- Email: [email protected]
P3-231: Dynamin2 reduction in Alzheimer's disease and alteration in APP and Abeta metabolism
T588
Poster Presentations P3:
association by genotyping an additional 38 SNPs including all coding and tagging SNPs in VDR using 492 cases and 496 controls. Results: We found a novel SNP with nominally significant association (P⫽0.04) in intron 2. Furthermore, we found multiple significant associations with LOAD with SNPs in intron1, intron 2, and promoter region in VDR (P⬍0.001). Conclusions: These results suggest that VDR is a strong candidate for a genetic risk factor for LOAD. P3-229
GAB2, GSTP1 AND GAPDH POLYMORPHISMS AND THEIR POTENTIAL ROLE IN LATE-ONSET ALZHEIMER’S DISEASE
Giselle Izzo1, C. C. Kukita1, O. V. Forlenza1, P. H. F. Bertollucci2, E. Dias Neto1, L. L. Talib1, B. S. O. Diniz1, W. Gattaz1, E. B. Ojopi1, 1 Laboratory of Neurosciences (LIM-27), University of Sao Paulo, Sao Paulo, Brazil; 2Department of Neurology and Neurosurgery, Federal University of Sao Paulo, Sao Paulo, Brazil. Contact e-mail: [email protected] Background: Although the etiology of Alzheimer disease (AD) has not yet been identified, many mechanisms have been implied in neurodegenerative pathogenesis. GSTP1 has an important role on oxidative stress, GAPDH may have role on neuronal apoptosis and GAB2 on neuronal differentiation. APOE affect lipid metabolism and has been shown as the most well established genetic factor for Alzheimer disease. In this study, we have analyzed GAPDH, GSTP1, and GAB2 gene polymorphisms and their interactions with the APOE*E4 allele in a sample of late onset AD. Methods: DNA was extracted from peripheral blood leukocytes of AD patients and elderly controls. We performed genotypic analysis by using allelic discrimination on Real-Time PCR. We have analyzed 7 single nucleotide polymorphisms (SNPs) on 4 different genes (APOE, GAPDH, GSTP1 and GAB2) in a sample of 139 AD patients and 74 normal elderly controls. Results: As expected, the APOE*E2 allele variant was more frequently found among controls and the APOE*E4 allele was associated with the diagnosis of AD (P ⫽ 0,00127). In AD group, we found significant associations with the GSTP1 rs1138272 and the GAB2 rs2373115 polymorphisms. Regarding the GSTP1 gene, the CT genotype was found exclusively in the control group (P ⫽ 0,003). Suggesting that this genotype may yield a protective effect on control group. The combination of the C allele and the APOE-E4 genotype conferred a even stronger association with AD (P ⫽ 0,007). Regarding the GAB2 gene, the presence of the TT genotype was associated with AD (P ⫽ 0,002) and the GG genotype associated with at least one *E4 allele resulted in increased risk for AD (P ⫽ 0,005). Conclusions: Considering the multifactorial nature of AD including both environmental and genetics features, and the fact that except for apolipoprotein E (APOE) polymorphisms little is known about the genetic causes of AD, other genes with relevant roles in neuronal homeostasis, such as oxidative stress, neuronal apoptosis and neuronal differentiation need to be investigated. If those associations prove consistent in even larger samples, the underlying biological roles of GSTP1 and GAB2 will require further clarification. P3-230
ALTERATIONS IN THE EXPRESSION OF GENES IMPORTANT IN ALZHEIMER’S DISEASE (APP, PRESENILIN 1, TAU) IN THE HFE KNOCKOUT MOUSE MODEL OF THE IRON DISORDER HEMOCHROMATOSIS 1
2
2
1
Daniel Johnstone , Ross Graham , Deborah Trinder , Rodney Scott , John Olynyk2, Elizabeth Milward1, 1University of Newcastle, Callaghan, Australia; 2University of Western Australia, Fremantle, Australia. Contact e-mail: [email protected] Background: Iron deposits in brain are associated with several neurodegenerative diseases including Alzheimer’s disease (AD), however the impact of abnormal iron status on AD risk remains controversial. The genetic disorder hereditary hemochromatosis commonly occurs as the result of mutations in the hemochromatosis HFE gene. It is characterized by tissue
iron loading, typically in the liver but other organs can also be affected. Recent evidence from magnetic resonance imaging studies suggests that higher levels of iron can accumulate in the brains of individuals with hemochromatosis and there has been speculation that HFE mutations may be a risk factor for AD. We investigated genome-wide changes of brain gene expression in a transgenic mouse model of hemochromatosis with disrupted function of the HFE gene. This model has previously been shown to have features similar to the human disorder, including elevated serum iron measures and increased hepatic iron concentration. Methods: RNA was isolated from brain hemispheres of biological replicates of each of wildtype AKR mice and HFE knockout mice (nⱖ4). Differential expression analysis by microarray was performed using Illumina Sentrix MouseRef-8 (v1.1) BeadChip arrays. Select changes were further investigated by real-time reverse-transcription PCR. Results: A number of genes implicated in AD were identified as having selectively altered expression levels in the hemochromatosis model compared to wildtype controls. Notably, in whole brain from HFE knockout mice, there was a 2-fold decrease in expression of the gene encoding amyloid precursor protein (APP), a decrease of up to 8-fold in expression of the presenilin 1 gene (Psen1) and a decrease of up to 2.4-fold in tau expression (all p⬍0.05). Other genes showing evidence of alterations included various lipoprotein receptor related protein family members. There was little evidence for altered expression of apolipoprotein E or various important inflammatory response genes including tumor necrosis factor alpha and most interleukins, notably interleukin 1beta. Conclusions: There are considerable changes in gene expression in the HFE knockout mouse brain, including effects on several important AD genes, however it is unclear whether the net effect would be more likely to predispose to AD, protect against AD or not alter AD risk in humans. P3-231
DYNAMIN2 REDUCTION IN ALZHEIMER’S DISEASE AND ALTERATION IN APP AND ABETA METABOLISM
Eiichiro Kamagata, Takashi Kudo, Ryo Kimura, Hitoshi Tanimukai, Kojin Kamino, Masatoshi Takeda, Osaka University, Osaka, Japan. Contact e-mail: [email protected] Background: Our previous data showed that a significant association of late onset Alzheimer disease (LOAD) with SNP markers of the dynamin2 (DNM2) gene. In this study, we investigated the relationship between the pathology of AD and the function of DNM2. Methods: Real time PCR was used for DNM2 mRNA analysis of AD brain. SH-SY5Y cells were prepared for Abeta and APP analysis. Abeta secretion was measured by Enzyme-linked immunosorbent assay (ELISA). To examine APP localization, immunohistochemistry and subfractionation were performed. Results: DNM2 mRNA expression was reduced in hippocampus of AD brains. According to the study on knockdown SH-SY5Y cells with siRNA of DNM1 and DNM2, the reduction of DNM significantly increased Abeta40 and Abeta42. Moreover, dominant negative SH-SY5Y with DNM1K44A and DNM2K44A plasmids had higher level of Abeta40 and Abeta42. In the double knockdown cells and the dominant negative cells, APP was predominantly located on plasma membrane. Conclusions: These observations indicate that the reduction of DNM2 in LOAD may influence APP localization to change amyloid metabolism. P3-232
SNPS IN SOAT1, TFAM, AND CNDP1 ARE ASSOCIATED WITH CEREBROSPINAL FLUID AMYLOID-BETA LEVELS
John S. K. Kauwe, Kevin Mayo, Sarah Bertelsen, Aarti R. Shah, John C. Morris, Anne M. Fagan, David M. Holtzman, Alison M. Goate, Washington University School of Medicine, St. Louis, MO, USA. Contact e-mail: [email protected] Background: Lack of replication among association studies should not be surprising as current case-control approaches may not have the statistical power to detect the small effect sizes we might expect in a complex disease
Poster Presentations P3:
association by genotyping an additional 38 SNPs including all coding and tagging SNPs in VDR using 492 cases and 496 controls. Results: We found a novel SNP with nominally significant association (P⫽0.04) in intron 2. Furthermore, we found multiple significant associations with LOAD with SNPs in intron1, intron 2, and promoter region in VDR (P⬍0.001). Conclusions: These results suggest that VDR is a strong candidate for a genetic risk factor for LOAD. P3-229
GAB2, GSTP1 AND GAPDH POLYMORPHISMS AND THEIR POTENTIAL ROLE IN LATE-ONSET ALZHEIMER’S DISEASE
Giselle Izzo1, C. C. Kukita1, O. V. Forlenza1, P. H. F. Bertollucci2, E. Dias Neto1, L. L. Talib1, B. S. O. Diniz1, W. Gattaz1, E. B. Ojopi1, 1 Laboratory of Neurosciences (LIM-27), University of Sao Paulo, Sao Paulo, Brazil; 2Department of Neurology and Neurosurgery, Federal University of Sao Paulo, Sao Paulo, Brazil. Contact e-mail: [email protected] Background: Although the etiology of Alzheimer disease (AD) has not yet been identified, many mechanisms have been implied in neurodegenerative pathogenesis. GSTP1 has an important role on oxidative stress, GAPDH may have role on neuronal apoptosis and GAB2 on neuronal differentiation. APOE affect lipid metabolism and has been shown as the most well established genetic factor for Alzheimer disease. In this study, we have analyzed GAPDH, GSTP1, and GAB2 gene polymorphisms and their interactions with the APOE*E4 allele in a sample of late onset AD. Methods: DNA was extracted from peripheral blood leukocytes of AD patients and elderly controls. We performed genotypic analysis by using allelic discrimination on Real-Time PCR. We have analyzed 7 single nucleotide polymorphisms (SNPs) on 4 different genes (APOE, GAPDH, GSTP1 and GAB2) in a sample of 139 AD patients and 74 normal elderly controls. Results: As expected, the APOE*E2 allele variant was more frequently found among controls and the APOE*E4 allele was associated with the diagnosis of AD (P ⫽ 0,00127). In AD group, we found significant associations with the GSTP1 rs1138272 and the GAB2 rs2373115 polymorphisms. Regarding the GSTP1 gene, the CT genotype was found exclusively in the control group (P ⫽ 0,003). Suggesting that this genotype may yield a protective effect on control group. The combination of the C allele and the APOE-E4 genotype conferred a even stronger association with AD (P ⫽ 0,007). Regarding the GAB2 gene, the presence of the TT genotype was associated with AD (P ⫽ 0,002) and the GG genotype associated with at least one *E4 allele resulted in increased risk for AD (P ⫽ 0,005). Conclusions: Considering the multifactorial nature of AD including both environmental and genetics features, and the fact that except for apolipoprotein E (APOE) polymorphisms little is known about the genetic causes of AD, other genes with relevant roles in neuronal homeostasis, such as oxidative stress, neuronal apoptosis and neuronal differentiation need to be investigated. If those associations prove consistent in even larger samples, the underlying biological roles of GSTP1 and GAB2 will require further clarification. P3-230
ALTERATIONS IN THE EXPRESSION OF GENES IMPORTANT IN ALZHEIMER’S DISEASE (APP, PRESENILIN 1, TAU) IN THE HFE KNOCKOUT MOUSE MODEL OF THE IRON DISORDER HEMOCHROMATOSIS 1
2
2
1
Daniel Johnstone , Ross Graham , Deborah Trinder , Rodney Scott , John Olynyk2, Elizabeth Milward1, 1University of Newcastle, Callaghan, Australia; 2University of Western Australia, Fremantle, Australia. Contact e-mail: [email protected] Background: Iron deposits in brain are associated with several neurodegenerative diseases including Alzheimer’s disease (AD), however the impact of abnormal iron status on AD risk remains controversial. The genetic disorder hereditary hemochromatosis commonly occurs as the result of mutations in the hemochromatosis HFE gene. It is characterized by tissue
iron loading, typically in the liver but other organs can also be affected. Recent evidence from magnetic resonance imaging studies suggests that higher levels of iron can accumulate in the brains of individuals with hemochromatosis and there has been speculation that HFE mutations may be a risk factor for AD. We investigated genome-wide changes of brain gene expression in a transgenic mouse model of hemochromatosis with disrupted function of the HFE gene. This model has previously been shown to have features similar to the human disorder, including elevated serum iron measures and increased hepatic iron concentration. Methods: RNA was isolated from brain hemispheres of biological replicates of each of wildtype AKR mice and HFE knockout mice (nⱖ4). Differential expression analysis by microarray was performed using Illumina Sentrix MouseRef-8 (v1.1) BeadChip arrays. Select changes were further investigated by real-time reverse-transcription PCR. Results: A number of genes implicated in AD were identified as having selectively altered expression levels in the hemochromatosis model compared to wildtype controls. Notably, in whole brain from HFE knockout mice, there was a 2-fold decrease in expression of the gene encoding amyloid precursor protein (APP), a decrease of up to 8-fold in expression of the presenilin 1 gene (Psen1) and a decrease of up to 2.4-fold in tau expression (all p⬍0.05). Other genes showing evidence of alterations included various lipoprotein receptor related protein family members. There was little evidence for altered expression of apolipoprotein E or various important inflammatory response genes including tumor necrosis factor alpha and most interleukins, notably interleukin 1beta. Conclusions: There are considerable changes in gene expression in the HFE knockout mouse brain, including effects on several important AD genes, however it is unclear whether the net effect would be more likely to predispose to AD, protect against AD or not alter AD risk in humans. P3-231
DYNAMIN2 REDUCTION IN ALZHEIMER’S DISEASE AND ALTERATION IN APP AND ABETA METABOLISM
Eiichiro Kamagata, Takashi Kudo, Ryo Kimura, Hitoshi Tanimukai, Kojin Kamino, Masatoshi Takeda, Osaka University, Osaka, Japan. Contact e-mail: [email protected] Background: Our previous data showed that a significant association of late onset Alzheimer disease (LOAD) with SNP markers of the dynamin2 (DNM2) gene. In this study, we investigated the relationship between the pathology of AD and the function of DNM2. Methods: Real time PCR was used for DNM2 mRNA analysis of AD brain. SH-SY5Y cells were prepared for Abeta and APP analysis. Abeta secretion was measured by Enzyme-linked immunosorbent assay (ELISA). To examine APP localization, immunohistochemistry and subfractionation were performed. Results: DNM2 mRNA expression was reduced in hippocampus of AD brains. According to the study on knockdown SH-SY5Y cells with siRNA of DNM1 and DNM2, the reduction of DNM significantly increased Abeta40 and Abeta42. Moreover, dominant negative SH-SY5Y with DNM1K44A and DNM2K44A plasmids had higher level of Abeta40 and Abeta42. In the double knockdown cells and the dominant negative cells, APP was predominantly located on plasma membrane. Conclusions: These observations indicate that the reduction of DNM2 in LOAD may influence APP localization to change amyloid metabolism. P3-232
SNPS IN SOAT1, TFAM, AND CNDP1 ARE ASSOCIATED WITH CEREBROSPINAL FLUID AMYLOID-BETA LEVELS
John S. K. Kauwe, Kevin Mayo, Sarah Bertelsen, Aarti R. Shah, John C. Morris, Anne M. Fagan, David M. Holtzman, Alison M. Goate, Washington University School of Medicine, St. Louis, MO, USA. Contact e-mail: [email protected] Background: Lack of replication among association studies should not be surprising as current case-control approaches may not have the statistical power to detect the small effect sizes we might expect in a complex disease