Comparative proteome analysis of human esophageal cancer and adjacent normal tissues.

OBJECTIVES: Ranking as the sixth commonest cancer, esophageal squamous cell carcinoma (ESCC) represents one of the leading causes of cancer death worldwide. One of the main reasons for the low survival of patients with esophageal cancer is its late diagnosis. MATERIALS AND METHODS: We used proteomics approach to analyze ESCC tissues with the aim of a better understanding of the malignant mechanism and searching candidate protein biomarkers for early diagnosis of esophageal cancer. The differential protein expression between cancerous and normal esophageal tissues was investigated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Then proteins were identified by matrix-assisted laser desorption/ ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and MASCOT web based search engine. RESULTS: We reported 4 differentially expressed proteins involved in the pathological process of esophageal cancer, such as annexinA1 (ANXA1), peroxiredoxin-2 (PRDX2), transgelin (TAGLN) andactin-aortic smooth muscle (ACTA2). CONCLUSION: In this report we have introduced new potential biomarker (ACTA2). Moreover, our data confirmed some already known markers for EC in our region.

Recognition and characterization of Erythropoietin binding-proteins in the brain of mice.

OBJECTIVES: Erythropoietin (EPO), is a 34KDa glycoprotein hormone, which belongs to type 1 cytokine superfamily. EPO involves in erythrocyte maturation through inhibition of apoptosis in erythroid cells. Besides its main function, protective effects of EPO in heart and brain tissues have been reported. EPO has a critical role in development, growth, and homeostasis of brain. Furthermore EPO has great potential in the recovery of different brain diseases which are still under studying. In this research, EPO binding pattern to brain proteins in animal model was studied. MATERIALS AND METHODS: EPO antibody was covalently crosslinked to protein A/G agarose. in order to interact between EPO and its target in brain, about 5µg EPO added to brain homogenates(500ul of 1 mg/ml) and incubate at 4ο C for 30 min. brain tissue lysate were added to agarose beads, After isolation of target proteins(EPO - protein) both one and two-dimensional gel electrophoresis were performed. Proteins were identified utilizing MALDI-TOF/TOF and MASCOT software. RESULTS: This research showed that EPO could physically interact with eightproteins including Tubulin beta, Actin cytoplasmic 2, T-complex protein 1, TPR and ankyrin repeat-containing protein 1, Centromere-associated protein E, Kinesin-like protein KIF7, Growth arrest-specific protein 2 and Pleckstrin homology-like domain family B member 2. CONCLUSION: Since EPO is a promising therapeutic drug for the treatment of neurological diseases, identified proteins may help us to have a better understanding about the mechanism of protective effects of EPO in the brain. Our data needs to be validated by complementary bioassays.

Effect of exposure to diazinon on adult rat's brain.

Diazinon (DZN), a commonly used agricultural organophosphate insecticide, is one of the major concerns for human health. This study was planned to investigate neurotoxic effects of subacute exposure to DZN in adult male Wistar rats. Animals received corn oil as control and 15 and 30 mg/kg DZN orally by gastric gavage for 4 weeks. The cerebrum malondialdehyde and glutathione (GSH) contents were assessed as biomarkers of lipid peroxidation and nonenzyme antioxidants, respectively. Moreover, activated forms of caspase 3, -9, and Bax/Bcl-2 ratios were evaluated as key apoptotic proteins. Results of this study suggested that chronic administration of DZN did not change lipid peroxidation and GSH levels significantly in comparison with control. Also, the active forms of caspase 3 and caspase 9 were not significantly altered in DZN-treated rat groups. Moreover, no significant changes were observed in Bax and Bcl-2 ratios. This study indicated that generation of reactive oxygen species was probably modulated by intracellular antioxidant system. In conclusion, subacute oral administration of DZN did not alter lipid peroxidation. Moreover, apoptosis induction was not observed in rat brain.

Protective effect of crocin on acrolein-induced tau phosphorylation in the rat brain.

Acrolein, as a by-product of lipid peroxidation, is implicated in brain aging and in the pathogenesis of oxidative stressmediated neurodegenerative disorders such as Alzheimer's disease (AD). Widespread human exposure to the toxic environmental pollutant that is acrolein renders it necessary to evaluate the effects of exogenous acrolein on the brain. This study investigated the toxic effects of oral administration of 3 mg/kg/day acrolein on the rat cerebral cortex. Moreover, the neuroprotective effects of crocin, the main constituent of saffron, against acrolein toxicity were evaluated. We showed that acrolein decreased concentration of glutathione (GSH) and increased levels of malondialdehyde (MDA), Amyloid-beta (Abeta) and phospho-tau in the brain. Simultaneously, acrolein activated Mitogen-Activated Protein Kinases (MAPKs) signalling pathways. Co-administration of crocin significantly attenuated MDA, Abeta and p-tau levels by modulating MAPKs signalling pathways. Our data demonstrated that environmental exposure to acrolein triggers some molecular events which contribute to brain aging and neurodisorders. Additionally, crocin as an antioxidant is a promising candidate for treatment of neurodegenerative disorders, such as brain aging and AD.

Evaluation of diazinon-induced hepatotoxicity and protective effects of crocin.

Diazinon (DZN) is one of the most widely used insecticides in agricultural pest control. Previous studies have shown that DZN may induce hepatotoxicity. Reactive oxygen species and apoptosis pathways are involved in the toxicity of DZN. Crocin, a constituent of saffron, has hepatoprotective effects due to its antioxidant activity. In this study, we examined the effects of subacute DZN exposure and ameliorating effect of crocin on lipid peroxidation and pathological changes in rat liver. Moreover, protein levels of activated and total caspases-3 and -9 and Bax/Bcl-2 ratio were measured. Five groups of rats were used in the experiment. Corn oil (control), DZN (15 mg/kg per day, orally) and crocin (12.5, 25 and 50 mg/kg per day, intraperitoneally in combination with DZN) were given to male Wistar rats (n = 6) for 4 weeks. The level of malondialdehyde (MDA) increased significantly in DZN group compared with the control group (p < 0.05). MDA level decreased significantly in the group that received DZN plus 25 mg crocin (p < 0.001). No gross or histological evidence of treatment-related damage to the liver after oral exposure to DZN was observed. DZN also induced apoptosis through activation of caspases-9 and -3 and increasing Bax/Bcl-2 ratio. Crocin attenuated the activation of caspases and reduced the Bax/Bcl-2 ratio. It is concluded that subacute exposure to DZN induces oxidative stress-mediated apoptosis and crocin may reduce DZN-induced hepatotoxicity.

Proteomics screening of molecular targets of curcumin in mouse brain.

AIMS: Curcumin is one of the most important constituent of Curcuma longa L. with antioxidant, anti-inflammatory and anticancer effects. In this study, we investigated potential intracellular targets of curcumin by affinity chromatography based on target deconvolution. Identification of curcumin interacting proteins may help in evaluating biological and side effects of this natural compound. MAIN METHODS: Curcumin was immobilized through a linker to sepharose beads as solid matrix. Pull down assay was performed by passing tissue lysate of mouse brain through the column to enrich and purify curcumin interacting proteins. Then proteins were separated using two-dimensional gel electrophoresis and identified using MALDI/TOF/TOF mass spectrometry. KEY FINDINGS: Our results show that curcumin physically binds to a wide range of cellular proteins including structural proteins, metabolic enzymes and proteins involved in apoptosis pathway. SIGNIFICANCE: Finding curcumin interacting proteins may help in understanding a part of curcumin pharmacological effects.

Alteration of protein profile in rat liver of animals exposed to subacute diazinon: a proteomic approach.

Diazinon, an organophosphorus insecticide, is employed to control pests in agriculture. Diazinon may contaminate the environment during the manufacturing process or agricultural application. Previous studies have revealed that diazinon may induce alteration in the protein profile of the liver. Here, a proteomics approach was used to investigate the effects on the protein profile in the liver of rats of subacute oral exposures at 15 mg/kg of diazinon. Liver proteins were separated using 2D-PAGE, and stained by MS-compatible silver staining and/or the fluorescent SYPRO® Ruby protein gel stain. Gels were scanned and analyzed using the Image Master software. Differentially displayed protein species were identified using MALDI-TOF/TOF and MASCOT software. Significantly altered protein species were identified to be involved in apoptosis, cell metabolism, transport, and antioxidant systems. Exposure to diazinon decreased levels of some species of catalase, peroxiredoxin-6, 3-ketoacyl-CoA thiolase, and glucose regulated protein78, whereas the level of protein disulfide-isomerase A3 increased. Our results suggested that diazinon may induce hepatotoxicity through oxidative stress, apoptosis, and metabolic disorders in rat liver.

Proteomic analysis of rat cerebral cortex following subchronic acrolein toxicity.

Acrolein, a member of reactive α,ß-unsaturated aldehydes, is a major environmental pollutant. Acrolein is also produced endogenously as a toxic by-product of lipid peroxidation. Because of high reactivity, acrolein may mediate oxidative damages to cells and tissues. It has been shown to be involved in a wide variety of pathological states including pulmonary, atherosclerosis and neurodegenerative diseases. In this study we employed proteomics approach to investigate the effects of subchronic oral exposures to 3mg/kg of acrolein on protein expression profile in the brain of rats. Moreover effects of acrolein on malondialdehyde (MDA) levels and reduced glutathione (GSH) content were investigated. Our results revealed that treatment with acrolein changed levels of several proteins in diverse physiological process including energy metabolism, cell communication and transport, response to stimulus and metabolic process. Interestingly, several differentially over-expressed proteins, including ß-synuclein, enolase and calcineurin, are known to be associated with human neurodegenerative diseases. Changes in the levels of some proteins were confirmed by Western blot. Moreover, acrolein increases the level of MDA, as a lipid peroxidation biomarker and decreased GSH concentrations, as a non-enzyme antioxidant in the brain of acrolein treated rats. These findings suggested that acrolein induces the oxidative stress and lipid peroxidation in the brain, and so that may contribute to the pathophysiology of neurological disorders.

"Silymarin", a promising pharmacological agent for treatment of diseases.

Widespread use of herbal drugs because of their protective effects on different organs toxicity has been shown in many studies. These protective effects have been illustrated in the fields of nephrotoxicity, hepatotoxicity, viral hepatitis, cancer, in vitro fertilization, neurotoxicity, depression, lung diseases, prostate diseases etc. Silymarin has cytoprotection activities due to its antioxidant activity and radical scavenging. The possible known mechanisms of action of silymarin protection are blockade and adjustment of cell transporters, p-glycoprotein, estrogenic and nuclear receptors. Moreover, silymarin anti-inflammatory effects through reduction of TNF-α, protective effects on erythrocyte lysis and cisplatin-induced acute nephrotoxicity have been indicated in some studies. Silymarin has also inhibited apoptosis and follicular development in patients undergoing IVF. Basis on such data, silymarin can be served as a novel medication in complementary medicine.