Keratinocyte growth factor: Expression by endometrial epithelia of the porcine uterus

Keratinocyte growth factor/fibroblast growth factor-7 (KGF/FGF-7) is an est ablished paracrine mediator of hormone-regulated epithelial growth and diff erentiation. In all organs studied, KGF is uniquely expressed in cells of m esenchymal origin. To determine whether KGF and its receptor, keratinocyte growth factor receptor (KGFR) or fibroblast growth factor receptor-2IIIb, w ere expressed in the porcine uterus as a potential paracrine system mediati ng progesterone action, we cloned KGF and KGFR partial cDNAs from the porci ne endometrium. KGF and KGFR expression was detected in endometrium by Nort hern blot hybridization. Interestingly, in situ hybridization results demon strated that KGF was expressed by endometrial epithelia and was particularl y abundant between Days 12 and 15 of the estrous cycle and pregnancy, KGF s ecretion into the lumen of the porcine uterus was also detected on Day 12 o f the estrous cycle and pregnancy. KGFR was expressed in both endometrial e pithelia and conceptus trophectoderm. These novel findings suggest that KGF may act on the uterine endometrial epithelium in an autocrine manner and o n the conceptus trophectoderm in a paracrine manner in the pig, which is th e only species possessing a true epitheliochorial type of placentation.