Association of PDE4B polymorphisms and schizophrenia in Northwestern Han Chinese

Specific Inhibition of Phosphodiesterase-4B Results in Anxiolysis and Facilitates Memory Acquisition

Cognitive dysfunction is a core feature of dementia and a prominent feature in psychiatric disease. As non-redundant regulators of intracellular cAMP gradients, phosphodiesterases (PDE) mediate fundamental aspects of brain function relevant to learning, memory, and higher cognitive functions. Phosphodiesterase-4B (PDE4B) is an important phosphodiesterase in the hippocampal formation, is a major Disrupted in Schizophrenia 1 (DISC1) binding partner and is itself a risk gene for psychiatric illness. To define the effects of specific inhibition of the PDE4B subtype, we generated mice with a catalytic domain mutant form of PDE4B (Y358C) that has decreased ability to hydrolyze cAMP. Structural modeling predictions of decreased function and impaired binding with DISC1 were confirmed in cell assays. Phenotypic characterization of the PDE4B(Y358C) mice revealed facilitated phosphorylation of CREB, decreased binding to DISC1, and upregulation of DISC1 and β-Arrestin in hippocampus and amygdala. In behavioral assays, PDE4B(Y358C) mice displayed decreased anxiety and increased exploration, as well as cognitive enhancement across several tests of learning and memory, consistent with synaptic changes including enhanced long-term potentiation and impaired depotentiation ex vivo. PDE4B(Y358C) mice also demonstrated enhanced neurogenesis. Contextual fear memory, though intact at 24 h, was decreased at 7 days in PDE4B(Y358C) mice, an effect replicated pharmacologically with a non-selective PDE4 inhibitor, implicating cAMP signaling by PDE4B in a very late phase of consolidation. No effect of the PDE4B(Y358C) mutation was observed in the prepulse inhibition and forced swim tests. Our data establish specific inhibition of PDE4B as a promising therapeutic approach for disorders of cognition and anxiety, and a putative target for pathological fear memory.

Association of PDE4B Polymorphisms with Susceptibility to Schizophrenia: A Meta-Analysis of Case-Control Studies

Background

The PDE4B single nucleotide polymorphisms (SNPs) have been reported to be associated with schizophrenia risk. However, current findings are ambiguous or even conflicting. To better facilitate the understanding the genetic role played by PDE4B in susceptibility to schizophrenia, we collected currently available data and conducted this meta-analysis.

Methods

A comprehensive electronic literature searching of PubMed, Embase, Web of Science and Cochrane Library was performed. The association between PDE4B SNPs and schizophrenia was evaluated by odds ratios (ORs) and 95% confidence intervals (CIs) under allelic, dominant and recessive genetic models. The random effects model was utilized when high between-study heterogeneity (I² > 50%) existed, otherwise the fixed effects model was used.

Results

Five studies comprising 2376 schizophrenia patients and 3093 controls were finally included for meta-analysis. The rs1040716 was statistically significantly associated with schizophrenia risk in Asian and Caucasian populations under dominant model (OR = 0.87, 95% CI: 0.76–0.99, P = 0.04). The rs2180335 was significantly related with schizophrenia risk in Asian populations under allelic (OR = 0.82, 95% CI: 0.72–0.93, P = 0.003) and dominant (OR = 0.75, 95% CI: 0.64–0.88, P < 0.001) models. A significant association was also observed between rs4320761 and schizophrenia in Asian populations under allelic model (OR = 0.87, 95% CI: 0.75–1.00, P = 0.048). In addition, a strong association tendency was found between rs6588190 and schizophrenia in Asian populations under allelic model (OR = 0.87, 95% CI: 0.76–1.00, P = 0.055).

Conclusion

This meta-analysis suggests that PDE4B SNPs are genetically associated with susceptibility to schizophrenia. However, due to limited sample size, more large-scale, multi-racial association studies are needed to further clarify the genetic association between various PDE4B variants and schizophrenia.

Two-stage comprehensive evaluation of genetic susceptibility of common variants in FBXO38, AP3B2 and WHAMM to severe chronic periodontitis

Chronic periodontitis is an oral disorder characterized with gingival inflammation and bone destruction. As the sixth-most prevalent condition affecting more than 743 million people around the world, it is classified as one of the seven destructive oral disorders. Early genetic epidemiological evidence indicated a major role for genetics in periodontal disease development. In this study, we conducted a two-stage comprehensive evaluation of the genetic susceptibility of FBXO38, AP3B2 and WHAMM with the diagnosis of severe chronic periodontitis. A total of 5,065 study subjects from the Han Chinese population consisting of 1,264 cases and 3,801 healthy controls were recruited, and 65 single nucleotide markers related to the three candidate genes were genotyped to investigate the susceptibility of patients with these polymorphisms to severe chronic periodontitis. To increase the coverage of genetic markers, we implemented imputation techniques to extend the number of tested makers to 416. Single marker and haplotype-based analyses were performed, and significant results were obtained for FBXO38 (rs10043775, P = 0.0009) and AP3B2 (rs11631963-rs11637433, CA, P = 9.98 × 10(-5); rs1864699-rs2099259-rs2278355, ATC, P = 3.84 × 10(-8)). Our findings provide direct evidence for the association of FBXO38 and AP3B2 with severe chronic periodontitis in the Han Chinese population.

Common variants of HTR1A and SLC6A4 confer the increasing risk of Schizophrenia susceptibility: A population-based association and epistasis analysis

Schizophrenia (SZ) is a complex psychiatric disorder strongly influenced by genetic variants, some of which are associated with mood disorders. The neurotransmitter 5-hydoxytryptamine (5-HT) and its related biochemical factors have been shown to play a significant role in maintaining mood balance. Recent studies evaluating the association between SZ and genetic polymorphisms in a serotonin transporter (encoded by SLC6A4) and serotonin receptor 1A (encoded by HTR1A) show conflicting results. In this study, we performed a case-control association analysis using 4,000 individuals with Chinese-Han ancestry. Of these participants, 1,000 were SZ cases and 3,000 were healthy controls. Thirty-six single nucleotide polymorphisms (SNPs) located in SLC6A4 and HTR1A were genotyped in our 4,000 study samples. Of those, 33 polymorphic SNPs with a minor allele frequency >0.05 were used for further analysis. We found that rs878567 in HTR1A (asymptotic P-value = 3.89×10(-4) , corrected P-value = 0.0106) was significantly associated with SZ. Further haplotype-based analyses revealed that a two-SNP haplotype, rs2054847-rs140701 (TG) in gene SLC6A4, was significantly associated with SZ (P-value = 1.63×10(-4) and corrected P-value = 0.002799). We did not identify any significant epistatic interactions between the two genes. Our findings provide supportive evidence that genetic polymorphisms in SLC6A4 and HTR1A may influence the risk of SZ in Han Chinese individuals. © 2015 Wiley Periodicals, Inc.

Evaluation of common variants in CNR2 gene for bone mineral density and osteoporosis susceptibility in postmenopausal women of Han Chinese

Postmenopausal osteoporosis is a major health problem with important genetic factors in postmenopausal women. We thoroughly evaluated the relationship of CNR2 polymorphisms with osteoporosis in a cohort of 1032 osteoporosis patients and 2089 healthy controls from Han Chinese postmenopausal women. Statistically significant differences, depending on different genotypes, were presented.

INTRODUCTION

Osteoporosis is a major health problem in postmenopausal women, which is a multifactorial disease in which genetic determinants are modulated by hormonal, environmental, and nutritional factors. An important clinical risk factor in the pathogenesis of osteoporosis is the presence of genetic polymorphism in susceptibility genes. The aim of our study was to investigate whether CNR2 gene, which attributes to osteoporosis susceptibility in some populations, is associated with bone mineral density (BMD) or osteoporosis in Han Chinese postmenopausal women.

METHODS

We examine 39 SNPs covering the region of CNR2 gene in 3121 Han Chinese postmenopausal women, consisting of 1032 osteoporosis patients and 2089 healthy controls, to evaluate the association with BMD and osteoporosis.

RESULTS

We found that rs4237 and rs2501431 were significantly associated with BMD and osteoporosis (corrected p = 0.020085 and 0.017199) in our sample, and the TT genotype of rs2501431 and the AA genotype of rs4237 had lower lumbar spine BMD and femoral neck BMD compared with the other genotypes. Additionally, analyses by haplotypes indicated that two haplotype blocks, containing rs4237 and rs2501431 respectively, in the CNR2 gene significantly associated with BMD and osteoporosis (both global permutation p < 0.001), and a risk haplotype (ATTT) in the block of rs3003336-rs2501431-rs2502992-rs2501432 had almost 4-fold increase in the cases.

CONCLUSIONS

Our results provide further supportive evidence for an important role of CNR2 gene in the etiology of osteoporosis and suggest that it may be a genetic risk factor for BMD and osteoporosis in Han Chinese postmenopausal women.

Endochondral ossification pathway genes and postmenopausal osteoporosis: Association and specific allele related serum bone sialoprotein levels in Han Chinese

Osteoporosis is a systemic skeletal disorder characterized by reduced bone mineral density (BMD) and disrupted bone architecture, predisposing the patient to increased fracture risk. Evidence from early genetic epidemiological studies has indicated a major role for genetics in the development of osteoporosis and the variation in BMD. In this study, we focused on two key genes in the endochondral ossification pathway, IBSP and PTHLH. Over 9,000 postmenopausal Han Chinese women were recruited, and 54 SNPs were genotyped. Two significant SNPs within IBSP, rs1054627 and rs17013181, were associated with BMD and postmenopausal osteoporosis by the two-stage strategy, and rs17013181 was also significantly associated with serum IBSP levels. Moreover, one haplotype (rs12425376-rs10843047-rs42294) covering the 5' end of PTHLH was associated with postmenopausal osteoporosis. Our results provide evidence for the association of these two key endochondral ossification pathway genes with BMD and osteoporosis in postmenopausal Han Chinese women. Combined with previous findings, we provide evidence that a particular SNP in IBSP has an allele-specific effect on mRNA levels, which would, in turn, reflect serum IBSP levels.

Evaluation of relationship between GRM3 polymorphisms and cognitive function in schizophrenia of Han Chinese

Recently, the novel SNP rs12704290 in GRM3 was identified in a genome-wide association study on schizophrenia susceptibility. Our study was to investigate the association of 29 selected SNPs (including rs12704290) with schizophrenia and to evaluate any possible relationship between them and cognition related to schizophrenia. The SNPs were analyzed in 1115 unrelated schizophrenic patients and 2289 healthy controls. The results showed significant associations between these SNPs and schizophrenia as well as with changes in cognition.

Association of common variants in H2AFZ gene with schizophrenia and cognitive function in patients with schizophrenia

Recently, the H2AFZ gene was reported in relation to schizophrenia in Japanese males. A two-stage case-control study was designed to investigate the association of the H2AFZ gene with schizophrenia and its relationship with cognitive function in Han Chinese patients with schizophrenia. This study included a testing set with 1115 patients and 2289 controls and a validation set with 1843 patients and 3155 controls. A total of 10 single-nucleotide polymorphisms (SNPs) in the H2AFZ gene were genotyped, and both independent data sets were analyzed in association with SNP and gender. The rs2276939 SNP was found to be significantly associated with schizophrenia, particularly in males. A similar pattern was observed in our two-stage study on conducting further imputation and haplotype association analyses. In addition, two of the SNPs (rs61203457 and rs2276939) and cognitive functioning were found to interact significantly when processing the perseverative error in the Wisconsin Card Sorting Test. Our findings suggest that the H2AFZ gene may confer a risk for schizophrenia and contribute to the impairment of executive function in Han Chinese patients with schizophrenia. These findings augment our current state of knowledge regarding the risk of schizophrenia and the impairment of cognitive performance in patients with this disorder.

Association studies of SEPS1 gene polymorphisms with Hashimoto's thyroiditis in Han Chinese

Although the connection between SEPS1 gene variants and Hashimoto's thyroiditis (HT) has been established in Europeans, the relationship between the SEPS1 gene and HT remains unclear in Han Chinese. Here we aimed to investigate the potential association between SEPS1 variants and HT in the Han population. In addition, the effects of SEPS1 haplotypes on the susceptibility of the development of immune-mediated diseases with an inflammatory component will also be evaluated. Seven single-nucleotide polymorphisms (SNPs) with minor allele frequency ⩾0.05 were genotyped in 1013 HT patients and 2998 healthy controls from genetically independent Han Chinese individuals. We identified that the rs28665122 SNP was significantly associated with HT, both in the female group (allelic P=0.002644 and genotypic P=0.010326) and the combined data set (allelic P=0.000518 and genotypic P=0.002731). Further analyses based on haplotypes indicated that a two-SNP haplotype (rs2009895-rs28665122) was significantly associated with HT (global P=0.0036), which was also observed in females (global P=0.0162) but not in males. Our findings provide further supporting evidence that confirms the results of previous studies, which suggested potential roles of the SEPS1 gene in the pathogenesis and etiology of HT.

Association study identifying a new susceptibility gene (AUTS2) for schizophrenia

Schizophrenia (SCZ) is a severe and debilitating mental disorder, and the specific genetic factors that underlie the risk for SCZ remain elusive. The autism susceptibility candidate 2 (AUTS2) gene has been reported to be associated with autism, suicide, alcohol consumption, and heroin dependence. We hypothesized that AUTS2 might be associated with SCZ. In the present study, three polymorphisms (rs6943555, rs7459368, and rs9886351) in the AUTS2 gene were genotyped in 410 patients with SCZ and 435 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and forced PCR-RFLP methods. We detected an association between SCZ and the rs6943555 genotype distribution (odds ratio (OR)=1.363, 95% confidence interval (CI): 0.848-2.191, p=0.001). The association remained significant after adjusting for gender, and a significant effect (p=0.001) was observed among the females. In the present study, rs6943555 was determined to be associated with female SCZ. Our results confirm previous reports which have suggested that rs6943555 might elucidate the pathogenesis of schizophrenia and play an important role in its etiology.

Analysis of interleukin-8 gene variants reveals their relative importance as genetic susceptibility factors for chronic periodontitis in the Han population

Interleukin (IL)-8, an important chemokine that regulates the inflammatory response, plays an important role in periodontitis. Previous studies indicate that certain IL-8 gene polymorphisms are associated with periodontitis susceptibility in some populations. However, the literature is somewhat contradictory, and not all IL-8 polymorphisms have been examined, particularly in Han Chinese individuals. The aim of this study was to investigate the association of every IL-8 SNP with chronic periodontitis in Han Chinese individuals. We analyzed 23 SNPs with minor allele frequency (MAF)≥0.01, which were selected from 219 SNPs in the NCBI dbSNP and preliminary HapMap data analyses from a cohort of 400 cases and 750 controls from genetically independent Han Chinese individuals. Single SNP, haplotype and gender-specific associations were performed. We found that rs4073 and rs2227307 were significantly associated with chronic periodontitis. Further haplotype analysis indicated that a haplotype block (rs4073-rs2227307-rs2227306) that spans the promoter and exon1 of IL-8 was highly associated with chronic periodontitis. Additionally, the ATC haplotype in this block was increased 1.5-fold in these cases. However, when analyzing the samples by gender, no significant gender-specific associations in IL-8 were observed, similar to the results of haplotype association analyses in female and male subgroups. Our results provide further evidence that IL-8 is associated with chronic periodontitis in Han Chinese individuals. Furthermore, our results confirm previous reports suggesting the intriguing possibilities that IL-8 plays a role in the pathogenesis of chronic periodontitis and that this gene may be involved in the etiology of this condition.

Genome-wide association study of bipolar disorder in Canadian and UK populations corroborates disease loci including SYNE1 and CSMD1

BACKGROUND

Recently, genome-wide association studies (GWAS) for cases versus controls using single nucleotide polymorphism microarray data have shown promising findings for complex neuropsychiatric disorders, including bipolar disorder (BD).

METHODS

Here we describe a comprehensive genome-wide study of bipolar disorder (BD), cross-referencing analysis from a family-based study of 229 small families with association analysis from over 950 cases and 950 ethnicity-matched controls from the UK and Canada. Further, loci identified in these analyses were supported by pathways identified through pathway analysis on the samples.

RESULTS

Although no genome-wide significant markers were identified, the combined GWAS findings have pointed to several genes of interest that support GWAS findings for BD from other groups or consortia, such as at SYNE1 on 6q25, PPP2R2C on 4p16.1, ZNF659 on 3p24.3, CNTNAP5 (2q14.3), and CDH13 (16q23.3). This apparent corroboration across multiple sites gives much confidence to the likelihood of genetic involvement in BD at these loci. In particular, our two-stage strategy found association in both our combined case/control analysis and the family-based analysis on 1q21.2 (closest gene: sphingosine-1-phosphate receptor 1 gene, S1PR1) and on 1q24.1 near the gene TMCO1, and at CSMD1 on 8p23.2, supporting several previous GWAS reports for BD and for schizophrenia. Pathway analysis suggests association of pathways involved in calcium signalling, neuropathic pain signalling, CREB signalling in neurons, glutamate receptor signalling and axonal guidance signalling.

CONCLUSIONS

The findings presented here show support for a number of genes previously implicated genes in the etiology of BD, including CSMD1 and SYNE1, as well as evidence for previously unreported genes such as the brain-expressed genes ADCY2, NCALD, WDR60, SCN7A and SPAG16.