Abstract: SA-PO844
Omega-3 Fatty Acid Modulates Molecules Associated with Sarcopenia in Muscle of 5/6 Nephrectomy Rats
Session Information
- Molecular Mechanisms of CKD - III
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 1903 CKD (Non-Dialysis): Mechanisms
Authors
- Son, Young ki, Dong-A University, Busan, Korea (the Republic of)
- Lee, Su mi, Dong-A University, Busan, Korea (the Republic of)
- Kim, Seong Eun, Dong-A University Hospital , Busan, Korea (the Republic of)
- An, Won Suk, Dong-A University, Busan, Korea (the Republic of)
Background
Sarcopenia is common in dialysis patients and result in frail status. Myostatin, a member of TGF-β superfamily, inhibits myocyte differentiation and is increased in patients with chronic kidney disease. Myogenin is also important mediator for myogensis. Recent report showed that omega-3 fatty acid (FA) supplementation improved muscle volume in elderly. The present study aimed to investigate whether omega-3 FA effect on myostatin and myogenin related with sarcopenia in 5/6 subtotal nephrectomy (Nx) rats.
Methods
Male Sprague Dawley rats were divided into three groups and treated for 6 weeks: sham control (0.9% saline), 5/6 Nx control (0.9% saline) and 5/6 Nx treated with omega-3 FA (300 mg/kg/day by gastric gavage). The expression of muscular myostatin, myogenin, MyoD, Akt, phosphorylated(p) Akt, PI3K, p-PI3k, AMPK, p-AMPK, smad2/3/4, NF-κB, IL-6, mTOR, FoxO, MuRF1, MAFbx and USP14 were examined by western blot analysis. H & E staining of gastrocnemius muscle was performed.
Results
BUN and serum creatinine levels were significantly increased in 5/6 Nx groups compared to sham control and were not significantly different between 5/6 Nx group treated with omega-3 FA and 5/6 Nx control group. Compared with sham control, 5/6 Nx control significantly up-regulated myostatin and down-regulated myogenin and MyoD in skeletal muscle. Increased expression of myostatin and decreased expression of myogenin were significantly recovered by omega-3 FA supplementation. However, MyoD expression was not changed by omega-3 FA supplementation. The expression of p-Akt and mTOR was down-regulated in skeletal muscle of 5/6 Nx control compared to sham control and was recovered by omega-3 FA supplementation. The expression of smad2/3/4, NF-κB, IL-6, FoxO, MuRF1, MAFbx and USP14 was significantly up-regulated in skeletal muscle of 5/6 Nx control compared to sham control but were not changed by omega-3 FA supplementation. The thickness of myofiber was decreased in 5/6 Nx control compared to sham control and was recovered by omega-3 FA supplementation.
Conclusion
Omega-3 FA may prevent sarcopenia mainly by decreasing myostatin, increasing myogenin expression and partly affecting Akt-mTOR axis in skeletal muscle of 5/6 Nx rats.