Expression of Heparin-Binding EGF-Like Growth Factor (HB-EGF) in Bovine Endometrium: Effects of HB-EGF and Interferon-τ on Prostaglandin Production.

Abstract

Heparin-binding EGF-like growth factor (HB-EGF) regulates several cell functions by binding to its membrane receptor (ErbB1 and ErbB4). Experimental evidences suggest that HB-EGF, prostaglandins (PGs) and interferon-τ (IFN-τ) regulate uterine function for pregnancy establishment in ruminants. In this study, the mRNA expressions of HB-EGF, ErbB1 and ErbB4 in bovine endometrium and the effects of HB-EGF and IFN-τ on PGE2 and PGF2-α production by endometrial cells were investigated. RT-PCR analysis revealed that HB-EGF mRNA was greater at the mid-luteal stage than at the early and regressed luteal stages (p<0.05). ErbB1 mRNA expression was greater at the mid- and late luteal stages than at the other luteal stages (p<0.05). IFN-τ increased the expression of HB-EGF, ErbB1 and ErbB4 mRNA in epithelial cells (p<0.05). HB-EGF did not affect PGF2-α or PGE2 production by bovine endometrial epithelial cells, but increased PGF2-α and PGE2 production by bovine endometrial stromal cells (p<0.05). IFN-τ significantly decreased HB-EGF-stimulated PGF2-α (p<0.05), but not PGE2 (p>0.05) production by stromal cells. These results indicate that HB-EGF and its receptors expression changed in bovine endometrium throughout the oestrous cycle. IFN-τ increased their expression in cultured endometrial cells. HB-EGF and IFN-τ have the ability to regulate PGs production by stromal cells and therefore may play a role in the local regulation of uterine function at the time of implantation in cattle.