Creatine enhances differentiation of myogenic C2C12 cells by activating both p38 and Akt/PKB pathways
Creatine enhances differentiation of myogenic C2C12 cells by activating both p38 and Akt/PKB pathways
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DOI：
10.1152/ajpcell.00162.2007
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发表时间：
2007-10-01
影响因子：
5.5
通讯作者：
Francaux, Marc
中科院分区：
文献类型：
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作者：
Deldicque, Louise;Theisen, Daniel;Francaux, Marc
在肌源性C2C12细胞中，5 mM肌酸增加了标记[S-35]蛋氨酸入肌浆蛋白（+ 20%,P < 0.05）和肌原纤维蛋白（+ 50%,P < 0.01）。肌酸还促进了成肌细胞的融合，通过增加肌管内合并细胞核的数量来评估（+ 40%,P < 0.001）。肌酸提高了肌球蛋白重链II型（+ 1300%,P < 0.001）、肌钙蛋白T （+65%, P < 0.01）和肌凝蛋白（+40%,P < 0.05）的表达。甘露醇、牛磺酸和β -丙氨酸没有模仿肌酸的作用，排除了渗透压依赖性机制。哺乳动物雷帕霉素/70-kDa核糖体S6蛋白激酶（mTOR/p70s6k）通路的靶蛋白抑制剂雷帕霉素和p38的抑制剂SB 202190的加入完全阻断了对照细胞的分化，而肌酸并没有逆转这种抑制，这表明mTOR/p70s6k和p38通路可能参与了肌酸诱导的分化作用。肌酸上调蛋白激酶B （Akt/PKB; +60%, P < 0.001）、糖原合成酶激酶3 （+70%,P < 0.001）和p70s6k （+50%, P < 0.001）的磷酸化。肌酸还影响p38的磷酸化状态（24 h +50%, 96 h +70%, P < 0.05）及其下游靶点肌细胞增强因子-2的核含量（48 h +55%, 96 h +170%, P < 0.05）和MyoD （+60%, P < 0.01）。综上所述，本研究指出p38和Akt/PKB-p70s6k通路参与了肌酸诱导C2C12细胞分化增强的过程。
In myogenic C2C12 cells, 5 mM creatine increased the incorporation of labeled [S-35] methionine into sarcoplasmic (+ 20%, P < 0.05) and myofibrillar proteins (+ 50%, P < 0.01). Creatine also promoted the fusion of myoblasts assessed by an increased number of nuclei incorporated within myotubes (+ 40%, P < 0.001). Expression of myosin heavy chain type II (+ 1,300%, P < 0.001), troponin T (+65%, P < 0.01), and titin (+40%, P < 0.05) was enhanced by creatine. Mannitol, taurine, and beta-alanine did not mimic the effect of creatine, ruling out an osmolaritydependent mechanism. The addition of rapamycin, the inhibitor of mammalian target of rapamycin/70-kDa ribosomal S6 protein kinase (mTOR/p70s6k) pathway, and SB 202190, the inhibitor of p38, completely blocked differentiation in control cells, and creatine did not reverse this inhibition, suggesting that the mTOR/p70s6k and p38 pathways could be potentially involved in the effect induced by creatine on differentiation. Creatine upregulated phosphorylation of protein kinase B (Akt/PKB; +60%, P < 0.001), glycogen synthase kinase-3 (+70%, P < 0.001), and p70s6k (+50%, P < 0.001). Creatine also affected the phosphorylation state of p38 (+50% at 24 h and +70% at 96 h, P < 0.05) as well as the nuclear content of its downstream targets myocyte enhancer factor-2 (+55% at 48 h and +170% at 96 h, P < 0.05) and MyoD (+60%, P < 0.01). In conclusion, this study points out the involvement of the p38 and the Akt/PKB-p70s6k pathways in the enhanced differentiation induced by creatine in C2C12 cells.