Department of Animal Science and Technology, Sanghuh College of Life Science, Konkuk University, Seoul, Korea.
College of Animal Sciences, Jilin University, Jilin Provincial Key Laboratory of Livestock and Poultry Feed and Feeding in Northeastern Frigid Area, Changchun, China.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae292.
Our study aimed to evaluate the dualistic effect of heat stress on muscle differentiation at different temperatures, and whether vitamin E, a powerful antioxidant, could offset any negative effects, using bovine skeletal-muscle-derived cells (BSMCs) with myogenic properties. The BSMCs were extracted from the skeletal muscle of 30-mo-old Korean native cattle and subjected to myogenic differentiation under 3 heat exposure conditions: 37 °C (control; CON), 39 °C (mild heat stress; MHS), and 41 °C (severe heat stress; SHS) for 24 h with or without vitamin E treatment (NE or VE). After 24 h treatments, the cells were returned to 37 °C incubators and differentiated until day 6. On day 1, because of the heat exposure, the gene expression of MYOG was the highest in MHS (P = 0.047), suggesting a promotive effect of mild heat stress on myogenic differentiation, while on day 6, compared with CON and MHS, MYOD (P = 0.013) and MYOG (P = 0.029) were the lowest in SHS. Vitamin E treatment also lowered MYOG (P = 0.097), regardless of heat exposure. On day 1, HSPB1 (P = 0.001) and HSP70 (P < 0.001) were the highest in SHS, and an interaction between heat exposure and vitamin E treatment was found on day 6 (P < 0.027). BCL-2 was also the highest on day 1 in SHS (P = 0.05), and an interaction of heat exposure and vitamin E treatment was found on day 1 on BAX expression (P = 0.038). For antioxidant genes, SOD1 (P = 0.002) and GPX1 (P < 0.001) were affected by heat exposure, with the highest levels being observed in SHS, and on day 6, GPX1 was still the highest in SHS (P = 0.027). The fusion index was also affected by heat exposure, showing a decrease in SHS and an increase in MHS compared with CON (P < 0.001). Significant effects were noted from heat exposure (P < 0.001), vitamin E treatment (P < 0.001), and the interaction of heat exposure and vitamin E treatment (P = 0.002) on the protein content. Taken together, our findings provide evidence that vitamin E could ameliorate the harmful effects of heat exposure by modulating heat shock proteins and apoptosis regulators, improving the protein synthesis of BSMCs during myogenic differentiation. These results suggest that vitamin E supplementation could potentially protect muscle development in beef cattle under summer heat stress.
我们的研究旨在评估热应激在不同温度下对肌肉分化的双重影响，以及维生素 E 作为一种强大的抗氧化剂，是否可以抵消任何负面影响，使用具有成肌特性的牛骨骼肌衍生细胞 (BSMC)。BSMC 从 30 月龄的韩国本土牛的骨骼肌中提取，并在 3 种热暴露条件下进行成肌分化：37°C（对照；CON）、39°C（轻度热应激；MHS）和 41°C（重度热应激；SHS），持续 24 小时，并在有或没有维生素 E 处理（NE 或 VE）的情况下进行。24 小时处理后，细胞返回 37°C 培养箱并分化至第 6 天。第 1 天，由于热暴露，MHS 中 MYOG 的基因表达最高（P=0.047），表明轻度热应激对成肌分化有促进作用，而第 6 天，与 CON 和 MHS 相比，SHS 中的 MYOD（P=0.013）和 MYOG（P=0.029）最低。维生素 E 处理也降低了 MYOG（P=0.097），无论热暴露如何。第 1 天，SHS 中的 HSPB1（P=0.001）和 HSP70（P<0.001）最高，并且在第 6 天发现了热暴露和维生素 E 处理之间的相互作用（P<0.027）。第 1 天，BSMC 中的 BCL-2 也最高（P=0.05），并且在第 1 天发现了 BAX 表达的热暴露和维生素 E 处理之间的相互作用（P=0.038）。对于抗氧化基因，SOD1（P=0.002）和 GPX1（P<0.001）受热暴露影响，SHS 中水平最高，第 6 天，SHS 中 GPX1 仍最高（P=0.027）。融合指数也受到热暴露的影响，与 CON 相比，SHS 降低，MHS 升高（P<0.001）。热暴露（P<0.001）、维生素 E 处理（P<0.001）以及热暴露和维生素 E 处理的相互作用（P=0.002）对蛋白质含量有显著影响。总之，我们的研究结果提供了证据，表明维生素 E 通过调节热休克蛋白和细胞凋亡调节剂，可以改善成肌分化过程中 BSMC 的蛋白质合成，从而减轻热暴露的有害影响。这些结果表明，在夏季热应激下，维生素 E 补充剂可能有助于保护肉牛的肌肉发育。
