College of Life Science, Northeast Agricultural University, 150030, Harbin, China.
College of Animal Science and Technology, Northeast Agricultural University, 150030, Harbin, China; Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, 150030, Harbin, China.
J Therm Biol. 2023 Aug;116:103658. doi: 10.1016/j.jtherbio.2023.103658. Epub 2023 Jul 14.
To investigate the effect of cold stimulation on heart, 300 1-day-old female broilers were divided into control (CON) and two cold stimulation (CS3 and CS9) groups. Birds in CON group were reared in normal ambient temperature during day 1-43; while birds in CS3 and CS9 groups were reared at 3 °C and 9 °C below CON group for 5 h at 1-day intervals from day 15 to day 35, respectively. Heart tissues were collected at day 22, 29, 36, and 43 to determine the indexes related to oxidative stress, inflammation and apoptosis. The H&E staining displayed that inflammatory cell infiltration and myocardial fiber break were obviously observed in CS9 group, and cardiac pathological score in CS9 group was higher than CON and CS3 groups (P < 0.05) at day 22, 36, and 43. Overall, compared to CON group, the concentrations of MDA and HO were elevated, the activities of SOD, CAT, GPx, and T-AOC were reduced, and mRNA expression of CAT, GPx, SOD, nuclear factor-erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) was downregulated in CS9 group at each time-point (P < 0.05). Compared to CON group, mRNA expression of NF-κBp65, COX-2, iNOS, PTGEs, TNF-α, and IL-1β, and mRNA and protein expression of Bax, Bak, Cyt-c, caspase-3, and caspase-9 were increased, while Bcl-2 and Bcl-2/Bax ratio were decreased in CS9 group (P < 0.05) at the most detected time-points. There were no significant differences in the levels of indexes associated with oxidative stress, Nrf2/HO-1 antioxidant system, inflammation, and apoptosis between CON and CS3 groups at the most detected time-points (P > 0.05). Therefore, this study suggests that severe cold stimulation at 9 °C below normal rearing temperature induces cardiomyocyte inflammation and apoptosis by regulating Nrf2/HO-1 pathway-related oxidative stress in broilers, and mild cold stimulation of CS3 group can improve the adaptability of hearts to cold environment.
为了研究冷刺激对心脏的影响，将 300 只 1 日龄雌性肉鸡分为对照组（CON）和 2 个冷刺激组（CS3 和 CS9）。CON 组雏鸡在 1-43 日龄期间在正常环境温度下饲养；而 CS3 和 CS9 组雏鸡在 15-35 日龄期间每隔 1 天在 3°C 和 9°C 下分别饲养 5 小时。在第 22、29、36 和 43 天采集心脏组织，以确定与氧化应激、炎症和细胞凋亡相关的指标。H&E 染色显示，CS9 组明显观察到炎性细胞浸润和心肌纤维断裂，CS9 组在第 22、36 和 43 天的心脏病理评分均高于 CON 和 CS3 组（P<0.05）。总的来说，与 CON 组相比，CS9 组 MDA 和 HO 的浓度升高，SOD、CAT、GPx 和 T-AOC 的活性降低，CAT、GPx、SOD、核因子-红细胞 2 相关因子 2（Nrf2）和血红素加氧酶-1（HO-1）的 mRNA 表达在各个时间点均下调（P<0.05）。与 CON 组相比，CS9 组 NF-κBp65、COX-2、iNOS、PTGEs、TNF-α 和 IL-1β 的 mRNA 表达，Bax、Bak、Cyt-c、caspase-3 和 caspase-9 的 mRNA 和蛋白表达增加，而 Bcl-2 和 Bcl-2/Bax 比值降低（P<0.05）。在大多数检测时间点，CON 和 CS3 组之间与氧化应激、Nrf2/HO-1 抗氧化系统、炎症和细胞凋亡相关的指标水平没有差异（P>0.05）。因此，本研究表明，在正常饲养温度下降低 9°C 的剧烈冷刺激通过调节肉鸡 Nrf2/HO-1 通路相关氧化应激引起心肌细胞炎症和凋亡，而 CS3 组的轻度冷刺激可提高心脏对冷环境的适应能力。
