Han, Sun-Ho Kim, Jun Seok Lee, Youngju Choi, Heesun Kim, Jong-Won Na, Duk Lyul Yang, Eun Gyeong Yu, Myeong-Hee Hwang, Daehee Lee, Cheolju Mook-Jung, Inhee 2024-01-20T10:32:52Z 2024-01-20T10:32:52Z 2021-09-04 2014-02 1535-9476 https://pubs.kist.re.kr/handle/201004/127182 Apolipoprotein E (ApoE) polymorphism has been appreciated as a valuable predictor of Alzheimer disease (AD), and the associated epsilon 4 allele has been recognized as an indicator of susceptibility to this disease. However, serum ApoE levels have been a controversial issue in AD, due to the great variability regarding the different target detection methods, ethnicity, and the geographic variations of cohorts. The aim of this study was to validate serum ApoE levels in relation to AD, particularly using two distinct detection methods, liquid chromatography-selected reaction monitoring (SRM) mass spectrometry and microsphere-based fluorescence-activated cell sorting (FACS) analysis, to overcome experimental variations. Also, comparison of serum ApoE levels was performed between the level of protein detection by FACS and peptide level by SRM in both control and AD patients. Results from the two detection methods were cross-confirmed and validated. Both methods produced fairly consistent results, showing a significant decrease of serum ApoE levels in AD patients relative to those of a control cohort (43 control versus 45 AD, p < 0.0001). Significant correlation has been revealed between results from FACS and SRM (p < 0.0001) even though lower serum ApoE concentration values were measured in protein by FACS analysis than in peptide-level detections by SRM. Correlation study suggested that a decrease of the serum ApoE level in AD is related to the mini-mental state exam score in both results from different experimental methods, but it failed to show consistent correlation with age, gender, or clinical dementia rating. English AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC E APOE POLYMORPHISM MINI-MENTAL-STATE CEREBROSPINAL-FLUID RISK-FACTORS CARDIOVASCULAR-DISEASE BIOMARKER VERIFICATION PLASMA-PROTEINS ALLELE DEMENTIA ASSAY Both Targeted Mass Spectrometry and Flow Sorting Analysis Methods Detected the Decreased Serum Apolipoprotein E Level in Alzheimer&apos;s Disease Patients Article 10.1074/mcp.M113.028639 1 MOLECULAR & CELLULAR PROTEOMICS, v.13, no.2, pp.407 - 419 MOLECULAR & CELLULAR PROTEOMICS 13 2 407 419 scie scopus 000331369000003 2-s2.0-84893208400 Biochemical Research Methods Biochemistry & Molecular Biology Article E APOE POLYMORPHISM MINI-MENTAL-STATE CEREBROSPINAL-FLUID RISK-FACTORS CARDIOVASCULAR-DISEASE BIOMARKER VERIFICATION PLASMA-PROTEINS ALLELE DEMENTIA ASSAY