title: Protein carbonylation after traumatic brain injury: cell specificity, regional susceptibility, and gender differences.
abstract: Protein carbonylation is a well-documented and quantifiable consequence of oxidative stress in several neuropathologies, including multiple sclerosis, Alzheimer׳s disease, and Parkinson׳s disease. Although oxidative stress is a hallmark of traumatic brain injury (TBI), little work has explored the specific neural regions and cell types in which protein carbonylation occurs. Furthermore, the effect of gender on protein carbonylation after TBI has not been studied. The present investigation was designed to determine the regional and cell specificity of TBI-induced protein carbonylation and how this response to injury is affected by gender. Immunohistochemistry was used to visualize protein carbonylation in the brains of adult male and female Sprague-Dawley rats subjected to controlled cortical impact (CCI) as an injury model of TBI. Cell-specific markers were used to colocalize the presence of carbonylated proteins in specific cell types, including astrocytes, neurons, microglia, and oligodendrocytes. Results also indicated that the injury lesion site, ventral portion of the dorsal third ventricle, and ventricular lining above the median eminence showed dramatic increases in protein carbonylation after injury. Specifically, astrocytes and limited regions of ependymal cells adjacent to the dorsal third ventricle and the median eminence were most susceptible to postinjury protein carbonylation. However, these patterns of differential susceptibility to protein carbonylation were gender dependent, with males showing significantly greater protein carbonylation at sites distant from the lesion. Proteomic analyses were also conducted and determined that the proteins most affected by carbonylation in response to TBI include glial fibrillary acidic protein, dihydropyrimidase-related protein 2, fructose-bisphosphate aldolase C, and fructose-bisphosphate aldolase A. Many other proteins, however, were not carbonylated by CCI. These findings indicate that there is both regional and protein specificity in protein carbonylation after TBI. The marked increase in carbonylation seen in ependymal layers distant from the lesion suggests a mechanism involving the transmission of a cerebral spinal fluid-borne factor to these sites. Furthermore, this process is affected by gender, suggesting that hormonal mechanisms may serve a protective role against oxidative stress.
authors.affiliation: Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Lazarus
authors.affiliation: Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Buonora
authors.affiliation: Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Jacobowitz
authors.affiliation: Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA. Electronic address: Gregory.mueller@usuhs.edu.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Mueller
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D015153:Blotting, Western; D001930:Brain Injuries / Q000378:metabolism*; D002478:Cells, Cultured; D004805:Ependyma / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007124:Immunoenzyme Techniques; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D017628:Microglia / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D018384:Oxidative Stress; D050050:Protein Carbonylation; D040901:Proteomics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics
chemical_list: D005904:Glial Fibrillary Acidic Protein; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; C095114:collapsin response mediator protein-2; D005634:Fructose-Bisphosphate Aldolase
keywords: Astrocytes; Carbonylation; Dorsal third ventricle; Ependymal cells; Free radicals; Median eminence; Reactive carbonyl species; Reactive oxygen species; Traumatic brain injury