Exploring the Diagnostic Potential of Core Targets of 6PPD and Its Metabolite 6PPD-Q in Cardiovascular Diseases: An Integrated Analysis Based on Network Toxicology, Molecular Docking, and In Vitro Validation.

Abstract

6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) and its oxidized form, 6PPD-Q (2-((4-methylpentan-2-yl)amino)-5-(phenylamino)cyclohexa-2,5-diene-1,4-dione), are commonly used in rubber-based materials and have been increasingly found in the environment. Recent studies suggest that these compounds may be toxic to the cardiovascular system, but the exact molecular mechanisms are not well understood. This study used a combination of network toxicology, molecular docking, and bioinformatics to investigate how 6PPD and 6PPD-Q affect the heart, particularly in relation to atherosclerosis, acute myocardial infarction, and heart failure. By screening multiple databases and analyzing Gene Expression Omnibus (GEO) transcriptome data, we identified key targets that are involved in these diseases. We built PPI networks and performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses to explore the related pathways. Additionally, we validated four core targets-nuclear receptor subfamily 4 group A member 3 (NR4A3), sphingosine-1-phosphate receptor 3 (S1PR3), nicotinamide phosphoribosyltransferase (NAMPT), and formyl peptide receptor 1 (FPR1)-that showed high diagnostic value in all three diseases using receiver operating characteristic (ROC) analysis. Molecular docking revealed that both 6PPD and 6PPD-Q strongly bind to these targets. Further in vitro experiments revealed that 6PPD and 6PPD-Q induce damage in H9c2 cells. The mechanism may be associated with these four targets. This study sheds light on how these environmental pollutants harm the cardiovascular system and demonstrates the value of combining network toxicology with omics and structural biology in risk assessment and therapeutic development.