Profiling of Virulence-associated Factors in Shigella Species Isolated from Acute Pediatric Diarrheal Samples in Tehran, Iran

OBJECTIVES: The genus Shigella comprises the most infectious and diarrheagenic bacteria causing severe diseases, mostly in children under five years of age. This study aimed to detect nine virulence genes (ipaBCD, VirA, sen, set1A, set1B, ial, ipaH, stx, and sat) in Shigella species (spp.) using multiplex polymerase chain reaction (MPCR) and to determine the relation of Shigella spp. from pediatric diarrheal samples with hospitalization and bloody diarrhea in Tehran, Iran. METHODS: Shigella spp. were isolated and identified using standard microbiological and serological methods. The virulence genes were detected using MPCR. RESULTS: Seventy-five Shigella spp. (40 S. sonnei, 33 S. flexneri, 1 S. dysenteriae, and 1 S. boydii) were isolated in this study. The prevalence of ial, sen, sat, set1A, and set1B was 74.7%, 45.4%, 28%, 24%, and 24%, respectively. All S. flexneri isolates, while no S. sonnei, S. dysenteriae, or S. boydii isolates, contained sat, set1A, and set1B. All isolates were positive for ipaH, ipaBCD, and virA, while one (1.4%) of the isolates contained stx. The highest prevalence of virulence determinants was found in S. flexneri serotype IIa. Nineteen (57.6%) of 33 S. flexneri isolates were positive for ipaBCD, ipaH, virA, ial, and sat. The sen determinants were found to be statistically significantly associated with hospitalization and bloody diarrhea (p = 0.001). CONCLUSION: This study revealed a high prevalence of enterotoxin genes in S. flexneri, especially in serotype 2a, and has presented relations between a few clinical features of shigellosis and numerous virulence determinants of clinical isolates of Shigella spp.

MicroRNA-146 a promotes proliferation of rat vascular smooth muscle cells by up-regulating cyclin D1 expression / 中国免疫学杂志

Objective:To detect and verifica the gene profile difference of microRNA-146a (miR-146a) and its role in the pro-liferation of vascular smooth muscle cells (VSMCs) by gene chip technology. Methods: Artificially synthesized miR-146a mimics(50 nmol/L) ,miR-146 inhibitor ( 50 nmol/L ) , scramble ( 50 nmol/L ) and PBS were transfected into cultured primary rat VSMCs in vitro. After transfection,Real time PCR was used to measure the levels of miR-146a and the cell counting kit 8(CCK8) was employed to investigate the proliferation of VSMCs. The VSMCs interfered by miR-146a inhibitor or miR-146a control were examined by gene chips and the profile of gene were analyzed by bioinformatics technology to detect the different genes and signal transduction pathway. The changes in mRNAs and proteins were accessed separately by Real time PCR and Western blot. Results: Compared with sham and control VSMCs,miR-146a expression level was significantly decreased in treatment with miR-146a inhibitor(P0. 05),however,the mRNA and protein expression levels of cyclin D1 significantly increased in treatment with miR-146a mimics VSMCs group and decreased in miR-146a inhibitor VSMCs group ( compared with sham VSMCs group, both P<0. 05 ) . Conclusion: Our data indicated that miR-146a may promote the proliferation of rat VSMCs by up-regulating cyclin D1 expression.

Host Gene Profiling of Coxsackievirus B3 H3- and 10A1-infected Mouse Heart

Coxsackievirus B3 (CVB3) is a non-enveloped virus that has a single-stranded RNA genome. CVB3 induces myocarditis, and ultimately, dilated cardiomyopathy. A myocarditis variant of CVB3 (CVB3 H3) and its antibody-escape mutant (CVB3 10A1) were studied previously; H3 was found to induce myocarditis and 10A1 was found to be attenuated in infected mice. Although amino acid residue 165, located in a puff region of VP2, was found to be altered (i.e., the H3 asparagine was altered to aspartate in 10A1), the detailed mechanism of attenuation was not clearly elucidated. Here, DNA microarray technology was used to monitor changes in mRNA levels of infected mouse hearts after CVB3 H3 and 10A1 infection. This tool was used to elucidate the pathogenic mechanisms of viral infection by understanding virus-host interactions. We identified several genes, including protein tyrosine kinases, Ddr2 and Ptk2, as well as Clqb and Crry, involved in complement reactions, which may be involved in these viral processes. Thus, gene profiling can provide an opportunity to understand host immune responses to viral infection for gene therapy and may contribute to the identification of the target gene that is modified during treatment of viral myocarditis.

Immortalization of cultures derived from primary breast carcinoma by ectopic expression of human telomerase reverse transcriptase and its significance / 中国癌症杂志

Background and purpose:Most breast cancer cell lines were derived from malignant pleural fluid or other tissues that metastasized from breast carcinoma.Breast carcinogenesis is under represented due to the significant distinction of biological characteristics between cancer cell lines and primary breast cancers.Few primary breast tumors spontaneously developed into immortal cell lines.Overexpression of human telomerase reverse transcriptase(hTERT) in normal epithelial cells led to immortalization.We aimed to establish immortalized cultures derived from primary breast cancer by introducing hTERT and determine the gene profile of hTERT-transfected cultures.Methods:hTERT was introduced into breast tumor cultures with a puromycin-resistant retroviral construct,pBABE-hTERT-puro.Real-Time RT-PCR was used to analyze the expression level of hTERT after transfection.The upregulated gene profile was determined with microarray techniques.Results:hTERT was stably over expressed,at least 1 400-fold in hTERT-transfected cells compared to pBABE-puro transfected cultures.These ectopic over-expressions led to immortalization of transfected cultures,which could undergo at least 40-50 passages.Microarray analysis further confirmed the over-expression of hTERT in transfected cultures and demonstrated that 22 genes were up-regulated due to over-expression of hTERT.No down-regulated genes were observed cross all cultures.Conclusions:Over-expression of hTERT led to immortalization of breast tumor primary cultures and up-regulated certain genes.

Anergy and Characteristics of Human T Cells Induced by Combination with B7-1 mAb and CsA / 中国肿瘤生物治疗杂志

To study the induced condition and characteristics of T cell anergy in vitro. Methods: Anergic Tcell was induced by combination of B7-1 mAb and cyclosporin A (CsA) in vitro, cytokine gene of anergic T cells was detected by RT-PCR. Results: T cell anergy was antigen-specific. The state of T cell anergy can be reversed by PHA, CD3 mAb and PMA plus A23187. IL-2 can prevent the induction of T cell anergy, but it can not reverse the state of un-responsiveness. IL-2 and IFN mRNA can not express in anergic T cells. In contrast, IL-4 and IL-10 mRNA were detectable. Conclusion: T cell anergy can be induced in vitro , cytokine profile of anergic T cells deviated to Th2-like phe-norype.