Essential Amino Acids and Anabolic Activity: The Effect of Leucine, Arginine, and Lysine on Young Skeletal Muscle Anabolic Activity
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Date
2019
Authors
Wheary, Lilli Armine
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
Total knee arthroplasty (TKA) procedures are projected to increase nearly seven-fold to 3.4 million surgeries performed annually in the U.S. by 2030. Although the surgery is effective at alleviating osteoarthritic pain, it causes long-term muscle wasting that inhibits functional mobility. A proof-of-principle report by our group showed that essential amino acid (EAA) supplementation was successful in mitigating muscle atrophy after surgery. To better understand the mechanisms of EAAs at the cellular level, we isolated human myoblasts and modeled the cellular responses to anabolic stimuli experimentally under controlled cell culture methods using young healthy isolated myoblasts as control. Methods: Cells from the biopsies were seeded in well plates and myogenic identity was confirmed via immunocytochemistry (ICC). After plating, cells were starved prior to stimulation in either untreated, LRK or LRK+I. Cells were lysed and phosphorylation status of targets of the mTORC1 signaling cascade were analyzed by Western Blot. Results: Preliminary results demonstrate that isolating myoblasts from older patients is more difficult than young controls. In the young, incubation with LRK only produced a significant effect on the phosphorylation of Akt at 15 minutes. Incubation with LRK + I showed a greater effect, with the phosphorylation status of Akt and Gsk3 being significantly greater than the control at 15 minutes, and the phosphorylation of Akt and rpS6 were significantly greater than the control at 30 minutes. Conclusions: Additional research is needed to refine our isolation methods and to better understand the mechanism(s) through which amino acids attenuate the atrophy of TKA patients. If successful, recovery strategies can be refined to improve functional mobility following surgery and enhance long-term quality of life for these older individuals.
Description
38 pages
Keywords
Human Physiology, Myoblasts, Signaling, Proteins, Physiology, Amino Acids