Silencing SARS-CoV Spike protein expression in cultured cells by RNA interference

AbstractThe severe acute respiratory syndrome (SARS) has been one of the most epidemic diseases threatening human health all over the world. Based on clinical studies, SARS-CoV (the SARS-associated coronavirus), a novel coronavirus, is reported as the pathogen responsible for the disease. To date, no effective and specific therapeutic method can be used to treat patients suffering from SARS-CoV infection. RNA interference (RNAi) is a process by which the introduced small interfering RNA (siRNA) could cause the degradation of mRNA with identical sequence specificity. The RNAi methodology has been used as a tool to silence genes in cultured cells and in animals. Recently, this technique was employed in anti-virus infections in human immunodeficiency virus and hepatitis C/B virus. In this study, RNAi technology has been applied to explore the possibility for prevention of SARS-CoV infection. We constructed specific siRNAs targeting the S gene in SARS-CoV. We demonstrated that the siRNAs could effectively and specifically inhibit gene expression of Spike protein in SARS-CoV-infected cells. Our study provided evidence that RNAi could be a tool for inhibition of SARS-CoV

SIRT5 promotes IDH2 desuccinylation and G6PD deglutarylation to enhance cellular antioxidant defense

Abstract Excess in mitochondrial reactive oxygen species (ROS) is considered as a major cause of cellular oxidative stress. NADPH, the main intracellular reductant, has a key role in keeping glutathione in its reduced form GSH, which scavenges ROS and thus protects the cell from oxidative damage. Here, we report that SIRT5 desuccinylates and deglutarylates isocitrate dehydrogenase 2 (IDH2) and glucose‐6‐phosphate dehydrogenase (G6PD), respectively, and thus activates both NADPH‐producing enzymes. Moreover, we show that knockdown or knockout of SIRT5 leads to high levels of cellular ROS. SIRT5 inactivation leads to the inhibition of IDH2 and G6PD, thereby decreasing NADPH production, lowering GSH, impairing the ability to scavenge ROS, and increasing cellular susceptibility to oxidative stress. Our study uncovers a SIRT5‐dependent mechanism that regulates cellular NADPH homeostasis and redox potential by promoting IDH2 desuccinylation and G6PD deglutarylation

Association of Gln27Glu and Arg16Gly Polymorphisms in Beta2-Adrenergic Receptor Gene with Obesity Susceptibility: A Meta-Analysis

<div><p>Background</p><p>The beta2-adrenergic receptor (ADRB2) gene polymorphism has been implicated in susceptibility to obesity, but study results are still controversial.</p><p>Objective</p><p>The present meta-analysis is performed to determine whether there are any associations between the Gln27Glu (rs1042714) or the Arg16Gly (rs1042713) polymorphisms in ADRB2 and obesity susceptibility.</p><p>Methods</p><p>The PubMed (1950–2014), Embase (1974–2014), and China National Knowledge Infrastructure (CNKI, 1994–2014) databases were searched using the search terms (“Beta2-adrenergic receptor”, “β2-adrenergic receptor” or “ADRB2”), “polymorphism,” and “obesity”. Fixed- or random-effects pooled measures were determined on the bias of heterogeneity tests across studies. Publication bias was examined by Egger's test and the modified Begg's test.</p><p>Results</p><p>Eighteen published articles were selected for meta-analysis. Overall analyses showed that rs1042714 (Gln27Glu) was associated with significantly increased obesity risk in the heterozygote model (Gln/Glu vs. Gln/Gln: OR: 1.16, 95% CI: 1.04–1.30, <i>I</i>² = 49%, P = 0.009) and the dominant model (Gln/Glu + Glu/Glu vs. Gln/Gln: OR: 1.2, 95% CI: 1.00–1.44, <i>I</i>² = 55%, P = 0.04), whereas no significant association was found in the other models for rs1042714. Also, no significant association was found between the rs1042713 (Arg16Gly) gene polymorphism and the risk of obesity in all genetic models. In addition, neither rs1042713 (Arg16Gly) nor rs1042714 (Gln27Glu) showed any significant association with obesity susceptibility when the population were stratified based on gender.</p><p>Conclusion</p><p>Our meta-analysis revealed that the rs1042714 (Gln27Glu) polymorphism is associated with obesity susceptibility. However, our results do not support an association between rs1042713 (Arg16Gly) polymorphisms and obesity in the populations investigated. This conclusion warrants confirmation by more case-control and cohort studies.</p></div

Funnel plot for rs1042714 (Gln27Glu) gene polymorphism on heterozygote Gln/Glu vs.

<p>Gln/Gln. The funnel plot showed no apparent evidence of publication bias.</p

Association between rs1042714 (Gln27Glu) gene polymorphism and obesity risk under dominant model.

<p>(Gln/Glu + Glu/Glu vs. Gln/Gln: OR: 1.2, 95% CI: 1.00–1.44, <i>I</i>² = 55%, P = 0.04).</p

Distributions of ADRB2 Gln27/Glu and Arg16/Gly genotypes of eligible studies included in the meta-analysis.

<p>ADRB2, Beta 2-adrenergic receptor gene; Gln27Glu (rs1042714), at codon 27; Arg16Gly (rs1042713), at codon 16.</p

Flow diagram of articles selection process for ADRB2 gene polymorphism and obesity risk.

<p>Flow diagram of articles selection process for ADRB2 gene polymorphism and obesity risk.</p

Meta-analysis of rs1042714 (Gln27Glu) polymorphism on risk of obesity.

<p>Abbreviations: OR, odds ratio; CI, confidence interval; <i>I</i>², Cochran's c–based Q-statistic test for assessing the heterogeneity (>50% indicates a substantial heterogeneity).</p

Methodological quality of 18 articles enrolled in our study by the “Newcastle-Ottawa Quality Assessment Scale”.

<p>Methodological quality of 18 articles enrolled in our study by the “Newcastle-Ottawa Quality Assessment Scale”.</p