Stem and progenitor cells in the pneumofibrosis patogenesis

Abstract

Model of the bleomycin-induced pneumofibrosis was used to demonstrate, that simultaneously with inflammatory cells (neutrophils, lymphocytes, macrophages, plasma cells) the CD34', (CD3, CD45R (B220), Ly6C, Ly6G (Gr1), CD11b (Mac1), TER-119)', Sca-1+, c-Kit+ (hematopoietic stem cells (HSC)) and progenitor hematopoietic cells (CD3, CD45R (B220), Ly6C, Ly6G (Gr1 ),CD11b (Mac 1), TER-119)', S e a -1 , c-Kit+) appear in the lung tissue of C57BL/6 mice. Inflammatory phase in HSC bleomycin lungs is characterized by the high mitotic activity and ability to differentiate into the myeloid cells. Infiltration of alveola’s and alveolar ducts’ interstition with immature hematopoietic cells is accompanied by an increase in the level of granulocyte-erithriod-macrophagemegakariocyte and granulocyte precursors in bone marrow and circulating blood. During collagen precipitation and influx of progenitor fibroblast cells in the bleomycin lungs’ parenchyma two subpopulations of mesenchymal stem cells (MSC) are determined: MSC1 (CD45', CD73+, CD90+, CD44+, CD106+) and MSC2 (CD3V, CD34', CD45', CD73+, CD90+). MSC are characterized by the high mitotic activity and the fibroblast – oriented differentiation; at that the chondrogenesis, as well as osteogenesis become infringed. Such MSC characteristics are observed on the background of the increase in clonal activity of the progenitor fibroblast cells from the bone marrow and those circulating in blood. We suppose that pharmacological modulation of the endogenous stem cells can be a perspective approach in treatment of fibrous lung diseases.