Genetic Evidence for Possible Involvement of the Calcium Channel Gene CACNA1A in Autism Pathogenesis in Chinese Han Population

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders. Recent studies suggested that calcium channel genes might be involved in the genetic etiology of ASD. CACNA1A, encoding an alpha-1 subunit of voltage-gated calcium channel, has been reported to play an important role in neural development. Previous study detected that a single nucleotide polymorphism (SNP) in CACNA1A confers risk to ASD in Central European population. However, the genetic relationship between autism and CACNA1A in Chinese Han population remains unclear. To explore the association of CACNA1A with autism, we performed a family-based association study. First, we carried out a family-based association test between twelve tagged SNPs and autism in 239 trios. To further confirm the association, the sample size was expanded to 553 trios by recruiting 314 additional trios. In a total of 553 trios, we identified association of rs7249246 and rs12609735 with autism though this would not survive after Bonferroni correction. Our findings suggest that CACNA1A might play a role in the etiology of autism.     

Sex-Specific Prevalence of Diabetes and Cardiovascular Risk Factors in the Middle-Aged Population of China: A Subgroup Analysis of the 2007–2008 China National Diabetes and Metabolic Disorders Study

The sex difference in the prevalence rates of diabetes and cardiovascular diseases (CVDs) among the middle-aged population in China remain largely unknown. Therefore, we analyzed differences in the prevalence of diabetes, self-reported CVDs, and some CVD risk factors among men and women in the middle-aged population (30–49 years) and in individuals aged 50 years and older using data from the China National Diabetes and Metabolic Disorders Study of 2007–2008. Middle-aged men appeared to have significantly a higher prevalence of diabetes and self-reported CVDs than middle-aged women (8.07% vs 5.06% for diabetes, P < 0.001; 0.64% vs 0.22% for CVDs, P < 0.001). Men also showed higher rates of central obesity, hypertension, and dyslipidemia than women (all P < 0.01). Compared with women, men were more likely to drink alcohol and smoke cigarettes but less likely to be under diet control. The sex-specific differences in prediabetes, CVD, and CVD risk factors between men and women were diminished or even reversed in the population aged 50 years and older. No sex-specific differences were found in the prevalences of a family history of diabetes, coronary heart disease, and hypertension (P > 0.05) in middle-aged population. Specific strategies to reduce modifiable risk factors for the prevention and control of diabetes and CVD may be warranted in this population.     

Targeting heat-shock protein 90 with ganetespib for molecularly targeted therapy of gastric cancer

Gastric cancer (GC) remains the fifth most common cancer worldwide. Heat-shock protein 90 (HSP90) has become an attractive therapeutic target in treating cancers, because of its abnormally high expression in cancers. Several successful cases of HSP90 inhibitors capable of inhibiting GC inspired us to try ganetespib, a clinically promising and actively investigated second-generation HSP90 inhibitor in GC treatment. In our study, we show that ganetespib markedly reduced the growth of MGC-803 and also significantly inhibited the growth of SGC-7901 and MKN-28 in a dose-dependent manner. It induced G2/M cell-cycle arrest and apoptosis in all three cell lines, together with the related markers affected significantly. Mechanistically, ganetespib caused pronounced decrease of expression of classic HSP90 client proteins. Specifically, it greatly affected epidermal growth factor receptor (EGFR) signaling cascades by markedly decreasing the levels of total EGFR and EGFR on cell membranes. EGFR knockdown also induced cell-cycle arrest and apoptosis accompanied with a decrease of several EGFR downstream proteins. These results strongly support that EGFR signaling greatly contributes to the ganetespib inhibitory effects. Besides, we found that the responses of GC cell lines to ganetespib correlated well with their EGFR expression levels: MGC-803, as well as AGS and BGC-803, with higher EGFR expression responded to ganetespib better, whereas SGC-7901 and MKN-28 with lower EGFR levels were much less sensitive to ganetespib. Although SGC-7901 and MKN-28 were not very sensitive to ganetespib, ganetespib worked synergistically with radiation and cisplatin in killing them. Importantly, ganetespib significantly inhibited the growth of xenograft tumors in vivo as a single agent or in combination with cisplatin. Results of hematoxylin/eosin staining, TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling) assays, and immunohistochemistry staining of phosphorylated cyclin-dependent kinase 1 (pCDK1), EGFR and Ki-67 revealed significant differences in ganetespib-treated tumors. Collectively, our data suggest that ganetespib, as a new potent treatment option, can be used for the molecularly targeted therapy of GC patients according to their expression profiles of EGFR.Gastric cancer (GC) remains the fifth most common cancer worldwide, with an estimated 9 52 000 new cases (7% of total cancer incidence) and 7 23 000 deaths (9% of total cancer mortality) in 2012.¹ As a highly aggressive and lethal malignancy, the aggressive nature of GC is linked to mutations in tumor suppressor genes, oncogenes, growth factors and their receptors, and so on.² Till now, there are few effective treatment options for advanced patients with distant metastasis or recurrence.³ The detailed mechanisms that regulate GC are not yet fully understood; therefore, such situations underscore the persistent unmet need to identify therapeutics that target pathways involved in GC progression.Consequently, identification of key regulatory molecules in GC is of high priority for understanding the mechanism for tumor dissemination as well as the development of novel interventions. Aberrant expression and kinase activity of Src have been found in many different tumors, including GC.^{4, 5} Previous studies have shown that phosphorylated mammalian target of rapamycin (p-mTOR) was significantly overexpressed in advanced GC patients'' tumors and suggested that the PI3K/AKT/mTOR (phosphoinositide 3-kinase/AKT/mTOR) pathway is activated in GC with potential prognostic and predictive significance.^{6, 7} Aurora A overexpression has recently been reported in GC, and it was suggested to be associated with cancer progression and poor prognosis.^{8, 9, 10}In our previous work, we conducted data mining meta-analyses integrating results from multiple small interfering RNA (siRNA) screens to identify gene targets, which are necessary for the growth of different cancer cells. Among those genes, we found that heat-shock protein 90 (HSP90) was one of the most vital proteins for cancer cell survival.¹¹ As we know, HSP90 is involved in the regulation of numerous proteins important for GC pathogenesis, such as proteins important for cell adhesion (e.g., focal adhesion kinase), cell motility (e.g., epidermal growth factor receptor (EGFR), c-Src, phosphoinositide-dependent protein kinase 1 (PDK1)), and angiogenesis (e.g., hypoxia-inducible factor-1 (HIF-1), vascular endothelial growth factor receptor (VEGFR)).^{12, 13, 14, 15} For these reasons, HSP90 has been of considerable interest as a therapeutic target in GC.As an ATP-dependent molecular chaperone protein, HSP90 conducts the proper folding of myriad proteins.^{12, 14} Abnormally high expression of HSP90 has been found in GC and been greatly considered as an independent prognostic marker of GC progression.^{16, 17, 18} HSP90 remains an attractive therapeutic target in a variety of cancers,^{19, 20, 21, 22} and inhibition of HSP90 showed potent growth inhibitory effects on GC in cell cultures and in mouse models.^{23, 24, 25} Ganetespib is a particularly promising second-generation HSP90 inhibitor that does not suffer from the toxicity issues associated with earlier-generation HSP90 inhibitors and exhibits increased potency compared with first- and other second-generation agents.^{11, 26, 27, 28, 29}In this current study, using cell culture and xenograft mouse models, we sought to evaluate the effects of ganetespib treatments on GC cells, individually or in combination with other treatments. In addition, we searched for the possible mechanisms underlying the antitumor activities of ganetespib. And, our results suggested that, as a promising drug candidate, ganetespib has potent antitumor activities on GC, and it is worth being investigated further clinically for the molecularly targeted therapy of GC patients.     

Co-Conserved MAPK Features Couple D-Domain Docking Groove to Distal Allosteric Sites via the C-Terminal Flanking Tail

Mitogen activated protein kinases (MAPKs) form a closely related family of kinases that control critical pathways associated with cell growth and survival. Although MAPKs have been extensively characterized at the biochemical, cellular, and structural level, an integrated evolutionary understanding of how MAPKs differ from other closely related protein kinases is currently lacking. Here, we perform statistical sequence comparisons of MAPKs and related protein kinases to identify sequence and structural features associated with MAPK functional divergence. We show, for the first time, that virtually all MAPK-distinguishing sequence features, including an unappreciated short insert segment in the β4-β5 loop, physically couple distal functional sites in the kinase domain to the D-domain peptide docking groove via the C-terminal flanking tail (C-tail). The coupling mediated by MAPK-specific residues confers an allosteric regulatory mechanism unique to MAPKs. In particular, the regulatory αC-helix conformation is controlled by a MAPK-conserved salt bridge interaction between an arginine in the αC-helix and an acidic residue in the C-tail. The salt-bridge interaction is modulated in unique ways in individual sub-families to achieve regulatory specificity. Our study is consistent with a model in which the C-tail co-evolved with the D-domain docking site to allosterically control MAPK activity. Our study provides testable mechanistic hypotheses for biochemical characterization of MAPK-conserved residues and new avenues for the design of allosteric MAPK inhibitors.     

Polymorphisms of Chicken TLR3 and 7 in Different Breeds

Toll-like receptors (TLRs) mediate immune responses via the recognition of pathogen-associated molecular patterns (PAMPs), thus playing important roles in host defense. Among the chicken (Ch) TLR family, ChTLR3 and 7 have been shown to recognize viral RNA. In our earlier studies, we have reported polymorphisms of TLR1, 2, 4, 5, 15 and 21. In the present study, we amplified TLR3 and 7 genes from different chicken breeds and analyzed their sequences. We identified 7 amino acid polymorphism sites in ChTLR3 with 6 outer part sites and 1 inner part site, and 4 amino acid polymorphism sites in ChTLR7 with 3 outer part sites and 1 inner part site. These results demonstrate that ChTLR genes are polymorphic among different chicken breeds, suggesting a varied resistance across numerous chicken breeds. This information might help improve chicken health by breeding and vaccination.     

Transgenic Expression of the Dicotyledonous Pattern Recognition Receptor EFR in Rice Leads to Ligand-Dependent Activation of Defense Responses

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components.     

Analysis of Conformational B-Cell Epitopes in the Antibody-Antigen Complex Using the Depth Function and the Convex Hull

The prediction of conformational b-cell epitopes plays an important role in immunoinformatics. Several computational methods are proposed on the basis of discrimination determined by the solvent-accessible surface between epitopes and non-epitopes, but the performance of existing methods is far from satisfying. In this paper, depth functions and the k-th surface convex hull are used to analyze epitopes and exposed non-epitopes. On each layer of the protein, we compute relative solvent accessibility and four different types of depth functions, i.e., Chakravarty depth, DPX, half-sphere exposure and half space depth, to analyze the location of epitopes on different layers of the proteins. We found that conformational b-cell epitopes are rich in charged residues Asp, Glu, Lys, Arg, His; aliphatic residues Gly, Pro; non-charged residues Asn, Gln; and aromatic residue Tyr. Conformational b-cell epitopes are rich in coils. Conservation of epitopes is not significantly lower than that of exposed non-epitopes. The average depths (obtained by four methods) for epitopes are significantly lower than that of non-epitopes on the surface using the Wilcoxon rank sum test. Epitopes are more likely to be located in the outer layer of the convex hull of a protein. On the benchmark dataset, the cumulate 10th convex hull covers 84.6% of exposed residues on the protein surface area, and nearly 95% of epitope sites. These findings may be helpful in building a predictor for epitopes.     

甘蓝型油菜Fad2与Fae1基因双干扰RNAi载体的构建

将来源于甘蓝型油菜XY15的Fad2与Fae1基因编码区,长度分别为349bp和426bp的两个保守序列片段连接成807bp的大片段。然后分别以正反向插入到pFGC5941干扰载体查耳酮合成酶内含子的两端,构建成RNAi载体。以期在菜籽中转录后能有效抑制Fad2与Fae1两个基因的表达。所构建的RNAi载体最终序列全长3kb,经限制性内切酶消化、PCR扩增验证和序列测定,证明目标序列与GenBank数据库中的碱基序列一致,并且为正反向插入到pFGC5941载体上。通过农杆菌介导的油菜转化,已获得油菜抗性再生植株144个。