Transforming growth factor-beta 1 at different concentrations induces the differentiation of bone marrow derived mesenchymal stem cell into smooth muscle-like cell

Yi CHEN; Wenwei CAI; Jing SHENG

ABSTRACT

BACKGROUND:

Bone marrow derived mesenchymal stem cells (BMSCs) will be homing to the lesions after balloon injury in the inflammatory reaction process.However,the molecular mechanism of transforming growth factor-β1 (TGF-β1) to promote BMSC into smooth muscle-like cell remains unclear.

OBJECTIVE:

To investigate the BMSC differentiation rate under different TGF-β1 levels after acute vascular injury.DESIGN,TIME AND

SETTING:

A randomized controlled animal experiment and in vitro induced cell observation were performed at the SPF Laboratory Animal Center and Laboratory of Tissue Engineering,Ninth People's Hospital of Shanghai Jiao Tong University Medical School between January 2008 and May 2009.MATERIALSA total of 24 male SD rats were randomly divided into normal control and model groups with 12 animals in each group.In addition,6 4-weak-old male SD rats were used to prepare BMSCs.

METHODS:

Model of acute carotid artery injury was established in model group.Serum of normal control group and model group after 1,3,7 days of injury to detect TGF-β1 level after the vascular injury by ABC-ELISA.The BMSCs after one passage were cultured at a density of (1.0-3.0)×10~5 cells/100 mm in culture dish,and divided into two groupsin routine culture group,cells were cultured in high-glucose DMEM containing 20% fetal bovine serum;in TGF-β1 group,cells were induced by different concentrations of TGF-β1 (1,3,5 and 10 μg/L) based on routine culture for 1 week.MAIN OUTCOME

MEASURES:

Serum TGF-β1 level after the vascular injury;,cell morphological changes by inverted phase contrast microscopy;smooth muscle α-actin expression.

RESULTS:

The normal serum TGF-β1 level in rat was low,but increased rapidly after 1 day of injury,reached its peak at 3 days,and declined gradually but did not return to the basic level till day 7.After 1 week of induction,BMSCs were confluent,forming peak valley appearance.Immunocytochemistry showed that compared with routine culture,the rate differentiation of smooth muscle-like cell was significantly increased in cells stimulated by TGF-β1,especially 5 and 10 μg/L TGF-β1 (P ＜ 0.01).Real-time quantitative PCR results were similar to immunocytochemistry.

CONCLUSION:

Serum TGF-β1 level increased after acute vascular injury and peaked at day 3.In vitro,a similar concentration of TGF-β1 could induce cultured BMSC to differentiate into smooth muscle-like cells.