Effect of Teaghrelin on Dexamethasone-Induced Skeletal Muscle Atrophy

• Main Authors: Hsin-Yi Lin, 林欣怡
• Other Authors: Jason T.C. Tzen
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/02796719622388290252

碩士 === 國立中興大學 === 生物科技學研究所 === 105 === 　　Cachexia is a common complication during cancer, diabetes, cardiac failure, renal failure, liver failure, chronic obstructive pulmonary disorder, and several other disease state. Primarily symptom is losing of skeletal muscle and body fat, which leads to substantial weight loss. It also causes difficulties on cancer treatment. Ghrelin is a peptide hormone mainly released from stomach. Recent studies have demonstrated that ghrelin is a potential therapeutic way for cachexia. It promotes skeletal muscle cell differentiation and prevents lose muscle mass. Previously, our lab have discovered a unique acylated flavonoid tetraglycosides, Teaghrelin, in Chin-shin oolong tea and demonstrated this Ghrelin-like compound can mimic the bioactivity in vivo. Because ghrelin and Teaghrelin shows similar bioactivity, therefore the potential of Teaghrelin on cachexia treatment is worth evaluating. In this study, Teaghrelin was treated on mouse skeletal muscle cells, C2C12. Teaghrelin (2.5x10-4M) induce C2C12 myoblast differentiation in growth medium. The extent of cells differentiation was measured by elongation index under light microscopy. The elongation index of myoblast increased about 20% in Teaghrelin treatment group. The expression of two differentiation-related proteins, myogenin and myosin heavy chain also increased after 72h incubation. These results indicate that Teaghrelin significantly stimulate C2C12 skeletal myoblast cell differentiation. Moreover, we discovered Teaghrelin can attenuate dexamethasone-induced muscle atrophy from preliminary experiment. The fully differentiated C2C12 co-incubated with Teaghrelin and dexamethasone for 24h. Teaghrelin (2.5x10-5M) recovered myotube diameters about 30% and reduced the expression of two ubiquitin ligase, Atrogin-1 and MuRF1, which drive muscle protein degradation. We considered that Teaghrelin has a positive effect to prevent muscle atrophy and it may have potential to be a new treatments of cachexia.