Proteogenomic signature of risk of Alzheimer's disease and related dementia risk in individuals with a history of major depression disorder

Abstract

The mechanisms linking a history of major depressive disorder (MDD) to an increased risk of Alzheimer's disease and related dementia (ADRD) are not fully understood. Using the UK Biobank available proteomic and genomic data, we evaluated the biological mechanisms linking both conditions. In participants with a history of MDD at baseline (n=3,615), we found that plasma levels of NfL, GFAP, PSG1 were associated with higher risk (HR=1.38; 1.37; 1.34, respectively; all adjusted p-values<0.05), while VGF, GET3, and HPGDS were associated with lower risk of incident ADRD (n=150) (HR=0.73; 0.71; 0.66, respectively; all adjusted p-values<0.05) during a mean follow-up of 13.7 years (SD=2.2). Two-sample Mendelian randomization analysis using cis-pQTLs genetic instruments revealed that a lower protein expression of apolipoprotein E and higher IL-10 receptor subunit B were causally linked to incident ADRD. Finally, we developed a Proteomic Risk Score (PrRS_MDD-ADRD), which showed strong discriminative power (C-statistic = 0.84) to identify participants with MDD that developed ADRD upon follow-up. In addition to demonstrating an association between plasma proteins associated with inflammation and future ADRD risk in individuals with MDD, our findings include an element of causality using Mendelian Randomization (MR) and PrRS_MDD-ADRD can be useful to identify individuals with the highest risk to develop ADRD in a highly vulnerable population.

Keywords: Alzheimer’s disease; Major depressive disorder; dementia; genomics; inflammation; proteomics.

Figure 1

Proteins significantly associated with incident ADRD in participants with a history of MDD at baseline

Figure 2

MR-Egger plots to show causal estimates from IVW vs. other MR methods for the effects of APOE and IL10RB (FDR-adjusted p<0.05) on incident ADRD in participants with a history of MDD at baseline. The slope estimates represent log(HR) per SD increase in genetically determined APOE or IL10RB.

Figure 3 -

Spearman correlations between PrRS_MDD-ADRD, age, and cognitive performance measures from baseline (reaction time, numeric memory, fluid intelligence score) or first imaging visit (symbol digit substitution, trail making, matrix pattern completion). Significance: ***p<0.001, **0.01<p<0.001, *0.01<p<0.05.

Figure 4

Spearman correlations of PrRS_MDD-ADRD with T1 structural and T2-weighted brain MRI image-derived phenotypes (IDPs), adjusting for head size. IDPs labeled if FDR-adjusted p<0.05 and Spearman correlation >0.2.