Scutellarin Attenuates Microglia Activation in LPS‐Induced BV‐2 Microglia via miRNA‐7036a/MAPT/PRKCG/ERK Axis

Abstract

Scutellarin is an herbal agent which can exert anti‐neuroinflammatory effects in activated microglia. However, it remains uncertain if it can inhibit microglia‐mediated neuroinflammation by regulating miRNAs. This study sought to elucidate the upstream regulatory mechanisms by endogenous microRNAs and its target gene in activated microglia in lipopolysaccharide (LPS)‐induced BV‐2 microglia. Results show that scutellarin suppressed the expression of tumor necrosis factor‐α (TNF‐α), interleukin‐1β (IL‐1β), and inducible nitric oxide synthase (iNOS) significantly in LPS‐stimulated BV‐2 microglia. As with the results of miRNAs function classification in vitro, the expression levels of mir‐7036a‐5p are upregulated in LPS‐activated BV‐2 microglia, but are downregulated by scutellarin. Rescue experiments indicated that mir‐7036a‐5p is a pro‐inflammatory factor in activated BV‐2 microglia. mir‐7036a‐5p agomir promoted the expression of phosphorylated tau proteins (p‐tau), protein kinase C gamma type (PRKCG), extracellular regulated protein kinases (ERK1/2), but the is reversed by mir‐7036a‐5p antagomir in vitro. It is shown here that mir‐7036a‐5p is involved in microglia‐mediated inflammation in LPS‐induced BV‐2 microglia. More important is the novel finding that scutellarin mitigated microglia inflammation by down‐regulating the mir‐7036a‐5p/MAPT/PRKCG/ERK signaling pathway.