Sirt1在急性炎症状态下糖尿病小鼠肾损伤中的作用

目的 探究Sirt1在急性炎症状态下糖尿病小鼠肾损伤中的作用及分子机制。方法选择SPF级C57BL/6J雄性小鼠40只,8周龄,体重20～25 g。采用随机数字表法将小鼠分为五组：对照组(C组)、糖尿病组(D组)、脂多糖(LPS)+糖尿病组(L组)、LPS+糖尿病+Sirt1阻断剂EX527组(E组)和LPS+糖尿病+Sirt1激动剂银杏黄酮苷元组(G组),每组8只。糖尿病小鼠模型制备成功后,L组腹腔注射LPS 10 mg/kg; E组在糖尿病小鼠给予LPS处理前1 h腹腔注射EX527 5 mg/kg(溶于DMSO 0.2 ml);G组在糖尿病小鼠给予LPS处理前1 h腹腔注射银杏黄酮苷元200 mg/kg(溶于DMSO 0.2 ml);C组和D组在相同时点腹腔注射2%DMSO 0.15 ml。收集24 h尿液测定24h尿量和24 h尿蛋白浓度,眼球取血检测血清肌酐(Scr)和尿素氮(BUN)浓度。取肾组织后采用ELISA法检测IL-1β、IL-18浓度,硝酸还原酶法检测一氧化氮(NO)含量,铁离子抗氧化能力法检测总抗氧能力(T-AOC),qPCR和Western blot法检测Si...     

E2-Induced Activation of the NLRP3 Inflammasome Triggers Pyroptosis and Inhibits Autophagy in HCC Cells

Emerging evidence suggests that 17β-estradiol (E2) and estrogen receptor (ER) signaling are protective against hepatocellular carcinoma (HCC). In our previous study, we showed that E2 suppressed the carcinogenesis and progression of HCC by targeting NLRP3 inflammasome activation, whereas the molecular mechanism by which the NLRP3 inflammasome initiated cancer cell death was not elucidated. The present study aimed to investigate the effect of NLRP3 inflammasome activation on cell death pathways and autophagy of HCC cells. First, we observed an increasing mortality in E2-treated HCC cells, and then apoptotic and pyroptotic cell death were both detected. The mortality of HCC cells was largely reversed by the caspase 1 antagonist, YVAD-cmk, suggesting that E2-induced cell death was associated with caspase 1-dependent pyroptosis. Second, the key role of the NLRP3 inflammasome in autophagy of HCC cells was assessed by E2-induced activation of the NLRP3 inflammasome, and we demonstrated that autophagy was inhibited by the NLRP3 inflammasome via the E2/ ERβ/AMPK/mTOR pathway. Last, the interaction of pyroptosis and autophagy was confirmed by flow cytometry methods. We observed that E2-induced pyroptosis was dramatically increased by 3-methyladenine (3-MA) treatment, which was abolished by YVAD-cmk treatment, suggesting that caspase 1-dependent pyroptosis was negatively regulated by autophagy. In conclusion, E2-induced activation of the NLRP3 inflammasome may serve as a suppressor in HCC progression, as it triggers pyroptotic cell death and inhibits protective autophagy.     

Gasdermin D-mediated hepatocyte pyroptosis expands inflammatory responses that aggravate acute liver failure by upregulating monocyte chemotactic protein 1/CC chemokine receptor-2 to recruit macrophages

BACKGROUND Massive hepatocyte death is the core event in acute liver failure(ALF).Gasdermin D(GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death. However, the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear.AIM To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis through in vitro and in vivo experiments.METHODS The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot.GSDMD short hairpin RNA(sh RNA) was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1(MCP1) and its receptor CC chemokine receptor-2(CCR2) in vitro. For in vivo experiments, we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide(D-Galn/LPS)-induced ALF mouse model.RESULTS The levels of pyroptosis pathway-associated proteins in liver tissue from ALFpatients and a hepatocyte injury model increased significantly. The level of GSDMD-N protein increased most obviously(P 0.001). In vitro, downregulation of GSDMD by sh RNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins(P 0.01). In vivo, GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of DGaln/LPS-induced ALF mice(P 0.001). Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin(IL)-1β and IL-18, GSDMDmediated hepatocyte pyroptosis recruited macrophages via MCP1/CCR2 to aggravate hepatocyte death. However, this pathological process was inhibited after knocking down GSDMD.CONCLUSION GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF, recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses. GSDMD knockout can reduce hepatocyte death and inflammatory responses, thus alleviating ALF.     

肾癌中调节性细胞死亡的新动向和未来展望

肾癌是泌尿系统常见的恶性肿瘤之一。近年来,我国肾癌的发病率呈逐年上升的趋势,严重威胁着人们的健康。调节性细胞死亡是由一种细胞主动有序的死亡方式,普遍存在于生命活动过程中,在维系生命活动的平衡中发挥着至关重要的作用。近期Science杂志上报道了一种新的调节性细胞死亡方式即铜死亡,进一步强化了生命体中细胞死亡的重要性。随着对调节性细胞死亡认识的不断深入,越来越多的研究显示不同的调节性细胞死亡（如铁死亡、焦亡、自噬等）均与肾癌的发生、发展密切相关。如诱导细胞铁死亡将显著抑制肾癌的侵袭和转移、并与肾癌患者的更好预后密切相关;细胞焦亡不仅可以诱导肾癌细胞死亡还可以激活抗肾癌的免疫应答;自噬在肾癌中具有“双向”作用,增强自噬可抑制肾癌细胞生长,但也可能减弱联合用药治疗的效果;抑制细胞凋亡和坏死性凋亡可以显著促进肾癌细胞的增殖、侵袭等。本文将综述铁死亡、细胞焦亡、自噬、细胞凋亡和坏死性凋亡的分子机制和在肾癌发生、发展中作用的研究进展并进行展望,为探索肾癌的发病机制和潜在的治疗靶点提供新的视角。     

从“一气周流”论述细胞焦亡与代谢综合征血管内皮损伤的相关性

“一气周流”是中医经典理论,其核心思想认为中气(脾胃之气)是整个气机运转的枢纽。脾胃虚弱,肝气郁结,水谷精微运化疏泄失常,日久痰浊瘀血内生,积聚于血管,引起代谢综合征血管内皮损伤。临床及实验研究均证实健脾疏肝方剂柴芪汤对代谢综合征及相关血管内皮损伤具有较好改善作用。细胞焦亡是一种促炎性程序性细胞死亡方式,在血管内皮炎症反应中具有重要作用,这一过程类似于中医“痰瘀浊毒”的积聚。基于“一气周流”理论探讨细胞焦亡与代谢综合征血管内皮损伤的机制,为中医经典理论和中医药防治代谢综合征血管并发症提供理论依据。     

细胞焦亡对肝癌发生发展的影响及中医药的干预作用

细胞焦亡是一种新发现的程序性细胞死亡方式,在肝癌中发挥着关键作用。故拟基于细胞焦亡的分子机制及其在肝癌发病机制中的作用进行深入分析,并结合中医药在调节焦亡肝癌发展过程中的作用进行探讨,以期为临床提供新的治疗思路。     

基于细胞焦亡探讨中医药干预肿瘤炎性微环境的新机制

细胞焦亡是一种能产生炎性反应并引发细胞膜破裂、溶解的新型死亡方式。该死亡方式依赖于半胱氨酸蛋白酶家族1的启动,以致炎性反应小体在病原体的反应下聚集,从而发生焦性细胞死亡。焦亡的细胞在形态学、生物学、基因学特征上与传统的细胞死亡方式均有明显的不同。细胞焦亡已被发现参与多种人类疾病进程,而在肿瘤发生发展中扮演的角色也引起高度关注。因此,细胞焦亡发生机制及传导通路的研究,将为肿瘤的防治提供重要的治疗策略。本文基于细胞焦亡的生物学特征和信号传导通路,以及焦亡与传统细胞死亡方式的区别,结合中医药在肿瘤中应用特点,为探索中医药治疗肿瘤的新策略提供了理论依据。     

炎症反应在细胞焦亡和动脉粥样硬化之间的作用

心血管疾病是全球慢性非传染性疾病中死亡率最高的一类疾病，而动脉粥样硬化（AS）在心血管疾病的发生发展中扮演了重要的角色。炎症反应与动脉粥样硬化形成密切相关，而其又广泛参与细胞焦亡过程。核苷酸结合寡聚化结构域样受体蛋白3（NLRP3）、适配器凋亡相关微粒蛋白（apoptosis-associated speck-like protein containing CARD，ASC）以及Caspase-1等细胞焦亡的重要功能分子均参与AS形成，细胞焦亡的过程中伴随白细胞介素等炎症介质的产生及释放，而炎症反应又可反过来促进细胞焦亡的发生发展。我们分别从炎症反应在动脉粥样硬化、细胞焦亡形成中的作用，炎症反应在这两者之间的桥梁作用等3个方面进行综述。     

Trichostatin A alleviated ovarian tissue damage caused by cigarette smoke exposure

Cigarette smoke (CS) has a negative impact on women's health and fertility. Studies have shown that histone deacetylases 1 and 2 (HDAC1/2) were involved in oocyte development. However, the roles of HDAC1/2 in ovarian toxicity caused by CS exposure and the therapeutic potential of trichostatin A (TSA, a HDAC inhibitor) for ovarian tissue damage have not been investigated. In this study, Female C57BL/6 mice were exposed to CS from six cigarettes mixed with indoor air for 120 min (one cigarette for 20 min) using a whole-body mainstream smoke exposure system twice daily for 30 days. TSA (0.6 mg/kg body weight) was injected intraperitoneally into mice in the Control + TSA group and CS + TSA group every two days for 30 days. We found that exposure to CS resulted in ovarian tissue damage and HDAC1/2 over-expression. TSA alleviated the structural changes of ovarian tissue induced by smoking and prevented the activation of HDAC1/2. Exposure to CS caused autophagy inhibition and pyroptosis activation. TSA treatment restored the expression of autophagy-associated proteins and decreased the levels of pyroptosis-related proteins induced by CS exposure. The TSA effect may be mediated by inhibition of HDAC1/2 involved in autophagy and pyroptosis process.     

Caspase-1在小鼠皮肤切创愈合过程中的规律性表达与损伤时间的关系研究

目的观察小鼠皮肤切创后不同时间内caspase-1的蛋白含量变化,探讨不同时间点蛋白表达的规律与损伤时间的关系。方法建立3个组别。制作小鼠皮肤切创模型,应用免疫组织化学技术检测切创后不同时间皮肤中caspase-1的表达,同时设立空白对照组和死后切创组。结果空白对照组,死后损伤组及生前损伤组0h的蛋白只表达在表皮层,毛囊,皮脂腺中。伤后3h,切创组及切创周边区可见多核粒细胞浸润且少量多核粒细胞表达caspase-1。6h～1d,部分浸润的多核粒细胞和单核细胞caspase-1阳性。伤后3～5d,成纤维细胞大量增生,此时caspase-1主要表现在单核细胞和成纤维细胞。伤后7d则蛋白表达阳性细胞以成纤维细胞为主。结论小鼠切创愈合过程中caspase-1主要在多核粒细胞、单核细胞及成纤维细胞表达,并随损伤时间延长,呈现规律变化趋势。其时序性变化可用于皮肤切创损伤时间的推断。