Icariin promotes expression of PGC-1α, PPARα, and NRF-1 during cardiomyocyte differentiation of murine embryonic stem cells in vitro
Icariin promotes expression of PGC-1α, PPARα, and NRF-1 during cardiomyocyte differentiation of murine embryonic stem cells in vitro
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DOI：
10.1111/j.1745-7254.2007.00648.x
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发表时间：
2007-10-01
影响因子：
8.2
通讯作者：
Lou, Yi-Jia
中科院分区：
文献类型：
--
作者：
Ding, Ling;Liang, Xing-Guang;Lou, Yi-Jia
目的：探讨淫羊藿苷对体外培养小鼠胚胎干细胞心肌细胞分化过程中过氧化物酶体增殖物激活受体γ -辅激活因子-1 α (PGC-1 α)、过氧化物酶体增殖物激活受体α (PPAR α)和核呼吸因子1 （NRF-1）表达的影响。方法：用共聚焦激光扫描显微镜对小鼠胚胎干细胞提取的心肌细胞进行免疫细胞化学鉴定。当类胚体（EB）用淫羊精或类视黄酸处理时，评估心脏特异性的肌肉合成蛋白（即α -肌动蛋白，肌钙蛋白T）。采用半定量RT-PCR和Western blotting分析心肌细胞分化过程中PGC-1 α、PPAR α和NRF-1的表达。我们研究了p38丝裂原活化蛋白激酶（MAPK）在分化过程中的磷酸化，并利用其特异性抑制剂SB203580来证实p38 MAPK在淫羊精诱导的心脏分化中的作用。结果：淫羊藿苷显著诱导EB心肌细胞分化，α -肌动蛋白和肌钙蛋白t的表达显著增加，PGC-1 α、PPAR α和NRF-1的表达在早期分化时一致升高，且在淫羊藿苷处理后呈剂量依赖性上调。p38 MAPK的磷酸化在第6天达到峰值，第8天开始下降，淫羊藿苷对EB的激活进一步增强和延长，与PGC-1 α、PPAR α和NRF-1的升高同时发生。此外，SB203580对p38 MAPK通路的抑制有效地消除了淫羊精刺激的心肌细胞分化，并导致PGC-1 α、PPAR α和NRF-1的上调。结论：综上所述，淫羊藿苷可促进体外小鼠ES细胞心肌细胞分化过程中PGC-1 α、PPAR α和NRF-1的表达，其作用可能与p38 MAPK的激活有关。
Aim: To investigate the effect of icariin on the expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1 alpha), peroxisome proliferator-activated receptor alpha (PPAR alpha), and nuclear respiratory factor 1 (NRF-1) on cardiomyocyte differentiation of murine embryonic stem (ES) cells in vitro. Methods: The cardiomyocytes derived from murine ES cells were verified by immunocytochemistry using confocal laser scanning microscopy. Cardiac-specific sarcomeric proteins (ie alpha-actinin, troponin T) were evaluated when embryoid bodies (EB) were treated with icariin or retinoid acid. The expression of PGC-1 alpha, PPAR alpha, and NRF-1 were analyzed using both semiquantitative RT-PCR and Western blotting in cardiomyocyte differentiation. The phosphorylation of the p38 mitogen-activated protein kinase (MAPK) was studied in the differentiation process, and its specific inhibitor SB203580 was employed to confirm the function of the p38 MAPK on icariin-induced cardiac differentiation. Results: The application of icariin significantly induced the cardiomyocyte differentiation of EB as indicated by the promoted expression of alpha-actinin and troponin T. The expression of PGC-1 alpha, PPAR alpha, and NRF-1 increased coincidently in early differentiation and the increase was dose-dependently upregulated by icariin treatment. The phosphorylation of the p38 MAPK peaked on d 6 and decreased after d 8, and the activation was further enhanced and prolonged when the EB were subjected to icariin, which was concurrent with the elevation of PGC-1 alpha, PPAR alpha, and NRF-1. Moreover, the inhibition of the p38 MAPK pathway by SB203580 efficiently abolished icariin-stimulated cardiomyocyte differentiation and resulted in the capture of the upregulation of PGC-1 alpha, PPAR alpha, and NRF-1. Conclusion: Taken together, icariin promoted the expression of PGC-1 alpha, PPAR alpha, and NRF-1 during cardiomyocyte differentiation of murine ES cells in vitro and the effect was partly responsible for the activation of the p38 MAPK.