Figure 7.

Immunofluorescence detection of resident or recruited BM-derived SMA-expressing perivascular mesenchymal cells in CNV lesions after BMT. Young mice received young (A) or old (B) GFP BM, followed by laser-induced CNV. Although both groups demonstrated high frequency of resident SMA-expressing cells (red, arrowheads) and GFP-labeled BM-derived cells, many more double-positive cells (yellow, arrows), representing BM-derived SMA/GFP-expressing cells, were observed in cross sections from mice receiving old marrow. Quantification of the frequency of total, resident, and BM-derived CD31 endothelial cells ([C], top) showed no difference in resident or BM-derived CD31-expressing endothelial cells between mice receiving young or old marrow. In contrast, significant differences (asterisks) were observed in the frequency of both resident and BM-derived SMA-expressing cells in CNV of mice receiving marrow from young versus old donors ([C], bottom). In particular, mice receiving old marrow had a 2.5-fold increase in marrow-derived SMA-expressing perivascular mesenchymal cells, contributing to nearly half of all SMA-expressing cells in the CNV. SMA, red; GFP, green; colocalization of GFP and SMA, yellow; DAPI, blue. Magnification: ×400; scale bars: 20 μm.