Plasma Gelsolin Induced Glomerular Fibrosis via the TGF-β1/Smads Signal Transduction Pathway in IgA Nephropathy
BACKGROUND Wharton's Jelly cells (WJCs) can be differentiated into adipocytes by cytoskeletal reorganisation in association with changes in the mechanical properties of cells. METHODS WJCs subjected to adipocyte induction were observed changes in the cell morphology and alterations in actin filament formation. Transfection with either small interfering RNAs (siRNAs) against formin-2 (FMN-2), tropomyosin-1 (Tm-1), caldesmon (CaD), and profilin (Pro) or a pcDNA6-gelsolin (GSN)-constructed vector in WJCs was used to establish their regulatory roles in controlling adipogenesis. Phenotypic transformation of the cell shape and changes in cell surface adhesion force were determined in WJCs after transformation. RESULTS The levels of protein and mRNA expression of β-actin and several key actin binding ptoteins (ABPs) were decreased during the early stage of adipogenic induction but were recovered in the later induction. The siFMN-2, siTm-1, siCaD, and siPro gene knockdown in WJCs caused a widening of the cell shape, while WJCs overexpressing GSN retained a fibroblast cell shape. For both transformations, atomic force microscopy revealed alterations in the biomechanical signals on the cell surface. However, the adipogenic potency was increased after siFMN-2, siTm-1, siCaD, and siPro gene knockdown and decreased during GSN overexpression. CONCLUSIONS siRNA gene knockdown of siFMN-2, siTm-1, siCaD, and siPro enhances the potency for WJCs commitment to adipocyte, while GSN overexpression modulates the PPAR-γ-independent pathway for the adipogenesis of WJCs. GENERAL SIGNIFICANCE The phenotypic changes associated with decreased ABP gene expression are critical for regulating the adipogenic differentiation of WJCs through the temporal control of actin filament organisation.