1 1124 38 COMPLETE GENOME SEQUENCE OF MORAXELLA CATARRHALIS STRAIN CCRI-195ME, ISOLATED FROM THE MIDDLE EAR. MORAXELLA CATARRHALIS IS AN IMPORTANT BACTERIAL PATHOGEN THAT CAUSES OTITIS MEDIA AND EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HERE, WE REPORT THE COMPLETE GENOME SEQUENCE OF M. CATARRHALIS STRAIN CCRI-195ME, WHICH CONTAINS THE PHASE-VARIABLE EPIGENETIC REGULATOR MODM3. 2017 2 4395 29 MODM DNA METHYLTRANSFERASE METHYLOME ANALYSIS REVEALS A POTENTIAL ROLE FOR MORAXELLA CATARRHALIS PHASEVARIONS IN OTITIS MEDIA. MORAXELLA CATARRHALIS IS A SIGNIFICANT CAUSE OF OTITIS MEDIA AND EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HERE, WE CHARACTERIZE A PHASE-VARIABLE DNA METHYLTRANSFERASE (MODM), WHICH CONTAINS 5'-CAAC-3' REPEATS IN ITS OPEN READING FRAME THAT MEDIATE HIGH-FREQUENCY MUTATION RESULTING IN REVERSIBLE ON/OFF SWITCHING OF MODM EXPRESSION. THREE MODM ALLELES HAVE BEEN IDENTIFIED (MODM1-3), WITH MODM2 BEING THE MOST COMMONLY FOUND ALLELE. USING SINGLE-MOLECULE, REAL-TIME (SMRT) GENOME SEQUENCING AND METHYLOME ANALYSIS, WE HAVE DETERMINED THAT THE MODM2 METHYLATION TARGET IS 5'-GAR(M6)AC-3', AND 100% OF THESE SITES ARE METHYLATED IN THE GENOME OF THE M. CATARRHALIS 25239 MODM2 ON STRAIN. PROTEOMIC ANALYSIS OF MODM2 ON AND OFF VARIANTS REVEALED THAT MODM2 REGULATES EXPRESSION OF MULTIPLE GENES THAT HAVE POTENTIAL ROLES IN COLONIZATION, INFECTION, AND PROTECTION AGAINST HOST DEFENSES. INVESTIGATION OF THE DISTRIBUTION OF MODM ALLELES IN A PANEL OF M. CATARRHALIS STRAINS, ISOLATED FROM THE NASOPHARYNX OF HEALTHY CHILDREN OR MIDDLE EAR EFFUSIONS FROM PATIENTS WITH OTITIS MEDIA, REVEALED A STATISTICALLY SIGNIFICANT ASSOCIATION OF MODM3 WITH OTITIS MEDIA ISOLATES. THE MODULATION OF GENE EXPRESSION VIA THE MODM PHASE-VARIABLE REGULON (PHASEVARION), AND THE SIGNIFICANT ASSOCIATION OF THE MODM3 ALLELE WITH OTITIS MEDIA, SUGGESTS A KEY ROLE FOR MODM PHASEVARIONS IN THE PATHOGENESIS OF THIS ORGANISM. 2014 3 6261 31 THE MORAXELLA CATARRHALIS PHASE-VARIABLE DNA METHYLTRANSFERASE MODM3 IS AN EPIGENETIC REGULATOR THAT AFFECTS BACTERIAL SURVIVAL IN AN IN VIVO MODEL OF OTITIS MEDIA. BACKGROUND: MORAXELLA CATARRHALIS IS A LEADING CAUSE OF OTITIS MEDIA (OM) AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). M. CATARRHALIS CONTAINS A TYPE III DNA ADENINE METHYLTRANSFERASE (MODM) THAT IS PHASE-VARIABLY EXPRESSED (I.E., ITS EXPRESSION IS SUBJECT TO RANDOM, REVERSIBLE ON/OFF SWITCHING). MODM HAS SIX TARGET RECOGNITION DOMAIN ALLELES (MODM1-6), AND WE HAVE PREVIOUSLY SHOWN THAT MODM2 IS THE PREDOMINANT ALLELE, WHILE MODM3 IS ASSOCIATED WITH OM. PHASE-VARIABLE DNA METHYLTRANSFERASES MEDIATE EPIGENETIC REGULATION AND MODULATE PATHOGENESIS IN SEVERAL BACTERIA. MODM2 OF M. CATARRHALIS REGULATES THE EXPRESSION OF A PHASEVARION CONTAINING GENES IMPORTANT FOR COLONIZATION AND INFECTION. HERE WE DESCRIBE THE PHASE-VARIABLE EXPRESSION OF MODM3, THE MODM3 METHYLATION SITE AND THE SUITE OF GENES REGULATED WITHIN THE MODM3 PHASEVARION. RESULTS: PHASE-VARIABLE EXPRESSION OF MODM3, MEDIATED BY VARIATION IN LENGTH OF A 5'-(CAAC)(N)-3' TETRANUCLEOTIDE REPEAT TRACT IN THE OPEN READING FRAME WAS DEMONSTRATED IN M. CATARRHALIS STRAIN CCRI-195ME WITH GENESCAN FRAGMENT LENGTH ANALYSIS AND WESTERN IMMUNOBLOT. WE DETERMINED THAT MODM3 IS AN ACTIVE N6-ADENINE METHYLTRANSFERASE THAT METHYLATES THE SEQUENCE 5'-AC(M6)ATC-3'. METHYLATION WAS DETECTED AT ALL 4446 5'-ACATC-3' SITES IN THE GENOME WHEN MODM3 IS EXPRESSED. RNASEQ ANALYSIS IDENTIFIED 31 GENES THAT ARE DIFFERENTIALLY EXPRESSED BETWEEN MODM3 ON AND OFF VARIANTS, INCLUDING FIVE GENES THAT ARE INVOLVED IN THE RESPONSE TO OXIDATIVE AND NITROSATIVE STRESS, WITH POTENTIAL ROLES IN BIOFILM FORMATION AND SURVIVAL IN ANAEROBIC ENVIRONMENTS. AN IN VIVO CHINCHILLA (CHINCHILLA LANIGERA) MODEL OF OTITIS MEDIA DEMONSTRATED THAT TRANSBULLAR CHALLENGE WITH THE MODM3 OFF VARIANT RESULTED IN AN INCREASED MIDDLE EAR BACTERIAL LOAD COMPARED TO A MODM3 ON VARIANT. IN ADDITION, CO-INFECTION EXPERIMENTS WITH NTHI AND M. CATARRHALIS MODM3 ON OR MODM3 OFF VARIANTS REVEALED THAT PHASE VARIATION OF MODM3 ALTERED SURVIVAL OF NTHI IN THE MIDDLE EAR DURING EARLY AND LATE STAGE INFECTION. CONCLUSIONS: PHASE VARIATION OF MODM3 EPIGENETICALLY REGULATES THE EXPRESSION OF A PHASEVARION CONTAINING MULTIPLE GENES THAT ARE POTENTIALLY IMPORTANT IN THE PROGRESSION OF OTITIS MEDIA. 2019 4 1080 29 CLOSED COMPLETE GENOME SEQUENCES OF TWO NONTYPEABLE HAEMOPHILUS INFLUENZAE STRAINS CONTAINING NOVEL MODA ALLELES FROM THE SPUTUM OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE. NONTYPEABLE HAEMOPHILUS INFLUENZAE (NTHI) IS AN IMPORTANT BACTERIAL PATHOGEN THAT CAUSES OTITIS MEDIA AND EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). HERE, WE REPORT THE COMPLETE GENOME SEQUENCES OF NTHI STRAINS 10P129H1 AND 84P36H1, ISOLATED FROM COPD PATIENTS, WHICH CONTAIN THE PHASE-VARIABLE EPIGENETIC REGULATORS MODA15 AND MODA18, RESPECTIVELY. 2018 5 4718 24 NON-TYPEABLE HAEMOPHILUS INFLUENZAE ISOLATES FROM PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE CONTAIN NEW PHASE-VARIABLE MODA METHYLTRANSFERASE ALLELES CONTROLLING PHASEVARIONS. PHASEVARIONS (PHASE-VARIABLE REGULONS) ARE EMERGING AS AN IMPORTANT AREA OF BACTERIAL GENE REGULATION. MANY BACTERIAL PATHOGENS CONTAIN PHASEVARIONS, WITH GENE EXPRESSION CONTROLLED BY THE PHASE-VARIABLE EXPRESSION OF DNA METHYLTRANSFERASES VIA EPIGENETIC MECHANISMS. NON-TYPEABLE HAEMOPHILUS INFLUENZAE (NTHI) CONTAINS THE PHASE-VARIABLE METHYLTRANSFERASE MODA, OF WHICH MULTIPLE ALLELIC VARIANTS EXIST (MODA1-21). WE HAVE PREVIOUSLY DEMONSTRATED 5 OF 21 THESE MODA ALLELES ARE OVERREPRESENTED IN NTHI STRAINS ISOLATED FROM CHILDREN WITH MIDDLE EAR INFECTIONS. IN THIS STUDY WE INVESTIGATED THE MODA ALLELE DISTRIBUTION IN NTHI STRAINS ISOLATED FROM PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE, COPD. WE DEMONSTRATE THAT THE DISTRIBUTION OF MODA ALLELES IN A LARGE PANEL OF COPD ISOLATES IS DIFFERENT TO THE DISTRIBUTION SEEN IN MIDDLE EAR INFECTIONS, SUGGESTING DIFFERENT MODA ALLELES MAY PROVIDE DISTINCT ADVANTAGES IN THE DIFFERING NICHES OF THE MIDDLE EAR AND COPD AIRWAYS. WE ALSO IDENTIFIED TWO NEW PHASE-VARIABLE MODA ALLELES - MODA15 AND MODA18 - AND DEMONSTRATE THAT THESE ALLELES METHYLATE DISTINCT DNA SEQUENCES AND CONTROL UNIQUE PHASEVARIONS. THE MODA15 AND MODA18 ALLELES HAVE ONLY BEEN OBSERVED IN COPD ISOLATES, INDICATING THAT THESE TWO ALLELES MAY BE MARKERS FOR ISOLATES LIKELY TO CAUSE EXACERBATIONS OF COPD. 2019 6 4494 28 MORAXELLA CATARRHALIS RESTRICTION-MODIFICATION SYSTEMS ARE ASSOCIATED WITH PHYLOGENETIC LINEAGE AND DISEASE. MORAXELLA CATARRHALIS IS A HUMAN-ADAPTED PATHOGEN, AND A MAJOR CAUSE OF OTITIS MEDIA (OM) AND EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. THE SPECIES IS COMPRISED OF TWO MAIN PHYLOGENETIC LINEAGES, RB1 AND RB2/3. RESTRICTION-MODIFICATION (R-M) SYSTEMS ARE AMONG THE FEW LINEAGE-ASSOCIATED GENES IDENTIFIED IN OTHER BACTERIAL GENERA AND HAVE MULTIPLE FUNCTIONS INCLUDING DEFENSE AGAINST FOREIGN INVADING DNA, MAINTENANCE OF SPECIATION, AND EPIGENETIC REGULATION OF GENE EXPRESSION. HERE, WE DEFINE THE REPERTOIRE OF R-M SYSTEMS IN 51 PUBLICLY AVAILABLE M. CATARRHALIS GENOMES AND REPORT THEIR DISTRIBUTION AMONG M. CATARRHALIS PHYLOGENETIC LINEAGES. AN ASSOCIATION WITH PHYLOGENETIC LINEAGE (RB1 OR RB2/3) WAS OBSERVED FOR SIX R-M SYSTEMS, WHICH MAY CONTRIBUTE TO THE EVOLUTION OF THE LINEAGES BY RESTRICTING DNA TRANSFORMATION. IN ADDITION, WE OBSERVED A RELATIONSHIP BETWEEN A MUTUALLY EXCLUSIVE TYPE I R-M SYSTEM AND A TYPE III R-M SYSTEM AT A SINGLE LOCUS CONSERVED THROUGHOUT A GEOGRAPHICALLY AND CLINICALLY DIVERSE SET OF M. CATARRHALIS ISOLATES. THE TYPE III R-M SYSTEM AT THIS LOCUS CONTAINS THE PHASE-VARIABLE TYPE III DNA METHYLTRANSFERASE, MODM, WHICH CONTROLS A PHASEVARION (PHASE-VARIABLE REGULON). WE OBSERVED AN ASSOCIATION BETWEEN MODM PRESENCE AND OM-ASSOCIATED MIDDLE EAR ISOLATES, INDICATING A POTENTIAL ROLE FOR MODM-MEDIATED EPIGENETIC REGULATION IN OM PATHOBIOLOGY. 2018 7 2273 21 EPIGENETIC REGULATION ALTERS BIOFILM ARCHITECTURE AND COMPOSITION IN MULTIPLE CLINICAL ISOLATES OF NONTYPEABLE HAEMOPHILUS INFLUENZAE. BIOFILMS PLAY A CRITICAL ROLE IN THE COLONIZATION, PERSISTENCE, AND PATHOGENESIS OF MANY HUMAN PATHOGENS. MULTIPLE MUCOSA-ASSOCIATED PATHOGENS HAVE EVOLVED A MECHANISM OF RAPID ADAPTATION, TERMED THE PHASEVARION, WHICH FACILITATES A COORDINATED REGULATION OF NUMEROUS GENES THROUGHOUT THE BACTERIAL GENOME. THIS EPIGENETIC REGULATION OCCURS VIA PHASE VARIATION OF A DNA METHYLTRANSFERASE, MOD. THE PHASEVARION OF NONTYPEABLE HAEMOPHILUS INFLUENZAE (NTHI) SIGNIFICANTLY AFFECTS THE SEVERITY OF EXPERIMENTAL OTITIS MEDIA AND REGULATES SEVERAL DISEASE-RELATED PROCESSES. HOWEVER, THE ROLE OF THE NTHI PHASEVARION IN BIOFILM FORMATION IS UNCLEAR. THE PRESENT STUDY SHOWS THAT THE PHASEVARIONS OF MULTIPLE NTHI CLINICAL ISOLATES REGULATE IN VITRO BIOFILM FORMATION UNDER DISEASE-SPECIFIC MICROENVIRONMENTAL CONDITIONS. THE IMPACT OF PHASEVARION REGULATION WAS GREATEST UNDER ALKALINE CONDITIONS THAT MIMIC THOSE KNOWN TO OCCUR IN THE MIDDLE EAR DURING DISEASE. UNDER ALKALINE CONDITIONS, NTHI STRAINS THAT EXPRESS THE MODA2 METHYLTRANSFERASE FORMED BIOFILMS WITH SIGNIFICANTLY GREATER BIOMASS AND LESS DISTINCT ARCHITECTURE THAN THOSE FORMED BY A MODA2-DEFICIENT POPULATION. THE BIOFILMS FORMED BY NTHI STRAINS THAT EXPRESS MODA2 ALSO CONTAINED LESS EXTRACELLULAR DNA (EDNA) AND SIGNIFICANTLY LESS EXTRACELLULAR HU, A DNABII DNA-BINDING PROTEIN CRITICAL FOR BIOFILM STRUCTURAL STABILITY. STABLE BIOFILM STRUCTURE IS CRITICAL FOR BACTERIAL PATHOGENESIS AND PERSISTENCE IN MULTIPLE EXPERIMENTAL MODELS OF DISEASE. THESE RESULTS IDENTIFY A ROLE FOR THE PHASEVARION IN REGULATION OF BIOFILM FORMATION, A PROCESS INTEGRAL TO THE CHRONIC NATURE OF MANY INFECTIONS. UNDERSTANDING THE ROLE OF THE PHASEVARION IN BIOFILM FORMATION IS CRITICAL TO THE DEVELOPMENT OF PREVENTION AND TREATMENT STRATEGIES FOR THESE CHRONIC DISEASES.IMPORTANCE UPPER RESPIRATORY TRACT INFECTIONS ARE THE NUMBER ONE REASON FOR A CHILD TO VISIT THE EMERGENCY DEPARTMENT, AND OTITIS MEDIA (MIDDLE EAR INFECTION) RANKS THIRD OVERALL. BIOFILMS CONTRIBUTE SIGNIFICANTLY TO THE CHRONIC NATURE OF BACTERIAL RESPIRATORY TRACT INFECTIONS, INCLUDING OTITIS MEDIA, AND MAKE THESE DISEASES PARTICULARLY DIFFICULT TO TREAT. SEVERAL MUCOSA-ASSOCIATED HUMAN PATHOGENS UTILIZE A MECHANISM OF RAPID ADAPTATION TERMED THE PHASEVARION, OR PHASEVARIABLE REGULON, TO RESIST ENVIRONMENTAL AND HOST IMMUNE PRESSURES. IN THIS STUDY, WE ASSESSED THE ROLE OF THE PHASEVARION IN REGULATION OF BIOFILM FORMATION BY NONTYPEABLE HAEMOPHILUS INFLUENZAE (NTHI), WHICH CAUSES NUMEROUS RESPIRATORY TRACT DISEASES. WE FOUND THAT THE NTHI PHASEVARION REGULATES BIOFILM STRUCTURE AND CRITICAL BIOFILM MATRIX COMPONENTS UNDER DISEASE-SPECIFIC CONDITIONS. THE FINDINGS OF THIS WORK COULD BE SIGNIFICANT IN THE DESIGN OF IMPROVED STRATEGIES AGAINST NTHI INFECTIONS, AS WELL AS DISEASES DUE TO OTHER PATHOGENS THAT UTILIZE A PHASEVARION. 2018 8 4493 18 MORAXELLA CATARRHALIS INDUCES INFLAMMATORY RESPONSE OF BRONCHIAL EPITHELIAL CELLS VIA MAPK AND NF-KAPPAB ACTIVATION AND HISTONE DEACETYLASE ACTIVITY REDUCTION. MORAXELLA CATARRHALIS IS A MAJOR CAUSE OF INFECTIOUS EXACERBATIONS OF CHRONIC OBSTRUCTIVE LUNG DISEASE (COPD) AND MAY ALSO CONTRIBUTE TO THE PATHOGENESIS OF COPD. LITTLE IS KNOWN ABOUT M. CATARRHALIS-BRONCHIAL EPITHELIUM INTERACTION. WE INVESTIGATED ACTIVATION OF M. CATARRHALIS INFECTED BRONCHIAL EPITHELIAL CELLS AND CHARACTERIZED THE SIGNAL TRANSDUCTION PATHWAYS. MOREOVER, WE TESTED THE HYPOTHESIS THAT THE M. CATARRHALIS-INDUCED CYTOKINE EXPRESSION IS REGULATED BY ACETYLATION OF HISTONE RESIDUES AND CONTROLLED BY HISTONE DEACETYLASE ACTIVITY (HDAC). WE DEMONSTRATED THAT M. CATARRHALIS INDUCED A STRONG TIME- AND DOSE-DEPENDENT INFLAMMATORY RESPONSE IN THE BRONCHIAL EPITHELIAL CELL LINE (BEAS-2B), CHARACTERIZED BY THE RELEASE OF IL-8 AND GM-CSF. FOR THIS CYTOKINE LIBERATION ACTIVATION OF THE ERK AND P38 MITOGEN-ACTIVATED PROTEIN (MAP) KINASES AND TRANSCRIPTION FACTOR NF-KAPPAB WAS REQUIRED. FURTHERMORE, M. CATARRHALIS-INFECTED BRONCHIAL EPITHELIAL CELLS SHOWED AN ENHANCED ACETYLATION OF HISTONE H3 AND H4 GLOBALLY AND AT THE PROMOTER OF THE IL8 GENE. PREVENTING HISTONE DEACETYLATION BY THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A AUGMENTED THE M. CATARRHALIS-INDUCED IL-8 RESPONSE. AFTER EXPOSURE TO M. CATARRHALIS, WE FOUND A DECREASE IN GLOBAL HISTONE DEACETYLASE EXPRESSION AND ACTIVITY. OUR FINDINGS SUGGEST THAT M. CATARRHALIS-INDUCED ACTIVATION OF IL8 GENE TRANSCRIPTION WAS CAUSED BY INTERFERENCE WITH EPIGENETIC MECHANISMS REGULATING IL8 GENE ACCESSIBILITY. OUR FINDINGS PROVIDE INSIGHT INTO IMPORTANT MOLECULAR AND CELLULAR MECHANISMS OF M. CATARRHALIS-INDUCED ACTIVATION OF HUMAN BRONCHIAL EPITHELIUM. 2006 9 2084 13 EPIGENETIC DYSFUNCTION IN TURNER SYNDROME IMMUNE CELLS. TURNER SYNDROME (TS) IS A CHROMOSOMAL CONDITION ASSOCIATED WITH PARTIAL OR COMPLETE ABSENCE OF THE X CHROMOSOME THAT INVOLVES CHARACTERISTIC FINDINGS IN MULTIPLE ORGAN SYSTEMS. IN ADDITION TO WELL-KNOWN CLINICAL CHARACTERISTICS SUCH AS SHORT STATURE AND GONADAL FAILURE, TS IS ALSO ASSOCIATED WITH T CELL IMMUNE ALTERATIONS AND CHRONIC OTITIS MEDIA, SUGGESTIVE OF A POSSIBLE IMMUNE DEFICIENCY. RECENTLY, UBIQUITOUSLY TRANSCRIBED TETRATRICOPEPTIDE REPEAT ON THE X CHROMOSOME (UTX), A HISTONE H3 LYSINE 27 (H3K27) DEMETHYLASE, HAS BEEN IDENTIFIED AS A DOWNREGULATED GENE IN TS IMMUNE CELLS. IMPORTANTLY, UTX IS AN X-LINKED GENE THAT ESCAPES X-CHROMOSOME INACTIVATION AND THUS IS HAPLOINSUFFICIENT IN TS. MICE WITH T CELL-SPECIFIC UTX DEFICIENCY HAVE IMPAIRED CLEARANCE OF CHRONIC VIRAL INFECTION DUE TO DECREASED FREQUENCIES OF T FOLLICULAR HELPER (TFH) CELLS, WHICH ARE CRITICAL FOR B CELL ANTIBODY GENERATION. IN PARALLEL, TS PATIENTS HAVE DECREASED TFH FREQUENCIES IN PERIPHERAL BLOOD. TOGETHER, THESE FINDINGS SUGGEST THAT HAPLOINSUFFICIENCY OF THE X-LINKED UTX GENE IN TS T CELLS UNDERLIES AN IMMUNE DEFICIT, WHICH MAY MANIFEST AS INCREASED PREDISPOSITION TO CHRONIC OTITIS MEDIA. 2016 10 2977 15 GENETIC AND PHENOTYPIC CHARACTERIZATION OF IN-HOST DEVELOPED AZOLE-RESISTANT ASPERGILLUS FLAVUS ISOLATES. ASPERGILLUS FLAVUS IS A PATHOGENIC FUNGAL SPECIES THAT CAN CAUSE PULMONARY ASPERGILLOSIS, AND TRIAZOLE COMPOUNDS ARE USED FOR THE TREATMENT OF THESE INFECTIONS. PROLONGED EXPOSURE TO AZOLES MAY SELECT FOR COMPENSATORY MUTATIONS IN THE A. FLAVUS GENOME, RESULTING IN AZOLE RESISTANCE. HERE, WE CHARACTERIZE A SERIES OF 11 ISOGENIC A. FLAVUS STRAINS ISOLATED FROM A PATIENT WITH PULMONARY ASPERGILLOSIS. OVER A PERIOD OF THREE MONTHS, THE INITIALLY AZOLE-SUSCEPTIBLE STRAIN DEVELOPED ITRACONAZOLE AND VORICONAZOLE RESISTANCE. SHORT TANDEM REPEAT ANALYSIS AND WHOLE-GENOME SEQUENCING REVEALED THE HIGH GENETIC RELATEDNESS OF ALL ISOLATES, INDICATING AN INFECTION WITH ONE SINGLE ISOLATE. IN CONTRAST, THE ISOLATES WERE MACROSCOPICALLY HIGHLY DIVERSE, SUGGESTING AN ADAPTATION TO THE ENVIRONMENT DUE TO (EPI)GENETIC CHANGES. THE WHOLE-GENOME SEQUENCING OF SUSCEPTIBLE AND AZOLE-RESISTANT STRAINS SHOWED A NUMBER OF MUTATIONS THAT MIGHT BE ASSOCIATED WITH AZOLE RESISTANCE. THE MAJORITY OF RESISTANT STRAINS CONTAIN A Y119F MUTATION IN THE CYP51A GENE, WHICH CORRESPONDS TO THE Y121F MUTATION FOUND IN A. FUMIGATUS. ONE AZOLE-RESISTANT STRAIN DEMONSTRATED A DIVERGENT SET OF MUTATIONS, INCLUDING A V99A MUTATION IN A MAJOR FACILITATOR SUPERFAMILY (MSF) MULTIDRUG TRANSPORTER (AFLA 083950). 2021 11 3025 14 GENETICS AND PATHOPHYSIOLOGY OF GRANULOMATOSIS WITH POLYANGIITIS (GPA) AND ITS MAIN AUTOANTIGEN PROTEINASE 3. GRANULOMATOSIS WITH POLYANGIITIS (GPA) IS A SEVERE AUTOIMMUNE DISEASE AND ONE OF THE SMALL VESSEL ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY (ANCA)-ASSOCIATED VASCULITIDES. ALTHOUGH ITS ETIOLOGY AND PATHOPHYSIOLOGY ARE STILL WIDELY UNKNOWN, IT IS ACCEPTED THAT INFECTIONS, ENVIRONMENTAL FACTORS, EPIGENETIC MODIFICATIONS, AND A GENETIC PREDISPOSITION PROVIDE THE BASIS FOR THIS SYSTEMIC DISORDER. GPA TYPICALLY EVOLVES INTO TWO PHASES: AN INITIAL PHASE CHARACTERIZED BY EAR, NOSE AND THROAT (ENT) MANIFESTATIONS, SUCH AS CHRONIC SINUSITIS AND OTITIS, ULCERATION OF THE ORAL CAVITY AND PHARYNX, AS WELL AS PULMONARY NODULES AND A SEVERE GENERALIZED PHASE, DEFINED BY THE OCCURRENCE OF RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS, PULMONARY HEMORRHAGE, AND ARTHRITIS. ANCAS, DIRECTED AGAINST THE NEUTROPHILIC ENZYMES PROTEINASE 3 AND MYELOPEROXIDASE, ARE PRESENT IN UP TO 90% OF THE AFFECTED PATIENTS IN THE SYSTEMIC PHASE. AS THE HUMORAL IMMUNITY IS PREDOMINANTLY DIRECTED AGAINST NEUTROPHILIC ANTIGENS, IT IS APPARENT THAT NEUTROPHILS PLAY A CRITICAL ROLE IN GPA BOTH AS TARGET AND EFFECTOR CELLS. ALTHOUGH GPA PATHOGENESIS IS NOT WELL KNOWN, SOME SUSCEPTIBILITY GENES AND LOCI HAVE BEEN IDENTIFIED BY CANDIDATE GENE APPROACHES, GENOME-WIDE ASSOCIATION STUDIES, AND META-ANALYSES, AS WELL AS FAMILIAL ASSOCIATION STUDIES. SUCH GENES ARE CTLA4, PTPN22, COL11A2, SERPINA1, AND THE MHC CLASS II GENE CLUSTER. THIS REVIEW HIGHLIGHTS THE CLINICAL, PATHOPHYSIOLOGICAL, AND GENETIC BACKGROUND OF GPA AND AIMS TO GIVE AN OVERVIEW OF RECENT EFFORTS TO IDENTIFY GPA SUSCEPTIBILITY GENES. WE POINT OUT THE GENETIC BASIS OF THE MAIN AUTOANTIGEN PR3 AND WHY IT IS SO DIFFICULT TO ESTABLISH A MURINE GPA MODEL. 2016 12 5340 12 QUORUM SENSING AND VIRULENCE OF PSEUDOMONAS AERUGINOSA DURING LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. PSEUDOMONAS AERUGINOSA IS THE PREDOMINANT MICROORGANISM IN CHRONIC LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. THE CHRONIC LUNG INFECTION IS PRECEDED BY INTERMITTENT COLONIZATION. WHEN THE CHRONIC INFECTION BECOMES ESTABLISHED, IT IS WELL ACCEPTED THAT THE ISOLATED STRAINS DIFFER PHENOTYPICALLY FROM THE INTERMITTENT STRAINS. DOMINATING CHANGES ARE THE SWITCH TO MUCOIDITY (ALGINATE OVERPRODUCTION) AND LOSS OF EPIGENETIC REGULATION OF VIRULENCE SUCH AS THE QUORUM SENSING (QS). TO ELUCIDATE THE DYNAMICS OF P. AERUGINOSA QS SYSTEMS DURING LONG TERM INFECTION OF THE CF LUNG, WE HAVE INVESTIGATED 238 ISOLATES OBTAINED FROM 152 CF PATIENTS AT DIFFERENT STAGES OF INFECTION RANGING FROM INTERMITTENT TO LATE CHRONIC. ISOLATES WERE CHARACTERIZED WITH REGARD TO QS SIGNAL MOLECULES, ALGINATE, RHAMNOLIPID AND ELASTASE PRODUCTION AND MUTANT FREQUENCY. THE GENETIC BASIS FOR CHANGE IN QS REGULATION WERE INVESTIGATED AND IDENTIFIED BY SEQUENCE ANALYSIS OF LASR, RHLR, LASI AND RHLI. THE FIRST QS SYSTEM TO BE LOST WAS THE ONE ENCODED BY LAS SYSTEM 12 YEARS (MEDIAN VALUE) AFTER THE ONSET OF THE LUNG INFECTION WITH SUBSEQUENT LOSS OF THE RHL ENCODED SYSTEM AFTER 17 YEARS (MEDIAN VALUE) SHOWN AS DEFICIENCIES IN PRODUCTION OF THE 3-OXO-C12-HSL AND C4-HSL QS SIGNAL MOLECULES RESPECTIVELY. THE CONCOMITANT DEVELOPMENT OF QS MALFUNCTION SIGNIFICANTLY CORRELATED WITH THE REDUCED PRODUCTION OF RHAMNOLIPIDS AND ELASTASE AND WITH THE OCCURRENCE OF MUTATIONS IN THE REGULATORY GENES LASR AND RHLR. ACCUMULATION OF MUTATIONS IN BOTH LASR AND RHLR CORRELATED WITH DEVELOPMENT OF HYPERMUTABILITY. INTERESTINGLY, A HIGHER NUMBER OF MUCOID ISOLATES WERE FOUND TO PRODUCE C4-HSL SIGNAL MOLECULES AND RHAMNOLIPIDS COMPARED TO THE NON-MUCOID ISOLATES. AS SEEN FROM THE PRESENT DATA, WE CAN CONCLUDE THAT P. AERUGINOSA AND PARTICULARLY THE MUCOID STRAINS DO NOT LOSE THE QS REGULATION OR THE ABILITY TO PRODUCE RHAMNOLIPIDS UNTIL THE LATE STAGE OF THE CHRONIC INFECTION. 2010 13 6632 14 UNDERSTANDING THE ROLE OF THE CHROMOSOME 15Q25.1 IN COPD THROUGH EPIGENETICS AND TRANSCRIPTOMICS. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A MAJOR HEALTH BURDEN IN ADULTS AND CIGARETTE SMOKING IS CONSIDERED THE MOST IMPORTANT ENVIRONMENTAL RISK FACTOR OF COPD. CHROMOSOME 15Q25.1 LOCUS IS ASSOCIATED WITH BOTH COPD AND SMOKING. OUR STUDY AIMS AT UNDERSTANDING THE MECHANISM UNDERLYING THE ASSOCIATION OF CHROMOSOME 15Q25.1 WITH COPD THROUGH EPIGENETIC AND TRANSCRIPTIONAL VARIATION IN A POPULATION-BASED SETTING. TO ASSESS IF COPD-ASSOCIATED VARIANTS IN 15Q25.1 ARE METHYLATION QUANTITATIVE TRAIT LOCI, EPIGENOME-WIDE ASSOCIATION ANALYSIS OF FOUR GENETIC VARIANTS, PREVIOUSLY ASSOCIATED WITH COPD (P < 5 X 10(-8)) IN THE 15Q25.1 LOCUS (RS12914385:C>T-CHRNA3, RS8034191:T>C-HYKK, RS13180:C>T-IREB2 AND RS8042238:C>T-IREB2), WAS PERFORMED IN THE ROTTERDAM STUDY (N = 1489). ALL FOUR VARIANTS WERE SIGNIFICANTLY ASSOCIATED (P < 1.4 X 10(-6)) WITH BLOOD DNA METHYLATION OF IREB2, CHRNA3 AND PSMA4, OF WHICH TWO, INCLUDING IREB2 AND PSMA4, WERE ALSO DIFFERENTIALLY METHYLATED IN COPD CASES AND CONTROLS (P < 0.04). FURTHER ADDITIVE AND MULTIPLICATIVE EFFECTS OF SMOKING WERE EVALUATED AND NO SIGNIFICANT EFFECT WAS OBSERVED. TO EVALUATE IF THESE FOUR GENETIC VARIANTS ARE EXPRESSION QUANTITATIVE TRAIT LOCI, TRANSCRIPTOME-WIDE ASSOCIATION ANALYSIS WAS PERFORMED IN 1087 LUNG SAMPLES. ALL FOUR VARIANTS WERE ALSO SIGNIFICANTLY ASSOCIATED WITH DIFFERENTIAL EXPRESSION OF THE IREB2 3'UTR IN LUNG TISSUES (P < 5.4 X 10(-95)). WE CONCLUDE THAT REGULATORY MECHANISMS AFFECTING THE EXPRESSION OF IREB2 GENE, SUCH AS DNA METHYLATION, MAY EXPLAIN THE ASSOCIATION BETWEEN GENETIC VARIANTS IN CHROMOSOME 15Q25.1 AND COPD, LARGELY INDEPENDENT OF SMOKING. 2018 14 31 12 A CASE OF INFECTION-ASSOCIATED ANTIPROTEINASE-3-NEGATIVE CYTOPLASMIC ANTINEUTROPHIL CYTOPLASMIC ANTIBODY PAUCI-IMMUNE FOCAL NECROTIZING GLOMERULONEPHRITIS. WE PRESENT THE CASE OF A MAN WITH GRAM-NEGATIVE SEPSIS AND EXPOSURE TO ORAL SILICA WHO DEVELOPED PAUCI-IMMUNE FOCAL NECROTIZING GLOMERULONEPHRITIS (PI-FNGN) IN THE SETTING OF A SUBACUTE POLYMICROBIAL CENTRAL VENOUS LINE (CVL) INFECTION. HE DEVELOPED A CYTOPLASMIC ANTINEUTROPHIL CYTOPLASMIC AUTOANTIBODY (C-ANCA) THAT WAS ANTIPROTEINASE-3 (PR-3) AND ANTIMYELOPEROXIDASE (MPO) ANTIBODY NEGATIVE. WE BELIEVE THIS IS THE FIRST REPORTED CASE OF GRAM-NEGATIVE SEPSIS-ASSOCIATED PI-FNGN. CHRONIC SILICA EXPOSURE IS A LEADING ENVIRONMENTAL RISK FACTOR IN THE DEVELOPMENT OF ANCA VASCULITIS. ORAL SILICA IS A COMMON PHARMACEUTICAL ADDITIVE AND ITS BIOAVAILABILITY IS BEING RECOGNIZED. ORAL SILICA, THEREFORE, MAY ALSO BE A RISK FOR DEVELOPMENT OF AUTOREACTIVITY. THE PI-FNGN RESOLVED WITH ANTIBIOTIC THERAPY ALONE. THE C-ANCA TITER DECLINED AS THE PI-FNGN RESOLVED. THE CASE SUPPORTS EXPERIMENTAL AND OBSERVATIONAL RESEARCH THAT ENVIRONMENTAL EXPOSURES ACT AS ADJUVANTS FOR AN IMMUNE RESPONSE AND ALSO PROVIDE EPIGENETIC TRIGGERS FOR AUTOREACTIVITY. THE C-ANCA WAS NEGATIVE FOR PR-3, ITS MAJOR ANTIGEN. C-ANCA ANTIGEN SPECIFICITY MAY DEPEND ON THE PATHOGENESIS OF THE UNDERLYING DISEASE, POTENTIALLY ELICITED BY A CROSS-REACTION OF AN ANTIBODY TO FOREIGN AND SELF TARGET ANTIGEN SEQUENCE HOMOLOGY OR ALTERNATIVELY ELICITED BY ANTIGENIC EPITOPE SPREAD. 2010 15 5228 15 PRMT7 TARGETS OF FOXM1 CONTROLS ALVEOLAR MYOFIBROBLAST PROLIFERATION AND DIFFERENTIATION DURING ALVEOLOGENESIS. ALTHOUGH ABERRANT ALVEOLAR MYOFIBROBLASTS (AMYFS) PROLIFERATION AND DIFFERENTIATION ARE OFTEN ASSOCIATED WITH ABNORMAL LUNG DEVELOPMENT AND DISEASES, SUCH AS BRONCHOPULMONARY DYSPLASIA (BPD), CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), AND IDIOPATHIC PULMONARY FIBROSIS (IPF), EPIGENETIC MECHANISMS REGULATING PROLIFERATION AND DIFFERENTIATION OF AMYFS REMAIN POORLY UNDERSTOOD. PROTEIN ARGININE METHYLTRANSFERASE 7 (PRMT7) IS THE ONLY REPORTED TYPE III ENZYME RESPONSIBLE FOR MONOMETHYLATION OF ARGININE RESIDUE ON BOTH HISTONE AND NONHISTONE SUBSTRATES. HERE WE PROVIDE EVIDENCE FOR PRMT7'S FUNCTION IN REGULATING AMYFS PROLIFERATION AND DIFFERENTIATION DURING LUNG ALVEOLOGENESIS. IN PRMT7-DEFICIENT MICE, WE FOUND REDUCED AMYFS PROLIFERATION AND DIFFERENTIATION, ABNORMAL ELASTIN DEPOSITION, AND FAILURE OF ALVEOLAR SEPTUM FORMATION. WE FURTHER SHOWN THAT ONCOGENE FORKHEAD BOX M1 (FOXM1) IS A DIRECT TARGET OF PRMT7 AND THAT PRMT7-CATALYZED MONOMETHYLATION AT HISTONE H4 ARGININE 3 (H4R3ME1) DIRECTLY ASSOCIATE WITH CHROMATIN OF FOXM1 TO ACTIVATE ITS TRANSCRIPTION, AND THEREBY REGULATE OF CELL CYCLE-RELATED GENES TO INHIBIT AMYFS PROLIFERATION AND DIFFERENTIATION. OVEREXPRESSION OF FOXM1 IN ISOLATED MYOFIBROBLASTS (MYFS) SIGNIFICANTLY RESCUED PRMT7-DEFICIENCY-INDUCED CELL PROLIFERATION AND DIFFERENTIATION DEFECTS. THUS, OUR RESULTS REVEAL A NOVEL EPIGENETIC MECHANISM THROUGH WHICH PRMT7-MEDIATED HISTONE ARGININE MONOMETHYLATION ACTIVATES FOXM1 TRANSCRIPTIONAL EXPRESSION TO REGULATE AMYFS PROLIFERATION AND DIFFERENTIATION DURING LUNG ALVEOLOGENESIS AND MAY REPRESENT A POTENTIAL TARGET FOR INTERVENTION IN PULMONARY DISEASES. 2021 16 1187 14 COPD GWAS VARIANT AT 19Q13.2 IN RELATION WITH DNA METHYLATION AND GENE EXPRESSION. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS AMONG THE MAJOR HEALTH BURDENS IN ADULTS. WHILE CIGARETTE SMOKING IS THE LEADING RISK FACTOR, A GROWING NUMBER OF GENETIC VARIATIONS HAVE BEEN DISCOVERED TO INFLUENCE DISEASE SUSCEPTIBILITY. EPIGENETIC MODIFICATIONS MAY MEDIATE THE RESPONSE OF THE GENOME TO SMOKING AND REGULATE GENE EXPRESSION. CHROMOSOME 19Q13.2 REGION IS ASSOCIATED WITH BOTH SMOKING AND COPD, YET ITS FUNCTIONAL ROLE IS UNCLEAR. OUR STUDY AIMED TO DETERMINE WHETHER RS7937 (RAB4B, EGLN2), A TOP GENETIC VARIANT IN 19Q13.2 REGION IDENTIFIED IN GENOME-WIDE ASSOCIATION STUDIES OF COPD, IS ASSOCIATED WITH DIFFERENTIAL DNA METHYLATION IN BLOOD (N = 1490) AND GENE EXPRESSION IN BLOOD (N = 721) AND LUNGS (N = 1087). WE COMBINED GENETIC AND EPIGENETIC DATA FROM THE ROTTERDAM STUDY (RS) TO PERFORM THE EPIGENOME-WIDE ASSOCIATION ANALYSIS OF RS7937. FURTHER, WE USED GENETIC AND TRANSCRIPTOMIC DATA FROM BLOOD (RS) AND FROM LUNG TISSUE (LUNG EXPRESSION QUANTITATIVE TRAIT LOCI MAPPING STUDY), TO PERFORM THE TRANSCRIPTOME-WIDE ASSOCIATION STUDY OF RS7937. RS7937 WAS SIGNIFICANTLY (FDR < 0.05) AND CONSISTENTLY ASSOCIATED WITH DIFFERENTIAL DNA METHYLATION IN BLOOD AT 4 CPG SITES IN CIS, INDEPENDENT OF SMOKING. ONE METHYLATION SITE (CG11298343-EGLN2) WAS ALSO ASSOCIATED WITH COPD (P = 0.001). ADDITIONALLY, RS7937 WAS ASSOCIATED WITH GENE EXPRESSION LEVELS IN BLOOD IN CIS (EGLN2), 42% MEDIATED THROUGH CG11298343, AND IN LUNG TISSUE, IN CIS AND TRANS (NUMBL, EGLN2, DNMT3A, LOC101929709 AND PAK2). OUR RESULTS SUGGEST THAT CHANGES OF DNA METHYLATION AND GENE EXPRESSION MAY BE INTERMEDIATE STEPS BETWEEN GENETIC VARIANTS AND COPD, BUT FURTHER CAUSAL STUDIES IN LUNG TISSUE SHOULD CONFIRM THIS HYPOTHESIS. 2018 17 5016 17 PERSISTENT BACTERIAL COINFECTION OF A COVID-19 PATIENT CAUSED BY A GENETICALLY ADAPTED PSEUDOMONAS AERUGINOSA CHRONIC COLONIZER. PSEUDOMONAS AERUGINOSA IS A BIOFILM-FORMING OPPORTUNISTIC PATHOGEN WHICH CAUSES CHRONIC INFECTIONS IN IMMUNOCOMPROMISED PATIENTS AND LEADS TO HIGH MORTALITY RATE. IT IS IDENTIFIED AS A COMMON COINFECTING PATHOGEN IN COVID-19 PATIENTS CAUSING EXACERBATION OF ILLNESS. IN OUR HOSPITAL, P. AERUGINOSA IS ONE OF THE TOP COINFECTING BACTERIA IDENTIFIED AMONG COVID-19 PATIENTS. WE COLLECTED A STRONG BIOFILM-FORMING P. AERUGINOSA STRAIN DISPLAYING SMALL COLONY VARIANT MORPHOLOGY FROM A SEVERE COVID-19 PATIENT. GENOMIC AND TRANSCRIPTOMIC SEQUENCING ANALYSES WERE PERFORMED WITH PHENOTYPIC VALIDATION TO INVESTIGATE ITS ADAPTATION IN SARS-COV-2 INFECTED ENVIRONMENT. GENOMIC CHARACTERIZATION PREDICTED SPECIFIC GENOMIC ISLANDS HIGHLY ASSOCIATED WITH VIRULENCE, TRANSCRIPTIONAL REGULATION, AND DNA RESTRICTION-MODIFICATION SYSTEMS. EPIGENETIC ANALYSIS REVEALED A SPECIFIC N(6)-METHYL ADENINE (M(6)A) METHYLATING PATTERN INCLUDING METHYLATION OF ALGINATE, FLAGELLAR AND QUORUM SENSING ASSOCIATED GENES. DIFFERENTIAL GENE EXPRESSION ANALYSIS INDICATED THAT THIS ISOLATE FORMED EXCESSIVE BIOFILM BY REDUCING FLAGELLAR FORMATION (7.4 TO 1,624.1 FOLDS) AND OVERPRODUCING EXTRACELLULAR MATRIX COMPONENTS INCLUDING CDRA (4.4 FOLDS), ALGINATE (5.2 TO 29.1 FOLDS) AND PEL (4.8-5.5 FOLDS). IN SUMMARY, WE DEMONSTRATED THAT P. AEUGINOSA CLINICAL ISOLATES WITH NOVEL EPIGENETIC MARKERS COULD FORM EXCESSIVE BIOFILM, WHICH MIGHT ENHANCE ITS ANTIBIOTIC RESISTANCE AND IN VIVO COLONIZATION IN COVID-19 PATIENTS. 2021 18 6072 15 THE DNA METHYLOME OF HUMAN VASCULAR ENDOTHELIUM AND ITS USE IN LIQUID BIOPSIES. BACKGROUND: VASCULAR ENDOTHELIAL CELLS (VECS) ARE AN ESSENTIAL COMPONENT OF EACH TISSUE, CONTRIBUTE TO MULTIPLE PATHOLOGIES, AND ARE TARGETED BY IMPORTANT DRUGS. YET, THERE IS A SHORTAGE OF BIOMARKERS TO ASSESS VEC TURNOVER. METHODS: TO DEVELOP DNA METHYLATION-BASED LIQUID BIOPSIES FOR VECS, WE DETERMINED THE METHYLOME OF VECS ISOLATED FROM FRESHLY DISSOCIATED HUMAN TISSUES. FINDINGS: A COMPARISON WITH A HUMAN CELL-TYPE METHYLOME ATLAS YIELDED THOUSANDS OF LOCI THAT ARE UNIQUELY UNMETHYLATED IN VECS. THESE SITES ARE TYPICALLY GENE ENHANCERS, OFTEN RESIDING ADJACENT TO VEC-SPECIFIC GENES. WE ALSO IDENTIFIED HUNDREDS OF GENOMIC LOCI THAT ARE DIFFERENTIALLY METHYLATED IN ORGANOTYPIC VECS, INDICATING THAT VECS FEEDING SPECIFIC ORGANS ARE DISTINCT CELL TYPES WITH A STABLE EPIGENETIC IDENTITY. WE ESTABLISHED UNIVERSAL AND LUNG-SPECIFIC VEC MARKERS AND EVALUATED THEIR PRESENCE IN CIRCULATING CELL-FREE DNA (CFDNA). NEARLY 2.5% OF CFDNA IN THE PLASMA OF HEALTHY INDIVIDUALS ORIGINATES FROM VECS. SEPSIS, GRAFT VERSUS HOST DISEASE, AND CARDIAC CATHETERIZATION ARE ASSOCIATED WITH ELEVATED LEVELS OF VEC-DERIVED CFDNA, INDICATIVE OF VASCULAR DAMAGE. LUNG-SPECIFIC VEC CFDNA IS SELECTIVELY ELEVATED IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) OR LUNG CANCER, REVEALING TISSUE-SPECIFIC VASCULAR TURNOVER. CONCLUSIONS: VEC CFDNA BIOMARKERS INFORM VASCULAR DYNAMICS IN HEALTH AND DISEASE, POTENTIALLY CONTRIBUTING TO EARLY DIAGNOSIS AND MONITORING OF PATHOLOGIES, AND ASSESSMENT OF DRUG ACTIVITY. FUNDING: THIS WORK WAS SUPPORTED BY THE BEUTLER RESEARCH PROGRAM, HELMSLEY CHARITABLE TRUST, JDRF, GRAIL AND THE DON FOUNDATION (TO Y.D.). Y.D HOLDS THE WALTER & GRETA STIEL CHAIR IN HEART STUDIES. B.G., R.S., J.M., D.N., T.K., AND Y.D. FILED PATENTS ON CFDNA ANALYSIS. 2023 19 1422 11 DIFFERENTIAL CPG DNA METHYLATION OF PERIPHERAL B CELLS, CD4(+) T CELLS, AND SALIVARY GLAND TISSUES IN IGG4-RELATED DISEASE. OBJECTIVES: IMMUNOGLOBULIN-G4-RELATED DISEASE (IGG4-RD) IS A DISTINCT SYSTEMIC AUTOIMMUNE-MEDIATED DISEASE MANIFESTING AS CHRONIC INFLAMMATION AND TISSUE FIBROSIS. SINCE THE ROLE OF DNA METHYLATION IN THE PATHOGENESIS OF IGG4-RD IS STILL UNCLEAR, WE CONDUCT THIS STUDY TO INVESTIGATE EPIGENETIC MODIFICATIONS IN IGG4-RD. METHODS: A GENOME-WIDE DNA METHYLATION STUDY WAS CONDUCTED WITH B CELLS, CD4(+) T CELLS, AND SALIVARY GLAND TISSUES FROM IGG4-RD PATIENTS AND MATCHED CONTROLS BY USING THE ILLUMINA HUMANMETHYLATION 850K BEADCHIP. WE FURTHER PERFORMED PYROSEQUENCING AND IMMUNOHISTOCHEMISTRY ASSAYS TO VALIDATE THE METHYLATION STATUS OF SOME TARGETS OF INTEREST. RESULTS: WE IDENTIFIED DIFFERENTIALLY METHYLATED CPG SITES INCLUDING 44 HYPOMETHYLATED AND 166 HYPERMETHYLATED DIFFERENTIALLY METHYLATED PROBES (DMPS) IN B CELLS AND 260 HYPOMETHYLATED AND 112 HYPERMETHYLATED DMPS IN CD4(+) T CELLS FROM 10 IGG4-RD PATIENTS COMPARED WITH 10 HEALTHY CONTROLS. WE ALSO IDENTIFIED 36945 HYPOMETHYLATED AND 78380 HYPERMETHYLATED DMPS IN SALIVARY GLAND TISSUES OF 4 IGG4-RD PATIENTS COMPARED WITH 4 CONTROLS. DPM2 (CG21181453), IQCK (CG10266221), AND ABCC13 (CG05699681, CG04985582) WERE HYPERMETHYLATED AND MBP (CG18455083) WAS HYPOMETHYLATED IN B CELLS, CD4(+) T CELLS, AND SALIVARY GLAND TISSUES OF IGG4-RD PATIENTS. WE ALSO OBSERVED THE HYPOMETHYLATED HLA-DQB2 IN CD4(+) T CELLS FROM IGG4-RD PATIENTS. KYOTO ENCYCLOPEDIA OF GENES AND GENOMES (KEGG) PATHWAY ANALYSIS OF DMPS IN SALIVARY GLAND TISSUES OF IGG4-RD PATIENTS REVEALED ENRICHMENT OF PATHWAYS INVOLVED IN THE REGULATION OF IMMUNE CELL RESPONSES AND FIBROSIS. CONCLUSION: THIS IS THE FIRST DNA METHYLATION STUDY IN PERIPHERAL B CELLS, CD4(+) T CELLS, AND SALIVARY GLAND TISSUES FROM IGG4-RD PATIENTS. OUR FINDINGS HIGHLIGHTED THE ROLE OF EPIGENETIC MODIFICATION OF DNA METHYLATION AND IDENTIFIED SEVERAL GENES AND PATHWAYS POSSIBLY INVOLVED IN IGG4-RD PATHOGENESIS. 2023 20 916 10 CHRONIC HIGH GLUCOSE AND INSULIN STIMULATE BONE-MARROW STROMAL CELLS ADIPOGENIC DIFFERENTIATION IN YOUNG SPONTANEOUSLY HYPERTENSIVE RATS. WE EVALUATED WHETHER GENETIC PREDISPOSITION IS SUFFICIENT TO INDUCE CHANGES DUE TO CHRONIC HIGH GLUCOSE (HG; 25 MMOL/L) IN THE PRESENCE OR ABSENCE OF INSULIN (HGI; 10 MUG/ML) ON OSTEOGENIC DIFFERENTIATION AND MARKERS IN BONE-MARROW MESENCHYMAL STEM CELLS (BMSCS) FROM YOUNG WISTAR (WBMSCS) AND SPONTANEOUS HYPERTENSIVE RATS (SBMSCS) WITHOUT HYPERTENSION. HG SUPPRESSED OSTEOGENIC DIFFERENTIATION IN BOTH THE STRAINS, OBSERVED BY MINERALIZATION INHIBITION AND DECREASED LEVELS OF THE OSTEOGENIC MARKERS RUNX2, OSTERIX, OSTEOPONTIN, AND BONE SIALOPROTEIN, COMPARED TO OSTEOGENIC MEDIUM (OM) CELLS. IN WBMSCS, THE EFFECTS OF HG WERE ASSOCIATED WITH THE DOWN REGULATION OF ERK1/2 AND UP REGULATION OF P38 ACTIVITIES; HOWEVER, HGI DID NOT REVERT THE EFFECTS OF HG ON MAPK ACTIVITIES. MOREOVER, HG DID NOT AFFECT MAPK SIGNALING IN SBMSCS COMPARED TO THAT IN OM. HGI INCREASED MINERALIZATION IN WBMSCS COMPARED TO THAT IN OM, BUT NOT IN SBMSCS. HIGH EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AND GLUCOSE TRANSPORTER TYPE 4 IN OM COULD BE RELATED WITH THE PREDISPOSITION TO ADIPOGENIC DIFFERENTIATION NOTED IN SBMSCS AND WAS CONFIRMED BY EMERGENCE OF ADIPOCYTE-LIKE CELLS BY HGI TREATMENT. DOWNREGULATION OF P38 AND UPREGULATION OF JNK ACTIVITIES WERE OBSERVED IN BOTH BMSCS TREATED WITH HGI COMPARED TO THOSE TREATED BY HG. MA (OSMOTIC CONTROL) ALSO SUPPRESSED OSTEOGENIC DIFFERENTIATION IN BOTH THE STRAINS. IN CONCLUSION, WE DEMONSTRATED THAT SBMSCS FROM YOUNG SPONTANEOUS HYPERTENSIVE RATS, WITHOUT HYPERTENSION BUT WITH GENETIC AND EPIGENETIC PREDISPOSITION, EXHIBITED DECREASED OSTEOBLASTIC DIFFERENTIATION UNDER HG AND HGI DID NOT REVERT THE EFFECTS OF HG IN SBMSCS BUT INCREASED ADIPOGENIC DIFFERENTIATION. 2018