Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058, Basel, Switzerland.
InSphero AG, Wagistrasse 27, 8952, Schlieren, Switzerland.
Adv Biosyst. 2020 Mar;4(3):e1900291. doi: 10.1002/adbi.201900291. Epub 2020 Jan 29.
Insulin is released from pancreatic islets in a biphasic and pulsatile manner in response to elevated glucose levels. This highly dynamic insulin release can be studied in vitro with islet perifusion assays. Herein, a novel platform to perform glucose-stimulated insulin secretion (GSIS) assays with single islets is presented for studying the dynamics of insulin release at high temporal resolution. A standardized human islet model is developed and a microfluidic hanging-drop-based perifusion system is engineered, which facilitates rapid glucose switching, minimal sample dilution, low analyte dispersion, and short sampling intervals. Human islet microtissues feature robust and long-term glucose responsiveness and demonstrate reproducible dynamic GSIS with a prominent first phase and a sustained, pulsatile second phase. Perifusion of single islet microtissues produces a higher peak secretion rate, higher secretion during the first and second phases of insulin release, as well as more defined pulsations during the second phase in comparison to perifusion of pooled islets. The developed platform enables to study compound effects on both phases of insulin secretion as shown with two classes of insulin secretagogs. It provides a new tool for studying physiologically relevant dynamic insulin secretion at comparably low sample-to-sample variation and high temporal resolution.
胰岛素在响应升高的葡萄糖水平时以双相和脉冲方式从胰岛中释放。这种高度动态的胰岛素释放可以通过胰岛灌注测定法在体外进行研究。本文提出了一种新的平台，用于使用单个胰岛进行葡萄糖刺激的胰岛素分泌 (GSIS) 测定，以高时间分辨率研究胰岛素释放的动力学。开发了标准化的人类胰岛模型，并设计了基于微流控悬挂滴的灌注系统，该系统有利于快速切换葡萄糖、最小化样品稀释、降低分析物分散和缩短采样间隔。人类胰岛微组织具有稳健且长期的葡萄糖反应性，并表现出可重复的动态 GSIS，具有明显的第一相和持续的、脉冲式的第二相。与灌注混合胰岛相比，灌注单个胰岛微组织会产生更高的峰值分泌率、在胰岛素释放的第一和第二相期间更高的分泌率以及在第二相期间更明确的脉冲。所开发的平台能够研究两种胰岛素分泌激动剂对胰岛素分泌两个阶段的复合影响。它提供了一种新工具，可在具有可比性的低样品间变异性和高时间分辨率的情况下研究生理相关的动态胰岛素分泌。
