Spinal NKCC1 blockade inhibits TRPV1-dependent referred allodynia

Background The Na+, K+, 2Cl- type I cotransporter (NKCC1) and TRPV1 receptors, at the level of the dorsal horn, have been implicated in mediating allodynia in response to an inflammatory insult. The NKCC1 cotransporter regulates intracellular [Cl-] and thus the magnitude and polarity of GABAA receptor responses in neurons. TRPV1 receptors transduce diverse chemical and natural stimuli in nociceptors and are critical for inflammatory hyperalgesia.Results Here we have tested the role of spinal NKCC1 cotransporters and TRPV1 receptors in referred allodynia in a model of visceral hyperalgesia in mice. Intrathecal (IT) injection of the NKCC1 inhibitor bumetanide (BUM, 1 nmol) inhibited referred, abdominal allodynia evoked by an intracolonic capsaicin injection. BUM was effective when injected IT either before or up to 4 hrs after the establishment of referred allodynia. The TRPV1 antagonist AMG 9810 (1 nmol) also inhibited referred allodynia in this model suggesting the involvement of an endogenous TRPV1 agonist in the dorsal horn in referred allodynia. In support of this suggestion, the endovanilloid TRPV1 agonist, narachidonoyl- dopamine (NADA, 1 or 10 nmol, IT) evoked stroking allodynia in the hindpaw that was blocked by co-treatment with AMG 9810 (1 nmol). The TRPV1-dependent stroking allodynia caused by NADA appeared to be functionally linked to NKCC1 because BUM (1 nmol) also inhibited NADA-evoked stroking allodynia.Conclusion Our findings indicate that spinal NKCC1 and TRPV1 are critical for referred allodynia mediated by a painful visceral stimulus. Moreover, they suggest that endogenous TRPV1 agonists, released in the CNS in painful conditions, might stimulate TRPV1 receptors on primary afferents that, in turn, play a role in increasing NKCC1 activity leading to allodynia.This work was supported by the National Institutes for Neurological Disorders and Stroke (NINDS, DA19959, to TJP), the American Pain Society (to TJP), the Spanish Secretaria de Estado de Educacion y Universidades: Formacion de Profesorado Universitario Grant (to JME), the Canadian Foundation for Innovation (CFI, to FC), the Canadian Institutes of Health Research (CIHR, to FC) and the Fonds de la recherche en santé du Québec (FRSQ, to FC)

Local activation of cannabinoid CB1 receptors in the urinary bladder reduces the inflammation-induced sensitization of bladder afferents

<p>Abstract</p> <p>Background</p> <p>Systemic administration of cannabinoid agonists is known to reduce pain induced by bladder inflammation and to modulate cystometric parameters <it>in vivo</it>. We have previously reported that intravesical administration of a cannabinoid agonist reduces the electrical activity of bladder afferents under normal conditions. However, the effects of local activation of bladder cannabinoid receptors on afferent activity during inflammation are unknown. This study was aimed to assess the effects of intravesical administration of a cannabinoid agonist on the discharges of afferent fibers in inflamed bladders <it>ex vivo</it>. We also characterized the expression of CB₁receptors in the bladder and their localization and co-expression with TRPV1, a marker of nociceptive afferents.</p> <p>Results</p> <p>Compared to untreated animals, afferent fiber activity in inflamed bladders was increased for intravesical pressures between 10 and 40 mmHg. Local treatment with a non selective cannabinoid agonist (AZ12646915) significantly reduced the afferent activity at intravesical pressures above 20 mmHg. This effect was blocked by AM251 but not by AM630 (selective for CB₁and CB₂respectively). Finally, CB₁was co-expressed with TRPV1 in control and inflamed bladders.</p> <p>Conclusion</p> <p>These results demonstrate that sensitization of bladder afferents induced by inflammation is partly suppressed by intravesical activation of cannabinoid receptors, an effect that appears to be mediated by CB₁receptors. Also, TRPV1 positive fibers were found to co-express CB₁, supporting the hypothesis of a direct action of the cannabinoid agonist on nociceptive afferents. Taken together, these results indicate a peripheral modulation by the cannabinoid system of bladder hypersensitivity during inflammation.</p

PKMζ is essential for spinal plasticity underlying the maintenance of persistent pain

<p>Abstract</p> <p>Background</p> <p>Chronic pain occurs when normally protective acute pain becomes pathologically persistent. We examined here whether an isoform of protein kinase C (PKC), PKMζ, that underlies long-term memory storage in various brain regions, also sustains nociceptive plasticity in spinal cord dorsal horn (SCDH) mediating persistent pain.</p> <p>Results</p> <p>Cutaneous injury or spinal stimulation produced persistent increases of PKMζ, but not other atypical PKCs in SCDH. Inhibiting spinal PKMζ, but not full-length PKCs, reversed plasticity-dependent persistent painful responses to hind paw formalin and secondary mechanical hypersensitivity and SCDH neuron sensitization after hind paw capsaicin, without affecting peripheral sensitization-dependent primary heat hypersensitivity after hind paw capsaicin. Inhibiting spinal PKMζ, but not full-length PKCs, also reversed mechanical hypersensitivity in the rat hind paw induced by spinal stimulation with intrathecal dihydroxyphenylglycine. Spinal PKMζ inhibition also alleviated allodynia 3 weeks after ischemic injury in rats with chronic post-ischemia pain (CPIP), at a point when allodynia depends on spinal changes. In contrast, spinal PKMζ inhibition did not affect allodynia in rats with chronic contriction injury (CCI) of the sciatic nerve, or CPIP rats early after ischemic injury, when allodynia depends on ongoing peripheral inputs.</p> <p>Conclusions</p> <p>These results suggest spinal PKMζ is essential for the maintenance of persistent pain by sustaining spinal nociceptive plasticity.</p

Developing models for future real-time platforms: Virtual simulation and design of new components and systems for aircraft and remotely piloted aircraft systems

In the development of electrified and other vehicle systems, the modelling and simulation of the vehicle is very important. With these tools the preliminary design, as well as later detailed studies of the systems developed, allow engineers to spend less time on each phase of their projects or address them with an integrated approach. In addition, this integrated approach provides the possibility of building hardware-in-the loop models with all the components required. This vehicle modelling and simulation has gained more interest with the increasing use of a wide variety of RPAS, ranging from light weight micro aircraft to large vehicles of various tons. For this reason, the previously-described building tools are the final objective of the developing models to be used in real-time platform projects. The first step presented in this paper is to build a simulator that reproduces the behaviour of a selected aircraft and validate it. This paper presents the study of the performances and behaviour of an OPV used to validate the simulator developed later. At the end, some preliminary tests and estimations of the performances for the selected OPV with an electric motor are presented

Changes in the immune response against SARS-CoV-2 in individuals with severe COVID-19 treated with high dose of vitamin D

Main cause of severe illness and death in COVID-19 patients appears to be an excessive but ineffectual inflammatory immune response that may cause severe acute respiratory distress syndrome (ARDS). Vitamin D may favour an anti-inflammatory environment and improve cytotoxic response against some infectious diseases. A multicenter, single-blind, prospective, randomized clinical trial was approved in patients with COVID-19 pneumonia and levels of 25-hydroxyvitamin D (25(OH)D) of 14.8 ng/ml (SD: 6.18) to test antiviral efficacy, tolerance and safety of 10,000 IU/day of cholecalciferol (vitamin D3) for 14 days, in comparison with 2000 IU/day. After supplementation, mean serum 25(OH)D levels increased to 19 ng/ml on average in 2000 IU/day versus 29 ng/ml in 10,000 IU/day group (p < 0.0001). Although levels of inflammatory cytokines were not modified by treatment with 10,000 IU/day, there was an increase of anti-inflammatory cytokine IL-10 and higher levels of CD4+ T cells, with predominance of T central memory subpopulation. Cytotoxic response against pseudotyped SARS-CoV-2 infected cells was increased more than 4-fold in patients who received 10,000 IU/day. Moreover, levels of IFNγ were significantly higher in this group. Beneficial effect of supplementation with 10,000 IU/day was also observed in participants who developed ARDS and stayed at the hospital for 8.0 days, whereas those who received 2000 IU/day stayed for 29.2 days (p = 0.0381). Administration of high doses of vitamin D3 as adjuvant of the standard care treatment during hospitalization for COVID-19 may improve the inflammatory environment and cytotoxic response against pseudotyped SARS-CoV-2 infected cells, shortening the hospital stay and, possibly, improving the prognosis.We greatly appreciate all the patients for their participation in this study. We thank the excellent secretarial assistance of Mrs Olga Palao at the Centro Nacional de Microbiología (CNM, Instituto de Salud Carlos III). The authors also acknowledge María C. de la Cruz at Unidad Central de Apoyo a la Investigación Clínica y Ensayos Clínicos (Instituto de Investigación Sanitaria Gregorio Marañon; IiSGM) for her advice and assistance related to the clinical research with medicines. This work was supported by the Coordinated Research Activities at CNM (Instituto de Salud Carlos III) (COV20_00679) to promote an integrated response against SARS-CoV-2 in Spain (Spanish Ministry of Science and Innovation) that is coordinated by Dr Inmaculada Casas (WHO National Influenza Center of the CNM); the Spanish Ministry of Science and Innovation (PID2019–110275RB-I00); the Spanish AIDS Research Network RD16CIII/0002/0001 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2016–2020, Instituto de Salud Carlos III, European Region Development Fund (ERDF) and Fundación Universidad Alfonso X el Sabio (FUAX, Madrid, Spain; Reference 1012010). The work of Montserrat Torres is financed by the Coordinated Research Activities at the CNM (Instituto de Salud Carlos III) (COV20_00679). The work of María Rosa López-Huertas and Sara Rodríguez-Mora is financed by NIH grant R01AI143567. The work of Lorena Vigón is supported by a pre-doctoral grant from Instituto de Salud Carlos III (FIS PI16CIII/00034-ISCIII-FEDER). The work of Fernando Ramos Martín is financed by the Spanish Ministry of Science and Innovation (PID2019–110275RB-I00). Drug Cholecalciferol (vitamin D) used in the study was donated by Italfarmaco Group (Cholecalciferol 25,000IU/2,5 ml oral solution). Italfarmaco Group had no role in the design and conduct of the study, in the collection, management, analysis, and interpretation of the data, or the preparation, review, or approval of the manuscript.S

Resumen ejecutivo del documento de consenso sobre el manejo de la patología renal en pacientes con infección por VIH

El objetivo de este documento es actualizar las recomendaciones sobre la evaluación y el manejo de la afectación renal en pacientes con infección por el VIH del año 2010. La función renal debe monitorizarse en todos los pacientes e incluir la medida de la concentración sérica de creatinina, la estimación del filtrado glomerular (ecuación CKD-EPI), la medida del cociente proteína/creatinina en orina y un sedimento urinario. El estudio básico de la función tubular ha de incluir la concentración sérica de fosfato y la tira reactiva de orina (glucosuria). En ausencia de alteraciones, el cribado será anual. En pacientes tratados con tenofovir o con factores de riesgo para el desarrollo de enfermedad renal crónica (ERC), se recomienda una evaluación más frecuente. Se debe evitar el uso de antirretrovirales potencialmente nefrotóxicos en pacientes con ERC o factores de riesgo para evitar su progresión. También se revisan las indicaciones de la biopsia renal, cuándo enviar el paciente al nefrólogo y las indicaciones, evaluación y manejo del paciente en diálisis o del trasplante renal

eIF2α phosphorylation controls thermal nociception

A response to environmental stress is critical to alleviate cellular injury and maintain cellular homeostasis. Eukaryotic initiation factor 2 (eIF2) is a key integrator of cellular stress responses and an important regulator of mRNA translation. Diverse stress signals lead to the phosphorylation of the α subunit of eIF2 (Ser51), resulting in inhibition of global protein synthesis while promoting expression of proteins that mediate cell adaptation to stress. Here we report that eIF2α is instrumental in the control of noxious heat sensation. Mice with decreased eIF2α phosphorylation (eIF2α(+/S51A)) exhibit reduced responses to noxious heat. Pharmacological attenuation of eIF2α phosphorylation decreases thermal, but not mechanical, pain sensitivity, whereas increasing eIF2α phosphorylation has the opposite effect on thermal nociception. The impact of eIF2α phosphorylation (p-eIF2α) on thermal thresholds is dependent on the transient receptor potential vanilloid 1. Moreover, we show that induction of eIF2α phosphorylation in primary sensory neurons in a chronic inflammation pain model contributes to thermal hypersensitivity. Our results demonstrate that the cellular stress response pathway, mediated via p-eIF2α, represents a mechanism that could be used to alleviate pathological heat sensation