This research identifies vascular tissue-resident macrophages (VRMs) as essential protectors against abdominal aortic aneurysm (AAA) progression. These specific cells, located in the outer layer of the artery, secrete a protein called Sparcl1 to maintain vascular health. When Sparcl1 is absent, the growth factor FGF2 triggers abnormal lymphatic vessel growth and the formation of tertiary lymphoid structures, which severely weaken the aortic wall. To address this, scientists developed a therapeutic peptide named Spa17 that mimics the protective function of the protein. Experimental results demonstrate that this peptide effectively limits lymphatic leakage and immune cell infiltration, offering a promising noninvasive strategy for treating vascular disease. These findings highlight a previously unknown biological axis that governs arterial stability through the regulation of the immune microenvironment.

References:

• Chen M H, Hua Y J, Li Y, et al. Sparcl1 mitigates abdominal aortic aneurysm through inhibiting lymphangiogenesis-mediated TLS formation[J]. Nature Immunology, 2026: 1-12.