Abstract
The molecular mechanisms that control the ability of adipose-derived mesenchymal stem cells (AMSCs) to remodel three-dimensional extracellular matrix barriers during differentiation are not clearly understood. Herein, we studied the expression of matrix metalloproteinases (MMPs) during the differentiation of AMSCs to endothelial cells (ECs) in vitro. MSCs were isolated from porcine abdominal adipose tissue, and characterized by immunopositivity to CD44, CD90, CD105, and immunonegativity to CD14 and CD45. Plasticity of AMSCs was confirmed by multilineage differentiation. The mRNA transcripts for MMPs and Tissue Inhibitor of Metalloproteinases (TIMPs), and protein expression of EC markers were analyzed. The enzyme activity and protein expression were analyzed by gelatin zymography, enzyme-linked immunosorbent assay (ELISA), and Western blot. The differentiation of AMSCs to ECs was confirmed by mRNA and protein expressions of the endothelial markers. The mRNA transcripts for MMP-2 and MMP-14 were significantly increased during the differentiation of MSCs into ECs. Findings revealed an elevated MMP-14 and MMP-2 expression, and MMP2 enzyme activity. Silencing of MMP-2 and MMP-14 significantly increased the expression of EC markers, formation of capillary tubes, and acetylated-low-density lipoprotein uptake, and decreased the cleavage of vascular endothelial growth factor receptor type 2 (VEGFR2). Inhibition of VEGFR2 significantly decreased the expression of EC markers. These novel findings demonstrate that the upregulation of MMP2 and MMP14 has an inhibitory effect on the differentiation of AMSCs to ECs, and silencing these MMPs inhibit the cleavage of VEGFR2 and stimulate the differentiation of AMSCs to ECs. These findings provide a potential mechanism for the regulatory role of MMP-2 and MMP-14 in the re-endothelialization of coronary arteries following intervention.