Abstract 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
Fund:Th is work was supported by the National Natural Science Foundation (81500033) and National Youth Science Foundation (81770042), China.
ZENG Zhengpeng,SUN Shenghua,XIE Lihua. Effect of miR-21 on autophagy, proliferation and apoptosis of macrophages induced by cigarette smoke extract[J]. Journal of Central South University(Medical Scienc, 2018, 43(12): 1281-1287.