Notoginsenoside R1 alleviates lipopolysaccharide-triggered PC-12 inflammatory damage via elevating microRNA-132

Background Delayed inflammatory response is closely associated with the severity of Spinal cord injury (SCI). Herein, the function and molecular mechanism of notoginsenoside R1 (NGR1) in the in vitro model of SCI inflammation injury were explored.Methods PC-12 neuronal cells were subjected with LPS to construct a cell-based model of SCI inflammatory injury. NGR1 was applied in this cell model. miR-132 was silenced by transfection with miR-132 inhibitor. Cell viability and apoptosis were assessed, respectively. Then, the expression changes of pro-inflammatory cytokines and JNK pathway were examined.Results In this model, LPS was neurotoxic, with inhibiting PC-12 cell viability, inducing apoptosis, and enhancing concentrations of IL-6, IL-8 and TNF-α. However, NGR1 weakened the influence of LPS on PC-12 cells via elevating cell viability, decreasing apoptosis, decreasing pro-inflammatory cytokines expression, and suppressing activation of JNK signalling pathway. miR-132 was up-regulated by NGR1 treatment. Silence of miR-132 eliminated the influence of NGR1 on LPS-stimulated PC-12 cells.Conclusion NGR1 relieved PC-12 cells from LPS-triggered inflammatory damage via elevating miR-132 and hereafter suppressing JNK pathway.