Soto-Heras Sandra, Catalá Maria-Gracia, Roura Montserrat, Menéndez-Blanco Irene, Piras Anna-Rita, Izquierdo Dolors, Paramio Maria-Teresa
Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain.
Department of Veterinary Medicine, Università degli Studi di Sassari, Sardegna, Italy.
Reprod Domest Anim. 2019 Feb;54(2):381-390. doi: 10.1111/rda.13378. Epub 2018 Dec 4.
Melatonin enhances in vitro embryo development in several species by improving the oocyte developmental competence during in vitro maturation (IVM). Melatonin has a wide range of actions, from scavenging reactive oxygen species (ROS) to regulating gene expression, and it can also act by way of melatonin receptors. The aim of this study was to determine the mechanism of action of melatonin during the IVM of juvenile goat oocytes and the role of the membrane receptors. Melatonin receptor 1 was immunolocalized in cumulus cells and oocytes before and after 24 hr of IVM. The effect of melatonin on oocyte developmental competence was tested in three experimental IVM groups: (a) control, (b) 10 M melatonin, and (c) 10 M melatonin +10 M luzindole (an inhibitor of both melatonin receptors). After IVM oocytes were assessed for ROS levels, mitochondrial activity, adenosine 5'-triphosphate (ATP) concentration and relative gene expression (ACTB, SLC1A1, SOD1, GPx1, BAX, DNMT1, GCLC and GDF9). IVM-oocytes were in vitro fertilized and cultured under conventional conditions. Blastocyst rate and quality (differential cell count) were assessed at 8 days post-fertilization. Melatonin decreased ROS levels, increased mitochondrial activity and ATP content and increased blastocyst quality compared to control group (55.8 vs. 30.4 inner cell mass ICM, p < 0.05). There was no effect on the relative gene expression due to treatment with melatonin. In conclusion, we have showed that melatonin improves oocyte developmental competence in juvenile goats by reducing ROS levels and improving mitochondrial activity.
褪黑素通过提高体外成熟（IVM）过程中卵母细胞的发育能力，增强了多个物种的体外胚胎发育。褪黑素具有广泛的作用，从清除活性氧（ROS）到调节基因表达，它还可以通过褪黑素受体发挥作用。本研究的目的是确定褪黑素在幼年山羊卵母细胞IVM过程中的作用机制以及膜受体的作用。在IVM 24小时前后，褪黑素受体1在卵丘细胞和卵母细胞中进行了免疫定位。在三个实验性IVM组中测试了褪黑素对卵母细胞发育能力的影响：（a）对照组，（b）10 μM褪黑素，和（c）10 μM褪黑素+10 μM鲁辛朵（一种褪黑素受体抑制剂）。IVM后，评估卵母细胞的ROS水平、线粒体活性、腺苷5'-三磷酸（ATP）浓度和相对基因表达（ACTB、SLC1A1、SOD1、GPx1、BAX、DNMT1、GCLC和GDF9）。IVM卵母细胞在常规条件下进行体外受精和培养。在受精后8天评估囊胚率和质量（差异细胞计数）。与对照组相比，褪黑素降低了ROS水平，增加了线粒体活性和ATP含量，并提高了囊胚质量（55.8对30.4内细胞团ICM，p<0.05）。褪黑素处理对相对基因表达没有影响。总之，我们表明褪黑素通过降低ROS水平和改善线粒体活性来提高幼年山羊卵母细胞的发育能力。
