1 4510 191 MTOR-DEPENDENT OXIDATIVE STRESS REGULATES OXLDL-INDUCED TRAINED INNATE IMMUNITY IN HUMAN MONOCYTES. INTRODUCTION: CELLS OF THE INNATE IMMUNE SYSTEM PARTICULARLY MONOCYTES AND MACROPHAGES HAVE BEEN RECOGNIZED AS PIVOTAL PLAYERS BOTH DURING THE INITIAL INSULT AS WELL AS THE CHRONIC PHASE OF ATHEROSCLEROSIS. IT HAS RECENTLY BEEN SHOWN THAT OXIDIZED LOW-DENSITY LIPOPROTEIN (OXLDL) INDUCES A LONG-TERM PRO-INFLAMMATORY RESPONSE IN MONOCYTES DUE TO EPIGENETIC AND METABOLIC REPROGRAMMING, AN EMERGING NEW CONCEPT CALLED TRAINED INNATE IMMUNITY. CHANGES IN THE CELLULAR REDOX STATE ARE CRUCIAL EVENTS IN THE REGULATION OF MANY PHYSIOLOGIC FUNCTIONS IN MACROPHAGES INCLUDING TRANSCRIPTION, DIFFERENTIATION AND INFLAMMATORY RESPONSE. HERE WE HAVE ANALYZED THE ROLE OF REACTIVE OXYGEN SPECIES (ROS) IN REGULATING THIS PROINFLAMMATORY MONOCYTE PRIMING IN RESPONSE TO OXLDL-TREATMENT. METHODS AND RESULTS: HUMAN MONOCYTES WERE ISOLATED AND INCUBATED WITH OXLDL FOR 24 H. AFTER 5 DAYS OF RESTING, OXLDL TREATED CELLS PRODUCED SIGNIFICANTLY MORE INFLAMMATORY CYTOKINES UPON RESTIMULATION WITH THE TLR2-AGONIST PAM3CYS. FURTHERMORE, OXLDL INCUBATION INDUCED PERSISTENT MTOR ACTIVATION, ROS FORMATION, HIF1ALPHA ACCUMULATION AND HIF1ALPHA TARGET GENE EXPRESSION, WHILE PHARMACOLOGIC MTOR INHIBITION OR SIRNA MEDIATED INHIBITION OF THE MTORC1 SUBUNIT RAPTOR PREVENTED ROS FORMATION AND PROINFLAMMATORY PRIMING. MTOR DEPENDENT ROS FORMATION WAS ASSOCIATED WITH INCREASED EXPRESSION OF NAPDH OXIDASES AND NECESSARY FOR THE EMERGENCE OF THE PRIMED PHENOTYPE AS ANTIOXIDANT TREATMENT BLOCKED OXLDL PRIMING. INHIBITION OF CYTOSOLIC ROS FORMATION COULD ALSO BLOCK MTOR ACTIVATION AND HIF1ALPHA ACCUMULATION SUGGESTING A POSITIVE FEEDBACK LOOP BETWEEN MTOR AND CYTOSOLIC ROS. ALTHOUGH MITOCHONDRIAL ROS SCAVENGING DID NOT BLOCK HIF1ALPHA-ACCUMULATION AT AN EARLY TIME POINT (24 H), IT WAS PERSISTENTLY REDUCED ON DAY 6. THEREFORE, MITOCHONDRIAL ROS FORMATION APPEARS TO OCCUR INITIALLY DOWNSTREAM OF THE MTOR-CYTOROS-HIF1ALPHA FEEDBACK LOOP BUT SEEMS TO BE A CRUCIAL FACTOR THAT CONTROLS THE LONG-TERM ACTIVATION OF THE MTOR-HIF1ALPHA-AXIS. CONCLUSION: IN SUMMARY, OUR DATA DEMONSTRATE THAT MTOR DEPENDENT ROS PRODUCTION CONTROLS THE OXLDL-INDUCED TRAINED INNATE IMMUNITY PHENOTYPE IN HUMAN MONOCYTE DERIVED MACROPHAGES. PHARMACOLOGIC MODULATION OF THESE PATHWAYS MIGHT PROVIDE A POTENTIAL APPROACH TO MODULATE INFLAMMATION, ASSOCIATED WITH ABERRANT MONOCYTE ACTIVATION, DURING ATHEROSCLEROSIS DEVELOPMENT. 2018 2 4391 51 MODERATE EXERCISE INDUCES TRAINED IMMUNITY IN MACROPHAGES. DESPITE ITS IMPORTANCE IN PROTECTING THE HOST FROM INFECTIONS AND INJURY, EXCESSIVE INFLAMMATION MAY LEAD TO SERIOUS HUMAN DISEASES INCLUDING AUTOIMMUNE DISORDERS, CARDIOVASCULAR DISEASES, DIABETES, AND CANCER. EXERCISE IS A KNOWN IMMUNOMODULATOR; HOWEVER, WHETHER EXERCISE CAUSES LONG-TERM CHANGES IN INFLAMMATORY RESPONSES AND HOW THESE CHANGES OCCUR ARE LACKING. HERE, WE SHOW THAT CHRONIC MODERATE-INTENSITY TRAINING OF MICE LEADS TO PERSISTENT METABOLIC REWIRING AND CHANGES TO CHROMATIN ACCESSIBILITY IN BONE MARROW-DERIVED MACROPHAGES (BMDMS), WHICH, IN TURN, TEMPERS THEIR INFLAMMATORY RESPONSES. WE SHOW THAT BMDMS FROM EXERCISED MICE EXHIBITED A DECREASE IN LIPOPOLYSACCHARIDE (LPS)-INDUCED NF-KAPPAB ACTIVATION AND PROINFLAMMATORY GENE EXPRESSION ALONG WITH AN INCREASE IN M2-LIKE-ASSOCIATED GENES WHEN COMPARED WITH BMDMS FROM SEDENTARY MICE. THIS WAS ASSOCIATED WITH IMPROVED MITOCHONDRIAL QUALITY AND INCREASED RELIANCE ON OXIDATIVE PHOSPHORYLATION ACCOMPANIED WITH REDUCED MITOCHONDRIAL REACTIVE OXYGEN SPECIES (ROS) PRODUCTION. MECHANISTICALLY, ASSAY FOR TRANSPOSASE-ACCESSIBLE CHROMATIN (ATAC)-SEQ ANALYSIS SHOWED CHANGES IN CHROMATIN ACCESSIBILITY OF GENES ASSOCIATED WITH INFLAMMATORY AND METABOLIC PATHWAYS. OVERALL, OUR DATA SUGGEST THAT CHRONIC MODERATE EXERCISE CAN INFLUENCE THE INFLAMMATORY RESPONSES OF MACROPHAGES BY REPROGRAMMING THEIR METABOLIC AND EPIGENETIC LANDSCAPE.NEW & NOTEWORTHY IN THIS STUDY, WE EXPLAIN HOW LONG-TERM MODERATE EXERCISE TRAINING CAN REDUCE INFLAMMATION IN MOUSE MACROPHAGES BY REPROGRAMMING THE WAY THEY SENSE AND RESPOND TO THE PRESENCE OF PATHOGENS. WE COMPLETED A THOROUGH ANALYSIS AND SHOWED THAT THESE CHANGES PERSIST IN MACROPHAGES BECAUSE EXERCISE IMPROVES THE ABILITY OF CELLS TO UTILIZE OXYGEN WITHOUT PRODUCING DAMAGING COMPOUNDS, AND CHANGES THE WAY THEY ACCESS THEIR DNA. 2023 3 4332 54 MICRORNAS: IMPORTANT MODULATORS OF OXLDL-MEDIATED SIGNALING IN ATHEROSCLEROSIS. OXIDIZED LOW-DENSITY LIPOPROTEIN (OXLDL) IS KNOWN TO BE A MAJOR RISK FACTOR FOR THE INITIATION AND DEVELOPMENT OF ATHEROSCLEROSIS. IT CAN ELICIT AN ARRAY OF ATHEROGENIC RESPONSES IN MULTIPLE TYPES OF CELLS RESIDING IN THE ARTERIAL WALL, SUCH AS ENDOTHELIAL CELLS (ECS), MACROPHAGES, DENDRITIC CELLS (DCS), AND VASCULAR SMOOTH MUSCLE CELLS (VSMCS). ALTHOUGH THEY HAVE BEEN STUDIED FOR MANY YEARS, THE DETAILED MECHANISMS MODULATING OXLDL-INDUCED INFLAMMATION HAVE NOT BEEN FULLY ELUCIDATED. EPIGENETIC MECHANISMS CONSIST OF DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATIONS (PTMS), AND MICRORNA (MIRNA) ALTERATIONS. RECENTLY, EPIGENETIC FACTORS, ESPECIALLY MIRNAS, HAVE EMERGED AS NOVEL COMPONENTS OF THE GENE EXPRESSION REGULATING OXLDL-TRIGGERED SIGNAL TRANSDUCTION. IN ADDITION TO THEIR REGULATORY ROLES IN SIGNALING MOLECULES, INCREASING EVIDENCE SUGGESTS THAT THE DIFFERENT GENETIC STABILITY AND CROSS-TALK REGULATION AMONG THESE EPIGENETIC FACTORS MAY BE PARTICULARLY IMPORTANT TO THE SUSTAINED INFLAMMATION INITIATED BY TEMPORAL OXLDL STIMULATION. THEREFORE, IN THIS REVIEW, WE PRIMARILY FOCUSED ON THE FUNCTIONAL ROLE OF MIRNAS, AS WELL AS OTHER EPIGENETIC FACTORS, ON MODULATING OXLDL-INDUCED SIGNAL TRANSDUCTION IN DIFFERENT VASCULAR CELLS, WITH A SPECIAL EMPHASIS ON THE CROSSTALK INTERACTIONS BETWEEN MIRNAS AND OTHER EPIGENETIC PLAYERS THAT HELP TRANSLATE TRANSIENT ENVIRONMENT INSULTS INTO CHRONIC INFLAMMATION. MOREOVER, WE EXTENSIVELY DISCUSSED THE POTENTIAL APPLICABILITY OF MIRNAS AS DISEASE BIOMARKERS AND THERAPEUTIC TARGETS IN DIAGNOSING AND TREATING ATHEROSCLEROSIS. 2013 4 3436 49 HYPERGLYCEMIC MEMORY OF INNATE IMMUNE CELLS PROMOTES IN VITRO PROINFLAMMATORY RESPONSES OF HUMAN MONOCYTES AND MURINE MACROPHAGES. IT HAS BEEN WELL ESTABLISHED THAT THE PRESENCE OF DIABETES IS ACCOMPANIED BY A CHRONIC INFLAMMATORY STATE PROMOTING VARIOUS DIABETES-ASSOCIATED COMPLICATIONS. ONE POTENTIAL DRIVER OF THIS ENHANCED INFLAMMATORY STATE IN PATIENTS WITH DIABETES IS HYPERGLYCEMIA. EVEN AFTER BLOOD GLUCOSE CONTROL IS ACHIEVED, DIABETES-ASSOCIATED COMPLICATIONS PERSIST, SUGGESTING THE PRESENCE OF A "HYPERGLYCEMIC MEMORY." INNATE IMMUNE CELLS, CRITICALLY INVOLVED IN VARIOUS COMPLICATIONS ASSOCIATED WITH DIABETES, CAN BUILD NONSPECIFIC, IMMUNOLOGICAL MEMORY (TRAINED IMMUNITY) VIA EPIGENETIC REGULATION. WE EXAMINE THE POTENTIAL INVOLVEMENT OF HYPERGLYCEMIA-INDUCED TRAINED IMMUNITY IN PROMOTING INFLAMMATION. OUR RESULTS SHOW THAT HYPERGLYCEMIA INDUCES A TRAINED PHENOTYPE IN VIVO IN MICE AND IN VITRO IN HUMAN MONOCYTES, REPRESENTATIVE BY AN INCREASED TNF-ALPHA SECRETION AFTER EX VIVO STIMULATION WITH LPS. THESE EFFECTS WERE LARGELY MEDIATED BY EPIGENETIC CHANGES CONTROLLED BY THE MIXED LINEAGE LEUKEMIA (MLL) FAMILY BECAUSE TREATMENT WITH THE MLL INHIBITOR MENIN-MLL DURING THE PROCESS OF TRAINED IMMUNITY ACQUISITION REPRESSED THE PROINFLAMMATORY PHENOTYPE. COLLECTIVELY, OUR RESULTS IDENTIFY A NOVEL LINK BETWEEN HYPERGLYCEMIA AND INFLAMMATION IN INNATE IMMUNE CELLS THAT MIGHT EXPLAIN THE INCREASED PROINFLAMMATORY STATE DURING DIABETES POTENTIALLY CONTRIBUTING TO THE DEVELOPMENT OF VARIOUS DIABETES-ASSOCIATED COMPLICATIONS. 2021 5 2067 40 EPIGENETIC CONTROL OF MACROPHAGE SHAPE TRANSITION TOWARDS AN ATYPICAL ELONGATED PHENOTYPE BY HISTONE DEACETYLASE ACTIVITY. INFLAMMATORY CHRONIC PATHOLOGIES ARE COMPLEX PROCESSES CHARACTERIZED BY AN IMBALANCE BETWEEN THE RESOLUTION OF THE INFLAMMATORY PHASE AND THE ESTABLISHMENT OF TISSUE REPAIR. THE MAIN PLAYERS IN THESE INFLAMMATORY PATHOLOGIES ARE BONE MARROW DERIVED MONOCYTES (BMDMS). HOWEVER, HOW MONOCYTE DIFFERENTIATION IS MODULATED TO GIVE RISE TO SPECIFIC MACROPHAGE SUBPOPULATIONS (M1 OR M2) THAT MAY EITHER MAINTAIN THE CHRONIC INFLAMMATORY PROCESS OR LEAD TO WOUND HEALING IS STILL UNCLEAR. CONSIDERING THAT INHIBITORS OF HISTONE DEACETYLASE (HDAC) HAVE AN ANTI-INFLAMMATORY ACTIVITY, WE ASKED WHETHER THIS ENZYME WOULD PLAY A ROLE ON MONOCYTE DIFFERENTIATION INTO M1 OR M2 PHENOTYPE AND IN THE CELL SHAPE TRANSITION THAT FOLLOWS. WE THEN INDUCED MURINE BONE MARROW PROGENITORS INTO MONOCYTE/MACROPHAGE DIFFERENTIATION PATHWAY USING MEDIA CONTAINING GM-CSF AND THE HDAC BLOCKER, TRICHOSTATIN A (TSA). WE FOUND THAT THE PHARMACOLOGICAL INHIBITION OF HDAC ACTIVITY LED TO A SHAPE TRANSITION FROM THE TYPICAL MACROPHAGE PANCAKE-LIKE SHAPE INTO AN ELONGATED MORPHOLOGY, WHICH WAS CORRELATED TO A MIXED M1/M2 PROFILE OF CYTOKINE AND CHEMOKINE SECRETION. OUR RESULTS PRESENT, FOR THE FIRST TIME, THAT HDAC ACTIVITY ACTS AS A REGULATOR OF MACROPHAGE DIFFERENTIATION IN THE ABSENCE OF LYMPHOCYTE STIMULI. WE PROPOSE THAT HDAC ACTIVITY DOWN REGULATES MACROPHAGE PLASTICITY FAVORING THE PRO-INFLAMMATORY PHENOTYPE. 2015 6 4969 46 PATHOLOGICAL NEUROINFLAMMATORY CONVERSION OF REACTIVE ASTROCYTES IS INDUCED BY MICROGLIA AND INVOLVES CHROMATIN REMODELING. FOLLOWING BRAIN INJURY OR IN NEURODEGENERATIVE DISEASES, ASTROCYTES BECOME REACTIVE AND MAY SUFFER PATHOLOGICAL REMODELING, FEATURES OF WHICH ARE THE LOSS OF THEIR HOMEOSTATIC FUNCTIONS AND A PRO-INFLAMMATORY GAIN OF FUNCTION THAT FACILITATES NEURODEGENERATION. PHARMACOLOGICAL INTERVENTION TO MODULATE THIS ASTROGLIAL RESPONSE AND NEUROINFLAMMATION IS AN INTERESTING NEW THERAPEUTIC RESEARCH STRATEGY, BUT IT STILL REQUIRES A DEEPER UNDERSTANDING OF THE UNDERLYING CELLULAR AND MOLECULAR MECHANISMS OF THE PHENOMENON. BASED ON THE KNOWN MICROGLIAL-ASTROGLIAL INTERACTION, THE PROMINENT ROLE OF THE NUCLEAR FACTOR KAPPA B (NF-KAPPAB) PATHWAY IN MEDIATING ASTROGLIAL PATHOLOGICAL PRO-INFLAMMATORY GAIN OF FUNCTION, AND ITS ABILITY TO RECRUIT CHROMATIN-REMODELING ENZYMES, WE FIRST EXPLORED THE MICROGLIAL ROLE IN THE INITIATION OF ASTROGLIAL PRO-INFLAMMATORY CONVERSION AND THEN MONITORED THE PROGRESSION OF EPIGENETIC CHANGES IN THE ASTROCYTIC CHROMATIN. DIFFERENT CONFIGURATIONS OF PRIMARY GLIAL CULTURE WERE USED TO MODULATE MICROGLIA-ASTROCYTE CROSSTALK WHILE INDUCING PRO-INFLAMMATORY GAIN OF FUNCTION BY LIPOPOLYSACCHARIDE (LPS) EXPOSURE. IN VIVO, BRAIN ISCHEMIA BY CORTICAL DEVASCULARIZATION (PIAL DISRUPTION) WAS PERFORMED TO VERIFY THE PRESENCE OF EPIGENETIC MARKS IN REACTIVE ASTROCYTES. OUR RESULTS SHOWED THAT 1) MICROGLIA IS REQUIRED TO INITIATE THE PATHOLOGICAL CONVERSION OF ASTROCYTES BY TRIGGERING THE NF-KAPPAB SIGNALING PATHWAY; 2) THIS INTERACTION IS MEDIATED BY SOLUBLE FACTORS AND INDUCES STABLE ASTROGLIAL PHENOTYPIC CHANGES; 3) THE PATHOLOGICAL CONVERSION PROMOTES CHROMATIN REMODELING WITH STABLE INCREASE IN H3K9K14AC, TEMPORARY INCREASE IN H3K27AC, AND TEMPORARY REDUCTION IN HETEROCHROMATIN MARK H3K9ME3; AND 4) IN VIVO REACTIVE ASTROCYTES SHOW INCREASED H3K27AC MARK IN THE NEUROINFLAMMATORY MILIEU FROM THE ISCHEMIC PENUMBRA. OUR FINDINGS INDICATE THAT ASTROGLIAL PATHOLOGICAL PRO-INFLAMMATORY GAIN OF FUNCTION IS ASSOCIATED WITH PROFOUND CHANGES IN THE CONFIGURATION OF ASTROCYTIC CHROMATIN, WHICH IN TURN ARE INITIATED BY MICROGLIA-DERIVED CUES. THESE RESULTS OPEN A NEW AVENUE IN THE STUDY OF POTENTIAL PHARMACOLOGICAL INTERVENTIONS THAT MODIFY THE INITIATION AND STABILIZATION OF ASTROGLIAL PATHOLOGICAL REMODELING, WHICH WOULD BE USEFUL IN ACUTE AND CHRONIC CNS INJURY. EPIGENETIC CHANGES REPRESENT A PLAUSIBLE PHARMACOLOGICAL TARGET TO INTERFERE WITH THE STABILIZATION OF THE PATHOLOGICAL ASTROGLIAL PHENOTYPE. 2021 7 2228 35 EPIGENETIC MODIFICATIONS OF HISTONES IN PERIODONTAL DISEASE. PERIODONTITIS IS A CHRONIC INFECTIOUS DISEASE DRIVEN BY DYSBIOSIS, AN IMBALANCE BETWEEN COMMENSAL BACTERIA AND THE HOST ORGANISM. PERIODONTITIS IS A LEADING CAUSE OF TOOTH LOSS IN ADULTS AND OCCURS IN ABOUT 50% OF THE US POPULATION. IN ADDITION TO THE CLINICAL CHALLENGES ASSOCIATED WITH TREATING PERIODONTITIS, THE PROGRESSION AND CHRONIC NATURE OF THIS DISEASE SERIOUSLY AFFECT HUMAN HEALTH. EMERGING EVIDENCE SUGGESTS THAT PERIODONTITIS IS ASSOCIATED WITH MECHANISMS BEYOND BACTERIA-INDUCED PROTEIN AND TISSUE DEGRADATION. HERE, WE HYPOTHESIZE THAT BACTERIA ARE ABLE TO INDUCE EPIGENETIC MODIFICATIONS IN ORAL EPITHELIAL CELLS MEDIATED BY HISTONE MODIFICATIONS. IN THIS STUDY, WE FOUND THAT DYSBIOSIS IN VIVO LED TO EPIGENETIC MODIFICATIONS, INCLUDING ACETYLATION OF HISTONES AND DOWNREGULATION OF DNA METHYLTRANSFERASE 1. IN ADDITION, IN VITRO EXPOSURE OF ORAL EPITHELIAL CELLS TO LIPOPOLYSACCHARIDES RESULTED IN HISTONE MODIFICATIONS, ACTIVATION OF TRANSCRIPTIONAL COACTIVATORS, SUCH AS P300/CBP, AND ACCUMULATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB). GIVEN THAT ORAL EPITHELIAL CELLS ARE THE FIRST LINE OF DEFENSE FOR THE PERIODONTIUM AGAINST BACTERIA, WE ALSO EVALUATED WHETHER ACTIVATION OF PATHOGEN RECOGNITION RECEPTORS INDUCED HISTONE MODIFICATIONS. WE FOUND THAT ACTIVATION OF THE TOLL-LIKE RECEPTORS 1, 2, AND 4 AND THE NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN PROTEIN 1 INDUCED HISTONE ACETYLATION IN ORAL EPITHELIAL CELLS. OUR FINDINGS CORROBORATE THE EMERGING CONCEPT THAT EPIGENETIC MODIFICATIONS PLAY A ROLE IN THE DEVELOPMENT OF PERIODONTITIS. 2016 8 2002 33 EPIGENETIC AND POST-TRANSCRIPTIONAL REPRESSION SUPPORT METABOLIC SUPPRESSION IN CHRONICALLY HYPOXIC GOLDFISH. GOLDFISH ENTER A HYPOMETABOLIC STATE TO SURVIVE CHRONIC HYPOXIA. WE RECENTLY DESCRIBED TISSUE-SPECIFIC CONTRIBUTIONS OF MEMBRANE LIPID COMPOSITION REMODELING AND MITOCHONDRIAL FUNCTION TO METABOLIC SUPPRESSION ACROSS DIFFERENT GOLDFISH TISSUES. HOWEVER, THE MOLECULAR AND ESPECIALLY EPIGENETIC FOUNDATIONS OF HYPOXIA TOLERANCE IN GOLDFISH UNDER METABOLIC SUPPRESSION ARE NOT WELL UNDERSTOOD. HERE WE SHOW THAT COMPONENTS OF THE MOLECULAR OXYGEN-SENSING MACHINERY ARE ROBUSTLY ACTIVATED ACROSS TISSUES IRRESPECTIVE OF HYPOXIA DURATION. INDUCTION OF GENE EXPRESSION OF ENZYMES INVOLVED IN DNA METHYLATION TURNOVER AND MICRORNA BIOGENESIS SUGGEST A ROLE FOR EPIGENETIC TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL SUPPRESSION OF GENE EXPRESSION IN THE HYPOXIA-ACCLIMATED BRAIN. CONVERSELY, MECHANISTIC TARGET OF RAPAMYCIN-DEPENDENT TRANSLATIONAL MACHINERY ACTIVITY IS NOT REDUCED IN LIVER AND WHITE MUSCLE, SUGGESTING THIS PATHWAY DOES NOT CONTRIBUTE TO LOWERING CELLULAR ENERGY EXPENDITURE. FINALLY, MOLECULAR EVIDENCE SUPPORTS PREVIOUSLY REPORTED CHRONIC HYPOXIA-DEPENDENT CHANGES IN MEMBRANE CHOLESTEROL, LIPID METABOLISM AND MITOCHONDRIAL FUNCTION VIA CHANGES IN TRANSCRIPTS INVOLVED IN CHOLESTEROL BIOSYNTHESIS, BETA-OXIDATION, AND MITOCHONDRIAL FUSION IN MULTIPLE TISSUES. OVERALL, THIS STUDY SHOWS THAT CHRONIC HYPOXIA ROBUSTLY INDUCES EXPRESSION OF OXYGEN-SENSING MACHINERY ACROSS TISSUES, INDUCES REPRESSIVE TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL EPIGENETIC MARKS ESPECIALLY IN THE CHRONIC HYPOXIA-ACCLIMATED BRAIN AND SUPPORTS A ROLE FOR MEMBRANE REMODELING AND MITOCHONDRIAL FUNCTION AND DYNAMICS IN PROMOTING METABOLIC SUPPRESSION. 2022 9 3342 42 HISTONE DEACETYLASE9 REPRESENTS THE EPIGENETIC PROMOTION OF M1 MACROPHAGE POLARIZATION AND INFLAMMATORY RESPONSE VIA TLR4 REGULATION. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY RESPONSE MEDIATED BY VARIOUS FACTORS, WHERE EPIGENETIC REGULATION INVOLVING HISTONE DEACETYLATION IS ENVISAGED TO MODULATE THE EXPRESSION OF RELATED PROTEINS BY REGULATING THE BINDING OF TRANSCRIPTION FACTORS TO DNA, THEREBY INFLUENCING THE DEVELOPMENT OF ATHEROSCLEROSIS. THE MECHANISM OF ATHEROSCLEROSIS BY HISTONE DEACETYLATION IS PARTLY KNOWN; HENCE, THIS PROJECT AIMED AT INVESTIGATING THE ROLE OF HISTONE DEACETYLASE 9 (HDAC9) IN ATHEROSCLEROSIS. FOR THIS PURPOSE, SERUM WAS SEPARATED FROM BLOOD SAMPLES FOLLOWING CLOTTING AND CENTRIFUGATION FROM ATHEROSCLEROTIC AND HEALTHY PATIENTS (N = 40 EACH), AND THEN, VARIOUS TESTS WERE PERFORMED. THE RESULTS INDICATED THAT TOLL-LIKE RECEPTOR 4 (TLR4) WAS NOT ONLY POSITIVELY CORRELATED TO THE HDAC9 GENE, BUT WAS ALSO UPREGULATED IN ATHEROSCLEROSIS, WHERE IT WAS ALSO SIGNIFICANTLY UPREGULATED IN THE ATHEROSCLEROSIS CELL MODEL OF OXIDIZED LOW-DENSITY LIPOPROTEIN-INDUCED MACROPHAGES. CONVERSELY, THE TLR4 WAS SIGNIFICANTLY DOWNREGULATED IN INSTANCES OF LOSS OF HDAC9 FUNCTION, CEMENTING THE BRIDGING RELATIONSHIP BETWEEN HDAC9 AND MACROPHAGE POLARIZATION, WHERE THE HDAC9 WAS FOUND TO UPREGULATE M1 MACROPHAGE POLARIZATION WHICH TRANSLATED INTO THE RELEASE OF HIGHER CONTENT OF PROINFLAMMATORY CYTOKINES SUCH AS INTERLEUKIN-1BETA (IL-1BETA) AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA), WHICH TEND TO SIGNIFICANTLY DECREASE FOLLOWING THE DELETION OF TLR4. HENCE, THIS STUDY REPORTS NOVEL RELATION BETWEEN EPIGENETIC CONTROL AND ATHEROSCLEROSIS, WHICH COULD PARTLY BE EXPLAINED BY HISTONE DEACETYLATION. 2022 10 6505 51 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 11 911 39 CHRONIC EXPOSURE TO TNF REPROGRAMS CELL SIGNALING PATHWAYS IN FIBROBLAST-LIKE SYNOVIOCYTES BY ESTABLISHING LONG-TERM INFLAMMATORY MEMORY. FIBROBLAST-LIKE SYNOVIOCYTES (FLS) PLAY A CRITICAL ROLE IN THE PATHOGENESIS OF RHEUMATOID ARTHRITIS (RA). CHRONIC INFLAMMATION INDUCES TRANSCRIPTOMIC AND EPIGENETIC MODIFICATIONS THAT IMPARTS A PERSISTENT CATABOLIC PHENOTYPE TO THE FLS, DESPITE THEIR DISSOCIATION FROM THE INFLAMMATORY ENVIRONMENT. WE ANALYZED HIGH THROUGHPUT GENE EXPRESSION AND CHROMATIN ACCESSIBILITY DATA FROM HUMAN AND MOUSE FLS FROM OUR AND OTHER STUDIES AVAILABLE ON PUBLIC REPOSITORIES, WITH THE GOAL OF IDENTIFYING THE PERSISTENTLY REPROGRAMMED SIGNALING PATHWAYS DRIVEN BY CHRONIC INFLAMMATION. WE FOUND THAT THE GENE EXPRESSION CHANGES INDUCED BY SHORT-TERM TUMOR NECROSIS FACTOR-ALPHA (TNF) TREATMENT WERE LARGELY SUSTAINED IN THE FLS EXPOSED TO CHRONIC INFLAMMATION. THESE CHANGES THAT INCLUDED BOTH ACTIVATION AND REPRESSION OF GENE EXPRESSION, WERE ACCOMPANIED BY THE REMODELING OF CHROMATIN ACCESSIBILITY. THE SUSTAINED ACTIVATED GENES (SAGS) INCLUDED ESTABLISHED PRO-INFLAMMATORY SIGNALING COMPONENTS KNOWN TO ACT AT MULTIPLE LEVELS OF NF-KAPPAB, STAT AND AP-1 SIGNALING CASCADES. INTERESTINGLY, THE SUSTAINED REPRESSED GENES (SRGS) INCLUDED CRITICAL MEDIATORS AND TARGETS OF THE BMP SIGNALING PATHWAY. WE THUS IDENTIFIED SUSTAINED REPRESSION OF BMP SIGNALING AS A UNIQUE CONSTITUENT OF THE LONG-TERM INFLAMMATORY MEMORY INDUCED BY CHRONIC INFLAMMATION. WE POSTULATE THAT SIMULTANEOUS TARGETING OF THESE ACTIVATED AND REPRESSED SIGNALING PATHWAYS MAY BE NECESSARY TO COMBAT RA PERSISTENCE. 2020 12 3921 48 LINKING INFLAMMATION TO CELL CYCLE PROGRESSION. RISK OF GASTROINTESTINAL CANCERS IS CLOSELY RELATED TO INCREASED LEVELS OF OXIDANTS IN THE BALANCE BETWEEN OXIDANT AND ANTI-OXIDANT AGENTS. A POSSIBLE EXPLANATION OF THIS EPIDEMIOLOGICAL OBSERVATION IS THE LOCAL LOSS OF THE EPITHELIAL BARRIER FUNCTION WITH A FOCAL INFLAMMATORY RESPONSE. ACCORDINGLY, CHRONIC INFLAMMATORY DISEASES REPRESENT WELL-KNOWN RISK FACTORS FOR CANCER AND, ON THE OTHER HAND, IT IS KNOWN THAT ANTI-INFLAMMATORY AGENTS, DEMULCENTS AND ANTIOXIDANTS MARKEDLY INHIBIT THE DEVELOPMENT OF COLON CANCER IN ANIMAL MODELS AS WELL IN HUMANS. AT MOLECULAR LEVEL A KEY ROLE IN THE PROCESS THAT LINK INFLAMMATION TO CELLULAR TRANSFORMATION SEEMS TO BE PLAYED BY ACTIVATION OF CYCLOOXYGENASE-2 (COX-2) TOGETHER WITH PRODUCTION OF REACTIVE OXYGEN INTERMEDIATE (ROI). BOTH THESE EVENTS HAVE BEEN STRICTLY LINKED WITH CELL PROLIFERATION AND TRANSFORMATION, ALTHOUGH THE INTRACELLULAR PATHWAYS INVOLVED IN THESE PROCESSES ARE STILL NOT COMPLETELY UNDERSTOOD. THE UNCONTROLLED PROLIFERATION, WHICH IS A LANDMARK OF CELLULAR TRANSFORMATION, IS ACCOMPANIED BY THE DEREGULATION OF PROTEINS INVOLVED IN THE CONTROL OF CELL CYCLE CHECKPOINTS. ALTERED EXPRESSION AND FUNCTION OF CYCLOOXYGENASE AND NITRIC OXIDE SYNTHASE SEEM TO INFLUENCE, AMONG OTHERS, THE EXPRESSION OF PROTEINS INVOLVED IN THE REGULATION OF CELL CYCLE PROGRESSION. SIMILARLY, ANTI-INFLAMMATORY AND ANTIOXIDANT AGENTS MAY ALSO ACT ON THE EXPRESSION AND FUNCTION OF SEVERAL CELL CYCLE REGULATING PROTEINS. UNDERSTANDING THE MECHANISMS BY WHICH CHRONIC INFLAMMATION CONTRIBUTES TO GENETIC AND EPIGENETIC CHANGES INVOLVED IN THE REGULATION OF CRITICAL CELL CYCLE CHECKPOINTS MAY HELP TO DEVELOP MORE AND MORE SPECIFIC TREATMENT STRATEGIES FOR REDUCING MALIGNANT TRANSFORMATION OF THESE INFLAMMATORY DISEASES. 2004 13 4044 41 MACROPHAGES IN OXIDATIVE STRESS AND MODELS TO EVALUATE THE ANTIOXIDANT FUNCTION OF DIETARY NATURAL COMPOUNDS. ANTIOXIDANT TESTING OF NATURAL PRODUCTS HAS ATTRACTED INCREASING INTEREST IN RECENT YEARS, MAINLY DUE TO THE FACT THAT AN ANTIOXIDANT-RICH DIET MIGHT PROVIDE HEALTH BENEFITS. ACTIVATED MACROPHAGES ARE A MAJOR SOURCE OF REACTIVE OXYGEN SPECIES, REACTIVE NITROGEN SPECIES, AND PEROXYNITRITE GENERATED THROUGH THE SO-CALLED RESPIRATORY BURST. CONSTITUTIVELY RELEASED PROINFLAMMATORY CYTOKINE, ESPECIALLY TUMOR NECROSIS FACTOR-ALPHA, TRIGGERS NUCLEAR FACTOR-KAPPAB, AND ACTIVATOR PROTEIN-1 TRANSLOCATION LEADING TO THE OVER PRODUCTION OF REACTIVE OXYGEN SPECIES AND REACTIVE NITROGEN SPECIES IN MACROPHAGES. ACTIVATION OF TRANSCRIPTION FACTORS IN THE LONG-LIVED TISSUE-RESIDENT MACROPHAGES AND/OR MONOCYTE-DERIVED MACROPHAGES, TRIGGER EPIGENETIC MODIFICATIONS LEADING TO THE PATHOGENESIS OF CHRONIC DISEASES. NUTRACEUTICALS INCLUDING LIPID RAFT STRUCTURE DISRUPTION AGENT, CHOLESTEROL DEPLETION AGENT, FARNESYLTRANSFERASE INHIBITOR, NUCLEAR FACTOR-KAPPAB BLOCKER (ALPHA,BETA-UNSATURATED CARBONYL COMPOUNDS), GLUCOCORTICOID RECEPTOR AGONIST, AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AGONIST HAVE LONG BEEN USED TO INACTIVE MACROPHAGE. THE INHIBITION EFFECTS ON THE FORMATION OF NITRIC OXIDE, SUPEROXIDE, AND NITRITE PEROXIDE MAY BE RESPONSIBLE FOR THE ANTI-INFLAMMATORY FUNCTIONALITIES. ACTIVATED MACROPHAGE MODELS COULD BE USED TO IDENTIFY THE ACTIVE COMPONENTS FOR FUNCTIONAL DIETS DEVELOPMENT THROUGH A MULTIPLE TARGETS STRATEGY. 2017 14 5872 32 SUSTAINED TNF-ALPHA STIMULATION LEADS TO TRANSCRIPTIONAL MEMORY THAT GREATLY ENHANCES SIGNAL SENSITIVITY AND ROBUSTNESS. TRANSCRIPTIONAL MEMORY ALLOWS CERTAIN GENES TO RESPOND TO PREVIOUSLY EXPERIENCED SIGNALS MORE ROBUSTLY. HOWEVER, WHETHER AND HOW THE KEY PROINFLAMMATORY CYTOKINE TNF-ALPHA MEDIATES TRANSCRIPTIONAL MEMORY ARE POORLY UNDERSTOOD. USING HEK293F CELLS AS A MODEL SYSTEM, WE REPORT THAT SUSTAINED TNF-ALPHA STIMULATION INDUCES TRANSCRIPTIONAL MEMORY DEPENDENT ON TET ENZYMES. THE HYPOMETHYLATED STATUS OF TRANSCRIPTIONAL REGULATORY REGIONS CAN BE INHERITED, FACILITATING NF-KAPPAB BINDING AND MORE ROBUST SUBSEQUENT ACTIVATION. A HIGH INITIAL METHYLATION LEVEL AND CPG DENSITY AROUND KAPPAB SITES ARE CORRELATED WITH THE FUNCTIONAL POTENTIAL OF TRANSCRIPTIONAL MEMORY MODULES. INTERESTINGLY, THE CALCB GENE, ENCODING THE PROVEN MIGRAINE THERAPEUTIC TARGET CGRP, EXHIBITS THE BEST TRANSCRIPTIONAL MEMORY. A NEIGHBORING PRIMATE-SPECIFIC ENDOGENOUS RETROVIRUS STIMULATES MORE RAPID, MORE STRONG, AND AT LEAST 100-FOLD MORE SENSITIVE CALCB INDUCTION IN SUBSEQUENT TNF-ALPHA STIMULATION. OUR STUDY REVEALS THAT TNF-ALPHA-MEDIATED TRANSCRIPTIONAL MEMORY IS GOVERNED BY ACTIVE DNA DEMETHYLATION AND GREATLY SENSITIZES MEMORY GENES TO MUCH LOWER DOSES OF INFLAMMATORY CUES. 2020 15 1382 54 DIABETES ALTERS ACTIVATION AND REPRESSION OF PRO- AND ANTI-INFLAMMATORY SIGNALING PATHWAYS IN THE VASCULATURE. A CENTRAL MECHANISM DRIVING VASCULAR DISEASE IN DIABETES IS IMMUNE CELL-MEDIATED INFLAMMATION. IN DIABETES, ENHANCED OXIDATION AND GLYCATION OF MACROMOLECULES, SUCH AS LIPOPROTEINS, INSULTS THE ENDOTHELIUM, AND ACTIVATES BOTH INNATE AND ADAPTIVE ARMS OF THE IMMUNE SYSTEM BY GENERATING NEW ANTIGENS FOR PRESENTATION TO ADAPTIVE IMMUNE CELLS. CHRONIC INFLAMMATION OF THE ENDOTHELIUM IN DIABETES LEADS TO CONTINUOUS INFILTRATION AND ACCUMULATION OF LEUKOCYTES AT SITES OF ENDOTHELIAL CELL INJURY. WE WILL DESCRIBE THE CENTRAL ROLE OF THE MACROPHAGE AS A SOURCE OF SIGNALING MOLECULES AND DAMAGING BY-PRODUCTS WHICH ACTIVATE INFILTRATING LYMPHOCYTES IN THE TISSUE AND CONTRIBUTE TO THE PRO-OXIDANT AND PRO-INFLAMMATORY MICROENVIRONMENT. AN IMPORTANT ASPECT TO BE CONSIDERED IS THE DIABETES-ASSOCIATED DEFECTS IN THE IMMUNE SYSTEM, SUCH AS FEWER OR DYSFUNCTIONAL ATHERO-PROTECTIVE LEUKOCYTE SUBSETS IN THE DIABETIC LESION COMPARED TO NON-DIABETIC LESIONS. THIS REVIEW WILL DISCUSS THE KEY PRO-INFLAMMATORY SIGNALING PATHWAYS RESPONSIBLE FOR LEUKOCYTE RECRUITMENT AND ACTIVATION IN THE INJURED VESSEL, WITH PARTICULAR FOCUS ON PRO- AND ANTI-INFLAMMATORY PATHWAYS ABERRANTLY ACTIVATED OR REPRESSED IN DIABETES. WE AIM TO DESCRIBE THE INTERACTION BETWEEN ADVANCED GLYCATION END PRODUCTS AND THEIR PRINCIPLE RECEPTOR RAGE, ANGIOTENSIN II, AND THE ANG II TYPE 1 RECEPTOR, IN ADDITION TO REACTIVE OXYGEN SPECIES (ROS) PRODUCTION BY NADPH-OXIDASE ENZYMES THAT ARE RELEVANT TO VASCULAR AND IMMUNE CELL FUNCTION IN THE CONTEXT OF DIABETIC VASCULOPATHY. FURTHERMORE, WE WILL TOUCH ON RECENT ADVANCES IN EPIGENETIC MEDICINE THAT HAVE REVEALED HIGH GLUCOSE-MEDIATED CHANGES IN THE TRANSCRIPTION OF GENES WITH KNOWN PRO-INFLAMMATORY DOWNSTREAM TARGETS. FINALLY, NOVEL ANTI-ATHEROSCLEROSIS STRATEGIES THAT TARGET THE VASCULAR IMMUNE INTERFACE WILL BE EXPLORED; SUCH AS VACCINATION AGAINST MODIFIED LOW-DENSITY LIPOPROTEIN AND PHARMACOLOGICAL INHIBITION OF ROS-PRODUCING ENZYMES. 2013 16 5415 41 REGULATION OF CELLULAR IMMUNE RESPONSES IN SEPSIS BY HISTONE MODIFICATIONS. SEVERE SEPSIS, SEPTIC SHOCK, AND RELATED INFLAMMATORY SYNDROMES ARE DRIVEN BY THE ABERRANT EXPRESSION OF PROINFLAMMATORY MEDIATORS BY IMMUNE CELLS. DURING THE ACUTE PHASE OF SEPSIS, OVEREXPRESSION OF CHEMOKINES AND CYTOKINES DRIVES PHYSIOLOGICAL STRESS LEADING TO ORGAN FAILURE AND MORTALITY. FOLLOWING RECOVERY FROM SEPSIS, THE IMMUNE SYSTEM EXHIBITS PROFOUND IMMUNOSUPPRESSION, EVIDENCED BY AN INABILITY TO PRODUCE THE SAME PROINFLAMMATORY MEDIATORS THAT ARE REQUIRED FOR NORMAL RESPONSES TO INFECTIOUS MICROORGANISMS. GENE EXPRESSION IN INFLAMMATORY RESPONSES IS INFLUENCED BY THE TRANSCRIPTIONAL ACCESSIBILITY OF THE CHROMATIN, WITH HISTONE POSTTRANSLATIONAL MODIFICATIONS DETERMINING WHETHER INFLAMMATORY GENE LOCI ARE SET TO TRANSCRIPTIONALLY ACTIVE, REPRESSED, OR POISED STATES. EXPERIMENTAL EVIDENCE INDICATES THAT HISTONE MODIFICATIONS PLAY A CENTRAL ROLE IN GOVERNING THE CYTOKINE STORM OF SEVERE SEPSIS, AND THAT ABERRANT CHROMATIN MODIFICATIONS INDUCED DURING THE ACUTE PHASE OF SEPSIS MAY MEDIATE CHRONIC IMMUNOSUPPRESSION IN SEPSIS SURVIVORS. THIS REVIEW WILL FOCUS ON THE ROLE OF HISTONE MODIFICATIONS IN GOVERNING IMMUNE RESPONSES IN SEVERE SEPSIS, WITH AN EMPHASIS ON SPECIFIC LEUKOCYTE SUBSETS AND THE HISTONE MODIFICATIONS OBSERVED IN THESE CELLS DURING CHRONIC STAGES OF SEPSIS. ADDITIONALLY, THE EXPRESSION AND FUNCTION OF CHROMATIN-MODIFYING ENZYMES (CMES) WILL BE DISCUSSED IN THE CONTEXT OF SEVERE SEPSIS, AS POTENTIAL MEDIATORS OF EPIGENETIC REGULATION OF GENE EXPRESSION IN SEPSIS RESPONSES. IN SUMMARY, THIS REVIEW WILL ARGUE FOR THE USE OF CHROMATIN MODIFICATIONS AND CME EXPRESSION IN LEUKOCYTES AS POTENTIAL BIOMARKERS OF IMMUNOSUPPRESSION IN PATIENTS WITH SEVERE SEPSIS. 2017 17 1357 54 DEVELOPMENT OF INNATE IMMUNE MEMORY BY NON-IMMUNE CELLS DURING STAPHYLOCOCCUS AUREUS INFECTION DEPENDS ON REACTIVE OXYGEN SPECIES. INTRODUCTION: THE MECHANISMS UNDERLYING INNATE IMMUNE MEMORY (TRAINED IMMUNITY) COMPRISE EPIGENETIC REPROGRAMMING OF TRANSCRIPTIONAL PATHWAYS ASSOCIATED WITH ALTERATIONS OF INTRACELLULAR METABOLISM. WHILE THE MECHANISMS OF INNATE IMMUNE MEMORY CARRIED OUT BY IMMUNE CELLS ARE WELL CHARACTERIZED, SUCH PROCESSES IN NON-IMMUNE CELLS, ARE POORLY UNDERSTOOD. THE OPPORTUNISTIC PATHOGEN, STAPHYLOCOCCUS AUREUS, IS RESPONSIBLE FOR A MULTITUDE OF HUMAN DISEASES, INCLUDING PNEUMONIA, ENDOCARDITIS AND OSTEOMYELITIS, AS WELL AS ANIMAL INFECTIONS, INCLUDING CHRONIC CATTLE MASTITIS THAT ARE EXTREMELY DIFFICULT TO TREAT. AN INDUCTION OF INNATE IMMUNE MEMORY MAY BE CONSIDERED AS A THERAPEUTIC ALTERNATIVE TO FIGHT S. AUREUS INFECTION. METHODS: IN THE CURRENT WORK, WE DEMONSTRATED THE DEVELOPMENT OF INNATE IMMUNE MEMORY IN NON-IMMUNE CELLS DURING S. AUREUS INFECTION EMPLOYING A COMBINATION OF TECHNIQUES INCLUDING ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA), MICROSCOPIC ANALYSIS, AND CYTOMETRY. RESULTS: WE OBSERVED THAT TRAINING OF HUMAN OSTEOBLAST-LIKE MG-63 CELLS AND LUNG EPITHELIAL A549 CELLS WITH BETA-GLUCAN INCREASED IL-6 AND IL-8 PRODUCTION UPON A STIMULATION WITH S. AUREUS, CONCOMITANT WITH HISTONES MODIFICATIONS. IL-6 AND IL-8 PRODUCTION WAS POSITIVELY CORRELATED WITH AN ACETYLATION OF HISTONE 3 AT LYSINE 27 (H3K27), THUS SUGGESTING EPIGENETIC REPROGRAMMING IN THESE CELLS. AN ADDITION OF THE ROS SCAVENGER N-ACETYLCYSTEINE, NAC, PRIOR TO BETA-GLUCAN PRETREATMENT FOLLOWED BY AN EXPOSURE TO S. AUREUS, RESULTED IN DECREASED IL-6 AND IL-8 PRODUCTION, THEREBY SUPPORTING THE INVOLVEMENT OF ROS IN THE INDUCTION OF INNATE IMMUNE MEMORY. EXPOSURE OF CELLS TO LACTOCOCCUS LACTIS RESULTED IN INCREASED IL-6 AND IL-8 PRODUCTION BY MG-63 AND A549 CELLS UPON A STIMULATION WITH S. AUREUS THAT WAS CORRELATED WITH H3K27 ACETYLATION, SUGGESTING THE ABILITY OF THIS BENEFICIAL BACTERIUM TO INDUCE INNATE IMMUNE MEMORY. DISCUSSION: THIS WORK IMPROVES OUR UNDERSTANDING OF INNATE IMMUNE MEMORY IN NON-IMMUNE CELLS IN THE CONTEXT OF S. AUREUS INFECTION. IN ADDITION TO KNOWN INDUCERS, PROBIOTICS MAY REPRESENT GOOD CANDIDATES FOR THE INDUCTION OF INNATE IMMUNE MEMORY. OUR FINDINGS MAY HELP THE DEVELOPMENT OF ALTERNATIVE THERAPEUTIC APPROACHES FOR THE PREVENTION OF S. AUREUS INFECTION. 2023 18 5937 46 TARGETING HISTONE DEACETYLASE ACTIVITY IN RHEUMATOID ARTHRITIS AND ASTHMA AS PROTOTYPES OF INFLAMMATORY DISEASE: SHOULD WE KEEP OUR HATS ON? CELLULAR ACTIVATION, PROLIFERATION AND SURVIVAL IN CHRONIC INFLAMMATORY DISEASES IS REGULATED NOT ONLY BY ENGAGEMENT OF SIGNAL TRANS-DUCTION PATHWAYS THAT MODULATE TRANSCRIPTION FACTORS REQUIRED FOR THESE PROCESSES, BUT ALSO BY EPIGENETIC REGULATION OF TRANSCRIPTION FACTOR ACCESS TO GENE PROMOTER REGIONS. HISTONE ACETYL TRANSFERASES COORDINATE THE RECRUITMENT AND ACTIVATION OF TRANSCRIPTION FACTORS WITH CONFORMATIONAL CHANGES IN HISTONES THAT ALLOW GENE PROMOTER EXPOSURE. HISTONE DEACETYLASES (HDACS) COUNTERACT HISTONE ACETYL TRANSFERASE ACTIVITY THROUGH THE TARGETING OF BOTH HISTONES AS WELL AS NONHISTONE SIGNAL TRANSDUCTION PROTEINS IMPORTANT IN INFLAMMATION. NUMEROUS STUDIES HAVE INDICATED THAT DEPRESSED HDAC ACTIVITY IN PATIENTS WITH INFLAMMATORY AIRWAY DISEASES MAY CONTRIBUTE TO LOCAL PROINFLAMMATORY CYTOKINE PRODUCTION AND DIMINISH PATIENT RESPONSES TO CORTICOSTEROID TREATMENT. RECENT OBSERVATIONS THAT HDAC ACTIVITY IS DEPRESSED IN RHEUMATOID ARTHRITIS PATIENT SYNOVIAL TISSUE HAVE PREDICTED THAT STRATEGIES RESTORING HDAC FUNCTION MAY BE THERAPEUTIC IN THIS DISEASE AS WELL. PHARMACOLOGICAL INHIBITORS OF HDAC ACTIVITY, HOWEVER, HAVE DEMONSTRATED POTENT THERAPEUTIC EFFECTS IN ANIMAL MODELS OF ARTHRITIS AND OTHER CHRONIC INFLAMMATORY DISEASES. IN THE PRESENT REVIEW WE ASSESS AND RECONCILE THESE OUTWARDLY PARADOXICAL STUDY RESULTS TO PROVIDE A WORKING MODEL FOR HOW ALTERATIONS IN HDAC ACTIVITY MAY CONTRIBUTE TO PATHOLOGY IN RHEUMATOID ARTHRITIS, AND HIGHLIGHT KEY QUESTIONS TO BE ANSWERED IN THE PRECLINICAL EVALUATION OF COMPOUNDS MODULATING THESE ENZYMES. 2008 19 5710 38 SIRT1 DEFICIENCY IN MICROGLIA CONTRIBUTES TO COGNITIVE DECLINE IN AGING AND NEURODEGENERATION VIA EPIGENETIC REGULATION OF IL-1BETA. AGING IS THE PREDOMINANT RISK FACTOR FOR NEURODEGENERATIVE DISEASES. ONE KEY PHENOTYPE AS THE BRAIN AGES IS AN ABERRANT INNATE IMMUNE RESPONSE CHARACTERIZED BY PROINFLAMMATION. HOWEVER, THE MOLECULAR MECHANISMS UNDERLYING AGING-ASSOCIATED PROINFLAMMATION ARE POORLY DEFINED. WHETHER CHRONIC INFLAMMATION PLAYS A CAUSAL ROLE IN COGNITIVE DECLINE IN AGING AND NEURODEGENERATION HAS NOT BEEN ESTABLISHED. HERE WE REPORT A MECHANISTIC LINK BETWEEN CHRONIC INFLAMMATION AND AGING MICROGLIA AND A CAUSAL ROLE OF AGING MICROGLIA IN NEURODEGENERATIVE COGNITIVE DEFICITS. WE SHOWED THAT SIRT1 IS REDUCED WITH THE AGING OF MICROGLIA AND THAT MICROGLIAL SIRT1 DEFICIENCY HAS A CAUSATIVE ROLE IN AGING- OR TAU-MEDIATED MEMORY DEFICITS VIA IL-1BETA UPREGULATION IN MICE. INTERESTINGLY, THE SELECTIVE ACTIVATION OF IL-1BETA TRANSCRIPTION BY SIRT1 DEFICIENCY IS LIKELY MEDIATED THROUGH HYPOMETHYLATING THE SPECIFIC CPG SITES ON IL-1BETA PROXIMAL PROMOTER. IN HUMANS, HYPOMETHYLATION OF IL-1BETA IS STRONGLY ASSOCIATED WITH CHRONOLOGICAL AGE AND WITH ELEVATED IL-1BETA TRANSCRIPTION. OUR FINDINGS REVEAL A NOVEL EPIGENETIC MECHANISM IN AGING MICROGLIA THAT CONTRIBUTES TO COGNITIVE DEFICITS IN AGING AND NEURODEGENERATIVE DISEASES. 2015 20 6535 43 TRANSCRIPTIONAL REGULATION OF THE ANTI-INFLAMMATORY CYTOKINE IL-10 IN ACQUIRED IMMUNE CELLS. ALTHOUGH THE MAJOR ROLE OF THE IMMUNE RESPONSE IS HOST DEFENSE FROM A WIDE RANGE OF POTENTIALLY PATHOGENIC MICROORGANISMS, EXCESS IMMUNE RESPONSES CAN RESULT IN SEVERE HOST DAMAGE. THE HOST THUS REQUIRES ANTI-INFLAMMATORY MECHANISMS TO PREVENT REACTIVITY TO SELF. INTERLEUKIN-10 (IL-10) IS A CYTOKINE WITH BROAD ANTI-INFLAMMATORY PROPERTIES INVOLVED IN THE PATHOGENESIS OF VARIOUS DISEASES. IL-10 WAS ORIGINALLY DESCRIBED AS A T HELPER (T(H)2) DERIVED CYTOKINE, BUT FURTHER STUDIES INDICATED THAT IL-10 IS EXPRESSED NOT ONLY BY MANY CELLS OF THE ADAPTIVE IMMUNE SYSTEM, INCLUDING T AND B CELLS, BUT ALSO BY THE INNATE IMMUNE CELLS, INCLUDING DENDRITIC CELLS (DCS), MACROPHAGES, MAST CELLS, AND NATURAL KILLER (NK) CELLS. IN ADDITION, IL-10 CAN BE INDUCED IN T(H)1 AND T(H)17 CELLS BY CHRONIC INFLAMMATION AS A SYSTEM OF FEEDBACK REGULATION. IN THIS REVIEW, WE FOCUS ON THE MOLECULAR MECHANISMS UNDERLYING IL10 GENE EXPRESSION IN ADAPTIVE IMMUNE CELLS AND SUMMARIZE THE RECENT PROGRESSES IN EPIGENETIC AND TRANSCRIPTIONAL REGULATION OF THE IL10 GENE. UNDERSTANDING THE TRANSCRIPTIONAL REGULATORY EVENTS MAY HELP IN THE DEVELOPMENT OF NEW STRATEGIES TO CONTROL INFLAMMATORY DISEASES. 2012