The role of CD36 in peripheral nerve remyelination after crush injury.
We previously demonstrated that the deficiency of class A macrophage scavenger receptor type I/II was involved in the delayed phagocytosis of degraded myelin by macrophages in class A macrophage scavenger receptor type I/II knockout mice after crush injury of the sciatic nerve [Naba et al. (2000) Exp. Neurol., 166, 83-89]. In order to elucidate the role of CD36, one of the scavenger receptors, here we inflicted crush injury to the sciatic nerves of CD36 knockout mice and investigated the remyelination after crush injury in comparison with that of class A macrophage scavenger receptor type I/II knockout mice. Although we previously reported a lot of onion-bulbs in class A macrophage scavenger receptor type I/II knockout mice at 3 weeks, the number of onion-bulbs was limited both in CD36 knockout mice and wild-type mice. In the morphometry, the remyelination was seriously delayed, and the infiltrating macrophages into the nerve fascicles were quite frequent in CD36 knockout mice compared with wild-type mice at 3 and 6 weeks postinjury. The immunohistochemistry with the monoclonal antibody reacted with oxidized phosphatidylcholine and oil red O staining were positive in wild-type mice, but were negative in CD36 knockout mice, suggesting that the oxidation of phosphatidylcholine and the generation of neutral lipids in macrophages were disturbed in CD36 knockout mice. We hypothesize that the delayed phagocytosis by macrophages and the defect in reuse of lipids from degraded myelin are related to seriously delayed remyelination and a small number of onion-bulbs in CD36 knockout mice.
Eto
Masaki
M
Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka 565-0871, Japan.
Yoshikawa
Hiroo
H
Fujimura
Harutoshi
H
Naba
Ichiro
I
Sumi-Akamaru
Hisae
H
Takayasu
Satoshi
S
Itabe
Hiroyuki
H
Sakoda
Saburo
S
D000818:Animals; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism*; D002452:Cell Count; D004195:Disease Models, Animal; D005260:Female; D051528:Guanylate Kinases; D007150:Immunohistochemistry / Q000379:methods; D037102:Lectins / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009186:Myelin Sheath / Q000378:metabolism / Q000473:pathology; D009409:Nerve Crush / Q000379:methods; D009413:Nerve Fibers, Myelinated / Q000378:metabolism* / Q000473:pathology; D009479:Neuropeptides; D009687:Nuclear Proteins / Q000378:metabolism; D010523:Peripheral Nervous System Diseases / Q000378:metabolism* / Q000473:pathology; D051117:Scavenger Receptors, Class A; D012584:Sciatic Nerve / Q000293:injuries / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
D018955:CD36 Antigens; D037102:Lectins; D008565:Membrane Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D051117:Scavenger Receptors, Class A; D014157:Transcription Factors; C491075:Dlgh3 protein, mouse; D051528:Guanylate Kinases