Proteomic investigation of the prefrontal cortex in the rat clomipramine model of depression.

Neonatal rodents chronically treated with the tricyclic antidepressant clomipramine show depression-like behavior, which persists throughout adulthood. Therefore, this animal model is suitable to investigate the pathomechanism of depression, which is still largely unknown at the molecular level beyond monoaminergic dysfunctions. Here, we describe protein level changes in the prefrontal cortex of neonatally clomipramine-treated adult rats correlating with behavioral abnormalities. Clomipramine was administered to rat pups twice daily between postnatal days 8-21, while controls received saline injections. Behavioral tests were performed on 3months old rats. The proteomic study was conducted using two-dimensional differential gel electrophoresis. We have identified 32 proteins by mass spectrometry analysis of the significantly altered protein spots. The changed proteins are related to several biological functions, such as inflammation, transcription, cell metabolism and cytoskeleton organization. Among the altered proteins, the level of macrophage migration inhibitory factor showed the largest alteration, which was confirmed with Western blot. Macrophage migration inhibitory factor showed widespread distribution and was predominantly expressed in astrocytes in the forebrain of rats which were described using immunohistochemistry. We conclude that neonatal clomipramine exposure induces sustained modification in the proteome, which may form the molecular basis of the observed depression-like behavior in adult rats. BIOLOGICAL SIGNIFICANCE: It is known that some of the psychiatric disorders, such as autism, depression or schizophrenia may be at least in part, developmental disorders. We hypothesized that clomipramine treatment in early stage of brain development, which is known to induce depression-like behavior in adult rats, results in pathological distortion in neuronal and glial network development, which can be reflected by the cellular proteome in adulthood. Thus, we performed an unbiased proteomics experiment in adult rats, which were neonatally administered with clomipramine to reveal protein level changes three months after treatment. Many of the identified changed proteins are previously associated with depressive symptoms, e.g., the macrophage migration inhibitory factor (MIF), the level of which showed the largest alteration among the identified proteins. Based on our data, we suggest that neonatal clomipramine treatment is a reliable model to study the developmental effect of psychoactive drugs applied in the sensitive early phase of brain development. Furthermore, our findings support the idea that the alteration of early development of the brain induced by antidepressant treatment could result in sustained pathological changes in the cellular phenotype in the prefrontal cortex leading to depression-like behavioral symptoms.

Proteomic profiling of the spinal cord in ALS: decreased ATP5D levels suggest synaptic dysfunction in ALS pathogenesis.

BACKGROUND: We aimed to gain new insights into the pathogenesis of sporadic ALS (sALS) through a comprehensive proteomic analysis. METHODS: Protein profiles of the anterior and posterior horn in post-mortem spinal cord samples of 10 ALS patients and 10 controls were analysed using 2D-differential gel electrophoresis. The identified protein spots with statistically significant level changes and a spot ratio >2.0 were analysed by LC-MS/MS. RESULTS: In the posterior horn only 3 proteins were differentially expressed. In the anterior horn, 16 proteins with increased levels and 2 proteins with decreased levels were identified in ALS compared to controls. The identified proteins were involved in mitochondrial metabolism, calcium homeostasis, protein metabolism, glutathione homeostasis, protein transport and snRNP assembly. The two proteins with decreased levels, ATP5D and calmodulin, were validated by Western blot and immunostaining. Immunohistochemical and immunofluorescent double staining of ATP5D and synaptophysin showed that the reduction of ATP5D was most pronounced at synapses. CONCLUSIONS: We speculate that mitochondrial dysfunction in synaptic clefts could play an important role in sALS pathogenesis. A similar approach revealed decreased calmodulin expression mainly in the neuronal body and dendrites of ALS patients. These findings contribute to a deeper understanding of the disease process underlying ALS.

Differential proteomic analysis of human genetic prion disease patients in frontal lobe tissues / 中华实验和临床病毒学杂志

Objective@#To search for biomarkers for human familial prion disease.@*Methods@#Two-dimensional differential gel electrophoresis (2D-DIGE) proteomic analysis has been performed in frontal lobe tissues of 3 patients suffering from human familial prion disease (PrP) and 3 age-and sex-matched patients suffering from sudden death due to heart failure without neurological disease.@*Results@#The maps revealed 14 polypeptide chains differentially modulated in the PrP samples, among those, 7 could be identified upon digestion and MALDI-TOF/MS analysis, of which 6 appeared to be up-regulated, 1 being down-regulated.@*Conclusions@#We highlight Galectin-1(Gal-1), ryanodine receptor 2 (RyR2), ubiquitin, Rab-interacting lysosomes protein-like protein 1 (RILPL-1) profillin 2 (PFN2), in the differential map. These proteins are related to neurogenesis, the clearance of misfolded proteins, stasis of calium channel, myoclonus and so on. These proteins are potential biomarkers or targets for treatment of prion disease.

Synaptic mitochondria: a brain mitochondria cluster with a specific proteome.

The synapse is a particularly important compartment of neurons. To reveal its molecular characteristics we isolated whole brain synaptic (sMito) and non-synaptic mitochondria (nsMito) from the mouse brain with purity validated by electron microscopy and fluorescence activated cell analysis and sorting. Two-dimensional differential gel electrophoresis and mass spectrometry based proteomics revealed 22 proteins with significantly higher and 34 proteins with significantly lower levels in sMito compared to nsMito. Expression differences in some oxidative stress related proteins, such as superoxide dismutase [Mn] (Sod2) and complement component 1Q subcomponent-binding protein (C1qbp), as well as some tricarboxylic acid cycle proteins, including isocitrate dehydrogenase subunit alpha (Idh3a) and ATP-forming ß subunit of succinyl-CoA ligase (SuclA2), were verified by Western blot, the latter two also by immunohistochemistry. The data suggest altered tricarboxylic acid metabolism in energy supply of synapse while the marked differences in Sod2 and C1qbp support high sensitivity of synapses to oxidative stress. Further functional clustering demonstrated that proteins with higher synaptic levels are involved in synaptic transmission, lactate and glutathione metabolism. In contrast, mitochondrial proteins associated with glucose, lipid, ketone metabolism, signal transduction, morphogenesis, protein synthesis and transcription were enriched in nsMito. Altogether, the results suggest a specifically tuned composition of synaptic mitochondria. BIOLOGICAL SIGNIFICANCE: Neurons communicate with each other through synapse, a compartment metabolically isolated from the cell body. Mitochondria are concentrated in presynaptic terminals by active transport to provide energy supply for information transfer. Mitochondrial composition in the synapse may be different than in the cell body as some examples have demonstrated altered mitochondrial composition with cell type and cellular function in the muscle, heart and liver. Therefore, we posed the question whether protein composition of synaptic mitochondria reflects its specific functions. The determined protein difference pattern was in accordance with known functional specialties of high demand synaptic mitochondria. The data also suggest specifically tuned metabolic fluxes for energy production by means of interaction with glial cells surrounding the synapse. These findings provide possible mechanisms for dynamically adapting synaptic mitochondrial output to actual demand. In turn, an increased vulnerability of synaptic mitochondria to oxidative stress is implied by the data. This is important from theoretical but potentially also from therapeutic aspects. Mitochondria are known to be affected in some neurodegenerative and psychiatric disorders, and proteins with elevated level in synaptic mitochondria, e.g. C1qbp represent targets for future drug development, by which synaptic and non-synaptic mitochondria can be differentially affected.

Subtoxic and toxic concentrations of benzene and toluene induce Nrf2-mediated antioxidative stress response and affect the central carbon metabolism in lung epithelial cells A549.

Since people in industrialized countries spend most of their time indoors, the effects of indoor contaminants such as volatile organic compounds become more and more relevant. Benzene and toluene are among the most abundant compounds in the highly heterogeneous group of indoor volatile organic compounds. In order to understand their effects on lung epithelial cells (A549) representing lung's first line of defense, we chose a global proteome and a targeted metabolome approach in order to detect adverse outcome pathways caused by exposure to benzene and toluene. Using a DIGE approach, 93 of 469 detected protein spots were found to be differentially expressed after exposure to benzene, and 79 of these spots were identified by MS. Pathway analysis revealed an enrichment of proteins involved in Nrf2-mediated and oxidative stress response glycolysis/gluconeogenesis. The occurrence of oxidative stress at nonacute toxic concentrations of benzene and toluene was confirmed by the upregulation of the stress related proteins NQO1 and SOD1. The changes in metabolism were validated by ion chromatography MS/MS analysis revealing significant changes of glucose-6-phosphate, fructose-6-phosphate, 3-phosphoglycerate, and NADPH. The molecular alterations identified as a result of benzene and toluene exposure demonstrate the detrimental effect of nonacute toxic concentrations on lung epithelial cells. The data provided here will allow for a targeted validation in in vivo models.

Differential expression of serum proteins in chromic arsenic exposed population / 中国地方病学杂志

Objectives To screen the differentially expressed proteins in serum of population chronically exposed to arsenic in drinking water,thus to provide candidate protein biomarkers for arsenic exposure and arsenicosis.Methods Subjects were selected from the drinking water type of endemic arsenicosis areas in Shanxi province,China.Demographic characteristics,history of arsenic exposure,cigarette smoking,alcohol drinking,health and other information were collected using questionnaire.The subjects were divided into low-arsenic group (with arsenic in drinking water ＜ 10 μg/L),medium-arsenic group( 10 - 50 μg/L),high-arsenic group( ＞ 50 μg/L),and arsenicosis group(the drinking water with arsenic ＞ 50 μg/L was replaced by low arsenic water ＜ 10 μg/L).The number of cases in each group was 30.The arsenicosis patients were diagnosed according to “Standard of Diagnosis for Endemic Arsenism” (WS/T 211-2001 ).With the principle of informed consent,blood samples were collected.Differentially expressed serum proteins of different arsenic exposure groups and arsenicosis group were screened by two-dimensional differential gel electrophoresis(2-D DIGE),and further identified by mass spectrometry (MS).Results An average of (1299 ± 167) protein spots were identified in 6 gel images and 688 protein spots were discovered repeatedly in at least 5 gels.There were 33 protein spots differentially expressed among low-,medium- and high-arsenic groups P ＜ 0.01).Fifty four protein spots were significantly different among low-,medium-,high-arsenic exposure groups and arsenicosis group(P ＜ 0.01 ).Twenty five protein spots were selected for MS analysis,and13 protein spots were identified.Compared with low-arsenic group,the expressions of apolipoprotein A-Ⅳ,retinol binding protein,and estrogen receptor hypothalamic isoform in medium- and higharsenic exposure groups were down regulated,and the expressions of component 4A and 4B were up regulated.Compared with low-,medium- and high-arsenic groups,the expressions of beta-2-glycoprotein Ⅰ,Keratin 1,hemopexin,complement C1r subcomponent,and ficolin-3 in arsenicosis group were down regulated,and the expressions of pigment epithelial-differentiating factor,alpha-1-microglobulin and carboxypeptidase N catalytic chain were up regulated.Conclusions Chronic arsenic exposure can significantly change population's serum protein expression.Differentially expressed proteins in arsenicosis patients will not decline with the decline of arsenic in a short term.Whether or not the differentially expressed proteins identified in this study can be used as biomarkers for arsenic exposure and arsenicosis needs to be further verified.