Ali Jahanian-Najafabadi - Academia.edu (original) (raw)

Papers by Ali Jahanian-Najafabadi

Clinical Laboratory, 2016

Hepatitis C virus (HCV) genome contains an overlapping reading frame which results in alternative... more Hepatitis C virus (HCV) genome contains an overlapping reading frame which results in alternative core protein (ARFP). Baculovirus expression system was used as a powerful eukaryotic vector system to express core+1/F protein for the first time. This recombinant core+1/F protein was used to assess the anti-core+1 antibody in anti-HCV drug resistant and sustained virologic response (SVR) patients. The core+1 coding sequence from HCV genotype 1 was designed and synthesized in pUC57 vector. It was subcloned into baculovirus donor plasmid pFastBacTM HTA and transposed into baculovirus shuttle vector (bacmid) to transfect Sf9 cells. Recombinant core+1 protein was purified using Ni-NTA agarose under native condition and verified using SDS-PAGE electrophoresis and Western blotting. An enzyme-linked immunosorbent assay (ELISA) was developed using this purified protein to assess anti-core+1 antibody in 28 anti-HCV drug resistant patients and in 34 patients with sustained virologic response (SVR) in comparison with 31 healthy volunteers used as the negative control. Expression of HCV core+1 protein in Sf9 cells was confirmed by using SDS-PAGE and Western blotting. Antibody titer against core+1 protein in anti-HCV drug resistant patients was significantly higher than that in both the healthy volunteers and SVR patients (p < 0.0001). HCV core+1 protein was expressed successfully in a baculovirus expression system in high yield in order to develop an ELISA to assess the anti-core+1 antibody. Further studies are needed to reveal the potential application of core+1 protein in anti-HCV treatment prognosis.

Chemistry & Biodiversity, 2016

Cytotoxic and antimicrobial agents structurally based on quinazolinone, benzofuran and imidazole ... more Cytotoxic and antimicrobial agents structurally based on quinazolinone, benzofuran and imidazole pharmacophores, have been designed and synthesized. Spectral (IR, (1) H-NMR) and elemental analysis data established the structures of these novel 3-[1-(1-benzofuran-2-yl)-2-(4-oxoquinazolin-3(4H)-yl)ethyl]-1-methyl-1H-imidazol-3-ium chloride hybrid derivatives. All the synthesized compounds were evaluated for in vitro cytotoxicity and antimicrobial activities. Cytotoxic evaluation using MTT assay revealed that compounds 12c, 12g and 12i exhibited significant cytotoxicity with IC50 values 1, 1, and 0.57 μm on this cell line, respectively. Biological activity of the synthesized compounds as antibacterial agent were also evaluated against three Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi), three Gram-positive (Staphylococcus aureus, Bacillus subtilis and Listeria monocitogenes) and one yeast-like fungi (Candida albicans) strains. All compounds 12a - 12i showed slightly higher activity against Gram-positive bacteria than the Gram-negative one. Among the nine new compounds screened, 3-[1-(5-bromo-1-benzofuran-2-yl)-2-(6-chloro-4-oxoquinazolin-3(4H)-yl)ethyl]-1-methyl-1H-imidazol-3-ium chloride (12e) has pronounced higher antimicrobial activity against all tested strains. These results demonstrated potential importance of molecular hybridization in the development of new lead molecules with major cytotoxicity and antimicrobial activity.

Advanced Biomedical Research, 2016

Chimeric proteins consisting of a targeting moiety and a cytotoxic moiety are now under intense r... more Chimeric proteins consisting of a targeting moiety and a cytotoxic moiety are now under intense research focus for targeted therapy of cancer. Here, we report cloning, expression, and purification of such a targeted chimeric protein made up of p28 peptide as both targeting and anticancer moiety fused to NRC peptide as a cytotoxic moiety. However, since the antimicrobial activity of the NRC peptide would intervene expression of the chimeric protein in Escherichia coli, we evaluated the effects of two fusion tags, that is, thioredoxin (Trx) and 6x-His tags, and various expression conditions, on the expression of p28-NRC chimeric protein. In order to express the chimeric protein with only 6x-His tag, pET28 expression plasmid was used. Cloning in pET32 expression plasmid was performed to add both Trx and 6x-His tags to the chimeric protein. Expression of the chimeric protein with both plasmids was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis following optimization of expression conditions and host strains. Expression of the chimeric protein in pET28a was performed. However, expression yield of the chimeric protein was low. Optimization of culture conditions and host strains led to reasonable expression yield of the toxic chimeric protein in pET32a vector. In cases of both plasmids, approximately 10 kDa deviation of the apparent molecular weight from the theoretical one was seen in SDS-PAGE of purified chimeric proteins. The study leads to proper expression and purification yield of p28-NRC chimeric protein with Trx tag following optimizing culture conditions and host strains.

Iranian biomedical journal, Jan 31, 2015

A baculovirus expression system is one of the most attractive and powerful eukaryotic expression ... more A baculovirus expression system is one of the most attractive and powerful eukaryotic expression systems for the production of recombinant proteins. The presence of a biomarker is required to monitor transfection efficiency or protein expression levels in insect cells. The aim of this study was to construct a baculovirus expression vector encoding a copepod super green fluorescent protein (copGFP). In this light, the resultant vector was constructed and used for transfection of Spodoptera frugiperda cells. Expression of the copGFP protein in insect cells was confirmed by fluorescent microscopy and Western-blot analysis. The application of copGFP control bacmid can be considered as an appropriate control for insect cell transfection.

Research in pharmaceutical sciences

Reteplase is a potent thrombolytic agent which is widely used in the management of acute myocardi... more Reteplase is a potent thrombolytic agent which is widely used in the management of acute myocardial infarction and stroke. It belongs to the third generation of the thrombolytic drugs and has been derived from native human tissue plasminogen activator by removing three domains of it and keeping the Kringle 2 and Serine protease domains. However, the high cost of this drug, has limited the application of this drug especially in the developing and third world countries. The most laborious steps in the bacterial production of this drug is its purification and refolding steps which keep the process yield low and the cost high. Therefore, in the present study we evaluated the expression of reteplase by a non-lytic insect cell expression system. Following cloning and transfection procedures, recombinant Sf9 insect cell clones expressing the reteplase protein were selected. Primarily, the expression was verified by dot-blot analysis and subsequently it was confirmed by Western Blotting sho...

Research in pharmaceutical sciences, 2012

One of the emerging therapeutic strategies for targeted treatment of most cancers is the use of i... more One of the emerging therapeutic strategies for targeted treatment of most cancers is the use of immunotoxins which are fusion proteins consisted of a targeting and a toxic moieties. We previously showed that the recombinant A254-GMCSF fusion protein selectively kills acute myeloblastic leukemia cells which harbor a large number of granulocyte-macrophage colony stimulating factor (GMCSF) receptors. Since further in vitro and preclinical studies require large amounts of this fusion protein free from any troublesome material like lipopolysacharide, we selected the insect cell expression system. Thus, the coding sequences of the A254-GMCSF and its truncated form, A247-GMCSF, were cloned and expressed by Sf9 cells. Subsequently, specific cytotoxicity of the purified proteins was evaluated on GMCSF receptor positive cell lines. SDS-PAGE and Western blot analysis of the expressed A254GMCSF and A247GMCSF fragments revealed bands of about 60 kD which were larger than the theoretically predic...

Yersinia pestis which is the causative agent of pneumonic plague and distributed in all continent... more Yersinia pestis which is the causative agent of pneumonic plague and distributed in all continents has led to many deaths during the history. Because of its high mortality rate, it must be diagnosed and treated at the earliest time post infection and therefore, rapid diagnostic tests are required. In the present study, we cloned the coding sequence of F1 capsular antigen of the bacteria in the pBAD/gIII plasmid for later expression and purification of the protein to produce poly and monoclonal antibodies against this antigen, and subsequently to develop rapid and efficient diagnostics tools for Y. pestis infections.

Hematology, 2014

Bacterial contamination of platelet products is the major infectious risk in blood transfusion me... more Bacterial contamination of platelet products is the major infectious risk in blood transfusion medicine, which can result in life-threatening sepsis in recipient. Lipocalin 2 (Lcn2) is an iron-sequestering protein in the antibacterial innate immune response, which inhibit bacterial growth. This study was aimed to evaluate the antibacterial property of Lcn2 in preventing bacterial contamination of platelets. Recombinant Lcn2 was expressed in a eukaryotic expression system and following purification and characterization of the recombinant Lcn2, its minimum inhibitory concentration was determined. Then, platelet concentrates were inoculated with various concentrations of Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterococcus faecalis, and the antibacterial effects of Lcn2 was evaluated at 20-24 °C. Results revealed that Lcn2 effectively inhibited the growth of 1.5 × 10(4) CFU/ml S. epidermidis, P. aeruginosa, K. pneumoniae, E. coli, and E. faecalis at 40 ng/ml. At this concentration, Lcn2 also inhibited the growth of 1.5 × 10(3) CFU/ml Staphylococcus aureus and Proteus mirabilis. Recombinant Lcn2 inhibited growth of a variety of platelet-contaminating bacteria. Therefore, supplementation of platelet concentrates with Lcn2 may reduce bacterial contamination.

Cell Stress and Chaperones, 2013

Despite many advantages of mesenchymal stem cells (MSCs) that make them suitable for cell therapy... more Despite many advantages of mesenchymal stem cells (MSCs) that make them suitable for cell therapy purposes, their therapeutic application has been limited due to their susceptibility to several stresses (e.g., nutrient-poor environment, oxidative stress, and hypoxic and masses of cytotoxic factors) to which they are exposed during their preparation and following transplantation. Hence, reinforcing MSCs against these stresses is a challenge for both basic and clinician scientists. Recently, much attention has been directed toward equipping MSCs with cytoprotective factors to strengthen them against unfavorable microenvironments. Here, we engineered MSCs with lipocalin 2 (Lcn2), a cytoprotective factor that is naturally induced following exposure of cells to stresses imposed by the microenvironment. Lcn2 overexpression not only did not interfere with the multidifferentiation capacity of the MSCs but also granted many protective properties to them. Lcn2 potentiated MSCs to withstand oxidative, hypoxia, and serum deprivation (SD) conditions via antagonizing their induced cytotoxicity and apoptosis. Adhesion rate of MSCs to coated culture plates was also enhanced by Lcn2 overexpression. In addition, Lcn2 induced antioxidants and upregulated some growth factors in MSCs. Our findings suggested a new strategy for prevention of graft cell death in MSC-based cell therapy.

Bioscience, Biotechnology, and Biochemistry, 2012

Immunotoxins are fusion proteins consisting of two elements, a targeting and a toxin moiety, and ... more Immunotoxins are fusion proteins consisting of two elements, a targeting and a toxin moiety, and are designed for specific elimination of tumor cells. Previously we expressed a recombinant fusion protein consisting of the toxic fragment of Shiga toxin (A1) and GMCSF (A1-GMCSF) in Escherichia coli, and evaluated its cytotoxic properties in acute myeloid leukemia and colon carcinoma cell lines. In view of the specific cytotoxic effects of this immunotoxin, further detailed in-vitro and preclinical studies were undertaken. Large amounts of the recombinant protein of high purity and free of unwanted side products, such as lipopolysaccharides (LPS), were required. Since GMCSF is of mammalian origin and it requires proper disulfide bond formation, we intended to use the baculovirus expression vector system (BEVS) for the expression of the recombinant fusion protein. However, despite previous reports on the expression of several other immunotoxins by this system, the A1 derived fusion proteins revealed an inhibitory effect on baculoviral particle formation and even caused cell death in insect cells. This observation was further pursued and confirmed by the use of other baculoviral specific promoters. The salient features of this finding are described below.

Archives of Medical Research, 2013

Background and Aims. The major limiting factor in therapeutic application of mesenchymal stem cel... more Background and Aims. The major limiting factor in therapeutic application of mesenchymal stem cells (MSCs) is their high vulnerability during the early days of transplantation. Hence, researchers have been encouraged to find various strategies to make the cells resistant to different stresses before and after transplantation. Overexpression of HIF-1a in MSCs to confer resistance against harmful conditions was the aim of this study. Methods. Using an in vitro approach, we engineered MSCs to overexpress HIF-1a and then evaluated their viability following exposure to hypoxic and oxidative stresses. The inherent expression of HIF-1a was downregulated by siRNA. Viability and apoptosis of the MSCs were then evaluated in vitro following their exposure to hypoxic and oxidative stress conditions. Results. Whereas overexpression of HIF-1a in MSCs was protective against cell death and apoptosis triggered by hypoxic and oxidative stress conditions, its downregulation increased apoptosis and death rate. Conclusions. Our study is the first to demonstrate how human MSCs can be manipulated to gain protection against stresses that potentially limit their clinical application. Ó 2013 IMSS. Published by Elsevier Inc.

Cytotechnology, Jan 2, 2017

Acute kidney injury (AKI) is one of the most common health-threatening diseases in the world. The... more Acute kidney injury (AKI) is one of the most common health-threatening diseases in the world. There is still no effective medical treatment for AKI. Recently, Mesenchymal stem cell (MSC)-based therapy has been proposed for treatment of AKI. However, the microenvironment of damaged kidney tissue is not favorable for survival of MSCs which would be used for therapeutic intervention. In this study, we genetically manipulated MSCs to up-regulate lipocalin-2 (Lcn2) and investigated whether the engineered MSCs (MSC-Lcn2) could improve cisplatin-induced AKI in a rat model. Our results revealed that up-regulation of Lcn2 in MSCs efficiently enhanced renal function. MSC Lcn2 up-regulates expression of HGF, IGF, FGF and VEGF growth factors. In addition, they reduced molecular biomarkers of kidney injury such as KIM-1 and Cystatin C, while increased the markers of proximal tubular epithelium such as AQP-1 and CK18 following cisplatin-induced AKI. Overall, here we over-expressed Lcn2, a well-kn...

Research in pharmaceutical sciences, 2016

The aim of this study was to produce a recombinant protein consisting of the catalytic and transl... more The aim of this study was to produce a recombinant protein consisting of the catalytic and translocation domains of diphtheria toxin for its later application as a vaccine candidate against Corynebacterium diphtheria. To achieve this goal, at first, the amino acid sequence of DT386 was used for prediction of T and B cell epitopes using on-line servers. The DT386 coding sequence was synthesized and subcloned into the NcoI and XhoI sites of pET28a plasmid and recombinant pET28a plasmid was used to transform Escherichia coli BL21 (DE3) host cells. Afterwards, recombinant cells were selected and subjected to induction of expression by 1 mM isopropyl β-D-1-thiogalactopyranoside, (IPTG). Expression of the desired protein was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting, and finally, the recombinant protein was purified using nickel affinity chromatography. The results of epitope prediction using on-line servers established the abil...

Advanced Biomedical Research, 2017

The aim of this study was to determine the best condition for the production of DT386-BR2 fusion ... more The aim of this study was to determine the best condition for the production of DT386-BR2 fusion protein, an immunotoxin consisting of catalytic and translocation domains of diphtheria toxin fused to BR2, a cancer specific cell penetrating peptide, for targeted eradication of cancer cells, in terms of the host, cultivation condition, and culture medium. Recombinant pET28a vector containing the codons optimized for the expression of the DT386-BR2 gene was transformed to different strains of Escherichia coli (E. coli BL21 DE3, E. coli Rosetta DE3 and E. coli Rosetta-gami 2 DE3), followed by the induction of expression using 1 mM IPTG. Then, the strain with the highest ability to produce recombinant protein was selected and used to determine the best expression condition using response surface methodology (RSM). Finally, the best culture medium was selected. Densitometry analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the expressed fusion protein showed that E. coli Rosetta DE3 produced the highest amounts of the recombinant fusion protein when quantified by 1 mg/ml bovine serum albumin (178.07 μg/ml). Results of RSM also showed the best condition for the production of the recombinant fusion protein was induction with 1 mM IPTG for 2 h at 37°C. Finally, it was established that terrific broth could produce higher amounts of the fusion protein when compared to other culture media. In this study, we expressed the recombinant DT386-BR2 fusion protein in large amounts by optimizing the expression host, cultivation condition, and culture medium. This fusion protein will be subjected to purification and evaluation of its cytotoxic effects in future studies.

Asian Pacific Journal of Tropical Medicine, 2016

To express human vascular endothelial growth factor121 (VEGF121) in insect cells. A gene construc... more To express human vascular endothelial growth factor121 (VEGF121) in insect cells. A gene construct containing VEGF was cloned in the pFastBac-HTA vector, followed by transformation in DH10BAC. The recombinant bacmid was then extracted, and transfected into Sf9 insect cells. The transfected cells were harvested, and then VEGF expression was confirmed by western blotting using specific antibodies. The tube formation assay was used for functional assessment of VEGF. Our results showed that VEGF could be successfully expressed in the baculovirus system. Purified VEGF was able to stimulate in vitro tube formation of human endothelial cells. Results from this study demonstrated that the recombinantly-produced VEGF can be considered as a promising candidate for therapeutic purposes.

Research in Pharmaceutical Sciences, 2016

Hepatitis B virus (HBV) is considered as a global health concern and hepatitis B surface antigen ... more Hepatitis B virus (HBV) is considered as a global health concern and hepatitis B surface antigen (HBsAg) is the most immunogenic protein of HBV. The purpose of this study was to evaluate the expression of HBsAg on the cell surface of human embryonic kidney cell line (HEK293T). After transformation of expression vector pcDNA/HBsAg to E.coli TOP10F', plasmid was extracted and digested with BglII. Afterwards, the linearized vector was transfected to cells and treated with hygromycin B for 5 weeks to expand the resulted clonies. The permanent expression of HBsAg followed by flow cytometry uptill now about one year. Genomic DNA was extracted from transfected cells and the existence of HBsAg gene was assessed by PCR. Real-time RT-PCR was utilized to measure the expression at the RNA level and flow cytometery was carried out to assess protein expression. Insertion of HBsAg cDNA in HEK293T genome was confirmed by PCR. The results of real-time RT-PCR illustrated that each cell expresses 2275 copies of mRNA molecule. Flow cytometry showed that compared with negative control cells, 99.9% of transfected cells express HBsAg on their surface. In conclusion, stable expression of hepatitis B surface antigen on the membrane of HEK293T provides an accurate post-translational modification, proper structure, and native folding in contrast with purified protein from prokaryotic expression systems. Therefore, these exposing HBsAg cells are practical in therapeutic, pharmaceutical, and biological sets of research.

Journal of Microbiological Methods, 2016

The aim of this study was to produce a fusion protein consisting of the catalytic and translocati... more The aim of this study was to produce a fusion protein consisting of the catalytic and translocation domains of diphtheria toxin fused to BR2, a cancer specific cell penetrating peptide, and evaluation of its cytotoxic effects for targeted eradication of cancer cells. For this purpose, The DT386-BR2 structure was predicted using Modeller 9.14 and the best predicted model was selected based on the minimum DOPE score. A synthetic gene encoding DT386-BR2 was cloned in pET28a expression vector, expressed and purified by affinity chromatography. SDS-PAGE and Western blotting confirmed the expression of the DT386-BR2 fusion protein by revealing a band of about 47kDa after the induction of the expression. Finally, the purified protein was subjected to MTT assay for evaluation of its cyto-lethal effects on cancer and normal cell lines. Statistical analysis showed significant reduction in survival percent of HeLa and MCF-7 cancer cells in comparison to negative control (PBS), while the cytotoxic effect was not significant on the normal cells, i.e. HUVEC and HEK 293. The IC50 of DT386-BR2 for HeLa and MCF-7 was about 0.55 and 2.08μg/ml, respectively. In conclusion, the production and purification of DT386-BR2 fusion protein was successfully achieved and its cytotoxic effects on the studied cancer cell lines was established. The promising cytotoxic effects of this newly constructed fusion protein made it a suitable candidate for targeted therapy of cancer, and further in vitro and in vivo studies on this fusion protein is underway.

Iranian Journal of Medical Sciences, Mar 3, 2012

Background: Natural medicines have been recently considered more reasonable for human use most no... more Background: Natural medicines have been recently considered more reasonable for human use most notably due to their safety and tolerance. HESA-A is a marine-originated herbal medicine with a variety of healing effects. However, its exact biological mechanism is not clear. The present study aimed at the evaluation of the HESA-A antioxidant effect. Methods: Chinese hamster ovary (CHO) and human embryonic kidney (HEK293T) cells were treated with different concentrations of HESA-A and H2O2 followed by cell proliferation assays. The antioxidant effect of the HESA-A preparations was evaluated by an antioxidant assay kit. Results: The viability of CHO and HEK293T cells were about 89% following their incubation with 100 and 200 ng/ml HESA-A, respectively for 1.5 hrs. However, when the cells were incubated with concentrations of 300 ng/ml or more, the cell viability significantly decreased to 48% compare to the control cells. The cytotoxic effects of H2O2 were observed after 2 hrs of incubation of the HEK293T or CHO cells with 10 mM or 16 mM H2O2, respectively, while in the presence of HESA-A the cytotoxicity was significantly decreased. Antioxidant assay revealed that HESA-A scavenges free radicals. Conclusion: The findings indicate that HESA-A had cytoprotective effects in vitro, and that such an effect might be due to antioxidant properties.

Objective(s)Mesenchymal stem cells (MSCs) are nonhematopoietic stromal cells that are capable of ... more Objective(s)Mesenchymal stem cells (MSCs) are nonhematopoietic stromal cells that are capable of differentiating into and contribute to the regeneration of mesenchymal tissues. Human mesenchymal stem cells (hMSCs) are ideal targets in cell transplantation and tissue engineering. ...

Research in pharmaceutical sciences

Pinus eldarica Medw. (Iranian pine) is native to Transcaucasian region and has been vastly plante... more Pinus eldarica Medw. (Iranian pine) is native to Transcaucasian region and has been vastly planted in Iran, Afghanistan, and Pakistan. Various parts of this plant have been widely used in traditional medicine for the treatment of various diseases including infectious conditions (e.g. infectious wounds). In this study we aimed to investigate the antibacterial activity of P. eldarica bark extract, essential oil and proanthocyanidins on three important bacteria, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Antibacterial analysis was performed using standard disk diffusion method with different concentrations of essential oil, bark total hydroalcoholic extract, and bark proanthocyanidins (0.5, 1, 2 and 3 mg/ml). After incubation at 37°C for 24 h, the antibacterial activity was assessed by measuring the zone of growth inhibition surrounding the disks. The results indicated that the essential oil, total hydroalcoholic extract, and proanthocyanidins of the bark of th...

Clinical Laboratory, 2016

Hepatitis C virus (HCV) genome contains an overlapping reading frame which results in alternative... more Hepatitis C virus (HCV) genome contains an overlapping reading frame which results in alternative core protein (ARFP). Baculovirus expression system was used as a powerful eukaryotic vector system to express core+1/F protein for the first time. This recombinant core+1/F protein was used to assess the anti-core+1 antibody in anti-HCV drug resistant and sustained virologic response (SVR) patients. The core+1 coding sequence from HCV genotype 1 was designed and synthesized in pUC57 vector. It was subcloned into baculovirus donor plasmid pFastBacTM HTA and transposed into baculovirus shuttle vector (bacmid) to transfect Sf9 cells. Recombinant core+1 protein was purified using Ni-NTA agarose under native condition and verified using SDS-PAGE electrophoresis and Western blotting. An enzyme-linked immunosorbent assay (ELISA) was developed using this purified protein to assess anti-core+1 antibody in 28 anti-HCV drug resistant patients and in 34 patients with sustained virologic response (SVR) in comparison with 31 healthy volunteers used as the negative control. Expression of HCV core+1 protein in Sf9 cells was confirmed by using SDS-PAGE and Western blotting. Antibody titer against core+1 protein in anti-HCV drug resistant patients was significantly higher than that in both the healthy volunteers and SVR patients (p < 0.0001). HCV core+1 protein was expressed successfully in a baculovirus expression system in high yield in order to develop an ELISA to assess the anti-core+1 antibody. Further studies are needed to reveal the potential application of core+1 protein in anti-HCV treatment prognosis.

Chemistry & Biodiversity, 2016

Cytotoxic and antimicrobial agents structurally based on quinazolinone, benzofuran and imidazole ... more Cytotoxic and antimicrobial agents structurally based on quinazolinone, benzofuran and imidazole pharmacophores, have been designed and synthesized. Spectral (IR, (1) H-NMR) and elemental analysis data established the structures of these novel 3-[1-(1-benzofuran-2-yl)-2-(4-oxoquinazolin-3(4H)-yl)ethyl]-1-methyl-1H-imidazol-3-ium chloride hybrid derivatives. All the synthesized compounds were evaluated for in vitro cytotoxicity and antimicrobial activities. Cytotoxic evaluation using MTT assay revealed that compounds 12c, 12g and 12i exhibited significant cytotoxicity with IC50 values 1, 1, and 0.57 μm on this cell line, respectively. Biological activity of the synthesized compounds as antibacterial agent were also evaluated against three Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi), three Gram-positive (Staphylococcus aureus, Bacillus subtilis and Listeria monocitogenes) and one yeast-like fungi (Candida albicans) strains. All compounds 12a - 12i showed slightly higher activity against Gram-positive bacteria than the Gram-negative one. Among the nine new compounds screened, 3-[1-(5-bromo-1-benzofuran-2-yl)-2-(6-chloro-4-oxoquinazolin-3(4H)-yl)ethyl]-1-methyl-1H-imidazol-3-ium chloride (12e) has pronounced higher antimicrobial activity against all tested strains. These results demonstrated potential importance of molecular hybridization in the development of new lead molecules with major cytotoxicity and antimicrobial activity.

Advanced Biomedical Research, 2016

Chimeric proteins consisting of a targeting moiety and a cytotoxic moiety are now under intense r... more Chimeric proteins consisting of a targeting moiety and a cytotoxic moiety are now under intense research focus for targeted therapy of cancer. Here, we report cloning, expression, and purification of such a targeted chimeric protein made up of p28 peptide as both targeting and anticancer moiety fused to NRC peptide as a cytotoxic moiety. However, since the antimicrobial activity of the NRC peptide would intervene expression of the chimeric protein in Escherichia coli, we evaluated the effects of two fusion tags, that is, thioredoxin (Trx) and 6x-His tags, and various expression conditions, on the expression of p28-NRC chimeric protein. In order to express the chimeric protein with only 6x-His tag, pET28 expression plasmid was used. Cloning in pET32 expression plasmid was performed to add both Trx and 6x-His tags to the chimeric protein. Expression of the chimeric protein with both plasmids was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis following optimization of expression conditions and host strains. Expression of the chimeric protein in pET28a was performed. However, expression yield of the chimeric protein was low. Optimization of culture conditions and host strains led to reasonable expression yield of the toxic chimeric protein in pET32a vector. In cases of both plasmids, approximately 10 kDa deviation of the apparent molecular weight from the theoretical one was seen in SDS-PAGE of purified chimeric proteins. The study leads to proper expression and purification yield of p28-NRC chimeric protein with Trx tag following optimizing culture conditions and host strains.

Iranian biomedical journal, Jan 31, 2015

A baculovirus expression system is one of the most attractive and powerful eukaryotic expression ... more A baculovirus expression system is one of the most attractive and powerful eukaryotic expression systems for the production of recombinant proteins. The presence of a biomarker is required to monitor transfection efficiency or protein expression levels in insect cells. The aim of this study was to construct a baculovirus expression vector encoding a copepod super green fluorescent protein (copGFP). In this light, the resultant vector was constructed and used for transfection of Spodoptera frugiperda cells. Expression of the copGFP protein in insect cells was confirmed by fluorescent microscopy and Western-blot analysis. The application of copGFP control bacmid can be considered as an appropriate control for insect cell transfection.

Research in pharmaceutical sciences

Reteplase is a potent thrombolytic agent which is widely used in the management of acute myocardi... more Reteplase is a potent thrombolytic agent which is widely used in the management of acute myocardial infarction and stroke. It belongs to the third generation of the thrombolytic drugs and has been derived from native human tissue plasminogen activator by removing three domains of it and keeping the Kringle 2 and Serine protease domains. However, the high cost of this drug, has limited the application of this drug especially in the developing and third world countries. The most laborious steps in the bacterial production of this drug is its purification and refolding steps which keep the process yield low and the cost high. Therefore, in the present study we evaluated the expression of reteplase by a non-lytic insect cell expression system. Following cloning and transfection procedures, recombinant Sf9 insect cell clones expressing the reteplase protein were selected. Primarily, the expression was verified by dot-blot analysis and subsequently it was confirmed by Western Blotting sho...

Research in pharmaceutical sciences, 2012

One of the emerging therapeutic strategies for targeted treatment of most cancers is the use of i... more One of the emerging therapeutic strategies for targeted treatment of most cancers is the use of immunotoxins which are fusion proteins consisted of a targeting and a toxic moieties. We previously showed that the recombinant A254-GMCSF fusion protein selectively kills acute myeloblastic leukemia cells which harbor a large number of granulocyte-macrophage colony stimulating factor (GMCSF) receptors. Since further in vitro and preclinical studies require large amounts of this fusion protein free from any troublesome material like lipopolysacharide, we selected the insect cell expression system. Thus, the coding sequences of the A254-GMCSF and its truncated form, A247-GMCSF, were cloned and expressed by Sf9 cells. Subsequently, specific cytotoxicity of the purified proteins was evaluated on GMCSF receptor positive cell lines. SDS-PAGE and Western blot analysis of the expressed A254GMCSF and A247GMCSF fragments revealed bands of about 60 kD which were larger than the theoretically predic...

Yersinia pestis which is the causative agent of pneumonic plague and distributed in all continent... more Yersinia pestis which is the causative agent of pneumonic plague and distributed in all continents has led to many deaths during the history. Because of its high mortality rate, it must be diagnosed and treated at the earliest time post infection and therefore, rapid diagnostic tests are required. In the present study, we cloned the coding sequence of F1 capsular antigen of the bacteria in the pBAD/gIII plasmid for later expression and purification of the protein to produce poly and monoclonal antibodies against this antigen, and subsequently to develop rapid and efficient diagnostics tools for Y. pestis infections.

Hematology, 2014

Bacterial contamination of platelet products is the major infectious risk in blood transfusion me... more Bacterial contamination of platelet products is the major infectious risk in blood transfusion medicine, which can result in life-threatening sepsis in recipient. Lipocalin 2 (Lcn2) is an iron-sequestering protein in the antibacterial innate immune response, which inhibit bacterial growth. This study was aimed to evaluate the antibacterial property of Lcn2 in preventing bacterial contamination of platelets. Recombinant Lcn2 was expressed in a eukaryotic expression system and following purification and characterization of the recombinant Lcn2, its minimum inhibitory concentration was determined. Then, platelet concentrates were inoculated with various concentrations of Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterococcus faecalis, and the antibacterial effects of Lcn2 was evaluated at 20-24 °C. Results revealed that Lcn2 effectively inhibited the growth of 1.5 × 10(4) CFU/ml S. epidermidis, P. aeruginosa, K. pneumoniae, E. coli, and E. faecalis at 40 ng/ml. At this concentration, Lcn2 also inhibited the growth of 1.5 × 10(3) CFU/ml Staphylococcus aureus and Proteus mirabilis. Recombinant Lcn2 inhibited growth of a variety of platelet-contaminating bacteria. Therefore, supplementation of platelet concentrates with Lcn2 may reduce bacterial contamination.

Cell Stress and Chaperones, 2013

Despite many advantages of mesenchymal stem cells (MSCs) that make them suitable for cell therapy... more Despite many advantages of mesenchymal stem cells (MSCs) that make them suitable for cell therapy purposes, their therapeutic application has been limited due to their susceptibility to several stresses (e.g., nutrient-poor environment, oxidative stress, and hypoxic and masses of cytotoxic factors) to which they are exposed during their preparation and following transplantation. Hence, reinforcing MSCs against these stresses is a challenge for both basic and clinician scientists. Recently, much attention has been directed toward equipping MSCs with cytoprotective factors to strengthen them against unfavorable microenvironments. Here, we engineered MSCs with lipocalin 2 (Lcn2), a cytoprotective factor that is naturally induced following exposure of cells to stresses imposed by the microenvironment. Lcn2 overexpression not only did not interfere with the multidifferentiation capacity of the MSCs but also granted many protective properties to them. Lcn2 potentiated MSCs to withstand oxidative, hypoxia, and serum deprivation (SD) conditions via antagonizing their induced cytotoxicity and apoptosis. Adhesion rate of MSCs to coated culture plates was also enhanced by Lcn2 overexpression. In addition, Lcn2 induced antioxidants and upregulated some growth factors in MSCs. Our findings suggested a new strategy for prevention of graft cell death in MSC-based cell therapy.

Bioscience, Biotechnology, and Biochemistry, 2012

Immunotoxins are fusion proteins consisting of two elements, a targeting and a toxin moiety, and ... more Immunotoxins are fusion proteins consisting of two elements, a targeting and a toxin moiety, and are designed for specific elimination of tumor cells. Previously we expressed a recombinant fusion protein consisting of the toxic fragment of Shiga toxin (A1) and GMCSF (A1-GMCSF) in Escherichia coli, and evaluated its cytotoxic properties in acute myeloid leukemia and colon carcinoma cell lines. In view of the specific cytotoxic effects of this immunotoxin, further detailed in-vitro and preclinical studies were undertaken. Large amounts of the recombinant protein of high purity and free of unwanted side products, such as lipopolysaccharides (LPS), were required. Since GMCSF is of mammalian origin and it requires proper disulfide bond formation, we intended to use the baculovirus expression vector system (BEVS) for the expression of the recombinant fusion protein. However, despite previous reports on the expression of several other immunotoxins by this system, the A1 derived fusion proteins revealed an inhibitory effect on baculoviral particle formation and even caused cell death in insect cells. This observation was further pursued and confirmed by the use of other baculoviral specific promoters. The salient features of this finding are described below.

Archives of Medical Research, 2013

Background and Aims. The major limiting factor in therapeutic application of mesenchymal stem cel... more Background and Aims. The major limiting factor in therapeutic application of mesenchymal stem cells (MSCs) is their high vulnerability during the early days of transplantation. Hence, researchers have been encouraged to find various strategies to make the cells resistant to different stresses before and after transplantation. Overexpression of HIF-1a in MSCs to confer resistance against harmful conditions was the aim of this study. Methods. Using an in vitro approach, we engineered MSCs to overexpress HIF-1a and then evaluated their viability following exposure to hypoxic and oxidative stresses. The inherent expression of HIF-1a was downregulated by siRNA. Viability and apoptosis of the MSCs were then evaluated in vitro following their exposure to hypoxic and oxidative stress conditions. Results. Whereas overexpression of HIF-1a in MSCs was protective against cell death and apoptosis triggered by hypoxic and oxidative stress conditions, its downregulation increased apoptosis and death rate. Conclusions. Our study is the first to demonstrate how human MSCs can be manipulated to gain protection against stresses that potentially limit their clinical application. Ó 2013 IMSS. Published by Elsevier Inc.

Cytotechnology, Jan 2, 2017

Acute kidney injury (AKI) is one of the most common health-threatening diseases in the world. The... more Acute kidney injury (AKI) is one of the most common health-threatening diseases in the world. There is still no effective medical treatment for AKI. Recently, Mesenchymal stem cell (MSC)-based therapy has been proposed for treatment of AKI. However, the microenvironment of damaged kidney tissue is not favorable for survival of MSCs which would be used for therapeutic intervention. In this study, we genetically manipulated MSCs to up-regulate lipocalin-2 (Lcn2) and investigated whether the engineered MSCs (MSC-Lcn2) could improve cisplatin-induced AKI in a rat model. Our results revealed that up-regulation of Lcn2 in MSCs efficiently enhanced renal function. MSC Lcn2 up-regulates expression of HGF, IGF, FGF and VEGF growth factors. In addition, they reduced molecular biomarkers of kidney injury such as KIM-1 and Cystatin C, while increased the markers of proximal tubular epithelium such as AQP-1 and CK18 following cisplatin-induced AKI. Overall, here we over-expressed Lcn2, a well-kn...

Research in pharmaceutical sciences, 2016

The aim of this study was to produce a recombinant protein consisting of the catalytic and transl... more The aim of this study was to produce a recombinant protein consisting of the catalytic and translocation domains of diphtheria toxin for its later application as a vaccine candidate against Corynebacterium diphtheria. To achieve this goal, at first, the amino acid sequence of DT386 was used for prediction of T and B cell epitopes using on-line servers. The DT386 coding sequence was synthesized and subcloned into the NcoI and XhoI sites of pET28a plasmid and recombinant pET28a plasmid was used to transform Escherichia coli BL21 (DE3) host cells. Afterwards, recombinant cells were selected and subjected to induction of expression by 1 mM isopropyl β-D-1-thiogalactopyranoside, (IPTG). Expression of the desired protein was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting, and finally, the recombinant protein was purified using nickel affinity chromatography. The results of epitope prediction using on-line servers established the abil...

Advanced Biomedical Research, 2017

The aim of this study was to determine the best condition for the production of DT386-BR2 fusion ... more The aim of this study was to determine the best condition for the production of DT386-BR2 fusion protein, an immunotoxin consisting of catalytic and translocation domains of diphtheria toxin fused to BR2, a cancer specific cell penetrating peptide, for targeted eradication of cancer cells, in terms of the host, cultivation condition, and culture medium. Recombinant pET28a vector containing the codons optimized for the expression of the DT386-BR2 gene was transformed to different strains of Escherichia coli (E. coli BL21 DE3, E. coli Rosetta DE3 and E. coli Rosetta-gami 2 DE3), followed by the induction of expression using 1 mM IPTG. Then, the strain with the highest ability to produce recombinant protein was selected and used to determine the best expression condition using response surface methodology (RSM). Finally, the best culture medium was selected. Densitometry analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the expressed fusion protein showed that E. coli Rosetta DE3 produced the highest amounts of the recombinant fusion protein when quantified by 1 mg/ml bovine serum albumin (178.07 μg/ml). Results of RSM also showed the best condition for the production of the recombinant fusion protein was induction with 1 mM IPTG for 2 h at 37°C. Finally, it was established that terrific broth could produce higher amounts of the fusion protein when compared to other culture media. In this study, we expressed the recombinant DT386-BR2 fusion protein in large amounts by optimizing the expression host, cultivation condition, and culture medium. This fusion protein will be subjected to purification and evaluation of its cytotoxic effects in future studies.

Asian Pacific Journal of Tropical Medicine, 2016

To express human vascular endothelial growth factor121 (VEGF121) in insect cells. A gene construc... more To express human vascular endothelial growth factor121 (VEGF121) in insect cells. A gene construct containing VEGF was cloned in the pFastBac-HTA vector, followed by transformation in DH10BAC. The recombinant bacmid was then extracted, and transfected into Sf9 insect cells. The transfected cells were harvested, and then VEGF expression was confirmed by western blotting using specific antibodies. The tube formation assay was used for functional assessment of VEGF. Our results showed that VEGF could be successfully expressed in the baculovirus system. Purified VEGF was able to stimulate in vitro tube formation of human endothelial cells. Results from this study demonstrated that the recombinantly-produced VEGF can be considered as a promising candidate for therapeutic purposes.

Research in Pharmaceutical Sciences, 2016

Hepatitis B virus (HBV) is considered as a global health concern and hepatitis B surface antigen ... more Hepatitis B virus (HBV) is considered as a global health concern and hepatitis B surface antigen (HBsAg) is the most immunogenic protein of HBV. The purpose of this study was to evaluate the expression of HBsAg on the cell surface of human embryonic kidney cell line (HEK293T). After transformation of expression vector pcDNA/HBsAg to E.coli TOP10F', plasmid was extracted and digested with BglII. Afterwards, the linearized vector was transfected to cells and treated with hygromycin B for 5 weeks to expand the resulted clonies. The permanent expression of HBsAg followed by flow cytometry uptill now about one year. Genomic DNA was extracted from transfected cells and the existence of HBsAg gene was assessed by PCR. Real-time RT-PCR was utilized to measure the expression at the RNA level and flow cytometery was carried out to assess protein expression. Insertion of HBsAg cDNA in HEK293T genome was confirmed by PCR. The results of real-time RT-PCR illustrated that each cell expresses 2275 copies of mRNA molecule. Flow cytometry showed that compared with negative control cells, 99.9% of transfected cells express HBsAg on their surface. In conclusion, stable expression of hepatitis B surface antigen on the membrane of HEK293T provides an accurate post-translational modification, proper structure, and native folding in contrast with purified protein from prokaryotic expression systems. Therefore, these exposing HBsAg cells are practical in therapeutic, pharmaceutical, and biological sets of research.

Journal of Microbiological Methods, 2016

The aim of this study was to produce a fusion protein consisting of the catalytic and translocati... more The aim of this study was to produce a fusion protein consisting of the catalytic and translocation domains of diphtheria toxin fused to BR2, a cancer specific cell penetrating peptide, and evaluation of its cytotoxic effects for targeted eradication of cancer cells. For this purpose, The DT386-BR2 structure was predicted using Modeller 9.14 and the best predicted model was selected based on the minimum DOPE score. A synthetic gene encoding DT386-BR2 was cloned in pET28a expression vector, expressed and purified by affinity chromatography. SDS-PAGE and Western blotting confirmed the expression of the DT386-BR2 fusion protein by revealing a band of about 47kDa after the induction of the expression. Finally, the purified protein was subjected to MTT assay for evaluation of its cyto-lethal effects on cancer and normal cell lines. Statistical analysis showed significant reduction in survival percent of HeLa and MCF-7 cancer cells in comparison to negative control (PBS), while the cytotoxic effect was not significant on the normal cells, i.e. HUVEC and HEK 293. The IC50 of DT386-BR2 for HeLa and MCF-7 was about 0.55 and 2.08μg/ml, respectively. In conclusion, the production and purification of DT386-BR2 fusion protein was successfully achieved and its cytotoxic effects on the studied cancer cell lines was established. The promising cytotoxic effects of this newly constructed fusion protein made it a suitable candidate for targeted therapy of cancer, and further in vitro and in vivo studies on this fusion protein is underway.

Iranian Journal of Medical Sciences, Mar 3, 2012

Background: Natural medicines have been recently considered more reasonable for human use most no... more Background: Natural medicines have been recently considered more reasonable for human use most notably due to their safety and tolerance. HESA-A is a marine-originated herbal medicine with a variety of healing effects. However, its exact biological mechanism is not clear. The present study aimed at the evaluation of the HESA-A antioxidant effect. Methods: Chinese hamster ovary (CHO) and human embryonic kidney (HEK293T) cells were treated with different concentrations of HESA-A and H2O2 followed by cell proliferation assays. The antioxidant effect of the HESA-A preparations was evaluated by an antioxidant assay kit. Results: The viability of CHO and HEK293T cells were about 89% following their incubation with 100 and 200 ng/ml HESA-A, respectively for 1.5 hrs. However, when the cells were incubated with concentrations of 300 ng/ml or more, the cell viability significantly decreased to 48% compare to the control cells. The cytotoxic effects of H2O2 were observed after 2 hrs of incubation of the HEK293T or CHO cells with 10 mM or 16 mM H2O2, respectively, while in the presence of HESA-A the cytotoxicity was significantly decreased. Antioxidant assay revealed that HESA-A scavenges free radicals. Conclusion: The findings indicate that HESA-A had cytoprotective effects in vitro, and that such an effect might be due to antioxidant properties.

Objective(s)Mesenchymal stem cells (MSCs) are nonhematopoietic stromal cells that are capable of ... more Objective(s)Mesenchymal stem cells (MSCs) are nonhematopoietic stromal cells that are capable of differentiating into and contribute to the regeneration of mesenchymal tissues. Human mesenchymal stem cells (hMSCs) are ideal targets in cell transplantation and tissue engineering. ...

Research in pharmaceutical sciences

Pinus eldarica Medw. (Iranian pine) is native to Transcaucasian region and has been vastly plante... more Pinus eldarica Medw. (Iranian pine) is native to Transcaucasian region and has been vastly planted in Iran, Afghanistan, and Pakistan. Various parts of this plant have been widely used in traditional medicine for the treatment of various diseases including infectious conditions (e.g. infectious wounds). In this study we aimed to investigate the antibacterial activity of P. eldarica bark extract, essential oil and proanthocyanidins on three important bacteria, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Antibacterial analysis was performed using standard disk diffusion method with different concentrations of essential oil, bark total hydroalcoholic extract, and bark proanthocyanidins (0.5, 1, 2 and 3 mg/ml). After incubation at 37°C for 24 h, the antibacterial activity was assessed by measuring the zone of growth inhibition surrounding the disks. The results indicated that the essential oil, total hydroalcoholic extract, and proanthocyanidins of the bark of th...