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Increased hexosamine biosynthetic pathway flux alters cell–cell adhesion in INS-1E cells and murine islets

PURPOSE: In type 2 Diabetes, β-cell failure is caused by loss of cell mass, mostly by apoptosis, but also by simple dysfunction (dedifferentiation, decline of glucose-stimulated insulin secretion). Apoptosis and dysfunction are caused, at least in part, by glucotoxicity, in which increased flux of g...

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Detalles Bibliográficos
Autores principales: Lofrumento, Dario Domenico, Miraglia, Alessandro, La Pesa, Velia, Treglia, Antonella Sonia, Chieppa, Marcello, De Nuccio, Francesco, Nicolardi, Giuseppe, Miele, Claudia, Beguinot, Francesco, Garbi, Corrado, Di Jeso, Bruno
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer US 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10403402/
https://www.ncbi.nlm.nih.gov/pubmed/37306934
http://dx.doi.org/10.1007/s12020-023-03412-9
Descripción
Sumario:PURPOSE: In type 2 Diabetes, β-cell failure is caused by loss of cell mass, mostly by apoptosis, but also by simple dysfunction (dedifferentiation, decline of glucose-stimulated insulin secretion). Apoptosis and dysfunction are caused, at least in part, by glucotoxicity, in which increased flux of glucose in the hexosamine biosynthetic pathway plays a role. In this study, we sought to clarify whether increased hexosamine biosynthetic pathway flux affects another important aspect of β-cell physiology, that is β-cell–β-cell homotypic interactions. METHODS: We used INS-1E cells and murine islets. The expression and cellular distribution of E-cadherin and β-catenin was evaluated by immunofluorescence, immunohistochemistry and western blot. Cell–cell adhesion was examined by the hanging-drop aggregation assay, islet architecture by isolation and microscopic observation. RESULTS: E-cadherin expression was not changed by increased hexosamine biosynthetic pathway flux, however, there was a decrease of cell surface, and an increase in intracellular E-cadherin. Moreover, intracellular E-cadherin delocalized, at least in part, from the Golgi complex to the endoplasmic reticulum. Beta-catenin was found to parallel the E-cadherin redistribution, showing a dislocation from the plasmamembrane to the cytosol. These changes had as a phenotypic consequence a decreased ability of INS-1E to aggregate. Finally, in ex vivo experiments, glucosamine was able to alter islet structure and to decrease surface abundandance of E-cadherin and β-catenin. CONCLUSION: Increased hexosamine biosynthetic pathway flux alters E-cadherin cellular localization both in INS-1E cells and murine islets and affects cell–cell adhesion and islet morphology. These changes are likely caused by alterations of E-cadherin function, highlighting a new potential target to counteract the consequences of glucotoxicity on β-cells.