Human Islet Microtissues as an In Vitro and an In Vivo Model System for Diabetes

Abstract

Loss of pancreatic β-cell function is a critical event in the pathophysiology of type 2 diabetes. However, studies of its underlying mechanisms as well as the discovery of novel targets and therapies have been hindered due to limitations in available experimental models. In this study we exploited the stable viability and function of standardized human islet microtissues to develop a disease-relevant, scalable, and reproducible model of β-cell dysfunction by exposing them to long-term glucotoxicity and glucolipotoxicity. Moreover, by establishing a method for highly-efficient and homogeneous viral transduction, we were able to monitor the loss of functional β-cell mass in vivo by transplanting reporter human islet microtissues into the anterior chamber of the eye of immune-deficient mice exposed to a diabetogenic diet for 12 weeks. This newly developed in vitro model as well as the described in vivo methodology represent a new set of tools that will facilitate the study of β-cell failure in type 2 diabetes and would accelerate the discovery of novel therapeutic agents.

HIF-1α inhibitor PX-478 preserves pancreatic β cell function in diabetes

“…8, E and F). In accordance with previous studies ( 42 ), insulin content was reduced by exposing islet organoids to high glucose (fig. S12, A and B).…”

“…To assess whether PX-478 improves the function of human β cells under high metabolic workload, we performed experiments using human islet organoids. Similarly to what has been observed with human islets, prolonged exposure of human islet organoids to high glucose concentrations leads to a marked up-regulation of basal insulin secretion with the correspondent collapse of the stimulation index ( 41 , 42 ). However, when cultured at normal glucose concentrations, human islet organoids have the advantage, when compared to native human islets, to display higher responses to glucose in terms of insulin secretion ( 43 ).…”

“…We also investigated the ability of PX-478 to improve human β cell function in human islet organoids chronically exposed to high glucose. Prolonged exposure of human islets or islet organoids to high glucose leads to a marked increase of basal insulin secretion ( 41 , 42 ). Elevated fasting insulin is observed in obese, prediabetic, and some diabetic subjects ( 6 , 7 , 62 , 63 ).…”

Beta cell and immune cell interactions in autoimmune type 1 diabetes: How they meet and talk to each other

“…This is a difficult question to address in humans but is an important one to consider. The recent development of pancreatic islet microtissues by InSphero [ 129 ] may provide one platform in which this could be assessed. Islet microtissues pretreated with factors that enhance non-classical HLAI expression (and likely also classical HLAI) could be co-cultured with CD8 + T cell subsets with varying specificities to assess the impact this has on islet viability.…”

Ectopic Leptin Production by Intraocular Pancreatic Islet Organoids Ameliorates the Metabolic Phenotype of ob/ob Mice

“…In fact, transplantation of a sufficient number of islets to the ACE (75-300 islets in mice) showed that these islet grafts are capable of maintaining glycaemia in streptozotocintreated diabetic mice ( [1], reviewed in [2]). Islet organoids (also called pseudo-islets) that are formed by self-reassembly of islet cells following disaggregation and genetic manipulation, for example by adenoviral-mediated ectopic gene expression [3,4], behave similarly to native islets. Because of these features, we wanted to test the hypothesis that genetically engineered intraocular islet organoids can serve as production sites for blood-born proteins/peptides as a novel treatment strategy.…”