Ferdous Rastgar Jazii

BACKGROUND: Salinity is one of the most widespread agricultural problems in arid and semi-arid regions that makes fields unproductive, and soil salinization is a serious problem in the entire world. To determine the effects of salt stress on soybean seedlings, a proteomic technique was used. RESULTS: Soybean plants were exposed to 0, 20, 40, or 80 mM NaCl for one week. The effect of treatment at 20 mM NaCl on plant growth was not severe, at 80 mM NaCl was lethal, and at 40 mM NaCl was significant but not lethal. Based on these results, proteins were extracted from the leaves, hypocotyls and roots of soybean treated with 40 mM NaCl. Nineteen, 22 and 14 proteins out of 340, 330 and 235 proteins in the leaves, hypocotyls and roots, respectively, were up- and down-regulated by NaCl treatment. In leaves, hypocotyls and roots, metabolism related proteins were mainly down-regulated with NaCl treatment. Glyceraldehyde-3-phosphate dehydrogenase was down-regulated in the leaf/hypocotyls, and fructokinase 2 was down-regulated in the hypocotyls/root with NaCl treatment. Stem 31 kDa glycoprotein precursor was up-regulated in all three organs with NaCl treatment. Glyceraldehyde-3-phosphate dehydrogenase was specifically down-regulated at the RNA and protein levels by salt stress. CONCLUSION: These results suggest that metabolism related proteins play a role in each organ in the adaptation to saline conditions.

A proteomic approach was used to identify proteins affected by salt in the halophyte C(4) plant Aeluropus lagopoides (Poaceae) in an attempt to understand the mechanism of salt tolerance. Plants were treated with 450 mM NaCl for 10 days, and proteins were then extracted from the shoots and separated by two-dimensional polyacrylamide gel electrophoresis. A total of 1805 protein spots were detected, of which 39 were up-regulated and 44 were down-regulated by treatment with NaCl. Metabolism-related proteins were up-regulated, whereas photosynthesis-related proteins were down-regulated. Dose-dependence studies showed that the up-regulation continued at NaCl concentrations above 450 mM for defense-related proteins alone. Western blot analysis confirmed the down-regulation of RuBisCO LSU and RuBisCO SSU and severe down-regulation of RuBisCO activase. The activity of glyoxalase I increased with increasing NaCl concentration. Metabolome studies indicated up-regulation of amino acids and down-regulation of tricarboxylic acid cycle-related metabolites. These studies suggest that up-regulation of energy formation, amino acid biosynthesis, C(4) photosynthesis, and detoxification are the main strategies for salt tolerance in A. lagopoides.

AIM: To assess the proteome of normal versus tumor tissue in squamous cell carcinoma of the esophagus (SCCE) in Iranian patients and compare our results with former reports by using proteomics. METHODS: Protein was extracted from normal and tumor tissues. Two dimensional electrophoresis was carried out and spots with differential expression were identified with mass spectrometry. RNA extraction and RT-PCR along with immunodetection were performed. RESULTS: Fourteen proteins were found whose expression levels differed in tumor compared to normal tissues. Mass spectrometric analysis resulted in the identification of beta-tropomyosin (TMbeta), myosin light chain 2 (and its isoform), myosin regulatory light chain 2, peroxyredoxin 2, annexin I and an unknown polypeptide as the down regulated polypeptides in tumor tissue. Heat shock protein 70 (HSP70), TPM4-ALK fusion oncoprotein 2, myosin light polypeptide 6, keratin I, GH16431p and calreticulin were the up-regulated polypeptides found in tumor tissue. Several of these proteins, such as TMbeta, HSP70, annexin I, calreticulin, TPM4-ALK and isoforms of myosins, have been well recognized in tumorigenesis of esophageal or other types of cancers. CONCLUSION: Our study not only supports the involvement of some of the formerly reported proteins in SCCE but also introduces additional proteins found to be lost in SCCE, including TMbeta.

Cold represents one of the major abiotic factors influencing plant growth and development worldwide. We analysed the long-term responsiveness of an Iranian spring wheat (cv. Kohdasht) to cold from a proteomic point of view, in order to unravel the molecular mechanisms helping a cold-sensitive cultivar to survive exposure to suboptimal temperatures. Plants were grown at 20 or 4°C until entering the reproductive stage and a cross-comparison on the leaf proteomes was performed. Quantitative analyses on protein alterations occurring upon low-temperature exposure showed a reinforcement in ascorbate recycling (dehydroascorbate reductase, ascorbate peroxidase) and protein processing (proteasome subunit, cysteine proteinase), as well as the accumulation of the enzyme devoted to tetrapyrrole resynthesis (glutamate semialdehyde aminomutase). In contrast, among proteins down-regulated after cold stress, we could identify some key Krebs cycle enzymes (isocitrate dehydrogenase, malate dehydrogenase), together with many photosynthesis-related proteins (oxygen-evolving complex proteins, ATP synthase subunits, ferredoxin NADPH oxidoreductase and some Calvin cycle enzymes). Physiological and biochemical parameters (such as shoot apex dissection, chlorophyll, proline and sugar content determination) sustained proteomics findings allowing the present research to contribute to the current knowledge on these long-term responses, which may be crucial to stress adaptation under field conditions.

BACKGROUND: Squamous cell carcinoma of esophagus (SCCE) occurs at a high incidence rate in certain parts of the world. This feature necessitates that different aspects of the disease and in particular genetic characteristics be investigated in such regions. In addition, such investigations might lead to achievement of molecular markers helpful for early detection, successful treatment and follow up of the disease. Adenomatous Polyposis Coli (APC) promoter hypermethylation has been shown to be a suitable marker for both serum and solid tumors of adenocarcinoma of esophagus. We investigated the status of APC promoter hypermethylation in Iranian patients, compared the results with the former studies, and evaluated its applicability as a candidate molecular marker by examining association between survival of SCCE patients and APC promoter methylation. METHODS: For evaluating the status of APC promoter hypermethylation and its association with SCCE, a qualitative methylation specific PCR (MSP) was used. DNA was extracted and digested with an appropriate restriction enzyme, treated with sodium bisulfite in agarose beads and amplified in two-step PCR reaction by applying either methylated or unmethylated promoter specific primers. Universally methylated DNA and methylase treated blood DNA of healthy donors were used as positive controls as well. Survival of patients was followed up for two years after treatment and survival rate of patients with methylated APC promoter was compared with that of unmethylated patients. RESULTS: Assessment of APC promoter methylation revealed that normal tissues were unmethylated, while twenty out of forty five (44.4%) tumor tissues were hypermethylated either in one or both alleles of APC. Among the tissues in which methylation was detected, seven were hypermethylated in both alleles while the other thirteen were hypermethylated in one of the two alleles of APC. Analyzing two-year survival rate of patients with respect to promoter hypermethylation showed a lower rate of survival for patients with methylated APC promoter following their treatment. Further investigation into the association between promoter hypermethylation and tumor differentiation status indicated that patients with well differentiated tumors were more likely to develop promoter hypermethylation. CONCLUSION: Observing similar level of APC promoter hypermethylation in patients with SCCE in this high risk region and comparing it with other parts of the world could support the hypothesis that a common molecular mechanism might be involved in tumorigenesis of SCCE. In addition, the higher rate of two-year survival for patients with unmethylated APC promoter as well as its relationship with tumor differentiation would suggest that this tumor suppressor could be an appropriate candidate molecular marker for evaluating tumor malignancy and predicting survival of patients subsequent to treatment.