S1PR3 and brain ischemia: Meanwhile, S1P3 has been shown to promote activation of inflammatory macrophages in microglia, while a model of brain ischemia has demonstrated that S1P3 regulates expression levels of inflammatory genes (e.g., IL-6, IL-1β, TNF-α, iNOS, and COX-2) via induction of lipopolysaccharide (LPS) [49,50].