Time dependent activation of molecular signatures is associated with Trimethylamine N oxide induced endothelial dysfunction in human microvascular endothelial cells

Cardiovascular diseases (CVD) are the principal cause of death worldwide. Endothelial dysfunction is recognized as a crucial initiating contributing factor for CVD. Trimethylamine–N–oxide (TMAO), a gut microbiome-derived metabolite is involved in CVD progression. However, the underlying time-dependent molecular mechanisms resulting in the pathogenesis of TMAO in endothelial cells remain unclear. To investigate the time-dependent molecular signatures of TMAO-induced endothelial dysfunction in human microvascular endothelial cells (HMEC–1), we performed transcriptomics and metabolomics analysis on TMAO (50 μM) treated cells for 24H or 48H. Differentially expressed genes were used for overrepresentation analysis of pathways to determine the various molecular signatures involved. These were validated with quantitative real–time PCR, cell viability (prestoblue), and reactive oxygen species generation (DCFDA). TMAO treatment for 24H and 48H induced endothelial dysfunction, demonstrated by lowered cell viability, and elevated oxidative stress. Interestingly, time–dependent modifications in the molecular signatures were unique between time points. Indicatively, there were fewer GO biological processes and KEGG pathways suppressed, after 24H TMAO treatment. They were involved in cellular response and developmental processes. Compared to 48H treatment, a greater number of molecular signatures were activated and suppressed for GO biological processes and KEGG pathways. Upregulated DEG was enriched in pathways like oxidative stress and the production of inflammatory phenotypes, while suppressed pathways were associated with the structural organization of the ECM, endothelial cell proliferation, and collagen metabolism. This study indicates that TMAO–induced endothelial dysfunction is regulated through the mitigation of molecular gene signatures involved in oxidative stress and inflammation, activating endothelial cell remodelling. Funding source: SUTD Start-up Research Grant, and SUTD Kickstarter Initiative, Singapore This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.