2119-P: Deep Profiling of Phosphorylation Dynamics in Human Islets in Response to Inflammatory Cytokines

Human islets, particularly beta cells, are sensitive to their environment and face many types of stressors. These stressors may stem from intense demand for hormone production, viral insult, impaired intra-islet signaling, immune activation, or a combination of any/all of the previously mentioned stressors. How islets respond to these stressors is vital to the continued function and whole-body cooperation of these important cells, especially in patients which are already carry predisposed risk. It is well understood that once immune invasion occurs, islets face a veritable barrage of cytokine/chemokine chemical stressors. Elucidating the early cellular response to these stressors is paramount to understanding the complex interconnected balance at play between the immune system and the islet. The initial response is critical and must occur quickly; this is why we chose to look at changes in phosphorylation-based dynamics which occur at these short time scales. Islet samples from 10 donor patients were harvested and cytokine treated ex vivo and subsequently collected over a time course of 10 min, 30 min and 2 hours. Samples were then prepared for mass-spectrometry-based proteomics analysis using the newly-developed BASIL (Boosting to Amplify Signal using Isobaric Labeling) method for small-scale enriched phosphoproteomics. This technique allowed for unprecedented deep phosphoproteome coverage and signaling network reconstruction of cytokine-induced stressed human islets; thereby allowing us to observe a molecular-level response to this kind of stress in this critical phase of disease pathogenesis. Disclosure A.C. Swensen: None. Y. Ye: None. E. Dirice: None. R. Kulkarni: None. W. Qian: None. Funding National Institutes of Health (UC4DK104167, R01DK122160)