MAPK3/1 is conducive to luteinizing hormone-mediated C-type natriuretic peptide decrease in bovine granulosa cells

Area of Science:

• Reproductive biology
• Endocrinology
• Cell signaling

Background:

• C-type natriuretic peptide (CNP) functions as an oocyte maturation inhibitor (OMI) across various species, including cattle.
• The precise influence of luteinizing hormone (LH) on CNP expression and its underlying mechanisms in bovine granulosa cells remain largely unelucidated.

Purpose of the Study:

• To investigate the effects of LH on CNP expression in bovine granulosa cells.
• To elucidate the molecular signaling pathways involved in LH-mediated regulation of CNP.

Main Methods:

• Primary bovine granulosa cells were cultured and treated with LH.
• Key signaling molecules, including epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase 3/1 (MAPK3/1), were assessed for activation (phosphorylation).
• CNP mRNA levels were quantified using RT-qPCR.

Main Results:

• LH treatment led to increased phosphorylation of EGFR and activation of MAPK3/1 in bovine granulosa cells.
• LH significantly decreased CNP mRNA expression.
• Inhibition of EGFR or MAPK3/1 pathways attenuated the LH-induced decrease in CNP expression.

Conclusions:

• LH suppresses CNP expression in bovine granulosa cells.
• The EGFR and MAPK3/1 signaling pathways are crucial mediators of LH's effect on CNP expression.
• These findings provide insights into the hormonal regulation of oocyte maturation in cattle.