- Email: [email protected]
Nlrp6 inflammasome in lung epithelium repair, inflammation and fibrosis after bleomycin-induced pulmonary injury
672 against AM-mediated P.a killing. LasB does not influence inflammatory influx but acts through down-regulating IL-1 production ex vivo and in vivo. We have shown previously [2] that IL-1 is instrumental in PAO1 killing and we are currently investigating signalling pathway linking LasB to IL-1 production. Références [1] Eur J Immunol 2007;37:3030—9. [2] PNAS 2012;5:1619—24. http://dx.doi.org/10.1016/j.rmr.2014.04.063
variety of tissues/fluids were collected from these animals to begin a tissue/secretion samples bank for future studies. Conclusions.— The cause of death of the CFTR KO piglets is not currently known, and we are still improving the post-operative cares. As the incidence of meconium ileus is of 100% in CFTR-/- animals, the diagnosis could be done faster by CT scan (and confirmed later by the PCR). By reducing the birth-to-surgery time, we hope to improve the survival. The tissues that we have collected provide an original opportunity to investigate initiating mechanisms of disease, with CF and non-CF comparisons, but without confounders.
64
1 Equal
Preliminary studies for the establishment of a model of CFTR-deficient piglets
2 Equal
A. Guillon a,∗,1 , C. Barc b,1 , C. Chevaleyre c,1 , M. Riou b , J. Pezant b , M. Olivier c , J. Coigné d , E. Venturi e , H. Lardy f , T. Villemagne f , J. Moënne-Loccoz g , D. Brea a , N. Winter c , S. Mélo c , F. Gauthier a , B. Schwartz b , A. Bähr h , E. Wolf h , F. Meurens c,2 , M. Berri c,2 , R. Ramphal a,2 , S. Attucci a,2 , D. Buzoni-Gatel c,2 , M. Si-Tahar a,2 , P. Sarradin b,2 a Inserm, Centre d’Étude des Pathologies Respiratoires, UMR 1100/EA6305, Tours, France b INRA, PFIE, Nouzilly, France c INRA, ISP, Nouzilly, France d INRA, CIRE, Nouzilly, France e INRA, UEPAO, Nouzilly, France f CHU Clocheville, Service de Chirurgie Pédiatrique, Tours, France g CHU Bretonneau, Service de Réanimation Médicale, Tours, France h Gene Center, LMU, Munich, Germany ∗ Corresponding author. Adresse e-mail : [email protected] (A. Guillon) Keywords: Infection; Inflammation Introduction.— Cystic fibrosis (CF) is a life-shortening disease caused by mutations in the Cystic Fibrosis Trans membrane conductance Regulator (CFTR) gene. The lack of an animal model with lung abnormalities similar to those typically found in human CF has hindered studies of pathogenesis, treatment and prevention of infection in this disease. We aim to establish in Tours a CF pig model with a mutant CFTR that was engineered by our collaborator E. Wolf (Gene Center, LMU, Munich, Germany). Methods.— Pigs with mutant CFTR are bred in Tours, France. One difficulty with this CF pig model is a 100% prevalence of meconium ileus leading to death in the first days of birth. We therefore organized a multidisciplinary team at Tours (Inserm-INRA-CHU of Tours) and produced animals by mating CFTR+/- male and female pigs. Newborn CF piglets were anesthetized for surgical procedure after the diagnosis of CFTR-/- was confirmed by PCR. Prior to surgery, an attempt to diagnose the intestinal obstruction by abdominal ultrasonography and computerized tomography (CT) scan was made. Results.— Eleven CFTR-/- piglets (1.2 ± 0.2 kg) were born from Nov 2012 to Apr 2013. Nine of them were anesthetized for exploratory laparotomy; the two others were stillborn or euthanized (moribund). The mean birth-to-surgery time was 12.9 ± 2.8 h and included the time for PCR analysis. All CFTR-/- piglets developed meconium ileus, with distended intestine proximal to the obstruction and had poorly developed colon (microcolon). Four piglets had non-viable lesions (intestinal perforation). Ileostomies (intestinal by-pass) were performed for the setting-up of the anesthesia and surgical procedures, but the piglets were eventually euthanized. Finally, five piglets were waking up with an ileostomy. In addition to post-operative care, maternal-milk bottle-feeding has been started six hours after the surgery, with feces passing through the ileostomy. They survived one to three days. We failed to identify the meconium ileus by ultrasonography, but succeed by CT scan. A wide
contribution. contribution.
http://dx.doi.org/10.1016/j.rmr.2014.04.064 65
Nlrp6 inflammasome in lung epithelium repair, inflammation and fibrosis after bleomycin-induced pulmonary injury A. Gombault a,∗ , B. Villeret a , F. Savigny a , L. Baron a , N. Guillou a , M. Chamaillard b , I. Couillin a a University of Orleans and CNRS, INEM-UMR7355, Orleans, France b Institut Pasteur Inserm U1019, CNRS UMR 8204, Lille, France ∗ Corresponding author. Adresse e-mail : [email protected] (A. Gombault) Keywords: Infection; Inflammation Introduction.— The NLRs (nucleotide-binding oligomerization domain-like receptors) are involved in the activation of caspase-1 through formation of multimeric complexes called inflammasomes which lead to maturation of pro-inflammatory cytokines IL-1 and IL-18. Several NLRs such as Nlrp1, Nlrp2, Nlrp3, Nlrc4 and more recently Nlrp6 were shown to form inflammasome complexes. However, the activators and the physiological functions of the Nlrp6 inflammasome are not known. In mouse it has been shown that Nlrp6 is highly expressed in intestine and lung and importantly in epithelial cells and myofibroblasts but not in hematopoietic cells in the intestine. Moreover, using Nlrp6 deficient mice, Nlrp6 was shown to play a role in intestinal epithelium repair and control of inflammation in a dextran sulfate sodium colitis model. It allows to recovery intestinal epithelial damage and limit tumorigenic potential. We investigated here the implication of Nlrp6 inflammasome in remodeling and lung epithelium recovery upon lung injury and in pulmonary inflammation and fibrosis induced by bleomycin (BLM). Methods.— Wild-type mice (B6) or Nlpr6 deficient mice (Nlp6 KO) were instillated with BLM during 1 or 14 days. Broncho-alveolar lavage fluids (BALF) were done and cell infiltration was determined. Total protein content and different pro-inflammatory or profibrotic cytokines were measured in BALF and lung homogenates. Results.— Our first results 1 day after instillation showed reduced early total cells and neutrophils recruitments into the BALF upon BLM-induced injury in Nlrp6 KO mice indicating that Nlrp6 is involved in establishment of acute inflammation as observed in colon. Moreover total protein content in BALF is greatly increased in Nlrp6 KO mice suggesting a role for Nlrp6 in alveolar epithelial barrier integrity as shown in colon. In addition, late inflammation and level of the profibrotic factor TGF- were attenuated 14 days after BLM instillation in absence of Nlrp6. Conclusion.— Our first results suggest that Nlrp6 plays a key role in the development of pulmonary inflammation, repair and fibrosis after lung injury-induced by bleomycin. To confirm these results, Nlrp6 expression in hematopoietic and resident pulmonary cells will be tested at steady state and after challenge with bleomycin.
Recherche en pneumologie http://dx.doi.org/10.1016/j.rmr.2014.04.065 66
Type II transmembrane serine protease Matriptase is a mediator of pulmonary fibrosis O. Bardou a,∗ , C. Francois a , N. Carlier a , H. Mal b , B. Crestani a,b , K. Borensztajn a a U700, Inserm, Paris, France b Hôpital Bichat, AP—HP, Paris, France ∗ Corresponding author. Adresse e-mail : [email protected] (O. Bardou) Keywords: Infection; Inflammation Introduction.— Idiopathic pulmonary fibrosis (IPF) is a devastating lung disorder which remains refractory to therapies. Recently, type II transmembrane serine proteases have emerged as key actors in pathophysiology, by proteolysis of cell surface receptors and/or cell environment, thereby orchestrating cell crosstalks. Among them, deregulation of the matriptase contributes to various proliferative disorders. Hence, we sought to investigate the role of matriptase in pulmonary fibrosis. Methods.— Matriptase expression and activity were analyzed in human lung material from controls and IPF patients. Human fibroblasts were stimulated with recombinant matriptase and the activation of key signaling pathways involved in IPF was analyzed. Using the murine model of bleomycin-induced pulmonary fibrosis, mice were administrated for 14 days with 0 or 0.5 mg of camostat mesylate, a matriptase inhibitor, and the markers of tissue fibrosis in lung homogenate, and inflammatory cell influx in the bronchoalveolar lavage fluid (BALF) of the animals were assessed. Results.— We show that matriptase is upregulated in the lung and BALF of IPF patients compared to controls. In fibroblasts, matriptase induced the activation of p42/44, Akt, and Smad2/3 pathways. Finally, camostat administration in bleomycin-treated mice led to a significant decrease in mortality. Fibronectin, collagen and ␣SMA expression, and inflammatory cell influx, were increased in bleomycin-treated mice compared to saline-treated animals. In the camostat-treated mice group, these markers of pulmonary fibrosis were decreased. Conclusion.— Taken together, matriptase seems instrumental in pulmonary fibrosis, and camostat mesylate could be a promising target for the treatment of IPF. http://dx.doi.org/10.1016/j.rmr.2014.04.066 67
Le canal calcique TRPV4 : une cible potentielle pour contrôler l’inflammation respiratoire E. Dalloneau a,b,∗ , C. Henry a,b , D. Brea a,b , R. Aimar a,b , T. Baranek a,b , M. Potier-Cartereau b,c , F. Esnard a,b , C. Vandier b,c , M. Si-Tahar a,b a Centre d’étude des pathologies respiratoires, Inserm U1100/EA6305, Tours, France b Université Franc ¸ois-Rabelais, Tours, France c Inserm U1069, Tours, France ∗ Auteur correspondant. Adresse e-mail : [email protected] (E. Dalloneau) Mots clés : Infection ; Inflammation Introduction.— La bronchopneumopathie chronique obstructive et la mucoviscidose sont des pathologies respiratoires inflammatoires qui représentent des problèmes majeurs de santé publique. Les mécanismes sous-jacents impliqueraient une réaction inflammatoire chronique, avec des conséquences souvent fatales. Cette
673 réponse inflammatoire représente donc une cible importante pour la mise au point de nouveaux traitements. Ainsi, notre étude vise à déterminer le rôle du transient receptor potential vanilloid 4 (TRPV4) dans l’inflammation respiratoire à l’aide de modèles in vitro et in vivo. Méthodes.— L’expression de TRPV4 a été évaluée dans plusieurs lignées et cellules épithéliales pulmonaires primaires humaines, à l’état basal et en présence d’un activateur spécifique dérivé de l’acide arachidonique : le 4␣PDD. L’analyse fonctionnelle de TRPV4 dans ces cellules a été analysée en termes de sécrétion d’IL-6 et IL-8 et par la mobilisation calcique intracellulaire. In vivo, l’effet de l’administration intranasale de 4␣PDD a été comparé dans des souris normales et CFTR-/− . Résultats.— TRPV4 est exprimé de manière constitutive dans les cellules épithéliales pulmonaires humaines. La stimulation de ces cellules par le 4␣PDD induit une entrée de calcium intracellulaire et une sécrétion de cytokines pro-inflammatoires. La co-stimulation de ces cellules avec le LPS bactérien et le 4␣PDD produit un effet synergique sur la production d’IL-6 et d’IL-8. Par ailleurs, l’instillation de 4␣PDD chez la souris induit une sécrétion de médiateurs inflammatoires ainsi qu’un recrutement de neutrophiles dans les poumons. Le nombre de neutrophiles recrutés est de plus significativement plus élevé chez la souris CFTR-/− . Conclusions.— Ces travaux démontrent un rôle du TRPV4 dans la réponse inflammatoire au niveau pulmonaire. Du point de vue thérapeutique, ces données pourraient soutenir le développement de molécules ciblant l’activité du TRPV4, capables de réduire l’inflammation excessive associée à des maladies telles que la BPCO ou la mucoviscidose. http://dx.doi.org/10.1016/j.rmr.2014.04.067 68
Un nouveau rôle potentiel de Human Airway Trypsin-like protease dans la fibrose pulmonaire N. Carlier a,∗ , C. Francois a , O. Bardou a , J. Marchal-Somme a , B. Crestani a,b , K. Borensztajn a a Inserm U700, université Paris 7, Paris, France b Service de pneumologie A, hôpital Bichat, AP—HP, Paris, France ∗ Auteur correspondant. Adresse e-mail : [email protected] (N. Carlier) Mot clé : Inflammation Introduction.— La fibrose pulmonaire idiopathique (FPI) est une maladie d’évolution progressive, caractérisée par une perte des cellules épithéliales alvéolaires, une différenciation aberrante des fibroblastes en myofibroblastes, et une synthèse de matrice extracellulaire dérégulée. Human Airway Trypsin-like protease (HAT) appartient à la nouvelle famille des type II transmembrane serine proteases. Un de ses substrats connus est Protease Activated Receptor-2 (PAR-2), un récepteur qui joue un rôle important dans les mécanismes de fibrogénèse pulmonaire [1]. Dans cette étude, nous avons examiné le rôle de HAT dans la fibrogenèse pulmonaire. Méthodes.— L’expression de HAT a été analysée par Western Blot dans de l’homogénat pulmonaire, ainsi que sur des fibroblastes pulmonaires humains issus de sujets contrôles ou avec FPI. Nous avons également analysé la modulation de l’expression d’HAT dans le modèle murin de fibrose pulmonaire induite par la bléomycine. Nous avons ensuite observé in vitro si HAT est capable d’induire une signalisation intracellulaire sur les fibroblastes pulmonaires humains, puis les conséquences fonctionnelles sur leur différenciation en myofibroblastes, et la production de matrice extracellulaire. Enfin, nous avons déterminé les effets de HAT sur la survie de deux lignées de cellules épithéliales pulmonaires. Résultats.— L’expression de HAT est significativement augmentée dans les poumons de patients atteints de FPI. Elle est égale-
variety of tissues/fluids were collected from these animals to begin a tissue/secretion samples bank for future studies. Conclusions.— The cause of death of the CFTR KO piglets is not currently known, and we are still improving the post-operative cares. As the incidence of meconium ileus is of 100% in CFTR-/- animals, the diagnosis could be done faster by CT scan (and confirmed later by the PCR). By reducing the birth-to-surgery time, we hope to improve the survival. The tissues that we have collected provide an original opportunity to investigate initiating mechanisms of disease, with CF and non-CF comparisons, but without confounders.
64
1 Equal
Preliminary studies for the establishment of a model of CFTR-deficient piglets
2 Equal
A. Guillon a,∗,1 , C. Barc b,1 , C. Chevaleyre c,1 , M. Riou b , J. Pezant b , M. Olivier c , J. Coigné d , E. Venturi e , H. Lardy f , T. Villemagne f , J. Moënne-Loccoz g , D. Brea a , N. Winter c , S. Mélo c , F. Gauthier a , B. Schwartz b , A. Bähr h , E. Wolf h , F. Meurens c,2 , M. Berri c,2 , R. Ramphal a,2 , S. Attucci a,2 , D. Buzoni-Gatel c,2 , M. Si-Tahar a,2 , P. Sarradin b,2 a Inserm, Centre d’Étude des Pathologies Respiratoires, UMR 1100/EA6305, Tours, France b INRA, PFIE, Nouzilly, France c INRA, ISP, Nouzilly, France d INRA, CIRE, Nouzilly, France e INRA, UEPAO, Nouzilly, France f CHU Clocheville, Service de Chirurgie Pédiatrique, Tours, France g CHU Bretonneau, Service de Réanimation Médicale, Tours, France h Gene Center, LMU, Munich, Germany ∗ Corresponding author. Adresse e-mail : [email protected] (A. Guillon) Keywords: Infection; Inflammation Introduction.— Cystic fibrosis (CF) is a life-shortening disease caused by mutations in the Cystic Fibrosis Trans membrane conductance Regulator (CFTR) gene. The lack of an animal model with lung abnormalities similar to those typically found in human CF has hindered studies of pathogenesis, treatment and prevention of infection in this disease. We aim to establish in Tours a CF pig model with a mutant CFTR that was engineered by our collaborator E. Wolf (Gene Center, LMU, Munich, Germany). Methods.— Pigs with mutant CFTR are bred in Tours, France. One difficulty with this CF pig model is a 100% prevalence of meconium ileus leading to death in the first days of birth. We therefore organized a multidisciplinary team at Tours (Inserm-INRA-CHU of Tours) and produced animals by mating CFTR+/- male and female pigs. Newborn CF piglets were anesthetized for surgical procedure after the diagnosis of CFTR-/- was confirmed by PCR. Prior to surgery, an attempt to diagnose the intestinal obstruction by abdominal ultrasonography and computerized tomography (CT) scan was made. Results.— Eleven CFTR-/- piglets (1.2 ± 0.2 kg) were born from Nov 2012 to Apr 2013. Nine of them were anesthetized for exploratory laparotomy; the two others were stillborn or euthanized (moribund). The mean birth-to-surgery time was 12.9 ± 2.8 h and included the time for PCR analysis. All CFTR-/- piglets developed meconium ileus, with distended intestine proximal to the obstruction and had poorly developed colon (microcolon). Four piglets had non-viable lesions (intestinal perforation). Ileostomies (intestinal by-pass) were performed for the setting-up of the anesthesia and surgical procedures, but the piglets were eventually euthanized. Finally, five piglets were waking up with an ileostomy. In addition to post-operative care, maternal-milk bottle-feeding has been started six hours after the surgery, with feces passing through the ileostomy. They survived one to three days. We failed to identify the meconium ileus by ultrasonography, but succeed by CT scan. A wide
contribution. contribution.
http://dx.doi.org/10.1016/j.rmr.2014.04.064 65
Nlrp6 inflammasome in lung epithelium repair, inflammation and fibrosis after bleomycin-induced pulmonary injury A. Gombault a,∗ , B. Villeret a , F. Savigny a , L. Baron a , N. Guillou a , M. Chamaillard b , I. Couillin a a University of Orleans and CNRS, INEM-UMR7355, Orleans, France b Institut Pasteur Inserm U1019, CNRS UMR 8204, Lille, France ∗ Corresponding author. Adresse e-mail : [email protected] (A. Gombault) Keywords: Infection; Inflammation Introduction.— The NLRs (nucleotide-binding oligomerization domain-like receptors) are involved in the activation of caspase-1 through formation of multimeric complexes called inflammasomes which lead to maturation of pro-inflammatory cytokines IL-1 and IL-18. Several NLRs such as Nlrp1, Nlrp2, Nlrp3, Nlrc4 and more recently Nlrp6 were shown to form inflammasome complexes. However, the activators and the physiological functions of the Nlrp6 inflammasome are not known. In mouse it has been shown that Nlrp6 is highly expressed in intestine and lung and importantly in epithelial cells and myofibroblasts but not in hematopoietic cells in the intestine. Moreover, using Nlrp6 deficient mice, Nlrp6 was shown to play a role in intestinal epithelium repair and control of inflammation in a dextran sulfate sodium colitis model. It allows to recovery intestinal epithelial damage and limit tumorigenic potential. We investigated here the implication of Nlrp6 inflammasome in remodeling and lung epithelium recovery upon lung injury and in pulmonary inflammation and fibrosis induced by bleomycin (BLM). Methods.— Wild-type mice (B6) or Nlpr6 deficient mice (Nlp6 KO) were instillated with BLM during 1 or 14 days. Broncho-alveolar lavage fluids (BALF) were done and cell infiltration was determined. Total protein content and different pro-inflammatory or profibrotic cytokines were measured in BALF and lung homogenates. Results.— Our first results 1 day after instillation showed reduced early total cells and neutrophils recruitments into the BALF upon BLM-induced injury in Nlrp6 KO mice indicating that Nlrp6 is involved in establishment of acute inflammation as observed in colon. Moreover total protein content in BALF is greatly increased in Nlrp6 KO mice suggesting a role for Nlrp6 in alveolar epithelial barrier integrity as shown in colon. In addition, late inflammation and level of the profibrotic factor TGF- were attenuated 14 days after BLM instillation in absence of Nlrp6. Conclusion.— Our first results suggest that Nlrp6 plays a key role in the development of pulmonary inflammation, repair and fibrosis after lung injury-induced by bleomycin. To confirm these results, Nlrp6 expression in hematopoietic and resident pulmonary cells will be tested at steady state and after challenge with bleomycin.
Recherche en pneumologie http://dx.doi.org/10.1016/j.rmr.2014.04.065 66
Type II transmembrane serine protease Matriptase is a mediator of pulmonary fibrosis O. Bardou a,∗ , C. Francois a , N. Carlier a , H. Mal b , B. Crestani a,b , K. Borensztajn a a U700, Inserm, Paris, France b Hôpital Bichat, AP—HP, Paris, France ∗ Corresponding author. Adresse e-mail : [email protected] (O. Bardou) Keywords: Infection; Inflammation Introduction.— Idiopathic pulmonary fibrosis (IPF) is a devastating lung disorder which remains refractory to therapies. Recently, type II transmembrane serine proteases have emerged as key actors in pathophysiology, by proteolysis of cell surface receptors and/or cell environment, thereby orchestrating cell crosstalks. Among them, deregulation of the matriptase contributes to various proliferative disorders. Hence, we sought to investigate the role of matriptase in pulmonary fibrosis. Methods.— Matriptase expression and activity were analyzed in human lung material from controls and IPF patients. Human fibroblasts were stimulated with recombinant matriptase and the activation of key signaling pathways involved in IPF was analyzed. Using the murine model of bleomycin-induced pulmonary fibrosis, mice were administrated for 14 days with 0 or 0.5 mg of camostat mesylate, a matriptase inhibitor, and the markers of tissue fibrosis in lung homogenate, and inflammatory cell influx in the bronchoalveolar lavage fluid (BALF) of the animals were assessed. Results.— We show that matriptase is upregulated in the lung and BALF of IPF patients compared to controls. In fibroblasts, matriptase induced the activation of p42/44, Akt, and Smad2/3 pathways. Finally, camostat administration in bleomycin-treated mice led to a significant decrease in mortality. Fibronectin, collagen and ␣SMA expression, and inflammatory cell influx, were increased in bleomycin-treated mice compared to saline-treated animals. In the camostat-treated mice group, these markers of pulmonary fibrosis were decreased. Conclusion.— Taken together, matriptase seems instrumental in pulmonary fibrosis, and camostat mesylate could be a promising target for the treatment of IPF. http://dx.doi.org/10.1016/j.rmr.2014.04.066 67
Le canal calcique TRPV4 : une cible potentielle pour contrôler l’inflammation respiratoire E. Dalloneau a,b,∗ , C. Henry a,b , D. Brea a,b , R. Aimar a,b , T. Baranek a,b , M. Potier-Cartereau b,c , F. Esnard a,b , C. Vandier b,c , M. Si-Tahar a,b a Centre d’étude des pathologies respiratoires, Inserm U1100/EA6305, Tours, France b Université Franc ¸ois-Rabelais, Tours, France c Inserm U1069, Tours, France ∗ Auteur correspondant. Adresse e-mail : [email protected] (E. Dalloneau) Mots clés : Infection ; Inflammation Introduction.— La bronchopneumopathie chronique obstructive et la mucoviscidose sont des pathologies respiratoires inflammatoires qui représentent des problèmes majeurs de santé publique. Les mécanismes sous-jacents impliqueraient une réaction inflammatoire chronique, avec des conséquences souvent fatales. Cette
673 réponse inflammatoire représente donc une cible importante pour la mise au point de nouveaux traitements. Ainsi, notre étude vise à déterminer le rôle du transient receptor potential vanilloid 4 (TRPV4) dans l’inflammation respiratoire à l’aide de modèles in vitro et in vivo. Méthodes.— L’expression de TRPV4 a été évaluée dans plusieurs lignées et cellules épithéliales pulmonaires primaires humaines, à l’état basal et en présence d’un activateur spécifique dérivé de l’acide arachidonique : le 4␣PDD. L’analyse fonctionnelle de TRPV4 dans ces cellules a été analysée en termes de sécrétion d’IL-6 et IL-8 et par la mobilisation calcique intracellulaire. In vivo, l’effet de l’administration intranasale de 4␣PDD a été comparé dans des souris normales et CFTR-/− . Résultats.— TRPV4 est exprimé de manière constitutive dans les cellules épithéliales pulmonaires humaines. La stimulation de ces cellules par le 4␣PDD induit une entrée de calcium intracellulaire et une sécrétion de cytokines pro-inflammatoires. La co-stimulation de ces cellules avec le LPS bactérien et le 4␣PDD produit un effet synergique sur la production d’IL-6 et d’IL-8. Par ailleurs, l’instillation de 4␣PDD chez la souris induit une sécrétion de médiateurs inflammatoires ainsi qu’un recrutement de neutrophiles dans les poumons. Le nombre de neutrophiles recrutés est de plus significativement plus élevé chez la souris CFTR-/− . Conclusions.— Ces travaux démontrent un rôle du TRPV4 dans la réponse inflammatoire au niveau pulmonaire. Du point de vue thérapeutique, ces données pourraient soutenir le développement de molécules ciblant l’activité du TRPV4, capables de réduire l’inflammation excessive associée à des maladies telles que la BPCO ou la mucoviscidose. http://dx.doi.org/10.1016/j.rmr.2014.04.067 68
Un nouveau rôle potentiel de Human Airway Trypsin-like protease dans la fibrose pulmonaire N. Carlier a,∗ , C. Francois a , O. Bardou a , J. Marchal-Somme a , B. Crestani a,b , K. Borensztajn a a Inserm U700, université Paris 7, Paris, France b Service de pneumologie A, hôpital Bichat, AP—HP, Paris, France ∗ Auteur correspondant. Adresse e-mail : [email protected] (N. Carlier) Mot clé : Inflammation Introduction.— La fibrose pulmonaire idiopathique (FPI) est une maladie d’évolution progressive, caractérisée par une perte des cellules épithéliales alvéolaires, une différenciation aberrante des fibroblastes en myofibroblastes, et une synthèse de matrice extracellulaire dérégulée. Human Airway Trypsin-like protease (HAT) appartient à la nouvelle famille des type II transmembrane serine proteases. Un de ses substrats connus est Protease Activated Receptor-2 (PAR-2), un récepteur qui joue un rôle important dans les mécanismes de fibrogénèse pulmonaire [1]. Dans cette étude, nous avons examiné le rôle de HAT dans la fibrogenèse pulmonaire. Méthodes.— L’expression de HAT a été analysée par Western Blot dans de l’homogénat pulmonaire, ainsi que sur des fibroblastes pulmonaires humains issus de sujets contrôles ou avec FPI. Nous avons également analysé la modulation de l’expression d’HAT dans le modèle murin de fibrose pulmonaire induite par la bléomycine. Nous avons ensuite observé in vitro si HAT est capable d’induire une signalisation intracellulaire sur les fibroblastes pulmonaires humains, puis les conséquences fonctionnelles sur leur différenciation en myofibroblastes, et la production de matrice extracellulaire. Enfin, nous avons déterminé les effets de HAT sur la survie de deux lignées de cellules épithéliales pulmonaires. Résultats.— L’expression de HAT est significativement augmentée dans les poumons de patients atteints de FPI. Elle est égale-