Regulation of synthesis function of porcine ovarian granulose cells by mitogen-activated protein kinase signaling pathway

Abstract

To investigate the role of mitogen-activated protein kinase (MAPK) signaling pathway regulating synthesis function of steroid hormone of porcine ovarian granulose cells. Porcine ovarian granulose cells were cultured in medium added with dimethyl sulfoxide (DMSO) at concentration of 50 micromol/L or with MAPK inhibitor PD98059 (PD) for 48 hours. Then, granulose cells in DMSO medium were added with activator of adenylate cyclase (20 micromol/L) or blank agent for next 48 hours incubation, which were defined as observation group 1 and control group 1, similarly, granulose cells in PD medium were also added with activator of adenylate cyclase (20 micromol/L) or blank agent for next 48 hours, which were defined as observation group 2 and control group 2. The level of estradiol (E(2)), progesterone (P) and testosterone (T) were detected by chemoluminescence. The mRNA expression of 17alpha-hydroxylase/17,20-lyase (CYP17) and aromatase P450 (P450 arom) were assessed by RT-PCR. (1) Hormone expression: the level of T, P and E(2) were (29.5 +/- 2.5) nmol/L, (80 +/- 5) nmol/L, (49 +/- 4) pmol/L in control group 1 and (42.3 +/- 3.4) nmol/L, (170 +/- 15) nmol/L, (75 +/- 6) pmol/L in control group 2, which showed significant difference (P < 0.05). In the mean time, the level of T, P and E(2) were (106.2 +/- 7.6) nmol/L, (210 +/- 16) nmol/L, (130 +/- 11) pmol/L in observation group 2 and (47.2 +/- 3.5) nmol/L, (130 +/- 6) nmol/L, (81 +/- 6) pmol/L in observation group 1, which also reach statistical difference (P < 0.05). (2) The expression of enzyme: the expression of CYP17 mRNA was increased by 50% and P450 arom mRNA was decreased by 20% between control group 1 and 2. However, the mRNA expression of P450 arom and CYP17 were upregulated remarkably, especially, the expression of CYP17 mRNA were increased by 125%. MAPK signaling pathway plays an inhibitory role in regulating synthesis of steroid hormone of ovarian granulose cell.