The hepatocyte growth factor system in menstruation and post-menstrual endometrial repair (#283)
Objective: Characterize the HGF/c-MET paracrine system during menstruation and post-menstrual endometrial repair.
Design: Studies of archived samples and in vitro studies on endometrial cell lines.
Materials and Methods: Ovariectomized rhesus macaques were treated with estradiol and progesterone to induce artificial 28-day menstrual-cycles . Samples were collected on day 0-7 and 14 of the artificial cycle and analyzed for HGF and c-MET by real-time PCR, and immunohistochemistry (IHC). Human samples were obtained from women on menstrual-cycle days 25-28 (late secretory phase), 1-4 (menstrual/repair phase) and 5-6 (late repair/proliferative phase) and examined for HGF and c-MET by IHC. Human endometrial luminal epithelial cells were grown to over-confluence and then wounded. Wounded monolayers were treated with HGF neutralizing antibody (0.5mg/ml) or matched IgG. Repair of wounded areas was assessed daily by determining wound area vs day 0 (day of wounding).
Results: HGF and c-MET expression coincided with late menstruation and post menstrual repair. In macaques HGF mRNA was minimal in the late secretory and premenstrual phase and increased to maximum on day 5 (P<0.05). c-MET mRNA was minimal in the premenstrual phase and increased by day 3 (P<0.05). IHC revealed stromal localization of HGF whereas c-MET was localized to the glandular and repairing luminal epithelium. IHC of human endometrium revealed minimal HGF in the late secretory phase. On day 1 of menses HGF localized to stroma only. During the repair phase HGF localized to stroma, glandular epithelium and repairing/repaired luminal epithelium. c-MET localized to glandular epithelium and leukocytes in late secretory phase, stroma and leukocytes on day 1 of menses and to glandular and luminal epithelium during repair. Treatment of wounded epithelial cell monolayers in vitro with anti-HGF IgG significantly reduced in vitro epithelial repair by > 50% vs irrelevant IgG.
Conclusions:Our results support a functional role for the HGF/c-MET paracrine system during postmenstrual endometrial repair.