Screening And Identification Of Serum Protein Markers In Patients With Acute Ischemic Stroke

Background:Acute ischemic stroke（AIS）is the most common type of stroke.In China,AIS has the characteristics of high mortality and high disability rate,resulting in a heavy social medical burden.At present,the diagnosis of AIS is mainly based on the clinical signs and imaging examination of patients,the effect is relatively limited,there is an urgent need to find AIS markers that are helpful for early diagnosis and screening.Proteomics technology can quickly,accurately and high-throughput detect the differences of protein expression in biological samples under different physiological and pathological conditions,which provides a powerful research tool for the development of many disease biomarkers.Matrix-Assisted Laser Desorption Ioniza-tion Time of Flight Mass Spectrometry（MALDI-TOF-MS）proteomics technology can quickly and accurately study the differences of protein expression among different biological samples,which provides a good research platform for screening and identification of AIS markers.Objective:The difference of serum protein spectrum between AIS group and Healthy Controls（HC）group was analyzed and compared,and the diagnostic prediction model of AIS was established,and the specific protein markers of AIS were screened and identified.Methods:1.The serum total proteins of acute ischemic stroke group（AIS）and healthy control group（HC）were separated and purified by Magnetic Beads Based Weak Cation exchange（MB-WCX）.2.MALDI-TOF-MS was used to detect,and Clin Pro Tools software was used to analyze the differential expression peak between AIS group and HC group,and the diagnostic prediction model of AIS was established.3.The differentially expressed peptides in serum of AIS and HC groups were identified by Liquid Chromatography-tandem Mass Spectrometry/Mass Spectrometry（LC-MS/MS）.The peptide sequences were identified in Uniprot-human database by Sequest and Proteome Discoverer software.Results:1.There was a significant difference in serum protein spectrum between AIS group and HC group,a total of 92 differential expression peaks were found,and 48 peaks were significantly different（P < 0.05）.Of the 48 peaks with significant difference,14 were up-regulated in AIS serum and decreased in HC serum,while 34 were down-regulated in AIS serum and increased in HC serum.2.The genetic algorithm was used to establish the diagnostic prediction model of AIS,which included five mass spectrum peaks（m/z: 5068.92,m/z:3244.61,m/z:4286.63,m/z:4057.88,m/z:823.51）.The sensitivity and specificity of this model for diagnosing AIS were 91.66% and 100%,respectively.Further independent samples blindly verified that the sensitivity and specificity of the model to AIS diagnosis were 88.89% and76.47%,respectively,and the Yoden index was 65.36.3.The four peaks up-regulated most significantly（>1.5 times）in AIS serum were ALB,m/z:1468.34;TUBB2C,m/z:1816.13;C3,m/z:1868.56;TUBB,m/z:1619.99.Conclusion:1.There is a significant difference in serum protein spectrum between AIS group and HC group.Proteomics technology based on MALDI-TOF-MS is an effective method to screen and identify AIS markers.2.The diagnostic prediction model of AIS with five mass spectrum peaks（m/z:5068.92,m/z:3244.61,m/z:4286.63,m/z: 4057.88,m/z:823.51）has high sensitivity and specificity,and is expected to be used as an auxiliary tool for clinical diagnosis of AIS.3.ALB,TUBB2 C,C3 and TUBB have obvious dynamic changes in the serum samples of AIS and HC groups,which is expected to be used as serum protein markers for screening and diagnosis of AIS.