COVID-19 infection in pregnancy epigenetically affects cells of offspring via transcriptional responses of Sp1-related genes

Background: Maternal Immune Activation (MIA) is a state of maternal stress and inflammation during pregnancy that has been associated with genome-wide DNA-methylation (DNAme) changes in offspring. MIA can be caused by environmental exposures such as viral infections. In utero DNAme alterations have been demonstrated to influence the development of lung diseases later in life. Dysfunction of the fetal airway epithelium has been identified as a potential origin of lung diseases. However, the impact of MIA-induced DNAme changes on the function of the airway epithelium remains poorly studied.

Objective: We aim to explore the relationship between MIA and DNAme in affected offspring with potential consequences for the airway epithelium.

Methods: DNA isolated from umbilical cord blood mononucleated cells from mothers with or without COVID-19 infection during pregnancy (n=6 each, balanced for male and female children) from the PRINCE cohort was analysed using Illumina EPIC 2.0 DNA methylation arrays. Differential methylation analysis using the R software package limma produced CpGs that were mapped against single-cell sequencing data from fetal human lungs (Cao et al. 2023). Corresponding gene expression was clustered for cell type using JMP Pro 17 and a network-analysis was performed for each cluster using Cytoscape 3.10.2 string-database.

Results: DNAme analysis revealed n=88.615 differentially methylated CpGs (FDR<0,05) in cord blood mononucleated cells. Cytoscape string-db analysis of COVID-19-associated differentially altered CpGs matched to human fetal lung single-cell sequencing data revealed enrichment for the GO terms of protein binding (p=6,51*10–11, p=8,68*10–12) and the transcription factor (TF) Sp1 (p=2,49*10–8, p=4,13*10–10) in both, ciliated epithelium and squamous cell epithelium. In contrast, the cluster for lower respiratory tract cells showed enrichment for the GO terms of TF HA95 (p=7.30 x10–6) and ZNF670 (p=6.51 x10–11).

Discussion: COVID-19-infection in pregnancy significantly alters DNAme in cord blood mononucleated cells. These alterations project onto genes in fetal human lung epithelium associated with TF Sp1 and modify protein binding in ciliated epithelium and squamous cell epithelium, but not in lower respiratory tract cells. This may suggest an epigenetically dysregulated function of epithelium and respiratory mucosa. However, further studies are needed to identify the direct effects of altered Sp1-functionality on the airway epithelium.

Publikationsverlauf

Artikel online veröffentlicht:
28. Februar 2025