title: Age-related changes in scavenger receptor-mediated endocytosis in rat liver sinusoidal endothelial cells.
abstract: Liver sinusoidal endothelial cells (LSECs) play an essential role in systemic waste clearance by effective endocytosis of blood-borne waste macromolecules. We aimed to study LSECs' scavenger function during aging, and whether age-related morphological changes (eg, defenestration) affect this function, in F344/BN F1 rats. Endocytosis of the scavenger receptor ligand formaldehyde-treated serum albumin was significantly reduced in LSECs from old rats. Ligand degradation, LSEC protein expression of the major scavenger receptors for formaldehyde-treated serum albumin endocytosis, stabilin-1 and stabilin-2, and their staining patterns along liver sinusoids, was similar at young and old age, suggesting that other parts of the endocytic machinery are affected by aging. Formaldehyde-treated serum albumin uptake per cell, and cell porosity evaluated by electron microscopy, was not correlated, indicating that LSEC defenestration is not linked to impaired endocytosis. We report a significantly reduced LSEC endocytic capacity at old age, which may be especially important in situations with increased circulatory waste loads.
authors.affiliation: Department of Medical Biology, University of Tromsø, NO-9037 Tromsø, Norway.
authors.forename: Jaione
authors.initials: J
authors.lastname: Simon-Santamaria
authors.forename: Ivana
authors.initials: I
authors.lastname: Malovic
authors.forename: Alessandra
authors.initials: A
authors.lastname: Warren
authors.forename: Ana
authors.initials: A
authors.lastname: Oteiza
authors.forename: David
authors.initials: D
authors.lastname: Le Couteur
authors.forename: Bård
authors.initials: B
authors.lastname: Smedsrød
authors.forename: Peter
authors.initials: P
authors.lastname: McCourt
authors.forename: Karen Kristine
authors.initials: KK
authors.lastname: Sørensen
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002478:Cells, Cultured; D004705:Endocytosis; D042783:Endothelial Cells / Q000378:metabolism*; D005557:Formaldehyde / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000648:ultrastructure; D008297:Male; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D051381:Rats; D011916:Rats, Inbred F344; D011956:Receptors, Cell Surface / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D011956:Receptors, Cell Surface; C486732:Stab1 protein, mouse; C486733:Stab2 protein, mouse; D005557:Formaldehyde; D012710:Serum Albumin, Bovine