Gannon Nicholas P, Schnuck Jamie K, Mermier Christine M, Conn Carole A, Vaughan Roger A
School of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Biochemistry and Molecular Biology, University of New Mexico, Health Sciences Center, School of Medicine, Albuquerque, NM 87131, USA.
Department of Exercise Science, High Point University, High Point, NC 27268, USA.
Biochimie. 2015 Dec;119:45-51. doi: 10.1016/j.biochi.2015.10.001. Epub 2015 Oct 9.
Type 2 diabetes is characterized by insulin resistance and chronic hyperglycemia, and is increasing in incidence and severity. This work explored the effects of trans-cinnamaldehyde (CA) on carbohydrate metabolism, mitochondrial content, and related metabolic gene and protein expression in cultured myotubes treated with various concentrations of CA for up to 24 h. CA treatment increased myotube myocyte enhancer factor 2 (MEF2) along with glucose transporter 4 (GLUT4) content. CA treatment also significantly increased expression of markers of improved oxidative metabolism including 5' adenosine monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α), cytochrome c (CytC), as well as peroxisome proliferator-activated receptor α (PPARα) and PPARβ/δ. Despite increased expression of proteins associated with improved oxidative metabolism and glucose uptake, CA-treated myotubes exhibited significantly reduced oxidative metabolism compared with controlled cells. Additionally, CA treatment increased markers of glucose-mediated lipid biosynthesis without elevated PPARγ and sterol receptor element binding protein 1c (SREBP-1c) expression. The ability of CA to stimulate mitochondrial biogenesis and GLUT4 expression suggests CA may offer possible benefits for metabolic disease. However, increases in markers of fatty acid synthesis with simultaneously reduced oxidative metabolism suggest CA may have counterproductive effects for metabolic disease, warranting a need for further investigation.
2型糖尿病的特征是胰岛素抵抗和慢性高血糖，其发病率和严重程度正在上升。这项研究探讨了反式肉桂醛（CA）对培养的肌管中碳水化合物代谢、线粒体含量以及相关代谢基因和蛋白质表达的影响，将肌管用不同浓度的CA处理长达24小时。CA处理增加了肌管中的肌细胞增强因子2（MEF2）以及葡萄糖转运蛋白4（GLUT4）的含量。CA处理还显著增加了改善氧化代谢的标志物的表达，包括5'腺苷单磷酸激活蛋白激酶（AMPK）、过氧化物酶体增殖物激活受体γ共激活因子1α（PGC-1α）、细胞色素c（CytC），以及过氧化物酶体增殖物激活受体α（PPARα）和PPARβ/δ。尽管与改善氧化代谢和葡萄糖摄取相关的蛋白质表达增加，但与对照细胞相比，CA处理的肌管的氧化代谢显著降低。此外，CA处理增加了葡萄糖介导的脂质生物合成的标志物，而PPARγ和固醇受体元件结合蛋白1c（SREBP-1c）的表达没有升高。CA刺激线粒体生物发生和GLUT4表达的能力表明CA可能对代谢疾病有潜在益处。然而，脂肪酸合成标志物增加而氧化代谢同时降低表明CA可能对代谢疾病有适得其反的影响，因此需要进一步研究。
