A genome-wide association study confirms previously reported loci for type 2 diabetes in Han Chinese

Background

Genome-wide association study (GWAS) has identified more than 30 loci associated with type 2 diabetes (T2D) in Caucasians. However, genomic understanding of T2D in Asians, especially Han Chinese, is still limited.

Methods and Principal Findings

A two-stage GWAS was performed in Han Chinese from Mainland China. The discovery stage included 793 T2D cases and 806 healthy controls genotyped using Illumina Human 660- and 610-Quad BeadChips; and the replication stage included two independent case-control populations (a total of 4445 T2D cases and 4458 controls) genotyped using TaqMan assay. We validated the associations of KCNQ1 (rs163182, p = 2.085×10⁻¹⁷, OR 1.28) and C2CD4A/B (rs1370176, p = 3.677×10⁻⁴, OR 1.124; rs1436953, p = 7.753×10⁻⁶, OR 1.141; rs7172432, p = 4.001×10⁻⁵, OR 1.134) in Han Chinese.

Conclusions and Significance

Our study represents the first GWAS of T2D with both discovery and replication sample sets recruited from Han Chinese men and women residing in Mainland China. We confirmed the associations of KCNQ1 and C2CD4A/B with T2D, with the latter for the first time being examined in Han Chinese. Arguably, eight more independent loci were replicated in our GWAS.     

基于响应面分析的高抗原活性猪水肿病大肠杆菌疫苗培养基的研制及效果评价

【背景】猪水肿病大肠杆菌引发的疾病造成了很大的危害,但现有培养基存在培养密度低的问题。【目的】研制出高抗原活性猪水肿病大肠杆菌疫苗培养基。【方法】以常用的市售猪水肿培养基为对照,通过单因素试验、爬坡试验(Plackett-Burman, PB)、响应面(Box-Behnken, BB)试验对猪水肿培养基进行响应面优化,得到猪水肿培养基最优配方。以响应面试验得到的培养基培养猪水肿病大肠杆菌,评价不同培养时间点菌株的抗原活性,制作灭活疫苗,进行动物免疫保护试验。【结果】对研制的培养基进行扩大培养验证,发现扩大培养得到的菌株活菌数可达5×10⁹ CFU/mL以上,约为对照组的2倍。制备的灭活疫苗效价可达1:140 000,并在9 h时抗原蛋白效价达到最高。【结论】本研究研制出的疫苗培养基显著提高了猪大肠杆菌菌体密度,并可提高菌体抗原活性,为猪水肿病灭活疫苗的制备提供了技术指引。     

Expression of Panton-Valentine Leukocidin mRNA among Staphylococcus aureus Isolates Associates with Specific Clinical Presentations

Panton-Valentine leukocidin (PVL; gene designation lukF/S-PV) is likely an important virulence factor for Staphylococcus aureus (S. aureus), as qualitative expression of the protein correlates with severity for specific clinical presentations, including skin and soft tissue infections (SSTIs). Development of genetic approaches for risk-assessment of patients with S. aureus infections may prove clinically useful, and whether lukF/S-PV gene expression correlates with specific clinical presentations for S. aureus has been largely unexplored. In the present study, we quantified lukS-PV mRNA among 96 S. aureus isolates to determine whether expression levels correlated with specific clinical presentations in adults and children. Expression level of lukS-PV mRNA among isolates from skin and soft tissue infections (SSTIs) was significantly greater than among isolates from blood stream infection (BSIs), and expression level of lukS-PV mRNA among BSI isolates from children was significantly greater than for BSI isolates among adults. Moreover, expression level of lukS-PV mRNA among community-acquired (CA) isolates was significantly greater than for hospital-acquired (HA) isolates. These data justify additional studies to determine the potential clinical utility for lukS-PV mRNA quantification as a predictive tool for severity of S. aureus infection.     

DNA-PKcs, but not TLR9, is required for activation of Akt by CpG-DNA

CpG-DNA and its related synthetic CpG oligodeoxynucleotides (CpG-ODNs) play an important role in immune cell survival. It has been suggested that Akt is one of the CpG-DNA-responsive serine/threonine kinases; however, the target protein of CpG-DNA that leads to Akt activation has not been elucidated. Here, we report that ex vivo stimulation of bone marrow-derived macrophages (BMDMs) from mice lacking the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) results in defective phosphorylation and activation of Akt by CpG-DNA. Unexpectedly, loss of the Toll-like receptor 9 has a minimal effect on Akt activation in response to CpG-DNA. Further in vitro analysis using purified DNA-PK and recombinant Akt proteins reveals that DNA-PK directly induces phosphorylation and activation of Akt. In addition, in BMDMs, DNA-PKcs associates with Akt upon CpG-DNA stimulation and triggers transient nuclear translocation of Akt. Thus, our findings establish a novel role for DNA-PKcs in CpG-DNA signaling and define a CpG-DNA/DNA-PKcs/Akt pathway.     

Proteome analysis of human lung squamous carcinoma

Few lung cancer-specific molecular markers have been established in regard of "early-stage" diagnosis and prognosis. In this study the proteome analysis of human lung squamous carcinoma (hLSC) was carried out using two strategies to explore the carcinogenic mechanisms and identify its molecular markers more directly and comprehensively. Comparative proteome analysis on 20 hLSC tissues and paired normal bronchial epithelial tissues revealed 76 differential proteins, among which 68 proteins were identified by PMF. The identified proteins fell into three categories: oncoproteins, cell cycle regulators and signaling molecules. To validate the identified differential proteins, the expressions levels of three differential proteins mdm2, c-jun and EGFR were determined by immunohistochemical staining and immunoblots. The results verified proteome analysis results. Serological proteome analysis (SERPA) of ten hLSC tissues was performed to identify the tumor-associated antigens. The results revealed 36 +/- 8 differential proteins reactive with patients' autologous sera, of which 14 proteins were identified. Six of the 14 proteins, alpha enolase, pre-B cell-enhancing factor precursor, triosephosphate isomerase, phosphoglycerate mutase 1, fructose-bisphosphate aldolase A, and guanine nucleotide-binding protein beta subunit-like protein, were also up-regulated in hLSCs in the comparative proteomic study, which suggests potential application of these 6 hLSC-associated antigens in diagnosis and therapy of hLSC.     

Triple light chain antibodies: Factors that influence its formation in cell culture

THIOMABs are recombinant antibodies engineered with reactive cysteines, which can be covalently conjugated to drugs of interest to generate targeted therapeutics. During the analysis of THIOMABs secreted by stably transfected Chinese Hamster Ovary (CHO) cells, we discovered the existence of a new species—Triple Light Chain Antibody (3LC). This 3LC species is the product of a disulfide bond formed between an extra light chain and one of the engineered cysteines on the THIOMAB. We characterized the 3LC by size exclusion chromatography, mass spectrometry, and microchip electrophoresis. We also investigated the potential causes of 3LC formation during cell culture, focusing on the effects of free light chain (LC) polypeptide concentration, THIOMAB amino acid sequence, and glutathione (GSH) production. In studies covering 12 THIOMABs produced by 66 stable cell lines, increased free LC polypeptide expression—evaluated as the ratio of mRNA encoding for LC to the mRNA encoding for heavy chain (HC)—correlated with increased 3LC levels. The amino acid sequence of the THIOMAB molecule also impacted its susceptibility to 3LC formation: hydrophilic LC polypeptides showed elevated 3LC levels. Finally, increased GSH production—evaluated as the ratio of the cell‐specific production rate of GSH (q_GSH) to the cell‐specific production rate of THIOMAB (q_p)—corresponded to decreased 3LC levels. In time‐lapse studies, changes in extracellular 3LC levels during cell culture corresponded to changes in mRNA LC/HC ratio and q_GSH/q_p ratio. In summary, we found that cell lines with low mRNA LC/HC ratio and high q_GSH/q_p ratio yielded the lowest levels of 3LC. These findings provide us with factors to consider in selecting a cell line to produce THIOMABs with minimal levels of the 3LC impurity. Biotechnol. Bioeng. 2010. 105: 748–760. © 2009 Wiley Periodicals, Inc.     

A systematic review and meta-analysis of the relationship between lipoprotein lipase Asn291Ser variant and diseases

This systematic review attempted to summarize the associations between the Asn291Ser variant in the lipoprotein lipase (LPL) gene and dyslipidemia, the risk of type 2 diabetes mellitus (T2DM), and coronary heart disease (CHD). In addition, the relationships between the Asn291Ser variant and other metabolic diseases such as obesity and high blood pressure were also investigated in this systematic review. We systematically reviewed the literature by means of a meta-analysis. Twenty-one articles, including 19,246 white subjects, were selected for this meta-analysis. The summary standardized mean difference (SMD) of plasma triglyceride (TG) for carriers compared with noncarriers of the Asn291Ser variant was 3.23 (P < 0.00001). The summary SMD of plasma HDL-cholsterol (HDL-C) for carriers compared with noncarriers of the Asn291Ser variant was -3.42 (P < 0.0001). The summary SMD of the association of the Asn291Ser variant with plasma TG increased with increasing age and weight gain. Significant interactions between the LPL Asn291Ser variant and fasting glucose, T2DM, and CHD were seen (P = 0.02, 0.04, and 0.01, respectively). No significant interactions were seen between the LPL Asn291Ser variant and body mass index, waist-hip ratio, and blood pressure (P > 0.05). This meta-analysis indicates that the Asn291Ser variant in the LPL gene is a risk factor for dyslipidemia, characterized by hypertriglyceridemia and low HDL-C levels. And the Asn291Ser variant in the LPL gene predisposes to more severe dyslipidemia with increasing age and weight gain. Also, this meta-analysis shows that the LPL Asn291Ser variant is associated with CHD and T2DM.     

Expression and distribution of trihydrophobin 1 in postnatal developing mouse testis

The human trihydrophobin 1 (TH1) is a highly conserved and widely expressed protein. It is clear that TH1 serves as a new specific negative regulator of A-Raf kinase. In this study, we found that TH1 associated with A-Raf in mouse testis by using coimmunoprecipitation analysis. Then we characterized the gene expression of TH1 in mouse testis and analyzed the changes of TH1 protein during postnatal development. The protein expression of TH1 in mouse testis was further analyzed by immunohistochemistry staining. Strong signals were detected in the seminiferous tubules and the distribution patterns varied with the different ages of postnatal mouse testis. TH1 was distributed in spermatocytes and Sertoli cells at 2 weeks postnatal, and was abundant in spermatogonia at 8 weeks postnatal. Leydig cells were positive to TH1 throughout testicular development. A high expression of TH1 in both Leydig cells and mouse Leydig tumor cells (mLTC-1cells) was found to be concentrated in the cytoplasm. The colocalization of TH1 and A-Raf in mLTC-1 cells or in adult testis was also observable.     

Down-regulation of the expression of beta1,4-galactosyltransferase V promotes integrin beta1 maturation

In previous study, we have shown that beta1,4-galactosyltransferase V (GalT V) functions as a positive growth regulator in glioma. Here, we reported that down-regulation of the expression of GalT V in SHG44 cells by transfection with antisense cDNA specifically up-regulated the expression of cell surface integrin beta1 without the change of its mRNA, and with integrin beta1 125 kDa mature form increased and 105 kDa precursor form decreased. It is well known that the N-glycans of integrins modulate the location and functions of integrins. The SHG44 cells transfected with antisense cDNA of GalT V demonstrated decreased Golgi localization of integrin beta1, strengthened the interaction between integrin alpha5 and beta1 subunit, and enhanced the adhesion ability to fibronectin and the level of focal adhesion kinase phosphorylation. Our results suggested that the down-regulation of the expression of GalT V could promote the expression of cell surface integrin beta1 and subsequently inhibit glioma malignant phenotype.