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Objective: Evidence links initiation of integrase strand-transfer inhibitors (INSTIs) to excess weight gain in people living with HIV, potentially through changes in β-cell function. Thus, our goal was to investigate potential mechanisms that contribute to alterations in pancreatic β-cells insulin secretion by following exposure to two commonly used integrase inhibitors, Dolutegravir (DTG) and Elvitegravir (ELV). Methods: Insulin content and secretion were measured from clonal pancreatic ß-cells (INS-1) cultured in medium containing 4 mM and 11 mM glucose and were exposed to either dimethyl sulfoxide (DMSO) as a control, DTG, or ELV at physiological concentrations 72 hours. Insulin was measured by fluorescence using an HTRF insulin kit (Perkin Elmer). Changes in mitochondrial function were determined using a Seahorse mitochondrial stress test. Intracellular Ca2+ was measured in fura-2 loaded INS-1 cells as the ratio of fluorescence at 340 nm to 380 nm using a Hitachi 2000 spectrofluorometer. The data were presented as mean ± standard deviation (SD). Statistical analysis was conducted using Student's t-test or analysis of variance (ANOVA). Results: Dolutegravir treatment significantly reduced insulin secretion in cells cultured at 11G, even when normalizing for insulin content. In the 11G condition, Dolutegravir administration reduced oxygen consumption rate (OCR) compared to ELV and control, but no such difference was observed in the 4G condition. Consistent with reduced oxygen consumption, when INS-1 cells were cultured at 11 mM glucose with Dolutegravir, the glucose-stimulated increase in intracellular Ca2+ was observed to be reduced by 80% compared to the control group. Conclusion: Our study reveals that exposure to DTG leads to impaired insulin secretion, less oxygen consumption and reduced calcium influx in β-cells under high glucose conditions. These findings provide important insights into the potential effects of Dolutegravir (DTG) on β-cell function and glucose regulation regarding the weight gain observed in people living with HIV (PLWH) who started or switched to INSTI treatment. Further investigations are warranted to elucidate the underlying mechanisms responsible for the observed effects of DTG on insulin synthesis, storage, and calcium signaling pathways. Understanding these mechanisms could potentially lead to the development of strategies to mitigate the detrimental impacts of DTG on β-cell function and optimize therapeutic approaches in patients receiving DTG therapy. |
