104 research outputs found

    Purinergic receptor mediated calcium signalling in urothelial cells

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    Non-neuronal ATP released from the urothelium in response to bladder stretch is a key modulator of bladder mechanosensation. Whilst non-neuronal ATP acts on the underlying bladder afferent nerves to facilitate sensation, there is also the potential for ATP to act in an autocrine manner, modulating urothelial cell function. The aim of this study was to systematically characterise the functional response of primary mouse urothelial cells (PMUCs) to ATP. PMUCs isolated from male mice (14-16 weeks) were used for live-cell fluorescent calcium imaging and qRT-PCR to determine the expression profile of P2X and P2Y receptors. The majority of PMUCs (74-92%) responded to ATP (1 μM-1 mM), as indicted by an increase in intracellular calcium (iCa2+). PMUCs exhibited dose-dependent responses to ATP (10 nM-1 mM) in both calcium containing (2 mM, EC50 = 3.49 ± 0.77 μM) or calcium free (0 mM, EC50 = 9.5 ± 1.5 μM) buffers. However, maximum iCa2+ responses to ATP were significantly attenuated upon repetitive applications in calcium containing but not in calcium free buffer. qRT-PCR revealed expression of P2X1-6, and P2Y1-2, P2Y4, P2Y6, P2Y11-14, but not P2X7 in PMUCs. These findings suggest the major component of ATP induced increases in iCa2+ are mediated via the liberation of calcium from intracellular stores, implicating functional P2Y receptors that are ubiquitously expressed on PMUCs.Russell Chess-Williams, Donna J. Sellers, Stuart M. Brierley, David Grundy, Luke Grund

    Mechanisms Underlying Overactive Bladder and Interstitial Cystitis/Painful Bladder Syndrome

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    The bladder is innervated by extrinsic afferents that project into the dorsal horn of the spinal cord, providing sensory input to the micturition centers within the central nervous system. Under normal conditions, the continuous activation of these neurons during bladder distension goes mostly unnoticed. However, for patients with chronic urological disorders such as overactive bladder syndrome (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS), exaggerated bladder sensation and altered bladder function are common debilitating symptoms. Whilst considered to be separate pathological entities, there is now significant clinical and pre-clinical evidence that both OAB and IC/PBS are related to structural, synaptic, or intrinsic changes in the complex signaling pathways that mediate bladder sensation. This review discusses how urothelial dysfunction, bladder permeability, inflammation, and cross-organ sensitisation between visceral organs can regulate this neuroplasticity. Furthermore, we discuss how the emotional affective component of pain processing, involving dysregulation of the HPA axis and maladaptation to stress, anxiety and depression, can exacerbate aberrant bladder sensation and urological dysfunction. This review reveals the complex nature of urological disorders, highlighting numerous interconnected mechanisms in their pathogenesis. To find appropriate therapeutic treatments for these disorders, it is first essential to understand the mechanisms responsible, incorporating research from every level of the sensory pathway, from bladder to brain

    Mechanisms Underlying Overactive Bladder and Interstitial Cystitis/Painful Bladder Syndrome

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    Copyright © 2018 Grundy, Caldwell and Brierley. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The bladder is innervated by extrinsic afferents that project into the dorsal horn of the spinal cord, providing sensory input to the micturition centers within the central nervous system. Under normal conditions, the continuous activation of these neurons during bladder distension goes mostly unnoticed. However, for patients with chronic urological disorders such as overactive bladder syndrome (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS), exaggerated bladder sensation and altered bladder function are common debilitating symptoms. Whilst considered to be separate pathological entities, there is now significant clinical and pre-clinical evidence that both OAB and IC/PBS are related to structural, synaptic, or intrinsic changes in the complex signaling pathways that mediate bladder sensation. This review discusses how urothelial dysfunction, bladder permeability, inflammation, and cross-organ sensitisation between visceral organs can regulate this neuroplasticity. Furthermore, we discuss how the emotional affective component of pain processing, involving dysregulation of the HPA axis and maladaptation to stress, anxiety and depression, can exacerbate aberrant bladder sensation and urological dysfunction. This review reveals the complex nature of urological disorders, highlighting numerous interconnected mechanisms in their pathogenesis. To find appropriate therapeutic treatments for these disorders, it is first essential to understand the mechanisms responsible, incorporating research from every level of the sensory pathway, from bladder to brain

    Deletion of Interleukin-6 Signal Transducer gp130 in Small Sensory Neurons Attenuates Mechanonociception and Down-Regulates TRPA1 Expression

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    Creative Commons Attribution-Noncommercial-Share Alike 3.0 License Unported (http://creativecommons.org/licenses/by-nc-sa/3.0). agreement This allows data and text mining, use of figures in presentations, and posting the article online, as long as the original article is attributed.Glycoprotein 130 (gp130) is the signal transducing receptor subunit for cytokines of the interleukin-6 (IL-6) family, and it is expressed in a multitude of cell types of the immune and nervous system. IL-6-like cytokines are not only key regulators of innate immunity and inflammation but are also essential factors for the differentiation and development of the somatosensory system. Mice with a null mutation of gp130 in primary nociceptive afferents (SNS-gp130−/−) are largely protected from hypersensitivity to mechanical stimuli in mouse models of pathological pain. Therefore, we set out to investigate how neuronal gp130 regulates mechanonociception. SNS-gp130−/− mice revealed reduced mechanosensitivity to high mechanical forces in the von Frey assay in vivo, and this was associated with a reduced sensitivity of nociceptive primary afferents in vitro. Together with these findings, transient receptor potential ankyrin 1 (TRPA1) mRNA expression was significantly reduced in DRG from SNS-gp130−/− mice. This was also reflected by a reduced number of neurons responding with calcium transients to TRPA1 agonists in primary DRG cultures. Downregulation of Trpa1 expression was predominantly discovered in nonpeptidergic neurons, with the deficit becoming evident during stages of early postnatal development. Regulation of Trpa1 mRNA expression levels downstream of gp130 involved the classical Janus kinase family-signal transducer and activator of transcription pathway. Our results closely link proinflammatory cytokines to the expression of TRPA1, both of which have been shown to contribute to hypersensitive pain states. We suggest that gp130 has an essential role in mechanonociception and in the regulation of TRPA1 expression

    α-Conotoxin Vc1.1 inhibits human dorsal root ganglion neuroexcitability and mouse colonic nociception via GABA\u3csub\u3eB\u3c/sub\u3e receptors

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    Objective α-Conotoxin Vc1.1 is a small disulfidebonded peptide from the venom of the marine cone snail Conus victoriae. Vc1.1 has antinociceptive actions in animal models of neuropathic pain, but its applicability to inhibiting human dorsal root ganglion (DRG) neuroexcitability and reducing chronic visceral pain (CVP) is unknown. Design We determined the inhibitory actions of Vc1.1 on human DRG neurons and on mouse colonic sensory afferents in healthy and chronic visceral hypersensitivity (CVH) states. In mice, visceral nociception was assessed by neuronal activation within the spinal cord in response to noxious colorectal distension (CRD). Quantitativereverse- transcription-PCR, single-cell-reversetranscription- PCR and immunohistochemistry determined ?-aminobutyric acid receptor B (GABABR) and voltagegated calcium channel (CaV2.2, CaV2.3) expression in human and mouse DRG neurons. Results Vc1.1 reduced the excitability of human DRG neurons, whereas a synthetic Vc1.1 analogue that is inactive at GABABR did not. Human DRG neurons expressed GABABR and its downstream effector channels CaV2.2 and CaV2.3. Mouse colonic DRG neurons exhibited high GABABR, CaV2.2 and CaV2.3 expression, with upregulation of the CaV2.2 exon-37a variant during CVH. Vc1.1 inhibited mouse colonic afferents ex vivo and nociceptive signalling of noxious CRD into the spinal cord in vivo, with greatest efficacy observed during CVH. A selective GABABR antagonist prevented Vc1.1-induced inhibition, whereas blocking both CaV2.2 and CaV2.3 caused inhibition comparable with Vc1.1 alone. Conclusions Vc1.1-mediated activation of GABABR is a novel mechanism for reducing the excitability of human DRG neurons. Vc1.1-induced activation of GABABR on the peripheral endings of colonic afferents reduces nociceptive signalling. The enhanced antinociceptive actions of Vc1.1 during CVH suggest it is a novel candidate for the treatment for CVP

    Impact of the Mt. Pinatubo volcaniceruption on the lower ionosphere andatmospheric waves over Central Europe

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    The very strong volcanic eruption of Mt. Pinatubo in June 1991 directly affected the troposphere and lower and middle stratosphere. Here we look at its effects in the mesopause region as revealed by the radio wave absorption measurements in the lower ionosphere over Central Europe and inferred planetary and gravity wave activity. The gravity wave activity inferred from the nighttime LF radio wave absorption displays an evident enhancement for waves of periods of about 2-3 h coinciding with regional measurements of the optical depth of (volcanic) aerosols, while there is no detectable effect for short period waves (T < 1 h). There is no detectable effect in the planetary wave activity inferred from the daytime HF radio wave absorption. As for the absorption itself, the results on the impact of the Mt. Pinatubo eruption do not provide an observable effect

    The effect of dapagliflozin on glycaemic control and other cardiovascular disease risk factors in type 2 diabetes mellitus:a real-world observational study

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    Aims/hypothesis: Dapagliflozin, a sodium–glucose cotransporter 2 (SGLT2) inhibitor, is indicated for improving glycaemic control in type 2 diabetes mellitus. Whether its effects on HbA1c and other variables, including safety outcomes, in clinical trials are obtained in real-world practice needs to be established. Methods: We used data from the comprehensive national diabetes register, the Scottish Care Information-Diabetes (SCI-Diabetes) collaboration database, available from 2004 to mid-2016. Data within this database were linked to mortality data from the General Registrar, available from the Information Services Division (ISD) of the National Health Service in Scotland. We calculated crude within-person differences between pre- and post-drug-initiation values of HbA1c, BMI, body weight, systolic blood pressure (SBP) and eGFR. We used mixed-effects regression models to adjust for within-person time trajectories in these measures. For completeness, we evaluated safety outcomes, cardiovascular disease events, lower-limb amputation and diabetic ketoacidosis, focusing on cumulative exposure effects, using Cox proportional hazard models, though power to detect such effects was limited. Results: Among 8566 people exposed to dapagliflozin over a median of 210 days the crude within-person change in HbA1c was −10.41 mmol/mol (−0.95%) after 3 months’ exposure. The crude change after 12 months was −12.99 mmol/mol (−1.19%) but considering the expected rise over time in HbA1c gave a dapagliflozin-exposure-effect estimate of −15.14 mmol/mol (95% CI −15.87, −14.41) (−1.39% [95% CI −1.45, −1.32]) at 12 months that was maintained thereafter. A drop in SBP of −4.32 mmHg (95% CI −4.84, −3.79) on exposure within the first 3 months was also maintained thereafter. Reductions in BMI and body weight stabilised by 6 months at −0.82 kg/m2 (95% CI −0.87, −0.77) and −2.20 kg (95% CI −2.34, −2.06) and were maintained thereafter. eGFR declined initially by −1.81 ml min−1 [1.73 m]−2 (95% CI −2.10, −1.52) at 3 months but varied thereafter. There were no significant effects of cumulative drug exposure on safety outcomes. Conclusions/interpretation: Dapagliflozin exposure was associated with reductions in HbA1c, SBP, body weight and BMI that were at least as large as in clinical trials. Dapagliflozin also prevented the expected rise in HbA1c and SBP over the period of study

    Real-time risk analysis for hybrid earthquake early warning systems

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    Earthquake Early Warning Systems (EEWS), based on real-time prediction of ground motion or structural response measures, may play a role in reducing vulnerability and/or exposition of buildings and lifelines. In fact, recently seismologists developed efficient methods for rapid estimation of event features by means of limited information of the P-waves. Then, when an event is occurring, probabilistic distributions of magnitude and source-to-site distance are available and the prediction of the ground motion at the site, conditioned to the seismic network measures, may be performed in analogy with the Probabilistic Seismic Hazard Analysis (PSHA). Consequently the structural performance may be obtained by the Probabilistic Seismic Demand Analysis (PSDA), and used for real-time risk management purposes. However, such prediction is performed in very uncertain conditions which have to be taken into proper account to limit false and missed alarms. In the present study, real-time risk analysis for early warning purposes is discussed. The magnitude estimation is performed via the Bayesian approach, while the earthquake localization is based on the Voronoi cells. To test the procedure it was applied, by simulation, to the EEWS under development in the Campanian region (southern Italy). The results lead to the conclusion that the PSHA, conditioned to the EEWS, correctly predicts the hazard at the site and that the false/missed alarm probabilities may be controlled by set up of an appropriate decisional rule and alarm threshold

    Manipulation of the unfolded protein response: A pharmacological strategy against coronavirus infection.

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    Coronavirus infection induces the unfolded protein response (UPR), a cellular signalling pathway composed of three branches, triggered by unfolded proteins in the endoplasmic reticulum (ER) due to high ER load. We have used RNA sequencing and ribosome profiling to investigate holistically the transcriptional and translational response to cellular infection by murine hepatitis virus (MHV), often used as a model for the Betacoronavirus genus to which the recently emerged SARS-CoV-2 also belongs. We found the UPR to be amongst the most significantly up-regulated pathways in response to MHV infection. To confirm and extend these observations, we show experimentally the induction of all three branches of the UPR in both MHV- and SARS-CoV-2-infected cells. Over-expression of the SARS-CoV-2 ORF8 or S proteins alone is itself sufficient to induce the UPR. Remarkably, pharmacological inhibition of the UPR greatly reduced the replication of both MHV and SARS-CoV-2, revealing the importance of this pathway for successful coronavirus replication. This was particularly striking when both IRE1α and ATF6 branches of the UPR were inhibited, reducing SARS-CoV-2 virion release (~1,000-fold). Together, these data highlight the UPR as a promising antiviral target to combat coronavirus infection
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