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Principal Investigator: Yiliang Chen
Organization: MEDICAL COLLEGE OF WISCONSIN
Fiscal Year: 2024
Award: $523,513
Funding agency: National Heart Lung and Blood Institute
Atherosclerosis (AS) is a chronic inflammatory disease of medium and large arteries and remains the leading
cause of death worldwide from its sequelae of heart attack, stroke and limb loss. During AS progression
chronic activation of immune cells in the vessel wall, especially macrophages, leads to formation of lipid-loaded
foam cells which become the major component of atherosclerotic plaque. The goal is to discover molecular
mechanisms through which dyslipidemia and oxidative stress, which are major risk factors for AS, are linked to
chronic macrophage activation via dysregulated function of fat cells (adipocytes). The proposal will explore
how adipocyte-derived exosomes (Ad-Exo) carrying specific pro-atherogenic cargo such as miRNAs, are
generated under oxidative stress, and how they activate macrophages. Focus is CD36, type II scavenger
receptor highly expressed in adipocytes and macrophages that acts as a receptor for the atherogenic ligand
oxidized LDL (oxLDL). The oxLDL/CD36 signaling axis creates an inflammatory paracrine loop between
macrophages and adipocytes and facilitates oxidative stress and pro-inflammatory cytokine secretion through
Src family kinase (SFK) activation. Na/K-ATPase (NKA) α1 subunit serves both as a CD36 co- receptor and a
scaffold for the SFK, allowing conformational changes in the NKA to activate membrane bound SFK and
initiate signaling cascades, a mechanism distinct from its well-understood pumping function. Hypothesis of this
proposal is that activation of NKA/CD36 signaling in adipocytes produces oxidative stress that causes release
of adipokines and exosomes (Ad-Exo). These released factors initiate and augment AS by stimulating
macrophages. To test this hypothesis, 3 specific aims have been developed. The first will test the hypothesis
that adipocyte NKA/CD36 signaling complex promotes AS through production of cellular oxidative stress
leading to abnormal adipokines/exosome secretion. The approach will include use of the apoe null mouse
model and lentiviral vectors to deliver cell-specific NaKtide, a peptide reagent derived from the NKA α1 domain
that behaves as a specific inhibitor of the NKA/SFK pathway. Oxidant stress, AS plaque formation, and
adipocyte gene expression will be assessed using state-of-the-art techniques, such as next generation
RNASeq. The second aim will test whether Ad-Exo can modulate macrophage function in vitro and in vivo by
characterizing the proteome, lipidome and miRNA profile of Ad-Exo released in response to oxidative stress
and tracking their delivery to monocytes and AS plaque. A newly developed mouse model, GFP-
CD63flox/Adipoq Cre mice will be used as an excellent Ad-Exo reporter animal model for these studies. The
third aim will determine if Ad-Exo regulate macrophage lipid metabolism and mitochondrial function using
sophisticated metabolic flux assays along with lipidomic and gene expression assays. Successful completion
of this project will define an important concept that adipocyte CD36/NKA and downstream Ad-Exo secretion is
a driving force for chronic macrophage activation in AS, thereby identifying novel therapeutic targets.
Terms: <Adipocytes><Adipose Cell><Adipose tissue><Amino Acids><Animal Model><Animal Models and Related Studies><Apo-E><ApoE><ApoE protein><Apolipoprotein E><Apoplexy><Arterial Fatty Streak><Arterial Fatty Streaks><Arteries><Assay><Atheroma><Atheromatous><Atheromatous degeneration><Atheromatous plaque><Atherosclerosis><Atherosclerotic Cardiovascular Disease><Attenuated><Binding><Bioassay><Biochemical><Biological Assay><Blood monocyte><Body Tissues><Brain Vascular Accident><CD36><CD36 gene><Cardiac infarction><Cause of Death><Cell Body><Cell Communication and Signaling><Cell Signaling><Cells><Cerebral Stroke><Cerebrovascular Apoplexy><Cerebrovascular Stroke><Chronic><Complex><Data><Development><Distant><Dyslipidemias><Endocrine Gland Secretion><Fat Cells><Fatty Tissue><Foam Cells><GP3B><GP4><GPIV><Gene Expression><Gene Expression Monitoring><Gene Expression Pattern Analysis><Gene Expression Profiling><Genetic><Goals><Hormones><Immune Cell Activation><In Vitro><Incubated><Inflammation><Inflammatory><Initiation Factors><Injections><Intracellular Communication and Signaling><Ions><KO mice><Kinases><Knock-out Mice><Knockout Mice><Label><Lentiviral Vector><Lentivirus Vector><Ligands><Link><Lipids><Lipocytes><Location><Macrophage><Macrophage Activation><Marrow monocyte><Mature Lipocyte><Mature fat cell><Mediating><Mediator><Membrane><Metabolic><Methods><Mice><Mice Mammals><Micro RNA><MicroRNAs><Mitochondria><Modeling><Molecular><Molecular Configuration><Molecular Conformation><Molecular Interaction><Molecular Stereochemistry><Murine><Mus><Myocardial Infarct><Myocardial Infarction><Mφ><N Domain><Null Mouse><OxLDL><Oxidative Stress><Pathway interactions><Peptide Initiation Factors><Peptides><Phenotype><Phosphotransferase Gene><Phosphotransferases><Play><Production><Proteins><Proteome><Publishing><Pump><RNA Seq><RNA sequencing><RNAseq><Reagent><Receptor Protein><Reporter><Risk Factors><Role><SCARB3><Signal Transduction><Signal Transduction Systems><Signaling><Stroke><Study models><Techniques><Testing><Therapeutic><Therapeutic Hormone><Therapeutic Intervention><Tissues><Transcript Expression Analyses><Transcript Expression Analysis><Translation Initiation Factor><Translational Initiation Factor><Transphosphorylases><Work><acetyl-LDL receptor><acetylated LDL receptor><adipocyte biology><adipocytokines><adipokines><adipose><aminoacid><analyze gene expression><atherogenesis><atheromatosis><atherosclerosis plaque><atherosclerotic disease><atherosclerotic lesions><atherosclerotic plaque><atherosclerotic vascular disease><attenuate><attenuates><biological signal transduction><brain attack><cardiac infarct><cell type><cerebral vascular accident><cerebrovascular accident><chronic inflammatory disease><conformation><conformational><conformational state><conformationally><conformations><coronary attack><coronary infarct><coronary infarction><cytokine><developmental><diagnostic biomarker><diagnostic marker><driving force><exosome><fat metabolism><gene expression analysis><gene expression assay><heart attack><heart infarct><heart infarction><immune activation><improved><in vivo><inhibitor><intervention therapy><ischemic limb><limb ischemia><limb loss><lipid metabolism><lipidome><lipidomics><lost limb><membrane structure><miRNA><miRNAs><mitochondrial><model of animal><molecular phenotype><monocyte><mouse model><murine model><new diagnostics><new drug target><new druggable target><new pharmacotherapy target><new therapeutic approach><new therapeutic intervention><new therapeutic strategies><new therapeutic target><new therapy approaches><new therapy target><new treatment approach><new treatment strategy><next generation><next generation diagnostics><novel><novel diagnostics><novel drug target><novel druggable target><novel pharmacotherapy target><novel therapeutic approach><novel therapeutic intervention><novel therapeutic strategies><novel therapeutic target><novel therapy approach><novel therapy target><ox-LDL><oxidant stress><oxidized LDL><oxidized low density lipoprotein><paracrine><pathway><receptor><release factor><response><scaffold><scaffolding><scavenger receptor><social role><src Kinases><src Protein-Tyrosine Kinases><src Tyrosine Kinases><src-Family Kinases><src-Family Tyrosine Kinases><stroked><strokes><trafficking><transcriptional profiling><transcriptome sequencing><transcriptomic sequencing><vulnerable plaque><white adipose tissue><yellow adipose tissue>