Effects of α-AMPK knockout on exercise-induced gene activation in mouse skeletal muscle
Effects of α-AMPK knockout on exercise-induced gene activation in mouse skeletal muscle
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DOI：
10.1096/fj.04-3144fje
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发表时间：
2005-05-01
期刊：
影响因子：
4.8
通讯作者：
Pilegaard, H
中科院分区：
文献类型：
--
作者：
Jorgensen, SB;Wojtaszewski, JFP;Pilegaard, H
我们检验了以下假设：5'AMP激活的蛋白激酶（AMPK）在调节骨骼肌中代谢基因的急性，运动诱导的代谢基因激活中起重要作用敲除（KO）和野生型（WT）小鼠在静止，跑步机（90分钟）和恢复中。在Alpha 2-WT和Alpha 2-kO肌肉中，运行增加了AMPK的α1-AMPK激酶活性，AMPK的磷酸化（P）和乙酰-COA羧化酶（ACC）β（ACC）β，并且在Alpha 2-wt中增加了α2-KO肌肉和增加的α2-AmpK激酶活性。在α2-KO肌肉中，与Alpha 2-WT相比，AMPK-P和ACCβ-P明显低。但是，在α1-WT和α1-KO肌肉中，AMPK-P和ACCβ-P水平在静止状态相同，并且在两种基因型中运动过程中类似地增加。 Alpha 2-KO降低了过氧化物酶体增生剂激活的受体7共激活因子（PGC）-1α，解偶联蛋白-3（UCP3）和己糖酶II（HKII）II（HKII）转录，但并不影响运动诱导的转录。运动增加了PGC-1 Alpha，Forkhead Box o（FoxO）1，HKII和丙酮酸脱氢酶激酶4（PDK4）的mRNA含量，在α2-WT和α2-KO中类似棕榈酰转移酶I（CPTI），脂蛋白脂肪酶和UCP3在两种基因型中运动都没有改变mRNA。在所有时间点，α2-ko肌肉中的CPTI mRNA低于α2-wt肌肉的CPTI mRNA。在Alpha 1-WT和Alpha 1-KO肌肉中，同样，运行的肌肉增加了PGC-1 Alpha和FoxO1的mRNA含量。 Alpha 2-KO与较低的肌肉腺苷5'-三磷酸含量有关，仅在运动结束时，仅在Alpha 2-KO肌肉中，单磷酸肌苷含量就大大增加。此外，皮下注射5-氨基咪唑-4-羧酰胺-1-β-4-核呋喃糖苷（AICAR）增加了PGC-1 Alpha，HKII，FOXO1，PDK4，PDK4和UCP3和UCP3和Alpha 2-KO-2-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO 2-KO-KO-KO-KO-KO 2-KO-KO-KO-KO-KO-KO-KO ALPHA 2-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO-KO 2-KO 2-KO-KO-KO-KO-KO-KO AICAR诱导的PGC-1α和HKII mRNA的增加。总之，Alpha 2-的KO，但在运行过程中Alpha 1-AMPK同工型显着降低了AMPK激活。然而，在α-或α2-ampk ko肌肉中，运动诱导的小鼠骨骼肌中所研究基因的激活并没有受到损害。尽管不能排除剩余的α-同工型的激活足以增加运动过程中的基因激活，但目前的数据不支持AMPK在调节骨骼肌中运动诱导的基因激活中的重要作用。
We tested the hypothesis that 5'AMP-activated protein kinase (AMPK) plays an important role in regulating the acute, exercise-induced activation of metabolic genes in skeletal muscle, which were dissected from whole-body alpha 2- and alpha 1-AMPK knockout (KO) and wild-type (WT) mice at rest, after treadmill running (90 min), and in recovery. Running increased alpha 1-AMPK kinase activity, phosphorylation (P) of AMPK, and acetyl-CoA carboxylase (ACC)beta in alpha 2-WT and alpha 2-KO muscles and increased alpha 2-AMPK kinase activity in alpha 2-WT. In alpha 2-KO muscles, AMPK-P and ACC beta-P were markedly lower compared with alpha 2-WT. However, in alpha 1-WT and alpha 1-KO muscles, AMPK-P and ACC beta-P levels were identical at rest and increased similarly during exercise in the two genotypes. The alpha 2-KO decreased peroxisome-proliferator-activated receptor 7 coactivator (PGC)-1 alpha, uncoupling protein-3 (UCP3), and hexokinase II (HKII) transcription at rest but did not affect exercise-induced transcription. Exercise increased the mRNA content of PGC-1 alpha, Forkhead box class O (FOXO)1, HKII, and pyruvate dehydrogenase kinase 4 (PDK4) similarly in alpha 2-WT and alpha 2-KO mice, whereas glucose transporter GLUT 4, carnitine palmitoyltransferase I (CPTI), lipoprotein lipase, and UCP3 mRNA were unchanged by exercise in both genotypes. CPTI mRNA was lower in alpha 2-KO muscles than in alpha 2-WT muscles at all time-points. In alpha 1-WT and alpha 1-KO muscles, running increased the mRNA content of PGC-1 alpha and FOXO1 similarly. The alpha 2-KO was associated with lower muscle adenosine 5'-triphosphate content, and the inosine monophosphate content increased substantially at the end of exercise only in alpha 2-KO muscles. In addition, subcutaneous injection of 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR) increased the mRNA content of PGC-1 alpha, HKII, FOXO1, PDK4, and UCP3, and alpha 2-KO abolished the AICAR-induced increases in PGC-1 alpha and HKII mRNA. In conclusion, KO of the alpha 2- but not the alpha 1-AMPK isoform markedly diminished AMPK activation during running. Nevertheless, exercise-induced activation of the investigated genes in mouse skeletal muscle was not impaired in alpha- or alpha 2-AMPK KO muscles. Although it cannot be ruled out that activation of the remaining alpha-isoform is sufficient to increase gene activation during exercise, the present data do not support an essential role of AMPK in regulating exercise-induced gene activation in skeletal muscle.