Mechanism of action of resolvin D1 in inhibiting the progression of aortic dissection in mice

Abstract

Background: To investigate the protective effect of resolvin D1 (RvD1) on aortic dissection (AD) in mice and explore the related mechanisms.

Methods: Mice were randomly divided into a blank group, model group, and RvD1 group. The RvD1 and model groups were administered 0.4% β-aminopropionitrile (BAPN) solution, while the blank group was administered distilled water. When the experiment began, whether mice had AD was determined by echocardiogram. The RvD1 group was also administered RvD1 (30 µg/kg), while the model and blank groups were administered saline intraperitoneally. After 21 d, body weight trend and survival rate in the three groups were compared. The diameter of the ascending aorta of mice was detected by echocardiography. Then, the mice were sacrificed, and histopathological staining procedures were performed. Enzyme-linked immunosorbent assay (ELISA) was used to detect cytokines and chemokines in blood and tissue, respectively.

Results: At 21 d, there was no statistically significant difference in body weight between three groups (P>0.05). The survival rate showed a significant difference between the RvD1 and model group (P<0.05). Echocardiography revealed that compared with the RvD1 and blank groups, aortic dilatation was significant in the model group. Pathological staining showed that the destruction of the aortic wall structure and inflammatory cell infiltration were more noticeable in the model group than in the RvD1 group. A slight disintegration of elastic fibers and collagen in the aorta was observed in the RvD1 group, and the aortic structure was clear. The results of ELISA showed that the inflammatory factors levels in the RvD1 group, although higher than those in blank group, were significantly decreased compared with the model group. The ELISA results of AD tissue showed that at 21 d, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels in the aorta were significantly decreased in the RvD1 group compared with the model group (P<0.05).

Conclusions: Administration of RvD1 significantly delayed aortic dilation and disintegration and inhibited local macrophage and neutrophil infiltration in the early stages of aortic injury. Moreover, RvD1 significantly downregulated the expression of cytokines and chemokines in aortic tissues and serum and improved aortic remodeling.

Keywords: Aortic dissection (AD); inflammatory factor; macrophage; resolvin D1 (RvD1); β-aminopropionitrile (BAPN).