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

Méthodes alternatives in vitro pour l’étude des interactions hôte-pathogène du poumon

Les maladies respiratoires, qu’elles touchent les animaux et/ou les hommes, ont un impact sanitaire et économique considérable sur notre société. Pouvoir mieux les contrôler, les traiter et les prédire, nécessite de pouvoir les étudier. Pour cela des modèles d’études pertinents, reproductibles, efficaces aisés d’utilisation, et alternatifs à l’expérimentation animale doivent être proposés. D’énormes progrès méthodologiques ont été réalisés ces dernières années avec l’émergence de modèles in vitro qui miment le poumon en reproduisant la diversité des types cellulaires, l’architecture du tissu et certaines de ses fonctionnalités (activité ciliaire, sécrétion). Cette revue présente les avancées dans la génération de ces modèles chez le bovin : les organoïdes, les cultures Air-liquide-interface (ALI) et les coupes fines de poumon (PCLS). Ils sont utilisés pour mieux décrire et comprendre les processus physiopathologiques induits par des infections (virus, bactérie, parasite) respiratoires et permettent de tester des approches prophylactiques ou curatives

Minimal Information for Studies of Extracellular Vesicles 2018 (MISEV2018): A Position Statement of the International Society for Extracellular Vesicles and Update of the MISEV2014 Guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Alzheimer’s disease genetic risk and sleep phenotypes: association with more slow-waves and daytime sleepiness

peer reviewedStudy objectives: Sleep disturbances and genetic variants have been identified as risk factors for Alzheimer's disease. Our goal was to assess whether genome-wide polygenic risk scores (PRS) for AD associate with sleep phenotypes in young adults, decades before typical AD symptom onset. Methods: We computed whole-genome Polygenic Risk Scores (PRS) for AD and extensively phenotyped sleep under different sleep conditions, including baseline sleep, recovery sleep following sleep deprivation and extended sleep opportunity, in a carefully selected homogenous sample of healthy 363 young men (22.1 y ± 2.7) devoid of sleep and cognitive disorders. Results: AD PRS was associated with more slow wave energy, i.e. the cumulated power in the 0.5-4 Hz EEG band, a marker of sleep need, during habitual sleep and following sleep loss, and potentially with large slow wave sleep rebound following sleep deprivation. Furthermore, higher AD PRS was correlated with higher habitual daytime sleepiness. Conclusions: These results imply that sleep features may be associated with AD liability in young adults, when current AD biomarkers are typically negative, and the notion that quantifying sleep alterations may be useful in assessing the risk for developing AD

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Organoïdes pulmonaires et cultures air-liquide interface pour mimer le poumon

International audienc

Research on emerging viruses at IVPC UMR754

International audienc

Organoïdes pulmonaires et cultures air-liquide interface pour mimer le poumon

International audienc