Study on the HIF ‐1α regulated by glycolytic pathways and mitochondrial function in yaks of different altitudes during postmortem aging

Abstract

The study investigated the glycolysis pathway mediated by hypoxia-inducible factor-1α (HIF-1α) and the mechanism of its regulation. The results indicated that HIF-1α expression initially increased before subsequently decreasing with aging time during postmortem (p < .01). Glucose transporter-1 (GLUT-1), lactate dehydrogenase (LDH), and hexokinase (HK) displayed a similar trend with aging time (p < .01) while pyruvate dehydrogenase kinase 1 (PDK-1) increased gradually within the first 12 hr before decreasing at 24-120 hr. However, after treatment with a HIF-1α inhibitor, no significant differences were observed in the mitochondrial morphology. Furthermore, lactate content decreased, along with LDH, HK, and F0F1-ATP activities as well as GLUT-1 and PDK-1 expression (p < .01). The shear force for all groups also increased during postmortem aging (p < .01), with that of the controls being significantly higher compared with the treatment groups (p < .01). These findings confirmed that, after slaughter, the hypoxic environment within the muscles provided essential conditions for HIF-1α expression, which, in turn, activated the glycolysis pathway by mediating changes in the activities of glycolytic enzymes and mitochondrial function. Moreover, in accelerating glycolysis rate, the expression of HIF-1α further played a negative role in meat tenderization during postmortem aging. This, it was concluded that HIF-1α expression plays a significant role in postmortem yak meat tenderization by regulating the glycolysis pathway.Pratical applications: While converting muscle into meat through hypoxic glycolysis during postmortem aging is undeniable, the biochemical mechanism of this process mediated remains quite obscure. However, the meat quality difference which impact muscle regulation mechanism during postmortem aging has not been reported. The study investigated the HIF-1α played a major role in both the glycolytic pathway and as well as meat tenderness during the postmortem aging of yak meat. The glycolysis pathway is mediated by hypoxia-inducible factor-1α (HIF-1α), the mechanism of its regulation, and meat tenderness during the postmortem aging of yak meat.

Effects of altitude on meat quality difference and its relationship with HIF ‐1α during postmortem maturation of beef

“…In addition, the findings suggest that HIF-1α expression increases with increasing hypoxia time, although it will eventually decrease for longer periods of hypoxia. These results were consistent with previously published findings from the authors of the current study (Xin, Chai, et al, 2022;Xin, Hu, et al, 2022) who pointed out that hypoxia increased the hypoxia-inducible factor-1α expression. To further explore the expression of HIF-1α during postmortem aging, the protein was detected in muscle cells by fluorescence double staining with a HIF-1α antibody (Figure 3).…”

“…The NADH produced by mitochondrial respiration during the early phase of postmortem increases the activity of methomyoglobin reductase in the muscle, thus inducing an increase in the amount of oxygenated myoglobin as well as in the a* value. However, with aging time, the internal oxygen content decreases, the brown metmyoglobin gradually becomes dominant and mitochondrial respiration of yak meat decreases significantly with increasing altitude (Xin, Chai, et al, 2022; Xin, Hu, et al, 2022), thereby reducing the a* value. In the case of b* , the value increased at 0–120 hr postmortem for all groups ( p < .05), but the differences between the groups were not significant during postmortem aging ( p > .05; Table 4).…”

“…This experiment also demonstrated the negative correlation coefficients between pH and glycolytic potential (r = −.73, p < .05). HIF-1α can not only regulate hexokinase to decompose glycogen and kinetic changes involving mitochondrial functional patterns trigger enhanced glycolytic flux but lactate dehydrogenase can product with lactate; all glycolysis reaction products are precursors for cascade reactions that influence the pH value during the meat storage period (Dunn et al, 2021;Xin, Chai, et al, 2022;Xin, Hu, et al, 2022). Although existing studies are yet to determine how HIF-1α mediates glycolysis rate during aging, the fact remains that pH, as the final reaction of the glycolytic pathway, gene in hypoxia as the latter can cause the EPO level of oxygen plateau species to be higher than that of normal species (Leon-Velarde et al, 1991).…”

“…As a key transcription factor activated by hypoxia, HIF‐1α is involved in metabolic adaptation while regulating metastasis and anti‐apoptosis of hypoxic cells. Yaks exhibit unique lung and heart properties that enable them to adapt to high‐altitude environments, a characteristic which, according to (Xin et al, 2022; Xin, Hu, Han, & Yu, 2022), could be related to hypoxia‐inducible factor‐mediated signaling. Indeed, when studying the transcriptome associated with the tenderization of mutton during postmortem aging, the hypoxia‐inducible factor 1 (HIF‐1) signaling pathway was confirmed to be involved in hypoxia adaptation by studying the transcriptome associated with tenderization of mutton during postmortem aging (Ji, Liu, & Luo, 2022).…”

High oxygen-modified packaging (HiOx-MAP) mediates HIF-1α regulation of tenderness changes during postmortem aging of yak meat

“…Therefore, it is highly essential to investigate the underlying mechanism of yak meat tenderness. Hypoxia enhances the rate of glycolysis and inhibits mitochondrial oxygen consumption in yak meat during postmortem aging ( Xin et al, 2022 ). Thus, hypoxia induces the glycolysis pathway of meat, and the downregulation of pH contributes to worse tenderness ( Wicks et al, 2019 ).…”