- Email: [email protected]
P1-328
Poster Presentations P1 P1-327
TESTING FOR ASSOCIATION BETWEEN ALZHEIMER’S DISEASE WITH PSYCHOSIS AND FUNCTIONAL GENE CANDIDATES
Rebecca Sims1, Paul Hollingworth1, Natalie Cope1, Luke Jehu1, Angharad Morgan1, Valentina Moskvina2, Simon Lovestone3, Carol Brayne4, David C. Rubinsztein4, Michael O’Donovan1, Michael Owen1, Julie Williams1,2, Richard Abraham1, 1Department of Psychological Medicine, Cardiff University, Cardiff, United Kingdom; 2 Biostatistics and Bioinformatics Unit, Cardiff University, Cardiff, United Kingdom; 3Institute of Psychiatry, King’s College, London, United Kingdom; 4University of Cambridge, Cambridge, United Kingdom. Contact e-mail: [email protected] Background: As Alzheimer’s disease (AD) progresses many sufferers experience additional behavioral and psychological symptoms such as psychosis. Psychotic symptoms are reported to affect 40-60% of individuals with AD and are associated with more rapid cognitive and functional decline, more severe cognitive impairment, premature institutionalization, and increased risks for agitated and aggressive behavior. Several studies demonstrate excess aggregation of psychosis in families, suggesting that psychosis in Alzheimer’s disease (AD⫹P) represents a distinct subtype that is, in part, genetically determined. Recent studies in schizophrenia, bipolar affective disorder (BPAD) and AD⫹P suggest that psychosis susceptibility or modifier genes may act across the “disease divide”. Support for this hypothesis includes the results of multiple linkage studies, which indicate that a gene or genes influencing AD⫹P, schizophrenia and BPAD may reside within the same or proximal chromosomal regions. Objective(s): To investigate putative functional candidate genes in regions implicated by our AD⫹P linkage screen. To study susceptibility markers for psychosis related disorders in AD and AD⫹P. Methods: Polymorphisms were chosen on the basis of location in putative functional and positional candidate genes. Well defined susceptibility markers and haplotypes for schizophrenia, BPAD with psychosis and Huntingdon’s disease (HD) with psychosis were also studied. Polymorphisms from four genes (GRIK2, COMT, NRG1 and DTNBP1) were individually genotyped in a large AD sample (1205 Caucasian UK patients; 1361 controls matched for age, sex and ethnicity). Results: Initial results show little association of the chosen polymorphisms with AD or AD⫹P. The GRIK2 SNP rs6922753 showed significant association with BPAD in two independent samples (combined p⫽0.00033). Analysis of rs6922753 in the AD sample (968 cases and 1142 controls) showed that there were no differences in either genotype (p⫽0.55) or allele frequency (p⫽0.31). Stratification for gender (664 female patients; allelic p⫽0.39: 274 male patients; allelic p⫽0.50) and AD⫹P (n⫽340; p⫽0.968) also showed no significant association. P1-328
ASSOCIATION ANALYSIS OF 22 POSITIONAL/ FUNCTIONAL CANDIDATE GENES ON CHROMOSOME 10 WITH LATE ONSET ALZHEIMER’S DISEASE
Angharad R. Morgan1, Luke Jehu1, Dragana Turic1, Denise Harold1, Gillian Hamilton2, Paul Hollingworth1, Pamela Moore1, Kimberley Dowzell1, Valentina Moskvina1, Lesley Jones1, John Powell2, Simon Lovestone2, Carol Brayne3, David C. Rubinsztein3, Michael O’Donovan1, Mike J. Owen1, Julie Williams1, 1Cardiff University, Cardiff, United Kingdom; 2Kings College, London, United Kingdom; 3University of Cambridge, Cambridge, United Kingdom. Contact e-mail: [email protected] Background: The brain in Alzheimer’s disease is characterized by intracellular neurofibrillary tangles and the extracellular deposition of A in senile plaques. A has been shown to mediate neurodegenerative and inflammatory changes associated with amyloid plaques, although the pathological mechanism of A remains largely unknown. Recent evidence suggests that the FISH adapter protein binds to, and potentially regulates, a disintegrin and metalloprotease 12 to mediate the neurotoxic effect of A. The ADAM12 gene lies on chromosome 10q26.3, and the gene
S193
encoding FISH, SH3MD1, lies within a region of linkage to late-onset Alzheimer’s disease on 10q25.1. Objective(s): This study investigates whether there is a relationship between variation in ADAM12 and SH3MD1 and susceptibility to LOAD. Methods: We used a powerful sample of 1051 well characterized AD cases (probable AD:NINCDSADCDA criteria) and 1269 matched controls from the UK population. Results: We identified significant interactions between variants in the two genes that may influence susceptibility to late-onset Alzheimer’s disease. The most significant statistical interaction is between rs3740473, a synonymous SNP in SH3MD1 and rs11244787, an intronic SNP in ADAM12 (effect size⫽2.1 for interaction term, p⫽0.006). Conclusions: A combination of variants in two functionally interactive genes show evidence of conferring susceptibility to develop AD. P1-329
PRESENILIN-1 MUTATION E318G IN ITALIAN POPULATION: GENETIC SCREENING AND EFFECT ON BETA AMYLOID METABOLISM IN HUMAN FIBROBLASTS
Gianluigi Forloni1, Sara Batelli1, Francesca Prati1, Francesca Prato1, Marzia Pesaresi2, Daniela Galimberti3, Elio Scarpini4, Amalia Bruni5, Massimo Franceschi6, Ignazio Roiter7, Vladimiro Artuso8, Diego Albani1, 1Istituto di Ricerche Farmacologiche ‘Mario Negri’, Milano, Italy; 2Istituto di Ricerche Farmacologiche Negri’, Milano, Italy; 3Department of Neurological Sciences,‘Dino Ferrari’ Center, University of Milan, “Ospedale Maggiore Policlinico”, Milano, Italy; 4 Department of Neurological Sciences, ‘Dino Ferrari’ Center, University of Milan, “Ospedale Maggiore Policlinico”, Milano, Italy; 5 Regional Center for Neurogenetics, Lamezia Terme (CZ), Italy; 6 Department of Neurology, Multimedica - Santa Maria, Castellanza (VA), Italy; 7Department of Internal Medicine, Hospital of Treviso, Treviso, Italy; 8ASL “Marcon”, Venice, Milano, Italy. Contact e-mail: [email protected] Background: Presenilin-1 (PSEN-1) is a key catalytic component of the ␥-secretase complex involved in -amyloid precursor protein (APP) processing. To date, about 150 pathogenic mutations in the PSEN-1 gene have been identified; their main biochemical effect is to increase the production of the fibrillogenic peptide A(1-42) that accumulates in cerebral senile plaques of AD patients. An interesting exception is represented by PSEN-1[E318G] mutation that does not seem to alter A(1-42) generation and that was found also in old-aged, cognitively normal subjects. Consequently, this substitution is generally considered a non-pathogenic polymorphism. Nevertheless, PSEN-1[E318G] mutation was reported to represent an independent genetic risk factor for familial Alzheimer’s disease (FAD) in the Australian population. Objectives: To confirm this indication, we performed a case-control association study in the Italian population; we determined in human fibroblasts from PSEN-1[E318G] carriers and PSEN-1[wild type] controls belonging to the same Italian family the  amyloid precursor metabolism and finally we extensively analyzed if this mutation altered also PSEN-1 stability or cellular localization. Methods: The genetic screening of PSEN-1[E318G] was performed by DHPLC, the evaluation of A(1-42) and A(1-40) concentration in fibroblasts conditioned media was determined by ELISA kits. The stability and cellular distribution of PSEN-1 was investigated by Western blot and immunocytochemical analysis in human fibroblasts obtained by skin biopsy. Results: We found a statistically significant association (p⬍0.05, Fisher’s exact test) between PSEN-1[E318G] presence and FAD. The evaluation by ELISA kit of A(1-42) and A(1-40) concentration in fibroblasts conditioned media cultured from PSEN-1[E318G] carriers and PSEN-1[wild type] controls belonging to the same Italian family revealed a statistically significant increase of A(1-40) and consequently reduction of A(1-42)/A(1-40) ratio in PSEN-1[E318G] carriers. No modification was seen in the stability or localization of PSEN-1 in primary skin fibroblasts cultured from PSEN-1[E318G] carriers compared to wild type condition. Conclusions: PSEN-1[E318G] is a genetic risk in a Italian FAD population. The mutation increased the production of A(1-40) in fibro-
TESTING FOR ASSOCIATION BETWEEN ALZHEIMER’S DISEASE WITH PSYCHOSIS AND FUNCTIONAL GENE CANDIDATES
Rebecca Sims1, Paul Hollingworth1, Natalie Cope1, Luke Jehu1, Angharad Morgan1, Valentina Moskvina2, Simon Lovestone3, Carol Brayne4, David C. Rubinsztein4, Michael O’Donovan1, Michael Owen1, Julie Williams1,2, Richard Abraham1, 1Department of Psychological Medicine, Cardiff University, Cardiff, United Kingdom; 2 Biostatistics and Bioinformatics Unit, Cardiff University, Cardiff, United Kingdom; 3Institute of Psychiatry, King’s College, London, United Kingdom; 4University of Cambridge, Cambridge, United Kingdom. Contact e-mail: [email protected] Background: As Alzheimer’s disease (AD) progresses many sufferers experience additional behavioral and psychological symptoms such as psychosis. Psychotic symptoms are reported to affect 40-60% of individuals with AD and are associated with more rapid cognitive and functional decline, more severe cognitive impairment, premature institutionalization, and increased risks for agitated and aggressive behavior. Several studies demonstrate excess aggregation of psychosis in families, suggesting that psychosis in Alzheimer’s disease (AD⫹P) represents a distinct subtype that is, in part, genetically determined. Recent studies in schizophrenia, bipolar affective disorder (BPAD) and AD⫹P suggest that psychosis susceptibility or modifier genes may act across the “disease divide”. Support for this hypothesis includes the results of multiple linkage studies, which indicate that a gene or genes influencing AD⫹P, schizophrenia and BPAD may reside within the same or proximal chromosomal regions. Objective(s): To investigate putative functional candidate genes in regions implicated by our AD⫹P linkage screen. To study susceptibility markers for psychosis related disorders in AD and AD⫹P. Methods: Polymorphisms were chosen on the basis of location in putative functional and positional candidate genes. Well defined susceptibility markers and haplotypes for schizophrenia, BPAD with psychosis and Huntingdon’s disease (HD) with psychosis were also studied. Polymorphisms from four genes (GRIK2, COMT, NRG1 and DTNBP1) were individually genotyped in a large AD sample (1205 Caucasian UK patients; 1361 controls matched for age, sex and ethnicity). Results: Initial results show little association of the chosen polymorphisms with AD or AD⫹P. The GRIK2 SNP rs6922753 showed significant association with BPAD in two independent samples (combined p⫽0.00033). Analysis of rs6922753 in the AD sample (968 cases and 1142 controls) showed that there were no differences in either genotype (p⫽0.55) or allele frequency (p⫽0.31). Stratification for gender (664 female patients; allelic p⫽0.39: 274 male patients; allelic p⫽0.50) and AD⫹P (n⫽340; p⫽0.968) also showed no significant association. P1-328
ASSOCIATION ANALYSIS OF 22 POSITIONAL/ FUNCTIONAL CANDIDATE GENES ON CHROMOSOME 10 WITH LATE ONSET ALZHEIMER’S DISEASE
Angharad R. Morgan1, Luke Jehu1, Dragana Turic1, Denise Harold1, Gillian Hamilton2, Paul Hollingworth1, Pamela Moore1, Kimberley Dowzell1, Valentina Moskvina1, Lesley Jones1, John Powell2, Simon Lovestone2, Carol Brayne3, David C. Rubinsztein3, Michael O’Donovan1, Mike J. Owen1, Julie Williams1, 1Cardiff University, Cardiff, United Kingdom; 2Kings College, London, United Kingdom; 3University of Cambridge, Cambridge, United Kingdom. Contact e-mail: [email protected] Background: The brain in Alzheimer’s disease is characterized by intracellular neurofibrillary tangles and the extracellular deposition of A in senile plaques. A has been shown to mediate neurodegenerative and inflammatory changes associated with amyloid plaques, although the pathological mechanism of A remains largely unknown. Recent evidence suggests that the FISH adapter protein binds to, and potentially regulates, a disintegrin and metalloprotease 12 to mediate the neurotoxic effect of A. The ADAM12 gene lies on chromosome 10q26.3, and the gene
S193
encoding FISH, SH3MD1, lies within a region of linkage to late-onset Alzheimer’s disease on 10q25.1. Objective(s): This study investigates whether there is a relationship between variation in ADAM12 and SH3MD1 and susceptibility to LOAD. Methods: We used a powerful sample of 1051 well characterized AD cases (probable AD:NINCDSADCDA criteria) and 1269 matched controls from the UK population. Results: We identified significant interactions between variants in the two genes that may influence susceptibility to late-onset Alzheimer’s disease. The most significant statistical interaction is between rs3740473, a synonymous SNP in SH3MD1 and rs11244787, an intronic SNP in ADAM12 (effect size⫽2.1 for interaction term, p⫽0.006). Conclusions: A combination of variants in two functionally interactive genes show evidence of conferring susceptibility to develop AD. P1-329
PRESENILIN-1 MUTATION E318G IN ITALIAN POPULATION: GENETIC SCREENING AND EFFECT ON BETA AMYLOID METABOLISM IN HUMAN FIBROBLASTS
Gianluigi Forloni1, Sara Batelli1, Francesca Prati1, Francesca Prato1, Marzia Pesaresi2, Daniela Galimberti3, Elio Scarpini4, Amalia Bruni5, Massimo Franceschi6, Ignazio Roiter7, Vladimiro Artuso8, Diego Albani1, 1Istituto di Ricerche Farmacologiche ‘Mario Negri’, Milano, Italy; 2Istituto di Ricerche Farmacologiche Negri’, Milano, Italy; 3Department of Neurological Sciences,‘Dino Ferrari’ Center, University of Milan, “Ospedale Maggiore Policlinico”, Milano, Italy; 4 Department of Neurological Sciences, ‘Dino Ferrari’ Center, University of Milan, “Ospedale Maggiore Policlinico”, Milano, Italy; 5 Regional Center for Neurogenetics, Lamezia Terme (CZ), Italy; 6 Department of Neurology, Multimedica - Santa Maria, Castellanza (VA), Italy; 7Department of Internal Medicine, Hospital of Treviso, Treviso, Italy; 8ASL “Marcon”, Venice, Milano, Italy. Contact e-mail: [email protected] Background: Presenilin-1 (PSEN-1) is a key catalytic component of the ␥-secretase complex involved in -amyloid precursor protein (APP) processing. To date, about 150 pathogenic mutations in the PSEN-1 gene have been identified; their main biochemical effect is to increase the production of the fibrillogenic peptide A(1-42) that accumulates in cerebral senile plaques of AD patients. An interesting exception is represented by PSEN-1[E318G] mutation that does not seem to alter A(1-42) generation and that was found also in old-aged, cognitively normal subjects. Consequently, this substitution is generally considered a non-pathogenic polymorphism. Nevertheless, PSEN-1[E318G] mutation was reported to represent an independent genetic risk factor for familial Alzheimer’s disease (FAD) in the Australian population. Objectives: To confirm this indication, we performed a case-control association study in the Italian population; we determined in human fibroblasts from PSEN-1[E318G] carriers and PSEN-1[wild type] controls belonging to the same Italian family the  amyloid precursor metabolism and finally we extensively analyzed if this mutation altered also PSEN-1 stability or cellular localization. Methods: The genetic screening of PSEN-1[E318G] was performed by DHPLC, the evaluation of A(1-42) and A(1-40) concentration in fibroblasts conditioned media was determined by ELISA kits. The stability and cellular distribution of PSEN-1 was investigated by Western blot and immunocytochemical analysis in human fibroblasts obtained by skin biopsy. Results: We found a statistically significant association (p⬍0.05, Fisher’s exact test) between PSEN-1[E318G] presence and FAD. The evaluation by ELISA kit of A(1-42) and A(1-40) concentration in fibroblasts conditioned media cultured from PSEN-1[E318G] carriers and PSEN-1[wild type] controls belonging to the same Italian family revealed a statistically significant increase of A(1-40) and consequently reduction of A(1-42)/A(1-40) ratio in PSEN-1[E318G] carriers. No modification was seen in the stability or localization of PSEN-1 in primary skin fibroblasts cultured from PSEN-1[E318G] carriers compared to wild type condition. Conclusions: PSEN-1[E318G] is a genetic risk in a Italian FAD population. The mutation increased the production of A(1-40) in fibro-