Neferine inhibits angiotensin II-stimulated proliferation in vascular smooth muscle cells through heme oxygenase-1.
OBJECTIVE
To explore the effect of neferine on angiotensin II (Ang II)-induced vascular smooth muscle cell (VSMC) proliferation.


METHODS
Human umbilical vein smooth muscle cells (HUVSMCs) were used. Cell proliferation was determined by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis. Heme oxygenase (HO)-1 protein expression was tested by Western blot analysis. Extracellular signal-regulated protein kinase 1/2 (ERK1/2) activation was determined by using immunoblotting.


RESULTS
Pre-incubation of HUVSMCs with neferine (0.1, 0.5, 1.0, and 5.0 micromol/L) significantly inhibited Ang II-induced cell proliferation in a concentration-dependent manner and neferine 5.0 micromol/L increased HO-1 expression by 259% compared with control. The antiproliferative effect of neferine was significantly attenuated by coapplication of zinc protoporphyrin IX (ZnPP IX, an HO-1 inhibitor) with neferine. Ang II-enhanced ERK1/2 phosphorylation was markedly reversed by neferine. By inhibiting HO-1 activity with ZnPP IX, the inhibitive effect of neferine on ERK1/2 phosphorylation was significantly attenuated. Cobalt-protoporphyrin (CoPP), an HO-1 inducer, significantly decreased Ang II-induced ERK1/2 phosphorylation and inhibited Ang II-induced cell proliferation. The ERK1/2 pathway inhibitor PD98059 significantly blocked Ang II-enhanced ERK1/2 phosphorylation and inhibited cell proliferation.


CONCLUSIONS
These findings suggest that neferine can inhibit Ang II-induced HUVSMC proliferation by upregulating HO-1, leading to the at least partial downregulation of ERK1/2 phosphorylation.
Li
Xiao-chun
XC
Department of Geratology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Tong
Guo-xin
GX
Zhang
Yu
Y
Liu
Shan-xin
SX
Jin
Qi-hui
QH
Chen
Huai-hong
HH
Chen
Peng
P
D000804:Angiotensin II / Q000494:pharmacology*; D044182:Benzylisoquinolines / Q000494:pharmacology*; D015153:Blotting, Western; D002316:Cardiotonic Agents / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*
D044182:Benzylisoquinolines; D002316:Cardiotonic Agents; D004365:Drugs, Chinese Herbal; D000804:Angiotensin II; C057222:neferine; D051547:Heme Oxygenase-1; D048049:Extracellular Signal-Regulated MAP Kinases