石斛类外泌体囊泡调控巨噬细胞极化抗动脉粥样硬化的作用机制OA

Objective To investigate the mechanism of dendrobium-derived exosome-like nanovesicles in treating atherosclerosis and their effects on macrophage polarization.Methods Dendrobium-derived exosome-like nanovesicles were isolated by density gradient centrifugation and characterized with transmission electron microscopy and nanoparticle tracking analysis.Nanovesicle uptake by RAW264.7 macrophages was observed using confocal laser scanning microscopy.Nanovesicle chemical components were analyzed by high-performance liquid chromatography-mass spectrometry(HPLC-MS).Combined with network pharmacology,core nanovesicle targets and key pathways in regulating macrophage polarization for atherosclerosis treatment were screened.In vitro,an M1-type macrophage polarization model was established through lipopolysaccharide and interferon-γ induction.Different nanovesicle concentrations were tested for intervention.Inflammatory factor expression levels were detected by RT-qPCR.In vivo,an atherosclerosis model was constructed using ApoE-/-mice;after intraperitoneal injection,the effects of nanovesicles on atherosclerotic plaque area,blood lipid levels,inflammatory factors,and macrophage polarization-related signaling were evaluated by oil red O staining,hematoxylin-eosin staining,blood lipid detection,enzyme-linked immunosorbent assay,RT-qPCR,immunofluorescence,and immunohistochemistry.Results Dendrobium-derived exosome-like nanovesicles exhibited a typical cup-shaped morphology with an average particle size of 154.2 nm,and could be internalized by macrophages.A total of 316 compounds were identified by HPLC-MS,among which 209 compounds had a comprehensive score>60.Network pharmacology analysis identified 128 common targets of dendrobium-derived exosome-like nanovesicles,atherosclerosis,and macrophage polarization,which were enriched in signaling pathways related to inflammatory response regulation.In vitro experiments indicated that nanovesicles could suppress M1-type macrophage polarization in a concentration-dependent pattern,accompanied by decreased levels of pro-inflammatory factors interleukin(IL)-1β and iNOS and increased expression of the anti-inflammatory factor IL-10.In vivo experiments demonstrated that nanovesicles significantly reduced aortic plaque area,improved blood lipid levels,alleviated aortic pathological damage,decreased serum IL-1β,and increased serum IL-10 in atherosclerotic mice.Nanovesicles reduced the proportion of M1-type macrophages,elevated that of M2-type macrophages in the aortic root,and suppressed JAK2/STAT3 signaling activation.Conclusions Dendrobium-derived exosome-like nanovesicles exerted anti-atherosclerotic effects by regulating the balance of macrophage polarization,alleviating inflammatory responses,and improving lipid metabolism;the related mechanism may be associated with JAK2/STAT3 signaling inhibition.