Investigation of β cell-derived extracellular vesicles in stimulating the insulin secretion in mouse cell spheroids
Sarah Boucenna1, Maryam Tabrizian1,2
1Faculty of Dental Medicine and Oral Health Sciences, ÎÛÎÛ²ÝÝ®ÊÓƵ University, Montreal, Canada. 2Department of Biomedical Engineering, ÎÛÎÛ²ÝÝ®ÊÓƵ University, Montreal Canada,
Type 1 Diabetes (T1D) targets insulin-producing beta cells, causing chronic hyperglycemia and severe complications. Current treatments, involving exogenous insulin and donor islet transplantation present some limitations such as the loss of islet graft functionality, i.e. insulin secretion soon after transplantation, immune rejection and vascularization issues. In our work, we aim to address some of these limitations by proposing the use of beta-cell derived extracellular vesicles (EVs) as a stimulator of functionality in insulin producing beta cells. Generally, EVs are heterogeneous population of lipid- bilayer membrane vesicles naturally released by cells and carry the fingerprints of their parent cells. EVs have raised growing interest due to their role in intercellular communication through their cargo of biologically active molecules. Their cellular source makes them less likely to be rapidly cleared by the body. Our approach consists in isolating EVs from mouse insulinoma (MIN 6) and immortalized human Endoc-BH1 cell line and use them as a potential therapeutic modality to dysfunctional beta cells. First, EVs are isolated using tangential flow filtration and ultracentrifugation, and are characterized via nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blotting. Secondly, MIN6 cells are used to create spheroids as pseudo-islet models for EV uptake and to investigate the effect of this uptake of the pseudo-islet insulin secretion. Confocal microscopy has confirmed successful uptake, with no cytotoxic effects as revealed via Alamar blue assays. Next, the effect of EVs on insulin production and macrophage polarization are assessed. Our preliminary results suggest that EV-derived beta cells present a promising therapy to enhance the beta cell function and propose an avenue to increase the outcome of islet transplantation in clinical setting.