Figure 5
From: M2 macrophage polarisation is associated with alveolar formation during postnatal lung development
CSF-1 increases developmental macrophages and promotes M2 gene and IGF-1 upregulation. Flow cytometric analysis of macrophages (A-E) and qPCR analysis of gene expression in whole lungs (F&G) at P5, following administration of mrCSF-1 (1 μg/g i.p. at final volume of 50μl; black bars) or PBS vehicle control (white bars) to littermate neonatal Csf1r-EGFP mice at P1, 2 and 3. Cells from whole lungs (A) were gated on Csf1r-EGFP+CD45+ myeloid cells (C) and further gated on F4/80 expression to assess macrophage number and proportion (B), as displayed in representative histograms from control (D) and CSF-1-treated mice (E). Staining (blue) is overlayed with an isotype control (red). Igf1 (G) and M2 gene Fizz1 (F) expression was normalised against β-actin expression and presented as RQ compared to controls. n=3-4 littermate lungs/treatment. *=p<0.05. Photomicrographs of in situ hybridisation for a Csf1r riboprobe at E12.5 (H; purple) and fluorescence Csf1r-EGFP transgene expression at P5 (I; green) demonstrated that during development the CSF-1R is expressed on interstitial myeloid cells (arrows), and not on the developing lung epithelium.