Closed head injury induces up-regulation of ErbB-4 receptor at the site of injury.
ErbB-4 receptor tyrosine kinase and its ligand neu differentiation factor (NDF/neuregulin) are widely expressed in the brain. The closed head injury model was used to investigate the possible role of ErbB-4 receptor in neurodegeneration. It is demonstrated that levels of ErbB-4 are dramatically increased at the site of injury. Activated microglia/macrophages constitute the major population of cells with the highest receptor levels at the site of injury. In addition ErbB-4 expression after injury is elevated also in neurons but not in astrocytes. Confocal microscopy analysis suggests that the high level of ErbB-4 protein in activated microglia/macrophages is probably due to phagocytosis of neuronal cells. These findings show for the first time that ErbB-4 receptors play a role in brain responses to head trauma. Overexpression of ErbB-4 receptors may be important for directing activated microglia/macrophages to the lesion site.
Erlich
S
S
Department of Neurobiochemistry, Tel-Aviv University, Ramat-Aviv, 69978, Israel.
Shohami
E
E
Pinkas-Kramarski
R
R
D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D066246:ErbB Receptors / Q000032:analysis / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D037502:Galectin 3; D016489:Head Injuries, Closed / Q000378:metabolism*; D020287:In Situ Nick-End Labeling; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000737:chemistry / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D066247:Receptor, ErbB-4; D015854:Up-Regulation / Q000502:physiology
D000943:Antigens, Differentiation; D037502:Galectin 3; D066246:ErbB Receptors; C587690:Erbb4 protein, mouse; D066247:Receptor, ErbB-4