Angelica polysaccharide protects PC-12 cells from lipopolysaccharide-induced injury via down-regulating microRNA-223

Abstract Background Spinal cord injury (SCI) is a damage of spinal cord that caused by trauma or diseases. Angelica Polysaccharide (AP) is one of the most major active components isolated from the root of Angelica sinensis (Oliv.) Diels. This study aimed to investigate the effects of AP on lipopolysaccharide (LPS)-induced SCI cell injury model (PC-12 cell injury model). Methods Cell viability was detected using cell counting kit-8 (CCK-8) assay. Cell apoptosis was assessed using Guava Nexin assay. qRT-PCR was conducted to measure the expression of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α) and microRNA-223 (miR-223). Cell transfection was performed to up-regulate the expression of miR-223. Finally, protein expression levels of key factors involved in cell apoptosis, inflammatory reaction and nuclear factor kappa-B (NF-κB) pathway were evaluated using western blotting. Results We found that AP pre-treatment or post-treatment both significantly alleviated LPS-induced PC-12 cell viability inhibition, apoptosis and the elevated expression of inflammatory cytokines. Mechanistically, we revealed that AP pre-treatment attenuated LPS-induced miR-223 expression level increase in PC-12 cells. Overexpression of miR-223 reversed the protective effects of AP pre-treatment on LPS-treated PC-12 cells. Furthermore, we pointed out that AP pre-treatment inactivated NF-κB pathway in LPS-treated PC-12 cells by down-regulating miR-223. Conclusion AP protected PC-12 cells from LPS-induced inflammatory injury at least partially by down-regulating miR-223 and then inactivating NF-κB pathway. This study provides evidence for further understanding the anti-inflammatory effects of AP and offers theoretical basis for deeply exploring the prevention and treatment of SCI by using AP.