High Glucose Exposure Impairs L-Cell Differentiation in Intestinal Organoids: Molecular Mechanisms and Clinical Implications.

Agnese Filippello,Salvatore Piro,Roberta Malaguarnera,Sebastiano Alfio Torrisi,Gian Marco Leggio,Francesco Purrello,Alessandra Scamporrino,Antonino Di Pino,Stefania Di Mauro,Roberto Scicali

doi:10.3390/ijms22136660

Abstract

Intestinal organoids are used to analyze the differentiation of enteroendocrine cells (EECs) and to manipulate their density for treating type 2 diabetes. EEC differentiation is a continuous process tightly regulated in the gut by a complex regulatory network. However, the effect of chronic hyperglycemia, in the modulation of regulatory networks controlling identity and differentiation of EECs, has not been analyzed. This study aimed to investigate the effect of glucotoxicity on EEC differentiation in small intestinal organoid platforms. Mouse intestinal organoids were cultured in the presence/absence of high glucose concentrations (35 mM) for 48 h to mimic glucotoxicity. Chronic hyperglycemia impaired the expression of markers related to the differentiation of EEC progenitors (Ngn3) and L-cells (NeuroD1), and it also reduced the expression of Gcg and GLP-1 positive cell number. In addition, the expression of intestinal stem cell markers was reduced in organoids exposed to high glucose concentrations. Our data indicate that glucotoxicity impairs L-cell differentiation, which could be associated with decreased intestinal stem cell proliferative capacity. This study provides the identification of new targets involved in new molecular signaling mechanisms impaired by glucotoxicity that could be a useful tool for the treatment of type 2 diabetes.

Highlights

Over the last ten years, the study of type 2 diabetes has been extended with novel physiopathological aspects related to the actions of gastrointestinal hormones
Cell Viability of Organoids Treated with High Glucose
In order to evaluate glucose cytotoxicity, we performed the MTT assay in organoids exposed to increasing glucose concentrations (25 and 35 mM) and in control organoids exposed to increasing glucose concentrations (25 and 35 mM) and in control organoids exposed to 17.5 mM of glucose for different periods of time (24, 48, or 72 h)

Summary

Introduction

Over the last ten years, the study of type 2 diabetes has been extended with novel physiopathological aspects related to the actions of gastrointestinal hormones. It has been recognized that glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), produced by the enteroendocrine L- and K-cells, respectively, constitute >90% of all incretin effects. These two incretins and enteroendocrine cells (EECs) have represented additional novel potential molecular targets for the management of type 2 diabetes. It is important to understand if hyperglycemia impairs L-cell function or, in contrast, deregulation of EEC secretions induces diabetes onset In light of these considerations, the study of EEC functions could allow us to understand the specific contribution of endocrine pancreatic and intestinal secretions in diabetes pathogenesis

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