Regulatory Effects Of Extracellular Vesicles Derived From Houttuynia Cordata On Mitochondrial Metabolism And Inflammatory Response Of Macrophages

Extracellular vesicles(EVs)are usually defined as lipid bilayer-enclosed,cytoplasmic vesicles that are released by the cell to the extracellular space and participate in intercellular communication.In plants,extracellular vesicles are mainly protective compartments where multiple nutrients are transported between cells,and contribute to plant growth and development,defense responses,and the symbiosis of plants and microorganisms,which can protect plant against pathogens,but currently it is unclear whether it can mediate interspecific communication between plant cells and mammalian cells.Macrophages are effector immune cells that display different transition states between M1(classical activation pathway)and M2(alternative activation pathway)phenotypes.The purpose of this study was to explore the role of extracellular vesicles derived from Houttuynia cordata to regulate the immune response of macrophages and whether they are involved in mitochondrial metabolism Therefore,we isolated and extracted extracellular vesicles from Houttuynia cordata root,an exosome-like nanoparticle(HDNPs).Its immunoregulatory role in RAW264.7 macrophages induced by LPS and the potential mechanism was investigated.First,we used differential centrifugation to isolate and purify HDNPs from fresh Houttuynia cordata roots.The morphology was observed by transmission electron microscope as a membrane-like structure.Nanoparticle tracking analysis(NTA)determined that the size distribution was around 200 nm.HDNPs were subsequently used as immunomodulators of macrophages to study their anti-inflammatory activity at the animal level.Analyze the changes of pro-inflammatory cytokines(such as IL-6,IL-1?,TNF-?)or anti-inflammatory cytokines(such as Arg-1,IL-10)at the transcription level.In addition,we analyzed the M1/M2 status of RAW264.7 cells pretreated with HDNPs with and without lipopolysaccharide(LPS)stimulation.Finally,the study on the effects of HDNPs on mitochondrial metabolism and function suggests that the immunomodulatory effect of HDNPs may be related to repairing damaged mitochondria.In summary,this study first extracted and characterized vesicles from the roots of the traditional Chinese herbal medicine Houttuynia cordata,and found that vesicles are involved in regulating the immune response of inflammatory mediators in macrophages stimulated by LPS in vivo and in vitro.This study provides a pharmacological basis for the use of HDNPs to control inflammatory diseases and provides new methods and ideas for the research of Houttuynia cordata functions.