Shipin Kexue (Feb 2023)
Reactive Oxygen Species Accelerates Energy Metabolism by Activating Hypoxia-Inducible Factor-1α in Bovine Muscle at the Initial Stage of Postmortem Aging
Abstract
This study aimed to investigate the effect of reactive oxygen species (ROS) on early postmortem energy metabolism in bovine muscle via regulating the expression of hypoxia-inducible factor-1α (HIF-1α). The muscle samples were treated with hydrogen peroxide (H2O2), N-acetyl-L-cysteine (NAC), and normal saline (control), separately. The ROS content, proline hydroxylase (PHD) activity, phosphoinositide-3 kinase/protein kinase B (PI3K/AKT) and HIF-1α expression levels, energy metabolism, and pH were determined at 0.5, 6, 12, 24 and 48 h postmortem. The results revealed that the H2O2-treated group showed a significantly higher ROS content than the other two groups at 0.5 h postmortem (P < 0.05) and remained at a high level within 48 h, while NAC inhibited the accumulation of ROS for a short period of time (during 0.5–12 h) postmortem. The PHD activity in the H2O2-treated group was significantly lower than that in the other two groups during 0.5–48 h (P < 0.05). Meanwhile, the expression levels of PI3K from 0.5 to 12 h and phosphorylated AKT (p-AKT) from 0.5 to 6 h were significantly higher than those in the other groups (P < 0.05). Consequently, the expression level of HIF-1α in the H2O2-treated group was significantly higher than that of the other two groups during 6–48 h (P < 0.05), the rate of glycogenolysis and the rate of increase in R value were significantly faster in the H2O2-treated group during 6–24 h (P < 0.05), and the pH of the H2O2-treated group reached the limit value earlier (at 12 h). In conclusion, ROS can activate the stable expression of HIF-1α by reducing the activity of PHD and up-regulating the PI3K/AKT signaling pathway and consequently accelerate energy metabolism dominated by glycolysis and the decrease in pH in bovine muscle at the initial stage of postmortem aging, which may have a crucial impact on meat quality.
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