Beijing An Zhen Hospital, Capital Medical University; The Key Laboratory of Remodeling-related Cardiovascular Diseases, Ministry of Education, Institute of Heart Lung and Blood Vessel Diseases, Beijing, China.
PLoS One. 2013 May 2;8(5):e62001. doi: 10.1371/journal.pone.0062001. Print 2013.
Delayed or impaired reendothelialization is a major cause of stent thrombosis in the interventional treatment of coronary heart disease. T cells are involved in neointima formation of injured arteries. However, the regulated mechanism of reendothelialization and the role of CD8 T cell in reendothelialization are unclear.
Immunofluorescence staining showed that CD8 positive cells were increased in wire injured femoral artery of mice. On day 21 after injury, elastin staining showed that knockout of CD8 (CD8(-/-)) significantly increased intimal thickness and a ratio of intima to media by 1.8 folds and 1.9 folds respectively in injured arteries. Evans blue staining showed that knockout of CD8 delayed the reendothelialization area on day 7 after injury (18.8±0.5% versus 42.1±5.6%, p<0.05). In vitro, a migration assay revealed that CD8(-/-) T cells co-cultured with WT macrophages significantly inhibited the migration of the endothelial cells (ECs); compared to CD4(+) T cells, and CD8(+) T cells could promote the ECs migration. Furthermore, real-time PCR analysis showed that knockout of CD8 increased the level of tumor necrosis factor α (TNF-α) in injured arteries and cytometric bead cytokine array showed that TNF-α was elevated in cultured CD8(-/-) T cells. Finally, a wound-healing assay showed that recombinant TNF-α significantly inhibited the migration of ECs.
Our study suggested that CD8(+) T cells could promote the reendothelialization and inhibit the neointima formation after the artery wire injury, and this effect is at least partly dependent on decreasing TNF-α production promoting ECs migration.
在冠心病的介入治疗中，延迟或受损的再内皮化是支架内血栓形成的主要原因。T 细胞参与受损动脉的新生内膜形成。然而，再内皮化的调节机制和 CD8 T 细胞在再内皮化中的作用尚不清楚。
免疫荧光染色显示，小鼠钢丝损伤股动脉中 CD8 阳性细胞增加。损伤后第 21 天，弹力蛋白染色显示，CD8 敲除（CD8（-/-））显著增加损伤动脉的内膜厚度和内膜与中膜的比值，分别为 1.8 倍和 1.9 倍。伊文思蓝染色显示，CD8 敲除延迟损伤后第 7 天的再内皮化面积（18.8±0.5%比 42.1±5.6%，p<0.05）。体外迁移实验显示，CD8（-/-）T 细胞与 WT 巨噬细胞共培养显著抑制内皮细胞（ECs）的迁移；与 CD4（+）T 细胞相比，CD8（+）T 细胞可促进 ECs 的迁移。此外，实时 PCR 分析显示，CD8 敲除增加了损伤动脉中肿瘤坏死因子 α（TNF-α）的水平，细胞因子微珠阵列显示培养的 CD8（-/-）T 细胞中 TNF-α升高。最后，划痕实验显示重组 TNF-α显著抑制 ECs 的迁移。
我们的研究表明，CD8（+）T 细胞可促进动脉钢丝损伤后再内皮化，抑制新生内膜形成，这种作用至少部分依赖于减少 TNF-α的产生，促进 ECs 的迁移。
