350 research outputs found

    Non-invasive assessment of pulmonary vascular resistance in pulmonary hypertension: Current knowledge and future direction

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    Pulmonary Hypertension (PHT) is relatively common, dangerous and under-recognised. Pulmonary hypertension is not a diagnosis in itself; it is caused by a number of differing diseases each with different treatments and prognoses. Therefore, timely and accurate recognition of the underlying cause for PHT is essential for appropriate management. This is especially true for patients with Pulmonary Arterial Hypertension (PAH) in the current era of disease-specific drug therapy. Measurement of Pulmonary Vascular Resistance (PVR) helps separate pre-capillary from post-capillary PHT, and is measured with right heart catheterisation (RHC). Echocardiography has been used to derive a number of non-invasive surrogates for PVR, with varying accuracy. Ultimately, the goal of non-invasive assessment of PVR is to separate PHT due to left heart disease from PHT due to increased PVR, to help streamline investigation and subsequent treatment. In this review, we summarise the physiology and pathophysiology of pulmonary blood flow, the various causes of pulmonary hypertension, and non-invasive surrogates for PVR

    Impaired DNA double-strand break repair contributes to chemoresistance in HIF-1α-deficient mouse embryonic fibroblasts

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    A mismatch between metabolic demand and oxygen delivery leads to microenvironmental changes in solid tumors. The resulting tumor hypoxia is associated with malignant progression, therapy resistance and poor prognosis. However, the molecular mechanisms underlying therapy resistance in hypoxic tumors are not fully understood. The hypoxia-inducible factor (HIF) is a master transcriptional activator of oxygen-regulated gene expression. Transformed mouse embryonic fibroblasts (MEFs) derived from HIF-1α-deficient mice are a popular model to study HIF function in tumor progression. We previously found increased chemotherapy and irradiation susceptibility in the absence of HIF-1α. Here, we show by single-cell electrophoresis, histone 2AX phosphorylation and nuclear foci formation of γH2AX and 53BP1, that the number of DNA double-strand breaks (DSB) is increased in untreated and etoposide-treated HIF-deficient MEFs. In etoposide-treated cells, cell cycle control and p53-dependent gene expression were not affected by the absence of HIF-1α. Using a candidate gene approach to screen 17 genes involved in DNA repair, messenger RNA (mRNA) and protein of three members of the DNA-dependent protein kinase complex were found to be decreased in HIF-deficient MEFs. Of note, residual HIF-1α protein in cancer cells with a partial HIF-1α mRNA knockdown was sufficient to confer chemoresistance. In summary, these data establish a novel molecular link between HIF and DNA DSB repair. We suggest that selection of early, non-hypoxic tumor cells expressing low levels of HIF-1α might contribute to HIF-dependent tumor therapy resistanc

    Examining the effect of cyber twin and blockchain technologies for industrial applications using AI

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    In current generation the concept of cyber twin technology has been emerging as an improved platform for different applications. This paper emphasize on examining the effect of cyber twin technology for manufacturing equipment in Industry 4.0 applications by solving three different elementary objectives. For the proposed conception a new system model is identified for integrating triobjective cases with artificial intelligence algorithm. In addition, high security measures are also incorporated using blockchain technology which is one basic requirement for industrial applications for creating real twins. Both system model and algorithm have been combined for providing effective performance in real time using a physical entity. The effectiveness of the proposed model is tested with sensor prototype and simulated with four scenarios where the projected model provides better performance for more than 72% when compared with existing methodologies

    Plant polysaccharides for protein binding

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    Polysaccharides are polymeric carbohydrates that are made up of many monosaccharide units linked together by glycosidic linkages. They are architecturally complex biomacromolecules because of the different monosaccharides and their infinite ways to form the building blocks with each other

    A Bioinformatics Resource for TWEAK-Fn14 Signaling Pathway

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    TNF-related weak inducer of apoptosis (TWEAK) is a new member of the TNF superfamily. It signals through TNFRSF12A, commonly known as Fn14. The TWEAK-Fn14 interaction regulates cellular activities including proliferation, migration, differentiation, apoptosis, angiogenesis, tissue remodeling and inflammation. Although TWEAK has been reported to be associated with autoimmune diseases, cancers, stroke, and kidney-related disorders, the downstream molecular events of TWEAK-Fn14 signaling are yet not available in any signaling pathway repository. In this paper, we manually compiled from the literature, in particular those reported in human systems, the downstream reactions stimulated by TWEAK-Fn14 interactions. Our manual amassment of the TWEAK-Fn14 pathway has resulted in cataloging of 46 proteins involved in various biochemical reactions and TWEAK-Fn14 induced expression of 28 genes. We have enabled the availability of data in various standard exchange formats from NetPath, a repository for signaling pathways. We believe that this composite molecular interaction pathway will enable identification of new signaling components in TWEAK signaling pathway. This in turn may lead to the identification of potential therapeutic targets in TWEAK-associated disorders

    Identifying chondroprotective diet-derived bioactives and investigating their synergism

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    Osteoarthritis (OA) is a multifactorial disease and nutrition is a modifiable factor that may contribute to disease onset or progression. A detailed understanding of mechanisms through which diet-derived bioactive molecules function and interact in OA is needed. We profiled 96 diet-derived, mainly plant-based bioactives using an in vitro model in chondrocytes, selecting four candidates for further study. We aimed to determine synergistic interactions between bioactives that affected the expression of key genes in OA. Selected bioactives, sulforaphane, apigenin, isoliquiritigenin and luteolin, inhibited one or more interleukin-1-induced metalloproteinases implicated in OA (MMP1, MMP13, ADAMTS4, ADAMTS5). Isoliquiritigenin and luteolin showed reactive oxygen species scavenging activity in chondrocytes whereas sulforaphane had no effect and apigenin showed only a weak trend. Sulforaphane inhibited the IL-1/NFκB and Wnt3a/TCF/Lef pathways and increased TGFβ/Smad2/3 and BMP6/Smad1/5/8 signalling. Apigenin showed potent inhibition of the IL-1/NFκB and TGFβ/Smad2/3 pathways, whereas luteolin showed only weak inhibition of the IL-1/NFκB pathway. All four bioactives inhibited cytokine-induced aggrecan loss from cartilage tissue explants. The combination of sulforaphane and isoliquiritigenin was synergistic for inhibiting MMP13 gene expression in chondrocytes. We conclude that dietary-derived bioactives may be important modulators of cartilage homeostasis and synergistic relationships between bioactives may have an anti-inflammatory and chondroprotective role

    Quercetin Inhibits IL-1β-Induced Inflammation, Hyaluronan Production and Adipogenesis in Orbital Fibroblasts from Graves' Orbitopathy

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    Management of Graves' orbitopathy (GO) is challenging, as no reliable, specific, and safe medical therapeutic agents have yet been developed. We investigated the effect of quercetin in primary cultured orbital fibroblasts from GO, targeting pathways of inflammation, aberrant accumulation of extracellular matrix macromolecules, and adipose tissue expansion. Quercetin significantly attenuated intercellular adhesion molecule-1 (ICAM-1), interleukin (IL) -6, IL-8, and cyclooxygenase (COX) -2 mRNA expression, and inhibited IL-1β-induced increases in ICAM-1, IL-6, and IL-8 mRNA. Increased hyaluronan production induced by IL-1β or tumor necrosis factor-α was suppressed by quercetin in a dose- and time-dependent manner. Treatment with noncytotoxic doses of quercetin inhibited accumulation of intracytoplasmic lipid droplets and resulted in a dose-dependent decrease in expression of peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein (C/EBP) α, and C/EBPβ proteins. In conclusion, inhibition of inflammation, hyaluronan production, and adipogenesis by the natural plant product quercetin in vitro provides the basis for further study of its potential use in the treatment of GO

    A Dual Fluorescence–Spin Label Probe for Visualization and Quantification of Target Molecules in Tissue by Multiplexed FLIM–EPR Spectroscopy

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    Simultaneous visualization and concentration quantification of molecules in biological tissue is an important though challenging goal. The advantages of fluorescence lifetime imaging microscopy (FLIM) for visualization, and electron paramagnetic resonance (EPR) spectroscopy for quantification are complementary. Their combination in a multiplexed approach promises a successful but ambitious strategy because of spin label-mediated fluorescence quenching. Here, we solved this problem and present the molecular design of a dual label (DL) compound comprising a highly fluorescent dye together with an EPR spin probe, which also renders the fluorescence lifetime to be concentration sensitive. The DL can easily be coupled to the biomolecule of choice, enabling in vivo and in vitro applications. This novel approach paves the way for elegant studies ranging from fundamental biological investigations to preclinical drug research, as shown in proof-of-principle penetration experiments in human skin ex vivo

    Stem Cell Therapy with Overexpressed VEGF and PDGF Genes Improves Cardiac Function in a Rat Infarct Model

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    Therapeutic potential was evaluated in a rat model of myocardial infarction using nanofiber-expanded human cord blood derived hematopoietic stem cells (CD133+/CD34+) genetically modified with VEGF plus PDGF genes (VIP).Myocardial function was monitored every two weeks up to six weeks after therapy. Echocardiography revealed time dependent improvement of left ventricular function evaluated by M-mode, fractional shortening, anterior wall tissue velocity, wall motion score index, strain and strain rate in animals treated with VEGF plus PDGF overexpressed stem cells (VIP) compared to nanofiber expanded cells (Exp), freshly isolated cells (FCB) or media control (Media). Improvement observed was as follows: VIP>Exp> FCB>media. Similar trend was noticed in the exercise capacity of rats on a treadmill. These findings correlated with significantly increased neovascularization in ischemic tissue and markedly reduced infarct area in animals in the VIP group. Stem cells in addition to their usual homing sites such as lung, spleen, bone marrow and liver, also migrated to sites of myocardial ischemia. The improvement of cardiac function correlated with expression of heart tissue connexin 43, a gap junctional protein, and heart tissue angiogenesis related protein molecules like VEGF, pNOS3, NOS2 and GSK3. There was no evidence of upregulation in the molecules of oncogenic potential in genetically modified or other stem cell therapy groups.Regenerative therapy using nanofiber-expanded hematopoietic stem cells with overexpression of VEGF and PDGF has a favorable impact on the improvement of rat myocardial function accompanied by upregulation of tissue connexin 43 and pro-angiogenic molecules after infarction

    DELLA-Induced Early Transcriptional Changes during Etiolated Development in Arabidopsis thaliana

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    The hormones gibberellins (GAs) control a wide variety of processes in plants, including stress and developmental responses. This task largely relies on the activity of the DELLA proteins, nuclear-localized transcriptional regulators that do not seem to have DNA binding capacity. The identification of early target genes of DELLA action is key not only to understand how GAs regulate physiological responses, but also to get clues about the molecular mechanisms by which DELLAs regulate gene expression. Here, we have investigated the global, early transcriptional response triggered by the Arabidopsis DELLA protein GAI during skotomorphogenesis, a developmental program tightly regulated by GAs. Our results show that the induction of GAI activity has an almost immediate effect on gene expression. Although this transcriptional regulation is largely mediated by the PIFs and HY5 transcription factors based on target meta-analysis, additional evidence points to other transcription factors that would be directly involved in DELLA regulation of gene expression. First, we have identified cis elements recognized by Dofs and type-B ARRs among the sequences enriched in the promoters of GAI targets; and second, an enrichment in additional cis elements appeared when this analysis was extended to a dataset of early targets of the DELLA protein RGA: CArG boxes, bound by MADS-box proteins, and the E-box CACATG that links the activity of DELLAs to circadian transcriptional regulation. Finally, Gene Ontology analysis highlights the impact of DELLA regulation upon the homeostasis of the GA, auxin, and ethylene pathways, as well as upon pre-existing transcriptional networks
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