Schaftoside ameliorates oxygen glucose deprivation-induced inflammation associated with the TLR4/Myd88/Drp1-related mitochondrial fission in BV2 microglia cells

Abstract

Background: Neuroinflammation plays a major role in the development of ischemic stroke, and regulation of the proinflammatory TLR4 signaling pathway in microglia stands to be a promising therapeutic strategy for stroke intervention. Recently, the homeostasis of mitochondrial dynamics has also been raised as a vital component in maintaining neuronal health, but its relevance in microglia hasn't been investigated. Schaftoside, a natural flavonoid compound and a promising treatment for inflammation, has demonstrated potency against LPS-induced lung inflammation in mice; however, its action on TLR4-induced neuroinflammation and mitochondrial dynamics in microglia is still unknown. Methods: The effects of schaftoside in regulating inflammation and mitochondrial dynamics were investigated in vitro in oxygen glucose deprivation (OGD)-stimulated BV2 microglia cells. Results: Schaftoside inhibited mRNA and protein expressions of proinflammatory cytokines (IL-1β, TNF-α, and IL-6) after 4 h in OGD-stimulated BV2 microglia cells, similar to the effect of TAK242, an inhibitor of TLR4. TLR4/Myd88 signaling pathway was effectively suppressed by schaftoside. In addition, both schaftoside and TAK242 treatments significantly decreased Drp1 expression, phosphorylation, translocation and mitochondrial fission in OGD-stimulated BV2 cells. Conclusions: Our study suggested that schaftoside was able to reduce neuroinflammation, which is mediated in part by reducing TLR4/Myd88/Drp1-related mitochondrial fission in BV2 microglia cells. Keywords: Mitochondrial fission, Microglia, TLR4, Stroke, Schaftoside