Hemoglobin gene expression in non-erythroid cells has been previously reported in activated macrophages from adult mice and lens cells, and recent studies indicate that alveolar epithelial cells can be derived from hematopoietic stem cells. Our laboratory has now produced strong evidence that hemoglobin is expressed by alveolar type II (ATII) cells and Clara cells, the primary producers of pulm...

BACKGROUND The excess and persistent accumulation of fibroblasts due to aberrant tissue repair results in fibrotic diseases such as idiopathic pulmonary fibrosis. Recent reports have revealed significant changes in microRNAs during idiopathic pulmonary fibrosis and evidence in support of a role for microRNAs in myofibroblast differentiation and the epithelial-mesenchymal transition in the conte...

Alveolar epithelial cells outnumber alveolar macrophages by ~500 fold and increasing evidence suggests Mycobacterium tuberculosis may replicate dramatically in these cells during the initial weeks of infecting the lung [1,2]. Here, we report in experimental detail the transcriptional profiling of Mycobacterium tuberculosis replicating at 72 hr post-infection in the human type II alveolar epithe...

Nuclear erythroid related factor 2 (Nrf2) is a redox-sensitive transcription factor which is involved in the transcriptional regulation of many antioxidant genes, including glutamatecysteine ligase (GCL). Cigarette smoke is known to cause oxidative stress and deplete glutathione (GSH) levels in alveolar epithelial cells. We hypothesized that resveratrol, a polyphenolic phytoalexin, possesses an...

The pathogenesis of reexpansion pulmonary edema is not yet fully understood. We therefore studied its mechanism in a rat model in which the left lung was collapsed by bronchial occlusion for 1 h and then reexpanded and ventilated for an additional 3 h. We then evaluated the production of reactive oxygen species in the lungs using fluorescent imaging and cerium deposition electron microscopic te...

Periplakin is a component of the desmosomes that acts as a cytolinker between intermediate filament scaffolding and the desmosomal plaque. Periplakin is strongly expressed by epithelial cells in the lung and is a target antigen for autoimmunity in idiopathic pulmonary fibrosis. The aim of this study was to determine the role of periplakin during lung injury and remodeling in a mouse model of lu...

Exposure of human populations to chronically elevated levels of ambient particulate matter air pollution < 2.5 μm in diameter (PM(2.5)) has been associated with an increase in lung cancer incidence. Over 70% of lung cancer cell lines exhibit promoter methylation of the tumor suppressor p16, an epigenetic modification that reduces its expression. We exposed mice to concentrated ambient PM(2.5) v...

This paper describes a new human alveolar epithelial cell line (hAELVi - human Alveolar Epithelial Lentivirus immortalized) with type I-like characteristics and functional tight junctions, suitable to model the air-blood barrier of the peripheral lung. Primary human alveolar epithelial cells were immortalized by a novel regimen, grown as monolayers on permeable filter supports and characterized...

The diversity of mesenchymal cell types in the lung that influence epithelial homeostasis and regeneration is poorly defined. We used genetic lineage tracing, single-cell RNA sequencing, and organoid culture approaches to show that Lgr5 and Lgr6, well-known markers of stem cells in epithelial tissues, are markers of mesenchymal cells in the adult lung. Lgr6+ cells comprise a subpopulation of sm...

A case of desquamative interstitial pneumonia (DIP) has been studied by electron microscopy in order to determine the nature of the alveolar cells. Those lining the alveolar walls proved to be granular pneumocytes (type II alveolar epithelial cells) while cells free in the lumen were alveolar macrophages. The brief literature describing the electron microscopic findings in DIP is reviewed. All ...