MiR-21对香烟烟雾提取物诱导的巨噬细胞自噬、增殖及凋亡的影响

目的：探讨微小RNA(micro RNA，miR)-21对香烟烟雾提取物(cigarette smoke extract，CSE)诱导的巨噬细胞 自噬、增殖和凋亡的影响。方法：实验分为对照组、CSE干预巨噬细胞组(CSE组)、miR-21抑制剂+CSE干预巨噬细胞 组(miR-21抑制剂+CSE组)。采用实时聚合酶链反应(real-time PCR)检测3组巨噬细胞miR-21表达水平，Western印迹、 MTT试验及流式细胞术检测miR-21抑制剂对巨噬细胞自噬、增殖及凋亡的影响。结果：与对照组相比，CSE组miR- 21表达和自噬水平均增加，差异有统计学意义(均P<0.05)。MiR-21抑制剂+CSE组miR-21的表达量较CSE组明显降低 (P<0.05)。Western印迹显示：与正常组比较，CSE组的微管相关蛋白1轻链3(microtubule associated protein 1 light chain 3 alpha，LC3)和自噬相关蛋白7(autophagy related 7，ATG7)表达增加，而miR-21抑制剂可减少LC3与ATG7的表达。MTT 试验显示：与对照组比较，CSE组的巨噬细胞增殖减少，而miR-21抑制物+CSE组2，3，4 d的增殖率分别为CSE组的 1.41，1.54和1.70倍(均P<0.05)。流式细胞术显示：对照组凋亡率为(2.57±1.35)%，CSE组为(18.70±2.16)%，miR-21抑制 剂+CSE组为(6.28±1.08)%，3组比较差异有统计学意义(P<0.05)。结论：CSE可通过影响巨噬细胞miR-21的表达及自噬 水平而使巨噬细胞的自噬和凋亡增加，增殖减少。

Effect of miR-21 on autophagy,proliferation and apoptosis of macrophages induced by cigarette smoke extract

Objective: To explore the eff ects of miR-21 on macrophage autophagy, proliferation and apoptosis induced by cigarett e smoke extract (CSE). Methods: The cells was divided into a control group, a CSE interventine macrophage group (CSE group), and a miR-21 inhibitor+CSE intervention macrophage group (miR-21 inhibitor+CSE group). The expression of miR-21 in the 3 groups was detected by real-time PCR. The effects of miR-21 inhibitor on macrophage autophagy, proliferation and apoptosis were detected by Western blot, MTT assay and flow cytometry. Results: Compared with the control group, the levels of miR-21 and autophagy in the CSE group were significantly increased (both P<0.05). The expression of miR-21 in the miR-21 inhibitor+CSE group was significantly lower than that in the CSE group (P<0.05). Compared with the control group, the expressions of macrophage microtubule associated protein 1 light chain 3 alpha (LC3) and autophagy related 7 (ATG7) in the CSE group were increased, which was attenuated by miR- 21 inhibitor. Compared with the control group, the macrophage proliferation in the CSE group was inhibited by the miR-21, which could be reversed by adding miR-21 inhibitor; the proliferative rates in the miR-21 inhibitor+CSE group in 2, 3 or 4 days were increased by 1.41, 1.54 or 1.70 times compared with those in the CSE group (all P<0.05). Flow cytometry showed that the apoptosis rate in the control group was (2.57+1.35)%, which was (18.70+2.16)% in the CSE group and (6.28+1.08)% in the miR-21 inhibitor+CSE group (P<0.05). Conclusion: CSE intervention macrophage increase the autophagy and apoptosis of macrophages, decrease the cell proliferation by affecting the expression of miR-21 and the level of autophagy in macrophages.