1 2403 160 EPIGENETIC REPROGRAMMING: A POSSIBLE ETIOLOGICAL FACTOR IN BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS? PURPOSE: THE ETIOLOGY OF BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS IS POORLY UNDERSTOOD. THE POSSIBILITY THAT EPIGENETIC REPROGRAMMING MAY HAVE A ROLE IS DISCUSSED. MATERIALS AND METHODS: A LITERATURE SEARCH WAS PERFORMED WITH THE ENTREZ-PUBMED(R) DATABASE USING THE KEY WORDS URINARY BLADDER, EPIGENETICS, EPIGENETIC MECHANISMS, INTERSTITIAL CYSTITIS, DIAGNOSIS, ETIOLOGY, UROTHELIAL CELLS, MAST CELLS, NERVE FIBERS, NERVES, NERVE GROWTH FACTOR, RECURRENT INJURY, STEM CELLS, INFLAMMATORY MEDIATORS AND DEMETHYLASES. RESULTS: THE UROEPITHELIUM IS INTIMATELY ASSOCIATED WITH THE NERVOUS SYSTEM. SENSORY INPUT AT THE APICAL SURFACE OF UMBRELLA CELLS REGULATES BLADDER FUNCTION VIA A TRANSMURAL SIGNALING PATHWAY. WHEN UMBRELLA CELLS ARE SHED IN RESPONSE TO NOXIOUS STIMULI, STEM CELLS IN THE BASAL LAYER BECOME EXPOSED. THE POLYCOMB GROUP GENES ARE KEY IN THE MAINTENANCE OF ADULT STEM CELLS. THE POLYCOMB GROUP GENES MEDIATE GENE SILENCING AND REPRESS TRANSDIFFERENTIATION BY METHYLATING LYSINE 27 OF HISTONE H3 (H3K27ME3). JMJD3, AN ENZYME DEMETHYLATING H3K27ME3, ANTAGONIZES POLYCOMB GROUP GENES MEDIATED SILENCING. INFLAMMATORY STIMULI ARE STRONG INDUCERS OF JMJD3 AND MAY REVERSE GENE SILENCING IN STEM CELLS, MODIFYING THE DIFFERENTIATION PATTERN. EPIGENETIC PROCESSES INVOLVING H3K27 METHYLATION ARE MULTISTABLE PROCESSES. TRANSIENT SIGNALING, EG BY LIPOPOLYSACCHARIDE, TRIGGERS EPIGENETIC REPROGRAMMING AND ESTABLISHES ONE OF THE ALTERNATIVE REGULATORY STATES. ONCE ESTABLISHED SUCH STATES CAN BE MAINTAINED AND PROPAGATED EVEN IN THE ABSENCE OF THE INITIAL SIGNAL. CONCLUSIONS: WE POSTULATE THAT SIMILAR EPIGENETIC REPROGRAMMING MECHANISMS IN THE BLADDER MAY PROVIDE AN EXPLANATION FOR UROEPITHELIAL, MAST CELLS AND NERVE CELL ABNORMALITIES IN BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS, AS WELL AS PROPAGATION OF THIS ALTERED STATE IN THE ABSENCE OF THE SIGNAL THAT MAY HAVE TRIGGERED IT. IT ALSO PROVIDES A NEW EXPERIMENTAL PARADIGM FOR EXPLORING THE ETIOLOGY OF BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS. DATA SUPPORTING THIS HYPOTHESIS WOULD PROVIDE A RATIONALE FOR NEW DIAGNOSTIC AS WELL AS TREATMENT OPTIONS FOR BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS. 2009 2 4427 34 MOLECULAR BASIS OF ELECTROPHILIC AND OXIDATIVE DEFENSE: PROMISES AND PERILS OF NRF2. INDUCTION OF DRUG-METABOLIZING ENZYMES THROUGH THE ANTIOXIDANT RESPONSE ELEMENT (ARE)-DEPENDENT TRANSCRIPTION WAS INITIALLY IMPLICATED IN CHEMOPREVENTION AGAINST CANCER BY ANTIOXIDANTS. RECENT PROGRESS IN UNDERSTANDING THE BIOLOGY AND MECHANISM OF INDUCTION REVEALED A CRITICAL ROLE OF INDUCTION IN CELLULAR DEFENSE AGAINST ELECTROPHILIC AND OXIDATIVE STRESS. INDUCTION IS MEDIATED THROUGH A NOVEL SIGNALING PATHWAY VIA TWO REGULATORY PROTEINS, THE NUCLEAR FACTOR ERYTHROID 2-RELATED FACTOR 2 (NRF2) AND THE KELCH-LIKE ERYTHROID CELL-DERIVED PROTEIN WITH CNC HOMOLOGY-ASSOCIATED PROTEIN 1 (KEAP1). NRF2 BINDS TO KEAP1 AT A TWO SITE-BINDING INTERFACE AND IS UBIQUITINATED BY THE KEAP1/CULLIN 3/RING BOX PROTEIN-1-UBIQUITIN LIGASE, RESULTING IN A RAPID TURNOVER OF NRF2 PROTEIN. ELECTROPHILES AND OXIDANTS MODIFY CRITICAL CYSTEINE THIOLS OF KEAP1 AND NRF2 TO INHIBIT NRF2 UBIQUITINATION, LEADING TO NRF2 ACTIVATION AND INDUCTION. INDUCTION INCREASES STRESS RESISTANCE CRITICAL FOR CELL SURVIVAL, BECAUSE KNOCKOUT OF NRF2 IN MICE INCREASED SUSCEPTIBILITY TO A VARIETY OF TOXICITY AND DISEASE PROCESSES. COLLATERAL TO DIVERSE FUNCTIONS OF NRF2, GENOME-WIDE SEARCH HAS LED TO THE IDENTIFICATION OF A PLETHORA OF ARE-DEPENDENT GENES REGULATED BY NRF2 IN AN INDUCER-, TISSUE-, AND DISEASE-DEPENDENT MANNER TO CONTROL DRUG METABOLISM, ANTIOXIDANT DEFENSE, STRESS RESPONSE, PROTEASOMAL DEGRADATION, AND CELL PROLIFERATION. THE PROTECTIVE NATURE OF NRF2 COULD ALSO BE HIJACKED IN A NUMBER OF PATHOLOGICAL CONDITIONS BY MEANS OF SOMATIC MUTATION, EPIGENETIC ALTERATION, AND ACCUMULATION OF DISRUPTOR PROTEINS, PROMOTING DRUG RESISTANCE IN CANCER AND PATHOLOGIC LIVER FEATURES IN AUTOPHAGY DEFICIENCY. THE REPERTOIRE OF ARE INDUCERS HAS EXPANDED ENORMOUSLY; THE THERAPEUTIC POTENTIAL OF THE INDUCERS HAS BEEN EXAMINED BEYOND CANCER PREVENTION. DEVELOPING POTENT AND SPECIFIC ARE INDUCERS AND NRF2 INHIBITORS HOLDS CERTAIN NEW PROMISE FOR THE PREVENTION AND THERAPY AGAINST CANCER, CHRONIC DISEASE, AND TOXICITY. 2012 3 1874 31 EMERGING ROLE OF NF-KAPPAB SIGNALING IN THE INDUCTION OF SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). THE MAJOR HALLMARK OF CELLULAR SENESCENCE IS AN IRREVERSIBLE CELL CYCLE ARREST AND THUS IT IS A POTENT TUMOR SUPPRESSOR MECHANISM. GENOTOXIC INSULTS, E.G. OXIDATIVE STRESS, ARE IMPORTANT INDUCERS OF THE SENESCENT PHENOTYPE WHICH IS CHARACTERIZED BY AN ACCUMULATION OF SENESCENCE-ASSOCIATED HETEROCHROMATIC FOCI (SAHF) AND DNA SEGMENTS WITH CHROMATIN ALTERATIONS REINFORCING SENESCENCE (DNA-SCARS). INTERESTINGLY, SENESCENT CELLS SECRETE PRO-INFLAMMATORY FACTORS AND THUS THE CONDITION HAS BEEN CALLED THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). EMERGING DATA HAS REVEALED THAT NF-KAPPAB SIGNALING IS THE MAJOR SIGNALING PATHWAY WHICH STIMULATES THE APPEARANCE OF SASP. IT IS KNOWN THAT DNA DAMAGE PROVOKES NF-KAPPAB SIGNALING VIA A VARIETY OF SIGNALING COMPLEXES CONTAINING NEMO PROTEIN, AN NF-KAPPAB ESSENTIAL MODIFIER, AS WELL AS VIA THE ACTIVATION OF SIGNALING PATHWAYS OF P38MAPK AND RIG-1, RETINOIC ACID INDUCIBLE GENE-1. GENOMIC INSTABILITY EVOKED BY CELLULAR STRESS TRIGGERS EPIGENETIC CHANGES, E.G. RELEASE OF HMGB1 PROTEINS WHICH ARE ALSO POTENT ENHANCERS OF INFLAMMATORY RESPONSES. MOREOVER, ENVIRONMENTAL STRESS AND CHRONIC INFLAMMATION CAN STIMULATE P38MAPK AND CERAMIDE SIGNALING AND INDUCE CELLULAR SENESCENCE WITH PRO-INFLAMMATORY RESPONSES. ON THE OTHER HAND, TWO CYCLIN-DEPENDENT KINASE INHIBITORS, P16INK4A AND P14ARF, ARE EFFECTIVE INHIBITORS OF NF-KAPPAB SIGNALING. WE WILL REVIEW IN DETAIL THE SIGNALING PATHWAYS WHICH ACTIVATE NF-KAPPAB SIGNALING AND TRIGGER SASP IN SENESCENT CELLS. 2012 4 1656 34 DOUBLE STRAND BREAKS CAN INITIATE GENE SILENCING AND SIRT1-DEPENDENT ONSET OF DNA METHYLATION IN AN EXOGENOUS PROMOTER CPG ISLAND. CHRONIC EXPOSURE TO INDUCERS OF DNA BASE OXIDATION AND SINGLE AND DOUBLE STRAND BREAKS CONTRIBUTE TO TUMORIGENESIS. IN ADDITION TO THE GENETIC CHANGES CAUSED BY THIS DNA DAMAGE, SUCH TUMORS OFTEN CONTAIN EPIGENETICALLY SILENCED GENES WITH ABERRANT PROMOTER REGION CPG ISLAND DNA HYPERMETHYLATION. WE HEREIN EXPLORE THE RELATIONSHIPS BETWEEN SUCH DNA DAMAGE AND EPIGENETIC GENE SILENCING USING AN EXPERIMENTAL MODEL IN WHICH WE INDUCE A DEFINED DOUBLE STRAND BREAK IN AN EXOGENOUS PROMOTER CONSTRUCT OF THE E-CADHERIN CPG ISLAND, WHICH IS FREQUENTLY ABERRANTLY DNA HYPERMETHYLATED IN EPITHELIAL CANCERS. FOLLOWING THE ONSET OF REPAIR OF THE BREAK, WE OBSERVE RECRUITMENT TO THE SITE OF DAMAGE OF KEY PROTEINS INVOLVED IN ESTABLISHING AND MAINTAINING TRANSCRIPTIONAL REPRESSION, NAMELY SIRT1, EZH2, DNMT1, AND DNMT3B, AND THE APPEARANCE OF THE SILENCING HISTONE MODIFICATIONS, HYPOACETYL H4K16, H3K9ME2 AND ME3, AND H3K27ME3. ALTHOUGH IN MOST CELLS SELECTED AFTER THE BREAK, DNA REPAIR OCCURS FAITHFULLY WITH PRESERVATION OF ACTIVITY OF THE PROMOTER, A SMALL PERCENTAGE OF THE PLATED CELLS DEMONSTRATE INDUCTION OF HERITABLE SILENCING. THE CHROMATIN AROUND THE BREAK SITE IN SUCH A SILENT CLONE IS ENRICHED FOR MOST OF THE ABOVE SILENT CHROMATIN PROTEINS AND HISTONE MARKS, AND THE REGION HARBORS THE APPEARANCE OF INCREASING DNA METHYLATION IN THE CPG ISLAND OF THE PROMOTER. DURING THE ACUTE BREAK, SIRT1 APPEARS TO BE REQUIRED FOR THE TRANSIENT RECRUITMENT OF DNMT3B AND SUBSEQUENT METHYLATION OF THE PROMOTER IN THE SILENT CLONES. TAKEN TOGETHER, OUR DATA SUGGEST THAT NORMAL REPAIR OF A DNA BREAK CAN OCCASIONALLY CAUSE HERITABLE SILENCING OF A CPG ISLAND-CONTAINING PROMOTER BY RECRUITMENT OF PROTEINS INVOLVED IN SILENCING. FURTHERMORE, WITH CONTRIBUTION OF THE STRESS-RELATED PROTEIN SIRT1, THE BREAK CAN LEAD TO THE ONSET OF ABERRANT CPG ISLAND DNA METHYLATION, WHICH IS FREQUENTLY ASSOCIATED WITH TIGHT GENE SILENCING IN CANCER. 2008 5 1276 29 DAMPS, AGEING, AND CANCER: THE 'DAMP HYPOTHESIS'. AGEING IS A COMPLEX AND MULTIFACTORIAL PROCESS CHARACTERIZED BY THE ACCUMULATION OF MANY FORMS OF DAMAGE AT THE MOLECULAR, CELLULAR, AND TISSUE LEVEL WITH ADVANCING AGE. AGEING INCREASES THE RISK OF THE ONSET OF CHRONIC INFLAMMATION-ASSOCIATED DISEASES SUCH AS CANCER, DIABETES, STROKE, AND NEURODEGENERATIVE DISEASE. IN PARTICULAR, AGEING AND CANCER SHARE SOME COMMON ORIGINS AND HALLMARKS SUCH AS GENOMIC INSTABILITY, EPIGENETIC ALTERATION, ABERRANT TELOMERES, INFLAMMATION AND IMMUNE INJURY, REPROGRAMMED METABOLISM, AND DEGRADATION SYSTEM IMPAIRMENT (INCLUDING WITHIN THE UBIQUITIN-PROTEASOME SYSTEM AND THE AUTOPHAGIC MACHINERY). RECENT ADVANCES INDICATE THAT DAMAGE-ASSOCIATED MOLECULAR PATTERN MOLECULES (DAMPS) SUCH AS HIGH MOBILITY GROUP BOX 1, HISTONES, S100, AND HEAT SHOCK PROTEINS PLAY LOCATION-DEPENDENT ROLES INSIDE AND OUTSIDE THE CELL. THESE PROVIDE INTERACTION PLATFORMS AT MOLECULAR LEVELS LINKED TO COMMON HALLMARKS OF AGEING AND CANCER. THEY CAN ACT AS INDUCERS, SENSORS, AND MEDIATORS OF STRESS THROUGH INDIVIDUAL PLASMA MEMBRANE RECEPTORS, INTRACELLULAR RECOGNITION RECEPTORS (E.G., ADVANCED GLYCOSYLATION END PRODUCT-SPECIFIC RECEPTORS, AIM2-LIKE RECEPTORS, RIG-I-LIKE RECEPTORS, AND NOD1-LIKE RECEPTORS, AND TOLL-LIKE RECEPTORS), OR FOLLOWING ENDOCYTIC UPTAKE. THUS, THE DAMP HYPOTHESIS IS NOVEL AND COMPLEMENTS OTHER THEORIES THAT EXPLAIN THE FEATURES OF AGEING. DAMPS REPRESENT IDEAL BIOMARKERS OF AGEING AND PROVIDE AN ATTRACTIVE TARGET FOR INTERVENTIONS IN AGEING AND AGE-ASSOCIATED DISEASES. 2015 6 6293 27 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 7 2481 35 EPIGENETIC UPREGULATION OF LNCRNAS AT 13Q14.3 IN LEUKEMIA IS LINKED TO THE IN CIS DOWNREGULATION OF A GENE CLUSTER THAT TARGETS NF-KB. NON-CODING RNAS ARE MUCH MORE COMMON THAN PREVIOUSLY THOUGHT. HOWEVER, FOR THE VAST MAJORITY OF NON-CODING RNAS, THE CELLULAR FUNCTION REMAINS ENIGMATIC. THE TWO LONG NON-CODING RNA (LNCRNA) GENES DLEU1 AND DLEU2 MAP TO A CRITICAL REGION AT CHROMOSOMAL BAND 13Q14.3 THAT IS RECURRENTLY DELETED IN SOLID TUMORS AND HEMATOPOIETIC MALIGNANCIES LIKE CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). WHILE NO POINT MUTATIONS HAVE BEEN FOUND IN THE PROTEIN CODING CANDIDATE GENES AT 13Q14.3, THEY ARE DEREGULATED IN MALIGNANT CELLS, SUGGESTING AN EPIGENETIC TUMOR SUPPRESSOR MECHANISM. WE THEREFORE CHARACTERIZED THE EPIGENETIC MAKEUP OF 13Q14.3 IN CLL CELLS AND FOUND HISTONE MODIFICATIONS BY CHROMATIN-IMMUNOPRECIPITATION (CHIP) THAT ARE ASSOCIATED WITH ACTIVATED TRANSCRIPTION AND SIGNIFICANT DNA-DEMETHYLATION AT THE TRANSCRIPTIONAL START SITES OF DLEU1 AND DLEU2 USING 5 DIFFERENT SEMI-QUANTITATIVE AND QUANTITATIVE METHODS (APRIMES, BIOCOBRA, MCIP, MASSARRAY, AND BISULFITE SEQUENCING). THESE EPIGENETIC ABERRATIONS WERE CORRELATED WITH TRANSCRIPTIONAL DEREGULATION OF THE NEIGHBORING CANDIDATE TUMOR SUPPRESSOR GENES, SUGGESTING A COREGULATION IN CIS OF THIS GENE CLUSTER. WE FOUND THAT THE 13Q14.3 GENES IN ADDITION TO THEIR PREVIOUSLY KNOWN FUNCTIONS REGULATE NF-KB ACTIVITY, WHICH WE COULD SHOW AFTER OVEREXPRESSION, SIRNA-MEDIATED KNOCKDOWN, AND DOMINANT-NEGATIVE MUTANT GENES BY USING WESTERN BLOTS WITH PREVIOUSLY UNDESCRIBED ANTIBODIES, BY A CUSTOMIZED ELISA AS WELL AS BY REPORTER ASSAYS. IN ADDITION, WE PERFORMED AN UNBIASED SCREEN OF 810 HUMAN MIRNAS AND IDENTIFIED THE MIR-15/16 FAMILY OF GENES AT 13Q14.3 AS THE STRONGEST INDUCERS OF NF-KB ACTIVITY. IN SUMMARY, THE TUMOR SUPPRESSOR MECHANISM AT 13Q14.3 IS A CLUSTER OF GENES CONTROLLED BY TWO LNCRNA GENES THAT ARE REGULATED BY DNA-METHYLATION AND HISTONE MODIFICATIONS AND WHOSE MEMBERS ALL REGULATE NF-KB. THEREFORE, THE TUMOR SUPPRESSOR MECHANISM IN 13Q14.3 UNDERLINES THE ROLE BOTH OF EPIGENETIC ABERRATIONS AND OF LNCRNA GENES IN HUMAN TUMORIGENESIS AND IS AN EXAMPLE OF COLOCALIZATION OF A FUNCTIONALLY RELATED GENE CLUSTER. 2013 8 1357 41 DEVELOPMENT OF INNATE IMMUNE MEMORY BY NON-IMMUNE CELLS DURING STAPHYLOCOCCUS AUREUS INFECTION DEPENDS ON REACTIVE OXYGEN SPECIES. INTRODUCTION: THE MECHANISMS UNDERLYING INNATE IMMUNE MEMORY (TRAINED IMMUNITY) COMPRISE EPIGENETIC REPROGRAMMING OF TRANSCRIPTIONAL PATHWAYS ASSOCIATED WITH ALTERATIONS OF INTRACELLULAR METABOLISM. WHILE THE MECHANISMS OF INNATE IMMUNE MEMORY CARRIED OUT BY IMMUNE CELLS ARE WELL CHARACTERIZED, SUCH PROCESSES IN NON-IMMUNE CELLS, ARE POORLY UNDERSTOOD. THE OPPORTUNISTIC PATHOGEN, STAPHYLOCOCCUS AUREUS, IS RESPONSIBLE FOR A MULTITUDE OF HUMAN DISEASES, INCLUDING PNEUMONIA, ENDOCARDITIS AND OSTEOMYELITIS, AS WELL AS ANIMAL INFECTIONS, INCLUDING CHRONIC CATTLE MASTITIS THAT ARE EXTREMELY DIFFICULT TO TREAT. AN INDUCTION OF INNATE IMMUNE MEMORY MAY BE CONSIDERED AS A THERAPEUTIC ALTERNATIVE TO FIGHT S. AUREUS INFECTION. METHODS: IN THE CURRENT WORK, WE DEMONSTRATED THE DEVELOPMENT OF INNATE IMMUNE MEMORY IN NON-IMMUNE CELLS DURING S. AUREUS INFECTION EMPLOYING A COMBINATION OF TECHNIQUES INCLUDING ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA), MICROSCOPIC ANALYSIS, AND CYTOMETRY. RESULTS: WE OBSERVED THAT TRAINING OF HUMAN OSTEOBLAST-LIKE MG-63 CELLS AND LUNG EPITHELIAL A549 CELLS WITH BETA-GLUCAN INCREASED IL-6 AND IL-8 PRODUCTION UPON A STIMULATION WITH S. AUREUS, CONCOMITANT WITH HISTONES MODIFICATIONS. IL-6 AND IL-8 PRODUCTION WAS POSITIVELY CORRELATED WITH AN ACETYLATION OF HISTONE 3 AT LYSINE 27 (H3K27), THUS SUGGESTING EPIGENETIC REPROGRAMMING IN THESE CELLS. AN ADDITION OF THE ROS SCAVENGER N-ACETYLCYSTEINE, NAC, PRIOR TO BETA-GLUCAN PRETREATMENT FOLLOWED BY AN EXPOSURE TO S. AUREUS, RESULTED IN DECREASED IL-6 AND IL-8 PRODUCTION, THEREBY SUPPORTING THE INVOLVEMENT OF ROS IN THE INDUCTION OF INNATE IMMUNE MEMORY. EXPOSURE OF CELLS TO LACTOCOCCUS LACTIS RESULTED IN INCREASED IL-6 AND IL-8 PRODUCTION BY MG-63 AND A549 CELLS UPON A STIMULATION WITH S. AUREUS THAT WAS CORRELATED WITH H3K27 ACETYLATION, SUGGESTING THE ABILITY OF THIS BENEFICIAL BACTERIUM TO INDUCE INNATE IMMUNE MEMORY. DISCUSSION: THIS WORK IMPROVES OUR UNDERSTANDING OF INNATE IMMUNE MEMORY IN NON-IMMUNE CELLS IN THE CONTEXT OF S. AUREUS INFECTION. IN ADDITION TO KNOWN INDUCERS, PROBIOTICS MAY REPRESENT GOOD CANDIDATES FOR THE INDUCTION OF INNATE IMMUNE MEMORY. OUR FINDINGS MAY HELP THE DEVELOPMENT OF ALTERNATIVE THERAPEUTIC APPROACHES FOR THE PREVENTION OF S. AUREUS INFECTION. 2023 9 3469 39 HYPOXIA-INDUCIBLE HISTONE LYSINE DEMETHYLASES: IMPACT ON THE AGING PROCESS AND AGE-RELATED DISEASES. HYPOXIA IS AN ENVIRONMENTAL STRESS AT HIGH ALTITUDE AND UNDERGROUND CONDITIONS BUT IT IS ALSO PRESENT IN MANY CHRONIC AGE-RELATED DISEASES, WHERE BLOOD FLOW INTO TISSUES IS IMPAIRED. THE OXYGEN-SENSING SYSTEM STIMULATES GENE EXPRESSION PROTECTING TISSUES AGAINST HYPOXIC INSULTS. HYPOXIA STABILIZES THE EXPRESSION OF HYPOXIA-INDUCIBLE TRANSCRIPTION FACTOR-1ALPHA (HIF-1ALPHA), WHICH CONTROLS THE EXPRESSION OF HUNDREDS OF SURVIVAL GENES RELATED TO E.G. ENHANCED ENERGY METABOLISM AND AUTOPHAGY. MOREOVER, MANY STRESS-RELATED SIGNALING MECHANISMS, SUCH AS OXIDATIVE STRESS AND ENERGY METABOLIC DISTURBANCES, AS WELL AS THE SIGNALING CASCADES VIA CERAMIDE, MTOR, NF-KAPPAB, AND TGF-BETA PATHWAYS, CAN ALSO INDUCE THE EXPRESSION OF HIF-1ALPHA PROTEIN TO FACILITATE CELL SURVIVAL IN NORMOXIA. HYPOXIA IS LINKED TO PROMINENT EPIGENETIC CHANGES IN CHROMATIN LANDSCAPE. SCREENING STUDIES HAVE INDICATED THAT THE STABILIZATION OF HIF-1ALPHA INCREASES THE EXPRESSION OF DISTINCT HISTONE LYSINE DEMETHYLASES (KDM). HIF-1ALPHA STIMULATES THE EXPRESSION OF KDM3A, KDM4B, KDM4C, AND KDM6B, WHICH ENHANCE GENE TRANSCRIPTION BY DEMETHYLATING H3K9 AND H3K27 SITES (REPRESSIVE EPIGENETIC MARKS). IN ADDITION, HIF-1ALPHA INDUCES THE EXPRESSION OF KDM2B AND KDM5B, WHICH REPRESS TRANSCRIPTION BY DEMETHYLATING H3K4ME2,3 SITES (ACTIVATING MARKS). HYPOXIA-INDUCIBLE KDMS SUPPORT LOCALLY THE GENE TRANSCRIPTION INDUCED BY HIF-1ALPHA, ALTHOUGH THEY CAN ALSO CONTROL GENOME-WIDE CHROMATIN LANDSCAPE, ESPECIALLY KDMS WHICH DEMETHYLATE H3K9 AND H3K27 SITES. THESE EPIGENETIC MARKS HAVE IMPORTANT ROLE IN THE CONTROL OF HETEROCHROMATIN SEGMENTS AND 3D FOLDING OF CHROMOSOMES, AS WELL AS THE GENETIC LOCI REGULATING CELL TYPE COMMITMENT, PROLIFERATION, AND CELLULAR SENESCENCE, E.G. THE INK4 BOX. A CHRONIC STIMULATION OF HIF-1ALPHA CAN PROVOKE TISSUE FIBROSIS AND CELLULAR SENESCENCE, WHICH BOTH ARE INCREASINGLY PRESENT WITH AGING AND AGE-RELATED DISEASES. WE WILL REVIEW THE REGULATION OF HIF-1ALPHA-DEPENDENT INDUCTION OF KDMS AND CLARIFY THEIR ROLE IN PATHOLOGICAL PROCESSES EMPHASIZING THAT LONG-TERM STRESS-RELATED INSULTS CAN IMPAIR THE MAINTENANCE OF CHROMATIN LANDSCAPE AND PROVOKE CELLULAR SENESCENCE AND TISSUE FIBROSIS ASSOCIATED WITH AGING AND AGE-RELATED DISEASES. 2016 10 4836 27 ONCOGENIC FUNCTIONS OF THE TRANSCRIPTION FACTOR NRF2. NUCLEAR FACTOR E2-RELATED FACTOR 2 (NRF2) IS A TRANSCRIPTION FACTOR THAT CONTROLS THE EXPRESSION OF A LARGE POOL OF ANTIOXIDANT AND CYTOPROTECTIVE GENES REGULATING THE CELLULAR RESPONSE TO OXIDATIVE AND ELECTROPHILIC STRESS. NRF2 IS NEGATIVELY REGULATED BY KELCH-LIKE ECH-ASSOCIATED PROTEIN 1 (KEAP1) AND, UPON STIMULATION BY AN OXIDATIVE OR ELECTROPHILIC INSULT, IS RAPIDLY ACTIVATED BY PROTEIN STABILIZATION. OWING TO ITS CYTOPROTECTIVE FUNCTIONS, NRF2 HAS BEEN TRADITIONALLY STUDIED IN THE FIELD OF CHEMOPREVENTION; HOWEVER, THERE IS ACCUMULATED EVIDENCE THAT KEAP1/NRF2 MUTATIONS OR UNBALANCED REGULATION THAT LEADS TO OVEREXPRESSION OR HYPERACTIVATION OF NRF2 MAY PARTICIPATE IN TUMORIGENESIS AND BE INVOLVED IN CHEMORESISTANCE OF A WIDE NUMBER OF SOLID CANCERS AND LEUKEMIAS. IN ADDITION TO PROTECTING CELLS FROM REACTIVE OXYGEN SPECIES, NRF2 SEEMS TO PLAY A DIRECT ROLE IN CELL GROWTH CONTROL AND IS RELATED TO APOPTOSIS-REGULATING PATHWAYS. MOREOVER, NRF2 ACTIVITY IS CONNECTED WITH ONCOGENIC KINASE PATHWAYS, STRUCTURAL PROTEINS, HORMONAL REGULATION, OTHER TRANSCRIPTION FACTORS, AND EPIGENETIC ENZYMES INVOLVED IN THE PATHOGENESIS OF VARIOUS TYPES OF TUMORS. THE AIM OF THIS REVIEW IS TO COMPILE AND SUMMARIZE EXISTING KNOWLEDGE OF THE ONCOGENIC FUNCTIONS OF NRF2 TO PROVIDE A SOLID BASIS FOR ITS POTENTIAL USE AS A MOLECULAR MARKER AND PHARMACOLOGICAL TARGET IN CANCER. 2013 11 5140 25 POTENTIAL REGULATORS OF THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE DURING SENESCENCE AND AGING. SENESCENT CELLS EXPRESS AND SECRETE A VARIETY OF EXTRACELLULAR MODULATORS THAT INCLUDE CYTOKINES, CHEMOKINES, PROTEASES, GROWTH FACTORS, AND SOME ENZYMES ASSOCIATED WITH EXTRACELLULAR MATRIX REMODELING, DEFINED AS THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). SASP REINFORCES SENESCENT CELL CYCLE ARREST, STIMULATES AND RECRUITS IMMUNE CELLS FOR IMMUNE-MEDIATED CLEARANCE OF POTENTIALLY TUMORIGENIC CELLS, LIMITS OR INDUCES FIBROSIS, AND PROMOTES WOUND HEALING AND TISSUE REGENERATION. ON THE OTHER HAND, SASP MEDIATES CHRONIC INFLAMMATION LEADING TO THE DESTRUCTION OF TISSUE STRUCTURE AND FUNCTION AND STIMULATING THE GROWTH AND SURVIVAL OF TUMOR CELLS. SASP IS HIGHLY HETEROGENEOUS AND THE ROLE OF SASP DEPENDS ON THE CONTEXT. THE REGULATION OF SASP OCCURS AT MULTIPLE LEVELS INCLUDING CHROMATIN REMODELING, TRANSCRIPTION, MRNA TRANSLATION, INTRACELLULAR TRAFFICKING, AND SECRETION. SEVERAL SASP MODULATORS HAVE ALREADY BEEN IDENTIFIED SETTING THE STAGE FOR FUTURE RESEARCH ON THEIR CLINICAL APPLICATIONS. IN THIS REVIEW, WE SUMMARIZE IN DETAIL THE POTENTIAL SIGNALING PATHWAYS THAT TRIGGER AND REGULATE SASP PRODUCTION DURING AGING AND SENESCENCE. 2022 12 6045 30 THE COMPLEXITY OF THE NRF2 PATHWAY: BEYOND THE ANTIOXIDANT RESPONSE. THE NF-E2-RELATED FACTOR 2 (NRF2)-MEDIATED SIGNALLING PATHWAY PROVIDES LIVING ORGANISMS AN EFFICIENT AND PIVOTAL LINE OF DEFENSIVE TO COUNTERACT ENVIRONMENTAL INSULTS AND ENDOGENOUS STRESSORS. NRF2 COORDINATES THE BASAL AND INDUCIBLE EXPRESSION OF ANTIOXIDANT AND PHASE II DETOXIFICATION ENZYMES TO ADAPT TO DIFFERENT STRESS CONDITIONS. THE STABILITY AND CELLULAR DISTRIBUTION OF NRF2 IS TIGHTLY CONTROLLED BY ITS INHIBITORY BINDING PROTEIN KELCH-LIKE ECH-ASSOCIATED PROTEIN 1. NRF2 SIGNALLING IS ALSO REGULATED BY POSTTRANSLATIONAL, TRANSCRIPTIONAL, TRANSLATIONAL AND EPIGENETIC MECHANISMS, AS WELL AS BY OTHER PROTEIN PARTNERS, INCLUDING P62, P21 AND IQ MOTIF-CONTAINING GTPASE ACTIVATING PROTEIN 1. MANY STUDIES HAVE DEMONSTRATED THAT NRF2 IS A PROMISING TARGET FOR PREVENTING CARCINOGENESIS AND OTHER CHRONIC DISEASES, INCLUDING CARDIOVASCULAR DISEASES, NEURODEGENERATIVE DISEASES AND PULMONARY INJURY. HOWEVER, CONSTITUTIVE ACTIVATION OF NRF2 IN ADVANCED CANCER CELLS MAY CONFER DRUG RESISTANCE. HERE, WE REVIEW THE MOLECULAR MECHANISMS OF NRF2 SIGNALLING, THE DIVERSE CLASSES OF NRF2 ACTIVATORS, INCLUDING BIOACTIVE NUTRIENTS AND OTHER CHEMICALS, AND THE CELLULAR FUNCTIONS AND DISEASE RELEVANCE OF NRF2 AND DISCUSS THE DUAL ROLE OF NRF2 IN DIFFERENT CONTEXTS. 2015 13 6076 46 THE DYNAMICS OF NUCLEAR RECEPTORS AND NUCLEAR RECEPTOR COREGULATORS IN THE PATHOGENESIS OF ENDOMETRIOSIS. BACKGROUND: ENDOMETRIOSIS IS DEFINED AS THE COLONIZATION AND GROWTH OF ENDOMETRIAL TISSUE AT ANATOMIC SITES OUTSIDE THE UTERINE CAVITY. UP TO 15% OF REPRODUCTIVE-AGED WOMEN IN THE USA SUFFER FROM PAINFUL SYMPTOMS OF ENDOMETRIOSIS, SUCH AS INFERTILITY, PELVIC PAIN, MENSTRUAL CYCLE ABNORMALITIES AND INCREASED RISK OF CERTAIN CANCERS. HOWEVER, MANY OF THE CURRENT CLINICAL TREATMENTS FOR ENDOMETRIOSIS ARE NOT SUFFICIENTLY EFFECTIVE AND YIELD UNACCEPTABLE SIDE EFFECTS. THERE IS CLEARLY AN URGENT NEED TO IDENTIFY NEW MOLECULAR MECHANISMS THAT CRITICALLY UNDERPIN THE INITIATION AND PROGRESSION OF ENDOMETRIOSIS IN ORDER TO DEVELOP MORE SPECIFIC AND EFFECTIVE THERAPEUTICS WHICH LACK THE SIDE EFFECTS OF CURRENT THERAPIES. THE AIM OF THIS REVIEW IS TO DISCUSS HOW NUCLEAR RECEPTORS (NRS) AND THEIR COREGULATORS PROMOTE THE PROGRESSION OF ENDOMETRIOSIS. UNDERSTANDING THE PATHOGENIC MOLECULAR MECHANISMS FOR THE GENESIS AND MAINTENANCE OF ENDOMETRIOSIS AS MODULATED BY NRS AND COREGULATORS CAN REVEAL NEW THERAPEUTIC TARGETS FOR ALTERNATIVE ENDOMETRIOSIS TREATMENTS. METHODS: THIS REVIEW WAS PREPARED USING PUBLISHED GENE EXPRESSION MICROARRAY DATA SETS OBTAINED FROM PATIENTS WITH ENDOMETRIOSIS AND PUBLISHED LITERATURE ON NRS AND THEIR COREGULATORS THAT DEAL WITH ENDOMETRIOSIS PROGRESSION. USING THE ABOVE OBSERVATIONS, OUR CURRENT UNDERSTANDING OF HOW NRS AND NR COREGULATORS ARE INVOLVED IN THE PROGRESSION OF ENDOMETRIOSIS IS SUMMARIZED. RESULTS: ABERRANT LEVELS OF NRS AND NR COREGULATORS IN ECTOPIC ENDOMETRIOSIS LESIONS ARE ASSOCIATED WITH THE PROGRESSION OF ENDOMETRIOSIS. AS AN EXAMPLE, ENDOMETRIOTIC CELL-SPECIFIC ALTERATIONS IN GENE EXPRESSION ARE CORRELATED WITH A DIFFERENTIAL METHYLATION STATUS OF THE GENOME COMPARED WITH THE NORMAL ENDOMETRIUM. THESE DIFFERENTIAL EPIGENETIC REGULATIONS CAN GENERATE FAVORABLE CELL-SPECIFIC NR AND COREGULATOR MILIEUS FOR ENDOMETRIOSIS PROGRESSION. GENETIC ALTERATIONS, SUCH AS SINGLE NUCLEOTIDE POLYMORPHISMS AND INSERTION/DELETION POLYMORPHISMS OF NR AND COREGULATOR GENES, ARE FREQUENTLY DETECTED IN ECTOPIC LESIONS COMPARED WITH THE NORMAL ENDOMETRIUM. THESE GENETIC VARIATIONS IMPART NEW MOLECULAR PROPERTIES TO NRS AND COREGULATORS TO INCREASE THEIR CAPACITY TO STIMULATE PROGRESSION OF ENDOMETRIOSIS. FINALLY, POST-TRANSLATIONAL MODIFICATIONS OF NR COREGULATORS, SUCH AS PROTEOLYTIC PROCESSING, GENERATE ENDOMETRIOSIS-SPECIFIC ISOFORMS. COMPARED WITH THE UNMODIFIED COREGULATORS, THESE COREGULATOR ISOFORMS HAVE UNIQUE FUNCTIONS THAT ENHANCE THE PATHOGENESIS OF ENDOMETRIOSIS. CONCLUSIONS: EPIGENETIC/GENETIC VARIATIONS AND POSTTRANSLATIONAL MODIFICATIONS OF NRS AND COREGULATORS ALTER THEIR ORIGINAL FUNCTION SO THAT THEY BECOME POTENT 'DRIVERS' OF ENDOMETRIOSIS PROGRESSION. 2014 14 4597 20 NATURAL PRODUCTS WITH ANTI-AGING POTENTIAL: AFFECTED TARGETS AND MOLECULAR MECHANISMS. IN RECENT YEARS, THERE HAS BEEN A GREAT DEAL OF ATTENTION TOWARD THE MOLECULAR MACHINERY RELEVANT TO AGE-RELATED PROGRESSION CONTROLLED THROUGH THE EXTERNAL INTERVENTION OF POLYPHENOLS- AN EPIGENETIC-MODULATING DIET. NATURAL PRODUCTS MODULATE CELLULAR LONGEVITY THROUGH HISTONE POST-TRANSLATIONAL MODIFICATION AND CAN ALSO INDUCE THE UPREGULATION OF AUTOPHAGY, THUS REDUCING THE LEVEL OF ACETYL COENZYME A (ACCOA). IN ADDITION, THE EFFECT OF CALORIC RESTRICTION (CR) ON CANCER-RELATED CHRONIC INFLAMMATION IS OF GREAT SIGNIFICANCE IN AGING. IN LINE WITH THIS, SIRT1 PROTEIN LEVELS ARE EXPANDED IN RESPONSE TO CALORIE RESTRICTION MIMETICS (CRM), IN THIS WAY ACTING AS AUTOPHAGY INDUCERS RELEVANT TO CANCER PREVENTION. 2018 15 4268 45 MICROBIAL AGENTS AS PUTATIVE INDUCERS OF B CELL LYMPHOMA IN SJOGREN'S SYNDROME THROUGH AN IMPAIRED EPIGENETIC CONTROL: THE STATE-OF-THE-ART. INTRODUCTION: UNDERSTANDING THE MECHANISMS UNDERLYING THE PATHOGENESIS OF SJOGREN'S SYNDROME (SS) IS CRUCIALLY IMPORTANT IN ORDER TO BE ABLE TO DISCRIMINATE THE STEPS THAT LEAD TO B CELL TRANSFORMATION AND PROMPTLY IDENTIFY THE PATIENTS AT RISK OF LYMPHOMAGENESIS. THE AIM OF THIS NARRATIVE REVIEW IS TO DESCRIBE THE EVIDENCE CONCERNING THE ROLE THAT INFECTIONS OR DYSBIOSIS PLAYS IN THE EPIGENETIC CONTROL OF GENE EXPRESSION IN SS PATIENTS AND THEIR POSSIBLE INVOLVEMENT IN B CELL LYMPHOMAGENESIS. MATERIALS AND METHODS: WE SEARCHED THE PUBMED AND GOOGLE SCHOLAR DATABASES AND SELECTED A TOTAL OF 92 ARTICLES PUBLISHED DURING THE LAST 25 YEARS THAT DESCRIBE EXPERIMENTAL AND CLINICAL STUDIES OF THE POTENTIAL ASSOCIATIONS OF MICROBIOTA AND EPIGENETIC ABERRATIONS WITH THE RISK OF B CELL LYMPHOMA IN SS PATIENTS. RESULTS AND DISCUSSION: THE GENETIC BACKGROUND OF SS PATIENTS IS CHARACTERIZED BY THE HYPEREXPRESSION OF GENES THAT ARE MAINLY INVOLVED IN REGULATING THE INNATE AND ADAPTIVE IMMUNE RESPONSES AND ONCOGENESIS. IN ADDITION, SALIVARY GLAND EPITHELIAL CELLS AND LYMPHOCYTES BOTH HAVE AN ALTERED EPIGENETIC BACKGROUND THAT ENHANCES THE ACTIVATION OF PROINFLAMMATORY AND SURVIVAL PATHWAYS. DYSBIOSIS OR CHRONIC LATENT INFECTIONS MAY TUNE THE IMMUNE RESPONSE AND MODIFY THE CELL EPIGENETIC MACHINERY IN SUCH A WAY AS TO GIVE B LYMPHOCYTES AN ACTIVATED OR TRANSFORMED PHENOTYPE. IT IS ALSO WORTH NOTING THAT TRANSPOSABLE INTEGRATED RETROELEMENTS MAY PARTICIPATE IN THE PATHOGENESIS OF SS AND B CELL LYMPHOMAGENESIS BY INDUCING DNA BREAKS, MODULATING CELL GENE EXPRESSION, OR GENERATING ABERRANT TRANSCRIPTS THAT CHRONICALLY STIMULATE THE IMMUNE SYSTEM. CONCLUSIONS: MICROORGANISMS MAY EPIGENETICALLY MODIFY TARGET CELLS AND INDUCE THEIR TRANSCRIPTOME TO GENERATE AN ACTIVATED OR TRANSFORMED PHENOTYPE. THE OCCURRENCE OF LYMPHOMA IN MORE THAN 15% OF SS PATIENTS MAY BE THE END RESULT OF A COMBINATION OF GENETICS, EPIGENETICS, AND DYSBIOSIS OR LATENT INFECTIONS. 2019 16 4969 39 PATHOLOGICAL NEUROINFLAMMATORY CONVERSION OF REACTIVE ASTROCYTES IS INDUCED BY MICROGLIA AND INVOLVES CHROMATIN REMODELING. FOLLOWING BRAIN INJURY OR IN NEURODEGENERATIVE DISEASES, ASTROCYTES BECOME REACTIVE AND MAY SUFFER PATHOLOGICAL REMODELING, FEATURES OF WHICH ARE THE LOSS OF THEIR HOMEOSTATIC FUNCTIONS AND A PRO-INFLAMMATORY GAIN OF FUNCTION THAT FACILITATES NEURODEGENERATION. PHARMACOLOGICAL INTERVENTION TO MODULATE THIS ASTROGLIAL RESPONSE AND NEUROINFLAMMATION IS AN INTERESTING NEW THERAPEUTIC RESEARCH STRATEGY, BUT IT STILL REQUIRES A DEEPER UNDERSTANDING OF THE UNDERLYING CELLULAR AND MOLECULAR MECHANISMS OF THE PHENOMENON. BASED ON THE KNOWN MICROGLIAL-ASTROGLIAL INTERACTION, THE PROMINENT ROLE OF THE NUCLEAR FACTOR KAPPA B (NF-KAPPAB) PATHWAY IN MEDIATING ASTROGLIAL PATHOLOGICAL PRO-INFLAMMATORY GAIN OF FUNCTION, AND ITS ABILITY TO RECRUIT CHROMATIN-REMODELING ENZYMES, WE FIRST EXPLORED THE MICROGLIAL ROLE IN THE INITIATION OF ASTROGLIAL PRO-INFLAMMATORY CONVERSION AND THEN MONITORED THE PROGRESSION OF EPIGENETIC CHANGES IN THE ASTROCYTIC CHROMATIN. DIFFERENT CONFIGURATIONS OF PRIMARY GLIAL CULTURE WERE USED TO MODULATE MICROGLIA-ASTROCYTE CROSSTALK WHILE INDUCING PRO-INFLAMMATORY GAIN OF FUNCTION BY LIPOPOLYSACCHARIDE (LPS) EXPOSURE. IN VIVO, BRAIN ISCHEMIA BY CORTICAL DEVASCULARIZATION (PIAL DISRUPTION) WAS PERFORMED TO VERIFY THE PRESENCE OF EPIGENETIC MARKS IN REACTIVE ASTROCYTES. OUR RESULTS SHOWED THAT 1) MICROGLIA IS REQUIRED TO INITIATE THE PATHOLOGICAL CONVERSION OF ASTROCYTES BY TRIGGERING THE NF-KAPPAB SIGNALING PATHWAY; 2) THIS INTERACTION IS MEDIATED BY SOLUBLE FACTORS AND INDUCES STABLE ASTROGLIAL PHENOTYPIC CHANGES; 3) THE PATHOLOGICAL CONVERSION PROMOTES CHROMATIN REMODELING WITH STABLE INCREASE IN H3K9K14AC, TEMPORARY INCREASE IN H3K27AC, AND TEMPORARY REDUCTION IN HETEROCHROMATIN MARK H3K9ME3; AND 4) IN VIVO REACTIVE ASTROCYTES SHOW INCREASED H3K27AC MARK IN THE NEUROINFLAMMATORY MILIEU FROM THE ISCHEMIC PENUMBRA. OUR FINDINGS INDICATE THAT ASTROGLIAL PATHOLOGICAL PRO-INFLAMMATORY GAIN OF FUNCTION IS ASSOCIATED WITH PROFOUND CHANGES IN THE CONFIGURATION OF ASTROCYTIC CHROMATIN, WHICH IN TURN ARE INITIATED BY MICROGLIA-DERIVED CUES. THESE RESULTS OPEN A NEW AVENUE IN THE STUDY OF POTENTIAL PHARMACOLOGICAL INTERVENTIONS THAT MODIFY THE INITIATION AND STABILIZATION OF ASTROGLIAL PATHOLOGICAL REMODELING, WHICH WOULD BE USEFUL IN ACUTE AND CHRONIC CNS INJURY. EPIGENETIC CHANGES REPRESENT A PLAUSIBLE PHARMACOLOGICAL TARGET TO INTERFERE WITH THE STABILIZATION OF THE PATHOLOGICAL ASTROGLIAL PHENOTYPE. 2021 17 2800 36 FEEDBACK REGULATORS OF HYPOXIA-INDUCIBLE FACTORS AND THEIR ROLE IN CANCER BIOLOGY. MALIGNANT TUMORS ARE CHARACTERIZED BY REGIONS OF LOW OXYGEN CONCENTRATION (HYPOXIA). THE HYPOXIC TUMOR MICROENVIRONMENT CONTRIBUTES TO TUMOR PROGRESSION BY ACTIVATING A SET OF ADAPTIVE RESPONSES VIA THE KEY TRANSCRIPTIONAL REGULATORS HIF-1ALPHA AND HIF-2ALPHA. THESE FACTORS HAVE BEEN TRADITIONALLY LINKED TO AN AGGRESSIVE TUMOR PHENOTYPE BY PROMOTING PROCESSES ESSENTIAL FOR TUMOR GROWTH, SUCH AS ANGIOGENESIS, GLYCOLYSIS, METASTASIS AND INVASION, AS WELL AS DIFFERENTIATION AND SELF RENEWAL. NOTABLY, THE COMPLEX HIF PATHWAY ALSO INITIATES ANTI-TUMORIGENIC MECHANISMS THAT LEAD TO CELL CYCLE ARREST OR CELL DEATH, INDICATING THE NEED FOR A STRINGENT CONTROL OF THE EXTENT AND THE DIRECTION OF THE HYPOXIA RESPONSE. THE IMPORTANCE OF THIS CONTROL FOR TUMOR CELL SURVIVAL IS ILLUSTRATED BY THE INTRICATE REGULATION OF HIF ACTIVITY AT THE MRNA, PROTEIN AND EPIGENETIC LEVEL BY A COMPLEX NETWORK OF POSITIVE AND NEGATIVE FEEDBACK REGULATORS. WE PROPOSE THAT THESE FEEDBACK REGULATORS HELP TO FLEXIBLY ADJUST AND ADAPT HIF ACTIVATED RESPONSES TO THE FLUCTUATING OXYGEN CONCENTRATIONS WITHIN TUMORS DURING ACUTE AND CHRONIC HYPOXIA AND TO CURTAIL THE TUMOR-SUPPRESSING COMPONENTS OF THE HIF PATHWAY. MOREOVER, FEEDBACK REGULATION OF HIF INDUCES A SWITCH FROM HIF-1ALPHA TO HIF-2ALPHA DRIVEN RESPONSES UNDER CHRONIC HYPOXIA WHICH MAY HAVE ESSENTIAL FUNCTIONS IN THE REGULATION OF TUMOR CELL DIFFERENTIATION AND TUMOR STEM CELL MAINTENANCE. GIVEN THEIR CENTRAL ROLE IN CANCER BIOLOGY, HIF FEEDBACK REGULATORS MAY REPRESENT AN ATTRACTIVE AND NOVEL ANTI-TUMOR THERAPY TARGET TO OVERCOME CELL DEATH RESISTANCE IN TUMORS. 2010 18 6771 38 [ACQUIRED DISORDERS AND EPIGENETICS]. EPIGENETIC MODIFICATIONS, INVOLVING DNA METHYLATION AND HISTONE MODIFICATIONS, ARE MAINTAINED UPON SOMATIC CELL REPLICATION, AND ARE FUNDAMENTAL MECHANISMS FOR CELLULAR MEMORY. DNA METHYLATION OF PROMOTER CPG ISLANDS OF TUMOR-SUPPRESSOR GENES CAN SILENCE THEIR DOWNSTREAM GENES, AND CAN BE CAUSALLY INVOLVED IN CANCER DEVELOPMENT AND PROGRESSION. SINCE THIS EFFECT IS THE SAME WITH THAT OF INACTIVATING MUTATIONS, THE NATURES OF DNA METHYLATION WERE ONCE CONSIDERED TO BE SIMILAR TO MUTATIONS. HOWEVER, RECENTLY, IT WAS REVEALED THAT A LARGE NUMBER OF EPIGENETIC ALTERATIONS ARE PRESENT IN A SINGLE CANCER CELL, THAT A LARGE NUMBER OF CELLS HAVE AN EPIGENETIC ALTERATION OF A SPECIFIC GENE IN NON-CANCEROUS, THUS POLYCLONAL, TISSUES, THAT GENE SPECIFICITY IN METHYLATION INDUCTION IS PRESENT ACCORDING TO TISSUE TYPES AND INDUCERS, AND THAT CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN METHYLATION INDUCTION. THESE FACTS SUGGEST THAT EPIGENETIC ALTERATIONS OF KEY GENES INVOLVED IN ACQUIRED CHRONIC DISORDERS CAN BE PRESENT IN A SIGNIFICANT FRACTION OF CELLS IN A TISSUE, AND THUS CAN IMPAIR THE FUNCTION OF THE TISSUE. ASSOCIATIONS BETWEEN EPIGENETIC ALTERATIONS AND BEHAVIOR, MEMORY, MENTAL DISORDERS, NEUROLOGICAL DISORDERS, METABOLIC DISORDERS, ALLERGY, AUTOIMMUNE DISORDERS, AND OTHER DISORDERS HAVE BEEN REPORTED. FURTHER RESEARCH IN THE FIELD IS NECESSARY TO CLARIFY THE CAUSAL ROLES OF THESE EPIGENETIC ALTERATIONS IN DISEASE DEVELOPMENT, AND TO APPLY THE FINDINGS TO NEW STRATEGIES OF DISEASE PREVENTION, DIAGNOSIS, AND TREATMENT. 2010 19 2405 40 EPIGENETIC RESPONSE IN MICE MASTITIS: ROLE OF HISTONE H3 ACETYLATION AND MICRORNA(S) IN THE REGULATION OF HOST INFLAMMATORY GENE EXPRESSION DURING STAPHYLOCOCCUS AUREUS INFECTION. BACKGROUND: THERE IS RENEWED INTEREST TOWARDS UNDERSTANDING THE HOST-PATHOGEN INTERACTION IN THE LIGHT OF EPIGENETIC MODIFICATIONS. ALTHOUGH EPITHELIAL TISSUE IS THE MAJOR SITE FOR HOST-PATHOGEN INTERACTIONS, THERE IS HANDFUL OF STUDIES TO SHOW HOW EPITHELIAL CELLS RESPOND TO PATHOGENS. BACTERIAL INFECTION IN THE MAMMARY GLAND PARENCHYMA INDUCES LOCAL AND SUBSEQUENTLY SYSTEMIC INFLAMMATION THAT RESULTS IN A COMPLEX DISEASE CALLED MASTITIS. GLOBALLY STAPHYLOCOCCUS AUREUS IS THE SINGLE LARGEST MASTITIS PATHOGEN AND THE INFECTION CAN ULTIMATELY RESULT IN EITHER SUBCLINICAL OR CHRONIC AND SOMETIMES LIFELONG INFECTION. RESULTS: IN THE PRESENT REPORT WE HAVE ADDRESSED THE DIFFERENTIAL INFLAMMATORY RESPONSE IN MICE MAMMARY TISSUE DURING INTRAMAMMARY INFECTION AND THE ALTERED EPIGENETIC CONTEXT INDUCED BY TWO CLOSELY RELATED STRAINS OF S. AUREUS, ISOLATED FROM FIELD SAMPLES. IMMUNOHISTOCHEMICAL AND IMMUNOBLOTTING ANALYSIS SHOWED STRAIN SPECIFIC HYPERACETYLATION AT HISTONE H3K9 AND H3K14 RESIDUES. GLOBAL GENE EXPRESSION ANALYSIS IN S. AUREUS INFECTED MICE MAMMARY TISSUE REVEALED A SELECTIVE SET OF UPREGULATED GENES THAT SIGNIFICANTLY CORRELATED WITH THE PROMOTER SPECIFIC, HISTONE H3K14 ACETYLATION. FURTHERMORE, WE HAVE IDENTIFIED SEVERAL DIFFERENTIALLY EXPRESSED KNOWN MIRNAS AND 3 NOVEL MIRNAS IN S. AUREUS INFECTED MICE MAMMARY TISSUE BY SMALL RNA SEQUENCING. BY EMPLOYING THESE GENE EXPRESSION DATA, AN ATTEMPT HAS BEEN MADE TO DELINEATE THE GENE REGULATORY NETWORKS IN THE STRAIN SPECIFIC INFLAMMATORY RESPONSE. APPARENTLY, ONE OF THE ISOLATES OF S. AUREUS ACTIVATED THE NF-KAPPAB SIGNALING LEADING TO DRASTIC INFLAMMATORY RESPONSE AND INDUCTION OF IMMUNE SURVEILLANCE, WHICH COULD POSSIBLY LEAD TO RAPID CLEARANCE OF THE PATHOGEN. THE OTHER STRAIN REPRESSED MOST OF THE INFLAMMATORY RESPONSE, WHICH MIGHT HELP IN ITS SUSTENANCE IN THE HOST TISSUE. CONCLUSION: TAKEN TOGETHER, OUR STUDIES SHED SUBSTANTIAL LIGHTS TO UNDERSTAND THE MECHANISMS OF STRAIN SPECIFIC DIFFERENTIAL INFLAMMATORY RESPONSE TO S. AUREUS INFECTION DURING MASTITIS. IN A BROADER PERSPECTIVE THIS STUDY ALSO PAVES THE WAY TO UNDERSTAND HOW CERTAIN BACTERIA CAN EVADE THE IMMUNE SURVEILLANCE AND CAUSE SUSTAINED INFECTION WHILE OTHERS ARE RAPIDLY CLEARED FROM THE HOST BODY. 2014 20 6176 41 THE HISTONE H3 LYSINE-27 DEMETHYLASE JMJD3 LINKS INFLAMMATION TO INHIBITION OF POLYCOMB-MEDIATED GENE SILENCING. EPIGENETIC CHROMATIN MARKS RESTRICT THE ABILITY OF DIFFERENTIATED CELLS TO CHANGE GENE EXPRESSION PROGRAMS IN RESPONSE TO ENVIRONMENTAL CUES AND TO TRANSDIFFERENTIATE. POLYCOMB GROUP (PCG) PROTEINS MEDIATE GENE SILENCING AND REPRESS TRANSDIFFERENTIATION IN A MANNER DEPENDENT ON HISTONE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3). HOWEVER, MACROPHAGES MIGRATED INTO INFLAMED TISSUES CAN TRANSDIFFERENTIATE, BUT IT IS UNKNOWN WHETHER INFLAMMATION ALTERS PCG-DEPENDENT SILENCING. HERE WE SHOW THAT THE JMJC-DOMAIN PROTEIN JMJD3 IS A H3K27ME DEMETHYLASE EXPRESSED IN MACROPHAGES IN RESPONSE TO BACTERIAL PRODUCTS AND INFLAMMATORY CYTOKINES. JMJD3 BINDS PCG TARGET GENES AND REGULATES THEIR H3K27ME3 LEVELS AND TRANSCRIPTIONAL ACTIVITY. THE DISCOVERY OF AN INDUCIBLE ENZYME THAT ERASES A HISTONE MARK CONTROLLING DIFFERENTIATION AND CELL IDENTITY PROVIDES A LINK BETWEEN INFLAMMATION AND REPROGRAMMING OF THE EPIGENOME, WHICH COULD BE THE BASIS FOR MACROPHAGE PLASTICITY AND MIGHT EXPLAIN THE DIFFERENTIATION ABNORMALITIES IN CHRONIC INFLAMMATION. 2007