HIF-1α作用下宰后成熟初期牛肉糖酵解能力研究

Glycolysis Capacity of Bovine Muscle during Early Stage of Postmortem Aging under Action of HIF-1α

为明确缺氧诱导因子-1α(HIF-1α)对宰后成熟初期牛肉糖酵解能力的影响机制,以牛背最长肌为研究材料,分别在宰后不同成熟时间(0、6、12、24、48 h)分析了对照组和HIF-1α抑制剂3-(5′-羟甲基-2′-呋喃基)-1-苯甲基唑(YC1)处理组中HIF-1α细胞聚集和核转位水平、HIF-1α和糖原运载体-1(GLUT-1)表达水平、糖酵解限速酶活力、糖酵解水平以及pH值的变化情况。结果表明,宰后成熟初期HIF-1α在对照组细胞中聚集并向细胞核转移,HIF-1α表达水平在0~6 h迅速升高1.20倍(P<0.05),并在6~48 h显著高于YC1处理组(P<0.05)。伴随着HIF-1稳定积累,对照组GLUT-1表达水平在0~6 h内显著升高1.91倍(P<0.05),己糖激酶(HK)和磷酸果糖激酶(PFK)活力分别在0~6 h和0~12 h显著升高至197.43 U/g和27.33 U/g(P<0.05)。糖酵解水平方面,对照组糖原消耗和乳酸积累速率均显著高于YC-1处理组(P<0.05),糖酵解潜力在0~12 h显著升高1.10倍(P<0.05),并在6~24 h内显著高于YC-1处理组(P<0.05)。同时,对照组pH值在0~12 h显著降低至极限pH值(pHu值)(P<0.05),比YC-1处理组提前了12 h。综上可知,HIF-1α通过诱导GLUT-1表达和糖酵解限速酶活力升高,在提升宰后初期牛肉糖酵解能力方面发挥重要作用。

Aiming to investigate the effect mechanism of hypoxia-inducible factor1α(HIF-1α)on glycolysis capacity of postmortem bovine muscle,the bovine M.Longissimus dorsi was selected as the experimental material,the cellular aggregation and nuclear migration of HIF-1α,expression of HIF-1αand glycogen transporter1,glycolysis rate-limiting enzymes activities,glycolytic potential,and pH values were determined at different time points of postmortem aging(0 h,6 h,12 h,24 h,and 48 h)in the control group and 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole(YC-1)-treated group.The results showed that HIF-1αwas aggregated and translocated to the cell nucleus in bovine muscle at the early stage of postmortem aging.The expression levels of HIF-1αwere increased by 1.20-fold at 0~6 h(P<0.05),which were significantly higher than those in the YC-1-treated group at 6~48 h(P<0.05).With the steady accumulation of HIF-1α,the expression levels of GLUT-1 were significantly increased by 1.91-fold within 0~6 h in the control group(P<0.05).The hexokinase(HK)and phosphofructokinase(PFK)activities were significantly elevated to 197.43 U/g protein and 27.33 U/g protein at 0~6 h and 0~12 h,respectively(P<0.05).As for the glycolysis capacity,the glycogen consumption and lactate accumulation rates were significantly higher in the control than those in the YC-1-treated group(P<0.05).The glycolytic potential was significantly increased by 1.10-fold at 0~12 h(P<0.05)and was significantly higher than that of YC-1 treatment from 6h to 24 h(P<0.05).Meanwhile,pH values in the control group were significantly decreased to the ultimate pH(pHu)at 0~12 h(P<0.05),which was 12 h earlier than that in the YC-1-treated group.The results indicated that HIF-1αplayed an important role in enhancing the glycolytic capacity of bovine muscle by inducing GLUT-1 expression and elevating the activities of glycolysis rate-limiting enzymes at the early stage of postmortem aging.