宰后早期活性氮（RNS）对活性氧（ROS）介导牦牛肉肌细胞凋亡的调控机制

细胞凋亡是由活性氧（ROS）引发的程序性细胞死亡，研究发现活性氮（RNS）可通过氧化还原体系及Ca2+释放影响这一过程。因牦牛具有包括氧化还原能力（清除ROS）和肌肉收缩（影响Ca2+平衡）等方面的地域特征，其在RNS影响细胞凋亡的机制方面也具有地域特色。为探明RNS对牦牛肉宰后成熟中ROS介导细胞凋亡的影响机制，本项目拟分析牦牛肉RNS水平与ROS积累及细胞凋亡之间的关联，组建孵化培养模型，干预RNS水平，以验证2条可能途径：1）氧化还原途径，分析GSH/GSSG和GR等活力，探明氧化还原系统所受影响；分析ASK1和ASK1-Trx1，研究凋亡信号释放；分析线粒体mPTP、膜电位、VDAC活力，研究线粒体功能；2）Ca2+释放途径，分析细胞质与线粒体Ca2+浓度、RYR构象等，研究Ca2+释放与凋亡启动的关联。阐明RNS对牦牛肉宰后早期ROS介导细胞凋亡影响机制，完善肉类成熟理论。

Apoptosis is the starting point of the "muscle-to-meat" conversion and a key factor in the formation of meat quality. Studies have shown that RNS may influence the apoptosis process of muscle cells through the pathways related to REDOX system and Ca2+ release. Because of their regional hypoxic resistance, yaks may also have regional characteristics in the regulation of post-mortem apoptosis by RNS. In order to investigate the influence mechanism of RNS on the mode of apoptosis of myocytes in early post-mortem of yaks, The correlation between the RNS and apoptosis will be analyzed. A myocyte incubation culture model well be established to artificially interfere with the level of RNS. Two possible approaches well be verified: 1) the REDOX pathway, GSH/GSSG, GR activity, Trx activity and TR activity will be analyzed to investigate the impact of RNS on the REDOX system. ASK1 and ASK1-Trx1 will be be analyzed to investigate release of exogenous apoptotic signals under the regulation of RNS. Mitochondrial mPTP, membrane potential and VDAC activity were analyzed to study the influence of RNS on the permeability of the mitochondrial apoptosis pathway. 2) Ca2+ release pathway, concentration of Ca2+ ions in cytoplasm and mitochondria, calcium channel (RYR) conformation, calcium pump (SERCA) activity, cytochrome C will be analyzed to study the influence of RNS on Ca2+ release and apoptosis initiation. It is hoped that the mechanism of the influence of RNS on the apoptosis of early myocytes in post-mortem yak will be clarified to improve the mature theory of post-mortem of meat.