Transforming growth factor-beta increases the expression of vascular smooth muscle cell markers in human multi-lineage progenitor cells.

Vascular smooth muscle cell (SMC) differentiation is an essential component of vascular repair and tissue engineering. However, currently used cell models for the study of SMC differentiation have several limitations. Multi-lineage progenitor cells (MLPCs) originate from human umbilical cord blood and are cloned from a single cell. The object of this study was to investigate whether MLPCs could differentiate into SMCs in vitro with induction by transforming growth factor beta1 (TGF-beta1). MLPCs were treated without or with TGF-beta1 (1 and 5 ng/mL) in mesenchymal stem cell media plus 1% FBS for 7 days. Total RNA was isolated from the MLPCs, and semi-quantitative real-time PCR was performed to test the following mRNA levels: early and late phase SMC-specific markers, two endothelial cell (EC)-specific markers, endothelial progenitor cell (EPC) marker CD34, TGF-beta1 accessory protein CD105, and adhesion molecule CD146. TGF-beta1 (1 ng/mL) significantly increased the mRNA levels of SMC-specific markers SM22α, calponin-1, SM α-actin, caldesmon, tropomyosin and MLCK as well as adhesion molecule CD146. The mRNA levels of EC-specific markers VE-cadherin and VEGFR-2, EPC marker CD34 and TGF-beta1 accessory protein CD105 were decreased significantly, after MLPC were treated with TGF-beta1 (1 ng/mL). TGF-beta1 at 5 ng/mL showed similar effect on the expression of these genes. This study demonstrates that in the presence of TGF-beta1, MLPCs undergo SMC lineage differentiation indicating that MLPCs are a promising cell model for SMC lineage differentiation studies, which may contribute to advances in vascular repair and tissue engineering.