The Neuroprotective Mechanisms Of Tirofiban In A Mouse Model Of Photochemical Ischemia

Background:Acute ischaemic stroke is a severe human disease with limited treatment options.The inflammatory response plays an important role in the pathogenesis of acute ischemic stroke(AIS).However,whether tirofiban,an antiplatelet agent,can reduce neuroinflammation after AIS in mice is unclear.The present study was designed to investigate the effects and mechanisms of tirofiban on neuroinflammation in a photochemically induced ischemic stroke model and to find a new strategy for treating acute ischemic stroke.Methods:In this study,male C57 mice weighing 25-30 g were randomly divided into a control group and a tirofiban group(7.5 mg/kg).Preparation of an acute ischemic stroke model using photochemical methods.After successful molding,the mice in the tirofiban group were immediately given tirofiban in the tail vein,and the control group was injected with the same volume of saline.Twenty-four hours later,behavioral and TTC staining methods were applied to assess the mice and neurobehavioral function and brain infarct volume,and immunofluorescence methods were applied to observe the proliferation and activation of microglia in the ischemia penumbra and applied to assess the apoptosis of neurons using TUNEL.Meanwhile,gene expression profiles were determined using DNA microarray analysis to reveal the possible mechanism of tirofiban on AIS,and protein microarray were applied to further detect the expression of inflammatory factors in the ischemia penumbra.Results:The mice’s brain infarct volume and m NSS scores in the tirofiban administration group significantly decreased.Tunel staining revealed that tirofiban reduced neuronal apoptosis in the ischemic penumbra after acute cerebral ischemic.The immunofluorescence staining results suggested that the expression of CD16 in microglia was reduced and statistically significant in the tirofiban-administered group compared with the control group.The expression of CD206 was increased and statistically significant compared with the control group.The immunofluorescence results indicated that tirofiban reduced the activation of M1 microglia and promoted the generation of M2 microglia in the ischemic penumbra.In addition,we performed a DNA microarray analysis of the ischemic penumbra in mice,and KEGG analysis revealed that inflammation-related pathways were highly enriched.Next,using protein microarray analysis,we showed that tirofiban inhibited the expression of proinflammatory cytokines,such as IL-1α,IL-6,and TNF-α.Conclusion:Tirofiban reduced infarct size,improved neurological deficits,and reduced neuronal apoptosis in mice with acute ischemic stroke.In addition,tirofiban altered the gene expression profile of mice,exerting neuroprotective effects by down-regulating inflammatory-related genes and up-regulating neurological-related genes.We also found that tirofiban reduced inflammatory factor secretion and shifted microglia from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype.Tirofiban attenuated post-ischemic oxidative stress injury and reduced cholesterol pathway ANGPTL4 expression levels.