Downregulation of miR-199b promotes the acute spinal cord injury through IKKβ-NF-κB signaling pathway activating microglial cells.
Inflammatory response played an important role in the progression of spinal cord injury (SCI). Several miRNAs were associated with the pathology of SCI. However, the molecular mechanism of miRNA involving in inflammatory response in acute SCI (ASCI) was poorly understood. Sprague-Dawley (SD) rats were divided into 2 groups: control group (n=6) and acute SCI (ASCI) group (n=6). The expression of miR-199b and IκB kinase β-nuclear factor-kappa B (IKKβ-NF-κB) signaling pathway were evaluated by quantitative reverse transcription-PCR (qRT-PCR) in rats with ASCI and in primary microglia activated by lipopolysaccharide (LPS). We found that downregulation of miR-199b and activation of IKKβ/NF-κB were observed in rats after ASCI and in activated microglia. miR-199b negatively regulated IKKβ by targeting its 3'- untranslated regions (UTR) through using luciferase reporter assay. Overexpression of miR-199b reversed the up-regulation of IKKβ, p-p65, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in LPS-treated BV2 cells assessed by western blotting analysis. In addition, BMS-345541 reversed the up-regulation effects of miR-199b inhibitor on the expression of TNF-α and IL-1β. In the SCI rats, overexpression of miR-199b attenuated ASCI and decreased the expression of IKKβ-NF-κB signaling pathway and TNF-α and IL-1β. These results indicated that miR-199b attenuated ASCI at least partly through IKKβ-NF-κB signaling pathway and affecting the function of microglia. Our findings suggest that miR-199b may be employed as therapeutic for spinal cord injury.
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Heng-Jun
HJ
Zhou
Department of Anesthesia, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China.
Li-Qing
LQ
Wang
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Qing-Sheng
QS
Xu
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Zuo-Xu
ZX
Fan
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Yu
Y
Zhu
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Hao
H
Jiang
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Xiu-Jue
XJ
Zheng
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China.
Yue-Hui
YH
Ma
Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang, China. Electronic address: zhanry148@163.com.
Ren-Ya
RY
Zhan
D000208:Acute Disease; D000818:Animals; D015536:Down-Regulation; D005260:Female; D051550:I-kappa B Kinase / Q000378:metabolism*; D007249:Inflammation / Q000473:pathology; D008070:Lipopolysaccharides; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D017628:Microglia / Q000378:metabolism* / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013119:Spinal Cord Injuries / Q000235:genetics* / Q000473:pathology*; D051996:Transcription Factor RelA / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics
D008070:Lipopolysaccharides; C552425:MIRN199 microRNA, rat; D035683:MicroRNAs; D016328:NF-kappa B; D051996:Transcription Factor RelA; D051550:I-kappa B Kinase
IKKβ-NF-κB signaling pathway; MiR-199b; Microglia; Spinal cord injury