1. The Association Of Polymorphisms And Transcriptional Regulation In The HLA-DQA1 Gene With Autoimmune Disease (Type 1 Diabetes And Vogt-Koyanagi-Harada Syndrome) 2. Polymorphisms In The ApoM Gene Confer The Susceptibility To Type 2 Diabetes In Chinese H

BackgroundType 1 diabetes (T1D) and Vogt-Koyanagi-Harada syndrome (VKH) are considered as autoimmune disease mediated by T-lymphocyte and directed against insulinβcells and melanocytes. HLA class-â…¡molecules play an important role in the autoimmunity related to T lymphocyte. In this study a population based case-control study was used to analyze the association of polymorphisms in the HLA-DQA1 gene and transcriptional activities of variations in the DQA1 promoter (QAP) with the development of T1D and VKH in Chinese Han population.MethodsNinety-eight T1D patients, 88 VKH patients and 146 control subjects without autoimmune disease were selected. Genotyping of polymorphisms in the coding region of HLA-DQA1 gene were performed with polymerase chain reaction-sequence specific primer (PCR-SSP). Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP), cloning and sequencing were used to screen the mutations in the promoter region of HLA-DQA1 gene. The plasmids of different alleles in the promoter of HLA-DQA1 gene were constructed with pGL3-Basic vector. Dual-luciferase^? reporter assay system was used to detect the transcriptional activities.Results1. Association of polymorphism in the HLA-DQA1 gene with T1 D(1) The frequency of DQA1*0302/3 allele in T1D patients was significantly higher than that in control subjects (32.7% vs 14.4%, Pc＜0.001, OR=2.886, 95%CI 1.854-4.493). The frequency of DQA1*0102 allele in T1D patients was significantly lower than that in control subjects (7.1% vs 18.8%, Pc=0.003, OR=0.331, 95%CI 0.179-0.615).(2) The frequencies of QAP3.11 and QAP3.12 alleles in T1D patients and control subjects were 27.0% vs 14.4% and 24.0% vs 11.3%, respectively, there were clearly significant difference between the two groups (Pc=0.008; Pc=0.002). The frequencies of QAP1.2, QAP1.3 and QAP4.2 alleles in T1D patients were significantly lower than those in control subjects (5.1% vs 20.2%, Pc＜0.001; 4.6% vs 13.0%, Pc=0.016; 0.5% vs 9.2%, Pc＜0.001).(3) The haplotypes of QAP3.12-DQA1*0302/3 and QAP3.11-DQA1*0302/3 showed significant risk to T1D (20.4% vs 9.9%, P=0.001, OR=2.325; 12.2% vs 3.4%, P＜0.001, OR=3.935). While QAP1.2-DQA1*0102 haplotype had significant resistance to T1D (3.1% vs 13.7%, P＜0.001, OR=0.199).2. Association ofpolymorphism in the HLA-DQA1 gene with VKH(1) The frequency of DQA1*0302/3 allele in VKH patients was significantly higher than that in control subjects (40.9% vs 14.4%, Pc＜0.001, OR=4.121, 95%CI 2.634-6.424). The frequencies of DQA1*0103 and DQA1*0501 alleles in VKH patients were significantly lower than those in control subjects (1.7% vs 9.9%, Pc=0.006, OR=0.157, 95%CI 0.047-0.524; 11.9% vs 22.6%, Pc:0.040, OR=0.464, 95%CI 0.273-0.790).(2) The frequencies of QAP3.11 allele in VKH patients and control subjects were 42.6% vs 14.4%, which showed a significantly association with VKH (Pc＜0.001). While the frequency of QAP1.3 allele in VKH patients was significantly lower than that in control subjects (2.8% vs 13.0%, Pc=0.002).(3) The haplotypes of QAP3.11-DQA1*0302/3 and QAP3.12-DQA1*0301 showed significant risk to VKH (37.5% vs 3.4%, P＜0.001, OR=16.920; 5.7% vs 0.7%, P=0.001, OR=8.735), respectively.3. The pairwise linkage disequilibrium (LD) analysis between the alleles of QAP and alleles in the coding region of HLA-DQA1 gene in control subjects without AD The significant LD were observed in haplotypes QAP2.1-DQA1*0201 and QAP4.1-DQA1*0501 (D'=1.000, r²=0.943, P＜0.001; D'=1.000, r²=0.889, P＜0.001).4. Transcriptional activities of QAP allelesThe transcriptional activity of QAP 1.2 allele was 1.67-fold than that of QAP4.1. ConclusionThe alleles DQA1*0302/3, QAP3.11, QAP3.12 and haplotypes QAP3.12-DQA1*0302/3, QAP3.11-DQA1*0302/3 are associated with susceptibility to T1D, while the alleles DQA1*0102, QAP1.2, QAP1.3, QAP4.2, and haplotype QAP1.2-DQA1*0102 are associated with resistance to T1D. The alleles DQA1*0302/3, QAP3.11 and haplotypes QAP3.11-DQA1*0302/3, QAP3.12-DQA1*0301 are susceptible factors to VKH, while DQA1*0103, *0501 and QAP1.3 alleles are resistant factors to VKH. The haplotypes QAP2.1-DQA1*0201 and QAP4.1-DQA1*0501 are in strong linkage disequilibrium. The polymorphisms in the promoter region and coding region of HLA-DQA1 gene are important factors involved in the development of autoimmune disease by influencing the molecular structure and transcriptional activity. ObjectiveApolipoprotein M (ApoM), as a high-density lipoprotein (HDL) -associated apolipoprotein, has been recently found to be an important regulator for the formation of pre-βHDL and blood cholesterol (CHO) efflux. Dyslipidemia correlating to insulin resistance is one of the key features in type 2 diabetes (T2D). In present study, we investigated the potential association of ApoM genetic variation with development of T2D.MethodsThe case-control study was conducted. Genotyping of SNPs G-1529A, C-1065A, T-855C, T-778C and C2343T in ApoM gene were performed with PCR-RFLP in 170 T2D patients and 156 non-diabetic control subjects of Han Chinese.Results1. There were no polymorphisms for SNPs G-1529A and C2343T. No significant differences were observed for SNPs C-1065A and T-855C between type 2 diabetic patients and non-diabetic controls.2. Single marker analysis for SNP T-778C indicated that T2D patients had increased frequency of C allele in comparison with non-diabetic controls (10.6% vs 5.8%, P=0.026, OR=1.934, 95% CI 1.074-3.483). In non-diabetic controls, the carriers with CT and CC genotypes had higher plasma CHO (221.7 vs 204.2 mg/dl, P＝0.033) and fasting plasma glucose (FPG) (92.6 vs 89.7 mg/dl, P＝0.041) levels than the subjects with TT genotype. Further analysis with adjustment for age, BMI, SBP, DBP, CHO and TG demonstrated that -778(CT+CC) was an independently susceptible factor of T2D (P=0.013, OR=2.287).3. Further haplotype analysis for those three SNPs (C-1065A, T-855C and T-778C) indicated that the frequency of haplotype CTC was higher in type 2 diabetic patients than that in control subjects, but there was no significant difference (9.1% vs 5.8%, P=0.105). The common haplotype C-T-C was associated with increased CHO and FPG levels in non-diabetic controls (221.7 vs 205.3 mg/dl, P=0.039; 92.6 vs 89.9 mg/dl, P=0.048).ConclusionThis study provided the first evidence that SNP T-778C in the proximal promoter region of ApoM gene were associated with the levels of plasma CHO and FPG and also conferred the risk in development of T2D among Han Chinese.