摘要
目的观察褪黑素(melatonin,MLT)对NLRP3炎症小体和肝脏纤维化的影响,阐明其对非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)防治作用及相关的分子机制。方法利用高脂饮食(high-fat diet,HFD)喂养的方法构建NAFLD动物模型,分为正常饮食组(NFD组)、HFD组、褪黑素干预组(HFD+MLT组);采用游离脂肪酸(free fatty acids,FFA)干预HepG2细胞的方法构建NAFLD细胞模型,分为未处理组(ctl组)、模型组(FFA组)、褪黑素干预组(FFA+MLT组)、褪黑素干预同时过表达lncRNA MALAT1组(FFA+MLT+MALAT1组);分别检测NLRP3炎症小体、纤维化、lncRNA MALAT1等相关指标。结果HFD+MLT组小鼠血清中TG、TC和LDL的水平低于HFD组(P<0.05);HFD组小鼠肝脏组织中NLRP3、ASC、活化caspase-1、TGF-β1和p-Smad2蛋白相对表达量高于NFD组(P<0.05)和HFD+MLT组(P<0.05);与HFD组相比,HFD+MLT组小鼠肝脏组织中lncRNA MALAT1、collageⅠ和collageⅢmRNA水平明显降低(P<0.05);与FFA组相比,FFA+MLT组中NLRP3、ASC、活化caspase-1、TGF-β1、p-Smad2和lncRNA MALAT1表达明显降低(P<0.05)。与FFA+MLT组相比,FFA+MLT+MALAT1组中NLRP3、ASC、活化caspase-1、TGF-β1和p-Smad2蛋白相对表达量减少现象得到逆转(P<0.05)。结论褪黑素通过抑制NLRP3炎症小体介导的炎症反应和TGF-β1/Smad介导的纤维化,改善NAFLD,其与下调lncRNA MALAT1有关。
Objective To detect the effect of melatonin(MLT)on NLRP3 inflammasome and fibrosis,and to identify the protective role and related molecular mechanism of MLT on nonalcoholic fatty liver disease(NAFLD).Methods The animal model of NAFLD was established by high fat diet(HFD),which were divided into NFD group,HFD group,HFD+MLT group;The in vitro model of NAFLD was established by free fatty acid(FFA)treatment in HepG2 cells,which were divided into control group,FFA group,FFA+MLT group and FFA+MLT+MALAT1 group;The contents of NLRP3 inflammasome,fibrosis and lncRNA MALAT1 were detected.Results The levels of TG,TC and LDL in HFD+MLT group were lower than that in HFD group(P<0.05).The relative protein levels of NLRP3,ASC,cleaved caspase-1,TGF-β1 and p-Smad2 in HFD group were higher than that in NFD group(P<0.05)and in HFD+MLT group(P<0.05).Compared with HFD group,the mRNA levels of lncRNA MALAT1,collagenⅠand collagenⅢin HFD+MLT group were significantly decreased(P<0.05).The relative protein levels of NLRP3,ASC,cleaved caspase-1,TGF-β1 and p-Smad2 in FFA+MLT group were reduced compared with FFA group(P<0.05).Compared with FFA+MLT group,the increased levels of NLRP3,ASC,cleaved caspase-1,TGF-β1 and p-Smad2 were reversed in FFA+MLT+MALAT1 group(P<0.05).Conclusion Melatonin can improve NAFLD by inhibiting the NLRP3 inflammasome-associated inflammatory response and TGF-β1/Smad-mediated fibrosis,which is associated with downregulation of lncRNA MALAT1.
作者
孟宪红
李立
曹巍
王大秀
刘勇
MENG Xian-hong;LI Li;CAO Wei;WANG Da-xiu;LIU Yong(Department of Gastroenterology,The Fourth Affiliated Hospital of Harbin Medical University,Harbin 150001,China)
出处
《哈尔滨医科大学学报》
CAS
2021年第5期451-456,共6页
Journal of Harbin Medical University
基金
黑龙江省自然科学基金面上项目(H2017011)。
