[Translocation of p38 MAPK induced by retinoic acid in H9c2 cells]

To study the distribution of p38 MAPK and translocation of p38 induced by all-trans retinoic acid (atRA) in cardiomyocytes.

H9c2 cells were cultured in the normal growth medium containing 10% fetal bovine serum. Cells were serum-starved overnight followed by atRA (0.05 micromol/L) treatment or SB202190 (10 micromol/L) pretreatment. The localization of p38 under different conditions was detected by Confocal Laser Scanning Microscopy. Then the ratio of p38 localized in nuclei to cytoplasm was analyzed by a Leica Microsystem. Thus, the statistical analysis of these data showed the effects of atRA or SB202 190 on p38 translocation.

p38 was located more in the cytoplasm without stimulation, while in the cells with atRA treatment for 5 min and 30 min, p38 labeled with green fluorescence in the cytoplasm decreased. The p38 ratio of nuclei to cytoplasm showed that there was a significant difference between atRA groups and control. As the specific inhibitor of p38, SB202190 could obviously inhibited the nuclear translocation of p38 induced by atRA (P < 0.01). And compared with control, SB202190 could make the nuclear translocation of p38 decrease by 26.1%.

atRA could induce the nuclear translocation of p38 in cardiomyocytes. And p38 pathway might participate in the regulation of heart development.