Advisor Information
Dustin Slivka
Location
Criss Library
Presentation Type
Poster
Start Date
1-3-2019 10:45 AM
End Date
1-3-2019 12:00 PM
Abstract
BACKGROUND: Skeletal muscle biopsies are extensively used in research to determine the effects of exercise. Usually, sequential biopsies are taken before and after exercise in order to determine the influence of exercise on gene expression. Often it is not clear if the results are due to exercise or as a result of damage cause by the biopsy to the muscle. Previous studies have proven that multiple biopsies in the same leg cause stress to the muscle and such stress leads to inflammation and other response pathways that alter the gene expression. PURPOSE: The purpose of this study is to determine the day to day variance in skeletal muscle gene expression in the same leg and between legs to establish an experimental design that eliminates artifacts and reduces the number of biopsies needed for a study.METHODS: Eight participants had a muscle biopsy taken from the vastus lateralis muscle on three separate occasions approximately 1 week apart after repeating the same diet and exercise for 24 hours prior. Legs were randomized and altered on subsequent weeks. Genes related to mitochondrial development and stable reference were measured using real-time PCR. The first biopsy was defined as stable reference control condition and gene expression was normalized using 2-∆∆CT and 2-∆CT method. Results: No difference was found in gene expression from day to day variation or between legs for ERRa (p = 0.85), GABPA (P = 0.85), MEF2a (P = 0.86), NRF1 (P = 0.97), PPARG (P = 0.38), PGC1a(p = 0.88), SIRT1 (p = 0.299), TFAM (p = 0.99), and VEGF (p = 0.61). For FNDC5 there was a difference between legs, trial 1 compared to trial 2 (p = 0.04), but trial 2 compared to trial 3 did not show a difference (p = 0.906) and not within the same leg trial 1 to trial 3 (p = 0.946). The reference genes B2M (p = 0.005) and CYC (p = 0.002) were different between biopsies; GAPDH and RPS18 were not different between biopsies (p > 0.05). Conclusion: While many genes are statistically not different between legs and between days, researchers need to determine the amount of error that is acceptable in each study design.
Day to Day and Leg to Leg Variation in Gene Expression
Criss Library
BACKGROUND: Skeletal muscle biopsies are extensively used in research to determine the effects of exercise. Usually, sequential biopsies are taken before and after exercise in order to determine the influence of exercise on gene expression. Often it is not clear if the results are due to exercise or as a result of damage cause by the biopsy to the muscle. Previous studies have proven that multiple biopsies in the same leg cause stress to the muscle and such stress leads to inflammation and other response pathways that alter the gene expression. PURPOSE: The purpose of this study is to determine the day to day variance in skeletal muscle gene expression in the same leg and between legs to establish an experimental design that eliminates artifacts and reduces the number of biopsies needed for a study.METHODS: Eight participants had a muscle biopsy taken from the vastus lateralis muscle on three separate occasions approximately 1 week apart after repeating the same diet and exercise for 24 hours prior. Legs were randomized and altered on subsequent weeks. Genes related to mitochondrial development and stable reference were measured using real-time PCR. The first biopsy was defined as stable reference control condition and gene expression was normalized using 2-∆∆CT and 2-∆CT method. Results: No difference was found in gene expression from day to day variation or between legs for ERRa (p = 0.85), GABPA (P = 0.85), MEF2a (P = 0.86), NRF1 (P = 0.97), PPARG (P = 0.38), PGC1a(p = 0.88), SIRT1 (p = 0.299), TFAM (p = 0.99), and VEGF (p = 0.61). For FNDC5 there was a difference between legs, trial 1 compared to trial 2 (p = 0.04), but trial 2 compared to trial 3 did not show a difference (p = 0.906) and not within the same leg trial 1 to trial 3 (p = 0.946). The reference genes B2M (p = 0.005) and CYC (p = 0.002) were different between biopsies; GAPDH and RPS18 were not different between biopsies (p > 0.05). Conclusion: While many genes are statistically not different between legs and between days, researchers need to determine the amount of error that is acceptable in each study design.