2,586 research outputs found
Circulating MCP-1 level and 2518 gene polymorphism as a marker of nephropathy development in Egyptian patients
Objective: Monocyte chemoattractant protein-1 (MCP-1) is a member of CC chemokine that plays an important role in the recruitment of monocytes/macrophages into renal tubulointerstitium. A biallelic A/G polymorphism at position 2518 in the MCP-1 gene was found to regulateMCP-1 expression. MCP-1 and its A/G gene polymorphism have been implicated in the pathogenesis of some renal diseases. The aim of this study was to evaluate the role of circulating MCP-1 level and the relevance of functional genetic variations of MCP-1 as early predictors of the development of glomerulonephropathy (GN) in Egyptian patients.Methods: This is a case control study that was conducted in 50 GN patients, 20 non-GN cases and 20 ethnically matched healthy controls. MCP-1 serum level was detected by ELISA technique, while genotyping of polymorphisms in the MCP-1 genes was performed using a polymerasechain reaction (PCR) followed by restriction fragment length polymorphism (RFLP)detection.Results: High MCP-1 circulating levels and subsequently MCP-1 2518G polymorphism are associated with the developing of nephropathy irrespective to the underlying etiology. MCP-1 serum level was significantly high when compared with healthy controls (P = 0.0007) and non-GN cases (P = 0.01). There was predominance of A allele at 2518 of MCP-1 gene in healthy controls (87.5%) and non-GN cases (77.5%). The frequency of the 2518G MCP-1 polymorphism was significantly higher in GN patients than in healthy controls (
Liver sinusoidal endothelial transcription factors in metabolic homeostasis and disease.
Liver sinusoidal endothelial cells (LSECs) are highly specialized endothelial cells that form the liver microvasculature. LSECs maintain liver homeostasis, scavenging bloodborne molecules, regulating immune response, and actively promoting hepatic stellate cell quiescence. These diverse functions are underpinned by a suite of unique phenotypical attributes distinct from other blood vessels. In recent years, studies have begun to reveal the specific contributions of LSECs to liver metabolic homeostasis and how LSEC dysfunction associates with disease aetiology. This has been particularly evident in the context of non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of metabolic syndrome, which is associated with loss of key LSEC phenotypical characteristics and molecular identity. Comparative transcriptome studies of LSECs and other endothelial cells, together with rodent knockout models, have revealed that loss of LSEC identity through disruption of core transcription factor activity leads to impaired metabolic homeostasis and to hallmarks of liver disease. This review explores the current knowledge of LSEC transcription factors, covering their roles in LSEC development and maintenance of key phenotypic features, which, when disturbed, lead to loss of liver metabolic homeostasis and promote features of chronic liver diseases, such as non-alcoholic liver disease
lemmingA encodes the Apc11 subunit of the APC/C in Drosophila melanogaster that forms a ternary complex with the E2-C type ubiquitin conjugating enzyme, Vihar and Morula/Apc2
<p>Abstract</p> <p>Background</p> <p>Ubiquitin-dependent protein degradation is a critical step in key cell cycle events, such as metaphase-anaphase transition and mitotic exit. The anaphase promoting complex/cyclosome (APC/C) plays a pivotal role in these transitions by recognizing and marking regulatory proteins for proteasomal degradation. Its overall structure and function has been elucidated mostly in yeasts and mammalian cell lines. The APC/C is, however, a multisubunit assembly with at least 13 subunits and their function and interaction within the complex is still relatively uncharacterized, particularly in metazoan systems. Here, <it>lemming </it>(<it>lmg</it>) mutants were used to study the APC/C subunit, Apc11, and its interaction partners in <it>Drosophila melanogaster</it>.</p> <p>Results</p> <p>The <it>lmg </it>gene was initially identified through a pharate adult lethal P element insertion mutation expressing developmental abnormalities and widespread apoptosis in larval imaginal discs and pupal abdominal histoblasts. Larval neuroblasts were observed to arrest mitosis in a metaphase-like state with highly condensed, scattered chromosomes and frequent polyploidy. These neuroblasts contain high levels of both cyclin A and cyclin B. The <it>lmg </it>gene was cloned by virtue of the <it>lmg<sup>03424 </sup></it>P element insertion which is located in the 5' untranslated region. The <it>lemming </it>locus is transcribed to give a 2.0 kb mRNA that contains two ORFs, <it>lmgA </it>and <it>lmgB</it>. The <it>lmgA </it>ORF codes for a putative protein with more than 80% sequence homology to the APC11 subunit of the human APC/C. The 85 amino acid protein also contains a RING-finger motif characteristic of known APC11 subunits. The <it>lmgA </it>ORF alone was sufficient to rescue the lethal and mitotic phenotypes of the <it>lmg<sup>138 </sup></it>null allele and to complement the temperature sensitive lethal phenotype of the <it>APC11-myc9 </it>budding yeast mutant. The LmgA protein interacts with Mr/Apc2, and they together form a binding site for Vihar, the E2-C type ubiquitin conjugating enzyme. Despite being conserved among <it>Drosophila </it>species, the LmgB protein is not required for viability or fertility.</p> <p>Conclusions</p> <p>Our work provides insight into the subunit structure of the <it>Drosophila </it>APC/C with implications for its function. Based on the presented data, we suggest that the Lmg/Apc11 subunit recruits the E2-C type ubiquitin conjugating enzyme, Vihar, to the APC/C together with Mr/Apc2 by forming a ternary complex.</p
Double Parton Scattering Singularity in One-Loop Integrals
We present a detailed study of the double parton scattering (DPS)
singularity, which is a specific type of Landau singularity that can occur in
certain one-loop graphs in theories with massless particles. A simple formula
for the DPS singular part of a four-point diagram with arbitrary
internal/external particles is derived in terms of the transverse momentum
integral of a product of light cone wavefunctions with tree-level matrix
elements. This is used to reproduce and explain some results for DPS
singularities in box integrals that have been obtained using traditional loop
integration techniques. The formula can be straightforwardly generalised to
calculate the DPS singularity in loops with an arbitrary number of external
particles. We use the generalised version to explain why the specific MHV and
NMHV six-photon amplitudes often studied by the NLO multileg community are not
divergent at the DPS singular point, and point out that whilst all NMHV
amplitudes are always finite, certain MHV amplitudes do contain a DPS
divergence. It is shown that our framework for calculating DPS divergences in
loop diagrams is entirely consistent with the `two-parton GPD' framework of
Diehl and Schafer for calculating proton-proton DPS cross sections, but is
inconsistent with the `double PDF' framework of Snigirev.Comment: 29 pages, 8 figures. Minor corrections and clarifications added.
Version accepted for publication in JHE
Monocyte activation drives preservation of membrane thiols by promoting release of oxidised membrane moieties via extracellular vesicles
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The redox state of cellular exofacial molecules is reflected by the amount of available thiols. Furthermore, surface thiols can be considered as indicators of immune cell activation. One group of thiol containing proteins, peroxiredoxins, in particular, have been associated with inflammation. In this study, we assessed surface thiols of the U937 and Thp1 monocyte cell lines and primary monocytes in vitro upon inflammatory stimulation by irreversibly labelling the cells with a fluorescent derivative of maleimide. We also investigated exofacial thiols on circulating blood mononuclear cells in patients with rheumatoid arthritis and healthy controls. When analysing extracellular vesicles, we combined thiol labelling with the use of antibodies to specific CD markers to exclude extracellular vesicle mimicking signals from thiol containing protein aggregates. Furthermore, differential detergent lysis was applied to confirm the vesicular nature of the detected extracellular events in blood plasma. We found an increase in exofacial thiols on monocytes upon in vitro stimulation by LPS or TNF, both in primary monocytes and monocytic cell lines (p<0.0005). At the same time, newly released extracellular vesicles showed a decrease in their exofacial thiols compared with those from unstimulated cells (p<0.05). We also found a significant elevation of surface thiols on circulating monocytes in rheumatoid arthritis patients (p<0.05) and newly released extracellular vesicles of isolated CD14(+) cells from rheumatoid arthritis patients had decreased thiol levels compared with healthy subjects (p<0.01). Exofacial peroxiredoxin 1 was demonstrated on the surface of primary and cultured monocytes, and the number of peroxiredoxin 1 positive extracellular vesicles was increased in rheumatoid arthritis blood plasma (p<0.05). Furthermore, an overoxidised form of peroxiredoxin was detected in extracellular vesicle-enriched preparations from blood plasma. Our data show that cell surface thiols play a protective role and reflect oxidative stress resistance state in activated immune cells. Furthermore, they support a role of extracellular vesicles in the redox regulation of human monocytes, possibly representing an antioxidant mechanism.This work was supported by the National Scientific Research Program of Hungary (OTKA) grant no. PD 104369 to KSZT, grant no. PD 112085 to VVK and grant no. 111958 and 120237 to EIB, the MEDINPROT Program (Synergy programs I, III and IV), BMBS COST Action(BM1202), the János Bolyai Research Fellowship of the Hungarian Academy of Sciences (to KVV) and the Kerpel Fronius Program of the Semmelweis University (Astellas Pharma Grant to BSW)
Impact of CT-apelin and NT-proBNP on identifying non-responders to cardiac resynchronization therapy
CONTEXT: Assessment of response to cardiac resynchronization therapy (CRT) is essential. OBJECTIVE: To assess the predictive value of CT-apelin together with NT-proBNP in patients undergoing CRT. METHODS: Serum CT-apelin and NT-proBNP were measured by ELISA before, and 6-month after CRT. Primary endpoint was non-response (<4% increase in LVEF) after 6-month. RESULTS: From 81 patients, 15 proved to be non-responders. Six-month CT-apelin was superior compared to NT-proBNP in identifying non-responders by multivariate ROC (CT-apelin:p = 0.01, NT-proBNP:p = 0.13) and by logistic regression (CT-apelin:p = 0.01, NT-proBNP:p = 0.41) analyzes. CONCLUSION: Six-month CT-apelin might be valuable novel biomarker in identifying non-responders to CRT that was superior to NT-proBNP
Why are tumour blood vessels abnormal and why is it important to know?
Tumour blood vessels differ from their normal counterparts for reasons that have received little attention. We report here that they are of at least six distinct types, we describe how each forms, and, looking forward, encourage the targeting of tumour vessel subsets that have lost their vascular endothelial growth factor-A (VEGF-A) dependency and so are likely unresponsive to anti-VEGF-A therapies
MicroRNAs targeting oncogenes are down-regulated in pancreatic malignant transformation from benign tumors
BACKGROUND
MicroRNA (miRNA) expression profiles have been described in pancreatic ductal adenocarcinoma (PDAC), but these have not been compared with pre-malignant pancreatic tumors. We wished to compare the miRNA expression signatures in pancreatic benign cystic tumors (BCT) of low and high malignant potential with PDAC, in order to identify miRNAs deregulated during PDAC development. The mechanistic consequences of miRNA dysregulation were further evaluated.
METHODS
Tissue samples were obtained at a tertiary pancreatic unit from individuals with BCT and PDAC. MiRNA profiling was performed using a custom microarray and results were validated using RT-qPCR prior to evaluation of miRNA targets.
RESULTS
Widespread miRNA down-regulation was observed in PDAC compared to low malignant potential BCT. We show that amongst those miRNAs down-regulated, miR-16, miR-126 and let-7d regulate known PDAC oncogenes (targeting BCL2, CRK and KRAS respectively). Notably, miR-126 also directly targets the KRAS transcript at a "seedless" binding site within its 3'UTR. In clinical specimens, miR-126 was strongly down-regulated in PDAC tissues, with an associated elevation in KRAS and CRK proteins. Furthermore, miR-21, a known oncogenic miRNA in pancreatic and other cancers, was not elevated in PDAC compared to serous microcystic adenoma (SMCA), but in both groups it was up-regulated compared to normal pancreas, implicating early up-regulation during malignant change.
CONCLUSIONS
Expression profiling revealed 21 miRNAs down-regulated in PDAC compared to SMCA, the most benign lesion that rarely progresses to invasive carcinoma. It appears that miR-21 up-regulation is an early event in the transformation from normal pancreatic tissue. MiRNA expression has the potential to distinguish PDAC from normal pancreas and BCT. Mechanistically the down-regulation of miR-16, miR-126 and let-7d promotes PDAC transformation by post-transcriptional up-regulation of crucial PDAC oncogenes. We show that miR-126 is able to directly target KRAS; re-expression has the potential as a therapeutic strategy against PDAC and other KRAS-driven cancers
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