1 4287 125 MICRORNA EXPRESSION PROFILING IN BEHCET'S DISEASE. BACKGROUND: BEHCET'S DISEASE (BD) IS A CHRONIC INFLAMMATORY MULTISYSTEM DISEASE CHARACTERIZED BY ORAL AND GENITAL ULCERS, UVEITIS, AND SKIN LESIONS. MICRORNAS (MIRNAS) ARE KEY REGULATORS OF IMMUNE RESPONSES. DIFFERENTIAL EXPRESSION OF MIRNAS HAS BEEN REPORTED IN SEVERAL INFLAMMATORY AUTOIMMUNE DISEASES; HOWEVER, THEIR ROLE IN BD IS NOT FULLY ELUCIDATED. WE AIMED TO IDENTIFY MIRNA EXPRESSION SIGNATURES ASSOCIATED WITH BD AND TO INVESTIGATE THEIR POTENTIAL IMPLICATION IN THE DISEASE PATHOGENESIS. METHODS: MIRNA MICROARRAY ANALYSIS WAS PERFORMED IN BLOOD CELLS OF BD PATIENTS AND HEALTHY CONTROLS. MIRNA EXPRESSION PROFILES WERE ANALYZED USING AFFYMETRIX ARRAYS WITH A COMPREHENSIVE COVERAGE OF MIRNA SEQUENCES. PATHWAY ANALYSES WERE PERFORMED, AND THE GLOBAL MIRNA PROFILING WAS COMBINED WITH TRANSCRIPTOMA DATA IN BD. DEREGULATION OF SELECTED MIRNAS WAS VALIDATED BY REAL-TIME PCR. RESULTS: WE IDENTIFIED SPECIFIC MIRNA SIGNATURES ASSOCIATED WITH BD PATIENTS WITH ACTIVE DISEASE. THESE MIRNAS TARGET PATHWAYS RELEVANT IN BD, SUCH AS TNF, IFN GAMMA, AND VEGF-VEGFR SIGNALING CASCADES. NETWORK ANALYSIS REVEALED SEVERAL MIRNAS REGULATING HIGHLY CONNECTED GENES WITHIN THE BD TRANSCRIPTOMA. CONCLUSIONS: THE COMBINED ANALYSIS OF DEREGULATED MIRNAS AND BD TRANSCRIPTOME SHEDS LIGHT ON SOME EPIGENETIC ASPECTS OF BD IDENTIFYING SPECIFIC MIRNAS, WHICH MAY REPRESENT PROMISING CANDIDATES AS BIOMARKERS AND/OR FOR THE DESIGN OF NOVEL THERAPEUTIC STRATEGIES IN BD. 2018 2 2909 48 GENE EXPRESSION PROFILING IN FIBROMYALGIA INDICATES AN AUTOIMMUNE ORIGIN OF THE DISEASE AND OPENS NEW AVENUES FOR TARGETED THERAPY. FIBROMYALGIA IS A CHRONIC DISORDER CHARACTERIZED BY WIDESPREAD PAIN AND BY SEVERAL NON-PAIN SYMPTOMS. AUTOIMMUNITY, SMALL FIBER NEUROPATHY AND NEUROINFLAMMATION HAVE BEEN SUGGESTED TO BE INVOLVED IN THE PATHOGENESIS OF THE DISEASE. WE HAVE INVESTIGATED THE GENE EXPRESSION PROFILE IN PERIPHERAL BLOOD MONONUCLEAR CELLS OBTAINED FROM TEN PATIENTS AND TEN HEALTHY SUBJECTS. OF THE 545,500 TRANSCRIPTS ANALYZED, 1673 RESULTED MODULATED IN FIBROMYALGIC PATIENTS. THE MAJORITY OF THESE GENES ARE INVOLVED IN BIOLOGICAL PROCESSES AND PATHWAYS LINKED TO THE CLINICAL MANIFESTATIONS OF THE DISEASE. MOREOVER, GENES INVOLVED IN IMMUNOLOGICAL PATHWAYS CONNECTED TO INTERLEUKIN-17 AND TO TYPE I INTERFERON SIGNATURES WERE ALSO MODULATED, SUGGESTING THAT AUTOIMMUNITY PLAYS A ROLE IN THE DISEASE. WE THEN AIMED AT IDENTIFYING DIFFERENTIALLY EXPRESSED LONG NON-CODING RNAS (LNCRNAS) FUNCTIONALLY CONNECTED TO MODULATED GENES BOTH DIRECTLY AND VIA MICRORNA TARGETING. ONLY TWO LNCRNAS OF THE 298 FOUND MODULATED IN PATIENTS, WERE ABLE TO TARGET THE MOST HIGHLY CONNECTED GENES IN THE FIBROMYALGIA INTERACTOME, SUGGESTING THEIR INVOLVEMENT IN CRUCIAL GENE REGULATION. OUR GENE EXPRESSION DATA WERE CONFIRMED BY REAL TIME PCR, BY AUTOANTIBODY TESTING, DETECTION OF SOLUBLE MEDIATORS AND TH-17 POLARIZATION IN A VALIDATION COHORT OF 50 PATIENTS. OUR RESULTS INDICATE THAT GENETIC AND EPIGENETIC MECHANISMS AS WELL AS AUTOIMMUNITY PLAY A PIVOTAL ROLE IN THE PATHOGENESIS OF FIBROMYALGIA. 2020 3 3026 36 GENETICS OF BEHCET'S DISEASE: FUNCTIONAL GENETIC ANALYSIS AND ESTIMATING DISEASE HERITABILITY. BEHCET'S DISEASE IS A CHRONIC MULTISYSTEMIC INFLAMMATORY DISORDER CHARACTERIZED BY RECURRENT ORAL AND GENITAL ULCERS. ALTHOUGH ITS ETIOLOGY REMAINS UNCLEAR, IT IS THOUGHT THAT BOTH GENETIC AND ENVIRONMENTAL FACTORS CONTRIBUTE TO THE ONSET AND PROGRESSION OF BEHCET'S DISEASE. HERE, WE PROVIDE AN UPDATED VIEW OF THE GENETIC LANDSCAPE AND ARCHITECTURE OF BEHCET'S DISEASE. LARGE-SCALE GENETIC STUDIES PERFORMED TO DATE REVEALED 21 GENETIC SUSCEPTIBILITY LOCI ASSOCIATED WITH THE DISEASE AT A GWAS LEVEL OF SIGNIFICANCE (P-VALUE = 5 X 10(-8)). WE PERFORMED EPIGENETIC PATTERN ENRICHMENT ANALYSIS IN BEHCET'S DISEASE ASSOCIATED LOCI, PROVIDING NEW INSIGHTS INTO THE MOLECULAR MECHANISMS UNDERLYING ITS PATHOPHYSIOLOGY. OUR DATA SUGGEST THE CRUCIAL INVOLVEMENT OF SEVERAL IMMUNE CELL TYPES, INCLUDING NATURAL KILLER CELLS, MONOCYTES, AND B CELLS IN THE PATHOGENESIS OF THE DISEASE. PATHWAY ENRICHMENT ANALYSIS IDENTIFIED IMPORTANT BIOLOGICAL PROCESSES INVOLVED. USING LARGE-SCALE GENETIC DATA AVAILABLE FROM ~200 IMMUNE-RELATED LOCI (IMMUNOCHIP), WE ESTIMATE BEHCET'S DISEASE HERITABILITY TO BE AT LEAST 16%. WE FURTHER USED THE SAME APPROACH TO ESTIMATE THE HERITABILITY EXPLAINED BY THE KNOWN BEHCET'S DISEASE-ASSOCIATED LOCI, SUGGESTING THAT THEY EXPLAIN ~ 60% OF THE GENETIC COMPONENT UNDERLYING BEHCET'S DISEASE. THESE RESULTS INDICATE A SIGNIFICANT ROLE OF NON-GENETIC FACTORS IN CAUSING BEHCET'S DISEASE AND THAT ADDITIONAL GENETIC VARIATION INFLUENCING THE RISK OF BEHCET'S DISEASE REMAINS TO BE IDENTIFIED. FINALLY, WE CALCULATED A CUMULATIVE GENETIC RISK SCORE ACROSS POPULATIONS REINFORCING THE LINK BETWEEN GEOGRAPHIC VARIATIONS IN DISEASE PREVALENCE WITH ITS GENETIC COMPONENT. 2021 4 3023 37 GENETICS AND IMMUNODYSFUNCTION UNDERLYING BEHCET'S DISEASE AND IMMUNOMODULANT TREATMENT APPROACHES. BEHCET'S DISEASE (BD) IS A CHRONIC AUTOIMMUNE CONDITION PRIMARILY PREVALENT IN POPULATIONS ALONG THE MEDITERRANEAN SEA. THE EXACT ETIOLOGY OF BD HAS NOT BEEN FULLY EXPLAINED YET, BUT THE DISEASE OCCURRENCE IS ASSOCIATED WITH A GENETIC FACTOR, HUMAN LEUKOCYTE ANTIGEN (HLA)-B51 ANTIGEN. AMONG THE VARIOUS IMMUNODYSFUNCTIONS THAT ARE FOUND IN BD, PATIENTS ARE INCREASED NEUTROPHIL MOTILITY AND SUPEROXIDE PRODUCTION, AS WELL AS ELEVATED PRODUCTION OF TUMOR NECROSIS FACTOR (TNF)-ALPHA AND DECREASED PRODUCTION OF INTERLEUKIN (IL)-10. ELEVATED LEVELS OF INFLAMMATORY CYTOKINES LIKE IL-1 AND IL-17 IN BD HAVE BEEN FOUND ASSOCIATED WITH ABERRANT EXPRESSION OF MICRORNA. GENE POLYMORPHISMS IN BD PATIENTS HAVE BEEN OBSERVED IN MOLECULES INVOLVED IN RESPONSES TO PATHOGENS THAT CAN ULTIMATELY MODULATE THE HOST ANTIMICROBIAL RESPONSE. MOREOVER, SEVERAL SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) HAVE BEEN REPORTED IN GENES ENCODING CHEMOKINES AND ADHESION MOLECULES; MANY OF THESE CHANGES MANIFEST AS INCREASES IN VASCULAR INFLAMMATION AND VASCULAR DAMAGE. LASTLY, GENETIC AND EPIGENETIC CHANGES HAVE BEEN SUGGESTED AS INVOLVED IN THE PATHOGENESIS OF BD. MODIFICATIONS IN DNA METHYLATION HAVE BEEN FOUND IN BD PATIENT MONOCYTES AND LYMPHOCYTES, LEADING TO ADVERSE FUNCTION OF THESE CELLS. THIS REVIEW PRESENTS A COMPREHENSIVE COMPILATION OF THE LITERATURE WITH REGARD TO THE IMMUNODYSFUNCTION UNDERLYING BD, AS WELL AS OF THE GENETICS, NEWLY DESCRIBED CLINICAL SPECIFICATIONS AND NOVEL TREATMENT STRATEGIES USING IMMUNOMODULANTS BASED ON THE CURRENT UNDERSTANDING OF BD. 2017 5 3503 33 IDENTIFICATION OF POTENTIAL DIFFERENTIALLY METHYLATED GENE-RELATED BIOMARKERS IN ENDOMETRIOSIS. AIM: TO IDENTIFY EPIGENETIC ALTERATIONS OF DIFFERENTIALLY EXPRESSED GENES AND SCREEN OUT TARGETED THERAPEUTIC DRUGS IN ENDOMETRIOSIS. METHODS: BASED ON THE GENE EXPRESSION OMNIBUS DATABASE AND A SERIES OF BIOLOGICAL INFORMATION ANALYSIS TOOLS, SUPPLEMENTED BY VALIDATION OF CLINICAL SAMPLES, ABERRANT DNA METHYLATION-DRIVEN GENES AND THEIR FUNCTIONS WERE EXPLORED, AS WELL AS POSSIBLE TARGETED DRUGS. RESULTS: THIS STUDY SCREENED OUT A RANGE OF DNA METHYLATION-DRIVEN GENES THAT WERE ASSOCIATED WITH POWERFUL PROPERTIES AND CORRESPONDING PATHWAYS. AMONG THEM, BDNF AND CCL2 WERE KEY GENES IN THE DEVELOPMENT OF ENDOMETRIOSIS. FOUR CHEMICAL AGENTS HAVE BEEN FLAGGED AS POTENTIAL TREATMENTS FOR ENDOMETRIOSIS. CONCLUSION: THESE CANDIDATE GENES AND SMALL-MOLECULE AGENTS MAY BE FURTHER EXPLORED AS POTENTIAL TARGETS AND DRUGS FOR ENDOMETRIOSIS DIAGNOSIS AND THERAPY, RESPECTIVELY. 2022 6 1508 49 DNA METHYLATION AND MRNA AND MICRORNA EXPRESSION OF SLE CD4+ T CELLS CORRELATE WITH DISEASE PHENOTYPE. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS AN AUTOIMMUNE DISEASE WELL KNOWN FOR ITS CLINICAL HETEROGENEITY, AND ITS ETIOLOGY SECONDARY TO A CROSS-TALK INVOLVING GENETIC PREDISPOSITION AND ENVIRONMENTAL STIMULI. ALTHOUGH GENOME-WIDE ANALYSIS HAS CONTRIBUTED GREATLY TO OUR UNDERSTANDING OF THE GENETIC BASIS OF SLE, THERE IS INCREASING EVIDENCE FOR A ROLE OF EPIGENETICS. INDEED, RECENT DATA HAVE DEMONSTRATED THAT IN PATIENTS WITH SLE, THERE ARE STRIKING ALTERATIONS OF DNA METHYLATION, HISTONE MODIFICATIONS, AND DEREGULATED MICRORNA EXPRESSION, THE SUM OF WHICH CONTRIBUTE TO OVER-EXPRESSION OF SELECT AUTOIMMUNE-RELATED GENES AND LOSS OF TOLERANCE. TO ADDRESS THIS ISSUE AT THE LEVEL OF CLINICAL PHENOTYPE, WE PERFORMED DNA METHYLATION, MRNA AND MICRORNA EXPRESSION SCREENING USING HIGH-THROUGHPUT SEQUENCING OF PURIFIED CD4+ T CELLS FROM PATIENTS WITH SLE, COMPARED TO AGE AND SEX MATCHED CONTROLS. IN PARTICULAR, WE STUDIED 42 PATIENTS WITH SLE AND DIVIDED THIS GROUP INTO THREE CLINICAL PHENOTYPES: A) THE PRESENCE OF SKIN LESIONS WITHOUT SIGNS OF SYSTEMIC PATHOLOGY; B) SKIN LESIONS BUT ALSO CHRONIC RENAL PATHOLOGY; AND C) SKIN LESIONS, CHRONIC RENAL PATHOLOGY AND POLYARTICULAR DISEASE. INTERESTINGLY, AND AS EXPECTED, SEQUENCING DATA REVEALED CHANGES IN DNA METHYLATION IN SLE COMPARED TO CONTROLS. HOWEVER, AND MORE IMPORTANTLY, ALTHOUGH THERE WERE COMMON METHYLATION CHANGES FOUND IN ALL GROUPS OF SLE COMPARED TO CONTROLS, THERE WAS SPECIFIC DNA METHYLATION CHANGES THAT CORRELATED WITH CLINICAL PHENOTYPE. THESE INCLUDED CHANGES IN THE NOVEL KEY TARGET GENES NLRP2, CD300LB AND S1PR3, AS WELL AS CHANGES IN THE CRITICAL PATHWAYS, INCLUDING THE ADHERENS JUNCTION AND LEUKOCYTE TRANSENDOTHELIAL MIGRATION. WE ALSO NOTED THAT A SIGNIFICANT PROPORTION OF GENES UNDERGOING DNA METHYLATION CHANGES WERE INVERSELY CORRELATED WITH GENE EXPRESSION AND THAT MIRNA SCREENING REVEALED THE EXISTENCE OF SUBSETS WITH CHANGES IN EXPRESSION. INTEGRATED ANALYSIS OF THIS DATA HIGHLIGHTS SPECIFIC SETS OF MIRNAS CONTROLLED BY DNA METHYLATION, AND GENES THAT ARE ALTERED BY METHYLATION AND TARGETED BY MIRNAS. IN CONCLUSION, OUR FINDINGS SUGGEST SELECT EPIGENETIC MECHANISMS THAT CONTRIBUTE TO CLINICAL PHENOTYPES AND FURTHER SHED LIGHT ON A NEW VENUE FOR BASIC SLE RESEARCH. 2014 7 3765 43 INTEGRATIVE ANALYSIS OF TRANSCRIPTOMIC AND PROTEOMIC PROFILING IN INFLAMMATORY BOWEL DISEASE COLON BIOPSIES. BACKGROUND: CROHN'S DISEASE (CD) AND ULCERATIVE COLITIS (UC) ARE INTESTINAL CHRONIC INFLAMMATORY CONDITIONS CHARACTERIZED BY ALTERED EPITHELIAL BARRIER FUNCTION AND TISSUE DAMAGE. DESPITE SIGNIFICANT EFFORTS TO UNDERSTANDING THE BIOLOGICAL MECHANISMS RESPONSIBLE FOR GUT INFLAMMATION, THE PATHOPHYSIOLOGY OF CD AND UC REMAINS POORLY UNDERSTOOD. METHODS: TO HELP ELUCIDATE THE POTENTIAL MECHANISMS RESPONSIBLE FOR GUT INFLAMMATION IN CD AND UC, TRANSCRIPTOMIC AND PROTEOMIC PROFILING OF HUMAN COLON BIOPSY SPECIMENS WAS PERFORMED. DYSREGULATED GENES AND PROTEINS IN DISEASE TISSUES COMPARED WITH NORMAL TISSUES WERE CHARACTERIZED FROM THE EXPRESSION PROFILES AND FURTHER SUBJECTED TO PATHWAY ANALYSIS TO IDENTIFY ALTERED BIOLOGICAL PROCESSES AND SIGNALING PATHWAYS. RESULTS: SAMPLE ANALYSIS SHOWED 4250 GENES WITH MATCHED PROTEIN EXPRESSION AND A WIDE RANGE OF CORRELATION OF RNA-PROTEIN ABUNDANCE ACROSS SAMPLES. PATHWAY ANALYSIS OF DYSREGULATED GENES AND PROTEINS IN CD AND UC SHOWED ALTERATIONS IN IMMUNE AND INFLAMMATORY RESPONSES, COMPLEMENT CASCADE, AND THE SUPPRESSION OF METABOLIC PROCESSES AND PPAR SIGNALING. IN CD, INCREASED T-HELPER CELL DIFFERENTIATION AND ELEVATED TOLL-LIKE RECEPTOR AND JAK/STAT SIGNALING WERE OBSERVED. INTERESTINGLY, INCREASED MAPK SIGNALING WAS ONLY OBSERVED IN UC. WEIGHTED GENE CO-EXPRESSION NETWORK ANALYSIS SUGGESTED A POSSIBLE ROLE OF EPIGENETIC REGULATION IN UC. OF NOTE, A LARGE DISCREPANCY BETWEEN REGULATION OF RNA AND PROTEIN LEVELS IN INFLAMED COLON SAMPLES WAS DETECTED FOR PREVIOUSLY IDENTIFIED BIOMARKERS INCLUDING MMP14 AND LAMP1. CONCLUSIONS: WITH THE ANALYSIS OF DYSREGULATED GENES AND PATHWAYS, THE PRESENT STUDY UNRAVELS KEY MECHANISMS CONTRIBUTING TO CD AND UC PATHOGENESIS AND EMPHASIZES THAT INTEGRATIVE ANALYSIS OF MULTI-OMICS DATA SETS CAN PROVIDE MORE INSIGHT INTO UNDERSTANDING COMPLEX DISEASE MECHANISMS. 2019 8 2920 38 GENE-SET ANALYSIS IS SEVERELY BIASED WHEN APPLIED TO GENOME-WIDE METHYLATION DATA. MOTIVATION: DNA METHYLATION IS AN EPIGENETIC MARK THAT CAN STABLY REPRESS GENE EXPRESSION. BECAUSE OF ITS BIOLOGICAL AND CLINICAL SIGNIFICANCE, SEVERAL METHODS HAVE BEEN DEVELOPED TO COMPARE GENOME-WIDE PATTERNS OF METHYLATION BETWEEN GROUPS OF SAMPLES. THE APPLICATION OF GENE SET ANALYSIS TO IDENTIFY RELEVANT GROUPS OF GENES THAT ARE ENRICHED FOR DIFFERENTIALLY METHYLATED GENES IS OFTEN A MAJOR COMPONENT OF THE ANALYSIS OF THESE DATA. THIS CAN BE USED, FOR EXAMPLE, TO IDENTIFY PROCESSES OR PATHWAYS THAT ARE PERTURBED IN DISEASE DEVELOPMENT. WE SHOW THAT GENE-SET ANALYSIS, AS IT IS TYPICALLY APPLIED TO GENOME-WIDE METHYLATION ASSAYS, IS SEVERELY BIASED AS A RESULT OF DIFFERENCES IN THE NUMBERS OF CPG SITES ASSOCIATED WITH DIFFERENT CLASSES OF GENES AND GENE PROMOTERS. RESULTS: WE DEMONSTRATE THIS BIAS USING PUBLISHED DATA FROM A STUDY OF DIFFERENTIAL CPG ISLAND METHYLATION IN LUNG CANCER AND A DATASET WE GENERATED TO STUDY METHYLATION CHANGES IN PATIENTS WITH LONG-STANDING ULCERATIVE COLITIS. WE SHOW THAT SEVERAL OF THE GENE SETS THAT SEEM ENRICHED WOULD ALSO BE IDENTIFIED WITH RANDOMIZED DATA. WE SUGGEST TWO EXISTING APPROACHES THAT CAN BE ADAPTED TO CORRECT THE BIAS. ACCOUNTING FOR THE BIAS IN THE LUNG CANCER AND ULCERATIVE COLITIS DATASETS PROVIDES NOVEL BIOLOGICAL INSIGHTS INTO THE ROLE OF METHYLATION IN CANCER DEVELOPMENT AND CHRONIC INFLAMMATION, RESPECTIVELY. OUR RESULTS HAVE SIGNIFICANT IMPLICATIONS FOR MANY PREVIOUS GENOME-WIDE METHYLATION STUDIES THAT HAVE DRAWN CONCLUSIONS ON THE BASIS OF SUCH STRONGLY BIASED ANALYSIS. CONTACT: CATHAL.SEOIGHE@NUIGALWAY.IE SUPPLEMENTARY INFORMATION: SUPPLEMENTARY DATA ARE AVAILABLE AT BIOINFORMATICS ONLINE. 2013 9 1131 44 COMPREHENSIVE CIRCULAR RNA EXPRESSION PROFILING WITH ASSOCIATED CERNA NETWORK REVEALS THEIR THERAPEUTIC POTENTIAL IN CHOLESTEATOMA. CHOLESTEATOMA IS A CHRONIC DISEASE THAT PATHOLOGICALLY DISPLAYS A BENIGN TUMOR WITH EXCESSIVE SQUAMOUS EPITHELIAL CELL PROLIFERATION IN THE MIDDLE EAR. CLINICALLY, HOWEVER, IT CAN MANIFEST MALIGNANT BEHAVIOR BY DESTROYING ADJACENT TISSUES AND ORGANS. ALTHOUGH PREVIOUS STUDIES HAVE DEMONSTRATED THAT THE PATHOGENESIS OF CHOLESTEATOMA IS CORRELATED WITH EPIGENETIC DYSREGULATION, THE EXACT MECHANISM REMAINS UNCLEAR. CIRCULAR RNAS (CIRCRNAS) HAVE BEEN REVEALED AS BEING ABUNDANTLY EXPRESSED IN VARIOUS ORGANISMS AND HAVE BEEN FOUND TO CONTRIBUTE TO THE REGULATION OF MANY DISEASES. TO DATE, NO REPORTS HAVE ELUCIDATED THEIR EXPRESSION PROFILES AND FUNCTIONS IN CHOLESTEATOMA. IN THE PRESENT STUDY, THE CIRCRNA EXPRESSION PROFILE IN CHOLESTEATOMA WAS EXPLORED FOR THE FIRST TIME BY USING MICROARRAY ANALYSIS. WE OBTAINED A TOTAL OF 355 SIGNIFICANTLY DIFFERENTIALLY EXPRESSED CIRCRNAS IN CHOLESTEATOMA, AMONG WHICH 101 WERE IDENTIFIED TO BE UPREGULATED AND 254 DOWNREGULATED. BY CONSTRUCTING CIRCRNA?LNCRNA?MIRNA?MRNA COMPETING ENDOGENOUS RNA (CERNA) NETWORK, IT WAS DISCOVERED THAT CIRCRNAS MAY FUNCTION AS CERNAS AND CONTRIBUTE TO THE FORMATION OF CHOLESTEATOMA. THESE RESULTS PROVIDE NOVEL INSIGHT INTO THE PATHOGENESIS OF CHOLESTEATOMA AND SUGGEST CIRCRNAS AS POTENTIAL PROMISING THERAPEUTIC TARGETS FOR CHOLESTEATOMA. 2020 10 1717 37 DYSREGULATED IMMUNE SYSTEM NETWORKS IN WAR VETERANS WITH PTSD IS AN OUTCOME OF ALTERED MIRNA EXPRESSION AND DNA METHYLATION. POST-TRAUMATIC STRESS DISORDER PATIENTS EXPERIENCE CHRONIC SYSTEMIC INFLAMMATION. HOWEVER, THE MOLECULAR PATHWAYS INVOLVED AND MECHANISMS REGULATING THE EXPRESSION OF GENES INVOLVED IN INFLAMMATORY PATHWAYS IN PTSD ARE REPORTED INADEQUATELY. THROUGH RNA SEQUENCING AND MIRNA MICROARRAY, WE IDENTIFIED 326 GENES AND 190 MIRNAS THAT WERE SIGNIFICANTLY DIFFERENT IN THEIR EXPRESSION LEVELS IN THE PBMCS OF PTSD PATIENTS. EXPRESSION PAIRING OF THE DIFFERENTIALLY EXPRESSED GENES AND MIRNAS INDICATED AN INVERSE RELATIONSHIP IN THEIR EXPRESSION. FUNCTIONAL ANALYSIS OF THE DIFFERENTIALLY EXPRESSED GENES INDICATED THEIR INVOLVEMENT IN THE CANONICAL PATHWAYS SPECIFIC TO IMMUNE SYSTEM BIOLOGY. DNA METHYLATION ANALYSIS OF DIFFERENTIALLY EXPRESSED GENES ALSO SHOWED A GRADUAL TREND TOWARDS DIFFERENCES BETWEEN CONTROL AND PTSD PATIENTS, AGAIN INDICATING A POSSIBLE ROLE OF THIS EPIGENETIC MECHANISM IN PTSD INFLAMMATION. OVERALL, COMBINING DATA FROM THE THREE TECHNIQUES PROVIDED A HOLISTIC VIEW OF SEVERAL PATHWAYS IN WHICH THE DIFFERENTIALLY EXPRESSED GENES WERE IMPACTED THROUGH EPIGENETIC MECHANISMS, IN PTSD. THUS, ANALYSIS COMBINING DATA FROM RNA-SEQ, MIRNA ARRAY AND DNA METHYLATION, CAN PROVIDE KEY EVIDENCE ABOUT DYSREGULATED PATHWAYS AND THE CONTROLLING MECHANISM IN PTSD. MOST IMPORTANTLY, THE PRESENT STUDY PROVIDES FURTHER EVIDENCE THAT INFLAMMATION IN PTSD COULD BE EPIGENETICALLY REGULATED. 2016 11 665 51 BLOOD TRANSCRIPTOMICS OF DRUG-NAIVE SPORADIC PARKINSON'S DISEASE PATIENTS. BACKGROUND: PARKINSON'S DISEASE (PD) IS A CHRONIC PROGRESSIVE NEURODEGENERATIVE DISORDER THAT IS CLINICALLY DEFINED IN TERMS OF MOTOR SYMPTOMS. THESE ARE PRECEDED BY PRODROMAL NON-MOTOR MANIFESTATIONS THAT PROVE THE SYSTEMIC NATURE OF THE DISEASE. IDENTIFYING GENES AND PATHWAYS ALTERED IN LIVING PATIENTS PROVIDE NEW INFORMATION ON THE DIAGNOSIS AND PATHOGENESIS OF SPORADIC PD. METHODS: CHANGES IN GENE EXPRESSION IN THE BLOOD OF 40 SPORADIC PD PATIENTS AND 20 HEALTHY CONTROLS ("DISCOVERY SET") WERE ANALYZED BY TAKING ADVANTAGE OF THE AFFYMETRIX PLATFORM. PATIENTS WERE AT THE ONSET OF MOTOR SYMPTOMS AND BEFORE INITIATING ANY PHARMACOLOGICAL TREATMENT. DATA ANALYSIS WAS PERFORMED BY APPLYING RANKING-PRINCIPAL COMPONENT ANALYSIS, PUMA AND SIGNIFICANCE ANALYSIS OF MICROARRAYS. FUNCTIONAL ANNOTATIONS WERE ASSIGNED USING GO, DAVID, GSEA TO UNVEIL SIGNIFICANT ENRICHED BIOLOGICAL PROCESSES IN THE DIFFERENTIALLY EXPRESSED GENES. THE EXPRESSIONS OF SELECTED GENES WERE VALIDATED USING RT-QPCR AND SAMPLES FROM AN INDEPENDENT COHORT OF 12 PATIENTS AND CONTROLS ("VALIDATION SET"). RESULTS: GENE EXPRESSION PROFILING OF BLOOD SAMPLES DISCRIMINATES PD PATIENTS FROM HEALTHY CONTROLS AND IDENTIFIES DIFFERENTIALLY EXPRESSED GENES IN BLOOD. THE MAJORITY OF THESE ARE ALSO PRESENT IN DOPAMINERGIC NEURONS OF THE SUBSTANTIA NIGRA, THE KEY SITE OF NEURODEGENERATION. TOGETHER WITH NEURONAL APOPTOSIS, LYMPHOCYTE ACTIVATION AND MITOCHONDRIAL DYSFUNCTION, ALREADY FOUND IN PREVIOUS ANALYSIS OF PD BLOOD AND POST-MORTEM BRAINS, WE UNVEILED TRANSCRIPTOME CHANGES ENRICHED IN BIOLOGICAL TERMS RELATED TO EPIGENETIC MODIFICATIONS INCLUDING CHROMATIN REMODELING AND METHYLATION. CANDIDATE TRANSCRIPTS AS CBX5, TCF3, MAN1C1 AND DOCK10 WERE VALIDATED BY RT-QPCR. CONCLUSIONS: OUR DATA SUPPORT THE USE OF BLOOD TRANSCRIPTOMICS TO STUDY NEURODEGENERATIVE DISEASES. IT IDENTIFIES CHANGES IN CRUCIAL COMPONENTS OF CHROMATIN REMODELING AND METHYLATION MACHINERIES AS EARLY EVENTS IN SPORADIC PD SUGGESTING EPIGENETICS AS TARGET FOR THERAPEUTIC INTERVENTION. 2015 12 1500 45 DNA METHYLATION ANALYSIS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE THAT IS CHARACTERIZED BY ABERRANT CROSS-TALK BETWEEN KERATINOCYTES AND IMMUNE CELLS SUCH AS CD4+ T CELLS, RESULTING IN KERATINOCYTE HYPERPROLIFERATION IN THE EPIDERMIS. DNA METHYLATION, ONE OF SEVERAL EPIGENETIC MECHANISMS, PLAYS AN IMPORTANT ROLE IN GENE EXPRESSION WITHOUT CHANGING THE DNA SEQUENCE. SEVERAL STUDIES HAVE SUGGESTED THE INVOLVEMENT OF EPIGENETIC REGULATION IN SKIN LESIONS FROM PATIENTS WITH PSORIASIS. IN THIS STUDY, WE INVESTIGATED THE GENOME-WIDE DNA METHYLATION STATUS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS COMPARED WITH HEALTHY SUBJECTS USING METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING (MEDIP-SEQ). THE RESULTS OF MEDIP-SEQ SHOWED THAT THE GLOBAL METHYLATION VALUES OF CD4+ T CELLS ARE HIGHER IN PATIENTS WITH PSORIASIS THAN IN HEALTHY CONTROLS, PARTICULARLY IN THE PROMOTER REGIONS. AMONG THE MOST HYPERMETHYLATED GENES IN THE PROMOTER REGIONS, WE SELECTED THE GENES WHOSE EXPRESSION IS SIGNIFICANTLY REDUCED IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. STUDIES USING THE METHYLATION INHIBITOR 5-AZACYTIDINE IN VITRO METHYLATION ASSAYS HAVE SHOWN THAT THE DIFFERENTIAL EXPRESSION LEVELS WERE ASSOCIATED WITH THE METHYLATION STATUS OF EACH GENE. BISULFITE SEQUENCING OF THE TRANSCRIPTION START REGION OF PHOSPHATIDIC ACID PHOSPHATASE TYPE 2 DOMAIN CONTAINING 3 (PPAPDC3), ONE OF THE SELECTED GENES, SHOWED HYPERMETHYLATION IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. THESE RESULTS SUGGESTED THAT THE METHYLATION STATUS, WHICH IS IDENTIFIED BY MEDIP-SEQ OF THE GENES, WAS CORRELATED WITH THE MRNA EXPRESSION LEVEL OF THE GENES. COLLECTIVELY, THE DNA METHYLATION STATUS IN CD4+ T CELLS MIGHT BE ASSOCIATED WITH THE PATHOGENESIS OF PSORIASIS. 2014 13 6149 41 THE EXPRESSION PROFILE OF MIR-23B IS NOT ALTERED IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES. IDIOPATHIC INFLAMMATORY MYOPATHIES (IIM) BELONG TO A GROUP OF AUTOIMMUNE DISORDERS, PRIMARILY CHARACTERIZED BY CHRONIC INFLAMMATION OF HUMAN SKELETAL MUSCLE TISSUE. THE ETIOLOGY OF THESE DISEASES IS UNKNOWN, HOWEVER, GENETIC PREDISPOSITION PLAYS A SIGNIFICANT ROLE IN DISEASE ONSET. BESIDE THE KNOWN GENETIC RISK LOCATED IN THE MHC COMPLEX, THE EPIGENETIC MODIFICATIONS INCLUDING CHANGES IN MIRNAS EXPRESSION PROFILES HAVE BEEN RECENTLY IMPLICATED RECENTLY IN MANY AUTOIMMUNE DISEASES. MICRO RNA MOLECULES ARE INVOLVED IN MANY PHYSIOLOGICAL PROCESSES, INCLUDING THE REGULATION OF THE IMMUNE RESPONSE. IN OUR STUDY WE HAVE FOCUSED ON THE MIR-23B, AS IT REPRESENTS A NOVEL PROMISING AUTOIMMUNITY REGULATOR MOLECULE. DOWNREGULATION OF MIR-23B WAS RECENTLY DESCRIBED IN PATIENTS WITH RHEUMATOID ARTHRITIS AND SYSTEMIC LUPUS ERYTHEMATOSUS. WE HAVE MEASURED THE EXPRESSION MIR-23B PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH DERMATOMYOSITIS AND POLYMYOSITIS. NO MEANINGFUL DIFFERENCE WAS FOUND IN COMPARISON WITH HEALTHY CONTROLS. 2013 14 822 34 CHARACTERIZATION OF BLOOD SURROGATE IMMUNE-METHYLATION BIOMARKERS FOR IMMUNE CELL INFILTRATION IN CHRONIC INFLAMMAGING DISORDERS. ALZHEIMER'S DISEASE (AD) AND ATHEROSCLEROSIS ARE BOTH CHRONIC AGE- AND INFLAMMATION-DEPENDENT DISEASES. IN ADDITION, ATHEROSCLEROSIS IS FREQUENTLY OBSERVED IN AD PATIENTS INDICATING COMMON INVOLVEMENT OF VASCULAR COMPONENTS IN BOTH DISEASE ETIOLOGIES. RECENTLY, EPIGENOME-WIDE ASSOCIATION STUDIES HAVE IDENTIFIED EPIGENETIC ALTERATIONS, AND IN PARTICULARLY DNA METHYLATION CHANGES FOR BOTH DISORDERS. WE HYPOTHESIZED THE EXISTENCE OF A COMMON DNA METHYLATION PROFILE IN ATHEROSCLEROSIS AND AD WHICH MAY BE VALUABLE AS A BLOOD-BASED DNA METHYLATION INFLAMMAGING BIOMARKER. USING PUBLICLY AVAILABLE 450K ILLUMINA METHYLATION DATASETS, WE IDENTIFIED A CO-METHYLATION NETWORK ASSOCIATED WITH BOTH ATHEROSCLEROSIS AND AD IN WHOLE BLOOD SAMPLES. THIS METHYLATION PROFILE APPEARED TO INDICATE SHIFTS IN BLOOD IMMUNE CELL TYPE DISTRIBUTION. REMARKABLY, SIMILAR METHYLATION CHANGES WERE ALSO DETECTED IN DISEASE TISSUES, INCLUDING AD BRAIN TISSUES, ATHEROSCLEROTIC PLAQUES, AND TUMORS AND WERE FOUND TO CORRELATE WITH IMMUNE CELL INFILTRATION. IN ADDITION, THIS IMMUNE-RELATED METHYLATION PROFILE COULD ALSO BE DETECTED IN OTHER INFLAMMAGING DISEASES, INCLUDING PARKINSON'S DISEASE AND OBESITY, BUT NOT IN MULTIPLE SCLEROSIS, SCHIZOPHRENIA, AND OSTEOPOROSIS. IN CONCLUSION, WE IDENTIFIED A BLOOD-BASED IMMUNE-RELATED DNA METHYLATION SIGNATURE IN MULTIPLE INFLAMMAGING DISEASES ASSOCIATED WITH CHANGES IN BLOOD IMMUNE CELL COUNTS AND PREDICTIVE FOR IMMUNE CELL INFILTRATION IN DISEASED TISSUES. IN ADDITION TO EPIGENETIC CLOCK MEASUREMENTS, THIS IMMUNE-METHYLATION SIGNATURE MAY BECOME A VALUABLE BLOOD-BASED BIOMARKER TO PREVENT CHRONIC INFLAMMATORY DISEASE DEVELOPMENT OR MONITOR LIFESTYLE INTERVENTION STRATEGIES WHICH PROMOTE HEALTHY AGING. 2019 15 2771 39 EXTENSIVE PROMOTER DNA HYPERMETHYLATION AND HYPOMETHYLATION IS ASSOCIATED WITH ABERRANT MICRORNA EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA. DYSREGULATED MICRORNA (MIRNA) EXPRESSION CONTRIBUTES TO THE PATHOGENESIS OF HEMATOPOIETIC MALIGNANCIES, INCLUDING CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). HOWEVER, AN UNDERSTANDING OF THE MECHANISMS THAT CAUSE ABERRANT MIRNA TRANSCRIPTIONAL CONTROL IS LACKING. IN THIS STUDY, WE COMPREHENSIVELY INVESTIGATED THE ROLE AND EXTENT OF MIRNA EPIGENETIC REGULATION IN CLL. GENOME-WIDE PROFILING CONDUCTED ON 24 CLL AND 10 HEALTHY B CELL SAMPLES REVEALED GLOBAL DNA METHYLATION PATTERNS UPSTREAM OF MIRNA SEQUENCES THAT DISTINGUISHED MALIGNANT FROM HEALTHY CELLS AND IDENTIFIED PUTATIVE MIRNA PROMOTERS. INTEGRATION OF DNA METHYLATION AND MIRNA PROMOTER DATA LED TO THE IDENTIFICATION OF 128 RECURRENT MIRNA TARGETS FOR ABERRANT PROMOTER DNA METHYLATION. DNA HYPOMETHYLATION ACCOUNTED FOR MORE THAN 60% OF ALL ABERRANT PROMOTER-ASSOCIATED DNA METHYLATION IN CLL, AND PROMOTER DNA HYPOMETHYLATION WAS RESTRICTED TO WELL-DEFINED REGIONS. INDIVIDUAL HYPER- AND HYPOMETHYLATED PROMOTERS ALLOWED DISCRIMINATION OF CLL SAMPLES FROM HEALTHY CONTROLS. PROMOTER DNA METHYLATION PATTERNS WERE CONFIRMED IN AN INDEPENDENT PATIENT COHORT, WITH 11 MIRNAS CONSISTENTLY SHOWING AN INVERSE CORRELATION BETWEEN DNA METHYLATION STATUS AND EXPRESSION LEVEL. TOGETHER, OUR FINDINGS CHARACTERIZE THE ROLE OF EPIGENETIC CHANGES IN THE REGULATION OF MIRNA TRANSCRIPTION AND CREATE A REPOSITORY OF DISEASE-SPECIFIC PROMOTER REGIONS THAT MAY PROVIDE ADDITIONAL INSIGHTS INTO THE PATHOGENESIS OF CLL. 2012 16 4313 40 MICRORNAS AS CANDIDATES FOR BIPOLAR DISORDER BIOMARKERS. BIPOLAR DISORDER (BD) IS A COMMON, RECURRING PSYCHIATRIC ILLNESS WITH UNKNOWN PATHOGENESIS. MUCH LIKE OTHER PSYCHIATRIC DISEASES, BD SUFFERS FROM THE CHRONIC LACK OF RELIABLE BIOMARKERS AND INNOVATIVE PHARMACOLOGICAL INTERVENTIONS. BETTER CHARACTERIZATION OF CLINICAL PROFILES, EXPERIMENTAL MEDICINE, GENOMIC DATA MINING, AND THE UTILIZATION OF EXPERIMENTAL MODELS, INCLUDING STEM CELL AND GENETICALLY MODIFIED MICE, ARE SUGGESTED WAYS FORWARD. ENVIRONMENT, INCLUDING EARLY CHILDHOOD EXPERIENCES, HAS BEEN DOCUMENTED TO MODULATE THE RISK FOR THE DEVELOPMENT OF PSYCHIATRIC DISORDERS VIA EPIGENETIC MECHANISMS. KEY EPIGENETIC REGULATORS, MICRORNAS (MIRNAS, MIRS), GOVERN NORMAL NEURONAL FUNCTIONING AND SHOW ALTERED EXPRESSION IN DIVERSE BRAIN PATHOLOGIES. WE OBSERVED SIGNIFICANT ALTERATIONS OF EXOSOMAL MIR-29C LEVELS IN PREFRONTAL CORTEX (BRODMANN AREA 9, BA9) OF BD PATIENTS. WE ALSO DEMONSTRATED THAT EXOSOMES EXTRACTED FROM THE ANTERIOR CINGULATE CORTEX (BA24), A CRUCIAL AREA FOR MODULATING EMOTIONAL EXPRESSION AND AFFECT, HAVE INCREASED LEVELS OF MIR-149 IN BD PATIENTS COMPARED TO CONTROLS. BECAUSE MIR-149 HAS BEEN SHOWN TO INHIBIT GLIAL PROLIFERATION, WE HYPOTHESIZED THAT INCREASED MIR-149 EXPRESSION IN BA24-DERIVED EXOSOMES MAY BE CONSISTENT WITH THE PREVIOUSLY REPORTED REDUCED GLIAL CELL NUMBERS IN BA24 OF PATIENTS DIAGNOSED WITH FAMILIAL BD. QPCR ANALYSIS OF LASER-MICRODISSECTED NEURONAL AND GLIAL CELLS FROM BA24 CORTICAL SAMPLES OF BD PATIENTS VERIFIED THAT THE GLIAL, BUT NOT NEURONAL, POPULATION EXHIBITS SIGNIFICANTLY INCREASED MIR-149 EXPRESSION. THESE FINDINGS SUPPORT NEURON-GLIA INTERACTION AS A POSSIBLE TARGET MECHANISM IN BD, IMPLICATED BY OTHERS IN NEUROIMAGING, POSTMORTEM, AND IN VIVO STUDIES OF THE PATHOLOGICAL CHANGES MEDIATED BY GLIAL CELLS. 2021 17 1336 28 DESCRIBING A TRANSCRIPTION FACTOR DEPENDENT REGULATION OF THE MICRORNA TRANSCRIPTOME. WHILE THE TRANSCRIPTION REGULATION OF PROTEIN CODING GENES WAS EXTENSIVELY STUDIED, LITTLE IS KNOWN ON HOW TRANSCRIPTION FACTORS ARE INVOLVED IN TRANSCRIPTION OF NON-CODING RNAS, SPECIFICALLY OF MICRORNAS. HERE, WE PROPOSE A STRATEGY TO STUDY THE POTENTIAL ROLE OF TRANSCRIPTION FACTOR IN REGULATING TRANSCRIPTION OF MICRORNAS USING PUBLICALLY AVAILABLE DATA, COMPUTATIONAL RESOURCES AND HIGH THROUGHPUT DATA. WE USE THE H3K4ME3 EPIGENETIC SIGNATURE TO IDENTIFY MICRORNA PROMOTERS AND CHROMATIN IMMUNOPRECIPITATION (CHIP)-SEQUENCING DATA FROM THE ENCODE PROJECT TO IDENTIFY MICRORNA PROMOTERS THAT ARE ENRICHED WITH TRANSCRIPTION FACTOR BINDING SITES. BY TRANSFECTING CELLS OF INTEREST WITH SHRNA TARGETING A TRANSCRIPTION FACTOR OF INTEREST AND SUBJECTING THE CELLS TO MICRORNA ARRAY, WE STUDY THE EFFECT OF THIS TRANSCRIPTION FACTOR ON THE MICRORNA TRANSCRIPTOME. AS AN ILLUSTRATIVE EXAMPLE WE USE OUR STUDY ON THE EFFECT OF STAT3 ON THE MICRORNA TRANSCRIPTOME OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS. 2016 18 1979 34 EPIGENETIC ALTERATIONS IN CHRONIC DISEASE FOCUSING ON BEHCET'S DISEASE: REVIEW. OBJECTIVE: 'EPIGENETICS' IS SPECIFIED AS THE INHERITABLE CHANGES IN GENE EXPRESSION WITH NO ALTERATIONS IN DNA SEQUENCES. EPIGENETICS IS A RAPIDLY OVERSPREADING SCIENTIFIC FIELD, AND THE STUDY OF EPIGENETIC REGULATION IN CHRONIC DISEASE IS EMERGING. THIS STUDY AIMS TO EVALUATE EPIGENETIC CHANGES INCLUDING DNA METHYLATION, HISTONE MODIFICATION, AND NON-CODING RNAS (NCRNAS) IN INFLAMMATORY DISEASE, WITH FOCUS ON BEHCET'S DISEASE. IN THIS REVIEW, FIRST WE DESCRIBE THE HISTORY AND CLASSIFICATION OF EPIGENETIC CHANGES, AND THEN THE ROLE OF EPIGENETIC ALTERATIONS IN CHRONIC DISEASES IS EXPLAINED. METHODS: SYSTEMATIC SEARCH OF MEDLINE, EMBASE, AND COCHRANE LIBRARY WAS CONDUCTED FOR ALL COMPARATIVE STUDIES SINCE 2000 TO 2015 WITH THE LIMITATIONS OF THE ENGLISH LANGUAGE. RESULTS: FOR A NOTABLE PERIOD OF TIME, RESEARCHERS HAVE MAINLY FOCUSED ON THE EPIGENETIC PATHWAYS THAT ARE INVOLVED IN THE MODULATION OF INFLAMMATORY AND ANTI-INFLAMMATORY GENES. RECENT STUDIES HAVE PROPOSED A CENTRAL ROLE FOR CHRONIC INFLAMMATION IN THE PATHOGENESIS OF CHRONIC DISEASE, INCLUDING BEHCET'S DISEASE. CONCLUSION: STUDIES HAVE BEEN REPORTED ON THE EPIGENETIC OF BD SHOWED THE ROLE OF ALTERATIONS IN THE METHYLATION LEVEL OF IRS ELEMENTS; HISTONE MODIFICATIONS SUCH AS H3K4ME27 AND H3K4ME3; UP REGULATION OF MIR-182 AND MIR-3591-3P; DOWN REGULATION OF MIR-155, MIR-638 AND MIR-4488 IN THE PATHOGENESIS OF THE DISEASE. 2017 19 1307 37 DEFINING A METHYLATION SIGNATURE ASSOCIATED WITH OPERATIONAL TOLERANCE IN KIDNEY TRANSPLANT RECIPIENTS. OPERATIONAL TOLERANCE AFTER KIDNEY TRANSPLANTATION IS DEFINED AS STABLE GRAFT ACCEPTANCE WITHOUT THE NEED FOR IMMUNOSUPPRESSION THERAPY. HOWEVER, IT IS NOT CLEAR WHICH CELLULAR AND MOLECULAR PATHWAYS ARE DRIVING TOLERANCE IN THESE PATIENTS. WE PERFORMED GENOME-WIDE ANALYSIS OF DNA METHYLATION IN PERIPHERAL BLOOD MONONUCLEAR CELLS FROM KIDNEY TRANSPLANT RECIPIENTS WITH CHRONIC REJECTION AND OPERATIONAL TOLERANCE FROM THE GENETIC ANALYSIS OF MOLECULAR BIOMARKERS OF IMMUNOLOGICAL TOLERANCE (GAMBIT) STUDY. OUR RESULTS SHOWED THAT BOTH CLINICAL STAGES DIVERGE IN 2737 GENES, INDICATING THAT EACH ONE HAS A SPECIFIC METHYLATION SIGNATURE ASSOCIATED WITH TRANSPLANT OUTCOME. WE ALSO OBSERVED THAT TOLERANCE IS ASSOCIATED WITH DEMETHYLATION IN GENES INVOLVED IN IMMUNE FUNCTION, INCLUDING B AND T CELL ACTIVATION AND TH17 DIFFERENTIATION, WHILE IN CHRONIC REJECTION IT IS ASSOCIATED WITH INTRACELLULAR SIGNALING AND UBIQUITINATION PATHWAYS. USING CO-EXPRESSION NETWORK ANALYSIS, WE SELECTED 12 GENOMIC REGIONS THAT ARE SPECIFICALLY HYPOMETHYLATED OR HYPERMETHYLATED IN TOLERANT PATIENTS. ANALYSIS OF THESE GENES IN TRANSPLANTED PATIENTS WITH LOW DOSE OF STEROIDS SHOWED THAT THESE HAVE A SIMILAR METHYLATION SIGNATURE TO THAT OF TOLERANT RECIPIENTS. OVERALL, THESE RESULTS DEMONSTRATE THAT METHYLATION ANALYSIS CAN MIRROR THE IMMUNE STATUS ASSOCIATED WITH TRANSPLANT OUTCOME AND PROVIDES A STARTING POINT FOR UNDERSTANDING THE EPIGENETIC MECHANISMS ASSOCIATED WITH TOLERANCE. 2021 20 4228 27 METHYLATION OF INFLAMMATORY CELLS IN LUNG DISEASES. THIS CHAPTER OVERVIEWS ROLES OF DNA METHYLATION IN INFLAMMATORY CELL BIOLOGY WITH THE FOCUSES ON LYMPHOCYTES AND MACROPHAGES/MONOCYTES IN LUNG DISEASES, ALTHOUGH THE MOLECULAR MECHANISMS BY WHICH TARGET GENES ARE METHYLATED AND REGULATED IN LUNG DISEASES REMAIN UNCLEAR. MOST OF EPIGENETIC STUDIES ON DNA METHYLATION OF TARGET GENES IN LUNG DISEASES MAINLY DEMONSTRATED THE CORRELATION OF DNA METHYLATION OF TARGET GENES WITH THE LEVELS OF OTHER CORRESPONDING FACTORS, WITH THE SPECIFICITY OF CLINICAL PHENOMES, AND WITH THE SEVERITY OF LUNG DISEASES. THERE IS AN URGENT NEED TO IDENTIFY AND VALIDATE THE SPECIFICITY AND REGULATORY MECHANISMS OF INFLAMMATORY CELL EPIGENETICS IN DEPTH. THE EPIGENETIC HETEROGENEITY AMONG DIFFERENT SUBSETS OF T CELLS AND AMONG PROMOTERS OR NON-PROMOTERS OF TARGET GENES SHOULD BE FURTHERMORE CLARIFIED IN ACUTE OR CHRONIC LUNG DISEASES AND CANCERS. THE HYPER/HYPO-METHYLATION AND MODIFICATIONS OF CHROMOSOL AND EXTRACHROMOSOMAL DNA MAY RESULT IN ALTERNATIONS IN PROTEINS WITHIN INFLAMMATORY CELLS, WHICH CAN BE IDENTIFIED AS DISEASE-SPECIFIC BIOMARKERS AND THERAPEUTIC TARGETS. 2020