Possible involvement of AMPK in acute exercise-induced expression of monocarboxylate transporters MCT1 and MCT4 mRNA in fast-twitch skeletal muscle
Possible involvement of AMPK in acute exercise-induced expression of monocarboxylate transporters MCT1 and MCT4 mRNA in fast-twitch skeletal muscle
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DOI：
10.1016/j.metabol.2013.06.010
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发表时间：
2013-11-01
影响因子：
9.8
通讯作者：
Hamada, Taku
中科院分区：
文献类型：
--
作者：
Takimoto, Masaki;Takeyama, Mirei;Hamada, Taku
Objective.急性运动诱导骨骼肌单羧酸转运体MCT 1和MCT 4 mRNA表达的调控机制尚不清楚。5 '-腺苷活化蛋白激酶（AMPK）是在mRNA水平上调节基因表达的关键信号分子。我们研究AMPK激活是否参与急性运动诱导的快速收缩肌中MCT 1和MCT 4 mRNA的表达。雄性Sprague-Dawley大鼠进行5 min高强度间歇游泳（HIS）或6 h低强度延长游泳（LIS）的急性发作。急性的影响。在体内分析运动对AMPK（p-AMPK）、钙/钙调蛋白悬垂激酶II（p-CaMK II）、p38促分裂原活化蛋白激酶（p-p38 MAPK）和MCTs mRNA磷酸化的影响。为了观察AMPK激活对MCTs mRNA的直接影响，使用离体肌肉孵育模型在体外分析了5-氨基咪唑-4-甲酰胺-1-β-D-呋喃核糖苷（AICAR）、咖啡因和丹曲洛林的影响。结果。尽管p-CaMK Ⅱ和p-p38 MAPK仅在HIS后增加，但p-AMPK在HIS和US后均增加。无论运动强度如何，MCT 1和MCT 4 mRNA也被HIS和LIS瞬时上调。直接暴露于0.5 mmol/L AICAR或1 mmol/L咖啡因可激活p-AMPK，使上滑车肌中MCT 1和MCT 4 mRNA水平均升高。当丹曲洛林抑制pAMPK时，MCT 1和MCT 4 mRNA均未增加。结论。这些结果表明，急性运动诱导的MCT 1和MCT 4 mRNA表达的增加可能是由AMPK激活介导的，至少部分在快缩肌中。(C)2013 Elsevier Inc. All rights reserved.
Objective. The regulatory mechanisms responsible for acute exercise-induced expression of monocarboxylate transporters MCT1 and MCT4 mRNA in skeletal muscle remain unclear. 5'-adenosine-activated protein kinase (AMPK) is a key signaling molecule that regulates gene expression at the mRNA level. We examined whether AMPK activation is involved in acute exercise-induced expression of MCT1 and MCT4 mRNA in fast-twitch muscle.Materials/Methods. Male Sprague-Dawley rats were subjected to an acute bout of either 5 min high-intensity intermittent swimming (HIS) or 6-h low-intensity prolonged swimming (LIS). The effects of acute. exercise on the phosphorylation of AMPK (p-AMPK), calcium/calmodulin pendent kinase II (p-CaMKII), p38 mitogen-activated protein kinase (p-p38MAPK), and MCTs mRNA were analyzed in vivo. To observe the direct effects of AMPK activation on MCTs mRNA, the effects of 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), caffeine, and dantrolene were analyzed in vitro using an isolated muscle incubation model.Results. The p-AMPK increased in response to both HIS and US, although the p-CaMKII and p-p38MAPK were increased only following HIS. Irrespective of exercise intensity, MCT1 and MCT4 mRNA was also transiently upregulated by both HIS and LIS. Direct exposure of the epitrochlearis muscle to 0.5 mmol/L AICAR or 1 mmol/L caffeine, which activated p-AMPK increased both MCT1 and MCT4 mRNA levels. When pAMPK was inhibited by dantrolene, neither MCT1 nor MCT4 mRNA was increased.Conclusion. These results suggest that acute exercise-induced increases in MCT1 and MCT4 mRNA expression may be possibly mediated by AMPK activation, at least in part in fast-twitch muscle. (C) 2013 Elsevier Inc. All rights reserved.