CircHIPK3 alleviates inflammatory response and neuronal apoptosis via regulating miR-382-5p/DUSP1 axis in spinal cord injury

Spinal cord injury (SCI) is one of the serious neurological diseases with high morbidity which may be treated with hematopoietic stem cell (HSC) transplants. Circular RNAs (circRNAs) play vital roles in SCI. The study aimed to reveal the function and mechanism of circRNA homeodomain interacting protein kinase 3 (HIPK3) in SCI. SCI model in vitro was established by treating neuronal cells AGE1.HN with oxygen-glucose deprivation (OGD) and CoCl2. The levels of circHIPK3, miR-382-5p and dual specificity phosphatase 1 (DUSP1) were examined using quantitative real-time PCR (qRT-PCR) or western blot assay. Enzyme linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors (IL-6 and TNF-α). Cell proliferation and apoptosis were evaluated by 5′-ethynyl-2′-deoxyuridine (EdU) assay and flow cytometry. Caspase-3 Colorimetric Assay Kit was used to detect aaspase-3 activity. The interactions among circHIPK3, miR-382-5p and DUSP1 were confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. CircHIPK3 and DUSP1 were down-regulated, while miR-382-5p was up-regulated in OGD-induced AGE1.HN cells. Overexpression of circHIPK3 suppressed inflammatory response and cell apoptosis and promoted proliferation in OGD-induced AGE1.HN cells by sponging miR-382-5p. CircHIPK3 regulated DUSP1 expression by targeting miR-382-5p. MiR-382-5p inhibition hindered inflammatory response of IL-6 and TNF-α and neuronal apoptosis and promoted apoptosis via targeting DUSP1. CircHIPK3 overexpression alleviated OGD-induced AGE1.HN cell inflammatory response and neuronal apoptosis via regulating miR-382-5p/DUSP1 axis, indicating that circHIPK3 might be a promising therapeutic target for SCI. •LncRNA BDNF-AS was up-regulated in rat model of SCI.•Knockdown of BDNF-AS alleviated spinal cord injury in AGE1.HN cells.•BDNF-AS regulated TLR4 expression via sponging miR-150•BDNF-AS modulated spinal cord injury via miR-150/TLR4 axis.