SOCS-3在胰岛素抵抗中的作用机制及研究进展

细胞因子信号抑制物（suppressor of cytokine signaling,SOCS）家族是具有调控Janus激酶/信号转导与转录激活因子（janus kinase/signal transducer and activator of transcription,JAK/STAT）信号通路作用的蛋白质家族,包括SOCS-1-7及CIS。其中,SOCS-3对胰岛素信号转导具有重要调节作用,通过调控胰岛素受体、胰岛素受体底物、JAK 2、STAT 3、瘦素等信号转导因子,介导胰岛素抵抗的发生和发展。SOCS-3有望成为治疗胰岛素抵抗新的作用靶点。

SOCS3 Expression Correlates with Severity of Inflammation in Mouse Hepatitis Virus Strain 3-induced Acute Liver Failure and HBV-ACLF

Summary： Recently, suppressor of cytokine signaling-3 （SOCS3） has been shown to be an inducible endogenous negative regulator of Janus kinase/signal transducers and activators of transcription （JAK/STAT） pathway which is relevant in inflammatory response, while its functions in acute liver failure and HBV-induced acute-on-chronic liver failure （HBV-ACLF） have not been fully elucidated. In this study, we explored the role of SOCS3 in the development of mouse hepatitis virus strain 3 （MHV-3）-induced acute liver failure and its expression in liver and peripheral blood mononuclear cells （PBMCs） of patients with HBV-ACLF. Inflammation-related gene expression was detected by real-time PCR, immtmohistochemistry and Western blotting. The correlation between SOCS3 level and liver injury was studied. Our results showed that the SOCS3 expression was significantly elevated in both the liver tissue and PBMCs from patients with HBV-ACLF compared to mild chronic hepatitis B （CHB）. Moreover, a time course study showed that SOCS3 level was increased remarkably in the liver of BALB/cJ mice at 72 h post-infection. Pro-inflammatory cytokines, interleukin （IL）-1 β, IL-6, and tumor necrosis factor （TNF）-α, were also increased significantly at 72 h post-infection. There was a close correlation between hepatic SOCS3 level and IL-6, and the severity of liver injury defined by alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels, respectively. These data suggested that SOCS3 may play a pivotal role in the pathogenesis of MHV-3-induced acute liver failure and HBV-ACLF.

Expressions of SOCS-1 and SOCS-3 in the myocardium of patients with sudden cardiac death

BACKGROUND：As the regulators of cytokines, suppressors of cytokine signaling （SOCS） play an important role in the inflammation reaction. Some studies found that SOCS-1 and SOCS-3 were involved in the pathogenesis of some inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease. But the expressions of SOCS in coronary heart disease have not yet been reported. This study aimed to investigate the expression and clinical significance of SOCS-1 and SOCS-3 in the myocardium of patients with sudden cardiac death （SCD）.METHODS： Myocardial autopsy specimens were collected from 24 patients at the Forensic Medicine Department of Sun Yat-Sen University, Guangzhou, China between 2005 and 2006. Of them, 9 patients had autopsy findings consistent with coronary atherosclerosis （non-myocardial infarction） leading to SCD （non-MI group）, 7 died of acute myocardial infaction （MI group）, and 8 died from traffic accidents and trauma （control group）. The expressions of SOCS-1 mRNA and SOCS-3 mRNA in the myocardium of the non-MI, MI and control groups were detected using RT-PCR. The levels of SOCS-1 and SOCS-3 proteins were detected using immunohistochemistry. Statistical analyses were performed using SPSS version 13.0 sottware and the data were analyzed by ANOVA.RESULTS： The expressions of SOCS-1 mRNA and SOCS-3 mRNA in the non-MI and MI groups were significantly higher than those in the control group[（0.788±0.101）, （0.741±0.111） vs. （0.436±0.044）, （P〈0.01）; （0.841±0.092）, （0.776±0.070） vs. （0.454±0.076）, （P〈0.01）] respectively. The antibody-positive cells of SOCS-1 protein in the myocardium of the non-MI and MI groups were significantly higher than those in the myocardium of the control group[（320.00±48.48）, （347.14±70.88） vs. （42.50±10.35）, （P〈0.01）] respectively. The antibody-positive cells of SOCS-3 protein in the myocardium of the non-MI and MI groups were significantly higher than those in the myocardium of the control group[（381.11 ±59.25） vs. （40.00±10.69）, （P〈0.01）] and[（332.86±111.91） vs. （40.00±10.69）, （P=0.001）].CONCLUSION： The expressions of SOCS-1 and SOCS-3 in the myocardium of patients with SCD from coronary heart disease are significantly increased and contribute to the pathogenesis of SCD.

SOCS3基因3’端非翻译区野生型与突变型载体的构建及活性鉴定

目的研究非编码小RNA-1896（miRNA-1896）和miRNA-409—3p对细胞因子信号抑制蛋白-3（suppressors of cytokinesignaling-3，SOTS3）基因的调控作用，构建floes3基因3’端非翻译区（3’-untranslated re-gion，3’-UTR）野生型和突变型重组荧光素酶报告载体。方法以原代培养的小鼠星形胶质细胞总eDNA为模板，通过点突变和缺失突变的方式分别对SOCS33’-UTR序列中miRNA-1896和miRNA-409—3p种子区的结合位点CAGAGA（897—902位）和AACATT（1425—1430位）进行突变，并将野生型的3’-UTR序列与突变的3’-UTR序列分别插入到虫荧光素酶表达质粒pGL3-Promoter获得重组质粒，命名为pGL3-SOCS3-WT、pGL3-SOCS3-M1和pGL3-SOCS3-M2。将上述重组质粒分别与miRNA-1896和miRNA-409—3p共转染至HEK293T细胞中，测定虫荧光素酶的活性。结果酶切验证及测序结果表明，重组质粒pGL3-SOCS3-WT、pGL3-SOCS3-M1和pGL3-SOCS3-M2构建成功。与对照组相比，转染miRNA-1896和miRNA-409—3p均显著降低了pGL3-SOCS3-WT虫荧光素酶的活性，但对pGL3-SOCS3-M1和pGL3-SOCS3-M2荧光素酶的活性并无明显影响。结论成功构建了soc33’-UTR野生型及突变型的虫荧光素酶重组表达质粒，确认CA-GAGA（897—902位）和AACATr（1425—1430位）分别是miRNA-1896和miRNA-409—3p种子区与socs33’-UTR结合的关键位点。

Resveratrol and fenofibrate ameliorate fructose-induced nonalcoholic steatohepatitis by modulation of genes expression

AIM: To evaluate the effect of resveratrol, alone and in combination with fenofibrate, on fructose-induced metabolic genes abnormalities in rats.METHODS: Giving a fructose-enriched diet (FED) to rats for 12 wk was used as a model for inducing hepatic dyslipidemia and insulin resistance. Adult male albino rats (150-200 g) were divided into a control group and a FED group which was subdivided into 4 groups, a control FED, fenofibrate (FENO) (100 mg/kg), resveratrol (RES) (70 mg/kg) and combined treatment (FENO + RES) (half the doses). All treatments were given orally from the 9th week till the end of experimental period. Body weight, oral glucose tolerance test (OGTT), liver index, glucose, insulin, insulin resistance (HOMA), serum and liver triglycerides (TGs), oxidative stress (liver MDA, GSH and SOD), serum AST, ALT, AST/ALT ratio and tumor necrosis factor-α (TNF-α) were measured. Additionally, hepatic gene expression of suppressor of cytokine signaling-3 (SOCS-3), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), malonyl CoA decarboxylase (MCD), transforming growth factor-β1 (TGF-β1) and adipose tissue genes expression of leptin and adiponectin were investigated. Liver sections were taken for histopathological examination and steatosis area were determined.RESULTS: Rats fed FED showed damaged liver, impairment of glucose tolerance, insulin resistance, oxidative stress and dyslipidemia. As for gene expression, there was a change in favor of dyslipidemia and nonalcoholic steatohepatitis (NASH) development. All treatment regimens showed some benefit in reversing the described deviations. Fructose caused deterioration in hepatic gene expression of SOCS-3, SREBP-1c, FAS, MDA and TGF-β1 and in adipose tissue gene expression of leptin and adiponectin. Fructose showed also an increase in body weight, insulin resistance (OGTT, HOMA), serum and liver TGs, hepatic MDA, serum AST, AST/ALT ratio and TNF-α compared to control. All treatments improved SOCS-3, FAS, MCD, TGF-β1 and leptin genes expression while only RES and FENO + RES groups showed an improvement in SREBP-1c expression. Adiponectin gene expression was improved only by RES. A decrease in body weight, HOMA, liver TGs, AST/ALT ratio and TNF-α were observed in all treatment groups. Liver index was increased in FENO and FENO + RES groups. Serum TGs was improved only by FENO treatment. Liver MDA was improved by RES and FENO + RES treatments. FENO + RES group showed an increase in liver GSH content.CONCLUSION: When resveratrol was given with half the dose of fenofibrate it improved NASH-related fructose-induced disturbances in gene expression similar to a full dose of fenofibrate.

Heat shock factor 1 promotes neurite outgrowth and suppresses inflammation in the severed spinal cord of geckos

The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcription factor 1(HSF1),a master regulator of the heat shock response,plays neurogenetic and neuroprotective roles in the damaged or diseased central nervous system.However,the underlying mechanism has not been fully elucidated.In the present study,we used a gecko model of spontaneous nerve regeneration to investigate the potential roles of gecko HSF1(gHSF1) in the regulation of neurite outgrowth and inflammatory inhibition of macrophages following spinal cord injury.gHSF1 expression in neurons and microglia at the lesion site increased dramatically immediately after tail amputation.gHSF1 ove rexpression in gecko primary neuro ns significantly promoted axonal growth by suppressing the expression of suppressor of cytokine signaling-3,and fa cilitated neuro nal survival via activation of the mitogen-activated extracellular signal-regulated kinase/extracellular regulated protein kinases and phosphatidylinositol 3-kinase/protein kinase B pathways.Furthermore,gHSF1 efficiently inhibited the macrophagemediated inflammatory response by inactivating 1kappa B-alpha/NF-kappaB signaling.Our findings show that HSF1 plays dual roles in promoting axonal regrowth and inhibiting leukocyte inflammation,and provide new avenues of investigation for promoting spinal co rd injury repair in mammals.

心源性猝死患者心肌SOCS-1和SOCS-3表达的研究

目的 探讨心源性猝死（sudden cardiac death,SCD）患者心肌中细胞因子信号转导抑制分子-1（suppressor of cytokine signaling-1,SOCS-1）和SOCS-3的表达及临床意义.方法 取2005-2006年中山大学法医学系的尸检心肌标本24例,其中9例尸检符合冠状动脉粥样硬化（非心肌梗死）导致SCD（简称非心梗组）,7例尸检符合急性心肌梗死猝死（简称心梗组）,对照组8例选择了因交通事故、外伤等所致死亡的患者.以RT-PCR法检测对照组、非心梗组和心梗组心肌中SOCS-1,SOCS-3的mRNA表达,用免疫组化法检测对照组、非心梗组和心梗组心肌中SOCS-1,SOCS-3的蛋白表达.数据以SPSS13.0统计学软件处理,采用方差分析检验.结果 非心梗组和心梗组患者心肌中SOCS-1 mRNA,SOCS-3 mRNA的表达量均显著高于对照组,分别为[（0.788±0.101）,（0.741±0.111）vs.（0.436±0.044）,P〈0.01],及[（0.841±0.092）,（0.776±0.070）vs.（0.454±0.076）,P〈0.01].非心梗组和心梗组患者心肌中SOCS-1的蛋白抗体阳性细胞数均显著高于对照组,分别为[（320.00±48.48）,（347.14±70.88）vs.（42.50±10.35）,P〈0.01].非心梗组和心梗组患者心肌中SOCS-3的蛋白抗体阳性细胞数均显著高于对照组,分别为[（381.11±59.25）vs.（40.00±10.69）,P〈0.01]和[（332.86±111.91）vs.（40.00±10.69）,P〈0.01].结论 冠心病所致SCD患者的心肌中SOCS-1,SOCS-3的表达显著增加,提示它们可能参与了SCD的发病机制.