目的 观察小鼠异位气管移植后不同时间点NKG2D配体Rae-1和H60表达水平的变化,探讨其在肺移植后闭塞性细支气管炎(BOS)中的重要作用。方法 建立小鼠异位气管移植模型并于术后7、14、28 d取材。苏木素-伊红(HE)和Mallory染色形态学观察,并检测术后气管闭塞率,实时定量反转录聚合酶链反应(RT-qPCR)检测不同时间点移植物Rae-1和H60的mRNA表达;免疫组织化学检测不同时间点移植物的Rae-1和H60蛋白表达。结果 移植后随时间延长,HE染色提示BOS病理学不断进展,与对照组比较,气管移植物14 d和28 d管腔闭塞率不断增加[(30.82±7.61)%和(83.52±13.12)%比(3.75±1.78)%,P=0.012、0.007],Mallory染色和α-平滑肌肌动蛋白(α-SMA)的表达不断增强。RT-qPCR检测结果显示与对照组比较,移植后小鼠气管移植物14 d的H60(12.712 2±2.828 0比0.739 6±0.042 8,P=0.014)和28 d的Rae-1 mRNA(10.464 9±2.109 1比0.617 6±0.041 3,P=0.022)表达强度均明显提高。免疫组织化学检测结果显示气管移植物H60和Rae-1在蛋白水平表达分别在14 d(207.97±25.87比31.63±9.42,P=0.023)和28 d(185.34±24.06比32.84±7.85,P=0.026)明显高于对照组。结论 NKG2D配体可能参与了肺移植后BOS的发生发展,加强主要组织相容性Ⅰ类相关基因(MIC)配型或特意性阻断NKG2D通路有可能延缓并减少肺移植后BOS的产生。
Objective To observe the changes of expression of NKG2D ligand Rae-1 and H60 at different time points after heterotopic tracheal transplantation in mice, and to explore its important role in bronchiolitis obliterans syndrome (BOS) after lung transplantation. Methods The model of heterotopic tracheal transplantation in mice was established and drawn at 7, 14 and 28 days after operation. Hematoxylin and eosin (HE) staining and Mallory staining were used to observe the postoperative tracheal occlusion rate. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect the mRNA expression of Rae-1 and H60 at different time points. The expression of Rae-1 and H60 protein was detected by immunohistochemistry correspondingly.Results After transplantation, HE staining showed that BOS pathology continued to progress, and luminal occlusion rate at 14 d and 28 d in tracheal grafts was increased [(30.82±7.61)% and (83.52±13.12)% vs. (3.75±1.78)%, P=0.012, 0.007]. Mallory staining and α-smooth muscle actin (α-SMA) expression was increased. The results of RT-qPCR showed that the expression of H60 mRNA (14 d: 12.712 2±2.828 0 vs. 0.739 6±0.042 8, P=0.014) and Rae-1 mRNA (28 d: 10.464 9±2.109 1 vs. 0.617 6±0.041 3, P=0.022) was increased after transplantation as compared with the control group. Immunohistochemistry showed that the expression of H60 and Rae-1 proteins was significantly higher than that in the control group at 14 d (207.97±25.87 vs. 31.63±9.42, P=0.023) and 28 d (185.34±24.06 vs. 32.84±7.85, P=0.026).ConclusionNKG2D ligand may be involved in the development of BOS after lung transplantation. Strengthening the major histocompatibility complex (MHC) class Ⅰ chain related (MIC) typing or specifically blocking NKG2D pathway may delay and reduce BOS after lung transplantation.