The role of HAX-1 in adipocytes with an overexpression of long-chain fatty acids

• Sienna White, Biological Sciences, University of Delaware

• Chi Keung Lam, Biological Sciences, University of Delaware

Obesity is a metabolic condition that has become a prevalent issue in both the United States and throughout the world. In the United States alone, 2 in 5 adults are considered obese, and globally this number surpasses one billion. The protein Hematopoietic Cell-Specific Lyn Substrate 1-associated protein X-1 (HAX-1), encoded by the HAX-1 gene, protects cells against apoptosis. HAX-1 has been studied extensively in the heart, but is understudied in other tissues, such as adipose. Our lab recently discovered that HAX-1 is differentially expressed in the two abdominal adipose depots, subcutaneous and visceral fat. Fatty acids, long carbon chains containing a carboxylic acid, are the building blocks of lipids, the major source of long-term energy. Fatty acids are characterized by either unsaturated or saturated, where unsaturated fatty acids have at least one double bond, causing a “kink” in the carbon chain. These compounds are a major component of diet, as the human body cannot produce fatty acids on its own. To investigate the role of HAX-1 in adipocytes under the stress of excess fatty acids, plates of cells were treated with the long-chain unsaturated fatty acid oleic acid and the long-chain saturated fatty acid palmitic acid. Differences in adipogenesis markers, such as leptin and perilipin-1, were measured through western blotting and qPCR, while lipid accumulation was measured through Oil Red O staining. Determining whether saturated and unsaturated, or further short chain or long chain, fatty acids affect adipocytes differently could propose new avenues for obesity research and what, if any, roles HAX-1 could play in obesity. Understanding this is vital as it could change the way we think about our diet.