Inhibition of aortic CX3CR1+ macrophages mitigates thoracic aortic aneurysm progression in Marfan syndrome in mice
Jiaqi Huang, … , Wei Kong, Yi Fu
Jiaqi Huang, … , Wei Kong, Yi Fu
Published January 16, 2025
Citation Information: J Clin Invest. 2025;135(2):e178198. https://doi.org/10.1172/JCI178198.
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Research Article Inflammation Vascular biology

Inhibition of aortic CX3CR1+ macrophages mitigates thoracic aortic aneurysm progression in Marfan syndrome in mice

Abstract

The pathogenesis of thoracic aortic aneurysm (TAA) in Marfan syndrome (MFS) is generally attributed to vascular smooth muscle cell (VSMC) pathologies. However, the role of immune cell–mediated inflammation remains elusive. Single-cell RNA sequencing identified a subset of CX3CR1+ macrophages mainly located in the intima in the aortic roots and ascending aortas of Fbn1C1041G/+ mice, further validated in MFS patients. Specific elimination of CX3CR1+ cells by diphtheria toxin in Cx3cr1-CreERT2iDTRF/+Fbn1C1041G/+ mice efficiently ameliorated TAA progression. Administering the monoclonal antibodies to respectively neutralize TNF-α and IGF1 produced by CX3CR1+ cells from MFS patients greatly suppressed the cocultured MFS patient–specific induced pluripotent stem cell–derived VSMC inflammation. BM transplantation and parabiosis revealed that CX3CR1+ macrophages are mainly originated from BM-derived monocytes. Targeting TNF-α and IGF1 in CX3CR1+ macrophages via shRNA lentivirus transduction in BM cells efficiently suppressed TAA development in BM-transplanted Fbn1C1041G/+ mice. Application of the CCR2 antagonist RS504393 to inhibit monocyte infiltration markedly reduced the accumulation of CX3CR1+ macrophages and subsequently alleviated TAA progression in Fbn1C1041G/+ mice. In summary, CX3CR1+ macrophages mainly located in aortic intima mediate TAA formation by paracrinally causing VSMC inflammation, and targeting them offers a potential antiinflammatory therapeutic strategy for MFS-related TAA.

Authors

Jiaqi Huang, Hao Liu, Zhujiang Liu, Zhenting Wang, Hanshi Xu, Zhuofan Li, Shan Huang, Xueyuan Yang, Yicong Shen, Fang Yu, Yulin Li, Junming Zhu, Wei Li, Li Wang, Wei Kong, Yi Fu

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Figure 1

CX3CR1+ macrophages accumulated in the intima of thoracic aortas of MFS mice and patients.

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CX3CR1+ macrophages accumulated in the intima of thoracic aortas of MFS ...
(A) UMAP visualization of leukocytes in aortic root and ascending aortas from 20-week-old WT and Fbn1C1041G/+ male mice. (B) Selected marker gene expression in distinct leukocyte subtypes. (C) Cell counts in each leukocyte subtype. WT, n = 6,508 cells versus Fbn1C1041G/+, n = 3,827 cells. χ2 test to compare the cell quantitative changes. (D) GO analysis of genes enriched in CX3CR1+ macrophages (cluster 0). (E) The expression of CX3CR1 in distinct leukocyte subtypes. (F) Flow cytometry analysis of CX3CR1+ macrophages in aortic root and ascending aortas from WT and Fbn1C1041G/+ mice at different ages. n = 5. *P < 0.05 by 2-way ANOVA followed by Tukey’s test for post hoc comparison. (G) En face immunofluorescence staining of VE-cadherin (green) and CX3CR1 (red) in the intima of ascending aortas from 6- or 20-week-old WT and Fbn1C1041G/+ mice. The nuclei were stained blue with DAPI. Scale bars: 20 μm. Data were quantified as the percentages of CX3CR1+ cells (red cells) in total intima cells (the number of nuclei) averaged from 4 randomly selected areas of ascending aortas for each mouse. n = 4 mice. *P < 0.05 by 2-way ANOVA followed by Tukey’s test for post hoc comparison. (H) Immunofluorescence staining of CX3CR1 (green) and CD31 (red) in cross-sections of normal aortic tissues from control individuals (controls) and aneurysmal tissues from MFS patients. The nuclei were stained blue with DAPI. Scale bars:100 μm. Data were quantified as the relative fluorescence intensities of CX3CR1 staining in CD31 intimal areas averaged from 4 randomly selected areas for each patient. The average of intensities of CX3CR1 staining in normal controls was set as 1, while the intensities in MFS samples were presented as the relative values. n = 4. *P < 0.05 by unpaired Student’s t test.