1 5261 129 PROGRESSIVE SILENCING OF THE ZINC TRANSPORTER ZIP8 (SLC39A8) IN CHRONIC CADMIUM-EXPOSED LUNG EPITHELIAL CELLS. CADMIUM (CD), A NON-ESSENTIAL METAL, STEALTHILY ENTERS THE CELLS BY UTILIZING THE ESSENTIAL METAL IMPORTING PATHWAYS. THE ZINC TRANSPORTERS ZIP8, ZIP14, AND DIVALENT METAL TRANSPORTER 1 (DMT1) ARE NOW EMERGING AS SEVERAL IMPORTANT METAL TRANSPORTERS INVOLVED IN CELLULAR CD INCORPORATION AND THEIR EXPRESSIONS HAVE BEEN SHOWN TO BE DOWN-REGULATED IN SEVERAL CD-RESISTANT (CDR) CELL LINES, HOWEVER, THE INVOLVEMENT OF THESE TRANSPORTERS DURING THE DEVELOPMENT OF CD-RESISTANCE IN LUNG CELLS IS UNCLEAR. IN THIS STUDY, WE THEREFORE CHECK THE EXPRESSION OF THESE METAL TRANSPORTERS IN OUR PREVIOUSLY ESTABLISHED RAT LUNG EPITHELIAL CELLS (LECS) AND SHOW THAT THE LEVEL OF ZIP8 IS PROGRESSIVELY SILENCED WHEN LECS ARE ADAPTED TO INCREASING CONCENTRATIONS OF CDCL2 (FROM 1 TO 20 MUM). SUBSEQUENT MEASUREMENT OF THE CELLULAR CD CONTENT INDICATED THAT CDR LECS EXHIBIT A MARKED DECREASE OF CD ACCUMULATION, POSSIBLY DUE TO THE LOSS OF ZIP8 EXPRESSION. WE INVESTIGATE THE POSSIBILITY THAT EPIGENETIC SILENCING OF THE ZIP8 GENE BY DNA HYPERMETHYLATION IS INVOLVED IN THE DOWN-REGULATION OF ZIP8 EXPRESSION. CDR LECS SHOW A HIGHER MRNA LEVEL OF DNA METHYLTRANSFERASE 3B (DNMT3B) THAN PARENTAL CELLS. TREATMENT OF CDR LECS WITH 5-AZA-2'-DEOXYCYTIDINE, AN INHIBITOR OF DNA METHYLTRANSFERASES, REVERTED THE EXPRESSION OF ZIP8 AND SENSITIVITY TO CD IN THESE CELLS, INDICATING THE CRITICAL ROLE OF ZIP8 FOR CD IMPORT. TAKEN TOGETHER, OUR RESULTS DEMONSTRATE THAT THE PROGRESSIVE SILENCING OF ZIP8 EXPRESSION IS INVOLVED IN THE ACQUISITION OF RESISTANCE AGAINST CD IN LUNG CELLS, REPRESENTING AN ADAPTIVE SURVIVAL MECHANISM THAT RESISTS CD-INDUCED CYTOTOXICITY. 2017 2 3049 33 GENOME-WIDE ANALYSIS REVEALS ZINC TRANSPORTER ZIP9 REGULATED BY DNA METHYLATION PROMOTES RADIATION-INDUCED SKIN FIBROSIS VIA THE TGF-BETA SIGNALING PATHWAY. RADIATION-INDUCED SKIN FIBROSIS IS A DETRIMENTAL AND CHRONIC DISORDER THAT OCCURS AFTER RADIATION EXPOSURE. DNA METHYLATION HAS BEEN CHARACTERIZED AS AN IMPORTANT REGULATORY MECHANISM OF MULTIPLE PATHOLOGICAL PROCESSES. IN THIS STUDY, WE COMPARED THE GENOME-WIDE DNA METHYLATION STATUS IN RADIATION-INDUCED FIBROTIC SKIN AND ADJACENT NORMAL TISSUES OF RATS BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. RADIATION-INDUCED FIBROTIC SKIN SHOWED DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH 3,650 PROTEIN-CODING GENES, 72 MICRORNAS, 5,836 LONG NONCODING RNAS AND 3 PIWI-INTERACTING RNAS. BY INTEGRATING THE MRNA AND METHYLATION PROFILES, THE ZINC TRANSPORTER SLC39A9/ZIP9 WAS INVESTIGATED IN GREATER DETAIL. THE PROTEIN LEVEL OF ZIP9 WAS INCREASED IN IRRADIATED SKIN TISSUES OF HUMANS, MONKEYS, AND RATS, ESPECIALLY IN RADIOGENIC FIBROTIC SKIN TISSUES. RADIATION INDUCED THE DEMETHYLATION OF A CPG DINUCLEOTIDE IN EXON 1 OF ZIP9 THAT RESULTED IN RECRUITMENT OF THE TRANSCRIPTIONAL FACTOR SP1 AND INCREASED ZIP9 EXPRESSION. OVEREXPRESSION OF ZIP9 RESULTED IN ACTIVATION OF THE PROFIBROTIC TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY THROUGH PROTEIN KINASE B IN HUMAN FIBROBLASTS. IN ADDITION, RADIATION-INDUCED SKIN FIBROSIS WAS ASSOCIATED WITH INCREASED ZINC ACCUMULATION. THE ZINC CHELATOR N,N,N',N'-TETRAKIS(2-PYRIDYLMETHYL)-1,2-ETHYLENEDIAMINE ABROGATED ZIP9-INDUCED ACTIVATION OF THE TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY AND ATTENUATED RADIATION-INDUCED SKIN FIBROSIS IN A RAT MODEL. IN SUMMARY, OUR FINDINGS ILLUSTRATE EPIGENETIC REGULATION OF ZIP9 AND ITS CRITICAL ROLE IN PROMOTING RADIATION-INDUCED SKIN FIBROSIS. 2020 3 1334 33 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL. 2011 4 3468 45 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 5 984 36 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022 6 3474 31 IDENTIFICATION OF A RICE METALLOCHAPERONE FOR CADMIUM TOLERANCE BY AN EPIGENETIC MECHANISM AND POTENTIAL USE FOR CLEAN UP IN WETLAND. CADMIUM (CD) IS A TOXIC HEAVY METAL THAT INITIATES DIVERSE CHRONIC DISEASES THROUGH FOOD CHAINS. DEVELOPING A BIOTECHNOLOGY FOR MANIPULATING CD UPTAKE IN PLANTS IS BENEFICIAL TO REDUCE ENVIRONMENTAL AND HEALTH RISKS. HERE, WE IDENTIFIED A NOVEL EPIGENETIC MECHANISM UNDERLYING CD ACCUMULATION REGULATED BY AN UNCHARACTERIZED METALLOCHAPERONE NAMELY HEAVY METAL RESPONSIVE PROTEIN (HMP) IN RICE PLANTS. OSHMP RESIDES IN CYTOPLASM AND NUCLEUS, DOMINANTLY INDUCED BY CD STRESS AND BINDS DIRECTLY TO CD IONS. OSHMP OVEREXPRESSION ENHANCED THE RICE GROWTH UNDER CD STRESS BUT ACCUMULATED MORE CD, WHEREAS KNOCKOUT OR KNOCKDOWN OF OSHMP SHOWED A CONTRASTING EFFECT. THE ENHANCED CD ACCUMULATION IN THE TRANSGENIC LINES WAS CONFIRMED BY A LONG-TERM EXPERIMENT WITH RICE GROWING AT THE ENVIRONMENTALLY REALISTIC CD CONCENTRATION IN SOIL. THE BISULFITE SEQUENCING AND CHROMATIN IMMUNOPRECIPITATION ASSESSMENTS REVEALED THAT CD STRESS REDUCED SIGNIFICANTLY THE DNA METHYLATION AT CPG (CYTOSINE-GUANINE) AND HISTONE H3K9ME2 MARKS IN THE UPSTREAM OF OSHMP. BY IDENTIFYING A COUPLE OF MUTANTS DEFECTIVE IN DNA METHYLATION AND HISTONE MODIFICATION (H3K9ME2) SUCH AS OSMET1 (METHYLATRANSFEASE1) AND OSSDG714 (KRYPTONITE), WE FOUND THAT THE CD-INDUCED EPIGENETIC HYPOMETHYLATION AT THE REGION WAS ASSOCIATED WITH OSHMP OVEREXPRESSION, WHICH CONSEQUENTLY LED TO CD DETOXIFICATION IN RICE. THE CAUSAL RELATIONSHIP WAS CONFIRMED BY THE GUS REPORTER GENE COUPLED WITH OSHMP AND OSMET1 WHEREBY OSMET1 REPRESSED DIRECTLY THE OSHMP EXPRESSION. OUR WORK SIGNIFIES THAT EXPRESSION OF OSHMP IS REQUIRED FOR CD DETOXIFICATION IN RICE PLANTS, AND THE CD-INDUCED HYPOMETHYLATION IN THE SPECIFIC REGION IS RESPONSIBLE FOR THE ENHANCED OSHMP EXPRESSION. IN SUMMARY, THIS STUDY GAINED AN INSIGHT INTO THE EPIGENETIC MECHANISM FOR ADDITIONAL OSHMP EXPRESSION WHICH CONSEQUENTLY ENSURES RICE ADAPTATION TO THE CD-CONTAMINATED ENVIRONMENT. 2021 7 3390 34 HOPX PLAYS A CRITICAL ROLE IN ANTIRETROVIRAL DRUGS INDUCED EPIGENETIC MODIFICATION AND CARDIAC HYPERTROPHY. PEOPLE LIVING WITH HIV (PLWH) HAVE TO TAKE AN ANTIRETROVIRAL THERAPY (ART) FOR LIFE AND SHOW NONCOMMUNICABLE ILLNESSES SUCH AS CHRONIC INFLAMMATION, IMMUNE ACTIVATION, AND MULTIORGAN DYSREGULATION. RECENT STUDIES SUGGEST THAT LONG-TERM USE OF ART INDUCES COMORBID CONDITIONS AND IS ONE OF THE LEADING CAUSES OF HEART FAILURE IN PLWH. HOWEVER, THE MOLECULAR MECHANISM OF ANTIRETROVIRAL DRUGS (ARVS) INDUCED HEART FAILURE IS UNCLEAR. TO DETERMINE THE MECHANISM OF ARVS INDUCED CARDIAC DYSFUNCTION, WE PERFORMED GLOBAL TRANSCRIPTOMIC PROFILING OF ARVS TREATED NEONATAL RAT VENTRICULAR CARDIOMYOCYTES IN CULTURE. DIFFERENTIALLY EXPRESSED GENES WERE IDENTIFIED BY RNA-SEQUENCING. OUR DATA SHOW THAT ARVS TREATMENT CAUSES UPREGULATION OF SEVERAL BIOLOGICAL FUNCTIONS ASSOCIATED WITH CARDIOTOXICITY, HYPERTROPHY, AND HEART FAILURE. GLOBAL GENE EXPRESSION DATA WERE VALIDATED IN CARDIAC TISSUE ISOLATED FROM HIV PATIENTS HAVING A HISTORY OF ART. INTERESTINGLY, WE FOUND THAT HOMEODOMAIN-ONLY PROTEIN HOMEOBOX (HOPX) EXPRESSION WAS SIGNIFICANTLY INCREASED IN CARDIOMYOCYTES TREATED WITH ARVS AND IN THE HEART TISSUE OF HIV PATIENTS. FURTHERMORE, WE FOUND THAT HOPX PLAYS A CRUCIAL ROLE IN ARVS MEDIATED CELLULAR HYPERTROPHY. MECHANISTICALLY, WE FOUND THAT HOPX PLAYS A CRITICAL ROLE IN EPIGENETIC REGULATION, THROUGH DEACETYLATION OF HISTONE, WHILE THE HDAC INHIBITOR, TRICHOSTATIN A, CAN RESTORE THE ACETYLATION LEVEL OF HISTONE 3 IN THE PRESENCE OF ARVS. 2021 8 5101 34 POLYCOMB FACTOR PHF19 CONTROLS CELL GROWTH AND DIFFERENTIATION TOWARD ERYTHROID PATHWAY IN CHRONIC MYELOID LEUKEMIA CELLS. POLYCOMB GROUP (PCG) OF PROTEINS ARE A GROUP OF HIGHLY CONSERVED EPIGENETIC REGULATORS INVOLVED IN MANY BIOLOGICAL FUNCTIONS, SUCH AS EMBRYONIC DEVELOPMENT, CELL PROLIFERATION, AND ADULT STEM CELL DETERMINATION. PHD FINGER PROTEIN 19 (PHF19) IS AN ASSOCIATED FACTOR OF POLYCOMB REPRESSOR COMPLEX 2 (PRC2), OFTEN UPREGULATED IN HUMAN CANCERS. IN PARTICULAR, MYELOID LEUKEMIA CELL LINES SHOW INCREASED LEVELS OF PHF19, YET LITTLE IS KNOWN ABOUT ITS FUNCTION. HERE, WE HAVE CHARACTERIZED THE ROLE OF PHF19 IN MYELOID LEUKEMIA CELLS. WE DEMONSTRATED THAT PHF19 DEPLETION DECREASES CELL PROLIFERATION AND PROMOTES CHRONIC MYELOID LEUKEMIA (CML) DIFFERENTIATION. MECHANISTICALLY, WE HAVE SHOWN HOW PHF19 REGULATES THE PROLIFERATION OF CML THROUGH A DIRECT REGULATION OF THE CELL CYCLE INHIBITOR P21. FURTHERMORE, WE OBSERVED THAT MTF2, A PHF19 HOMOLOG, PARTIALLY COMPENSATES FOR PHF19 DEPLETION IN A SUBSET OF TARGET GENES, INSTRUCTING SPECIFIC ERYTHROID DIFFERENTIATION. TAKEN TOGETHER, OUR RESULTS SHOW THAT PHF19 IS A KEY TRANSCRIPTIONAL REGULATOR FOR CELL FATE DETERMINATION AND COULD BE A POTENTIAL THERAPEUTIC TARGET FOR MYELOID LEUKEMIA TREATMENT. 2021 9 136 34 ABERRANT DNA HYPERMETHYLATION PATTERNS LEAD TO TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS OF MICE. OVEREXPOSURE OF THE HUMAN SKIN TO SOLAR ULTRAVIOLET (UV) RADIATION IS THE MAJOR ETIOLOGIC FACTOR FOR DEVELOPMENT OF SKIN CANCERS. HERE, WE REPORT THE RESULTS OF EPIGENETIC MODIFICATIONS IN UV-EXPOSED SKIN AND SKIN TUMORS IN A SYSTEMATIC MANNER. THE SKIN AND TUMOR SAMPLES WERE COLLECTED AFTER CHRONIC EXPOSURE OF THE SKIN OF SKH-1 HAIRLESS MICE TO UVB RADIATION USING A WELL-ESTABLISHED PHOTOCARCINOGENESIS PROTOCOL. WE FOUND A DISTINCT DNA HYPERMETHYLATION PATTERN IN THE UVB-EXPOSED EPIDERMAL SKIN AND UVB-INDUCED SKIN TUMORS THAT WAS ASSOCIATED WITH THE ELEVATED EXPRESSION AND ACTIVITY OF THE DNA METHYLTRANSFERASES (DNMT) 1, DNMT3A AND DNMT3B. TO EXPLORE THE ROLE OF HYPERMETHYLATION IN SKIN PHOTOCARCINOGENESIS, WE FOCUSED ON THE P16(INK4A) AND RASSF1A TUMOR SUPPRESSOR GENES, WHICH ARE TRANSCRIPTIONALLY SILENCED ON METHYLATION. WE ESTABLISHED THAT THE SILENCING OF THESE GENES IN UVB-EXPOSED EPIDERMIS AND UVB-INDUCED SKIN TUMORS IS ASSOCIATED WITH A NETWORK OF EPIGENETIC MODIFICATIONS, INCLUDING HYPOACETYLATION OF HISTONE H3 AND H4 AND INCREASED HISTONE DEACETYLATION, AS WELL AS RECRUITMENT OF METHYL-BINDING PROTEINS, INCLUDING MECP2 AND MBD1, TO THE METHYLATED CPGS. HIGHER LEVELS OF DNA METHYLATION AND DNMT ACTIVITY IN HUMAN SQUAMOUS CELL CARCINOMA SPECIMENS THAN IN NORMAL HUMAN SKIN SUGGEST THAT THE DATA ARE RELEVANT CLINICALLY. OUR DATA INDICATE FOR THE FIRST TIME THAT UVB-INDUCED DNA HYPERMETHYLATION, ENHANCED DNMT ACTIVITY AND HISTONE MODIFICATIONS OCCUR IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS AND SUGGEST THAT THESE EVENTS ARE INVOLVED IN THE SILENCING OF TUMOR SUPPRESSOR GENES AND IN SKIN TUMOR DEVELOPMENT. 2011 10 3465 34 HYPOTHESIS: REGULATION OF NEUROPLASTICITY MAY INVOLVE I-MOTIF AND G-QUADRUPLEX DNA FORMATION MODULATED BY EPIGENETIC MECHANISMS. RECENT STUDIES DEMONSTRATED THE EXISTENCE IN VIVO OF VARIOUS FUNCTIONAL DNA STRUCTURES THAT DIFFER FROM THE DOUBLE HELIX. THE G-QUADRUPLEX (G4) AND INTERCALATED MOTIF (I-MOTIF OR IM) DNA STRUCTURES ARE FORMED AS KNOTS WHERE, CORRESPONDINGLY, GUANINES OR CYTOSINES ON THE SAME STRAND OF DNA BIND TO EACH OTHER. THERE ARE GROUNDS TO BELIEVE THAT G4 AND IM SEQUENCES PLAY A SIGNIFICANT ROLE IN REGULATING GENE EXPRESSION CONSIDERING THEIR TENDENCY TO BE FOUND IN OR NEAR REGULATORY SITES (SUCH AS PROMOTERS, ENHANCERS, AND TELOMERES) AS WELL AS THE CORRELATION BETWEEN THE PREVALENCE OF G4 OR IM CONFORMATIONS AND SPECIFIC PHASES OF CELL CYCLE. NOTABLY, G4 AND IM CAPABLE SEQUENCES TEND TO BE FOUND ON THE OPPOSITE STRANDS OF THE SAME DNA SITE WITH AT MOST ONE OF THE TWO STRUCTURES FORMED AT ANY GIVEN TIME. THE RECENT EVIDENCE THAT K(+), MG(2+) CONCENTRATIONS DIRECTLY AFFECT IM FORMATION (AND LIKELY G4 FORMATION INDIRECTLY) LEAD US TO BELIEVE THAT THESE STRUCTURES MAY PLAY A MAJOR ROLE IN SYNAPTIC PLASTICITY OF NEURONS, AND, THEREFORE, IN A VARIETY OF CENTRAL NERVOUS SYSTEM (CNS) FUNCTIONS INCLUDING MEMORY, LEARNING, HABITUAL BEHAVIORS, PAIN PERCEPTION AND OTHERS. FURTHERMORE, EPIGENETIC MECHANISMS, WHICH HAVE AN IMPORTANT ROLE IN SYNAPTIC PLASTICITY AND MEMORY FORMATION, WERE ALSO SHOWN TO INFLUENCE FORMATION AND STABILITY OF G4S AND IMS. OUR HYPOTHESIS IS THAT NON-CANONICAL DNA AND RNA STRUCTURES COULD BE AN INTEGRAL PART OF NEUROPLASTICITY CONTROL VIA GENE EXPRESSION REGULATION AT THE LEVEL OF TRANSCRIPTION, TRANSLATION AND SPLICING. WE PROPOSE THAT THE REGULATORY ACTIVITY OF DNA IM AND G4 STRUCTURES IS MODULATED BY DNA METHYLATION/DEMETHYLATION OF THE IM AND/OR G4 SEQUENCES, WHICH FACILITATES THE SWITCH BETWEEN CANONICAL AND NON-CANONICAL CONFORMATION. OTHER NEURONAL MECHANISMS INTERACTING WITH THE FORMATION AND REGULATORY ACTIVITY OF NON-CANONICAL DNA AND RNA STRUCTURES, PARTICULARLY G4, IM AND TRIPLEXES, MAY INVOLVE MICRORNAS AS WELL AS ION AND PROTON FLUXES. WE ARE PROPOSING EXPERIMENTS IN ACUTE BRAIN SLICES AND IN VIVO TO TEST OUR HYPOTHESIS. THE PROPOSED STUDIES WOULD PROVIDE NEW INSIGHTS INTO FUNDAMENTAL NEURONAL MECHANISMS IN HEALTH AND DISEASE AND POTENTIALLY OPEN NEW AVENUES FOR TREATING MENTAL HEALTH DISORDERS. 2019 11 5153 25 PPP2R2B HYPERMETHYLATION CAUSES ACQUIRED APOPTOSIS DEFICIENCY IN SYSTEMIC AUTOIMMUNE DISEASES. CHRONIC INFLAMMATION CAUSES TARGET ORGAN DAMAGE IN PATIENTS WITH SYSTEMIC AUTOIMMUNE DISEASES. THE FACTORS THAT ALLOW THIS PROTRACTED RESPONSE ARE POORLY UNDERSTOOD. WE ANALYZED THE TRANSCRIPTIONAL REGULATION OF PPP2R2B (B55SS), A MOLECULE NECESSARY FOR THE TERMINATION OF THE IMMUNE RESPONSE, IN PATIENTS WITH AUTOIMMUNE DISEASES. ALTERED EXPRESSION OF B55SS CONDITIONED RESISTANCE TO CYTOKINE WITHDRAWAL-INDUCED DEATH (CWID) IN PATIENTS WITH AUTOIMMUNE DISEASES. THE IMPAIRED UPREGULATION OF B55SS WAS CAUSED BY INFLAMMATION-DRIVEN HYPERMETHYLATION OF SPECIFIC CYTOSINES LOCATED WITHIN A REGULATORY ELEMENT OF PPP2R2B PREVENTING CTCF BINDING. THIS PHENOTYPE COULD BE INDUCED IN HEALTHY T CELLS BY EXPOSURE TO TNF-ALPHA. OUR RESULTS REVEAL A GENE WHOSE EXPRESSION IS AFFECTED BY AN ACQUIRED DEFECT, THROUGH AN EPIGENETIC MECHANISM, IN THE SETTING OF SYSTEMIC AUTOIMMUNITY. BECAUSE FAILURE TO REMOVE ACTIVATED T CELLS THROUGH CWID COULD CONTRIBUTE TO AUTOIMMUNE PATHOLOGY, THIS MECHANISM ILLUSTRATES A VICIOUS CYCLE THROUGH WHICH AUTOIMMUNE INFLAMMATION CONTRIBUTES TO ITS OWN PERPETUATION. 2019 12 3942 40 LNCRNA DUXAP10 UPREGULATION AND THE HEDGEHOG PATHWAY ACTIVATION ARE CRITICALLY INVOLVED IN CHRONIC CADMIUM EXPOSURE-INDUCED CANCER STEM CELL-LIKE PROPERTY. CADMIUM (CD) IS A WELL-KNOWN LUNG CARCINOGEN. HOWEVER, THE MECHANISM OF CD CARCINOGENESIS REMAINS TO BE CLEARLY DEFINED. CD HAS BEEN SHOWN TO ACT AS A WEAK MUTAGEN, SUGGESTING THAT IT MAY EXERT TUMORIGENIC EFFECT THROUGH NONGENOTOXIC WAYS, SUCH AS EPIGENETIC MECHANISMS. LONG NONCODING RNAS (LNCRNAS) REFER TO RNA MOLECULES THAT ARE LONGER THAN 200 NUCLEOTIDES IN LENGTH BUT LACK PROTEIN-CODING CAPACITIES. REGULATION OF GENE EXPRESSIONS BY LNCRNAS IS CONSIDERED AS ONE OF IMPORTANT EPIGENETIC MECHANISMS. THE GOAL OF THIS STUDY IS TO INVESTIGATE THE MECHANISM OF CD CARCINOGENESIS FOCUSING ON THE ROLE OF LNCRNA DYSREGULATIONS. CD-INDUCED MALIGNANT TRANSFORMATION OF HUMAN BRONCHIAL EPITHELIA BEAS-2B CELLS WAS ACCOMPLISHED BY A 9-MONTH LOW-DOSE CD (CDCL2, 2.5 MICROM) EXPOSURE. THE CD-EXPOSED CELLS FORMED SIGNIFICANTLY MORE COLONIES IN SOFT AGAR, DISPLAYED CANCER STEM CELL (CSC)-LIKE PROPERTY, AND FORMED TUMORS IN NUDE MICE. MECHANISTICALLY, CHRONIC LOW-DOSE CD EXPOSURE DID NOT CAUSE SIGNIFICANT GENOTOXIC EFFECTS BUT DYSREGULATED LNCRNA EXPRESSIONS. FURTHER Q-PCR ANALYSIS CONFIRMED THE SIGNIFICANT UPREGULATION OF THE ONCOGENIC LNCRNA DUXAP10 IN CD-TRANSFORMED CELLS. DUXAP10 KNOCKDOWN IN CD-TRANSFORMED CELLS SIGNIFICANTLY REDUCED THEIR CSC-LIKE PROPERTY. FURTHER MECHANISTIC STUDIES SHOWED THAT THE HEDGEHOG PATHWAY IS ACTIVATED IN CD-TRANSFORMED CELLS AND INHIBITION OF THIS PATHWAY REDUCES CD-INDUCED CSC-LIKE PROPERTY. DUXAP10 KNOCKDOWN CAUSED THE HEDGEHOG PATHWAY INACTIVATION IN CD-TRANSFORMED CELLS. FURTHERMORE, PAX6 EXPRESSION WAS UPREGULATED IN CD-TRANSFORMED CELLS AND PAX6 KNOCKDOWN SIGNIFICANTLY REDUCED THEIR DUXAP10 LEVELS AND CSC-LIKE PROPERTY. IN SUMMARY, THESE FINDINGS SUGGEST THAT THE LNCRNA DUXAP10 UPREGULATION MAY PLAY AN IMPORTANT ROLE IN CD CARCINOGENESIS. 2021 13 1121 26 COMPARISON OF EPIGENETIC PROFILES OF HUMAN ORAL EPITHELIAL CELLS FROM HIV-POSITIVE (ON HAART) AND HIV-NEGATIVE SUBJECTS. HIV-INFECTED SUBJECTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) ARE SUSCEPTIBLE TO COMORBID MICROBIAL INFECTIONS IN THE ORAL CAVITY. WE OBSERVED THAT PRIMARY ORAL EPITHELIAL CELLS (POECS) ISOLATED FROM HIV+ SUBJECTS ON HAART GROW MORE SLOWLY AND ARE LESS INNATE IMMUNE RESPONSIVE TO MICROBIAL CHALLENGE WHEN COMPARED WITH POECS FROM NORMAL SUBJECTS. THESE ABERRANT CELLS ALSO DEMONSTRATE EPIGENETIC DIFFERENCES THAT INCLUDE REDUCTION IN HISTONE DEACETYLASE 1 (HDAC-1) LEVELS AND REDUCED TOTAL DNA METHYLTRANSFERASE (DNMT) ACTIVITY SPECIFIC TO ENZYMES DNMT1 AND DNMT3A. THE DNMT ACTIVITY CORRELATES WELL WITH GLOBAL DNA METHYLATION, INDICATING THAT ABERRANT DNMT ACTIVITY IN HIV+ (ON HAART) POECS LEADS TO AN ABERRANTLY METHYLATED EPITHELIAL CELL PHENOTYPE. OVERALL, OUR RESULTS LEAD US TO HYPOTHESIZE THAT, IN PATIENTS WITH CHRONIC HIV INFECTION ON HAART, EPIGENETIC CHANGES IN KEY GENES RESULT IN INCREASED VULNERABILITY TO MICROBIAL INFECTION IN THE ORAL CAVITY. 2013 14 2763 29 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 15 662 28 BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME ANALYSES REVEAL LOCI ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. LITTLE IS KNOWN REGARDING THE EPIGENETIC BASIS OF ATHEROSCLEROSIS. HERE WE PRESENT THE CD14+ BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME SIGNATURES ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. THE TRANSCRIPTOME SIGNATURE INCLUDES TRANSCRIPTION COACTIVATOR, ARID5B, WHICH IS KNOWN TO FORM A CHROMATIN DEREPRESSOR COMPLEX WITH A HISTONE H3K9ME2-SPECIFIC DEMETHYLASE AND PROMOTE ADIPOGENESIS AND SMOOTH MUSCLE DEVELOPMENT. ARID5B CPG (CG25953130) METHYLATION IS INVERSELY ASSOCIATED WITH BOTH ARID5B EXPRESSION AND ATHEROSCLEROSIS, CONSISTENT WITH THIS CPG RESIDING IN AN ARID5B ENHANCER REGION, BASED ON CHROMATIN CAPTURE AND HISTONE MARKS DATA. MEDIATION ANALYSIS SUPPORTS ASSUMPTIONS THAT ARID5B EXPRESSION MEDIATES EFFECTS OF CG25953130 METHYLATION AND SEVERAL CARDIOVASCULAR DISEASE RISK FACTORS ON ATHEROSCLEROTIC BURDEN. IN LIPOPOLYSACCHARIDE-STIMULATED HUMAN THP1 MONOCYTES, ARID5B KNOCKDOWN REDUCED EXPRESSION OF GENES INVOLVED IN ATHEROSCLEROSIS-RELATED INFLAMMATORY AND LIPID METABOLISM PATHWAYS, AND INHIBITED CELL MIGRATION AND PHAGOCYTOSIS. THESE DATA SUGGEST THAT ARID5B EXPRESSION, POSSIBLY REGULATED BY AN EPIGENETICALLY CONTROLLED ENHANCER, PROMOTES ATHEROSCLEROSIS BY DYSREGULATING IMMUNOMETABOLISM TOWARDS A CHRONIC INFLAMMATORY PHENOTYPE.THE MOLECULAR MECHANISMS MEDIATING THE IMPACT OF ENVIRONMENTAL FACTORS IN ATHEROSCLEROSIS ARE UNCLEAR. HERE, THE AUTHORS EXAMINE CD14+ BLOOD MONOCYTE'S TRANSCRIPTOME AND EPIGENOME SIGNATURES TO FIND DIFFERENTIAL METHYLATION AND EXPRESSION OF ARID5B TO BE ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. 2017 16 142 40 ABERRANT DNA METHYLATION OF PHOSPHODIESTERASE [CORRECTED] 4D ALTERS AIRWAY SMOOTH MUSCLE CELL PHENOTYPES. AIRWAY HYPERRESPONSIVENESS (AHR) IS A HALLMARK FEATURE IN ASTHMA CHARACTERIZED BY EXAGGERATED AIRWAY CONTRACTILE RESPONSE TO STIMULI DUE TO INCREASED AIRWAY SENSITIVITY AND CHRONIC AIRWAY REMODELING. WE HAVE PREVIOUSLY SHOWN THAT ALLERGEN-INDUCED AHR IN MICE IS ASSOCIATED WITH ABERRANT DNA METHYLATION IN THE LUNG GENOME, SUGGESTING THAT AHR COULD BE EPIGENETICALLY REGULATED, AND THESE CHANGES MIGHT PREDISPOSE THE ANIMALS TO ASTHMA. PREVIOUS STUDIES DEMONSTRATED THAT OVEREXPRESSION OF PHOSPHODIESTERASE 4D (PDE4D) IS ASSOCIATED WITH INCREASED AHR. HOWEVER, EPIGENETIC REGULATION OF THIS GENE IN ASTHMATIC AIRWAY SMOOTH MUSCLE CELLS (ASMCS) HAS NOT BEEN EXAMINED. IN THIS STUDY, WE AIMED TO EXAMINE THE RELATIONSHIP BETWEEN EPIGENETIC REGULATION OF PDE4D AND ASMC PHENOTYPES. WE IDENTIFIED CPG SITE-SPECIFIC HYPOMETHYLATION AT PDE4D PROMOTER IN HUMAN ASTHMATIC ASMCS. WE NEXT USED METHYLATED OLIGONUCLEOTIDES TO INTRODUCE CPG SITE-SPECIFIC METHYLATION AT PDE4D PROMOTER AND EXAMINED ITS EFFECT ON ASMCS. WE SHOWED THAT PDE4D METHYLATION DECREASED CELL PROLIFERATION AND MIGRATION OF ASTHMATIC ASMCS. WE FURTHER ELUCIDATED THAT METHYLATED PDE4D DECREASED PDE4D EXPRESSION IN ASTHMATIC ASMCS, INCREASED CAMP LEVEL, AND INHIBITED THE ABERRANT INCREASE IN CA(2+) LEVEL. MOREOVER, PDE4D METHYLATION REDUCED THE PHOSPHORYLATION LEVEL OF DOWNSTREAM EFFECTORS OF CA(2+) SIGNALING, INCLUDING MYOSIN LIGHT CHAIN KINASE AND P38. TAKEN TOGETHER, OUR FINDINGS DEMONSTRATE THAT GENE-SPECIFIC EPIGENETIC CHANGES MAY PREDISPOSE ASMCS TO ASTHMA THROUGH ALTERATIONS IN CELL PHENOTYPES. MODULATION OF ASMC PHENOTYPES BY METHYLATED PDE4D OLIGONUCLEOTIDES CAN REVERSE THE ABERRANT ASMC FUNCTIONS TO NORMAL PHENOTYPES. THIS HAS PROVIDED NEW INSIGHT TO THE DEVELOPMENT OF NOVEL THERAPEUTIC OPTIONS FOR THIS DEBILITATIVE DISEASE. 2016 17 2432 32 EPIGENETIC SILENCING OF MIR-708 ENHANCES NF-KAPPAB SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. MICRORNAS (MIRNAS) ARE POST-TRANSCRIPTIONAL REGULATORS OF GENE EXPRESSION AND THEIR DEREGULATION IS INVOLVED IN TUMOR DEVELOPMENT. EPIGENETIC GENE SILENCING IN CANCER BY DNA METHYLATION CONTRIBUTES TO THE SILENCING OF TUMOR-SUPPRESSOR GENES, INCLUDING MIRNAS. WE HAVE RECENTLY SHOWN THAT THE PROMOTER OF MIR-708 IS ABERRANTLY METHYLATED IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). TO CHARACTERIZE THE MOLECULAR SIGNALING NETWORKS THAT ARE INFLUENCED BY MIR-708, WE PERFORMED A LUCIFERASE-BASED SCREEN EVALUATING THE EFFECTS OF ECTOPIC MIR-708 EXPRESSION ON LEUKEMIA-RELEVANT SIGNALING PATHWAYS. WE FOUND THAT MIR-708 STRONGLY REPRESSED NF-KAPPAB SIGNALING, A PATHWAY KNOWN TO BE DEREGULATED IN CLL. AMONG THE PREDICTED MIR-708 TARGETS WAS IKKBETA (INHIBITOR OF KAPPA LIGHT POLYPEPTIDE GENE ENHANCER IN B CELLS, KINASE-BETA/IKBKB), A KEY KINASE FACILITATING NF-KAPPAB SIGNALING. WE VALIDATED THE INTERACTION OF MIR-708 WITH THE 3'-UNTRANSLATED REGION OF IKKBETA AND FOUND THAT MIR-708 OVEREXPRESSION REPRESSES ENDOGENOUS IKKBETA. PHOSPHORYLATION OF THE IKKBETA TARGET IKAPPABALPHA AND EXPRESSION OF KNOWN NF-KAPPAB TARGET GENES WERE IMPAIRED BY MIR-708. FURTHERMORE, WE IDENTIFIED AN ENHANCER REGION DOWNSTREAM OF THE MIR-708 PROMOTER THAT DISPLAYS A DISTINCT DNA METHYLATION STATUS IN CLL. HIGH ENHANCER METHYLATION IS SIGNIFICANTLY CORRELATED WITH LOWER MIR-708 EXPRESSION AND IS PREDOMINANTLY FOUND IN PATIENTS WITH POOR PROGNOSIS AND SHORTER TIME TO TREATMENT. THESE RESULTS DEMONSTRATE THAT MIR-708 REGULATES THE NF-KAPPAB PATHWAY BY TARGETING IKKBETA, AND THAT METHYLATION OF A KEY ENHANCER REGION CONTRIBUTES TO ITS SUPPRESSION IN CLL. 2015 18 3327 27 HISTONE DEACETYLASE 4 PROMOTES CHOLESTATIC LIVER INJURY IN THE ABSENCE OF PROHIBITIN-1. PROHIBITIN-1 (PHB1) IS AN EVOLUTIONARILY CONSERVED PLEIOTROPIC PROTEIN THAT PARTICIPATES IN DIVERSE PROCESSES DEPENDING ON ITS SUBCELLULAR LOCALIZATION AND INTERACTOME. RECENT DATA HAVE INDICATED A DIVERSE ROLE FOR PHB1 IN THE PATHOGENESIS OF OBESITY, CANCER, AND INFLAMMATORY BOWEL DISEASE, AMONG OTHERS. DATA PRESENTED HERE SUGGEST THAT PHB1 IS ALSO LINKED TO CHOLESTATIC LIVER DISEASE. EXPRESSION OF PHB1 IS MARKEDLY REDUCED IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS AND BILIARY ATRESIA OR WITH ALAGILLE SYNDROME, TWO MAJOR PEDIATRIC CHOLESTATIC CONDITIONS. IN THE EXPERIMENTAL MODEL OF BILE DUCT LIGATION, SILENCING OF PHB1 INDUCED LIVER FIBROSIS, REDUCED ANIMAL SURVIVAL, AND INDUCED BILE DUCT PROLIFERATION. IMPORTANTLY, THE MODULATORY EFFECT OF PHB1 IS NOT DEPENDENT ON ITS KNOWN MITOCHONDRIAL FUNCTION. ALSO, PHB1 INTERACTS WITH HISTONE DEACETYLASE 4 (HDAC4) IN THE PRESENCE OF BILE ACIDS. HENCE, PHB1 DEPLETION LEADS TO INCREASED NUCLEAR HDAC4 CONTENT AND ITS ASSOCIATED EPIGENETIC CHANGES. REMARKABLY, HDAC4 SILENCING AND THE ADMINISTRATION OF THE HDAC INHIBITOR PARTHENOLIDE DURING OBSTRUCTIVE CHOLESTASIS IN VIVO PROMOTE GENOMIC REPROGRAMMING, LEADING TO REGRESSION OF THE FIBROTIC PHENOTYPE IN LIVER-SPECIFIC PHB1 KNOCKOUT MICE. CONCLUSION: PHB1 IS AN IMPORTANT MEDIATOR OF CHOLESTATIC LIVER INJURY THAT REGULATES THE ACTIVITY OF HDAC4, WHICH CONTROLS SPECIFIC EPIGENETIC MARKERS; THESE RESULTS IDENTIFY POTENTIAL NOVEL STRATEGIES TO TREAT LIVER INJURY AND FIBROSIS, PARTICULARLY AS A CONSEQUENCE OF CHRONIC CHOLESTASIS. 2015 19 5636 34 SERELAXIN ALLEVIATES CARDIAC FIBROSIS THROUGH INHIBITING ENDOTHELIAL-TO-MESENCHYMAL TRANSITION VIA RXFP1. RATIONALE: CARDIAC FIBROSIS IS AN INTEGRAL CONSTITUENT OF EVERY FORM OF CHRONIC HEART DISEASE, AND PERSISTENCE OF FIBROSIS REDUCES TISSUE COMPLIANCE AND ACCELERATES THE PROGRESSION TO HEART FAILURE. RELAXIN-2 IS A HUMAN HORMONE, WHICH HAS VARIOUS PHYSIOLOGICAL FUNCTIONS SUCH AS MEDIATING RENAL VASODILATION IN PREGNANCY. ITS RECOMBINANT FORM SERELAXIN HAS RECENTLY BEEN TESTED IN CLINICAL TRIALS AS A THERAPY FOR ACUTE HEART FAILURE BUT DID NOT MEET ITS PRIMARY ENDPOINTS. THE AIM OF THIS STUDY IS TO EXAMINE WHETHER SERELAXIN HAS AN ANTI-FIBROTIC EFFECT IN THE HEART AND THEREFORE COULD BE BENEFICIAL IN CHRONIC HEART FAILURE. METHODS: WE UTILIZED TWO DIFFERENT CARDIAC FIBROSIS MOUSE MODELS (ASCENDING AORTIC CONSTRICTION (AAC) AND ANGIOTENSIN II (ATII) ADMINISTRATION VIA OSMOTIC MINIPUMPS) TO ASSESS THE ANTI-FIBROTIC POTENTIAL OF SERELAXIN. HISTOLOGICAL ANALYSIS, IMMUNOFLUORESCENCE STAINING AND MOLECULAR ANALYSIS WERE PERFORMED TO ASSESS THE FIBROSIS LEVEL AND INDICATE ENDOTHELIAL CELLS WHICH ARE UNDERGOING ENDMT. IN VITRO TGFBETA1-INDUCED ENDOTHELIAL-TO-MESENCHYMAL TRANSITION (ENDMT) ASSAYS WERE PERFORMED IN HUMAN CORONARY ARTERY ENDOTHELIAL CELLS AND MOUSE CARDIAC ENDOTHELIAL CELLS (MCECS) AND WERE EXAMINED USING MOLECULAR METHODS. CHROMATIN IMMUNOPRECIPITATION-QPCR ASSAY WAS UTILIZED TO IDENTIFY THE SERELAXIN EFFECT ON CHROMATIN REMODELING IN THE RXFP1 PROMOTER REGION IN MCECS. RESULTS: OUR RESULTS DEMONSTRATE A SIGNIFICANT AND DOSE-DEPENDENT ANTI-FIBROTIC EFFECT OF SERELAXIN IN THE HEART IN BOTH MODELS. WE FURTHER SHOW THAT SERELAXIN MEDIATES THIS EFFECT, AT LEAST IN PART, THROUGH INHIBITION OF ENDMT THROUGH THE ENDOTHELIAL RELAXIN FAMILY PEPTIDE RECEPTOR 1 (RXFP1). WE FURTHER DEMONSTRATE THAT SERELAXIN ADMINISTRATION IS ABLE TO INCREASE ITS OWN RECEPTOR EXPRESSION (RXFP1) THROUGH EPIGENETIC REGULATION IN FORM OF HISTONE MODIFICATIONS BY ATTENUATING TGFBETA-PSMAD2/3 SIGNALING IN ENDOTHELIAL CELLS. CONCLUSIONS: THIS STUDY IS THE FIRST TO IDENTIFY THAT SERELAXIN INCREASES THE EXPRESSION OF ITS OWN RECEPTOR RXFP1 AND THAT THIS MEDIATES THE INHIBITION OF ENDMT AND CARDIAC FIBROSIS, SUGGESTING THAT SERELAXIN MAY HAVE A BENEFICIAL EFFECT AS ANTI-FIBROTIC THERAPY IN CHRONIC HEART FAILURE. 2020 20 493 29 ASSESSMENT OF P53 AND ATM FUNCTIONALITY IN CHRONIC LYMPHOCYTIC LEUKEMIA BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION. THE ATM-P53 DNA-DAMAGE RESPONSE (DDR) PATHWAY HAS A CRUCIAL ROLE IN CHEMORESISTANCE IN CLL, AS INDICATED BY THE ADVERSE PROGNOSTIC IMPACT OF GENETIC ABERRATIONS OF TP53 AND ATM. IDENTIFYING AND DISTINGUISHING TP53 AND ATM FUNCTIONAL DEFECTS HAS BECOME RELEVANT AS EPIGENETIC AND POSTTRANSCRIPTIONAL DYSREGULATION OF THE ATM/P53 AXIS IS INCREASINGLY BEING RECOGNIZED AS THE UNDERLYING CAUSE OF CHEMORESISTANCE. ALSO, SPECIFIC TREATMENTS SENSITIZING TP53- OR ATM-DEFICIENT CLL CELLS ARE EMERGING. WE THEREFORE DEVELOPED A NEW ATM-P53 FUNCTIONAL ASSAY WITH THE AIM TO (I) IDENTIFY AND (II) DISTINGUISH ABNORMALITIES OF TP53 VERSUS ATM AND (III) ENABLE THE IDENTIFICATION OF ADDITIONAL DEFECTS IN THE ATM-P53 PATHWAY. REVERSED TRANSCRIPTASE MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION (RT-MLPA) WAS USED TO MEASURE ATM AND/OR P53-DEPENDENT GENES AT THE RNA LEVEL FOLLOWING DNA DAMAGE USING IRRADIATION. HERE, WE SHOWED THAT THIS ASSAY IS ABLE TO IDENTIFY AND DISTINGUISH THREE SUBGROUPS OF CLL TUMORS (I.E., TP53-DEFECTIVE, ATM-DEFECTIVE AND WT) AND IS ALSO ABLE TO DETECT ADDITIONAL SAMPLES WITH A DEFECTIVE DDR, WITHOUT MOLECULAR ABERRATIONS IN TP53 AND/OR ATM. THESE FINDINGS MAKE THE ATM-P53 RT-MLPA FUNCTIONAL ASSAY A PROMISING PROGNOSTIC TOOL FOR PREDICTING TREATMENT RESPONSES IN CLL. 2015