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MicroRNA-9-5p alleviates blood-brain barrier damage and neuroinflammation after traumatic brain injury.

ABSTRACT: The level of microRNA-9-5p (miRNA-9-5p) in brain tissues is significantly changed after traumatic brain injury (TBI). However, the effect of miRNA-9-5p for brain function in TBI has not been elucidated. In this study, a controlled cortical impact model was used to induce TBI in Sprague-Dawley rats, and an oxygen glucose deprivation model was used to mimic the pathological state in vitro. Brain microvascular endothelial cells (BMECs) and astrocytes were extracted from immature Sprague-Dawley rats and cocultured to reconstruct blood-brain barrier (BBB) in vitro. The results show that the level of miRNA-9-5p was significantly increased in brain tissues after TBI, and up-regulation of miRNA9-5p contributed to the recovery of neurological function. Up-regulation of miRNA-9-5p with miRNA agomir may significantly alleviate apoptosis, neuroinflammation, and BBB damage in rats after TBI. Moreover, a dual luciferase reporter assay confirmed that miRNA-9-5p is a post-transcriptional modulator of Ptch-1. In in vitro experiments, the results confirmed that up-regulation of miRNA-9-5p with miRNA mimic alleviates cellular apoptosis, inflammatory response, and BBB damage mainly by inhibiting Ptch-1. In addition, we found that the activation of Hedgehog pathway was accompanied by inhibition of NF-?B/MMP-9 pathway in the BMECs treated with miRNA-9-5p mimic. Taken together, these results indicate that up-regulation of miRNA-9-5p alleviates BBB damage and neuroinflammatory responses by activating the Hedgehog pathway and inhibiting NF-?B/MMP-9 pathway, which promotes the recovery of neurological function after TBI.

SUBMITTER: Wu J

PROVIDER: S-EPMC7317896 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature

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microRNA-9-5p alleviates blood-brain barrier damage and neuroinflammation after traumatic brain injury.

Wu Jingchuan J He Junchi J Tian Xiaocui X Luo Yuetao Y Zhong Jianjun J Zhang Hongrong H Li Hui H Cen Bo B Jiang Tao T Sun Xiaochuan X

Journal of neurochemistry 20200211 6

The level of microRNA-9-5p (miRNA-9-5p) in brain tissues is significantly changed after traumatic brain injury (TBI). However, the effect of miRNA-9-5p for brain function in TBI has not been elucidated. In this study, a controlled cortical impact model was used to induce TBI in Sprague-Dawley rats, and an oxygen glucose deprivation model was used to mimic the pathological state in vitro. Brain microvascular endothelial cells (BMECs) and astrocytes were extracted from immature Sprague-Dawley rats ...[more]

PMID: 31951014

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Project description:Low-level blast exposure can result in neurological impairment for military personnel. Currently, there is a lack of experimental data using sex as a biological variable in neurovascular outcomes following blast exposure. To model mild blast traumatic brain injury (mbTBI), male and female rats were exposed to a single 11 psi static peak overpressure blast wave using the McMillan blast device and cohorts were then euthanized at 6 h, 24 h, 7 d and 14 d post-blast followed by isolation of the amygdala. After mbTBI, animals experience immediate bradycardia, although no changes in oxygen saturation levels or weight loss are observed. Male mbTBI animals displayed significantly higher levels of anxiety-like behavior (open field and elevated plus maze) compared to male sham groups; however, there was no anxiety phenotype in female mbTBI animals. Blast-induced neurovascular damage was explored by measuring expression of tight junction (TJ) proteins (zonula occludens-1 (ZO-1), occludin and claudin-5), glial fibrillary acidic protein (GFAP) and astrocyte end-feet coverage around the blood-brain barrier (BBB). Western blot analysis demonstrates that TJ protein levels were significantly decreased at 6 h and 24 h post-mbTBI in male rats, but not in female rats, compared to sham. Female animals have decreased GFAP at 6 h post-mbTBI while male animals display decreased GFAP expression at 24 h post-mbTBI. By 7 d post-mbTBI, there were no significant differences in TJ or GFAP levels between groups in either sex. At 24 h post-mbTBI, vascular integrity and astrocytic end-feet coverage around the BBB was significantly decreased in males following mbTBI. These results demonstrate that loss of GFAP expression may be due to astrocytic damage at the BBB. Our findings also demonstrate sex differences in acute vascular and behavioral outcomes after single mbTBI. Female animals display a lack of BBB pathology after mbTBI corresponding to improved acute neuropsychological outcomes as compared to male animals.

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MicroRNA-9-5p alleviates blood-brain barrier damage and neuroinflammation after traumatic brain injury.

Publications

microRNA-9-5p alleviates blood-brain barrier damage and neuroinflammation after traumatic brain injury.

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