1Schizophr. Res. 2005 Jul 76: 231-8
PMID15949655
TitleInvestigation of the apolipoprotein-L (APOL) gene family and schizophrenia using a novel DNA pooling strategy for public database SNPs.
AbstractWe performed an extensive genetic association study of the six known apolipoprotein-L (APOL) genes and schizophrenia (SZ) using a novel DNA pooling strategy. The APOL genes are both positional and functional candidate genes for SZ. This gene family maps to chromosome 22q12.3, a region implicated by SZ linkage studies as likely to contain one or more SZ susceptibility genes. A recent gene expression study demonstrated up-regulation of APOL1, 2, and 4 in post-mortem brain samples from SZ patients compared to controls in two independent samples. To test for genetic association with SZ, we analyzed 143 SNPs from dbSNP from across the APOL genes in an Irish sample of 219 cases and 231 controls. Of these 143 SNPs, 51 (36%) were polymorphic in our Irish sample and were genotyped using a novel three-stage DNA pooling strategy. This strategy does not require the identification of a heterozygous individual for DNA pooling association analysis and is therefore very efficient when using public database SNPs. We found no evidence to support the hypothesis that genetic variation at the APOL genes contributes to SZ susceptibility in our sample.
SCZ Keywordsschizophrenia, schizophrenic
2Schizophr. Res. 2008 Sep 104: 153-64
PMID18632255
TitleAssociation of SNPs and haplotypes in APOL1, 2 and 4 with schizophrenia.
AbstractPrior work found the APOL1, 2 and 4 genes, located on chromosome 22q12.3-q13.1, to be upregulated in brains of schizophrenic patients. We performed a family-based association study using 130 SNPs tagging the APOL gene family (APOL1-6). The subjects were 112 African-American (AA), 114 European-American (EA), 109 Chinese (Ch) and 42 Japanese (Jp) families with schizophrenia (377 families, 1161 genotyped members and 647 genotyped affected in total). Seven SNPs had p-values<0.05 in the APOL1, 2 and 4 regions for the AA, EA and combined (AA and EA) samples. In the AA sample, two SNPs, rs9610449 and rs6000200 showed low p-values; and a haplotype which comprised these two SNPs yielded a p-value of 0.00029 using the global test (GT) and the allele specific test (AST). The two SNPs and the haplotype were associated with risk for schizophrenia in African-Americans. In the combined (AA and EA) sample, two SNPs, rs2003813 and rs2157249 showed low p-values; and a three SNP haplotype including these two SNPs was significant using the GT (p=0.0013) and the AST (p=0.000090). The association of this haplotype with schizophrenia was significant for the entire (AA, EA, Ch and Jp) sample using the GT (p=0.00054) and the AST (p=0.00011). Although our study is not definitive, it suggests that the APOL genes should be more extensively studied in schizophrenia.
SCZ Keywordsschizophrenia, schizophrenic
3Schizophr. Res. 2008 Sep 104: 153-64
PMID18632255
TitleAssociation of SNPs and haplotypes in APOL1, 2 and 4 with schizophrenia.
AbstractPrior work found the APOL1, 2 and 4 genes, located on chromosome 22q12.3-q13.1, to be upregulated in brains of schizophrenic patients. We performed a family-based association study using 130 SNPs tagging the APOL gene family (APOL1-6). The subjects were 112 African-American (AA), 114 European-American (EA), 109 Chinese (Ch) and 42 Japanese (Jp) families with schizophrenia (377 families, 1161 genotyped members and 647 genotyped affected in total). Seven SNPs had p-values<0.05 in the APOL1, 2 and 4 regions for the AA, EA and combined (AA and EA) samples. In the AA sample, two SNPs, rs9610449 and rs6000200 showed low p-values; and a haplotype which comprised these two SNPs yielded a p-value of 0.00029 using the global test (GT) and the allele specific test (AST). The two SNPs and the haplotype were associated with risk for schizophrenia in African-Americans. In the combined (AA and EA) sample, two SNPs, rs2003813 and rs2157249 showed low p-values; and a three SNP haplotype including these two SNPs was significant using the GT (p=0.0013) and the AST (p=0.000090). The association of this haplotype with schizophrenia was significant for the entire (AA, EA, Ch and Jp) sample using the GT (p=0.00054) and the AST (p=0.00011). Although our study is not definitive, it suggests that the APOL genes should be more extensively studied in schizophrenia.
SCZ Keywordsschizophrenia, schizophrenic
4Psychiatry Res 2010 Sep 179: 126-9
PMID20483474
TitleTesting the antagonistic pleiotropy model of schizophrenia susceptibility by analysis of DAOA, PPP1R1B, and APOL1 genes.
Abstractschizophrenia is a common disease associated with reduced fertility. Therefore, the existence of common susceptibility alleles not removed by natural selection may be considered an evolutionary paradox. The antagonistic pleiotropy model, proposed to explain this paradox, states that an allele may be common because of its overall selective advantage, in spite of deleterious effects on specific traits. Recent work on DAOA, PPP1R1B, and APOL1 suggests that these genes present common alleles associated to increase risk of schizophrenia but conferring an overall selective advantage, related to better cognitive performance (DAOA and PPP1R1B) or protection against pathogens (APOL1). To test if these genes fit the antagonistic pleiotropy model, we searched for recent natural selection at these loci applying the long-range haplotype test on data from the HapMap Project; and performed case-control association analysis in a well-powered sample, including 301 schizophrenic patients and 604 controls from Spain. For DAOA and PPP1R1B, we genotyped the Single-nucleotide polymorphisms (SNPs) needed to replicate previous associations, while for APOL1, we genotyped 15 tagSNPs, and seven putative functional SNPs. We did not detect evidence of recent natural selection. Furthermore, we did not find significant associations. Thus, these genes do not fit the antagonistic pleiotropy model.
SCZ Keywordsschizophrenia, schizophrenic
5Psychiatry Res 2010 Sep 179: 126-9
PMID20483474
TitleTesting the antagonistic pleiotropy model of schizophrenia susceptibility by analysis of DAOA, PPP1R1B, and APOL1 genes.
Abstractschizophrenia is a common disease associated with reduced fertility. Therefore, the existence of common susceptibility alleles not removed by natural selection may be considered an evolutionary paradox. The antagonistic pleiotropy model, proposed to explain this paradox, states that an allele may be common because of its overall selective advantage, in spite of deleterious effects on specific traits. Recent work on DAOA, PPP1R1B, and APOL1 suggests that these genes present common alleles associated to increase risk of schizophrenia but conferring an overall selective advantage, related to better cognitive performance (DAOA and PPP1R1B) or protection against pathogens (APOL1). To test if these genes fit the antagonistic pleiotropy model, we searched for recent natural selection at these loci applying the long-range haplotype test on data from the HapMap Project; and performed case-control association analysis in a well-powered sample, including 301 schizophrenic patients and 604 controls from Spain. For DAOA and PPP1R1B, we genotyped the Single-nucleotide polymorphisms (SNPs) needed to replicate previous associations, while for APOL1, we genotyped 15 tagSNPs, and seven putative functional SNPs. We did not detect evidence of recent natural selection. Furthermore, we did not find significant associations. Thus, these genes do not fit the antagonistic pleiotropy model.
SCZ Keywordsschizophrenia, schizophrenic
6FEBS Lett. 2012 Apr 586: 947-55
PMID22569246
TitleHuman apolipoprotein L1 (ApoL1) in cancer and chronic kidney disease.
AbstractHuman apolipoprotein L1 (APOL1) possesses both extra- and intra-cellular functions crucial in host defense and cellular homeostatic mechanisms. Alterations in APOL1 function due to genetic, environmental, and lifestyle factors have been associated with African sleeping sickness, atherosclerosis, lipid disorders, obesity, schizophrenia, cancer, and chronic kidney disease (CKD). Importantly, two alleles of APOL1 carrying three coding-sequence variants have been linked to CKD, particularly in Sub-Saharan Africans and African Americans. Intracellularly, elevated APOL1 can induce autophagy and autophagy-associated cell death, which may be critical in the maintenance of cellular homeostasis in the kidney. Similarly, APOL1 may protect kidney cells against renal cell carcinoma (RCC). We summarize the role of APOL1 in RCC and CKD, highlighting the critical function of APOL1 in autophagy.
SCZ Keywordsschizophrenia, schizophrenic
7Transl Psychiatry 2013 -1 3: e321
PMID24169640
TitleGene expression profiling by mRNA sequencing reveals increased expression of immune/inflammation-related genes in the hippocampus of individuals with schizophrenia.
AbstractWhole-genome expression profiling in postmortem brain tissue has recently provided insight into the pathophysiology of schizophrenia. Previous microarray and RNA-Seq studies identified several biological processes including synaptic function, mitochondrial function and immune/inflammation response as altered in the cortex of subjects with schizophrenia. Now using RNA-Seq data from the hippocampus, we have identified 144 differentially expressed genes in schizophrenia cases as compared with unaffected controls. Immune/inflammation response was the main biological process over-represented in these genes. The upregulation of several of these genes, IFITM1, IFITM2, IFITM3, APOL1 (Apolipoprotein L1), ADORA2A (adenosine receptor 2A), IGFBP4 and CD163 were validated in the schizophrenia subjects using data from the SNCID database and with quantitative RT-PCR. We identified a co-expression module associated with schizophrenia that includes the majority of differentially expressed genes related to immune/inflammation response as well as with the density of parvalbumin-containing neurons in the hippocampus. The results indicate that abnormal immune/inflammation response in the hippocampus may underlie the pathophysiology of schizophrenia and may be associated with abnormalities in the parvalbumin-containing neurons that lead to the cognitive deficits of the disease.
SCZ Keywordsschizophrenia, schizophrenic