Modares Journal of Biotechnology

Abstract Transforming growth factor beta (TGF-β), is a small homodimeric signaling protein. The TGF-β isoforms (TGFβ1, β2 and β3) are involved in many cellular processes including growth inhibition, extracellular matrix remodeling, tissue development, cell migration, invasion and immune regulation. For research aims, TGFβs are overexpressed using recombinant eukaryotic cell or bacterial expression systems. For achieving an efficient purification of TGF-β by immobilized metal ion affinity chromatography (IMAC), a histidine tag was placed either at the C-terminal (C-TGFβ) or N-terminal (N-TGFβ) region of the sequence and the effect of His-tag on TGF-β structure has been studied by computational tools. Proteins 3D structures were modeled using MODELLER software and molecular dynamics simulation of native TGF-β and modelled proteins, N-TGFβ and C-TGFβ were studied in water by GROMACS package. Protein dynamics modeling indicated that the His-tag attached at the C-terminus but not at the N-terminus of the TGF-β can affect the fluctuations of amino acids and protein structure. It is concluded that the C-terminal tagging may cause distortion and misfolding in the structure.

Abstract Aims: Breast cancer is the most common malignancy in women throughout the world. Among the various methods for preventing and treating cancer, plant natural compounds have more benefits than chemical drugs and have less side effects. Recently, many studies have been carried out on the antioxidant, anticancer, antiproliferation, and antiinflammatory properties of plant lignans, indicating the importance of these compounds in the prevention and treatment of various diseases. In the present study, the cytotoxic effects and inducing apoptosis of pinoresinol and lariciresinol lignans were investigated on SKBr3 breast cancer cell line.
Materials & Methods: SKBr3 cells were treated with different concentrations of both pinoresinol and lariciresinol, separately for 72 hours. Then, cell viability and cells morphological changes were determined using MTT assay and inverted light microscope, respectively. Also, apoptosis induction was analyzed by flow cytometry using an Annexin V-FITC apoptosis detection kit.
Findings: Both pinoresinol and lariciresinol treatments induced morphological changes, decreased cell growth, survival, proliferation and a significant increase in apoptosis induction in SKBr3 cell line compared to control cells in a concentration-dependent manner.
Conclusion: Inducing apoptosis and preventing the growth and proliferation of cancer cells are important mechanisms in the treatment of cancer. Pinoresinol and lariciresinol can be used to reduce cell proliferation and increase apoptosis induction in prevention and treatment of breast cancer.

Abstract Aims: Due to their unique properties, functionalized GNPs provide a high potential for solving many problems, such as diagnosis and treatment of genetic diseases using nanotechnology. Depending on the purpose of each experiment, a particular interaction of DNA and nanoparticle is desirable that can be achieved by changing various parameters. The purpose of this study was to investigate the effect of gold nanoparticles surface charge on the conjugation process and the type of DNA interactions, as well as increasing the loading of DNA on the surface of gold nanoparticles.
Materials and Methods: Two types of 30nm gold nanoparticles with positive and negative charge were synthesized. Gold nanoparticles were functionalized with three different concentrations of DNA. Bioconjugation was investigated using UV-Vis and fluorescence spectroscopy. Quantification of the DNA loading on each nanoparticle surface was done using two methods by fluorescence assay.
Findings: The SPR spectrum of nanoparticles confirmed the binding of DNA to the surface of nanoparticles and also illustrates the level of DNA loading to the surface of the nanoparticle, as well as the effect of the surface charge of nanoparticles on the bioconjugation process. The fluorescence assay showed a higher loading of DNA in CTAB-stabilized nanoparticles and more non-specific than citrate-stabilized nanoparticles.
Conclusion: Depending on the surface charge of GNPs, DNA loading on the surface of GNPs occurs with different affinities. Based on the purpose of the study, citrate stabilized GNPs and high concentration of DNA was appropriate to achieve this goal.

Abstract In recent years, many studies have been performed on for use in various of science. The proper design and synthesis of these has a direct impact on their -chemical properties and their applications, especially in the field of biological sciences. There are several methods for magnetic synthesis. One of the simplest and most efficient methods for synthesis of magnetic is a chemical co-precipitation method, but of magnetic is one of the limitations of this method. In this study, various protocols for the synthesis of magnetic by co-precipitation method and silica coating of magnetic were performed and the effect of different factors such as the type of alkaline compound, the use of , temperature and in dispersion, aggregation of magnetic nanoparticles and their stability in aqueous solutions was investigated. Finally, a simple and reproducible protocol for magnetic synthesis with appropriate size distribution and high dispersion in aqueous solutions was optimized for use in biological applications.

Abstract Aims: Nitric oxide (NO) plays an important role in maintaining cellular stem status, and the range of electromagnetic fields (EMF) is very deep in contrast to the electric field. The aim of this study was to investigate the effect of electromagnetic field and nitric oxide on the neural differentiation proteins marker and viability of the rat bone marrow mesenchymal stem cells.
Materials and Methods: The present experimental research was conducted on bone marrow mesenchymal stem cells of Vistar rats. For treatments of the cells, high (1mM) and low (10micromolar Deta-NO) concentrations were used as a nitric oxide donor molecule and 50Hz low-frequency electromagnetic field and they were compare with the control group. The cell viability was recorded by MTT assay test, the neural differentiation pathway gene expression was investigated by RT-PCR technique, and the neural differentiation marker protein expression was evaluated by Immunocytochemistry technique. The data were analyzed by one-way ANOVA, using SPSS 13 software.
Findings: After 24 hours of treatment with nitric oxide and EMF, the rate of viability in all groups was significantly decreased compared to the control group. After 48 hours, EMF alone, as well as with low concentration of nitric oxide did not decrease the rate of viability and cell growth increased compared to the control group. In the group treated with high nitric oxide concentration along with EMF, MAP2 protein was expressed in the number of cells more than the control group and the one treated with EMF.
Conclusion: The electromagnetic field, along with its high concentration of nitric oxide, decreases the number of rat bone marrow mesenchymal stem cells and, by increasing cell size, gene expression and neural differentiation proteins marker facilitates their differentiation to nerve-like cells.

Abstract Linum album is an herbaceous and medicinal plant that has important lignan such as podophyllotoxin (PTOX). PTOX has antiviral and anticancer properties. Since the chemical synthesis of PTOX is an expensive process, production of PTOX using cell and cultures of linum species is a cost-effective alternative approach. Various strategies have been employed to increase the production of secondary metabolites in cell cultures. In this study, we have verified the effect of chitosan on cell growth, PTOX production in 1, 2, 3 and 5 days after treatment. Cells elicited with chitosan for 5 days yielded the highest amount of PTOX. To study mechanism of chitosan action, expression of phenylalanine ammonio-lyase (PAL), cinnamoyl-CoA reductase (CCR), cinnamyl alcohol dehydrogenase (CAD) and pinoresinol lariciresinol reductase (PLR) genes were investigated. The expression of genes were increased, reaching a peak at 3 day after treatment. Chitosan up-regulate the production of PTOX, by effecting on gene expression of PTOX biosynthesis pathway.

Abstract Sheath blight, caused by Rhizoctonia solani AG1-IA, is one of the most destructive disease. Conventional methods of disease control using fungicides may develop new problems. Therefore, understanding molecular mechanisms of plant–pathogen interaction is necessary to adopt effective approaches for managing the disease. Here for the first time, by using bioinformatics tools and RT-PCR analysis and sequencing confirmed the presence of a Magnaporthe oryzae Avr-pita gene orthologous sequence designated as Rhiz-pita1 gene in three different geographic isolates of R. solani AG1- IA( A2,R1 and T2) genome. SignalP program predicted a secretion signal upstream of Rhiz-pita1 gene. Nucleotide sequences of 5' region of Rhiz-pita1 gene from geographical isolates showed 99% identity in exons and 100% in introns which are characteristics of fast evolving effector proteins. Also, 98% homology between Rhiz-pita and M.oryza-pita1gene suggests that Rhiz-pita encodes an effector protein. Howevere, more researchs are necessary to confirm of this suggestion. Keywords: Rhizoctonia solani, signal peptide Rice blast , Effector

Abstract Abstract: ATP sulfurylase (ATPS) is widely distributed in all living organisms. Several different physiological roles have been proposed for ATPS in different species, including sulfate assimilation, sulfate reduction and pyrophosphate recycling. Also, ATP sulfurylase has many different industrial and laboratory applications. The aim of this study was to clone and express the gene that producing the recombinant ATPS protein from an Iranian strain of Geobacillus. After Isolation and identification of Geobacillus kaustophilus strain, DNA genomic was extracted. ATPS gene was amplified from genomic DNA by using a couple of specific primers for interested gene. PCR product of ATPS gene was observed as an 1188bp band on agarose gel. Then the PCR product was purified and cloned into the cloning vector. The ATPS band was sequenced after cloning and result of homology search in the NCBI database confirmed that the cloned gene was ATPS. The ATPS gene was subcloned in expression pET28a plasmid. Expression of recombinant ATPS protein in E. Coli BL21 (DE3) was analyzed using SDS-PAGE gel. Analysis of expressed ATPS protein on SDS-PAGE gel revealed a band at 47.5 KD. Using ATP luminescence method for measuring enzymatic activity of the protein showed that the recombinant protein is active. This is the first study on cloning, expression and enzymatic activity of the ATPS gene from the Geobacillus kaustophilus bacteria.

Abstract Atropine and scopolamine are two important tropane alkaloids, widely use as anticholinergic drugs. Such as most solanaceae plants, Atropa belladonna produces these two tropane alkaloids. Carbohydrates are not only act as carbon sources for solanaceus plants in vitro cultures, but also have some effects as signal molecules on tropane alkaloids metabolism. Effect of sorbitol, mannitol and sucrose on growth, chlorophyll, hyoscyamine and scopolamine contents, and hyoscyamine 6- beta hydroxylase (H6H) gene expression, investigated. These treatments decreased the growth of plantlets but increased chlorophyll, hyoscyamine and scopolamine contents. The treatments increase h6h gene expression in different organs of Atropa belladonna plantlets. There was an agreement between h6h expression pattern and scopolamine contents.