中国神经再生研究(英文版) ›› 2020, Vol. 15 ›› Issue (on line): 1-9.

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Downregulation of miR-491-5p promotes neovascularization after traumatic brain injury and discussion on its molecular mechanism

  

  • 出版日期:2020-01-01 发布日期:2021-04-22

Wei Tang, Zong-Duo Guo, Wei-Na Chai, Dong-Lin Du, Xiao-Min Yang, Lang Cao, Hong Chen, Chao Zhou, Chong-Jie Cheng, Xiao-Chuan Sun, Zhi-Jian Huang, Jian-Jun Zhong   

  1. 1Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China; 2Department of Ophthalmology, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
  • Online:2020-01-01 Published:2021-04-22
  • Contact: Zhi-Jian Huang, MD, PhD, zhijian@cqmu.edu.cn; Jian-Jun Zhong, MD, PhD, jianjun@hospital.cqmu.edu.cn.
  • Supported by:
    This work was funded by grants of National Natural Science Foundation of China, No. 82071397 (to XCS), No. 82071332 (to ZDG); Youth Fund of National Natural Science Foundation of China, No. 81801230 (to JJZ); and the Excellent Scientific Research Talents Fund of the First Affiliated Hospital of Chongqing Medical University, China (to JJZ).

摘要:

https://orcid.org/0000-0002-8241-0761 (Zhi-Jian Huang); 

https://orcid.org/0000-0002-9481-5088 (Jian-Jun Zhong) 

Abstract:

MicroRNA-491-5p (miR-491-5p) plays an important role in regulating cell proliferation and migration, but the effect of miR-491-5p on neovascularization after traumatic brain injury remains poorly understood. In this study, a controlled cortical injury model in C57BL/6 mice and an oxygen-glucose deprivation model in mice brain microvascular endothelial cells were established to simulate traumatic brain injury in vivo and in vitro. In vivo, quantitative real time-polymerase chain reaction results found that the expression of miR-491-5p was increased or decreased with an intracerebroventricular injection of a miR-491-5p agomir or antagomir, and the expression of miR-491-5p was found to be slightly decreased after traumatic brain injury. To detect the neuroprotective effect of miR-491-p, the neurological severity scores, Morris water maze test, laser speckle techniques and immunofluorescence staining results found that downregulation of miR-491-5p could alleviate the neurological dysfunction and promote the recovery of regional cerebral blood flow, increase the number of lectin-stained microvessels and increase the survival of neurons after traumatic brain injury. In vitro, to explore of the potential mechanism of miR-491-5p on neovascularization, quantitative real time-polymerase chain reaction results found that the expression of miR-491-5p was increased or decreased in brain microvascular endothelial cells after transfected with miR-491-5p mimic or inhibitor. Dual-luciferase and western blot assays verified that metallothionein-2 was a target gene of miR-491-5p. CCK-8 assay, flow cytometry and DCFH-DA assay results confirmed that downregulation of miR-491-5p could increase brain microvascular endothelial cell viability, reduced cell apoptosis and alleviated oxidative stress under oxygen-glucose deprivation treatment. Cell scratch assay, Transwell assay, tube formation assay and western blot assay results demonstrated that downregulation of miR-491-5p could promote the migration, proliferation and tube formation of brain microvascular endothelial cells in a metallothionein-2-dependent hypoxia-inducible factor-1a/ vascular endothelial growth factor pathway. Above data confirm that downregulation of miR-491-5p can promote neovascularization, restore cerebral blood flow and improve the recovery of neurological function after traumatic brain injury. The mechanism may be mediated through a metallothionein-2-dependent hypoxia-inducible factor-1a/vascular endothelial growth factor signaling pathway and alleviation of oxidative stress.  

Key words: brain injury, cell migration, cell proliferation, endothelial cell, hypoxia-inducible factor-1 alpha, metallothionein 2, microRNA, neovascularization, neurons, vascular endothelial growth factor