Study On Exosomal MicroRNA Expression And Its Clinical Significance In Patients With Ischemic Stroke

Exosomes,as nanoscale extracellular vesicles,participates in the intercellular transfer of substances and signal conduction.In recent years,exosomal microRNA has became an immediate area of research focus,known as biomarkers and therapeutic targets for various diseases such as cancer,immunological disease and ischemic disease.At present,there has been no reported clinical study about exosomal microRNA expression in patients with ischemic stroke.The circulating exosomes is enriched in microRNA-223,which is claimed to be involved in the pathogenesis of inflammation and angiogenesis after ischemic injury and recovery.But the expression alteration of circulating exosomal microRNA-223 after brain ischemia remains unclear.Here we mainly explore whether the circulating exosomal microRNA can serve as biomarker of acute ischemic stroke and analyze its clinical significance,providing theory foundation for utilizing exosomes as stroke assessment and targeted therapy.Methods:Blood samples were collected from acute ischemic stroke patients(within 72h,n=50)and non-stroke control group(n=33).Serum exosomes were exacted by Exoquick exosome isolation kit and characterized through transmission electron microscopy for its size and appearance as well as Western Blot for protein markers.The level of several stroke relevant microRNA(microRNA-21?microRNA-145?microRNA-223)expression were determined by RT-PCR.The relationship between the microRNA expression and NIHSS scores,brain infarct volume and patient outcome were analyzed.Results:We isolated exosomes from serum samples and determined its presence by catching the view of 30?100nm size particles under transmission electron microscopy and detecting the expression of protein marker CD9,CD63,Tsg101 based on Western Blot.Exosomal microRNA-223 was significantly up-regulated in patients with acute ischemic stroke(p<0.05),while exosomal microRNA-21 and microRNA-145 remained the same.Exosomal microRNA-223 expression was shown to be positively associated with NIHSS scores.The level of exosomal microRNA-223 in stroke patient with poor outcome was higher than those with good outcome.Conclusion:Circulating exosomal microRNA-223 potentially predicts stroke outcome as a novel biomarker.The role of exosomal microRNA-223 in stroke occurrence,progression and repair needs further exploration.