1 6353 89 THE ROLE OF GENETIC AND EPIGENETIC REGULATION IN INTESTINAL FIBROSIS IN INFLAMMATORY BOWEL DISEASE: A DESCENDING PROCESS OR A PROGRAMMED CONSEQUENCE? INFLAMMATORY BOWEL DISEASES (IBDS) ARE A GROUP OF CHRONIC DISEASES CHARACTERIZED BY RECURRING PERIODS OF EXACERBATION AND REMISSION. FIBROSIS OF THE INTESTINE IS ONE OF THE MOST COMMON COMPLICATIONS OF IBD. BASED ON CURRENT ANALYSES, IT IS EVIDENT THAT GENETIC FACTORS AND MECHANISMS, AS WELL AS EPIGENETIC FACTORS, PLAY A ROLE IN THE INDUCTION AND PROGRESSION OF INTESTINAL FIBROSIS IN IBD. KEY GENETIC FACTORS AND MECHANISMS THAT APPEAR TO BE SIGNIFICANT INCLUDE NOD2, TGF-BETA, TLRS, IL23R, AND ATG16L1. DEOXYRIBONUCLEIC ACID (DNA) METHYLATION, HISTONE MODIFICATION, AND RIBONUCLEIC ACID (RNA) INTERFERENCE ARE THE PRIMARY EPIGENETIC MECHANISMS. GENETIC AND EPIGENETIC MECHANISMS, WHICH SEEM TO BE IMPORTANT IN THE PATHOPHYSIOLOGY AND PROGRESSION OF IBD, MAY POTENTIALLY BE USED IN TARGETED THERAPY IN THE FUTURE. THEREFORE, THE AIM OF THIS STUDY WAS TO GATHER AND DISCUSS SELECTED MECHANISMS AND GENETIC FACTORS, AS WELL AS EPIGENETIC FACTORS. 2023 2 2601 37 EPIGENETICS, DNA ORGANIZATION, AND INFLAMMATORY BOWEL DISEASE. INFLAMMATORY BOWEL DISEASES (IBDS) ARE CHRONIC INFLAMMATORY DISORDERS AFFECTING THE GASTROINTESTINAL TRACT. THE INCIDENCE OF IBD IS INCREASING, WITH MORE CASES OCCURRING IN DEVELOPED COUNTRIES. MULTIPLE FACTORS SUCH AS GENETICS, ENVIRONMENTAL CHANGES, GUT MICROBIOTA, AND IMMUNE ABNORMALITIES HAVE BEEN ASSOCIATED WITH DEVELOPMENT OF IBD. IN RECENT YEARS, IT HAS BECOME INCREASINGLY APPARENT THAT EPIGENETIC MODIFICATIONS OF CHROMATIN AND THE MANNER IN WHICH CHROMATIN IS ORGANIZED IN THE NUCLEUS ARE ADDITIONALLY IMPORTANT ELEMENTS THAT CAN INFLUENCE RESPONSES INDUCED BY THE FACTORS DESCRIBED ABOVE, AND MAY THEREFORE CONTRIBUTE TO THE ONSET AND PATHOGENESIS OF IBD. EPIGENETICS AND CHROMATIN ORGANIZATION REGULATE DIVERSE FUNCTIONS THAT INCLUDE MAINTENANCE OF HOMEOSTASIS IN THE INTESTINAL EPITHELIUM, THE DEVELOPMENT AND DIFFERENTIATION OF IMMUNE CELLS, AND MODULATION OF RESPONSES GENERATED BY THE IMMUNE SYSTEM TO DEFEND AGAINST POTENTIAL PATHOGENS. FURTHERMORE, CHANGES IN EPIGENETIC CHROMATIN MARKS AND IN CHROMATIN ORGANIZATION HAVE NOW BEEN LINKED TO DIFFERENTIAL GENE EXPRESSION IN IBD PATIENT CELLS. ALTHOUGH DIRECT EVIDENCE FOR A ROLE OF HISTONE MODIFICATIONS IN IBD IS CURRENTLY VERY LIMITED, IN THIS REVIEW, WE SUMMARIZE THE LINKS BETWEEN VARIOUS EPIGENETIC MODIFICATIONS, THE PROTEINS THAT CATALYZE OR RECOGNIZE THESE MODIFICATIONS, AND THE DEVELOPMENT OR PROGRESSION OF IBD IN HUMAN AND EXPERIMENTAL IBD. WE ALSO DISCUSS HOW EPIGENETICS INFLUENCE THE ORGANIZATION OF DNA CONTACTS TO REGULATE GENE EXPRESSION AND THE IMPLICATIONS THIS MAY HAVE FOR DIAGNOSING AND TREATING IBD. 2019 3 4670 29 NEW INSIGHTS INTO THE EPIGENETIC REGULATION OF INFLAMMATORY BOWEL DISEASE. INFLAMMATORY BOWEL DISEASE (IBD) IS A CHRONIC INFLAMMATORY DISEASE OF THE COLONIC MUCOSA. ENVIRONMENTAL FACTORS, GENETICS, INTESTINAL MICROBIOTA, AND THE IMMUNE SYSTEM ARE ALL INVOLVED IN THE PATHOPHYSIOLOGY OF IBD. LATELY, ACCUMULATING EVIDENCE HAS SHOWN THAT ABNORMAL EPIGENETIC CHANGES IN DNA METHYLATION, HISTONE MARKERS, AND NON-CODING RNA EXPRESSION GREATLY CONTRIBUTE TO THE DEVELOPMENT OF THE ENTIRE DISEASE. EPIGENETICS REGULATES MANY FUNCTIONS, SUCH AS MAINTAINING THE HOMEOSTASIS OF THE INTESTINAL EPITHELIUM AND REGULATING THE IMMUNE SYSTEM OF THE IMMUNE CELLS. IN THE PRESENT STUDY, WE SYSTEMATICALLY SUMMARIZED THE LATEST ADVANCES IN EPIGENETIC MODIFICATION OF IBD AND HOW EPIGENETICS REVEALS NEW MECHANISMS OF IBD. OUR PRESENT REVIEW PROVIDED NEW INSIGHTS INTO THE PATHOPHYSIOLOGY OF IBD. MOREOVER, EXPLORING THE PATTERNS OF DNA METHYLATION AND HISTONE MODIFICATION THROUGH EPIGENETICS CAN NOT ONLY BE USED AS BIOMARKERS OF IBD BUT ALSO AS A NEW TARGET FOR THERAPEUTIC INTERVENTION IN IBD PATIENTS. 2022 4 3541 32 IMMUNOEPIGENETIC REGULATION OF INFLAMMATORY BOWEL DISEASE: CURRENT INSIGHTS INTO NOVEL EPIGENETIC MODULATIONS OF THE SYSTEMIC IMMUNE RESPONSE. THE IMMUNE SYSTEM AND ENVIRONMENTAL FACTORS ARE INVOLVED IN VARIOUS DISEASES, SUCH AS INFLAMMATORY BOWEL DISEASE (IBD), THROUGH THEIR EFFECT ON GENETICS, WHICH MODULATES IMMUNE CELLS. IBD ENCOMPASSES TWO MAIN PHENOTYPES, CROHN'S DISEASE, AND ULCERATIVE COLITIS, WHICH ARE MANIFESTED AS CHRONIC AND SYSTEMIC RELAPSE-REMITTING GASTROINTESTINAL TRACT DISORDERS WITH RISING GLOBAL INCIDENCE AND PREVALENCE. THE PATHOPHYSIOLOGY OF IBD IS COMPLEX AND NOT FULLY UNDERSTOOD. EPIGENETIC RESEARCH HAS RESULTED IN VALUABLE INFORMATION FOR UNRAVELING THE ETIOLOGY OF THIS IMMUNE-MEDIATED DISEASE. THUS, THE MAIN OBJECTIVE OF THE PRESENT REVIEW IS TO SUMMARIZE THE CURRENT FINDINGS ON THE ROLE OF EPIGENETIC MECHANISMS IN IBD TO SHED LIGHT ON THEIR POTENTIAL CLINICAL RELEVANCE. THIS REVIEW FOCUSES ON THE LATEST EVIDENCE REGARDING PERIPHERAL BLOOD MONONUCLEAR CELLS AND EPIGENETIC CHANGES IN HISTONE MODIFICATION, DNA METHYLATION, AND TELOMERE SHORTENING IN IBD. THE VARIOUS IDENTIFIED EPIGENETIC DNA PROFILES WITH CLINICAL VALUE IN IBD COULD BE USED AS BIOMARKERS FOR MORE ACCURATELY PREDICTING DISEASE DEVELOPMENT, TREATMENT RESPONSE, AND THERAPY-RELATED ADVERSE EVENTS. ULTIMATELY, THE INFORMATION PRESENTED HERE COULD BE OF POTENTIAL RELEVANCE FOR FUTURE CLINICAL PRACTICE IN DEVELOPING MORE EFFICIENT AND PRECISE MEDICINE TO IMPROVE THE QUALITY OF LIFE FOR PATIENTS WITH IBD. 2023 5 3017 31 GENETICS AND EPIGENETICS OF INFLAMMATORY BOWEL DISEASE. THE RELEVANCE OF GENETIC AND EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF INFLAMMATORY BOWEL DISEASE (IBD) IS STILL POORLY UNDERSTOOD. SO FAR, 240 RISK GENE LOCI HAVE BEEN ASSOCIATED WITH IBD. THEY ARE MAINLY INVOLVED IN REGULATING INNATE AND ADAPTIVE IMMUNITY, AS WELL AS MAINTAINING INTESTINAL EPITHELIAL BARRIER FUNCTION. HOWEVER, THE FUNCTIONAL CONSEQUENCES OF THE IDENTIFIED GENETIC POLYMORPHISMS FOR IBD PATHOGENESIS IN VIVO ARE OFTEN UNKNOWN. EVEN LESS IS KNOWN ABOUT THE ROLE FOR EPIGENETIC MODIFICATIONS IN IBD PATHOGENESIS. THOUGH A NUMBER OF EPIGENETIC EVENTS SEEM TO BE CAUSATIVELY INVOLVED IBD PATHOGENESIS, OUR KNOWLEDGE ABOUT THE FUNCTIONAL RELEVANCE OF THOSE EPIGENETIC MODIFICATIONS IS SCANTY. THIS OPENS UP A BROAD RESEARCH FIELD THAT GENERATES NOVEL INSIGHTS INTO THE PATHOPHYSIOLOGY OF INTESTINAL AND CHRONIC INFLAMMATORY DISEASE. PATTERNS OF DNA METHYLATION AND HISTONE MODIFICATIONS MIGHT SERVE NOT ONLY AS BIOMARKERS OF DISEASE ACTIVITY OR DISEASE COURSE, BUT ALSO AS NEW TARGETS IN THERAPEUTIC INTERVENTIONS IN IBD PATIENTS. 2018 6 5528 24 RNA MODIFICATION IN INFLAMMATORY BOWEL DISEASES. INFLAMMATORY BOWEL DISEASE (IBD) IS A CHRONIC INFLAMMATORY DISORDER CHARACTERIZED BY DAMAGE TO THE INTESTINAL MUCOSA, WHICH IS CAUSED BY A COMBINATION OF FACTORS. THESE INCLUDE GENETIC AND EPIGENETIC ALTERATIONS, ENVIRONMENTAL INFLUENCE, MICROORGANISM INTERACTIONS, AND IMMUNE CONDITIONS. SOME POPULATIONS WITH IBD SHOW A CANCER-PRONE PHENOTYPE. RECENT STUDIES HAVE PROVIDED INSIGHT INTO THE INVOLVEMENT OF RNA MODIFICATIONS IN THE SPECIFIC PATHOGENESIS OF IBD THROUGH REGULATION OF RNA BIOLOGY IN EPITHELIAL AND IMMUNE CELLS. STUDIES OF SEVERAL RNA MODIFICATION-TARGETING REAGENTS HAVE SHOWN PREFERABLE OUTCOMES IN PATIENTS WITH COLITIS. HERE, WE NOTE A NEW AWARENESS OF RNA MODIFICATION IN THE TARGETING OF IBD AND RELATED DISEASES, WHICH WILL CONTRIBUTE TO EARLY DIAGNOSIS, DISEASE MONITORING, AND POSSIBLE CONTROL BY INNOVATIVE THERAPEUTIC APPROACHES. 2022 7 2578 32 EPIGENETICS OF INFLAMMATORY BOWEL DISEASES. INFLAMMATORY BOWEL DISEASES ARE MULTIFACTORIAL, CHRONIC, CONTINUOUS, RELAPSING, AND IMMUNE-MEDIATED DISEASES OF THE GASTROINTESTINAL TRACT. IT HAS BEEN BELIEVED THAT MECHANISMS UNDERLYING INFLAMMATORY BOWEL DISEASES INCLUDE GENETIC PREDISPOSITION, ENVIRONMENTAL FACTORS, AND ALTERED IMMUNE RESPONSE TO THE GUT MICROBIOME. THE EPIGENETIC MODULATION TAKES PLACE VIA CHROMATIN MODIFICATIONS, INCLUDING PHOSPHORYLATION, ACETYLATION, METHYLATION, SUMOYLATION, AND UBIQUITINATION. THE METHYLATION LEVELS OF COLONIC TISSUE WERE FOUND WELL CORRELATED TO BLOOD SAMPLES IN INFLAMMATORY BOWEL DISEASES. MOREOVER, THE METHYLATION LEVEL OF SPECIFIC GENES WAS DIFFERENT BETWEEN CROHN'S DISEASE AND ULCERATIVE COLITIS. IT HAS BEEN SHOWN THAT THE ENZYMES AFFECTING HISTONE MODIFICATIONS LIKE HISTONE DEACETYLASES AND HISTONE ACETYLTRANSFERASES DO NOT ACT SOLELY ON HISTONES BUT ALSO AFFECT THE ACETYLATION OF MANY PROTEINS SUCH AS P53 AND STAT3. IT HAS BEEN ALREADY SHOWN THAT A NONSELECTIVE HISTONE DEACETYLASE INHIBITOR, VORINOSTAT (SAHA), WHICH IS CURRENTLY BEING USED IN SEVERAL CANCER TREATMENTS, SHOWED ANTI-INFLAMMATORY ACTIVITIES IN MOUSE MODELS. AMONG EPIGENETIC ALTERATIONS, LONG NON-CODING RNAS AND MICRORNAS PLAY SIGNIFICANT ROLES IN T-CELL MATURATION, DIFFERENTIATION, ACTIVATION, AND SENILITY. THE LONG NON-CODING RNA AND MICRORNA EXPRESSION PROFILES CAN PERFECTLY SEPARATE INFLAMMATORY BOWEL DISEASE PATIENTS FROM HEALTHY CONTROLS AND ARE REMARKED AS BIOMARKERS OF INFLAMMATORY BOWEL DISEASES. OVERALL, MANY STUDIES HAVE SHOWN THAT EPIGENETIC INHIBITORS CAN TARGET SIGNIFICANT SIGNAL PATHWAYS IN THE PATHOGENESIS OF INFLAMMATORY BOWEL DISEASES, AND THE IMPACT OF EPIGENETIC INHIBITORS IS BEING STUDIED IN CLINICAL TRIALS. IN CONCLUSION, EXPLORING MORE EPIGENETIC PATHWAYS REGARDING INFLAMMATORY BOWEL DISEASE PATHOGENESIS WILL HELP US TO DISCOVER THERAPEUTIC TARGETS AND NEW DRUGS AND AGENTS TARGETING MIRNAS IN INFLAMMATORY BOWEL DISEASES. IN GENERAL, DISCOVERING EPIGENETIC TARGETS COULD IMPROVE THE DIAGNOSIS AND TREATMENT OF INFLAMMATORY BOWEL DISEASES. 2023 8 2233 34 EPIGENETIC MODIFICATIONS OF THE NUCLEAR FACTOR KAPPA B SIGNALLING PATHWAY AND ITS IMPACT ON INFLAMMATORY BOWEL DISEASE. BACKGROUND: INFLAMMATORY BOWEL DISEASE (IBD) IS A MULTIFACTORIAL CONDITION INFLUENCED BY THE IMMUNE SYSTEM, THE INTESTINAL MICROBIOTA, ENVIRONMENTAL FACTORS, GENETIC AND EPIGENETIC FACTORS. GENETIC- AND ENVIRONMENT- INDUCED DYSREGULATION OF THE NUCLEAR FACTOR-KAPPA B (NF-KAPPAB) TRANSCRIPTION FACTOR PATHWAY HAS BEEN LINKED TO IBD PATHOGENESIS. OBJECTIVE: TO ASSESS THE CURRENT EVIDENCE IN RELATION TO THE CONTRIBUTION OF THE CLASSICAL AND ALTERNATIVE NF-KAPPAB PATHWAYS IN IBD AND TO DISCUSS THE EPIGENETIC MECHANISMS THAT IMPACT ON NF-KAPPAB FUNCTION. METHODS: A MEDLINE SEARCH FOR 'NF-KAPPAB/NF-KAPPAB', IN COMBINATION WITH TERMS INCLUDING 'INFLAMMATORY BOWEL DISEASE/IBD', 'INTESTINAL INFLAMMATION', 'CROHN'S DISEASE', 'ULCERATIVE COLITIS', 'COLITIS'; 'EPIGENETICS', 'DNA METHYLATION', 'HISTONES', 'MICRORNAS/MIRNAS' AND 'SHORT NON-CODING/LONG NON-CODING RNAS' WAS PERFORMED. RESULTS: BOTH NF-KAPPAB PATHWAYS CONTRIBUTE TO THE CHRONIC INFLAMMATION UNDERLYING IBD BY REGULATING THE INFLAMMATORY IMMUNE RESPONSES AND HOMEOSTASIS OF THE INTESTINAL EPITHELIUM (CLASSICAL PATHWAY) OR REGULATING BOWEL INFLAMMATION AND EPITHELIAL MICROFOLD (M) CELL FUNCTION (ALTERNATIVE PATHWAY). DNA METHYLATION IS A COMMON EPIGENETIC MODIFICATION IN INTESTINAL INFLAMMATION, INCLUDING NFKB1 AND RELA LOCI. CONVERSELY, LITTLE IS UNDERSTOOD REGARDING EPIGENETIC EFFECTS ON GENES ENCODING OTHER NF-KAPPAB SUBUNITS, PARTICULARLY THOSE OF THE ALTERNATIVE PATHWAY, AND IN THE CONTEXT OF IBD. HOWEVER, NF-KAPPAB INTERACTION WITH CHROMATIN MODIFIERS IS ALSO SEEN TO BE AN ESSENTIAL MECHANISM OF REGULATION OF DOWNSTREAM TARGET GENES RELEVANT TO NF-KAPPAB-MEDIATED INFLAMMATORY RESPONSES. CONCLUSION: FURTHER RESEARCH IS CLEARLY WARRANTED IN THIS AREA, AS UNDERSTANDING THE CELL-SPECIFIC REGULATION OF THE NF-KAPPAB PATHWAYS WILL BRING RESEARCHERS INTO A POSITION TO ACHIEVE MORE EFFICIENT STRATIFICATION OF IBD PATIENTS, AND MORE TARGETED AND EFFECTIVE CHOICE OF TREATMENT. 2021 9 6340 32 THE ROLE OF EPIGENETIC FACTORS IN PSORIASIS. PSORIASIS IS A CHRONIC, SYSTEMIC, IMMUNE-MEDIATED DISEASE WITH AN INCIDENCE OF APPROXIMATELY 2%. THE PATHOGENESIS OF THE DISEASE IS COMPLEX AND NOT YET FULLY UNDERSTOOD. GENETIC FACTORS PLAY A SIGNIFICANT ROLE IN THE PATHOGENESIS OF THE DISEASE. IN PREDISPOSED INDIVIDUALS, MULTIPLE TRIGGER FACTORS MAY CONTRIBUTE TO DISEASE ONSET AND EXACERBATIONS OF SYMPTOMS. ENVIRONMENTAL FACTORS (STRESS, INFECTIONS, CERTAIN MEDICATIONS, NICOTINISM, ALCOHOL, OBESITY) PLAY A SIGNIFICANT ROLE IN THE PATHOGENESIS OF PSORIASIS. IN ADDITION, EPIGENETIC MECHANISMS ARE CONSIDERED RESULT IN MODULATION OF INDIVIDUAL GENE EXPRESSION AND AN INCREASED LIKELIHOOD OF THE DISEASE. STUDIES HIGHLIGHT THE SIGNIFICANT ROLE OF EPIGENETIC FACTORS IN THE ETIOLOGY AND PATHOGENESIS OF PSORIASIS. EPIGENETIC MECHANISMS IN PSORIASIS INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNAS. EPIGENETIC MECHANISMS INDUCE GENE EXPRESSION CHANGES UNDER THE INFLUENCE OF CHEMICAL MODIFICATIONS OF DNA AND HISTONES, WHICH ALTER CHROMATIN STRUCTURE AND ACTIVATE TRANSCRIPTION FACTORS OF SELECTED GENES, THUS LEADING TO TRANSLATION OF NEW MRNA WITHOUT AFFECTING THE DNA SEQUENCE. EPIGENETIC FACTORS CAN REGULATE GENE EXPRESSION AT THE TRANSCRIPTIONAL (VIA HISTONE MODIFICATION, DNA METHYLATION) AND POSTTRANSCRIPTIONAL LEVELS (VIA MICRORNAS AND LONG NON-CODING RNAS). THIS STUDY AIMS TO PRESENT AND DISCUSS THE DIFFERENT EPIGENETIC MECHANISMS IN PSORIASIS BASED ON A REVIEW OF THE AVAILABLE LITERATURE. 2021 10 4365 34 MIRNA MOLECULES-LATE BREAKING TREATMENT FOR INFLAMMATORY BOWEL DISEASES? MICRORNAS (MIRNAS) ARE A GROUP OF NON-CODING RNAS THAT PLAY A CRITICAL ROLE IN REGULATING EPIGENETIC MECHANISMS IN INFLAMMATION-RELATED DISEASES. INFLAMMATORY BOWEL DISEASES (IBDS), WHICH PRIMARILY INCLUDE ULCERATIVE COLITIS (UC) AND CROHN'S DISEASE (CD), ARE CHARACTERIZED BY CHRONIC RECURRENT INFLAMMATION OF INTESTINAL TISSUES. DUE TO THE MULTIFACTORIAL ETIOLOGY OF THESE DISEASES, THE DEVELOPMENT OF INNOVATIVE TREATMENT STRATEGIES THAT CAN EFFECTIVELY MAINTAIN REMISSION AND ALLEVIATE DISEASE SYMPTOMS IS A MAJOR CHALLENGE. IN RECENT YEARS, EVIDENCE FOR THE REGULATORY ROLE OF MIRNAS IN THE PATHOGENETIC MECHANISMS OF VARIOUS DISEASES, INCLUDING IBD, HAS BEEN ACCUMULATING. IN LIGHT OF THESE FINDINGS, MIRNAS REPRESENT POTENTIAL INNOVATIVE CANDIDATES FOR THERAPEUTIC APPLICATION IN IBD. IN THIS REVIEW, WE DISCUSS RECENT FINDINGS ON THE ROLE OF MIRNAS IN REGULATING INFLAMMATORY RESPONSES, MAINTAINING INTESTINAL BARRIER INTEGRITY, AND DEVELOPING FIBROSIS IN CLINICAL AND EXPERIMENTAL IBD. THE FOCUS IS ON THE EXISTING LITERATURE, INDICATING POTENTIAL THERAPEUTIC APPLICATION OF MIRNAS IN BOTH PRECLINICAL EXPERIMENTAL IBD MODELS AND TRANSLATIONAL DATA IN THE CONTEXT OF CLINICAL IBD. TO DATE, A LARGE AND DIVERSE DATA SET, WHICH IS GROWING RAPIDLY, SUPPORTS THE POTENTIAL USE OF MIRNA-BASED THERAPIES IN CLINICAL PRACTICE, ALTHOUGH MANY QUESTIONS REMAIN UNANSWERED. 2023 11 2333 33 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 12 3681 28 INFLAMMATION, DNA METHYLATION AND COLITIS-ASSOCIATED CANCER. INFLAMMATION CAN RESULT FROM A RANGE OF SOURCES INCLUDING MICROBIAL INFECTIONS, EXPOSURE TO ALLERGENS AND TOXIC CHEMICALS, AUTOIMMUNE DISEASE AND OBESITY. A WELL-BALANCED IMMUNE RESPONSE CAN BE ANTI-TUMORIGENIC; HOWEVER, A SUSTAINED OR CHRONIC INFLAMMATORY RESPONSE IS GENERALLY HARMFUL AS THE IMMUNE RESPONSE BECOMES DISTORTED. A CAUSAL LINK BETWEEN CHRONIC INFLAMMATION AND CANCER IS NOW WELL ACCEPTED AND MANY CHRONICALLY INFLAMED ORGANS OF THE GASTROINTESTINAL TRACT SHOW THIS ASSOCIATION. FOR EXAMPLE, PATIENTS WITH INFLAMMATORY BOWEL DISEASE (IBD), INCLUDING BOTH ULCERATIVE COLITIS AND CROHN'S DISEASE, HAVE A 2- TO 3-FOLD GREATER LIFETIME RISK OF DEVELOPING COLORECTAL CANCER COMPARED WITH THE GENERAL POPULATION. THE DEVELOPMENT OF COLITIS-ASSOCIATED CANCER (CAC) IS THOUGHT TO BE MULTIFACETED AND IS PROBABLY DUE TO A COMBINATION OF GENETIC FACTORS, EPIGENETIC FACTORS AND THE DURATION, EXTENT AND SEVERITY OF DISEASE. RECENTLY, EPIGENETIC ALTERATIONS, IN PARTICULAR ALTERATIONS IN DNA METHYLATION, HAVE BEEN OBSERVED DURING INFLAMMATION AND INFLAMMATION-ASSOCIATED CARCINOGENESIS. THE MEDIATORS OF THIS, THE SIGNIFICANCE OF THESE CHANGES IN DNA METHYLATION AND THE EFFECT THIS HAS ON GENE EXPRESSION AND THE MALIGNANT TRANSFORMATION OF THE EPITHELIAL CELLS DURING IBD AND CAC ARE DISCUSSED IN THIS REVIEW. THE RECENT ADVANCES IN TECHNOLOGIES TO STUDY GENOME-WIDE DNA METHYLATION AND THE THERAPEUTIC POTENTIAL OF UNDERSTANDING THESE MOLECULAR MECHANISMS ARE ALSO HIGHLIGHTED. 2012 13 2368 27 EPIGENETIC REGULATION OF T HELPER CELLS AND INTESTINAL PATHOGENICITY. INFLAMMATORY BOWEL DISEASES (IBDS) ARE CHARACTERIZED BY RELAPSING AND REMITTING CHRONIC INTESTINAL INFLAMMATION. PREVIOUS STUDIES HAVE DEMONSTRATED THE CONTRIBUTIONS OF GENETIC BACKGROUND, ENVIRONMENTAL FACTORS (FOOD, MICROBIOTA, USE OF ANTIBIOTICS), AND HOST IMMUNITY IN THE DEVELOPMENT OF IBDS. MORE THAN 200 GENES HAVE BEEN SHOWN TO INFLUENCE IBD SUSCEPTIBILITY, MOST OF WHICH ARE INVOLVED IN IMMUNITY. THE VERTEBRATE IMMUNE SYSTEM COMPRISES A COMPLEX NETWORK OF INNATE AND ADAPTIVE IMMUNE CELLS THAT PROTECT THE HOST FROM INFECTION AND CANCER. DYSREGULATION OF THE MUTUALISTIC RELATIONSHIP BETWEEN THE IMMUNE SYSTEM AND THE GUT ENVIRONMENT RESULTS IN IBD. CONSIDERING THE FUNDAMENTAL ROLE OF EPIGENETIC REGULATION IN IMMUNE CELLS, EPIGENETIC MECHANISMS, PARTICULARLY IN T HELPER (TH) CELLS, MAY PLAY A MAJOR ROLE IN THE COMPLEX REGULATION OF MUCOSAL IMMUNITY. EPIGENETIC REGULATION AND DYSREGULATION OF TH CELLS ARE INVOLVED IN THE MAINTENANCE OF INTESTINAL HOMEOSTASIS AND ITS BREAKDOWN IN IBD. 2019 14 1522 36 DNA METHYLATION CHANGE PROFILING OF COLORECTAL DISEASE: SCREENING TOWARDS CLINICAL USE. COLON CANCER REMAINS ONE OF THE LEADING CAUSES OF CANCER-RELATED DEATHS WORLDWIDE. TRANSFORMATION OF COLON EPITHELIAL CELLS INTO INVASIVE ADENOCARCINOMAS HAS BEEN WELL KNOWN TO BE DUE TO THE ACCUMULATION OF MULTIPLE GENETIC AND EPIGENETIC CHANGES. IN THE PAST DECADE, THE ETIOLOGY OF INFLAMMATORY BOWEL DISEASE (IBD) WHICH IS CHARACTERIZED BY CHRONIC INFLAMMATION OF THE INTESTINAL MUCOSA, WAS ONLY PARTIALLY EXPLAINED BY GENETIC STUDIES PROVIDING SUSCEPTIBILITY LOCI, BUT RECENTLY EPIGENETIC STUDIES HAVE PROVIDED CRITICAL EVIDENCES AFFECTING IBD PATHOGENESIS. OVER THE PAST DECADE, A DEEP UNDERSTANDING OF EPIGENETICS ALONG WITH TECHNOLOGICAL ADVANCES HAVE LED TO IDENTIFYING NUMEROUS GENES THAT ARE REGULATED BY PROMOTER DNA HYPERMETHYLATION IN COLORECTAL DISEASES. RECENT ADVANCES IN OUR UNDERSTANDING OF THE ROLE OF DNA METHYLATION IN COLORECTAL DISEASES COULD IMPROVE A MULTITUDE OF POWERFUL DNA METHYLATION-BASED BIOMARKERS, PARTICULARLY FOR USE AS DIAGNOSIS, PROGNOSIS, AND PREDICTION FOR THERAPEUTIC APPROACHES. THIS REVIEW FOCUSES ON THE EMERGING POTENTIAL FOR TRANSLATIONAL RESEARCH OF EPIGENETIC ALTERATIONS INTO CLINICAL UTILITY AS MOLECULAR BIOMARKERS. MOREOVER, THIS REVIEW DISCUSSES RECENT PROGRESS REGARDING THE IDENTIFICATION OF UNKNOWN HYPERMETHYLATED GENES IN COLON CANCERS AND IBD, AS WELL AS THEIR POSSIBLE ROLE IN CLINICAL PRACTICE, WHICH WILL HAVE IMPORTANT CLINICAL SIGNIFICANCE, PARTICULARLY IN THE ERA OF THE PERSONALIZED MEDICINE. 2021 15 3703 25 INFLAMMATORY SIGNALLING AS MEDIATOR OF EPIGENETIC MODULATION IN TISSUE-SPECIFIC CHRONIC INFLAMMATION. RECENT SUCCESSES OF THERAPEUTIC INTERVENTION IN CHRONIC INFLAMMATORY DISEASES USING EPIGENETIC MODIFIERS SUCH AS HISTONE DEACETYLASE INHIBITORS AND INHIBITORS OF DNA METHYLATION SUGGEST THAT EPIGENETIC REPROGRAMMING PLAYS A ROLE IN THE AETIOLOGY OF THESE DISEASES. THE EPIGENETIC SIGNATURE OF A GIVEN IMMUNE CELL IS REFLECTED IN THE HISTORY OF MODIFICATIONS FROM DIFFERENT SIGNALS THE CELL HAS BEEN SUBJECTED TO DURING DIFFERENTIATION. LIKE OTHER CELLS, DIFFERENTIATING IMMUNE CELLS ARE DEPENDENT ON A COMPLEX COMBINATION OF INTER- AND INTRACELL SIGNALLING AS WELL AS TRANSCRIPTION MACHINERIES TO MODULATE THEIR EPIGENOMES IN ORDER TO MEDIATE DIFFERENTIATION. DESPITE EXTENSIVE RESEARCH INTO THESE PROCESSES, THE LINK BETWEEN CELLULAR SIGNALLING AND EPIGENETIC MODULATION REMAINS POORLY UNDERSTOOD. HERE, WE REVIEW RECENT PROGRESS AND DISCUSS KEY FACTORS DRIVING EPIGENETIC MODULATION IN CHRONIC INFLAMMATION. 2009 16 1606 27 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 17 1172 31 CONTRIBUTION OF THE ENVIRONMENT, EPIGENETIC MECHANISMS AND NON-CODING RNAS IN PSORIASIS. DESPITE THE INCREASING RESEARCH AND CLINICAL INTEREST IN THE PREDISPOSITION OF PSORIASIS, A CHRONIC INFLAMMATORY SKIN DISEASE, THE MULTITUDE OF GENETIC AND ENVIRONMENTAL FACTORS INVOLVED IN ITS PATHOGENESIS REMAIN UNCLEAR. THIS COMPLEXITY IS FURTHER EXACERBATED BY THE SEVERAL CELL TYPES THAT ARE IMPLICATED IN PSORIASIS'S PROGRESSION, INCLUDING KERATINOCYTES, MELANOCYTES AND VARIOUS IMMUNE CELL TYPES. THE OBSERVED INTERACTIONS BETWEEN THE GENETIC SUBSTRATE AND THE ENVIRONMENT LEAD TO EPIGENETIC ALTERATIONS THAT DIRECTLY OR INDIRECTLY AFFECT GENE EXPRESSION. CHANGES IN DNA METHYLATION AND HISTONE MODIFICATIONS THAT ALTER DNA-BINDING SITE ACCESSIBILITY, AS WELL AS NON-CODING RNAS IMPLICATED IN THE POST-TRANSCRIPTIONAL REGULATION, ARE MECHANISMS OF GENE TRANSCRIPTIONAL ACTIVITY MODIFICATION AND THEREFORE AFFECT THE PATHWAYS INVOLVED IN THE PATHOGENESIS OF PSORIASIS. IN THIS REVIEW, WE SUMMARIZE THE RESEARCH CONDUCTED ON THE ENVIRONMENTAL FACTORS CONTRIBUTING TO THE DISEASE ONSET, EPIGENETIC MODIFICATIONS AND NON-CODING RNAS EXHIBITING DEREGULATION IN PSORIASIS, AND WE FURTHER CATEGORIZE THEM BASED ON THE UNDER-STUDY CELL TYPES. WE ALSO ASSESS THE RECENT LITERATURE CONSIDERING THERAPEUTIC APPLICATIONS TARGETING MOLECULES THAT COMPROMISE THE EPIGENOME, AS A WAY TO SUPPRESS THE INFLAMMATORY CUTANEOUS CASCADE. 2022 18 2027 36 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 19 5932 32 TARGETING EPIGENETIC REGULATORS FOR INFLAMMATION: MECHANISMS AND INTERVENTION THERAPY. EMERGING EVIDENCE INDICATES THAT RESOLUTION OF INFLAMMATION IS A CRITICAL AND DYNAMIC ENDOGENOUS PROCESS FOR HOST TISSUES DEFENDING AGAINST EXTERNAL INVASIVE PATHOGENS OR INTERNAL TISSUE INJURY. IT HAS LONG BEEN KNOWN THAT AUTOIMMUNE DISEASES AND CHRONIC INFLAMMATORY DISORDERS ARE CHARACTERIZED BY DYSREGULATED IMMUNE RESPONSES, LEADING TO EXCESSIVE AND UNCONTROL TISSUE INFLAMMATION. THE DYSREGULATION OF EPIGENETIC ALTERATIONS INCLUDING DNA METHYLATION, POSTTRANSLATIONAL MODIFICATIONS TO HISTONE PROTEINS, AND NONCODING RNA EXPRESSION HAS BEEN IMPLICATED IN A HOST OF INFLAMMATORY DISORDERS AND THE IMMUNE SYSTEM. THE INFLAMMATORY RESPONSE IS CONSIDERED AS A CRITICAL TRIGGER OF EPIGENETIC ALTERATIONS THAT IN TURN INTERCEDE INFLAMMATORY ACTIONS. THUS, UNDERSTANDING THE MOLECULAR MECHANISM THAT DICTATES THE OUTCOME OF TARGETING EPIGENETIC REGULATORS FOR INFLAMMATORY DISEASE IS REQUIRED FOR INFLAMMATION RESOLUTION. IN THIS ARTICLE, WE ELUCIDATE THE CRITICAL ROLE OF THE NUCLEAR FACTOR-KAPPAB SIGNALING PATHWAY, JAK/STAT SIGNALING PATHWAY, AND THE NLRP3 INFLAMMASOME IN CHRONIC INFLAMMATORY DISEASES. AND WE FORMULATE THE RELATIONSHIP BETWEEN INFLAMMATION, CORONAVIRUS DISEASE 2019, AND HUMAN CANCERS. ADDITIONALLY, WE REVIEW THE MECHANISM OF EPIGENETIC MODIFICATIONS INVOLVED IN INFLAMMATION AND INNATE IMMUNE CELLS. ALL THAT MATTERS IS THAT WE PROPOSE AND DISCUSS THE REJUVENATION POTENTIAL OF INTERVENTIONS THAT TARGET EPIGENETIC REGULATORS AND REGULATORY MECHANISMS FOR CHRONIC INFLAMMATION-ASSOCIATED DISEASES TO IMPROVE THERAPEUTIC OUTCOMES. 2022 20 2501 26 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