慢性乙型肝炎信号转导及转录激活因子3、5与Treg/Th17平衡的关系

慢性乙型肝炎持续感染的免疫机制与T淋巴细胞密切相关,T淋巴细胞的发育需要多种细胞因子的协调作用,而信号转导及转录激活因子家族蛋白主要参与细胞因子的信号转导,尤其是STAT5a/b和STAT3在调节性T淋巴细胞(Treg)和辅助性T淋巴细胞17(Th17)的分化、发育过程中有着重要作用。本文主要就在慢性乙型肝炎中,对信号转导及转录激活因子3、5与Treg/Th17平衡的关系进行分析,研究HBV感染的慢性化及其引起的肝脏炎症调控机制。     

Phosphatase of regenerating liver-3 is regulated by signal transducer and activator of transcription 3 in acute myeloid leukemia

1. Download : Download high-res image (61KB)
2. Download : Download full-size image

     

甲泼尼龙冲击治疗对重症系统性红斑狼疮患者T细胞STATI活性调控的研究

目的 探讨甲泼尼龙冲击治疗对重症系统性红斑狼疮(SEE)T细胞内磷酸化转录激活因子1(STATI)表达和对STATI DNA结合活性的作用.方法 6例重症SLE患者进入本研究.采用蛋白免疫印迹和电泳迁移率实验分别检测甲泼尼龙冲击治疗对SLE T细胞内磷酸化STATI的表达和对STATIDNA结合活性的作用.结果 甲泼尼龙冲击治疗后72 h,磷酸化STATI的表达大约被降低30%.甲泼尼龙冲击治疗可降低SLE T细胞内STATI的DNA结合活性和表达量.冲击治疗72 h后,STATI的DNA结合活性被抑制约40%,差异有统计学意义(t=3.058,P<0.05).结论 抑制磷酸化STATI表达和STATIDNA结合活性是甲泼尼龙发挥作用的可能机制之一.     

雨蛙素诱导的急性胰腺炎体外细胞模型的信号转导通路研究

目的 观察急性胰腺炎(AP)体外细胞模型Janus激酶/信号转导和转录激活子(JAK/STAT)信号转导通路及细胞因子表达的变化,探讨其机制.方法 应用雨蛙素处理大鼠胰腺外分泌细胞株AR42J细胞建立AP体外模型,再用雷帕霉素(RPM)及AG490干预.采用Western blotting检测细胞JAK1、磷酸化JAK1(P-JAK1)、STAT1、P-STAT1及TNF-α、IL-1β、IL-6蛋白表达水平;RT-PCR检测TNF-α、IL-1β、IL-6 mRNA表达;台盼蓝染色测定细胞存活率.结果 未经雨蛙素处理的AR42J细胞的JAK1、P-JAK1、STAT1、P-STAT1及TNF-α、IL-1β、IL-6蛋白的相对表达量分别为0.09±0.04、0.14±0.08、0.21±0.09、0.12±0.12、0.10±0.02、0.08±0.03、0.02±0.02.雨蛙素处理后,AR42J细胞上述蛋白的表达呈时间依赖性增加,24 h时的表达量分别为0.53±0.09、0.53±0.13、0.56±0.09、0.55±0.10、0.25±0.04、0.25±0.09、0.27±0.07,均较雨蛙素未处理组显著增加(P＜0.05).再分别应用RPM和AG490抑制24 h后,细胞TNF-α、IL-1β、IL-6蛋白表达量显著降低到0.17±0.03和0.17±0.01、0.15±0.05和0.14±0.07、0.19±0.04和0.19±0.05,它们的mRNA表达量也显著降低(P值均＜0.05);RPM和AG490抑制组的细胞存活率分别为(72.4±11.2)%、(69.7±9.8)%,均显著高于单用雨蛙素处理细胞组的(42.2±12.3)%(P＜0.05).结论 JAK1/STAT1信号通路早期参与雨蛙素诱导的AP细胞促炎症细胞因子释放.早期抑制JAK1/STAT1信号通路有利于控制AP的炎症反应.     

Adipose-specific disruption of signal transducer and activator of transcription 3 increases body weight and adiposity

To determine the role of STAT3 in adipose tissue, we used Cre-loxP DNA recombination to create mice with an adipocyte-specific disruption of the STAT3 gene (ASKO mice). aP2-Cre-driven disappearance of STAT3 expression occurred on d 6 of adipogenesis, a time point when preadipocytes have already undergone conversion to adipocytes. Thus, this knockout model examined the role of STAT3 in mature but not differentiating adipocytes. Beginning at 9 wk of age, ASKO mice weighed more than their littermate controls and had increased adipose tissue mass, associated with adipocyte hypertrophy, but not adipocyte hyperplasia, hyperphagia, or reduced energy expenditure. Leptin-induced, but not isoproterenol-induced, lipolysis was impaired in ASKO adipocytes, which may partially explain the increased cell size. Despite reduced adiponectin and increased liver triacylglycerol, ASKO mice displayed normal glucose tolerance. Overall, these findings demonstrate that adipocyte STAT3 regulates body weight homeostasis in part through direct effects of leptin on adipocytes.