Melatonin Alleviates Hypoxia-Induced Apoptosis of Granulosa Cells by Reducing ROS and Activating MTNR1B–PKA–Caspase8/9 Pathway
Jing-Li Tao,
Xuan Zhang,
Jia-Qi Zhou,
Cheng-Yu Li,
Ming-Hui Yang,
Zhao-Jun Liu,
Liang-Liang Zhang,
Shou-Long Deng,
Lu Zhang,
Ming Shen,
Guo-Shi Liu,
Hong-Lin Liu
Affiliations
Jing-Li Tao
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Xuan Zhang
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Jia-Qi Zhou
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Cheng-Yu Li
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Ming-Hui Yang
National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
Zhao-Jun Liu
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Liang-Liang Zhang
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Shou-Long Deng
CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
Lu Zhang
National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
Ming Shen
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Guo-Shi Liu
National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
Hong-Lin Liu
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
In mammalian ovaries, the avascular environment within follicular cavity is supposed to cause hypoxic status in granulosa cells (GCs), leading to apoptotic cell death accompanied by cumulative reactive oxygen species (ROS) production. Melatonin (N-acetyl-5-methoxytryptamine, MT), a broad-spectrum antioxidant that exists in porcine follicle fluid, was suggested to maintain GCs survival under stress conditions. In this study, using the established hypoxic model (1% O2) of cultured porcine GCs, we explored the effect of MT on GCs apoptosis. The results showed that MT restored cell viability and reduced the apoptosis of GCs during hypoxia exposure. In addition, GCs treated with MT exhibited decreased ROS levels and increased expression of antioxidant enzymes including heme oxygenase-1 (HO-1), glutathione S-transferase (GST), superoxide dismutase 1 (SOD1), and catalase (CAT) upon hypoxia incubation. Moreover, the hypoxia-induced expression of cleaved caspase 3, 8, and 9 was significantly inhibited after MT treatment. In contrast, blocking melatonin receptor 2 (MTNR1B) with a competitive antagonist 4-phenyl-2-propionamidotetralin (4P-PDOT) diminished the inhibitory effects of MT on caspase 3 activation. By detecting levels of protein kinase (PKA), a downstream kinase of MTNR1B, we further confirmed the involvement of MT–MTNR1B signaling in mediating GCs protection during hypoxia stress. Together, the present data provide mechanistic evidence suggesting the role of MT in defending GCs from hypoxia-induced apoptosis.
