目的 研究大黄素对LPS诱导的炎症反应的抑制作用及其相关的信号通路.方法 将小鼠巨噬细胞RAW264.7细胞分为6组,即Control组、LPS组、大黄素组(Emodin组)、LPS+大黄素组(LPS+ Emodin组)、LPS+大黄素组+ siRNA-PPARγ(LPS+ Emodin+ siRNA-PPARγ组)、LPS+大黄素组+ siRNA-scrambled(LPS-+-Emodin+siRNA-scrambled组).使用ELISA测定TNF-α水平,qPCR和western blot测定ICAM-1、MCP-1和PPARγ mRNA和蛋白水平,并使用western blot测定NF-κB p65磷酸化水平.结果 与Control组相比较,LPS干预6小时后RAW264.7细胞TNF-α、ICAM-1和MCP-1的表达以及NF-κB p65磷酸化水平均明显升高,PPARγ表达水平明显下降,差异均有统计学意义(P均<0.05);与LPS+ Emodin组相比较,LPS组TNF-α、ICAM-1和MCP-1的表达以及NF-κB p65磷酸化水平升高更明显,PPARγ表达水平下降更明显,差异均有统计学意义(P均<0.05);同时siRNA-PPARγ可以有效阻断Emodin的作用,差异均有统计学意义(P均<0.05);且LPS+ Emodin组和LPS+ Emodin+ siRNA-scrambled组间各分子表达及磷酸化水平未见明显差别,差异均无明显统计学差异(P>0.05).结论 大黄素可能通过PPARγ/NF-κB信号通路抑制LPS诱导的RAW264.7细胞炎症反应,为大黄素应用于支气管哮喘及ARDS等炎症相关性疾病的临床治疗奠定了基础.
Objective To explore whether emodin could attenuate LPS-induced in ammation in RAW264.7 cells,and its involved potential mechanism.Methods RAW264.7 cells were divided into Control group,LPS group,Emodin group,LPS+Emodin group,LPS+ Emodin+ siRNA-PPARγand LPS+ Emodin+ siRNA-scrambled group.The mRNA and protein expres-sion of ICAM-1,MCP-1 and PPARγ were measured by qRCR and western blot.The level of TNF-α was evaluated by ELISA.Then,the phosphorylation of NF-κB p65 was also detected by western blot.Meanwhile,siRNA-PPARγ transfection was performed to knockdown PPARγ expression in cells.Results After 6 hours LPS stimulation,LPS-enhanced ICAM-1,MCP-1 and TNF-α expression,LPS-reduced PPARγ expression,and LPS-promoted NF-κB p65 activation were substantially compromised by emdoin in RAW264.7 cells.However,these effects of emodin was noticeably blocked by siRNA-PPARγ in cells.Conclusion Our results indicate that LPS-induced in ammation is potently compromised by emodin very likely through the PPARγ-dependent inactivation of NF-κB in RAW264.7cells.