Induction of heme oxygenase-1 (HO-1) in glia after traumatic brain injury.
In this study we examined the induction of heme oxygenase-1 (HO-1) in glia in the traumatized rat brain. HO-1 was immunolocalized in fixed sections of brain 3 h to 5 days after injury. Induction of this enzyme in astrocytes, microglia/macrophages, and oligodendrocytes was evaluated using immunofluorescent double labeling with monoclonal antibodies to glial fibrillary acidic protein, complement C3bi receptor, and myelin basic protein. Induction of HO-1 was apparent in the injured hemisphere and cerebellum as early as 24 h postinjury. The protein was likewise noted in similar regions of the brain at 72 h postinjury but appeared to be more widespread in its distribution. At 5 days postinjury, there was a notable decline in the degree of immunostaining for HO-1. HO-1 was typically induced in astrocytes in the cerebral cortex at the site of impact, in the deep cortical layers adjacent to the hemorrhagic lesions, and in the hippocampus. HO-1 was induced in Bergmann glia in the vermis of cerebellum. In addition, HO-1 was also induced in microglia/macrophages scattered throughout the ipsilateral cerebral cortex, cerebellum and subarachnoid space. These findings demonstrate prolonged glial induction of HO-1 in the traumatized brain. Such a response may reflect a protective role of these cells against secondary insults including oxidative stress.
Fukuda
K
K
Department of Neurosurgery, University of California, San Francisco, USA.
Richmon
J D
JD
Sato
M
M
Sharp
F R
FR
Panter
S S
SS
Noble
L J
LJ
D000818:Animals; D001253:Astrocytes / Q000201:enzymology / Q000473:pathology; D001794:Blood Pressure; D001921:Brain / Q000201:enzymology* / Q000473:pathology; D001930:Brain Injuries / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D002531:Cerebellum / Q000201:enzymology; D002540:Cerebral Cortex / Q000201:enzymology; D004790:Enzyme Induction; D005455:Fluorescent Antibody Technique; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis*; D008297:Male; D017628:Microglia / Q000201:enzymology / Q000473:pathology; D009457:Neuroglia / Q000201:enzymology* / Q000473:pathology; D009836:Oligodendroglia / Q000201:enzymology / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
D005904:Glial Fibrillary Acidic Protein; D006419:Heme Oxygenase (Decyclizing)