We initially analyzed the RNA-seq from the Mayo Clinic Brain Bank that includes bulk RNA-seq from the TC and CB for 191 participants [18] (Table 1). In the TC, we observed a significant higher astrocyte relative proportion (β = 0.23; p = 5.01 × 10−09; Table 2; Fig. 2; Additional file 1: Table S6) in AD brains compared to control brains. We also found a significant lower relative proportion of neurons (β = − 0.17; p = 1.58 × 10−07; Table 2; Fig. 2; Additional file 1: Table S6) and oligodendrocytes (β = − 0.07; p = 1.8 × 10−02; Table 2; Additional file 1: Figure S5; Additional file 1: Table S6). As expected given the absence of pathology, we did not observe a significant difference in the cell-type composition in the CB (Table 2).Table 2Comparison of the cellular population structure (AD vs neuropath-free controls) from the brains in the Mayo Clinic and Mount Sinai Brain BankBrain regionsSample sizeNeuronAstrocyteOligodendrocyteMicroglia n Effectp valueEffectp valueEffectp valueEffectp valueMayoAD vs ControlCB119− 0.032.74 × 10−010.058.65 × 10−02− 0.021.07 × 10−01−3.19 × 10−049.19 × 10−01TC119− 0.171.58
