9 research outputs found
Study on neurons and keratinocytes of molecular and cellular mechanisms involved in ciguatera fish poisoning pruritus
La ciguatĂ©ra est une forme dâintoxication faisant suite Ă lâingestion de poissons contaminĂ©s par des toxines appelĂ©es « ciguatoxines ». Cette intoxication endĂ©mique des rĂ©gions tropicales est un problĂšme Ă©conomique et de santĂ© non nĂ©gligeable qui tend Ă prendre de plus en plus dâampleur. Lâessor du tourisme, le rĂ©chauffement climatique et la hausse des exportations internationales de poissons tropicaux favorisent lâexpansion de la ciguatĂ©ra aux parties du globe au climat tempĂ©rĂ©, jusquâalors peu concernĂ©es par cette maladie. Les enjeux thĂ©rapeutiques et Ă©conomiques de la ciguatĂ©ra sont de taille puisquâil nâexiste aucun moyen rapide et fiable de dĂ©tecter un poisson contaminĂ© et quâaucun traitement efficace permettant sa prise en charge nâa actuellement Ă©tĂ© Ă©tabli.Le prurit, terme mĂ©dical dĂ©signant les dĂ©mangeaisons est un symptĂŽme notamment associĂ© aux maladies de peau qui impacte grandement la qualitĂ© de vie des patients qui en souffrent.Ces derniĂšres dĂ©cennies, de nombreuses Ă©tudes scientifiques ont permis de mieux comprendre sa physiopathologie. Le prurit est un symptĂŽme frĂ©quemment observĂ© chez les personnes atteintes de ciguatĂ©ra, dâoĂč lâappellation « la Gratte », souvent employĂ©e pour faire rĂ©fĂ©rence Ă la pathologie.Dans le but dâĂ©tudier les mĂ©canismes cellulaires Ă lâorigine du prurit et des autres troubles sensoriels cutanĂ©s survenant lors de la ciguatĂ©ra, nous avons Ă©tudiĂ© lâeffet des ciguatoxines sur un modĂšle in vitro de neurones sensoriels cocultivĂ©s avec des kĂ©ratinocytes. Nous avons mis en Ă©vidence la libĂ©ration dans le surnageant des neuropeptides de l'inflammation neurogĂšne, SP et CGRP. L'effet d'antagonistes sĂ©lectionnĂ©s a Ă©tĂ© testĂ© afin mettre en Ă©vidence les mĂ©diateurs impliquĂ©s dans la libĂ©ration de neuropeptides. Par ailleurs, la signalisation cellulaire sous-jacente de cette sĂ©crĂ©tion de neuropeptides a Ă©tĂ© Ă©tudiĂ©e par des expĂ©riences dâimagerie calcique rĂ©alisĂ©es sur neurones et kĂ©ratinocytes.Les rĂ©sultats obtenus valident notre coculture en tant que modĂšle de choix pour lâĂ©tude in vitro des mĂ©canismes cellulaires, et plus gĂ©nĂ©ralement, dans les troubles neurocutanĂ©s impliquĂ©s dans le prurit ciguatĂ©rique. Parmi les antagonistes testĂ©s, une molĂ©cule sâest avĂ©rĂ©e particuliĂšrement intĂ©ressante pour inhiber les effets constatĂ©s de la toxine. Ces rĂ©sultats originaux, obtenus avec lâantagoniste dâun mĂ©diateur du prurit, prĂ©sentent une perspective thĂ©rapeutique nouvelle et prometteuse, pour rĂ©pondre Ă un enjeu de santĂ© publique futur.Ciguatera fish poisoning (CFP) is a seafood poisoning occurring after contaminated fish fleshes ingestion containing toxins called « ciguatoxines » (CTXs). This illness, originating from tropical and subtropical areas, is an economic and health problems which becomes substantial in relation to international tropical fishes export and tourism development, as well as global warming rise. Those factors contribute to CFP sprouting in non-endemic temperate climate regions which were not until then concerned by CFP. Economic and health stakes of CFP are important since no reliable and ready-to-use detection system for CTXs in fishes have been developed, along with no relevant cure has been established to treat CFP.Pruritus, medical term refer to itch, is a clinical sign usually associated to skin diseases which strongly alter patientsâ quality of life. Last decades, several studies allowed to better understand pruritus pathophysiology. Interestingly, people suffering from CFP frequently present pruritus, hence designation âLa Gratteâ or âLa Gratel (le)â employed in endemic areas.The aim of these works was to study cellular and molecular mechanisms of CTXs at the root of neurological cutaneous troubles occurring in CFP. Here, we evaluated CTXs effects on in vitro model composed of sensory neurons cocultived with primary keratinocytes, quantifying neuropeptides known to be involved in pruritus. Compiling knowledges about CFP and pruritus pathophysiology, some antagonists were tested to neutralize CTXs-mediated neuropeptide release. To deal with signaling pathways in depth of neuropeptide exocytosis induced by CTXs, mechanism known to be accurately regulated by calcium homeostasis, calcium imaging experiments were performed.Results obtained in this project confirm the use of such a model to elucidate cellular mechanism of CFP pruritus, but also constitute an alternative in vitro tool to study chemicals inducing abnormal cutaneous senses. Among antagonists tested, one stands out from the crowd and was proved to be effective to inhibit CTXs-evoked effects studied. Those originals results, collected with antagonist of pruritus mediator, show new and promiscuous therapeutic prospects for future health concern
Etude sur neurones sensoriels et kératinocytes des mécanismes cellulaires et moléculaires impliqués dans le prurit de la ciguatéra
Ciguatera fish poisoning (CFP) is a seafood poisoning occurring after contaminated fish fleshes ingestion containing toxins called « ciguatoxines » (CTXs). This illness, originating from tropical and subtropical areas, is an economic and health problems which becomes substantial in relation to international tropical fishes export and tourism development, as well as global warming rise. Those factors contribute to CFP sprouting in non-endemic temperate climate regions which were not until then concerned by CFP. Economic and health stakes of CFP are important since no reliable and ready-to-use detection system for CTXs in fishes have been developed, along with no relevant cure has been established to treat CFP.Pruritus, medical term refer to itch, is a clinical sign usually associated to skin diseases which strongly alter patientsâ quality of life. Last decades, several studies allowed to better understand pruritus pathophysiology. Interestingly, people suffering from CFP frequently present pruritus, hence designation âLa Gratteâ or âLa Gratel (le)â employed in endemic areas.The aim of these works was to study cellular and molecular mechanisms of CTXs at the root of neurological cutaneous troubles occurring in CFP. Here, we evaluated CTXs effects on in vitro model composed of sensory neurons cocultived with primary keratinocytes, quantifying neuropeptides known to be involved in pruritus. Compiling knowledges about CFP and pruritus pathophysiology, some antagonists were tested to neutralize CTXs-mediated neuropeptide release. To deal with signaling pathways in depth of neuropeptide exocytosis induced by CTXs, mechanism known to be accurately regulated by calcium homeostasis, calcium imaging experiments were performed.Results obtained in this project confirm the use of such a model to elucidate cellular mechanism of CFP pruritus, but also constitute an alternative in vitro tool to study chemicals inducing abnormal cutaneous senses. Among antagonists tested, one stands out from the crowd and was proved to be effective to inhibit CTXs-evoked effects studied. Those originals results, collected with antagonist of pruritus mediator, show new and promiscuous therapeutic prospects for future health concern.La ciguatĂ©ra est une forme dâintoxication faisant suite Ă lâingestion de poissons contaminĂ©s par des toxines appelĂ©es « ciguatoxines ». Cette intoxication endĂ©mique des rĂ©gions tropicales est un problĂšme Ă©conomique et de santĂ© non nĂ©gligeable qui tend Ă prendre de plus en plus dâampleur. Lâessor du tourisme, le rĂ©chauffement climatique et la hausse des exportations internationales de poissons tropicaux favorisent lâexpansion de la ciguatĂ©ra aux parties du globe au climat tempĂ©rĂ©, jusquâalors peu concernĂ©es par cette maladie. Les enjeux thĂ©rapeutiques et Ă©conomiques de la ciguatĂ©ra sont de taille puisquâil nâexiste aucun moyen rapide et fiable de dĂ©tecter un poisson contaminĂ© et quâaucun traitement efficace permettant sa prise en charge nâa actuellement Ă©tĂ© Ă©tabli.Le prurit, terme mĂ©dical dĂ©signant les dĂ©mangeaisons est un symptĂŽme notamment associĂ© aux maladies de peau qui impacte grandement la qualitĂ© de vie des patients qui en souffrent.Ces derniĂšres dĂ©cennies, de nombreuses Ă©tudes scientifiques ont permis de mieux comprendre sa physiopathologie. Le prurit est un symptĂŽme frĂ©quemment observĂ© chez les personnes atteintes de ciguatĂ©ra, dâoĂč lâappellation « la Gratte », souvent employĂ©e pour faire rĂ©fĂ©rence Ă la pathologie.Dans le but dâĂ©tudier les mĂ©canismes cellulaires Ă lâorigine du prurit et des autres troubles sensoriels cutanĂ©s survenant lors de la ciguatĂ©ra, nous avons Ă©tudiĂ© lâeffet des ciguatoxines sur un modĂšle in vitro de neurones sensoriels cocultivĂ©s avec des kĂ©ratinocytes. Nous avons mis en Ă©vidence la libĂ©ration dans le surnageant des neuropeptides de l'inflammation neurogĂšne, SP et CGRP. L'effet d'antagonistes sĂ©lectionnĂ©s a Ă©tĂ© testĂ© afin mettre en Ă©vidence les mĂ©diateurs impliquĂ©s dans la libĂ©ration de neuropeptides. Par ailleurs, la signalisation cellulaire sous-jacente de cette sĂ©crĂ©tion de neuropeptides a Ă©tĂ© Ă©tudiĂ©e par des expĂ©riences dâimagerie calcique rĂ©alisĂ©es sur neurones et kĂ©ratinocytes.Les rĂ©sultats obtenus valident notre coculture en tant que modĂšle de choix pour lâĂ©tude in vitro des mĂ©canismes cellulaires, et plus gĂ©nĂ©ralement, dans les troubles neurocutanĂ©s impliquĂ©s dans le prurit ciguatĂ©rique. Parmi les antagonistes testĂ©s, une molĂ©cule sâest avĂ©rĂ©e particuliĂšrement intĂ©ressante pour inhiber les effets constatĂ©s de la toxine. Ces rĂ©sultats originaux, obtenus avec lâantagoniste dâun mĂ©diateur du prurit, prĂ©sentent une perspective thĂ©rapeutique nouvelle et prometteuse, pour rĂ©pondre Ă un enjeu de santĂ© publique futur
Self-maintenance of neurogenic inflammation contributes to a vicious cycle in skin
International audienc
Release of neuropeptides from a neuro-cutaneous co-culture model: a novel in vitro model for studying sensory effects of ciguatoxins
Ciguatoxins are the major toxins responsible for ciguatera fish poisoning, a disease dominated by muco-cutaneous sensory disorders including paresthesiae, cold dysesthesia and pruritus. While the ciguatoxins are well known to target voltage-gated sodium channels (VGSCs), the ensuing molecular mechanisms underlying these sensory disorders remain poorly understood. In this study, we propose a primary sensory neuron-keratinocyte co-culture as an appropriate model to study the neuro-cutaneous effects of ciguatoxins. Using this model, we show for the first time that nanomolar concentrations of Pacific ciguatoxin-2 (P-CTX-2) induced a VGSC-dependent release of substance P (SP) and calcitonin gene-related peptide (CGRP). As these neuropeptides are known mediators of pain and itch sensations, the ciguatoxin-induced sensory disturbances in ciguatera fish poisoning may involve the release of these neuropeptides. We further determined time- and P-CTX-2 concentration-dependence of the release of SP and CGRP from the co-culture model. Moreover, we highlighted the influence of extracellular calcium on the release of neuropeptides elicited by P-CTX-2. These findings underline the usefulness of this novel in vitro model for studying the cellular and molecular mechanisms of the neuro-cutaneous effects of ciguatoxins, which may assist with identifying potential therapeutics for ciguatera fish poisoning
A new tool to test active ingredient using lactic acid in vitro, a help to understand cellular mechanism involved in stinging test: An example using a bacterial polysaccharide (Fucogel Âź )
International audienc
Major Role for TRPV1 and InsP3R in PAR2-Elicited Inflammatory Mediator Production in Differentiated Human Keratinocytes
International audienc
Keratinocytes Communicate with Sensory Neurons via Synapticâlike Contacts
International audienc