[Mechanism of astragaloside â £ modulation of Nrf2/HO-1/GPX4 pathway to inhibit ferroptosis and ameliorate atherosclerosis in ApoE~(-/-) mice].

ABSTRACT

The intervention effect of astragaloside Ⅳ(AS-Ⅳ) on atherosclerosis in apolipoprotein E gene knockout(ApoE)~(-/-) mice was observed based on the nuclear factor erythroid-2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)/glutathione peroxidase 4(GPX4) signaling pathway to explore the potential mechanism of AS-Ⅳ in improving ferroptosis in atherosclerotic mice. This study established an atherosclerosis mouse model by feeding them a high-fat diet. After modeling for 8 weeks, ApoE~(-/-) mice were randomly divided into the model group, AS-Ⅳ group, AS-Ⅳ+Nrf2 inhibitor(ML385) group, and ferrostatin-1(Fer-1) group. Additionally, a blank control group was also established. Corresponding drugs were administered via intraperitoneal injection, with the control group receiving an equivalent amount of normal saline injection as the model group. After the experiment, serum biochemical levels were measured using an automatic blood lipid analyzer, hematoxylin-eosin(HE) staining was used to observe morphological changes in aortic sinus tissues, colorimetric methods were used to detect levels of ferrous ion(Fe~(2+)), malondialdehyde(MDA), glutathione(GSH), and superoxide dismutase(SOD) in mouse serum, immunofluorescence was used to observe the expressions of ferritin heavy chain 1(FTH1) and ferritin light chain(FTL) proteins in the aortic sinus of mice, Western blot was used to detect the protein levels of Nrf2, HO-1, and GPX4 in mouse aortic tissues, and transmission electron microscopy was used to observe ultrastructural changes in aortic tissues. RESULTS: showed that compared to the control group, the model group of mice had significantly increased calcification and plaque deposition areas in the aortic sinus, increased mitochondrial membrane density, decreased or disappeared mitochondrial cristae, elevated levels of total cholesterol(TC), triglycerides(TG), low-density lipoprotein cholesterol(LDL-C), Fe~(2+), and MDA, decreased levels of high-density lipoprotein cholesterol(HDL-C), SOD, and GSH, and significant inhibition of Nrf2, HO-1, GPX4 proteins, as well as iron storage proteins FTH1 and FTL expressions in the aorta. Compared to the model group, AS-Ⅳ treatment resulted in decreased serum TC, TG, LDL-C, Fe~(2+), and MDA levels, increased HDL-C, SOD, and GSH levels, increased expressions of Nrf2, HO-1, and GPX4 proteins, and iron storage proteins FTH1 and FTL, and significant improvement in aortic tissue morphology. Compared to the AS-Ⅳ group, the Nrf2 inhibitor ML385 could reverse the therapeutic effect of AS-Ⅳ on atherosclerosis mice. These findings suggest that AS-Ⅳ can inhibit ferroptosis and improve atherosclerosis in ApoE~(-/-) mice, and its mechanism of action may be related to the regulation of the Nrf2/HO-1/GPX4 signaling pathway.