[Effect of rapamycin on proliferation of rat heart valve interstitial cells in vitro].
OBJECTIVE
To investigate the effect of rapamycin on the proliferation of rat valvular interstitial cells in primary culture.


METHODS
The interstitial cells isolated from rat aortic valves were cultured and treated with rapamycin, and the cell growth and cell cycle changes were analyzed using MTT assay and flow cytometry, respectively. RT-PCR was used to detect mRNA expression levels of S6 and P70S6K in cells, and the protein expressions level of S6, P70S6K, P-S6, and P-P70S6K were detected using Western blotting.


RESULTS
Rat aortic valvular interstitial cells was isolated successfully. The rapamycin-treated cells showed a suppressed proliferative activity (P<0.05), but the cell cycle distribution remained unaffected. Rapamycin treatment resulted in significantly decreased S6 and P70S6K protein phosphorylation level in the cells (P<0.05).


CONCLUSIONS
The mechanism by which rapamycin inhibits the proliferation of valvular interstitial cells probably involves suppression of mTOR to lower S6 and P70S6K phosphorylation level but not direct regulation of the cell cycle.
Southern Medical University, Guangzhou 510515, China. E-mail: 82959011@qq.com.
Yan
Y
Tan
Ji-Ye
JY
Wang
Ren-Liang
RL
Yi
Jian
J
Qiu
D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D006351:Heart Valves / Q000166:cytology*; D010766:Phosphorylation; D051381:Rats; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D020123:Sirolimus / Q000494:pharmacology*
D038762:Ribosomal Protein S6 Kinases, 70-kDa; D020123:Sirolimus