A selective antagonist of prostaglandin E receptor subtype 4 attenuates abdominal aortic aneurysm

Figures

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  Figure 1. A selective EP4 antagonist CJ‐42794 attenuated angiotensin II‐induced AAA. (A) Time‐course of angiotensin II infusion and CJ‐42794 treatment. (B) Representative images of the abdominal aorta from control and CJ‐42794‐treated (0.2 mg/kg per day) groups (Control and CJ, respectively). Scale bars, 1 mm. (C) Quantification of maximum external diameter of angiotensin II‐induced AAA in ApoE−/− mice. n = 5 (Control) and 6 (CJ). (D) Representative elastica van Gieson stain images of traverse section of angiotensin II‐induced AAA. Scale bars, 200 μm. (E) Medial elastic fiber degradation was graded using an arbitrary scale from grade 1 to grade 4. n = 5 (Control) and 6 (CJ). (F and G) Quantification of MMP‐2 and MMP‐9 activation in mouse AAA tissues measured using gelatin zymography. n = 5 (Control) and 6 (CJ). The data were obtained from two independent experiments.

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  Figure 2. The effect of CJ‐42794 on IL‐6 protein expression in angiotensin II‐induced AAA. (A) Immunohistochemistry for IL‐6 in angiotensin II‐induced AAA treated with or without CJ‐42794 (CJ and Control, respectively). A brown color indicates a positive immunoreaction for IL‐6. Scale bar, 100 μm. (B) Quantification of positive immune‐reactive area for IL‐6 proteins in the tunica media of A. n = 5 (Control) and 6 (CJ). (C) Quantification of IL‐6 proteins in mouse AAA using ELISA. n = 5 (Control) and 6 (CJ). The data were obtained from two independent experiments.

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  Figure 3. CJ‐42794 decreased CaCl2 ‐induced AAA formation. (A) Time‐course of CaCl2 application and CJ‐42794 treatment for (B–D) CJ‐42794 administration began at the same day as CaCl2 application and continued for 4 weeks (CaCl2 4 weeks). (B) Representative elastica van Gieson stain images of the traverse section of AAA 4 weeks after CaCl2 application. Vehicle (control) and CJ‐42794 (CJ)‐treated mice are shown. Scale bars, 100 μm. (C) Quantification of maximum external diameter of AAA 4 weeks after CaCl2 application. n = 9 (Control) and 10 (CJ). (D) Medial elastic fiber degradation of mouse AAA 4 weeks after CaCl2 application was graded using an arbitrary scale from grade 1 to grade 4. n = 9 (Control) and 10 (CJ). (E) Time‐course of CaCl2 application and CJ‐42794 treatment for (F–H). CJ‐42794 administration began 2 weeks after CaCl2 application and continued for additional 4 weeks (CaCl2 6 weeks). n = 5–6. (F) Representative elastica van Gieson stain images of traverse section of AAA 6 weeks after CaCl2 application. Scale bars, 100 μm. (G) Quantification of the maximum external AAA diameter 6 weeks after CaCl2 application. n = 5 (Control) and 6 (CJ). (H) Medial elastic fiber degradation of…

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  Figure 4. The effect of CJ‐42794 on IL‐6 production and MMP‐2 activation in human aortic smooth muscle cells isolated from AAAs. (A) IL‐6 production in hAASMCs treated with PGE 2 (1 μM) in the presence or absence of CJ‐42794 for 6 h was measured by ELISA. Data were obtained from three independent experiments using hAASMCs isolated from three individuals with AAA. n = 9, *P < 0.05; ***P < 0.001; NS, not significant. (B) Representative images of gelatin zymography. hAASMCs were treated with PGE 2 (1 μmol/L) or PGE 2 + CJ‐42794 (1 μmol/L) for 48 h. (C) Quantification of MMP‐2 activation in B. Data were obtained from three independent experiments using hAASMCs isolated from three individuals with AAA. n = 9, *P < 0.05; ***P < 0.001; NS, not significant.