Polypose naso-sinusienne : rôle des facteurs inflammatoires dans les dysfonctions épithéliales et perspectives thérapeutiques

The sinonasal polyposis (SNP) is a chronic and common inflammatory disease of the nose and sinuses mucosa (4% of the population). SNP usually begins at around 40 years old. Association with asthma is particularly common (40% of cases). Sometimes SNP is associated with intolerance to aspirin and anti-inflammatory [1]. SNP manifestations are chronic nasal obstruction, smell disorders and invalidant chronic rhinorrhea, sneezing and facial pain. This inflammatory disease is characterized by a rich eosinophilic infiltrate, like asthma, and a remodeling of the nasal epithelium consists of a variable combination of squamous metaplasia, hyperplasia of mucous cells, basal and/or glandular, and thickening of the basement membrane. Changes to the connective tissue are constant: focal fibrosis, mucosal oedema and neovascularization [2]. Different studies showed the involvement of the epithelium in the pathophysiology of SNP, thus constituting a deregulated repair model. Normally after injury mechanisms, there is a repair of epithelium: migration of cells lining the injured area on naked extracellular matrix, cell proliferation, and after a few days, the establishment of junction between cells to obtain a sealed epithelium, and finally a process of differentiation [3]. This repair process is done through the secretion of growth factors by both the injured epithelial cells and the cells of the underlying connective tissue [3]. In the SNP, there is an inability to repair “ad integrum” the epithelium. Causes and mechanisms of these alterations of "tissue repair," are not yet characterized.The nasal epithelium is the first airway defense line with the mucociliary transport. The differentiated epithelium cells and especially the intercellular junctional complexes ensure the protection of epithelium from external agents [3]. This epithelium is submitted to different stresses: (i) inflammatory factors released in large quantities, (ii) mechanical shear stress generated by disturbances of the nasal air flow related the volume of polyps, but also (iii) microbiological and chemical stresses due to airborne contaminants or pathogens. All these attacks will have consequences who could participate to the local inflammation and the development of polyps (i) at the organ level (changing nasal resistances and/or nasal compliance) (ii) at the cellular level (properties of the cytoskeleton, cell interactions within the epithelium, migration and differentiation capabilities, mucociliary cleaning function) and (iii) at the molecular level (characteristics of mucus, ciliary alterations, proinflammatory signal activation). [4]La Polypose nasosinusienne (PNS) est une maladie inflammatoire chronique de la muqueuse du nez et des sinus, fréquente, affectant jusqu'à 4% de la population. La PNS débute généralement vers l’âge de 40 ans et l’association à un asthme est particulièrement fréquente (40% des cas environ) parfois complétée par l’association à une intolérance à l’aspirine et aux AINS [1]. La PNS se manifeste par une obstruction nasale chronique, des troubles de l’odorat et une rhinorrhée chronique invalidante, des éternuements et une pesanteur faciale. Cette maladie inflammatoire avec infiltrat riche en éosinophiles est, à l’instar de l’asthme, caractérisée par un remodelage de l’épithélium nasal constitué de l’association variable d’une métaplasie malpighienne, d’une hyperplasie des cellules à mucus, basales et/ou glandulaire, et d’un épaississement de la membrane basale. Les modifications du tissu conjonctif sont constantes associant fibrose focale, œdème muqueux et néovascularisation [2]. Les différents travaux montrent l’implication importante de l’épithélium dans la physiopathologie de la PNS qui constituerait un modèle de réparation dysrégulée. Normalement après un processus lésionnel, il existe un mécanisme de réparation de l’épithélium: la migration, sur la matrice extracellulaire dénudée, des cellules bordant la zone lésée, puis la prolifération cellulaire, et au bout de quelques jours , l’établissement de la jonctionnalité et de l’étanchéité épithéliale, et enfin un processus de « re »-différenciation [3]. Ce processus de réparation se fait grâce à la sécrétion de facteurs de croissance par les cellules épithéliales lésées et aussi par les cellules du tissu conjonctif sous jacent [3]. Dans la PNS, il existe une incapacité à réparer, l’épithélium ad integrum. Les causes et mécanismes précis de ces altérations de la "réparation tissulaire" ne sont pas encore caractérisées.L’épithélium nasal constitue la première ligne de défense des voies aériennes grâce au transport muco-ciliaire qui suppose un épithélium différencié cohésif, notamment au niveau des complexes jonctionnels intercellulaires qui assurent l’imperméabilité de l’épithélium vis à vis des agents extérieurs [3]. Cet épithélium est soumis à des stress de différentes natures à savoir: (i) inflammatoire à cause des facteurs libérés en grande quantité dans la PNS, (ii) mécanique à cause des contraintes de cisaillement générées par les perturbations de l’écoulement aérien nasal liées au volume des polypes, mais aussi (iii) microbiologiques et chimiques à cause de agents aérocontaminants ou infectieux. L’ensemble de ces agressions vont avoir des conséquences notamment biomécaniques qui pourraient participer à l’autoentretien local de l’inflammation et au développement des polypes : (i) à l'échelle de l’organe (modification des résistances et/ou de la compliance nasales) (ii) à l’échelle cellulaire et tissulaire (propriétés du cytosquelette, interactions cellulaires au sein de l’épithélium, capacités de migration et de différenciation, fonction d’épuration muco-ciliaire) et (iii) sous-jacentes à l’échelle moléculaire (caractéristiques du mucus, altérations des moteurs ciliaires, activations signalétiques pro-inflammatoires)[4]

Naso-sinus polyposis : role of factors inflammatory in epithelial dysfunctions and therapeutic perspectives

La Polypose nasosinusienne (PNS) est une maladie inflammatoire chronique de la muqueuse du nez et des sinus, fréquente, affectant jusqu'à 4% de la population. La PNS débute généralement vers l’âge de 40 ans et l’association à un asthme est particulièrement fréquente (40% des cas environ) parfois complétée par l’association à une intolérance à l’aspirine et aux AINS [1]. La PNS se manifeste par une obstruction nasale chronique, des troubles de l’odorat et une rhinorrhée chronique invalidante, des éternuements et une pesanteur faciale. Cette maladie inflammatoire avec infiltrat riche en éosinophiles est, à l’instar de l’asthme, caractérisée par un remodelage de l’épithélium nasal constitué de l’association variable d’une métaplasie malpighienne, d’une hyperplasie des cellules à mucus, basales et/ou glandulaire, et d’un épaississement de la membrane basale. Les modifications du tissu conjonctif sont constantes associant fibrose focale, œdème muqueux et néovascularisation [2]. Les différents travaux montrent l’implication importante de l’épithélium dans la physiopathologie de la PNS qui constituerait un modèle de réparation dysrégulée. Normalement après un processus lésionnel, il existe un mécanisme de réparation de l’épithélium: la migration, sur la matrice extracellulaire dénudée, des cellules bordant la zone lésée, puis la prolifération cellulaire, et au bout de quelques jours , l’établissement de la jonctionnalité et de l’étanchéité épithéliale, et enfin un processus de « re »-différenciation [3]. Ce processus de réparation se fait grâce à la sécrétion de facteurs de croissance par les cellules épithéliales lésées et aussi par les cellules du tissu conjonctif sous jacent [3]. Dans la PNS, il existe une incapacité à réparer, l’épithélium ad integrum. Les causes et mécanismes précis de ces altérations de la "réparation tissulaire" ne sont pas encore caractérisées.L’épithélium nasal constitue la première ligne de défense des voies aériennes grâce au transport muco-ciliaire qui suppose un épithélium différencié cohésif, notamment au niveau des complexes jonctionnels intercellulaires qui assurent l’imperméabilité de l’épithélium vis à vis des agents extérieurs [3]. Cet épithélium est soumis à des stress de différentes natures à savoir: (i) inflammatoire à cause des facteurs libérés en grande quantité dans la PNS, (ii) mécanique à cause des contraintes de cisaillement générées par les perturbations de l’écoulement aérien nasal liées au volume des polypes, mais aussi (iii) microbiologiques et chimiques à cause de agents aérocontaminants ou infectieux. L’ensemble de ces agressions vont avoir des conséquences notamment biomécaniques qui pourraient participer à l’autoentretien local de l’inflammation et au développement des polypes : (i) à l'échelle de l’organe (modification des résistances et/ou de la compliance nasales) (ii) à l’échelle cellulaire et tissulaire (propriétés du cytosquelette, interactions cellulaires au sein de l’épithélium, capacités de migration et de différenciation, fonction d’épuration muco-ciliaire) et (iii) sous-jacentes à l’échelle moléculaire (caractéristiques du mucus, altérations des moteurs ciliaires, activations signalétiques pro-inflammatoires)[4].The sinonasal polyposis (SNP) is a chronic and common inflammatory disease of the nose and sinuses mucosa (4% of the population). SNP usually begins at around 40 years old. Association with asthma is particularly common (40% of cases). Sometimes SNP is associated with intolerance to aspirin and anti-inflammatory [1]. SNP manifestations are chronic nasal obstruction, smell disorders and invalidant chronic rhinorrhea, sneezing and facial pain. This inflammatory disease is characterized by a rich eosinophilic infiltrate, like asthma, and a remodeling of the nasal epithelium consists of a variable combination of squamous metaplasia, hyperplasia of mucous cells, basal and/or glandular, and thickening of the basement membrane. Changes to the connective tissue are constant: focal fibrosis, mucosal oedema and neovascularization [2]. Different studies showed the involvement of the epithelium in the pathophysiology of SNP, thus constituting a deregulated repair model. Normally after injury mechanisms, there is a repair of epithelium: migration of cells lining the injured area on naked extracellular matrix, cell proliferation, and after a few days, the establishment of junction between cells to obtain a sealed epithelium, and finally a process of differentiation [3]. This repair process is done through the secretion of growth factors by both the injured epithelial cells and the cells of the underlying connective tissue [3]. In the SNP, there is an inability to repair “ad integrum” the epithelium. Causes and mechanisms of these alterations of "tissue repair," are not yet characterized.The nasal epithelium is the first airway defense line with the mucociliary transport. The differentiated epithelium cells and especially the intercellular junctional complexes ensure the protection of epithelium from external agents [3]. This epithelium is submitted to different stresses: (i) inflammatory factors released in large quantities, (ii) mechanical shear stress generated by disturbances of the nasal air flow related the volume of polyps, but also (iii) microbiological and chemical stresses due to airborne contaminants or pathogens. All these attacks will have consequences who could participate to the local inflammation and the development of polyps (i) at the organ level (changing nasal resistances and/or nasal compliance) (ii) at the cellular level (properties of the cytoskeleton, cell interactions within the epithelium, migration and differentiation capabilities, mucociliary cleaning function) and (iii) at the molecular level (characteristics of mucus, ciliary alterations, proinflammatory signal activation). [4

FcRn as a Transporter for Nasal Delivery of Biologics: A Systematic Review

International audienceFcRn plays a major role in regulating immune homeostasis, but it is also able to transport biologics across cellular barriers. The question of whether FcRn could be an efficient transporter of biologics across the nasal epithelial barrier is of particular interest, as it would allow a less invasive strategy for the administration of biologics in comparison to subcutaneous, intramuscular or intravenous administrations, which are often used in clinical practice. A focused systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. It was registered on the international prospective register of systematic reviews PROSPERO, which helped in identifying articles that met the inclusion criteria. Clinical and preclinical studies involving FcRn and the nasal delivery of biologics were screened, and the risk of bias was assessed across studies using the Oral Health Assessment Tool (OHAT). Among the 12 studies finally included in this systematic review (out of the 758 studies screened), 11 demonstrated efficient transcytosis of biologics through the nasal epithelium. Only three studies evaluated the potential toxicity of biologics’ intranasal delivery, and they all showed that it was safe. This systematic review confirmed that FcRn is expressed in the nasal airway and the olfactory epithelium, and that FcRn may play a role in IgG and/or IgG-derived molecule-transcytosis across the airway epithelium. However, additional research is needed to better characterize the pharmacokinetic and pharmacodynamic properties of biologics after their intranasal delivery

Towards the in-vivo automated assessment of nasal cilia mobility

International audienceIntroduction. Cilia motility is an important diagnostic feature for various nasal diseases, both of acquired and genetic origin. So far this assessment has been performed ex-vivo in nasal samples. Sampling is invasive and may damage cilia, and ex-vivo measurements may not always reflect the in-vivo cilia function. In this work we investigated the possibility of assessing cilia motility in vivo in humans with a preliminary study using confocal micro-endoscopy.Materials and methods. We used the high-power laser confocal endoscope developed by Mauna Kea Technology (MKT). This device has a 1µm spatial resolution and a temporal resolution varying between 8 and 90 Hz. Ex-vivo pig trachea samples and human nasal biopsy samples were labelled with fluorescent marker Octadecyl Rhodamine B Chloride (R18). Beating cilia were easily identified allowing the acquisition of 40 videos ready for analysis. Using in-house software that estimates frequencies based on luminance variation in a small window and FFT analysis, we evaluated cilia and compared the beat frequency with ground truth.Results. We validated our estimations on all sequences acquired between 30 and 90Hz. Videos acquired at less than 30Hz did not offer sufficient temporal resolution We only observed occasional errors when the software identified a harmonic oscillation instead of the fundamental frequency

Nasal response to stress test in healthy subjects: an experimental pilot study Short tittle: Nasal response to stress

International audiencePurpose: Stress has been suspected to play a role in rhinitis. The role of stress on nasal patency has been not yet elucidated. The aim was to evaluate the potential effects of stress on nasal patency in healthy subjects.Methods: We conducted a prospective pilot study including 12 healthy subjects. Experimental protocol was divided in three periods (pre-task, task and recovery). In the task period, subjects were exposed to the "Trier Social Stress Test" (TSST), a standardized laboratory stressor. Different parameters including Spielberger State Anxiety Inventory (SSAI) score, visual analogic scale (VAS) of nasal patency feeling, heart rate, acoustic rhinometry measurements have been compared between the three different periods. The study population was divided into two groups according to the Spielberger Trait Anxiety Inventory (STAI) score: A "non anxious" group and a "weakly anxious" group.Results: Seven subjects were in the "non anxious" group and five in the "weakly anxious" group. TSST significantly increased heart rate in all volunteers. SSAI score was significantly increased (p = 0.04) after the task period (36.6 ± 11.3) when compared to the SSAI score in pre-task period (31.9 ± 12.6). VAS score of nasal patency feeling significantly decreased from pre-task to task and recovery periods. Mean minimal cross-sectional areas and mean volumes of the nasal cavities were not significantly different between the three periods, except in "weakly anxious" group, but the small number of subjects does not allow to draw a definite conclusion.Conclusion: We observed that stress influenced the feeling of nasal patency in healthy subjects. However, the objective effects of stress on nasal geometry were globally non-significant except in "weakly anxious" group. This latter result of our pilot study needs to be confirmed in a larger cohort

Oncostatin M Contributes to Airway Epithelial Cell Dysfunction in Chronic Rhinosinusitis with Nasal Polyps

International audienceChronic rhinosinusitis with nasal polyps (CRSwNP) is a typical type-2 inflammation involving several cytokines and is associated with epithelial cell dysfunction. Oncostatin M (OSM) (belonging to the interleukin(IL)-6 family) could be a key driver of epithelial barrier dysfunction. Therefore, we investigated the presence of OSM and IL-6 and the expression pattern of tight junctions (TJs) in the nasal tissue of CRSwNP patients and controls using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and Western blotting. Then, their potential role in the epithelial barrier was evaluated in vitro in 27 different primary cultures of human nasal epithelial cells (HNECs) by measuring TJ expression and transepithelial electric resistance (TEER) with or without OSM or IL-6 (1, 10, and 100 ng/mL). The effect on ciliary beating efficiency was evaluated by high-speed videomicroscopy and on repair mechanisms with a wound healing model with or without OSM. OSM and IL-6 were both overexpressed, and TJ (ZO-1 and occludin) expression was decreased in the nasal polyps compared to the control mucosa. OSM (100 ng/mL) but not IL-6 induced a significant decrease in TJ expression, TEER, and ciliary beating efficiency in HNECs. After 24 h, the wound repair rate was significantly higher in OSM-stimulated HNECs at 100 ng/mL. These results suggest that OSM could become a new target for monoclonal antibodies

FcRn-Dependent Transcytosis of Monoclonal Antibody in Human Nasal Epithelial Cells In Vitro: A Prerequisite for a New Delivery Route for Therapy?

Monoclonal antibodies (mAbs) are promising therapies to treat airway chronic inflammatory disease (asthma or nasal polyps). To date, no study has specifically assessed, in vitro, the potential function of neonatal Fc receptor (FcRn) in IgG transcytosis through the human nasal airway epithelium. The objective of this study was to report the in vitro expression and function of FcRn in nasal human epithelium. FcRn expression was studied in an air–liquid interface (ALI) primary culture model of human nasal epithelial cells (HNEC) from polyps. FcRn expression was characterized by quantitative RT-PCR, western blot, and immunolabeling. The ability of HNECs to support mAb transcytosis via FcRn was assessed by transcytosis assay. This study demonstrates the expression of FcRn mRNA and protein in HNEC. We report a high expression of FcRn in the cytosol of ciliated, mucus, and basal cells by immunohistochemistry with a higher level of FcRn proteins in differentiated HNEC. We also proved in vitro transepithelial delivery of an IgG1 therapeutic mAb with a dose–response curve. This is the first time that FcRn expression and mAb transcytosis has been shown in a model of human nasal respiratory epithelium in vitro. This study is a prerequisite for FcRn-dependent nasal administration of mAbs

Pathogenesis of chronic rhinosinusitis with nasal polyps: role of IL-6 in airway epithelial cell dysfunction

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Dupilumab prevents nasal epithelial function alteration by IL‐4 in vitro: Evidence for its efficacy

International audienceBackground:Chronic rhinosinusitis with nasal polyp (CRSwNP) is a typical type 2 inflammation involving interleukin (IL)‐4 and IL‐13. Dupilumab is a fully human monoclonal antibody targeting IL‐4 receptor α subunit, thereby blocking signaling by both cytokines. Our hypothesis was that IL‐4 and IL‐13, by inducing a severe epithelial dysregulation, are involved in CRSwNP pathogenesis. This study aimed to evaluate the in vitro direct effect of IL‐4, IL‐13, and dupilumab on nasal epithelial functions.Methods:Nasal polyps and control mucosa from 28 patients, as well as human nasal epithelial cells (HNEC) from 35 patients with CRSwNP were used. Three major epithelial functions were investigated: the epithelial barrier function (characterized by transepithelial electrical resistance measurements and tight junction protein expression), the ciliary motion (characterized by the ciliary beating efficiency index), and wound healing (characterized by the wound repair rate) under various stimulations (IL‐4, IL‐13, and dupilumab). The main outcome was a significant change in epithelial functions following exposure to IL‐4, IL‐13, and dupilumab for 48 h in the basal media.Results:IL‐4 (1, 10, and 100 ng/mL) but not IL‐13 induced a significant decrease in occludin and zonula‐occludens protein expression, ciliary beating efficiency, and wound repair rate in HNEC. Dupilumab (0.04 mg/mL) had no effect on HNEC and specifically restored all epithelial functions altered when cells were exposed to a 48‐h IL‐4 stimulation.Conclusion:Dupilumab, in vitro, restored epithelial integrity by counteracting the effect of IL‐4 on the epithelial barrier (increased epithelial permeability, decreased ciliary beating efficiency, and decreased wound repair rate)