OBJECTIVETo explore the effect of MicroRNA-146b-5p (miR-146b-5p) on the mouse bone essence derived MSC adipogenic differentiation.

METHODSMSC were isolated from bone essence of C57BL/6 mice. The expression level of miR-146b-5p in the process of adipogenic differentiation of MSC was detected by q-PCR; the role of miR-146b-5p mimics or inhibitors in the process of mouse bone essence derived MSC adipogenic differentiation was analyzed through oil red staining the expression of C/EBPα and PPARγ after cultured for 14 days was detected by q-PCR; the protein level of PPARγ after miR-146b-5p transfection was detected by Western blot.

RESULTSThe MSC were successfully isolated from bone essence of mice, the q-PCR results showed an increasing expression level of miR-146-5p in the process of MSC adipogenic differentiation. Compared with the control group, MSC transfected with miR-146b-5p mimic could up-regulate the expression of miR-146b-5p (P<0.001), while miR-146b-5p inhibitor transfection could down-regulate the endogenous miR-146b-5p expression (P<0.01). After culture for 14 d, the result of Oil red staining showed that the miR-146b-5p inhibitor could inhibit adipogenic differentiation, while the miR-146b-5p mimic could promote the adipogenic differentiation of MSC. After induction for 14 d, compared with control, the PPARγ and C/EBPα in mimic group were higher expressed PPARγ and C/EBPα (P<0.01). Compared with induced group, the PPAPγ and C/EBPα were lower expressed in inhibitor group (P<0.05). The results of Western blot showed that the expression level of PPARγ was high in minic group, and it was low in inhibitor group.

CONCLUSIONmiR-146b-5p is up-regulated in the process of MSC adipogenic differentiation, and it promotes the adipogenesis of MSC originated from mouse bone essence.