中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2019, Vol. 14 ›› Issue (9): 1594-1602.doi: 10.4103/1673-5374.255975

• 原著:退行性病与再生 • 上一篇    下一篇

白细胞介素4可影响小胶质细胞的自噬

  

  • 出版日期:2019-09-15 发布日期:2019-09-15
  • 基金资助:

    辽宁省自然科学基金（20170541036）

Interleukin-4 affects microglial autophagic flux

Run-Hong Tang 1 , Rui-Qun Qi 2 , Hua-Yan Liu 1   

  1. 1 Department of Neurology, the First Hospital of China Medical University, Shenyang, Liaoning Province, China
    2 Department of Dermatology, Key Laboratory of Immunodermatology, the First Hospital of China Medical University, Shenyang, Liaoning Province, China
  • Online:2019-09-15 Published:2019-09-15
  • Contact: Hua-Yan Liu, PhD, liuhuayancmu@163.com.
  • Supported by:

    This study was supported by the Natural Science Foundation of Liaoning Province of China, No. 20170541036 (to HYL).

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摘要：

白细胞介素4通过调节小胶质细胞表型和调节β-淀粉样蛋白的吞噬作用以及分泌抗炎和神经营养因子在阿尔茨海默病中发挥重要的保护作用。最近许多证据表明，自噬通过影响M1/M2极化来调节先天免疫。然而，白细胞介素4如何在小胶质细胞自噬过程中发挥作用尚不清楚。鉴于此，实验用0，10，20和50 ng/mL白细胞介素4处理BV2小胶质细胞24，48，72 h，然后通过蛋白质印迹试验检测LC3 II和P62蛋白表达水平。实验将BV2小胶质细胞分别用20 ng/mL的白细胞介素4，500 μM的3-甲基腺嘌呤（自噬抑制剂，作为阴性对照），100 nM的雷帕霉素（自噬诱导剂，作为阳性对照），500 μM的3-甲基腺嘌呤+ 20 ng/mL的白细胞介素4分别预处理24 h，然后用1 μM β-淀粉样蛋白处理或不处理(作为对照)24 h，随后通过蛋白质印迹试验检测细胞LC3 II和P62蛋白表达水平；通过实时荧光定量PCR评估M1和M2表型的多个标记物的表达；通过酶联免疫吸附测定法测量细胞内和上清液β-淀粉样蛋白水平。结果表明：(1)白细胞介素4诱导了小胶质细胞自噬通量，在剂量为20 ng/mL处理48 h时最显著；(2)β-淀粉样蛋白阻断了小胶质细胞自噬通量，该效应可被白细胞介素4逆转；(3)β-淀粉样蛋白激活小胶质细胞并可使小胶质细胞极化为M1表型，而白细胞介素4可使β-淀粉样蛋白诱导的M1表型转变为M2表型，该过程不依赖于自噬；(4)白细胞介素4处理的小胶质细胞增加了β-淀粉样蛋白的摄取和降解，其部分通过自噬介导；(5)上述数据说明，白细胞介素4部分通过小胶质细胞自噬途径增加Aβ的摄取和降解，可能以此发挥对阿尔茨海默病的保护作用。

orcid: 0000-0001-9806-9003 (Hua-Yan Liu)

关键词: 阿尔茨海默病, 白细胞介素4, &beta, -淀粉样蛋白, 小胶质细胞自噬, 小胶质细胞极化, 小胶质细胞, M1表型, M2 表型, 肽降解, 神经再生

Abstract:

Interleukin-4 plays an important protective role in Alzheimer’s disease by regulating microglial phenotype, phagocytosis of amyloid-β, and secretion of anti-inflammatory and neurotrophic cytokines. Recently, increasing evidence has suggested that autophagy regulates innate immunity by affecting M1/M2 polarization of microglia/macrophages. However, the role of interleukin-4 in microglial autophagy is unknown. In view of this, BV2 microglia were treated with 0, 10, 20 or 50 ng/mL interleukin-4 for 24, 48, or 72 hours. Subsequently, light chain 3-II and p62 protein expression levels were detected by western blot assay. BV2 microglia were incubated with interleukin-4 (20 ng/mL, experimental group), 3-methyladenine (500 μM, autophagy inhibitor, negative control group), rapamycin (100 nM, autophagy inductor, positive control group), 3-methyladenine + interleukin-4 (rescue group), or without treatment for 24 hours, and then exposed to amyloid-β (1 μM, model group) or vehicle control (control) for 24 hours. LC3-II and p62 protein expression levels were again detected by western blot assay. In addition, expression levels of multiple markers of M1 and M2 phenotype were assessed by real-time fluorescence quantitative polymerase chain reaction, while intracellular and supernatant amyloid-β protein levels were measured by enzyme-linked immunosorbent assay. Our results showed that interleukin-4 induced microglial autophagic flux, most significantly at 20 ng/mL for 48 hours. Interleukin-4 pretreated microglia inhibited blockade of amyloid-β-induced autophagic flux, and promoted amyloid-β uptake and degradation partly through autophagic flux, but inhibited switching of amyloid-β-induced M1 phenotype independent on autophagic flux. These results indicate that interleukin-4 pretreated microglia increases uptake and degradation of amyloid-β in a process partly me¬diated by autophagy, which may play a protective role against Alzheimer’s disease.

Key words: nerve regeneration, Alzheimer’s disease, interleukin-4, amyloid-β, microglial autophagy, microglial polarization, microglia, M1 phenotype, M2 phenotype, peptide degradation, neural regeneration