Immunohistochemical Expressions of Main PGE2 Biosynthesis-related Enzymes and PGE2 Receptor in Rat Nephrogenesis

摘要

Endogenous prostaglandin (PG) E2 plays important roles in renal homeostasis.Immunoexpressions of PGE2 biosynthesis-related enzymes, cyclooxygenase (COX)-2and microsomal PGE2 synthetase (mPGES)-1 and EP4 (a PGE2 receptor),were investigated in renal development. Kidney tissues were obtained from fetuses ongestation days 18 and 21 and neonates on days 1 to 18. In fetuses and early neonates, theexpressions of COX-2, mPGES-1 and EP4 were observed in developing renal tubules,indicating that COX-2 and its product, PGE2, play important roles in blastemalcell-derived renal tubular development via EP4. Cyclin D1 expression was seen in both thenucleus and cytoplasm of the developing tubules. These findings differed from thedecreased COX-2 expression and exclusive nuclear expression of cyclin D1 seen in abnormalepithelial regeneration of injured renal tubules in cisplatin-treated rats in our previousarticles. Collectively, PGE2, induced by COX-2, regulates renal tubularepithelial formation via EP4.