Differentiation of vascular myofibroblasts induced by transforming growth factor-beta1 requires the involvement of protein kinase Calpha.
In response to vascular injury, adventitial fibroblasts can modulate their phenotype to myofibroblasts, cells that participate in arterial remodeling. However, the signaling mechanisms underlying the vascular myofibroblast differentiation remain unknown. Since protein kinase C (PKC) is a key enzyme for cell differentiation, we examined whether PKC isoforms were involved in the vascular myofibroblast differentiation. The association between PKCalpha and myofibroblast differentiation was investigated in cultured rat aortic fibroblasts treated with transforming growth factor-beta1 (TGFbeta1). Confocal immunofluorescence microscopy indicated that fibroblasts expressed alpha-smooth muscle actin (alpha-SM actin) after TGFbeta1 treatment. Moreover, TGFbeta1 stimulation increased both PKCalpha mRNA expression (measured by real-time quantitative RT-PCR) and PKC activity (determined by histone-like pseudosubstrate phosphorylation) in adventitial fibroblasts. Western blot analysis indicated that PKCalpha protein expression was higher in TGFbeta1-treated fibroblasts than in untreated cells. TGFbeta1-induced expression of alpha-SM actin was inhibited in a dose-dependent manner by treating cells with a PKC inhibitor, calphostin C, and was abolished by depleting PKCalpha with antisense PKCalpha oligodeoxynucleotides. Our results demonstrate that TGFbeta1 induces adventitial myofibroblast differentiation via a PKCalpha-dependent process.
Gao
Ping J
PJ
Department of Vascular Biology, Shanghai Institute of Hypertension, State Key Laboratory for Medical Genomics, Ruijin Hospital, Shanghai Health Science Center, Shanghai Second Medical University, 197, Ruijing 2nd Road, Shanghai 200025, China.
Li
Yan
Y
Sun
Ai J
AJ
Liu
Jian J
JJ
Ji
Kai D
KD
Zhang
Yu Z
YZ
Sun
Wei L
WL
Marche
Pierre
P
Zhu
Ding L
DL
D000199:Actins / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D009281:Naphthalenes / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D051571:Protein Kinase C-alpha; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D000199:Actins; D004791:Enzyme Inhibitors; D009281:Naphthalenes; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; C058819:calphostin C