Melatonin protects porcine oocyte in vitro maturation from heat stress

Abstract

Melatonin is a pleiotropic molecule which plays an important role in animal reproductive activities. Because of the increased global warming, the impact of heat stress (HS) on stockbreeding has become an inevitable issue to be solved. To investigate the potential effects of melatonin on the in vitro maturation of porcine oocyte under the HS, a HS model for porcine oocyte maturation has been used in this study and the different concentrations of melatonin (10(-6) -10(-9) m) were also tested for their protective effects on oocytes. The polar body rate, the index of the nuclear maturation of the oocytes, and the cleavage rate as well as the blastocyst rate were measured to evaluate the developmental competence of the oocytes after parthenogenetic activation (PA). The results showed that HS [in vitro maturation (IVM) 20-24 hr, 42°C] significantly reduced the polar body rate of oocytes and the blastocyte rate of porcine PA embryos, while melatonin (10(-7) m) application not only improved polar body rate and blastocyte rate, but also preserved the normal levels of steroid hormone which is disrupted by HS. The presence of melatonin (10(-7) m) during the oocyte maturation under the HS reduced reactive oxygen species (ROS) formation, enhanced glutathione (GSH) production, inhibited cell apoptosis, and increased the gene expressions of SIRT1, AKT2, and Polg2. Importantly, the endogenously occurring melatonin of cumulus-oocyte complexes was significantly induced by HS. The results indicated that melatonin application effectively protected the oocytes from HS. These observations warranted the further studies in vivo regarding to improve the reproductive activities of animals under the global warming environment.

Melatonin and tannic acid supplementation in vitro improve fertilization and embryonic development in pigs

“…In agreement with those studies, our results indicated that supplementing melatonin during oocyte maturation improved early embryonic development rates. Melatonin has also been shown to reduce levels of ROS and enhance glutathione production and decrease apoptosis in pig oocytes (Li et al, 2015). Our results agree with this study, as we found supplementation of melatonin to decrease the ROS produced during maturation.…”

“…Supplementation of melatonin has shown to lower ROS levels during oocyte maturation in mice (Salehi et al, 2014), bovine (Cebrian-Serrano et al, 2013) and humans (Wei et al, 2013). In pigs, melatonin his been shown to support oocyte maturation and embryo culture (Do et al, 1015) and to protect the oocyte against ROS (Li et al, 2015).…”

Melatonin implantation improved the egg-laying rate and quality in hens past their peak egg-laying age

“…The ROS caused by reproductive ageing is associated with changes in oocyte mitochondrial dynamics and function and mtDNA quantity and prevents oocyte maturation40. It has been reported that heat shock results in an inhibitory effect on porcine oocyte maturation in vitro by improving the ROS in the oocytes41. Maternal-restraint stress increases oocyte aneuploidy by impairing metaphase I spindle assembly and reducing spindle assembly checkpoint proteins in mice42.…”

Inhibition of ERK1/2 Signaling Pathway is Involved in Melatonin's Antiproliferative Effect on Human MG-63 Osteosarcoma Cells

“…Melatonin plays key roles in the biologic regulation of circadian rhythms [27,28], sleep [29,30], antioxidant protection [31][32][33][34][35], cell aging [36], tumor growth [12,37], reproduction [31,38], and bone physiology [39,40]. A growing amount of data indicates that the age-related decline in the level of melatonin is closely associated with bone diseases: osteosarcoma, adolescent idiopathic scoliosis and osteoporosis [1,39].…”