Presenter(s): Lillian Wheary
Co Presenter(s): Sam Kirby, Nick Belair
Faculty Mentor(s): Hans Dreyer & Doug Foote
Poster 27
Session: Sciences
Total knee arthroplasty (TKA) procedures are projected to increase nearly seven-fold to 3.4 million per year in the U.S. by 2030. Nearly all patients undergoing this surgery experience some degree of muscle loss during the first two weeks after surgery. Although effective at eliminating osteoarthritic pain, muscle atrophy and functional deficits persist. Essential amino acid (EAA) supplementation has been successful used by us in mitigating muscle atrophy after TKA. To understand how EAAs work at the cellular level, we isolated myoblasts from biopsies. Our goal was to model the cellular responses to anabolic stimuli using cell culture methods. Our objectives were: 1) isolate myoblasts from biopsies with >80% purity, 2) measure changes in anabolic mTORC1 response to anabolic amino acids (leucine, lysine and arginine (LRK)) ± insulin, and 3) measure changes to the leucine metabolite hydroxy-beta-methylbutyrate (HMB). Cells were seeded and myogenic purity confirmed via immunocytochemistry (ICC). Phosphorylation status of anabolic and catabolic signaling were determined. Preliminary results: isolating myoblasts from older muscle is more difficult than young controls. LRK+I produced a significant increase in rpS6 and Akt phosphorylation while no change was detected when myoblasts were incubated with HMB. Additional research is needed to refine our isolation methods and to better understand the mechanism(s) through which amino acids can help to maximally preserve muscle mass after common orthopedic procedures in older adults. If successful, recovery strategies such as amino acid supplementation will improve functional mobility following surgery and enhance long-term quality of life for these older individuals.