Fig. 1

The workflow of the study. After literature search, 18 datasets from ten different MS-based proteomic studies, using either labeled or label-free quantification, were retrieved. These studies were done on postmortem human brain tissue, which were categorized into frontal or temporal lobes, severely affected regions by AD pathology, and consisted of AD (5 ≤ n ≤ 252) and control (5 ≤ n ≤ 94) cases. Subsequently, data pre-processing was done so that datasets would be comparable for further statistical analyses. Sample distributions and the presence of any clustering patterns were assessed using principal component analysis (PCA). The datasets generated by labeled and label-free MS approaches were concatenated separately, and meta-analysis using a random-effects-model was performed. Lastly, for better biological interpretation of our findings, gene set analysis was performed.