Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.
Department of Chemistry, Wesleyan University, Middletown, CT 06457, USA.
Cells. 2020 Nov 27;9(12):2551. doi: 10.3390/cells9122551.
Pancreatic islet transplantation is the fundamental treatment for insulin-dependent diabetes; however, donor shortage is a major hurdle in its use as a standard treatment. Accordingly, differentiated insulin-producing cells (DIPCs) are being developed as a new islet source. Differentiation efficiency could be enhanced if the spheroid structure of the natural islets could be recapitulated. Here, we fabricated DIPC spheroids using concave microwells, which enabled large-scale production of spheroids of the desired size. We prepared DIPCs from human liver cells by trans-differentiation using transcription factor gene transduction. Islet-related gene expression and insulin secretion levels were higher in spheroids compared to those in single-cell DIPCs, whereas actin-myosin interactions significantly decreased. We verified actin-myosin-dependent insulin expression in single-cell DIPCs by using actin-myosin interaction inhibitors. Upon transplanting cells into the kidney capsule of diabetic mouse, blood glucose levels decreased to 200 mg/dL in spheroid-transplanted mice but not in single cell-transplanted mice. Spheroid-transplanted mice showed high engraftment efficiency in in vivo fluorescence imaging. These results demonstrated that spheroids fabricated using concave microwells enhanced the engraftment and functions of DIPCs via actin-myosin-mediated cytoskeletal changes. Our strategy potentially extends the clinical application of DIPCs for improved differentiation, glycemic control, and transplantation efficiency of islets.
胰岛移植是治疗胰岛素依赖型糖尿病的根本方法；然而，供体短缺是其作为标准治疗方法的主要障碍。因此，正在开发分化的胰岛素产生细胞（DIPCs）作为新的胰岛来源。如果能够再现天然胰岛的球体结构，分化效率可以得到提高。在这里，我们使用凹微井制造了 DIPC 球体，从而能够大规模生产所需大小的球体。我们通过转录因子基因转导，从人肝细胞中转分化制备 DIPCs。与单细胞 DIPCs 相比，球体中的胰岛相关基因表达和胰岛素分泌水平更高，而肌动球蛋白相互作用显著降低。我们通过使用肌动球蛋白相互作用抑制剂验证了单细胞 DIPCs 中肌动球蛋白依赖性胰岛素表达。将细胞移植到糖尿病小鼠的肾囊后，球体移植小鼠的血糖水平降至 200mg/dL，而单细胞移植小鼠则没有。球体移植小鼠在体内荧光成像中的嵌合效率较高。这些结果表明，使用凹微井制造的球体通过肌动球蛋白介导的细胞骨架变化增强了 DIPCs 的植入和功能。我们的策略有可能扩展 DIPCs 的临床应用，以改善分化、血糖控制和胰岛移植效率。
