The Regulatory Effect of VEGF-Ax on Rat Bone Marrow Mesenchymal Stem Cells' Angioblastic Differentiation and Its Proangiogenic Ability.

Vascular endothelial growth factor A (VEGFA), which plays a key role in angiogenesis, is composed of many isoforms. Distinct VEGFA isoforms are generated by alternative splicing of VEGFA mRNA and named as VEGF _xxx , where _xxx represents the number of amino acids present in the final protein sequence. These isoforms have opponent pro- and antiangiogenic effects. VEGF-Ax, an additional isoform containing a 22-amino-acid extension in the COOH terminus, arising from VEGFA mRNA, programmed translational readthrough. The function of VEGF-Ax is not clear, especially the conclusion that VEGF-Ax regulates angiogenesis is contradictory. Thus, we investigated the effect of VEGF-Ax on differentiation and angiogenesis of rat bone marrow mesenchymal stem cells (BMMSCs). The results showed that VEGF-Ax could promote the proliferation and migration of BMMSCs, stimulate the differentiation of BMMSCs into endothelial cell-like cells, and protect BMMSCs from endoplasmic reticulum stress-induced apoptosis.