Tian Xiuzhi, Wang Feng, Zhang Lu, He Changjiu, Ji Pengyun, Wang Jing, Zhang Zhenzhen, Lv Dongying, Abulizi Wusiman, Wang Xuguang, Lian Zhengxing, Liu Guoshi
National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
College of Animal Science, Xinjiang Agricultural University, Urumqi 830052, China.
Int J Mol Sci. 2017 Apr 17;18(4):834. doi: 10.3390/ijms18040834.
(1) Background: The binding sites of melatonin, as a multifunctional molecule, have been identified in human, porcine, and bovine samples. However, the binding sites and mechanisms of melatonin have not been reported in sheep; (2) Methods: Cumulus-oocyte complexes (COCs) were cultured in TCM-199 supplemented with melatonin at concentrations of 0, 10, 10, 10, 10, and 10 M. Melatonin receptors (MT1 and MT2) were evaluated via immunofluorescence and Western blot. The effects of melatonin on cumulus cell expansion, nuclear maturation, embryo development, and related gene (9, 1, , , and ) expression were investigated. The level of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were evaluated in oocytes and cumulus, respectively; (3) Results: Both MT1 and MT2 were expressed in oocytes, cumulus cells, and granulosa cells. Melatonin with a concentration of 10 M significantly enhanced the rates of nuclear maturation, cumulus cells expansion, cleavage, and blastocyst. Melatonin enhanced the expression of 15 in oocytes and of , , and in cumulus cells. Melatonin decreased the cAMP level of oocytes but enhanced the cGMP level in oocytes and cumulus cells; (4) Conclusion: The higher presence of MT1 in GV cumulus cells and the beneficial effects of melatonin indicated that its roles in regulating sheep oocyte maturation may be mediated mainly by the MT1 receptor.
(1) 背景：褪黑素作为一种多功能分子，其结合位点已在人、猪和牛的样本中得到鉴定。然而，褪黑素在绵羊中的结合位点和作用机制尚未见报道；(2) 方法：将卵丘 - 卵母细胞复合体（COCs）培养于添加了浓度为0、10、10、10、10和10 μM褪黑素的TCM - 199中。通过免疫荧光和蛋白质印迹法评估褪黑素受体（MT1和MT2）。研究褪黑素对卵丘细胞扩展、核成熟、胚胎发育以及相关基因（9、1、 、 、和 ）表达的影响。分别评估卵母细胞和卵丘中环状单磷酸腺苷（cAMP）和环状单磷酸鸟苷（cGMP）的水平；(3) 结果：MT1和MT2均在卵母细胞、卵丘细胞和颗粒细胞中表达。浓度为10 μM的褪黑素显著提高了核成熟、卵丘细胞扩展、卵裂和囊胚形成率。褪黑素增强了卵母细胞中15的表达以及卵丘细胞中 、 、和 的表达。褪黑素降低了卵母细胞的cAMP水平，但提高了卵母细胞和卵丘细胞中的cGMP水平；(4) 结论：GV期卵丘细胞中MT1的较高表达以及褪黑素的有益作用表明，其在调节绵羊卵母细胞成熟中的作用可能主要由MT1受体介导。
