Involvement of ERK and AKT signaling in the growth effect of arginine vasopressin on adult rat cardiac fibroblast and the modulation by simvastatin.
Arginine vasopressin (AVP) has been shown to directly induce neonatal rat cardiac fibroblasts (CFs) proliferation, a major component involved in cardiac hypertrophy. Herein, we explored whether AVP is also a growth factor for adult rat CFs and, if so, whether the growth effect could be inhibited by simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. AVP significantly increased DNA synthesis in adult rat CFs by 73.5 +/- 5.1% (P < or = 0.05), an effect inhibited by V1 receptor antagonist, d(CH(2))(5)[Tyr(2)(Me), Arg(8)]-vasopressin. AVP also activated extracellular signal-regulated kinase 1/2 (ERK1/2) as assessed by MBP phosphotransferase activity (5.1 +/- 0.6 fold over basal level, P < or = 0.05) and Western blot analysis, and effects were mimicked by protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), but abolished by inhibiting cellular PKC through chronic PMA incubation. In addition, AVP induced PKC activation (27.2 +/- 3.8% from a basal value of 9.3 +/- 0.7%, P < or = 0.05). AVP-induced increase in DNA synthesis could be attenuated by the specific inhibitors of ERK1/2 (PD98059), PI3K (LY294002), and AKT (1L-6-hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate, HIMO). Simvastatin inhibited the effects of AVP on DNA synthesis, ERK1/2, and PKC activation in a dose-dependent manner. Phosphatidylinositol-3-kinase (PI3K)-dependent AKT activation induced by AVP was also inhibited by simvastatin. The effects of simvastatin on ERK1/2, PKC, and AKT activation and DNA synthesis could be reversed by mevalonate. These results support a growth-inducing effect of AVP on adult rat CFs through ERK and AKT signalings and the growth effect could be attenuated by simvastatin via inhibiting these two pathways.
He
Yan-Ping
YP
Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, No. 1, Xinsi Street, Baqiao District, Xi'an, Shaanxi, 710038, People's Republic of China.
Zhao
Lian-You
LY
Zheng
Qiang-Sun
QS
Liu
Shao-Wei
SW
Zhao
Xiao-Yan
XY
Lu
Xiao-Long
XL
Niu
Xiao-Lin
XL
Li
Xia
X
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008798:Mevalonic Acid / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009206:Myocardium / Q000166:cytology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D019821:Simvastatin / Q000494:pharmacology*
D001127:Arginine Vasopressin; D004247:DNA; D019821:Simvastatin; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D011493:Protein Kinase C; D048049:Extracellular Signal-Regulated MAP Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D008798:Mevalonic Acid