Integrated proteomic, transcriptomic, and epigenomic profiling identifies SRA1 as a novel therapeutic target for postpartum depression
TL;DR
This study reveals that SRA1 is a novel therapeutic target for PPD, which enhances the understanding of its molecular aetiology and the development of therapeutic strategies.
Abstract
Postpartum depression (PPD) is among the most common complications of childbirth, and identifying novel treatments is vital. We aimed to identify potential drug targets for PPD by integrating the plasma proteome, transcriptome and epigenome. We designed a comprehensive analysis pipeline involving two-sample Mendelian randomisation (MR) (for proteins), colocalisation (for coding genes), and summary-based MR (SMR) (for mRNA and DNA methylation) to identify potential therapeutic targets for PPD. Genetic data on the plasma proteome were obtained from 4907 aptamers in 35,559 Icelanders and 7596 proteins in 828 FinnGen participants. The PPD genome-wide association study data were sourced from the Psychiatric Genomics Consortium (PGC) (Ncase = 17,339, Ncontrol = 53,426). A two-step MR approach was used to assess whether brain imaging-derived phenotypes (IDPs) and metabolites from blood, brain and cerebrospinal fluid mediated the observed effects. Across the two proteome datasets, the genetically predicted levels of 18 plasma proteins were nominally significantly associated with PPD, and the expression of steroid receptor RNA activator 1 (SRA1), a regulator of steroid hormone signalling, was significantly associated with PPD. SRA1, angiotensinogen (AGT, a key mediator of the renin-angiotensin and stress-response system), and glycerol-3-phosphate phosphatase (PGP, involved in lipid metabolism and cellular stress) showed increased colocalisation. The methylation of SRA1 at cg02434007 in the brain was associated with increased expression of SRA1 and a high risk of PPD, which aligns with the positive effect of SRA1 gene expression on PPD risk. Isoleucine (mediation proportion: 5.8%, p = 0.042) from blood metabolites and the IDP ICA100 edge 442 (mediation proportion: 7.6%, p = 0.044) may play mediating roles. This study reveals that SRA1 is a novel therapeutic target for PPD, which enhances the understanding of its molecular aetiology and the development of therapeutic strategies.