Résumé
AIM: To investigate the molecular mechanism of microRNA-21 (miR-21) in the regulation of Schwann cell proliferation following nerve injury.METHODS:The expression of miR-2l was detected by real-time PCR. Synthetic miR-21 mimic and its control were transfected into rat Schwann cells.CCK-8 assay was performed to evaluate the influence of miR-21 on the proliferation of Schwann cells.The cell cycle distribution was determined by flow cytometry. The expression of transforming growth factorβ-induced protein ( TGFBI) and cyclin D1 were detected by Western blotting. RESULTS:The expression of miR-21 in model group was 7.87 ±0.75 and 7.75 ±0.80 times higher than that in sham operation group and blank group respectively.After transfected with miR-21 mimic, the expression of miR-21 in experimen-tal group was 2.21 ±0.14 and 2.29 ±0.21 times higher than that in negative control group and blank group respectively. Moreover, the A450 value of CCK-8 assay in experimental group at 48 h was higher than that in negative control group and blank group.The proliferation index in experimental group was higher than that in negative control group and blank group. At the same time, the expression of TGFBI obviously decreased and the cyclin D1 increased in the Schwann cells 48 h after transfection with miR-21.CONCLUSION:miR-21 promotes the proliferation activity of Schwann cells by down-regulating TGFBI expression.