MicroRNA-214 Affects Fibroblast Differentiation of Adipose-Derived Mesenchymal Stem Cells by Targeting Mitofusin-2 during Pelvic Floor Dysfunction in SD Rats with Birth Trauma

Abstract

Background/Aims: This study investigated whether microRNA-214 (miR-214) targets mitofusin-2 (Mfn2) in the process of fibroblast differentiation of adipose-derived mesenchymal stem cells (ADMSCs) during pelvic floor dysfunction (PFD) in Sprague Dawley (SD) rats with birth trauma. Methods: The ADMSCs were isolated from 4-6 week male SD rats (n = 20) and were cultured and divided into the blank, miR-214 mimic negative control (NC), miR-214 mimic, miR-214 inhibitor NC, miR-214 inhibitor, empty vector, Mfn2 over-expression and miR-214 + Mfn2 over-expression groups. Fibroblast differentiation of ADMSCs was measured with immunocytochemistry and immunofluorescence methods. The expression of miR-214 and the mRNA and protein expression of Mfn2, FSP1, Collagen I, Collagen III, Elastin, LOX, Fibulin-5, PPAR-γ and Runx2 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting, respectively. A dual-luciferase reporter assay was performed to confirm whether Mfn2 was the target gene of miR-214. Results: During ADMSC differentiation into fibroblasts, miR-214 expression was up-regulated, but the expression of Mfn2 was down-regulated. Fibroblast differentiation of ADMSCs was promoted in the miR-214 mimic group but was inhibited in the miR-214 inhibitor and Mfn2 over-expression groups. The expression of Mfn2 was decreased, but the expression of FSP1, Collagen I, Collagen III, Elastin, LOX, Fibulin-5, PPAR-γ or Runx2 was increased in the miR-214 mimic group; the miR-214 inhibitor group and Mfn2 over-expression group exhibited the opposite results. Mfn2 was the target gene of miR-214. Conclusions: The study provided strong evidence that miR-214 could promote fibroblast differentiation of ADMSCs by down-regulating Mfn2 to improve PFD in SD rats with birth trauma.