Project description:The human lung differs substantially from its murine counterpart, resulting in a distinct distal airway architecture affected by disease pathology in chronic obstructive pulmonary disease. In humans, the distal branches of the airway interweave with the alveolar gas exchange niche, forming an anatomical structure known as the respiratory airways. Due to the lack of a murine counterpart, the cellular and molecular characterization of the respiratory airways in the human lung remains an enigma. We show that human respiratory airways contain a unique secretory cell population that is distinct from cells in larger proximal airways. Stem cell modeling reveal that these respiratory airway secretory cells (RASCs) act as unidirectional progenitors for alveolar type 2 cells, which are essential for maintaining and regenerating the alveolar niche. RASC lineage differentiation into AT2 cells is regulated, in part, by Notch signaling. In COPD, RASCs are altered transcriptionally, corresponding to abnormal AT2 cell states. These data identify a distinct progenitor in a region of the human lung not found in mouse that plays a critical role in maintaining the gas exchange compartment and is altered in chronic lung disease.
Project description:The human lung differs substantially from its mouse counterpart, resulting in a distinct distal airway architecture affected by disease pathology in chronic obstructive pulmonary disease. In humans, the distal branches of the airway interweave with the alveolar gas-exchange niche, forming an anatomical structure known as the respiratory bronchioles. Owing to the lack of a counterpart in mouse, the cellular and molecular mechanisms that govern respiratory bronchioles in the human lung remain uncharacterized. Here we show that human respiratory bronchioles contain a unique secretory cell population that is distinct from cells in larger proximal airways. Organoid modelling reveals that these respiratory airway secretory (RAS) cells act as unidirectional progenitors for alveolar type 2 cells, which are essential for maintaining and regenerating the alveolar niche. RAS cell lineage differentiation into alveolar type 2 cells is regulated by Notch and Wnt signalling. In chronic obstructive pulmonary disease, RAS cells are altered transcriptionally, corresponding to abnormal alveolar type 2 cell states, which are associated with smoking exposure in both humans and ferrets. These data identify a distinct progenitor in a region of the human lung that is not found in mouse that has a critical role in maintaining the gas-exchange compartment and is altered in chronic lung disease.
Project description:Pulmonary alveoli are complex architectural units thought to undergo endogenous or pharmacologically induced programs of regeneration and degeneration. To study the molecular mechanism of alveoli loss mice were calorie restricted at different timepoints. Lungs were harvested and processed for RNA extraction. Keywords: other
Project description:Pulmonary alveoli are complex architectural units thought to undergo endogenous or pharmacologically induced programs of regeneration and degeneration. To study the molecular mechanism of alveoli loss mice were calorie restricted at different timepoints. Lungs were harvested and processed for RNA extraction.
Project description:It has been shown that dexamethasone (Dex) impairs the normal lung septation that occurs in the early postnatal period. Treatment with retinoic acid (ATRA) abrogates the effects of Dex. To understand the molecular basis for the Dex indiced inhibition of the formation of the alveoli and the ability of ATRA to prevent the inhibition of septation, gene expression was analyzed in 4-day old mice treated with diluent (control), Dex-treated and ATRA+Dex-treated. Keywords: other
Project description:BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by structural changes in alveoli and airways. Our aim was to analyse the numbers of alpha-smooth muscle actin (?-SMA) positive cells, as a marker of myofibroblasts, in different lung compartments in non-smokers and smokers with normal lung function or COPD. METHODS: ?-SMA, tenascin-C (Tn-C) and EDA-fibronectin in alveolar level and airways were assayed by immunohistochemistry and quantified by image analysis. Immunohistochemical findings were correlated with clinical data. ?-SMA protein was also analysed by Western blotting from fibroblastic cells cultured from peripheral lung of non-smokers, smokers without COPD and smokers with COPD. RESULTS: In many cases, the endings of the detached alveolar walls were widened, the structures of which were named as widened alveolar tips. Widened alveolar tips contained ?-SMA positive cells, which were obviously myofibroblasts. There were less alveolar tips containing positive cells for ?-SMA in alveoli and ?-SMA positive cells in bronchioles in smokers and in COPD compared to non-smokers. The quantity of ?-SMA positive cells was increased in bronchi in COPD. Tn-C was elevated in bronchi in COPD and smokers' lung. The ?-SMA protein level was 1.43-fold higher in stromal cells cultured from non-smokers than in those of smokers. CONCLUSIONS: Myofibroblasts are localized variably in normal and diseased lung. This indicates that they have roles in both regeneration of lung and pathogenesis of COPD. The widened alveolar tips, these newly characterized histological structures, seemed to be the source of myofibroblasts at the alveolar level.
Project description:The extremely limited regenerative potential of adult mammalian hearts has prompted the need for novel cell-based therapies that can restore contractile function in heart disease. We have previously shown the regenerative potential of mixed fetal cells that were naturally found migrating to the injured maternal heart. Exploiting this intrinsic mechanism led to the current hypothesis that Caudal-type homeobox-2 (Cdx2) cells in placenta may represent a novel cell type for cardiac regeneration. Using a lineage-tracing strategy, we specifically labeled fetal-derived Cdx2 cells with enhanced green fluorescent protein (eGFP). Cdx2-eGFP cells from end-gestation placenta were assayed for cardiac differentiation in vitro and in vivo using a mouse model of myocardial infarction. We observed that these cells differentiated into spontaneously beating cardiomyocytes (CMs) and vascular cells in vitro, indicating multipotentiality. When administered via tail vein to infarcted wild-type male mice, they selectively and robustly homed to the heart and differentiated to CMs and blood vessels, resulting in significant improvement in contractility as noted by MRI. Proteomics and immune transcriptomics studies of Cdx2-eGFP cells compared with embryonic stem (ES) cells reveal that they appear to retain "stem"-related functions of ES cells but exhibit unique signatures supporting roles in homing and survival, with an ability to evade immune surveillance, which is critical for cell-based therapy. Cdx2-eGFP cells may potentially represent a therapeutic advance in allogeneic cell therapy for cardiac repair.
Project description:This SuperSeries is composed of the following subset Series: GSE32600: Distal airway stem cells yield alveoli in vitro and during lung regeneration following H1N1 influenza infection (colony) GSE32602: Distal airway stem cells yield alveoli in vitro and during lung regeneration following H1N1 influenza infection (LCM_Four populations of cells) GSE32604: Distal airway stem cells yield alveoli in vitro and during lung regeneration following H1N1 influenza infection (stem cell clones NESC,TASC,DASC) Refer to individual Series