Nutrition, Hospitality, and Retailing Research

• Effects of fibrin degradation products on adipose inflammation, adipogenesis, and fibrosis
  We suspect that fibrin degradation products may be mediating adipocyte inflammation and subsequent insulin resistance. We also know that FDP's can promote excessive fibroblast turnover which may be increasing adipose tissue fibrosis at the expense of adipogenesis. This project is intended to define the role of FDP's on glucose disposal and establish them as a primary cause of impaired glucose tolerance with obesity.
• Muscle specific accumulation of linoleic acid to promote metabolic and cardiovascular health
  Our recent mouse model that overexpressed the enzyme stearoyl-CoA desaturase-1 in the skeletal muscle provided a great deal of insight into the beneficial effects of monounsaturated fatty acid (MUFA) synthesis and accumulation. By increasing MUFA production in skeletal muscle, these animals also spared the omega-6 polyunsaturated fatty acid linoleate (18:2n6), which serves as a PPARδ ligand. SCD1 transgenic mice have improved fat oxidation, glucose tolerance, and dramatically increased exercise performance and we are attempting to determine if we can recapitulate these results by providing linoleic acid supplementation in mice and cell culture models.
• Effects of diacylglycerol versus free fatty acids on muscle insulin resistance
  Recent studies have shown quite clearly that diacylglycerol (DAG) is responsible for inducing muscle insulin resistance. However, we feel that intracellular free fatty acids (FFA) have not been completely studied due in part to the difficulty in uncoupling saturated fatty acid (SFA) conversion into monounsaturated fatty acids (MUFA) versus DAG conversion into triglyceride. Oleate (MUFA) is a better substrate for DGAT mediated TG synthesis compared to palmitate or stearate (SFA). Thus, in the presence of increased MUFA production, the conversion of SFA into MUFA is likely to enhance DAG → TG conversion with a concomitant decrease in DAG levels. In light of this phenomenon, determining the independent effects of DAG versus FFA on muscle insulin sensitivity has been nearly impossible, that is until now. We have developed cell and mouse models that allow us to uncouple MUFA synthesis from TG synthesis using a combination of enzymatic overexpression and small molecule mediated enzymatic inhibition. We will attempt to determine which of these two metabolic intermediates (e.g. DAG or FFA) are responsible for impaired glucose disposal using mouse and cell models.

Undergraduate Research Projects

The importance of undergraduate students obtaining research experience cannot be understated and is a central theme to our lab. Since beginning my faculty position at TTU, I have been an active faculty member in the Center for Undergraduate Research to recruit students to participate in the lab. I also take on students who express interest in research and are looking to volunteer in the lab or conduct research for credits. Typically, each undergraduate student is assigned to work with a graduate student mentor from my lab and I meet on a weekly basis with each undergraduate student researcher as well. While the graduate students are primarily responsible for teaching laboratory procedures and current research protocols, I spend time mentoring all students in areas such as scientific writing, abstract preparation, attending and presenting at scientific meetings, networking and forming collaborations, working on a CV, and exploring the possibilities for a career in research and/or academia. The students in my lab help with data collection and analysis and learning about data interpretation and manuscript preparation.