1 744 183 CANNABINOID WIN55,212-2 REPROGRAMS MONOCYTES AND MACROPHAGES TO INHIBIT LPS-INDUCED INFLAMMATION. INTRODUCTION: CHRONIC OR UNCONTROLLED ACTIVATION OF MYELOID CELLS INCLUDING MONOCYTES, MACROPHAGES AND DENDRITIC CELLS (DCS) IS A HALLMARK OF IMMUNE-MEDIATED INFLAMMATORY DISORDERS. THERE IS AN URGENT NEED FOR THE DEVELOPMENT OF NOVEL DRUGS WITH THE CAPACITY TO IMPAIR INNATE IMMUNE CELL OVERACTIVATION UNDER INFLAMMATORY CONDITIONS. COMPELLING EVIDENCE POINTED OUT CANNABINOIDS AS POTENTIAL THERAPEUTIC TOOLS WITH ANTI-INFLAMMATORY AND IMMUNOMODULATORY CAPACITY. WIN55,212-2, A NON-SELECTIVE SYNTHETIC CANNABINOID AGONIST, DISPLAYS PROTECTIVE EFFECTS IN SEVERAL INFLAMMATORY CONDITIONS BY MECHANISMS PARTIALLY DEPENDING ON THE GENERATION OF TOLEROGENIC DCS ABLE TO INDUCE FUNCTIONAL REGULATORY T CELLS (TREGS). HOWEVER, ITS IMMUNOMODULATORY CAPACITY ON OTHER MYELOID CELLS SUCH AS MONOCYTES AND MACROPHAGES REMAINS INCOMPLETELY UNDERSTOOD. METHODS: HUMAN MONOCYTE-DERIVED DCS (HMODCS) WERE DIFFERENTIATED IN THE ABSENCE (CONVENTIONAL HMODCS) OR PRESENCE OF WIN55,212-2 (WIN-HMODCS). CELLS WERE STIMULATED WITH LPS, COCULTURED WITH NAIVE T LYMPHOCYTES AND THEIR CYTOKINE PRODUCTION AND ABILITY TO INDUCE T CELL RESPONSES WERE ANALYSED BY ELISA OR FLOW CYTOMETRY. TO EVALUATE THE EFFECT OF WIN55,212-2 IN MACROPHAGE POLARIZATION, HUMAN AND MURINE MACROPHAGES WERE ACTIVATED WITH LPS OR LPS/IFNGAMMA, IN THE PRESENCE OR ABSENCE OF THE CANNABINOID. CYTOKINE, COSTIMULATORY MOLECULES AND INFLAMMASOME MARKERS WERE ASSAYED. METABOLIC AND CHROMATIN IMMUNOPRECIPITATION ASSAYS WERE ALSO PERFORMED. FINALLY, THE PROTECTIVE CAPACITY OF WIN55,212-2 WAS STUDIED IN VIVO IN BALB/C MICE AFTER INTRAPERITONEAL INJECTION WITH LPS. RESULTS: WE SHOW FOR THE FIRST TIME THAT THE DIFFERENTIATION OF HMODCS IN THE PRESENCE OF WIN55,212-2 GENERATES TOLEROGENIC WIN-HMODCS THAT ARE LESS RESPONSIVE TO LPS STIMULATION AND ABLE TO PRIME TREGS. WIN55,212-2 ALSO IMPAIRS THE PRO-INFLAMMATORY POLARIZATION OF HUMAN MACROPHAGES BY INHIBITING CYTOKINE PRODUCTION, INFLAMMASOME ACTIVATION AND RESCUING MACROPHAGES FROM PYROPTOTIC CELL DEATH. MECHANISTICALLY, WIN55,212-2 INDUCED A METABOLIC AND EPIGENETIC SHIFT IN MACROPHAGES BY DECREASING LPS-INDUCED MTORC1 SIGNALING, COMMITMENT TO GLYCOLYSIS AND ACTIVE HISTONE MARKS IN PRO-INFLAMMATORY CYTOKINE PROMOTERS. WE CONFIRMED THESE DATA IN EX VIVO LPS-STIMULATED PERITONEAL MACROPHAGES (PMPHIS), WHICH WERE ALSO SUPPORTED BY THE IN VIVO ANTI-INFLAMMATORY CAPACITY OF WIN55,212-2 IN A LPS-INDUCED SEPSIS MOUSE MODEL. CONCLUSION: OVERALL, WE SHED LIGHT INTO THE MOLECULAR MECHANISMS BY WHICH CANNABINOIDS EXERT ANTI-INFLAMMATORY PROPERTIES IN MYELOID CELLS, WHICH MIGHT WELL CONTRIBUTE TO THE FUTURE RATIONAL DESIGN OF NOVEL THERAPEUTIC STRATEGIES FOR INFLAMMATORY DISORDERS. 2023 2 4391 47 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 3436 44 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 4 2067 42 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 5 2641 45 EPIGENOMIC AND TRANSCRIPTOMIC ANALYSES REVEAL DIFFERENCES BETWEEN LOW-GRADE INFLAMMATION AND SEVERE EXHAUSTION IN LPS-CHALLENGED MURINE MONOCYTES. EMERGING STUDIES SUGGEST THAT MONOCYTES CAN BE TRAINED BY BACTERIAL ENDOTOXIN TO ADOPT DISTINCT MEMORY STATES RANGING FROM LOW-GRADE INFLAMMATION TO IMMUNE EXHAUSTION. WHILE LOW-GRADE INFLAMMATION MAY CONTRIBUTE TO THE PATHOGENESIS OF CHRONIC DISEASES, EXHAUSTED MONOCYTES WITH PATHOGENIC AND IMMUNE-SUPPRESSIVE CHARACTERISTICS MAY UNDERLIE THE PATHOGENESIS OF POLYMICROBIAL SEPSIS INCLUDING COVID-19. HOWEVER, DETAILED PROCESSES BY WHICH THE DYNAMIC ADAPTION OF MONOCYTES OCCUR REMAIN POORLY UNDERSTOOD. HERE WE EXPOSED MURINE BONE-MARROW DERIVED MONOCYTES TO CHRONIC LIPOPOLYSACCHARIDE (LPS) STIMULATION AT LOW-DOSE OR HIGH-DOSE, AS WELL AS A PBS CONTROL. THE CELLS WERE PROFILED FOR GENOME-WIDE H3K27AC MODIFICATION AND GENE EXPRESSION. THE GENE EXPRESSION OF TRAM-DEFICIENT AND IRAK-M-DEFICIENT MONOCYTES WITH LPS EXPOSURE WAS ALSO ANALYZED. WE DISCOVER THAT LOW-GRADE INFLAMMATION PREFERENTIALLY UTILIZES THE TRAM-DEPENDENT PATHWAY OF TLR4 SIGNALING, AND INDUCES THE EXPRESSION OF INTERFERON RESPONSE GENES. IN CONTRAST, HIGH DOSE LPS UNIQUELY UPREGULATES EXHAUSTION SIGNATURES WITH METABOLIC AND PROLIFERATIVE PATHWAYS. THE EXTENSIVE DIFFERENCES IN THE EPIGENOMIC LANDSCAPE BETWEEN LOW-DOSE AND HIGH-DOSE CONDITIONS SUGGEST THE IMPORTANCE OF EPIGENETIC REGULATIONS IN DRIVING DIFFERENTIAL RESPONSES. OUR DATA PROVIDE POTENTIAL TARGETS FOR FUTURE MECHANISTIC OR THERAPEUTIC STUDIES. 2022 6 5872 27 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 7 5223 53 PRIMARY MURINE CD4+ T CELLS FAIL TO ACQUIRE THE ABILITY TO PRODUCE EFFECTOR CYTOKINES WHEN ACTIVE RAS IS PRESENT DURING TH1/TH2 DIFFERENTIATION. CONSTITUTIVE RAS SIGNALING HAS BEEN SHOWN TO AUGMENT IL-2 PRODUCTION, REVERSE ANERGY, AND FUNCTIONALLY REPLACE MANY ASPECTS OF CD28 CO-STIMULATION IN CD4+ T CELLS. THESE DATA RAISE THE POSSIBILITY THAT INTRODUCTION OF ACTIVE RAS INTO PRIMARY T CELLS MIGHT RESULT IN IMPROVED FUNCTIONALITY IN PATHOLOGIC SITUATIONS OF T CELL DYSFUNCTION, SUCH AS CANCER OR CHRONIC VIRAL INFECTION. TO TEST THE BIOLOGIC EFFECTS OF ACTIVE RAS IN PRIMARY T CELLS, CD4+ T CELLS FROM COXSACKIE-ADENOVIRUS RECEPTOR TRANSGENIC MICE WERE TRANSDUCED WITH AN ADENOVIRUS ENCODING ACTIVE RAS. AS EXPECTED, ACTIVE RAS AUGMENTED IL-2 PRODUCTION IN NAIVE CD4+ T CELLS. HOWEVER, WHEN CELLS WERE CULTURED FOR 4 DAYS UNDER CONDITIONS TO PROMOTE EFFECTOR CELL DIFFERENTIATION, ACTIVE RAS INHIBITED THE ABILITY OF CD4+ T CELLS TO ACQUIRE A TH1 OR TH2 EFFECTOR CYTOKINE PROFILE. THIS DIFFERENTIATION DEFECT WAS NOT DUE TO DEFICIENT STAT4 OR STAT6 ACTIVATION BY IL-12 OR IL-4, RESPECTIVELY, NOR WAS IT ASSOCIATED WITH DEFICIENT INDUCTION OF T-BET AND GATA-3 EXPRESSION. IMPAIRED EFFECTOR CYTOKINE PRODUCTION IN ACTIVE RAS-TRANSDUCED CELLS WAS ASSOCIATED WITH DEFICIENT DEMETHYLATION OF THE IL-4 GENE LOCUS. OUR RESULTS INDICATE THAT, DESPITE AUGMENTING ACUTE ACTIVATION OF NAIVE T CELLS, CONSTITUTIVE RAS SIGNALING INHIBITS THE ABILITY OF CD4+ T CELLS TO PROPERLY DIFFERENTIATE INTO TH1/TH2 EFFECTOR CYTOKINE-PRODUCING CELLS, IN PART BY INTERFERING WITH EPIGENETIC MODIFICATION OF EFFECTOR GENE LOCI. ALTERNATIVE STRATEGIES TO POTENTIATE RAS PATHWAY SIGNALING IN T CELLS IN A MORE REGULATED FASHION SHOULD BE CONSIDERED AS A THERAPEUTIC APPROACH TO IMPROVE IMMUNE RESPONSES IN VIVO. 2014 8 2026 34 EPIGENETIC CHANGES IN BONE MARROW PROGENITOR CELLS INFLUENCE THE INFLAMMATORY PHENOTYPE AND ALTER WOUND HEALING IN TYPE 2 DIABETES. CLASSICALLY ACTIVATED (M1) MACROPHAGES ARE KNOWN TO PLAY A ROLE IN THE DEVELOPMENT OF CHRONIC INFLAMMATION ASSOCIATED WITH IMPAIRED WOUND HEALING IN TYPE 2 DIABETES (T2D); HOWEVER, THE MECHANISM RESPONSIBLE FOR THE DOMINANT PROINFLAMMATORY (M1) MACROPHAGE PHENOTYPE IN T2D WOUNDS IS UNKNOWN. SINCE EPIGENETIC ENZYMES CAN DIRECT MACROPHAGE PHENOTYPES, WE ASSESSED THE ROLE OF HISTONE METHYLATION IN BONE MARROW (BM) STEM/PROGENITOR CELLS IN THE PROGRAMMING OF MACROPHAGES TOWARD A PROINFLAMMATORY PHENOTYPE. WE HAVE FOUND THAT A REPRESSIVE HISTONE METHYLATION MARK, H3K27ME3, IS DECREASED AT THE PROMOTER OF THE IL-12 GENE IN BM PROGENITORS AND THIS EPIGENETIC SIGNATURE IS PASSED DOWN TO WOUND MACROPHAGES IN A MURINE MODEL OF GLUCOSE INTOLERANCE (DIET-INDUCED OBESE). THESE EPIGENETICALLY "PREPROGRAMMED" MACROPHAGES RESULT IN POISED MACROPHAGES IN PERIPHERAL TISSUE AND NEGATIVELY IMPACT WOUND REPAIR. WE FOUND THAT IN DIABETIC CONDITIONS THE H3K27 DEMETHYLASE JMJD3 DRIVES IL-12 PRODUCTION IN MACROPHAGES AND THAT IL-12 PRODUCTION CAN BE MODULATED BY INHIBITING JMJD3. USING HUMAN T2D TISSUE AND MURINE MODELS, WE HAVE IDENTIFIED A PREVIOUSLY UNRECOGNIZED MECHANISM BY WHICH MACROPHAGES ARE PROGRAMMED TOWARD A PROINFLAMMATORY PHENOTYPE, ESTABLISHING A PATTERN OF UNRESTRAINED INFLAMMATION ASSOCIATED WITH NONHEALING WOUNDS. HENCE, HISTONE DEMETHYLASE INHIBITOR-BASED THERAPY MAY REPRESENT A NOVEL TREATMENT OPTION FOR DIABETIC WOUNDS. 2015 9 6535 39 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 10 2389 45 EPIGENETIC REPOLARIZATION OF T LYMPHOCYTES FROM CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS USING 5-AZA-2'-DEOXYCYTIDINE. T CELL IMMUNE DYSFUNCTION HAS AN IMPORTANT ROLE IN THE PROFOUND IMMUNE SUPPRESSION THAT CHARACTERIZES CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). IMPROPER POLARIZATION OF T CELLS HAS BEEN PROPOSED AS ONE OF THE MECHANISM INVOLVED. MOUNTING DATA IMPLICATES CHROMATIN REGULATION, NAMELY PROMOTER METHYLATION, IN THE PLASTICITY OF NAIVE HUMAN T CELLS. RECENT IN VITRO EVIDENCE INDICATES THAT THIS PLASTICITY MAY BE PHENOTYPICALLY ALTERED BY USING METHYLATION INHIBITORS WHICH ARE APPROVED FOR CLINICAL USE IN CERTAIN TYPES OF CANCER. THESE RESULTS BEG THE QUESTION: CAN THE INEFFECTIVE POLARIZATION OF T LYMPHOCYTES IN THE CONTEXT OF CLL BE EFFECTIVELY MODULATED USING METHYLATION INHIBITORS IN A SUSTAINABLE THERAPEUTIC FASHION? TO ANSWER THIS QUESTION OUR LABORATORY HAS STUDIED THE EFFECTS OF 5-AZA-2'-DEOXYCYTIDINE (5A2) IN HELPER AND CYTOTOXIC T LYMPHOCYTES FROM HEALTHY DONORS AND CLL PATIENTS IN WELL CHARACTERIZED MOLECULAR AND EPIGENETIC SIGNALING PATHWAYS INVOLVED IN EFFECTIVE POLARIZATION. MOREOVER, WE SOUGHT TO INVESTIGATE THE CONSEQUENCES OF METHYLATION INHIBITOR TREATMENT ON LYMPHOCYTE SURVIVAL, ACTIVATION INTENSITY, AND NAIVE CELL POLARIZATION. OUR DATA INDICATES THAT 5A2 TREATMENT CAN DEPOLARIZE TH2 CELLS TO EFFECTIVELY SECRETE INTERFERON GAMMA, SIGNAL VIA T-BET, AND ACHIEVE DEMETHYLATION OF CRITICAL TH1 SPECIFIC PROMOTERS. MOREOVER, WE DEMONSTRATE THAT 5A2 CAN FORCE TH1 POLARIZATION OF NAIVE T CELLS DESPITE A STRONG IL-4 STIMULI AND A LACK OF IL-12. IN CONCLUSION OUR DATA SEEKS TO DEFINE A MODALITY IN WHICH IMPROPER OR INEFFECTIVE T CELL POLARIZATION CAN BE ALTERED BY 5AZA AND COULD BE INCORPORATED IN FUTURE THERAPEUTIC INTERVENTIONS. 2011 11 5431 32 REGULATORY T CELLS: PATHOPHYSIOLOGICAL ROLES AND CLINICAL APPLICATIONS. INFLAMMATION AND IMMUNE RESPONSES AFTER TISSUE INJURY PLAY PIVOTAL ROLES IN THE RESOLUTION OF INFLAMMATION, TISSUE RECOVERY, FIBROSIS, AND REMODELING. REGULATORY T CELLS (TREGS) ARE RESPONSIBLE FOR IMMUNE TOLERANCE AND ARE USUALLY ACTIVATED IN SECONDARY LYMPHATIC TISSUES. ACTIVATED TREGS SUBSEQUENTLY REGULATE EFFECTOR T CELL AND DENDRITIC CELL ACTIVATION. FOR CLINICAL APPLICATIONS SUCH AS THE SUPPRESSION OF BOTH AUTOIMMUNE DISEASES AND THE REJECTION OF TRANSPLANTED ORGANS, METHODS TO GENERATE STABILIZED ANTIGEN-SPECIFIC TREGS ARE REQUIRED. FOR THIS PURPOSE, TRANSCRIPTIONAL AND EPIGENETIC REGULATION OF FOXP3 EXPRESSION HAS BEEN INVESTIGATED. IN ADDITION TO CONVENTIONAL TREGS, THERE ARE SOME TREGS THAT RESIDE IN TISSUES AND ARE CALLED TISSUE TREGS. TISSUE TREGS EXHIBIT TISSUE-SPECIFIC FUNCTIONS THAT CONTRIBUTE TO THE MAINTENANCE OF TISSUE HOMEOSTASIS AND REPAIR. SUCH TISSUE TREGS COULD ALSO BE USEFUL FOR TREG-BASED CELL THERAPY. WE RECENTLY DISCOVERED BRAIN TREGS THAT ACCUMULATE IN THE BRAIN DURING THE CHRONIC PHASE OF ISCHEMIC BRAIN INJURY. BRAIN TREGS RESEMBLE OTHER TISSUE TREGS, BUT ARE UNIQUE IN EXPRESSING NEURAL CELL-SPECIFIC GENES SUCH AS THE SEROTONIN RECEPTOR (HTR7); CONSEQUENTLY, BRAIN TREGS RESPOND TO SEROTONIN. HERE, WE DESCRIBE OUR EXPERIENCES IN THE USE OF TREGS TO SUPPRESS GRAFT-VERSUS-HOST DISEASE AND TO PROMOTE NEURAL RECOVERY AFTER STROKE. 2020 12 6764 46 ZINC DEFICIENCY ENHANCED INFLAMMATORY RESPONSE BY INCREASING IMMUNE CELL ACTIVATION AND INDUCING IL6 PROMOTER DEMETHYLATION. SCOPE: ZINC DEFICIENCY RESULTS IN IMMUNE DYSFUNCTION AND PROMOTES SYSTEMIC INFLAMMATION. THE OBJECTIVE OF THIS STUDY WAS TO EXAMINE THE EFFECTS OF ZINC DEFICIENCY ON CELLULAR IMMUNE ACTIVATION AND EPIGENETIC MECHANISMS THAT PROMOTE INFLAMMATION. THIS WORK IS POTENTIALLY RELEVANT TO THE AGING POPULATION GIVEN THAT AGE-RELATED IMMUNE DEFECTS, INCLUDING CHRONIC INFLAMMATION, COINCIDE WITH DECLINING ZINC STATUS. METHODS AND RESULTS: AN IN VITRO CELL CULTURE SYSTEM AND THE AGED MOUSE MODEL WERE USED TO CHARACTERIZE IMMUNE ACTIVATION AND DNA METHYLATION PROFILES THAT MAY CONTRIBUTE TO THE ENHANCED PROINFLAMMATORY RESPONSE MEDIATED BY ZINC DEFICIENCY. ZINC DEFICIENCY UPREGULATED CELL ACTIVATION MARKERS ICAM1, MHC CLASS II, AND CD86 IN THP1 CELLS, WHICH COINCIDED WITH INCREASED IL1BETA AND IL6 RESPONSES FOLLOWING LPS STIMULATION. A DECREASED ZINC STATUS IN AGED MICE WAS SIMILARLY ASSOCIATED WITH INCREASED ICAM1 AND IL6 GENE EXPRESSION. REDUCED IL6 PROMOTER METHYLATION WAS OBSERVED IN ZINC-DEFICIENT THP1 CELLS, AS WELL AS IN AGED MICE AND HUMAN LYMPHOBLASTOID CELL LINES DERIVED FROM AGED INDIVIDUALS. CONCLUSION: ZINC DEFICIENCY INDUCED INFLAMMATORY RESPONSE IN PART BY ELICITING ABERRANT IMMUNE CELL ACTIVATION AND ALTERED PROMOTER METHYLATION. OUR RESULTS SUGGESTED POTENTIAL INTERACTIONS BETWEEN ZINC STATUS, EPIGENETICS, AND IMMUNE FUNCTION, AND HOW THEIR DYSREGULATION COULD CONTRIBUTE TO CHRONIC INFLAMMATION. 2015 13 5415 35 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 14 2228 32 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 15 6293 36 THE PRO- AND ANTI-INFLAMMATORY POTENTIAL OF IL-12: THE DUAL ROLE OF TH1 CELLS. THE DIFFERENTIATION OF T-HELPER (TH) LYMPHOCYTES INTO VARIOUS TYPES OF T-HELPER EFFECTOR AND MEMORY CELLS WITH DISTINCT FUNCTIONS DEPENDING ON THE TYPE OF CONCOMITANT SIGNALS THEY RECEIVE UPON ACTIVATION IS A CRITICAL EVENT DETERMINING THE COURSE OF AN IMMUNE REACTION. TH1 CELLS CHARACTERIZED BY THE EXPRESSION OF IFN-GAMMA AND THE RECENTLY DESCRIBED TH17 CELLS PROMOTE INFLAMMATION AND ARE CRITICALLY INVOLVED IN THE INDUCTION AND MAINTENANCE OF AUTOIMMUNITY, WHEREAS THE SECRETION OF IL-4 IS A HALLMARK OF TH2 CELLS MEDIATING PROTECTION FROM PARASITES AND ALLERGY. ORIGINAL STIMULATION IN THE PRESENCE OF IL-12 RESULTS IN THE IMPRINTING OF TH1 MEMORY CELLS FOR THE EXPRESSION OF IFN-GAMMA BY EXPRESSION OF THE TRANSCRIPTION FACTOR T-BET AND EPIGENETIC MODIFICATION OF THE IFNGAMMA GENE. IT HAS BEEN DEMONSTRATED THAT TH1 CELLS ARE POTENT INDUCERS OF INFLAMMATION. HOWEVER, IN THE CHRONIC PHASE OF SUCH INFLAMMATION, THE REGULATORY POTENTIAL OF IL-12 AND TH1 CELLS THEMSELVES MAY PLAY AN IMPORTANT ROLE IN LIMITING IMMUNOPATHOLOGY. 2007 16 1479 30 DIVERSE TARGETS OF THE TRANSCRIPTION FACTOR STAT3 CONTRIBUTE TO T CELL PATHOGENICITY AND HOMEOSTASIS. STAT3, AN ESSENTIAL TRANSCRIPTION FACTOR WITH PLEIOTROPIC FUNCTIONS, PLAYS CRITICAL ROLES IN THE PATHOGENESIS OF AUTOIMMUNITY. DESPITE RECENT DATA LINKING STAT3 WITH INFLAMMATORY BOWEL DISEASE, EXACTLY HOW IT CONTRIBUTES TO CHRONIC INTESTINAL INFLAMMATION IS NOT KNOWN. USING A T CELL TRANSFER MODEL OF COLITIS, WE FOUND THAT STAT3 EXPRESSION IN T CELLS WAS ESSENTIAL FOR THE INDUCTION OF BOTH COLITIS AND SYSTEMIC INFLAMMATION. STAT3 WAS CRITICAL IN MODULATING THE BALANCE OF T HELPER 17 (TH17) AND REGULATORY T (TREG) CELLS, AS WELL AS IN PROMOTING CD4(+) T CELL PROLIFERATION. WE USED CHROMATIN IMMUNOPRECIPITATION AND MASSIVE PARALLEL SEQUENCING (CHIP-SEQ) TO DEFINE THE GENOME-WIDE TARGETS OF STAT3 IN CD4(+) T CELLS. WE FOUND THAT STAT3 BOUND TO MULTIPLE GENES INVOLVED IN TH17 CELL DIFFERENTIATION, CELL ACTIVATION, PROLIFERATION, AND SURVIVAL, REGULATING BOTH EXPRESSION AND EPIGENETIC MODIFICATIONS. THUS, STAT3 ORCHESTRATES MULTIPLE CRITICAL ASPECTS OF T CELL FUNCTION IN INFLAMMATION AND HOMEOSTASIS. 2010 17 4510 53 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 18 5592 36 ROLE OF TUMOR NECROSIS FACTOR-ALPHA IN THE HUMAN SYSTEMIC ENDOTOXIN-INDUCED TRANSCRIPTOME. TNFALPHA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES. DIFFERENT STRATEGIES TO INHIBIT TNFALPHA IN PATIENTS WITH SEPSIS AND CHRONIC INFLAMMATORY CONDITIONS HAVE SHOWN CONTRASTING OUTCOMES. ALTHOUGH TNFALPHA INHIBITORS ARE WIDELY USED IN CLINICAL PRACTICE, THE IMPACT OF TNFALPHA ANTAGONISM ON WHITE BLOOD CELL GENE EXPRESSION PROFILES DURING ACUTE INFLAMMATION IN HUMANS IN VIVO HAS NOT BEEN ASSESSED. WE HERE LEVERAGED THE ESTABLISHED MODEL OF HUMAN ENDOTOXEMIA TO EXAMINE THE EFFECT OF THE TNFALPHA ANTAGONIST, ETANERCEPT, ON THE GENOME-WIDE TRANSCRIPTIONAL RESPONSES IN CIRCULATING LEUKOCYTES INDUCED BY INTRAVENOUS LPS ADMINISTRATION IN MALE SUBJECTS. ETANERCEPT PRE-TREATMENT RESULTED IN A MARKEDLY DAMPENED TRANSCRIPTIONAL RESPONSE TO LPS. GENE CO-EXPRESSION NETWORK ANALYSIS REVEALED THIS LPS-INDUCED TRANSCRIPTOME CAN BE CATEGORIZED AS TNFALPHA RESPONSIVE AND NON-RESPONSIVE MODULES. HIGHLY SIGNIFICANT TNFALPHA RESPONSIVE MODULES INCLUDE NF-KB SIGNALING, ANTIVIRAL RESPONSES AND T-CELL MEDIATED RESPONSES. WITHIN THESE TNFALPHA RESPONSIVE MODULES WE DELINEATE FUNDAMENTAL GENES INVOLVED IN EPIGENETIC MODIFICATIONS, TRANSCRIPTIONAL INITIATION AND ELONGATION. THUS, WE PROVIDE COMPREHENSIVE INFORMATION ABOUT MOLECULAR PATHWAYS THAT MIGHT BE TARGETED BY THERAPEUTIC INTERVENTIONS THAT SEEK TO INHIBIT TNFALPHA ACTIVITY DURING HUMAN INFLAMMATORY DISEASES. 2013 19 6520 50 TRANSCRIPTIONAL AND EPIGENETIC REGULATION OF MONOCYTE AND MACROPHAGE DYSFUNCTION BY CHRONIC ALCOHOL CONSUMPTION. DRINKING ALCOHOL, EVEN IN MODERATION, CAN AFFECT THE IMMUNE SYSTEM. STUDIES HAVE SHOWN DISPROPORTIONATE EFFECTS OF ALCOHOL ON CIRCULATING AND TISSUE-RESIDENT MYELOID CELLS (GRANULOCYTES, MONOCYTES, MACROPHAGES, DENDRITIC CELLS). THESE CELLS ORCHESTRATE THE BODY'S FIRST LINE OF DEFENSE AGAINST MICROBIAL CHALLENGES AS WELL AS MAINTAIN TISSUE HOMEOSTASIS AND REPAIR. ALCOHOL'S EFFECTS ON THESE CELLS ARE DEPENDENT ON EXPOSURE PATTERN, WITH ACUTE DRINKING DAMPENING BUT CHRONIC DRINKING ENHANCING PRODUCTION OF INFLAMMATORY MEDIATORS. ALTHOUGH CHRONIC DRINKING IS ASSOCIATED WITH HEIGHTENED SYSTEMIC INFLAMMATION, STUDIES ON TISSUE RESIDENT MACROPHAGE POPULATIONS IN SEVERAL ORGANS INCLUDING THE SPLEEN, LIVER, BRAIN, AND LUNG HAVE ALSO SHOWN COMPROMISED FUNCTIONAL AND METABOLIC CAPACITIES OF THESE CELLS. MANY OF THESE EFFECTS ARE THOUGHT TO BE MEDIATED BY OXIDATIVE STRESS CAUSED BY ALCOHOL AND ITS METABOLITES WHICH CAN DIRECTLY IMPACT THE CELLULAR EPIGENETIC LANDSCAPES. IN ADDITION, SINCE MYELOID CELLS ARE RELATIVELY SHORT-LIVED IN CIRCULATION AND ARE UNDER CONSTANT REPOPULATION FROM THE BONE MARROW COMPARTMENT, ALCOHOL'S EFFECTS ON BONE MARROW PROGENITORS AND HEMATOPOIESIS ARE IMPORTANT FOR UNDERSTANDING THE IMPACT OF ALCOHOL SYSTEMICALLY ON THESE MYELOID POPULATIONS. ALCOHOL-INDUCED DISRUPTION OF PROGENITOR, CIRCULATING, AND TISSUE RESIDENT MYELOID POPULATIONS CONTRIBUTE TO THE INCREASED SUSCEPTIBILITY OF PATIENTS WITH ALCOHOL USE DISORDERS TO VIRAL AND BACTERIAL INFECTIONS. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF THE IMPACT OF CHRONIC ALCOHOL CONSUMPTION ON THE FUNCTION OF MONOCYTES AND MACROPHAGES IN HOST DEFENSE, TISSUE REPAIR AND INFLAMMATION. WE THEN SUMMARIZE OUR CURRENT UNDERSTANDING OF THE MECHANISMS UNDERLYING ALCOHOL-INDUCED DISRUPTION AND EXAMINE CHANGES IN TRANSCRIPTOME AND EPIGENOME OF MONOCYTES AND MCROPHAGES. OVERALL, CHRONIC ALCOHOL CONSUMPTION LEADS TO HYPER-INFLAMMATION CONCOMITANT WITH DECREASED MICROBIAL AND WOUND HEALING RESPONSES BY MONOCYTES/MACROPHAGES DUE TO A REWIRING OF THE EPIGENTIC AND TRANSCRIPTIONAL LANDSCAPE. HOWEVER, IN ADVANCED ALCOHOLIC LIVER DISEASE, MYELOID CELLS BECOME IMMUNOSUPPRESSED AS A RESPONSE TO THE SURROUNDING HYPER-INFLAMMATORY MILIEU. THEREFORE, THE EFFECT OF CHRONIC ALCOHOL ON THE INFLAMMATORY RESPONSE DEPENDS ON DISEASE STATE AND THE IMMUNE CELL POPULATION. 2022 20 331 38 ALTERATION IN MITOCHONDRIAL DYNAMICS PROMOTES THE PROINFLAMMATORY RESPONSE OF MICROGLIA AND IS INVOLVED IN CEREBELLAR DYSFUNCTION OF YOUNG AND AGED MICE FOLLOWING LPS EXPOSURE. CEREBELLAR DYSFUNCTION IS IMPLICATED IN IMPAIRED MOTOR COORDINATION AND BALANCE, THUS DISTURBING THE DYNAMICS OF SENSORIMOTOR INTEGRATION. NEUROINFLAMMATION AND AGING COULD BE PROMINENT CONTRIBUTORS TO CEREBELLAR ABERRATION. ADDITIONALLY, CHANGES IN MITOCHONDRIAL DYNAMICS MAY PRECEDE MICROGLIA ACTIVATION IN SEVERAL CHRONIC NEURODEGENERATIVE DISEASES; HOWEVER, THE UNDERLYING MECHANISM REMAINS LARGELY UNKNOWN. HERE USING LPS (1 MG/KG I.P. FOR FOUR CONSECUTIVE DAYS) STIMULATION IN BOTH YOUNG (3 MONTHS OLD) AND AGED (12 MONTHS OLD) MICE, FOLLOWED BY MOLECULAR ANALYSIS ON THE 21ST DAY, WE HAVE EXPLORED THE CORRELATION BETWEEN AGING AND MITOCHONDRIAL DYNAMIC ALTERATION IN THE BACKDROP OF CHRONIC NEUROINFLAMMATION. FOLLOWING LPS STIMULATION, WE OBSERVED MICROGLIA ACTIVATION AND SUBSEQUENT ELEVATION IN PROINFLAMMATORY CYTOKINES (M1; TNF-ALPHA, IFN-GAMMA) WITH NLRP3 ACTIVATION AND A CONCOMITANT REDUCTION IN THE EXPRESSION OF ANTI-INFLAMMATORY MARKERS (M2; YM1, TGF-BETA1) IN THE CEREBELLAR TISSUE OF AGED MICE COMPARED WITH THE YOUNG LPS AND AGED CONTROLS. REMARKABLY, SENESCENCE (P21, P27, P53) AND EPIGENETIC (HDAC2) MARKERS WERE FOUND UPREGULATED IN THE CEREBELLUM TISSUE OF THE AGED LPS GROUP, SUGGESTING THEIR CRUCIAL ROLE IN LPS-INDUCED CEREBELLAR DEFICIT. FURTHER, WE DEMONSTRATED ALTERATION IN THE ANTAGONISTIC FORCES OF MITOCHONDRIAL FUSION AND FISSION WITH INCREASED EXPRESSION OF THE MITOCHONDRIAL FISSION-RELATED GENE [FIS1] AND DECREASED FUSION-RELATED GENES [MFN1 AND MFN2]. WE NOTED INCREASED MTDNA COPY NUMBER, MICROGLIA ACTIVATION, AND INFLAMMATORY RESPONSE OF IL1-BETA AND IFN-GAMMA POST-CHRONIC NEUROINFLAMMATION IN AGED LPS GROUP. OUR RESULTS SUGGEST THAT THE CROSSTALK BETWEEN MITOCHONDRIAL DYNAMICS AND ALTERED MICROGLIAL ACTIVATION PARADIGM IN CHRONIC NEUROINFLAMMATORY CONDITIONS MAY BE THE KEY TO UNDERSTANDING THE CEREBELLAR MOLECULAR MECHANISM. 2023