Alterations in apoptotic signaling in human idiopathic cardiomyopathic hearts in failure

Dilated cardiomyopathy, a disease of unknown etiology and pathogenesis, is associated with heart failure and compensatory hypertrophy. Although cell and animal models suggest a role for altered gene expression in the transition to heart failure, there is a paucity of data derived from the study of human heart tissue. In this study, we used DNA microarray profiling to investigate changes in the expression of genes involved in apoptosis that occur in human idiopathic dilated cardiomyopathic hearts that had progressed to heart failure. We observed altered gene expression consistent with a proapoptotic shift in the TNF-alpha signaling pathway. Specifically, we found decreased expression of TNF-alpha- and NF-kappaB-induced antiapoptotic genes such as growth arrest and DNA damage-inducible (GADD)45beta, Flice inhibitory protein (FLIP), and TNF-induced protein 3 (A20). Consistent with a role for apoptosis in heart failure, we also observed a significant decrease in phosphorylation of BAD at Ser-112. This study identifies several pathways that are altered in human heart failure and provides new targets for therapy.     

Evaluation of exosomal miR-9 and miR-155 targeting PTEN and DUSP14 in highly metastatic breast cancer and their effect on low metastatic cells

Breast cancer is one of the most prevalent cancers in women. Triple-negative breast cancer consists 15% to 20% of breast cancer cases and has a poor prognosis. Cancerous transformation has several causes one of which is dysregulation of microRNAs (miRNAs) expression. Exosomes can transfer miRNAs to neighboring and distant cells. Thus, exosomal miRNAs can transfer cancerous phenotype to distant cells. We used gene expression omnibus (GEO) datasets and miRNA target prediction tools to find overexpressed miRNA in breast cancer cells and their target genes, respectively. Exosomes were extracted from MDA-MB-231 and MCF-7 cells and characterized. Overexpression of the miRNAs of MDA-MB-231 cells and their exosomes were analyzed using quantitative Real-time PCR. The target genes expression was also evaluated in the cell lines. Luciferase assay was performed to confirm the miRNAs: mRNAs interactions. Finally, MCF-7 cells were treated with MDA-MB-231 cells’ exosomes. The target genes expression was evaluated in the recipient cells. GSE60714 results indicated that miR-9 and miR-155 were among the overexpressed miRNAs in highly metastatic triple negative breast cancer cells and their exosomes. Bioinformatic studies showed that these two miRNAs target PTEN and DUSP14 tumor suppressor genes. Quantitative Real-time PCR confirmed the overexpression of the miRNAs and downregulation of their targets. Luciferase assay confirmed that the miRNAs target PTEN and DUSP14. Treatment of MCF-7 cells with MDA-MB-231 cells’ exosomes resulted in target genes downregulation in MCF-7 cells. We found that miR-9 and miR-155 were enriched in metastatic breast cancer exosomes. Therefore, exosomal miRNAs can transfer from cancer cells to other cells and can suppress their target genes in the recipient cells.     

Challenges facing antiangiogenesis therapy: The significant role of hypoxia-inducible factor and MET in development of resistance to anti-vascular endothelial growth factor-targeted therapies

It is now fully recognized that along with multiple physiological functions, angiogenesis is also involved in the fundamental process and pathobiology of several disorders including cancer. Recent studies have fully established the role of angiogenesis in cancer progression as well as invasion and metastasis. Consequently, many therapeutic agents such as monoclonal antibodies targeting angiogenesis pathway have been introduced in clinic with the hope for improving the outcomes of cancer therapy. Bevacizumab (Avastin®) was the first anti-vascular endothelial growth factor (VEGF) targeting monoclonal antibody developed with this purpose and soon received its accelerated US Food and Drug Administration (FDA) approval for treatment of patients with metastatic breast cancer in 2008. However, the failure to meet expecting results in different follow-up studies, forced FDA to remove bevacizumab approval for metastatic breast cancer. Investigations have now revealed that while suppressing VEGF pathway initially decreases tumor progression rate and vasculature density, activation of several interrelated pathways and signaling molecules following VEGF blockade compensate the insufficiency of VEGF and initially blocked angiogenesis, explaining in part the failure observed with bevacizumab single therapy. In present review, we introduce some of the main pathways and signaling molecules involved in angiogenesis and then propose how their interconnection may result in development of resistance to bevacizumab.     

A comparison of three strategies for biopanning of phage-scFv library against diphtheria toxin

The biopanning process is a critical step in phage display for isolating peptides or proteins with specific binding properties. Conventional panning methods are sometimes not so effective and may result in nonspecific or low-yield positive results. In this study, three different strategies including soluble antibody-capturing, pH-stepwise elution, and conventional panning were used for enrichment of specific clones against diphtheria toxoid. The reactivity of the selected clones was evaluated using an indirect enzyme-linked immunosorbent assay. The positive clones were screened using Vero cell viability assay. The neutralizing clones were expressed in HB2151 strain of Escherichia coli and soluble single-chain fragment variable (scFv) fragments were purified by nickel-nitrilotriacetic acid affinity chromatography. Finally, the ability of scFv fragments for neutralizing diphtheria toxin (DT) were evaluated again using Vero cell viability assay. After four rounds of panning, the soluble antibody-capturing method yielded 15 positive phage-scFv clones against diphtheria toxoid. Conventional panning and pH-stepwise elution model resulted from nine and five positive phage-scFv clones, respectively. Among all positive clones, three clones were able to neutralize DT in Vero cell viability assay. Two of these clones belonged to a soluble antibody-capturing method and one of them came from conventional panning. Three neutralizing clones were used for soluble expression and purification of scFvs fragments. It was found that these soluble scFv fragments possessed neutralizing activity ranging from 0.15 to 0.6 µg against two-fold cytotoxic dose 99% of DT. In conclusion, the results of our study indicate that soluble antibody-capturing method is an efficient method for isolation of specific scFv fragments.     

Modeling of the aorta artery aneurysms and renal artery stenosis using cardiovascular electronic system

Background  

The aortic aneurysm is a dilatation of the aortic wall which occurs in the saccular and fusiform types. The aortic aneurysms can rupture, if left untreated. The renal stenosis occurs when the flow of blood from the arteries leading to the kidneys is constricted by atherosclerotic plaque. This narrowing may lead to the renal failure. Previous works have shown that, modelling is a useful tool for understanding of cardiovascular system functioning and pathophysiology of the system. The present study is concerned with the modelling of aortic aneurysms and renal artery stenosis using the cardiovascular electronic system.     

Methylenetetrahydrofolate reductase C677T genetic polymorphisms and risk of leukaemia among the North Indian population

Background: Leukaemia is a heterogeneous disease in which haematopoietic progenitor cells acquire genetic lesions that lead to a block in differentiation, increased self-renewal, and unregulated proliferation. The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR), involved in folate metabolism, plays a crucial role in cells because folate availability is important for DNA integrity. The aim of this case–control study was to evaluate the association of the C677T MTHFR gene polymorphism with acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL), chronic myeloid leukaemia (CML) and chronic lymphocytic leukaemia (CLL). Materials and methods: A total of 275 leukaemia cases – including AML (n = 112), ALL (n = 81), CML (n = 43), CLL (n = 39) – and 251 age/sex-matched healthy control individuals participated in this study. MTHFR C677T polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: The average MTHFR 677CC, 677CT, 677TT genotype frequencies of total leukaemia cases were 68.73%, 19.64%, and 11.64% in cases, and 71.71%, 24.30%, and 3.98% in healthy controls, respectively. The average frequency of the MTHFR 677T allele was 21.45% among the cases compared to 16.13% among the controls. Conclusions: In the present case–control study we have observed a higher frequency of the MTHFR 677TT genotype in cases of leukaemia (AML, ALL, CML and CLL) as compared with controls; this might be due to ethnic and geographic variation. As per our findings, although the frequency of the MTHFR 677T allele is moderately high in AML, ALL and CLL, no statistically significant association was found; on the other hand statistically significant association was found in the context of CML cases.     

Low representation of Fc receptor-like 1–5 molecules in leukemic cells from Iranian patients with acute lymphoblastic leukemia

Recent studies have demonstrated expression of Fc receptor-like (FCRL) molecules, a newly identified family with preferential B-cell lineage expression, in some chronic B-cell leukemias with possible implication for classification and/or targeted immunotherapy. In this study, the expression pattern of FCRL1-5 genes was studied in 73 Iranian ALL patients and 35 normal subjects using semi-quantitative RT-PCR method. FCRL protein expression was also investigated by flow cytometry. Our results indicate significant down-regulation of all FCRL genes in ALL compared to normal subjects. Although, FCRL mRNA expression was almost exclusively confined to normal isolated B-cells compared to T-cells, but these genes were similarly expressed in B-ALL, T-ALL and different B-ALL immunophenotypic subtypes. Surface protein expression of FCRL1, 2, 4, and 5 molecules in 10 ALL and 5 normal samples confirmed the PCR results. Expression profile of FCRL molecules in different subtypes of ALL argues against their potential implication as suitable targets for classification and/or immunotherapy of ALL. T. Kazemi, H. Asgarian-Omran and A. Memarian have contributed equally to this study.     

Association of MTHFR and PPARγ2 gene polymorphisms in relation to type 2 diabetes mellitus cases among north Indian population

Background

Type 2 diabetes mellitus is a multifactorial and polygenic disease, which is considered as a major life threatening problem all over the world. There has been a worldwide effort in the identification of susceptibility genes for type 2 diabetes mellitus and its complications. At present, adequate data is not available dealing with MTHFR (rs1801133) and PPARγ2 (rs1801282) gene polymorphisms and its association with type 2 diabetes mellitus cases among north Indian populations. Thus, we conceived the need for further studies to investigate MTHFR and PPARγ2 gene polymorphisms and their susceptibility to type 2 diabetes mellitus in north Indian population.

Materials and methods

In this study, a total 175 subjects including 87 type 2 diabetes mellitus cases and 88 controls were enrolled. MTHFR and PPARγ2 gene polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR–RFLP).

Results

The MTHFR gene CC, CT, TT genotype frequencies obtained were 40%, 43%, and 17% in type 2 diabetes mellitus cases and 56%, 29%, and 15% in healthy controls respectively. The OR for CC was 0.54 (95%CI 0.29–0.98, P = 0.041, χ2 = 4.18, power = 0.98), for CT 1.76 (95%CI 0.94–3.30, P = 0.07, χ2 = 3.2, power = 0.96), and for TT 1.2 (95%CI 0.53–2.70, P = 0.66, χ2 = 0.198, power = 0.76). The PPARγ2 gene GG CG, CC genotype frequencies obtained were 28%, 41%, and 31% in cases and 40%, 39%, and 21% in healthy controls respectively. OR for GG was 0.58 (95%CI 0.30–1.09, P = 0.08, χ2 = 2.9, power = 0.96), for CG 1.12 (95%CI 0.61–2.05, P = 0.71, χ2 = 0.137, power = 0.778), and for CC 1.63 (95%CI 0.82–3.23, P = 0.156, χ2 = 2.01, power = 0.92).

Conclusion

It might be recommended that MTHFR CC genotype seems to be a good marker for the early identification of population at risk of type 2 diabetes mellitus. While we have detected significant difference in allelic frequencies of PPARγ2 C (Proline) and G (Alanine), but at genotypic level significant difference was not detected in this case–control study. Further study with larger groups may be required to validate the study.     

Validation of delay‐multiply‐and‐standard‐deviation weighting factor for improved photoacoustic imaging of sentinel lymph node

Delay‐and‐sum (DAS) is one of the most common algorithms used to construct the photoacoustic images due to its low complexity. However, it results in images with high sidelobes and low resolution. Delay‐and‐standard‐deviation (DASD) weighting factor can improve the contrast of the images compared to DAS. However, it still suffers from high sidelobes. In this work, a new weighting factor, named delay‐multiply‐and‐standard‐deviation (DMASD) is introduced to enhance the contrast of the reconstructed images compared to other mentioned methods. In the proposed method, the SD of the mutual multiplied delayed signals are calculated, normalized and multiplied to DAS beamformed data. The results show that DMASD improves the signal‐to‐noise‐ratio about 19.29 and 7.3 dB compared to DAS and DASD, respectively, for in vivo imaging of the sentinel lymph node. Moreover, the contrast ratio is improved by the DMASD about 23.61 and 10.81 dB compared to DAS and DASD, respectively.