Transforming growth factor-? conjugated with cytotoxin saporin inhibits specifically proliferating vascular smooth muscle cells / 中国药理学通报

ABSTRACT

AIM To testify the special cytotoxicity of TGF? SAP on proliferating vascular smooth muscle cells and endothelial cells. METHODS Conjugation of saporin to TGF? was accomplished after derivatization of saporin and TGF? with N succinimidyl 3 (2 pyridyldithio) proprionate. Cytotoxicity assays were measured by cell count. The studies of influence of TGF? SAP on values of thymidine and leucine incorporation into SMCs and ECs were measured by 3H thymidine uptake and 3H leucine uptake, respectively. RESULTS Cytotoxicity assays testified TGF? SAP conjugate could inhibit remarkably proliferation of SMCs in culture. The values of thymidine of TGF? SAP group (1?10 -9 mol?L -1 and 1?10 -7 mol?L -1 ) in comparison significantly decreased to 60 9% and 56 0% of the control group respectively, suggesting that cellular DNA synthesis obviously decreased as TGF? SAP was added. But saporin did not affect cellular DNA synthesis at higher level. The rate of 3H leucine incorporation of TGF? SAP group significantly decreased to 47 3% of the control group, suggesting that SMCs protein synthesis obviously decreased as TGF? SAP was added. But TGF? SAP at the same level did not affect DNA synthesis and protein synthesis of ECs compared with the control group. CONCLUSION TGF? SAP possesses the more effective cytotoxicity than saporin and the more specific citotoxicity on proliferating vascular smooth muscle cells than on proliferating endothelial cells.