Free Fatty Acids (FFAs) have been shown to be involved in several membrane-mediated cellular processes (e.g. insulin secretion). However, altered plasma FFAs levels typical of obese and/or diabetic subjects have been proposed to contribute to the onset and progression of type 2 diabetes mellitus through both their possible involvement in altered metabolic pathways (1) and their direct action on cell membranes likely contributing to pancreatic β-cells failure due to amylin fibrils (2,3). Among several studies, few works are devoted to a thermodynamic characterization of the role of FFAs on the overall membrane stability, however without considering the compositional complexity of real biological vesicles (4). In such a frame, the present work was aimed at the calorimetric investigation of complex 15-components model membranes mimicking the phospholipid bilayer of Insulin Secretory Granules (ISGs), vesicles located in the pancreatic Langerhans -cells and which are responsible for insulin and amylin storage and secretion in response to nutrients in take. This study was performed through micro-DSC and allowed to dissect each single thermodynamic contribution to the overall membrane stability(5). High FFAs concentrations were added to the membranes revealing that their stabilizing or destabilizing effect only depend on their chemical structure, not on vesicle complexity Moreover, the influence of increasing percentages of cholesterol on pure membranes was highlighted.
|Titolo:||Calorimetric Investigation on the Influence of Free Fatty Acids on the Stability of Insulin Secretory Granule Model Membranes|
SAITTA, FRANCESCA (Primo) (Corresponding)
FESSAS, DIMITRIOS (Ultimo)
|Data di pubblicazione:||mag-2019|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Citazione:||Calorimetric Investigation on the Influence of Free Fatty Acids on the Stability of Insulin Secretory Granule Model Membranes / F. Saitta, M. Signorelli, D. Fessas. ((Intervento presentato al convegno Membrane Lipids tenutosi a Berlin nel 2019.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|