神经降压素受体1在大鼠肺缺血再灌注损伤中的表达及作用

Effect of NTR1 expression in rats with lung ischemia-reperfusion injury and mechanism

摘要:

目的  观察神经降压素受体1（NTR1）在大鼠肺缺血再灌注损伤LIRI模型中的表达和作用及其与Toll样受体4（TLR4）和缺氧诱导因子（HIF-1α）的关系，探讨NTR1在LIRI中的病理作用机制。方法  40只雄性SD大鼠，分为8组进行观察。①假手术组；②LIRI组；③LIRI+生理盐水对照组；④LIRI+DMSO对照组；⑤LIRI+脂多糖干预组（TLR4激活组）；⑥LIRI+TAK-242干预组（TLR4抑制组）；⑦LIRI+NT干预组（NTR1激活组）；⑧LIRI+SR48692干预组（NTR1抑制组）。制作大鼠原位LIRI模型，取各组大鼠左肺组织，观察肺组织病理变化、行逆转录-聚合酶链反应（RT-PCR）及蛋白质印迹法检测，统计分析NTR1在大鼠LIRI模型中的表达及作用及其与TLR4和HIF-1α的关系。结果  肺IRI组NTR1 mRNA及蛋白的表达较假手术组增加（P <0.05）；NT可进一步增加LIRI的炎症因子水平、细胞凋亡及肺组织病理损伤，而SR48692可减轻上述改变（P <0.05）；与LIRI组比较，脂多糖干预组NTR1表达进一步增强，而TAK-242干预组NTR1表达则受到抑制（P <0.05）；与LIRI组比较，HIF-1α mRNA和蛋白表达被SR48692抑制，而被NT增强（P <0.05）。结论  NT-NTR1与LIRI关系密切，参与了LIRI的发病机制，在LIRI中，可能存在TLR4-NTR1-HIF-1α信号通路，本研究为发现新的LIRI有效治疗靶点提供了理论依据。

Abstract:

Objective  To investigate neurotensin receptor 1 (NTR1) expression and the effect and mechanism of NTR1 expression in rats with lung ischemia-reperfusion injury (LIRI). Methods Forty SD rats were randomly grouped as Sham group, LIRI group, LIRI+saline control group, LIRI+DMSO control group, LIRI+TLR4-activated group, LIRI+TAK-242 group (TLR4-inhibited group), LIRI+NTR1-activated group and LIRI+ NTR1-inhibited group. The NTR1 expression and the role of NTR1 in the LIRI rats were detected with RT-PCR and Western blot and statistically analyzed. Results NTR1 mRNA and protein expressions in the LIRI group were significantly increased comparing with the sham group (P < 0.05). NT further increased the levels of inflammatory cytokines, apoptosis and lung pathological injury in the LIRI group, while SR48692 significantly reduced the above changes (P < 0.05). Compared with the LIRI group, NTR1 expression was further enhanced in the LIRI+LPS group and was significantly inhibited in the LIRI+TAK-242 group (P < 0.05). HIF-1α mRNA and protein expressions were significantly inhibitedby SR48692 and was significantly enhanced by NT compared with the LIRI group(P < 0.05). Conclusions There is a close relationship between NTR1 and LIRI. NT-NTR1 is involved in the pathogenesis of LIRI. There may be TLR4-NTR1-HIF-1α signal pathway in LIRI and the theoretical basis is provided to find new effective therapeutic targets in LIRI.