Involvement of p53-dependent pathway in the antiproliferative activity of emodin in human smooth muscle cell
Wang, X-fei.; Ge, J-bo.; Sun, A-jun.; Xu, D-ling.; Wang, K-qiang.
Zhonghua Xin Xue Guan Bing Za Zhi 34(1): 44-49
2006
ISSN/ISBN: 0253-3758 PMID: 16626549 Document Number: 598971
Objective To investigate whether p53 pathway participates in the effect of emodin on vascular smooth muscle cell proliferation. Methods The effects of emodin on vascular smooth muscle cell proliferation were evaluated by cell count, senescent-associated P-galactosidase staining, and annexin V staining. DNA synthesis was determeined by H-3-thymidine corporation, cell cycle was analyzed by FACS, the p53 protein level was measured by Western blot and cDNA expression array technology was used to demonstrate the effect of emodin on the simultaneous expression of a large number of genes in cultured vascular smooth muscle cells. Results Emodin at 1.6-3.1 mu g/ml inhibited VSMC growth, at 6.3-12.5 mu g/mlpromoted VSMC aging and induced VSMC apoptosis at 25.0 mu g/ml 24 hours after exposure. Unscheduled DNA synthesis, which was a sensitive indicator for DNA injury, was observed in VSMC following 24 hours emodin exposure. The mRNA and protein levels of p53 were up-regulated in a concentration-dependent manner. Proliferation/carcinogenesis-related genes were down-regulated and other genes related to cell senescence, apoptosis, and DNA damage/repair were up-regulated in VSMC after exposure to emodin for 24 hours. Emodin readily permeated VSMC membrane and mostly located in the cytoplasm and few of them in the nucleus. Conclusions The p53 pathway in VSMC was activated post emodin exposure in a concentration-dependent manner and which might be responsible for the observed anti proliferative effects of emodin in vascular smooth muscle cells.