721 research outputs found

    Angiotensin-Induced Growth Related Metabolism Is Activated in Cultured Smooth Muscle Cells From Spontaneously Hypertensive Rats and Wistar-Kyoto Rats

    Get PDF
    Smooth muscle cells from spontaneously hypertensive rats (SHR) proliferate in culture faster than those isolated from sex- and age-matched Wistar- Kyoto (WKY) animals. There was no difference in the kinetics of S6 kinase activation in the two cultures, but later metabolic events associated with proliferation were stimulated earlier in SHR cells than in WKY, eg, activation of ornithine decarboxylase. Both cell types elaborated an extensive extracellular matrix in culture composed of a different blend of connective tissue macromolecules. Matrix material from SHR cells was more stimulatory to growth of WKY cultures than their own matrices. Angiotensin stimulated the growth and synthesis of extra-cellular matrix material in SHR more than in WKY derived vascular smooth muscle cell cul-tures. Am J Hypertens 1991;4:183-18

    Atrial Natriuretic Peptide: Binding and Cyclic GMP Response in Cultured Vascular SmoothMuscle Cells From Spontaneously Hypertensive Rats

    Get PDF
    Atrial natriuretic peptide (ANP) is vasodilatory and natriuretic, but whereas increased plasma ANP levels occur in spontaneously hypertensive rats, their elevated vascular resistance suggests inappropriate target tissue responsiveness to ANP. This study examines ANP-receptor binding properties (at 25 °C and 4°C) in cultured vascular aortic smooth muscle cells from spontaneously hypertensive (SHR) and control Wistar-Kyoto (WKY) rats. [I125]-human ANP saturation (0.0625-12.0 nmol) profiles were analyzed using nonlinear regression (LIGAND). Vascular smooth muscle cells from WKY possessed both high affinity (KD1 0.3 nmol; R1 33 fmol/105 cells) and low affinity (KD2 15 nmol; R2 400 fmol/105 cells) binding sites for ANP. In contrast, for smooth muscle cells from SHR, two receptor forms could not be resolved using identical analytical protocols. Parameter estimates at 25 °C and 4°C were not different for either SHR or WKY. The number of receptors for SHR (Bmax ~ 100 fmol/105 cells) was lower than the total number of receptors for WKY (high plus low affinity ~ 430 fmol/105 cells). The intermediary KD value (~1.0 nmol) for ANP binding in SHR suggests an ANPreceptor interconversion from high affinity to low affinity in smooth muscle cells from SHR. Competition-binding experiments also revealed a decreased affinity for ANP in SHR-derived smooth muscle cells. The cyclic GMP response (intracellular accumulation and extracellular levels) was decreased in SHR smooth muscle cells compared to WKY, although this difference was evident only after prolonged (one hour) stimulation with ANP. Our data indicate a reduced sustained vascular responsiveness to ANP in hypertension. Am J Hypertens 1989; 2:32-3

    CCL2 is transcriptionally controlled by the lysosomal protease cathepsin S in a CD74-dependent manner

    Get PDF
    Cathepsins S (CatS) has been implicated in numerous tumourigenic processes and here we document for the first time its involvement in CCL2 regulation within the tumour microenvironment. Analysis of syngeneic tumours highlighted reduced infiltrating macrophages in CatS depleted tumours. Interrogation of tumours and serum revealed genetic ablation of CatS leads to the depletion of several pro-inflammatory chemokines, most notably, CCL2. This observation was validated in vitro, where shRNA depletion of CatS resulted in reduced CCL2 expression. This regulation is transcriptionally mediated, as evident from RT-PCR analysis and CCL2 promoter studies. We revealed that CatS regulation of CCL2 is modulated through CD74 (also known as the invariant chain), a known substrate of CatS and a mediator of NFkB activity. Furthermore, CatS and CCL2 show a strong clinical correlation in brain, breast and colon tumours. In summary, these results highlight a novel mechanism by which CatS controls CCL2, which may present a useful pharmacodynamic marker for CatS inhibition

    A bioavailable cathepsin S nitrile inhibitor abrogates tumor development

    Get PDF
    BACKGROUND: Cathepsin S has been implicated in a variety of malignancies with genetic ablation studies demonstrating a key role in tumor invasion and neo-angiogenesis. Thus, the application of cathepsin S inhibitors may have clinical utility in the treatment of cancer. In this investigation, we applied a cell-permeable dipeptidyl nitrile inhibitor of cathepsin S, originally developed to target cathepsin S in inflammatory diseases, in both in vitro and in vivo tumor models. METHODS: Validation of cathepsin S selectivity was carried out by assaying fluorogenic substrate turnover using recombinant cathepsin protease. Complete kinetic analysis was carried out and true K(i) values calculated. Abrogation of tumour invasion using murine MC38 and human MCF7 cell lines were carried out in vitro using a transwell migration assay. Effect on endothelial tube formation was evaluated using primary HUVEC cells. The effect of inhibitor in vivo on MC38 and MCF7 tumor progression was evaluated using cells propagated in C57BL/6 and BALB/c mice respectively. Subsequent immunohistochemical staining of proliferation (Ki67) and apoptosis (TUNEL) was carried out on MCF7 tumors. RESULTS: We confirmed that this inhibitor was able to selectively target cathepsin S over family members K, V, L and B. The inhibitor also significantly reduced MC38 and MCF7 cell invasion and furthermore, significantly reduced HUVEC endothelial tubule formation in vitro. In vivo analysis revealed that the compound could significantly reduce tumor volume in murine MC38 syngeneic and MCF7 xenograft models. Immunohistochemical analysis of MCF7 tumors revealed cathepsin S inhibitor treatment significantly reduced proliferation and increased apoptosis. CONCLUSIONS: In summary, these results highlight the characterisation of this nitrile cathepsin S inhibitor using in vitro and in vivo tumor models, presenting a compound which may be used to further dissect the role of cathepsin S in cancer progression and may hold therapeutic potential. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12943-016-0513-7) contains supplementary material, which is available to authorized users

    Stroke-Specific Swimming Critical Speed Testing: Balancing Feasibility and Scientific Rigour.

    Get PDF
    This study aimed to assess the reliability of a two-distance critical speed protocol in the specialist strokes of national-level swimmers and understand the practical feasibility of extending the protocol to increase its validity. Thirty-two national-level swimmers (butterfly n = 7; backstroke n = 8; breaststroke n = 7; front crawl n = 10) swum three 200-m and three 400-m performance trials over a three-week period. Critical speed and supra-critical speed distance capacity were computed from the linear modelling of the distance-time relationship. Swimmers were subsequently asked whether they felt they could or would want to complete an 800-m trial as part of a three-distance critical speed protocol to enhance validity. Both 200-m and 400-m performances (coefficient of variation of < 2%) and derived critical speed (typical error of ≤ 0.04 m·s ; coefficient of variation of < 4%) were reliable for all strokes, while supra-critical speed distance capacity (typical error from 4 to 9 m; coefficient of variation from 13 to 45%) was not reliable. Response rates to the follow-up questions were 100%. Few butterfly swimmers said they felt they could complete an 800-m performance trial (39%), with more positive responses for breaststroke (71%), backstroke (100%), and front crawl swimmers (100%). Butterfly swimmers were significantly less likely to say they could or would want to complete an 800-m trial than backstroke and front crawl swimmers (p < 0.05). Including a third distance 800-m trial to increase critical speed validity would not be acceptable to butterfly swimmers, would be challenging to breaststroke swimmers, but would be acceptable to front crawl and backstroke swimmers. [Abstract copyright: Copyright: © Academy of Physical Education in Katowice.

    A systematic review and meta-analysis of the prevalence of common mental disorders in people with non-communicable diseases in Bangladesh, India, and Pakistan

    Get PDF
    Background: The prevalence of mental and physical comorbidities is unknown in South Asia, as estimates of mental ill health in patients with non-communicable diseases (NCDs) have predominantly come from studies based in the United States, Europe and Australasia. This systematic review and meta-analysis summarises evidence and provides pooled estimates of the prevalence of common mental disorders in adults with non-communicable diseases in South Asia. Methods: We included prevalence studies of depression and anxiety in adults with diabetes, cancer, cardiovascular disease, and chronic respiratory conditions in Bangladesh, India, and Pakistan, published from 1990 onwards in international and country-specific databases. Results: Out of 96 included studies, 83 provided data for random effects meta-analyses. The pooled prevalence of depression was 44% (95% confidence interval (CI) = 26 to 62) for patients with COPD, 40% (95% CI = 34 to 45) for diabetes, 39% (95% CI = 23 to 56) for stroke, 38% (95% CI = 32 to 45) for hypertension, and 37% (95% CI = 30 to 45) for cancer. The pooled prevalence of anxiety based on 28 studies was 29% (95% CI = 22 to 36). Many quality issues were identified in a critical appraisal of included studies, mostly relating to the sampling frame and selection process, the description of the methods and basic data, and the description of non-responders. Conclusions: Depression and anxiety are prevalent and underdiagnosed in people with physical comorbidities in Bangladesh, India, and Pakistan

    New Approach Methodologies for the Endocrine Activity Toolbox: Environmental Assessment for Fish and Amphibians

    Get PDF
    Multiple in vivo test guidelines focusing on the estrogen, androgen, thyroid, and steroidogenesis pathways have been developed and validated for mammals, amphibians, or fish. However, these tests are resource-intensive and often use a large number of laboratory animals. Developing alternatives for in vivo tests is consistent with the replacement, reduction, and refinement principles for animal welfare considerations, which are supported by increasing mandates to move toward an “animal-free” testing paradigm worldwide. New approach methodologies (NAMs) hold great promise to identify molecular, cellular, and tissue changes that can be used to predict effects reliably and more efficiently at the individual level (and potentially on populations) while reducing the number of animals used in (eco)toxicological testing for endocrine disruption. In a collaborative effort, experts from government, academia, and industry met in 2020 to discuss the current challenges of testing for endocrine activity assessment for fish and amphibians. Continuing this cross-sector initiative, our review focuses on the current state of the science regarding the use of NAMs to identify chemical-induced endocrine effects. The present study highlights the challenges of using NAMs for safety assessment and what work is needed to reduce their uncertainties and increase their acceptance in regulatory processes. We have reviewed the current NAMs available for endocrine activity assessment including in silico, in vitro, and eleutheroembryo models. New approach methodologies can be integrated as part of a weight-of-evidence approach for hazard or risk assessment using the adverse outcome pathway framework. The development and utilization of NAMs not only allows for replacement, reduction, and refinement of animal testing but can also provide robust and fit-for-purpose methods to identify chemicals acting via endocrine mechanisms.publishedVersio

    Antibody Targeting of Cathepsin S Inhibits Angiogenesis and Synergistically Enhances Anti-VEGF

    Get PDF
    Angiogenesis is a key hallmark of tumourigenesis and its inhibition is a proven strategy for the development of novel anti-cancer therapeutics. An important aspect of early angiogenesis is the co-ordinated migration and invasion of endothelial cells through the hypoxic tumour tissue. Cathepsin S has been shown to play an important role in angiogenesis as has vascular endothelial growth factor (VEGF). We sought to assess the anti-angiogenic effect of Fsn0503, a novel cathepsin S inhibitory antibody, when combined with anti-VEGF on vascular development. where it significantly retarded the development of vasculature in human xenograft models. Furthermore, when Fsn0503 was combined with an anti-VEGF antibody, a synergistic inhibition of microvascular development was observed.Taken together, this data demonstrates that the antibody-mediated targeting of cathepsin S represents a novel method of inhibiting angiogenesis. Furthermore, when used in combination with anti-VEGF therapies, Fsn0503 has the potential to significantly enhance current treatments of tumour neovascularisation and may also be of use in the treatment of other conditions associated with inappropriate angiogenesis

    Ion-channel function and cross-species determinants in viral assembly of nonprimate hepacivirus p7

    Get PDF
    Nonprimate hepacivirus (NPHV), the closest homolog of hepatitis C virus (HCV) described to date, has recently been discovered in horses. Even though the two viruses share a similar genomic organization, conservation of the encoded hepaciviral proteins remains undetermined. The HCV p7 protein is localized within endoplasmic reticulum (ER) membranes and is important for the production of infectious particles. In this study, we analyzed the structural and functional features of NPHV p7 in addition to its role during virus assembly. Three-dimensional homology models for NPHV p7 using various nuclear magnetic resonance spectroscopy (NMR) structures were generated, highlighting the conserved residues important for ion channel function. By applying a liposome permeability assay, we observed that NPHV p7 exhibited liposome permeability features similar to those of HCV p7, indicative of similar ion channel activity. Next, we characterized the viral protein using a p7-based trans-complementation approach. A similar subcellular localization pattern at the ER membrane was observed, although production of infectious particles was likely hindered by genetic incompatibilities with HCV proteins. To further characterize these cross-species constraints, chimeric viruses were constructed by substituting different regions of HCV p7 with NPHV p7. The N terminus and transmembrane domains were nonexchangeable and therefore constitute a cross-species barrier in hepaciviral assembly. In contrast, the basic loop and the C terminus of NPHV p7 were readily exchangeable, allowing production of infectious trans-complemented viral particles. In conclusion, comparison of NPHV and HCV p7 revealed structural and functional homology of these proteins, including liposome permeability, and broadly acting determinants that modulate hepaciviral virion assembly and contribute to the host-species barrier were identified

    Protocol for a multi-site randomised controlled feasibility study investigating intermittently scanned blood continuous glucose monitoring use for gestational diabetes : the RECOGNISE study

    Get PDF
    Background: Incidence of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes including macrosomia, pre-eclampsia, and pre-term delivery. Optimum glycaemic control can reduce these adverse perinatal outcomes. Continuous glucose monitoring (CGM) informs users about interstitial glucose levels allowing early detection of glycaemic excursions and pharmacological or behavioural intervention. Few adequately powered RCTs to evaluate the impact of using CGM in women with GDM on perinatal outcomes have been undertaken. We aim to establish the feasibility of a multi-site RCT to evaluate the clinical- and cost-effectiveness of an intermittently scanned continuous glucose monitor (isCGM) compared with self-monitored blood glucose (SMBG) in women with GDM for reducing fetal macrosomia and improving maternal and fetal outcomes. We will evaluate recruitment and retention rates, adherence to device requirements, adequacy of data capture and acceptability of trial design and isCGM devices. Methods: Open-label multicentre randomised controlled feasibility trial. Inclusion criteria: pregnant women, singleton pregnancy, recent diagnosis of GDM (within 14 days of commencing medication, up to 34 weeks gestation) prescribed metformin and/or insulin. Women will be consecutively recruited and randomised to isCGM (FreestyleLibre2) or SMBG. At every antenatal visit, glucose measurements will be evaluated. The SMBG group will use blinded isCGM for 14 days at baseline (~ 12–32 weeks) and ~ 34–36 weeks. The primary outcome is the recruitment rate and absolute number of women participating. Clinical assessments of maternal and fetal/infant health will be undertaken at baseline, birth, up to ~ 13 weeks post-natal. Psychological, behavioural and health economic measures will be assessed at baseline and ~ 34–36 weeks gestation. Qualitative interviews will be undertaken with study decliners, participants, and professionals to explore trial acceptability, of using isCGM and SMBG. Discussion: GDM can be associated with adverse pregnancy outcomes. isCGM could offer a timely, easy-to-engage-with intervention, to improve glycaemic control, potentially reducing adverse pregnancy, birth and long-term health outcomes for mother and child. This study will determine the feasibility of conducting a large-scale multisite RCT of isCGM in women with GDM. Trial registration: This study has been registered with the ISRCTN (reference: ISRCTN42125256, Date registered: 07/11/2022)
    corecore