Fig. 3

AAA-MSCs possess elevated osteogenic potential. AAA-MSCs were compared with ha-MSCs for expression of lineage-specific markers at time 0 and after stimulation with osteogenic medium. a Significant down-regulation of PPAR-γ and pronounced expression of OPN in AAA-MSCs. Results are expressed as fold changes relative to ha-MSCs. b In-situ detection of OPN protein was carried out on healthy and aneurysm aortic tissues. Diffuse positivity to OPN was detected on the whole AAA tissue (boxes), and predominantly on SMCs and inflammatory cells (arrows and stars). Scale bar: 100 μm. c Representative Alizarin Red staining of the mineralization process on ha-MSCs and AAA-MSCs, after exposure to osteogenic induction medium for 21 days. Quantitative data are expressed as mean ± standard deviation and compared with undifferentiated ha-MSCs. d Real-time PCR analysis of osteogenic markers in ha-MSCs and AAA-MSCs after osteogenic stimulation. Results are expressed as fold changes relative to undifferentiated ha-MSCs. e MMP-9 mRNA and protein detection on ha-MSCs after osteogenic differentiation; increased MMP-9 transcription (6-fold) and staining were observed on differentiated vs undifferentiated ha-MSCs. Scale bar 50 μm. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. BMP-2 bone morphogenetic protein-2, IHC immunohistochemistry, OPN osteopontin, OCN osteocalcin, PPAR-γ peroxisome proliferation activated receptor gamma, ha-MSC healthy aortic MSC, AAA-MSC abdominal aortic aneurysm MSC, MSC mesenchymal stem cell, os-ind osteogenic-induced, MMP-9 matrix metalloproteinase-9, ctrl control