背景:外周动脉疾病引起的外周缺血与全身性炎症有关,这可能会加剧潜在的合并症,如动脉粥样硬化和心力衰竭。然而,外周动脉疾病患者炎症和炎症细胞产生增加的机制仍然知之甚少.
方法:我们使用从患有外周动脉疾病的患者收集的外周血,并在喂食西方饮食的Apoe-/-小鼠和使用标准实验室饮食的C57BL/6J小鼠中进行后肢缺血(HI)。批量和单细胞RNA测序分析,整体安装显微镜,和流式细胞术分析造血干细胞和祖细胞(HSPC)的增殖,分化,和搬迁。
结果:我们观察到患有外周动脉疾病的患者和患有HI的Apoe-/-小鼠的血液中白细胞数量增加。RNA测序和骨髓的整体成像显示,HSPC从成骨细胞生态位迁移到血管生态位,以及它们的过度增殖和分化。单细胞RNA测序证明了负责炎症的基因的改变,骨髓细胞动员,HI后的HSPC分化。HI后Apoe-/-小鼠炎症加重,动脉粥样硬化加重。令人惊讶的是,HI后,骨髓HSPC表达较高的IL(白介素)-1和IL-3受体。同时,HI后,Il1r1和Il3rb的启动子增强了H3K4me3和H3K27ac标记。这些受体的遗传和药理学抑制导致抑制HSPC增殖,减少白细胞产生,改善动脉粥样硬化.
结论:我们的研究结果表明炎症增加,骨髓血管壁龛中的HSPC丰度,HI后HSPC中IL-3Rb和IL-1R1(IL-1受体1)表达升高。此外,IL-3Rb和IL-1R1信号在HSPC增殖中起关键作用,白细胞丰度,HI后动脉粥样硬化加重。
Peripheral ischemia caused by peripheral artery disease is associated with systemic inflammation, which may aggravate underlying comorbidities such as atherosclerosis and heart failure. However, the mechanisms of increased inflammation and inflammatory cell production in patients with peripheral artery disease remain poorly understood.
We used peripheral blood collected from patients with peripheral artery disease and performed hind limb ischemia (HI) in Apoe-/- mice fed a Western diet and C57BL/6J mice with a standard laboratory diet. Bulk and single-cell RNA sequencing analysis, whole-mount microscopy, and flow cytometry were performed to analyze hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and relocation.
We observed augmented numbers of leukocytes in the blood of patients with peripheral artery disease and Apoe-/- mice with HI. RNA sequencing and whole-mount imaging of the bone marrow revealed HSPC migration into the vascular niche from the osteoblastic niche and their exaggerated proliferation and differentiation. Single-cell RNA sequencing demonstrated alterations in the genes responsible for inflammation, myeloid cell mobilization, and HSPC differentiation after HI. Heightened inflammation in Apoe-/- mice after HI aggravated atherosclerosis. Surprisingly, bone marrow HSPCs expressed higher amounts of the receptors for IL (interleukin)-1 and IL-3 after HI. Concomitantly, the promoters of Il1r1 and Il3rb had augmented H3K4me3 and H3K27ac marks after HI. Genetic and pharmacological inhibition of these receptors resulted in suppressed HSPC proliferation, reduced leukocyte production, and ameliorated atherosclerosis.
Our findings demonstrate increased inflammation, HSPC abundance in the vascular niches of the bone marrow, and elevated IL-3Rb and IL-1R1 (IL-1 receptor 1) expression in HSPC following HI. Furthermore, the IL-3Rb and IL-1R1 signaling plays a pivotal role in HSPC proliferation, leukocyte abundance, and atherosclerosis aggravation after HI.