Homeostatic inflammation in the placenta is protective against adult cardiovascular and depressive outcomes

Pathological placental inflammation increases the risk for several adult disorders, but these mediators are also expressed under homeostatic conditions, where their contribution to adult health outcomes is unknown. Here we define an expression signature of homeostatic inflammation in the term placenta and use expression quantitative trait loci (eQTLs) to create a polygenic score (PGS) predictive of its expression. Using this PGS in the UK Biobank we carried out a phenome-wide association study, followed by mendelian randomization and identified protective, sex-dependent effects of the placental module on cardiovascular and depressive outcomes. Genes differentially regulated by intra-amniotic infection and preterm birth were also over-represented within the module. Our data support a model where disruption of placental homeostatic inflammation, following preterm birth or intra-amniotic infection, contributes to the increased risk of depression and cardiovascular disease observed in these individuals. Finally, we identify aspirin as a putative modulator of this homeostatic inflammatory signature. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Funding for this study was provided through funding of the Depression Task Force of the Hope for Depression Research Foundation to Michael J Meaney. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval for GUSTO was granted by the relevant institutional boards (DSRB reference D/09/021 and CIRB reference 2009/280/D). Ehical approval for the UK Biobank was obtained by the Northwest Multicentre Research Ethics Committee (REC reference 11/NW/0382), the National Information Governance Board for Health and Social Care and the Community Health Index Advisory Group. Access to data used in the current study was obtained under application #41975. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Access to data from the GUSTO and UK Biobank are dependent on approved application to the respective data access committees.