Abstract:Using a serum-free culture method, we investigated the effects of vitamin A on the proliferation of human distal airway epithelial cells. Outgrowth of epithelial cells from lung tissue explants was enhanced by treatment with all-trans retinol at concentrations of 10(-8) to 10(-7) M. The colony-forming activity of cells harvested from the primary culture and replated onto Swiss 3T3 fibroblastic feeders was, in contrast, significantly reduced by 10(-7) M to 10(-5) M retinol. When the primary cells were harvested… Show more
The cells lining the airway consist of epithelial cells, of which there are several types including columnar cells, basal cells, and secretory/goblet cells. It is these cells which are the first lines of defense against airborne inflammatory agents. Initially, it was thought that the epithelium just formed a physical barrier between the lumen and the underlying-cells in the lung. However, epithelial cells themselves do exhibit many anti-inflammatory features and may actively participate in the inflammatory processes in the lung. The development of in vitro cell culture systems of airway epithelia has added to studies into the pathology of airway inflammation.
The cells lining the airway consist of epithelial cells, of which there are several types including columnar cells, basal cells, and secretory/goblet cells. It is these cells which are the first lines of defense against airborne inflammatory agents. Initially, it was thought that the epithelium just formed a physical barrier between the lumen and the underlying-cells in the lung. However, epithelial cells themselves do exhibit many anti-inflammatory features and may actively participate in the inflammatory processes in the lung. The development of in vitro cell culture systems of airway epithelia has added to studies into the pathology of airway inflammation.
Vitamin A and its derivatives have been postulated to play an important role in renal tubulogenesis and compensatory hypertrophy. This study examined the effects of two carboxylic derivatives of vitamin A on Lewis lung carcinoma-porcine kidney-1 (LLC-PK1) renal tubular epithelial cell mito- and motogenesis and cell size. It was found that all-trans and 13-cis retinoic acids exerted modest, dose-dependent effects to stimulate incorporation of 3H-thymidine into acid-precipitable material of LLC-PK1 cells. The effects of all-trans retinoic acid to promote 3H-thymidine uptake in LLC-PK1 cells modestly enhanced that seen with acidic fibroblastic growth factor. Similar findings of these two retinoic acid derivatives to promote 3H-thymidine uptake and to enhance 3H-thymidine uptake stimulated by another growth factor (platelet-derived growth factor BB) were also observed in cultured bovine aortic smooth muscle cells. Both retinoic acids promoted healing of denuded areas made within confluent monolayers of serum-starved LLC-PK1 cells. All-trans retinoic acid also stimulated recovery of mechanically denuded areas within bovine aortic smooth muscle monolayers. Neither all-trans nor 13-cis retinoic acids s affected cell size as assessed by forward light scatter with flow cytometry, suggesting lack of effect to induce hypertrophy. These results demonstrate that two carboxylic acid derivatives of vitamin A are capable of stimulation of basal and growth factor-induced incorporation of 3H-thymidine uptake into acid-precipitable material and healing of denuded areas in disparate cell types. These findings are compatible with a role for vitamin A and its analogues in the tissue repair process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.