Inhibitory effect of cyclosporin A on growth and collagen synthesis of rat cardiac fibroblasts induced by arginine vasopressin.
OBJECTIVE
To investigate the effects of cyclosporin A (CsA) on growth and collagen synthesis of cardiac fibroblasts (CFs) induced by arginine vasopressin (AVP).


METHODS
CFs of neonatal Sprague-Dawley rats were isolated by trypsinization and cultured; growth-arrested CFs were stimulated with 1 x 10(-7) mol x L(-1) AVP in the presence or absence of CsA (0.05, 0.5 and 5 micromol x L(-1)). MTT and flow cytometry techniques were adopted to measure cell number and analyze cell cycle respectively. Collagen synthesis was determined by measurement of hydroxyproline content in culture supernatant with colorimetry. Calcineurin activity was estimated by chemiluminescence. Trypan blue staining to test the viability of CFs.


RESULTS
0.05, 0.5 and 5 micromol x L(-1) CsA inhibited the increase of CFs number induced by 1 x 10(-7) mol x L(-1) AVP in a dose-dependent manner, with the inhibitory rates by 12%, 24% and 29%, respectively (P < 0.05). Furthermore, cell cycle analysis showed 0.5 micromol x L(-1) CsA decreased the S stage percentage and proliferation index of CFs stimulated by AVP (P < 0.05). In culture medium, the hydroxyproline content induced by AVP decreased by 0.5 and 5 micromol x L(-1) CsA (P < 0.05), with the inhibitory rates of 29% and 33%, respectively. CsA completely inhibited the increment of calcineurin activity induced by AVP (P < 0.01), but CsA itself had no effect on the baseline of calcineurin activity and CFs viability.


CONCLUSIONS
CsA inhibits proliferation and collagen synthesis of CFs by virtue of blocking calcineurin signaling pathway and might provide a novel target for prevention and treatment to cardiac fibrosis.
Shang
Fu-jun
FJ
Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi' an 710038, China.
Zhao
Lian-you
LY
Zheng
Qiang-sun
QS
Wang
Jie-pin
JP
D000818:Animals; D000831:Animals, Newborn; D001127:Arginine Vasopressin / Q000494:pharmacology*; D019703:Calcineurin / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis*; D016572:Cyclosporine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006909:Hydroxyproline / Q000378:metabolism; D009206:Myocardium / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley
D001127:Arginine Vasopressin; D016572:Cyclosporine; D003094:Collagen; D019703:Calcineurin; D006909:Hydroxyproline