Epithelial STAT6 O-GlcNAcylation drives a concerted anti-helminth alarmin response dependent on tuft cell hyperplasia and Gasdermin C

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Interplay between bile acids and the gut microbiota promotes intestinal carcinogenesis

The gut microbiota and the bile acid pool play pivotal roles in maintaining intestinal homeostasis. Bile acids are produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. Gut dysbiosis has been reported to be associated with colorectal cancer. However, the interplay between bile acid metabolism and the gut microbiota during intestinal carcinogenesis remains unclear. In the present study, we investigated the potential roles of bile acids and the gut microbiota in the cholic acid (CA; a primary bile acid)‐induced intestinal adenoma‐adenocarcinoma sequence. Apc ^min/+ mice, which spontaneously develop intestinal adenomas, were fed a diet supplemented with 0.4% CA for 12 weeks. Mice that were fed a normal diet were regarded as untreated controls. In CA‐treated Apc ^min/+ mice, the composition of the gut microbiota was significantly altered, and CA was efficiently transformed into deoxycholic acid (a secondary bile acid) by the bacterial 7α‐dehydroxylation reaction. The intestinal adenoma‐adenocarcinoma sequence was observed in CA‐treated Apc ^min/+ mice and was accompanied by an impaired intestinal barrier function and IL‐6/STAT3‐related low‐grade inflammation. More importantly, microbiota depletion using an antibiotic cocktail globally compromised CA‐induced intestinal carcinogenesis, suggesting a leading role for the microbiota during this process. Overall, our data suggested that the crosstalk between bile acids and the gut microbiota mediated intestinal carcinogenesis, which might provide novel therapeutic strategies against intestinal tumor development.     

活性多酚化合物LM49对RAW264.7巨噬细胞极化的影响

目的初步探讨LM49(2,4'三羟基-5,2'-二溴二苯甲酮)对脂多糖(LPS)联合干扰素γ(IFN-γ)诱导的小鼠单核巨噬细胞(RAW264.7)M1/M2极化的影响及其调控机制。方法四曱基偶氮唑蓝(MTT)法测定LM49对细胞活力的影响;流式细胞术、实时荧光定量聚合酶链反应(PCR)和Westem-blot法测定LM49(5,10,20μmol·L^-1)与LPS/INF-γ共同作用于RAW264.7细胞后,巨噬细胞亚型标志物的表达情况及对核因子(NF)-κB和JAK/STAT信号通路的影响。结果与LPS/INF-γ造模组相比,LM49显著抑制CD16/32^+细胞数及诱导型一氧化氮合酶(iNOS)、白细胞介素(IL)4和肿瘤坏死因子(TNF)-αmRNA的表达,升高CD206^+细胞数及Arg-1和IL-10 mRNA的表达,且降低巨噬细胞M1/M2的比值;Westem-blot法验证LM49可显著降低TLR4、Myd88、NF-κB和STAT1蛋白的表达量,同时抑制p-JAK2和p-STATl蛋白磷酸化水平。结论LM49通过抑制TLR4-Myd88-NF-κB和JAK2-STAT1信号通路,抑制巨噬细胞Ml型极化及促进巨噬细胞M2型极化,调节巨噬细胞M1/M2的平衡。     

基于JAK2/STAT3信号通路探讨大黄素保护AR42J胰腺腺泡细胞损伤的作用机制

目的基于JAK2/STAT3信号通路探讨大黄素保护AR42J胰腺腺泡细胞损伤的作用机制。方法将AR42J细胞以1×10~5/mL铺于6孔板,分为对照组、雨蛙素组(雨蛙素10~(-8) mol/L)、大黄素组(终浓度0.25、0.5、1.0mg/L),通过碘-淀粉比色法淀粉酶(AMS)试剂盒测定细胞上清淀粉酶活力水平,确定雨蛙素刺激AR42J胰腺腺泡细胞损伤的收样时间;ELISA法检测TNF-α活力;Western blot法分析JAK2/STAT3通路相关蛋白的表达情况。结果①与对照组比较,雨蛙素组中的AMS、TNF-α、JAK2/STAT3通路相关蛋白表达量显著提高,差异有统计学意义(P0.05)。②与雨蛙素组比较,大黄素各干预组可显著降低雨蛙素诱导的胰腺腺泡细胞损伤的淀粉酶活力、TNF-α含量、JAK2和STAT3的mRNA相对表达量,差异有统计学意义(P0.01)。③大黄素0.5、1.0 mg/L干预组的作用优于0.25 mg/L干预组,差异有统计学意义(P0.001)。结论大黄素能够减轻雨蛙素诱导的胰腺腺泡细胞损伤,其作用机制可能与调控JAK2/STAT3信号通路有关。     

右归丸经IL-6/STAT3信号通路对膝骨关节炎模型大鼠软骨组织退变的调控机制

目的:观察右归丸对膝骨关节炎(KOA)模型鼠软骨组织信号转导和转录激活因子3(STAT3)和白细胞介素-6(IL-6)表达水平的影响。方法:将大鼠随机分为假手术组、模型组、硫酸氨基葡萄糖组、右归丸高、中、低剂量组,每组10只。采用改良Hulth法制备大鼠KOA模型,假手术组和模型组给予等体积生理盐水灌胃,右归丸高、中、低剂量组分别给予右归丸4.8,2.4,1.2 g·kg^-1灌胃,硫酸氨基葡萄糖组给予硫酸氨基葡萄糖0.17 g·kg^-1灌胃,连续给药8周。干预结束24 h后股动脉采血处死各组大鼠,取鼠膝关节软骨,采用苏木素-伊红(HE)染色法观察各组软骨的病理改变,并进行Mankin评分;免疫组化法检测各组关节软骨组织中STAT3,超氧化物歧化酶3(SOD3)和Wnt抑制因子1(WIF1)的表达;实时荧光定量聚合酶链式反应(Real-time PCR)检测软骨组织中IL-6 mRNA的表达;蛋白免疫印迹法(Western blot)检测各组关节软骨组中WIF1蛋白的表达。结果:与假手术组比较,模型组大鼠软骨组织Makin评分明显升高,软骨组织STAT3在蛋白水平上的表达明显增加和IL-6 mRNA水平上的表达显著增加,WIF1在蛋白水平上的表达显著降低(P<0.01);模型组关节软骨边缘严重破坏,软骨细胞排列紊乱。与模型组比较,右归丸高剂量干预组大鼠软骨组织Makin评分,STAT3的在蛋白水平上的表达明显降低,右归丸各干预组IL-6 mRNA水平上的表达显著降低,WIF1在蛋白水平上的表达显著增加(P<0.05,P<0.01),软骨结构趋于正常,软骨细胞分布仅偶见不均,关节软骨表面欠光滑。结论:右归丸能显著改善KOA大鼠的关节软骨退变,抑制KOA中软骨组织的炎症反应,这可能与其抑制STAT3和IL-6的表达有关。