The effect of prostaglandin E2 receptor (PTGER2) activation on growth factor expression and cell proliferation in bovine endometrial explants

Abstract

The domestic animal endometrium undergoes regular periods of regeneration and degeneration during cycles of oestrus and dioestrus. If blastocyst implantation occurs in the uterus, the endometrium will prepare for pregnancy by changing its pattern of development to build a connection with the embryo to nourish it. Prostaglandin E₂ (PGE₂) secretion synchronized with endometrial growth in these processes and could be involved in endometrial growth. One of the PGE₂ receptors (PTGER2) is present in endometrium and its increased expression accompanies with endometrial growth in above processes. However, the association between PTGER2 and endometrial growth remains unclear. Endometrial growth factors and cell proliferation is the foundation for endometrial growth. Therefore, in this study, the response of growth factors and cell proliferation essential for endometrial growth to PTGER2 activation were investigated in bovine endometrium. The results indicated that mRNA and protein expression of connective tissue growth factor (CTGF), fibroblast growth factor-2 (FGF-2), interleukin-8 (IL-8), transforming growth factor-β1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and vascular endothelial growth factor A (VEGFA) were up-regulated after PTGER2 activation by corresponding agonist butaprost (P < 0.05), and proliferation of endometrial epithelia and fibroblasts were induced in response to increased levels of proliferating cell nuclear antigen (PCNA), cytokeratin-18 (CK-18) and fibroblast-specific protein 1 (FSP-1) expression in bovine endometrial explants in vitro (P < 0.05).

Keywords: Bovine endometrium; Cell proliferation; Growth factors; PTGER2.