miR-195通过靶向调控趋化因子5促进胃癌细胞增殖、转移及侵袭的实验研究

目的:研究miR-195通过靶向调控趋化因子5促进胃癌细胞增殖、转移及侵袭的分子机制。方法:选取MGC803及NCI-N87细胞,根据转染不同分为:miR-NC组(空质粒),miR-195-mimics组(模拟序列)。实时荧光定量PCR法检测miR-195表达;MTT检测细胞增殖能力;Transwell侵袭实验检测细胞侵袭力;细胞划痕实验检测细胞转移能力;流式细胞术检测细胞凋亡情况;Western blot检测chemokine 5表达水平;Spearman相关分析miR-195及chemokine 5相关性。荧光素酶实验验证miR-195与chemokine 5的靶向关系。结果:miR-195-mimics组细胞miR-195水平高于miR-NC组(P0.05);miR-195 mimics组第1、2、3、4 d细胞活力低于miR-NC组(P0.05);miR-195 mimics组G1细胞高于miR-NC组,G2期、S期细胞低于miR-NC组,G2/S期细胞比值低于miR-NC组(P0.05);miR-195 mimics组划痕距离大于miR-NC组(P0.05);miR-195 mimics组细胞侵袭数低于miR-NC组(P0.05);miR-195-mimics组细chemokine 5蛋白含量低于miR-NC组(P0.05);miR-195 m RNA水平与chemokine 5蛋白含量负相关(r=-0.398,P=0.00);miR-195可直接靶向chemokine 5。结论:miR-195可通过靶向chemokine 5促进胃癌MGC803及NCI-N87细胞的增殖、转移及侵袭。     

社区2型糖尿病患者血糖自我管理水平调查及并发糖尿病周围神经病变的影响因素分析

摘要 目的：调查社区2型糖尿病（T2DM）患者血糖自我管理水平及分析T2DM并发糖尿病周围神经病变（DPN）的影响因素。方法：于2016年6月~2017年6月期间采用整群随机抽样法随机抽取苏州市6个社区符合纳排标准的539例T2DM患者进行问卷调查,了解社区T2DM患者血糖自我管理水平情况,对患者进行体格检查并检测血生化指标,统计社区T2DM患者的DPN发生情况,采用多因素logistic回归分析T2DM患者并发DPN的影响因素。结果：本次研究共发放调查问卷539份,实际回收531份,其中T2DM并发DPN者86例,根据是否并发DPN将所有入选患者分为DPN组（n=86）和无DPN组（n=445）。社区T2DM患者的糖尿病自我管理行为量表（SDSCA）平均得分率为（49.38±5.23）%,DPN组和无DPN组在病程、体质量指数（BMI）、腰围、糖化血红蛋白（HbAlc）、空腹胰岛素（FINS）、低 密 度 脂 蛋 白（LDL-C）、血 尿 素 氮（BUN）、血肌酐（Cr）、合并外周动脉疾病（PAD）、合并糖尿病视网膜病变（DR）中比较差异有统计学意义（P<0.05）。多因素logistic回归分析结果显示：病程≥7年、HbAlc≥8 mmol/L、合并PAD、合并DR、BMI≥25 kg/m²是社区 T2DM患者并发DPN的危险因素（P<0.05）。结论：苏州市6个社区的T2DM患者血糖自我管理水平较低,且T2DM并发DPN的概率较高,病程≥7年、HbAlc≥8 mmol/L、合并PAD、合并DR、BMI≥25 kg/m²均是社区 T2DM患者并发DPN的危险因素,临床可对上述危险因素采取积极有效的措施,以有效降低T2DM并发DPN的发生率。     

Could urinary ACE2 protein level help identify individuals susceptible to SARS-CoV-2 infection and complication?

Science China Life Sciences -     

Diverse Roles of the Salicylic Acid Receptors NPR1 and NPR3/NPR4 in Plant Immunity

The plant defense hormone salicylic acid (SA) is perceived by two classes of receptors, NPR1 and NPR3/NPR4. They function in two parallel pathways to regulate SA-induced defense gene expression. To better understand the roles of the SA receptors in plant defense, we systematically analyzed their contributions to different aspects of Arabidopsis (Arabidopsis thaliana) plant immunity using the SA-insensitive npr1-1 npr4-4D double mutant. We found that perception of SA by NPR1 and NPR4 is required for activation of N-hydroxypipecolic acid biosynthesis, which is essential for inducing systemic acquired resistance. In addition, both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) are severely compromised in the npr1-1 npr4-4D double mutant. Interestingly, the PTI and ETI attenuation in npr1-1 npr4-4D is more dramatic compared with the SA-induction deficient2-1 (sid2-1) mutant, suggesting that the perception of residual levels of SA in sid2-1 also contributes to immunity. Furthermore, NPR1 and NPR4 are involved in positive feedback amplification of SA biosynthesis and regulation of SA homeostasis through modifications including 5-hydroxylation and glycosylation. Thus, the SA receptors NPR1 and NPR4 play broad roles in plant immunity.     

Tripartite motif protein 52 (TRIM52) promoted fibrosis in LX‐2 cells through PPM1A‐mediated Smad2/3 pathway

To investigate the roles of tripartite motif containing 52 (TRIM52) in human hepatic fibrosis in vitro, human hepatic stellate cell line LX‐2 cells were transfected with hepatitis B virus (HBV) replicon to establish HBV‐induced fibrosis in LX‐2 cells, and then treated with small interfering RNA‐mediated knockdown of TRIM52 (siTRIM52). LX‐2 cells without HBV replicon transfection were treated with lentiviruses‐mediated overexpression of TRIM52 and phosphatase magnesium dependent 1A (PPM1A). Fibrosis response of LX‐2 cells were assessed by the production of hydroxyproline (Hyp) and collagen I/III, as well as protein levels of α‐smooth muscle actin (α‐SMA). PPM1A and phosphorylated (p)‐Smad2/3 were measured to assess the mechanism. The correlation between TRIM52 and PPM1A was determined using co‐immunoprecipitation, and whether and how TRIM52 regulated the degradation of PPM1A were determined by ubiquitination assay. Our data confirmed HBV‐induced fibrogenesis of LX‐2 cells, as evidenced by significant increase in Hyp and collagen I/III and α‐SMA, which was associated with reduction of PPM1A and elevation of transforming growth factor‐β (TGF‐β), p‐Smad2/3, and p‐Smad3L. However, those changes induced by HBV were significantly attenuated with additional siTRIM52 treatment. Similar to HBV, overexpression of TRIM52 exerted promoted effect in the fibrosis of LX‐2 cells. Interestingly, TRIM52 induced the fibrogenesis of LX‐2 cells and the activation of TGF‐β/Smad pathway were significantly reversed by PPM1A overexpression. Furthermore, our data confirmed TRIM52 as a deubiquitinase that influenced the accumulation of PPM1A protein, and subsequently regulated the fibrogenesis of LX‐2 cells. TRIM52 was a fibrosis promoter in hepatic fibrosis in vitro, likely through PPM1A‐mediated TGF‐β/Smad pathway.     

Exosome biogenesis,secretion and function of exosomal miRNAs in skeletal muscle myogenesis

Exosomes are membrane‐bound extracellular vesicles that are produced in the endosomal compartment of most mammalian cell types and then released. Exosomes are effective carriers for the intercellular material transfer of material that can influence a series of physiological and pathological processes in recipient cells. Among loaded cargoes, non‐coding RNAs (ncRNAs) vary for the exosome‐producing cell and its homeostatic state, and characterization of the biogenesis and secretion of exosomal ncRNAs and the functions of these ncRNAs in skeletal muscle myogenesis remain preliminary. In this review, we will describe what is currently known of exosome biogenesis, release and uptake of exosomal ncRNAs, as well as the varied functions of exosomal miRNAs in skeletal muscle myogenesis.     

Alteration of protein homeostasis mediates the interaction of Pseudomonas aeruginosa with Staphylococcus aureus

Intracellular protein degradation is essential for the survival of all organisms, but its role in interspecies interaction is unknown. Here, we show that the ClpXP protease of Pseudomonas aeruginosa suppresses its antimicrobial activity against Staphylococcus aureus, a common pathogen co-isolated with P. aeruginosa from polymicrobial human infections. Using proteomic, biochemical, and molecular genetic approaches, we found that this effect is due to the inhibitory effects of ClpXP on the quorum sensing (QS) of P. aeruginosa, mainly by degrading proteins (e.g., PhnA, PhnB, PqsR, and RhlI) which are critical for the production of QS signal molecules PQS and C4-HSL. We provide evidence that co-culturing with S. aureus induces a decrease in the activity of ClpXP in P. aeruginosa, an effect which was also achieved by the treatment of P. aeruginosa with N-acetylglucosamine (GlcNAc), a widespread chemical present on the surface of diverse cell types from bacteria to humans. These findings extend the range of biological events governed by proteolytic machinery to microbial community structure, thus also suggesting that a chemical-induced alteration of protein homeostasis is a mechanism for interspecies interactions.