[Effect of cordyceps sinensis extract on Klotho expression and apoptosis in renal tubular epithelial cells induced by angiotensin II].
OBJECTIVE
To investigate the effect of cordyceps sinensis (CS) extract and losartan (Los) on the expression of Klotho (Kl), P53, P21, and apoptosis in renal tubular epithelial cell NRK-52E induced by angiotensin II (Ang II), and to elucidate its therapeutical mechanism in Ang II induced renal tubular epithelial cell apoptosis.


METHODS
NRK-52E cells were incubated with CS with or without Ang II for 24 hours. Experimental groups were divided according to the increasing concentrations of CS:0 (serving as controls), 5, 10, 20, 40, and 80 mg/L. The optimal concentration of CS was selected and cells were divided into 5 groups: controls, Ang II (1*10(-8) mol/L), Ang II (1*10(-8) mol/L)+CS (40 mg/L), Ang II (1*10(-8) mol/L)+Los (1*10(-5) mol/L), and Ang II (1*10(-8) mol/L)+CS (40 mg/L)+Los (1*10(-5) mol/L). After 24 hours, cell proliferation was evaluated by MTT assay. The mRNA and protein expression of Kl, P53 and P21 were measured by RT-PCR. Activity of caspase-3 was evaluated by caspase-3 activity assay Kit. Cell apoptosis was determined by Annexin V-FITC/PI double staining and flow cytometry.


RESULTS
Certain concentrations of CS promoted the proliferation of NRK-52E cells and increased cells proliferation inhibited by Ang II (P<0.01 or P<0.05 ). Ang II significantly down-regulated the mRNA and protein expression of Kl, and up-regulated the levels of P53 and P21. Caspase-3 activity and apoptotic rates were decreased, too (all P values<0.01). CS or/and Los significantly increased the expression of Kl mRNA and protein down-regulated by Ang II, decreased P53 mRNA and protein expression, P21 mRNA and protein expression,and inhibited caspase-3 activity and apoptotic rates(all P values<0.05). No cooperative effects were observed in the two drugs (P>0.05).


CONCLUSIONS
CS can increase the expression of Kl down-regulated by Ang II, decrease P53 and P21 expression and caspase-3 activity, and reduce Ang II induced NRK-52E cell apoptosis, which may be part of its mechanism of the protective effects on hypertensive renal damage.
Tang
Rong
R
Department of Nephrology, Xiangya Hospital, Central South University, Changsha 410008, China.
Zhou
Qiaoling
Q
Shu
Jinyong
J
Tang
Tianfeng
T
Ao
Xiang
X
Peng
Weisheng
W
Zhang
Yide
Y
D000804:Angiotensin II / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D032661:Cordyceps / Q000737:chemistry*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007684:Kidney Tubules / Q000166:cytology / Q000378:metabolism*; D000090265:Klotho Proteins; D019808:Losartan / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D000804:Angiotensin II; D005966:Glucuronidase; D000090265:Klotho Proteins; C505407:CASP3 protein, human; D053148:Caspase 3; D019808:Losartan