Effect of melatonin on regulation of apoptosis and steroidogenesis in cultured buffalo granulosa cells

Abstract

This study was aimed to address melatonin receptor expression, mRNA level of hypothalamus and hypophysis hormone receptors (GnRHR, FSHR, and LHR), steroidogenesis, cell cycle, apoptosis, and their regulatory factors after addition of melatonin for 24 hr in cultured buffalo granulosa cells (GCs). The results revealed that direct addition of different concentrations of melatonin (100 pM, 1 nM, and 100 nM) resulted in significant upregulation (p < 0.05) of mRNA level of melatonin receptor 1a (MT1) without affecting melatonin receptor 1b (MT2). Melatonin treatment significantly downregulated (p < 0.05) mRNA level of FSH and GnRH receptors, whereas 100 nM dose of melatonin significantly increased mRNA level of LH receptor. Treatment with 100 nM of melatonin significantly decreased the basal progesterone production with significant decrease (p < 0.05) in mRNA levels of StAR and p450ssc, and lower mRNA level of genes (Insig1, Lipe, and Scrab1) that affect cholesterol availability. Melatonin supplementation suppressed apoptosis (100 nM, p < 0.05) and enhanced G2/M phase (1 nM, 100 nM, p < 0.05) of cell cycle progression which was further corroborated by decrease in protein expression of caspase‐3, p21, and p27 and increase in bcl2. Our results demonstrate that melatonin regulates gonadotrophin receptors and ovarian steroidogenesis through MT1. Furthermore, the notion of its incorporation in apoptosis and proliferation of buffalo GCs extends its role in buffalo ovaries.

Melatonin Protects the Apoptosis of Sheep Granulosa Cells by Suppressing Oxidative Stress via MAP3K8 and FOS Pathway

“…Granulosa cell apoptosis is a key influencing factor for follicular atresia [4]. Melatonin exerts anti-apoptotic effects in the process of follicular atresia in a variety of animals, inhibits granulosa cell apoptosis, and promotes follicular development [5][6][7][8][9][10][11]. Melatonin can not only directly affect the growth status of granulosa cells and the production of steroid hormones but also indirectly alleviate the damage caused by extracellular stimuli [11][12][13][14].…”

Melatonin alleviates endoplasmic reticulum stress to improve ovarian function by regulating the mTOR pathway in aged laying hens

“…The activation of Caspase-3 is an indicator of apoptosis. MEL treatment significantly reduces Caspase-3 mRNA expression level ( Riaz et al, 2019 ). The activation and expression of Caspase-3 in bovine oocytes in vitro could be inhibited by MEL and in bovine oocytes in vitro.…”

Melatonin alleviates ovarian function damage and oxidative stress induced by dexamethasone in the laying hens through FOXO1 signaling pathway

“…For example, Ricassio et al measured Caspase-3 in mice and showed that feeding 20 mg/kg melatonin reduces the activation and expression of Caspase-3 and inhibits follicular atresia ( Barberino et al, 2017 ). Riaz et al also showed that melatonin could increase the Bcl-2 protein expression and inhibit Caspase-3 activation and expression in bovine oocytes in vitro ( Riaz et al, 2019 ). Melatonin nuclear receptors RORα/RORγ mediate G→B-inhibited bursal B lymphocyte apoptosis via reducing caspase-3 and Bax expression in the bursa of chickens ( Li et al, 2022 ).…”