Figure 1.

m⁶A Modification and METTL3 Expression Are Upregulated in AAA

(A) Representative photographs showing the macroscopic features of 4-week Ang II-induced AAAs in male ApoE^−/− mice or 6-week CaCl₂-induced AAAs in male C57BL/6J mice. (B) m⁶A modification of total RNA from AAA tissues and control aortic tissues (n = 5). (C) m⁶A modification of rRNA-free poly(A)⁺ RNA from AAA tissues and control aortic tissues as detected by m⁶A immunoblot analysis. (D) Equal amounts of RNA from AAA tissues and control aortic tissues were stained with ethidium bromide. (E) mRNA levels of METTL3, METTL14, and Wilms tumour 1-associating protein (WTAP) in saline- or Ang II-induced mouse AAA samples (n = 4). (F) Western blot analysis of monocyte chemoattractant protein 1 (MCP1), matrix metalloproteinase 2 (MMP2), P21, and METTL3 in saline- or Ang II-induced mouse AAA homogenates (n = 4). (G) Representative immunofluorescent staining of METTL3, smooth muscle 22α (SM22α, green), and 4’,6-diamidino-2-phenylindole (DAPI) in suprarenal aortas from saline- or Ang II-induced mouse AAAs (scale bars, 50 μm). (H) Number of accumulated METTL3-positive cells in the suprarenal aortic walls of saline- or Ang II-infused mice (n = 4). Three different visual fields were captured for each section. (I) Representative western blot analyses of MCP1, MMP2, P21, and METTL3 in human AAA and adjacent nonaneurysmal aortic samples. (J–M) Representative immunostaining (J) and densitometric analysis of METTL3 (K), SM22α (L), and α-SMA (M) in human AAA samples and adjacent control aortas (n = 4; scale bars, 50 μm). The data are presented as the mean ± SD. ∗p < 0.05, ∗∗p < 0.01.