Mitogen-activated protein kinases and cardiomyocyte hypertrophy

Because p38 Mitogen-activated protein kinases is a stress-activated kinase, its activation and function has been studied in cardiomyocyte hypertrophy. Both p38a and p38b activity were increased during the progression of hypertrophy. Activation of the p38 pathway by the introduction of constitutively active MKK6- and MKK3-elicited hypertrophic responses, including an increase in cell size, enhanced sarcomeric organisation and elevated atrial natriuretic factor expression. Furthermore, p38a and p38b appear to have different functions in cardiomyocytes. p38b seems to be more potent in inducing hypertrophy, whereas p38a appears to be more important in cardiomyocyte apoptosis. In this review, we summarize the characteristics of the major components of the p38 signalling transduction pathway and role of them in cardiomyocyte hypertrophy