فهرست مطالب

  • Volume:11 Issue: 2, 2020
  • تاریخ انتشار: 1399/01/09
  • تعداد عناوین: 7
  • Azadeh Haghighitalab, Maryam M. Matin, Fatemeh Khakrah, Ahmad Asoodeh, Ahmad Reza Bahrami* Pages 42-54

    Despite the prominent therapeutic potentials of stem cells, their use in cell therapy has been challenged with some unreproducible and inconsistent outcomes in addition to the risk of rejection and tumorigenesis. Gaining novel insights to the importance of the conditioned medium, secretory factors and extracellular vesicles as the functional components of the cultured stem cells, suggested the idea of substituting the cells with their cell-free counterparts. Biological properties of these products are influenced by the cues received from their microenvironment. Hence, providing optimal and fully defined culture conditions is essential for their preparation. Fetal bovine serum (FBS), one of the most routine supplements of cell culture, is enriched by endogenous extracellular vesicles (EVs). These EVs will affect the yield, purity and functional features of the cell-free products. Here, we endeavored to examine and compare three different methods including ultrasonication, ultrafiltration and polymer-based precipitation, to deplete EVs from FBS. We chose easy to perform and fast methods with the capacity for high-throughput applications. Based on our observations, although all examined methods were able to deplete EVs from FBS to some extent, polymer-based precipitation could be considered as the method of choice with minimal consequences on the biological requirements of FBS to support cell growth and characteristics. Due to similarities between FBS and some other biological solutions, this strategy would be suitable for EV-depletion from other liquids with high concentrations of proteins and nutrients. Moreover, it could be applied for preparation of optimal culture conditions for nanoparticle applications.

    Keywords: Extracellular vesicle-depletion, Exosome, Polyethylene glycol, Ultrafiltration, Ultrasonication, Fetalbovine serum
  • Maryam M. Matin*, David P. Hornby Pages 55-58

    We have developed a rapid, quantitative method for analysing the outcome of the first strand synthesis step in cDNA library preparation, yield and molecular weight range of the final cDNA products are determined after size fractionation. This method involves conventional cDNA library construction including all enzymatic steps usually required, but replaces radioactive labelling of nucleic acids with fluorescence detection. The separation and quantification steps all involve ion-pair reversed-phase high performance liquid chromatography (IP RP HPLC). This quantitative method replaces the use of autoradiography and size exclusion chromatography with combined ion-pair reversed-phase high performance liquid chromatography and in line fluorescence detection. The result of this approach is combination of speed with the generation of reproducible, high quality cDNA libraries.

    Keywords: cDNA, library construction, IP RP HPLC, size fractionation
  • Zohreh Sohrabi Nezhad, Hassan Marashi, Nasrin Moshtaghi * Pages 59-65

    Silver nanoparticles are widely used in manufacturing of different products considering their unique physical and chemical properties. Also they have been noticed in medical diagnosis and treatment because of their antibacterial properties. Physical and chemical methods of producing nanoparticles, are expensive and are not safe enough as toxic substances may remain in the final preparations. To solve this problem, biological production of nanoparticles is considered as an efficient alternative method. In present study, synthesis of silver nanoparticles via seeds, petals, roots, and hairy root extracts of Calendula officinalis were performed. These nanoparticles were characterized by means of spectrophotometer, particle size analyzer and transmission electron microscope. Nanoparticles which were synthesized by hairy root extract showed the highest absorption at 430 nm (1/6 a.u) and the smallest size (5/3 nm), in comparison to other examined particles. Results confirmed the better performance of hairy root extracts in the synthesis of silver nanoparticles.

    Keywords: Calendula officinalis, Marigold, Hairy roots, Silver nanoparticles
  • Parisa Farrokh *, Fatemeh Salimi Pages 66-81

    Thermostable proteases are one of the pivotal enzymatic groups which play fundamental roles in biotechnologyrelated industries. The identification of bacterial thermostable enzymes through screening programs is a time and cost consuming process. So, extensive bioinformatics and experimental studies have been conducted to reveal thermo stabilizing factors. The current study was aimed to evaluate distinctive indicators among 33 thermostable and 10 mesostable proteolytic enzymes. The frequency of individual amino acids, aliphatic indexes, melting temperatures, isoelectric points, as well as, the frequency of AXXXA and GXXXG motifs were determined and compared among these enzymes. In addition, types of proteolytic enzymes and their active sites were assigned. Moreover, the frequency of alpha helixes, polar surface regions, and packing volumes of these enzymes with the known structures were characterized. Results showed that the frequency of Ala and AXXXA motifs were significantly higher in thermostable proteolytic enzymes, while they possess lower contents of Met, His, Lys and Leu in comparison to mesostable enzymes (P<0.05). According to statistical analysis, thermostable proteolytic enzymes indicated meaningful lower packing volumes than mesostable enzymes (P<0.05). Findings of the current study in addition to more detailed investigations on the thermostability mechanisms of various protein families are essential for designing more efficient industrial enzymes with functional properties at high temperatures.

    Keywords: Bioinformatics analysis, Protein engineering, Proteolytic enzyme, Thermostability
  • Roghaye Lorestani, Sohrab Boozarpour*, Sakineh Alijanpour, Leila Ahangar Pages 82-89

    Schizophrenia is an irritating mental disorder that affects around 1% of the world's population. The immune system contributes to the onset of the disease, particularly through production and secretion of some cytokines. In patients with schizophrenia, the balance of Th1 to Th2 ratio is often altered. In the present study, we investigated these changes by measuring the gene expression levels of IFN-γ and T-bet as Th1 indicators, as well as IL-4 and GATA-3 as representatives for Th2. Blood samples of schizophrenic patients (n=25) and healthy individuals (n=10) were obtained. Total RNA was extracted from leukocytes and cDNA synthesis was performed based on provided protocols. Real-time PCR technique was utilized for the assessment of gene expression levels. Results indicated a significant increase in the expression of IFN-γ and its transcription factor, T-bet, while IL-4 gene expression was reduced significantly. The expression level of GATA-3 gene revealed no meaningful changes. Altogether, results confirmed the relative shift of Th1 to Th2 status in the patient with schizophrenia and reemphasize the importance of the inflammatory events in the incidence of the disease. Moreover, a new index was introduced based on the IFN-γ and T-bet genes expression, which can determine healthy condition with total accuracy of 79%.

    Keywords: Molecular marker, Schizophrenia, Th1, Th2, IFN-γ, T-bet
  • Sepideh sadat Hosseini, Shadi Mehrzad, Halimeh Hassanzadeh, Hamid Reza Bidkhori, Mahdi Mirahmadi, Madjid Momeni Moghaddam, Fatemeh Sadeghifar, Moein Farshchian* Pages 90-98

    Mesenchymal stem/stromal cells (MSCs) as one of the most important types of adult stem cells secrete a variety of immunomodulatory cytokines. However, their immunomodulatory features strongly depend on the molecular cross-talk between cells and the surrounding microenvironment. Hence, some strategies were proposed to empower their beneficial effects during cell-therapeutic procedures to avoid confusing results. Licensing the cells with chemical compounds could be considered as one of the most applicable methods for induction of anti-inflammatory status in the cells. Human chorionic gonadotropin (hCG) is a pregnancy related hormone which has been shown to be essential for the establishment of a successful pregnancy. HCG supports the implantation of fetus in the maternal endometrium, due to its immunomodulatory effects. Moreover, the regulatory role of hCG has been previously mentioned in case of some autoimmune-based diseases. In the present study, the capacity of this hormone for induction of different immuneencountered genes expression was examined in primary cultures of human adipose tissue derived mesenchymal stem cells (Ad-MSCs). In this regard, Ad-MSCs were exposed to 10 IU of hCG for 72 hours. Molecular studies via quantitative Real-time PCR (qRT-PCR) experiments were performed to detect gene expression modifications based on the application of SYBR Green as the fluorescent dye and in comparison to the RPLP0 as the housekeeping gene. Results confirmed that hCG significantly upregulated TSG-6, TGF-β1, IL-1β and IL-6 expression levels comparing with the control group, while it downregulates COX-2 expression, and had no statistically significant effects on IL-10 and TDO2. In conclusion, priming Ad-MSCs with hCG may enhance the proliferation and immunoregulatory potential of these cells, although it needs further investigations to reveal involved molecular pathways.

    Keywords: Mesenchymal stem cells, Human Chorionic Gonadotropin, Pregnancy, Immunomodulation, Pretreatment
  • Shadi Mehrzad, Sepideh sadat Hosseini, Madjid Momeni Moghaddam, Moein Farshchian, Halimeh Hassanzadeh, Mahdi Mirahmadi, Fatemeh Sadeghifar*, Hamid Reza Bidkhori* Pages 99-107

    species (ROS)) and antioxidants in cells. Several studies have shown that there is a close relationship between oxidative stress and inflammation at the sites of injury. Mesenchymal stem cells (MSCs) are exposed to endogenous and exogenous oxidants generated during their ex vivo expansion or following in vivo transplantation. α-tocopherol (vitamin E) is a fat-soluble compound known for its anti-oxidant and antiinflammatory properties. In many studies, the immunomodulatory effects of vitamin E have been observed in vivo. This study aimed to determine whether pretreatment of MSCs with antioxidants like vitamin E, will enhance the anti-inflammatory and immunomodulatory properties of these cells. For this purpose, adiposederived MSCs (ASCs) were treated with vitamin E (600 µM) for 48 h. Quantitative PCR (qPCR) experiments were performed to evaluate the expression of genes related to inflammation (IL-1β, IL-6, IL-17, IL-10) or immunomodulation (TSG-6, COX-2, TDO2, TGF-β1). Results indicated that vitamin E significantly increased the expression of COX-2, TSG-6, and IL-1β genes at the mRNA level compared with the control group, while it significantly decreased IL-6 and TGF-β expressions. No effect was observed for IL-17, IL-10, and TDO2 genes. These results suggest that in vitro preconditioning of ASCs with vitamin E may allow the cells to improve their anti-inflammatory and immunoregulatory capacities. Vitamin E pretreatment could lead to the improvement of their therapeutic abilities in conditions that are influenced by oxidative stress.

    Keywords: Mesenchymal Stem Cells, Vitamin E, Immunomodulation, Oxidative stress, Preconditioning