RESUMEN

BACKGROUND AND PURPOSE: Fibromyalgia is a complex clinical disorder with an unknown aetiology, characterized by generalized pain and co-morbid symptoms such as anxiety and depression. An imbalance of oxidants and antioxidants is proposed to play a pivotal role in the pathogenesis of fibromyalgia symptoms. However, the precise mechanisms by which oxidative stress contributes to fibromyalgia-induced pain remain unclear. The transient receptor potential ankyrin 1 (TRPA1) channel, known as both a pain sensor and an oxidative stress sensor, has been implicated in various painful conditions. EXPERIMENTAL APPROACH: The feed-forward mechanism that implicates reactive oxygen species (ROS) driven by TRPA1 was investigated in a reserpine-induced fibromyalgia model in C57BL/6J mice employing pharmacological interventions and genetic approaches. KEY RESULTS: Reserpine-treated mice developed pain-like behaviours (mechanical/cold hypersensitivity) and early anxiety-depressive-like disorders, accompanied by increased levels of oxidative stress markers in the sciatic nerve tissues. These effects were not observed upon pharmacological blockade or global genetic deletion of the TRPA1 channel and macrophage depletion. Furthermore, we demonstrated that selective silencing of TRPA1 in Schwann cells reduced reserpine-induced neuroinflammation (NADPH oxidase 1-dependent ROS generation and macrophage increase in the sciatic nerve) and attenuated fibromyalgia-like behaviours. CONCLUSION AND IMPLICATIONS: Activated Schwann cells expressing TRPA1 promote an intracellular pathway culminating in the release of ROS and recruitment of macrophages in the mouse sciatic nerve. These cellular and molecular events sustain mechanical and cold hypersensitivity in the reserpine-evoked fibromyalgia model. Targeting TRPA1 channels on Schwann cells could offer a novel therapeutic approach for managing fibromyalgia-related behaviours.

Asunto(s)

Fibromialgia , Ratones Endogámicos C57BL , Estrés Oxidativo , Especies Reactivas de Oxígeno , Reserpina , Células de Schwann , Canal Catiónico TRPA1 , Animales , Reserpina/farmacología , Fibromialgia/inducido químicamente , Fibromialgia/metabolismo , Canal Catiónico TRPA1/metabolismo , Canal Catiónico TRPA1/antagonistas & inhibidores , Canal Catiónico TRPA1/genética , Estrés Oxidativo/efectos de los fármacos , Células de Schwann/metabolismo , Células de Schwann/efectos de los fármacos , Masculino , Ratones , Especies Reactivas de Oxígeno/metabolismo , Dolor/metabolismo , Dolor/inducido químicamente , Nervio Ciático/metabolismo , Modelos Animales de Enfermedad , Ratones Noqueados , Canales de Potencial de Receptor Transitorio/metabolismo , Canales de Potencial de Receptor Transitorio/antagonistas & inhibidores , Canales de Potencial de Receptor Transitorio/genética

RESUMEN

The physical and functional interaction between transient receptor potential channel ankyrin 1 (TRPA1) and neuronal calcium sensor 1 (NCS-1) was assessed. NCS-1 is a calcium (Ca2+) sensor found in many tissues, primarily neurons, and TRPA1 is a Ca2+ channel involved not only in thermal and pain sensation but also in conditions such as cancer and chemotherapy-induced peripheral neuropathy, in which NCS-1 is also a regulatory component.We explored the interactions between these two proteins by employing western blot, qRT-PCR, co-immunoprecipitation, Ca2+ transient monitoring with Fura-2 spectrophotometry, and electrophysiology assays in breast cancer cells (MDA-MB-231) with different levels of NCS-1 expression and neuroblastoma cells (SH-SY5Y).Our findings showed that the expression of TRPA1 was directly correlated with NCS-1 levels at both the protein and mRNA levels. Additionally, we found a physical and functional association between these two proteins. Physically, the NCS-1 and TRPA1 co-immunoprecipitate. Functionally, NCS-1 enhanced TRPA1-dependent Ca2+ influx, current density, open probability, and conductance, where the functional effects depended on PI3K. Conclusion: NCS-1 appears to act not only as a Ca2+ sensor but also modulates TRPA1 protein expression and channel function in a direct fashion through the PI3K pathway. These results contribute to understanding how Ca2+ homeostasis is regulated and provides a mechanism underlying conditions where Ca2+ dynamics are compromised, including breast cancer. With a cellular pathway identified, targeted treatments can be developed for breast cancer and neuropathy, among other related diseases.

Asunto(s)

Neoplasias de la Mama , Proteínas Sensoras del Calcio Neuronal , Neuropéptidos , Canal Catiónico TRPA1 , Femenino , Humanos , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Calcio/metabolismo , Señalización del Calcio , Línea Celular Tumoral , Proteínas Sensoras del Calcio Neuronal/metabolismo , Proteínas Sensoras del Calcio Neuronal/genética , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Neuropéptidos/metabolismo , Neuropéptidos/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal , Canal Catiónico TRPA1/metabolismo , Canal Catiónico TRPA1/genética

RESUMEN

Background: Transient receptor potential ankyrin 1 (TRPA1) activation is implicated in neuropathic pain-like symptoms. However, whether TRPA1 is solely implicated in pain-signaling or contributes to neuroinflammation in multiple sclerosis (MS) is unknown. Here, we evaluated the TRPA1 role in neuroinflammation underlying pain-like symptoms using two different models of MS. Methods: Using a myelin antigen, Trpa1+/+ or Trpa1-/- female mice developed relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE) (Quil A as adjuvant) or progressive experimental autoimmune encephalomyelitis (PMS)-EAE (complete Freund's adjuvant). The locomotor performance, clinical scores, mechanical/cold allodynia, and neuroinflammatory MS markers were evaluated. Results: Mechanical and cold allodynia detected in RR-EAE, or PMS-EAE Trpa1+/+ mice, were not observed in Trpa1-/- mice. The increased number of cells labeled for ionized calcium-binding adapter molecule 1 (Iba1) or glial fibrillary acidic protein (GFAP), two neuroinflammatory markers in the spinal cord observed in both RR-EAE or PMS-EAE Trpa1+/+ mice, was reduced in Trpa1-/- mice. By Olig2 marker and luxol fast blue staining, prevention of the demyelinating process in Trpa1-/- induced mice was also detected. Conclusions: Present results indicate that the proalgesic role of TRPA1 in EAE mouse models is primarily mediated by its ability to promote spinal neuroinflammation and further strengthen the channel inhibition to treat neuropathic pain in MS.

Asunto(s)

Encefalomielitis Autoinmune Experimental , Esclerosis Múltiple , Neuralgia , Canales de Potencial de Receptor Transitorio , Femenino , Animales , Ratones , Esclerosis Múltiple/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Canal Catiónico TRPA1/metabolismo , Hiperalgesia/tratamiento farmacológico , Nocicepción , Canales de Potencial de Receptor Transitorio/metabolismo , Enfermedades Neuroinflamatorias , Médula Espinal/metabolismo , Neuralgia/tratamiento farmacológico

RESUMEN

RATIONALE: Major depressive disorder (MDD) is one of the most diagnosed mental disorders. Despite this, its pathophysiology remains poorly understood. In this context, basic research aims to unravel the pathophysiological mechanisms of MDD as well as investigate new targets and substances with therapeutic potential. Transient receptor potential ankyrin 1 (TRPA1) is a transmembrane channel considered a sensor for inflammation and oxidative stress. Importantly, both inflammation and oxidative stress have been suggested as participants in the pathophysiology of MDD. However, the potential participation of TRPA1 in depressive disorder remains poorly investigated. OBJECTIVE: To investigate the involvement of the TRPA1 channel in the behavioral changes induced by chronic corticosterone administration (CCA) in male mice. METHODS: Swiss male mice were exposed to 21 days of CCA protocol and then treated with HC-030031 or A-967079, TRPA1 antagonists. Behavioral tests, analyzes of oxidative parameters and TRPA1 immunocontent were performed in the prefrontal cortex (PFC) and hippocampus (HIP). RESULTS: CCA induced despair-like behavior in mice accompanied by an increase in the levels of hydrogen peroxide (H2O2), a TRPA1 agonist, which was reversed by TRPA1 antagonists and ketamine (positive control). In addition, CCA protocol reduced the immunocontent of this channel in the HIP and showed a tendency to increase the TRPA1 protein expression in the PFC. CONCLUSION: Our work suggests that TRPA1 channel appears crucial to mediate the behavioral impairment induced by CCA in male Swiss mice.

Asunto(s)

Corticosterona , Trastorno Depresivo Mayor , Masculino , Animales , Ratones , Canal Catiónico TRPA1/metabolismo , Peróxido de Hidrógeno/metabolismo , Inflamación

RESUMEN

Paclitaxel (PTX) is a frequently used anticancer drug that causes peripheral neuropathy. Transient receptor potential ankyrin 1 (TRPA1), a plasma membrane calcium channel, has been associated with PTX toxicity and with other chemotherapy agents such as oxaliplatin and vincristine. However, the effect of PTX on the functional expression and calcium currents of TRPA1 has not been determined. The present study shows the effect of PTX on TRPA1 activity in a neuronal cell line (SH-SY5Y). The effect of PTX on the expression of TRPA1 was assessed through quantitative PCR and Western blot analyses to determine the relative mRNA and protein expression levels. To assess the effect on calcium flux and currents, cells were exposed to PTX; simultaneously, a specific agonist and antagonist of TRPA1 were added to evaluate the differential response in exposed versus control cells. To assess the effect of PKA, PKC and PI3K on PTX-induced TRPA1 increased activity, selective inhibitors were added to these previous experiments. PTX increased the mRNA and protein expression of TRPA1 as well as the TRPA1-mediated Ca2+ currents and intracellular Ca2+ concentrations. This effect was dependent on AITC (a selective specific agonist) and was abolished with HC-030031 (a selective specific antagonist). The inhibition of PKA and PKC reduced the effect of PTX on the functional expression of TRPA1, whereas the inhibition of PI3K had no effects. PTX-induced neuropathy involves TRPA1 activity through an increase in functional expression and is regulated by PKA and PKC signaling. These findings support the role of the TRPA1 channel in the mechanisms altered by PTX, which can be involved in the process that lead to chemotherapy-induced neuropathy.

Asunto(s)

Antineoplásicos , Neuroblastoma , Canales de Potencial de Receptor Transitorio , Humanos , Paclitaxel/farmacología , Canal Catiónico TRPA1/metabolismo , Calcio/metabolismo , Canales de Potencial de Receptor Transitorio/genética , Canales de Potencial de Receptor Transitorio/metabolismo , Proteínas del Citoesqueleto/metabolismo , ARN Mensajero/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo

RESUMEN

Transient receptor potential (TRP) channels are involved in the development of oxaliplatin-induced neuropathic pain, a frequent and debilitating side effect of cancer therapy. Here we explored whether oxaliplatin-induced changes in the expression of TRP channels, as well as the development of pain-related behaviours, differed between male and female animals. Adult rats were injected with oxaliplatin or saline and mechanical and cold allodynia were evaluated using Von Frey and Choi Tests. The mRNA levels of TRPV1, TRPM8 and TRPA1 were assessed in lumbar ganglia and spinal cord by using real time RT-PCR. Oxaliplatin administration induced mechanical and cold hypersensitivity and allodynia in both sexes, with more severe responses to cold stimulation detected in females. Oxaliplatin also induced a significant increase in the expression of TRPV1, TRPM8 and TRPA1 in lumbar dorsal root ganglia. Interestingly, while TRPV1 and TRPA1 upregulation showed no sex difference, the increase in TRPM8 mRNA levels was more pronounced in female ganglia, correlating with the increased sensitivity to innocuous cold stimuli observed in females. TRPV1 and TRPM8 were also found to be upregulated in the spinal cord of animals of both sexes. Our results reveal previously undescribed changes in the expression of TRP channels occurring in peripheral ganglia and spinal cord of both male and female oxaliplatin-treated animals, with some of these changes exhibiting sex-related differences that could underlie the development of sex-specific patterns of pain-related behaviours.

Asunto(s)

Neuralgia , Canales Catiónicos TRPM , Canales de Potencial de Receptor Transitorio , Animales , Frío , Síndromes Periódicos Asociados a Criopirina , Femenino , Ganglios Espinales/metabolismo , Hiperalgesia/inducido químicamente , Hiperalgesia/metabolismo , Masculino , Neuralgia/metabolismo , Compuestos Organoplatinos/efectos adversos , Compuestos Organoplatinos/metabolismo , Oxaliplatino/efectos adversos , ARN Mensajero/metabolismo , Ratas , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPM/metabolismo , Canales de Potencial de Receptor Transitorio/metabolismo

RESUMEN

Chronic pain is a common symptom experienced during cancer progression. Additionally, some patients experience bone pain caused by cancer metastasis, which further complicates the prognosis. Cancer pain is often treated using opioid-based pharmacotherapy, but these drugs possess several adverse effects. Accordingly, new mechanisms for cancer pain management are being explored, including transient receptor potential channels (TRPs). TRP ion channels are expressed in several tissues and play a key role in pain detection, especially TRP vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1). In the present review, we describe the role of TRPV1 and TRPA1 involved in cancer pain mechanisms. Several studies have revealed that the administration of TRPV1 or TRPA1 agonists/antagonists and TRPV1 or TRPA1 knockdown reduced sensitivity to nociception in cancer pain models. TRPV1 was also found to be involved in various models of cancer-induced bone pain (CIBP), with TRPV1 expression reportedly enhanced in some models. These studies have demonstrated the TRPV1 or TRPA1 association with cancer pain in models induced by tumour cell inoculation into the bone cavity, hind paw, mammary fat pad, and sciatic nerve in mice or rats. To date, only resiniferatoxin, a TRPV1 agonist, has been evaluated in clinical trials for cancer pain and showed preliminary positive results. Thus, TRP channels are potential targets for managing cancer-related pain syndromes.

Asunto(s)

Dolor en Cáncer/tratamiento farmacológico , Dolor en Cáncer/fisiopatología , Canales de Potencial de Receptor Transitorio/metabolismo , Animales , Ensayos Clínicos como Asunto , Humanos , Manejo del Dolor , Canal Catiónico TRPA1/agonistas , Canal Catiónico TRPA1/antagonistas & inhibidores , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPV/agonistas , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/metabolismo , Canales de Potencial de Receptor Transitorio/agonistas , Canales de Potencial de Receptor Transitorio/antagonistas & inhibidores , Canales de Potencial de Receptor Transitorio/genética

RESUMEN

Spirulina platensis is a "super-food" and has attracted researchers' attention due to its anti-inflammatory, antioxidant, and analgesic properties. Herein, we investigated the antinociceptive effects of Spirulina in different rodent behavior models of inflammatory pain. Male Swiss mice were treated with Spirulina (3-300 mg/kg, p.o.), indomethacin (10 mg/kg, p.o.), or vehicle (0.9% NaCl 10 mL/kg). Behavioral tests were performed with administration of acetic acid (0.6%, i.p.), formalin 2.7% (formaldehyde 1%, i.pl.), menthol (1.2 µmol/paw, i.pl.), cinnamaldehyde (10 nmol/paw, i.pl.), capsaicin (1.6 µg/paw, i.pl.), glutamate (20 µmol/paw, i.pl.), or naloxone (1 mg/kg, i.p.). The animals were also exposed to the rotarod and open field test to determine possible effects of Spirulina on locomotion and motor coordination. The quantitative phytochemical assays exhibited that Spirulina contains significant concentrations of total phenols and flavonoid contents, as well as it showed a powerful antioxidant effect with the highest scavenging activity. Oral administration of Spirulina completely inhibited the abdominal contortions induced by acetic acid (ED50 = 20.51 mg/kg). Spirulina treatment showed significant inhibition of formalin-induced nociceptive behavior during the inflammatory phase, and the opioid-selective antagonist markedly blocked this effect. Furthermore, our data indicate that the mechanisms underlying Spirulina analgesia appear to be related to its ability to modulate TRMP8 and TRPA1, but not by TRPV1 or glutamatergic system. Spirulina represents an orally active and safe natural analgesic that exhibits great therapeutic potential for managing inflammatory pain disorders.

Asunto(s)

Analgésicos/farmacología , Antagonistas de Narcóticos/farmacología , Dolor Nociceptivo/tratamiento farmacológico , Extractos Vegetales/farmacología , Spirulina/química , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPM/metabolismo , Analgésicos/uso terapéutico , Animales , Capsaicina/farmacología , Masculino , Ratones , Naloxona/farmacología , Nocicepción/efectos de los fármacos , Extractos Vegetales/uso terapéutico

RESUMEN

Transient receptor potential (TRP) channels are critical receptors in the transduction of nociceptive stimuli. The microenvironment of diverse types of cancer releases substances, including growth factors, neurotransmitters, and inflammatory mediators, which modulate the activity of TRPs through the regulation of intracellular signaling pathways. The modulation of TRP channels is associated with the peripheral sensitization observed in patients with cancer, which results in mild noxious sensory stimuli being perceived as hyperalgesia and allodynia. Secondary metabolites derived from plant extracts can induce the activation, blocking, and desensitization of TRP channels. Thus, these compounds could act as potential therapeutic agents, as their antinociceptive properties could be beneficial in relieving cancer-derived pain. In this review, we will summarize the role of TRPV1 and TRPA1 in pain associated with cancer and discuss molecules that have been reported to modulate these channels, focusing particularly on the mechanisms of channel activation associated with molecules released in the tumor microenvironment.

Asunto(s)

Dolor en Cáncer , Proteínas de Neoplasias , Neoplasias , Transducción de Señal , Canal Catiónico TRPA1 , Canales Catiónicos TRPV , Animales , Dolor en Cáncer/tratamiento farmacológico , Dolor en Cáncer/genética , Dolor en Cáncer/metabolismo , Humanos , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/genética , Hiperalgesia/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Canal Catiónico TRPA1/genética , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismo

RESUMEN

AIMS: Neuronal and non-neuronal TRPA1 channel plays an active role in the pathogenesis of several skin inflammatory diseases. Although a recent study identified the TRPA1 channel activation upon UVB exposure, its role in inflammatory, oxidative, and proliferative processes underlying UVB radiation-induced sunburn was not yet fully understood. We evaluated the TRPA1 channel contribution in inflammatory, oxidative, and proliferative states on skin inflammation induced by UVB radiation in mice. MAIN METHODS: TRPA1 role was evaluated from inflammatory (ear edema, myeloperoxidase, and N-acetyl-ß-D-glycosaminidase activities, histological changes, and cytokines levels), proliferative (epidermal hyperplasia, PCNA, and TRPA1 levels), and oxidative (reactive oxygen intermediates measure, H2O2 quantification, and NADPH oxidase activity) parameters caused by UVB radiation single (0.5 J/cm2) or repeated (0.1 J/cm2) exposure. We verified the contribution of non-neuronal and neuronal TRPA1 on UVB radiation-induced inflammatory parameters using RTX-denervation (50 µg/kg s.c.). KEY FINDINGS: TRPA1 blockade by the selective antagonist Lanette® N HC-030031 reduced all parameters induced by UVB radiation single (at concentration of 1%) or repeated (at concentration of 0.1%) exposure. We evidenced an up-regulation of the TRPA1 protein after UVB radiation repeated exposure, which was blocked by topical Lanette® N HC-030031 (0.1%). By RTX-denervation, we verified that non-neuronal TRPA1 also interferes in some inflammatory parameters induction. However, cutaneous nerve fibers seem to be most needed in the development of UVB radiation-induced inflammatory processes. SIGNIFICANCE: We propose the TRPA1 channel participates in the UVB radiation-induced sunburn in mice, and it could be a promising therapeutic target to treat skin inflammatory disorders.

Asunto(s)

Edema/patología , Inflamación/patología , Piel/patología , Canal Catiónico TRPA1/metabolismo , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Peróxido de Hidrógeno/metabolismo , Masculino , Ratones , Neuronas/metabolismo , Peroxidasa/metabolismo , Rayos Ultravioleta

RESUMEN

Opioids are the "gold standard" treatment for postoperative pain, but these drugs also have limiting adverse effects. Thus, adjuvant drugs might be useful in opioid therapy for postoperative pain. The aim of the present study was to evaluate the effect of Phα1ß, a dual blocker of Cav2 and TRPA1 channels, on antinociceptive and adverse actions of morphine in a model of postoperative pain. Phα1ß (100-300 pmol/site) or morphine (3-10 mg/kg), alone, largely reduced postoperative nociception. However, Phα1ß (100 pmol/site) or morphine (10 mg/kg) also produced motor impairment. Lower doses of Phα1ß (30 pmol/site) or morphine (1 mg/kg), that did not have an effect alone, showed antinociceptive effect when concomitantly administrated. Moreover, co-administration of Phα1ß (30 pmol/site) with morphine (1 or 10 mg/kg) was unable to cause motor impairment. Preoperative repeated treatment with morphine increased the expression of Cav2 and TRPA1 channels in spinal cord, and caused tolerance and withdrawal syndrome, which were reversed with a single injection of Phα1ß (30 pmol/site). When injected postoperatively, escalating doses of morphine worsened postoperative hyperalgesia, induced tolerance, and withdrawal syndrome. Similarly, Phα1ß (30 pmol/site) reversed these adverse effects. Single or repeated morphine caused constipation, which was not altered by Phα1ß. Thus, a low dose of Phα1ß potentiated the analgesia, and reversed some adverse effects of morphine on operated mice, indicating the potential use of this agent as an adjuvant drug in opioid therapy for postoperative pain.

Asunto(s)

Analgésicos Opioides/uso terapéutico , Quimioterapia Adyuvante/métodos , Dolor Postoperatorio/tratamiento farmacológico , Venenos de Araña/uso terapéutico , Analgésicos , Animales , Canales de Calcio Tipo N/metabolismo , Hiperalgesia/inducido químicamente , Ratones , Morfina , Venenos de Araña/farmacología , Canal Catiónico TRPA1/metabolismo

RESUMEN

Oxidative stress is implicated in retinal cell injury associated with glaucoma and other retinal diseases. However, the mechanism by which oxidative stress leads to retinal damage is not completely understood. Transient receptor potential ankyrin 1 (TRPA1) is a redox-sensitive channel that, by amplifying the oxidative stress signal, promotes inflammation and tissue injury. Here, we investigated the role of TRPA1 in retinal damage evoked by ischemia (1 hour) and reperfusion (I/R) in mice. In wild-type mice, retinal cell numbers and thickness were reduced at both day-2 and day-7 after I/R. By contrast, mice with genetic deletion of TRPA1 were protected from the damage seen in their wild-type littermates. Daily instillation of eye drops containing two different TRPA1 antagonists, an oxidative stress scavenger, or a NADPH oxidase-1 inhibitor also protected the retinas of C57BL/6J mice exposed to I/R. Mice with genetic deletion of the proinflammatory TRP channels, vanilloid 1 (TRPV1) or vanilloid 4 (TRPV4), were not protected from I/R damage. Surprisingly, genetic deletion or pharmacological blockade of TRPA1 also attenuated the increase in the number of infiltrating macrophages and in the levels of the oxidative stress biomarker, 4-hydroxynonenal, and of the apoptosis biomarker, active caspase-3, evoked by I/R. These findings suggest that TRPA1 mediates the oxidative stress burden and inflammation that result in murine retinal cell death. We also found that TRPA1 (both mRNA and protein) is expressed by human retinal cells. Thus, it is possible that inhibition of a TRPA1-dependent pathway could also attenuate glaucoma-related retinal damage.

Asunto(s)

Daño por Reperfusión/metabolismo , Retina/metabolismo , Canal Catiónico TRPA1/metabolismo , Animales , Muerte Celular , Inflamación , Isquemia , Masculino , Ratones , Ratones Endogámicos C57BL , NADPH Oxidasa 1/metabolismo , Estrés Oxidativo/fisiología , Reperfusión , Daño por Reperfusión/fisiopatología , Retina/fisiología , Enfermedades de la Retina , Canal Catiónico TRPA1/genética , Canal Catiónico TRPA1/fisiología , Canales Catiónicos TRPV/metabolismo , Canales de Potencial de Receptor Transitorio/genética

RESUMEN

Central neuropathic pain is the main symptom caused by spinal cord lesion in relapsing-remitting multiple sclerosis (RRMS), but its management is still not effective. The transient receptor potential ankyrin 1 (TRPA1) is a pain detecting ion channel involved in neuropathic pain development. Thus, the aim of our study was to evaluate the role of TRPA1 in central neuropathic nociception induced by relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE) mouse model. In this model, we observed the development of similar clinical conditions of RRMS in C57BL/6 female mice through RR-EAE using MOG35-55 antigen and Quil A adjuvant. At the thirty-fifth day post-induction, C57BL/6 female mice demonstrated alteration in the RR-EAE score without motor impairment, mechanical and cold allodynia. Also, significative changes in demyelinating (Mog and olig-1) and neuroinflammatory (Iba1, Gfap and Tnfa) markers were observed, but this model did not alter Trpa1 RNA expression levels in the spinal cord. The hydrogen peroxide and 4-hydroxynonenal levels (TRPA1 agonists) were increased in RR-EAE induced mice, as well as the NADPH oxidase activity. The intragastric treatment of RR-EAE induced mice with TRPA1 antagonists (HC-030031 and A-967079) and antioxidant (α-lipoic acid and apocynin) caused an antiallodynic effect. Moreover, the intrathecal administration of TRPA1 antisense oligonucleotide, HC-030031, α-lipoic acid, and apocynin transiently attenuated mechanical and cold allodynia. Thus, TRPA1 plays a key role in the induction of neuropathic pain in this model of RR-EAE and can be a possible target for investigating the development of pain in RRMS patients.

Asunto(s)

Encefalomielitis Autoinmune Experimental/metabolismo , Hiperalgesia/metabolismo , Neuralgia/metabolismo , Nocicepción/fisiología , Canal Catiónico TRPA1/metabolismo , Animales , Encefalomielitis Autoinmune Experimental/complicaciones , Femenino , Hiperalgesia/etiología , Ratones , Ratones Endogámicos C57BL , Neuralgia/etiología

RESUMEN

BACKGROUND: Ultraviolet B (UVB) radiation exposure promotes sunburn and thereby acute and chronic inflammatory processes, contributing to pain development and maintenance. New therapeutic alternatives are necessary because typical treatments can cause adverse effects. An attractive alternative would be to target the transient receptor potential ankyrin 1 (TRPA1), a calcium-permeable, non-selective cation channel, which is involved in a variety of inflammatory pain models. OBJECTIVE: Evaluate the peripheral participation of TRPA1 using a topical treatment (HC030031 gel formulation; a selective TRPA1 antagonist) in nociception and inflammation caused by a UVB radiation-induced burn model in male mice (25-30 g). METHODS: The mice were anaesthetised, and just the right hind paw was exposed to UVB radiation (0.75 J/cm2). Topical treatments were applied immediately after irradiation and once a day for 8 days. RESULTS: HC030031 gel presented suitable pH and spreadability factor, ensuring its quality and the therapeutic effect. HC030031 0.05 % reversed UVB-induced mechanical and cold allodynia, with maximum inhibition (Imax) of 69 ± 13 % and 100 % (on day 4), respectively. HC030031 0.05 % also reduced the paw edema and MPO activity, with Imax of 77 ± 6 % (on day 5) and 69 ± 28 %, respectively. Likewise, UVB radiation increased the H2O2 levels (a TRPA1 agonist) and the Ca2+ influx in mice spinal cord synaptosomes. UVB radiation-induced Ca2+ influx was reduced by HC030031. CONCLUSION: These findings confirm the activation of the TRPA1 channel by UVB radiation, suggesting that topical TRPA1 antagonists can be a new strategy for the adjuvant treatment of sunburn-associated pain and inflammation.

Asunto(s)

Acetanilidas/administración & dosificación , Inflamación/tratamiento farmacológico , Dolor/tratamiento farmacológico , Purinas/administración & dosificación , Quemadura Solar/tratamiento farmacológico , Canal Catiónico TRPA1/antagonistas & inhibidores , Administración Cutánea , Animales , Calcio/metabolismo , Modelos Animales de Enfermedad , Humanos , Peróxido de Hidrógeno/metabolismo , Inflamación/etiología , Masculino , Ratones , Nocicepción/efectos de los fármacos , Dolor/etiología , Dolor/patología , Piel/inmunología , Piel/patología , Piel/efectos de la radiación , Médula Espinal/citología , Médula Espinal/patología , Quemadura Solar/etiología , Quemadura Solar/patología , Sinaptosomas/metabolismo , Canal Catiónico TRPA1/metabolismo , Rayos Ultravioleta/efectos adversos

RESUMEN

Antineoplastic therapy has been associated with pain syndrome development characterized by acute and chronic pain. The chemotherapeutic agent dacarbazine, used mainly to treat metastatic melanoma, is reported to cause painful symptoms, compromising patient quality of life. Evidence has proposed that transient receptor potential ankyrin 1 (TRPA1) plays a critical role in chemotherapy-induced pain syndrome. Here, we investigated whether dacarbazine causes painful hypersensitivity in naive or melanoma-bearing mice and the involvement of TRPA1 in these models. Mouse dorsal root ganglion (DRG) neurons and human TRPA1-transfected HEK293 (hTRPA1-HEK293) cells were used to evaluate the TRPA1-mediated calcium response evoked by dacarbazine. Mechanical and cold allodynia were evaluated after acute or repeated dacarbazine administration in naive mice or after inoculation of B16-F10 melanoma cells in C57BL/6 mice. TRPA1 involvement was investigated by using pharmacological and genetic tools (selective antagonist or antisense oligonucleotide treatment and Trpa1 knockout mice). Dacarbazine directly activated TRPA1 in hTRPA1-HEK293 cells and mouse DRG neurons and appears to sensitize TRPA1 indirectly by generating oxidative stress products. Moreover, dacarbazine caused mechanical and cold allodynia in naive but not Trpa1 knockout mice. Also, dacarbazine-induced nociception was reduced by the pharmacological TRPA1 blockade (antagonism), antioxidants, and by ablation of TRPA1 expression. TRPA1 pharmacological blockade also reduced dacarbazine-induced nociception in a tumor-associated pain model. Thus, dacarbazine causes nociception by TRPA1 activation, indicating that this receptor may represent a pharmacological target for treating chemotherapy-induced pain syndrome in cancer patients submitted to antineoplastic treatment with dacarbazine.

Asunto(s)

Antineoplásicos Alquilantes/toxicidad , Dacarbazina/toxicidad , Hiperalgesia/inducido químicamente , Melanoma Experimental , Canal Catiónico TRPA1/efectos de los fármacos , Animales , Células HEK293 , Humanos , Hiperalgesia/metabolismo , Ratones , Ratones Endogámicos C57BL , Canal Catiónico TRPA1/metabolismo

RESUMEN

Contact dermatitis is a very common inflammatory reaction in the skin, causing not only aesthetic problems but also loss functionality at work. The molecular mechanisms of contact dermatitis induced by chemical irritants are still unclear. Considering that transient receptor potential channels (TRP) may induce neurogenic inflammation and the exacerbation of inflammatory responses, here we investigated the role of transient receptor potential channel ankyrin type-1 (TRPA1) in skin inflammation evoked by chemical irritants. Ear oedema and nociceptive responses elicited by the topical application of xylene and toluene were measured in Swiss mice, wild type and TRPA1 knockout (Trpa1-/-) C57BL/6 mice. Histological analyses were performed in mice subjected to the ear oedema assay. Topical application of xylene and toluene in the mouse ear induced an edematogenic response (0.113 ±â€¯0.008 mm and 0.067 ±â€¯0.011 mm), compared to vehicle (0.008 ±â€¯0.008 mm), assessed by ear thickness measurements and histological analyses. These responses were prevented by topical pretreatment with a selective TRPA1 antagonist, HC-030031 (% inhibition: xylene 36.8 ±â€¯9.4% and toluene 50.7 ±â€¯11.0%), and by the genetic deletion of TRPA1 ((% inhibition: xylene 66.6 ±â€¯16.7% and toluene 75 ±â€¯0%). In addition, the topical application of xylene and toluene to the mouse paw elicited nociceptive responses, which were significantly reduced by oral treatment with HC-030031 ((% of inhibition: 84.9 ±â€¯1.3% and 27.1 ±â€¯8.0%, respectively); nociceptive responses were almost completely abolished in Trpa1-/-mice. Our data suggest that the activation of TRPA1 could be involved in some of the symptoms of irritant-mediated contact dermatitis, such as oedema, pain and neurogenic inflammation.

Asunto(s)

Piel/efectos de los fármacos , Canal Catiónico TRPA1/metabolismo , Tolueno/farmacología , Xilenos/farmacología , Animales , Edema/inducido químicamente , Edema/genética , Edema/metabolismo , Edema/patología , Técnicas de Inactivación de Genes , Inflamación/inducido químicamente , Inflamación/metabolismo , Ratones , Ratones Endogámicos C57BL , Nocicepción/efectos de los fármacos , Canal Catiónico TRPA1/antagonistas & inhibidores , Canal Catiónico TRPA1/deficiencia , Canal Catiónico TRPA1/genética , Volatilización

RESUMEN

Wound healing can be delayed following colonization and infection with the common bacterium Pseudomonas aeruginosa. While multiple therapies are used for their treatment, these are ineffective, expensive, and labour-intensive. Thus, there is an enormous unmet need for the treatment of infected wounds. Cinnamaldehyde, the major component of cinnamon oil, is well known for its antimicrobial properties. Herein, we investigated the effects of sub-inhibitory concentrations of cinnamaldehyde in the virulence of P. aeruginosa. We also assessed its healing potential in P. aeruginosa-infected mouse skin wounds and the mechanisms involved in this response. Sub-inhibitory concentrations of cinnamaldehyde reduced P. aeruginosa metabolic rate and its ability to form biofilm and to cause haemolysis. Daily topical application of cinnamaldehyde on P. aeruginosa-infected skin wounds reduced tissue bacterial load and promoted faster healing. Lower interleukin-17 (IL-17), vascular endothelial growth factor (VEGF) and nitric oxide levels were detected in cinnamaldehyde-treated wound samples. Blockage of transient receptor potential ankyrin 1, the pharmacological target of cinnamaldehyde, abrogated its healing activity and partially reversed the inhibitory actions of this compound on VEGF and IL-17 generation. We suggest that topical application of sub-inhibitory concentrations of cinnamaldehyde may represent an interesting approach to improve the healing of P. aeruginosa-infected skin wounds.

Asunto(s)

Acroleína/análogos & derivados , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , Piel/microbiología , Cicatrización de Heridas/efectos de los fármacos , Acroleína/uso terapéutico , Animales , Antiinfecciosos/uso terapéutico , Biopelículas/efectos de los fármacos , Modelos Animales de Enfermedad , Femenino , Interleucina-17/metabolismo , Ratones , Infecciones por Pseudomonas/tratamiento farmacológico , Canal Catiónico TRPA1/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo

RESUMEN

There is a major, unmet need for the treatment of cancer pain, and new targets and medicines are required. The transient receptor potential ankyrin 1 (TRPA1), a cation channel expressed by nociceptors, is activated by oxidizing substances to mediate pain-like responses in models of inflammatory and neuropathic pain. As cancer is known to increase oxidative stress, the role of TRPA1 was evaluated in a mouse model of cancer pain. Fourteen days after injection of B16-F10 murine melanoma cells into the plantar region of the right hind paw, C57BL/6 mice exhibited mechanical and thermal allodynia and thigmotaxis behavior. While heat allodynia was partially reduced in TRP vanilloid 1 (TRPV1)-deficient mice, thigmotaxis behavior and mechanical and cold allodynia were absent in TRPA1-deficient mice. Deletion of TRPA1 or TRPV1 did not affect cancer growth. Intrathecal TRPA1 antisense oligonucleotides and two different TRPA1 antagonists (HC-030031 or A967079) transiently attenuated thigmotaxis behavior and mechanical and cold allodynia. A TRPV1 antagonist (capsazepine) attenuated solely heat allodynia. NADPH oxidase activity and hydrogen peroxide levels were increased in hind paw skin 14 days after cancer cell inoculation. The antioxidant, α-lipoic acid, attenuated mechanical and cold allodynia and thigmotaxis behavior, but not heat allodynia. Whereas TRPV1, via an oxidative stress-independent pathway, contributes partially to heat hypersensitivity, oxidative stress-dependent activation of TRPA1 plays a key role in mediating thigmotaxis behavior and mechanical and cold allodynia in a cancer pain model. TRPA1 antagonists might be beneficial in the treatment of cancer pain.

Asunto(s)

Dolor en Cáncer/metabolismo , Melanoma Experimental , Canal Catiónico TRPA1/metabolismo , Animales , Masculino , Ratones , Ratones Endogámicos C57BL

RESUMEN

Acmella oleracea (jambu), is used as ingredient for food and in folk medicine to relief toothache. Jambu edible flowers are rich in alkylamides, mainly spilanthol, which are responsible to evoke chemesthetic sensations. This study aimed to investigate the local effects promoted by the intraplantar injection of the hexanic fraction (HF) rich in alkylamides from jambu flowers and compare to synthetic isobutylalkyl amide (IBA). Swiss male mice were intraplantarly administrated with HF and IBA (0.1-30 µg/20 µL), and the underlying mechanisms associated to the antinociceptive (0.1 µg) and pronociceptive (30 µg) effects were evaluated in chemical and sensorial tests. HF and IBA at 0.1 µg promoted analgesia in neurogenic and inflammatory phases of formalin test, against glutamate-induced nociception and independent of the activation of endogenous opioidergic system and dependent of TRPV1 modulation, whereas only HF reduced both nociception and mast cell degranulation in hindpaw induced by compound 48/80. However, both potentiated the TRPA1-mediated nociception. In contrast, HF and IBA (30 µg)-evoked nociceptive behaviors were reduced by the activation of opioidergic system, by TRPA1 antagonist and TRP nociceptive fibers desensitization. In addition, 30 µg IBA-evoked nociception by activation of TRPV1, and 30 µg HF by mast cell degranulation. Furthermore, on the contrary of IBA, HF elevated both mechanical and thermal paw threshold. Altogether, these results indicate that alkylamides could elicited dual effects, adding new evidences and mechanisms for these opposite actions in different doses. Although further research is needed, we confirmed that alkylamides displays local analgesic and/or anesthetic effects.

Asunto(s)

Amidas/farmacología , Analgésicos/farmacología , Asteraceae/química , Nocicepción/efectos de los fármacos , Dolor/tratamiento farmacológico , Amidas/aislamiento & purificación , Analgésicos/aislamiento & purificación , Animales , Brasil , Flores/química , Masculino , Ratones , Dimensión del Dolor , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPV/metabolismo