Background:Elevated ambient temperature-caused heat stress is a major concern for livestock production due to its negative impact on animal feed intake, growth, reproduction, and health. Particularly, the germ cells are extremely sensitive to the heat stress. However, the effective approach and strategy regarding how to protect mammalian oocytes from heat stress-induced defects have not been determined. Methods:Germinal vesicle (GV) porcine oocytes were cultured at 41.5 ℃ for 24 h to induce heat stress, and then cultured at 38.5 ℃ to the specific developmental stage for subsequent analysis. Nicotinamide mononucleotide (NMN) was dissolved in water to 1 mol/L for a stock solution and further diluted with the maturation medium to the final concentrations of 10μmol/L, 20μmol/L, 50μmol/L or 100μmol/L, respectively, during heat stress. Immunostaining and fluorescence intensity quantification were applied to assess the effects of heat stress and NMN supplementation on the key processes during the oocyte meiotic maturation. Results:Here, we report that NMN supplementation improves the quality of porcine oocytes under heat stress. Specifically, we found that heat stress resulted in oocyte maturation failure by disturbing the dynamics of meiotic organelles, including the cytoskeleton assembly, cortical granule distribution and mitochondrial function. In addition, heat stress induced the production of excessive reactive oxygen species (ROS) and DNA damage, leading to the occurrence of apoptosis in oocytes and subsequent embryonic development arrest. More importantly, we validated that supplementation of NMN during heat stress restored the meiotic defects during porcine oocyte maturation. Conclusions:Taken together, our study documents that NMN supplementation is an effective approach to improve the quality of oocytes under heat stress by promoting both nuclear and cytoplasmic maturation.

Meijie Song;Yu Li;Yihang Zhou;Jiner Yan;Xiaohua Zhou;Qian Gao;Yilong Miao;Bo Xiong

College of Animal Science and Technology,Nanjing Agricultural University,Nanjing 210095,China;College of Veterinary Medicine,Nanjing Agricultural University,Nanjing 210095,China

畜牧与生物技术杂志（英文版）

[1]Meijie Song;Yu Li;Yihang Zhou;Jiner Yan;Xiaohua Zhou;Qian Gao;Yilong Miao;Bo Xiong-.Nicotinamide mononucleotide supplementation improves the quality of porcine oocytes under heat stress)[J].畜牧与生物技术杂志（英文版）,2022(05):1326-1339

Germinal

Nicotinamide,mononucleotide,supplementation,improves,quality,porcine,oocytes,under,heat,stress,Background,Elevated,ambient,temperature,caused,major,concern,livestock,due,its,negative,impact,animal,feed,intake,growth,reproduction,health,Particularly,germ,cells,are,extremely,sensitive,However,effective,approach,strategy,regarding,how,protect,mammalian,from,induced,defects,have,not,been,determined,Methods,vesicle,GV,were,cultured,then,specific,developmental,stage,subsequent,analysis,NMN,was,dissolved,water,solution,further,diluted,maturation,medium,final,concentrations,respectively,during,Immunostaining,fluorescence,intensity,quantification,applied,assess,effects,key,processes,meiotic,Results,Here,report,that,Specifically,found,resulted,failure,by,disturbing,dynamics,organelles,including,cytoskeleton,assembly,cortical,granule,distribution,mitochondrial,function,In,addition,excessive,reactive,oxygen,species,ROS,damage,leading,occurrence,apoptosis,embryonic,arrest,More,importantly,validated,restored,Conclusions,Taken,together,our,study,documents,promoting,both,nuclear,cytoplasmic

0.531173