摘要
目的探讨IL-33/ST2应答轴是否通过激活巨噬细胞NF-κB通路促进低氧性肺动脉高压(hypoxic pulmonary hypertension,HPH)的发生、发展。方法采用野生型(WT)、IL-33转基因(Il33 Tg)小鼠和St2基因敲除(St2-/-)小鼠制备HPH小鼠模型,采集小鼠支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)和肺组织标本;进行小鼠BALF总细胞和分类计数;用免疫荧光和免疫组化法检测IL-33、ST2在小鼠肺组织的表达水平和MAC-2+巨噬细胞聚集;用ELISA检测肺组织匀浆中的细胞因子含量;用免疫印迹(Western blot)检测转录因子NF-κB在模型鼠肺组织及体外IL-33刺激的小鼠巨噬细胞系RAW264.7的表达水平。结果 IL-33、ST2在HPH模型小鼠肺组织中表达上调并伴有MAC-2+巨噬细胞增加;Il33 Tg模型鼠肺部以巨噬细胞为主的炎性细胞浸润;低氧可诱导WT小鼠肺组织表达促炎因子IL-1β和巨噬细胞趋化蛋白(monocyte chemotactic protein 1,MCP-1),而St2基因缺失则下调上述细胞因子表达;低氧亦可诱导上调NF-κB在WT小鼠肺组织表达,而St2基因缺失则可抑制低氧诱导NF-κB的表达。体外实验显示IL-33能上调巨噬细胞NF-κB的表达。结论低氧可促进IL-33/ST2表达增强,进而诱导巨噬细胞内NF-κB通路的激活,导致促炎细胞因子MCP-1、IL-1β的产生,加重炎症反应并间接引起肺动脉血管重塑参与HPH的发生、发展。
Objective To investigate whether the IL-33/ST2 axis participates in development of hypoxia-induced pulmonary hypertension（ HPH） through upregulating the NF-κB pathway of macrophages. Methods Murine models with HPH were prepared by using wild type（ WT）,Il33 transgenic and St2 knockout（ St2-/-） mice. Bronchoalveolar lavage fluid（ BALF） and lungs tissue samples were collected from mice. The total number of cells and differential cellular counts in BALF were counted; immunofluorescence and immunohistochemistry were employed to detect the expression levels of IL-33 and ST2,and accumulation of MAC-2＋macrophages in the tissue sections from lungs of murine models; ELISA was used to measure concentrations of inflammatory cytokines and chemokines in lungs tissue homogenates. Western blot was used to detect the activation of NF-κB signaling pathway in murine lungs tissues and cultured mouse macrophage cell line RAW264.7 in the presence of IL-33. Results Expression of IL-33 and its receptor ST2,as well as MAC-2＋macrophages were up-regulated in the lungs tissues of WT mice with HPH compared with control mice. Under hypoxic conditions,Il33 transgenic mice had a increase in the total number of inflammatory cells especially,macrophages in BALF. Hypoxia induced expression of pro-inflammatory cytokine IL-1β and chemokine MCP-1 in lungs tissues of WT mice,but not in those of St2-/-mice. Hypoxia also induced the elevated expression of NF-κB in the lungs tissue of WT,but not of St2-/-mice. in vitro,IL-33 obviously promoted the expression of NF-κB in RAW264.7,a murine macrophage cell line. Conclusion Hypoxia promoted expression of IL-33 and its receptor ST2,while binding of IL-33/ST2 activated NF-κB pathway in macrophages,leading to the production of IL-1β and MCP-1,which further enlarge local tissue inflammation,directly or indirectly involved in the occurrence and development of HPH.
作者
刘杰
沙宇惠
高阳
杜晓楠
王文俊
黄琼
孙英
王炜
LIU Jie;SHA Yu-hui;GAO Yang;DU Xiao-nan;WANG Wen-jun;HUANG Qiong;SUN Ying;WANG Wei(Department of Immunology,School of Basic Medical Sciences,Capital Medical University,Beijing 100069,China)
出处
《微生物学免疫学进展》
2018年第4期26-34,共9页
Progress In Microbiology and Immunology
基金
国家自然科学基金(81370152
81471594
81770049)
作者简介
刘杰（1984-），男，硕士研究生，主要从事肺血管重塑的免疫学机制研究。;通信作者：王炜，副教授，E-mail：wy_robin@ccmu．edu．cn
