Roles And Signal Transduction Of Cardiotrophin-lin Promotion Of Cardiac Fibroblasts Growth

OBJECTIVE: To elucidate the roles and signaling pathways of cardiotrophin-1 (CT-1) in promotion of cardiac fibroblasts growth, and the relationship between CT-1 regulation of cardiac fibroblasts proliferation and the two genes: Bad (Promoter of apoptosis) and Id3(inhibitor of differentiation) METHODS: Cardiac fibroblasts were isolated from the ventricles of 1-3-day Sprague-Dawley neonatal rats and primarily cultured (digestion, different speed adherence method) ,then passaged to 3-4 generation for experiment. These cells were divided into five groups according to the different intervention factors: (1)control group (C), (2)pressure group( 160mmHg) (P), (3)pressure + CT-1 anti-sense oligonucleotide group(AS-ODN),(4)pressure + sense oligonucleotide group (S-ODN), (5) pressure + AG490 (Jak/STAT3 inhibitor) group (AG490), except control group, The rest of 4 groups were cultured via pressure(high hydrostatic pressure in vitro) for 8 hours. Cell proliferation was quantified by Mono-nuclear cell direc cytotoxicity assay (MTT assay), protein of Cardiotrophin-1 (CT-1) was determined by Western-blotting analysis, and mRNA expression of STAT3, Bad and Id3 were detected by RT-PCR analysis. RESULTS:(1) Compared with C, P group stimulated the proliferation of cardiac fibroblasts(0.153±0.011 vs 0.115±0.012, p<0.01),up-regulated the expression of CT-1 ( 1.56±0.24 vs 0.95±0.19, p<0.05 ) and increased the expression of STAT3mRNA (0.539±0.013 vs 0.398±0.011,P<0.05) and BadmRNA( 0.513± 0.025vs 0.325±0.023,P<0.05), but didn't significantly change the expression of Id3mRNA ( 0.592±0.019 vs 0.567±0.026,P>0.05). (2) Compared with p group, CT-1ASODN inhibited the proliferation of cardiac fibroblasts(0.132±0.13 vs 0.153±0.11, p<0.05), which also decreased the expression of STAT3mRNA (0.518±0.012vs 0.353±0.014 P<0.05), BadmRNA (0.502±0.022 vs 0.313±0.019,...