Dynamic glucose uptake, storage, and release by human microvascular endothelial cells

• Autores: Yazdani, Samaneh; Bilan, Philip J.; Jaldín Fincati, Javier Roberto; Pang, Janice; Ceban, Felicia; Saran, Ekambir; Brumell, John H.; Freeman, Spencer A.; Klip, Amira
• Año de publicación: 2022
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Glucose; Microvascular endothelial cells; 2-NBDG; GLUT1; GLUT3
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Endothelia determine blood-to-tissue solute delivery, yet glucose transit is poorly understood. To illuminate mechanisms, we tracked [3H]-2-deoxyglucose (2-DG) in human adipose-tissue microvascular endothelial cells. 2-DG uptake was largely facilitated by the glucose transporters GLUT1 and GLUT3. Once in the cytosol, >80% of 2-DG became phosphorylated and ∼20% incorporated into glycogen, suggesting that transported glucose is readily accessible to cytosolic enzymes. Interestingly, a fraction of intracellular 2-DG was released over time (15–20% over 30 min) with slower kinetics than for uptake, involving GLUT3. In contrast to intracellular 2-DG, the released 2-DG was largely unphosphorylated. Glucose release involved endoplasmic reticulum–resident translocases/phosphatases and was stimulated by adrenaline, consistent with participation of glycogenolysis and glucose dephosphorylation. Surprisingly, the fluorescent glucose derivative 2-NBD-glucose (2-NBDG) entered cells largely via fluid phase endocytosis and exited by recycling. 2-NBDG uptake was insensitive to GLUT1/GLUT3 inhibition, suggesting poor influx across membranes. 2-NBDG recycling, but not 2-DG efflux, was sensitive to N-ethyl maleimide. In sum, by utilizing radioactive and fluorescent glucose derivatives, we identified two parallel routes of entry: uptake into the cytosol through dedicated glucose transporters and endocytosis. This reveals the complex glucose handling by endothelial cells that may contribute to glucose delivery to tissues.
Fil: Yazdani, Samaneh. University Of Toronto. Hospital For Sick Children; Canadá
Fil: Bilan, Philip J.. University Of Toronto. Hospital For Sick Children; Canadá
Fil: Jaldín Fincati, Javier Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; Argentina. University Of Toronto. Hospital For Sick Children; Canadá
Fil: Pang, Janice. University Of Toronto. Hospital For Sick Children; Canadá
Fil: Ceban, Felicia. University Of Toronto. Hospital For Sick Children; Canadá
Fil: Saran, Ekambir. University Of Toronto. Hospital For Sick Children; Canadá
Fil: Brumell, John H.. University Of Toronto. Hospital For Sick Children; Canadá. University of Toronto; Canadá
Fil: Freeman, Spencer A.. University Of Toronto. Hospital For Sick Children; Canadá. University of Toronto; Canadá
Fil: Klip, Amira. University of Toronto; Canadá. University Of Toronto. Hospital For Sick Children; Canadá