Objective: CREB1 is an important downstream protein for many signaling pathways. By designing efficient siRNAs against CREB1, it may be possible to assess the role of molecules involved in signaling pathways in different cell types. In this research the efficiency of CREB1 knockdown by two different siRNAs in K562 cells has been studied. Materials and Methods: siRNAs have been designed according to the criteria suggested by Reynolds et al. K562 cells were transfected by siRNA using Lipofectamine 2000. The efficiency of CREB knockdown has been assessed by quantitative relative Real-time PCR. Results: Our results have shown that only one of the siRNAs has a high level of inhibitory effect on CREB1 gene expression. The expression of CREB1 by this siRNA was knocked-down by 87% in K562 cells. Conclusion: In this research, although two siRNAs were designed according to the Reynolds et al. criteria, only one showed an inhibitory effect. Reasons other than the aforementioned criteria may be involved in effectiveness of siRNAs.

Background: Dermatophytosis is common cutaneous fungal disease with worldwide distribution. Interleukin8 (IL-8) realized from keratinocytes in the presence of dermatophytic antigens causes induction of acute responses in dermatophyte infection and subsequently production of acute phase proteins occurs in hepatocytes. C-reactive protein (CRP) and Mannose-binding lectin (MBL) are acute phase proteins. Since few researches in the case of acute phase proteins in dermatophytic infections has been accomplished, this study has been designed for determining serum CRP and MBL levels in patients affected to dermatophytosis.Methods: This was a cross sectional study and samples were carried out on 96 healthy individuals and 105 patients affected to dermatophytosis with non probable and in access procedure. For isolation and identification of dermatophyte direct microscopic examination, culturing and complementary examinations were done and for determination of serum CRP and MBL levels in healthy individuals and in patients ELISA test were used. For investigation of relevance between variables, Chi-square, Fisher exact, Mann-Whitney and Roc curve analysis were used and p< 0.05 was considered as meaningful level.Results: The median serum CRP level in healthy individuals and in patients group was 3.31±3.32 mg/ml and 16.60±35.96 mg/ml (p<0.001) respectively and the median serum MBL level was 1.53±1.87 mg/ml and 1.97±2.03 mg/ml (p=0.039) respectively. CRP (p<0.001) and MBL (p=0.042) were determined meaningful parameters for dermatophytosis. MBL deficiency (MBL concentrations <1 mg/ml) was higher in control subjects (56.2%) than in patients (41.0%). Conclusion: Findings of this study indicate increased concentrations of CRP and MBL in patients affected to dermatophytosis and their role in this infection. Probably observation of high frequency of MBL deficiency in healthy individuals in compare with patients group indicates that it is not predisposing factor in affecting to dermatophytosis.

Introduction: Renin synthesis and release is the rate-limiting step in the renin-angiotensin system, because cyclic adenosine monophosphate (cAMP) has been identified as dominant pathway for renin gene expression, and cAMP response element-binding protein (CREB) is found in the human and mouse renin promoter.This study aimed to evaluate the role of CREB in expression of the renin gene.Materials and Methods: We created conditional deletion of CREB in mice with low-sodium diet, specifically in renin cells of the kidney. To assess the effect of CREB on renin expression, immunostaining of renin was used in samples from wild-type mice and mice with gene knock-down of CREB. Cyclic AMP response element-binding-protein-binding protein (CBP) and p300 were measured in cultured renin cells of the mice, and RNA detection was done with real-time polymerase chain reaction.Results: With low-sodium diet, renin was expressed along the whole wall of the afferent glomerular arterioles in wild-type mice, while there was no increase or even decrease in renin expression in CREB-specific deletion mice; RNA level of renin in cultured cells decreased by 50% with single knock-down of CREB, CBP, or p300, and decreased 70% with triple knock-down of CREB, CBP, and p300.Conclusions: This study found that CREB was important for renin synthesis and the role of CREB can be achieved through the recruitment of co-activators CBP and p300.

Background: Choline-binding proteins (CBPs) are a group of surface-exposed proteins, which play crucial and physiological roles in Streptococcus pneumoniae. The novel member of CBPs, choline-binding protein M (CbpM) may have binding activity to plasma proteins. This study aimed to clone and express CbpM and demonstrate its interaction with plasma proteins and patients’ sera.Methods: The total length of cbpM gene was cloned in pET21a vector and expressed in BL21 expression host. Verification of recombinant protein was evaluated by Western blot using anti-His tag monoclonal antibody. Binding ability of the recombinant protein to plasma proteins and the interaction with patients’ sera were assessed by Western blot and ELISA methods.Results: The cbpM gene was successfully cloned into pET21a and expressed in BL21 host. Binding activity to fibronectin and fibrinogen and antibody reaction of CbpM to patients’ sera was demonstrated by Western blot and ELISA methods, respectively.Conclusion: CbpM is one of the pneumococcal surface-exposed proteins, which mediates pneumococcal binding to fibronectin and fibrinogen proteins.

Background: Hepatitis E virus (HEV) is a major causative agent of acute clinical hepatitis in adults throughout much of Asia, the Middle East, and Africa. The lack of an efficient cell culture system for HEV has greatly limited our understanding of the mechanisms of infection, replication, and pathogenicity of this virus. The yeast two-hybridization system is considered to be an efficient method for determining protein-protein interactions and screening interactive proteins associated with host cells.Objectives: In order to identify the host-cell proteins interacting with the HEV-capsid proteins, a fragment of the HEV-capsid protein p239 (amino acids 368-606) was used as bait, human liver cDNA library was used as a source of host-cell proteins, and the screening was performed using the CytoTrap yeast two-hybrid system.Materials and Methods: The CytoTrap yeast two-hybrid system, which is also called Sos Recruitment System (SRS), was used to analyze the interaction of the p239 fragment with host-cell proteins.Results: We isolated 2 proteins, cytochrome P4502C8 (CYP4502C8) and retinol-binding protein 4 (RBP4) after 2 rounds of screening. Co-immunoprecipitation assays showed that both the proteins could bind in vitro to the HEV virion in HepG2 cells.Conclusions: CYP4502C8 and RBP4 screened from liver cDNA library using the CytoTrap yeast two-hybrid system interact with HEV capsid in vitro.

The mechanism of plasmid mediated silver (Ag) resistance was investigated in Acinetobacter baumannii BL54. The intracellular accumulation of Ag in both original strain BL54 and Escherichia coli K12 transconjugant containing plasmid pUPI276 began immediately and reached a maximum within 60 minutes. This initial accumulation was followed by net loss of Ag which reached a maximum within 180 min. Pre-treatment of cells with 0.5 mM 2,4 dinitrophenol (DNP); 20 mM N, N-dicyclohexylcarbodiimide (DCCD); 3% toluene; 25 mg/ml cefotaxime and polymyxin-B resulted in considerable decrease in the accumulation process. Ags plasmid less cured derivative (BL54.1) also accumulated silver but only onefourth the amount compared to the resistant strain BL54. The intracellular accumulated silver is detoxified by binding to a cysteine rich metal binding protein. The purified Ag-binding protein exhibited maximum absorption at 280/215 nm. From the above data it could be concluded that the intracellular detoxification of silver in A. baumannii BL54 is achieved through binding to a cysteine rich metalloprotein.

CTCF is a highly conserved DNA-binding protein involved in transcription regulation, chromatin insulation, genomic imprinting, X-chromosome inactivation, higher-order chromatin organization, and alternative splicing. These multifunctional properties of CTCF suggest an essential role in development and disease. CTCF is unique protein that known to mediate insulation function in vertebrates. Recent studies proposed that CTCF can be a heritable component in epigenetic and regulating the interaction between DNA methylation, higher-order chromatin structure, and developmentally regulated gene expression. In this review, we discuss roles of CTCF in these critical aspects of genome regulation. All information indicates that CTCF can emerge as a master weaver of the mammalian genome.