Dual Effect of 4-Methylumbelliferone on INS1E Cells: Enhancing Migration and Glucose-Stimulated Insulin Secretion

: Recent studies have demonstrated that the coumarin derivative 4-Methylumbelliferone (4MU) has an antidiabetic effect in rodent models. 4MU is known to decrease the availability of hyaluronan (HA) substrates and inhibit the activity of different HA synthases. Nevertheless, it has been observed that 4MU may also affect cellular metabolism. In this study, we utilize the rat insulinoma beta cell line (INS-1E) cultured in both two-dimensional (2D) and three-dimensional (3D) experimental settings (pseudo islets), as an in vitro model to study beta cell functionality. For the first time, we observed that treating INS1E cells with 4MU results in improved insulin secretion. Additionally, we discovered that 4MU treatment elicited morphological changes from multilayer to monolayer conditions, along with a varied distribution of insulin granules and cell adhesion properties. Notably, we found that insulin secretion is not correlated with HA production. The same result was observed in co-culture experiments involving INS-1E cells and stromal vascular fraction (SVF) from adipose tissue. These experiments aim to investigate the effects of 4MU on beta cells in the context of its potential use in early-stage type 1 diabetes and in enhancing islet transplantation outcomes.