Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Advanced Clinical Science and Therapeutics, The University of Tokyo, Tokyo, Japan.
Nat Commun. 2022 Sep 7;13(1):5117. doi: 10.1038/s41467-022-32658-6.
Although inflammation plays critical roles in the development of atherosclerosis, its regulatory mechanisms remain incompletely understood. Perivascular adipose tissue (PVAT) has been reported to undergo inflammatory changes in response to vascular injury. Here, we show that vascular injury induces the beiging (brown adipose tissue-like phenotype change) of PVAT, which fine-tunes inflammatory response and thus vascular remodeling as a protective mechanism. In a mouse model of endovascular injury, macrophages accumulate in PVAT, causing beiging phenotype change. Inhibition of PVAT beiging by genetically silencing PRDM16, a key regulator to beiging, exacerbates inflammation and vascular remodeling following injury. Conversely, activation of PVAT beiging attenuates inflammation and pathological vascular remodeling. Single-cell RNA sequencing reveals that beige adipocytes abundantly express neuregulin 4 (Nrg4) which critically regulate alternative macrophage activation. Importantly, significant beiging is observed in the diseased aortic PVAT in patients with acute aortic dissection. Taken together, vascular injury induces the beiging of adjacent PVAT with macrophage accumulation, where NRG4 secreted from the beige PVAT facilitates alternative activation of macrophages, leading to the resolution of vascular inflammation. Our study demonstrates the pivotal roles of PVAT in vascular inflammation and remodeling and will open a new avenue for treating atherosclerosis.
尽管炎症在动脉粥样硬化的发展中起着关键作用,但它的调节机制仍不完全清楚。已有研究报道,血管损伤会导致血管周围脂肪组织(PVAT)发生炎症改变。在这里,我们发现血管损伤会诱导 PVAT 的“褐变”(棕色脂肪组织样表型改变),这是一种微调炎症反应和血管重塑的保护机制。在血管内损伤的小鼠模型中,巨噬细胞在 PVAT 中积聚,导致褐变表型改变。通过基因沉默 PRDM16(褐变的关键调节因子)抑制 PVAT 褐变会加剧损伤后的炎症和血管重塑。相反,激活 PVAT 褐变可减轻炎症和病理性血管重塑。单细胞 RNA 测序显示,米色脂肪细胞大量表达神经调节蛋白 4(NRG4),它对巨噬细胞的激活有重要的调控作用。重要的是,在急性主动脉夹层患者的病变主动脉 PVAT 中观察到明显的褐变。总之,血管损伤会诱导相邻 PVAT 的褐变和巨噬细胞积聚,而从米色 PVAT 分泌的 NRG4 促进了巨噬细胞的替代激活,从而导致血管炎症的消退。我们的研究表明了 PVAT 在血管炎症和重塑中的关键作用,并为治疗动脉粥样硬化开辟了新途径。