162 research outputs found

    The analysis of 2-amino-2-thiazoline-4-carboxylic acid in the plasma of smokers and non-smokers

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    ATCA (2-amino-2-thiazoline-4-carboxylic acid) is a promising marker to assess cyanide exposure because of several advantages of ATCA analysis over direct determination of cyanide and alternative cyanide biomarkers (i.e. stability in biological matrices, consistent recovery, and relatively small endogenous concentrations). Concentrations of ATCA in the plasma of smoking and non-smoking human volunteers were analyzed using gas-chromatography mass-spectrometry to establish the feasibility of using ATCA as a marker for cyanide exposure. The levels of ATCA in plasma of smoking volunteers, 17.2 ng/ml, were found to be significantly (p < 0.001) higher than that of non-smoking volunteers, 11.8 ng/ml. Comparison of ATCA concentrations of smokers relative to non-smokers in both urine and plasma yielded relatively similar results. The concentration ratio of ATCA for smokers versus non-smokers in plasma and urine was compared to similar literature studies of cyanide and thiocyanate, and correlations are discussed. This study supports previous evidence that ATCA can be used to determine past cyanide exposure and indicates that further studies should be pursued to validate the use of ATCA as a marker of cyanide exposure

    CCN2/Connective Tissue Growth Factor Is Essential for Pericyte Adhesion and Endothelial Basement Membrane Formation during Angiogenesis

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    CCN2/Connective Tissue Growth Factor (CTGF) is a matricellular protein that regulates cell adhesion, migration, and survival. CCN2 is best known for its ability to promote fibrosis by mediating the ability of transforming growth factor β (TGFβ) to induce excess extracellular matrix production. In addition to its role in pathological processes, CCN2 is required for chondrogenesis. CCN2 is also highly expressed during development in endothelial cells, suggesting a role in angiogenesis. The potential role of CCN2 in angiogenesis is unclear, however, as both pro- and anti-angiogenic effects have been reported. Here, through analysis of Ccn2-deficient mice, we show that CCN2 is required for stable association and retention of pericytes by endothelial cells. PDGF signaling and the establishment of the endothelial basement membrane are required for pericytes recruitment and retention. CCN2 induced PDGF-B expression in endothelial cells, and potentiated PDGF-B-mediated Akt signaling in mural (vascular smooth muscle/pericyte) cells. In addition, CCN2 induced the production of endothelial basement membrane components in vitro, and was required for their expression in vivo. Overall, these results highlight CCN2 as an essential mediator of vascular remodeling by regulating endothelial-pericyte interactions. Although most studies of CCN2 function have focused on effects of CCN2 overexpression on the interstitial extracellular matrix, the results presented here show that CCN2 is required for the normal production of vascular basement membranes

    High-Sensitivity Cardiac Troponin-I Is Elevated in Patients with Rheumatoid Arthritis, Independent of Cardiovascular Risk Factors and Inflammation

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    We examined the hypothesis that cardiac-specific troponin-I (cTn-I), a biomarker of myocardial injury, is elevated in patients with rheumatoid arthritis (RA).RA patients have an increased incidence of heart failure (HF). Chronic myocardial injury in RA may be a mechanism for the development of HF.We compared cTn-I concentrations measured by high-sensitivity immunoassay in 164 patients with RA and 90 controls, excluding prior or active heart failure. We examined the relationship between cTn-I concentrations and cardiovascular risk factors, inflammation, and coronary artery calcium score (CACS), a measure of coronary atherosclerosis.cTn-I concentrations were 49% higher in patients with RA (median 1.15 pg/mL [IQR 0.73–1.92] than controls (0.77 pg/mL [0.49–1.28](P<0.001). The difference remained statistically significant after adjustment for demographic characteristics (P = 0.002), further adjustment for cardiovascular (CV) risk factors (P = 0.004), inflammatory markers (P = 0.008), and in a comprehensive model of CV risk factors and inflammatory markers (P = 0.03). In patients with RA, cTn-I concentrations were positively correlated with age (rho = 0.359), Framingham risk score (FRS) (rho = 0.366), and systolic blood pressure (rho = 0.248 (all P values ≤0.001)), but not with measures of inflammation or RA drug therapies. cTn-I was significantly correlated with CACS in RA in univariate analysis, but not after adjustment for age, race, sex and FRS (P = 0.79). Further model adjustments for renal function and coronary artery disease confirmed the significance of the findings.High-sensitivity cTn-I concentrations are elevated in patients with RA without heart failure, independent of cardiovascular risk profile and inflammatory markers. Elevated troponin concentrations in RA may indicate subclinical, indolent myocardial injury

    Expression of CCN family of genes in human skin in vivo and alterations by solar-simulated ultraviolet irradiation

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    The CCN family of proteins is involved in diverse biological functions such as cell growth, adhesion, migration, angiogenesis, and regulation of extracellular matrix. We have investigated expression of CCN family genes and alternations induced by solar-simulated ultraviolet irradiation in human skin in vivo. Transcripts of all six CCN genes were expressed in human skin in vivo. CCN5 was most abundantly expressed followed by CCN2>CCN3>CCN1>CCN4>CCN6. Solar-simulated ultraviolet irradiation increased mRNA expression of CCN1 and CCN2. In contrast, mRNA levels of CCN3, CCN4, CCN5, and CCN6, were reduced. Knowledge gained from this study provides the foundation to explore the functional roles of CCN gene products in cutaneous biology and responses to solar ultraviolet irradiation

    Mitochondrial and endoplasmic reticulum stress pathways cooperate in zearalenone-induced apoptosis of human leukemic cells

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    <p>Abstract</p> <p>Background</p> <p>Zearalenone (ZEA) is a phytoestrogen from <it>Fusarium </it>species. The aims of the study was to identify mode of human leukemic cell death induced by ZEA and the mechanisms involved.</p> <p>Methods</p> <p>Cell cytotoxicity of ZEA on human leukemic HL-60, U937 and peripheral blood mononuclear cells (PBMCs) was performed by using 3-(4,5-dimethyl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Reactive oxygen species production, cell cycle analysis and mitochondrial transmembrane potential reduction was determined by employing 2',7'-dichlorofluorescein diacetate, propidium iodide and 3,3'-dihexyloxacarbocyanine iodide and flow cytometry, respectively. Caspase-3 and -8 activities were detected by using fluorogenic Asp-Glu-Val-Asp-7-amino-4-methylcoumarin (DEVD-AMC) and Ile-Glu-Thr-Asp-7-amino-4-methylcoumarin (IETD-AMC) substrates, respectively. Protein expression of cytochrome c, Bax, Bcl-2 and Bcl-xL was performed by Western blot. The expression of proteins was assessed by two-dimensional polyacrylamide gel-electrophoresis (PAGE) coupled with LC-MS2 analysis and real-time reverse transcription polymerase chain reaction (RT-PCR) approach.</p> <p>Results</p> <p>ZEA was cytotoxic to U937 > HL-60 > PBMCs and caused subdiploid peaks and G1 arrest in both cell lines. Apoptosis of human leukemic HL-60 and U937 cell apoptosis induced by ZEA was via an activation of mitochondrial release of cytochrome c through mitochondrial transmembrane potential reduction, activation of caspase-3 and -8, production of reactive oxygen species and induction of endoplasmic reticulum stress. Bax was up regulated in a time-dependent manner and there was down regulation of Bcl-xL expression. Two-dimensional PAGE coupled with LC-MS2 analysis showed that ZEA treatment of HL-60 cells produced differences in the levels of 22 membrane proteins such as apoptosis inducing factor and the ER stress proteins including endoplasmic reticulum protein 29 (ERp29), 78 kDa glucose-regulated protein, heat shock protein 90 and calreticulin, whereas only <it>ERp29 </it>mRNA transcript increased.</p> <p>Conclusion</p> <p>ZEA induced human leukemic cell apoptosis via endoplasmic stress and mitochondrial pathway.</p

    Multi-Parametric Analysis and Modeling of Relationships between Mitochondrial Morphology and Apoptosis

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    Mitochondria exist as a network of interconnected organelles undergoing constant fission and fusion. Current approaches to study mitochondrial morphology are limited by low data sampling coupled with manual identification and classification of complex morphological phenotypes. Here we propose an integrated mechanistic and data-driven modeling approach to analyze heterogeneous, quantified datasets and infer relations between mitochondrial morphology and apoptotic events. We initially performed high-content, multi-parametric measurements of mitochondrial morphological, apoptotic, and energetic states by high-resolution imaging of human breast carcinoma MCF-7 cells. Subsequently, decision tree-based analysis was used to automatically classify networked, fragmented, and swollen mitochondrial subpopulations, at the single-cell level and within cell populations. Our results revealed subtle but significant differences in morphology class distributions in response to various apoptotic stimuli. Furthermore, key mitochondrial functional parameters including mitochondrial membrane potential and Bax activation, were measured under matched conditions. Data-driven fuzzy logic modeling was used to explore the non-linear relationships between mitochondrial morphology and apoptotic signaling, combining morphological and functional data as a single model. Modeling results are in accordance with previous studies, where Bax regulates mitochondrial fragmentation, and mitochondrial morphology influences mitochondrial membrane potential. In summary, we established and validated a platform for mitochondrial morphological and functional analysis that can be readily extended with additional datasets. We further discuss the benefits of a flexible systematic approach for elucidating specific and general relationships between mitochondrial morphology and apoptosis

    Upregulation of MAPK pathway is associated with survival in castrate-resistant prostate cancer

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    BACKGROUND: Recent evidence has implicated the MAP kinase (MAPK) pathway with the development of castrate-resistant prostate cancer (CRPC). We have previously reported gene amplification of critical members of this pathway with the development of castrate-resistant disease. In addition, we have shown that rising Raf-1 expression, with the development of CRPC, influences time to biochemical relapse. We therefore sought to further analyse the role of both Raf-1 and its downstream target MAPK in the molecular pathogenesis of CRPC. METHODS: Protein expression of Raf-1 and MAPK, including their activation status, was analysed using immunohistochemistry in a database of 65 paired tumour specimens obtained before and after the development of CRPC and correlated with other members of the pathway. RESULTS: Patients whose nuclear expression of MAPK rose with the development of CRPC had a significantly shorter median time to death following biochemical relapse (1.40 vs 3.00 years, P=0.0255) as well as reduced disease-specific survival when compared with those whose expression fell or remained unchanged (1.16 vs 2.62 years, P=0.0005). Significant correlations were observed between protein expression of Raf-1 and MAPK with the type 1 receptor tyrosine kinases, Her2 and epidermal growth factor receptor, as well as the transcription factor AP-1 in CRPC tumours. CONCLUSION: We conclude that the Her2/Raf-1/MAPK/AP-1 axis may promote the development of CRPC, leading to early relapse, and reduced disease-specific survival. In addition, members of the pathway may act as novel therapeutic and/or diagnostic targets for prostate cancer. British Journal of Cancer (2011) 104, 1920-1928. doi:10.1038/bjc.2011.163 www.bjcancer.com Published online 10 May 2011 (C) 2011 Cancer Research U

    NOV story: the way to CCN3

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    The principal aim of this historical review- the first in a new series- is to present the basic concepts that led to the discovery of NOV and to show how our ideas evolved regarding the role and functions of this new class of proteins. It should prove particularly useful to the new comers and to students who are engaged in this exciting field. It is also a good opportunity to acknowledge the input of those who participated in the development of this scientific endeavou
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