p21 regulation in lung epithelial cells

After lung injury epithelial cells are damaged may be shed thus denuding the basement membrane. The normal response to injury is usually an inflammatory reaction, deposition of new extracellular matrix that incorporates various growth factors, influx of inflammatory cells and regeneration of lost epithelial cells. Regeneration involves migration, proliferation and differentiation of stem cells to cover the exposed area. In the lung bronchiolar region Clara cell are thought to be the progenitor cells. We have studied changes in cell cycle and behaviour of lung epithelial cells in several models of lung injury and in vitro primary culture. We investigated the expression of the cell cycle control genes, p21, p53, PCNA and p27, in mouse models of three important human diseases mainly fibrosis, asthma and Mycobacterium tuberculosis infection.