Differential protein expression in the prefrontal white matter of human alcoholics: a proteomics study

Abstract

Neuroimaging and post-mortem studies indicate that chronic alcohol use induces global changes in brain morphology, such as cortical and subcortical atrophy. Recent studies have shown that frontal lobe structures are specifically susceptible to alcohol-related brain damage and shrinkage in this area is largely due to a loss of white matter. This may explain the high incidence of cognitive dysfunction observed in alcoholics. Using a proteomics-based approach, changes in protein expression in the dorsolateral prefrontal region (BA9) white matter were identified in human alcoholic brains. Protein extracts from the BA9 white matter of 25 human brains (10 controls; eight uncomplicated alcoholics; six alcoholics complicated with hepatic cirrhosis; one reformed alcoholic) were separated using two-dimensional gel electrophoresis. Overall, changes in the relative expression of 60 proteins were identified (Po0.05, ANOVA) in the alcoholic BA9 white matter. In total, 18 protein spots have been identified using MALDI-TOF; including hNP22, a-internexin, transketolase, creatine kinase chain B, ubiquitin carboxy-terminal hydrolase L1 and glyceraldehyde-3-phosphate dehydrogenase. Several of these proteins have been previously implicated in alcohol-related disorders and brain damage. By identifying changes in protein expression in this region from alcoholics, hypotheses may draw upon more mechanistic explanations as to how chronic ethanol consumption causes white matter damage.

Cytosolic proteomic alterations in the nucleus accumbens of cocaine overdose victims

“…46,[48][49][50][51] Such studies have confirmed the differential abundance of certain proteins and provided refined hypotheses regarding the molecular mechanisms of these diseases. Two-dimensional electrophoresis (2DE), which separates protein species by both isoelectric point and molecular weight, 52 has been widely used and recently been improved through the addition of direct labeling of proteins with cyanine (Cy) dyes to facilitate quantitation (two-dimensional difference gel electrophoresis (2D-DIGE)).…”

“…The selection of specific pH range used in the present study for separation of proteins in the first dimension was determined empirically and was based on the pH range that provided optimal resolution of proteins present in the complex mixture in question. Previous studies have utilized broad-range pH strips 46,49,50 as well as more narrow-range pH strips 51,55,56,72 for a range of complex protein samples. For complex protein mixtures, it has been noted that the majority of the protein spots resolved using 3-10 pH strip usually fall between 4 and 7 pH.…”

“…These studies suggest that multiple pathways are involved in the neuropathology and altered neuronal function of cocaine addicts. As noted for alcoholism, 46 such studies highlight the importance of using high-throughput technologies to study in more detail the neuropathology associated with addictive disorders. Although these studies have been highly informative in furthering our understanding of cocaine-induced transcriptional regulation contributing to long-term changes in primate brain, research determining coordinate changes in the expression of multiple proteins has been scarce.…”

A proteome analysis of the anterior cingulate cortex gray matter in schizophrenia

“…Sample preparation and two-dimensional gel electrophoresis (2DE) methodology was according to Alexander-Kaufman et al 23 Briefly, 0.04-0.07 g of crude ACC fresh frozen tissue was placed in Buffer 1 (7 M Urea, 2 M Thiourea, 1% C7bZO, 40 mM Tris). Sample suspensions were sonicated 3 Â 10 s at 40% intensity and centrifuged at 14 000 g for 20 min at 151C.…”

Proteomic Approaches and Identification of Novel Therapeutic Targets for Alcoholism

“…Proteomics was also used to investigate the effects of alcohol abuse in the dorsolateral PFC, which includes Brodmann area 9, with white (wBA9) (Alexander-Kaufman et al, 2006, 2007a and gray matter (gBA9) (AlexanderKaufman et al, 2007a). The dorsolateral PFC is connected to many brain regions involved in cognitive functions by reciprocal projections and is subject to significant shrinkage in alcoholics, particularly the white matter.…”