1 5003 184 PERIODONTITIS IS AN INFLAMMATORY DISEASE OF OXIDATIVE STRESS: WE SHOULD TREAT IT THAT WAY. PERIODONTITIS IS A HIGHLY PREVALENT DISEASE. AS IT PROGRESSES, IT CAUSES SERIOUS MORBIDITY IN THE FORM OF PERIODONTAL ABSCESSES AND TOOTH LOSS AND, IN THE LATTER STAGES, PAIN. IT IS ALSO NOW KNOWN THAT PERIODONTITIS IS STRONGLY ASSOCIATED WITH SEVERAL NONORAL DISEASES. THUS, PATIENTS WITH PERIODONTITIS ARE AT GREATER RISK FOR THE DEVELOPMENT AND/OR EXACERBATION OF DIABETES, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND CARDIOVASCULAR DISEASES, AMONG OTHER CONDITIONS. ALTHOUGH IT IS WITHOUT QUESTION THAT SPECIFIC GROUPS OF ORAL BACTERIA WHICH POPULATE DENTAL PLAQUE PLAY A CAUSATIVE ROLE IN THE DEVELOPMENT OF PERIODONTITIS, IT IS NOW THOUGHT THAT ONCE THIS DISEASE HAS BEEN TRIGGERED, OTHER FACTORS PLAY AN EQUAL, AND POSSIBLY MORE IMPORTANT, ROLE IN ITS PROGRESSION, PARTICULARLY IN SEVERE CASES OR IN CASES THAT PROVE DIFFICULT TO TREAT. IN THIS REGARD, WE ALLUDE TO THE HOST RESPONSE, SPECIFICALLY THE NOTION THAT THE HOST, ONCE INFECTED WITH ORAL PERIODONTAL PATHOGENIC BACTERIA, WILL MOUNT A DEFENSE RESPONSE MEDIATED LARGELY THROUGH THE INNATE IMMUNE SYSTEM. THE MOST ABUNDANT CELL TYPE OF THE INNATE IMMUNE SYSTEM - POLYMORPHONUCLEAR NEUTROPHILS - CAN, WHEN PROTECTING THE HOST FROM MICROBIAL INVASION, MOUNT A RESPONSE THAT INCLUDES UPREGULATION OF PROINFLAMMATORY CYTOKINES, MATRIX METALLOPROTEINASES, AND REACTIVE OXYGEN SPECIES, ALL OF WHICH THEN CONTRIBUTE TO THE TISSUE DAMAGE AND LOSS OF TEETH COMMONLY ASSOCIATED WITH PERIODONTITIS. OF THE MECHANISMS REFERRED TO HERE, WE SUGGEST THAT UPREGULATION OF REACTIVE OXYGEN SPECIES MIGHT PLAY ONE OF THE MOST IMPORTANT ROLES IN THE ESTABLISHMENT AND PROGRESSION OF PERIODONTITIS (AS WELL AS IN OTHER DISEASES OF INFLAMMATION) THROUGH THE DEVELOPMENT OF OXIDATIVE STRESS. IN THIS OVERVIEW, WE DISCUSS BOTH INNATE AND EPIGENETIC FACTORS (EG, DIABETES, SMOKING) THAT LEAD TO THE DEVELOPMENT OF OXIDATIVE STRESS. THIS OXIDATIVE STRESS THEN PROVIDES AN ENVIRONMENT CONDUCIVE TO THE DESTRUCTIVE PROCESSES OBSERVED IN PERIODONTITIS. THEREFORE, WE SHALL DESCRIBE SOME OF THE FUNDAMENTAL CHARACTERISTICS OF OXIDATIVE STRESS AND ITS EFFECTS ON THE PERIODONTIUM, DISCUSS THE DISEASES AND OTHER FACTORS THAT CAUSE OXIDATIVE STRESS, AND, FINALLY, REVIEW POTENTIALLY NOVEL THERAPEUTIC APPROACHES FOR THE MANAGEMENT (AND POSSIBLY EVEN THE REVERSAL) OF PERIODONTITIS, WHICH RELY ON THE USE OF THERAPIES, SUCH AS RESVERATROL AND OTHER ANTIOXIDANTS, THAT PROVIDE INCREASED ANTIOXIDANT ACTIVITY IN THE HOST. 2020 2 6288 54 THE POTENTIAL ROLE OF EPIGENETIC MODIFICATIONS ON DIFFERENT FACETS IN THE PERIODONTAL PATHOGENESIS. PERIODONTITIS IS A CHRONIC INFLAMMATORY DISEASE THAT AFFECTS THE SUPPORTING STRUCTURES OF TEETH. IN THE LITERATURE, THE ASSOCIATION BETWEEN THE PATHOGENICITY OF BACTERIA AND ENVIRONMENTAL FACTORS IN THIS REGARD HAVE BEEN EXTENSIVELY EXAMINED. IN THE PRESENT STUDY, WE WILL SHED LIGHT ON THE POTENTIAL ROLE THAT EPIGENETIC CHANGE CAN PLAY ON DIFFERENT FACETS OF ITS PROCESS, MORE PARTICULARLY THE MODIFICATIONS CONCERNING THE GENES INVOLVED IN INFLAMMATION, DEFENSE, AND IMMUNE SYSTEMS. SINCE THE 1960S, THE ROLE OF GENETIC VARIANTS IN THE ONSET AND SEVERITY OF PERIODONTAL DISEASE HAS BEEN WIDELY DEMONSTRATED. THESE MAKE SOME PEOPLE MORE SUSCEPTIBLE TO DEVELOPING IT THAN OTHERS. IT HAS BEEN DOCUMENTED THAT THE WIDE VARIATION IN ITS FREQUENCY FOR VARIOUS RACIAL AND ETHNIC POPULATIONS IS DUE PRIMARILY TO THE COMPLEX INTERPLAY AMONG GENETIC FACTORS WITH THOSE AFFECTING THE ENVIRONMENT AND THE DEMOGRAPHY. IN MOLECULAR BIOLOGY, EPIGENETIC MODIFICATIONS ARE DEFINED AS ANY CHANGE IN THE PROMOTER FOR THE CPG ISLANDS, IN THE STRUCTURE OF THE HISTONE PROTEIN, AS WELL AS POST-TRANSLATIONAL REGULATION BY MICRORNAS (MIRNAS), BEING KNOWN TO CONTRIBUTE TO THE ALTERATION IN GENE EXPRESSION FOR COMPLEX MULTIFACTORIAL DISEASES SUCH AS PERIODONTITIS. THE KEY ROLE OF EPIGENETIC MODIFICATION IS TO UNDERSTAND THE MECHANISM INVOLVED IN THE GENE-ENVIRONMENT INTERACTION, AND THE DEVELOPMENT OF PERIODONTITIS IS NOW THE SUBJECT OF MORE AND MORE STUDIES THAT ATTEMPT TO IDENTIFY WHICH FACTORS ARE STIMULATING IT, BUT ALSO AFFECT THE REDUCED RESPONSE TO THERAPY. 2023 3 2558 49 EPIGENETICS IN SUSCEPTIBILITY, PROGRESSION, AND DIAGNOSIS OF PERIODONTITIS. PERIODONTITIS IS CHARACTERIZED BY IRREVERSIBLE DESTRUCTION OF PERIODONTAL TISSUE. AT PRESENT, THE ACCEPTED ETIOLOGY OF PERIODONTITIS IS BASED ON A THREE-FACTOR THEORY INCLUDING PATHOGENIC BACTERIA, HOST FACTORS, AND ACQUIRED FACTORS. PERIODONTITIS DEVELOPMENT USUALLY TAKES A DECADE OR LONGER AND IS THEREFORE CALLED CHRONIC PERIODONTITIS (CP). TO SEARCH FOR GENETIC FACTORS ASSOCIATED WITH CP, SEVERAL GENOME-WIDE ASSOCIATION STUDY (GWAS) ANALYSES WERE CONDUCTED; HOWEVER, POLYMORPHISMS ASSOCIATED WITH CP HAVE NOT BEEN IDENTIFIED. EPIGENETICS, ON THE OTHER HAND, INVOLVES ACQUIRED TRANSCRIPTIONAL REGULATORY MECHANISMS DUE TO REVERSIBLY ALTERED CHROMATIN ACCESSIBILITY. EPIGENETIC STATUS IS A CONDITION SPECIFIC TO EACH TISSUE AND CELL, MOSTLY DETERMINED BY THE RESPONSES OF HOST CELLS TO STIMULATIONS BY LOCAL FACTORS, LIKE BACTERIAL INFLAMMATION, AND SYSTEMIC FACTORS SUCH AS NUTRITION STATUS, METABOLIC DISEASES, AND HEALTH CONDITIONS. SIGNIFICANTLY, EPIGENETIC STATUS HAS BEEN LINKED WITH THE ONSET AND PROGRESSION OF SEVERAL ACQUIRED DISEASES. THUS, EPIGENETIC FACTORS IN PERIODONTAL TISSUES ARE ATTRACTIVE TARGETS FOR PERIODONTITIS DIAGNOSIS AND TREATMENTS. IN THIS REVIEW, WE INTRODUCE ACCUMULATING EVIDENCE TO REVEAL THE EPIGENETIC BACKGROUND EFFECTS RELATED TO PERIODONTITIS CAUSED BY GENETIC FACTORS, SYSTEMIC DISEASES, AND LOCAL ENVIRONMENTAL FACTORS, SUCH AS SMOKING, AND CLARIFY THE UNDERLYING MECHANISMS BY WHICH EPIGENETIC ALTERATION INFLUENCES THE SUSCEPTIBILITY OF PERIODONTITIS. 2022 4 4392 42 MODIFIABLE RISK FACTORS IN PERIODONTAL DISEASE: EPIGENETIC REGULATION OF GENE EXPRESSION IN THE INFLAMMATORY RESPONSE. EPIGENETICS AS A MODIFIABLE RISK FACTOR IN PERIODONTAL DISEASES HAS BEEN INVESTIGATED IN LIGHT OF THE CURRENT KNOWLEDGE OF HOW CHRONIC INFECTION AND INFLAMMATION CAN AFFECT GENE-SPECIFIC EPIGENETIC REPROGRAMMING IN PERIODONTAL TISSUES. EPIGENOMIC PROGRAMMING MIGHT BE PARTICULARLY SENSITIVE TO ENVIRONMENTAL INFLUENCES, AND A COMBINATION OF PHYSIOLOGICAL STRESSORS AND ENVIRONMENTAL EXPOSURES APPEARS TO AFFECT THE EPIGENOMIC PROGRAM ACQUIRED BY A CELL DURING DIFFERENTIATION AND THROUGHOUT THE CELLULAR LINEAGE LIFESPAN. VIRAL AND BACTERIAL INFECTIONS CAN ESTABLISH SEVERAL TYPES OF EPIGENETIC MODIFICATIONS, WHICH SOMETIMES ENGAGE IN A COMPLEX EPIGENETIC CROSSTALK ALSO REFLECTING IN THE ESTABLISHMENT AND PROGRESS OF PERIODONTAL DISEASES. THE INFLAMMATORY AND METABOLIC STATES OF THE PERIODONTAL TISSUES ARE DRIVEN BY THE INFECTIOUS STIMULI, AND THE MAGNITUDE OF THE CELLULAR AND MOLECULAR SIGNATURE RESPONSE IS FURTHER DICTATED BY THE HOST GENETIC AND EPIGENETIC TRAITS ASSOCIATED WITH VARIOUS SYSTEMIC EXPOSURES, INCLUDING SMOKING, OBESITY AND DIABETES/HYPERGLYCEMIA. THIS REVIEW DISCUSSES THE ADVANCES IN EPIGENETICS, FOCUSING ON THE ROLE OF DNA METHYLATION IN THE PATHOGENESIS OF PERIODONTAL DISEASE AND THE POTENTIAL OF EPIGENETIC THERAPY. 2014 5 4393 40 MODIFIABLE RISK FACTORS IN PERIODONTITIS: AT THE INTERSECTION OF AGING AND DISEASE. CHRONIC INFLAMMATION IS A PROMINENT FEATURE OF AGING AND OF COMMON AGE-RELATED DISEASES, INCLUDING ATHEROSCLEROSIS, CANCER AND PERIODONTITIS. THIS VOLUME EXAMINES MODIFIABLE RISK FACTORS FOR PERIODONTITIS AND OTHER CHRONIC INFLAMMATORY DISEASES. ORAL BACTERIAL COMMUNITIES AND VIRAL INFECTIONS, PARTICULARLY WITH CYTOMEGALOVIRUS AND OTHER HERPESVIRUSES, ELICIT DISTINCT IMMUNE RESPONSES AND ARE CENTRAL IN THE INITIATION OF PERIODONTAL DISEASES. RISK OF DISEASE IS DYNAMIC AND CHANGES IN RESPONSE TO COMPLEX INTERACTIONS OF GENETIC, ENVIRONMENTAL AND STOCHASTIC FACTORS OVER THE LIFESPAN. MANY MODIFIABLE RISK FACTORS, SUCH AS SMOKING AND EXCESS CALORIC INTAKE, CONTRIBUTE TO INCREASES IN SYSTEMIC MARKERS OF INFLAMMATION AND CAN MODIFY GENE REGULATION THROUGH A VARIETY OF BIOLOGIC MECHANISMS (E.G. EPIGENETIC MODIFICATIONS). PERIODONTITIS AND OTHER COMMON CHRONIC INFLAMMATORY DISEASES SHARE MULTIPLE MODIFIABLE RISK FACTORS, SUCH AS TOBACCO SMOKING, PSYCHOLOGICAL STRESS AND DEPRESSION, ALCOHOL CONSUMPTION, OBESITY, DIABETES, METABOLIC SYNDROME AND OSTEOPOROSIS. INTERVENTIONS THAT TARGET MODIFIABLE RISK FACTORS HAVE THE POTENTIAL TO IMPROVE RISK PROFILES FOR PERIODONTITIS AS WELL AS FOR OTHER COMMON CHRONIC DISEASES. 2014 6 1871 48 EMERGING ROLE OF EPIGENETICS IN EXPLAINING RELATIONSHIP OF PERIODONTITIS AND CARDIOVASCULAR DISEASES. CARDIOVASCULAR DISEASES SUCH AS ISCHEMIC HEART DISEASES OR STROKE ARE AMONG THE LEADING CAUSE OF DEATHS GLOBALLY, AND EVIDENCE SUGGESTS THAT THESE DISEASES ARE MODULATED BY A MULTIFACTORIAL AND COMPLEX INTERPLAY OF GENETIC, ENVIRONMENTAL, AND LIFESTYLE FACTORS. GENETIC PREDISPOSITION AND CHRONIC EXPOSURE TO MODIFIABLE RISK FACTORS HAVE BEEN EXPLORED TO BE INVOLVED IN THE PATHOPHYSIOLOGY OF CVD. ENVIRONMENTAL FACTORS CONTRIBUTE TO AN INDIVIDUAL'S PROPENSITY TO DEVELOP MAJOR CARDIOVASCULAR RISK FACTORS THROUGH EPIGENETIC MODIFICATIONS OF DNA AND HISTONES VIA MIRNA REGULATION OF PROTEIN TRANSLATION THAT ARE TYPES OF EPIGENETIC MECHANISMS AND PARTICIPATE IN DISEASE DEVELOPMENT. PERIODONTAL DISEASE (PD) IS ONE OF THE MOST COMMON ORAL DISEASES IN HUMANS THAT IS CHARACTERIZED BY LOW-GRADE INFLAMMATION AND HAS BEEN SHOWN TO INCREASE THE RISK OF CVDS. RISK FACTORS INVOLVED IN PD AND CVD ARE DETERMINED BOTH GENETICALLY AND BEHAVIORALLY. PERIODONTAL DISEASES SUCH AS CHRONIC INFLAMMATION PROMOTE DNA METHYLATION. EPIGENETIC MODIFICATIONS INVOLVED IN THE INITIATION AND PROGRESSION OF ATHEROSCLEROSIS PLAY AN ESSENTIAL ROLE IN PLAQUE DEVELOPMENT AND VULNERABILITY. EPIGENETICS HAS OPENED A NEW WORLD TO UNDERSTAND AND MANAGE HUMAN DISEASES, INCLUDING CVDS AND PERIODONTAL DISEASES. GENETIC MEDICINE HAS STARTED A NEW ERA OF EPIGENETICS TO OVERCOME HUMAN DISEASES WITH VARIOUS NEW METHODOLOGY. EPIGENETIC PROFILING MAY AID IN BETTER DIAGNOSIS AND STRATIFICATION OF PATIENTS SHOWING POTENTIAL PREDISPOSED STATES FOR DISEASE. A BETTER UNDERSTANDING OF THE EXACT REGULATORY MECHANISMS OF EPIGENETIC PATHWAYS DRIVING INFLAMMATION IS SLOWLY EMERGING AND WILL AID IN DEVELOPING NOVEL TOOLS FOR THE TREATMENT OF DISEASE. 2021 7 2501 38 EPIGENETICS AND ITS ROLE IN PERIODONTAL DISEASES: A STATE-OF-THE-ART REVIEW. THE IMMUNE RESPONSE TO ORAL BACTERIA AND THE SUBSEQUENT ACTIVATION OF INFLAMMATORY SIGNALING IS NOT ONLY DEPENDENT ON GENETIC FACTORS. THE IMPORTANCE OF SO-CALLED EPIGENETIC MECHANISMS PRESENTS ADDITIONAL REGULATORY PATHWAYS OF GENES INVOLVED IN MAINTAINING CHRONIC INFLAMMATION, INCLUDING GINGIVITIS AND PERIODONTITIS. THE TERM EPIGENETICS RELATES TO CHANGES IN GENE EXPRESSION THAT ARE NOT ENCODED IN THE DNA SEQUENCE ITSELF AND INCLUDE CHEMICAL ALTERATIONS OF DNA AND ITS ASSOCIATED PROTEINS. THESE CHANGES LEAD TO REMODELING OF THE CHROMATIN AND SUBSEQUENT ACTIVATION OR INACTIVATION OF A GENE. EPIGENETIC MECHANISMS HAVE BEEN FOUND TO CONTRIBUTE TO DISEASE, INCLUDING CANCER AND AUTOIMMUNE OR INFLAMMATORY DISEASES. IN THIS STATE-OF-THE ART REVIEW, THE AUTHORS PROVIDE THE LATEST FINDINGS ON THE INVOLVEMENT OF EPIGENETIC MODIFICATIONS IN THE DEVELOPMENT OF PERIODONTAL DISEASE AND PRESENT EMERGING THERAPEUTIC STRATEGIES AIMED AT EPIGENETIC TARGETS (EPIDRUGS) ASSOCIATED WITH THE DISRUPTION OF TISSUE HOMEOSTASIS AND THE DEVELOPMENT OF PERIODONTITIS. 2015 8 4273 43 MICROBIOTA AND EPIGENETICS: HEALTH IMPACT. EPIGENETIC CHANGES ASSOCIATED WITH DISEASE DEVELOPMENT AND PROGRESSIONS ARE OF INCREASING IMPORTANCE BECAUSE OF THEIR POTENTIAL DIAGNOSTIC AND THERAPEUTIC APPLICATIONS. SEVERAL EPIGENETIC CHANGES ASSOCIATED WITH CHRONIC METABOLIC DISORDERS HAVE BEEN STUDIED IN VARIOUS DISEASES. EPIGENETIC CHANGES ARE MOSTLY MODULATED BY ENVIRONMENTAL FACTORS, INCLUDING THE HUMAN MICROBIOTA LIVING IN DIFFERENT PARTS OF OUR BODIES. THE MICROBIAL STRUCTURAL COMPONENTS AND THE MICROBIALLY DERIVED METABOLITES DIRECTLY INTERACT WITH HOST CELLS, THEREBY MAINTAINING HOMEOSTASIS. MICROBIOME DYSBIOSIS, ON THE OTHER HAND, IS KNOWN TO PRODUCE ELEVATED LEVELS OF DISEASE-LINKED METABOLITES, WHICH MAY DIRECTLY AFFECT A HOST METABOLIC PATHWAY OR INDUCE EPIGENETIC CHANGES THAT CAN LEAD TO DISEASE DEVELOPMENT. DESPITE THEIR IMPORTANT ROLE IN HOST PHYSIOLOGY AND SIGNAL TRANSDUCTION, THERE HAS BEEN LITTLE RESEARCH INTO THE MECHANICS AND PATHWAYS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. THIS CHAPTER FOCUSES ON THE RELATIONSHIP BETWEEN MICROBES AND THEIR EPIGENETIC EFFECTS IN DISEASED PATHOLOGY, AS WELL AS ON THE REGULATION AND METABOLISM OF THE DIETARY OPTIONS AVAILABLE TO THE MICROBES. FURTHERMORE, THIS CHAPTER ALSO PROVIDES A PROSPECTIVE LINK BETWEEN THESE TWO IMPORTANT PHENOMENA, TERMED "MICROBIOME AND EPIGENETICS." 2023 9 2333 40 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 10 5929 54 TARGETING EPIGENETIC MECHANISMS IN PERIODONTAL DISEASES. EPIGENETIC FACTORS ARE HERITABLE GENOME MODIFICATIONS THAT POTENTIALLY IMPACT GENE TRANSCRIPTION, CONTRIBUTING TO DISEASE STATES. EPIGENETIC MARKS PLAY AN IMPORTANT ROLE IN CHRONIC INFLAMMATORY CONDITIONS, AS OBSERVED IN PERIODONTAL DISEASES, BY ALLOWING MICROBIAL PERSISTENCE OR BY PERMITTING MICROBIAL INSULT TO PLAY A ROLE IN THE SO-CALLED 'HIT-AND-RUN' INFECTIOUS MECHANISM, LEADING TO LASTING PATHOGEN INTERFERENCE WITH THE HOST GENOME. EPIGENETICS ALSO AFFECTS THE HEALTH SCIENCES BY PROVIDING A DYNAMIC MECHANISTIC FRAMEWORK TO EXPLAIN THE WAY IN WHICH ENVIRONMENTAL AND BEHAVIORAL FACTORS INTERACT WITH THE GENOME TO ALTER DISEASE RISK. IN THIS ARTICLE WE REVIEW CURRENT KNOWLEDGE OF EPIGENOME REGULATION IN LIGHT OF THE MULTIFACTORIAL NATURE OF PERIODONTAL DISEASES. WE DISCUSS EPIGENETIC TAGGING IN IDENTIFIED GENES, AND CONSIDER THE POTENTIAL IMPLICATIONS OF EPIGENETIC CHANGES ON HOST-MICROBIOME DYNAMICS IN CHRONIC INFLAMMATORY STATES AND IN RESPONSE TO ENVIRONMENTAL STRESSORS. THE MOST RECENT ADVANCES IN GENOMIC TECHNOLOGIES HAVE PLACED US IN A POSITION TO ANALYZE INTERACTION EFFECTS (EG, BETWEEN PERIODONTAL DISEASE AND TYPE 2 DIABETES MELLITUS), WHICH CAN BE INVESTIGATED THROUGH EPIGENOME-WIDE ASSOCIATION ANALYSIS. FINALLY, BECAUSE OF THE INDIVIDUALIZED TRAITS OF EPIGENETIC BIOMARKERS, PHARMACOEPIGENOMIC PERSPECTIVES ARE ALSO CONSIDERED AS POTENTIALLY NOVEL THERAPEUTIC APPROACHES FOR IMPROVING PERIODONTAL DISEASE STATUS. 2018 11 1606 40 DNA METHYLATION, BACTERIA AND AIRWAY INFLAMMATION: LATEST INSIGHTS. PURPOSE OF REVIEW: DNA METHYLATION IS AN EPIGENETIC MECHANISM THAT HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES BY REGULATING DIFFERENTIATION, PROLIFERATION, APOPTOSIS, AND ACTIVATION OF IMMUNE CELLS. CHANGES IN THE METHYLATION STATUS OF RELEVANT GENES HAVE BEEN LINKED TO THE ORIGIN, PERPETUATION, AND SEVERITY OF AIRWAY DISEASES. THE DNA METHYLATION PROFILE CAN BE ALSO MODIFIED BY THE ACTION OF VIRAL AND BACTERIAL COLONIZATION. BACTERIA AND SPECIALLY STAPHYLOCOCCUS AUREUS TOXINS ARE RECOGNIZED INFLAMMATORY AMPLIFYING FACTORS IN BOTH LOWER AND UPPER AIRWAY CHRONIC DISEASES. THIS REVIEW SUMMARIZES THE EXISTENT KNOWLEDGE ABOUT THE ROLE OF DNA METHYLATION CHANGES IN CHRONIC AIRWAY DISEASES AND THE CONTRIBUTION OF BACTERIAL INFECTION ON THIS EVENT. RECENT FINDINGS: IT HAS BEEN DEMONSTRATED THAT CHANGES IN DNA METHYLATION, EITHER INTRINSIC OR INDUCED BY ALLERGEN OR INFECTION, MAY BE LINKED TO THE PATHOGENESIS OF ASTHMA AND ALLERGY. THESE CHANGES IN METHYLATION MAY SUPPRESS THE PRODUCTION OF ANTI-INFLAMMATORY MEDIATORS AND INCREASE THE SURVIVAL AND ACTIVATION OF PRO-INFLAMMATORY CELLS, AS WELL AS MODIFY THE IMMUNE RESPONSE IN RESPONSE TO BACTERIAL INFECTION, INCREASING THEIR SURVIVAL AND PATHOGENICITY WITHIN THE INFECTED ORGANISM. SUMMARY: UNDERSTANDING THE INTRINSIC EPIGENETIC MECHANISMS, AS WELL AS THE EFFECT OF ENVIRONMENT -FOR EXAMPLE, BACTERIAL INFECTION IN THE PATHOGENESIS OF AIRWAYS DISEASES - WILL GREATLY IMPROVE THE MANAGEMENT AND THE DIAGNOSIS OF THESE DISEASES. 2015 12 2396 47 EPIGENETIC REPROGRAMMING IN PERIODONTAL DISEASE: DYNAMIC CROSSTALK WITH POTENTIAL IMPACT IN ONCOGENESIS. PERIODONTITIS IS A CHRONIC MULTIFACTORIAL IN FL AMMATORY DISEASE ASSOCIATED WITH MICROBIAL DYSBIOSIS AND CHARACTERIZED BY PROGRESSIVE DESTRUCTION OF THE PERIODONTAL TISSUES. SUCH CHRONIC INFECTIOUS INFLAMMATORY DISEASE IS RECOGNIZED AS A MAJOR PUBLIC HEALTH PROBLEM WORLDWIDE WITH MEASURABLE IMPACT IN SYSTEMIC HEALTH. IT HAS BECOME EVIDENT THAT THE PERIODONTAL DISEASE PHENOTYPES ARE NOT ONLY DETERMINED BY THE MICROBIOME EFFECT, BUT THE EXTENT OF THE TISSUE RESPONSE IS ALSO DRIVEN BY THE HOST GENOME AND EPIGENOME PATTERNS RESPONDING TO VARIOUS ENVIRONMENTAL EXPOSURES. MORE RECENTLY THERE IS MOUNTING EVIDENCE INDICATING THAT EPIGENETIC REPROGRAMMING IN RESPONSE TO COMBINED INTRINSIC AND ENVIRONMENTAL EXPOSURES, MIGHT BE PARTICULARLY RELEVANT DUE ITS PLASTICITY AND POTENTIAL APPLICATION TOWARDS PRECISION HEALTH. THE COMPLEX EPIGENETIC CROSSTALK IS REFLECTED IN THE PROGNOSIS AND PROGRESS OF PERIODONTAL DISEASES AND MAY ALSO LEAD TO A FAVORABLE LANDSCAPE FOR CANCER DEVELOPMENT. THIS REVIEW DISCUSSES EPIGENOMICS MODIFICATIONS FOCUSING ON THE ROLE OF DNA METHYLATION AND PATHWAYS LINKING MICROBIAL INFECTION AND INFLAMMATORY PATHWAYS, WHICH ARE ALSO ASSOCIATED WITH CARCINOGENESIS. THERE IS A MORE CLEAR VISION WHEREAS 'OMICS' TECHNOLOGIES APPLIED TO UNVEIL RELEVANT EPIGENETIC FACTORS COULD PLAY A SIGNIFICANT ROLE IN THE TREATMENT OF PERIODONTAL DISEASE IN A PERSONALIZED MODE, EVIDENCING THAT PUBLIC HEALTH APPROACH SHOULD COEXIST WITH PRECISION INDIVIDUALIZED TREATMENT. 2020 13 6034 58 THE CHALLENGE BY MULTIPLE ENVIRONMENTAL AND BIOLOGICAL FACTORS INDUCE INFLAMMATION IN AGING: THEIR ROLE IN THE PROMOTION OF CHRONIC DISEASE. THE AGING PROCESS IS DRIVEN BY MULTIPLE MECHANISMS THAT LEAD TO CHANGES IN ENERGY PRODUCTION, OXIDATIVE STRESS, HOMEOSTATIC DYSREGULATION AND EVENTUALLY TO LOSS OF FUNCTIONALITY AND INCREASED DISEASE SUSCEPTIBILITY. MOST AGED INDIVIDUALS DEVELOP CHRONIC LOW-GRADE INFLAMMATION, WHICH IS AN IMPORTANT RISK FACTOR FOR MORBIDITY, PHYSICAL AND COGNITIVE IMPAIRMENT, FRAILTY, AND DEATH. AT ANY AGE, CHRONIC INFLAMMATORY DISEASES ARE MAJOR CAUSES OF MORBIMORTALITY, AFFECTING UP TO 5-8% OF THE POPULATION OF INDUSTRIALIZED COUNTRIES. SEVERAL ENVIRONMENTAL FACTORS CAN PLAY AN IMPORTANT ROLE FOR MODIFYING THE INFLAMMATORY STATE. GENETICS ACCOUNTS FOR ONLY A SMALL FRACTION OF CHRONIC-INFLAMMATORY DISEASES, WHEREAS ENVIRONMENTAL FACTORS APPEAR TO PARTICIPATE, EITHER WITH A CAUSATIVE OR A PROMOTIONAL ROLE IN 50% TO 75% OF PATIENTS. SEVERAL OF THOSE CHANGES DEPEND ON EPIGENETIC CHANGES THAT WILL FURTHER MODIFY THE INDIVIDUAL RESPONSE TO ADDITIONAL STIMULI. THE INTERACTION BETWEEN INFLAMMATION AND THE ENVIRONMENT OFFERS IMPORTANT INSIGHTS ON AGING AND HEALTH. THESE CONDITIONS, OFTEN DEPENDING ON THE INDIVIDUAL'S SEX, APPEAR TO LEAD TO DECREASED LONGEVITY AND PHYSICAL AND COGNITIVE DECLINE. IN ADDITION TO BIOLOGICAL FACTORS, THE ENVIRONMENT IS ALSO INVOLVED IN THE GENERATION OF PSYCHOLOGICAL AND SOCIAL CONTEXT LEADING TO STRESS. POOR PSYCHOLOGICAL ENVIRONMENTS AND OTHER SOURCES OF STRESS ALSO RESULT IN INCREASED INFLAMMATION. HOWEVER, THE MECHANISMS UNDERLYING THE ROLE OF ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS AND NUTRITION ON THE REGULATION OF INFLAMMATION, AND HOW THE RESPONSE ELICITED FOR THOSE FACTORS INTERACT AMONG THEM, ARE POORLY UNDERSTOOD. WHEREAS CERTAIN DELETERIOUS ENVIRONMENTAL FACTORS RESULT IN THE GENERATION OF OXIDATIVE STRESS DRIVEN BY AN INCREASED PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES, ENDOPLASMIC RETICULUM STRESS, AND INFLAMMATION, OTHER FACTORS, INCLUDING NUTRITION (POLYUNSATURATED FATTY ACIDS) AND BEHAVIORAL FACTORS (EXERCISE) CONFER PROTECTION AGAINST INFLAMMATION, OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS, AND THUS AMELIORATE THEIR DELETERIOUS EFFECT. HERE, WE DISCUSS PROCESSES AND MECHANISMS OF INFLAMMATION ASSOCIATED WITH ENVIRONMENTAL FACTORS AND BEHAVIOR, THEIR LINKS TO SEX AND GENDER, AND THEIR OVERALL IMPACT ON AGING. 2020 14 523 51 ASSOCIATIONS BETWEEN PERIODONTITIS AND SYSTEMIC INFLAMMATORY DISEASES: RESPONSE TO TREATMENT. THERE IS A SIGNIFICANT PREVALENCE OF SUBJECTS WITH PERIODONTITIS PRESENTING WITH OTHER INFLAMMATORY CONDITIONS SUCH AS CORONARY HEART DISEASE, INSULIN RESISTANCE AND ARTHRITIS. THIS PATTERN OF DISEASE PRESENTATION UNDERSCORES THE IMPORTANCE OF INFLAMMATORY LOADING FROM CHRONIC DISEASES, IN DRIVING THEIR PATHOGENESES IN A MULTIDIRECTIONAL MANNER. PRO-INFLAMMATORY CYTOKINES AND OTHER AGENTS PLAY AN IMPORTANT ROLE IN THIS PROCESS; FOR EXAMPLE, A SINGLE NUCLEOTIDE POLYMORPHISM OF THE TNF-ALPHA GENE IS ASSOCIATED WITH SIGNIFICANT PERIODONTAL ATTACHMENT LOSS IN PATIENTS WITH CORONARY HEART DISEASE. CHANGES IN GENE EXPRESSION ASSOCIATED WITH INFLAMMATION AND LIPID METABOLISM IN RESPONSE TO ORAL INFECTION WITH THE PERIODONTAL PATHOGEN PORPHYROMONAS GINGIVALIS (PG) HAVE BEEN DEMONSTRATED IN MOUSE MODELS, INDEPENDENT OF THE DEMONSTRATION OF ATHEROSCLEROTIC LESIONS. INSULIN RESISTANCE IS CONSIDERED TO BE A CHRONIC LOW-GRADE INFLAMMATORY CONDITION, ASSOCIATED WITH ALTERED GLUCOSE TOLERANCE, HYPERTRIGLYCERIDEMIA, CENTRAL OBESITY AND CORONARY HEART DISEASE. IT IS ACCOMPANIED BY ELEVATED LEVELS OF IL-1, IL-6 AND TNF-ALPHA ALSO RELEVANT TO THE PROGRESSION OF PERIODONTITIS. THERE IS EVIDENCE THAT UNCONTROLLED PERIODONTAL DISEASE CONTRIBUTES TO MAINTENANCE OF SYSTEMIC DISEASES, INCLUDING RHEUMATOID ARTHRITIS (RA), WITH INCREASED RISK OF PERIODONTITIS IN SUBJECTS WITH RA. THE PERIODONTAL PATHOGEN PG IS SIGNIFICANT IN CONTRIBUTING TO CITRULLINATION OF PROTEINS RESULTING IN IMMUNE DYSREGULATION AND AUTOIMMUNE RESPONSES, SEEN IN RA. HOWEVER, THEY ARE BOTH MULTIFACTORIAL CHRONIC DISEASES WITH COMPLEX ETIOPATHOGENESES THAT AFFECT THEIR PRESENTATION. CONSISTENT BUT WEAK ASSOCIATIONS ARE SEEN FOR SURROGATE MARKERS OF PERIODONTITIS SUCH AS TOOTH LOSS, WITH MULTIPLE SYSTEMIC CONDITIONS. EFFECTIVE TREATMENT OF PERIODONTITIS WOULD BE IMPORTANT IN REDUCING SYSTEMIC INFLAMMATORY LOADING FROM CHRONIC LOCAL INFLAMMATION AND IN ACHIEVING SYSTEMIC HEALTH. LACK OF A CONSISTENT CAUSE AND EFFECT RELATIONSHIP IN ALL SUBJECTS WOULD BE INFLUENCED BY GENETIC, EPIGENETIC AND OTHER SUBJECT VARIABLES, ALTHOUGH THERE ARE CLEAR MECHANISMS THAT LINK THE ASSOCIATIONS. THIS ARTICLE INCLUDES AN APPRAISAL OF PATENTS AND THEIR APPLICATIONS. 2013 15 5765 40 SOURCE OF CHRONIC INFLAMMATION IN AGING. AGING IS A COMPLEX PROCESS THAT RESULTS FROM A COMBINATION OF ENVIRONMENTAL, GENETIC, AND EPIGENETIC FACTORS. A CHRONIC PRO-INFLAMMATORY STATUS IS A PERVASIVE FEATURE OF AGING. THIS CHRONIC LOW-GRADE INFLAMMATION OCCURRING IN THE ABSENCE OF OVERT INFECTION HAS BEEN DEFINED AS "INFLAMMAGING" AND REPRESENTS A SIGNIFICANT RISK FACTOR FOR MORBIDITY AND MORTALITY IN THE ELDERLY. THE LOW-GRADE INFLAMMATION PERSISTS EVEN AFTER REVERSING PRO-INFLAMMATORY STIMULI SUCH AS LDL CHOLESTEROL AND THE RENIN-ANGIOTENSIN SYSTEM (RAS). RECENTLY, SEVERAL POSSIBLE SOURCES OF CHRONIC LOW-GRADE INFLAMMATION OBSERVED DURING AGING AND AGE-RELATED DISEASES HAVE BEEN PROPOSED. CELL SENESCENCE AND DYSREGULATION OF INNATE IMMUNITY IS ONE SUCH MECHANISM BY WHICH PERSISTENT PROLONGED INFLAMMATION OCCURS EVEN AFTER THE INITIAL STIMULUS HAS BEEN REMOVED. ADDITIONALLY, THE COAGULATION FACTOR THAT ACTIVATES INFLAMMATORY SIGNALING BEYOND ITS ROLE IN THE COAGULATION SYSTEM HAS BEEN IDENTIFIED. THIS SIGNAL COULD BE A NEW SOURCE OF CHRONIC INFLAMMATION AND CELL SENESCENCE. HERE, WE SUMMARIZED THE FACTORS AND CELLULAR PATHWAYS/PROCESSES THAT ARE KNOWN TO REGULATE LOW-GRADE PERSISTENT INFLAMMATION IN AGING AND AGE-RELATED DISEASE. 2018 16 3547 59 IMMUNOMODULATORY ROLE OF NUTRIENTS: HOW CAN PULMONARY DYSFUNCTIONS IMPROVE? NUTRITION IS AN IMPORTANT TOOL THAT CAN BE USED TO MODULATE THE IMMUNE RESPONSE DURING INFECTIOUS DISEASES. IN ADDITION, THROUGH DIET, IMPORTANT SUBSTRATES ARE ACQUIRED FOR THE BIOSYNTHESIS OF REGULATORY MOLECULES IN THE IMMUNE RESPONSE, INFLUENCING THE PROGRESSION AND TREATMENT OF CHRONIC LUNG DISEASES, SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN THIS WAY, NUTRITION CAN PROMOTE LUNG HEALTH STATUS. A RANGE OF NUTRIENTS, SUCH AS VITAMINS (A, C, D, AND E), MINERALS (ZINC, SELENIUM, IRON, AND MAGNESIUM), FLAVONOIDS AND FATTY ACIDS, PLAY IMPORTANT ROLES IN REDUCING THE RISK OF PULMONARY CHRONIC DISEASES AND VIRAL INFECTIONS. THROUGH THEIR ANTIOXIDANT AND ANTI-INFLAMMATORY EFFECTS, NUTRIENTS ARE ASSOCIATED WITH BETTER LUNG FUNCTION AND A LOWER RISK OF COMPLICATIONS SINCE THEY CAN DECREASE THE HARMFUL EFFECTS FROM THE IMMUNE SYSTEM DURING THE INFLAMMATORY RESPONSE. IN ADDITION, BIOACTIVE COMPOUNDS CAN EVEN CONTRIBUTE TO EPIGENETIC CHANGES, INCLUDING HISTONE DEACETYLASE (HDAC) MODIFICATIONS THAT INHIBIT THE TRANSCRIPTION OF PROINFLAMMATORY CYTOKINES, WHICH CAN CONTRIBUTE TO THE MAINTENANCE OF HOMEOSTASIS IN THE CONTEXT OF INFECTIONS AND CHRONIC INFLAMMATORY DISEASES. THESE NUTRIENTS ALSO PLAY AN IMPORTANT ROLE IN ACTIVATING IMMUNE RESPONSES AGAINST PATHOGENS, WHICH CAN HELP THE IMMUNE SYSTEM DURING INFECTIONS. HERE, WE PROVIDE AN UPDATED OVERVIEW OF THE ROLES PLAYED BY DIETARY FACTORS AND HOW THEY CAN AFFECT RESPIRATORY HEALTH. THEREFORE, WE WILL SHOW THE ANTI-INFLAMMATORY ROLE OF FLAVONOIDS, FATTY ACIDS, VITAMINS AND MICROBIOTA, IMPORTANT FOR THE CONTROL OF CHRONIC INFLAMMATORY DISEASES AND ALLERGIES, IN ADDITION TO THE ANTIVIRAL ROLE OF VITAMINS, FLAVONOIDS, AND MINERALS DURING PULMONARY VIRAL INFECTIONS, ADDRESSING THE MECHANISMS INVOLVED IN EACH FUNCTION. THESE MECHANISMS ARE INTERESTING IN THE DISCUSSION OF PERSPECTIVES ASSOCIATED WITH SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2 (SARS-COV-2) INFECTION AND ITS PULMONARY COMPLICATIONS SINCE PATIENTS WITH SEVERE DISEASE HAVE VITAMINS DEFICIENCY, ESPECIALLY VITAMIN D. IN ADDITION, RESEARCHES WITH THE USE OF FLAVONOIDS HAVE BEEN SHOWN TO DECREASE VIRAL REPLICATION IN VITRO. THIS WAY, A FULL UNDERSTANDING OF DIETARY INFLUENCES CAN IMPROVE THE LUNG HEALTH OF PATIENTS. 2021 17 1523 33 DNA METHYLATION CHANGES AND INFLAMMAGING IN AGING-ASSOCIATED DISEASES. AGING AS AN INEVITABLE PHENOMENON IS ASSOCIATED WITH PERVASIVE CHANGES IN PHYSIOLOGICAL FUNCTIONS. THERE IS A RELATIONSHIP BETWEEN AGING AND THE INCREASE OF SEVERAL CHRONIC DISEASES. MOST AGE-RELATED DISORDERS ARE ACCOMPANIED BY AN UNDERLYING CHRONIC INFLAMMATORY STATE, AS DEMONSTRATED BY LOCAL INFILTRATION OF INFLAMMATORY CELLS AND GREATER LEVELS OF PROINFLAMMATORY CYTOKINES IN THE BLOODSTREAM. WITHIN INFLAMMAGING, MANY EPIGENETIC EVENTS, ESPECIALLY DNA METHYLATION, CHANGE. DURING THE AGING PROCESS, DUE TO ABERRATIONS OF DNA METHYLATION, BIOLOGICAL PROCESSES ARE DISRUPTED, LEADING TO THE EMERGENCE OR PROGRESSION OF A VARIETY OF HUMAN DISEASES, INCLUDING CANCER, NEURODEGENERATIVE DISORDERS, CARDIOVASCULAR DISEASE AND DIABETES. THE FOCUS OF THIS REVIEW IS ON DNA METHYLATION, WHICH IS INVOLVED IN INFLAMMAGING-RELATED ACTIVITIES, AND HOW ITS DYSREGULATION LEADS TO HUMAN DISORDERS. 2022 18 6359 41 THE ROLE OF INFLAMMATION IN THE PATHOGENESIS OF LUNG CANCER. INTRODUCTION: IT IS REPORTED THAT CANCER MAY ARISE IN CHRONICALLY INFLAMED TISSUE. THERE IS MOUNTING EVIDENCE SUGGESTING THAT THE CONNECTION BETWEEN INFLAMMATION AND LUNG CANCER IS NOT COINCIDENTAL BUT MAY INDEED BE CAUSAL. THE INFLAMMATORY MOLECULES MAY BE RESPONSIBLE FOR AUGMENTED MACROPHAGE RECRUITMENT, DELAYED NEUTROPHIL CLEARANCE AND AN INCREASE IN REACTIVE OXYGEN SPECIES. THE CYTOKINES AND GROWTH FACTORS UNUSUALLY PRODUCED IN CHRONIC PULMONARY DISORDERS HAVE BEEN FOUND TO HAVE HARMFUL PROPERTIES THAT PAVE THE WAY FOR EPITHELIAL-TO-MESENCHYMAL TRANSITION AND TUMOR MICROENVIRONMENT. HOWEVER, THE ROLE OF INFLAMMATION IN LUNG CANCER IS NOT YET FULLY UNDERSTOOD. AREAS COVERED: THE ROLE OF CHRONIC INFLAMMATION IN THE PATHOGENESIS OF LUNG CANCER AND SOME OF THE POSSIBLE MECHANISMS INVOLVED, WITH PARTICULAR FOCUS ON INFLAMMATORY MEDIATORS, GENETIC AND EPIGENETIC ALTERATIONS, INFLAMMATORY MARKERS, TUMOR MICROENVIRONMENT AND ANTI-INFLAMMATORY DRUGS ARE DISCUSSED. A FRAMEWORK FOR UNDERSTANDING THE CONNECTION BETWEEN INFLAMMATION AND LUNG CANCER IS PROVIDED, WHICH MAY AFFORD THE OPPORTUNITY TO INTERCEDE IN SPECIFIC INFLAMMATORY DAMAGE MEDIATING LUNG CARCINOGENESIS AND THERAPEUTIC RESISTANCE. EXPERT OPINION: ADVANCES IN TUMOR IMMUNOLOGY SUPPORT THE CLINICAL IMPLEMENTATION OF IMMUNOTHERAPIES FOR LUNG CANCER. ALONG WITH THERAPEUTIC BENEFITS, IMMUNOTHERAPY PRESENTS THE CHALLENGES OF DRUG-RELATED TOXICITIES. GENE MODIFICATION OF IMMUNOCYTOKINE MAY LOWER THE ASSOCIATED TOXIC EFFECTS. 2011 19 4043 40 MACROPHAGES IN CHRONIC LIVER FAILURE: DIVERSITY, PLASTICITY AND THERAPEUTIC TARGETING. CHRONIC LIVER INJURY RESULTS IN IMMUNE-DRIVEN PROGRESSIVE FIBROSIS, WITH RISK OF CIRRHOSIS DEVELOPMENT AND IMPACT ON MORBIDITY AND MORTALITY. PERSISTENT LIVER CELL DAMAGE AND DEATH CAUSES IMMUNE CELL ACTIVATION AND INFLAMMATION. PATIENTS WITH ADVANCED CIRRHOSIS ADDITIONALLY EXPERIENCE PATHOLOGICAL BACTERIAL TRANSLOCATION, EXPOSURE TO MICROBIAL PRODUCTS AND CHRONIC ENGAGEMENT OF THE IMMUNE SYSTEM. BACTERIAL INFECTIONS HAVE A HIGH INCIDENCE IN CIRRHOSIS, WITH SPONTANEOUS BACTERIAL PERITONITIS BEING THE MOST COMMON, WHILE THE SUBSEQUENT SYSTEMIC INFLAMMATION, ORGAN FAILURE AND IMMUNE DYSREGULATION INCREASE THE MORTALITY RISK. TISSUE-RESIDENT AND RECRUITED MACROPHAGES PLAY A CENTRAL PART IN THE DEVELOPMENT OF INFLAMMATION AND FIBROSIS PROGRESSION. IN THE LIVER, ADIPOSE TISSUE, PERITONEUM AND INTESTINES, DIVERSE MACROPHAGE POPULATIONS EXHIBIT GREAT PHENOTYPIC AND FUNCTIONAL PLASTICITY DETERMINED BY THEIR ONTOGENY, EPIGENETIC PROGRAMMING AND LOCAL MICROENVIRONMENT. THESE CHANGES CAN, AT DIFFERENT TIMES, PROMOTE OR AMELIORATE DISEASE STATES AND THEREFORE REPRESENT POTENTIAL TARGETS FOR MACROPHAGE-DIRECTED THERAPIES. IN THIS REVIEW, WE DISCUSS THE EVIDENCE FOR MACROPHAGE PHENOTYPIC AND FUNCTIONAL ALTERATIONS IN TISSUE COMPARTMENTS DURING THE DEVELOPMENT AND PROGRESSION OF CHRONIC LIVER FAILURE IN DIFFERENT AETIOLOGIES AND HIGHLIGHT THE POTENTIAL OF MACROPHAGE MODULATION AS A THERAPEUTIC STRATEGY FOR LIVER DISEASE. 2021 20 5325 33 PULMONARY PATHOGEN-INDUCED EPIGENETIC MODIFICATIONS. EPIGENETICS GENERALLY INVOLVES GENETIC CONTROL BY FACTORS OTHER THAN OUR OWN DNA SEQUENCE. RECENT RESEARCH HAS FOCUSED ON DELINEATING THE MECHANISMS OF TWO MAJOR EPIGENETIC PHENOMENA: DNA METHYLATION AND HISTONE MODIFICATION. AS EPIGENETICS INVOLVES MANY CELLULAR PROCESSES, IT IS NO SURPRISE THAT IT CAN ALSO INFLUENCE DISEASE-ASSOCIATED GENE EXPRESSION. A DIRECT LINK BETWEEN RESPIRATORY INFECTIONS, HOST CELL EPIGENETIC REGULATIONS, AND CHRONIC LUNG DISEASES IS STILL UNKNOWN. RECENT STUDIES HAVE REVEALED BACTERIUM- OR VIRUS-INDUCED EPIGENETIC CHANGES IN THE HOST CELLS. IN THIS REVIEW, WE FOCUSED ON RESPIRATORY PATHOGENS (VIRUSES, BACTERIA, AND FUNGI) INDUCED EPIGENETIC MODULATIONS (DNA METHYLATION AND HISTONE MODIFICATION) THAT MAY CONTRIBUTE TO LUNG DISEASE PATHOPHYSIOLOGY BY PROMOTING HOST DEFENSE OR ALLOWING PATHOGEN PERSISTENCE. 2023