Epigenetic approaches by analysis of circulating miRNAs and global DNA methylation in veterinarians occupationally exposed to volatile anesthetics.

Exposure to waste anesthetic gases (WAGs) is an underestimated occupational hazard in veterinary operating rooms (VORs), where insufficient ventilation and the absence of scavenging systems remain common worldwide. Veterinarians occupationally exposed to WAGs have been poorly investigated to date. Addressing this critical gap, we present the first integrative study evaluating circulating microRNAs (miRNAs), global DNA methylation, and urinary anesthetic quantification in veterinarians occupationally exposed to WAGs isoflurane and sevoflurane. In a case-control design, plasma profiling revealed 11 dysregulated miRNAs in the exposed group (n = 29) compared to the control group (n = 28) based on nominal p-values (p < 0.05), as part of an exploratory screening approach, including seven upregulated miRNAs meeting a predefined fold-change criterion (FC≥1.5). Among these, hsa-miR-1252-5p and hsa-miR-520f-3p showed robust discriminatory performance based on Receiver Operating Characteristic (ROC) curve analysis (AUC≥0.70). Functional enrichment analysis highlighted epigenetic regulators as major network hubs. For hsa-miR-1252-5p, hubs included EP300, TP53, CREBBP, HDAC1 and SIRT1, linking miRNAs modulation to histone acetylation/deacetylation, DNA damage response, apoptosis, and stress regulation. For hsa-miR-520f-3p, included MAPK1, TNRC6B, MECP2 and KMT2A, associated with cell signaling pathways, proliferation and epigenetic regulation. Global DNA methylation levels did not differ significantly between groups, suggesting that exposure under the evaluated conditions may not trigger genome-wide alterations. Occupational exposure was confirmed by urinary quantification of isoflurane and sevoflurane, indicating highly polluted workplaces. In conclusion, although global DNA methylation remained unchanged, WAG exposure was associated with modulation of circulating miRNAs, and our findings suggest that hsa-miR-1252-5p and hsa-miR-520f-3p emerge as potential biomarkers of effect associated to WAG occupational exposure in veterinarians who work in inadequately equipped VORs.