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. 2018 Mar 8;3(5):e97493. doi: 10.1172/jci.insight.97493

Figure 1. Decrement of members of the VSMC contractile apparatus in patients with TAA.

Figure 1

(A) Expression pattern of VSMC phenotypic markers in human aortic tissue from control (n = 13) and TAAD (n = 30) donors. Loss of TAGLN (SM22α) transcript were more significant in patients who have experienced dissection (TAA FC = 0.55 vs TAAD FC = 0.12). (B) Immunoblotting analysis of SM22α protein in human aortic tissue from control (n = 7) and TAAD (n = 9) donors. (C) Anatomical reconstruction of patient images and immunofluorescence staining of contractile proteins of human aortas from control, TAA, and TAAD samples (top row). Verhoeff-Van Gieson stain (VVG) staining of aortic samples from patients demonstrates elastin fragmentation. Scale bar: 150 μm (second row). Immunofluorescence from aortic samples showing SM22α (magenta), calponin (Cnn) (green), DAPI (blue), vinculin (red), smoothelin (green), and DAPI (blue). Scale bar: 50 μm, inset zoom 3-fold magnification. (D) Representative photomicrographs of latex-injected WT and Fbn1C1039G/+ mouse hearts and ascending aortas. Red arrows indicate the ascending portion of the aorta. Aortic elastin fibers were stained with Verhoeff-Van Gieson stain (VVG), and immunofluorescence of DAPI (blue), F-actin (green), and Sm22α (magenta). Scale bar: 50 μm. (E) qPCR analysis of Tagln (Sm22α) transcript in aortic tissue and plasma from WT (n = 7) and Fbn1C1039G/+ (n = 7) 6-month-old mice. (F) Correlation of Tagln (Sm22α) tissue expression with aortic dimensions in Fbn1C1039G/+ aortas (n = 7) (least squares method used for curve fit). (G) Immunofluorescence staining of contractile proteins in aortic VMSC treated with siCtrl or siSM22α. Scale bar: 10 μm, zoom 3-fold magnification. (H) Immunoblotting analysis of SM22α inhibition and loss of its binding partner Cnn in aortic VMSC. Quantitation versus β-actin shown below. (I) siSM22α treatment of healthy VSMCs induce MMP activity as assessed by in vitro gelatin zymography. (*P < 0.05, **P < 0.01, ***P < 0.001, student’s t test, 2 tailed). FC, fold change; TAA, Thoracic aortic aneurysm; TAAD, Thoracic aortic aneurysm and dissection; Ctrl, control; SMTN, smoothelin; VCL, vinculin.