Response of Inflammatory Mediators, Extracellular Matrix Proteins and Stem and Progenitor Cells to Emphysema

Abstract

Inflammation, extracellular matrix proteins (hydroxyproline, connective tissue growth factor, collagen, and fibronectin), stem and progenitor cells (multipotent mesenchymal stromal cells, Clara cells, angiogenesis, precursors, endothelial and epithelial cells) were studied in female C57Bl/6 mice with experimental elastase-induced emphysema. Diffuse emphysema reduced the number of endothelial (CD45^–CD31⁺CD34⁺) and epithelial (CD45^–CD117⁺CD49f⁺) cells, induced microcirculation disturbances, and decreased the area occupied by the connective tissue. Emphysematous changes in the lungs were accompanied by infiltration of the alveolar septa with macrophages and lymphocytes, increase in the serum and lung concentrations of transforming growth factor-β, IL-1β, IL-2, IL-5, IL-10, and IL-13, and lung concentration of IL-17. In the lungs, inflammation was associated with marked increase in the number of multipotent mesenchymal stromal cells CD90⁺CD73⁺CD106⁺CD44⁺) and Clara cells (CD45^–CD34^–CD31^–Sca1⁺) and overexpression of extracellular matrix proteins (hydroxyproline, connective tissue growth factor, collagen, fibronectin) and Clara cells protein. On the other hand, elastase reduced the number of angiogenic precursor cells (CD45^–CD117⁺Flk1⁺).