Integrated Multilayer Omics Reveals the Underlying Mechanisms in Xylazine-Related Heart Injury in Rats.

Xylazine abuse is emerging as a global problem, whereas the toxic mechanisms of xylazine poisoning are seldom studied. The present study aims to assess the heart injury in xylazine poisoning and uncover the underlying mechanism. Forty male SD rats were randomly dived into four groups: control (saline), low dose (10 mg/kg xylazine), median dose (20 mg/kg xylazine) and high dose (40 mg/kg xylazine). The rats were injected with the drug intraperitoneally for 28 consecutive days, and then cardiac ultrasound examination was performed and serum and heart tissues were collected. Genomic, proteomic, and metabolic omics analyses were conducted. ELISA, RNA sequencing, histopathology examination, RT-qPCR, and Western blot were performed. Repeated injection of xylazine led to a decrease in the expression of cardiac output (CO), ventricular systole (VS), and ventricular diastole (VD), while concurrently elevating the levels of lactate dehydrogenase (LDH), creatine kinase myocardial band (CK-MB), and cardiac troponin T (c-TNT) in the serum. HE staining analysis showed evidence of contraction band necrosis, interstitial fibrosis, and infiltration by inflammatory cells in animals with xylazine poisoning. The modified genes, proteins, and metabolites were gathered, and the integration of transcriptomic, proteomic, and metabolic networks identified 25 overlapping pathways between the differentially expressed genes and metabolites (DEGs-DEMs) and the differentially expressed proteins and metabolites (DEPs-DEMs) joint pathways. The majority of these pathways pertained to the metabolism of sugars, amino acids, and fats. The proteins associated with fructose and mannose metabolism, as well as cholesterol metabolism, were validated, thereby substantiating their pivotal role in the development of xylazine-induced cardiac injury. Repeated injection of xylazine impaired heart function and the metabolism of fructose and mannose. Cholesterol metabolism pathways were critical in the process of xylazine-induced heart injury.