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低氧促进脂多糖诱导小胶质细胞CXCL10表达

史子毕¹, 胡月¹, 阮倩倩¹, 范明¹, 赵名¹, 朱玲玲^1,2,3,4,*

¹军事科学院军事医学研究院军事认知与脑科学研究所，北京 100850；²安徽医科大学生命科学学院，合肥 230032；³南华大学衡阳医学院，衡阳 421001；⁴南通大学神经再生协同创新中心，南通 226001

摘要

本文旨在观察低氧处理对脂多糖(lipopolysaccharide, LPS)诱导的小胶质细胞CXC趋化因子配体10 (CXC-chemokine ligand-10, CXCL10)表达的影响，并探讨其作用机制。将C57BL/6J小鼠随机分为对照组、低氧组、LPS组以及低氧联合LPS组，LPS组腹腔注射0.5 mg/kg LPS，低氧组放置于低压低氧舱(模拟海拔6 000 m)中，处理6 h后收集血清和海马组织样品。用ELISA法检测血清和海马组织中CXCL10的含量。用低氧(1% O2)和/或LPS (100 ng/mL)刺激小胶质细胞系BV2和原代小胶质细胞6 h，用实时定量PCR检测细胞CXCL10 mRNA表达水平，用ELISA检测细胞培养上清中CXCL10的含量，用Western blot检测核因子κB (nuclear factor κB, NF-κB)信号通路相关蛋白p65和IκBα的表达。另外，用小分子化合物PDTC阻断NF-κB信号通路后检测BV2细胞CXCL10 mRNA表达水平。结果显示，在LPS诱导的小鼠炎症模型中，低氧处理可促进LPS对小鼠血清和海马组织中CXCL10水平的上调作用。和LPS单独处理的细胞相比，低氧联合LPS处理的BV2细胞CXCL10 mRNA表达水平和培养上清中的CXCL10含量均显著上调；低氧联合LPS处理的原代小胶质细胞CXCL10 mRNA水平显著上调。和低氧或LPS单独处理的细胞相比，低氧联合LPS处理的BV2细胞p65和IκBα磷酸化水平显著提高。NF-κB信号通路特异性抑制剂PDTC可阻断LPS对BV2细胞CXCL10 mRNA表达的诱导作用。以上结果提示，在动物和细胞模型中，低氧均能够促进LPS对CXCL10的诱导作用，NF-κB信号通路在其中起着重要的作用。

关键词： 脂多糖; 低氧; 小胶质细胞; CXC趋化因子配体10

Hypoxia promotes lipopolysaccharide-induced CXCL10 expression in microglia

SHI Zi-Bi¹, HU Yue¹, RUAN Qian-Qian¹, FAN Ming¹, ZHAO Ming¹, ZHU Ling-Ling^1,2,3,4,*

¹Institute of Military Cognition and Brain Sciences, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing 100850, China；²School of Life Sciences, Anhui Medical University, Hefei 230032, China；³Hengyang Medical School, University of South China, Hengyang 421001, China；⁴Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China

Abstract

This study was aimed to investigate the effect of hypoxia on lipopolysaccharide (LPS)-induced CXC-chemokine ligand-10 (CXCL10) expression and the underlying mechanism. C57BL/6J mice were randomly divided into control, hypoxia, LPS, and hypoxia combined with LPS groups. The LPS group was intraperitoneally injected with 0.5 mg/kg LPS, and the hypoxia group was placed in a hypobaric hypoxia chamber (simulated altitude of 6 000 m). The serum and hippocampal tissue samples were collected after 6 h of the treatment. The levels of CXCL10 in the serum and hippocampal tissue of mice were detected by ELISA. The microglia cell line BV2 and primary microglia were stimulated with hypoxia (1% O2) and/or LPS (100 ng/mL) for 6 h. The mRNA expression level of CXCL10 and its content in culture supernatant were detected by real-time quantitative PCR and ELISA, respectively. The phosphorylation levels of nuclear factor κB (NF-κB) signaling pathway-related proteins, p65 and IκBα, were detected by Western blot. Moreover, after NF-κB signaling pathway being blocked with a small molecular compound, PDTC, CXCL10 mRNA expression level was detected in the BV2 cells. The results showed that in the LPS-induced mouse inflammatory model, hypoxia treatment could promote LPS-induced up-regulation of CXCL10 in both serum and hippocampus. Compared with the cells treated with LPS alone, the expression of CXCL10 mRNA and the content of CXCL10 in the culture supernatant of BV2 cells treated with hypoxia combined with LPS were significantly increased. The CXCL10 mRNA level of primary microglial cells treated with hypoxia combined with LPS was significantly up-regulated. Compared with the cells treated with hypoxia or LPS alone, the phosphorylation levels of p65 and IκBα in the BV2 cells treated with hypoxia combined with LPS were significantly increased. PDTC blocked the induction of CXCL10 gene expression by LPS in the BV2 cells. These results suggest that hypoxia promotes LPS-induced expression of CXCL10 in both animal and cell models, and NF-κB signaling pathway plays an important role in this process.

Key words: lipopolysaccharide (LPS); hypoxia; microglia; CXC-chemokine ligand-10

收稿日期：　　录用日期：

通讯作者：朱玲玲　　E-mail: linglingzhuamms@126.com

DOI: 10.13294/j.aps.2022.0087

引用本文：

史子毕, 胡月, 阮倩倩, 范明, 赵名, 朱玲玲. 低氧促进脂多糖诱导小胶质细胞CXCL10表达[J]. 生理学报 2023; 75 (2): 153-159.

SHI Zi-Bi, HU Yue, RUAN Qian-Qian, FAN Ming, ZHAO Ming, ZHU Ling-Ling. Hypoxia promotes lipopolysaccharide-induced CXCL10 expression in microglia. Acta Physiol Sin 2023; 75 (2): 153-159 (in Chinese with English abstract).