1 3778 145 INTERFERING WITH ALTERNATIVELY ACTIVATED MACROPHAGES BY CSF-1R INHIBITION EXERTS THERAPEUTIC CAPACITY ON ALLERGIC AIRWAY INFLAMMATION. PURPOSE: ALLERGIC ASTHMA IS A CHRONIC INFLAMMATORY DISORDER WITH AIRWAY HYPERRESPONSIVENESS AND TISSUE REMODELING AS THE MAIN PATHOLOGICAL CHARACTERISTICS. THE ETIOLOGY OF ASTHMA IS RELATIVELY COMPLICATED, INVOLVING GENETIC SUSCEPTIBILITY, EPIGENETIC REGULATION, ENVIRONMENTAL FACTORS, AND IMMUNE IMBALANCE. COLONY STIMULATING FACTOR 1 RECEPTOR (CSF-1R), HIGHLY EXPRESSED IN MYELOID MONOCYTES, PLAYS AN IMPORTANT ROLE IN REGULATING INFLAMMATION. HOWEVER, THE PATHOLOGICAL ROLE OF CSF-1R AND THE THERAPEUTIC EFFECTS OF CSF-1R INHIBITOR IN ALLERGIC AIRWAY INFLAMMATION REMAIN INDISTINCT. METHODS: THE HOUSE DUST MITE (HDM)-TRIGGERED ALLERGIC AIRWAY INFLAMMATION MODEL WAS CONDUCTED TO FULLY UNCOVER THE EFFICACIES OF CSF-1R INHIBITION, AS ILLUSTRATED BY HISTOPATHOLOGICAL EXAMINATIONS, BIOCHEMICAL ANALYSIS, ELISA, RT-PCR, WESTERN BLOTTING ASSAY, IMMUNOFLUORESCENCE, AND FLOW CYTOMETRY. FURTHERMORE, BONE MARROW-DERIVED MACROPHAGES (BMDMS) WERE DIFFERENTIATED AND POLARIZED UPON IL-4/IL-13 INDUCTION TO CLARIFY THE UNDERLYING MECHANISMS OF CSF-1R INHIBITION. RESULTS: HEREIN, WE PRESENTED THAT THE EXPRESSION OF CSF-1R WAS INCREASED IN HDM-INDUCED EXPERIMENTAL ASTHMA AND INHIBITION OF CSF-1R DISPLAYED DRAMATIC EFFECTS ON THE DISEASE SEVERITY OF ASTHMA, REFERRING TO SUPPRESSING THE SECRETION OF ALLERGIC MEDIATORS, DYSFUNCTION OF AIRWAY EPITHELIUM, AND INFILTRATION OF INFLAMMATORY CELLS. FURTHERMORE, CSF-1R INHIBITOR COULD MARKEDLY RESTRAIN THE POLARIZATION AND EXPRESSION OF TRANSCRIPTIONAL FACTORS OF ALTERNATIVELY ACTIVATED MACROPHAGES (AAMS) IN THE PRESENCE OF IL-4/IL-13 AND REDUCE THE RECRUITMENT OF CSF-1R-DOMINANT MACROPHAGES, BOTH IN ACUTE AND CHRONIC ALLERGIC AIRWAY INFLAMMATION MODEL. CONCLUSION: COLLECTIVELY, OUR FINDINGS DEMONSTRATED THE MOLECULAR PATHOLOGICAL MECHANISM OF CSF-1R IN ALLERGIC AIRWAY DISEASES AND SUGGESTED THAT TARGETING CSF-1R MIGHT BE AN ALTERNATIVE INTERVENTION STRATEGY ON THE HOMEOSTASIS OF AIRWAY IMMUNE MICROENVIRONMENT IN ASTHMA. 2022 2 4042 45 MACROPHAGES ACQUIRE A TNF-DEPENDENT INFLAMMATORY MEMORY IN ALLERGIC ASTHMA. BACKGROUND: INFECTIOUS AGENTS CAN REPROGRAM OR "TRAIN" MACROPHAGES AND THEIR PROGENITORS TO RESPOND MORE READILY TO SUBSEQUENT INSULTS. HOWEVER, WHETHER SUCH AN INFLAMMATORY MEMORY EXISTS IN TYPE 2 INFLAMMATORY CONDITIONS SUCH AS ALLERGIC ASTHMA WAS NOT KNOWN. OBJECTIVE: WE SOUGHT TO DECIPHER MACROPHAGE-TRAINED IMMUNITY IN ALLERGIC ASTHMA. METHODS: WE USED A COMBINATION OF CLINICAL SAMPLING OF HOUSE DUST MITE (HDM)-ALLERGIC PATIENTS, HDM-INDUCED ALLERGIC AIRWAY INFLAMMATION IN MICE, AND AN IN VITRO TRAINING SETUP TO ANALYZE PERSISTENT CHANGES IN MACROPHAGE EICOSANOID, CYTOKINE, AND CHEMOKINE PRODUCTION AS WELL AS THE UNDERLYING METABOLIC AND EPIGENETIC MECHANISMS. TRANSCRIPTIONAL AND METABOLIC PROFILES OF PATIENT-DERIVED AND IN VITRO TRAINED MACROPHAGES WERE ASSESSED BY RNA SEQUENCING OR METABOLIC FLUX ANALYSIS AND LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY ANALYSIS, RESPECTIVELY. RESULTS: WE FOUND THAT MACROPHAGES DIFFERENTIATED FROM BONE MARROW OR BLOOD MONOCYTE PROGENITORS OF HDM-ALLERGIC MICE OR ASTHMA PATIENTS SHOW INFLAMMATORY TRANSCRIPTIONAL REPROGRAMMING AND EXCESSIVE MEDIATOR (TNF-ALPHA, CCL17, LEUKOTRIENE, PGE(2), IL-6) RESPONSES UPON STIMULATION. MACROPHAGES FROM HDM-ALLERGIC MICE INITIALLY EXHIBITED A TYPE 2 IMPRINT, WHICH SHIFTED TOWARD A CLASSICAL INFLAMMATORY TRAINING OVER TIME. HDM-INDUCED ALLERGIC AIRWAY INFLAMMATION ELICITED A METABOLICALLY ACTIVATED MACROPHAGE PHENOTYPE, PRODUCING HIGH AMOUNTS OF 2-HYDROXYGLUTARATE (2-HG). HDM-INDUCED MACROPHAGE TRAINING IN VITRO WAS MEDIATED BY A FORMYL PEPTIDE RECEPTOR 2-TNF-2-HG-PGE(2)/PGE(2) RECEPTOR 2 AXIS, RESULTING IN AN M2-LIKE MACROPHAGE PHENOTYPE WITH HIGH CCL17 PRODUCTION. TNF BLOCKADE BY ETANERCEPT OR GENETIC ABLATION OF TNF IN MYELOID CELLS PREVENTED THE INFLAMMATORY IMPRINTING OF BONE MARROW-DERIVED MACROPHAGES FROM HDM-ALLERGIC MICE. CONCLUSION: ALLERGEN-TRIGGERED INFLAMMATION DRIVES A TNF-DEPENDENT INNATE MEMORY, WHICH MAY PERPETUATE AND EXACERBATE CHRONIC TYPE 2 AIRWAY INFLAMMATION AND THUS REPRESENTS A TARGET FOR ASTHMA THERAPY. 2022 3 5153 31 PPP2R2B HYPERMETHYLATION CAUSES ACQUIRED APOPTOSIS DEFICIENCY IN SYSTEMIC AUTOIMMUNE DISEASES. CHRONIC INFLAMMATION CAUSES TARGET ORGAN DAMAGE IN PATIENTS WITH SYSTEMIC AUTOIMMUNE DISEASES. THE FACTORS THAT ALLOW THIS PROTRACTED RESPONSE ARE POORLY UNDERSTOOD. WE ANALYZED THE TRANSCRIPTIONAL REGULATION OF PPP2R2B (B55SS), A MOLECULE NECESSARY FOR THE TERMINATION OF THE IMMUNE RESPONSE, IN PATIENTS WITH AUTOIMMUNE DISEASES. ALTERED EXPRESSION OF B55SS CONDITIONED RESISTANCE TO CYTOKINE WITHDRAWAL-INDUCED DEATH (CWID) IN PATIENTS WITH AUTOIMMUNE DISEASES. THE IMPAIRED UPREGULATION OF B55SS WAS CAUSED BY INFLAMMATION-DRIVEN HYPERMETHYLATION OF SPECIFIC CYTOSINES LOCATED WITHIN A REGULATORY ELEMENT OF PPP2R2B PREVENTING CTCF BINDING. THIS PHENOTYPE COULD BE INDUCED IN HEALTHY T CELLS BY EXPOSURE TO TNF-ALPHA. OUR RESULTS REVEAL A GENE WHOSE EXPRESSION IS AFFECTED BY AN ACQUIRED DEFECT, THROUGH AN EPIGENETIC MECHANISM, IN THE SETTING OF SYSTEMIC AUTOIMMUNITY. BECAUSE FAILURE TO REMOVE ACTIVATED T CELLS THROUGH CWID COULD CONTRIBUTE TO AUTOIMMUNE PATHOLOGY, THIS MECHANISM ILLUSTRATES A VICIOUS CYCLE THROUGH WHICH AUTOIMMUNE INFLAMMATION CONTRIBUTES TO ITS OWN PERPETUATION. 2019 4 6578 38 TREATMENT WITH TRICHURIS SUIS SOLUBLE PRODUCTS DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION REDUCES INFLAMMATORY RESPONSES THROUGH EPIGENETIC REMODELING. HELMINTHS HAVE STRONG IMMUNOREGULATORY PROPERTIES THAT MAY BE EXPLOITED IN TREATMENT OF CHRONIC IMMUNE DISORDERS, SUCH AS MULTIPLE SCLEROSIS AND INFLAMMATORY BOWEL DISEASE. ESSENTIAL PLAYERS IN THE PATHOGENESIS OF THESE DISEASES ARE PROINFLAMMATORY MACROPHAGES. WE PRESENT EVIDENCE THAT HELMINTHS MODULATE THE FUNCTION AND PHENOTYPE OF THESE INNATE IMMUNE CELLS. WE FOUND THAT SOLUBLE PRODUCTS DERIVED FROM THE TRICHURIS SUIS (TSSP) SIGNIFICANTLY AFFECT THE DIFFERENTIATION OF MONOCYTES INTO MACROPHAGES AND THEIR SUBSEQUENT POLARIZATION. TSSPS REDUCE THE EXPRESSION AND PRODUCTION OF INFLAMMATORY CYTOKINES, INCLUDING IL-6 AND TNF, IN HUMAN PROINFLAMMATORY M1 MACROPHAGES. TSSPS INDUCE A CONCOMITANT ANTI-INFLAMMATORY M2 SIGNATURE, WITH INCREASED IL-10 PRODUCTION. FURTHERMORE, THEY SUPPRESS CHIT ACTIVITY AND ENHANCE SECRETION OF MATRIX METALLOPROTEINASE 9. SHORT-TERM TRIGGERING OF MONOCYTES WITH TSSPS EARLY DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION IMPRINTED THESE PHENOTYPIC ALTERATIONS, SUGGESTING LONG-LASTING EPIGENETIC CHANGES. THE TSSP-INDUCED EFFECTS IN M1 MACROPHAGES WERE COMPLETELY REVERSED BY INHIBITING HISTONE DEACETYLASES, WHICH CORRESPONDED WITH DECREASED HISTONE ACETYLATION AT THE TNF AND IL6 PROMOTERS. THESE RESULTS DEMONSTRATE THAT TSSPS HAVE A POTENT AND SUSTAINED IMMUNOMODULATORY EFFECT ON HUMAN MACROPHAGE DIFFERENTIATION AND POLARIZATION THROUGH EPIGENETIC REMODELING AND PROVIDE NEW INSIGHTS INTO THE MECHANISMS BY WHICH HELMINTHS MODULATE HUMAN IMMUNE RESPONSES.-HOEKSEMA, M. A., LAAN, L. C., POSTMA, J. J., CUMMINGS, R. D., DE WINTHER, M. P. J., DIJKSTRA, C. D., VAN DIE, I., KOOIJ, G. TREATMENT WITH TRICHURIS SUIS SOLUBLE PRODUCTS DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION REDUCES INFLAMMATORY RESPONSES THROUGH EPIGENETIC REMODELING. 2016 5 984 38 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022 6 5009 33 PERK IS A CRITICAL METABOLIC HUB FOR IMMUNOSUPPRESSIVE FUNCTION IN MACROPHAGES. CHRONIC INFLAMMATION TRIGGERS COMPENSATORY IMMUNOSUPPRESSION TO STOP INFLAMMATION AND MINIMIZE TISSUE DAMAGE. STUDIES HAVE DEMONSTRATED THAT ENDOPLASMIC RETICULUM (ER) STRESS AUGMENTS THE SUPPRESSIVE PHENOTYPES OF IMMUNE CELLS; HOWEVER, THE MOLECULAR MECHANISMS UNDERPINNING THIS PROCESS AND HOW IT LINKS TO THE METABOLIC REPROGRAMMING OF IMMUNOSUPPRESSIVE MACROPHAGES REMAIN ELUSIVE. IN THE PRESENT STUDY, WE REPORT THAT THE HELPER T CELL 2 CYTOKINE INTERLEUKIN-4 AND THE TUMOR MICROENVIRONMENT INCREASE THE ACTIVITY OF A PROTEIN KINASE RNA-LIKE ER KINASE (PERK)-SIGNALING CASCADE IN MACROPHAGES AND PROMOTE IMMUNOSUPPRESSIVE M2 ACTIVATION AND PROLIFERATION. LOSS OF PERK SIGNALING IMPEDED MITOCHONDRIAL RESPIRATION AND LIPID OXIDATION CRITICAL FOR M2 MACROPHAGES. PERK ACTIVATION MEDIATED THE UPREGULATION OF PHOSPHOSERINE AMINOTRANSFERASE 1 (PSAT1) AND SERINE BIOSYNTHESIS VIA THE DOWNSTREAM TRANSCRIPTION FACTOR ATF-4. INCREASED SERINE BIOSYNTHESIS RESULTED IN ENHANCED MITOCHONDRIAL FUNCTION AND ALPHA-KETOGLUTARATE PRODUCTION REQUIRED FOR JMJD3-DEPENDENT EPIGENETIC MODIFICATION. INHIBITION OF PERK SUPPRESSED MACROPHAGE IMMUNOSUPPRESSIVE ACTIVITY AND COULD ENHANCE THE EFFICACY OF IMMUNE CHECKPOINT PROGRAMMED CELL DEATH PROTEIN 1 INHIBITION IN MELANOMA. OUR FINDINGS DELINEATE A PREVIOUSLY UNDESCRIBED CONNECTION BETWEEN PERK SIGNALING AND PSAT1-MEDIATED SERINE METABOLISM CRITICAL FOR PROMOTING IMMUNOSUPPRESSIVE FUNCTION IN M2 MACROPHAGES. 2022 7 662 32 BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME ANALYSES REVEAL LOCI ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. LITTLE IS KNOWN REGARDING THE EPIGENETIC BASIS OF ATHEROSCLEROSIS. HERE WE PRESENT THE CD14+ BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME SIGNATURES ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. THE TRANSCRIPTOME SIGNATURE INCLUDES TRANSCRIPTION COACTIVATOR, ARID5B, WHICH IS KNOWN TO FORM A CHROMATIN DEREPRESSOR COMPLEX WITH A HISTONE H3K9ME2-SPECIFIC DEMETHYLASE AND PROMOTE ADIPOGENESIS AND SMOOTH MUSCLE DEVELOPMENT. ARID5B CPG (CG25953130) METHYLATION IS INVERSELY ASSOCIATED WITH BOTH ARID5B EXPRESSION AND ATHEROSCLEROSIS, CONSISTENT WITH THIS CPG RESIDING IN AN ARID5B ENHANCER REGION, BASED ON CHROMATIN CAPTURE AND HISTONE MARKS DATA. MEDIATION ANALYSIS SUPPORTS ASSUMPTIONS THAT ARID5B EXPRESSION MEDIATES EFFECTS OF CG25953130 METHYLATION AND SEVERAL CARDIOVASCULAR DISEASE RISK FACTORS ON ATHEROSCLEROTIC BURDEN. IN LIPOPOLYSACCHARIDE-STIMULATED HUMAN THP1 MONOCYTES, ARID5B KNOCKDOWN REDUCED EXPRESSION OF GENES INVOLVED IN ATHEROSCLEROSIS-RELATED INFLAMMATORY AND LIPID METABOLISM PATHWAYS, AND INHIBITED CELL MIGRATION AND PHAGOCYTOSIS. THESE DATA SUGGEST THAT ARID5B EXPRESSION, POSSIBLY REGULATED BY AN EPIGENETICALLY CONTROLLED ENHANCER, PROMOTES ATHEROSCLEROSIS BY DYSREGULATING IMMUNOMETABOLISM TOWARDS A CHRONIC INFLAMMATORY PHENOTYPE.THE MOLECULAR MECHANISMS MEDIATING THE IMPACT OF ENVIRONMENTAL FACTORS IN ATHEROSCLEROSIS ARE UNCLEAR. HERE, THE AUTHORS EXAMINE CD14+ BLOOD MONOCYTE'S TRANSCRIPTOME AND EPIGENOME SIGNATURES TO FIND DIFFERENTIAL METHYLATION AND EXPRESSION OF ARID5B TO BE ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. 2017 8 1335 31 DERMAL FIBROBLASTS CULTURED FROM DONORS WITH TYPE 2 DIABETES MELLITUS RETAIN AN EPIGENETIC MEMORY ASSOCIATED WITH POOR WOUND HEALING RESPONSES. THE PREVALENCE OF TYPE 2 DIABETES MELLITUS (T2DM) IS ESCALATING GLOBALLY. PATIENTS SUFFER FROM MULTIPLE COMPLICATIONS INCLUDING THE DEVELOPMENT OF CHRONIC WOUNDS THAT CAN LEAD TO AMPUTATION. THESE WOUNDS ARE CHARACTERISED BY AN INFLAMMATORY ENVIRONMENT INCLUDING ELEVATED TUMOUR NECROSIS FACTOR ALPHA (TNF-ALPHA). DERMAL FIBROBLASTS (DF) ARE CRITICAL FOR EFFECTIVE WOUND HEALING, SO WE SOUGHT TO ESTABLISH WHETHER THERE WERE ANY DIFFERENCES IN DF CULTURED FROM T2DM DONORS OR THOSE WITHOUT DIABETES (ND-DF). ND- AND T2DM-DF WHEN CULTURED SIMILARLY IN VITRO SECRETED COMPARABLE CONCENTRATIONS OF TNF-ALPHA. FUNCTIONALLY, PRE-TREATMENT WITH TNF-ALPHA REDUCED THE PROLIFERATION OF ND-DF AND TRANSIENTLY ALTERED ND-DF MORPHOLOGY; HOWEVER, T2DM-DF WERE RESISTANT TO THESE TNF-ALPHA INDUCED CHANGES. IN CONTRAST, TNF-ALPHA INHIBITED ND- AND T2DM-DF MIGRATION AND MATRIX METALLOPROTEASE EXPRESSION TO THE SAME DEGREE, ALTHOUGH T2DM-DF EXPRESSED SIGNIFICANTLY HIGHER LEVELS OF TISSUE INHIBITOR OF METALLOPROTEASES (TIMP)-2. FINALLY, TNF-ALPHA SIGNIFICANTLY INCREASED THE SECRETION OF PRO-INFLAMMATORY CYTOKINES (INCLUDING CCL2, CXCL1 AND SERPINE1) IN ND-DF, WHILST THIS EFFECT IN T2DM-DF WAS BLUNTED, PRESUMABLY DUE TO THE TENDENCY TO HIGHER BASELINE PRO-INFLAMMATORY CYTOKINE EXPRESSION OBSERVED IN THIS CELL TYPE. COLLECTIVELY, THESE DATA DEMONSTRATE THAT T2DM-DF EXHIBIT A SELECTIVE LOSS OF RESPONSIVENESS TO TNF-ALPHA, PARTICULARLY REGARDING PROLIFERATIVE AND SECRETORY FUNCTIONS. THIS HIGHLIGHTS IMPORTANT PHENOTYPIC CHANGES IN T2DM-DF THAT MAY EXPLAIN THE SUSCEPTIBILITY TO CHRONIC WOUNDS IN THESE PATIENTS. 2021 9 5508 34 RHOA/RHO-KINASES IN ASTHMA: FROM PATHOGENESIS TO THERAPEUTIC TARGETS. ASTHMA IS A CHRONIC AND HETEROGENEOUS DISEASE CHARACTERISED BY AIRWAY INFLAMMATION AND INTERMITTENT AIRWAY NARROWING. THE KEY OBSTACLE IN THE PREVENTION AND TREATMENT OF ASTHMA HAS BEEN OUR INCOMPLETE UNDERSTANDING OF ITS AETIOLOGY AND BIOLOGICAL MECHANISMS. THE RAS HOMOLOG FAMILY MEMBER A (RHOA) OF THE RHO FAMILY GTPASES HAS BEEN CONSIDERED TO BE ONE OF THE MOST PROMISING AND NOVEL THERAPEUTIC TARGETS FOR ASTHMA. IT IS WELL KNOWN THAT RHOA/RHO-KINASES PLAY AN IMPORTANT ROLE IN THE PATHOPHYSIOLOGY OF ASTHMA, INCLUDING AIRWAY SMOOTH MUSCLE CONTRACTION, AIRWAY HYPER-RESPONSIVENESS, BETA-ADRENERGIC DESENSITISATION AND AIRWAY REMODELLING. HOWEVER, RECENT ADVANCES HAVE SUGGESTED NOVEL ROLES FOR RHOA IN REGULATING ALLERGIC AIRWAY INFLAMMATION. SPECIFICALLY, RHOA HAS BEEN SHOWN TO REGULATE ALLERGIC AIRWAY INFLAMMATION THROUGH CONTROLLING TH2 OR TH17 CELL DIFFERENTIATION AND TO REGULATE AIRWAY REMODELLING THROUGH REGULATING MESENCHYMAL STEM CELL (MSC) DIFFERENTIATION. IN THIS REVIEW, WE EVALUATE THE LITERATURE REGARDING THE RECENT ADVANCES IN THE ACTIVATION OF RHOA/RHO-KINASE, CYTOKINE AND EPIGENETIC REGULATION OF RHOA/RHO-KINASE, AND THE ROLE OF RHOA/RHO-KINASE IN REGULATING MAJOR FEATURES OF ASTHMA, SUCH AS AIRWAY HYPER-RESPONSIVENESS, REMODELLING AND INFLAMMATION. WE ALSO DISCUSS THE IMPORTANCE OF THE NEWLY IDENTIFIED ROLE OF RHOA/RHO-KINASE SIGNALLING IN MSC DIFFERENTIATION AND BRONCHIAL EPITHELIAL BARRIER DYSFUNCTION. THESE FINDINGS INDICATE THE FUNCTIONAL SIGNIFICANCE OF THE RHOA/RHO-KINASE PATHWAY IN THE PATHOPHYSIOLOGY OF ASTHMA AND SUGGEST THAT RHOA/RHO-KINASE SIGNALLING MAY BE A PROMISING THERAPEUTIC TARGET FOR THE TREATMENT OF ASTHMA. 2020 10 142 36 ABERRANT DNA METHYLATION OF PHOSPHODIESTERASE [CORRECTED] 4D ALTERS AIRWAY SMOOTH MUSCLE CELL PHENOTYPES. AIRWAY HYPERRESPONSIVENESS (AHR) IS A HALLMARK FEATURE IN ASTHMA CHARACTERIZED BY EXAGGERATED AIRWAY CONTRACTILE RESPONSE TO STIMULI DUE TO INCREASED AIRWAY SENSITIVITY AND CHRONIC AIRWAY REMODELING. WE HAVE PREVIOUSLY SHOWN THAT ALLERGEN-INDUCED AHR IN MICE IS ASSOCIATED WITH ABERRANT DNA METHYLATION IN THE LUNG GENOME, SUGGESTING THAT AHR COULD BE EPIGENETICALLY REGULATED, AND THESE CHANGES MIGHT PREDISPOSE THE ANIMALS TO ASTHMA. PREVIOUS STUDIES DEMONSTRATED THAT OVEREXPRESSION OF PHOSPHODIESTERASE 4D (PDE4D) IS ASSOCIATED WITH INCREASED AHR. HOWEVER, EPIGENETIC REGULATION OF THIS GENE IN ASTHMATIC AIRWAY SMOOTH MUSCLE CELLS (ASMCS) HAS NOT BEEN EXAMINED. IN THIS STUDY, WE AIMED TO EXAMINE THE RELATIONSHIP BETWEEN EPIGENETIC REGULATION OF PDE4D AND ASMC PHENOTYPES. WE IDENTIFIED CPG SITE-SPECIFIC HYPOMETHYLATION AT PDE4D PROMOTER IN HUMAN ASTHMATIC ASMCS. WE NEXT USED METHYLATED OLIGONUCLEOTIDES TO INTRODUCE CPG SITE-SPECIFIC METHYLATION AT PDE4D PROMOTER AND EXAMINED ITS EFFECT ON ASMCS. WE SHOWED THAT PDE4D METHYLATION DECREASED CELL PROLIFERATION AND MIGRATION OF ASTHMATIC ASMCS. WE FURTHER ELUCIDATED THAT METHYLATED PDE4D DECREASED PDE4D EXPRESSION IN ASTHMATIC ASMCS, INCREASED CAMP LEVEL, AND INHIBITED THE ABERRANT INCREASE IN CA(2+) LEVEL. MOREOVER, PDE4D METHYLATION REDUCED THE PHOSPHORYLATION LEVEL OF DOWNSTREAM EFFECTORS OF CA(2+) SIGNALING, INCLUDING MYOSIN LIGHT CHAIN KINASE AND P38. TAKEN TOGETHER, OUR FINDINGS DEMONSTRATE THAT GENE-SPECIFIC EPIGENETIC CHANGES MAY PREDISPOSE ASMCS TO ASTHMA THROUGH ALTERATIONS IN CELL PHENOTYPES. MODULATION OF ASMC PHENOTYPES BY METHYLATED PDE4D OLIGONUCLEOTIDES CAN REVERSE THE ABERRANT ASMC FUNCTIONS TO NORMAL PHENOTYPES. THIS HAS PROVIDED NEW INSIGHT TO THE DEVELOPMENT OF NOVEL THERAPEUTIC OPTIONS FOR THIS DEBILITATIVE DISEASE. 2016 11 3327 31 HISTONE DEACETYLASE 4 PROMOTES CHOLESTATIC LIVER INJURY IN THE ABSENCE OF PROHIBITIN-1. PROHIBITIN-1 (PHB1) IS AN EVOLUTIONARILY CONSERVED PLEIOTROPIC PROTEIN THAT PARTICIPATES IN DIVERSE PROCESSES DEPENDING ON ITS SUBCELLULAR LOCALIZATION AND INTERACTOME. RECENT DATA HAVE INDICATED A DIVERSE ROLE FOR PHB1 IN THE PATHOGENESIS OF OBESITY, CANCER, AND INFLAMMATORY BOWEL DISEASE, AMONG OTHERS. DATA PRESENTED HERE SUGGEST THAT PHB1 IS ALSO LINKED TO CHOLESTATIC LIVER DISEASE. EXPRESSION OF PHB1 IS MARKEDLY REDUCED IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS AND BILIARY ATRESIA OR WITH ALAGILLE SYNDROME, TWO MAJOR PEDIATRIC CHOLESTATIC CONDITIONS. IN THE EXPERIMENTAL MODEL OF BILE DUCT LIGATION, SILENCING OF PHB1 INDUCED LIVER FIBROSIS, REDUCED ANIMAL SURVIVAL, AND INDUCED BILE DUCT PROLIFERATION. IMPORTANTLY, THE MODULATORY EFFECT OF PHB1 IS NOT DEPENDENT ON ITS KNOWN MITOCHONDRIAL FUNCTION. ALSO, PHB1 INTERACTS WITH HISTONE DEACETYLASE 4 (HDAC4) IN THE PRESENCE OF BILE ACIDS. HENCE, PHB1 DEPLETION LEADS TO INCREASED NUCLEAR HDAC4 CONTENT AND ITS ASSOCIATED EPIGENETIC CHANGES. REMARKABLY, HDAC4 SILENCING AND THE ADMINISTRATION OF THE HDAC INHIBITOR PARTHENOLIDE DURING OBSTRUCTIVE CHOLESTASIS IN VIVO PROMOTE GENOMIC REPROGRAMMING, LEADING TO REGRESSION OF THE FIBROTIC PHENOTYPE IN LIVER-SPECIFIC PHB1 KNOCKOUT MICE. CONCLUSION: PHB1 IS AN IMPORTANT MEDIATOR OF CHOLESTATIC LIVER INJURY THAT REGULATES THE ACTIVITY OF HDAC4, WHICH CONTROLS SPECIFIC EPIGENETIC MARKERS; THESE RESULTS IDENTIFY POTENTIAL NOVEL STRATEGIES TO TREAT LIVER INJURY AND FIBROSIS, PARTICULARLY AS A CONSEQUENCE OF CHRONIC CHOLESTASIS. 2015 12 3390 36 HOPX PLAYS A CRITICAL ROLE IN ANTIRETROVIRAL DRUGS INDUCED EPIGENETIC MODIFICATION AND CARDIAC HYPERTROPHY. PEOPLE LIVING WITH HIV (PLWH) HAVE TO TAKE AN ANTIRETROVIRAL THERAPY (ART) FOR LIFE AND SHOW NONCOMMUNICABLE ILLNESSES SUCH AS CHRONIC INFLAMMATION, IMMUNE ACTIVATION, AND MULTIORGAN DYSREGULATION. RECENT STUDIES SUGGEST THAT LONG-TERM USE OF ART INDUCES COMORBID CONDITIONS AND IS ONE OF THE LEADING CAUSES OF HEART FAILURE IN PLWH. HOWEVER, THE MOLECULAR MECHANISM OF ANTIRETROVIRAL DRUGS (ARVS) INDUCED HEART FAILURE IS UNCLEAR. TO DETERMINE THE MECHANISM OF ARVS INDUCED CARDIAC DYSFUNCTION, WE PERFORMED GLOBAL TRANSCRIPTOMIC PROFILING OF ARVS TREATED NEONATAL RAT VENTRICULAR CARDIOMYOCYTES IN CULTURE. DIFFERENTIALLY EXPRESSED GENES WERE IDENTIFIED BY RNA-SEQUENCING. OUR DATA SHOW THAT ARVS TREATMENT CAUSES UPREGULATION OF SEVERAL BIOLOGICAL FUNCTIONS ASSOCIATED WITH CARDIOTOXICITY, HYPERTROPHY, AND HEART FAILURE. GLOBAL GENE EXPRESSION DATA WERE VALIDATED IN CARDIAC TISSUE ISOLATED FROM HIV PATIENTS HAVING A HISTORY OF ART. INTERESTINGLY, WE FOUND THAT HOMEODOMAIN-ONLY PROTEIN HOMEOBOX (HOPX) EXPRESSION WAS SIGNIFICANTLY INCREASED IN CARDIOMYOCYTES TREATED WITH ARVS AND IN THE HEART TISSUE OF HIV PATIENTS. FURTHERMORE, WE FOUND THAT HOPX PLAYS A CRUCIAL ROLE IN ARVS MEDIATED CELLULAR HYPERTROPHY. MECHANISTICALLY, WE FOUND THAT HOPX PLAYS A CRITICAL ROLE IN EPIGENETIC REGULATION, THROUGH DEACETYLATION OF HISTONE, WHILE THE HDAC INHIBITOR, TRICHOSTATIN A, CAN RESTORE THE ACETYLATION LEVEL OF HISTONE 3 IN THE PRESENCE OF ARVS. 2021 13 3049 35 GENOME-WIDE ANALYSIS REVEALS ZINC TRANSPORTER ZIP9 REGULATED BY DNA METHYLATION PROMOTES RADIATION-INDUCED SKIN FIBROSIS VIA THE TGF-BETA SIGNALING PATHWAY. RADIATION-INDUCED SKIN FIBROSIS IS A DETRIMENTAL AND CHRONIC DISORDER THAT OCCURS AFTER RADIATION EXPOSURE. DNA METHYLATION HAS BEEN CHARACTERIZED AS AN IMPORTANT REGULATORY MECHANISM OF MULTIPLE PATHOLOGICAL PROCESSES. IN THIS STUDY, WE COMPARED THE GENOME-WIDE DNA METHYLATION STATUS IN RADIATION-INDUCED FIBROTIC SKIN AND ADJACENT NORMAL TISSUES OF RATS BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. RADIATION-INDUCED FIBROTIC SKIN SHOWED DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH 3,650 PROTEIN-CODING GENES, 72 MICRORNAS, 5,836 LONG NONCODING RNAS AND 3 PIWI-INTERACTING RNAS. BY INTEGRATING THE MRNA AND METHYLATION PROFILES, THE ZINC TRANSPORTER SLC39A9/ZIP9 WAS INVESTIGATED IN GREATER DETAIL. THE PROTEIN LEVEL OF ZIP9 WAS INCREASED IN IRRADIATED SKIN TISSUES OF HUMANS, MONKEYS, AND RATS, ESPECIALLY IN RADIOGENIC FIBROTIC SKIN TISSUES. RADIATION INDUCED THE DEMETHYLATION OF A CPG DINUCLEOTIDE IN EXON 1 OF ZIP9 THAT RESULTED IN RECRUITMENT OF THE TRANSCRIPTIONAL FACTOR SP1 AND INCREASED ZIP9 EXPRESSION. OVEREXPRESSION OF ZIP9 RESULTED IN ACTIVATION OF THE PROFIBROTIC TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY THROUGH PROTEIN KINASE B IN HUMAN FIBROBLASTS. IN ADDITION, RADIATION-INDUCED SKIN FIBROSIS WAS ASSOCIATED WITH INCREASED ZINC ACCUMULATION. THE ZINC CHELATOR N,N,N',N'-TETRAKIS(2-PYRIDYLMETHYL)-1,2-ETHYLENEDIAMINE ABROGATED ZIP9-INDUCED ACTIVATION OF THE TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY AND ATTENUATED RADIATION-INDUCED SKIN FIBROSIS IN A RAT MODEL. IN SUMMARY, OUR FINDINGS ILLUSTRATE EPIGENETIC REGULATION OF ZIP9 AND ITS CRITICAL ROLE IN PROMOTING RADIATION-INDUCED SKIN FIBROSIS. 2020 14 6642 30 UNRAVELING THE PATHOGENESIS OF ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE OVERLAP: FOCUSING ON EPIGENETIC MECHANISMS. ASTHMA AND COPD OVERLAP (ACO) IS CHARACTERIZED BY PATIENTS PRESENTING WITH PERSISTENT AIRFLOW LIMITATION AND FEATURES OF BOTH ASTHMA AND COPD. IT IS ASSOCIATED WITH A HIGHER FREQUENCY AND SEVERITY OF EXACERBATIONS, A FASTER LUNG FUNCTION DECLINE, AND A HIGHER HEALTHCARE COST. SYSTEMIC INFLAMMATION IN COPD AND ASTHMA IS DRIVEN BY TYPE 1 T HELPER (TH1) AND TH2 IMMUNE RESPONSES, RESPECTIVELY, BOTH OF WHICH MAY CONTRIBUTE TO AIRWAY REMODELING IN ACO. ACO-RELATED BIOMARKERS CAN BE CLASSIFIED INTO FOUR CATEGORIES: NEUTROPHIL-MEDIATED INFLAMMATION, TH2 CELL RESPONSES, ARACHIDONIC ACID-EICOSANOIDS PATHWAY, AND METABOLITES. GENE-ENVIRONMENT INTERACTIONS ARE KEY CONTRIBUTORS TO THE COMPLEXITY OF ACO AND ARE REGULATED BY EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS, AND NON-CODING RNAS. THUS, THIS REVIEW FOCUSES ON THE LINK BETWEEN EPIGENETICS AND ACO, AND OUTLINES THE FOLLOWING: (I) INHERITING EPIGENOTYPES WITHOUT CHANGE WITH ENVIRONMENTAL STIMULI, OR EPIGENETIC CHANGES IN RESPONSE TO LONG-TERM EXPOSURE TO INHALED PARTICLES PLUS INTERMITTENT EXPOSURE TO SPECIFIC ALLERGENS; (II) EPIGENETIC MARKERS DISTINGUISHING ACO FROM COPD AND ASTHMA; (III) POTENTIAL EPIGENETIC DRUGS THAT CAN REVERSE OXIDATIVE STRESS, GLUCOCORTICOID INSENSITIVITY, AND CELL INJURY. IMPROVED UNDERSTANDING OF THE EPIGENETIC REGULATIONS HOLDS GREAT VALUE TO GIVE DEEPER INSIGHT INTO THE MECHANISMS, AND CLARIFY THEIR IMPLICATIONS FOR BIOMEDICAL RESEARCH IN ACO. 2022 15 5859 31 SULFORAPHANE PREVENTS AND REVERSES ALLERGIC AIRWAYS DISEASE IN MICE VIA ANTI-INFLAMMATORY, ANTIOXIDANT, AND EPIGENETIC MECHANISMS. SULFORAPHANE HAS BEEN INVESTIGATED IN HUMAN PATHOLOGIES AND PRECLINICAL MODELS OF AIRWAY DISEASES. TO PROVIDE FURTHER MECHANISTIC INSIGHTS, WE EXPLORED L-SULFORAPHANE (LSF) IN THE OVALBUMIN (OVA)-INDUCED CHRONIC ALLERGIC AIRWAYS MURINE MODEL, WITH KEY HALLMARKS OF ASTHMA. HISTOLOGICAL ANALYSIS INDICATED THAT LSF PREVENTED OR REVERSED OVA-INDUCED EPITHELIAL THICKENING, COLLAGEN DEPOSITION, GOBLET CELL METAPLASIA, AND INFLAMMATION. WELL-KNOWN ANTIOXIDANT AND ANTI-INFLAMMATORY MECHANISMS CONTRIBUTE TO THE BENEFICIAL EFFECTS OF LSF. FOURIER TRANSFORM INFRARED MICROSPECTROSCOPY REVEALED ALTERED COMPOSITION OF MACROMOLECULES, FOLLOWING OVA SENSITIZATION, WHICH WERE RESTORED BY LSF. RNA SEQUENCING IN HUMAN PERIPHERAL BLOOD MONONUCLEAR CELLS HIGHLIGHTED THE ANTI-INFLAMMATORY SIGNATURE OF LSF. FINDINGS INDICATED THAT LSF MAY ALTER GENE EXPRESSION VIA AN EPIGENETIC MECHANISM WHICH INVOLVES REGULATION OF PROTEIN ACETYLATION STATUS. LSF RESULTED IN HISTONE AND ALPHA-TUBULIN HYPERACETYLATION IN VIVO, AND CELLULAR AND ENZYMATIC ASSAYS INDICATED DECREASED EXPRESSION AND MODEST HISTONE DEACETYLASE (HDAC) INHIBITION ACTIVITY, IN COMPARISON WITH THE WELL-KNOWN PAN-HDAC INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA). MOLECULAR MODELING CONFIRMED INTERACTION OF LSF AND LSF METABOLITES WITH THE CATALYTIC DOMAIN OF METAL-DEPENDENT HDAC ENZYMES. MORE GENERALLY, THIS STUDY CONFIRMED KNOWN MECHANISMS AND IDENTIFIED POTENTIAL EPIGENETIC PATHWAYS ACCOUNTING FOR THE PROTECTIVE EFFECTS AND PROVIDE SUPPORT FOR THE POTENTIAL CLINICAL UTILITY OF LSF IN ALLERGIC AIRWAYS DISEASE. 2022 16 272 39 AGE-DEPENDENT DECREASE IN THE INDUCTION OF REGULATORY T CELLS IS ASSOCIATED WITH DECREASED EXPRESSION OF RALDH2 IN MESENTERIC LYMPH NODE DENDRITIC CELLS. A DECLINE IN IMMUNE FUNCTION WITH AGING HAS BEEN REPORTED. REGULATORY T CELL (TREG) INDUCTION IS KNOWN TO DECREASE WITH AGE, AND ELUCIDATING THE UNDERLYING MECHANISM IS IMPORTANT FOR PREVENTING AGE-RELATED DISEASES DUE TO AGE-RELATED CHRONIC INFLAMMATION. IN THE INTESTINE, DENDRITIC CELLS (DCS) PLAY AN IMPORTANT ROLE IN INDUCING TREGS SPECIFIC TO ORAL ANTIGENS, AND THEY EFFICIENTLY INDUCE TREGS VIA PRODUCTION OF RETINOIC ACID (RA), A VITAMIN A METABOLITE, CATALYZED BY THE ENZYME RETINALDEHYDE DEHYDROGENASE 2 (RALDH2). WE HAVE PREVIOUSLY REPORTED THAT IN THE MESENTERIC LYMPH NODE (MLN), A SECONDARY LYMPHOID TISSUE IN WHICH IMMUNE RESPONSES TO ORAL ANTIGENS ARE INDUCED, FOUR DC SUBSETS EXPRESS DIFFERENT LEVELS OF CD11B, CD103, AND PD-L1, AND WE HAVE REPORTED THAT THE CD11B(-)CD103(+)PD-L1(HIGH) SUBSET EXPRESSES THE HIGHEST LEVELS OF THE RALDH2 GENE AND INDUCES TREGS IN VITRO. WE EXAMINED TREG INDUCTION IN YOUNG AND AGED MICE USING A TREG INDUCTION MODEL BY ADMINISTERING A FOOD ANTIGEN, AND WE FOUND THAT ANTIGEN-SPECIFIC TREG INDUCTION WAS DECREASED IN AGED MICE. WE FURTHER INVESTIGATED THE MLN DCS, AND A SIGNIFICANT DECREASE IN RALDH2 GENE EXPRESSION WAS OBSERVED IN MLN DCS FROM AGED MICE. AS FACTORS, WE FOUND THAT THE PROPORTION OF THE CD11B(-)CD103(+)PD-L1(HIGH) SUBSET WAS DECREASED IN AGED MICE COMPARED WITH THAT IN YOUNG MICE AND THAT RALDH ENZYME ACTIVITY WAS DECREASED IN THE CD11B(-)CD103(+)PD-L1(HIGH) AND CD11B(+)CD103(+)PD-L1(HIGH) SUBSETS. FURTHERMORE, ANALYSIS OF THE METHYLATION OF THE RALDH2 GENE PROMOTER REGION REVEALED THAT CPG MOTIFS WERE MORE METHYLATED IN THE MLN DCS OF AGED MICE, SUGGESTING THAT RALDH2 EXPRESSION WAS SUPPRESSED BY EPIGENETIC CHANGES. FINALLY, WE FOUND THAT RA TREATMENT TENDED TO INCREASE TREG INDUCTION. THESE RESULTS SUGGEST THAT THE REGULATION OF RA PRODUCTION MAY BE INVOLVED IN THE AGE-RELATED DECREASE IN ANTIGEN-SPECIFIC TREG INDUCTION. 2020 17 4039 37 MACROPHAGE NOX2 NADPH OXIDASE MAINTAINS ALVEOLAR HOMEOSTASIS IN MICE. THE LEUKOCYTE NADPH OXIDASE 2 (NOX2) PLAYS A KEY ROLE IN PATHOGEN KILLING AND IMMUNOREGULATION. GENETIC DEFECTS IN NOX2 RESULT IN CHRONIC GRANULOMATOUS DISEASE (CGD), ASSOCIATED WITH MICROBIAL INFECTIONS AND INFLAMMATORY DISORDERS, OFTEN INVOLVING THE LUNG. ALVEOLAR MACROPHAGES (AMS) ARE THE PREDOMINANT IMMUNE CELL IN THE AIRWAYS AT STEADY STATE, AND LIMITING THEIR ACTIVATION IS IMPORTANT, GIVEN THE CONSTANT EXPOSURE TO INHALED MATERIALS, YET THE IMPORTANCE OF NOX2 IN THIS PROCESS IS NOT WELL UNDERSTOOD. IN THIS STUDY, WE SHOWED A PREVIOUSLY UNDESCRIBED ROLE FOR NOX2 IN MAINTAINING LUNG HOMEOSTASIS BY SUPPRESSING AM ACTIVATION, IN CGD MICE OR MICE WITH SELECTIVE LOSS OF NOX2 PREFERENTIALLY IN MACROPHAGES. AMS LACKING NOX2 HAD INCREASED CYTOKINE RESPONSES TO TOLL-LIKE RECEPTOR-2 (TLR2) AND TLR4 STIMULATION EX VIVO. MOREOVER, BETWEEN 4 AND 12 WEEK OF AGE, MICE WITH GLOBAL NOX2 DELETION DEVELOPED AN ACTIVATED CD11BHIGH SUBSET OF AMS WITH EPIGENETIC AND TRANSCRIPTIONAL PROFILES REFLECTING IMMUNE ACTIVATION COMPARED WITH WT AMS. THE PRESENCE OF CD11BHIGH AMS IN CGD MICE CORRELATED WITH AN INCREASED NUMBER OF ALVEOLAR NEUTROPHILS AND PROINFLAMMATORY CYTOKINES AT STEADY STATE AND INCREASED LUNG INFLAMMATION AFTER INSULTS. MOREOVER, DELETION OF NOX2 PREFERENTIALLY IN MACROPHAGES WAS SUFFICIENT FOR MICE TO DEVELOP AN ACTIVATED CD11BHIGH AM SUBSET AND ACCOMPANYING PROINFLAMMATORY SEQUELAE. IN ADDITION, WE SHOWED THAT THE ALTERED RESIDENT MACROPHAGE TRANSCRIPTIONAL PROFILE IN THE ABSENCE OF NOX2 IS TISSUE SPECIFIC, AS THOSE CHANGES WERE NOT SEEN IN RESIDENT PERITONEAL MACROPHAGES. THUS, THESE DATA DEMONSTRATE THAT THE ABSENCE OF NOX2 IN ALVEOLAR MACROPHAGES LEADS TO THEIR PROINFLAMMATORY REMODELING AND DYSREGULATES ALVEOLAR HOMEOSTASIS. 2022 18 2340 40 EPIGENETIC REGULATION OF LEUKOCYTE INFLAMMATORY MEDIATOR PRODUCTION DICTATES STAPHYLOCOCCUS AUREUS CRANIOTOMY INFECTION OUTCOME. STAPHYLOCOCCUS AUREUS IS A COMMON CAUSE OF SURGICAL-SITE INFECTIONS, INCLUDING THOSE ARISING AFTER CRANIOTOMY, WHICH IS PERFORMED TO ACCESS THE BRAIN FOR THE TREATMENT OF TUMORS, EPILEPSY, OR HEMORRHAGE. CRANIOTOMY INFECTION IS CHARACTERIZED BY COMPLEX SPATIAL AND TEMPORAL DYNAMICS OF LEUKOCYTE RECRUITMENT AND MICROGLIAL ACTIVATION. WE RECENTLY IDENTIFIED UNIQUE TRANSCRIPTIONAL PROFILES OF THESE IMMUNE POPULATIONS DURING S. AUREUS CRANIOTOMY INFECTION. EPIGENETIC PROCESSES ALLOW RAPID AND REVERSIBLE CONTROL OVER GENE TRANSCRIPTION; HOWEVER, LITTLE IS KNOWN ABOUT HOW EPIGENETIC PATHWAYS INFLUENCE IMMUNITY TO LIVE S. AUREUS. AN EPIGENETIC COMPOUND LIBRARY SCREEN IDENTIFIED BROMODOMAIN AND EXTRATERMINAL DOMAIN-CONTAINING (BET) PROTEINS AND HISTONE DEACETYLASES (HDACS) AS CRITICAL FOR REGULATING TNF, IL-6, IL-10, AND CCL2 PRODUCTION BY PRIMARY MOUSE MICROGLIA, MACROPHAGES, NEUTROPHILS, AND GRANULOCYTIC MYELOID-DERIVED SUPPRESSOR CELLS IN RESPONSE TO LIVE S. AUREUS. CLASS I HDACS (C1HDACS) WERE INCREASED IN THESE CELL TYPES IN VITRO AND IN VIVO DURING ACUTE DISEASE IN A MOUSE MODEL OF S. AUREUS CRANIOTOMY INFECTION. HOWEVER, SUBSTANTIAL REDUCTIONS IN C1HDACS WERE OBSERVED DURING CHRONIC INFECTION, HIGHLIGHTING TEMPORAL REGULATION AND THE IMPORTANCE OF THE TISSUE MICROENVIRONMENT FOR DICTATING C1HDAC EXPRESSION. MICROPARTICLE DELIVERY OF HDAC AND BET INHIBITORS IN VIVO CAUSED WIDESPREAD DECREASES IN INFLAMMATORY MEDIATOR PRODUCTION, WHICH SIGNIFICANTLY INCREASED BACTERIAL BURDEN IN THE BRAIN, GALEA, AND BONE FLAP. THESE FINDINGS IDENTIFY HISTONE ACETYLATION AS AN IMPORTANT MECHANISM FOR REGULATING CYTOKINE AND CHEMOKINE PRODUCTION ACROSS DIVERSE IMMUNE CELL LINEAGES THAT IS CRITICAL FOR BACTERIAL CONTAINMENT. ACCORDINGLY, ABERRANT EPIGENETIC REGULATION MAY BE IMPORTANT FOR PROMOTING S. AUREUS PERSISTENCE DURING CRANIOTOMY INFECTION. 2023 19 26 35 A 6-ALKYLSALICYLATE HISTONE ACETYLTRANSFERASE INHIBITOR INHIBITS HISTONE ACETYLATION AND PRO-INFLAMMATORY GENE EXPRESSION IN MURINE PRECISION-CUT LUNG SLICES. LYSINE ACETYLATIONS ARE POST-TRANSLATIONAL MODIFICATIONS OF CELLULAR PROTEINS, THAT ARE CRUCIAL IN THE REGULATION OF MANY CELLULAR PROCESSES. LYSINE ACETYLATIONS ON HISTONE PROTEINS ARE PART OF THE EPIGENETIC CODE REGULATING GENE EXPRESSION AND ARE INSTALLED BY HISTONE ACETYLTRANSFERASES. OBSERVATIONS THAT INFLAMMATORY LUNG DISEASES, SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE, ARE CHARACTERIZED BY INCREASED HISTONE ACETYLTRANSFERASE ACTIVITY INDICATE THAT DEVELOPMENT OF SMALL MOLECULE INHIBITORS FOR THESE ENZYMES MIGHT BE A VALUABLE APPROACH TOWARDS NEW THERAPIES FOR THESE DISEASES. THE 6-ALKYLSALICYLATE MG149 IS A CANDIDATE TO EXPLORE THIS HYPOTHESIS BECAUSE IT HAS BEEN DEMONSTRATED TO INHIBIT THE MYST TYPE HISTONE ACETYLTRANSFERASES. IN THIS STUDY, WE DETERMINED THE K(I) VALUE FOR INHIBITION OF THE MYST TYPE HISTONE ACETYLTRANSFERASE KAT8 BY MG149 TO BE 39 +/- 7.7 MUM. UPON INVESTIGATING WHETHER THE INHIBITION OF HISTONE ACETYLTRANSFERASES BY MG149 CORRELATES WITH INHIBITION OF HISTONE ACETYLATION IN MURINE PRECISION-CUT LUNG SLICES, INHIBITION OF ACETYLATION WAS OBSERVED USING AN LC-MS/MS BASED ASSAY ON HISTONE H4 RES 4-17, WHICH CONTAINS THE TARGET LYSINE OF KAT8. FOLLOWING UP ON THIS, UPON TREATMENT WITH MG149, REDUCED PRO-INFLAMMATORY GENE EXPRESSION WAS OBSERVED IN LIPOPOLYSACCHARIDE AND INTERFERON GAMMA STIMULATED MURINE PRECISION-CUT LUNG SLICES. BASED ON THIS, WE PROPOSE THAT 6-ALKYLSALICYLATES SUCH AS MG149 HAVE POTENTIAL FOR DEVELOPMENT TOWARDS APPLICATIONS IN THE TREATMENT OF INFLAMMATORY LUNG DISEASES. 2017 20 5863 34 SUPPRESSION OF ALLERGIC ASTHMA BY LOSS OF FUNCTION OF MIZ1-MEDIATED TH1 SKEWING. ASTHMA IS THE MOST PREVALENT CHRONIC RESPIRATORY DISEASE WORLDWIDE. THERE IS CURRENTLY NO CURE, AND IT REMAINS AN IMPORTANT CAUSE OF MORBIDITY AND MORTALITY. HERE WE REPORT THAT LUNG-SPECIFIC LOSS OF FUNCTION OF THE TRANSCRIPTION FACTOR MIZ1 (C-MYC-INTERACTING ZINC FINGER PROTEIN-1) UPREGULATES THE PRO-T-HELPER CELL TYPE 1 CYTOKINE IL-12. UPREGULATION OF IL-12 IN TURN STIMULATES A TH1 RESPONSE, THEREBY COUNTERACTING T-HELPER CELL TYPE 2 RESPONSE AND PREVENTING THE ALLERGIC RESPONSE IN MOUSE MODELS OF HOUSE DUST MITE- AND OVA (OVALBUMIN)-INDUCED ASTHMA. USING TRANSGENIC MICE EXPRESSING CRE UNDER A CELL-SPECIFIC PROMOTER, WE DEMONSTRATE THAT MIZ1 ACTS IN LUNG EPITHELIAL CELLS AND DENDRITIC CELLS IN ASTHMA. CHROMATIN IMMUNOPRECIPITATION COUPLED WITH HIGH-THROUGHPUT DNA SEQUENCING OR QUANTITATIVE PCR REVEALS THE BINDING OF MIZ1 ON THE IL12 PROMOTER INDICATING DIRECT REPRESSION OF IL-12 BY MIZ1. IN ADDITION, HDAC1 (HISTONE DEACETYLASE 1) IS RECRUITED TO THE IL12 PROMOTER IN A MIZ1-DEPDENENT MANNER, SUGGESTING EPIGENETIC REPRESSION OF IL12 BY MIZ1. FURTHERMORE, MIZ1 IS UPREGULATED IN THE LUNGS OF ASTHMATIC MICE. OUR DATA TOGETHER SUGGEST THAT MIZ1 IS UPREGULATED DURING ASTHMA, WHICH IN TURN PROMOTES ASTHMA PATHOGENESIS BY PREVENTING TH1 SKEWING THROUGH THE TRANSCRIPTIONAL REPRESSION OF IL-12. 2022