Estrogen Modulates Specific Life and Death Signals Induced by LH and hCG in Human Primary Granulosa Cells In Vitro

Int J Mol Sci. 2017 Apr 28;18(5):926. doi: 10.3390/ijms18050926.


Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) are glycoprotein hormones used for assisted reproduction acting on the same receptor (LHCGR) and mediating different intracellular signaling. We evaluated the pro- and anti-apoptotic effect of 100 pM LH or hCG, in the presence or in the absence of 200 pg/mL 17β-estradiol, in long-term, serum-starved human primary granulosa cells (hGLC) and a transfected granulosa cell line overexpressing LHCGR (hGL5/LHCGR). To this purpose, phospho-extracellular-regulated kinase 1/2 (pERK1/2), protein kinase B (pAKT), cAMP-responsive element binding protein (pCREB) activation and procaspase 3 cleavage were evaluated over three days by Western blotting, along with the expression of target genes by real-time PCR and cell viability by colorimetric assay. We found that LH induced predominant pERK1/2 and pAKT activation STARD1, CCND2 and anti-apoptotic XIAP gene expression, while hCG mediated more potent CREB phosphorylation, expression of CYP19A1 and procaspase 3 cleavage than LH. Cell treatment by LH is accompanied by increased (serum-starved) cell viability, while hCG decreased the number of viable cells. The hCG-specific, pro-apoptotic effect was blocked by a physiological dose of 17β-estradiol, resulting in pAKT activation, lack of procaspase 3 cleavage and increased cell viability. These results confirm that relatively high levels of steroidogenic pathway activation are linked to pro-apoptotic signals in vitro, which may be counteracted by other factors, i.e., estrogens.

Keywords: LH; apoptosis; gonadotropins; granulosa; hCG.

MeSH terms

  • Aromatase / metabolism
  • CREB-Binding Protein / metabolism
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Cell Survival / drug effects
  • Cells, Cultured
  • Chorionic Gonadotropin / pharmacology*
  • Estradiol / pharmacology*
  • Female
  • Gene Expression / drug effects
  • Granulosa Cells / cytology
  • Granulosa Cells / drug effects
  • Granulosa Cells / metabolism
  • Humans
  • Luteinizing Hormone / pharmacology*
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects*
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism


  • Chorionic Gonadotropin
  • Tumor Suppressor Protein p53
  • Estradiol
  • Luteinizing Hormone
  • Aromatase
  • CYP19A1 protein, human
  • CREB-Binding Protein
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Caspase 3