[Effects of chelerythrine on cell proliferation and p27 expression of cardiac fibroblasts modulated by arginine vasopressin].
OBJECTIVE
To study the effects of chelerythrine, a protein kinase C (PKC) inhibitor, on the cell proliferation and p27 expression of cardiac fibroblasts (CFs) modulated by arginine vasopressin (AVP) and to investigate the intracellular signal transduction mechanisms of AVP in CFs.


METHODS
The cultured CFs of neonatal Sprague-Dawley rats were divided into 3 groups: AVP group (10(-7) mol/L AVP was added into the culture), chelerythrine group (10(-6) mol/L chelerythrine and 10(-7) mol/L AVP were added into the culture), and control group. MTT assay was used to evaluate the cell proliferation. The cultured cells were collected and propidium iodide was used to label the DNA so as to identify the cell cycle. Specific mouse-versus-rat p27 protein monoclonal antibody and fluorescein isothiocyanate-labeled secondary antibody were added into the cell suspension to label the p27 protein in the cells. Flow cytometry was used to determine the distribution of cell cycles and p27 expression.


RESULTS
(1). The A value of CFs measured by MTT assay in AVP + chelerythrine group was 0.32 +/- 0.01, significantly lower than that of the AVP group (0.39 +/- 0.01, P < 0.01). (2). The percentage of CFs in S stage was 4.4% +/- 1.7% in the AVP + chelerythrine group, lower than those of the AVP group (15.5% +/- 1.4%, P < 0.01) and control group (7.5% +/- 1.0%). The PI of CFs was 20.9% +/- 1.2% in the AVP + chelerythrine group, significantly lower than that of the AVP group (31.4% +/- 1.5%, P < 0.01). The PI of the AVP group was significantly lower than that of the control group (26.0% +/- 1.0%, P < 0.01). The percentage of CFs in G(0)/G(1) stage was 79.1% +/- 1.2% in the AVP + 1 chelerythrine group, significantly higher than that in the AVP group (68.6% +/- 1.5%, P < 0.01). The percentage of CFs in G(0)/G(1) stage in the AVP group was significantly lower than that in the control group (74.0% +/- 1.0%, P < 0.01) too. (3). The expression rate of p27 protein was 91.7% +/- 2.2% in the AVP + chelerythrine group, significantly higher than that in the AVP group (63.3% +/- 1.9%, P < 0.01).


CONCLUSIONS
PKC inhibitor remarkably reverses the CFs proliferation and p27 downregulation induced by AVP. It may be involved in the intracellular signal transduction pathway of AVP in CFs.
Zhao
Lian-You
LY
Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
Chen
Yong-Qing
YQ
Tian
Jian-Wei
JW
Wang
Shi-Wen
SW
Peng
Yu-Hong
YH
Yang
Xue-Dong
XD
Xu
Lin
L
Fan
Yan-Hong
YH
D000470:Alkaloids; D000818:Animals; D000831:Animals, Newborn; D001127:Arginine Vasopressin / Q000494:pharmacology*; D053119:Benzophenanthridines; D018797:Cell Cycle Proteins; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism; D009206:Myocardium / Q000166:cytology*; D010617:Phenanthridines / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D025521:Tumor Suppressor Proteins
D000470:Alkaloids; D053119:Benzophenanthridines; C493962:Cdkn1b protein, rat; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D010617:Phenanthridines; D025521:Tumor Suppressor Proteins; D001127:Arginine Vasopressin; D050760:Cyclin-Dependent Kinase Inhibitor p27; C016299:chelerythrine; D011493:Protein Kinase C