1 2378 105 EPIGENETIC REGULATION OF VASCULAR SMOOTH MUSCLE CELL PHENOTYPE SWITCHING IN ATHEROSCLEROTIC ARTERY REMODELING: A MINI-REVIEW. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY EXTENSIVE REMODELING OF MEDIUM AND LARGE-SIZED ARTERIES. INWARD REMODELING (=LUMEN SHRINKAGE) OF THE VASCULAR WALLS IS THE UNDERLYING CAUSE FOR ISCHEMIA IN TARGET ORGANS. THEREFORE, INWARD REMODELING CAN BE CONSIDERED THE PREDOMINANT FEATURE OF ATHEROSCLEROTIC PATHOLOGY. OUTWARD REMODELING (=LUMEN ENLARGEMENT) IS A PHYSIOLOGICAL RESPONSE COMPENSATING FOR LUMEN SHRINKAGE CAUSED BY NEOINTIMAL HYPERPLASIA, BUT AS A PATHOLOGICAL RESPONSE TO CHANGES IN BLOOD FLOW, OUTWARD REMODELING LEADS TO SUBSTANTIAL ARTERIAL WALL THINNING. THINNED VASCULAR WALLS ARE PRONE TO RUPTURE, AND SUBSEQUENT THROMBUS FORMATION ACCOUNTS FOR THE MAJORITY OF ACUTE CARDIOVASCULAR EVENTS. PATHOLOGICAL REMODELING IS DRIVEN BY INFLAMMATORY CELLS WHICH INDUCE VASCULAR SMOOTH MUSCLE CELLS TO SWITCH FROM QUIESCENT TO A PROLIFERATIVE AND MIGRATORY PHENOTYPE. AFTER DECADES OF INTENSIVE RESEARCH, THE MOLECULAR MECHANISMS OF ARTERIAL REMODELING ARE STARTING TO UNFOLD. IN THIS MINI-REVIEW, WE SUMMARIZE THE CURRENT KNOWLEDGE OF THE EPIGENETIC AND TRANSCRIPTIONAL REGULATION OF VASCULAR SMOOTH MUSCLE CELL PHENOTYPE SWITCHING FROM THE CONTRACTILE TO THE SYNTHETIC PHENOTYPE INVOLVED IN ARTERIAL REMODELING AND DISCUSS POTENTIAL THERAPEUTIC OPTIONS. 2021 2 6214 34 THE INTRACELLULAR SIGNALING PATHWAYS GOVERNING MACROPHAGE ACTIVATION AND FUNCTION IN HUMAN ATHEROSCLEROSIS. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY LIPID ACCUMULATION AND PLAQUE FORMATION IN ARTERIAL VESSEL WALLS. ATHEROSCLEROTIC PLAQUES NARROW THE ARTERIAL LUMEN TO INCREASE THE RISK OF HEART ATTACKS, ISCHEMIC STROKE AND PERIPHERAL VASCULAR DISEASE, WHICH ARE MAJOR AND WORLDWIDE HEALTH AND ECONOMIC BURDENS. MACROPHAGE ACCUMULATION WITHIN PLAQUES IS CHARACTERISTIC OF ALL STAGES OF ATHEROSCLEROSIS AND THEIR PRESENCE IS A POTENTIAL MARKER OF DISEASE ACTIVITY AND PLAQUE STABILITY. MACROPHAGES ENGULF LIPIDS AND MODIFIED LIPOPROTEINS TO FORM FOAM CELLS THAT EXPRESS PRO-INFLAMMATORY AND CHEMOTACTIC EFFECTOR MOLECULES, STRESS INDUCING FACTORS AND REACTIVE OXYGEN SPECIES. THEY CONTROL PLAQUE STABILITY AND RUPTURE THROUGH SECRETION OF METALLOPROTEINASES AND EXTRACELLULAR MATRIX DEGRADATION. ALTHOUGH MACROPHAGES CAN WORSEN DISEASE BY PROPAGATING INFLAMMATION, THEY CAN STABILIZE ATHEROSCLEROTIC PLAQUES THROUGH TISSUE REMODELING, PROMOTING THE FORMATION OF A FIBROUS CAP, CLEARING APOPTOTIC CELLS TO PREVENT NECROTIC CORE FORMATION AND THROUGH VASCULAR REPAIR. IN ATHEROSCLEROSIS, MACROPHAGES RESPOND TO DYSLIPIDAEMIA, CYTOKINES, DYING CELLS, METABOLIC FACTORS, LIPIDS, PHYSICAL STIMULI AND EPIGENETIC FACTORS AND EXHIBIT HETEROGENEITY IN THEIR ACTIVATION DEPENDING ON THE STIMULI THEY RECEIVE. UNDERSTANDING THESE SIGNALS AND THE PATHWAYS DRIVING MACROPHAGE FUNCTION WITHIN DEVELOPING AND ESTABLISHED PLAQUES AND HOW THEY CAN BE PHARMACOLOGICALLY MODULATED, REPRESENTS A STRATEGY FOR THE PREVENTION AND TREATMENT OF ATHEROSCLEROSIS. THIS REVIEW FOCUSSES ON THE CURRENT UNDERSTANDING OF FACTORS CONTROLLING MACROPHAGE HETEROGENEITY AND FUNCTION IN ATHEROSCLEROSIS. PARTICULAR ATTENTION IS GIVEN TO THE MACROPHAGE INTRACELLULAR SIGNALING PATHWAYS AND TRANSCRIPTION FACTORS ACTIVATED BY BIOCHEMICAL AND BIOPHYSICAL STIMULI WITHIN PLAQUES, AND HOW THEY ARE INTEGRATED TO REGULATE PLAQUE FORMATION AND STABILITY. 2022 3 4303 26 MICRORNA-223 INHIBITS TISSUE FACTOR EXPRESSION IN VASCULAR ENDOTHELIAL CELLS. OBJECTIVE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY PROCESS, IN WHICH VASCULAR ENDOTHELIAL CELLS (ECS) BECOME DYSFUNCTIONAL OWING TO THE EFFECTS OF CHEMICAL SUBSTANCES, SUCH AS INFLAMMATORY FACTOR AND GROWTH FACTORS. TISSUE FACTOR (TF) EXPRESSION IS INDUCED BY THE ABOVE CHEMICAL SUBSTANCES IN ACTIVATED ECS. TF INITIATES THROMBOSIS ON DISRUPTED ATHEROSCLEROTIC PLAQUES WHICH PLAYS AN ESSENTIAL ROLE DURING THE ONSET OF ACUTE CORONARY SYNDROMES (ACS). INCREASING EVIDENCES SUGGEST THE IMPORTANT ROLE OF MICRORNAS AS EPIGENETIC REGULATORS OF ATHEROSCLEROTIC DISEASE. THE AIM OF OUR STUDY IS TO IDENTIFY IF MICRORNA-223 (MIR-223) TARGETS TF IN ECS. METHODS AND RESULTS: BIOINFORMATIC ANALYSIS SHOWED THAT TF IS A TARGET CANDIDATE OF MIR-223. WESTERN BLOTTING ANALYSIS REVEALED THAT TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA) INCREASED TF EXPRESSION IN AORTA OF C57BL/6J MICE AND CULTURED ECS (EA.HY926 CELLS AND HUVEC) AFTER 4 H TREATMENT. IN TNF-ALPHA TREATED ECS, TF MRNA WAS ALSO INCREASED MEASURED BY REAL-TIME PCR. REAL-TIME PCR RESULTS SHOWED THAT MIR-223 LEVELS WERE DOWNREGULATED IN TNF-ALPHA-TREATED AORTA OF C57BL/6J MICE AND CULTURED ECS. TRANSFECTION OF ECS WITH MIR-223 MIMIC OR MIR-223 INHIBITOR MODIFIED TF EXPRESSION BOTH IN MRNA AND PROTEIN LEVELS. LUCIFERASE ASSAYS CONFIRMED THAT MIR-223 SUPPRESSED TF EXPRESSION BY BINDING TO THE SEQUENCE OF TF 3'-UNTRANSLATED REGIONS (3'UTR). TF PROCOAGULANT ACTIVITY WAS INHIBITED BY OVEREXPRESSING MIR-223 WITH OR WITHOUT TNF-ALPHA STIMULATION. CONCLUSIONS: MIR-223-MEDIATED SUPPRESSION OF TF EXPRESSION PROVIDES A NOVEL MOLECULAR MECHANISM FOR THE REGULATION OF COAGULATION CASCADE, AND SUGGESTS A CLUE AGAINST THROMBOGENESIS DURING THE PROCESS OF ATHEROSCLEROTIC PLAQUE RUPTURE. 2014 4 6499 29 TRAINED IMMUNITY IN PERIVASCULAR ADIPOSE TISSUE OF ABDOMINAL AORTIC ANEURYSM-A NOVEL CONCEPT FOR A STILL ELUSIVE DISEASE. ABDOMINAL AORTIC ANEURYSM (AAA) IS A CHRONIC, LIFE-THREATENING VASCULAR DISEASE WHOSE ONLY THERAPEUTIC OPTION IS A SURGICAL REPAIR TO PREVENT VESSEL RUPTURE. THE LACK OF MEDICAL THERAPY RESULTS FROM AN INADEQUATE UNDERSTANDING OF THE ETIOPATHOGENESIS OF AAA. MANY STUDIES IN ANIMAL AND HUMAN MODELS INDICATE A 'SHORT-CIRCUITING' OF THE REGULATION OF THE INFLAMMATORY-IMMUNE RESPONSE AS A MAJOR PLAYER IN THE AAA CHRONIC PROCESS. IN THIS REGARD, PERIVASCULAR ADIPOSE TISSUE (PVAT) HAS RECEIVED INCREASING INTEREST BECAUSE ITS DYSFUNCTION AFFECTS LARGE ARTERIES PRIMARILY THROUGH IMMUNE CELL INFILTRATION. CONSISTENTLY, WE HAVE RECENTLY PRODUCED EVIDENCE THAT INNATE AND ADAPTIVE IMMUNE CELLS PRESENT IN THE PVAT OF AAAS CONTRIBUTE TO SUSTAINING A DAMAGING INFLAMMATORY LOOP. HOWEVER, IT IS STILL UNCLEAR HOW THE COMPLEX CROSSTALK BETWEEN ADAPTIVE AND INNATE IMMUNITY CAN BE SELF-SUSTAINING. FROM OUR PERSPECTIVE, TRAINED IMMUNITY MAY PLAY A ROLE IN THIS CROSSTALK. TRAINED IMMUNITY IS DEFINED AS A FORM OF INNATE IMMUNE MEMORY RESULTING IN ENHANCED RESPONSIVENESS TO REPEATED TRIGGERS. SPECIFIC INNATE STIMULI AND EPIGENETIC AND METABOLIC REPROGRAMMING EVENTS INDUCE AND SHAPE TRAINED IMMUNITY IN MYELOID PROGENITOR CELLS IMPROVING HOST DEFENSE, BUT ALSO CONTRIBUTING TO THE PROGRESSION OF IMMUNE-MEDIATED AND CHRONIC INFLAMMATORY DISEASES. HERE WE PRESENT THIS HYPOTHESIS WITH DATA FROM THE LITERATURE AND OUR OBSERVATIONS TO SUPPORT IT. 2022 5 4097 28 MATRIX STIFFNESS REGULATES MACROPHAGE POLARIZATION IN ATHEROSCLEROSIS. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE AND THE PATHOLOGICAL BASIS OF MANY FATAL CARDIOVASCULAR DISEASES. MACROPHAGES, THE MAIN INFLAMMATORY CELLS IN ATHEROSCLEROTIC PLAQUE, HAVE A PARADOX ROLE IN DISEASE PROGRESSION. IN RESPONSE TO DIFFERENT MICROENVIRONMENTS, MACROPHAGES MAINLY HAVE TWO POLARIZED DIRECTIONS: PRO-INFLAMMATORY MACROPHAGES AND ANTI-INFLAMMATORY MACROPHAGES. MORE AND MORE EVIDENCE SHOWS THAT MACROPHAGE IS MECHANOSENSITIVE AND MATRIX STIFFNESS REGULATE MACROPHAGE PHENOTYPES IN ATHEROSCLEROSIS. HOWEVER, THE MOLECULAR MECHANISM OF MATRIX STIFFNESS REGULATING MACROPHAGE POLARIZATION STILL LACKS IN-DEPTH RESEARCH, WHICH HINDERS THE DEVELOPMENT OF NEW ANTI-ATHEROSCLEROTIC THERAPIES. IN THIS REVIEW, WE DISCUSS THE IMPORTANT ROLE OF MATRIX STIFFNESS IN REGULATING MACROPHAGE POLARIZATION THROUGH MECHANICAL SIGNAL TRANSDUCTION (HIPPO, PIEZO, CYTOSKELETON, AND INTEGRIN) AND EPIGENETIC MECHANISMS (MIRNA, DNA METHYLATION, AND HISTONE). WE HOPE TO PROVIDE A NEW PERSPECTIVE FOR ATHEROSCLEROSIS THERAPY BY TARGETING MATRIX STIFFNESS AND MACROPHAGE POLARIZATION. 2022 6 5933 47 TARGETING EPIGENETICS AND NON-CODING RNAS IN ATHEROSCLEROSIS: FROM MECHANISMS TO THERAPEUTICS. ATHEROSCLEROSIS, THE PRINCIPAL CAUSE OF CARDIOVASCULAR DEATH WORLDWIDE, IS A PATHOLOGICAL DISEASE CHARACTERIZED BY FIBRO-PROLIFERATION, CHRONIC INFLAMMATION, LIPID ACCUMULATION, AND IMMUNE DISORDER IN THE VESSEL WALL. AS THE ATHEROMATOUS PLAQUES DEVELOP INTO ADVANCED STAGE, THE VULNERABLE PLAQUES ARE PRONE TO RUPTURE, WHICH CAUSES ACUTE CARDIOVASCULAR EVENTS, INCLUDING ISCHEMIC STROKE AND MYOCARDIAL INFARCTION. EMERGING EVIDENCE HAS SUGGESTED THAT ATHEROSCLEROSIS IS ALSO AN EPIGENETIC DISEASE WITH THE INTERPLAY OF MULTIPLE EPIGENETIC MECHANISMS. THE EPIGENETIC BASIS OF ATHEROSCLEROSIS HAS TRANSFORMED OUR KNOWLEDGE OF EPIGENETICS FROM AN IMPORTANT BIOLOGICAL PHENOMENON TO A BURGEONING FIELD IN CARDIOVASCULAR RESEARCH. HERE, WE PROVIDE A SYSTEMATIC AND UP-TO-DATE OVERVIEW OF THE CURRENT KNOWLEDGE OF THREE DISTINCT BUT INTERRELATED EPIGENETIC PROCESSES (INCLUDING DNA METHYLATION, HISTONE METHYLATION/ACETYLATION, AND NON-CODING RNAS), IN ATHEROSCLEROTIC PLAQUE DEVELOPMENT AND INSTABILITY. MECHANISTIC AND CONCEPTUAL ADVANCES IN UNDERSTANDING THE BIOLOGICAL ROLES OF VARIOUS EPIGENETIC MODIFIERS IN REGULATING GENE EXPRESSION AND FUNCTIONS OF ENDOTHELIAL CELLS (VASCULAR HOMEOSTASIS, LEUKOCYTE ADHESION, ENDOTHELIAL-MESENCHYMAL TRANSITION, ANGIOGENESIS, AND MECHANOTRANSDUCTION), SMOOTH MUSCLE CELLS (PROLIFERATION, MIGRATION, INFLAMMATION, HYPERTROPHY, AND PHENOTYPIC SWITCH), AND MACROPHAGES (DIFFERENTIATION, INFLAMMATION, FOAM CELL FORMATION, AND POLARIZATION) ARE DISCUSSED. THE INHERENTLY DYNAMIC NATURE AND REVERSIBILITY OF EPIGENETIC REGULATION, ENABLES THE POSSIBILITY OF EPIGENETIC THERAPY BY TARGETING EPIGENETIC "WRITERS", "READERS", AND "ERASERS". SEVERAL FOOD DRUG ADMINISTRATION-APPROVED SMALL-MOLECULE EPIGENETIC DRUGS SHOW PROMISE IN PRE-CLINICAL STUDIES FOR THE TREATMENT OF ATHEROSCLEROSIS. FINALLY, WE DISCUSS POTENTIAL THERAPEUTIC IMPLICATIONS AND CHALLENGES FOR FUTURE RESEARCH INVOLVING CARDIOVASCULAR EPIGENETICS, WITH AN AIM TO PROVIDE A TRANSLATIONAL PERSPECTIVE FOR IDENTIFYING NOVEL BIOMARKERS OF ATHEROSCLEROSIS, AND TRANSFORMING PRECISION CARDIOVASCULAR RESEARCH AND DISEASE THERAPY IN MODERN ERA OF EPIGENETICS. 2019 7 5423 26 REGULATION OF MACROPHAGE ACTIVATION AND DIFFERENTIATION IN ATHEROSCLEROSIS. CHRONIC INFLAMMATION IS A HALLMARK OF ATHEROSCLEROSIS AND MACROPHAGES PLAY A CENTRAL ROLE IN CONTROLLING INFLAMMATION AT ALL STAGES OF ATHEROSCLEROSIS. IN ATHEROSCLEROSIS, MACROPHAGES AND MONOCYTE-DERIVED MACROPHAGES ARE CONTINUOUSLY EXPOSED TO CHOLESTEROL, OXIDIZED LIPIDS, CELL DEBRIS, CYTOKINES, AND CHEMOKINES. NOT ONLY DO THESE STIMULI INDUCE A SPECIFIC MACROPHAGE PHENOTYPE, BUT THEY ALSO INTERACT EXTENSIVELY, LEADING TO MACROPHAGE HETEROGENEITY IN ATHEROSCLEROTIC PLAQUES. HEREIN, WE REVIEW THE DIVERSE PHENOTYPES OF MACROPHAGES, THE MECHANISMS UNDERLYING MACROPHAGE ACTIVATION, AND THE CONTRIBUTIONS OF MACROPHAGES TO ATHEROSCLEROSIS IN THIS CONTEXT. WE ALSO SUMMARIZE RECENT STUDIES ON FOAMY MACROPHAGES AND MONOCYTE-DERIVED MACROPHAGES IN PLAQUE DURING DISEASE PROGRESSION. WE PROVIDE A COMPREHENSIVE OVERVIEW OF TRANSCRIPTIONAL, EPIGENETIC, AND METABOLIC REPROGRAMMING OF MACROPHAGES AND DISCUSS THE EMERGING CONCEPTS OF TARGETING CYTOKINES AND MACROPHAGES TO MODULATE ATHEROSCLEROSIS. 2021 8 1853 32 ELEVATED METHIONINE FLUX DRIVES PYROPTOSIS EVASION IN PERSISTER CANCER CELLS. INDUCTION OF CELL DEATH REPRESENTS A PRIMARY GOAL OF MOST ANTICANCER TREATMENTS. DESPITE THE EFFICACY OF SUCH APPROACHES, A SMALL POPULATION OF "PERSISTERS" DEVELOP EVASION STRATEGIES TO THERAPY-INDUCED CELL DEATH. WHILE PREVIOUS STUDIES HAVE IDENTIFIED MECHANISMS OF RESISTANCE TO APOPTOSIS, THE MECHANISMS BY WHICH PERSISTERS DAMPEN OTHER FORMS OF CELL DEATH, SUCH AS PYROPTOSIS, REMAIN TO BE ELUCIDATED. PYROPTOSIS IS A FORM OF INFLAMMATORY CELL DEATH THAT INVOLVES FORMATION OF MEMBRANE PORES, ION GRADIENT IMBALANCE, WATER INFLOW, AND MEMBRANE RUPTURE. HEREIN, WE INVESTIGATE MECHANISMS BY WHICH CANCER PERSISTERS RESIST PYROPTOSIS, SURVIVE, THEN PROLIFERATE IN THE PRESENCE OF TYROSINE KINASE INHIBITORS (TKI). LUNG, PROSTATE, AND ESOPHAGEAL CANCER PERSISTER CELLS REMAINING AFTER TREATMENTS EXHIBITED SEVERAL HALLMARKS INDICATIVE OF PYROPTOSIS RESISTANCE. THE INFLAMMATORY ATTRIBUTES OF PERSISTERS INCLUDED CHRONIC ACTIVATION OF INFLAMMASOME, STING, AND TYPE I INTERFERONS. COMPREHENSIVE METABOLOMIC CHARACTERIZATION UNCOVERED THAT TKI-INDUCED PYROPTOTIC PERSISTERS DISPLAY HIGH METHIONINE CONSUMPTION AND EXCESSIVE TAURINE PRODUCTION. ELEVATED METHIONINE FLUX OR EXOGENOUS TAURINE PRESERVED PLASMA MEMBRANE INTEGRITY VIA OSMOLYTE-MEDIATED EFFECTS. INCREASED DEPENDENCY ON METHIONINE FLUX DECREASED THE LEVEL OF ONE CARBON METABOLISM INTERMEDIATE S-(5'-ADENOSYL)-L-HOMOCYSTEINE, A DETERMINANT OF CELL METHYLATION CAPACITY. THE CONSEQUENT INCREASE IN METHYLATION POTENTIAL INDUCED DNA HYPERMETHYLATION OF GENES REGULATING METAL ION BALANCE AND INTRINSIC IMMUNE RESPONSE. THIS ENABLED THWARTING TKI RESISTANCE BY USING THE HYPOMETHYLATING AGENT DECITABINE. IN SUMMARY, THE EVOLUTION OF RESISTANCE TO PYROPTOSIS CAN OCCUR VIA A STEPWISE PROCESS OF PHYSICAL ACCLIMATION AND EPIGENETIC CHANGES WITHOUT EXISTING OR RECURRENT MUTATIONS. SIGNIFICANCE: METHIONINE ENABLES CANCER CELLS TO PERSIST BY EVADING PYROPTOTIC OSMOTIC LYSIS, WHICH LEADS TO GENOME-WIDE HYPERMETHYLATION THAT ALLOWS PERSISTERS TO GAIN PROLIFERATIVE ADVANTAGES. 2023 9 1712 37 DYSFUNCTIONAL VASCULAR ENDOTHELIUM AS A DRIVER OF ATHEROSCLEROSIS: EMERGING INSIGHTS INTO PATHOGENESIS AND TREATMENT. ATHEROSCLEROSIS, THE CHRONIC ACCUMULATION OF CHOLESTEROL-RICH PLAQUE WITHIN ARTERIES, IS ASSOCIATED WITH A BROAD SPECTRUM OF CARDIOVASCULAR DISEASES INCLUDING MYOCARDIAL INFARCTION, AORTIC ANEURYSM, PERIPHERAL VASCULAR DISEASE, AND STROKE. ATHEROSCLEROTIC CARDIOVASCULAR DISEASE REMAINS A LEADING CAUSE OF MORTALITY IN HIGH-INCOME COUNTRIES AND RECENT YEARS HAVE WITNESSED A NOTABLE INCREASE IN PREVALENCE WITHIN LOW- AND MIDDLE-INCOME REGIONS OF THE WORLD. CONSIDERING THIS PROMINENT AND EVOLVING GLOBAL BURDEN, THERE IS A NEED TO IDENTIFY THE CELLULAR MECHANISMS THAT UNDERLIE THE PATHOGENESIS OF ATHEROSCLEROSIS TO DISCOVER NOVEL THERAPEUTIC TARGETS FOR PREVENTING OR MITIGATING ITS CLINICAL SEQUELAE. DESPITE DECADES OF RESEARCH, WE STILL DO NOT FULLY UNDERSTAND THE COMPLEX CELL-CELL INTERACTIONS THAT DRIVE ATHEROSCLEROSIS, BUT NEW INVESTIGATIVE APPROACHES ARE RAPIDLY SHEDDING LIGHT ON THESE ESSENTIAL MECHANISMS. THE VASCULAR ENDOTHELIUM RESIDES AT THE INTERFACE OF SYSTEMIC CIRCULATION AND THE UNDERLYING VESSEL WALL AND PLAYS AN ESSENTIAL ROLE IN GOVERNING PATHOPHYSIOLOGICAL PROCESSES DURING ATHEROGENESIS. IN THIS REVIEW, WE PRESENT EMERGING EVIDENCE THAT IMPLICATES THE ACTIVATED ENDOTHELIUM AS A DRIVER OF ATHEROSCLEROSIS BY DIRECTING SITE-SPECIFICITY OF PLAQUE FORMATION AND BY PROMOTING PLAQUE DEVELOPMENT THROUGH INTRACELLULAR PROCESSES, WHICH REGULATE ENDOTHELIAL CELL PROLIFERATION AND TURNOVER, METABOLISM, PERMEABILITY, AND PLASTICITY. MOREOVER, WE HIGHLIGHT NOVEL MECHANISMS OF INTERCELLULAR COMMUNICATION BY WHICH ENDOTHELIAL CELLS MODULATE THE ACTIVITY OF KEY VASCULAR CELL POPULATIONS INVOLVED IN ATHEROGENESIS, AND DISCUSS HOW ENDOTHELIAL CELLS CONTRIBUTE TO RESOLUTION BIOLOGY - A PROCESS THAT IS DYSREGULATED IN ADVANCED PLAQUES. FINALLY, WE DESCRIBE IMPORTANT FUTURE DIRECTIONS FOR PRECLINICAL ATHEROSCLEROSIS RESEARCH, INCLUDING EPIGENETIC AND TARGETED THERAPIES, TO LIMIT THE PROGRESSION OF ATHEROSCLEROSIS IN AT-RISK OR AFFECTED PATIENTS. 2021 10 1020 32 CIRCRNAS IN ATHEROSCLEROSIS, WITH SPECIAL EMPHASIS ON THE SPONGY EFFECT OF CIRCRNAS ON MIRNAS. ATHEROSCLEROSIS (AS) IS A CHRONIC INFLAMMATORY DISEASE, WHICH LEADS TO ATHEROSCLEROTIC RUPTURE, LUMEN STENOSIS AND THROMBOSIS, AND OFTEN ENDANGERS LIFE. CIRCULAR RNAS (CIRCRNAS) ARE A SPECIAL CLASS OF NON-CODING RNA MOLECULES, WHOSE ABNORMAL EXPRESSION HAS BEEN PROVED TO BE CLOSELY RELATED TO HUMAN DISEASES, INCLUDING AS. BOTH THE ABNORMAL REGULATION OF CIRCRNAS AND THE SPONGING EFFECT ON MIRNAS WOULD LEAD TO CHANGES IN GENE EXPRESSION IN THE FORM OF EPIGENETIC MODIFICATION, ULTIMATELY LEADING TO THE FORMATION OF AS. CIRCRNAS CAN BE USED AS PERIPHERAL BLOOD MARKERS OF AS, AND PLAY AN IMPORTANT REGULATORY ROLE IN THE PROLIFERATION, MIGRATION, INFLAMMATION AND APOPTOSIS OF VASCULAR SMOOTH MUSCLE CELLS, ENDOTHELIAL CELLS AND MACROPHAGE, WHICH ARE KEY CELLS FOR THE DEVELOPMENT OF AS. THE IN-DEPTH UNDERSTANDING OF CIRCRNAS IN AS NOT ONLY PROVIDES A NEW METHOD FOR THE DIAGNOSIS OF AS, BUT ALSO PROVIDES A NEW IDEA FOR THE TREATMENT OF AS. 2023 11 3734 32 INNATE IMMUNE MEMORY IN MONOCYTES AND MACROPHAGES: THE POTENTIAL THERAPEUTIC STRATEGIES FOR ATHEROSCLEROSIS. ATHEROSCLEROSIS IS A COMPLEX METABOLIC DISEASE CHARACTERIZED BY THE DYSFUNCTION OF LIPID METABOLISM AND CHRONIC INFLAMMATION IN THE INTIMAL SPACE OF THE VESSEL. AS THE MOST ABUNDANT INNATE IMMUNE CELLS, MONOCYTE-DERIVED MACROPHAGES PLAY A PIVOTAL ROLE IN THE INFLAMMATORY RESPONSE, CHOLESTEROL METABOLISM, AND FOAM CELL FORMATION. IN RECENT DECADES, IT HAS BEEN DEMONSTRATED THAT MONOCYTES AND MACROPHAGES CAN ESTABLISH INNATE IMMUNE MEMORY (ALSO TERMED TRAINED IMMUNITY) VIA ENDOGENOUS AND EXOGENOUS ATHEROGENIC STIMULI AND EXHIBIT A LONG-LASTING PROINFLAMMATORY PHENOTYPE. THE IMPORTANT CELLULAR METABOLISM PROCESSES, INCLUDING GLYCOLYSIS, OXIDATIVE PHOSPHORYLATION (OXPHOS), THE TRICARBOXYLIC ACID (TCA) CYCLE, FATTY ACID SYNTHESIS, AND CHOLESTEROL SYNTHESIS, ARE REPROGRAMMED. TRAINED MONOCYTES/MACROPHAGES WITH INNATE IMMUNE MEMORY CAN BE PERSISTENTLY HYPERACTIVATED AND CAN UNDERGO EXTENSIVE EPIGENETIC REWIRING, WHICH CONTRIBUTES TO THE PATHOPHYSIOLOGICAL DEVELOPMENT OF ATHEROSCLEROSIS VIA INCREASED PROINFLAMMATORY CYTOKINE PRODUCTION AND LIPID ACCUMULATION. HERE, WE PROVIDE AN OVERVIEW OF THE REGULATION OF CELLULAR METABOLIC PROCESSES AND EPIGENETIC MODIFICATIONS OF INNATE IMMUNE MEMORY IN MONOCYTES/MACROPHAGES AS WELL AS THE POTENTIAL ENDOGENOUS AND EXOGENOUS STIMULATIONS INVOLVED IN THE PROGRESSION OF ATHEROSCLEROSIS THAT HAVE BEEN REPORTED RECENTLY. THESE ELUCIDATIONS MIGHT BE BENEFICIAL FOR FURTHER UNDERSTANDING INNATE IMMUNE MEMORY AND THE DEVELOPMENT OF THERAPEUTIC STRATEGIES FOR INFLAMMATORY DISEASES AND ATHEROSCLEROSIS. 2022 12 6493 37 TRAINED IMMUNITY AND REACTIVITY OF MACROPHAGES AND ENDOTHELIAL CELLS. INNATE IMMUNE CELLS CAN DEVELOP EXACERBATED IMMUNOLOGIC RESPONSE AND LONG-TERM INFLAMMATORY PHENOTYPE FOLLOWING BRIEF EXPOSURE TO ENDOGENOUS OR EXOGENOUS INSULTS, WHICH LEADS TO AN ALTERED RESPONSE TOWARDS A SECOND CHALLENGE AFTER THE RETURN TO A NONACTIVATED STATE. THIS PHENOMENON IS KNOWN AS TRAINED IMMUNITY (TI). TI IS NOT ONLY IMPORTANT FOR HOST DEFENSE AND VACCINE RESPONSE BUT ALSO FOR CHRONIC INFLAMMATIONS SUCH AS CARDIOVASCULAR AND METABOLIC DISEASES SUCH AS ATHEROSCLEROSIS. TI CAN OCCUR IN INNATE IMMUNE CELLS SUCH AS MONOCYTES/MACROPHAGES, NATURAL KILLER CELLS, ENDOTHELIAL CELLS (ECS), AND NONIMMUNE CELLS, SUCH AS FIBROBLAST. IN THIS BRIEF REVIEW, WE ANALYZE THE SIGNIFICANCE OF TI IN ECS, WHICH ARE ALSO CONSIDERED AS INNATE IMMUNE CELLS IN ADDITION TO MACROPHAGES. TI CAN BE INDUCED BY A VARIETY OF STIMULI, INCLUDING LIPOPOLYSACCHARIDES, BCG (BACILLUS CALMETTE-GUERIN), AND OXLDL (OXIDIZED LOW-DENSITY LIPOPROTEIN), WHICH ARE DEFINED AS RISK FACTORS FOR CARDIOVASCULAR AND METABOLIC DISEASES. FURTHERMORE, TI IN ECS IS FUNCTIONAL FOR INFLAMMATION EFFECTIVENESS AND TRANSITION TO CHRONIC INFLAMMATION. REWIRING OF CELLULAR METABOLISM OF THE TRAINED CELLS TAKES PLACE DURING INDUCTION OF TI, INCLUDING INCREASED GLYCOLYSIS, GLUTAMINOLYSIS, INCREASED ACCUMULATION OF TRICARBOXYLIC ACID CYCLE METABOLITES AND ACETYL-COENZYME A PRODUCTION, AS WELL AS INCREASED MEVALONATE SYNTHESIS. SUBSEQUENTLY, THIS LEADS TO EPIGENETIC REMODELING, RESULTING IN IMPORTANT CHANGES IN CHROMATIN ARCHITECTURE THAT ENABLES INCREASED GENE TRANSCRIPTION AND ENHANCED PROINFLAMMATORY IMMUNE RESPONSE. HOWEVER, TI PATHWAYS AND INFLAMMATORY PATHWAYS ARE SEPARATED TO ENSURE MEMORY STAYS WHEN INFLAMMATION UNDERGOES RESOLUTION. ADDITIONALLY, REACTIVE OXYGEN SPECIES PLAY CONTEXT-DEPENDENT ROLES IN TI. THEREFORE, TI PLAYS SIGNIFICANT ROLES IN EC AND MACROPHAGE PATHOLOGY AND CHRONIC INFLAMMATION. HOWEVER, FURTHER CHARACTERIZATION OF TI IN ECS AND MACROPHAGES WOULD PROVIDE NOVEL INSIGHTS INTO CARDIOVASCULAR DISEASE PATHOGENESIS AND NEW THERAPEUTIC TARGETS. GRAPHIC ABSTRACT: A GRAPHIC ABSTRACT IS AVAILABLE FOR THIS ARTICLE. 2021 13 4489 22 MONOCYTE AND MACROPHAGE IMMUNOMETABOLISM IN ATHEROSCLEROSIS. ATHEROSCLEROSIS IS CHARACTERIZED BY CHRONIC LOW GRADE INFLAMMATION OF ARTERIES THAT RESULTS IN THE DEVELOPMENT OF LIPID DENSE PLAQUES. CHRONIC INFLAMMATION INDUCED BY WESTERN-TYPE DIET IS ASSOCIATED WITH THE RISK OF DEVELOPING ATHEROSCLEROSIS, AND NEW INSIGHTS SHED LIGHT ON THE IMPORTANCE OF METABOLIC AND FUNCTIONAL REPROGRAMMING IN MONOCYTES AND MACROPHAGES FOR PROGRESSION OF ATHEROSCLEROSIS. THIS REVIEW AIMS TO PROVIDE AN OVERVIEW OF OUR CURRENT UNDERSTANDING INTO HOW THE METABOLIC REPROGRAMMING OF GLUCOSE, CHOLESTEROL, FATTY ACID, AND AMINO ACID METABOLISM IN MACROPHAGES CONTRIBUTES TO INFLAMMATION DURING ATHEROSCLEROSIS. RECENT INSIGHTS SUGGEST THAT TRANSCRIPTIONAL AND EPIGENETIC ADAPTATION WITHIN INNATE IMMUNE CELLS (TERMED TRAINED IMMUNITY) PLAY AN IMPORTANT ROLE IN THE PATHOGENESIS OF ATHEROSCLEROSIS. WE PROPOSE THAT METABOLIC CHANGES INDUCED BY PRO-ATHEROGENIC LIPOPROTEINS PARTLY MEDIATE THESE CHANGES IN TRAINED MACROPHAGES. FINALLY, WE DISCUSS THE POSSIBILITY OF MANIPULATING CELLULAR METABOLISM OF IMMUNE CELLS FOR TARGETED THERAPEUTIC INTERVENTION AGAINST ATHEROSCLEROSIS. 2018 14 6498 29 TRAINED IMMUNITY IN MONOCYTE/MACROPHAGE: NOVEL MECHANISM OF PHYTOCHEMICALS IN THE TREATMENT OF ATHEROSCLEROTIC CARDIOVASCULAR DISEASE. ATHEROSCLEROSIS (AS) IS THE PATHOLOGY OF ATHEROSCLEROTIC CARDIOVASCULAR DISEASES (ASCVD), CHARACTERIZED BY PERSISTENT CHRONIC INFLAMMATION IN THE VESSEL WALL, IN WHICH MONOCYTES/MACROPHAGES PLAY A KEY ROLE. IT HAS BEEN REPORTED THAT INNATE IMMUNE SYSTEM CELLS CAN ASSUME A PERSISTENT PROINFLAMMATORY STATE AFTER SHORT STIMULATION WITH ENDOGENOUS ATHEROGENIC STIMULI. THE PATHOGENESIS OF AS CAN BE INFLUENCED BY THIS PERSISTENT HYPERACTIVATION OF THE INNATE IMMUNE SYSTEM, WHICH IS TERMED TRAINED IMMUNITY. TRAINED IMMUNITY HAS ALSO BEEN IMPLICATED AS A KEY PATHOLOGICAL MECHANISM, LEADING TO PERSISTENT CHRONIC INFLAMMATION IN AS. TRAINED IMMUNITY IS MEDIATED VIA EPIGENETIC AND METABOLIC REPROGRAMMING AND OCCURS IN MATURE INNATE IMMUNE CELLS AND THEIR BONE MARROW PROGENITORS. NATURAL PRODUCTS ARE PROMISING CANDIDATES FOR NOVEL PHARMACOLOGICAL AGENTS THAT CAN BE USED TO PREVENT OR TREAT CARDIOVASCULAR DISEASES (CVD). A VARIETY OF NATURAL PRODUCTS AND AGENTS EXHIBITING ANTIATHEROSCLEROTIC ABILITIES HAVE BEEN REPORTED TO POTENTIALLY INTERFERE WITH THE PHARMACOLOGICAL TARGETS OF TRAINED IMMUNITY. THIS REVIEW DESCRIBES IN AS MUCH DETAIL AS POSSIBLE THE MECHANISMS INVOLVED IN TRAINED IMMUNITY AND HOW PHYTOCHEMICALS OF THIS PROCESS INHIBIT AS BY AFFECTING TRAINED MONOCYTES/MACROPHAGES. 2023 15 2291 28 EPIGENETIC REGULATION IN PATHOLOGY OF ATHEROSCLEROSIS: A NOVEL PERSPECTIVE. ATHEROSCLEROSIS, CHARACTERIZED BY ATHEROSCLEROTIC PLAQUES, IS A COMPLEX PATHOLOGICAL PROCESS THAT INVOLVES DIFFERENT CELL TYPES AND CAN BE SEEN AS A CHRONIC INFLAMMATORY DISEASE. IN THE ADVANCED STAGE, THE RUPTURED ATHEROSCLEROTIC PLAQUE CAN INDUCE DEADLY ACCIDENTS INCLUDING ISCHEMIC STROKE AND MYOCARDIAL INFARCTION. EPIGENETICS REGULATION, INCLUDING DNA METHYLATION, HISTONE MODIFICATION, AND NON-CODING RNA MODIFICATION. MAINTAINS CELLULAR IDENTITY VIA AFFECTING THE CELLULAR TRANSCRIPTOME. THE EPIGENETIC MODIFICATION PROCESS, MEDIATING BY EPIGENETIC ENZYMES, IS DYNAMIC UNDER VARIOUS STIMULI, WHICH CAN BE REVERSELY ALTERED. RECENTLY, NUMEROUS STUDIES HAVE EVIDENCED THE CLOSE RELATIONSHIP BETWEEN ATHEROSCLEROSIS AND EPIGENETIC REGULATIONS IN ATHEROSCLEROSIS, PROVIDING US WITH A NOVEL PERSPECTIVE IN RESEARCHING MECHANISMS AND FINDING NOVEL THERAPEUTIC TARGETS OF THIS SERIOUS DISEASE. HERE, WE CRITICALLY REVIEW THE RECENT DISCOVERIES BETWEEN EPIGENETIC REGULATION MECHANISMS IN ATHEROSCLEROSIS. 2021 16 6774 31 [AGE-RELATED VASCULAR CHANGES EXEMPLIFIED BY THE CAROTID ARTERY]. ONE OF THE MAIN RISK FACTORS FOR THE PRESENCE OF CAROTID STENOSIS AND CAROTID-RELATED STROKE IS AGE. THE AIM OF THIS REVIEW ARTICLE IS TO PRESENT THE CURRENT STATE OF KNOWLEDGE ON AGE-RELATED VASCULAR CHANGES USING CAROTID STENOSIS AS AN EXAMPLE.VASCULAR AGING (VASCULAR SENESCENCE) IS A DECREASE OF STRUCTURAL AND FUNCTIONAL PROPERTIES OF THE VESSEL WALL THAT TAKES PLACE ON DIFFERENT LEVELS. AT THE MULTICELLULAR LEVEL AN INCREASE IN VESSEL VOLUME AND DIAMETER AS WELL AS INTIMA MEDIA THICKNESS OCCURS WITH AGE MAINLY DUE TO ATHEROSCLEROTIC CHANGES IN THE VESSEL WALL. AT THE CELLULAR AND EXTRACELLULAR LEVELS THERE IS A DECREASE IN ELASTIN FIBERS, SMOOTH MUSCLE CELLS, AND TOTAL CELLULARITY, AN INCREASE IN LIPID, CHOLESTEROL, AND CALCIUM PHOSPHATE DEPOSITION AS WELL AS NEOVASCULARIZATION. THE CAUSES OF VASCULAR AGING AT THE MOLECULAR LEVEL INCLUDE, IN PARTICULAR OXIDATIVE STRESS, CHRONIC INFLAMMATORY RESPONSE, MITOCHONDRIAL DYSFUNCTION, EPIGENETIC CHANGES, DYSREGULATION OF THE EXPRESSION OF NON-CODING RNAS (NCRNAS), AND THE INCREASE IN SENESCENCE. AGE-RELATED LOSS OF TISSUE HEALING AND REPAIR CAPACITY MAKE PLAQUES MORE VULNERABLE AND, IN THE CASE OF THE CAROTID ARTERY, MORE SUSCEPTIBLE TO ISCHEMIC STROKE.INCREASING KNOWLEDGE OF THE INFLUENCE OF AGING ON THE EPIGENETICS AND NCRNAS IN ATHEROSCLEROTIC PLAQUES CAN IN THE FUTURE MORE ACCURATELY QUANTIFY INDIVIDUAL PATIENT RISK AND CONTRIBUTE TO THE DEVELOPMENT OF TARGETED THERAPEUTIC STRATEGIES; HOWEVER, FURTHER STUDIES ARE NEEDED IN THIS FIELD TO UNDERSTAND THE FULL EXTENT OF VASCULAR AGING AND ITS ASSOCIATED DISEASES SO THAT THESE CAN THEN BE SPECIFICALLY TARGETED. 2022 17 1392 20 DIAGNOSTIC APPROACH TO PULMONARY HYPERTENSION IN PREMATURE NEONATES. BRONCHOPULMONARY DYSPLASIA (BPD) IS A FORM OF CHRONIC LUNG DISEASE IN PREMATURE INFANTS FOLLOWING RESPIRATORY DISTRESS AT BIRTH. WITH INCREASING SURVIVAL OF EXTREMELY LOW BIRTH WEIGHT INFANTS, ALVEOLAR SIMPLIFICATION IS THE DEFINING LUNG CHARACTERISTIC OF INFANTS WITH BPD, AND ALONG WITH PULMONARY HYPERTENSION, INCREASINGLY CONTRIBUTES TO BOTH RESPIRATORY MORBIDITY AND MORTALITY IN THESE INFANTS. GROWTH RESTRICTED INFANTS, INFANTS BORN TO MOTHERS WITH OLIGOHYDRAMNIOS OR FOLLOWING PROLONGED PRETERM RUPTURE OF MEMBRANES ARE AT PARTICULAR RISK FOR EARLY ONSET PULMONARY HYPERTENSION. ALTERED VASCULAR AND ALVEOLAR GROWTH PARTICULARLY IN CANALICULAR AND EARLY SACCULAR STAGES OF LUNG DEVELOPMENT FOLLOWING MECHANICAL VENTILATION AND OXYGEN THERAPY, RESULTS IN DEVELOPMENTAL LUNG ARREST LEADING TO BPD WITH PULMONARY HYPERTENSION (PH). EARLY RECOGNITION OF PH IN INFANTS WITH RISK FACTORS IS IMPORTANT FOR OPTIMAL MANAGEMENT OF THESE INFANTS. SCREENING TOOLS FOR EARLY DIAGNOSIS OF PH ARE EVOLVING; HOWEVER, ECHOCARDIOGRAPHY IS THE MAINSTAY FOR NON-INVASIVE DIAGNOSIS OF PH IN INFANTS. CARDIAC COMPUTED TOMOGRAPHY (CT) AND MAGNETIC RESONANCE ARE BEING USED AS IMAGING MODALITIES, HOWEVER THEIR ROLE IN IMPROVING OUTCOMES IN THESE PATIENTS IS UNCERTAIN. FOLLOW-UP OF INFANTS AT RISK FOR PH WILL HELP NOT ONLY IN EARLY DIAGNOSIS, BUT ALSO IN APPROPRIATE MANAGEMENT OF THESE INFANTS. AGGRESSIVE MANAGEMENT OF LUNG DISEASE, AVOIDANCE OF HYPOXEMIC EPISODES, AND OPTIMAL NUTRITION DETERMINE THE PROGRESSION OF PH, AS EPIGENETIC FACTORS MAY HAVE SIGNIFICANT EFFECTS, PARTICULARLY IN GROWTH-RESTRICTED INFANTS. INFANTS WITH DIAGNOSIS OF PH ARE MANAGED WITH PULMONARY VASODILATORS AND THOSE RESISTANT TO THERAPY NEED TO BE WORKED UP FOR THE PRESENCE OF CARDIO-VASCULAR ANOMALIES. THE MANAGEMENT OF INFANTS AND TODDLERS WITH PH, ESPECIALLY FOLLOWING PREMATURE BIRTH IS AN EMERGING FIELD. NONETHELESS, COMBINATION THERAPIES IN A MULTI-DISCIPLINARY SETTING IMPROVES OUTCOMES FOR THESE INFANTS. 2017 18 3776 35 INTERACTIONS BETWEEN DYSLIPIDEMIA AND THE IMMUNE SYSTEM AND THEIR RELEVANCE AS PUTATIVE THERAPEUTIC TARGETS IN ATHEROSCLEROSIS. CARDIOVASCULAR DISEASE (CVD) CONTINUES TO BE A LEADING CAUSE OF DEATH WORLDWIDE WITH ATHEROSCLEROSIS BEING THE MAJOR UNDERLYING PATHOLOGY. THE INTERPLAY BETWEEN LIPIDS AND IMMUNE CELLS IS BELIEVED TO BE A DRIVING FORCE IN THE CHRONIC INFLAMMATION OF THE ARTERIAL WALL DURING ATHEROGENESIS. ATHEROSCLEROSIS IS INITIATED AS LIPID PARTICLES ACCUMULATE AND BECOME TRAPPED IN VESSEL WALLS. THE SUBSEQUENT IMMUNE RESPONSE, INVOLVING BOTH ADAPTIVE AND IMMUNE CELLS, PROGRESSES PLAQUE DEVELOPMENT, WHICH MAY BE EXACERBATED UNDER DYSLIPIDEMIC CONDITIONS. BROAD EVIDENCE, ESPECIALLY FROM ANIMAL MODELS, CLEARLY DEMONSTRATES THE EFFECT OF LIPIDS ON IMMUNE CELLS FROM THEIR DEVELOPMENT IN THE BONE MARROW TO THEIR PHENOTYPIC SWITCHING IN CIRCULATION. INTERESTINGLY, RECENT RESEARCH HAS ALSO SHOWN A LONG-LASTING EPIGENETIC SIGNATURE FROM LIPIDS ON IMMUNE CELLS. TRADITIONALLY, CARDIOVASCULAR THERAPIES HAVE APPROACHED ATHEROSCLEROSIS THROUGH LIPID-LOWERING MEDICATIONS BECAUSE, UNTIL RECENTLY, ANTI-INFLAMMATORY THERAPIES HAVE BEEN LARGELY UNSUCCESSFUL IN CLINICAL TRIALS. HOWEVER, THE RECENT CANAKINUMAB ANTIINFLAMMATORY THROMBOSIS OUTCOMES STUDY (CANTOS) PROVIDED PIVOTAL SUPPORT OF THE INFLAMMATORY HYPOTHESIS OF ATHEROSCLEROSIS IN MAN SPURRING ON ANTI-INFLAMMATORY STRATEGIES TO TREAT ATHEROSCLEROSIS. IN THIS REVIEW, WE DESCRIBE THE INTERACTIONS BETWEEN LIPIDS AND IMMUNE CELLS ALONG WITH THEIR SPECIFIC OUTCOMES AS WELL AS DISCUSS THEIR FUTURE PERSPECTIVE AS POTENTIAL CARDIOVASCULAR TARGETS. 2019 19 539 19 ATHEROSCLEROSIS IS AN EPIGENETIC DISEASE. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY AND LIPID-DEPOSITORY DISEASE THAT EVENTUALLY LEADS TO ACUTE CARDIOVASCULAR EVENTS. EMERGING EVIDENCE SUPPORTS THAT EPIGENETIC PROCESSES SUCH AS DNA METHYLATION, HISTONE MODIFICATION, AND NONCODING RNAS PLAY AN IMPORTANT ROLE IN PLAQUE PROGRESSION AND VULNERABILITY, HIGHLIGHTING THE THERAPEUTIC POTENTIAL OF EPIGENETIC DRUGS IN CARDIOVASCULAR THERAPEUTICS. 2018 20 6505 30 TRAINED INNATE IMMUNITY AS A NOVEL MECHANISM LINKING INFECTION AND THE DEVELOPMENT OF ATHEROSCLEROSIS. RATIONALE: THERE IS STRONG EPIDEMIOLOGICAL EVIDENCE FOR AN ASSOCIATION BETWEEN ACUTE AND CHRONIC INFECTIONS AND THE OCCURRENCE OF ATHEROSCLEROTIC CARDIOVASCULAR DISEASE. THE UNDERLYING PATHOPHYSIOLOGICAL MECHANISMS REMAIN UNCLEAR. MONOCYTE-DERIVED MACROPHAGES ARE THE MOST ABUNDANT IMMUNE CELLS IN ATHEROSCLEROTIC PLAQUES. IT HAS RECENTLY BEEN ESTABLISHED THAT MONOCYTES/MACROPHAGES CAN DEVELOP A LONG-LASTING PROINFLAMMATORY PHENOTYPE AFTER BRIEF STIMULATION WITH MICRO-ORGANISMS OR MICROBIAL PRODUCTS, WHICH HAS BEEN TERMED TRAINED IMMUNITY. OBJECTIVE: THE AIM OF THIS STUDY IS TO ASSESS WHETHER TRAINED IMMUNITY MEDIATES THE LINK BETWEEN INFECTIONS AND ATHEROSCLEROTIC CARDIOVASCULAR DISEASE. METHODS AND RESULTS: BRIEF EXPOSURE OF MONOCYTES TO VARIOUS MICRO-ORGANISMS RESULTS IN THE DEVELOPMENT OF MACROPHAGES WITH A PERSISTENT PROINFLAMMATORY PHENOTYPE: THIS REPRESENTS A DE FACTO NONSPECIFIC INNATE IMMUNE MEMORY, WHICH HAS BEEN TERMED TRAINED IMMUNITY. THIS IS MEDIATED BY EPIGENETIC REPROGRAMMING AT THE LEVEL OF HISTONE METHYLATION AND A PROFOUND REWIRING OF INTRACELLULAR METABOLISM. ALTHOUGH THIS MECHANISM OFFERS POWERFUL PROTECTION AGAINST REINFECTION, TRAINED MACROPHAGES DISPLAY AN ATHEROGENIC PHENOTYPE IN TERMS OF CYTOKINE PRODUCTION AND FOAM CELL FORMATION. TRAINED MONOCYTES ARE PRESENT UP TO 3 MONTHS AFTER EXPERIMENTAL INFECTION IN HUMANS. MOREOVER, A TRAINED IMMUNITY PHENOTYPE IS PRESENT IN PATIENTS WITH ESTABLISHED ATHEROSCLEROSIS. CONCLUSIONS: WE PROPOSE THAT TRAINED IMMUNITY PROVIDES THE MISSING MECHANISTIC LINK THAT EXPLAINS THE ASSOCIATION BETWEEN INFECTIONS AND ATHEROSCLEROSIS. THEREFORE, PHARMACOLOGICAL MODULATION OF TRAINED IMMUNITY HAS THE POTENTIAL TO PREVENT INFECTION-RELATED ATHEROSCLEROTIC CARDIOVASCULAR DISEASE IN THE FUTURE. 2018