Characterization and comparison of human IAPP to IAPPs from Aquatic Mammals

BSC-Ursa Minor 92

Islet Amyloid Polypeptides (IAPPs) are one of the products secreted by pancreatic beta cells. These IAPPs and other amyloid peptides are notorious for aggregating into deposits that destroy beta cells, the primary producers of insulin. IAPP aggregation has been associated with the development of type II diabetes, a disease that affects 30.3 million people of all ages—or 9.4% of the U.S. population, and is an epidemic that has devastated the lives of many. This research explores the relationship between the IAPP sequences, their propensity to aggregate, and their effect on mammalian cell viability. It is unknown whether amyloids are the products of Type 2 diabetes or the cause of it. However, it is known that amyloids exist and that they are detrimental to beta cells. This study focuses on the examination of how IAPP sequence and aggregation propensity in various animals is associated with the prevalence of Type 2 diabetes. MTT assays were performed to assess cell viability of HeLa cells that were treated with the IAPPs of a Polar Bear, Weddell Seal, and Dolphin. Subsequently, LDH Cytotoxicity assays were conducted to test viability of cellular membrane upon addition of the same IAPPs. The MTT assay results showed that there was an inversely proportional relationship between IAPP concentration and cell viability in that the higher the concentration of IAPP resulted in lower cell viability. Increasing concentrations of polar bear IAPP had little to no effect on cell viability. Addition of IAPP from weddell seal and dolphin had an effect on cell viability. LDH Cytotoxicity results showed that polar bear had highest cell toxicity, while IAPP from a weddell seal and a dolphin were not as cytotoxic. Thus, more tests need to be conducted to find whether there is a correlation between IAPP sequence, toxicity, and its effect on cell viability.