Effect of inhibition of glycogen synthase kinase-3 on cardiac hypertrophy during acute pressure overload

Myocardial hypertrophy has been recognized to be an adaptive response to a variety of external stimuli (e.g., myocardial infarction, pressure overload, catecholamine treatment, endocrine disorders) that are involved in several subcellular factors that mediate signaling pathways, from external stimuli to nuclear protein synthesis. Glycogen synthase kinase-3β (GSK-3β) is one of the subcellular factors that regulate nuclear transcription factors, such as activated T-cell (NFAT) proteins, that are related to gene programming during cardiac hypertrophy. On the other hand, GSK-3β, known as a regulator of cardiomyocyte growth in Wnt signaling of cardiogenesis, is involved in β-catenin degradation. Inhibition of GSK-3β has been reported to induce cardiac hypertrophy. Tateishi et al. demonstrated in an aortic constriction-induced acute hypertrophy model using 6-week-old Wister rats that if GSK-3b is inhibited by LiCl up-regulated β-catenin expression and additional hypertrophy were observed. They suggested that Li2+ had an additive effect on pressure overload-induced hypertrophy through the GSK-3β-β-catenin pathway. Their article provides promising information on the mechanism of hypertrophic myocyte growth during acute pressure overload. © 2010 The Japanese Association for Thoracic Surgery.