球形 CTRP3 通过 AMPK/PGC-1α 通路促进心肌细胞中线粒体生物发生。
Globular CTRP3 promotes mitochondrial biogenesis in cardiomyocytes through AMPK/PGC-1α pathway.
机构信息
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.; Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, China.; Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
Department of Geriatrics, Peking University Third Hospital, Beijing 100191, China.
出版信息
Biochim Biophys Acta Gen Subj. 2017 Jan;1861(1 Pt A):3085-3094. doi: 10.1016/j.bbagen.2016.10.022. Epub 2016 Oct 26.
BACKGROUND
Mitochondrial biogenesis is crucial for the maintenance of mitochondrial function and cellular homeostasis. C1q/tumor necrosis factor-related protein-3 (CTRP3) is an adipokine that owns multiple functions on metabolic and cardiovascular diseases. However, whether CTRP3 affects mitochondrial biogenesis in cardiomyocytes remains unknown.
METHODS
Neonatal rat ventricular myocytes were cultured and treated with globular CTRP3 (gCTRP3). The expression of mitochondrial biogenesis related genes was measured by real-time PCR and western blot analysis. Mitochondrial morphology was assessed by a transmission electron microscope. ATP content, oxygen consumption rate (OCR), and sirtuin1 activity were measured with commercial kits.
RESULTS
gCTRP3 increased the expression of peroxisome proliferators activated receptor-γ co-activator-1α (PGC-1α), nuclear respiratory factor 1 (NRF-1), NRF-2, mitochondrial transcription factor A (TFAM), cytochrome B, and oxidative phosphorylation complexes III and V, and increased mitochondrial cristae components and OCR. Additionally, gCTRP3 enhanced mitochondrial DNA copy number and ATP content, while the induction was inhibited by knockdown of PGC-1α via small interfering RNA. gCTRP3 increased phosphorylation of AMP-activated protein kinase (AMPK), whereas adenine 9-β-d-arabinofuranoside (AraA), an AMPK inhibitor, attenuated gCTRP3-mediated induction of NRF-1, TFAM, and complexes III and V. gCTRP3 increased both the expression and activity of sirtuin1, whereas inhibition of sirtuin1 by EX-527 attenuated gCTRP3-induced responses. Meanwhile, gCTRP3-mediated activation of sirtuin1 was attenuated by AraA. Moreover, gCTRP3 restored the reduction of sirtuin1, PGC-1α, NRF-1, complex III and ATP content induced by hypoxia-reoxygenation injury.
CONCLUSION
CTRP3 promotes mitochondrial biogenesis in cardiomyocytes via AMPK/PGC-1α pathway.
GENERAL SIGNIFICANCE
CTRP3 is an endogenous modulator for mitochondrial biogenesis, and may protect cardiomyocytes by ameliorating mitochondrial dysfunction.
背景
线粒体生物发生对于维持线粒体功能和细胞内稳态至关重要。C1q/肿瘤坏死因子相关蛋白-3（CTRP3）是一种脂肪因子，在代谢和心血管疾病方面具有多种功能。然而，CTRP3 是否影响心肌细胞中的线粒体生物发生尚不清楚。
方法
培养新生大鼠心室肌细胞并进行球状 CTRP3（gCTRP3）处理。通过实时 PCR 和 Western blot 分析测量线粒体生物发生相关基因的表达。通过透射电子显微镜评估线粒体形态。使用商业试剂盒测量 ATP 含量、耗氧量（OCR）和 Sirtuin1 活性。
结果
gCTRP3 增加过氧化物酶体增殖物激活受体-γ共激活因子-1α（PGC-1α）、核呼吸因子 1（NRF-1）、NRF-2、线粒体转录因子 A（TFAM）、细胞色素 B 和氧化磷酸化复合物 III 和 V 的表达，并增加线粒体嵴成分和 OCR。此外，gCTRP3 增加线粒体 DNA 拷贝数和 ATP 含量，而通过小干扰 RNA 敲低 PGC-1α 则抑制诱导。gCTRP3 增加 AMP 激活的蛋白激酶（AMPK）的磷酸化，而 AMPK 抑制剂腺嘌呤 9-β-D-阿拉伯呋喃糖苷（AraA）则减弱 gCTRP3 介导的 NRF-1、TFAM 和复合物 III 和 V 的诱导。gCTRP3 增加 Sirtuin1 的表达和活性，而 Sirtuin1 的抑制剂 EX-527 则减弱 gCTRP3 诱导的反应。同时，AraA 减弱了 gCTRP3 介导的 Sirtuin1 激活。此外，gCTRP3 恢复了缺氧复氧损伤诱导的 Sirtuin1、PGC-1α、NRF-1、复合物 III 和 ATP 含量的降低。
结论
CTRP3 通过 AMPK/PGC-1α 途径促进心肌细胞中线粒体的生物发生。
一般意义
CTRP3 是线粒体生物发生的内源性调节剂，通过改善线粒体功能可能保护心肌细胞。
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