The PDE1A-PKCalpha signaling pathway is involved in the upregulation of alpha-smooth muscle actin by TGF-beta1 in adventitial fibroblasts.
BACKGROUND
Increasing evidence has suggested that differentiation of adventitial fibroblasts (AFs) to myofibroblasts plays an important role in arterial remodeling. The molecular mechanisms by which myofibroblast formation is regulated still remain largely unknown. This study aimed to evaluate the role of cyclic nucleotide phosphodiesterase 1A (PDE1A) in the formation of adventitial myofibroblasts induced by transforming growth factor (TGF)-beta(1).


RESULTS
AFs were cultured by the explant method. Western blot and immunocytochemistry were applied for alpha-smooth muscle actin (SMA) or protein kinase C (PKC) alpha protein analysis. Results showed that TGF-beta(1) upregulated PDE1A protein expression in rat aortic AFs and pharmacological inhibition of PDE1A blocked TGF-beta(1)-induced alpha-SMA expression, a marker of myofibroblast formation, suggesting that the upregulation of PDE1A may mediate TGF-beta(1)-induced AF transformation. Moreover, calphostin C (a PKC inhibitor) inhibited TGF-beta(1)-induced alpha-SMA expression, whereas phorbol-12-myristate-13-acetate (a PKC activator) induced it. Finally, the upregulation of PKCalpha expression by TGF-beta(1) was also inhibited by PDE1A inhibition.


CONCLUSIONS
Taken together, our data suggest that TGFbeta(1) induces alpha-SMA expression and myofibroblast formation via a PDE1A-PKCalpha-dependent mechanism. Our study thus unveils a novel signaling mechanism underlying TGF-beta(1)-induced adventitial myofibroblast formation.
Zhou
Hai-Yan
HY
Shanghai Key Laboratory of Vascular Biology, Ruijin Hospital, and Laboratory of Vascular Biology, Health Science Center, Shanghai JiaoTong University School of Medicine and Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai Institute of Hypertension, State Key Laboratory of Medical Genomics, Shanghai, China.
Chen
Wen-Dong
WD
Zhu
Ding-Liang
DL
Wu
Ling-Yun
LY
Zhang
Jia
J
Han
Wei-Qing
WQ
Li
Jian-Dong
JD
Yan
Chen
C
Gao
Ping-Jin
PJ
D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D054338:Cell Transdifferentiation / Q000187:drug effects; D002478:Cells, Cultured; D003238:Connective Tissue / Q000187:drug effects / Q000201:enzymology*; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1 / Q000378:metabolism*; D020536:Enzyme Activators / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology*; D005455:Fluorescent Antibody Technique; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D051571:Protein Kinase C-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D015854:Up-Regulation
D000199:Actins; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D020536:Enzyme Activators; D009281:Naphthalenes; D010726:Phosphodiesterase Inhibitors; D051571:Protein Kinase C-alpha; D047428:Protein Kinase Inhibitors; D013755:Tetradecanoylphorbol Acetate; D053773:Transforming Growth Factor beta1; C498862:Acta2 protein, rat; C517263:Pde1a protein, rat; C058819:calphostin C