Antigen presentation by lung epithelial cells directs CD4 T cell function and regulates barrier immunity.

Barrier tissues are populated by functionally plastic CD4 resident memory T (T) cells. Whether the barrier epithelium regulates CD4 T cell locations, plasticity and activities remains unclear. Here we report that lung epithelial cells, including distinct surfactant protein C (SPC)MHC epithelial cells, function as anatomically-segregated and temporally-dynamic antigen presenting cells.

Depletion of and in Murine Lung Epithelial Cells Ameliorates Bleomycin-Induced Lung Fibrosis by Inhibiting the β-Catenin Signaling Pathway.

Idiopathic pulmonary fibrosis (IPF) represents the most aggressive form of pulmonary fibrosis (PF) and is a highly debilitating disorder with a poorly understood etiology. The lung epithelium seems to play a critical role in the initiation and progression of the disease. A repeated injury of lung epithelial cells prompts type II alveolar cells to secrete pro-fibrotic cytokines, which induces differentiation of resident mesenchymal stem cells into myofibroblasts, thus promoting aberrant deposition of extracellular matrix (ECM) and formation of fibrotic lesions.

Multilineage murine stem cells generate complex organoids to model distal lung development and disease.

Organoids derived from mouse and human stem cells have recently emerged as a powerful tool to study organ development and disease. We here established a three-dimensional (3D) murine bronchioalveolar lung organoid (BALO) model that allows clonal expansion and self-organization of FACS-sorted bronchioalveolar stem cells (BASCs) upon co-culture with lung-resident mesenchymal cells. BALOs yield a highly branched 3D structure within 21 days of culture, mimicking the cellular composition of the bronchioalveolar compartment as defined by single-cell RNA sequencing and fluorescence as well as electron microscopic phenotyping.

Imaging lung regeneration by light sheet microscopy.

Optical clearing combined with deep imaging of large biological specimen allows organ-wide visualization of cells in three dimensions (3D) to explore regenerative processes in a spatial context. Here, we investigate the dynamics of airway regeneration following toxin-mediated epithelial injury in cleared whole lung preparations by light sheet microscopy. We use a recently developed knock-in mouse strain labeling bronchiolar Club cells (Scgb1a1-mCherry) to define an optimal clearing procedure that efficiently preserves genetically encoded fluorophores.

Bronchioalveolar stem cells are a main source for regeneration of distal lung epithelia .

Bronchioalveolar stem cells (BASCs) are a potential source for lung regeneration, but direct evidence for a multipotential lineage contribution during homeostasis and disease is critically missing, since specific genetic labeling of BASCs has not been possible. We developed a novel cell tracing approach based on intein-mediated assembly of newly engineered split-effectors, allowing selective targeting of dual-marker expressing BASCs in the mouse lung. RNA sequencing of isolated BASCs demonstrates that BASCs show a distinct transcriptional profile, characterized by co-expression of bronchiolar and alveolar epithelial genes.

Estimation of absolute number of alveolar epithelial type 2 cells in mouse lungs: a comparison between stereology and flow cytometry.

Accurate estimation of the absolute number of a particular cell-type in whole organs is increasingly important in studies on organogenesis, and the remodelling and repair of diseased tissues. The unbiased estimation of the absolute number of cells in an organ is complicated, and design-based stereology remains the method of choice. This has led investigators to explore alternative approaches - such as flow cytometry - as a faster and less labour-intensive replacement for stereology.

A novel mouse Cre-driver line targeting Perilipin 2-expressing cells in the neonatal lung.

Pulmonary diseases such as chronic obstructive pulmonary disease, lung fibrosis, and bronchopulmonary dysplasia are characterized by the destruction or malformation of the alveolar regions of the lung. The underlying pathomechanisms at play are an area of intense interest since these mechanisms may reveal pathways suitable for interventions to drive reparative processes. Lipid-laden fibroblasts (lipofibroblasts) express the Perilipin 2 (Plin2) gene-product, PLIN2, commonly called adipose-differentiation related protein (ADRP).

Broad AOX expression in a genetically tractable mouse model does not disturb normal physiology.

Plants and many lower organisms, but not mammals, express alternative oxidases (AOXs) that branch the mitochondrial respiratory chain, transferring electrons directly from ubiquinol to oxygen without proton pumping. Thus, they maintain electron flow under conditions when the classical respiratory chain is impaired, limiting excess production of oxygen radicals and supporting redox and metabolic homeostasis. AOX from Ciona intestinalis has been used to study and mitigate mitochondrial impairments in mammalian cell lines, Drosophila disease models and, most recently, in the mouse, where multiple lentivector-AOX transgenes conferred substantial expression in specific tissues.

Bronchoalveolar sublineage specification of pluripotent stem cells: effect of dexamethasone plus cAMP-elevating agents and keratinocyte growth factor.

Respiratory progenitors can be efficiently generated from pluripotent stem cells (PSCs). However, further targeted differentiation into bronchoalveolar sublineages is still in its infancy, and distinct specifying effects of key differentiation factors are not well explored. Focusing on airway epithelial Clara cell generation, we analyzed the effect of the glucocorticoid dexamethasone plus cAMP-elevating agents (DCI) on the differentiation of murine embryonic and induced pluripotent stem cells (iPSCs) into bronchoalveolar epithelial lineages, and whether keratinocyte growth factor (KGF) might further influence lineage decisions.

Nitric oxide-associated protein 1 (NOA1) is necessary for oxygen-dependent regulation of mitochondrial respiratory complexes.

In eukaryotic cells, maintenance of cellular ATP stores depends mainly on mitochondrial oxidative phosphorylation (OXPHOS), which in turn requires sufficient cellular oxygenation. The crucial role of proper oxygenation for cellular viability is reflected by involvement of several mechanisms, which sense hypoxia and regulate activities of respiratory complexes according to available oxygen concentrations. Here, we focus on mouse nitric oxide-associated protein 1 (mNOA1), which has been identified as an important component of the machinery that adjusts OXPHOS activity to oxygen concentrations.

Induction of smooth muscle cell migration during arteriogenesis is mediated by Rap2.

Objective: Collateral artery growth or arteriogenesis is the primary means of the circulatory system to maintain blood flow in the face of major arterial occlusions. Arteriogenesis depends on activation of fibroblast growth factor (FGF) receptors, but relatively little is known about downstream mediators of FGF signaling.

Methods And Results: We screened for signaling components that are activated in response to administration of FGF-2 to cultured vascular smooth muscle cells (VSMCs) and detected a significant increase of Rap2 but not of other Ras family members, which corresponded to a strong upregulation of Rap2 and C-Raf in growing collaterals from rabbits with femoral artery occlusion.