Tissue regeneration, such as pancreatic islet tissue propagation in vitro, could serve as a promising strategy for diabetes therapy and personalised drug testing. However, such a strategy has not been realised yet. Propagation could be divided into two steps, in vitro expansion and repeated passaging. Even the first step of the in vitro islet expansion has not been achieved to date. Here, we describe a method that enables the expansion of islet clusters isolated from pregnant mice or wild-type rats by employing a combination of specific regeneration factors and chemical compounds in vitro. The expanded islet clusters expressed insulin, glucagon and somatostatin, which are markers corresponding to pancreatic β cells, α cells and δ cells, respectively. These different types of cells grouped together, were spatially organised and functioned similarly to primary islets. Further mechanistic analysis revealed that forskolin in our recipe contributed to renewal and regeneration, whereas exendin-4 was essential for preserving islet cell identity. Our results provide a novel method for the in vitro expansion of islet clusters, which is an important step forward in developing future protocols and media used for islet tissue propagation in vitro. Such method is important for future regenerative diabetes therapies and personalised medicines using large amounts of pancreatic islets derived from the same person.

组织再生，例如体外胰岛组织增殖，可以作为糖尿病治疗和个性化药物测试的有前途的策略。然而，这样的战略尚未实现。繁殖可分为体外扩增和重复传代两个步骤。迄今为止，甚至还没有实现体外胰岛扩增的第一步。在这里，我们描述了一种方法，通过在体外结合使用特定的再生因子和化学化合物，能够扩展从怀孕小鼠或野生型大鼠中分离的胰岛簇。扩张的胰岛簇表达胰岛素、胰高血糖素和生长抑素，它们分别是对应于胰腺β细胞、α细胞和δ细胞的标记物。这些不同类型的细胞聚集在一起，在空间上组织和功能与原始胰岛类似。进一步的机制分析表明，我们的配方中的毛喉素有助于更新和再生，而 exendin-4 对于保持胰岛细胞特性至关重要。我们的结果为胰岛簇的体外扩增提供了一种新方法，这是开发用于体外胰岛组织增殖的未来协议和培养基的重要一步。这种方法对于未来使用来自同一个人的大量胰岛的再生糖尿病疗法和个性化药物非常重要。