Lung progenitors from lambs can differentiate into specialized alveolar or bronchiolar epithelial cells.

26International audienceBACKGROUND: Airways progenitors may be involved in embryogenesis and lung repair. The characterization of these important populations may enable development of new therapeutics to treat acute or chronic lung disease. In this study, we aimed to establish the presence of bronchioloalveolar progenitors in ovine lungs and to characterize their potential to differentiate into specialized cells. RESULTS: Lung cells were studied using immunohistochemistry on frozen sections of the lung. Immunocytochemistry and flow cytometry were conducted on ex-vivo derived pulmonary cells. The bronchioloalveolar progenitors were identified by their co-expression of CCSP, SP-C and CD34. A minor population of CD34pos/SP-Cpos/CCSPpos cells (0.33% +/- 0.31) was present ex vivo in cell suspensions from dissociated lungs. Using CD34 magnetic positive-cell sorting, undifferentiated SP-Cpos/CCSPpos cells were purified (>80%) and maintained in culture. Using synthetic media and various extracellular matrices, SP-Cpos/CCSPpos cells differentiated into either club cells (formerly named Clara cells) or alveolar epithelial type-II cells. Furthermore, these ex vivo and in vitro derived bronchioloalveolar progenitors expressed NANOG, OCT4 and BMI1, specifically described in progenitors or stem cells, and during lung development. CONCLUSIONS: We report for the first time in a large animal the existence of bronchioloalveolar progenitors with dual differentiation potential and the expression of specialized genes. These newly described cell population in sheep could be implicated in regeneration of the lung following lesions or in development of diseases such as cancers

IDENTIFICATION, ISOLEMENT ET CARACTERISATION DES PROGENITEURS BRONCHIOLOALVEOLAIRES OVINS

Bronchioloalveolar stem cells located at the bronchiolar/alveolar junction may be involved in embryogenesis or regeneration. These cells have not yet been described in large animals, and they may enable the development of new therapeutics to treat acute or chronic lung disease. In this study, we aimed to establish the presence of bronchioloalveolar stem cells in ovine lungs and to characterize their stemness properties. Lung cells were studied using immunohistochemistry on frozen sections of the lung, and immunocytochemistry and flow cytometry were conducted on derived cells. The stem cells were identified by co-expression of CCSP, SP-C and the CD34 hematopoietic stem-cell marker. A minor population of CD34pos/SP-Cpos/CCSPpos cells (0.33% ± 0.31) was present ex vivo in cell suspensions from dissociated lungs. Using CD34 magnetic positive cell sorting, undifferentiated SP-Cpos/CCSPpos cells were purified (>80%) and maintained in culture. Using synthetic media and various extracellular matrixes, SP-Cpos/CCSPpos cells differentiated into either Clara cells or alveolar epithelial type-II cells. Furthermore, bronchioloalveolar stem cells obtained ex vivo and in vitro expressed the stem cell-specific genes NANOG, OCT4 and BMI1. We report for the first time in a large animal the existence of bronchioloalveolar stem cells with dual differentiation potential and the expression of stem cell-specific genes.Les progéniteurs bronchioloalvéolaires situés aux jonctions bronchioloalvéolaires peuvent être impliqués dans l'embryogenèse ou la régénération. Ces cellules non décrites chez les gros animaux peuvent participer au développement de nouvelles thérapies contre les maladies pulmonaires aiguës ou chroniques. Dans cette étude, nous avons établi la présence de progéniteurs bronchioloalvéolaires dans les poumons des ovins nouveaux nés. Ces cellules ont été identifiées par leur co-expression des protéines CCSP, SP-C et CD34. Une population mineure de cellules CD34pos/SP-Cpos/CCSPpos (0,33% ± 0,31) était présente ex vivo. Le tri magnétique des cellules CD34pos a permis l'isolement des progéniteurs SP-Cpos/CCSPpos (> 80%). Ces cellules étaient maintenues et amplifiées in vitro en interface liquide/liquide. De même, ces progéniteurs étaient capables de se différencier soit en cellules de Clara soit en AEC II dans différents milieux de cultures synthétiques et diverses matrices extracellulaires. En outre, les progéniteurs bronchioloalvéolaires obtenus ex vivo et in vitro exprimaient les gènes NANOG, Oct4 et BMI1 spécifiques aux cellules souches. Nous rapportons ainsi, pour la première fois dans un grand animal, l'existence de cellules progénitrices bronchioloalvéolaires à fort potentiel de double différenciation et d'expression de certains gènes de cellules souches

Identification, isolement et caractérisation des progéniteurs bronchioloalvéolaires ovins

Bronchioloalveolar stem cells located at the bronchiolar/alveolar junction may be involved inembryogenesis or regeneration. These cells have not yet been described in large animals, and they mayenable the development of new therapeutics to treat acute or chronic lung disease. In this study, weaimed to establish the presence of bronchioloalveolar stem cells in ovine lungs and to characterize theirstemness properties. Lung cells were studied using immunohistochemistry on frozen sections of the lung,and immunocytochemistry and flow cytometry were conducted on derived cells. The stem cells wereidentified by co-expression of CCSP, SP-C and the CD34 hematopoietic stem-cell marker. A minorpopulation of CD34pos/SP-Cpos/CCSPpos cells (0.33% ± 0.31) was present ex vivo in cell suspensions fromdissociated lungs. Using CD34 magnetic positive cell sorting, undifferentiated SP-Cpos/CCSPpos cellswere purified (>80%) and maintained in culture. Using synthetic media and various extracellular matrixes,SP-Cpos/CCSPpos cells differentiated into either Clara cells or alveolar epithelial type-II cells. Furthermore,bronchioloalveolar stem cells obtained ex vivo and in vitro expressed the stem cell-specific genesNANOG, OCT4 and BMI1. We report for the first time in a large animal the existence ofbronchioloalveolar stem cells with dual differentiation potential and the expression of stem cell-specificgenes.Les progéniteurs bronchioloalvéolaires situés aux jonctions bronchioloalvéolaires peuvent être impliquésdans l'embryogenèse ou la régénération. Ces cellules non décrites chez les gros animaux peuventparticiper au développement de nouvelles thérapies contre les maladies pulmonaires aiguës ouchroniques. Dans cette étude, nous avons établi la présence de progéniteurs bronchioloalvéolaires dansles poumons des ovins nouveaux nés. Ces cellules ont été identifiées par leur co-expression desprotéines CCSP, SP-C et CD34. Une population mineure de cellules CD34pos/SP-Cpos/CCSPpos (0,33% ±0,31) était présente ex vivo. Le tri magnétique des cellules CD34pos a permis l’isolement des progéniteursSP-Cpos/CCSPpos (> 80%). Ces cellules étaient maintenues et amplifiées in vitro en interfaceliquide/liquide. De même, ces progéniteurs étaient capables de se différencier soit en cellules de Clarasoit en AEC II dans différents milieux de cultures synthétiques et diverses matrices extracellulaires. Enoutre, les progéniteurs bronchioloalvéolaires obtenus ex vivo et in vitro exprimaient les gènes NANOG,Oct4 et BMI1 spécifiques aux cellules souches. Nous rapportons ainsi, pour la première fois dans ungrand animal, l’existence de cellules progénitrices bronchioloalvéolaires à fort potentiel de doubledifférenciation et d’expression de certains gènes de cellules souches

Identification, isolement and characterization of ovine brochioloalveolar progenitors

Les progéniteurs bronchioloalvéolaires situés aux jonctions bronchioloalvéolaires peuvent être impliquésdans l'embryogenèse ou la régénération. Ces cellules non décrites chez les gros animaux peuventparticiper au développement de nouvelles thérapies contre les maladies pulmonaires aiguës ouchroniques. Dans cette étude, nous avons établi la présence de progéniteurs bronchioloalvéolaires dansles poumons des ovins nouveaux nés. Ces cellules ont été identifiées par leur co-expression desprotéines CCSP, SP-C et CD34. Une population mineure de cellules CD34pos/SP-Cpos/CCSPpos (0,33% ±0,31) était présente ex vivo. Le tri magnétique des cellules CD34pos a permis l’isolement des progéniteursSP-Cpos/CCSPpos (> 80%). Ces cellules étaient maintenues et amplifiées in vitro en interfaceliquide/liquide. De même, ces progéniteurs étaient capables de se différencier soit en cellules de Clarasoit en AEC II dans différents milieux de cultures synthétiques et diverses matrices extracellulaires. Enoutre, les progéniteurs bronchioloalvéolaires obtenus ex vivo et in vitro exprimaient les gènes NANOG,Oct4 et BMI1 spécifiques aux cellules souches. Nous rapportons ainsi, pour la première fois dans ungrand animal, l’existence de cellules progénitrices bronchioloalvéolaires à fort potentiel de doubledifférenciation et d’expression de certains gènes de cellules souches.Bronchioloalveolar stem cells located at the bronchiolar/alveolar junction may be involved inembryogenesis or regeneration. These cells have not yet been described in large animals, and they mayenable the development of new therapeutics to treat acute or chronic lung disease. In this study, weaimed to establish the presence of bronchioloalveolar stem cells in ovine lungs and to characterize theirstemness properties. Lung cells were studied using immunohistochemistry on frozen sections of the lung,and immunocytochemistry and flow cytometry were conducted on derived cells. The stem cells wereidentified by co-expression of CCSP, SP-C and the CD34 hematopoietic stem-cell marker. A minorpopulation of CD34pos/SP-Cpos/CCSPpos cells (0.33% ± 0.31) was present ex vivo in cell suspensions fromdissociated lungs. Using CD34 magnetic positive cell sorting, undifferentiated SP-Cpos/CCSPpos cellswere purified (>80%) and maintained in culture. Using synthetic media and various extracellular matrixes,SP-Cpos/CCSPpos cells differentiated into either Clara cells or alveolar epithelial type-II cells. Furthermore,bronchioloalveolar stem cells obtained ex vivo and in vitro expressed the stem cell-specific genesNANOG, OCT4 and BMI1. We report for the first time in a large animal the existence ofbronchioloalveolar stem cells with dual differentiation potential and the expression of stem cell-specificgenes

NON-STATIONARY HYPERSPECTRAL FORWARD MODEL AND HIGH-RESOLUTION

International audienceWe present in this work a forward model for an Integral Field Unit (IFU) instrument. Our model is general but primarily developed for the Mid Resolution Spectrometer of the Mid In-frared Instrument on board the James Webb Space Telescope (JWST). It takes a 3D spatio-spectral object as input and produces a set of 2D projected data with multiple detectors of different characteristics. However, these 2D outputs suffer from non-stationary spatial and spectral blurring, as well as under-sampling. Our first contribution is the development of the forward model in order to simulate data and the second is the use of this model to reconstruct a full 3D hyperspectral image from the projected measurements. This problem is ill-posed and we propose an algorithm based on the regularized least-square approach with convex edge-preserving regularization. We show on the simulation that our proposed model and algorithm allow a better reconstruction than the state of the art algorithm, thanks to spatial and spectral deconvolutions and denoising

Reconstruction hyperspectraleà haute résolutionà partir de mesures de spectrometrie

International audienceWe present in this work reconstruction of a 3D hyperspectral cube from 2D spectrometer data. In fact, the observed cube with two spatial dimensions $(\alpha,\beta)$ and one spectral dimension $\lambda$ is projected on a 2D detector with one spatial dimension and one spectral dimension. However, the instrument is not perfect and introduces a spatial blurring and a spectral blurring, spectrally variable. An algorithm based on the least square approach with convex Huber regularization is proposed to reconstruct the original 3D cube while inverting the blurring introduced by the instrument.Ce travail propose la reconstruction d'un cube hyperspectral infrarouge haute-résolution 2D+λà partir des données brutes 2D issues d'un spectromètreà intégrale de champ. En effet le cube 2D+λ,à deux dimensions spatiales et une dimension spectrale, est projeté sur des détecteurs 2D qui encodent une dimension spatiale et une dimension spectrale. Cependant, l'instrument n'est pas parfait et introduità la fois un flou spatial et un flou spectral, variables spectralement. Pour prendre en compte ces effets, nous proposons un nouvel algorithme basé sur une approche de type problème inverse reposant sur un nouveau modèle direct des mesures et la minimisation d'un critère composite. Le critère inclut un terme de moindres carrés pour l'attache aux données et un terme de régularisation convexe pour préserver les contours spatiaux

Super-Resolution Hyperspectral Reconstruction with Majorization-Minimization Algorithm and Low-Rank Approximation

International audienceHyperspectral imaging (HSI) has become an invaluable imaging tool for many applications in astrophysics or Earth observation. Unfortunately, direct observation of hyperspectral images is impossible since the actual measurements are 2D and suffer from strong spatial and spectral degradations, especially in the infrared. We present in this work an original method for high-resolution hyperspectral image reconstruction from heterogeneous 2D measurements degraded by integral field spectroscopy (IFS) instrument. A fundamental part of this work is developing a forward model that accounts for the limitations of the IFS instrument, such as wavelength-dependent spatial and spectral blur, subsampling, and inhomogeneous sampling steps. The reconstruction method inverts the forward model using a deterministic regularization framework for edge-preserving. It fuses information from different observations and spectral bands for resolution enhancements. We rely on the Majorize-Minimize memory gradient (3MG) optimization algorithm to solve the inverse problem while considering a low-rank approximation for the unknown to handle the high-dimensionality of the problem

Seroprevalence of Schmallenberg virus and other Simbu group viruses among the Lebanese sheep

In order to evaluate for the first time, the serological prevalence of Schmallenberg virus (SBV) and other Simbu group viruses in Lebanon, sheep originating from 15 Lebanese regions were sampled in September 2016. A total number of 750 serum samples from Awassi sheep were tested by ELISA for viral nucleoprotein antibodies. From the sampled animals, 122 animals were seropositive to SBV/Simbu group viruses. The seropositive sheep were mainly located in South Lebanon. At herd-level, a seroprevalence of 53.33% was recorded in the Seven Lebanese governorates. The animal-level seroprevalence was 16.26% and both animal and herd-level seroprevalences were negative in Mount-Lebanon. Despite that there was some serological evidence showed the presence of some Simbu group viruses in the Middle East, no study was done in Lebanon. In this study, we report for the first time the prevalence of SBV and other Simbu group viruses in Lebanon.Keywords: Lebanon, SBV, Schmallenberg virus, Sheep, Simbu group viruse