Emodin attenuates inflammation and demyelination in experimental autoimmune encephalomyelitis

Emodin,a substance extracted from herbs such as rhubarb,has a protective effect on the central nervous system.However,the potential therapeutic effect of emodin in the context of multiple sclerosis remains unknown.In this study,a rat model of experimental autoimmune encephalomyelitis was established by immune induction to simulate multiple sclerosis,and the rats were intraperitoneally injected with emodin(20 mg/kg/d)from the day of immune induction until they were sacrificed.In this model,the nucleotide-binding domain-like receptor family pyrin domain containing 3(NLRP3)inflammasome and the microglia exacerbated neuroinflammation,playing an important role in the development of multiple sclerosis.In addition,silent information regulator of transcription 1(SIRT1)/peroxisome proliferator-activated receptor-alpha coactivator(PGC-1α)was found to inhibit activation of the NLRP3 inflammasome,and SIRT1 activation reduced disease severity in experimental autoimmune encephalomyelitis.Furthermore,treatment with emodin decreased body weight loss and neurobehavioral deficits,alleviated inflammatory cell infiltration and demyelination,reduced the expression of inflammatory cytokines,inhibited microglial aggregation and activation,decreased the levels of NLRP3 signaling pathway molecules,and increased the expression of SIRT1 and PGC-1α.These findings suggest that emodin improves the symptoms of experimental autoimmune encephalomyelitis,possibly through regulating the SIRT1/PGC-1α/NLRP3 signaling pathway and inhibiting microglial inflammation.These findings provide experimental evidence for treatment of multiple sclerosis with emodin,enlarging the scope of clinical application for emodin.

MicroRNA-670 aggravates cerebral ischemia/reperfusion injury via the Yap pathway

Apoptosis is an important programmed cell death process involved in ischemia/reperfusion injury.MicroRNAs are considered to play an important role in the molecular mechanism underlying the regulation of cerebral ischemia and reperfusion injury.However,whether miR-670 can regulate cell growth and death in cerebral ischemia/reperfusion and the underlying mechanism are poorly understood.In this study,we established mouse models of transient middle artery occlusion and Neuro 2a cell models of oxygen-glucose deprivation and reoxygenation to investigate the potential molecular mechanism by which miR-670 exhibits its effects during cerebral ischemia/reperfusion injury both in vitro and in vivo.Our results showed that after ischemia/reperfusion injury,miR-670 expression was obviously increased.After miR-670 expression was inhibited with an miR-670 antagomir,cerebral ischemia/reperfusion injury-induced neuronal death was obviously reduced.When miR-670 overexpression was induced by an miR-670 agomir,neuronal apoptosis was increased.In addition,we also found that miR-670 could promote Yap degradation via phosphorylation and worsen neuronal apoptosis and neurological deficits.Inhibition of miR-670 reduced neurological impairments after cerebral ischemia/reperfusion injury.These results suggest that microRNA-670 aggravates cerebral ischemia/reperfusion injury through the Yap pathway,which may be a potential target for treatment of cerebral ischemia/reperfusion injury.The present study was approved by the Institutional Animal Care and Use Committee of China Medical University on February 27,2017(IRB No.2017PS035K).