Figure 3. KD platelets are internalized into VSMCs delivering miR-223 in lactobacillus casei cell wall extract (LCWE)-induced KD murine model.

The abdominal aorta tissues were collected from day 0 to day 14 after LCWE-injection. The PBS-injected wide type (WT) littermates were used as vehicle control. (A) Representative Hematoxylin and eosin (H & E) -stained sections from LCWE-injected mice were shown. Photomicrographs from I-V show the process of LCWE-induced abdominal aorta lesions (n=30). Scale bar: 50 μm. (B) Relative expression of miR-223 in platelets from PBS-treated WT littermates (n=5), LCWE-treated WT littermates (n=18), PBS-treated miR-223 KO mice (n=5), and LCWE-treated miR-223 KO mice (n=10) at two weeks (Kruskall-Wallis test and Dunn’s multiple comparisons test, ^**P<0.01, ^****P<0.0001 versus LCWE-injected WT littermates). (C) Corresponding immunofluorescence of CD41 and ACTA2 in abdominal aorta sections from PBS (n=6) and LCWE-injected WT littermates (n=6) at two weeks. CD41 stained as green, ACTA2 as red, and nuclei visualized with DAPI (blue). Scale bar: 20 μm. (D) Quantification of CD41 expression in sections was shown (Unpaired t test). (E) Representative images of the sections from PBS (n=6) and LCWE-injected PF4-cre: mT/mG WT mice (n=6). Scale bar: 20 μm. (F) Quantification of the mGFP positive cells in VSMCs of media layer two weeks after LCWE-injection (Unpaired t test). (G) Representative images of miR-223 and PDGFRβ expression in abdominal aorta sections from PBS or LCWE-injected WT littermates (n=4), PBS or LCWE-injected miR-223 knockout (KO) mice (n=4). miR-223 (red), PDGFRβ (green), and DAPI (blue). Scale bar: 20 μm. Quantification of miR-223 (H) and PDGFRβ (I) expression in situ shown (Kruskall-Wallis test and Dunn’s multiple comparisons test). Abbreviations: PBS, PBS-injected mice; LCWE, LCWE-injected mice; Littermates, WT littermates; miR-223 KO, miR-223 KO mice. ^**P<0.01 versus PBS-injected WT littermates; ^#P<0.05 versus PBS-injected miR-223 KO mice in G & H.