German Center for Diabetes Research (DZD e.V.), Tübingen, Germany.
Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen (IDM), Tübingen, Germany.
Sci Rep. 2019 Jul 16;9(1):10261. doi: 10.1038/s41598-019-46545-6.
Isolated human islets do not always meet the quality standards required for transplant survival and reliable functional in vitro studies. The formation of pseudoislets, i.e. the reaggregation of a defined number of islet cells after dissociation, improves insulin secretion. We present a simple method of pseudoislet formation from human islet cells and assess the transcriptome and function of isolated human islets and pseudoislets from the same organ donors. Following pseudoislet formation, insulin content/DNA and mRNA/RPS13 resembled that of islets. In pseudoislets, glucose-stimulated insulin secretion (GSIS) was significantly higher (8-13-fold) than in islets (2-4-fold). GSIS of pseudoislets was partly inhibited by the glucagon-like peptide-1 receptor (GLP-1R) antagonist exendin-9. The stimulatory effects of palmitate and forskolin at 12 mM glucose were also significantly higher in pseudoislets than in islets. Further analysis of pseudoislets revealed that regulation of secretion and insulin and glucagon content was maintained over a longer culture period (6-14 d). While adrenaline inhibited GSIS, adrenaline together with palmitate stimulated glucagon secretion 2-fold at low glucose, an effect suppressed by high glucose. Transcriptome analysis revealed that, unlike islets, pseudoislets were deprived of exocrine and endothelial cells. In conclusion, pseudoislet formation restores functional integrity of human islet cells and allows long-term in vitro testing.
从人胰岛中分离出的胰岛并不总是符合移植存活和可靠的体外功能研究所需的质量标准。假胰岛的形成，即胰岛细胞分离后重新聚集形成一定数量的胰岛，可改善胰岛素分泌。我们提出了一种从人胰岛细胞中形成假胰岛的简单方法，并评估了来自同一器官供体的分离胰岛和假胰岛的转录组和功能。形成假胰岛后，胰岛素含量/DNA 和 mRNA/RPS13 与胰岛相似。在假胰岛中，葡萄糖刺激的胰岛素分泌 (GSIS) 明显高于胰岛（2-4 倍）（8-13 倍）。胰高血糖素样肽-1 受体 (GLP-1R) 拮抗剂 exendin-9 部分抑制了假胰岛的 GSIS。在 12mM 葡萄糖下，棕榈酸和 forskolin 的刺激作用在假胰岛中也明显高于胰岛。对假胰岛的进一步分析表明，在较长的培养期（6-14 天）内，分泌和胰岛素及胰高血糖素含量的调节得以维持。虽然肾上腺素抑制 GSIS，但肾上腺素与棕榈酸一起在低血糖下刺激胰高血糖素分泌增加 2 倍，这一作用被高血糖抑制。转录组分析表明，与胰岛不同，假胰岛缺乏外分泌细胞和内皮细胞。总之，假胰岛的形成恢复了人胰岛细胞的功能完整性，并允许进行长期的体外测试。
