1,545 research outputs found

    Ligation of protease-activated receptor 1 enhances alpha(v)beta(6) integrin-dependent TGF-beta activation and promotes acute lung injury

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    Activation of latent TGF-beta by the alpha(v)beta(6) integrin is a critical step in the development of acute lung injury. However, the mechanism by which a alpha(v)beta(6)-mediated TGF-beta activation is regulated has not been identified. We show that thrombin, and other agonists of protease-activated receptor 1(PAR1), activate TGF-beta in an alpha(v)beta(6) integrin-specific manner. This effect is PART specific and is mediated by RhoA and Rho kinase. Intratracheal instillation of the PART-specific peptide TFLLRN increases lung edema during high-tidal-volume ventilation, and this effect is completely inhibited by a blocking antibody against the alpha(v)beta(6) integrin. Instillation of TFLLRN during high-tidal-volume ventilation is associated with increased pulmonary TGF-beta activation; however, this is not observed in Itgb6(-/-) mice. Furthermore, Itgb6(-/-) mice are also protected from ventilator-induced lung edema. We also demonstrate that pulmonary edema and TGF-beta activity are similarly reduced in Par1(-/-) mice following bleomycin-induced lung injury. These results suggest that PART-mediated enhancement of a alpha(v)beta(6)-dependent TGF-beta activation could be one mechanism by which activation of the coagulation cascade contributes to the development of acute lung injury, and they identify PART and the alpha(v)beta(6) integrin as potential therapeutic targets in this condition

    Intrinsic defence capacity and therapeutic potential of natriuretic peptides in pulmonary hypertension associated with lung fibrosis

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    This work was supported by the British Lung Foundation. C.J.S. is supported by a Medical Research Council Fellowship

    Extremely red radio galaxies

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    At least half the radio galaxies at z>1 in the 7C Redshift Survey have extremely red colours (R-K>5), consistent with stellar populations which formed at high redshift (z>5). We discuss the implications of this for the evolution of massive galaxies in general and for the fraction of near-IR-selected EROs which host AGN, a result which is now being tested by deep, hard X-ray surveys. The conclusion is that many massive galaxies undergo at least two active phases: one at z~5 when the black hole and stellar bulge formed and another at z~1-2 when activity is triggered by an event such as an interaction or merger.Comment: 6 pages, 2 figures, to appear in the proceedings of the workshop on "QSO hosts and their environments", IAA, Granada, 10-12 Jan 2001, Ed. I. Marque

    Medical Help-Seeking for Sexual Concerns in Prostate Cancer Survivors.

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    INTRODUCTION: Although sexual dysfunction is common after prostate cancer, men's decisions to seek help for sexual concerns are not well understood. AIM: Describe predictors of actual prior help-seeking and intended future medical help-seeking for sexual dysfunction in prostate cancer survivors. METHODS: A cross-sectional survey of 510 prostate cancer survivors assessed masculine beliefs, attitudes, support/approval from partner/peer networks (subjective norm), and perceived control as predictors of medical help-seeking for sexual concerns. A theory of planned behavior (TPB) perspective was used to examine actual prior and planned future behavior and contributing factors. Statistical analyses included multiple and logistic regressions. MAIN OUTCOME MEASURES: Intention to see a doctor for sexual advice or help in the next 6 months was measured using the intention subscale adapted from the Attitudes to Seeking Help after Cancer Scale. Prior help-seeking was measured with a dichotomous yes/no scale created for the study. RESULTS: Men were Mage 71.69 years (SD = 7.71); 7.54 years (SD = 4.68) post-diagnosis; received treatment(s) (58.1% radical prostatectomy; 47.1% radiation therapy; 29.4% hormonal ablation); 81.4% reported severe ED (IIED 0-6) and 18.6% moderate-mild ED (IIED 7-24). Overall, 30% had sought sexual help in the past 6 months, and 24% intended to seek help in the following 6 months. Prior help-seeking was less frequent among men with severe ED. Sexual help-seeking intentions were associated with lower education, prior sexual help-seeking, sexual importance/ priority, emotional self-reliance, positive attitude, and subjective norm (R(2) = 0.56). CONCLUSION: The TPB has utility as a theoretical framework to understand prostate cancer survivors' sexual help-seeking decisions and may inform development of more effective interventions. Masculine beliefs were highly salient. Men who were more emotionally self-reliant and attributed greater importance to sex formed stronger help-seeking intentions. Subjective norm contributed most strongly to help-seeking intentions suggesting that health professionals/partners/peers have a key role as support mechanisms and components of psycho-sexual interventions

    The anti-fibrotic effect of inhibition of TGFβ-ALK5 signalling in experimental pulmonary fibrosis in mice is attenuated in the presence of concurrent γ-herpesvirus infection.

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    Journal ArticleTGFβ-ALK5 pro-fibrotic signalling and herpesvirus infections have been implicated in the pathogenesis and exacerbation of pulmonary fibrosis. In this study we addressed the role of TGFβ-ALK5 signalling during the progression of fibrosis in a two-hit mouse model of murine γ-herpesvirus 68 (MHV-68) infection on the background of pre-existing bleomycin-induced pulmonary fibrosis. Assessment of total lung collagen levels in combination with ex vivo micro-computed tomography (µCT) analysis of whole lungs demonstrated that MHV-68 infection did not enhance lung collagen deposition in this two-hit model but led to a persistent and exacerbated inflammatory response. Moreover, µCT reconstruction and analysis of the two-hit model revealed distinguishing features of diffuse ground-glass opacities and consolidation superimposed on pre-existing fibrosis that were reminiscent of those observed in acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF). Virally-infected murine fibrotic lungs further displayed evidence of extensive inflammatory cell infiltration and increased levels of CCL2, TNFα, IL-1β and IL-10. Blockade of TGFβ-ALK5 signalling attenuated lung collagen accumulation in bleomycin-alone injured mice, but this anti-fibrotic effect was reduced in the presence of concomitant viral infection. In contrast, inhibition of TGFβ-ALK5 signalling in virally-infected fibrotic lungs was associated with reduced inflammatory cell aggregates and increased levels of the antiviral cytokine IFNγ. These data reveal newly identified intricacies for the TGFβ-ALK5 signalling axis in experimental lung fibrosis, with different outcomes in response to ALK5 inhibition depending on the presence of viral infection. These findings raise important considerations for the targeting of TGFβ signalling responses in the context of pulmonary fibrosis.MRCNovartis CASE studentshi

    A systematic review of cancer caregiver interventions: Appraising the potential for implementation of evidence into practice

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    © 2019 The Authors. Psycho-Oncology Published by John Wiley & Sons Ltd. Objective: nformal caregivers provide substantial support for people living with cancer. Previous systematic reviews report on the efficacy of cancer caregiver interventions but not their potential to be implemented. The aim of this systematic review was to explore the potential for cancer caregiver interventions to be implemented into practice. Methods: We searched three electronic databases to identify cancer caregiver interventions on 5 January 2018. We operationalised six implementation outcomes (acceptability, adoption, appropriateness, feasibility, fidelity, and costs) into a tool to guide data extraction. Results: The search yielded 33 papers (27 papers from electronic databases and six papers from other sources) reporting on 26 studies that met review criteria. Fewer than half the studies (46%) contained evidence about the acceptability of interventions from caregivers' perspectives; only two studies (8%) included interventions developed with input from caregivers. Two studies (8%) addressed potential adoption of interventions, and no studies discussed intentions, agreement, or action to implement interventions into practice. All studies reported on intervention appropriateness by providing a rationale for the interventions. For feasibility, on average less than one-third of caregivers who were eligible to be involved consented to participate. On fidelity, whether interventions were conducted as intended was reported in 62% of studies. Cost data were reported in terms of intervention delivery, requiring a median time commitment of staff of 180 minutes to be delivered. Conclusions: Caregiver intervention studies lack components of study design and reporting that could bridge the gap between research and practice. There is enormous potential for improvements in cancer caregiver intervention study design to plan for future implementation

    TGFβ upregulates PAR-1 expression and signalling responses in A549 lung adenocarcinoma cells.

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    The major high-affinity thrombin receptor, proteinase activated receptor-1 (PAR-1) is expressed at low levels by the normal epithelium but is upregulated in many types of cancer, including lung cancer. The thrombin-PAR-1 signalling axis contributes to the activation of latent TGFβ in response to tissue injury via an αvβ6 integrin-mediated mechanism. TGFβ is a pleiotropic cytokine that acts as a tumour suppressor in normal and dysplastic cells but switches into a tumour promoter in advanced tumours. In this study we demonstrate that TGFβ is a positive regulator of PAR-1 expression in A549 lung adenocarcinoma cells, which in turn increases the sensitivity of these cells to thrombin signalling. We further demonstrate that this effect is Smad3-, ERK1/2- and Sp1-dependent. We also show that TGFβ-mediated PAR-1 upregulation is accompanied by increased expression of integrin αv and β6 subunits. Finally, TGFβ pre-stimulation promotes increased migratory potential of A549 to thrombin. These data have important implications for our understanding of the interplay between coagulation and TGFβ signalling responses in lung cancer.Medical Research Council UK (MRC) CASE studentship with Novartis awarded to RCC, MRC Centenary Award awarded to NS and RCC, and MRC Career Development Award G0800340 to CJS

    Enhanced production of IL-17A in patients with severe asthma is inhibited by 1α,25-dihydroxyvitamin D3 in a glucocorticoid-independent fashion

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    Background: TH17 cells are proposed to play a role in the pathology of asthma, including steroid-resistant (SR) disease. We previously identified a steroid-enhancing function of vitamin D in patients with SR asthma in restoring the impaired response to steroids for production of the anti-inflammatory cytokine IL-10. / Objective: We sought to investigate the production of the TH17-associated cytokines IL-17A and IL-22 in culture in patients with moderate-to-severe asthma defined on the basis of their clinical response to steroids and the susceptibility of this response to inhibition by steroids and the active form of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25[OH]2D3). / Methods: PBMCs were stimulated in culture with or without dexamethasone and 1,25(OH)2D3. A cytometric bead array, ELISA, and intracellular cytokine staining were used to assess cytokine production. The role of CD39 in inhibition of the TH17 response was studied by using quantitative real-time PCR, flow cytometry, and addition of the antagonist POM-1 to culture. / Results: Asthmatic patients synthesized much higher levels of IL-17A and IL-22 than nonasthmatic control subjects, with patients with SR asthma expressing the highest levels of IL-17A. Glucocorticoids did not inhibit IL-17A cytokine expression in patients and enhanced production in cultures from control subjects. Treatment with 1,25(OH)2D3 with or without dexamethasone significantly reduced both IL-17A and IL-22 levels. An antagonist of the ectonucleotidase CD39 reversed 1,25(OH)2D3-mediated inhibition of the IL-17A response. / Conclusion: Patients with severe asthma exhibit increased levels of TH17 cytokines, which are not inhibited by steroids. 1,25(OH)2D3 inhibits TH17 cytokine production in all patients studied, irrespective of their clinical responsiveness to steroids, identifying novel steroid-enhancing properties of vitamin D in asthmatic patients

    Proteinase-Activated Receptor-1, CCL2 and CCL7 Regulate Acute Neutrophilic Lung Inflammation

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    PAR1 plays a central role in mediating the interplay between coagulation and inflammation, but its role in regulating acute neutrophilic inflammation is unknown. We report that antagonism of PAR1 was highly effective at reducing acute neutrophil accumulation in a mouse model of LPS-induced lung inflammation. PAR1 antagonism also reduced alveolar-capillary barrier disruption in these mice. This protection was associated with a reduction in the expression of the chemokines CCL2 and CCL7, but not the pro-inflammatory cytokines TNF and IL-6 or the classic neutrophil chemoattractants CXCL1 and CXCL2. Antibody neutralisation of CCL2 and CCL7 significantly reduced LPS-induced total leukocyte and neutrophil accumulation, recovered from the bronchoalveolar lavage fluid of challenged mice. Immunohistochemical analysis revealed CCL2 predominantly localised to alveolar macrophages and pulmonary epithelial cells, while CCL7 was restricted to the pulmonary epithelium. In keeping with these observations, the intranasal administration of rCCL2 and rCCL7 led to the accumulation of neutrophils within the lung airspaces of naïve mice in the absence of any underlying inflammation. Flow cytometry analysis further demonstrated an increase in Ly6Ghi neutrophils expressing the chemokine receptors CCR1 and CCR2 isolated from mouse lungs compared to circulating neutrophils. Conversely, the expression of CXCR2 decreased on neutrophils isolated from the lung compared to circulating neutrophils. Furthermore, this switch in chemokine receptor expression was accentuated following acute LPS-induced lung inflammation. Collectively, these findings reveal a novel role for PAR1 and the chemokines CCL2 and CCL7 during the early events of acute neutrophilic inflammation
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