1. Academic Validation
  2. Downregulation of Nogo-B ameliorates cerebral ischemia/reperfusion injury in mice through regulating microglia polarization via TLR4/NF-kappaB pathway

Downregulation of Nogo-B ameliorates cerebral ischemia/reperfusion injury in mice through regulating microglia polarization via TLR4/NF-kappaB pathway

  • Neurochem Int. 2023 May 23;167:105553. doi: 10.1016/j.neuint.2023.105553.
Peng Gong 1 Hui-Yu Jia 2 Rui Li 3 Zheng Ma 4 Min Si 5 Can Qian 6 Feng-Qin Zhu 7 Luo Sheng-Yong 8
Affiliations

Affiliations

  • 1 Department of Pharmacy, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, 230032, China. Electronic address: gongpeng2008.ok@163.com.
  • 2 Anhui Medical College (Anhui Academy of Medical Sciences), Hefei, Anhui, 230061, China. Electronic address: Jiahuiyu11@163.com.
  • 3 Anhui Medical College (Anhui Academy of Medical Sciences), Hefei, Anhui, 230061, China. Electronic address: liruianyi@163.com.
  • 4 Anhui Medical College (Anhui Academy of Medical Sciences), Hefei, Anhui, 230061, China. Electronic address: dodomz@sina.com.
  • 5 Anhui Medical College (Anhui Academy of Medical Sciences), Hefei, Anhui, 230061, China. Electronic address: 1198535115@qq.com.
  • 6 Anhui Medical College (Anhui Academy of Medical Sciences), Hefei, Anhui, 230061, China. Electronic address: 2210365067@qq.com.
  • 7 Cancer Hospital, Chinese Academy of Science, Hefei, Anhui, 230032, China. Electronic address: tczfq88@126.com.
  • 8 Anhui Medical College (Anhui Academy of Medical Sciences), Hefei, Anhui, 230061, China. Electronic address: lsy770728@126.com.
Abstract

Many studies have shown a close association between Nogo-B and inflammation-related diseases. However, uncertainty does exist, regarding Nogo-B function in the pathological progression of cerebral ischemia/reperfusion (I/R) injury. Middle cerebral artery occlusion/reperfusion (MCAO/R) model was utilized in C57BL/6L mice to mimic ischemic stroke in vivo. Using oxygen-glucose deprivation and reoxygenation (ODG/R) model in microglia cells (BV-2) to establish cerebral I/R injury in vitro. Various methods, including Nogo-B siRNA transfection, mNSS and the rotarod test, TTC, HE and Nissl staining, immunofluorescence staining, immunohistochemistry, Western blot, ELISA, TUNEL and qRT-PCR were employed to probe into the effect of Nogo-B downregulation on cerebral I/R injury and the potential mechanisms. A small amount of Nogo-B expression (protein and mRNA) was observed in cortex and hippocampus before ischemia, then Nogo-B expression increased significantly on day 1, reaching the maximum on day 3, remaining stable on day 14 after I/R, and decreasing gradually after 21 days, but it still rose significantly compared with that observed preischemia. Nogo-B down-regulation could markedly reduce the neurological score and infarct volume, improve the histopathological changes and neuronal Apoptosis, lower the number of CD86+/Iba1+ cells and the levels of IL-1β, IL-6, and TNF-α, and raise the density of NeuN fluorescence, the number of CD206+/Iba1+ cells, and the level of IL-4, IL-10 and TGF-β in brain of MCAO/R mice. Treatment with Nogo-B siRNA or TAK-242 in BV-2 cells could obviously decrease the CD86 fluorescence density and the mRNA expression of IL-1β, IL-6 and TNF-α, increase CD206 fluorescence density and the mRNA expression of IL-10 after OGD/R injury. In addition, the expression of TLR4, p-IκBα and p-p65 proteins significantly increased in the brain after MCAO/R and BV-2 cells exposed to OGD/R. Treatment with Nogo-B siRNA or TAK-242 prominently reduced the expression of TLR4, p-IκBα and p-p65. Our findings suggest that the down-regulation of Nogo-B exerts protective effect on cerebral I/R injury by modulating the microglia polarization through inhibiting TLR4/NF-κB signaling pathway. Nogo-B may be a potential therapeutic target for ischemic stroke.

Keywords

Ischemic stroke; Microglia; Nogo-B; Polarization; TLR4/NF-κB.

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