1 6316 118 THE RELEVANCE OF DNA METHYLATION AND HISTONE MODIFICATION IN PERIODONTITIS: A SCOPING REVIEW. BACKGROUND: PERIODONTITIS IS A CHRONIC INFLAMMATORY DISEASE INVOLVING AN INTERPLAY BETWEEN BACTERIA, INFLAMMATION, HOST RESPONSE GENES, AND ENVIRONMENTAL FACTORS. THE MANIFESTATION OF EPIGENETIC FACTORS DURING PERIODONTITIS PATHOGENESIS AND PERIODONTAL INFLAMMATION IS STILL NOT WELL UNDERSTOOD, WITH LIMITED REVIEWS ON HISTONE MODIFICATION WITH PERIODONTITIS MANAGEMENT. THIS SCOPING REVIEW AIMS TO EVALUATE CURRENT EVIDENCE OF GLOBAL AND SPECIFIC DNA METHYLATION AND HISTONE MODIFICATION IN PERIODONTITIS AND DISCUSS THE GAPS AND IMPLICATIONS FOR FUTURE RESEARCH AND CLINICAL PRACTICE. METHODS: A SCOPING LITERATURE SEARCH OF THREE ELECTRONIC DATABASES WAS PERFORMED IN SCOPUS, MEDLINE (PUBMED) AND EMBASE. AS EPIGENETICS IN PERIODONTITIS IS AN EMERGING RESEARCH FIELD, A SCOPING REVIEW WAS CONDUCTED TO IDENTIFY THE EXTENT OF STUDIES AVAILABLE AND DESCRIBE THE OVERALL CONTEXT AND APPLICABILITY OF THESE RESULTS. RESULTS: OVERALL, 30 STUDIES WERE EVALUATED, AND THE FINDINGS CONFIRMED THAT EPIGENETIC CHANGES IN PERIODONTITIS COMPRISE SPECIFIC MODIFICATIONS TO DNA METHYLATION PATTERNS AND HISTONE PROTEINS MODIFICATION, WHICH CAN EITHER DAMPEN OR PROMOTE THE INFLAMMATORY RESPONSE TO BACTERIAL CHALLENGE. CONCLUSIONS: THE PLASTICITY OF EPIGENETIC MODIFICATIONS HAS IMPLICATIONS FOR THE FUTURE DEVELOPMENT OF TARGETED EPI-DRUGS AND DIAGNOSTIC TOOLS IN PERIODONTITIS. SUCH ADVANCES COULD BE INVALUABLE FOR THE EARLY DETECTION AND MONITORING OF SUSCEPTIBLE INDIVIDUALS. 2022 2 2558 38 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 6288 40 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 4 6458 43 TIME COURSE OF DNA METHYLATION IN PAIN CONDITIONS: FROM EXPERIMENTAL MODELS TO HUMANS. BACKGROUND AND OBJECTIVE: THROUGHOUT THE LAST DECADE, RESEARCH HAS UNCOVERED ASSOCIATIONS BETWEEN PAIN AND EPIGENETIC ALTERATIONS CAUSED BY ENVIRONMENTAL FACTORS. SPECIFICALLY, STUDIES HAVE DEMONSTRATED CORRELATIONS BETWEEN PAIN CONDITIONS AND ALTERED DNA METHYLATION PATTERNS. THUS, DNA METHYLATION HAS BEEN REVEALED AS A POSSIBLE MODULATOR OR CONTRIBUTOR TO PAIN CONDITIONS, PROVIDING A POTENTIAL THERAPEUTIC TARGET FOR TREATMENT BY DNA METHYLATION MODIFICATION. TO DEVELOP SUCH TREATMENTS, IT IS NECESSARY TO CLARIFY A WIDE NUMBER OF ASPECTS ON HOW DNA METHYLATION AFFECTS PAIN PERCEPTION; FIRST AND FOREMOST, THE TEMPORAL DYNAMICS. THE OBJECTIVE OF THE PRESENT REVIEW IS TO PROVIDE AN OVERVIEW OF CURRENT KNOWLEDGE ON TEMPORAL DYNAMICS OF DNA METHYLATION IN RESPONSE TO PAIN, AND TO INVESTIGATE IF A TIMEFRAME CAN BE ESTABLISHED BASED ON THE DATA OF CURRENTLY PUBLISHED STUDIES. DATABASES AND DATA TREATMENT: PUBMED, MEDLINE, GOOGLE SCHOLAR AND EMBASE WERE SEARCHED COMPREHENSIVELY FOR STUDIES OF DNA METHYLATION IN NEUROPATHIC, INFLAMMATORY AND ALTERNATIVE ANIMAL PAIN MODELS, AND IN CHRONIC PAIN PATIENTS INCLUDING COMPLEX REGIONAL PAIN SYNDROME, CHRONIC POSTSURGICAL PAIN, CHRONIC WIDESPREAD PAIN, FIBROMYALGIA AND CROHN'S DISEASE. RESULTS: WE IDENTIFIED 34 ARTICLES HIGHLIGHTING VARIATIONS IN TEMPORAL DYNAMICS OF DNA METHYLATION ACROSS SPECIES AND BETWEEN DIFFERENT TYPES OF PAIN. THESE STUDIES REPRESENT A STARTING POINT TO UNCOVER NEW INSIGHTS IN THE DNA METHYLATION TIME COURSE IN PAIN. CONCLUSIONS: NO TIMEFRAME CAN CURRENTLY BE MADE FOR THE DNA METHYLATION RESPONSE TO PAIN IN ANY OF THE REVIEWED CONDITIONS, HIGHLIGHTING AN IMPORTANT FOCUS AREA FOR FUTURE RESEARCH. 2021 5 1546 33 DNA METHYLATION IN NASAL EPITHELIUM: STRENGTHS AND LIMITATIONS OF AN EMERGENT BIOMARKER FOR CHILDHOOD ASTHMA. ASTHMA IS ONE OF THE MOST WIDESPREAD CHRONIC RESPIRATORY CONDITIONS. THIS DISEASE PRIMARILY DEVELOPS IN CHILDHOOD AND IS INFLUENCED BY DIFFERENT FACTORS, MAINLY GENETICS AND ENVIRONMENTAL FACTORS. DNA METHYLATION IS AN EPIGENETIC MECHANISM WHICH MAY REPRESENT A BRIDGE BETWEEN THESE TWO FACTORS, PROVIDING A TOOL TO COMPREHEND THE INTERACTION BETWEEN GENETICS AND ENVIRONMENT. MOST EPIDEMIOLOGICAL STUDIES IN THIS FIELD HAVE BEEN CONDUCTED USING BLOOD SAMPLES, ALTHOUGH DNA METHYLATION MARKS IN BLOOD MAY NOT BE RELIABLE FOR DRAWING EXHAUSTIVE CONCLUSIONS ABOUT DNA METHYLATION IN THE AIRWAYS. BECAUSE OF THE ROLE OF NASAL EPITHELIUM IN ASTHMA AND THE TISSUE SPECIFICITY OF DNA METHYLATION, STUDYING THE RELATIONSHIP BETWEEN DNA METHYLATION AND CHILDHOOD ASTHMA MIGHT REVEAL CRUCIAL INFORMATION ABOUT THIS WIDESPREAD RESPIRATORY DISEASE. THE PURPOSE OF THIS REVIEW IS TO DESCRIBE CURRENT FINDINGS IN THIS FIELD OF RESEARCH. WE WILL PRESENT A VIEWPOINT OF SELECTED STUDIES, CONSIDER STRENGTHS AND LIMITATIONS, AND PROPOSE FUTURE RESEARCH IN THIS AREA. 2020 6 1240 33 CURRENT ADVANCES OF EPIGENETICS IN PERIODONTOLOGY FROM ENCODE PROJECT: A REVIEW AND FUTURE PERSPECTIVES. BACKGROUND: THE ENCYCLOPEDIA OF DNA ELEMENTS (ENCODE) PROJECT HAS ADVANCED OUR KNOWLEDGE OF THE FUNCTIONAL ELEMENTS IN THE GENOME AND EPIGENOME. THE AIM OF THIS ARTICLE WAS TO PROVIDE THE COMPREHENSION ABOUT CURRENT RESEARCH TRENDS FROM ENCODE PROJECT AND ESTABLISH THE LINK BETWEEN EPIGENETICS AND PERIODONTAL DISEASES BASED ON EPIGENOME STUDIES AND SEEK THE FUTURE DIRECTION. MAIN BODY: GLOBAL EPIGENOME RESEARCH PROJECTS HAVE EMPHASIZED THE IMPORTANCE OF EPIGENETIC RESEARCH FOR UNDERSTANDING HUMAN HEALTH AND DISEASE, AND CURRENT INTERNATIONAL CONSORTIA SHOW AN IMPROVED INTEREST IN THE IMPORTANCE OF ORAL HEALTH WITH SYSTEMIC HEALTH. THE EPIGENETIC STUDIES IN DENTAL FIELD HAVE BEEN MAINLY CONDUCTED IN PERIODONTOLOGY AND HAVE FOCUSED ON DNA METHYLATION ANALYSIS. ADVANCES IN SEQUENCING TECHNOLOGY HAVE BROADENED THE TARGET FOR EPIGENETIC STUDIES FROM SPECIFIC GENES TO GENOME-WIDE ANALYSES. CONCLUSIONS: IN LINE WITH GLOBAL RESEARCH TRENDS, FURTHER EXTENDED AND ADVANCED EPIGENETIC STUDIES WOULD PROVIDE CRUCIAL INFORMATION FOR THE REALIZATION OF COMPREHENSIVE DENTAL MEDICINE AND EXPAND THE SCOPE OF ONGOING LARGE-SCALE RESEARCH PROJECTS. 2021 7 2396 40 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 8 4392 33 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 9 6128 28 THE EPIGENETIC PARADIGM IN PERIODONTITIS PATHOGENESIS. EPIGENOME REFERS TO "EPI" MEANING OUTSIDE THE "GENOME." EPIGENETICS IS THE FIELD OF STUDY OF THE EPIGENOME. EPIGENETIC MODIFICATIONS INCLUDE CHANGES IN THE PROMOTER CPG ISLANDS, MODIFICATIONS OF HISTONE PROTEIN STRUCTURE, POSTTRANSLATIONAL REPRESSION BY MICRO-RNA WHICH CONTRIBUTES TO THE ALTERATION OF GENE EXPRESSION. EPIGENETICS PROVIDES AN UNDERSTANDING OF THE ROLE OF GENE-ENVIRONMENT INTERACTIONS ON DISEASE PHENOTYPE ESPECIALLY IN COMPLEX MULTIFACTORIAL DISEASES. PERIODONTITIS IS A CHRONIC INFLAMMATORY DISORDER THAT AFFECTS THE SUPPORTING STRUCTURES OF THE TOOTH. THE ROLE OF THE GENOME (IN TERMS OF GENETIC POLYMORPHISMS) IN PERIODONTITIS PATHOGENESIS HAS BEEN EXAMINED IN NUMEROUS STUDIES, AND CHRONIC PERIODONTITIS HAS BEEN ESTABLISHED AS A POLYGENIC DISORDER. THE POTENTIAL ROLE OF EPIGENETIC MODIFICATIONS IN THE VARIOUS FACETS OF PATHOGENESIS OF PERIODONTITIS IS DISCUSSED IN THIS PAPER BASED ON THE AVAILABLE LITERATURE. 2015 10 2523 39 EPIGENETICS AND THE TRANSITION FROM ACUTE TO CHRONIC PAIN. OBJECTIVE: THE OBJECTIVE OF THIS STUDY WAS TO REVIEW THE EPIGENETIC MODIFICATIONS INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN AND TO IDENTIFY POTENTIAL TARGETS FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED PAIN THERAPEUTICS. BACKGROUND: EPIGENETICS IS THE STUDY OF HERITABLE MODIFICATIONS IN GENE EXPRESSION AND PHENOTYPE THAT DO NOT REQUIRE A CHANGE IN GENETIC SEQUENCE TO MANIFEST THEIR EFFECTS. ENVIRONMENTAL TOXINS, MEDICATIONS, DIET, AND PSYCHOLOGICAL STRESSES CAN ALTER EPIGENETIC PROCESSES SUCH AS DNA METHYLATION, HISTONE ACETYLATION, AND RNA INTERFERENCE. AS EPIGENETIC MODIFICATIONS POTENTIALLY PLAY AN IMPORTANT ROLE IN INFLAMMATORY CYTOKINE METABOLISM, STEROID RESPONSIVENESS, AND OPIOID SENSITIVITY, THEY ARE LIKELY KEY FACTORS IN THE DEVELOPMENT OF CHRONIC PAIN. ALTHOUGH OUR KNOWLEDGE OF THE HUMAN GENETIC CODE AND DISEASE-ASSOCIATED POLYMORPHISMS HAS GROWN SIGNIFICANTLY IN THE PAST DECADE, WE HAVE NOT YET BEEN ABLE TO ELUCIDATE THE MECHANISMS THAT LEAD TO THE DEVELOPMENT OF PERSISTENT PAIN AFTER NERVE INJURY OR SURGERY. DESIGN: THIS IS A FOCUSED LITERATURE REVIEW OF EPIGENETIC SCIENCE AND ITS RELATIONSHIP TO CHRONIC PAIN. RESULTS: SIGNIFICANT LABORATORY AND CLINICAL DATA SUPPORT THE NOTION THAT EPIGENETIC MODIFICATIONS ARE AFFECTED BY THE ENVIRONMENT AND LEAD TO DIFFERENTIAL GENE EXPRESSION. SIMILAR TO MECHANISMS INVOLVED IN THE DEVELOPMENT OF CANCER, NEURODEGENERATIVE DISEASE, AND INFLAMMATORY DISORDERS, THE LITERATURE ENDORSES AN IMPORTANT POTENTIAL ROLE FOR EPIGENETICS IN CHRONIC PAIN. CONCLUSIONS: EPIGENETIC ANALYSIS MAY IDENTIFY MECHANISMS CRITICAL TO THE DEVELOPMENT OF CHRONIC PAIN AFTER INJURY, AND MAY PROVIDE NEW PATHWAYS AND TARGET MECHANISMS FOR FUTURE DRUG DEVELOPMENT AND INDIVIDUALIZED MEDICINE. 2012 11 5929 38 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 12 3038 41 GENOME ENGINEERING FOR OSTEOARTHRITIS: FROM DESIGNER CELLS TO DISEASE-MODIFYING DRUGS. BACKGROUND: OSTEOARTHRITIS (OA) IS A HIGHLY PREVALENT DEGENERATIVE JOINT DISEASE INVOLVING JOINT CARTILAGE AND ITS SURROUNDING TISSUES. OA IS THE LEADING CAUSE OF PAIN AND DISABILITY WORLDWIDE. AT PRESENT, THERE ARE NO DISEASE-MODIFYING OA DRUGS, AND THE PRIMARY THERAPIES INCLUDE EXERCISE AND NONSTEROIDAL ANTI-INFLAMMATORY DRUGS UNTIL TOTAL JOINT REPLACEMENT AT THE END-STAGE OF THE DISEASE. METHODS: IN THIS REVIEW, WE SUMMARIZED THE CURRENT STATE OF KNOWLEDGE IN GENETIC AND EPIGENETIC ASSOCIATIONS AND RISK FACTORS FOR OA AND THEIR POTENTIAL DIAGNOSTIC AND THERAPEUTIC APPLICATIONS. RESULTS: GENOME-WIDE ASSOCIATION STUDIES AND ANALYSIS OF EPIGENETIC MODIFICATIONS (SUCH AS MIRNA EXPRESSION, DNA METHYLATION AND HISTONE MODIFICATIONS) CONDUCTED ACROSS VARIOUS POPULATIONS SUPPORT THE NOTION THAT THERE IS A GENETIC BASIS FOR CERTAIN SUBSETS OF OA PATHOGENESIS. CONCLUSION: WITH RECENT ADVANCES IN THE DEVELOPMENT OF GENOME EDITING TECHNOLOGIES SUCH AS THE CRISPR-CAS9 SYSTEM, THESE GENETIC AND EPIGENETIC ALTERNATIONS IN OA CAN BE USED AS PLATFORMS FROM WHICH POTENTIAL BIOMARKERS FOR THE DIAGNOSIS, PROGNOSIS, DRUG RESPONSE, AND DEVELOPMENT OF POTENTIAL PERSONALIZED THERAPEUTIC TARGETS FOR OA CAN BE APPROACHED. FURTHERMORE, GENOME EDITING HAS ALLOWED THE DEVELOPMENT OF "DESIGNER" CELLS, WHEREBY THE RECEPTORS, GENE REGULATORY NETWORKS, OR TRANSGENES CAN BE MODIFIED AS A BASIS FOR NEW CELL-BASED THERAPIES. 2019 13 396 36 AN UPDATE ON EPIGENETICS AND CHILDHOOD RESPIRATORY DISEASES. EPIGENETIC MECHANISMS, DEFINED AS CHANGES IN PHENOTYPE OR GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE, HAVE BEEN PROPOSED TO CONSTITUTE A LINK BETWEEN GENETIC AND ENVIRONMENTAL FACTORS THAT AFFECT COMPLEX DISEASES. RECENT STUDIES SHOW THAT DNA METHYLATION, ONE OF THE KEY EPIGENETIC MECHANISMS, IS ALTERED IN CHILDREN EXPOSED TO AIR POLLUTANTS AND ENVIRONMENTAL TOBACCO SMOKE EARLY IN LIFE. SEVERAL CANDIDATE GENE STUDIES ON EPIGENETICS HAVE BEEN PUBLISHED TO DATE, BUT IT IS ONLY RECENTLY THAT GLOBAL METHYLATION ANALYSES HAVE BEEN PERFORMED FOR RESPIRATORY DISORDERS SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HOWEVER, LARGE-SCALE STUDIES WITH ADEQUATE POWER ARE YET TO BE PRESENTED IN CHILDREN, AND IMPLICATIONS FOR CLINICAL USE REMAIN TO BE EVALUATED. IN THIS REVIEW, WE SUMMARIZE THE RECENT ADVANCES IN EPIGENETICS AND RESPIRATORY DISORDERS IN CHILDREN, WITH A MAIN FOCUS ON METHODOLOGICAL CHALLENGES AND ANALYSES RELATED TO PHENOTYPE AND EXPOSURE USING GLOBAL METHYLATION APPROACHES. 2014 14 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 15 6809 29 [EPIGENETICS IN INFLAMMATORY SYSTEMIC DISEASES]. IN ADDITION TO ANALYSIS OF THE GENETIC CODE, IN RECENT YEARS MORE AND MORE STUDIES HAVE CONCENTRATED ON CHANGES IN THE EPIGENETIC CODE. EPIGENETIC MECHANISMS DETERMINE WHICH GENES IN A CELL ARE TRANSCRIBED AND THUS FORM THE PHENOTYPE OF A CELL. THE EPIGENETIC CODE CAN BE CHANGED BY ENVIRONMENTAL INFLUENCES, WHICH ALLOWS CELLS TO ADAPT TO LONGSTANDING CHANGES IN THE ENVIRONMENT. THEREFORE, IT IS FEASIBLE TO ASSUME THAT EPIGENETIC CHANGES ARE THE MOLECULAR BASIS FOR LONG-TERM EFFECTS OF THE ENVIRONMENT ON DISEASE DEVELOPMENT. IN PARTICULAR IN TUMORS AND CHRONIC INFLAMMATORY DISEASES EPIGENETIC CHANGES WERE FOUND TO CORRELATE WITH DISEASE SEVERITY AND PROGRESSION. KNOWLEDGE ABOUT THESE EPIGENETIC CHANGES MIGHT HELP THAT EPIGENETIC MODIFICATIONS CAN BE USED IN THE FUTURE AS BIOMARKERS, PROGNOSTIC FACTORS AND THERAPEUTIC TARGETS. 2014 16 2027 38 EPIGENETIC CHANGES IN CHRONIC INFLAMMATORY DISEASES. THE NUMBER OF PEOPLE DIAGNOSED WITH CHRONIC INFLAMMATORY DISEASES HAS INCREASED NOTEWORTHY IN THE LAST 40 YEARS. SPONDYLOARTHRITIS (SPA), INFLAMMATORY BOWEL DISEASES (IBD), AND PSORIASIS ARE THE MOST FREQUENT CHRONIC INFLAMMATORY DISEASES, RESULTING FROM A COMBINATION OF GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS. EPIGENETIC MODIFICATIONS INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND SMALL AND LONG NONCODING RNAS. THEY ARE INFLUENCED BY ENVIRONMENTAL EXPOSURE, LIFE-STYLE, AND AGING AND HAVE RECENTLY BEEN SHOWN TO BE ALTERED IN MANY COMPLEX DISEASES INCLUDING INFLAMMATORY DISEASES. WHILE EPIGENETIC MODIFICATIONS HAVE BEEN WELL CHARACTERIZED IN OTHER DISEASES SUCH AS CANCER AND AUTOIMMUNE DISEASES, KNOWLEDGE ON CHANGES IN INFLAMMATORY DISEASES IS LAGGING BEHIND WITH SOME DISEASE-SPECIFIC DIFFERENCES. WHILE THE DNA METHYLATION PROFILE OF DIFFERENT CELL TYPES IN PATIENTS WITH IBD HAS BEEN RELATIVELY WELL DESCRIBED, LESS IS KNOWN ON CHANGES IMPLICATED IN PSORIASIS, AND NO SYSTEMATIC GENOME-WIDE STUDIES HAVE SO FAR BEEN PERFORMED IN SPA. IN THIS CHAPTER, WE REVIEW IN DETAIL THE REPORTED CHANGES IN PATTERNS OF DNA METHYLATION AND POSTTRANSLATIONAL HISTONE MODIFICATIONS IN CHRONIC INFLAMMATORY DISEASES HIGHLIGHTING POTENTIAL CONNECTIONS BETWEEN DISEASE-ASSOCIATED PATHOPHYSIOLOGICAL CHANGES SUCH AS THE DYSBIOSIS OF THE MICROBIOME OR GENETIC VARIATIONS ASSOCIATED WITH DISEASE SUSCEPTIBILITY AND THE EPIGENOME. WE ALSO DISCUSS IMPORTANT PARAMETERS OF MEANINGFUL EPIGENETIC STUDIES SUCH AS THE USE OF WELL DEFINED, DISEASE-RELEVANT CELL POPULATIONS, AND ELUDE ON THE POTENTIAL FUTURE OF ENGINEERING OF THE EPIGENOME IN INFLAMMATORY DISEASES. 2017 17 1510 45 DNA METHYLATION AND NONCODING RNA IN OA: RECENT FINDINGS AND METHODOLOGICAL ADVANCES. INTRODUCTION: OSTEOARTHRITIS (OA) IS A CHRONIC MUSCULOSKELETAL DISEASE CHARACTERIZED BY PROGRESSIVE LOSS OF JOINT FUNCTION. HISTORICALLY, IT HAS BEEN CHARACTERIZED AS A DISEASE CAUSED BY MECHANICAL TRAUMA, SO-CALLED 'WEAR AND TEAR'. OVER THE PAST TWO DECADES, IT HAS COME TO BE UNDERSTOOD AS A COMPLEX SYSTEMIC DISORDER INVOLVING GENE-ENVIRONMENTAL INTERACTIONS. EPIGENETIC CHANGES HAVE BEEN INCREASINGLY IMPLICATED. RECENT IMPROVEMENTS IN MICROARRAY AND NEXT-GENERATION SEQUENCING (NGS) TECHNOLOGIES HAVE ALLOWED FOR EVER MORE COMPLEX EVALUATIONS OF EPIGENETIC ABERRATIONS ASSOCIATED WITH THE DEVELOPMENT AND PROGRESSION OF OA. METHODS: A SYSTEMATIC REVIEW WAS CONDUCTED IN THE PUBMED DATABASE. WE CURATED STUDIES THAT PRESENTED THE RESULTS OF DNA METHYLATION AND NONCODING RNA RESEARCH IN HUMAN OA AND OA ANIMAL MODELS SINCE 1985. RESULTS: HEREIN, WE DISCUSS RECENT FINDINGS AND METHODOLOGICAL ADVANCEMENTS IN OA EPIGENETICS, INCLUDING A DISCUSSION OF DNA METHYLATION, INCLUDING MICROARRAY AND NGS STUDIES, AND NONCODING RNAS. BEYOND CARTILAGE, WE ALSO HIGHLIGHT STUDIES IN SUBCHONDRAL BONE AND PERIPHERAL BLOOD MONONUCLEAR CELLS, WHICH HIGHLIGHT WIDESPREAD AND POTENTIALLY CLINICALLY IMPORTANT ALTERATIONS IN EPIGENETIC PATTERNS SEEN IN OA PATIENTS. FINALLY, WE DISCUSS EPIGENETIC EDITING APPROACHES IN THE CONTEXT OF OA. CONCLUSIONS: ALTHOUGH A SUBSTANTIAL BODY OF LITERATURE HAS ALREADY BEEN PUBLISHED IN OA, MUCH IS STILL UNKNOWN. FUTURE OA EPIGENETICS STUDIES WILL NO DOUBT CONTINUE TO BROADEN OUR UNDERSTANDING OF UNDERLYING PATHOPHYSIOLOGY AND PERHAPS OFFER NOVEL DIAGNOSTICS AND/OR TREATMENTS FOR HUMAN OA. 2021 18 2501 31 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 19 3706 34 INFLUENCE OF GENETICS ON DISEASE SUSCEPTIBILITY AND PROGRESSION. FOR MANY CHRONIC DISEASES, THE INFLUENCE OF GENETICS IS COMPLEX AND PHENOTYPES DO NOT CONFORM TO SIMPLE MENDELIAN PATTERNS OF INHERITANCE. DISCUSSED HERE ARE TWO TYPES OF GENETIC INFLUENCES ON HEALTHY AGING. THE FIRST INVOLVES VARIATION IN THE GENE SEQUENCE ITSELF AND HOW THIS MAY INFLUENCE DISEASE SUSCEPTIBILITY, PROGRESSION, AND SEVERITY, INTERACTING WITH OTHER RECOGNIZED RISK FACTORS. THE SECOND INVOLVES EPIGENETIC REGULATORY MECHANISMS THAT MAY POTENTIALLY PROVIDE INSIGHT INTO HOW ENVIRONMENTAL INFLUENCES AFFECT THE EXPRESSED GENOME, THUS IMPROVING OUR UNDERSTANDING OF THE GENETIC MECHANISMS UNDERLYING MULTIFACTORIAL DISEASES. THE INTERLEUKIN-1 FAMILY OF CYTOKINES CAN BE USED TO ILLUSTRATE HOW GENETIC SEQUENCE VARIATION MAY AFFECT SUCH DISEASES. THIS CYTOKINE FAMILY PLAYS A KEY ROLE IN MEDIATING INFLAMMATION, WHICH IS NOW UNDERSTOOD TO BE A CENTRAL COMPONENT OF A GROWING NUMBER OF CHRONIC DISEASES. RECENT WORK HAS REVEALED MANY SEQUENCE VARIATIONS IN THE REGULATORY DNA OF GENES ENCODING IMPORTANT MEMBERS OF THE INTERLEUKIN-1 FAMILY, AND THESE VARIATIONS ARE ASSOCIATED WITH DIFFERENTIAL EFFECTS ON THE INFLAMMATORY RESPONSE. THE INTERACTIONS OF ENVIRONMENTAL FACTORS WITH BOTH DNA SEQUENCE VARIATIONS AND EPIGENETIC MODIFICATIONS ARE LIKELY TO DETERMINE THE PHENOTYPES OF MULTIFACTORIAL DISEASES OF AGING AS WELL AS THE PHENOTYPE OF HEALTHY AGING. 2007 20 738 31 CANCER SUSCEPTIBILITY: EPIGENETIC MANIFESTATION OF ENVIRONMENTAL EXPOSURES. CANCER IS A DISEASE THAT RESULTS FROM BOTH GENETIC AND EPIGENETIC CHANGES. DISCORDANT PHENOTYPES AND VARYING INCIDENCES OF COMPLEX DISEASES SUCH AS CANCER IN MONOZYGOTIC TWINS AS WELL AS GENETICALLY IDENTICAL LABORATORY ANIMALS HAVE LONG BEEN ATTRIBUTED TO DIFFERENCES IN ENVIRONMENTAL EXPOSURES. ACCUMULATING EVIDENCE INDICATES, HOWEVER, THAT DISPARITIES IN GENE EXPRESSION RESULTING FROM VARIABLE MODIFICATIONS IN DNA METHYLATION AND CHROMATIN STRUCTURE IN RESPONSE TO THE ENVIRONMENT ALSO PLAY A ROLE IN DIFFERENTIAL SUSCEPTIBILITY TO DISEASE. DESPITE A GROWING CONSENSUS ON THE IMPORTANCE OF EPIGENETICS IN THE ETIOLOGY OF CHRONIC HUMAN DISEASES, THE GENES MOST PRONE TO EPIGENETIC DYSREGULATION ARE INCOMPLETELY DEFINED. MOREOVER, NEITHER THE ENVIRONMENTAL AGENTS MOST STRONGLY AFFECTING THE EPIGENOME NOR THE CRITICAL WINDOWS OF VULNERABILITY TO ENVIRONMENTALLY INDUCED EPIGENETIC ALTERATIONS ARE ADEQUATELY CHARACTERIZED. THESE MAJOR DEFICITS IN KNOWLEDGE MARKEDLY IMPAIR OUR ABILITY TO UNDERSTAND FULLY THE ETIOLOGY OF CANCER AND THE IMPORTANCE OF THE EPIGENOME IN DIAGNOSING AND PREVENTING THIS DEVASTATING DISEASE. 2007