The Truskey lab is a biomolecular and tissue engineering lab that has three groups of research: cardiovascular, musculoskeletal, and liver. All of these areas are working towards engineering human tissues that behave similarly to native human tissue in order to test the effects of drugs and find the most efficient treatments. I am working with Brittany Davis, a graduate student in the lab. She is studying the oxygen consumption rates of engineered human muscle bundles in order to help test the metabolic effects of drug candidates. Brittany is also helping me with my project. I am testing the effects of TNF- α on differentiating human muscle bundle myosin heavy chain gene expression. These projects will help lead to a screening method to test early stage drug toxicity.
Syndromes such as AIDS, cancer, chronic heart failure, and chronic pulmonary disease are associated with muscle wasting. We are not sure what the cause of the muscle wasting is, but one hypothesis is that there is a disproportion in processes that maintain skeletal muscle through degeneration, apoptosis and regeneration. Tumor necrosis factor (TNF-α), an inflammatory cytokine associated with many of these diseases, has been demonstrated to interfere with the satellite cell cycle exit, the expression of muscle-specific genes, and myotube formation. The hypothesis that I am testing is that 10,000 U/mL TNF-α inhibits gene expression of mature isoforms of myosin heavy chain during myogenesis of human skeletal muscle bundles. This is testing how the concentration of TNF-α affects the differentiation process, therefore inhibiting muscle regeneration.
To approach this hypothesis, I am treating differentiating human muscle bundles with different concentrations of TNF-α and then measuring the level of gene expression in order to determine the relationship between concentration and inhibition of myogenesis. The levels of gene expression of five isoforms of myosin heavy chain will be measured using RT-qPCR. These isoforms represent different levels of differentiation, so we will be able to tell the maturity of the cells based on the gene expression. These findings will tell us if TNF-α is contributing to muscle wasting.
