Endocytic Turnover of Endothelial Cell-Membrane Proteins as a Driver of Blood Brain Barrier Specialization and Dysfunction

ABSTRACT: The blood-brain barrier (BBB), formed primarily by specialized brain endothelial cells (BEC), exerts essential functions for proper brain activity, including nutrient transport, signal transduction, immune cell transmigration and pathogen restriction. While these functions are known to be regulated by the identity and abundance (i.e. composition) of cell-membrane proteins, a parameter which remains underexplored is how protein endocytic turnover rate (ETOR)—the rate of protein internalization from the cell membrane— governs BBB physiology. Employing high-throughput in vitro proteomics, we quantify the ETOR of large protein arrays (c. 1000 individual proteins) across endothelial phenotypes and pathological states to examine the mechanisms driving BBB specialization and the changes underlying BBB dysfunction. We find that BEC possess a specialized ETOR profile which differentiates them from peripheral endothelial cells beyond their cell-membrane protein composition. In addition, we demonstrate that inflammatory conditions disrupt the endocytic rates of BEC to a greater degree than disruptions in protein abundance, shifting the specialized ETOR profile of BEC towards a peripheral phenotype. Furthermore, we demonstrate that, while inflammation-induced changes in protein abundance identify proteins strongly involved in immune response, inflammation-induced changes in ETOR identifies proteins strongly involved in vasculature remodelling. Together, our results indicate that the ETOR of cell-membrane proteins is an important parameter driving the specialization of the BBB which becomes disrupted during pathological conditions independently of cell-membrane protein composition. Furthermore, it highlights that ETOR changes identify pathological mechanisms underlying BBB dysfunction not identified by changes in protein abundance.

INSTRUMENT(S):

ORGANISM(S): Rattus Norvegicus (rat)

TISSUE(S): Cell Culture, Endothelial Cell

DISEASE(S): Inflammation

SUBMITTER: Marta Vilaseca  

LAB HEAD: Marta Vilaseca

PROVIDER: PXD067112 | Pride | 2026-05-15

REPOSITORIES: Pride