Insulin-induced exocytosis regulates the cell surface level of low-density lipoprotein-related protein-1 in Müller Glial cells

ACTIS DATO, VIRGINIA; SÁNCHEZ, MARÍA C.; GROSSO, RUBÉN A.; FADER, CLAUDIO M.; CHIABRANDO, GUSTAVO A.

BIOCHEMICAL JOURNAL

PORTLAND PRESS LTD

Año: 2018 vol. 475 p. 1669 - 1669

0264-6021

ow-density lipoprotein (LDL) receptor-related protein-1 (LRP1) is expressed in retinal Müller glial cells (MGCs) and regulates intracellular translocation to the plasma membrane (PM) of the membrane proteins involved in cellular motility and activity. Different functions of MGCs may be influenced by insulin, including the removal of extracellular glutamate in the retina. In the present work, we investigated whether insulin promotes LRP1 translocation to the PM in the Müller glial-derived cell line MIO-M1. We demonstrated that LRP1 is stored in small vesicles containing an approximate size of 100 nm (mean diameter range of 100 nm to 120 nm), which were positive for sortilin and VAMP2, and also incorporated GLUT4 when it was transiently transfected. Next, we observed that LRP1 translocation to the PM was promoted by insulin-regulated exocytosis through intracellular activation of the IR/PI3K/Akt axis and Rab-GTPase proteins such as Rab8A and Rab10. In addition, these Rab-GTPases regulat