Shikonin from Chinese herbal medicine induces GSDME-controlled pyroptosis in tumor cells

ObjectiveTo investigate the potential anti-tumor mechanisms of naphthoquinone compound shikonin (SKN) extracted from the root of Chinese herbal medicine plant lithospermum (Lithospermum erythrorhizon Sieb. & Zucc.).MethodsWe first observed that SKN treatment led to swelling and bubbles in HeLa cells that were similar to the phenotype of cell pyroptosis. Subsequently, the HeLa cells experienced a pyroptotic process with SKN, and this was then assessed using lactate dehydrogenase (LDH) release and propidium iodide (PI)/Hoechst double staining experiments. Pyroptosis is defined as gasdermin-mediated programmed necroptosis. To identify the potential pyroptosis machinery, two strategies were utilized that included a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 screening experiment and a pyroptosis reconstitution assay executed by each of the five known gasdermins (GSDMA-E). Moreover, endogenous cleavage was also detected in a panel of tumor cell lines.ResultsCompared with the control, both the LDH release and PI/Hoechst double-staining experiments suggested that SKN induced perforation and enhancement of the permeability of the cell membranes that resulted in pyroptosis in HeLa cells (P = .028 and P = .032, respectively). In addition, the reconstitution assays in human embryonic kidney 293T (HEK-293T) cells and endogenous cleavage assays in HeLa cells indicated that the pyroptosis was controlled by GSDME. In addition, we also found SKN could trigger pyroptosis in a panel of tumor cell lines in which the cellular morphologies were proportional to the GSDME expression levels. Additionally, the cleavage of GSDME was also detected, and this was indicative of a similar GSDME-mediated mechanism.ConclusionOur study not only explained the molecular mechanism of cytotoxicity of SKN to various tumor cells, but also provided additional information for the potential clinical application of natural naphthoquinone compounds against cancer.     

益肾健脾泻浊中药对慢性肾脏病妊娠大鼠肾脏NLRP3/caspase-1/IL-1β信号通路及细胞焦亡的影响＊

目的 观察益肾健脾泻浊中药对慢性肾脏病妊娠大鼠肾脏NLRP3/caspase-1/IL-1β信号通路及细胞焦亡的影响。方法 将雌性Wistar大鼠随机分为6组，分别为对照组（Sham）、对照组 + 妊娠组（SP）、单侧输尿管结扎组（UUO）、UUO + 妊娠组（UP）、UUO + 妊娠 + 益肾健脾泻浊中药组（TCM）、UUO + 妊娠 + 依普利酮组（EPL）。UUO各组采用结扎单侧输尿管的方法复制慢性肾病模型，治疗组分别给予依普利酮100 mg?（kg?天）^-1和益肾健脾泻浊方3.11 g?（kg?天）^-1治疗。8周后妊娠各组大鼠按动情周期与雄鼠合笼，妊娠第19天处死母鼠。检测各组肾功能，醛固酮含量，采用SABC法及Western blot法检测核因子κB（Nuclear factor-kappa B，NF-κB）、核苷酸结合寡聚结构域样受体蛋白3 NOD［nucleotide-binding oligomerization domain-like receptor protein 3，NLRP3］、天冬氨酸特异性半胱氨酸蛋白1［Caspase-1］、白介素1β（Interleukine-1 beta，IL-1β）的表达，TUNEL法检测肾细胞DNA损伤情况。结果 与UUO组比较，UP组血清肌酐（Scr）、血尿素氮（BUN）和24 h尿蛋白及醛固酮含量较Sham组显著升高（P < 0.05），治疗后，两给药组Scr、BUN、24 h尿蛋白、醛固酮显著降低（P < 0.05）。与Sham组比较，SP组大鼠肾组织NF-κB、NLRP3、Caspase-1、IL-1β表达明显升高（P < 0.05），TUNEL阳性细胞少量增加（P < 0.05）。NLRP3炎症小体主要表达于浸润巨噬细胞及肾小管上皮细胞；Caspase-1和IL-1β主要表达于肾小管上皮细胞胞浆；TUNEL阳性细胞主要见于远端小管上皮细胞。与UUO组比较，UP组大鼠肾组织NF-κB、NLRP3、Pro-caspase-1、Caspase-1、Pro-IL-1β、IL-1β指标表达也明显升高（P < 0.05），TUNEL阳性细胞明显增多（P < 0.05）。与UP组比较，EPL、TCM组大鼠肾组织上述指标表达明显降低（P < 0.05），TUNEL阳性细胞明显减少（P < 0.05）。两个给药组间各项指标无明显差异。结论 益肾健脾泻浊方及依普利酮可缓解慢性肾病妊娠大鼠肾脏炎症损伤，下调肾脏NLRP3炎症小体信号通路分子表达，从而抑制细胞焦亡，减轻肾脏炎症损伤。     

淫羊藿苷通过抑制NLRP3炎性小体和Caspase-1通路减轻骨关节炎

目的:考察淫羊藿苷在治疗骨关节炎中的潜在价值,以及淫羊藿苷对核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体和半胱天冬酶-1(Caspase-1)的调控作用。方法:本研究通过脂多糖(LPS)诱导大鼠膝关节软骨细胞建立体外骨关节炎模型,通过碘乙酸单钠处理SD大鼠建立体内骨关节炎模型。通过乳酸脱氢酶漏出实验检测细胞毒性,通过MTT实验检测细胞活力。通过qRT-PCR检测NLRP3 mRNA的表达,通过Western Blotting检测NLRP3、IL-1β、IL-18、MMP-1、MMP-13、Collagen Ⅱ、Caspase-1、ASC和GSDMD的蛋白表达。用免疫荧光法和免疫组化法检测软骨细胞和大鼠软骨中的NLRP3表达;番红O/固绿染色评价大鼠软骨病变。结果:与LPS组比较,LPS+ICA组LDH的漏出率、IL-1β、IL-18、MMP-1、MMP-13、NLRP3、Caspase-1、ASC和GSDMD的表达水平明显降低,而Collagen Ⅱ明显升高(P<0.05)。与LPS+ICA+pcDNA3.1-NC组比较,LPS+ICA+pcDNA3.1-NLRP3组的乳酸脱氢酶漏出率及NLRP3炎性小体相关蛋白表达水平明显升高(P<0.05)。与对照组比较,OA组大鼠软骨组织中NLRP3阳性细胞数量显著增加,而OA+ICA组的NLRP3阳性细胞数量明显降低(P<0.05)。与OA组比较,OA+ICA组的NRLP3、IL-1β、IL-18、MMP-1、MMP-13、Caspase-1、ASC和GSDMD的蛋白表达水平明显降低,而Collagen的蛋白表达水平明显升高(P<0.05)。结论:淫羊藿苷通过抑制NLRP3和Caspase-1信号转导来抑制脂多糖诱导的软骨细胞损伤和细胞焦亡,从而减轻大鼠骨关节炎。     

基于数据库构建乳腺癌焦亡相关基因的预后风险模型

目的 探究焦亡相关差异表达基因(DEGs)在乳腺癌中预后价值并构建预后风险模型。 方法 从癌症基因组图谱(TCGA)和肿瘤基因表达数据库(GEO)官网下载乳腺癌的基因测序、临床数据,筛选焦亡相关DEGs。将乳腺癌患者进行聚类分析。在TCGA队列中以最小绝对收缩和选择算子(LASSO)方法建立模型。利用Kaplan-Meier生存曲线、受试者工作特征曲线(ROC)、单因素及多因素Cox回归独立预后因素分析等评价该模型。GEO队列为验证集。通过GO、KEGG、ssGSEA分析风险DEGs的富集情况。 结果 筛选出焦亡相关DEGs,聚类分析可见C2组总生存期(OS)延长,差异有统计学意义(P=0.020)。该模型K-M生存分析显示,高风险组OS缩短(TCGA队列中P<0.001,GEO队列中P=0.018)。ROC曲线下面积(AUC)表明该模型具有一定预测能力。单因素、多因素Cox回归分析表明,年龄、M、N分期和风险评分为OS的独立预测因子。GO、 KEGG富集与ssGSEA分析证实了风险相关DEGs与免疫炎症因子和通路有关。 结论 本研究构建了由9个焦亡相关基因组成的乳腺癌预后风险模型,为乳腺癌患者的风险预后评估提供了参考。     

Involvement of caspase-4 in IL-1 beta production and pyroptosis in human macrophages during dengue virus infection

Caspase-4 physically interacts with caspase-1 and is believed to be a proinflammatory caspase that can induce the inflammatory form of programmed cell death (pyroptosis) and the release of mature interleukin (IL)-1β. However, the function of caspase-4 in dengue virus infection is not yet fully understood. We examined the function of caspase-4 in IL-1β production and pyroptosis during dengue virus serotype-2 (DENV-2) infection in human macrophages. In this study, DENV-2 infection increased IL-1β protein level with activated caspase-4 activity. Using primary macrophages, we observed that caspase-4 induces activation of caspase-1 and secretion of IL-1β in response to DENV-2 infection, without the need for secondary signals to stimulate the assembly of the inflammasome. These findings indicate that the regulation of caspase-1 activity by capsase-4 could represent a unique mechanism. Our data suggest that caspase-4 is upstream of caspase-1 in the pathway that regulates pyroptosis and IL-1β synthesis in macrophages during DENV-2 infection.     

西格列汀对2型糖尿病大鼠心肌细胞焦亡的影响及其可能机制

目的:研究西格列汀(sitagliptin,SLT)对2型糖尿病大鼠心肌细胞焦亡的影响,并探讨其抑制糖尿病心肌病可能的作用机制。方法:建立2型糖尿病大鼠模型,并给予(3、10和30 mg/kg)和sirtuin(SIRT)家族抑制剂尼克酰胺(nicotinamide,NAM;500 mg/kg)灌胃4周。检测空腹血糖,采用免疫组织化学法和Western blot法检测心肌组织中相关蛋白表达。结果:与正常对照组相比,糖尿病大鼠心肌组织细胞SIRT3表达下调,而NLRP3表达上调(P0.05),糖尿病大鼠心肌组织发生焦亡的细胞明显增多。灌胃SLT能剂量依赖性地抑制糖尿病大鼠心肌细胞焦亡的发生,并上调SIRT3的表达,下调NLRP3蛋白表达(P0.05);SIRT3非特异性抑制剂NAM(500 mg/kg)能逆转SLT的心脏保护作用,与正常对照组相比,单独给予NAM(500 mg/kg)对正常大鼠心肌细胞SIRT3表达无明显作用,但NLRP3表达上调(P0.05),心肌组织发生焦亡的细胞增多。结论:SLT能抑制糖尿病诱导的心肌细胞焦亡,其作用机制可能涉及SIRT3/NLRP3信号途径。     

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.     

焦亡及其与头颈部肿瘤关系的研究进展

细胞程序性死亡是指细胞依赖于某些特定的基因编码信号或活动的死亡方式。细胞凋亡、自噬、胀亡、焦亡等均属于细胞程序性死亡。其中,焦亡是一种依赖含半胱氨酸的天冬氨酸蛋白水解酶（caspase）的细胞程序性死亡方式。近年来,国内外相关研究发现,焦亡与炎性疾病、自身免疫性疾病及肿瘤均有关系。充分了解焦亡发生的机制及其与肿瘤的关系,对肿瘤的治疗具有一定的指导意义。本文针对焦亡的相关机制及焦亡与头颈部肿瘤的相关研究进展进行综述。