Scavenger receptor class B type I (SR-BI) mediates adhesion of neonatal murine microglia to fibrillar beta-amyloid.
Class A scavenger receptors (SR-A) mediate microglial interaction with fibrillar beta-amyloid (fAbeta). We report here that neonatal microglia from SR-A knockout mice (SR-A-/-) adhere to surface-bound fAbeta, and produce reactive oxygen species (ROS) as efficiently as wildtype microglia; that both wildtype and SR-A-/- microglia express SR-BI; that antibodies against SR-BI do not affect adhesion or ROS production by wildtype microglia, but inhibit adhesion and ROS production of SR-A-/- microglia to immobilized fAbeta by approximately 40%. Adhesion to fAbeta-coated surfaces, and uptake of fAbeta by both wildtype and SR-A-/- microglia was almost completely inhibited by incubation with fucoidan. Thus SR-BI and SR-A mediate similar effector functions in neonatal microglia, which suggests that SR-BI plays as important a role as SR-A, and can maintain the wildtype phenotype in SR-A-/- microglia.
Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York, NY 10032, USA. jh577@columbia.edu
J
J
Husemann
J D
JD
Loike
T
T
Kodama
S C
SC
Silverstein
D000544:Alzheimer Disease / Q000276:immunology / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D000970:Antineoplastic Agents / Q000494:pharmacology; D001921:Brain / Q000166:cytology; D018955:CD36 Antigens / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D002232:Carbocyanines / Q000378:metabolism / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D005456:Fluorescent Dyes / Q000378:metabolism / Q000494:pharmacology; D015870:Gene Expression / Q000276:immunology; D008099:Liver / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D017628:Microglia / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism*; D011134:Polysaccharides / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B
D016229:Amyloid beta-Peptides; D000970:Antineoplastic Agents; D018955:CD36 Antigens; D002232:Carbocyanines; D005456:Fluorescent Dyes; D008565:Membrane Proteins; D010446:Peptide Fragments; D011134:Polysaccharides; D017382:Reactive Oxygen Species; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; C075222:amyloid beta-protein (1-42); C089187:cyanine dye 3; C007789:fucoidan