The role of CXCL12-CXCR4 signaling axis in the development of thoracic aortic dissection in mice

LIU Yan; ZHOU Mei; LI Yu-lin

doi:10.3969/j.issn.1672-5301.2025.07.015

Abstract：Objective To investigate the role and mechanism of the CXCL12-CXCR4 signaling axis in the development of thoracic aortic dissection(TAD)in mice.Method A TAD model was established in mice by β-aminopropionitrile(BAPN)administration.The binding of CXCL12 to CXCR4 was inhibited via subcutaneous injection of AMD3100(AMD).Eighty-four 3-week-old male C57BL/6J mice were completely randomly subjected to three groups according to the random digits table:control group(n=8),TAD group(n=38),and TAD+AMD group(n=38).After 4 weeks of BAPN treatment,quantitative PCR(qPCR)was performed to measure mRNA expression of Cxcl12 and Cxcr4 in aortic tissues,and ELISA was used to assess plasma CXCL12 levels.The incidence of TAD and survival rates of mice were recorded.Aortic wall structure and elastic fiber integrity were evaluated using HE and EVG staining,while smooth muscle cell loss was detected via immunohistochemistry staining of MYH11.Single-cell RNA sequencing(scRNA-seq)data of mouse aorta were analyzed to determine cellular localization of Cxcl12 and Cxcr4.Mac3 staining was employed to assess macrophage infiltration,and qPCR was used to evaluate inflammatory cytokine and chemokine mRNA levels.Results After 4 weeks of BAPN treatment,the TAD group showed a significant increase in aortic mRNA levels of Cxcl12 and Cxcr4,as well as the plasma CXCL12 protein levels compared to the control group.CXCR4 inhibitor AMD3100 reduced BAPN-induced TAD formation and rupture,improved survival rates,mitigated aortic elastic fiber degradation and smooth muscle cell loss.ScRNA-seq data revealed high expression of Cxcl12 in fibroblasts,smooth muscle cells,and endothelial cells,whereas Cxcr4 was predominantly expressed in immune cells(including monocytes,neutrophils,and T cells).AMD3100 also suppressed macrophage infiltration and downregulated mRNA expression of Il6 and Ccl2 in aortic tissues.Conclusion Inhibition of the CXCL12-CXCR4 signaling axis by AMD3100 alleviates thoracic aortic dissection development and rupture in mice,potentially through attenuation of inflammatory responses.