Histological and immunohistochemical analysis of control and ApoE−/− heart valve leaflets. A, B, Hematoxylin and eosin staining of control (A) and ApoE−/− (B) adult mice transverse sections. Notice the ApoE−/− aortic artery exhibits large plaques (indicated by *). C-E, Immunofluorescence staining of cad-11 protein (red) of ApoE−/− aortic and mitral valves (E) showed increased expression (C) compared to control aortic and mitral valves (D). Values are average fluorescence intensity and are means ± SEM (*p<0.05, section number = 3; **p<0.05, section number =3). F, Trends in expression of cad-11 protein from E11 to adult in the aortic valve progenitor cells and leaflets. G, Trends in expression of cad-11 protein from E11 to adult in the mitral valve progenitor cells and valve leaflets. Values are average fluorescence intensity and are means ± SEM (*p<0.05, between E11 and E14 mesenchymal fluorescence; **p<0.05, between E11 and E18 mesenchymal fluorescence; #p<0.05, between E11 and adult mesenchymal fluorescence; E11, n=9 (AoV), 9 (MV); E14, n=9 (AoV), 10 (MV); E18, n=10 (AoV), 11 (MV); Adult, n=10 (AoV), 9 (MV)). Abbreviations: AoV, aortic valve; MV, mitral valve. Scale bar = (A, B) 1mm, (D, E) 20 μm.