Key Laboratory of Meat Processing and Quality Control, Ministry of Education China, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
J Agric Food Chem. 2022 Feb 2;70(4):1252-1260. doi: 10.1021/acs.jafc.1c06516. Epub 2021 Dec 30.
The objective of the present study was to investigate the regulatory mechanism of protein S-nitrosylation on early postmortem beef muscle apoptosis. Beef semimembranosus (SM) muscles at 45 min postmortem were treated with nitric oxide (NO) donor, control (NaCl solution), or nitric oxide synthase (NOS) inhibitor for 24 h at 4 °C. Bcl-2 expression and mitochondrial membrane potential were significantly increased by the NO donor treatment at 6 h postmortem, while the NOS inhibitor group exhibited a lower Bcl-2 level and mitochondrial membrane potential in comparison with the control ( < 0.05). The cytochrome c expression analysis highlighted that NO donor incubation repressed cytochrome c release from mitochondria to the cytoplasm. Further, S-nitrosylation levels of caspase-3 and caspase-9 were elevated after incubation with the NO donor ( < 0.05), leading to decreased caspase-3 and caspase-9 activities ( < 0.05). The aforementioned findings imply that protein S-nitrosylation mediates postmortem apoptosis of beef SM through the mitochondrial apoptotic pathway.
本研究旨在探讨蛋白质 S-亚硝基化对宰后牛肉早期肌肉凋亡的调控机制。宰后 45 分钟的牛半膜肌（SM）肌肉在 4°C 下用一氧化氮（NO）供体、对照（NaCl 溶液）或一氧化氮合酶（NOS）抑制剂处理 24 小时。NO 供体处理后 6 小时，Bcl-2 表达和线粒体膜电位显著增加，而与对照组相比，NOS 抑制剂组的 Bcl-2 水平和线粒体膜电位较低（<0.05）。细胞色素 c 表达分析表明，NO 供体孵育抑制了细胞色素 c 从线粒体向细胞质的释放。此外，NO 供体孵育后 caspase-3 和 caspase-9 的 S-亚硝基化水平升高（<0.05），导致 caspase-3 和 caspase-9 活性降低（<0.05）。上述结果表明，蛋白质 S-亚硝基化通过线粒体凋亡途径介导宰后牛肉 SM 的凋亡。
