Figure 6.

Cells from injured lungs produce humoral factor(s) that cause BMDMSC proliferation and chemotaxis in vitro. BMDMSC obtained from GFP-positive mice were grown for 7 d, and equally distributed in the lower well of a 6-well Transwell plate. Cell preparations from lungs of normal mice or lungs from mice 14 d after bleomycin were placed in the upper well on a 1.5-inch filter with 3-μm pores. The co-cultures were maintained for 5 d and then analyzed for GFP-positive cells. (a) Photomicrographs of the upper and lower chambers of a Transwell in which the same number of BMDMSC were placed in the lower well and the same number of cells from either normal or bleomycin-injured lung was placed in the upper well. In the presence of injured lung, there were many more GFP-positive cells in the lower chamber. With normal lung, there was no evidence of migration of the GFP-positive cells to the upper chamber, but in the presence of injured lung there was marked migration and the cells appeared in clumps. (b) Quantitative assessment of GFP-positive cells in both upper and lower chambers by fluorescence intensity.