Yifeng Yang

Meta-analysis Added Power to Identify Variants in FTO Associated With Type 2 Diabetes and Obesity in the Asian Population

Several common variants in the intron 1 of FTO (fat mass and associated obesity) gene have been reliably associated with BMI and obesity in European populations. We analyzed two variants (rs9939609 and rs8050136) in 4,189 Chinese Han individuals and conducted a meta‐analysis of published studies in Asian population to investigate whether these variants are associated with type 2 diabetes (T2D) and obesity in Asian population. In this study, both the minor allele A of rs9939609 and the minor allele A of rs805136 were associated with increased risk of T2D, independent of measures of BMI; the odds ratios (ORs) per copy of the risk allele were 1.19 for rs9939609 (95% confidence interval (CI), 1.04–1.37; P = 0.01) and 1.22 for rs8050136 (95% CI, 1.07–1.40; P = 0.004) after adjusting for age, sex, and BMI. Our results also showed association with risk of obesity (rs9939609: OR = 1.39 (95% CI 1.04–1.85), P = 0.02; rs8050136: OR = 1.45 (95% CI 1.09–1.93), P = 0.01) but no association with overweight. These results were consistent with the pooled results from our meta‐analysis study (for diabetes, rs8050136, P = 1.3 × 10−3; rs9939609, P = 9.8 × 10−4; for obesity, rs8050136, P = 2.2 × 10−7; rs9939609, P = 9.0 × 10−9). Our findings indicate that the two variants (rs9939609 and rs8050136) in the FTO gene contribute to obesity and T2D in the Asian populations.

A Comparative Proteomics Analysis of Rat Mitochondria from the Cerebral Cortex and Hippocampus in Response to Antipsychotic Medications

An increasing number of experiments have found anomalies in mitochondria in the brains of psychotics, which suggests that mitochondrial dysfunction or abnormal cerebral energy metabolism might play an important role in the pathophysiology of schizophrenia (SCZ). We adopted a proteomic approach to identify the differential effects on the cerebral cortex and hippocampus mitochondrial protein expression of Sprague-Dawley (SD) rats by comparing exposure to typical and atypical antipsychotic medications. Differential mitochondrial protein expressions were assessed using two-dimensional (2D) gel electrophoresis for three groups with Chlorpromazine (CPZ), Clozapine (CLZ), quetiapine (QTP) and a control group. A total of 14 proteins, of which 6 belong to the respiratory electron transport chain (ETC) of oxidative phosphorylation (OXPHOS), showed significant changes in quantity including NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 10 (Ndufa10), NADH dehydrogenase (ubiquinone) flavoprotein 2 (Ndufv2), NADH dehydrogenase (ubiquinone) Fe-S protein 3 (Ndufs3), F1-ATPase beta subunit (Atp5b), ATPase, H+ transporting, lysosomal, beta 56/58 kDa, isoform 2 (Atp6v1b2) and ATPase, H+ transporting, V1 subunit A, isoform 1 (Atp6v1a1). The differential proteins subjected to 2D were assessed for levels of mRNA using quantitative real time PCR (Q-RT-PCR), and we also made partial use of Western blotting for assessing differential expression. The results of our study may help to explain variations in SD rats as well as in human response to antipsychotic drugs. In addition, they should improve our understanding of both the curative effects and side effects of antipsychotics and encourage new directions in SCZ research.

Abnormal changes of plasma acute phase proteins in schizophrenia and the relation between schizophrenia and haptoglobin (Hp) gene.

Summary.In this study we focused on detecting schizophrenia related changes of plasma proteins using proteomic technology and examining the relation between schizophrenia and haptoglobin (Hp) genotype. We investigated plasma proteins from schizophrenic subjects (n = 42) and healthy controls (n = 46) by two-dimensional gel electrophoresis (2-DE) in combination with mass spectrometry. To further reveal the genetic relationship between acute phase proteins (APPs) and schizophrenia disease, we tested Hp α1/Hp α2 (Hp 1/2) polymorphism and two single nucleotide polymorphisms (SNPs) of Hp, rs2070937 and rs5473, for associations with schizophrenia in the Chinese Han population. With the relatively high number of samples for 2-DE work, we found that four proteins in the family of positive APPs were all up-regulated in patients. In genetic association study, we found significant associations existing between schizophrenia and Hp polymorphisms, Hp 1/2 and rs2070937 variants. Schizophrenia is accompanied by both an altered expression of Hp protein and a different genotype distribution of Hp gene, demonstrating that Hp is associated with schizophrenia. The results from proteomic and genomic aspects both indicate that acute phase reaction is likely to be an aetiological agent in the pathophysiology of schizophrenia, but not just an accompanying symptom. The positive APPs are schizophrenic related proteins, with the highly concordant results on four positive APPs.

Polymorphisms of myelin-associated glycoprotein gene are associated with schizophrenia in the Chinese Han population.

Results of gene expression microarray and quantitative PCR studies have suggested abnormalities in the expression of myelin-related genes including myelin-associated glycoprotein (MAG) in schizophrenic patients. Research provides strong evidence for oligodendrocyte dysfunction in schizophrenics. In order to further assess the role of MAG in schizophrenia, we examined four single nucleotide polymorphisms (SNPs), namely rs2301600, rs3746248, rs720309 and rs720308, of this gene in Chinese schizophrenic patients (n=470) and healthy controls (n=470). The distribution of rs720309 T/A genotypes showed a strong association with schizophrenia (chi(2)=14.58, d.f.=2, P=0.0008). A haplotype constructed of rs720309-rs720308 also revealed a significant association with schizophrenia (chi(2)=11.914, d.f.=3, P=0.0084). Our findings of a significant associations between schizophrenia and the MAG gene suggest that this gene may be involved in susceptibility to schizophrenia in the Chinese Han population.

Possible association of the MAG locus with schizophrenia in a Chinese Han cohort of family trios

Neurotransmitter-based hypotheses have so far led to only moderate success in predicting new pathogenetic findings in etiology of schizophrenia. On the other hand, the more recent oligodendroglia hypotheses of this disorder have been supported by an increasing body of evidence. For example, the expression level of the myelin associated glycoprotein (MAG) gene has been shown to be significantly lower in schizophrenia patient groups compared to control groups. Such an effect might be a result of genetic variations of the MAG gene. In order to test this hypothesis, we genotyped four markers within the MAG locus in 413 trios sample of the Han Chinese using allele-specific PCR. None of the four markers revealed noticeable allelic significance. However, the four-marker and two-marker haplotypes covering components rs720309 and rs720308 were observed to be significantly associated with schizophrenia (P < 0.0001) in this study. In addition, we identified one common risk haplotype TA (rs720309-rs720308, present in 78.5% of the general population) that showed increased evidence of overtransmission from parents to affected offspring (P = 0.0001). The results demonstrated MAG might play a role in genetic susceptibility to schizophrenia. Furthermore, our finding of a possible association between the MAG locus and schizophrenia is in agreement with the hypotheses of oligodendrltic and myelination dysfunction.

Association study of the single nucleotide polymorphisms in adiponectin-associated genes with type 2 diabetes in Han Chinese.

Single-nucleotide polymorphisms (SNPs) of ADIPOQ, ADIPOR1, and ADIPOR2 have been associated with type 2 diabetes mellitus (T2DM), but there are many conflicting results especially in Chinese populations. To investigate the contribution of the adiponectin genes and their receptors to T2DM, a case-control study was performed and 11 SNPs of ADIPOQ, ADIPOR1, and ADIPOR2 were genotyped in 985 T2DM and 1,050 control subjects. rs16861194 (-11426 A>G) in the putative promoter of ADIPOQ was associated with T2DM (P = 0.007; OR = 1.29, 95%CI 1.08-1.55). None of the other 10 SNPs were associated with T2DM in this study, although rs2241766 and rs1501299 were reported to be associated with T2DM in previous Chinese studies. There was also no significant difference found from the ADIPOQ haplotype analysis, which contains rs16861194. In addition, we also assessed potential gene-gene interactions in three genes and no interactions were found. In conclusion, our results supported the ADIPOQ gene as a possible risk factor for type 2 diabetes in Han Chinese population.

Amyloid-β-Related Genes SORL1 and ACE are Genetically Associated With Risk for Late-onset Alzheimer Disease in the Chinese Population

Late-onset Alzheimer Disease (LOAD) is a common neurodegenerative disease, and one of its major pathologic characteristics is senile plaques. Proteins encoded by SORL1 and ACE have been shown to be related to the processing, trafficking, and degradation of Amyloid-&bgr;, the principal component of senile plaques. In this paper, we investigated whether SORL1 and ACE are associated with LOAD. We recruited 144 LOAD patients and 476 controls from Shanghai, China and conducted a case–control study on 9 single-nucleotide polymorphisms (SNPs): 6 in SORL1 (rs2070045, rs661057, rs668387, rs689021, rs3824968, rs2282649) and 3 in ACE (rs1800764, rs4343, rs1799752). Despite the small case sample size (144), we observed that rs1800764, rs4343, rs1799752 in ACE, and rs2070045, rs3824968, rs2282649 in SORL1 showed significantly different allele frequencies between patients and controls (P=4.57×10−2, 5.24×10−3, 1.95×10−4, 1.77×10−4, 6.44×10−3, and 3.11×10−3, respectively). Moreover, haplotypes on ACE and on SORL1 were significantly associated with LOAD (all P-value<0.009 in ACE and all P-value <0.003 in SORL1). In ACE, we found the most significant protective haplotype encompasses SNPs rs2070045, rs3824968, and rs2282649 (C-G-D: OR=0.20, P=8.96×10−14). In SORL1, we detected a “complementary” haplotype (G-A-T: OR=1.54, P=2.67×10−3; T-T-C: OR=0.63, P=2.36×10−3) composed of SNPs rs2070045, rs3824968, and rs2282649. In addition, we carried out meta-analysis with 3 other Asian populations on 3 SNPs in SORL1 (rs2070045, rs3824968, and rs2282649). Results supported our initial finding that these 3 SNPs were associated with LOAD. Our data suggested that SORL1 and ACE might play a role in LOAD susceptibility among Han Chinese.

Decreased levels of apolipoprotein A-I in plasma of schizophrenic patients

SummaryThis study aims to identify the effects of antipsychotics on plasma proteins, and on the proteins associated with schizophrenia. We applied proteomics technology to screen protein aberrations in Sprague-Dawley rats treated with antipsychotics and schizophrenic patients undergoing medication. ApoA-I was found significantly increased in the chlorpromazine-treated rats and decreased in the patients with treatment-resistant schizophrenia, which suggest that decreased levels of apoA-I might be associated with the pathology of schizophrenia and that chlorpromazine increases apoA-I levels as part of its therapeutic action.

Deletion of the Late Cornified Envelope Genes LCE3C and LCE3B Is Associated with Psoriasis in a Chinese Population

A common deletion comprising LCE3B and LCE3C, members of the late cornified envelope (LCE) gene cluster, has been shown to be significantly associated with psoriasis in several Caucasian populations. The expression of LCE can be induced by skin barrier disruption, leading to psoriatic lesions. To identify whether deletion of genes in the LCE region is a genetic risk factor in the pathogenesis of psoriasis, we genotyped the LCE3C and LCE3B deletion and single-nucleotide polymorphism rs4112788, which is in strong linkage disequilibrium with the LCE gene cluster, via direct sequencing in 468 psoriasis patients and 768 controls in a Chinese population. We found that deletion of the two LCE genes was associated with psoriasis (odds ratio=1.917; 95% confidence interval=1.291-2.847, P=0.001), a conclusion that was similar to that of another independent Chinese cohort study. The deletion was not significantly associated with the age of disease onset, and there was no significant epistatic interaction between deletion and PSORS1 risk allele on 6p21.3. Our study confirms an association between the deletion of LCE3C and LCE3B and psoriasis in a Chinese population.

Positive association between the brain-derived neurotrophic factor (BDNF) gene and bipolar disorder in the Han Chinese population.

Brain‐derived neurotrophic factor (BDNF) is the most widely distributed neurotrophin in the central nervous system (CNS), and services many biological functions such as neural survival, differentiation, and plasticity. Previous studies have suggested that the Val66Met (also known as rs6265 or G196A) variant of BDNF is associated with bipolar disorder (BPD), but the results have been inconclusive. We therefore genotyped the Val66Met polymorphism in a Han Chinese population sample (498 cases and 501 control subjects). We found that the BDNF genotype is associated with BPD in this population (χ2 = 9.4666, df = 2, P = 0.00884). Furthermore, our data suggested that the Met allele rather than the Val allele increased the risk for BPD in our Han population (OR = 1.44; 95% CI = 1.070–1.950; P = 0.016). Further studies are necessary to elucidate the involvement of the BDNF gene in the pathophysiology of BPD.