Fig. 3: Function of the LXR.α-ABCA1 axis is impaired in phenotypically switched VSMCs.
a Heatmap of proteomic analysis between synthetic and contractile VSMCs. b Analysis of KEGG pathway enriched by differentially expressed genes of proteomic analysis between synthetic and contractile VSMCs. c The mRNA expression of SM22α, LXRα, and ABCA1 in WT VSMCs treated with PDGF-BB for 0, 12, 24, and 48 h respectively (n = 3). d Confocal microscopy images of LXRα distribution in WT VSMCs incubated with PDGF-BB for 0, 12, 24, and 48 h respectively. Scale bar, 10 µm. e Confocal microscopy images of LXRα and ACTA2 in arterial walls of WT mice after ligation for 0, 7, 14, and 28 days. Scale bar, 20 µm. f Quantification of each lipid class in synthetic and contractile VSMCs. Lipid classes were expressed as μmol per g protein. g Heatmap of CEs between synthetic and contractile VSMCs. h ORO staining of WT VSMCs transducted with or without Ad-GFP-SM22α following with PDGF-BB and/or cholesterol treatment and quantification of positive ORO staining. Scale bar, 20 μm (n = 3) i M-mode and Doppler echocardiography images obtained from aortic arch and outflow tract of Sm22α−/− mice transducted with AAV-GFP (n = 10) and AAV-SM22α (n = 10) fed Paigen diet for 12 weeks. As: outflow tract and aortic diameter in systole; Ad: outflow tract and aortic diameter in diastole. j Representative images of en face ORO-stained aortas and quantification of lesion areas (n = 6). k Representative immunofluorescence of LXRα (green) and quantification of cells with nuclear LXRα in the aortic sections from Sm22α−/− mice transducted with AAV-GFP (n = 4) and AAV-SM22α (n = 4) fed Paigen diet for 24 weeks. Scale bar, 10 µm. Arrows indicated the distribution of LXRα. l Identification of SMC-derived foam cells within atherosclerotic lesion of Sm22α−/− mice infected with AAV-GFP (n = 4) and AAV-SM22α (n = 4) fed Paigen diet for 24 weeks by CD68 (blue), ACTA2 (red) and Bodipy (green). Scale bar, 25 µm. Arrows indicated foam cells that were VSMCs-derived. Data and images are representative of at least three independent experiments. Data in (c) were analyzed by two-way ANOVA. Data in (f), (h), (j), (k) and (l) were analyzed by unpaired t test. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001.
