1 5966 93 TERMINAL ADDITION IN A CELLULAR WORLD. RECENT ADVANCES IN OUR UNDERSTANDING OF EVOLUTIONARY DEVELOPMENT PERMIT A REFRAMED APPRAISAL OF TERMINAL ADDITION AS A CONTINUOUS HISTORICAL PROCESS OF CELLULAR-ENVIRONMENTAL COMPLEMENTARITY. WITHIN THIS FRAME OF REFERENCE, EVOLUTIONARY TERMINAL ADDITIONS CAN BE IDENTIFIED AS ENVIRONMENTAL INDUCTION OF EPISODIC ADJUSTMENTS TO CELL-CELL SIGNALING PATTERNS THAT YIELD THE CELLULAR-MOLECULAR PATHWAYS THAT LEAD TO DIFFERING DEVELOPMENTAL FORMS. PHENOTYPES DERIVE, THEREBY, THROUGH CELLULAR MUTUALISTIC/COMPETITIVE NICHE CONSTRUCTIONS IN RECIPROCATING RESPONSIVENESS TO ENVIRONMENTAL STRESSES AND EPIGENETIC IMPACTS. IN SUCH TERMS, TERMINAL ADDITION FLOWS ACCORDING TO A LOGIC OF CELLULAR NEEDS CONFRONTING ENVIRONMENTAL CHALLENGES OVER SPACE-TIME. A RECONCILIATION OF EVOLUTIONARY DEVELOPMENT AND TERMINAL ADDITION CAN BE ACHIEVED THROUGH A COMBINED FOCUS ON CELL-CELL SIGNALING, MOLECULAR PHYLOGENIES AND A BROADER UNDERSTANDING OF EPIGENETIC PHENOMENA AMONG EUKARYOTIC ORGANISMS. WHEN UNDERSTOOD IN THIS MANNER, TERMINAL ADDITION HAS AN IMPORTANT ROLE IN EVOLUTIONARY DEVELOPMENT, AND CHRONIC DISEASE MIGHT BE CONSIDERED AS A FORM OF 'REVERSE EVOLUTION' OF THE SELF-SAME PROCESSES. 2018 2 2184 25 EPIGENETIC MECHANISMS THAT UNDERPIN METABOLIC AND CARDIOVASCULAR DISEASES. CELLULAR COMMITMENT TO A SPECIFIC LINEAGE IS CONTROLLED BY DIFFERENTIAL SILENCING OF GENES, WHICH IN TURN DEPENDS ON EPIGENETIC PROCESSES SUCH AS DNA METHYLATION AND HISTONE MODIFICATION. DURING EARLY EMBRYOGENESIS, THE MAMMALIAN GENOME IS 'WIPED CLEAN' OF MOST EPIGENETIC MODIFICATIONS, WHICH ARE PROGRESSIVELY RE-ESTABLISHED DURING EMBRYONIC DEVELOPMENT. THUS, THE EPIGENOME OF EACH MATURE CELLULAR LINEAGE CARRIES THE RECORD OF ITS DEVELOPMENTAL HISTORY. THE SUBSEQUENT TRAJECTORY AND PATTERN OF DEVELOPMENT ARE ALSO RESPONSIVE TO ENVIRONMENTAL INFLUENCES, AND SUCH PLASTICITY IS LIKELY TO HAVE AN EPIGENETIC BASIS. EPIGENETIC MARKS MAY BE TRANSMITTED ACROSS GENERATIONS, EITHER DIRECTLY BY PERSISTING THROUGH MEIOSIS OR INDIRECTLY THROUGH REPLICATION IN THE NEXT GENERATION OF THE CONDITIONS IN WHICH THE EPIGENETIC CHANGE OCCURRED. DEVELOPMENTAL PLASTICITY EVOLVED TO MATCH AN ORGANISM TO ITS ENVIRONMENT, AND A MISMATCH BETWEEN THE PHENOTYPIC OUTCOME OF ADAPTIVE PLASTICITY AND THE CURRENT ENVIRONMENT INCREASES THE RISK OF METABOLIC AND CARDIOVASCULAR DISEASE. THESE CONSIDERATIONS POINT TO EPIGENETIC PROCESSES AS A KEY MECHANISM THAT UNDERPINS THE DEVELOPMENTAL ORIGINS OF CHRONIC NONCOMMUNICABLE DISEASE. HERE, WE REVIEW THE EVIDENCE THAT ENVIRONMENTAL INFLUENCES DURING MAMMALIAN DEVELOPMENT LEAD TO STABLE CHANGES IN THE EPIGENOME THAT ALTER THE INDIVIDUAL'S SUSCEPTIBILITY TO CHRONIC METABOLIC AND CARDIOVASCULAR DISEASE, AND DISCUSS THE CLINICAL IMPLICATIONS. 2009 3 2586 23 EPIGENETICS OF PAIN MEDIATORS. PURPOSE OF REVIEW: THE FIELD OF EPIGENETICS CONTINUES ITS INFLUENTIAL RISE AS A MEANS TO BETTER UNDERSTAND AN ORGANISM'S UNIQUE DEVELOPMENTAL IDENTITY OVER A LIFESPAN. WHEREAS A GENOME IS CONSTANT AND UNCHANGING, AN EPIGENOME IS DYNAMIC AND ALTERABLE. EPIGENETIC CHANGES ARE IN RESPONSE TO INNUMERABLE INTERNAL AND EXTERNAL INFLUENCES INCLUDING ENVIRONMENTAL CHANGES SUCH AS DIET, EXERCISE, DISEASE, TOXINS, AND STRESS. EPIGENETICS IS OF PARTICULAR INTEREST IN THE MEDICAL RESEARCH COMMUNITY BOTH FOR THE POTENTIAL TO CAUSE DISEASE AND AS A TARGET FOR THERAPEUTIC INTERVENTIONS. THIS ARTICLE PROVIDES A SUCCINCT EXPLANATION OF THE POTENTIAL FOR EPIGENETICS TO INFLUENCE THE UNDERSTANDING OF PAIN AS WELL AS A REVIEW OF RELEVANT RESEARCH ON THE TOPIC. RECENT FINDINGS: STUDIES ON EPIGENETICS AND PAIN REMAIN LARGELY PRECLINICAL AND INVESTIGATE THE THEORETICAL ABILITY OF EPIGENETICS TO ALTER THE NOCICEPTIVE PATHWAYS BOTH IN THE PERIPHERY AND CENTRALLY. SIGNIFICANT EVIDENCE NOW EXISTS FOR THE ABILITY OF EPIGENETICS TO MODIFY BROADLY CATEGORIZED PAIN TYPES, INCLUDING INFLAMMATORY, NEUROPATHIC, VISCERAL, AND CANCER RELATED. SUMMARY: BOTH PATIENTS AND PROVIDERS RECOGNIZE THAT NOVEL MEDICATIONS FOR THE TREATMENT OF BOTH ACUTE AND CHRONIC PAIN CONDITIONS ARE SORELY NEEDED. THE UNDERSTANDING OF EPIGENETICS AND ITS INFLUENCE ON NOCICEPTION REMAINS IN RELATIVE INFANCY BUT EARLY EVIDENCE IS STRONG FOR POTENTIAL THERAPEUTIC BENEFITS TO TREAT THESE CONDITIONS. 2018 4 2592 19 EPIGENETICS OF RENAL DEVELOPMENT AND DISEASE. AN UNDERSTANDING OF EPIGENETICS IS INDISPENSABLE TO OUR UNDERSTANDING OF GENE REGULATION UNDER NORMAL AND PATHOLOGICAL STATES. THIS KNOWLEDGE WILL HELP WITH DESIGNING BETTER THERAPEUTIC APPROACHES IN REGENERATIVE TISSUE MEDICINE. EPIGENETICS ALLOWS US TO PARSE OUT THE MECHANISMS BY WHICH TRANSCRIPTIONAL REGULATORS GAIN ACCESS TO SPECIFIC GENE LOCI THEREBY IMPRINTING EPIGENETIC INFORMATION AFFECTING CHROMATIN FUNCTION. THIS EPIGENETIC MEMORY FORMS THE BASIS OF CELL LINEAGE SPECIFICATION IN MULTICELLULAR ORGANISMS. POST-TRANSLATIONAL MODIFICATIONS TO DNA AND HISTONES IN THE NUCLEOSOME CORE FORM CHARACTERISTIC EPIGENETIC CODES WHICH ARE DISTINCT FOR SELF-RENEWING AND PRIMED PROGENITOR CELL POPULATIONS. STUDIES OF CHROMATIN MODIFIERS AND MODIFICATIONS IN RENAL DEVELOPMENT AND DISEASE HAVE BEEN GAINING MOMENTUM. BOTH CONGENITAL AND ADULT RENAL DISEASES HAVE A GENE-ENVIRONMENT COMPONENT, WHICH INVOLVES ALTERATIONS TO THE EPIGENETIC INFORMATION IMPRINTED DURING DEVELOPMENT. THIS EPIGENETIC MEMORY MUST BE CHARACTERIZED TO ESTABLISH OPTIMAL TREATMENT OF BOTH ACUTE AND CHRONIC RENAL DISEASES. 2016 5 1923 18 ENVIRONMENTAL EPIGENETIC MODIFICATIONS AND REPROGRAMMING-RECALCITRANT GENES. THE TERM "ENVIRONMENTAL EPIGENETIC MODIFICATIONS" REFERS TO ALTERATIONS IN PHENOTYPE TRIGGERED BY ENVIRONMENTAL STIMULI VIA EPIGENETIC MECHANISMS. EPIDEMIOLOGIC AND ANIMAL MODEL STUDIES SHOW THAT A SUBSET OF SUCH ENVIRONMENTAL EPIGENETIC MARKS MAY AFFECT SUSCEPTIBILITY TO CHRONIC DISEASES. A GROWING BODY OF EVIDENCE REGARDING INCOMPLETENESS OF REPROGRAMMING INDICATES THAT THE POTENTIAL RETENTION OF PATHOGENIC ENVIRONMENTAL EPIGENETICS IN HUMAN INDUCED PLURIPOTENT STEM CELLS (IPSCS) SHOULD BE SERIOUSLY CONSIDERED. GIVEN THIS POSSIBILITY, THE OPTIMIZATION OF METHODS FOR THE GENERATION OF HUMAN INDUC PLURIPOTENT STEM CELLS MAY REQUIRE THE IDENTIFICATION OF EPIGENETICALLY APPROPRIATE SOMATIC CELL SOURCES. SIMILARLY, TECHNIQUES FOR CONTROLLING EPIGENETIC MODIFICATION BY ENVIRONMENTAL FACTORS MAY ALSO PLAY A CRITICAL ROLE IN THE DEVELOPMENT OF EPIGENETICALLY STABLE SOURCES OF PLURIPOTENT STEM CELLS. 2010 6 1453 16 DISCOVERING HOW ENVIRONMENTAL EXPOSURES ALTER GENES COULD LEAD TO NEW TREATMENTS FOR CHRONIC ILLNESSES. EMERGING RESEARCH DEMONSTRATES THAT DIET, POLLUTION, AND OTHER ENVIRONMENTAL TRIGGERS CAN ALTER BOTH THE FUNCTION AND EXPRESSION OF HUMAN GENES AND LEAD TO A HEIGHTENED DISEASE RISK. THESE ENVIRONMENT-GENE INTERACTIONS CAN CAUSE SO-CALLED EPIGENETIC CHANGES IN GENE EXPRESSION-PATTERNS OF WHICH GENES ARE SWITCHED "ON" OR "OFF"-THAT MAY ACCOUNT FOR THE RISING MORTALITY FROM CHRONIC DISEASES IN INDUSTRIALIZED NATIONS. IN THIS PAPER, WE CALL FOR A NEW TRANSDISCIPLINARY APPROACH TO PUBLIC HEALTH THAT WOULD EXAMINE HOW ENVIRONMENTAL EXPOSURES, BOTH PHYSICAL AND SOCIAL, INFLUENCE GENE EXPRESSION AND A PERSON'S SUSCEPTIBILITY TO CHRONIC DISEASE. THIS INITIATIVE COULD LEAD TO NEW WAYS TO PREVENT AND TREAT SUCH ILLNESSES. 2011 7 2611 25 EPIGENETICS: A PROMISING PARADIGM FOR BETTER UNDERSTANDING AND MANAGING PAIN. EPIGENETIC REGULATION OF GENE EXPRESSION IS A RAPIDLY GROWING AREA OF RESEARCH. CONSIDERING THE LONGEVITY AND PLASTICITY OF NEURONS, THE STUDIES ON EPIGENETIC PATHWAYS IN THE NERVOUS SYSTEM SHOULD BE OF SPECIAL INTEREST FOR BOTH EPIGENETICISTS AND NEUROSCIENTISTS. ACTIVATION OR INACTIVATION OF DIFFERENT EPIGENETIC PATHWAYS BECOMES MORE PRONOUNCED WHEN THE CELLS EXPERIENCE RAPID CHANGES IN THEIR ENVIRONMENT, AND SUCH CHANGES CAN BE EASILY CAUSED BY INJURY AND INFLAMMATION, RESULTING IN PAIN PERCEPTION OR DISTORTION OF PAIN PERCEPTION (EG, HYPERALGESIA). THEREFORE, IN THIS REGARD, THE FIELD OF PAIN IS AT AN ADVANTAGE TO STUDY THE EPIGENETIC PATHWAYS. MORE IMPORTANTLY, UNDERSTANDING PAIN FROM AN EPIGENETICS POINT OF VIEW WOULD PROVIDE A NEW PARADIGM FOR DEVELOPING DRUGS OR STRATEGIES FOR PAIN MANAGEMENT. IN THIS REVIEW, WE INTRODUCE BASIC CONCEPTS OF EPIGENETICS, INCLUDING CHROMATIN DYNAMICS, HISTONE MODIFICATIONS, DNA METHYLATION, AND RNA-INDUCED GENE SILENCING. IN ADDITION, WE PROVIDE EVIDENCE FROM PUBLISHED STUDIES SUGGESTING WIDE IMPLICATION OF DIFFERENT EPIGENETIC PATHWAYS WITHIN PAIN PATHWAYS. PERSPECTIVE: THIS ARTICLE PROVIDES A BRIEF OVERVIEW OF EPIGENETIC PATHWAYS FOR GENE REGULATION AND HIGHLIGHTS THEIR INVOLVEMENT IN PAIN. OUR GOAL IS TO EXPOSE THE READERS TO THESE CONCEPTS SO THAT PAIN-RELATED PHENOTYPES CAN BE INVESTIGATED FROM THE EPIGENETIC POINT OF VIEW. 2013 8 4126 23 MECHANISMS OF DISEASE: THE DEVELOPMENTAL ORIGINS OF DISEASE AND THE ROLE OF THE EPIGENOTYPE. THERE IS ACCUMULATING EVIDENCE THAT MANY CHRONIC DISEASES SUCH AS TYPE 2 DIABETES AND CORONARY HEART DISEASE MIGHT ORIGINATE DURING EARLY LIFE. THIS EVIDENCE GIVES RISE TO THE DEVELOPMENTAL ORIGINS OF DISEASE HYPOTHESIS, AND IS SUPPORTED BY EPIDEMIOLOGICAL DATA IN HUMANS AND EXPERIMENTAL ANIMAL MODELS. A PERTURBED ENVIRONMENT IN EARLY LIFE IS THOUGHT TO ELICIT A RANGE OF PHYSIOLOGICAL AND CELLULAR ADAPTIVE RESPONSES IN KEY ORGAN SYSTEMS. THESE ADAPTIVE CHANGES RESULT IN PERMANENT ALTERATIONS AND MIGHT LEAD TO PATHOLOGY IN LATER LIFE. AGING ORGANS AND CELLS SEEM THEREFORE TO RETAIN A 'MEMORY' OF THEIR FETAL HISTORY AND ADAPTIVE RESPONSES. THE MECHANISMS UNDERLYING THE DEVELOPMENTAL ORIGINS OF DISEASE REMAIN POORLY DEFINED. EPIGENETIC TAGGING OF GENES, SUCH AS DNA METHYLATION AND HISTONE MODIFICATION, CONTROLS THE FUNCTION OF THE GENOME AT DIFFERENT LEVELS AND MAINTAINS CELLULAR MEMORY AFTER MANY CELLULAR DIVISIONS; IMPORTANTLY, TAGGING CAN BE MODULATED BY THE ENVIRONMENT AND IS INVOLVED IN ONSET OF DISEASES SUCH AS CANCER. HERE WE REVIEW THE EVIDENCE FOR THE DEVELOPMENTAL ORIGINS OF DISEASE AND DISCUSS THE ROLE OF THE EPIGENOTYPE AS A CONTRIBUTING MECHANISM. ENVIRONMENTALLY INDUCED CHANGES IN THE EPIGENOTYPE MIGHT BE KEY PRIMARY EVENTS IN THE DEVELOPMENTAL ORIGINS OF DISEASE, WITH IMPORTANT CLINICAL IMPLICATIONS. 2007 9 6886 21 [ROLE OF EPIGENETIC MODIFICATION IN HIGHER BRAIN DYSFUNCTION AND AGING]. EPIGENETIC MECHANISMS TYPICALLY INVOLVE HERITABLE ALTERATIONS IN CHROMATIN STRUCTURE, WHICH, IN TURN, REGULATE GENE EXPRESSION. FUNDAMENTAL INSIGHTS ABOUT EPIGENETIC HERITABILITY HAVE COME FROM STUDIES OF CELL DIVISION AND DEVELOPMENT. HOWEVER, THERE IS INCREASING EVIDENCE THAT THE REGULATION OF CHROMATIN STRUCTURE THROUGH HISTONE MODIFICATIONS AND DNA METHYLATION MIGHT MEDIATE THE EXPRESSION OF KEY GENES INVOLVED IN ACQUIRED CHRONIC DISORDERS. THIS IDEA IS FASCINATING BECAUSE SIMILAR MECHANISMS ARE USED FOR TRIGGERING AND STORING LONG-TERM MEMORIES AT THE CELLULAR LEVEL DURING, FOR EXAMPLE, HIGHER-BRAIN DYSFUNCTION, STRESS DISEASE, DRUG DEPENDENCE, AGING, AND CHRONIC PAIN. THIS REVIEW WILL EXPLORE THE MOST CURRENT ISSUES IN THE FIELD OF EPIGENETICS, WITH A FOCUS ON NEXT LEVELS OF TRANSCRIPTIONAL MECHANISMS UNDERLYING AGING, ENRICHED ENVIRONMENT AND DRUG ADDICTION. EPIGENETIC MECHANISMS, WHICH ARE KEY CELLULAR AND MOLECULAR PROCESSES THAT INTEGRATE DIVERSE ENVIRONMENTAL STIMULI TO EXERT POTENT AND OFTEN LONG-LASTING CHANGES IN GENE EXPRESSION THROUGH THE REGULATION OF CHROMATIN STRUCTURE, CONTRIBUTE TO TRANSCRIPTIONAL AND BEHAVIORAL CHANGES. 2012 10 4204 22 METABOLISM, EPIGENETICS, AND CAUSAL INFERENCE IN HEART FAILURE. EUKARYOTES MUST BALANCE THE METABOLIC AND CELL DEATH ACTIONS OF MITOCHONDRIA VIA CONTROL OF GENE EXPRESSION AND CELL FATE BY CHROMATIN, THEREBY FUNCTIONALLY BINDING THE METABOLOME AND EPIGENOME. THIS INTERACTION HAS FAR-REACHING IMPLICATIONS FOR CHRONIC DISEASES IN HUMANS, THE MOST COMMON OF WHICH ARE THOSE OF THE CARDIOVASCULAR SYSTEM. THE MOST DEVASTATING CONSEQUENCE OF CARDIOVASCULAR DISEASE, HEART FAILURE, IS NOT A SINGLE DISEASE, DIAGNOSIS, OR ENDPOINT. HUMAN AND ANIMAL STUDIES HAVE REVEALED THAT, REGARDLESS OF ETIOLOGY AND SYMPTOMS, HEART FAILURE IS UNIVERSALLY ASSOCIATED WITH ABNORMAL METABOLISM AND GENE EXPRESSION - TO FRAME THIS AS CAUSE OR CONSEQUENCE, HOWEVER, MAY BE TO WRONGFOOT THE QUESTION. THIS ESSAY AIMS TO CHALLENGE CURRENT THINKING ON METABOLIC-EPIGENETIC CROSSTALK IN HEART FAILURE, PRESENTING HYPOTHESES FOR HOW CHRONIC DISEASES ARISE, TAKE HOLD, AND PERSIST. WE UNPACK ASSUMPTIONS ABOUT THE ORDER OF OPERATIONS FOR GENE EXPRESSION AND METABOLISM, EXPLORING RECENT FINDINGS IN NONCARDIAC SYSTEMS THAT LINK METABOLIC INTERMEDIATES DIRECTLY TO CHROMATIN REMODELING. LASTLY, WE DISCUSS POTENTIAL MECHANISMS BY WHICH CHROMATIN MAY SERVE AS A SUBSTRATE FOR METABOLIC MEMORY, AND HOW CHANGES IN CELLULAR TRANSCRIPTOMES (AND HENCE IN CELLULAR BEHAVIOR) IN RESPONSE TO STRESS CORRESPOND TO GLOBAL CHANGES IN CHROMATIN ACCESSIBILITY AND STRUCTURE. 2020 11 2503 20 EPIGENETICS AND METABOLISM AT THE CROSSROADS OF STRESS-INDUCED PLASTICITY, STEMNESS AND THERAPEUTIC RESISTANCE IN CANCER. DESPITE THE RECENT ADVANCES IN THE TREATMENT OF CANCERS, ACQUIRED DRUG RESISTANCE REMAINS A MAJOR CHALLENGE IN CANCER MANAGEMENT. WHILE EARLIER STUDIES SUGGEST DARWINIAN FACTORS DRIVING ACQUIRED DRUG RESISTANCE, RECENT STUDIES POINT TO A MORE DYNAMIC PROCESS INVOLVING PHENOTYPIC PLASTICITY AND TUMOR HETEROGENEITY IN THE EVOLUTION OF ACQUIRED DRUG RESISTANCE. CHRONIC STRESS AFTER DRUG TREATMENT INDUCES INTRINSIC CELLULAR REPROGRAMMING AND CANCER STEMNESS THROUGH A SLOW-CYCLING PERSISTER STATE, WHICH SUBSEQUENTLY DRIVES CANCER PROGRESSION. BOTH EPIGENETIC AND METABOLIC MECHANISMS PLAY AN IMPORTANT ROLE IN THIS DYNAMIC PROCESS. IN THIS REVIEW, WE DISCUSS HOW EPIGENETIC AND METABOLIC REPROGRAMMING LEADS TO STRESS-INDUCED PHENOTYPIC PLASTICITY AND ACQUIRED DRUG RESISTANCE, AND HOW THE TWO REPROGRAMMING MECHANISMS CROSSTALK WITH EACH OTHER. 2020 12 2049 16 EPIGENETIC CODE AND POTENTIAL EPIGENETIC-BASED THERAPIES AGAINST CHRONIC DISEASES IN DEVELOPMENTAL ORIGINS. ACCUMULATED FINDINGS HAVE DEMONSTRATED THAT THE EPIGENETIC CODE PROVIDES A POTENTIAL LINK BETWEEN PRENATAL STRESS AND CHANGES IN GENE EXPRESSION THAT COULD BE INVOLVED IN THE DEVELOPMENTAL PROGRAMMING OF VARIOUS CHRONIC DISEASES IN LATER LIFE. MEANWHILE, BASED ON THE FACT THAT EPIGENETIC MODIFICATIONS ARE REVERSIBLE AND CAN BE MANIPULATED, THIS PROVIDES A UNIQUE CHANCE TO DEVELOP MULTIPLE NOVEL EPIGENETIC-BASED THERAPEUTIC STRATEGIES AGAINST MANY CHRONIC DISEASES IN EARLY DEVELOPMENTAL PERIODS. THIS ARTICLE WILL GIVE A SHORT REVIEW OF RECENT FINDINGS OF PRENATAL INSULT-INDUCED EPIGENETIC CHANGES IN DEVELOPMENTAL ORIGINS OF SEVERAL CHRONIC DISEASES, AND WILL ATTEMPT TO PROVIDE AN OVERVIEW OF THE CURRENT EPIGENETIC-BASED STRATEGIES APPLIED IN THE EARLY PREVENTION, DIAGNOSIS AND POSSIBLE THERAPIES FOR HUMAN CHRONIC DISEASES. 2014 13 3418 21 HUMAN HEALTH CONSEQUENCES OF ENVIRONMENTALLY-MODULATED GENE EXPRESSION: POTENTIAL ROLES OF ELF-EMF INDUCED EPIGENETIC VERSUS MUTAGENIC MECHANISMS OF DISEASE. IN ORDER TO DETERMINE IF THERE MIGHT BE BIOLOGICAL AND HEALTH CONSEQUENCES AFTER EXPOSURES TO EXTREMELY-LOW FREQUENCY ELECTROMAGNETIC FIELDS (ELF-EMF), EITHER EXPERIMENTALLY OR EPIDEMIOLOGICALLY, MECHANISTIC UNDERSTANDING OF THE POTENTIAL MEANS BY WHICH ANY ENVIRONMENTAL AGENT CAN AFFECT CELLS IN A MULTICELLULAR ORGANISM HAS TO BE REVIEWED. THE GOAL OF THIS LIMITED REVIEW IS TO DEMONSTRATE THAT, WHILE THE PREVAILING PARADIGM OF THE ENVIRONMENTALLY-INDUCED ACUTE AND CHRONIC DISEASES INVOLVES EITHER CELL KILLING (CYTOTOXICITY) OR GENE/CHROMOSOME MUTATIONS (GENOTOXICITY), ALTERATION OF THE EXPRESSION OF GENETIC INFORMATION AT THE TRANSCRIPTIONAL (TURNING GENES "ON" OR "OFF"), TRANSLATIONAL (STABILIZING OR DE-STABILIZING THE GENETIC MESSAGE), OR POSTTRANSLATIONAL (ALTERING THE GENE PRODUCT OR PROTEIN) LEVELS HAS THE POTENTIAL TO CONTRIBUTE TO VARIOUS DISEASES. THIS LATTER MECHANISM, "EPIGENETIC" TOXICITY, UNLIKE THE FORMER TWO WHICH ARE IRREVERSIBLE, IS CHARACTERIZED BY THRESHOLD-LIKE ACTION, MULTIPLE BIOCHEMICAL PATHWAYS AND CHRONIC, REGULAR EXPOSURES TO BE EFFECTIVE. ULTIMATELY, EPIGENETIC TOXICANTS AFFECT ONE OF FOUR POTENTIAL CELL STATES, NAMELY ALTERATION OF CELL PROLIFERATION, CELL DIFFERENTIATION, PROGRAMMED CELL DEATH (APOPTOSIS) OR ADAPTIVE RESPONSES OF DIFFERENTIATED CELLS. 2000 14 389 18 AN INTEGRATIVE HYPOTHESIS LINKING CANCER, DIABETES AND ATHEROSCLEROSIS: THE ROLE OF MUTATIONS AND EPIGENETIC CHANGES. IT APPEARS THAT THE DISEASE STATES OF CANCER, ALTHEROSCLEROSIS AND DIABETES MIGHT SHARE A COMMON ETIOLOGY. THESE CHRONIC DISEASES APPEAR TO BE MULTI-STAGED IN THEIR PROGRESSION, WITH GENETIC, NUTRITIONAL, PSYCHO-SOCIAL, ENVIRONMENTAL AND VIRAL FACTORS INFLUENCING THEIR APPEARANCE. WE OFFERED A HYPOTHESIS (A "MUTATION THEORY OF DISEASE"), STATING THAT THESE DISEASES CAN BE DESCRIBED BY INITIATION AND PROMOTION PHASES; INITIATION BEING THE RESULT OF THE PRODUCTION OF MUTATED CELLS AFTER UNREPAIRED DAMAGED DNA IS REPLICATED; PROMOTION BEING THE SELECTIVE PROLIFERATION OF THE INITIATED CELLS TO FORM CLONES OF MUTATED CELLS. IT WAS FURTHER POSTULATED THAT PROMOTION AFFECTS CELL PROLIFERATION BY ALTERING A MEMBRANE-CA++ REGULATORY SYSTEM. DEPENDING ON THE NATURE OF THE MUTATION IN THE CLONE OF CELLS, SPECIFIC DISEASE STATES WOULD RESULT. THE ROLES OF RADIATIONS, CHEMICALS, VIRUSES, GENES, NUTRITION AND PSYCHO-SOCIAL STRESS WERE RELATED TO EITHER THE INITIATION (MUTATION PRODUCTION) OR THE PROMOTION (CELL PROLIFERATION) PHASE OF THESE DISEASES. 1980 15 1865 29 EMERGING CONCEPTS ON THE ROLE OF EPIGENETICS IN THE RELATIONSHIPS BETWEEN NUTRITION AND HEALTH. UNDERSTANDING THE PHYSIOLOGICAL AND METABOLIC UNDERPINNINGS THAT CONFER INDIVIDUAL DIFFERENCES IN RESPONSES TO DIET AND DIET-RELATED CHRONIC DISEASE IS ESSENTIAL TO ADVANCE THE FIELD OF NUTRITION. THIS INCLUDES ELUCIDATING THE DIFFERENCES IN GENE EXPRESSION THAT ARE MEDIATED THROUGH PROGRAMMING OF THE GENOME THROUGH EPIGENETIC CHROMATIN MODIFICATIONS. EPIGENETIC LANDSCAPES ARE INFLUENCED BY AGE, GENETICS, TOXINS AND OTHER ENVIRONMENTAL FACTORS, INCLUDING DIETARY EXPOSURES AND NUTRITIONAL STATUS. EPIGENETIC MODIFICATIONS INFLUENCE TRANSCRIPTION AND GENOME STABILITY ARE ESTABLISHED DURING DEVELOPMENT WITH LIFE-LONG CONSEQUENCES. THEY CAN BE INHERITED FROM ONE GENERATION TO THE NEXT. THE COVALENT MODIFICATIONS OF CHROMATIN, WHICH INCLUDE METHYLATION AND ACETYLATION, ON DNA NUCLEOTIDE BASES, HISTONE PROTEINS AND RNA ARE DERIVED FROM INTERMEDIATES OF ONE-CARBON METABOLISM AND CENTRAL METABOLISM. THEY INFLUENCE KEY PHYSIOLOGICAL PROCESSES THROUGHOUT LIFE, AND TOGETHER WITH INHERITED DNA PRIMARY SEQUENCE, CONTRIBUTE TO RESPONSIVENESS TO ENVIRONMENTAL STRESSES, DIET AND RISK FOR AGE-RELATED CHRONIC DISEASE. REVEALING DIET-EPIGENETIC RELATIONSHIPS HAS THE POTENTIAL TO TRANSFORM NUTRITION SCIENCE BY INCREASING OUR FUNDAMENTAL UNDERSTANDING OF: (I) THE ROLE OF NUTRIENTS IN BIOLOGICAL SYSTEMS, (II) THE RESILIENCE OF LIVING ORGANISMS IN RESPONDING TO ENVIRONMENTAL PERTURBATIONS, AND (III) THE DEVELOPMENT OF DIETARY PATTERNS THAT PROGRAMME PHYSIOLOGY FOR LIFE-LONG HEALTH. EPIGENETICS MAY ALSO ENABLE THE CLASSIFICATION OF INDIVIDUALS WITH CHRONIC DISEASE FOR SPECIFIC DIETARY MANAGEMENT AND/OR FOR EFFICACIOUS DIET-PHARMACEUTICAL COMBINATION THERAPIES. THESE NEW EMERGING CONCEPTS AT THE INTERFACE OF NUTRITION AND EPIGENETICS WERE DISCUSSED, AND FUTURE RESEARCH NEEDS IDENTIFIED BY LEADING EXPERTS AT THE 26TH MARABOU SYMPOSIUM ENTITLED 'NUTRITION, EPIGENETICS, GENETICS: IMPACT ON HEALTH AND DISEASE'. FOR A COMPILATION OF THE GENERAL DISCUSSION AT THE MARABOU SYMPOSIUM, CLICK HERE HTTP://WWW.MARABOUSYMPOSIUM.ORG/. 2018 16 49 24 A CURRENT GENETIC AND EPIGENETIC VIEW ON HUMAN AGING MECHANISMS. THE PROCESS OF AGING IS ONE OF THE MOST COMPLEX AND INTRIGUING BIOLOGICAL PHENOMENONS. AGING IS A GENETICALLY REGULATED PROCESS IN WHICH THE ORGANISM'S MAXIMUM LIFESPAN POTENTIAL IS PRE-DETERMINED, WHILE THE RATE OF AGING IS INFLUENCED BY ENVIRONMENTAL FACTORS AND LIFESTYLE. CONSIDERING THE COMPLEXITY OF MECHANISMS INVOLVED IN THE REGULATION OF AGING PROCESS, UP TO THIS DATE THERE ISN'T A MAJOR, UNIFYING THEORY WHICH COULD EXPLAIN THEM. AS GENETIC/EPIGENETIC AND ENVIRONMENTAL FACTORS BOTH INEVITABLY INFLUENCE THE AGING PROCESS, HERE WE PRESENT A REVIEW ON THE GENETIC AND EPIGENETIC REGULATION OF THE MOST IMPORTANT MOLECULAR AND CELLULAR MECHANISMS INVOLVED IN THE PROCESS OF AGING. BASED ON THE STUDIES ON OXIDATIVE STRESS, METABOLISM, GENOME STABILITY, EPIGENETIC MODIFICATIONS AND CELLULAR SENESCENCE IN ANIMAL MODELS AND HUMANS, WE GIVE AN OVERVIEW OF KEY GENETIC AND MOLECULAR PATHWAYS RELATED TO AGING. AS MOST OF GENETIC MANIPULATIONS WHICH INFLUENCE THE AGING PROCESS ALSO AFFECT REPRODUCTION, WE DISCUSS AGING IN HUMANS AS A POST-REPRODUCTIVE GENETICALLY DETERMINED PROCESS. AFTER THE AGE OF REPRODUCTIVE SUCCESS, AGING CONTINOUSLY PROGRESSES WHICH CLINICALLY COINCIDES WITH THE ONSET OF MOST CHRONIC DISEASES, CANCERS AND DEMENTIONS. AS EVOLUTION SHAPES THE GENOMES FOR REPRODUCTIVE SUCCESS AND NOT FOR POST-REPRODUCTIVE SURVIVAL, AGING COULD BE DEFINED AS A PROTECTIVE MECHANISM WHICH ENSURES THE PRESERVATION AND PROGRESS OF SPECIES THROUGH THE MODIFICATION, TRASMISSION AND IMPROVEMENT OF GENETIC MATERIAL. 2009 17 4392 22 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 18 2412 28 EPIGENETIC SIDE-EFFECTS OF COMMON PHARMACEUTICALS: A POTENTIAL NEW FIELD IN MEDICINE AND PHARMACOLOGY. THE TERM "EPIGENETICS" REFERS TO DNA AND CHROMATIN MODIFICATIONS THAT PERSIST FROM ONE CELL DIVISION TO THE NEXT, DESPITE A LACK OF CHANGE IN THE UNDERLYING DNA SEQUENCE. THE "EPIGENOME" REFERS TO THE OVERALL EPIGENETIC STATE OF A CELL, AND SERVES AS AN INTERFACE BETWEEN THE ENVIRONMENT AND THE GENOME. THE EPIGENOME IS DYNAMIC AND RESPONSIVE TO ENVIRONMENTAL SIGNALS NOT ONLY DURING DEVELOPMENT, BUT ALSO THROUGHOUT LIFE; AND IT IS BECOMING INCREASINGLY APPARENT THAT CHEMICALS CAN CAUSE CHANGES IN GENE EXPRESSION THAT PERSIST LONG AFTER EXPOSURE HAS CEASED. HERE WE PRESENT THE HYPOTHESIS THAT COMMONLY-USED PHARMACEUTICAL DRUGS CAN CAUSE SUCH PERSISTENT EPIGENETIC CHANGES. DRUGS MAY ALTER EPIGENETIC HOMEOSTASIS BY DIRECT OR INDIRECT MECHANISMS. DIRECT EFFECTS MAY BE CAUSED BY DRUGS WHICH AFFECT CHROMATIN ARCHITECTURE OR DNA METHYLATION. FOR EXAMPLE THE ANTIHYPERTENSIVE HYDRALAZINE INHIBITS DNA METHYLATION. AN EXAMPLE OF AN INDIRECTLY ACTING DRUG IS ISOTRETINOIN, WHICH HAS TRANSCRIPTION FACTOR ACTIVITY. A TWO-TIER MECHANISM IS POSTULATED FOR INDIRECT EFFECTS IN WHICH ACUTE EXPOSURE TO A DRUG INFLUENCES SIGNALING PATHWAYS THAT MAY LEAD TO AN ALTERATION OF TRANSCRIPTION FACTOR ACTIVITY AT GENE PROMOTERS. THIS STIMULATION RESULTS IN THE ALTERED EXPRESSION OF RECEPTORS, SIGNALING MOLECULES, AND OTHER PROTEINS NECESSARY TO ALTER GENETIC REGULATORY CIRCUITS. WITH MORE CHRONIC EXPOSURE, CELLS ADAPT BY AN UNKNOWN HYPOTHETICAL PROCESS THAT RESULTS IN MORE PERMANENT MODIFICATIONS TO DNA METHYLATION AND CHROMATIN STRUCTURE, LEADING TO ENDURING ALTERATION OF A GIVEN EPIGENETIC NETWORK. THEREFORE, ANY EPIGENETIC SIDE-EFFECT CAUSED BY A DRUG MAY PERSIST AFTER THE DRUG IS DISCONTINUED. IT IS FURTHER PROPOSED THAT SOME IATROGENIC DISEASES SUCH AS TARDIVE DYSKINESIA AND DRUG-INDUCED SLE ARE EPIGENETIC IN NATURE. IF THIS HYPOTHESIS IS CORRECT THE CONSEQUENCES FOR MODERN MEDICINE ARE PROFOUND, SINCE IT WOULD IMPLY THAT OUR CURRENT UNDERSTANDING OF PHARMACOLOGY IS AN OVERSIMPLIFICATION. WE PROPOSE THAT EPIGENETIC SIDE-EFFECTS OF PHARMACEUTICALS MAY BE INVOLVED IN THE ETIOLOGY OF HEART DISEASE, CANCER, NEUROLOGICAL AND COGNITIVE DISORDERS, OBESITY, DIABETES, INFERTILITY, AND SEXUAL DYSFUNCTION. IT IS SUGGESTED THAT A SYSTEMS BIOLOGY APPROACH EMPLOYING MICROARRAY ANALYSES OF GENE EXPRESSION AND METHYLATION PATTERNS CAN LEAD TO A BETTER UNDERSTANDING OF LONG-TERM SIDE-EFFECTS OF DRUGS, AND THAT IN THE FUTURE, EPIGENETIC ASSAYS SHOULD BE INCORPORATED INTO THE SAFETY ASSESSMENT OF ALL PHARMACEUTICAL DRUGS. THIS NEW APPROACH TO PHARMACOLOGY HAS BEEN TERMED "PHAMACOEPIGENOMICS", THE IMPACT OF WHICH MAY BE EQUAL TO OR GREATER THAN THAT OF PHARMACOGENETICS. WE PROVIDE HERE AN OVERVIEW OF THIS POTENTIALLY MAJOR NEW FIELD IN PHARMACOLOGY AND MEDICINE. 2009 19 2528 23 EPIGENETICS AS A KEY LINK BETWEEN PSYCHOSOCIAL STRESS AND AGING: CONCEPTS, EVIDENCE, MECHANISMS . PSYCHOSOCIAL STRESS-ESPECIALLY WHEN CHRONIC, EXCESSIVE, OR OCCURRING EARLY IN LIFE-HAS BEEN ASSOCIATED WITH ACCELERATED AGING AND INCREASED DISEASE RISK. WITH RAPID AGING OF THE WORLD POPULATION, THE NEED TO ELUCIDATE THE UNDERLYING MECHANISMS IS PRESSING, NOW MORE SO THAN EVER. AMONG MOLECULAR MECHANISMS LINKING STRESS AND AGING, THE PRESENT ARTICLE REVIEWS EVIDENCE ON THE ROLE OF EPIGENETICS, BIOCHEMICAL PROCESSES THAT CAN BE SET INTO MOTION BY STRESSORS AND IN TURN INFLUENCE GENOMIC FUNCTION AND COMPLEX PHENOTYPES, INCLUDING AGING-RELATED OUTCOMES. THE ARTICLE FURTHER PROVIDES A CONCEPTUAL MECHANISTIC FRAMEWORK ON HOW STRESS MAY DRIVE EPIGENETIC CHANGES AT SUSCEPTIBLE GENOMIC SITES, THEREBY EXERTING SYSTEMS-LEVEL EFFECTS ON THE AGING EPIGENOME WHILE ALSO REGULATING THE EXPRESSION OF MOLECULES IMPLICATED IN AGING-RELATED PROCESSES. THIS EMERGING EVIDENCE, TOGETHER WITH WORK EXAMINING RELATED BIOLOGICAL PROCESSES, BEGINS TO SHED LIGHT ON THE EPIGENETIC AND, MORE BROADLY, MOLECULAR UNDERPINNINGS OF THE LONG-HYPOTHESIZED CONNECTION BETWEEN STRESS AND AGING. . 2019 20 3404 25 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