Growth factor modulation of equine trophoblast mitosis and prostaglandin gene expression

J Anim Sci. 2019 Feb 1;97(2):865-873. doi: 10.1093/jas/sky473.

Abstract

To provide insight into maternal recognition of pregnancy control in equids, the mitogenic and developmental effects of endometrium-expressed growth factors (epidermal growth factor (EGF), fibroblast growth factor 2 (FGF2), hepatocyte growth factor (HGF), and insulin-like growth factor-1 (IGF-1)) were examined in equine iTr cells, an equine trophectoderm cell line. Initial western blots revealed that HGF and IGF-1 stimulate phosphorylation of AKT serine/threonine kinase 1 (AKT1) and EGF, FGF2, or HGF resulted in phosphorylation of both extracellular signal-regulated kinase 1 (ERK1) and ERK2. Mitotic activity was stimulated (P < 0.05) by EGF, FGF2, and HGF. Chemical disruption of mitogen-activated protein kinase kinases 1 and 2 (MEK1/2) phosphorylation suppresses (P < 0.05) proliferation in control and growth factor treated cells demonstrating a dependence on ERK1/2 for mitotic activity. Treatment of iTr cells with EGF or HGF in the presence of an AKT1 inhibitor prohibits (P < 0.05) growth factor stimulated proliferation. The effect of EGF, FGF2, HGF, and IGF-1 on steroid biosynthetic enzyme gene expression, including prostaglandin-endoperoxide synthase 2 (PTGS2), was determined by real-time PCR. Neither EGF, FGF2, nor IGF-1 affected PTGS2 expression while HGF caused a two-fold increase (P < 0.05) in expression. Co-supplementation with HGF and an AKT1 inhibitor did not block PTGS2 expression, whereas providing an MEK1/2 inhibitor prevented (P < 0.05) the HGF-mediated increase in PTGS2. These results provide novel evidence of a role for HGF in equine trophectoderm proliferation and prostaglandin biosynthesis.

MeSH terms

  • Animals
  • Cell Line
  • Cell Proliferation / drug effects
  • Endometrium / metabolism
  • Epidermal Growth Factor / pharmacology*
  • Female
  • Fibroblast Growth Factor 2 / pharmacology*
  • Hepatocyte Growth Factor / pharmacology*
  • Horses / genetics
  • Horses / physiology*
  • Insulin-Like Growth Factor I / pharmacology*
  • Mitosis / drug effects*
  • Phosphorylation / drug effects
  • Pregnancy
  • Prostaglandins / biosynthesis
  • Prostaglandins / genetics
  • Trophoblasts / cytology

Substances

  • Prostaglandins
  • Fibroblast Growth Factor 2
  • Epidermal Growth Factor
  • Hepatocyte Growth Factor
  • Insulin-Like Growth Factor I