1 523 153 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 2 2558 41 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 3 5003 51 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 4 4393 42 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 5 6288 44 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 6 551 40 AUTOIMMUNITY AS AN ETIOLOGICAL FACTOR OF CANCER: THE TRANSFORMATIVE POTENTIAL OF CHRONIC TYPE 2 INFLAMMATION. RECENT EPIDEMIOLOGICAL STUDIES HAVE FOUND AN ALARMING TREND OF INCREASED CANCER INCIDENCE IN ADULTS YOUNGER THAN 50 YEARS OF AGE AND PROJECTED A SUBSTANTIAL RISE IN CANCER INCIDENCE OVER THE NEXT 10 YEARS IN THIS AGE GROUP. THIS TREND WAS EXEMPLIFIED IN THE INCIDENCE OF NON-CARDIA GASTRIC CANCER AND ITS DISPROPORTIONATE IMPACT ON NON-HISPANIC WHITE FEMALES UNDER THE AGE OF 50. THE TREND IS CONCURRENT WITH THE INCREASING INCIDENCE OF AUTOIMMUNE DISEASES IN INDUSTRIALIZED COUNTRIES, SUGGESTING A CAUSAL LINK BETWEEN THE TWO. WHILE AUTOIMMUNITY HAS BEEN SUSPECTED TO BE A RISK FACTOR FOR SOME CANCERS, THE EXACT MECHANISMS UNDERLYING THE CONNECTION BETWEEN AUTOIMMUNITY AND CANCER REMAIN UNCLEAR AND ARE OFTEN CONTROVERSIAL. THE LINK HAS BEEN ATTRIBUTED TO SEVERAL MEDIATORS SUCH AS IMMUNE SUPPRESSION, INFECTION, DIET, ENVIRONMENT, OR, PERHAPS MOST PLAUSIBLY, CHRONIC INFLAMMATION BECAUSE OF ITS WELL-RECOGNIZED ROLE IN TUMORIGENESIS. IN THAT REGARD, AUTOIMMUNE CONDITIONS ARE COMMON CAUSES OF CHRONIC INFLAMMATION AND MAY TRIGGER REPETITIVE CYCLES OF ANTIGEN-SPECIFIC CELL DAMAGE, TISSUE REGENERATION, AND WOUND HEALING. ILLUSTRATING THE CONNECTION BETWEEN AUTOIMMUNE DISEASES AND CANCER ARE PATIENTS WHO HAVE AN INCREASED RISK OF CANCER DEVELOPMENT ASSOCIATED WITH GENETICALLY PREDISPOSED INSUFFICIENCY OF CYTOTOXIC T LYMPHOCYTE-ASSOCIATED PROTEIN 4 (CTLA4), A PROTOTYPICAL IMMUNE CHECKPOINT AGAINST AUTOIMMUNITY AND ONE OF THE MAIN TARGETS OF CANCER IMMUNE THERAPY. THE TUMORIGENIC PROCESS TRIGGERED BY CTLA4 INSUFFICIENCY HAS BEEN SHOWN IN A MOUSE MODEL TO BE DEPENDENT ON THE TYPE 2 CYTOKINES INTERLEUKIN-4 (IL4) AND INTERLEUKIN-13 (IL13). IN THIS TYPE 2 INFLAMMATORY MILIEU, CROSSTALK WITH TYPE 2 IMMUNE CELLS MAY INITIATE EPIGENETIC REPROGRAMMING OF EPITHELIAL CELLS, LEADING TO A METAPLASTIC DIFFERENTIATION AND EVENTUALLY MALIGNANT TRANSFORMATION EVEN IN THE ABSENCE OF CLASSICAL ONCOGENIC MUTATIONS. THOSE FINDINGS COMPLEMENT A LARGE BODY OF EVIDENCE FOR TYPE 1, TYPE 3, OR OTHER INFLAMMATORY MEDIATORS IN INFLAMMATORY TUMORIGENESIS. THIS REVIEW ADDRESSES THE POTENTIAL OF AUTOIMMUNITY AS A CAUSAL FACTOR FOR TUMORIGENESIS, THE UNDERLYING INFLAMMATORY MECHANISMS THAT MAY VARY DEPENDING ON HOST-ENVIRONMENT VARIATIONS, AND IMPLICATIONS TO CANCER PREVENTION AND IMMUNOTHERAPY. 2021 7 4392 38 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 8 5002 38 PERIODONTITIS AND PERIODONTOPATHIC BACTERIA AS RISK FACTORS FOR RHEUMATOID ARTHRITIS: A REVIEW OF THE LAST 10 YEARS. RHEUMATOID ARTHRITIS (RA) IS CHARACTERIZED BY CHRONIC INFLAMMATORY DESTRUCTION OF JOINT TISSUE AND IS CAUSED BY AN ABNORMAL AUTOIMMUNE RESPONSE TRIGGERED BY INTERACTIONS BETWEEN GENETICS, ENVIRONMENTAL FACTORS, AND EPIGENETIC AND POSTTRANSLATIONAL MODIFICATIONS. RA HAS BEEN SUGGESTED TO BE INTERRELATED WITH PERIODONTITIS, A SERIOUS FORM OR STAGE OF CHRONIC INFLAMMATORY PERIODONTAL DISEASE ASSOCIATED WITH PERIODONTOPATHIC BACTERIAL INFECTIONS, GENETIC PREDISPOSITION, ENVIRONMENTAL FACTORS, AND EPIGENETIC INFLUENCES. OVER THE LAST DECADE, A NUMBER OF ANIMAL AND CLINICAL STUDIES HAVE BEEN CONDUCTED TO ASSESS WHETHER OR NOT PERIODONTITIS AND ASSOCIATED PERIODONTOPATHIC BACTERIA CONSTITUTE RISK FACTORS FOR RA. THE PRESENT REVIEW INTRODUCES RECENT ACCUMULATING EVIDENCE TO SUPPORT THE ASSOCIATIONS OF PERIODONTITIS AND PERIODONTOPATHIC BACTERIA WITH THE RISK OF RA OR THE OUTCOME OF RA PHARMACOLOGICAL TREATMENT WITH DISEASE-MODIFYING ANTIRHEUMATIC DRUGS. IN ADDITION, THE RESULTS FROM INTERVENTION STUDIES HAVE SUGGESTED AN IMPROVEMENT IN RA CLINICAL PARAMETERS AFTER NONSURGICAL PERIODONTAL TREATMENT. FURTHERMORE, THE POTENTIAL CAUSAL MECHANISMS UNDERLYING THE LINK BETWEEN PERIODONTITIS AND PERIODONTOPATHIC BACTERIA AND RA ARE SUMMARIZED. 2023 9 6791 31 [DOES THE NUMBER OF PATIENTS WITH AUTOIMMUNE DISORDERS AND THE FREQUENCY OF AUTOIMMUNE DISEASES INCREASE?]. AUTOIMMUNE DISEASES GENERALLY BELONG TO THE RARE DISEASES, HOWEVER, SOME OF THEM ARE FREQUENT IN THE POPULATION. IN THE PRESENT WORK THE AUTHORS ANALYSE WHETHER CAN ANY INCREASE BE OBSERVED IN THE NUMBER OF PATIENTS SUFFERING FROM AUTOIMMUNE DISEASES AND WHETHER DO THE FREQUENCY OF CERTAIN AUTOIMMUNE DISORDERS INCREASE. DUE MAINLY TO EPIGENETIC FACTORS THE INCIDENCE OF AUTOIMMUNE DISEASES ARE INCREASING, THEREFORE THERE ARE MORE PATIENTS RECOGNISED WITH PARTICULAR DISORDERS. ON THE OTHER HAND THE INCIDENCE IS INCREASED BY IMPROVING DIAGNOSTIC POSSIBILITIES, BY THE USE OF MORE SPECIFIC AND SENSITIVE CLASSIFICATION CRITERIA AND MORE SOPHISTICATED LABORATORY TESTS, RESULTED IN THE RECOGNITION OF MILDER AND ATYPICAL DISEASE VARIANTS AS WELL. THE PREVALENCE IS ALSO INCREASING IN CONSEQUENCE OF NOVEL IMMUNE SUPPRESSIVE THERAPEUTIC POSSIBILITIES AND THE CONSEQUENT IMPROVEMENT OF SURVIVAL IN THE MOST OF THESE DISEASES. BESIDES, MORE AND MORE DISEASES HAVE BEEN REVEALED TO HAVE AUTOIMMUNE BACKGROUND, AND LOT OF NEW AUTOIMMUNE SYNDROMES, DISEASES HAVE BEEN CHARACTERISED RECENTLY. THIS INCREASES THE NUMBER OF THE KNOWN AUTOIMMUNE RHEUMATIC DISORDERS WITH A CONSEQUENT INCREASE IN THE NUMBER OF AUTOIMMUNE PATIENTS. ASSIGNED TO THE INCREASING NUMBER OF VARIABLE CHRONIC AUTOIMMUNE DISORDERS, AND THE INCREASING NUMBER OF DISABLED PATIENTS WITH SUCH DISEASES INCREASING MEDICAL AND SOCIAL ATTENTION HAS TO BE FOCUSED ON. 2007 10 2396 43 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 11 2501 35 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 12 3549 46 IMMUNOSENESCENCE AND MULTIPLE SCLEROSIS. CHANGES IN THE IMMUNE SYSTEM ASSOCIATED WITH AGEING ARE KNOWN AS IMMUNOSENESCENCE. THIS IS CHARACTERISED BY A DECLINE IN IMMUNE RESPONSE, CHRONIC INFLAMMATION AND AN INCREASED RISK OF AUTOIMMUNE DISEASES. A CHRONIC INFLAMMATORY PROCESS WITH PERSISTENT PRODUCTION OF PROINFLAMMATORY MEDIATORS INCREASES THE RISK FOR MORBIDITY AND MORTALITY RELATED TO AGE, AND HAS BEEN DUBBED 'INFLAMM-AGEING'. IMMUNOSENESCENCE IS ASSOCIATED WITH A DECREASE IN THE NUMBER OF NAIVE T AND B CELLS, NK CELLS AND DISRUPTION OF THE PRO- AND ANTI-INFLAMMATORY BALANCE BY CHANGES IN THE PRODUCTION OF CYTOKINES. IN FACT, AGEING OF THE IMMUNE SYSTEM HAS A COMPLEX NETWORK OF UNDERLYING CAUSES WHICH INCLUDE NOT ONLY NATURAL MECHANISMS OF SENESCENCE BUT ALSO CHRONIC DISORDERS, LIFESTYLE, ENVIRONMENTAL AND EPIGENETIC FACTORS, AND INFECTIONS. MOREOVER, IMMUNOSENESCENCE HAS AN INFLUENCE ON THE COURSE OF CHRONIC DISEASES WHICH HAVE AN ONSET IN YOUNG ADULTS, SUCH AS MULTIPLE SCLEROSIS (MS). CURRENT DISEASE MODIFYING THERAPIES (DMTS) IN MS AIM TO REDUCE THE FREQUENCY OF RELAPSES AND TO SLOW DISEASE PROGRESSION, BUT THEY DO NOT NECESSARILY STOP THE ACCUMULATION OF DISABILITY RELATED TO DISEASE PROGRESSION. SOME FEATURES OF IMMUNOSENESCENCE FOUND IN AGED HEALTHY CONTROLS ARE ALREADY OBSERVED IN MS PATIENTS AT A YOUNGER AGE. THE OLDER POPULATION IS CHARACTERISED BY AN INCREASED SUSCEPTIBILITY TO INFECTIONS, A POOR RESPONSE TO VACCINATIONS, AND A HIGHER RISK OF DEVELOPING CANCER, VASCULAR DISEASES AND NEURODEGENERATION. IMMUNOSENESCENCE IS AN IMPORTANT FACTOR INFLUENCING THE COURSE OF MS, AND THE SAFETY AND EFFECTIVENESS OF DMTS. THE RELATIONSHIP BETWEEN THE PATHOGENIC PROCESS UNDERLYING THE DEVELOPMENT OF MS AND IMMUNOSENESCENCE REQUIRES FURTHER INVESTIGATION. 2022 13 3402 36 HOW DOES AGE DETERMINE THE DEVELOPMENT OF HUMAN IMMUNE-MEDIATED ARTHRITIS? DOES AGE SUBSTANTIALLY AFFECT THE EMERGENCE OF HUMAN IMMUNE-MEDIATED ARTHRITIS? CHILDREN DO NOT USUALLY DEVELOP IMMUNE-MEDIATED ARTICULAR INFLAMMATION DURING THEIR FIRST YEAR OF LIFE. IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS, THIS APPARENT 'IMMUNE PRIVILEGE' DISINTEGRATES, AND CHRONIC INFLAMMATION IS ASSOCIATED WITH VARIABLE AUTOANTIBODY SIGNATURES AND PATTERNS OF DISEASE THAT RESEMBLE ADULT ARTHRITIS PHENOTYPES. NUMEROUS MECHANISMS MIGHT BE INVOLVED IN THIS SHIFT, INCLUDING GENETIC AND EPIGENETIC PREDISPOSING FACTORS, MATURATION OF THE IMMUNE SYSTEM WITH A PROGRESSIVE MODULATION OF PUTATIVE TOLEROGENIC CONTROLS, PARALLEL DEVELOPMENT OF MICROBIAL DYSBIOSIS, ACCUMULATION OF A PRO-INFLAMMATORY BURDEN DRIVEN BY ENVIRONMENTAL EXPOSURES (THE EXPOSOME) AND COMORBIDITY-RELATED DRIVERS. BY EXPLORING THESE MECHANISMS, WE EXPAND THE DISCUSSION OF THREE (NOT MUTUALLY EXCLUSIVE) HYPOTHESES ON HOW THESE FACTORS CAN CONTRIBUTE TO THE DIFFERENCES AND SIMILARITIES BETWEEN THE LOSS OF IMMUNE TOLERANCE IN CHILDREN AND THE DEVELOPMENT OF ESTABLISHED IMMUNE-MEDIATED ARTHRITIS IN ADULTS. THESE THREE HYPOTHESES RELATE TO A CRITICAL WINDOW IN GENETICS AND EPIGENETICS, IMMUNE MATURATION, AND THE ACCUMULATION OF BURDEN. THE VARIED MANIFESTATION OF THE UNDERLYING MECHANISMS AMONG INDIVIDUALS IS ONLY BEGINNING TO BE CLARIFIED, BUT THE ESTABLISHMENT OF A FRAMEWORK CAN FACILITATE THE DEVELOPMENT OF AN INTEGRATED UNDERSTANDING OF THE PATHOGENESIS OF ARTHRITIS ACROSS ALL AGES. 2022 14 5119 44 POSSIBLE CONTRIBUTION OF CHRONIC INFLAMMATION IN THE INDUCTION OF CANCER IN RHEUMATIC DISEASES. SEVERAL CHRONIC INFLAMMATORY CONDITIONS AND AUTOIMMUNE DISEASES INVOLVING DIFFERENT ORGANS AND TISSUES HAVE BEEN FOUND AT RISK OF PROGRESSION TO CANCER. A WIDE ARRAY OF PROINFLAMMATORY CYTOKINES, PROSTAGLANDINS, NITRIC OXIDE PRODUCTS, AND MATRICELLULAR PROTEINS ARE CLOSELY INVOLVED IN PREMALIGNANT AND MALIGNANT TRANSITION OF CELLS ALMOST ALWAYS IN A BACKGROUND OF CHRONIC INFLAMMATION. INTERESTINGLY, EPIGENETIC PERTURBATIONS (I.E. MIRNA ABERRATIONS, ALTERED DNA METHYLATION) TOGETHER WITH IMPORTANT STEROID HORMONE METABOLIC CHANGES (I.E. OESTROGENS), OR THE ALTERED VITAMIN D CONCENTRATIONS THAT MAY UNBALANCE THE IMMUNE / INFLAMMATORY RESPONSE, HAVE BEEN FOUND LINKED TO THE RISK AND SEVERITY IN SEVERAL CHRONIC INFLAMMATORY CONDITIONS, AS WELL AS IN CANCER. IN PARTICULAR, IT IS EVIDENT, THAT NOT ONLY THE PARENT OESTROGEN BUT ALSO OESTROGEN METABOLITES SHOULD BE TAKEN INTO ACCOUNT WHEN THIS PROCESS IS EVALUATED, SPECIALLY THE FORMATION OF CATECHOLOESTROGEN METABOLITES, THAT ARE CAPABLE OF FORMING EITHER STABLE OR DEPURINATING DNA ADDUCTS, WHICH CAN CAUSE EXTENSIVE DNA DAMAGE. IT IS INTERESTING THAT TODAY THE SUCCESSFUL TREATMENT OF SEVERAL CHRONIC IMMUNE/INFLAMMATORY RHEUMATIC DISEASES IS OBTAINED ALSO BY USING MEDICATIONS INITIALLY DEVELOPED FOR THEIR USE IN ONCOLOGY. THE CIRCADIAN INCREASE OF GROWTH FACTORS, SPECIALLY DURING THE LATE NIGHT, IN BOTH CHRONIC INFLAMMATION AND IN CANCER PATIENTS, AS WELL AS THE PRESENCE OF OESTROGEN-REGULATED CIRCADIAN MECHANISMS, SUGGESTS FURTHER IMPORTANT LINKS. 2014 15 1871 45 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 16 2017 43 EPIGENETIC BIOMARKERS IN RHEUMATOLOGY - THE FUTURE? EPIGENETIC CHANGES ARE STABLE MODIFICATIONS OF DNA OR HISTONES THAT PROFOUNDLY ALTER GENE EXPRESSION. THEY CAN BE CHANGED BY ENVIRONMENTAL INFLUENCES AND CAN THEN BE PASSED ON TO DAUGHTER CELLS OR VIA THE GERM LINE TO OFFSPRING. A VARIETY OF CHANGES IN EPIGENETIC MARKS AND IN THE EXPRESSION OF NONCODING RNA HAS BEEN FOUND IN CANCER AS WELL AS IN CHRONIC INFLAMMATORY DISEASES. INTERESTINGLY, IN BOTH DISEASES SIMILAR MECHANISMS AND PATHWAYS ARE AFFECTED ALBEIT OFTEN TO A DIFFERENT EXTENT. DNA METHYLATION IS OFTEN LOST IN REPETITIVE SEQUENCES, WHILE IN PROMOTER REGIONS HYPO- AS WELL AS HYPERMETHYLATION IS FOUND. CHANGES IN MICRORNA LEVELS TYPICALLY AFFECT MICRORNAS THAT ARE CHANGED BY AN INFLAMMATORY ENVIRONMENT, BUT DISEASE SPECIFIC CHANGES HAVE ALSO BEEN FOUND IN THE BLOOD AND VARIOUS CELL TYPES OF PATIENTS WITH RHEUMATOID ARTHRITIS, SYSTEMIC LUPUS ERYTHEMATOSUS AND OTHER RHEUMATIC DISEASES. THEREFORE, CHANGES IN THE EXPRESSION OF MICRORNA IN PARTICULAR, BUT ALSO DEMETHYLATED GENE LOCI, HAVE BEEN PROPOSED AS POTENTIAL BIOMARKERS IN CHRONIC INFLAMMATORY DISEASES AND IN CANCER. POTENTIALLY, THESE CHANGES COULD BE USED FOR EARLY DIAGNOSIS AND ALSO TO PREDICT TREATMENT RESPONSE. UNFORTUNATELY MOST STUDIES IN RHEUMATOLOGY UP TO NOW WERE NOT DESIGNED TO VALIDATE THESE EPIGENETIC CHANGES AS BIOMARKERS. SINCE THE CANCER FIELD IS MUCH MORE ADVANCED IN THE USAGE OF BIOMARKERS FOR DISEASE SUBCLASSIFICATIONS AND SUBSEQUENT THERAPEUTIC DECISIONS, IT IS WORTHWHILE TO TAKE A CLOSER LOOK AT THE BIOMARKERS, METHODS AND PROCEDURES USED IN ONCOLOGY AND TO SEE WHICH OF THESE COULD ALSO BE APPLIED TO PREDICTING DISEASE SEVERITY AND THERAPEUTIC RESPONSE IN RHEUMATIC DISEASES. THIS ARTICLE WILL HIGHLIGHT COMMON EPIGENETIC PATHWAYS ACTIVATED IN CANCER AND VARIOUS RHEUMATIC DISEASES AND SUMMARISE EPIGENETIC CHANGES THAT HAVE THE POTENTIAL TO BECOME BIOMARKERS IN RHEUMATIC DISEASES. 2016 17 6344 32 THE ROLE OF EPIGENETICS IN AGING AND AUTOIMMUNITY. THE DECLINE IN IMMUNOCOMPETENCE WITH AGE IS ACCOMPANIED BY THE INCREASE IN THE INCIDENCE OF AUTOIMMUNE DISEASES. AGING OF THE IMMUNE SYSTEM, OR IMMUNOSENESCENCE, IS CHARACTERIZED BY A DECLINE OF BOTH T AND B CELL FUNCTION, AND PARADOXICALLY THE PRESENCE OF LOW-GRADE CHRONIC INFLAMMATION. THERE IS GROWING EVIDENCE THAT EPIGENETICS, THE STUDY OF INHERITED CHANGES IN GENE EXPRESSION THAT ARE NOT ENCODED BY THE DNA SEQUENCE ITSELF, CHANGES WITH AGING. INTERESTINGLY, EMERGING EVIDENCE SUGGESTS A KEY ROLE FOR EPIGENETICS IN HUMAN PATHOLOGIES, INCLUDING INFLAMMATORY AND NEOPLASTIC DISORDERS. HERE, WE WILL REVIEW THE POTENTIAL MECHANISMS THAT CONTRIBUTE TO THE INCREASE IN AUTOIMMUNE RESPONSES IN AGING. IN PARTICULAR, WE WILL DISCUSS HOW EPIGENETIC ALTERATIONS, ESPECIALLY DNA METHYLATION AND HISTONE ACETYLATION, ARE ACCUMULATED DURING AGING AND HOW THESE EVENTS CONTRIBUTE TO AUTOIMMUNITY RISK. 2010 18 1606 38 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 19 5765 34 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 20 6800 51 [EPIGENETIC DISTURBANCES IN SYSTEMIC LUPUS ERYTHEMATOSUS]. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE THAT RESULTS IN UNCONTROLLED IMMUNE SYSTEM ACTIVATION AND OVERPRODUCTION OF AUTOANTIBODIES. THE PATHOGENESIS OF THE DISEASE IS COMPLEX AND NOT FULLY UNDERSTOOD, NEVERTHELESS, GENETIC AND ENVIRONMENTAL FACTORS PLAY AN IMPORTANT ROLE. SO FAR, ABOUT 30 GENES HAVE BEEN IDENTIFIED TO BE INVOLVED IN THE SLE PATHOMECHANISM. HOWEVER, NOT ALL GENETICALLY PREDISPOSED INDIVIDUALS DEVELOP THE DISEASE. THIS PHENOMENON CAN BE ASSOCIATED WITH EPIGENETIC CHANGES THAT OCCUR UNDER THE INFLUENCE OF ENVIRONMENTAL FACTORS. THEY CAN AFFECT GENE EXPRESSION AND ARE POTENTIALLY HEREDITARY, BUT DO NOT LEAD TO CHANGES IN THE NUCLEOTIDE SEQUENCE. EPIGENETIC DYSFUNCTIONS, IDENTIFIED IN THE COURSE OF THE DISEASE, LEAD TO CHANGES IN THE EXPRESSION OF GENES THAT PLAY A KEY ROLE IN MAINTAINING THE BODY'S IMMUNE TOLERANCE. MAJOR MECHANISMS OF EPIGENETIC VARIABILITY ARE: DNA METHYLATION, HISTONE PROTEIN MODIFICATION, NON-CODING RNA EXPRESSION, AS WELL AS GENE IMPRINTING. THE MAJOR EPIGENETIC DYSFUNCTIONS AFFECTING THE PATHOGENESIS OF THE DISEASE ARE GLOBAL HYPOMETHYLATION ON CD4+ T CELLS RESULTING FROM ERK SIGNALING PATHWAY REGULATION, HISTONE HYPOACETYLATION, HISTONE H3 LYSINE METHYLATION, AND REACTIVATION OF INACTIVE CHROMOSOME X. IN LUPUS PATIENTS, VARIOUS EPIGENETIC MECHANISMS INTERACT WITH EACH OTHER, ENHANCING THE EXPRESSION OR SILENCING OF GENES RESPONSIBLE FOR THE PRODUCTION OF PRO-INFLAMMATORY AND ANTI-INFLAMMATORY CYTOKINES AND ACTIVATION OF AUTOREACTIVE B-LYMPHOCYTES. 2018