1 1225 101 CRITICAL ROLE OF EPIGENETIC MODIFICATION IN THE PATHOGENESIS OF ATOPIC DERMATITIS. ATOPIC DERMATITIS IS A CHRONIC INFLAMMATORY SKIN DISEASE CHARACTERISED BY RECURRENT ECZEMA-LIKE LESIONS AND SEVERE PRURITUS, ALONG WITH DRYING AND DECRUSTATION OF SKIN. CURRENT RESEARCH RELATES THE PATHOGENESIS OF ATOPIC DERMATITIS MAINLY TO GENETIC SUSCEPTIBILITY, ABNORMAL SKIN BARRIER FUNCTION, IMMUNE DISORDERS, STAPHYLOCOCCUS AUREUS COLONISATION, MICROBIOLOGICAL DYSFUNCTION AND VITAMIN D INSUFFICIENCY. EPIGENETIC MODIFICATIONS ARE DISTINCT GENETIC PHENOTYPES RESULTING FROM ENVIRONMENT-DRIVEN CHANGES IN CHROMOSOME FUNCTIONS IN THE ABSENCE OF NUCLEAR DNA SEQUENCE VARIATION. CLASSIC EPIGENETIC EVENTS INCLUDE DNA METHYLATION, HISTONE PROTEIN MODIFICATIONS AND NON-CODING RNA REGULATION. INCREASING EVIDENCE HAS INDICATED THAT EPIGENETIC EVENTS ARE INVOLVED IN THE PATHOGENESIS OF ATOPIC DERMATITIS BY THEIR EFFECTS ON MULTIPLE SIGNALLING PATHWAYS WHICH IN TURN INFLUENCE THE ABOVE FACTORS. THIS REVIEW PRIMARILY ANALYSES THE FUNCTION OF EPIGENETIC REGULATION IN THE PATHOGENESIS OF ATOPIC DERMATITIS. IN ADDITION, IT TRIES TO MAKE RECOMMENDATIONS FOR PERSONALISED EPIGENETIC TREATMENT STRATEGIES FOR ATOPIC DERMATITIS IN THE FUTURE. 2023 2 845 30 CHILDHOOD ATOPIC DERMATITIS: CURRENT DEVELOPMENTS, TREATMENT APPROACHES, AND FUTURE EXPECTATIONS. ATOPIC DERMATITIS (AD) IS THE MOST COMMON CHRONIC INFLAMMATORY SKIN DISORDER OF CHILDHOOD. UNDERLYING FACTORS THAT CONTRIBUTE TO AD ARE IMPAIRED EPITHELIAL BARRIER, ALTERATIONS IN THE LIPID COMPOSITION OF THE SKIN, IMMUNOLOGICAL IMBALANCE INCLUDING INCREASED TH2/TH1 RATIO, PROINFLAMMATORY CYTOKINES, DECREASED T REGULATORY CELLS, GENETIC MUTATIONS, AND EPIGENETIC ALTERATIONS. ATOPIC DERMATITIS IS A MULTIFACTORIAL DISEASE WITH A PARTICULARLY COMPLICATED PATHOPHYSIOLOGY. DISCOVERIES TO DATE MAY BE CONSIDERED THE TIP OF THE ICEBERG, AND THE INCREASING NUMBER OF STUDIES IN THIS FIELD INDICATE THAT THERE ARE MANY POINTS TO BE ELUCIDATED IN AD PATHOPHYSIOLOGY. IN THIS REVIEW, WE AIMED TO ILLUSTRATE THE CURRENT UNDERSTANDING OF THE UNDERLYING PATHOGENIC MECHANISMS IN AD, TO EVALUATE AVAILABLE TREATMENT OPTIONS WITH A FOCUS ON RECENTLY DISCOVERED THERAPEUTIC AGENTS, AND TO DETERMINE THE PERSONAL, FAMILIAL, AND ECONOMIC BURDENS OF THE DISEASE, WHICH ARE FREQUENTLY NEGLECTED ISSUES IN AD. CURRENTLY AVAILABLE THERAPIES ONLY PROVIDE TRANSIENT SOLUTIONS AND CANNOT FULLY CURE THE DISEASE. HOWEVER, ADVANCES IN THE UNDERSTANDING OF THE PATHOGENIC MECHANISMS OF THE DISEASE HAVE LED TO THE PRODUCTION OF NEW TREATMENT OPTIONS, WHILE ONGOING DRUG TRIALS ALSO HAVE HAD PROMISING RESULTS. 2019 3 6158 37 THE GENETICS AND EPIGENETICS OF ATOPIC DERMATITIS-FILAGGRIN AND OTHER POLYMORPHISMS. ATOPIC DERMATITIS (AD) IS A CHRONIC INFLAMMATORY SKIN DISEASE CAUSED BY A COMBINATION OF GENETIC AND ENVIRONMENTAL FACTORS. GENETIC EVIDENCES DEPICT A COMPLEX NETWORK COMPRISING BY EPIDERMAL BARRIER DYSFUNCTIONS AND DYSREGULATION OF INNATE AND ADAPTIVE IMMUNITY IN THE PATHOGENESIS OF AD. MUTATIONS IN THE HUMAN FILAGGRIN GENE (FLG) ARE THE MOST SIGNIFICANT AND WELL-REPLICATED GENETIC MUTATION ASSOCIATED WITH AD, AND OTHER MUTATIONS ASSOCIATED WITH EPIDERMAL BARRIERS SUCH AS SPINK5, FLG-2, SPRR3, AND CLDN1 HAVE ALL BEEN LINKED TO AD. GENE VARIANTS MAY ALSO CONTRIBUTE TO THE ABNORMAL INNATE AND ADAPTIVE RESPONSES FOUND IN AD, INCLUDING MUTATIONS IN PRRS AND AMPS, TSLP AND TSLPR, IL-1 FAMILY CYTOKINES AND RECEPTORS GENES, VITAMIN D PATHWAY GENES, FCER1A, AND TH2 AND OTHER CYTOKINES GENES. GWAS AND IMMUNOCHIP ANALYSIS HAVE IDENTIFIED A TOTAL OF 19 SUSCEPTIBILITY LOCI FOR AD. CANDIDATE GENES AT THESE SUSCEPTIBILITY LOCI IDENTIFIED BY GWAS AND IMMUNOCHIP ANALYSIS ALSO SUGGEST ROLES FOR EPIDERMAL BARRIER FUNCTIONS, INNATE AND ADAPTIVE IMMUNITY, INTERLEUKIN-1 FAMILY SIGNALING, REGULATORY T CELLS, THE VITAMIN D PATHWAY, AND THE NERVE GROWTH FACTOR PATHWAY IN THE PATHOGENESIS OF AD. INCREASING EVIDENCES SHOW THE MODERN LIFESTYLE (I.E., THE HYGIENE HYPOTHESIS, WESTERN DIET) AND OTHER ENVIRONMENTAL FACTORS SUCH AS POLLUTION AND ENVIRONMENTAL TOBACCO SMOKE (ETS) LEAD TO THE INCREASING PREVALENCE OF AD WITH THE DEVELOPMENT OF INDUSTRIALIZATION. EPIGENETIC ALTERATIONS IN RESPONSE TO THESE ENVIRONMENTAL FACTORS, INCLUDING DNA METHYLATION AND MICRORNA RELATED TO IMMUNE SYSTEM AND SKIN BARRIERS, HAVE BEEN FOUND TO CONTRIBUTE TO THE PATHOGENESIS OF AD. GENETIC VARIANTS AND EPIGENETIC ALTERATION MIGHT BE THE KEY TOOLS FOR THE MOLECULAR TAXONOMY OF AD AND PROVIDE THE BACKGROUND FOR THE PERSONALIZED MANAGEMENT. 2016 4 2553 35 EPIGENETICS IN PSORIASIS: PERSPECTIVE OF DNA METHYLATION. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE CHARACTERIZED BY EXCESSIVE PROLIFERATION OF KERATINOCYTES (KCS). ONSET OF PSORIASIS IS RELATED TO GENETIC, IMMUNE AND ENVIRONMENTAL FACTORS. THE ENVIRONMENT CAN INTERACT WITH THE GENOME THROUGH EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION, AND THIS MODIFICATION IS INVOLVED IN THE PATHOGENESIS OF PSORIASIS. IN ADDITION TO A SKIN DISEASE, PSORIASIS IS ALSO CONSIDERED A SYSTEMIC DISEASE. WE REVIEWED THE CURRENT LITERATURE OF PSORIATIC DNA METHYLATION FOR STUDIES FROM SEVERAL ASPECTS ON THE DNA METHYLATION DISTRIBUTION PATTERNS IN DIFFERENT TISSUES/CELLS, SINGLE-NUCLEOTIDE POLYMORPHISMS, AND CANDIDATE DISEASE GENES AND IDENTIFIED TARGET GENES REGULATED BY DNA METHYLATION THAT HAVE BEEN DIRECTLY/INDIRECTLY VALIDATED. THIS REVIEW CONTRIBUTES TO A COMPREHENSIVE UNDERSTANDING OF THE IMPORTANT A ROLE THAT DNA METHYLATION PLAYS IN PSORIASIS FROM A HOLISTIC PERSPECTIVE AND WILL PROMOTE THE IMPLEMENTATION OF DNA METHYLATION IN DIAGNOSTIC AND THERAPEUTIC STRATEGIES FOR PSORIATIC PATIENTS. 2021 5 2533 35 EPIGENETICS IN AUTOIMMUNE CONNECTIVE TISSUE DISEASES. BACKGROUND. AUTOIMMUNE CONNECTIVE TISSUE DISEASES (ACTDS) ENCOMPASS A HETEROGENEOUS GROUP OF CHRONIC IMMUNE-MEDIATED INFLAMMATORY DISORDERS, PRIMARILY AFFECTING CONNECTIVE TISSUES AND CLINICALLY CHARACTERIZED BY VARIABLE MULTISYSTEM MANIFESTATIONS, FREQUENTLY OVERLAPPING. ENVIRONMENTAL FACTORS ARE THOUGHT TO PROMOTE ACTD DEVELOPMENT IN GENETIC PREDISPOSING/ENDOCRINE PERMISSIVE BACKGROUND THROUGH THE INDUCTION OF EPIGENETIC MODIFICATIONS, CONSISTING OF STABLE, HERITABLE, BUT POTENTIALLY REVERSIBLE CHANGES IN GENE EXPRESSION, OCCURRING WITHOUT ALTERATIONS OF THE DNA SEQUENCE. ACTUALLY, EPIGENETIC MECHANISMS (SUCH AS HISTONE MODIFICATIONS, DNA METHYLATION, NUCLEOSOME POSITIONING, AND RNA INTERFERENCE) LINK GENOTYPE UPSTREAM AND PHENOTYPE DOWNSTREAM, AND, IF PERSISTENTLY ABERRANT, MAY CAUSE A VARIETY OF HUMAN DISEASES, INCLUDING ACTDS. WE AIMED TO REVIEW THE RECENT ADVANCES IN THE KNOWLEDGE OF THE ACTD EPIGENETIC ALTERATIONS. METHODS: A DETAILED SEARCH OF THE AVAILABLE LITERATURE WAS PERFORMED IN THE PUBMED (U.S. NATIONAL LIBRARY OF MEDICINE) DATABASE. RESULTS: GROWING EVIDENCE UNDERLINES THE RELEVANT ROLE OF EPIGENETIC DEFECTS IN THE ACTD PATHOGENESIS, AND SPECIFIC EPIGENETIC PATTERNS CAN REPRESENT DISEASE BIOMARKERS. IN PATIENTS WITH RHEUMATOID ARTHRITIS (RA), EPIGENETIC VARIATIONS INTERACT DETERMINING THE TYPICAL "AGGRESSIVE" PHENOTYPE DISPLAYED BY RA SYNOVIAL FIBROBLASTS. EPIGENETIC MODIFICATIONS ARE INVOLVED IN THE PROFIBROTIC PROCESS THAT CHARACTERIZES SYSTEMIC SCLEROSIS. IN SYSTEMIC LUPUS ERYTHEMATOSUS AND SJOGREN'S SYNDROME, COMPLEX EPIGENETIC CHANGES ALTERING GENE EXPRESSION HAVE BEEN DEMONSTRATED. CONCLUSIONS: COMPREHENSIVE STUDIES WILL CONTRIBUTE TO FURTHER DEFINE THE ABERRANT EPIGENETIC MECHANISMS INVOLVED IN THE ACTDS ETIOPATHOGENESIS. MOREOVER, BEING EPIGENETIC CHANGES POTENTIALLY REVERSIBLE, THE IDENTIFICATION OF ACTDS EPIGENETIC BIOMARKERS WILL ALLOW THE DEVELOPMENT OF THERAPEUTIC STRATEGIES ADDRESSED TO TARGET DYSREGULATED GENES AND CORRECT ABERRANT EPIGENOMIC ALTERATIONS. 2014 6 2064 29 EPIGENETIC CONTROL OF INFLAMMATION IN ATOPIC DERMATITIS. ATOPIC DERMATITIS (AD), ALSO KNOWN AS ATOPIC ECZEMA, IS A COMMON BUT ALSO COMPLEX CHRONIC, ITCHY SKIN CONDITION WITH UNDERLYING INFLAMMATION OF THE SKIN. THIS SKIN AILMENT IS PREVALENT WORLDWIDE AND AFFECTS PEOPLE OF ALL AGES, PARTICULARLY CHILDREN BELOW FIVE YEARS OF AGE. THE ITCHING AND RESULTING RASHES IN AD PATIENTS ARE OFTEN THE RESULT OF INFLAMMATORY SIGNALS, THUS NECESSITATING A CLOSER LOOK AT THE INFLAMMATION-REGULATING MECHANISMS FOR PUTATIVE RELIEF, CARE AND THERAPY. SEVERAL CHEMICAL- AS WELL AS GENETICALLY-INDUCED ANIMAL MODELS HAVE ESTABLISHED THE IMPORTANCE OF TARGETING PRO-INFLAMMATORY AD MICROENVIRONMENT. EPIGENETIC MECHANISMS ARE GAINING ATTENTION TOWARDS A BETTER UNDERSTANDING OF THE ONSET AS WELL AS THE PROGRESSION OF INFLAMMATION. SEVERAL PHYSIOLOGICAL PROCESSES WITH IMPLICATIONS IN PATHOPHYSIOLOGY OF AD, SUCH AS, BARRIER DYSFUNCTION EITHER DUE TO REDUCED FILAGGRIN / HUMAN BETA-DEFENSINS OR ALTERED MICROBIOME, REPROGRAMING OF FC RECEPTORS WITH RESULTING OVEREXPRESSION OF HIGH AFFINITY IGE RECEPTORS, ELEVATED EOSINOPHIL NUMBERS OR THE ELEVATED IL-22 PRODUCTION BY CD4 + T CELLS HAVE UNDERLYING EPIGENETIC MECHANISMS THAT INCLUDE DIFFERENTIAL PROMOTER METHYLATION AND/OR REGULATION BY NON-CODING RNAS. REVERSING THESE EPIGENETIC CHANGES HAS BEEN VERIFIED TO REDUCE INFLAMMATORY BURDEN THROUGH ALTERED SECRETION OF CYTOKINES IL-6, IL-4, IL-13, IL-17, IL-22 ETC, WITH BENEFIT AGAINST AD PROGRESSION IN EXPERIMENTAL MODELS. A THOROUGH UNDERSTANDING OF EPIGENETIC REMODELING OF INFLAMMATION IN AD HAS THE POTENTIAL OF OPENING AVENUES FOR NOVEL DIAGNOSTIC, PROGNOSTIC AND THERAPEUTIC OPTIONS. 2023 7 5998 33 THE ABERRANT EPIGENETIC MODIFICATIONS IN THE PATHOGENESIS OF PSORIASIS. PSORIASIS IS A CHRONIC AND RECURRENT INFLAMMATORY SKIN DISEASE THAT IS CHARACTERIZED BY ABNORMAL KERATINOCYTE PROLIFERATION, VASCULAR HYPERPLASIA, AND INFILTRATION OF INFLAMMATORY CELLS INTO THE DERMIS AND EPIDERMIS. IT IS GENERALLY ACCEPTED THAT THE CENTRAL PATHOGENESIS OF PSORIASIS IS DYSFUNCTION OF T LYMPHOCYTES, WHICH ARE AFFECTED BY THE COMPLEX INTERPLAY BETWEEN GENETIC AND ENVIRONMENTAL FACTORS, INCLUDING TRAUMA, INFECTIONS, STRESS, DRUGS, SMOKING, AND ALCOHOL CONSUMPTION (NESTLE ET AL., 2009). THE ENVIRONMENTALLY INDUCED EPIGENETIC CHANGES, INCLUDING DNA METHYLATION, HISTONE MODIFICATION, AND MICRORNAS, HAVE BEEN SHOWN TO BE INVOLVED IN THE PATHOGENESIS OF THIS DISEASE (ZHANG ET AL., 2012). 2018 8 3104 31 GENOMIC, EPIGENOMIC, TRANSCRIPTOMIC, PROTEOMIC AND METABOLOMIC APPROACHES IN ATOPIC DERMATITIS. ATOPIC DERMATITIS (AD) IS A CHRONIC INFLAMMATORY SKIN DISEASE WITH A HIGH PREVALENCE IN THE DEVELOPED COUNTRIES. IT IS ASSOCIATED WITH ATOPIC AND NON-ATOPIC DISEASES, AND ITS CLOSE CORRELATION WITH ATOPIC COMORBIDITIES HAS BEEN GENETICALLY DEMONSTRATED. ONE OF THE MAIN ROLES OF GENETIC STUDIES IS TO COMPREHEND THE DEFECTS OF THE CUTANEOUS BARRIER DUE TO FILAGGRIN DEFICIT AND EPIDERMAL SPONGIOSIS. RECENTLY, EPIGENETIC STUDIES STARTED TO ANALYZE THE INFLUENCE OF THE ENVIRONMENTAL FACTORS ON GENE EXPRESSION. THE EPIGENOME IS CONSIDERED TO BE A SUPERIOR SECOND CODE THAT CONTROLS THE GENOME, WHICH INCLUDES ALTERATIONS OF THE CHROMATIN. THE EPIGENETIC CHANGES DO NOT ALTER THE GENETIC CODE, HOWEVER, CHANGES IN THE CHROMATIN STRUCTURE COULD ACTIVATE OR INHIBIT THE TRANSCRIPTION PROCESS OF CERTAIN GENES AND CONSEQUENTLY, THE TRANSLATION PROCESS OF THE NEW MRNA INTO A POLYPEPTIDE CHAIN. IN-DEPTH ANALYSIS OF THE TRANSCRIPTOMIC, METABOLOMIC AND PROTEOMIC STUDIES ALLOW TO UNRAVEL DETAILED MECHANISMS THAT CAUSE AD. THE EXTRACELLULAR SPACE AND LIPID METABOLISM ARE ASSOCIATED WITH AD THAT IS INDEPENDENT OF THE FILAGGRIN EXPRESSION. ON THE OTHER HAND, AROUND 45 PROTEINS ARE CONSIDERED AS THE PRINCIPAL COMPONENTS IN THE ATOPIC SKIN. MOREOVER, GENETIC STUDIES BASED ON THE DISRUPTED CUTANEOUS BARRIER CAN LEAD TO THE DEVELOPMENT OF NEW TREATMENTS TARGETING THE CUTANEOUS BARRIER OR CUTANEOUS INFLAMMATION. UNFORTUNATELY, AT PRESENT, THERE ARE NO TARGET THERAPIES THAT FOCUS ON THE EPIGENETIC PROCESS OF AD. HOWEVER, IN THE FUTURE, MIR-143 COULD BE AN IMPORTANT OBJECTIVE FOR NEW THERAPIES, AS IT TARGETS THE MIR-335:SOX AXIS, THEREBY RESTORING THE MIR-335 EXPRESSION, AND REPAIRING THE CUTANEOUS BARRIER DEFECTS. 2023 9 6877 28 [REASONS FOR THE DEVELOPMENT OF ALLERGIES IN CHILDREN]. ALLERGIES ARE ONE OF THE MOST COMMON CHRONIC DISEASES IN CHILDHOOD, CONTRIBUTING TO A TREMENDOUS MEDICAL AND ECONOMICAL BURDEN IN HEALTH CARE SYSTEMS OF MOST INDUSTRIALIZED COUNTRIES. THE DEVELOPMENT OF ALLERGIES IS DEPENDENT ON A COMPLEX INTERACTION OF-AMONG OTHERS-ENVIRONMENTAL FACTORS, NUTRITION, GENETIC AND EPIGENETIC MECHANISMS AS WELL AS THE MICROBIOME. THESE DIVERSE FACTORS CAN INFLUENCE EARLY LIFE IMMUNE REGULATION INCLUDING INNATE AND ADAPTIVE IMMUNE MECHANISMS IN A COMPLEX FASHION. IN CASE OF ANY CHILDHOOD ALLERGIES HAVE INCREASED SIGNIFICANTLY IN PAST DECADES. IN ADDITION TO ENVIRONMENTAL FACTORS AND NUTRITION, GENETIC AND EPIGENETIC MECHANISMS AS WELL AS THE MICROBIOME OF CHILDREN PLAY AN IMPORTANT ROLE. OF RELEVANCE IS THE WAY IN WHICH THESE DIVERSE FACTORS INFLUENCE EARLY IMMUNE DEVELOPMENT OF THE INNATE AND ADAPTIVE IMMUNE SYSTEMS OF CHILDREN. THEIR COMPLEX REGULATION IS DECISIVE FOR WHETHER OR NOT A CHILD DEVELOPS AN ALLERGY THAT MANIFESTS IN MOST CASES AS ATOPIC DERMATITIS, BRONCHIAL ASTHMA, OR ALLERGIC RHINO CONJUNCTIVITIS, OR WHETHER A CHILD DEVELOPS AN IMMUNE TOLERANCE. THESE INFLUENCES CAN BEGIN PRENATALLY, ALREADY SETTING THE COURSE FOR LATER IMMUNE SYSTEM DEVELOPMENT AND OCCURRENCE OF DISEASE. 2019 10 2279 32 EPIGENETIC REGULATION IN ALLERGIC DISEASES AND RELATED STUDIES. ASTHMA, A CHRONIC INFLAMMATORY DISORDER OF THE AIRWAY, HAS FEATURES OF BOTH HERITABILITY AS WELL AS ENVIRONMENTAL INFLUENCES WHICH CAN BE INTRODUCED IN UTERO EXPOSURES AND MODIFIED THROUGH AGING, AND THE FEATURES MAY ATTRIBUTE TO EPIGENETIC REGULATION. EPIGENETIC REGULATION EXPLAINS THE ASSOCIATION BETWEEN EARLY PRENATAL MATERNAL SMOKING AND LATER ASTHMA-RELATED OUTCOMES. EPIGENETIC MARKS (DNA METHYLATION, MODIFICATIONS OF HISTONE TAILS OR NONCODING RNAS) WORK WITH OTHER COMPONENTS OF THE CELLULAR REGULATORY MACHINERY TO CONTROL THE LEVELS OF EXPRESSED GENES, AND SEVERAL ALLERGY- AND ASTHMA-RELATED GENES HAVE BEEN FOUND TO BE SUSCEPTIBLE TO EPIGENETIC REGULATION, INCLUDING GENES IMPORTANT TO T-EFFECTOR PATHWAYS (IFN-GAMMA, INTERLEUKIN [IL] 4, IL-13, IL-17) AND T-REGULATORY PATHWAYS (FOXP3). THEREFORE, THE MECHANISM BY WHICH EPIGENETIC REGULATION CONTRIBUTES TO ALLERGIC DISEASES IS A CRITICAL ISSUE. IN THE PAST MOST PUBLISHED EXPERIMENTAL WORK, WITH FEW EXCEPTIONS, HAS ONLY COMPRISED SMALL OBSERVATIONAL STUDIES AND MODELS IN CELL SYSTEMS AND ANIMALS. HOWEVER, VERY RECENTLY EXCITING AND ELEGANT EXPERIMENTAL STUDIES AND NOVEL TRANSLATIONAL RESEARCH WORKS WERE PUBLISHED WITH NEW AND ADVANCED TECHNOLOGIES INVESTIGATING EPIGENETIC MARK ON A GENOMIC SCALE AND COMPREHENSIVE APPROACHES TO DATA ANALYSIS. INTERESTINGLY, A POTENTIAL LINK BETWEEN EXPOSURE TO ENVIRONMENTAL POLLUTANTS AND THE OCCURRENCE OF ALLERGIC DISEASES IS REVEALED RECENTLY, PARTICULAR IN DEVELOPED AND INDUSTRIALIZED COUNTRIES, AND ENDOCRINE DISRUPTING CHEMICALS (EDCS) AS ENVIRONMENTAL HORMONE MAY PLAY A KEY ROLE. THIS REVIEW ADDRESSES THE IMPORTANT QUESTION OF HOW EDCS (NONYLPHENOL, 4 OCTYLPHENOL, AND PHTHALATES) INFLUENCES ON ASTHMA-RELATED GENE EXPRESSION VIA EPIGENETIC REGULATION IN IMMUNE CELLS, AND HOW ANTI-ASTHMATIC AGENTS PROHIBIT EXPRESSION OF INFLAMMATORY GENES VIA EPIGENETIC MODIFICATION. THE DISCOVERY AND VALIDATION OF EPIGENETIC BIOMARKERS LINKING EXPOSURE TO ALLERGIC DISEASES MIGHT LEAD TO BETTER EPIGENOTYPING OF RISK, PROGNOSIS, TREATMENT PREDICTION, AND DEVELOPMENT OF NOVEL THERAPIES. 2014 11 2059 27 EPIGENETIC CONTROL OF GENE EXPRESSION IN THE LUNG. EPIGENETICS IS TRADITIONALLY DEFINED AS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. THERE ARE THREE MAIN CLASSES OF EPIGENETIC MARKS--DNA METHYLATION, MODIFICATIONS OF HISTONE TAILS, AND NONCODING RNAS--EACH OF WHICH MAY BE INFLUENCED BY THE ENVIRONMENT, DIET, DISEASES, AND AGEING. IMPORTANTLY, EPIGENETIC MARKS HAVE BEEN SHOWN TO INFLUENCE IMMUNE CELL MATURATION AND ARE ASSOCIATED WITH THE RISK OF DEVELOPING VARIOUS FORMS OF CANCER, INCLUDING LUNG CANCER. MOREOVER, THERE IS EMERGING EVIDENCE THAT THESE EPIGENETIC MARKS AFFECT GENE EXPRESSION IN THE LUNG AND ARE ASSOCIATED WITH BENIGN LUNG DISEASES, SUCH AS ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND INTERSTITIAL LUNG DISEASE. TECHNOLOGICAL ADVANCES HAVE MADE IT FEASIBLE TO STUDY EPIGENETIC MARKS IN THE LUNG, AND IT IS ANTICIPATED THAT THIS KNOWLEDGE WILL ENHANCE OUR UNDERSTANDING OF THE DYNAMIC BIOLOGY IN THE LUNG AND LEAD TO THE DEVELOPMENT OF NOVEL DIAGNOSTIC AND THERAPEUTIC APPROACHES FOR OUR PATIENTS WITH LUNG DISEASE. 2011 12 6345 40 THE ROLE OF EPIGENETICS IN AUTOIMMUNE/INFLAMMATORY DISEASE. HISTORICALLY, SYSTEMIC SELF-INFLAMMATORY CONDITIONS WERE CLASSIFIED AS EITHER AUTOINFLAMMATORY AND CAUSED BY THE INNATE IMMUNE SYSTEM OR AUTOIMMUNE AND DRIVEN BY ADAPTIVE IMMUNE RESPONSES. HOWEVER, IT BECAME CLEAR THAT REALITY IS MUCH MORE COMPLEX AND THAT AUTOIMMUNE/INFLAMMATORY CONDITIONS RANGE ALONG AN "INFLAMMATORY SPECTRUM" WITH PRIMARILY AUTOINFLAMMATORY VS. AUTOIMMUNE CONDITIONS RESEMBLING EXTREMES AT EITHER END. EPIGENETIC MODIFICATIONS INFLUENCE GENE EXPRESSION AND ALTER CELLULAR FUNCTIONS WITHOUT MODIFYING THE GENOMIC SEQUENCE. METHYLATION OF CPG DNA DINUCLEOTIDES AND/OR THEIR HYDROXYMETHYLATION, POST-TRANSLATIONAL MODIFICATIONS TO AMINO TERMINI OF HISTONE PROTEINS, AND NON-CODING RNA EXPRESSION ARE MAIN EPIGENETIC EVENTS. THE PATHOPHYSIOLOGY OF AUTOIMMUNE/INFLAMMATORY DISEASES HAS BEEN CLOSELY LINKED WITH DISEASE CAUSING GENE MUTATIONS (RARE) OR A COMBINATION OF GENETIC SUSCEPTIBILITY AND EPIGENETIC MODIFICATIONS ARISING FROM EXPOSURE TO THE ENVIRONMENT (MORE COMMON). OVER RECENT YEARS, PROGRESS HAS BEEN MADE IN UNDERSTANDING MOLECULAR MECHANISMS INVOLVED IN SYSTEMIC INFLAMMATION AND THE CONTRIBUTION OF INNATE AND ADAPTIVE IMMUNE RESPONSES. EPIGENETIC EVENTS HAVE BEEN IDENTIFIED AS (I) CENTRAL PATHOPHYSIOLOGICAL FACTORS IN ADDITION TO GENETIC DISEASE PREDISPOSITION AND (II) AS CO-FACTORS DETERMINING CLINICAL PICTURES AND OUTCOMES IN INDIVIDUALS WITH MONOGENIC DISEASE. THUS, A COMPLETE UNDERSTANDING OF EPIGENETIC CONTRIBUTORS TO AUTOIMMUNE/INFLAMMATORY DISEASE WILL RESULT IN APPROACHES TO PREDICT INDIVIDUAL DISEASE OUTCOMES AND THE INTRODUCTION OF EFFECTIVE, TARGET-DIRECTED, AND TOLERABLE THERAPIES. HERE, WE SUMMARIZE RECENT FINDINGS THAT SIGNIFY THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN AUTOIMMUNE/INFLAMMATORY DISORDERS ALONG THE INFLAMMATORY SPECTRUM CHOOSING THREE EXAMPLES: THE AUTOINFLAMMATORY BONE CONDITION CHRONIC NONBACTERIAL OSTEOMYELITIS (CNO), THE "MIXED PATTERN" DISORDER PSORIASIS, AND THE AUTOIMMUNE DISEASE SYSTEMIC LUPUS ERYTHEMATOSUS (SLE). 2019 13 4872 40 OUTSIDE-IN HYPOTHESIS REVISITED: THE ROLE OF MICROBIAL, EPITHELIAL, AND IMMUNE INTERACTIONS. OBJECTIVE: OUR UNDERSTANDING OF THE ORIGIN OF ALLERGIC DISEASES HAS INCREASED IN RECENT YEARS, HIGHLIGHTING THE IMPORTANCE OF MICROBIAL DYSBIOSIS AND EPITHELIAL BARRIER DYSFUNCTION IN AFFECTED TISSUES. EXPLORING THE MICROBIAL-EPITHELIAL-IMMUNE CROSSTALK UNDERLYING THE MECHANISMS OF ALLERGIC DISEASES WILL ALLOW THE DEVELOPMENT OF NOVEL PREVENTION AND TREATMENT STRATEGIES FOR ALLERGIC DISEASES. DATA SOURCES: THIS REVIEW SUMMARIZES THE RECENT ADVANCES IN MICROBIAL, EPITHELIAL, AND IMMUNE INTERACTIONS IN ATOPIC DERMATITIS, ALLERGIC RHINITIS, CHRONIC RHINOSINUSITIS, AND ASTHMA. STUDY SELECTIONS: WE PERFORMED A LITERATURE SEARCH, IDENTIFYING RELEVANT RECENT PRIMARY ARTICLES AND REVIEW ARTICLES. RESULTS: DYNAMIC CROSSTALK BETWEEN THE ENVIRONMENTAL FACTORS AND MICROBIAL, EPITHELIAL, AND IMMUNE CELLS IN THE DEVELOPMENT OF ATOPIC DERMATITIS, ALLERGIC RHINITIS, CHRONIC RHINOSINUSITIS, AND ASTHMA UNDERLIES THE PATHOGENESIS OF THESE DISEASES. THERE IS SUBSTANTIAL EVIDENCE IN THE LITERATURE SUGGESTING THAT ENVIRONMENTAL FACTORS DIRECTLY AFFECT BARRIER FUNCTION OF THE EPITHELIUM. IN ADDITION, T-HELPER 2 (T(H)2) CELLS, TYPE 2 INNATE LYMPHOID CELLS, AND THEIR CYTOKINE INTERLEUKIN 13 (IL-13) DAMAGE SKIN AND LUNG BARRIERS. THE EFFECTS OF ENVIRONMENTAL FACTORS MAY AT LEAST IN PART BE MEDIATED BY EPIGENETIC MECHANISMS. HISTONE DEACETYLASE ACTIVATION BY TYPE 2 IMMUNE RESPONSE HAS A MAJOR EFFECT ON LEAKY BARRIERS AND BLOCKING OF HISTONE DEACETYLASE ACTIVITY CORRECTS THE DEFECTIVE BARRIER IN HUMAN AIR-LIQUID INTERFACE CULTURES AND MOUSE MODELS OF ALLERGIC ASTHMA WITH RHINITIS. WE ALSO PRESENT AND DISCUSS A NOVEL DEVICE TO DETECT AND MONITOR SKIN BARRIER DYSFUNCTION, WHICH PROVIDES AN OPPORTUNITY TO RAPIDLY AND ROBUSTLY ASSESS DISEASE SEVERITY. CONCLUSION: A COMPLEX INTERPLAY BETWEEN ENVIRONMENTAL FACTORS, EPITHELIUM, AND THE IMMUNE SYSTEM IS INVOLVED IN THE DEVELOPMENT OF SYSTEMIC ALLERGIC DISEASES. 2020 14 2591 43 EPIGENETICS OF PSORIASIS. PSORIASIS IS A CHRONIC AND RECURRENT INFLAMMATORY SKIN DISEASE, INVOLVING THE RAPID PROLIFERATION AND ABNORMAL DIFFERENTIATION OF KERATINOCYTES AND ACTIVATION OF T CELLS. IT IS GENERALLY ACCEPTED THAT THE CENTRAL PATHOGENESIS OF PSORIASIS IS A T CELL-DOMINANT IMMUNE DISORDER AFFECTED BY MULTIPLE FACTORS INCLUDING GENETIC SUSCEPTIBILITY, ENVIRONMENTAL FACTORS, INNATE AND ADAPTIVE IMMUNE RESPONSES, ETC. HOWEVER, THE EXACT ETIOLOGY IS LARGELY UNKNOWN. IN RECENT YEARS, EPIGENETIC INVOLVEMENTS, SUCH AS THE DNA METHYLATION, CHROMATIN MODIFICATIONS, AND NONCODING RNA REGULATION ARE REPORTED TO BE CRITICAL FOR THE PATHOGENESIS OF PSORIASIS. HOWEVER, THE INTERPLAY BETWEEN THESE FACTORS HAS ONLY RECENTLY BEEN STARTED TO BE UNRAVELED. NOTABLY, INHIBITORS OF ENZYMES THAT WORK IN EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLTRANSFERASES AND HISTONE DEACETYLASES, ARE BEGINNING TO APPEAR IN THE CLINICAL SETTING TO RESTORE NORMAL EPIGENETIC PATTERNS (GENERALI ET AL. IN J AUTOIMMUN 83:51-61, 2017), PROVIDING NOVEL THERAPEUTIC POTENTIAL AS NOVEL TREATMENT TARGETS FOR PSORIASIS. INDEED, MEDICATIONS PREVIOUSLY USED TO TREAT AUTOIMMUNE DISEASES HAVE LATER BEEN DISCOVERED TO EXERT THEIR ACTION VIA EPIGENETIC MECHANISMS. HEREIN, WE REVIEW THE FINDINGS ON EPIGENETICS ASSOCIATED WITH PSORIASIS, AND DISCUSS FUTURE PERSPECTIVES IN THIS FIELD. 2020 15 6255 26 THE MICROBIOTA AND EPIGENETIC REGULATION OF T HELPER 17/REGULATORY T CELLS: IN SEARCH OF A BALANCED IMMUNE SYSTEM. IMMUNE CELLS NOT ONLY AFFECT TISSUE HOMEOSTASIS AT THE SITE OF INFLAMMATION BUT ALSO EXERT SYSTEMIC EFFECTS CONTRIBUTING TO MULTIPLE CHRONIC CONDITIONS. RECENT EVIDENCE CLEARLY SUPPORTS AN ALTERED T HELPER 17/REGULATORY T CELL (TH17/TREG) BALANCE LEADING TO THE DEVELOPMENT AND PROGRESSION OF INFLAMMATORY DISEASES THAT NOT ONLY AFFECT THE GASTROINTESTINAL TRACT BUT ALSO HAVE WHOLE-BODY MANIFESTATIONS, INCLUDING INSULIN RESISTANCE. EPIGENETIC MECHANISMS ARE AMENABLE TO BOTH ENVIRONMENTAL AND CIRCULATING FACTORS AND CONTRIBUTE TO DETERMINING THE T CELL LANDSCAPE. THE RECENTLY IDENTIFIED PARTICIPATION OF THE GUT MICROBIOTA IN THE REMODELING OF THE EPIGENOME OF IMMUNE CELLS HAS TRIGGERED A PARADIGM SHIFT IN OUR UNDERSTANDING OF THE ETIOLOGY OF VARIOUS INFLAMMATORY DISEASES AND OPENED NEW PATHS TOWARD THERAPEUTIC STRATEGIES. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF THE CONTRIBUTION OF THE TH17/TREG BALANCE IN THE DEVELOPMENT AND PROGRESSION OF INFLAMMATORY BOWEL DISEASES AND METABOLIC DISEASES. WE DISCUSS THE INVOLVEMENT OF EPIGENETIC MECHANISMS IN THE REGULATION OF T CELL FUNCTION IN THE PARTICULAR CONTEXT OF DYSBIOSIS. FINALLY, WE EXAMINE THE POTENTIAL FOR NUTRITIONAL INTERVENTIONS AFFECTING THE GUT MICROBIOTA TO RESHAPE THE T CELL EPIGENOME AND ADDRESS THE INFLAMMATORY COMPONENT OF VARIOUS DISEASES. 2017 16 258 24 ADVANCES IN PATHOGENESIS AND NANOPARTICLES (NPS)-MEDIATED TREATMENT OF PSORIASIS. PSORIASIS IS A CHRONIC PAPULOSQUAMOUS SKIN DISEASE WITH AN AUTOIMMUNE PATHOGENIC TRAITS AND STRONG GENETIC PREDISPOSITION. IN THE PAST FEW DECADES, WITH THE RAPID DEVELOPMENT OF MOLECULAR BIOLOGY AND CELL BIOLOGY, THE INHERENT PATHOGENESIS OF PSORIASIS HAS BEEN GRADUALLY ELUCIDATED, IN WHICH CYTOKINE INFLAMMATORY LOOPS, CELL SIGNALING PATHWAYS, AND EPIGENETIC FACTORS SUCH AS MIRNAS HAVE BEEN DEMONSTRATED TO PLAY IMPORTANT ROLES IN REGULATING THE DEVELOPMENT AND PROGRESSION OF PSORIASIS. MORE IMPORTANTLY, UNDERSTANDING THE PATHOGENESIS OF PSORIASIS HAS PROMOTED THE DEVELOPMENT OF EFFECTIVE TREATMENT FOR PSORIASIS. IN THIS REVIEW, WE SYSTEMICALLY SUMMARIZED THE MOLECULAR MECHANISMS REGULATING THE DEVELOPMENT AND PROGRESSION PSORIASIS, INTRODUCED VARIOUS THERAPEUTICS USED FOR CLINICAL PSORIASIS THERAPY, AND HIGHLIGHTED THE RECENT ADVANCES IN NANOPARTICLES (NPS)-MEDIATED DRUG DELIVERY FOR PSORIASIS TREATMENT. 2022 17 1935 28 ENVIRONMENTAL RISK FACTORS AND EPIGENETIC ALTERNATIONS IN PSORIASIS. INTRODUCTION AND OBJECTIVE: PSORIASIS ISA QUITE COMMON, CHRONIC AND IMMUNE-MEDIATED SKIN DISORDER. THE PREVALENCE OF PSORIASIS DIFFERS IN VARIOUS COUNTRIES, BUT IT IS SAID TO AFFECT 2% OF THE WORLD'S POPULATION IN GENERAL. PSORIASIS HAS MANY DIFFERENT CLINICAL FEATURES BUT ALL LESIONS HAVE THE SAME CHARACTERISTIC: ERYTHEMA, THICKENING AND SCALE, ALTHOUGH OTHER CLINICAL FEATURES ARE ALSO CONNECTED, SUCH AS PSORIATIC ARTHRITIS, OBESITY AND METABOLIC SYNDROME. ALL OF THESE MAY LEAD TO CONDITIONS IMPAIRING THE QUALITY OF LIFE. THIS REVIEW IS AN ATTEMPT TO SUMMARIZE RECENT DATA REGARDING ENVIRONMENTAL FACTORS, TOGETHER WITH EPIGENETIC MARKERS AND PROCESSES PLAYING AN IMPORTANT ROLE IN PSORIASIS. STATE OF KNOWLEDGE: MANY DIFFERENT ENVIRONMENTAL FACTORS PLAY A ROLE IN GENETICALLY PREDISPOSED PATIENTS. THIS IS CAUSES EPIGENETIC ALTERNATIONS WHICH MAY BE A LINKING PART IN THE WHOLE PROCESS. MANY STUDIES HAVE INDICATED A CONNECTION BETWEEN PSORIASIS AND VARIOUS GENES AND ANTIGENS. THE PRESENCE OF HLA-CW6 IS COMMON AS WELL A STRONG LINK BETWEEN ITS PRESENCE AND THE ONSET OF PSORIASIS BEING OBSERVED. THE MAIN ALTERNATIONS ARE DNA METHYLATION, HISTONE'S MODIFICATIONS AND THE ROLE OF MICRORNA. EXCESSIVE REACTION IS USUALLY NOT PRESENT WITHOUT A TRIGGERING FACTOR. ENVIRONMENTAL FACTORS ARE MOSTLY RATED, SUCH AS DRUGS, LIFE STYLE AND HABITS (SMOKING, ALCOHOL), DIET, PHYSICAL TRAUMA (SKIN INJURY PROVOKING KOEBNER PHENOMENON), STRESS, MICROORGANISM AND INFECTIONS. CONCLUSIONS: THE CORRELATION BETWEEN PATHOGENESIS OF PSORIASIS AND ENVIRONMENTAL RISK FACTORS, TOGETHER WITH EPIGENETIC ALTERNATIONS STILL REQUIRE MORE INVESTIGATION. EDUCATION ABOUT DIET HABITS, NUTRITION, WEIGHT LOSS AND HEALTHY LIFESTYLE SEEMS TO BE IMPORTANT DURING THE TREATMENT OF PSORIASIS. 2020 18 4318 33 MICRORNAS IN ANKYLOSING SPONDYLITIS: FUNCTION, POTENTIAL AND CHALLENGES. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNA, ARE CONSIDERED THE ESSENTIAL CONNECTION BETWEEN A DISORDER'S ONSET AND THE ENVIRONMENT, ON A PERMISSIVE GENETIC BACKGROUND. AMONG AUTOIMMUNE AND INFLAMMATORY-MEDIATED DISORDERS, ANKYLOSING SPONDYLITIS (AS), A CHRONIC ARTHRITIS OF THE SPINE, IS A VERY GOOD EXAMPLE FOR THE WEIGHT OF EPIGENETICS' CONTRIBUTION. MICRORNAS (MIRNAS) ARE SINGLE-STRANDED NUCLEOTIDES WHICH REGULATE GENE EXPRESSION AND ARE INVOLVED IN PATHOLOGICAL AND PHYSIOLOGICAL PROCESSES. IN THIS MANUSCRIPT WE PROVIDE A CLARIFICATION ON THE ROLE OF MICRORNAS IN AS, WITH A FOCUS ON THE MECHANISMS OF PATHOGENESIS. IN SPECIFIC, WE HAVE EXAMINED THE CONTRIBUTION OF MIRNAS IN THE PROCESSES OF INFLAMMATION, NEW BONE FORMATION AND T-CELL FUNCTION, AND THE PATHWAYS (I.E. WNT, BMP, TGFBETA SIGNALLING ETC.) THEY REGULATE. THE UTILITY OF MIRNAS IN BETTER UNDERSTANDING AS PATHOGENESIS IS UNDISPUTED AND THEIR UTILITY AS THERAPEUTIC OPPORTUNITY IS STRONGLY INCREASING. 2020 19 395 31 AN UPDATE ON EPIGENETIC REGULATION IN AUTOIMMUNE DISEASES. AUTOIMMUNE DISEASES (AIDS) GENERALLY MANIFEST AS CHRONIC IMMUNE DISORDERS CHARACTERIZED BY SIGNIFICANT HETEROGENEITY AND COMPLEX SYMPTOMS. THE DISCORDANT INCIDENCE OF AIDS BETWEEN MONOZYGOTIC TWINS GUIDED PEOPLE TO ATTACH IMPORTANCE TO ENVIRONMENTAL FACTORS. EPIGENETICS IS ONE OF THE MAJOR WAYS TO BE INFLUENCED, SOME OF THEM CAN EVEN OCCUR YEARS BEFORE CLINICAL DIAGNOSIS. WITH THE ADVENT OF HIGH-THROUGHPUT OMICS TIMES, THE MYSTERIOUS VEIL OF EPIGENETIC MODIFICATION IN AIDS HAS BEEN GRADUALLY UNRAVELED, AND SOME PROGRESS HAS BEEN MADE IN UTILIZING IT AS INDICATORS OF DIAGNOSIS AND DISEASE ACTIVITY. FOR EXAMPLE, THE HYPOMETHYLATED IFI44L PROMOTER IN DIAGNOSING SYSTEMATIC LUPUS ERYTHEMATOSUS (SLE). MORE RECENTLY, NEWLY IDENTIFIED NONCODING RNAS (NCRNAS), INCLUDING LONG NONCODING RNAS (LNCRNAS) AND CIRCULAR RNAS (CIRCRNAS), ARE ALSO BELIEVED TO BE INVOLVED IN THE ETIOLOGY OF AIDS WHILE THE INITIAL FACTOR BEHIND THOSE EPIGENETIC ALTERATIONS CAN BE DIVERSE FROM METABOLISM TO MICROBIOTA. UPDATE AND COMPREHENSIVE INSIGHTS INTO EPIGENETICS IN AIDS CAN HELP US UNDERSTAND THE PATHOGENESIS AND FURTHER ORCHESTRATE IT TO BENEFIT PATIENTS IN THE FUTURE. THEREFORE, WE REVIEWED THE LATEST EPIGENETIC FINDINGS IN SLE, RHEUMATOID ARTHRITIS (RA), TYPE 1 DIABETES (T1D), SYSTEMIC SCLEROSIS (SSC) PRIMARILY FROM CELLULAR LEVELS. 2022 20 541 40 ATOPIC DERMATITIS: THE FATE OF THE FAT. ATOPIC DERMATITIS (AD) IS A CHRONIC AND RELAPSING INFLAMMATORY SKIN DISEASE IN WHICH DRY AND ITCHY SKIN MAY DEVELOP INTO SKIN LESIONS. AD HAS A STRONG GENETIC COMPONENT, AS CHILDREN FROM PARENTS WITH AD HAVE A TWO-FOLD INCREASED CHANCE OF DEVELOPING THE DISEASE. GENETIC RISK LOCI AND EPIGENETIC MODIFICATIONS REPORTED IN AD MAINLY LOCATE TO GENES INVOLVED IN THE IMMUNE RESPONSE AND EPIDERMAL BARRIER FUNCTION. HOWEVER, AD PATHOGENESIS CANNOT BE FULLY EXPLAINED BY (EPI)GENETIC FACTORS SINCE ENVIRONMENTAL TRIGGERS SUCH AS STRESS, POLLUTION, MICROBIOTA, CLIMATE, AND ALLERGENS ALSO PLAY A CRUCIAL ROLE. ALTERATIONS OF THE EPIDERMAL BARRIER IN AD, OBSERVED AT ALL STAGES OF THE DISEASE AND WHICH PRECEDE THE DEVELOPMENT OF OVERT SKIN INFLAMMATION, MANIFEST AS: DRY SKIN; EPIDERMAL ULTRASTRUCTURAL ABNORMALITIES, NOTABLY ANOMALIES OF THE LAMELLAR BODY CARGO SYSTEM; AND ABNORMAL EPIDERMAL LIPID COMPOSITION, INCLUDING SHORTER FATTY ACID MOIETIES IN SEVERAL LIPID CLASSES, SUCH AS CERAMIDES AND FREE FATTY ACIDS. THUS, A COMPELLING QUESTION IS WHETHER AD IS PRIMARILY A LIPID DISORDER EVOLVING INTO A CHRONIC INFLAMMATORY DISEASE DUE TO GENETIC SUSCEPTIBILITY LOCI IN IMMUNOGENIC GENES. IN THIS REVIEW, WE FOCUS ON LIPID ABNORMALITIES OBSERVED IN THE EPIDERMIS AND BLOOD OF AD PATIENTS AND EVALUATE THEIR PRIMARY ROLE IN ELICITING AN INFLAMMATORY RESPONSE. 2022