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Following cerebral infarction, activated microglia cells can release a large amount of inflammatory cytokines, thereby exacerbating neuronal damage. It has been demonstrated that the long non-coding RNA small nucleolar RNA host gene 1 (SNHG1) exerts a protective effect against cerebral infarction. However, its specific role in cerebral infarction and underlying mechanism have yet to be fully elucidated. The present study aimed to investigate the effects of the SNHG1 and microRNA (miR)-329-3p in cerebral infarction and to determine the underlying molecular mechanisms. An in vitro oxygen-glucose deprivation (OGD) model was established using the BV-2 microglial cell line. The mRNA expression levels of SNHG1 and miR-329-3p were analyzed using reverse transcription-quantitative PCR and the protein expression levels of cleaved caspase-3 and caspase-3 were detected using western blotting. The binding relationship between SNHG1 and miR-329-3p was predicted using starBase and verified using a dual luciferase reporter assay. The release of TNF-α and nitric oxide, as well as caspase-3 activity, were detected using appropriate commercial kits. Flow cytometry analysis was performed to measure cell apoptosis. The results of the present study revealed that the expression levels of SNHG1 were upregulated in the OGD-induced BV-2 cell model. miR-329-3p was discovered to directly target SNHG1, and its mRNA expression levels were downregulated in the OGD-induced BV-2 cell model. The SNHG1-plasmid downregulated miR-329-3p expression levels, while this effect was reversed by transfection with the miR-329-3p mimic. The overexpression of SNHG1 or knockdown of miR-329-3p inhibited OGD-induced BV-2 cell activation. In conclusion, the results of the present study suggested that SNHG1 may reduce microglial cell activity by regulating the expression of miR-329-3p, indicating its potential protective role in cerebral infarction.

BackgroundGBS is an autoimmune disease characterized by inflammatory infiltration and demyelination of peripheral nerves. Macrophage polarization is involved in different stages of GBS. Altering the polarization of macrophages may be an effective therapeutic strategy for GBS. Celastrol was previously shown to contribute to anti-neuroinflammation. However, the mechanism underlying the effect of celastrol in GBS animal model experimental autoimmune neuritis (EAN) is unclear. We hypothesized that celastrol may shift the polarization of macrophages through the NRF /HIF-1αpathway.MethodsClinical scores, weight and histological changes were assessed to investigate the effects of celastrol on EAN. To detect the polarization state of macrophages, flow cytometry and immunofluorescence staining were applied. Inflammation cytokines were evaluated by ELISA. The expression of NRF2 and HIF-1α were detected by western-blot and immunofluorescence staining.ResultsCelastrol treatment significantly ameliorates the severity and neuroinflammation of EAN. The polarization state of macrophages from M1 to M2 was observed upon celastrol application. Consistently, pro-inflammatory cytokines were decreased, whereas anti-inflammatory cytokines were increased upon celastrol treatment. Furthermore, we found that celastrol treatment may increase expression of Nrf2 and decrease the expression of HIF-1α. ConclusionTaken together, these data demonstrate that celastrol may ameliorate the severity and neuroinflammation of EAN via promoting the polarization state of macrophages into M2, likely by modulating the hypoxic response. Celastrol may therefore serve as a novel therapeutic agent for GBS.