Irisin liposomes inhibit ferroptosis and improve atherosclerosis in mouse models via the NRF2/HO-1 signaling pathway

Background: Atherosclerosis (AS)—a chronic arterial wall inflammation driven by lipid dysmetabolism—progresses through oxidative stress and inflammatory cascades. Ferroptosis is established as a pivotal pathogenic driver in AS. Here, we leverage exercise-induced cytokine irisin, delivered via liposomal carriers, to therapeutically suppress ferroptotic signaling and ameliorate atherosclerotic pathogenesis. Methods:Irisin liposomes were prepared using the complex emulsion method, and a suitable concentration of irisin was determined using the Cell Counting Kit-8 (CCK-8) method. A vascular endothelial cell injury model was constructed to investigate the protective effect of irisin liposomes on vascular endothelial cells using apoptosis detection, lactate dehydrogenase (LDH) detection, mitochondrial membrane potential detection, and transmission electron microscopy morphology detection. The expression levels of key genes in the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway were detected using western blotting and quantitative real-time polymerase chain reaction (qRT-PCR). A mouse model of atherosclerosis was constructed, and irisin liposomes were administered via tail vein injection to treat the mice. Serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), oxidized low-density lipoprotein (ox-LDL), reactive oxygen species (ROS), and Fe2+were detected by kits, and levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), oxidized glutathione (GSSG), and 4-hydroxynonenal (4-HNE) were detected by enzyme-linked immunosorbent assay (ELISA). Hematoxylin and eosin (H&E) staining and alizarin red staining were used to detect carotid artery tissues pathologically. ELISA, immunohistochemistry, western blot, and qRT-PCR were used to detect the expression levels of key genes in the Nrf2/HO-1 signaling pathway in carotid artery tissues.Results:The umbilical vein endothelial cells maintained high activity at an irisin concentration of 25 nmol/L. By comparing the apoptosis, cytotoxicity, and mitochondrial morphology and membrane potential changes in the blank serum group, vascular endothelial cell injury model group, and irisin group, the irisin liposome group had a better function of protecting vascular endothelial cells and activated the Nrf2/HO-1 signaling pathway. In the atherosclerosis mouse model, the irisin liposome group significantly downregulated the levels of TC, TG, LDL-C, and ox-LDL and upregulated the level of HDL-C. The irisin liposome group significantly downregulated the levels of Fe2+, MDA, ROS, GSSG, and 4-HNE and upregulated the levels of GSH, SOD, and irisin, which are indicators related to the ferroptosis. Simultaneously, it improved the pathology in the carotid artery tissues of atherosclerotic mice, mainly by activating the Nrf2/HO-1 signaling pathway, upregulating the levels of Nrf2, HO-1, glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11), and downregulating the expression levels of acyl-CoA synthetase long chain family member 4 (ACSL4) and tumor protein 53 (P53).Conclusions:Irisin liposomes exerted enhanced protective effects on vascular endothelial cells, inhibited ferroptosis by activating the Nrf2/HO-1 signaling pathway, and ameliorated damage in a mouse model of AS, which had a therapeutic effect on AS.