Prostaglandin F_2α-PTGFR signalling activation, growth factor expression and cell proliferation in bovine endometrial...

The endometrium of domestic animals undergoes regular periods of regeneration and degeneration and exhibits a remarkable capacity for self-repair during the oestrous cycle. The endometrial growth pattern is also observed during in the implantation period and early pregnancy, but the mechanism underlying endometrial growth in these processes remains unclear. A positive correlation between endometrial growth in these processes and prostaglandin (PG) F_2α secretion has been reported, but the roles that PGF_2α plays in endometrial growth is less studied. In the present study, cell proliferation and the responses of a series of growth factors essential for endometrial growth to PGF_2α receptor (PTGFR) activation were investigated in bovine endometrial explants in vitro. Using real-time reverse transcription-polymerase chain reaction and western blotting, mRNA and protein expression of connective tissue growth factor, fibroblast growth factor2, interleukin8, matrix metalloproteinase2, transforming growth factor β1 and vascular endothelial growth factor A was increased (P<0.05) and cell proliferation, including epithelial and fibroblast proliferation, was induced in response to increased levels of proliferating cell nuclear antigen, cytokeratin-18 and fibroblast-specific protein-1 (P<0.05) following PTGFR activation by adding fluprostenol (10^-9-10^-5 M) into culture medium of bovine endometrial explants. However, caspase-3 protein expression was reduced following treatment of explants with fluprostenol (10^-9-10^-5 M, P<0.05). These results may help define the possible roles the PGF_2α-PTGFR signalling pathway plays in endometrial growth.