1 3602 96 IMPRINTED GENES AND MULTIPLE SCLEROSIS: WHAT DO WE KNOW? MULTIPLE SCLEROSIS (MS) IS A CHRONIC AUTOIMMUNE NEURODEGENERATIVE DISEASE OF THE CENTRAL NERVOUS SYSTEM THAT ARISES FROM INTERPLAY BETWEEN NON-GENETIC AND GENETIC RISK FACTORS. THE EPIGENETICS FUNCTIONS AS A LINK BETWEEN THESE FACTORS, AFFECTING GENE EXPRESSION IN RESPONSE TO EXTERNAL INFLUENCE, AND THEREFORE SHOULD BE EXTENSIVELY STUDIED TO IMPROVE THE KNOWLEDGE OF MS MOLECULAR MECHANISMS. AMONG OTHERS, THE EPIGENETIC MECHANISMS UNDERLIE THE ESTABLISHMENT OF PARENT-OF-ORIGIN EFFECTS THAT APPEAR AS PHENOTYPIC DIFFERENCES DEPENDING ON WHETHER THE ALLELE WAS INHERITED FROM THE MOTHER OR FATHER. THE MOST WELL DESCRIBED MANIFESTATION OF PARENT-OF-ORIGIN EFFECTS IS GENOMIC IMPRINTING THAT CAUSES MONOALLELIC GENE EXPRESSION. IT BECOMES MORE OBVIOUS THAT DISTURBANCES IN IMPRINTED GENES AT THE LEAST AFFECTING THEIR EXPRESSION DO OCCUR IN MS AND MAY BE INVOLVED IN ITS PATHOGENESIS. IN THIS REVIEW WE WILL FOCUS ON THE POTENTIAL ROLE OF IMPRINTED GENES IN MS PATHOGENESIS. 2021 2 2139 38 EPIGENETIC INSIGHTS INTO MULTIPLE SCLEROSIS DISEASE PROGRESSION. MULTIPLE SCLEROSIS (MS), A CHRONIC INFLAMMATORY DEMYELINATING AND NEURODEGENERATIVE DISEASE OF THE CENTRAL NERVOUS SYSTEM, IS TODAY A LEADING CAUSE OF UNPREDICTABLE LIFELONG DISABILITY IN YOUNG ADULTS. THE TREATMENT OF PATIENTS IN PROGRESSIVE STAGES REMAINS HIGHLY CHALLENGING, ALLUDING TO OUR LIMITED UNDERSTANDING OF THE UNDERLYING PATHOLOGICAL PROCESSES. IN THIS REVIEW, WE PROVIDE INSIGHTS INTO THE MECHANISMS UNDERPINNING MS PROGRESSION FROM A PERSPECTIVE OF EPIGENETICS, THAT REFERS TO STABLE AND MITOTICALLY HERITABLE, YET REVERSIBLE, CHANGES IN THE GENOME ACTIVITY AND GENE EXPRESSION. WE FIRST RECAPITULATE FINDINGS FROM EPIGENETIC STUDIES EXAMINING THE BRAIN TISSUE OF PROGRESSIVE MS PATIENTS, WHICH SUPPORT A CONTRIBUTION OF DNA AND HISTONE MODIFICATIONS IN IMPAIRED OLIGODENDROCYTE DIFFERENTIATION, DEFECTIVE MYELINATION/REMYELINATION AND SUSTAINED NEURO-AXONAL VULNERABILITY. WE NEXT EXPLORE POSSIBILITIES FOR IDENTIFYING FACTORS AFFECTING PROGRESSION USING EASILY ACCESSIBLE TISSUES SUCH AS BLOOD BY COMPARING EPIGENETIC SIGNATURES IN PERIPHERAL IMMUNE CELLS AND BRAIN TISSUE. DESPITE MINOR OVERLAP AT INDIVIDUAL METHYLATION SITES, NEARLY 30% OF ALTERED GENES REPORTED IN PERIPHERAL IMMUNE CELLS OF PROGRESSIVE MS PATIENTS WERE FOUND IN BRAIN TISSUE, JOINTLY CONVERGING ON ALTERATIONS OF NEURONAL FUNCTIONS. WE FURTHER SPECULATE ABOUT THE MECHANISMS UNDERLYING SHARED EPIGENETIC PATTERNS BETWEEN BLOOD AND BRAIN, WHICH LIKELY IMPLY THE INFLUENCE OF INTERNAL (GENETIC CONTROL) AND/OR EXTERNAL (E.G. SMOKING AND AGEING) FACTORS IMPRINTING A COMMON SIGNATURE IN BOTH COMPARTMENTS. OVERALL, WE PROPOSE THAT EPIGENETICS MIGHT SHED LIGHT ON CLINICALLY RELEVANT MECHANISMS INVOLVED IN DISEASE PROGRESSION AND OPEN NEW AVENUES FOR THE TREATMENT OF PROGRESSIVE MS PATIENTS IN THE FUTURE. 2020 3 2404 34 EPIGENETIC RESEARCH IN MULTIPLE SCLEROSIS: PROGRESS, CHALLENGES, AND OPPORTUNITIES. MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY AND DEMYELINATING DISEASE OF THE CENTRAL NERVOUS SYSTEM. MS LIKELY RESULTS FROM A COMPLEX INTERPLAY BETWEEN PREDISPOSING CAUSAL GENE VARIANTS (THE STRONGEST INFLUENCE COMING FROM HLA CLASS II LOCUS) AND ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING, INFECTIOUS MONONUCLEOSIS, AND LACK OF SUN EXPOSURE/VITAMIN D. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS UNDERLYING MS DEVELOPMENT AND PROGRESSION. MOREOVER, THE CLINICAL HETEROGENEITY AND VARIABLE RESPONSE TO TREATMENT REPRESENT ADDITIONAL CHALLENGES TO A COMPREHENSIVE UNDERSTANDING AND EFFICIENT TREATMENT OF DISEASE. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION AND HISTONE POSTTRANSLATIONAL MODIFICATIONS, INTEGRATE INFLUENCES FROM THE GENES AND THE ENVIRONMENT TO REGULATE GENE EXPRESSION ACCORDINGLY. STUDYING EPIGENETIC MODIFICATIONS, WHICH ARE STABLE AND REVERSIBLE, MAY PROVIDE AN ALTERNATIVE APPROACH TO BETTER UNDERSTAND AND MANAGE DISEASE. WE HERE AIM TO REVIEW FINDINGS FROM EPIGENETIC STUDIES IN MS AND FURTHER DISCUSS THE CHALLENGES AND CLINICAL OPPORTUNITIES ARISING FROM EPIGENETIC RESEARCH, MANY OF WHICH APPLY TO OTHER DISEASES WITH SIMILAR COMPLEX ETIOLOGY. A GROWING BODY OF EVIDENCE SUPPORTS A ROLE OF EPIGENETIC PROCESSES IN THE MECHANISMS UNDERLYING IMMUNE PATHOGENESIS AND NERVOUS SYSTEM DYSFUNCTION IN MS. HOWEVER, DISPARITIES BETWEEN STUDIES SHED LIGHT ON THE NEED TO CONSIDER POSSIBLE CONFOUNDERS AND METHODOLOGICAL LIMITATIONS FOR A BETTER INTERPRETATION OF THE DATA. NEVERTHELESS, TRANSLATIONAL USE OF EPIGENETICS MIGHT OFFER NEW OPPORTUNITIES IN EPIGENETIC-BASED DIAGNOSTICS AND THERAPEUTIC TOOLS FOR A PERSONALIZED CARE OF MS PATIENTS. 2017 4 2004 32 EPIGENETIC ASPECTS OF MULTIPLE SCLEROSIS AND FUTURE THERAPEUTIC OPTIONS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY AND NEURODEGENERATIVE DISEASE ACCOMPANIED BY DEMYELINATION OF NEURONS IN THE CENTRAL NERVOUS SYSTEM THAT MOSTLY AFFECTS YOUNG ADULTS, ESPECIALLY WOMEN. THIS DISEASE HAS TWO PHASES INCLUDING RELAPSING-REMITTING FORM (RR-MS) BY EPISODES OF RELAPSE AND PERIODS OF CLINICAL REMISSION AND SECONDARY-PROGRESSIVE FORM (SP-MS), WHICH CAUSES MORE DISABILITY. THE INHERITANCE PATTERN OF MS IS NOT EXACTLY IDENTIFIED AND THERE IS AN AGREEMENT THAT IT HAS A COMPLEX PATTERN WITH AN INTERPLAY AMONG ENVIRONMENTAL, GENETIC AND EPIGENETIC ALTERNATIONS. EPIGENETIC MECHANISMS THAT ARE IDENTIFIED FOR MS PATHOGENESIS ARE DNA METHYLATION, HISTONE MODIFICATION AND SOME MICRORNAS' ALTERNATIONS. SEVERAL CELLULAR PROCESSES INCLUDING APOPTOSIS, DIFFERENTIATION AND EVOLUTION CAN BE MODIFIED ALONG WITH EPIGENETIC CHANGES. SOME ALTERNATIONS ARE ASSOCIATED WITH EPIGENETIC MECHANISMS IN MS PATIENTS AND THESE CHANGES CAN BECOME KEY POINTS FOR MS THERAPY. THEREFORE, THE AIM OF THIS REVIEW WAS TO DISCUSS EPIGENETIC MECHANISMS THAT ARE ASSOCIATED WITH MS PATHOGENESIS AND FUTURE THERAPEUTIC APPROACHES. 2021 5 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 6 738 29 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 7 6251 31 THE MICROBIOLOGICAL MEMORY, AN EPIGENETIC REGULATOR GOVERNING THE BALANCE BETWEEN GOOD HEALTH AND METABOLIC DISORDERS. IF THE TRANSMISSION OF BIOLOGICAL INFORMATION FROM ONE GENERATION TO THE NEXT IS BASED ON DNA, MOST HERITABLE PHENOTYPIC TRAITS SUCH AS CHRONIC METABOLIC DISEASES, ARE NOT LINKED TO GENETIC VARIATION IN DNA SEQUENCES. NON-GENETIC HERITABILITY MIGHT HAVE SEVERAL CAUSES INCLUDING EPIGENETIC, PARENTAL EFFECT, ADAPTIVE SOCIAL LEARNING, AND INFLUENCE OF THE ECOLOGICAL ENVIRONMENT. DISTINGUISHING AMONG THESE CAUSES IS CRUCIAL TO RESOLVE MAJOR PHENOTYPIC ENIGMAS. STRONG EVIDENCE INDICATES THAT CHANGES IN DNA EXPRESSION THROUGH VARIOUS EPIGENETIC MECHANISMS CAN BE LINKED TO PARENT-OFFSPRING RESEMBLANCE IN TERMS OF SENSITIVITY TO METABOLIC DISEASES. AMONG NON-GENETIC HERITABLE TRAITS, EARLY NUTRITION COULD ACCOUNT FOR A LONG TERM DEVIANT PROGRAMMING OF GENES EXPRESSION RESPONSIBLE FOR METABOLIC DISEASES IN ADULTHOOD. NUTRITION COULD SHAPE AN INADEQUATE GUT MICROBIOTA (DYSBIOSIS), TRIGGERING EPIGENETIC DEREGULATION OF TRANSCRIPTION WHICH CAN BE OBSERVED IN CHRONIC METABOLIC DISEASES. WE REVIEW HEREIN THE EVIDENCE THAT DYSBIOSIS MIGHT BE A MAJOR CAUSE OF HERITABLE EPIGENETIC PATTERNS FOUND TO BE ASSOCIATED WITH METABOLIC DISEASES. BY TAKING INTO ACCOUNT THE RECENT ADVANCES ON THE GUT MICROBIOME, WE HAVE AGGREGATED TOGETHER DIFFERENT OBSERVATIONS SUPPORTING THE HYPOTHESIS THAT THE GUT MICROBIOTA COULD PROMOTE THE MOLECULAR CROSSTALK BETWEEN BACTERIA AND SURROUNDING HOST CELLS WHICH CONTROLS THE PATHOLOGICAL EPIGENETIC SIGNATURE. WE INTRODUCE FOR THE FIRST TIME THE CONCEPT OF "MICROBIOLOGICAL MEMORY" AS THE MAIN REGULATOR OF THE EPIGENETIC SIGNATURES, THEREBY INDICATING THAT DIFFERENT CAUSES OF NON-GENETIC HERITABILITY CAN INTERACT IN COMPLEX PATHWAYS TO PRODUCE INHERITANCE. 2018 8 6288 39 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 9 6812 26 [EPIGENETICS, INTERFACE BETWEEN ENVIRONMENT AND GENES: ROLE IN COMPLEX DISEASES]. EPIGENETICS IS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION OR CELLULAR PHENOTYPE CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. EPIGENETICS IS ONE OF THE MAJOR MECHANISMS EXPLAINING THE "DEVELOPMENTAL ORIGIN OF HEALTH AND DISEASES" (DOHAD). BESIDES GENETIC BACKGROUND INHERITED FROM PARENTS, WHICH CONFERS SUSCEPTIBILITY TO CERTAIN PATHOLOGIES, EPIGENETIC CHANGES CONSTITUTE THE MEMORY OF PREVIOUS EVENTS, EITHER POSITIVE OR NEGATIVE, ALONG THE LIFE CYCLE, INCLUDING AT THE IN UTERO STAGE. THE LATER EXPOSITION TO HOSTILE ENVIRONMENT MAY REVEAL SUCH SUSCEPTIBILITY, WITH THE DEVELOPMENT OF VARIOUS PATHOLOGIES, AMONG THEM NUMEROUS CHRONIC COMPLEX DISEASES. THE DEMONSTRATION OF SUCH A SEQUENCE OF EVENTS HAS BEEN SHOWN FOR METABOLIC DISEASES AS OBESITY, METABOLIC SYNDROME AND TYPE 2 DIABETES, CARDIOVASCULAR DISEASE AND CANCER. IN CONTRAST TO GENETIC PREDISPOSITION, WHICH IS IRREVERSIBLE, EPIGENETIC CHANGES ARE POTENTIALLY REVERSIBLE, THUS GIVING TARGETS NOT ONLY FOR PREVENTION, BUT POSSIBLY ALSO FOR THE TREATMENT OF CERTAIN COMPLEX DISEASES. 2012 10 6021 36 THE BENEFICIAL AND DEBILITATING EFFECTS OF ENVIRONMENTAL AND MICROBIAL TOXINS, DRUGS, ORGANIC SOLVENTS AND HEAVY METALS ON THE ONSET AND PROGRESSION OF MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS), A CHRONIC INFLAMMATORY DISEASE OF THE CENTRAL NERVOUS SYSTEM IS COMMON AMONGST YOUNG ADULTS, LEADING TO MAJOR PERSONAL AND SOCIOECONOMIC BURDENS. HOWEVER, IT IS STILL CONSIDERED COMPLEX AND CHALLENGING TO UNDERSTAND AND TREAT, IN SPITE OF THE EFFORTS MADE TO EXPLAIN ITS ETIOPATHOLOGY. DESPITE THE DISCOVERY OF MANY GENETIC AND ENVIRONMENTAL FACTORS THAT MIGHT BE RELATED TO ITS ETIOLOGY, NO CLEAR ANSWER WAS FOUND ABOUT THE CAUSES OF THE ILLNESS AND NEITHER ABOUT THE DETAILED MECHANISM OF THESE ENVIRONMENTAL TRIGGERS THAT MAKE INDIVIDUALS SUSCEPTIBLE TO MS. IN THIS REVIEW, WE WILL ATTEMPT TO EXPLORE THE MAJOR CONTRIBUTORS TO MS AUTOIMMUNITY INCLUDING GENETIC, EPIGENETIC AND ECOLOGICAL FACTORS WITH A PARTICULAR FOCUS ON TOXINS, CHEMICALS OR DRUGS THAT MAY TRIGGER, MODIFY OR PREVENT MS DISEASE. 2019 11 1518 37 DNA METHYLATION AS AN EPIGENETIC MECHANISM IN THE DEVELOPMENT OF MULTIPLE SCLEROSIS. THE EPIGENETIC MECHANISMS OF GENE EXPRESSION REGULATION ARE A GROUP OF THE KEY CELLULAR AND MOLECULAR PATHWAYS THAT LEAD TO INHERITED ALTERATIONS IN GENES' ACTIVITY WITHOUT CHANGING THEIR CODING SEQUENCE. DNA METHYLATION AT THE C5 POSITION OF CYTOSINE IN CPG DINUCLEOTIDES IS AMONGST THE CENTRAL EPIGENETIC MECHANISMS. CURRENTLY, THE NUMBER OF STUDIES THAT ARE DEVOTED TO THE IDENTIFICATION OF METHYLATION PATTERNS SPECIFIC TO MULTIPLE SCLEROSIS (MS), A SEVERE CHRONIC AUTOIMMUNE DISEASE OF THE CENTRAL NERVOUS SYSTEM, IS ON A RAPID RISE. HOWEVER, THE ISSUE OF THE CONTRIBUTION OF DNA METHYLATION TO THE DEVELOPMENT OF THE DIFFERENT CLINICAL PHENOTYPES OF THIS HIGHLY HETEROGENEOUS DISEASE HAS ONLY BEGUN TO ATTRACT THE ATTENTION OF RESEARCHERS. THIS REVIEW SUMMARIZES THE DATA ON THE MOLECULAR MECHANISMS UNDERLYING DNA METHYLATION AND THE MS RISK FACTORS THAT CAN AFFECT THE DNA METHYLATION PROFILE AND, THEREBY, MODULATE THE EXPRESSION OF THE GENES INVOLVED IN THE DISEASE'S PATHOGENESIS. THE FOCUS OF OUR ATTENTION IS CENTERED ON THE ANALYSIS OF THE PUBLISHED DATA ON THE DIFFERENTIAL METHYLATION OF DNA FROM VARIOUS BIOLOGICAL SAMPLES OF MS PATIENTS OBTAINED USING BOTH THE CANDIDATE GENE APPROACH AND HIGH-THROUGHPUT METHODS. 2021 12 2282 28 EPIGENETIC REGULATION IN EXPOSOME-INDUCED TUMORIGENESIS: EMERGING ROLES OF NCRNAS. ENVIRONMENTAL FACTORS, INCLUDING POLLUTANTS AND LIFESTYLE, CONSTITUTE A SIGNIFICANT ROLE IN SEVERE, CHRONIC PATHOLOGIES WITH AN ESSENTIAL SOCIETAL, ECONOMIC BURDEN. THE MEASUREMENT OF ALL ENVIRONMENTAL EXPOSURES AND ASSESSING THEIR CORRELATION WITH EFFECTS ON INDIVIDUAL HEALTH IS DEFINED AS THE EXPOSOME, WHICH INTERACTS WITH OUR UNIQUE CHARACTERISTICS SUCH AS GENETICS, PHYSIOLOGY, AND EPIGENETICS. EPIGENETICS INVESTIGATES MODIFICATIONS IN THE EXPRESSION OF GENES THAT DO NOT DEPEND ON THE UNDERLYING DNA SEQUENCE. SOME STUDIES HAVE CONFIRMED THAT ENVIRONMENTAL FACTORS MAY PROMOTE DISEASE IN INDIVIDUALS OR SUBSEQUENT PROGENY THROUGH EPIGENETIC ALTERATIONS. VARIATIONS IN THE EPIGENETIC MACHINERY CAUSE A SPECTRUM OF DIFFERENT DISORDERS SINCE THESE MECHANISMS ARE MORE SENSITIVE TO THE ENVIRONMENT THAN THE GENOME, DUE TO THE INHERENT REVERSIBLE NATURE OF THE EPIGENETIC LANDSCAPE. SEVERAL EPIGENETIC MECHANISMS, INCLUDING MODIFICATIONS IN DNA (E.G., METHYLATION), HISTONES, AND NONCODING RNAS CAN CHANGE GENOME EXPRESSION UNDER THE EXOGENOUS INFLUENCE. NOTABLY, THE ROLE OF LONG NONCODING RNAS IN EPIGENETIC PROCESSES HAS NOT BEEN WELL EXPLORED IN THE CONTEXT OF EXPOSOME-INDUCED TUMORIGENESIS. IN THE PRESENT REVIEW, OUR SCOPE IS TO PROVIDE RELEVANT EVIDENCE INDICATING THAT EPIGENETIC ALTERATIONS MEDIATE THOSE DETRIMENTAL EFFECTS CAUSED BY EXPOSURE TO ENVIRONMENTAL TOXICANTS, FOCUSING MAINLY ON A MULTI-STEP REGULATION BY DIVERSE NONCODING RNAS SUBTYPES. 2022 13 6809 27 [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 14 3404 31 HOW EPIGENETICS IMPACTS ON HUMAN DISEASES. EPIGENETICS IS A RAPIDLY GROWING FIELD OF BIOLOGY THAT STUDIES THE CHANGES IN GENE EXPRESSION THAT ARE NOT DUE TO ALTERATIONS IN THE DNA SEQUENCE BUT RATHER THE CHEMICAL MODIFICATIONS OF DNA AND ITS ASSOCIATED PROTEINS. EPIGENETIC MECHANISMS CAN PROFOUNDLY INFLUENCE GENE EXPRESSION, CELL DIFFERENTIATION, TISSUE DEVELOPMENT, AND DISEASE SUSCEPTIBILITY. UNDERSTANDING EPIGENETIC CHANGES IS ESSENTIAL TO ELUCIDATE THE MECHANISMS UNDERLYING THE INCREASINGLY RECOGNIZED ROLE OF ENVIRONMENTAL AND LIFESTYLE FACTORS IN HEALTH AND DISEASE AND THE INTERGENERATIONAL TRANSMISSION OF PHENOTYPES. RECENT STUDIES SUGGEST EPIGENETICS MAY BE CRITICAL IN VARIOUS DISEASES, FROM CARDIOVASCULAR DISEASE AND CANCER TO NEURODEVELOPMENTAL AND NEURODEGENERATIVE DISORDERS. EPIGENETIC MODIFICATIONS ARE POTENTIALLY REVERSIBLE AND COULD PROVIDE NEW THERAPEUTIC AVENUES FOR TREATING THESE DISEASES USING EPIGENETIC MODULATORS. MOREOVER, EPIGENETICS PROVIDE INSIGHT INTO DISEASE PATHOGENESIS AND BIOMARKERS FOR DISEASE DIAGNOSIS AND RISK STRATIFICATION. NEVERTHELESS, EPIGENETIC INTERVENTIONS HAVE THE POTENTIAL FOR UNINTENDED CONSEQUENCES AND MAY POTENTIALLY LEAD TO INCREASED RISKS OF UNEXPECTED OUTCOMES, SUCH AS ADVERSE DRUG REACTIONS, DEVELOPMENTAL ABNORMALITIES, AND CANCER. THEREFORE, RIGOROUS STUDIES ARE ESSENTIAL TO MINIMIZE THE RISKS ASSOCIATED WITH EPIGENETIC THERAPIES AND TO DEVELOP SAFE AND EFFECTIVE INTERVENTIONS FOR IMPROVING HUMAN HEALTH. THIS ARTICLE PROVIDES A SYNTHETIC AND HISTORICAL VIEW OF THE ORIGIN OF EPIGENETICS AND SOME OF THE MOST RELEVANT ACHIEVEMENTS. 2023 15 1914 29 ENVIRONMENTAL AND GENETIC RISK FACTORS FOR MS: AN INTEGRATED REVIEW. RECENT FINDINGS HAVE PROVIDED A MOLECULAR BASIS FOR THE COMBINED CONTRIBUTIONS OF MULTIFACETED RISK FACTORS FOR THE ONSET OF MULTIPLE SCLEROSIS (MS). MS APPEARS TO START AS A CHRONIC DYSREGULATION OF IMMUNE HOMEOSTASIS RESULTING FROM COMPLEX INTERACTIONS BETWEEN GENETIC PREDISPOSITIONS, INFECTIOUS EXPOSURES, AND FACTORS THAT LEAD TO PRO-INFLAMMATORY STATES, INCLUDING SMOKING, OBESITY, AND LOW SUN EXPOSURE. THIS IS SUPPORTED BY THE DISCOVERY OF GENE-ENVIRONMENT (GXE) INTERACTIONS AND EPIGENETIC ALTERATIONS TRIGGERED BY ENVIRONMENTAL EXPOSURES IN INDIVIDUALS WITH PARTICULAR GENETIC MAKE-UPS. IT IS NOTABLE THAT SEVERAL OF THESE PRO-INFLAMMATORY FACTORS HAVE NOT EMERGED AS STRONG PROGNOSTIC INDICATORS. BIOLOGICAL PROCESSES AT PLAY DURING THE RELAPSING PHASE OF THE DISEASE MAY RESULT FROM INITIAL INFLAMMATORY-MEDIATED INJURY, WHILE RISK FACTORS FOR THE LATER PHASE OF MS, WHICH IS WEIGHTED TOWARD NEURODEGENERATION, ARE NOT YET WELL DEFINED. THIS INTEGRATED REVIEW OF CURRENT EVIDENCE GUIDES RECOMMENDATIONS FOR CLINICAL PRACTICE AND HIGHLIGHTS RESEARCH GAPS. 2019 16 2963 27 GENETIC AND EPIGENETIC MECHANISMS LINKING PAIN AND PSYCHIATRIC DISORDERS. THE NEUROPHYSIOLOGICAL LINK BETWEEN NEUROPATHIC PAIN AND DEPRESSION REMAINS UNKNOWN DESPITE EVIDENT HIGH COMORBIDITY OF THESE TWO DISORDERS. HOWEVER, THERE IS CONVINCING EVIDENCE THAT GENOTYPE PLAYS A ROLE IN BOTH PAIN AND DEPRESSION. USING VARIOUS TYPES OF GENETIC ANALYSIS - POPULATION GENETICS, CYTOGENETICS AND MOLECULAR TECHNOLOGIES - SPECIFIC GENES HAVE BEEN IMPLICATED IN MEDIATING ALMOST ALL ASPECTS OF NOCICEPTION AND MOOD DISORDERS. THE CURRENT REVIEW ATTEMPTS TO IDENTIFY SPECIFIC GENES AND EPIGENETIC MECHANISMS COMMON TO BOTH DISORDERS. IT IS CONCLUDED THAT EXTERNAL AND INTERNAL FACTORS (INFLAMMATION, STRESS, GENDER, ETC.) THAT CONTRIBUTE TO THE PATHOLOGIES MAY DO SO THROUGH EPIGENETIC MECHANISMS THAT MAY AFFECT EXPRESSION OF THESE PARTICULAR GENES. THE POSSIBLE INVOLVEMENT OF EPIGENETIC REGULATION IN PAIN AND PSYCHIATRIC DISORDERS SUGGESTS THAT TREATMENTS TARGETING EPIGENETIC MECHANISMS THAT MEDIATE ADVERSE LIFE EVENTS SHOULD BE CONSIDERED. 2015 17 6905 22 [THE ROLE OF EPIGENETIC REGULATIONS IN EARLY CHILDHOOD DISEASES]. WITH THE ACCEPTANCE OF "THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE" CONCEPT IN THE 1990S, IT BECAME CLEAR THAT EPIGENETIC INHERITANCE, WHICH DO NOT INVOLVE CHANGES IN THE DNA SEQUENCE HAS IMPORTANT ROLE IN THE PATHOGENESIS OF DISEASES. EPIGENETIC REGULATION SERVES THE ADAPTATION TO THE CHANGING ENVIRONMENT AND MAINTAINS THE REPRODUCTIVE FITNESS EVEN ON THE DRAWBACK OF INCREASED RISK OF DISEASES IN LATER LIFE. THE ROLE OF EPIGENETIC MECHANISMS IN CHRONIC NON-COMMUNICABLE DISEASES HAS BEEN WELL ESTABLISHED. RECENT STUDIES HAVE REVEALED THAT EPIGENETIC CHANGES HAVE ALSO CAUSAL ROLE IN CERTAIN PEDIATRIC DISEASES. THE REVIEW EVALUATES THE RECENT EPIGENETIC FINDINGS IN THE PATHOMECHANISM OF COMMON PEDIATRIC DISEASES. THE WIDE RANGE AND LONG-LASTING DURATION OF EPIGENETIC REGULATIONS GIVE IMPORTANCE TO THE SUBJECT. METHODS ARE ALREADY AVAILABLE TO EVALUATE A PART OF THE EPIGENETIC CHANGES IN THE CLINICAL PRACTICE, PRESENTLY AIMING PRIMARILY THE ESTIMATION OF THE DISEASE RISK OR DEFINITION OF DIAGNOSIS. FURTHERMORE, THERE ARE ALREADY AVAILABLE LIMITED MEANS TO INFLUENCE THE EPIGENETIC REGULATION. 2019 18 3848 23 IS EPIGENETICS AN IMPORTANT LINK BETWEEN EARLY LIFE EVENTS AND ADULT DISEASE? BACKGROUND: EPIGENETIC MECHANISMS PROVIDE ONE POTENTIAL EXPLANATION FOR HOW ENVIRONMENTAL INFLUENCES IN EARLY LIFE CAUSE LONG-TERM CHANGES IN CHRONIC DISEASE SUSCEPTIBILITY. WHEREAS EPIGENETIC DYSREGULATION IS INCREASINGLY IMPLICATED IN VARIOUS RARE DEVELOPMENTAL SYNDROMES AND CANCER, THE ROLE OF EPIGENETICS IN COMPLEX CHRONIC DISEASES, SUCH AS CARDIOVASCULAR DISEASE, TYPE 2 DIABETES AND OBESITY, REMAINS LARGELY UNCHARACTERIZED. EXTENSIVE WORK IN ANIMAL MODELS IS REQUIRED TO DEVELOP SPECIFIC HYPOTHESES THAT CAN BE PRACTICABLY TESTED IN HUMANS. ANIMAL MODELS: WE HAVE DEVELOPED A MOUSE MODEL SHOWING THAT METHYL DONOR SUPPLEMENTATION PREVENTS TRANSGENERATIONAL AMPLIFICATION OF OBESITY, SUGGESTING A ROLE FOR DNA METHYLATION IN THE DEVELOPMENTAL ESTABLISHMENT OF BODY WEIGHT REGULATION. CONCLUSIONS: COUPLING SUCH MODELS WITH RECENTLY DEVELOPED EPIGENOMIC TECHNOLOGIES SHOULD ULTIMATELY ENABLE US TO DETERMINE IF EPIGENETICS IS AN IMPORTANT LINK BETWEEN EARLY LIFE EVENTS AND ADULT DISEASE. 2009 19 2523 35 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 20 5376 34 RECENT DEVELOPMENTS IN EPIGENETICS OF ACUTE AND CHRONIC KIDNEY DISEASES. THE GROWING EPIDEMIC OF OBESITY AND DIABETES, THE AGING POPULATION AS WELL AS PREVALENCE OF DRUG ABUSE HAS LED TO SIGNIFICANT INCREASES IN THE RATES OF THE CLOSELY ASSOCIATED ACUTE AND CHRONIC KIDNEY DISEASES, INCLUDING DIABETIC NEPHROPATHY. FURTHERMORE, EVIDENCE SHOWS THAT PARENTAL BEHAVIOR AND DIET CAN AFFECT THE PHENOTYPE OF SUBSEQUENT GENERATIONS VIA EPIGENETIC TRANSMISSION MECHANISMS. THESE DATA SUGGEST A STRONG INFLUENCE OF THE ENVIRONMENT ON DISEASE SUSCEPTIBILITY AND THAT, APART FROM GENETIC SUSCEPTIBILITY, EPIGENETIC MECHANISMS NEED TO BE EVALUATED TO GAIN CRITICAL NEW INFORMATION ABOUT KIDNEY DISEASES. EPIGENETICS IS THE STUDY OF PROCESSES THAT CONTROL GENE EXPRESSION AND PHENOTYPE WITHOUT ALTERATIONS IN THE UNDERLYING DNA SEQUENCE. EPIGENETIC MODIFICATIONS, INCLUDING CYTOSINE DNA METHYLATION AND COVALENT POST-TRANSLATIONAL MODIFICATIONS OF HISTONES IN CHROMATIN, ARE PART OF THE EPIGENOME, THE INTERFACE BETWEEN THE STABLE GENOME AND THE VARIABLE ENVIRONMENT. THIS DYNAMIC EPIGENETIC LAYER RESPONDS TO EXTERNAL ENVIRONMENTAL CUES TO INFLUENCE THE EXPRESSION OF GENES ASSOCIATED WITH DISEASE STATES. THE FIELD OF EPIGENETICS HAS SEEN REMARKABLE GROWTH IN THE PAST FEW YEARS WITH SIGNIFICANT ADVANCES IN BASIC BIOLOGY, CONTRIBUTIONS TO HUMAN DISEASE, AS WELL AS EPIGENOMICS TECHNOLOGIES. FURTHER UNDERSTANDING OF HOW THE RENAL CELL EPIGENOME IS ALTERED BY METABOLIC AND OTHER STIMULI CAN YIELD NOVEL NEW INSIGHTS INTO THE PATHOGENESIS OF KIDNEY DISEASES. IN THIS REVIEW, WE HAVE DISCUSSED THE CURRENT KNOWLEDGE ON THE ROLE OF EPIGENETIC MECHANISMS (PRIMARILY DNAME AND HISTONE MODIFICATIONS) IN ACUTE AND CHRONIC KIDNEY DISEASES, AND THEIR TRANSLATIONAL POTENTIAL TO IDENTIFY MUCH NEEDED NEW THERAPIES. 2015