Growth of putative progenitors of type II pneumocytes in culture of human cystic fibrosis alveoli

Abstract

Alveolar type II pneumocytes are thought to be progenitor cells capable of self-renewal and differentiation into type I pneumocytes. Nevertheless, the existence of an alveolar stem cell has been postulated. In lungs from patients with cystic fibrosis, the alveolar epithelium is damaged with ulceration and subsequent regeneration. We characterized alveolar modifications histologically and immunohistochemically in the pulmonary tissue of a patient homozygous for the DF508 mutation. Alveoli were of variable size and surrounded by an inflammatory infiltrate. They were lined by a continuous layer of cuboidal cells with very weak proliferative activity. These cells resembled type II pneumocytes. They expressed thyroid transcription factor-1, cystic fibrosis transmembrane conductance regulator, cytokeratin 7 and contained lamellar bodies. Weak expression of cytokeratin 5 considered to be a marker of progenitor cells of the bronchial and bronchiolar epithelium was detected. Explantation of this alveolar epithelium produced primary cultures and subcultures of epithelial cells that had acquired proliferative properties showing signs of dedifferentiation with a loss of lamellar bodies and a lack of expression of thyroid transcription factor-1. Persistence of the expression of cytokeratin 7 and a strong expression of cytokeratin 5 were observed. The culture conditions were thought to have circumvented the inhibition of proliferation observed in vivo due to the inflammatory peri-alveolar environment. They thus favored the multiplication of a population of cells co-expressing cytokeratin 5 and certain characteristics of type II pneumocytes. The presence of these cells of intermediate phenotype is indicative of the existence of immature precursors for type II pneumocytes.

Stem Cells and Cell Therapies in Lung Biology and Lung Diseases

“…More suggestive information is available for the genetic lung disease, cystic fibrosis (CF). The airway epithelium in patients with CF contains cuboidal cells that express primitive cell markers, including thyroid transcription factor and cytokeratin 7 (99). Neuroepithelial cells also express the CF transmembrane conductance regulator protein (CFTR), the defective protein in patients with CF that appears to play a role in neuropeptide secretion (100,101).…”

Involvement of KATPand KvLQT1 K+channels in EGF-stimulated alveolar epithelial cell repair processes

“…lung; adenosine 5Ј-triphosphate-stimulated potassium channel; Kv-LQT1 K ϩ channels; epidermal growth factor; alveolar cell repair; migration; proliferation RESPIRATORY PATHOLOGIES SUCH as adult respiratory distress syndrome or cystic fibrosis, characterized by dysfunctional ion (Na ϩ and Cl Ϫ ) transport and fluid clearance, are also associated with extensive damage of airway and alveolar epithelia (4,15,18,19,42,49). Several processes are sequentially engaged in pulmonary epithelia regeneration after injury: 1) spreading and migration of healthy cells, 2) proliferation, and 3) differentiation of stem cells (4,15,29,42,62).…”

Technical and theoretical considerations about gradient perfusion culture for epithelia used in tissue engineering, biomaterial testing and pharmaceutical research

“…An innovative construction principle allows the application of gradient perfusion culture containers at minimal financial expenditure and the individual modules can be combined as needed to build a number of advanced customized culture set-ups. A further goal is to close the experimental gap between conventional cell cultures and animal experiments by providing a possibility to culture functionally differentiated epithelia for extended periods of time [50][51][52][53]. These cultures can combine different cell types to allow the study of cellular communication, optimal epithelial tissue development and the long-term effects of newly developed pharmaceuticals.…”