Mouse restin inhibits bovine aortic endothelial cell proliferation and causes cell apoptosis.

Restin, a homologous protein of endostatin, was found by Ramchandran et al. It was the C-terminal fragment of type XV collagen. To analysis the inhibition activity of mouse restin on the proliferation of endothelial cells, the cDNA of restin was amplified from the total RNA of the mouse muscle and cloned into the prokaryotic expression plasmid pQE32. The recombinant protein was expressed in inclusion body with a yield about 60%--70% of total protein. After refolding, the purified recombinant protein specifically inhibits bovine aortic endothelial (BAE) cell proliferation stimulated by basic fibroblast growth factor (bFGF) in a dose-dependent manner, but the activity of restin was weaker than that of endostatin. Treatment of BAE cell with recombinant restin caused G(1) arrest and apoptosis in BAE cells.