• Guang Yang and Yuan Zhao.
• Department of Pediatrics, Shanxi Medical University, Taiyuan, China.
• Yonsei Med. J. 2020 Aug 1; 61 (8): 660-669.

PurposeNeonatal hypoxic ischemic encephalopathy (HIE) is an essential factor underlying neonatal death and disability. This study sought to explore the role of miR-146b-5p in regulating neonatal HIE.Materials And MethodsIn vitro and in vivo HIE models were established in PC12 cells and 10-day neonatal Sprague Dawley rats, respectively. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to assess miR-146b-5p expression and inflammatory factors [interleukin (IL)-6 and tumor necrosis factor (TNF)-α] in brain lesions and PC12 cells, while enzyme-linked immunosorbent assay was employed to detect the expression of oxidative stress factors (SOD and GSH-Px). Gain- and loss-assays of miR-146b-5p were conducted to verify its role in modulating the viability and apoptosis of PC12 cells under oxygen-glucose deprivation (OGD) treatment. Expression of TLR4, IRAK1, TRAF6, TAK1, and NF-κB were examined by qRT-PCR and/or Western blot. Dual luciferase activity assay was conducted to identify relationships between miR-146b-5p and IRAK1.ResultsIn the HIE models, significant oxidative stress and inflammatory responses emerged upon upregulation of TLR4/IRAK1/TRAF6/TAK1/NF-κB signaling. Overexpression of miR-146b-5p greatly inhibited OGD-induced PC12 cell injury, inflammatory responses, and oxidative stress. Inhibiting miR-146b-5p, however, had the opposite effects. IRAK1 was found to be a target of miR-146b-5p, and miR-146b-5p overexpression suppressed the activation of IRAK1/TRAF6/TAK1/NF-κB signaling.ConclusionThis study demonstrated that miR-146b-5p overexpression alleviates HIE-induced neuron injury by inhibiting the IRAK1/TRAF6/TAK1/NF-κB pathway.© Copyright: Yonsei University College of Medicine 2020.

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