROKE IN ICELANDIC PATIENTS WITH AMYLOID ANGIOPATHY IS RELATED TO A MUTATION IN THE CYSTATIN-C GENE, AN INHIBITOR OF CYSTEINE PROTEASES
Levy, E; Lopezotin, C; Ghiso, J; Geltner, D; Frangione, B
1989 Apr;37(2):A541-A541, Clinical research
— id: 31712, year: 1989, vol: 37, page: A541, stat: Journal Article,

FUNCTION AND REGULATION OF EXPRESSION OF THE GENES ENCODING NEUROFILAMENT PROTEIN AND THE GLIAL FIBRILLARY ACIDIC PROTEIN
Cowan, NJ; Levy, E; Sarkan, S; Gordon, J; Lewis, S
1987 May 1;46(6):2145-2145, Federation Proceedings (Federation of American Societies for Experimental Biology)
— id: 31361, year: 1987, vol: 46, page: 2145, stat: Journal Article,

Structure and evolutionary origin of the gene encoding mouse NF-M, the middle-molecular-mass neurofilament protein
Levy E; Liem RK; D'Eustachio P; Cowan NJ
1987 Jul 1;166(1):71-77, European journal of biochemistry
We describe the complete sequence of the gene encoding mouse NF-M, the middle-molecular-mass neurofilament protein. The coding sequence is interrupted by two intervening sequences which align perfectly with the first two intervening sequences in the gene encoding NF-L (the low-molecular-mass neurofilament protein); there is no intron in the gene encoding NF-M corresponding to the third intron in NF-L. Therefore, both the number of introns and their arrangement in the genes coding NF-L and NF-M contrast sharply with the number and arrangement of introns in the genes of known sequence, encoding other members of the intermediate filament multigene family (desmin, vimentin, glial fibrillary acidic protein and the acidic and basic keratins); with the exception of a single truncated keratin gene that lacks an encoded tailpiece, these genes all contain eight introns, of which at least six are placed at homologous locations. Assuming the existence of a primordial intermediate filament gene containing most (if not all) the introns found in contemporary non-neurofilament intermediate filament genes, it seems likely that an RNA-mediated transposition event was involved in the generation of an ancestral gene encoding the NF polypeptides. A combination of insertional transposition and gene-duplication events could then explain the anomalous number and placement of introns within these genes. Consistent with this notion, we show that the genes encoding NF-M and NF-L are linked
— id: 17141, year: 1987, vol: 166, page: 71, stat: Journal Article,

DEFECTIVE GAMMA-INTERFERON PRODUCTION IN LEPROSY - REVERSAL WITH ANTIGEN AND INTERLEUKIN-2
NOGUEIRA, N; KAPLAN, G; LEVY, E; SARNO, EN; KUSHNER, P; GRANELLIPIPERNO, A; VIEIRA, L; GOULD, VC; LEVIS, W; STEINMAN, R; YIP, YK; COHN, ZA
1983 ;158(6):2165-2170, Journal of experimental medicine
— id: 40483, year: 1983, vol: 158, page: 2165, stat: Journal Article,