Fig. 6: Myosin light chain kinase (MYLK) ameliorates miR-1204-induced senescence-associated secretory phenotype (SASP) and contractile phenotype loss in vitro and in vivo.

A Representative images of senescence-associated-β-galactosidase (SA-β-gal) staining (left) and quantification (right) in the indicated groups. n = 6 biological replicates. Statistical analysis was performed using a one-way ANOVA followed by Tukey’s multiple comparison test. Scale bar represents 100 μm. B Interleukin 6 (IL-6) concentration in the culture supernatant of VSMCs in the indicated groups. n = 6 biological replicates. Statistical analysis was performed using a one-way ANOVA followed by Tukey’s multiple comparison test. C Monocyte chemotactic protein 1 (MCP-1) concentration in the culture supernatant of VSMCs in the indicated groups. n = 6 biological replicates. Statistical analysis was performed using a one-way ANOVA followed by Tukey’s multiple comparison test. D Quantification of the mRNA levels of SASP components in VSMCs transfected with miR-1204 mimics or miR-ctl in the indicated groups. n = 6 biological replicates. Statistical analysis was performed using a one-way ANOVA followed by Tukey’s multiple comparison test. E–G Representative plots (upper panel) and quantification (lower panel) of immunoblot analysis of contractile markers, myosin heavy chain 11 (MYH11), α-smooth muscle actin (α-SMA), and smooth muscle protein 22 (SM22) in the indicated groups. n = 6 biological replicates. Statistical analysis was performed using a one-way ANOVA followed by Tukey’s multiple comparison test. H Scheme of AngII-induced aortic aneurysm and dissection (AAD) experiments. MiR-1204 agomir or miR-ctl (10 nmol) was administered by tail vein injection to 4-month-old male and female C57BL/6 mice every 3 d for a total of five times. Then the mice were administered MYLK adenovirus or blank adenovirus via tail vein prior to 4-weeks of AngII-infusion. I AAD incidence. AA aortic aneurysm, AD aortic dissection. Statistical analysis was performed using two-tailed Fisher’s exact test. J Representative photographs of aortas in the indicated groups. Bar indicates 4 mm. K Representative images of SA-β-gal staining in the indicated groups. Scale bar indicates 4 mm. L Representative B-mode ultrasound and doppler ultrasound (DUS) detection of abdominal aortas (upper) and quantification of abdominal aorta diameters (below). n = 17 biological replicates for AngII + miR-1204 group. n = 20 biological replicates for other groups. Statistical analysis was performed using a one-way ANOVA followed by Tukey’s multiple comparison test. The white arrow indicates an aneurysm. M Representative images of immunofluorescence staining of MYLK, MCP-1, and IL-6 in mouse aortas in the indicated groups. Scale bar represents 100 μm. N Contraction of isolated aortic rings from indicated groups in response to the phenylephrine (Phe) treatment. n = 8 biological replicates. Statistical analysis was performed using two-tailed repeated-measures ANOVA with Bonferroni’s multiple comparison test. Data are presented as mean ± SD. Source data are provided as a source data file.