Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada.
Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Departments of Medicine and Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
Cell Rep Methods. 2023 Oct 23;3(10):100602. doi: 10.1016/j.crmeth.2023.100602. Epub 2023 Oct 10.
First-phase glucose-stimulated insulin secretion is mechanistically linked to type 2 diabetes, yet the underlying metabolism is difficult to discern due to significant islet-to-islet variability. Here, we miniaturize a fluorescence anisotropy immunoassay onto a microfluidic device to measure C-peptide secretion from individual islets as a surrogate for insulin (InsC-chip). This method measures secretion from up to four islets at a time with ∼7 s resolution while providing an optical window for real-time live-cell imaging. Using the InsC-chip, we reveal two glucose-dependent peaks of insulin secretion (i.e., a double peak) within the classically defined 1 phase (<10 min). By combining real-time secretion and live-cell imaging, we show islets transition from glycolytic to oxidative phosphorylation (OxPhos)-driven metabolism at the nadir of the peaks. Overall, these data validate the InsC-chip to measure glucose-stimulated insulin secretion while revealing new dynamics in secretion defined by a shift in glucose metabolism.
第一时相葡萄糖刺激的胰岛素分泌与 2 型糖尿病在机制上有关联，然而由于胰岛间存在显著的变异性，其潜在代谢过程难以被察觉。在这里，我们将荧光各向异性免疫测定法小型化到微流控装置上，以测量来自单个胰岛的 C 肽分泌作为胰岛素的替代物（InsC-chip）。该方法可同时测量多达四个胰岛的分泌情况，分辨率约为 7 s，同时为实时活细胞成像提供光学窗口。使用 InsC-chip，我们揭示了经典定义的 1 相（<10 min）内胰岛素分泌的两个葡萄糖依赖性峰（即双峰）。通过结合实时分泌和活细胞成像，我们表明在峰的最低点，胰岛从糖酵解向氧化磷酸化（OxPhos）驱动的代谢转变。总的来说，这些数据验证了 InsC-chip 可用于测量葡萄糖刺激的胰岛素分泌，同时揭示了由葡萄糖代谢转变定义的分泌的新动态。
