Uptake of fibrillar beta-amyloid by microglia isolated from MSR-A (type I and type II) knockout mice.
To characterize the receptors involved in binding fibrillar amyloid A-beta (fA beta), we compared the uptake of fA beta in microglia from wildtype (MSR-A+/+) and MSR-A knockout (MSR-A-/-) mice. On average, there was a 60% reduction in the uptake of Cy3-fA beta in microglia from the MSR-A-/- mice. Cy3-fA beta uptake in the MSR-A-/- mice was still competable by scavenger receptor ligands, including acetylated low-density lipoprotein (Ac-LDL) and fucoidan. This indicates that uptake by MSR-B and/or other MSRs is also involved in the uptake of fA beta by microglia. However, the significant reduction in the uptake of fA beta in the MSR-A-/- microglia suggests that fA beta gets internalized mostly by MSR-As in microglia. Uptake of modified fA beta (ClqA beta) was similar in the MSR-A-/- microglia as in the wildtype indicating that the uptake of the opsonized fA beta is independent of MSR-A.
Chung
H
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Department of Biochemistry, Weill Medical College of Cornell University, Room E215, 1300 York Avenue, New York, NY 10021, USA.
Brazil
M I
MI
Irizarry
M C
MC
Hyman
B T
BT
Maxfield
F R
FR
D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D002232:Carbocyanines / Q000378:metabolism; D002469:Cell Separation; D002478:Cells, Cultured; D005456:Fluorescent Dyes / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D017628:Microglia / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000172:deficiency* / Q000235:genetics*; D051116:Receptors, Scavenger
D016229:Amyloid beta-Peptides; D002232:Carbocyanines; D005456:Fluorescent Dyes; D007074:Immunoglobulin G; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; C089187:cyanine dye 3