Human connective tissue growth factor expressed in Escherichia coli is a non-mitogenic inhibitor of apoptosis

After cloning and sequencing chicken connective tissue growth factor (cCTGF) we showed that in serum-deprived chicken embryo fibroblasts (CEF) the initial decline of cCTGF mRNA was followed by an increase. Human CTGF that was produced as a soluble protein in Escherichia coli by thioredoxin co-expression inhibited serum-deprivation induced apoptosis of CEF at I(50) of approximately 8pM, demonstrating a function of CTGF at concentrations observed in supernatants of fibroblasts. CTGF was neither mitogenic for CEF nor for other cell types. In conclusion CTGF supports very efficiently survival of certain cells without stimulating their cell growth.