Prostaglandin E induced cardiac hypertrophy through EP2 receptor-dependent activation of β-catenin in 5/6 nephrectomy rats.

Aims: Prostaglandin E (PGE2) is involved in the development of cardiac hypertrophy. However, whether PGE2 regulates the chronic kidney disease-associated cardiac hypertrophy and the tentative mechanism remains to be elucidated.

Methods And Results: We explored the effect of PGE2 receptor inhibitors on cardiac hypertrophy in vitro and in a 5/6 nephrectomy (5/6NT) rat model using quantitative reverse transcription polymerase chain reaction, western blotting, enzyme-linked immunosorbent assay, immunohistochemical staining, and immunofluorescence staining assays. The result showed that EP2 and EP4 receptors were both up-regulated in the PGE2-treated cardiomyocyte cells. PGE2 treatment enhanced active β-catenin (non-phosphorylated) signalling through mediating EP2 and EP4 receptors. Interestingly, inhibition of EP2 receptor suppressed PGE2-induced cardiomyocyte hypertrophy and cardiac fibrosis-related proteins in vitro. In the 5/6NT rat model, the increased secretion PGE2 was identified in the 5/6NT rat model for 2 weeks (P = 0.0251). EP2 receptor inhibitor administration significantly improved the cardiac function and fibrosis in 5/6NT rats.

Conclusions: Our study demonstrated that inhibition of EP2 receptor could improve PGE2-induced cardiac hypertrophy in 5/6NT rats. The exploration of these mechanisms may contribute to the optimization of therapy in chronic kidney disease accompanied cardiac hypertrophy in clinic.