1 2640 102 EPIGENOMIC AND TRANSCRIPTIONAL PROFILING IDENTIFIES IMPAIRED GLYOXYLATE DETOXIFICATION IN NAFLD AS A RISK FACTOR FOR HYPEROXALURIA. EPIGENETIC MODIFICATIONS (E.G. DNA METHYLATION) IN NAFLD AND THEIR CONTRIBUTION TO DISEASE PROGRESSION AND EXTRAHEPATIC COMPLICATIONS ARE POORLY EXPLORED. HERE, WE USE AN INTEGRATED EPIGENOME AND TRANSCRIPTOME ANALYSIS OF MOUSE NAFLD HEPATOCYTES AND IDENTIFY ALTERATIONS IN GLYOXYLATE METABOLISM, A PATHWAY RELEVANT IN KIDNEY DAMAGE VIA OXALATE RELEASE-A HARMFUL WASTE PRODUCT AND KIDNEY STONE-PROMOTING FACTOR. DOWNREGULATION AND HYPERMETHYLATION OF ALANINE-GLYOXYLATE AMINOTRANSFERASE (AGXT), WHICH DETOXIFIES GLYOXYLATE, PREVENTING EXCESSIVE OXALATE ACCUMULATION, IS ACCOMPANIED BY INCREASED OXALATE FORMATION AFTER METABOLISM OF THE PRECURSOR HYDROXYPROLINE. VIRAL-MEDIATED AGXT TRANSFER OR INHIBITING HYDROXYPROLINE CATABOLISM RESCUES EXCESSIVE OXALATE RELEASE. IN HUMAN STEATOTIC HEPATOCYTES, AGXT IS ALSO DOWNREGULATED AND HYPERMETHYLATED, AND IN NAFLD ADOLESCENTS, STEATOSIS SEVERITY CORRELATES WITH URINARY OXALATE EXCRETION. THUS, THIS WORK IDENTIFIES A REDUCED CAPACITY OF THE STEATOTIC LIVER TO DETOXIFY GLYOXYLATE, TRIGGERING ELEVATED OXALATE, AND PROVIDES A MECHANISTIC EXPLANATION FOR THE INCREASED RISK OF KIDNEY STONES AND CHRONIC KIDNEY DISEASE IN NAFLD PATIENTS. 2021 2 760 17 CASZ1: CURRENT IMPLICATIONS IN CARDIOVASCULAR DISEASES AND CANCERS. CASTOR ZINC FINGER 1 (CASZ1) IS A C2H2 ZINC FINGER FAMILY PROTEIN THAT HAS TWO SPLICING VARIANTS, CASZ1A AND CASZ1B. IT IS INVOLVED IN MULTIPLE PHYSIOLOGICAL PROCESSES, SUCH AS TISSUE DIFFERENTIATION AND ALDOSTERONE ANTAGONISM. GENETIC AND EPIGENETIC ALTERNATIONS OF CASZ1 HAVE BEEN CHARACTERIZED IN MULTIPLE CARDIOVASCULAR DISORDERS, SUCH AS CONGENITAL HEART DISEASES, CHRONIC VENOUS DISEASES, AND HYPERTENSION. HOWEVER, LITTLE IS KNOWN ABOUT HOW CASZ1 MECHANICALLY PARTICIPATES IN THE PATHOGENESIS OF THESE DISEASES. OVER THE PAST DECADES, AT FIRST GLANCE, PARADOXICAL INFLUENCES ON CELL BEHAVIORS AND PROGRESSIONS OF DIFFERENT CANCER TYPES HAVE BEEN DISCOVERED FOR CASZ1, WHICH MAY BE EXPLAINED BY A "DOUBLE-AGENT" ROLE FOR CASZ1. IN THIS REVIEW, WE DISCUSS THE PHYSIOLOGICAL FUNCTION OF CASZ1, AND FOCUS ON THE ASSOCIATION OF CASZ1 ABERRATIONS WITH THE PATHOGENESIS OF CARDIOVASCULAR DISEASES AND CANCERS. 2023 3 238 17 ADENOSINE KINASE: A KEY REGULATOR OF PURINERGIC PHYSIOLOGY. ADENOSINE (ADO) IS AN ESSENTIAL BIOMOLECULE FOR LIFE THAT PROVIDES CRITICAL REGULATION OF ENERGY UTILIZATION AND HOMEOSTASIS. ADENOSINE KINASE (ADK) IS AN EVOLUTIONARY ANCIENT RIBOKINASE DERIVED FROM BACTERIAL SUGAR KINASES THAT IS WIDELY EXPRESSED IN ALL FORMS OF LIFE, TISSUES AND ORGAN SYSTEMS THAT TIGHTLY REGULATES INTRACELLULAR AND EXTRACELLULAR ADO CONCENTRATIONS. THE FACILE ABILITY OF ADK TO ALTER ADO AVAILABILITY PROVIDES A "SITE AND EVENT" SPECIFICITY TO THE ENDOGENOUS PROTECTIVE EFFECTS OF ADO IN SITUATIONS OF CELLULAR STRESS. IN ADDITION TO MODULATING THE ABILITY OF ADO TO ACTIVATE ITS COGNATE RECEPTORS (P1 RECEPTORS), NUCLEAR ADK ISOFORM ACTIVITY HAS BEEN LINKED TO EPIGENETIC MECHANISMS BASED ON TRANSMETHYLATION PATHWAYS. PREVIOUS DRUG DISCOVERY RESEARCH HAS TARGETED ADK INHIBITION AS A THERAPEUTIC APPROACH TO MANAGE EPILEPSY, PAIN, AND INFLAMMATION. THESE EFFORTS GENERATED MULTIPLE CLASSES OF HIGHLY POTENT AND SELECTIVE INHIBITORS. HOWEVER, CLINICAL DEVELOPMENT OF EARLY ADK INHIBITORS WAS STOPPED DUE TO APPARENT MECHANISTIC TOXICITY AND THE LACK OF SUITABLE TRANSLATIONAL MARKERS. NEW INSIGHTS REGARDING THE POTENTIAL ROLE OF THE NUCLEAR ADK ISOFORM (ADK-LONG) IN THE EPIGENETIC MODULATION OF MALADAPTIVE DNA METHYLATION OFFERS THE POSSIBILITY OF IDENTIFYING NOVEL ADK-ISOFORM SELECTIVE INHIBITORS AND NEW INTERVENTIONAL STRATEGIES THAT ARE INDEPENDENT OF ADO RECEPTOR ACTIVATION. 2021 4 1679 24 DRUG RESISTANCE IN GIARDIA DUODENALIS. GIARDIA DUODENALIS IS A MICROAEROPHILIC PARASITE OF THE HUMAN GASTROINTESTINAL TRACT AND A MAJOR CONTRIBUTOR TO DIARRHEAL AND POST-INFECTIOUS CHRONIC GASTROINTESTINAL DISEASE WORLD-WIDE. TREATMENT OF G. DUODENALIS INFECTION CURRENTLY RELIES ON A SMALL NUMBER OF DRUG CLASSES. NITROHETEROCYCLICS, IN PARTICULAR METRONIDAZOLE, HAVE REPRESENTED THE FRONT LINE TREATMENT FOR THE LAST 40 YEARS. NITROHETEROCYCLIC-RESISTANT G. DUODENALIS HAVE BEEN ISOLATED FROM PATIENTS AND CREATED IN VITRO, PROMPTING CONSIDERABLE RESEARCH INTO THE BIOMOLECULAR MECHANISMS OF RESISTANCE. THESE COMPOUNDS ARE REDOX-ACTIVE AND ARE BELIEVED TO DAMAGE PROTEINS AND DNA AFTER BEING ACTIVATED BY OXIDOREDUCTASE ENZYMES IN METABOLICALLY ACTIVE CELLS. IN THIS REVIEW, WE EXPLORE THE MOLECULAR PHENOTYPES OF NITROHETEROCYCLIC-RESISTANT G. DUODENALIS DESCRIBED TO DATE IN THE CONTEXT OF THE PROTIST'S UNUSUAL GLYCOLYTIC AND ANTIOXIDANT SYSTEMS. WE PROPOSE THAT RESISTANCE MECHANISMS ARE LIKELY TO EXTEND WELL BEYOND CURRENTLY DESCRIBED RESISTANCE-ASSOCIATED ENZYMES (I.E., PYRUVATE FERREDOXIN OXIDOREDUCTASES AND NITROREDUCTASES), TO INCLUDE NAD(P)H- AND FLAVIN-GENERATING PATHWAYS, AND POSSIBLY REDOX-SENSITIVE EPIGENETIC REGULATION. MECHANISMS THAT ALLOW G. DUODENALIS TO TOLERATE OXIDATIVE STRESS MAY LEAD TO RESISTANCE AGAINST BOTH OXYGEN AND NITROHETEROCYCLICS, WITH IMPLICATIONS FOR CLINICAL CONTROL. THE PRESENT REVIEW HIGHLIGHTS THE POTENTIAL FOR SYSTEMS BIOLOGY TOOLS AND ADVANCED BIOINFORMATICS TO FURTHER INVESTIGATE THE MULTIFACETED MECHANISMS OF NITROHETEROCYCLIC RESISTANCE IN THIS IMPORTANT PATHOGEN. 2015 5 2080 33 EPIGENETIC DNA METHYLATION OF EBI3 MODULATES HUMAN INTERLEUKIN-35 FORMATION VIA NFKB SIGNALING: A PROMISING THERAPEUTIC OPTION IN ULCERATIVE COLITIS. ULCERATIVE COLITIS (UC), A SEVERE CHRONIC DISEASE WITH UNCLEAR ETIOLOGY THAT IS ASSOCIATED WITH INCREASED RISK FOR COLORECTAL CANCER, IS ACCOMPANIED BY DYSREGULATION OF CYTOKINES. EPSTEIN-BARR VIRUS-INDUCED GENE 3 (EBI3) ENCODES A SUBUNIT IN THE UNIQUE HETERODIMERIC IL-12 CYTOKINE FAMILY OF EITHER PRO- OR ANTI-INFLAMMATORY FUNCTION. AFTER HAVING RECENTLY DEMONSTRATED THAT UPREGULATION OF EBI3 BY HISTONE ACETYLATION ALLEVIATES DISEASE SYMPTOMS IN A DEXTRAN SULFATE SODIUM (DSS)-TREATED MOUSE MODEL OF CHRONIC COLITIS, WE NOW AIMED TO EXAMINE A POSSIBLE FURTHER EPIGENETIC REGULATION OF EBI3 BY DNA METHYLATION UNDER INFLAMMATORY CONDITIONS. TREATMENT WITH THE DNA METHYLTRANSFERASE INHIBITOR (DNMTI) DECITABINE (DAC) AND TNFALPHA LED TO SYNERGISTIC UPREGULATION OF EBI3 IN HUMAN COLON EPITHELIAL CELLS (HCEC). USE OF DIFFERENT SIGNALING PATHWAY INHIBITORS INDICATED NFKAPPAB SIGNALING WAS NECESSARY AND PROPORTIONAL TO THE SYNERGISTIC EBI3 INDUCTION. MALDI-TOF/MS AND HPLC-ESI-MS/MS ANALYSIS OF DAC/TNFALPHA-TREATED HCEC IDENTIFIED IL-12P35 AS THE MOST PROBABLE BINDING PARTNER TO FORM A FUNCTIONAL PROTEIN. EBI3/IL-12P35 HETERODIMERS (IL-35) INDUCE THEIR OWN GENE UPREGULATION, SOMETHING THAT WAS INDEED OBSERVED IN HCEC CULTURED WITH MEDIA FROM PREVIOUSLY DAC/TNFALPHA-TREATED HCEC. THESE RESULTS SUGGEST THAT UNDER INFLAMMATORY AND DEMETHYLATING CONDITIONS THE UPREGULATION OF EBI3 RESULTS IN THE FORMATION OF ANTI-INFLAMMATORY IL-35, WHICH MIGHT BE CONSIDERED AS A THERAPEUTIC TARGET IN COLITIS. 2021 6 681 30 BRAIN LIPOTOXICITY OF PHYTANIC ACID AND VERY LONG-CHAIN FATTY ACIDS. HARMFUL CELLULAR/MITOCHONDRIAL ACTIVITIES IN REFSUM DISEASE AND X-LINKED ADRENOLEUKODYSTROPHY. IT IS INCREASINGLY UNDERSTOOD THAT IN THE AGING BRAIN, ESPECIALLY IN THE CASE OF PATIENTS SUFFERING FROM NEURODEGENERATIVE DISEASES, SOME FATTY ACIDS AT PATHOLOGICALLY HIGH CONCENTRATIONS EXERT DETRIMENTAL ACTIVITIES. TO STUDY SUCH ACTIVITIES, WE HERE ANALYZE GENETIC DISEASES, WHICH ARE DUE TO COMPROMISED METABOLISM OF SPECIFIC FATTY ACIDS, EITHER THE BRANCHED-CHAIN PHYTANIC ACID OR VERY LONG-CHAIN FATTY ACIDS (VLCFAS). MICROMOLAR CONCENTRATIONS OF PHYTANIC ACID OR OF VLCFAS DISTURB THE INTEGRITY OF NEURAL CELLS BY IMPAIRING CA(2+) HOMEOSTASIS, ENHANCING OXIDATIVE STRESS OR DE-ENERGIZING MITOCHONDRIA. FINALLY, THESE COMBINED HARMFUL ACTIVITIES ACCELERATE CELL DEATH. MITOCHONDRIA ARE MORE SEVERELY TARGETED BY PHYTANIC ACID THAN BY VLCFAS. THE INSERTION OF VLCFAS INTO THE INNER MEMBRANE DISTORTS THE ARRANGEMENT OF MEMBRANE CONSTITUENTS AND THEIR FUNCTIONAL INTERACTIONS. PHYTANIC ACID EXERTS SPECIFIC PROTONOPHORIC ACTIVITY, INDUCES REACTIVE OXYGEN SPECIES (ROS) GENERATION, AND REDUCES ATP GENERATION. A CLEAR INHIBITION OF THE NA(+), K(+)-ATPASE ACTIVITY BY PHYTANIC ACID HAS ALSO BEEN REPORTED. IN ADDITION TO THE INSTANTANEOUS EFFECTS, A CHRONIC EXPOSURE OF BRAIN CELLS TO LOW MICROMOLAR CONCENTRATIONS OF PHYTANIC ACID MAY PRODUCE NEURONAL DAMAGE IN REFSUM DISEASE BY ALTERING EPIGENETIC TRANSCRIPTIONAL REGULATION. MYELIN-PRODUCING OLIGODENDROCYTES RESPOND WITH PARTICULAR SENSITIVITY TO VLCFAS. DELETERIOUS ACTIVITY OF VLCFAS ON ENERGY-DEPENDENT MITOCHONDRIAL FUNCTIONS DECLINES WITH INCREASING THE HYDROCARBON CHAIN LENGTH (C22:0 > C24:0 > C26:0). IN CONTRAST, THE REVERSE SEQUENCE HOLDS TRUE FOR CELL DEATH INDUCTION BY VLCFAS (C22:0 < C24:0 < C26:0). IN ADRENOLEUKODYSTROPHY, THE UPTAKE OF VLCFAS BY PEROXISOMES IS IMPAIRED BY DEFECTS OF THE ABCD1 TRANSPORTER. STUDYING MITOCHONDRIA FROM ABCD1-DEFICIENT AND WILD-TYPE MICE PROVES THAT THE ENERGY-DEPENDENT FUNCTIONS ARE NOT ALTERED IN THE DISEASE MODEL. THUS, A DEFECTIVE ABCD1 APPARENTLY EXERTS NO OBVIOUS ADAPTIVE PRESSURE ON MITOCHONDRIA. FURTHER RESEARCH HAS TO ELUCIDATE THE DETAILED MECHANISTIC BASIS FOR THE FAILURES CAUSING FATTY ACID-MEDIATED NEURODEGENERATION AND SHOULD HELP TO PROVIDE POSSIBLE THERAPEUTIC INTERVENTIONS. 2016 7 3239 29 HEPATIC INACTIVATION OF THE TYPE 2 DEIODINASE CONFERS RESISTANCE TO ALCOHOLIC LIVER STEATOSIS. BACKGROUND: A MOUSE WITH HEPATOCYTE-SPECIFIC DEIODINASE TYPE II INACTIVATION (ALB-D2KO) IS RESISTANT TO DIET-INDUCED OBESITY, HEPATIC STEATOSIS, AND HYPERTRIGLYCERIDEMIA DUE TO PERINATAL EPIGENETIC MODIFICATIONS IN THE LIVER. THIS PHENOTYPE IS LINKED TO LOW LEVELS OF ZFP125, A HEPATIC TRANSCRIPTIONAL REPRESSOR THAT PROMOTES LIVER STEATOSIS BY INHIBITING GENES INVOLVED IN PACKAGING AND SECRETION OF VERY-LOW-DENSITY LIPOPROTEIN. METHODS: HERE, WE USED CHRONIC AND BINGE ETHANOL (ETOH) IN MICE TO CAUSE LIVER STEATOSIS. RESULTS: THE ETOH TREATMENT CAUSES A 2.3-FOLD INCREASE IN HEPATIC TRIGLYCERIDE CONTENT; ZFP125 LEVELS WERE APPROXIMATELY 50% HIGHER IN THESE ANIMALS. IN CONTRAST, ALB-D2KO MICE DID NOT DEVELOP ETOH-INDUCED LIVER STEATOSIS. THEY ALSO FAILED TO ELEVATE ZFP125 TO THE SAME LEVELS, DESPITE BEING ON THE ETOH-CONTAINING DIET FOR THE SAME PERIOD OF TIME. THEIR PHENOTYPE WAS ASSOCIATED WITH 1.3- TO 2.9-FOLD UP-REGULATION OF HEPATIC GENES INVOLVED IN LIPID TRANSPORT AND EXPORT THAT ARE NORMALLY REPRESSED BY ZFP125, THAT IS, MTTP, ABCA1, LDLR, APOC1, APOC3, APOE, APOH, AND AZGP1. FURTHERMORE, GENES INVOLVED IN THE ETOH METABOLIC PATHWAY, THAT IS, ALDH2 AND ACSS2, WERE ALSO 1.6- TO 3.1-FOLD UP-REGULATED IN ALB-D2KO ETOH MICE COMPARED WITH CONTROL ANIMALS KEPT ON ETOH. CONCLUSIONS: ETOH CONSUMPTION ELEVATES EXPRESSION OF ZFP125. ALB-D2KO ANIMALS, WHICH HAVE LOWER LEVELS OF ZFP125, ARE MUCH LESS SUSCEPTIBLE TO ETOH-INDUCED LIVER STEATOSIS. 2019 8 5511 19 RIBONUCLEASES IN TUMOR GROWTH. THIS REVIEW SUMMARIZES DATA ON AMBIGUOUS BIOLOGICAL FUNCTIONS OF RIBONUCLEASES (RNASES) AT TUMOR GROWTH. IN SOME CASES THE RAISED LEVEL OF ENZYME ACTIVITY IN BIOLOGICAL FLUIDS CAN BE REGARDED AS AN ADDITIONAL MARKER OF MALIGNANT GROWTH (PANCREAS CANCER, CHRONIC MYELOID LEUKEMIA, ETC.). AT THE SAME TIME THE ACTIVITY OF RNASES IS OFTEN LOWERED IN TUMOR TISSUE. HIGH SUBSTRATE SPECIFICITY OF PARTICULAR RNASES PROVIDES METABOLIC BALANCE BETWEEN VARIOUS KINDS OF RNAS WITH VARIOUS HALF-TIME EXCHANGE TURN. RNASES ARE THE IMPORTANT FACTORS OF EPIGENETIC REGULATION OF GENE ACTIVITY IN CELLS. THE ACTIVITY OF RNASES IS ADJUSTABLE BY INHIBITORS AND OTHER FACTORS, AND DEFINES TIME OF EXISTENCE OF DIFFERENT KINDS OF RNAS. RNASES (THE MODIFIED VARIANTS OF RNASE A, RNASES OF SEMEN FLUID OF THE CATTLE, RNASE OF AMPHIBIA OOCYTES) CAN BE USED AS ANTI-TUMOR THERAPEUTIC AGENTS. ON THE OTHER HAND, SOME INHIBITORS OF RNASES OF NATURAL OR SYNTHETIC ORIGIN WERE DEMONSTRATED TO BE PERSPECTIVE DRUGS THAT INHIBIT TUMOR GROWTH. 2009 9 1016 22 CIITA EXPRESSION IS REGULATED BY HISTONE DEACETYLASE ENZYMES AND HAS A ROLE IN ALPHA-SYNUCLEIN PRE-FORMED FIBRIL-INDUCED ANTIGEN PRESENTATION IN MURINE MICROGLIAL CELL LINE. AIM: PARKINSON'S DISEASE (PD) IS A CHRONIC NEURODEGENERATIVE DISORDER RELATED WITH SEVERAL GENETIC AND EPIGENETIC FACTORS. IN THE CONTEXT OF EPIGENETIC FACTORS, HISTONE ACETYLATION IS ONE OF THE MOST ASSOCIATED MECHANISMS WITH PARKINSON'S DISEASE PROGRESSION. THIS STUDY INVESTIGATES THE EFFECTS OF THE INCREASED HISTONE ACETYLATION ON ANTIGEN PRESENTATION IN MICROGLIAL CELLS WHICH WERE INDUCED BY PRE-FORMED FIBRILS OF ALPHA-SYNUCLEIN (PFF ALPHA-SYNUCLEIN). METHODS: PARKINSON'S DISEASE MODEL WAS CREATED WITH PFF ALPHA-SYNUCLEIN ADMINISTRATION TO THE BV-2 MICROGLIAL CELLS. BV-2 CELLS WERE CO-TREATED WITH CUDC-907 AND TMP-195 TO INCREASE HISTONE ACETYLATION IN THE PRESENCE OF ALPHA-SYNUCLEIN. ANTIGEN REPRESENTATION WAS EVALUATED BY DETERMINING EXPRESSION LEVELS OF MAJOR HISTOCOMPATIBILITY COMPLEX-II (MHC-II) AND CLASS-II MAJOR HISTOCOMPATIBILITY COMPLEX (CIITA). RESULTS: OUR RESULTS SHOWED THAT PFF ALPHA-SYNUCLEIN SIGNIFICANTLY INCREASED MHC-II EXPRESSION, AND THAT EFFECT WAS MOST SEVERE AT 6 H OF ADMINISTRATION OF ALPHA-SYNUCLEIN. INCREASING HISTONE ACETYLATION VIA CUDC-907 AND TMP-195 ENHANCED MHC-II LEVELS EXPRESSION, WHICH WAS MORE SEVERE IN CUDC-907. ADDITIONALLY, CIITA EXPRESSION LEVELS WERE SIGNIFICANTLY INCREASED WITH PFF ALPHA-SYNUCLEIN ADMINISTRATION AND INTENSIFIED WITH THE CO-TREATMENT OF CUDC-907 AND TMP-195. FURTHERMORE, PFF ALPHA-SYNUCLEIN CAUSED A TIME-DEPENDENT INCREASE IN THE IFN-GAMMA (IFN-?) AND INTERLEUKIN-16(IL-16) LEVELS, AND THAT INCREASE WAS POTENTIATED WITH CUDC-907 AND TMP-195. CONCLUSION: CHANGES IN MHC-II AND CIITA EXPRESSION INDICATE THAT HISTONE ACETYLATION INCREASES THE ANTIGEN PRESENTATION PROPERTIES OF MICROGLIAL CELLS AFTER PFF ALPHA-SYNUCLEIN OR HISTONE DEACETYLASE INHIBITOR (HDACI) ADMINISTRATION. OUR RESULTS SHOW THAT MICROGLIAL ANTIGEN PRESENTATION MIGHT HAVE AN ESSENTIAL ROLE IN THE PATHOLOGY OF PARKINSON'S DISEASE, AND ALPHA-SYNUCLEIN LIKELY TO PLAY A PRIMARY ROLE IN THIS MECHANISM. 2022 10 768 20 CD47 (CLUSTER OF DIFFERENTIATION 47). CD47, ALSO KNOWN AS INTEGRIN-ASSOCIATED PROTEIN, IS A CONSTITUTIVELY AND UBIQUITOUSLY EXPRESSED TRANSMEMBRANE RECEPTOR. CD47 IS CONSERVED ACROSS AMNIOTES INCLUDING MAMMALS, REPTILES, AND BIRDS. EXPRESSION IS INCREASED IN MANY CANCERS AND, IN NON-MALIGNANT CELLS, BY STRESS AND WITH AGING. THE UP-REGULATION OF CD47 EXPRESSION IS GENERALLY EPIGENETIC, WHEREAS GENE AMPLIFICATION OCCURS WITH LOW FREQUENCY IN SOME CANCERS. CD47 IS A HIGH AFFINITY SIGNALING RECEPTOR FOR THE SECRETED PROTEIN THROMBOSPONDIN-1 (THBS1) AND THE COUNTER-RECEPTOR FOR SIGNAL REGULATORY PROTEIN-ALPHA (SIRPA, SIRPALPHA) AND SIRPGAMMA (SIRPG). CD47 INTERACTION WITH SIRPALPHA SERVES AS A MARKER OF SELF TO INNATE IMMUNE CELLS AND THEREBY PROTECTS CANCER CELLS FROM PHAGOCYTIC CLEARANCE. CONSEQUENTLY, HIGHER CD47 CORRELATES WITH A POOR PROGNOSIS IN SOME CANCERS, AND THERAPEUTIC BLOCKADE CAN SUPPRESS TUMOR GROWTH BY ENHANCING INNATE ANTITUMOR IMMUNITY. CD47 EXPRESSED ON CYTOTOXIC T CELLS, DENDRITIC CELLS, AND NK CELLS MEDIATES INHIBITORY THBS1 SIGNALING THAT FURTHER LIMITS ANTITUMOR IMMUNITY. CD47 LATERALLY ASSOCIATES WITH SEVERAL INTEGRINS AND THEREBY REGULATES CELL ADHESION AND MIGRATION. CD47 HAS ADDITIONAL LATERAL BINDING PARTNERS IN SPECIFIC CELL TYPES, AND LIGATION OF CD47 IN SOME CASES MODULATES THEIR FUNCTION. THBS1-CD47 SIGNALING IN NON-MALIGNANT CELLS INHIBITS NITRIC OXIDE/CGMP, CALCIUM, AND VEGF SIGNALING, MITOCHONDRIAL HOMEOSTASIS, STEM CELL MAINTENANCE, PROTECTIVE AUTOPHAGY, AND DNA DAMAGE RESPONSE, AND PROMOTES NADPH OXIDASE ACTIVITY. CD47 SIGNALING IS A PHYSIOLOGICAL REGULATOR OF PLATELET ACTIVATION, ANGIOGENESIS AND BLOOD FLOW. THBS1/CD47 SIGNALING IS FREQUENTLY DYSREGULATED IN CHRONIC DISEASES. 2021 11 1951 24 EPIGENETIC ACTIVATION OF THE TUSC3 GENE AS A POTENTIAL THERAPY FOR XMEN DISEASE. BACKGROUND: X-LINKED MAGT1 DEFICIENCY WITH INCREASED SUSCEPTIBILITY TO EPSTEIN-BARR VIRUS INFECTION AND N-LINKED GLYCOSYLATION DEFECT (XMEN) DISEASE IS A RARE COMBINED IMMUNODEFICIENCY CAUSED BY LOSS-OF-FUNCTION MUTATIONS IN THE MAGNESIUM TRANSPORTER 1 (MAGT1) GENE. MAGT1 DEFICIENCY IMPAIRS MAGNESIUM TRANSPORT AND THE N-LINKED GLYCOSYLATION OF A PANEL OF PROTEINS, WHICH SUBSEQUENTLY ABOLISHES THE EXPRESSION OF KEY IMMUNE RECEPTORS SUCH AS NATURAL KILLER GROUP 2, MEMBER D (AKA NKG2D). THESE EFFECTS INDUCE IMMUNE SYSTEM ABNORMALITIES, CHRONIC EPSTEIN-BARR VIRUS INFECTION, AND NEOPLASIA. RECENT RESEARCH SHOWS THAT MAGT1 AND TUMOR CANDIDATE SUPPRESSOR 3 (TUSC3) SHARE HIGH SEQUENCE AND FUNCTIONAL SIMILARITY. OBJECTIVE: WE SOUGHT TO INVESTIGATE THE FEASIBILITY OF ACTIVATING TUSC3 EXPRESSION TO PROVIDE A POTENTIAL THERAPEUTIC STRATEGY FOR XMEN DISEASE. METHODS: THE EXPRESSION PROFILES OF MAGT1 AND TUSC3 WERE ANALYZED USING MULTIPLE DATABASES, REAL-TIME QUANTITATIVE PCR, AND WESTERN BLOT. THE EFFECTS OF DECITABINE AND PANOBINOSTAT ON THE REGULATION OF TUSC3 EXPRESSION WERE EXPLORED IN BOTH MAGT1 KNOCKOUT (KO)/PATIENT-DERIVED LYMPHOCYTES AND MAGT1 KO HEPATOCYTES. RESULTS: ALTHOUGH TUSC3 IS WIDELY EXPRESSED, IT IS UNDETECTABLE SPECIFICALLY IN THE IMMUNE SYSTEM AND LIVER, CONSISTENT WITH THE MAIN DISEASED TISSUES IN PATIENTS WITH XMEN DISEASE. CRISPR/CAS9-MEDIATED KO OF MAGT1 IN THE NKL CELL LINE SUCCESSFULLY MIMICKED THE PHENOTYPES OF XMEN PATIENT-DERIVED LYMPHOCYTES, AND EXOGENOUS EXPRESSION OF TUSC3 RESCUED THE DEFICIENCIES IN KO NKL CELLS. USING THIS IN VITRO MODEL, WE IDENTIFIED 2 EPIGENETIC DRUGS, DECITABINE AND PANOBINOSTAT, BY SCREENING. COMBINATION TREATMENT USING THESE 2 DRUGS SIGNIFICANTLY UPREGULATED TUSC3 EXPRESSION AND RESCUED THE IMMUNE AND LIVER ABNORMALITIES. CONCLUSIONS: EPIGENETIC ACTIVATION OF TUSC3 EXPRESSION CONSTITUTES AN EFFECTIVE THERAPEUTIC STRATEGY FOR XMEN DISEASE. 2023 12 2263 25 EPIGENETIC PROGRAMMING AT THE MOGAT1 LOCUS MAY LINK NEONATAL OVERNUTRITION WITH LONG-TERM HEPATIC STEATOSIS AND INSULIN RESISTANCE. POSTNATAL OVERFEEDING INCREASES THE RISK OF CHRONIC DISEASES LATER IN LIFE, INCLUDING OBESITY, INSULIN RESISTANCE, HEPATIC STEATOSIS, AND TYPE 2 DIABETES. EPIGENETIC MECHANISMS MIGHT UNDERLIE THE LONG-LASTING EFFECTS ASSOCIATED WITH EARLY NUTRITION. HERE WE AIMED TO EXPLORE THE MOLECULAR PATHWAYS INVOLVED IN EARLY DEVELOPMENT OF INSULIN RESISTANCE AND HEPATIC STEATOSIS, AND WE EXAMINED THE POTENTIAL CONTRIBUTION OF DNA METHYLATION AND HISTONE MODIFICATIONS TO LONG-TERM PROGRAMMING OF METABOLIC DISEASE. WE USED A WELL-CHARACTERIZED MOUSE MODEL OF NEONATAL OVERFEEDING AND EARLY ADIPOSITY BY LITTER SIZE REDUCTION. NEONATAL OVERFEEDING LED TO HEPATIC INSULIN RESISTANCE VERY EARLY IN LIFE THAT PERSISTED THROUGHOUT ADULTHOOD DESPITE NORMALIZING FOOD INTAKE. UP-REGULATION OF MONOACYLGLYCEROL O-ACYLTRANSFERASE ( MOGAT) 1 CONCEIVABLY MEDIATES HEPATIC STEATOSIS AND INSULIN RESISTANCE THROUGH INCREASING INTRACELLULAR DIACYLGLYCEROL CONTENT. EARLY AND SUSTAINED DEREGULATION OF MOGAT1 WAS ASSOCIATED WITH A COMBINATION OF HISTONE MODIFICATIONS THAT MIGHT FAVOR MOGAT1 EXPRESSION. IN SUM, POSTNATAL OVERFEEDING CAUSES EXTREMELY RAPID DERANGEMENTS OF HEPATIC INSULIN SENSITIVITY THAT REMAIN RELATIVELY STABLE UNTIL ADULTHOOD. EPIGENETIC MECHANISMS, PARTICULARLY HISTONE MODIFICATIONS, COULD CONTRIBUTE TO SUCH LONG-LASTING EFFECTS. OUR DATA SUGGEST THAT TARGETING HEPATIC MONOACYLGLYCEROL ACYLTRANSFERASE ACTIVITY DURING EARLY LIFE MIGHT PROVIDE A NOVEL STRATEGY TO IMPROVE HEPATIC INSULIN SENSITIVITY AND PREVENT LATE-ONSET INSULIN RESISTANCE AND FATTY LIVER DISEASE.-RAMON-KRAUEL, M., PENTINAT, T., BLOKS, V. W., CEBRIA, J., RIBO, S., PEREZ-WIENESE, R., VILA, M., PALACIOS-MARIN, I., FERNANDEZ-PEREZ, A., VALLEJO, M., TELLEZ, N., RODRIGUEZ, M. A., YANES, O., LERIN, C., DIAZ, R., PLOSCH, T., TIETGE, U. J. F., JIMENEZ-CHILLARON, J. C. EPIGENETIC PROGRAMMING AT THE MOGAT1 LOCUS MAY LINK NEONATAL OVERNUTRITION WITH LONG-TERM HEPATIC STEATOSIS AND INSULIN RESISTANCE. 2018 13 35 19 A CHROMATIN ACTIVITY-BASED CHEMOPROTEOMIC APPROACH REVEALS A TRANSCRIPTIONAL REPRESSOME FOR GENE-SPECIFIC SILENCING. IMMUNE CELLS DEVELOP ENDOTOXIN TOLERANCE (ET) AFTER PROLONGED STIMULATION. ET INCREASES THE LEVEL OF A REPRESSION MARK H3K9ME2 IN THE TRANSCRIPTIONALLY SILENT CHROMATIN SPECIFICALLY ASSOCIATED WITH PRO-INFLAMMATORY GENES. HOWEVER, IT IS NOT CLEAR WHAT PROTEINS ARE FUNCTIONALLY INVOLVED IN THIS PROCESS. HERE WE SHOW THAT A NOVEL CHROMATIN ACTIVITY-BASED CHEMOPROTEOMIC (CHAC) APPROACH CAN DISSECT THE FUNCTIONAL CHROMATIN PROTEIN COMPLEXES THAT REGULATE ET-ASSOCIATED INFLAMMATION. USING UNC0638 THAT BINDS THE ENZYMATICALLY ACTIVE H3K9-SPECIFIC METHYLTRANSFERASE G9A/GLP, CHAC REVEALS THAT G9A IS CONSTITUTIVELY ACTIVE AT A G9A-DEPENDENT MEGA-DALTON REPRESSOME IN PRIMARY ENDOTOXIN-TOLERANT MACROPHAGES. G9A/GLP BROADLY IMPACTS THE ET-SPECIFIC REPROGRAMMING OF THE HISTONE CODE LANDSCAPE, CHROMATIN REMODELLING AND THE ACTIVITIES OF SELECT TRANSCRIPTION FACTORS. WE DISCOVER THAT THE G9A-DEPENDENT EPIGENETIC ENVIRONMENT PROMOTES THE TRANSCRIPTIONAL REPRESSION ACTIVITY OF C-MYC FOR GENE-SPECIFIC CO-REGULATION OF CHRONIC INFLAMMATION. CHAC MAY ALSO BE APPLICABLE TO DISSECT OTHER FUNCTIONAL PROTEIN COMPLEXES IN THE CONTEXT OF PHENOTYPIC CHROMATIN ARCHITECTURES. 2014 14 6636 30 UNRAVELING A NEW PLAYER IN MULTIPLE SCLEROSIS PATHOGENESIS: THE RNA-BINDING PROTEIN HUR. BACKGROUND: ELAV-LIKE PROTEINS ARE A SMALL FAMILY OF RNA-BINDING PROTEINS THAT ARE FUNDAMENTAL PLAYERS IN POST-TRANSCRIPTIONAL MECHANISMS AND ARE INVOLVED IN THE PATHOGENESIS OF NEUROLOGIC AND PSYCHIATRIC DISORDERS. HUR, THE UBIQUITOUSLY EXPRESSED MEMBER OF THE FAMILY, IS ALSO IMPLICATED IN SUSTAINING INFLAMMATION AND INFLAMMATORY DISEASES, SUPPORTING THE PRODUCTION OF PRO-INFLAMMATORY CYTOKINES. INFLAMMATION PLAYS A CENTRAL ROLE IN MULTIPLE SCLEROSIS (MS), WHICH REPRESENTS THE MOST COMMON CAUSE OF PERMANENT PHYSICAL DISABILITY IN YOUNG ADULTS. MS IS A CHRONIC AUTOIMMUNE DISEASE AFFECTING THE CENTRAL NERVOUS SYSTEM, WITH A COMPLEX AETIOLOGY INVOLVING GENETIC, ENVIRONMENTAL AND EPIGENETIC FACTORS. NO DATA ARE AVAILABLE ON THE POTENTIAL ENTANGLEMENT OF HUR IN MS PATHOGENESIS IN PATIENTS. IN THE PRESENT WORK, WE AIMED AT EXPLORING HUR PROTEIN LEVELS IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM MS PATIENTS, COMPARED TO HEALTHY CONTROLS. TO FURTHER ELUCIDATE THE POSSIBLE INVOLVEMENT OF HUR IN MS, WE ALSO INVESTIGATED THE RELATIONSHIP BETWEEN THIS SPECIFIC RNA-BINDING PROTEIN AND HSP70-2 PROTEIN, ALSO CONSIDERING THE HSP70-2 RS1061581 POLYMORPHISM, GIVEN THAT HSP70-2 MRNA HAS BEEN REPORTED AS A HUR TARGET AND THIS SPECIFIC POLYMORPHISM TO BE ASSOCIATED WITH MS RISK. METHODS: ALLELES AND GENOTYPES FOR HSP70-2 RS1061581 POLYMORPHISM WERE ASSESSED, BY USING A POLYMERASE CHAIN REACTION-RESTRICTION FRAGMENT LENGTH POLYMORPHISM, FOLLOWED BY DIGESTION WITH RESTRICTION ENZYME, IN MS PATIENTS AND HEALTHY CONTROLS. PBMCS FROM A SUBGROUP OF PATIENTS AND CONTROLS WERE USED TO EVALUATE HUR AND HSP70-2 PROTEIN CONTENT BY WESTERN BLOT. RESULTS: PBMCS FROM 52 MS PATIENTS HAD A LOWER HUR AND HIGHER HSP70-2 PROTEIN CONTENT COMPARED TO 43 HEALTHY CONTROLS. AN INCREASE OF 100 UNITS OF HUR SIGNIFICANTLY DECREASED THE RISK OF DEVELOPING MS BY 9.8% (OR: 0.902, 95% CI: 0.83-0.98), CONTROLLING FOR HSP70-2 PROTEIN EXPRESSION, HSP70-2 RS1061581 GENOTYPE, AGE AND SEX. MOREOVER, HOLDING HUR LEVELS, AN INCREASE OF 100 UNITS OF HSP70-2 PROTEIN SIGNIFICANTLY INCREASED THE MS RISK BY 18.1% (OR: 1.181, 95% CI: 1.03-1.36) AND THE GENETIC SUSCEPTIBILITY OF DEVELOPING MS FOR HSP70-2 RS1061581 GG CARRIERS IS CONFIRMED. OF INTEREST, MS PATIENTS WITH A MODERATE TO SEVERE FORM OF MS (MSSS >/= 3) SHOWED A TREND TOWARDS A REDUCTION OF HUR PROTEIN LEVELS COMPARED TO PATIENTS WITH MILD DISEASE SEVERITY (MSSS < 3). CONCLUSIONS: HUR PROTEIN LEVELS ARE REDUCED IN MS PATIENTS COMPARED TO HEALTHY SUBJECTS, AND THE PROTEIN AMOUNT MAY CONTINUE TO DECLINE WITH DISEASE PROGRESSION, SUGGESTING A PUTATIVE ROLE OF THIS RNA-BINDING PROTEIN. MOREOVER, OUR RESULTS SUGGEST THAT MS PATHOLOGY MAY HAVE DISRUPTED THE LINK BETWEEN HUR AND ITS TARGET TRANSCRIPT HSP70-2. IT WILL BE IMPORTANT TO FURTHER EXPLORE THE EXACT ROLE OF HUR IN MS, CONSIDERING THE COMPLEX INTERPLAY WITH OTHER RNA-BINDING FACTORS AND TARGET MRNAS. 2020 15 1282 25 DECIPHERING THE ACTIVE CONSTITUENTS OF DABUSHEN DECOCTION OF AMELIORATING OSTEOARTHRITIS VIA PPARGAMMA PRESERVATION BY TARGETING DNMT1. OSTEOARTHRITIS (OA) IS A MULTIFACTORIAL AND CHRONIC DEGENERATIVE JOINT DISEASE. DUE TO THE ADVERSE EFFECTS OF CURRENTLY USED DRUGS, A SAFER AND MORE EFFECTIVE THERAPY FOR TREATING OA IS NEEDED. PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA) IS A KEY PROTEIN PROTECTING CARTILAGE. DNMT1-MEDIATED HYPERMETHYLATION OF PPARGAMMA PROMOTER LEADS TO ITS SUPPRESSION. THEREFORE, DNMT1 MIGHT BE AN EFFECTIVE TARGET FOR EXERTING CARTILAGE PROTECTIVE EFFECTS BY REGULATING THE EPIGENETIC EXPRESSION OF PPARGAMMA. DABUSHEN DECOCTION (DD) IS A REPRESENTATIVE PRESCRIPTION OF DUNHUANG ANCIENT MEDICAL PRESCRIPTION, WHICH HAS A POTENTIAL THERAPEUTIC EFFECT ON OA. SO FAR, THE RESEARCH OF THE EFFICACY AND MATERIAL BASIS OF DD IN THE TREATMENT OF OA REMAINS UNCLEAR. IN THIS STUDY, MICRO-CT, HE STAINING, S-O STAINING, AND IMMUNOHISTOCHEMISTRY ANALYSIS WERE USED TO DEMONSTRATE THAT DD INCREASED THE EXPRESSION OF PPARGAMMA AND COLLAGEN SYNTHESIS IN AN OA RAT MODEL. NEXT, THE STRUCTURE OF DNMT1 WAS USED TO SCREEN THE ACTIVE CONSTITUENTS OF DD BY MOLECULAR DOCKING METHOD FOR TREATMENT OA. SEVEN POTENTIAL ACTIVE CONSTITUENTS, INCLUDING ISOLIQUIRITIGENIN, EMODIN, TAXIFOLIN, CATALPOL, ALISOL A, ZINGERONE, AND SCHISANDRIN C WERE HITED. THE PROTECTIVE EFFECT OF THE POTENTIAL ACTIVE CONSTITUENTS TO CHONDROCYTES WERE EVALUATED BY PROTEIN CAPILLARY ELECTROPHORESIS, IMMUNOFLUORESCENCE ASSAYS, AND EX VIVO CULTURE OF RAT KNEE CARTILAGE. THE FIVE CONSTITUENTS, SUCH AS ALISOL A, EMODIN, TAXIFOLIN, ISOLIQUIRITIGENIN, AND SCHISANDRIN C COULD PROMOTE THE EXPRESSION OF PPARGAMMA AND AMELIORATE IL-1BETA-INDUCED DOWNREGULATION OF COLLAGEN II AND THE PRODUCTION OF MMP-13. ALISOL A AND EMODIN COULD EFFECTIVELY MITIGATE CARTILAGE DAMAGE. AT LAST, MOLECULAR DYNAMICS SIMULATIONS WITH MM-GBSA METHOD WAS APPLIED TO INVESTIGATE THE INTERACTION PATTERN OF THE ACTIVE CONSTITUENTS AND DNMT1 COMPLEXES. THE FIVE CONSTITUENTS, SUCH AS ALISOL A, EMODIN, TAXIFOLIN, ISOLIQUIRITIGENIN, AND SCHISANDRIN C ACHIEVED A STABLE BINDING PATTERN WITH DNMT1, IN WHICH ALISOL A HAS A RELATIVELY HIGH BINDING FREE ENERGY. IN CONCLUSION, THIS STUDY ELUCIDATES THAT THE ACTIVE CONSTITUENTS OF DD (ALISOL A, EMODIN, TAXIFOLIN, ISOLIQUIRITIGENIN, AND SCHISANDRIN C) COULD AMELIORATE OSTEOARTHRITIS VIA PPARGAMMA PRESERVATION BY TARGETING DNMT1.THESE FINDINGS FACILITATED CLINICAL USE OF DD AND PROVIDED A VALUABLE STRATEGY FOR DEVELOPING NATURAL EPIGENETIC MODULATORS FROM CHINESE HERBAL FORMULA. 2022 16 2818 15 FIBROSIS UNDER ARREST. APPROXIMATELY 5% OF PEOPLE THAT ARE HOSPITALIZED FOR ANY REASON DEVELOP ACUTE KIDNEY FAILURE, WHICH, IN SOME CASES, PROGRESSES TO A CHRONIC CONDITION RESULTING IN FIBROSIS OF THE KIDNEY AND PERMANENT CHANGES IN THE ORGAN'S FUNCTION. TWO NEW STUDIES SUGGEST THAT CELL CYCLE ARREST OF EPITHELIAL CELLS AND EPIGENETIC MODIFICATIONS HAVE KEY ROLES IN THE SWITCH TO CHRONIC DISEASE (PAGES 535-543 AND 544-550). 2010 17 460 26 ARACHIDONIC ACID 15-LIPOXYGENASE: EFFECTS OF ITS EXPRESSION, METABOLITES, AND GENETIC AND EPIGENETIC VARIATIONS ON AIRWAY INFLAMMATION. ARACHIDONIC ACID 15-LIPOXYGENASE (ALOX15) IS AN ENZYME THAT CAN OXIDIZE POLYUNSATURATED FATTY ACIDS. ALOX15 IS STRONGLY EXPRESSED IN AIRWAY EPITHELIAL CELLS, WHERE IT CATALYZES THE CONVERSION OF ARACHIDONIC ACID TO 15-HYDROXYEICOSATETRAENOIC ACID (15-HETE) INVOLVED IN VARIOUS AIRWAY INFLAMMATORY DISEASES. INTERLEUKIN (IL)-4 AND IL-13 INDUCE ALOX15 EXPRESSION BY ACTIVATING JAK2 AND TYK2 KINASES AS WELL AS SIGNAL TRANSDUCERS AND ACTIVATORS OF TRANSCRIPTION (STATS) 1/3/5/6. ALOX15 UP-REGULATION AND SUBSEQUENT ASSOCIATION WITH PHOSPHATIDYLETHANOLAMINE-BINDING PROTEIN 1 (PEBP1) ACTIVATE THE MITOGEN-ACTIVATED EXTRACELLULAR SIGNAL-REGULATED KINASE (MEK)-EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK) PATHWAY, THUS INDUCING EOSINOPHIL-MEDIATED AIRWAY INFLAMMATION. IN ADDITION, ALOX15 PLAYS A SIGNIFICANT ROLE IN PROMOTING THE MIGRATION OF IMMUNE CELLS, SUCH AS IMMATURE DENDRITIC CELLS, ACTIVATED T CELLS, AND MAST CELLS, AND AIRWAY REMODELING, INCLUDING GOBLET CELL DIFFERENTIATION. GENOME-WIDE ASSOCIATION STUDIES HAVE REVEALED MULTIPLE ALOX15 VARIANTS AND THEIR SIGNIFICANT CORRELATION WITH THE RISK OF DEVELOPING AIRWAY DISEASES. THE EPIGENETIC MODIFICATIONS OF THE ALOX15 GENE, SUCH AS DNA METHYLATION AND HISTONE MODIFICATIONS, HAVE BEEN SHOWN TO CLOSELY RELATE WITH AIRWAY INFLAMMATION. THIS REVIEW SUMMARIZES THE ROLE OF ALOX15 IN DIFFERENT PHENOTYPES OF ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, CHRONIC RHINOSINUSITIS, ASPIRIN-EXACERBATED RESPIRATORY DISEASE, AND NASAL POLYPS, SUGGESTING NEW TREATMENT STRATEGIES FOR THESE AIRWAY INFLAMMATORY DISEASES WITH COMPLEX ETIOLOGY AND POOR TREATMENT RESPONSE. 2021 18 1668 26 DOWNREGULATION OF SOCS1 INCREASES INTERFERON-INDUCED ISGYLATION DURING DIFFERENTIATION OF INDUCED-PLURIPOTENT STEM CELLS TO HEPATOCYTES. BACKGROUND & AIMS: INCREASED EXPRESSION OF IFN-STIMULATED GENE 15 (ISG15) AND SUBSEQUENTLY INCREASED ISGYLATION ARE KEY FACTORS IN THE HOST RESPONSE TO VIRAL INFECTION. IN THIS STUDY, WE SOUGHT TO CHARACTERIZE THE EXPRESSION OF ISG15, ISGYLATION, AND ASSOCIATED ENZYMES AT EACH STAGE OF DIFFERENTIATION FROM INDUCED PLURIPOTENT STEM CELLS (IPSCS) TO HEPATOCYTES. METHODS: TO STUDY THE REGULATION OF ISGYLATION, WE UTILIZED PATIENT SAMPLES AND IN VITRO CELL CULTURE MODELS INCLUDING IPSCS, HEPATOCYTES-LIKE CELLS, IMMORTALIZED CELL LINES, AND PRIMARY HUMAN HEPATOCYTES. PROTEIN/MRNA EXPRESSION WERE MEASURED FOLLOWING TREATMENT WITH POLY(I:C), IFNALPHA AND HCV INFECTION. RESULTS: WHEN COMPARED TO HLCS, WE OBSERVED SEVERAL NOVEL ASPECTS OF THE ISGYLATION PATHWAY IN IPSCS. THESE INCLUDE A LOWER BASELINE EXPRESSION OF THE ISGYLATION-ACTIVATING ENZYME, UBE1L, A LACK OF IFN-INDUCED EXPRESSION OF THE ISGYLATION-CONJUGATION ENZYME UBE2L6, AN ATTENUATED ACTIVATION OF THE TRANSCRIPTION FACTOR STAT1 AND CONSTITUTIVE EXPRESSION OF SOCS1. ISGYLATION WAS OBSERVED IN IPSCS FOLLOWING DOWNREGULATION OF SOCS1, WHICH FACILITATED STAT1 ACTIVATION AND SUBSEQUENTLY INCREASED EXPRESSION OF UBE2L6. INTRIGUINGLY, HCV PERMISSIVE TRANSFORMED HEPATOMA CELL LINES DEMONSTRATED HIGHER INTRINSIC EXPRESSION OF SOCS1 AND WEAKER ISGYLATION FOLLOWING IFN TREATMENT. SOCS1 DOWNREGULATION IN HCV-INFECTED HUH 7.5.1 CELLS LED TO INCREASED ISGYLATION. CONCLUSIONS: HEREIN, WE SHOW THAT HIGH BASAL LEVELS OF SOCS1 INHIBIT STAT1 ACTIVATION AND SUBSEQUENTLY IFN-INDUCED UBE2L6 AND ISGYLATION IN IPSCS. FURTHERMORE, AS IPSCS DIFFERENTIATE INTO HEPATOCYTES, EPIGENETIC MECHANISMS REGULATE ISGYLATION BY MODIFYING UBE1L AND SOCS1 EXPRESSION LEVELS. OVERALL, THIS STUDY DEMONSTRATES THAT THE DEVELOPMENT OF CELL-INTRINSIC INNATE IMMUNITY DURING THE DIFFERENTIATION OF IPSCS TO HEPATOCYTES PROVIDES INSIGHT INTO CELL TYPE-SPECIFIC REGULATION OF HOST DEFENSE RESPONSES AND RELATED ONCOGENIC PROCESSES. IMPACT AND IMPLICATIONS: TO ELUCIDATE THE MECHANISM UNDERLYING REGULATION OF ISGYLATION, A KEY PROCESS IN THE INNATE IMMUNE RESPONSE, WE STUDIED CHANGES IN ISGYLATION-ASSOCIATED GENES AT THE DIFFERENT STAGES OF DIFFERENTIATION FROM IPSCS TO HEPATOCYTES. WE FOUND THAT HIGH BASAL LEVELS OF SOCS1 INHIBIT STAT1 ACTIVATION AND SUBSEQUENTLY IFN-INDUCED UBE2L6 AND ISGYLATION IN IPSCS. IMPORTANTLY, EPIGENETIC REGULATION OF SOCS1 AND SUBSEQUENTLY ISGYLATION MAY BE IMPORTANT FACTORS IN THE DEVELOPMENT OF CELL TYPE-SPECIFIC HOST DEFENSE RESPONSES IN HEPATOCYTES THAT SHOULD BE CONSIDERED WHEN STUDYING CHRONIC INFECTIONS AND ONCOGENIC PROCESSES IN THE LIVER. 2022 19 1843 20 EFFECTS OF TELOMERASE INHIBITOR ON EPIGENETIC CHROMATIN MODIFICATION ENZYMES IN MALIGNANCIES. TELOMERASE HAS A CRITICAL ROLE IN CELL PROLIFERATION, TUMOR MAINTAINING, AND THERAPY RESISTANCE, WHICH ACT BY MODIFYING MANY SIGNALING PATHWAYS. 2-[(E)-3-NAPHTALEN-2-YL-BUT-2-ENOYLAMINO]-BENZOIC ACID (BIBR1532) IS ONE OF THE MOST STUDIED TELOMERASE INHIBITORS, AND IT TARGETS TELOMERASE COMPONENTS TERC AND TERT. IN THIS NOVEL STUDY, WE AIMED TO INVESTIGATE THE EPIGENETIC EFFECTS OF BIBR1532 ON BOTH HEMATOLOGIC MALIGNANCIES AND SOLID TUMORS. K-562 HUMAN CHRONIC MYELOID LEUKEMIA CELL LINE AND U87MG GLIOBLASTOMA CELL LINE WERE COMPARED WITH CONTROL GROUPS WITHOUT BIBR1532 TREATMENT. CYTOTOXIC EFFECTS OF BIBR1532 WERE DETERMINED BY USING WST-1 ASSAY. APOPTOTIC EFFECTS OF BIBR1532 WERE DETECTED BY USING ANNEXIN V METHOD. TO ASSESS EXPRESSION CHANGES IN THE HUMAN EPIGENETIC CHROMATIN MODIFICATION ENZYME GENES, TOTAL RNA WAS ISOLATED FROM K-562 AND U87MG CELLS TREATED WITH BIBR1532 AND UNTREATED CONTROL CELLS. BIBR1532 INDUCED 2.41-FOLD APOPTOTIC CELL DEATH IN U87MG CELL LINES COMPARED WITH CONTROL GROUPS. APOPTOSIS WAS SLIGHTLY INDUCED IN K-562 CELLS WITH BIBR1532 TREATMENT COMPARED WITH CONTROL CELLS. WE OBSERVED THAT BIBR1532 ALSO REGULATES SIMILAR GENES IN BOTH CELL LINES, AND IT IS USEFUL ON EPIGENETIC MECHANISMS. AS A RESULT, TELOMERASE INHIBITOR BIBR1532 HAS A SIGNIFICANT EFFECT ON BOTH HEMATOLOGICAL MALIGNANCIES AND SOLID TUMORS. 2018 20 5487 24 REVERSIBLE ALTERATION IN THE EXPRESSION OF THE GAP JUNCTIONAL PROTEIN CONNEXIN 32 DURING TUMOR PROMOTION IN RAT LIVER AND ITS ROLE DURING CELL PROLIFERATION. ALTHOUGH NUMEROUS BIOCHEMICAL MARKERS CAN IDENTIFY PUTATIVE PRENEOPLASTIC ALTERED HEPATIC FOCI (AHF) IN RAT LIVER, NO CONSISTENT PATTERN OF EXPRESSION DURING HEPATOCARCINOGENESIS HAS EMERGED. USING QUANTITATIVE STEREOLOGIC ANALYSES WE DEMONSTRATED THAT DECREASED EXPRESSION OF THE MAJOR HEPATOCYTE GAP JUNCTION PROTEIN, CONNEXIN 32 (CX32), IN RAT AHF IS A CONSISTENT OBSERVATION IN SEVERAL PROTOCOLS OF MULTISTAGE HEPATOCARCINOGENESIS. THIS CHANGE WAS OBSERVED AFTER INITIATION BY EITHER ETHYLNITROSOUREA (ENU) OR DIETHYLNITROSAMINE (DEN), FOLLOWED BY PROMOTION WITH PHENOBARBITAL (PB), DIOXIN, CHLORENDIC ACID, C.I. SOLVENT YELLOW, OR TAMOXIFEN. AHF GENERATED BY WY-14,643, CIPROFIBRATE, AND A CHOLINE/METHIONINE-DEFICIENT DIETARY REGIMEN ALSO SHOWED DECREASED CX32 EXPRESSION. THE DECREASE OF CX32 IN AHF WAS RAPIDLY REVERSIBLE AFTER WITHDRAWAL OF PB, AND THIS CHANGE PRECEDED A REDUCTION IN PLACENTAL ISOZYME OF GLUTATHIONE-S-TRANSFERASE (GST) EXPRESSION IN THE SAME AHF. WITHIN 20 DAYS OF WITHDRAWAL, FEWER THAN 4% OF GST-POSITIVE AHF WERE CX32 DEFICIENT, WHILE THE VOLUME OF TOTAL AHF DECREASED 30%. CHRONIC PB TREATMENT ALSO RESULTED IN A REVERSIBLE DECREASE IN CX32 SPECIFICALLY IN MID- AND CENTRO-LOBULAR HEPATOCYTES. CONTINUOUS THYMIDINE LABELING DEMONSTRATED THAT CX32 COULD BE UNCOUPLED FROM THE CELL CYCLE, SUGGESTING THAT SOME LIVER PROMOTERS MAY ACT DIRECTLY TO ALTER THE EXPRESSION OF CX32. THESE OBSERVATIONS SUGGEST THAT A DECREASE IN CX32 CONTENT WAS A RELATIVELY COMMON EPIGENETIC CHANGE IN AHF INDUCED DURING HEPATOCARCINOGENESIS BY A NUMBER OF INITIATING AND PROMOTING AGENTS BUT THAT THIS CHANGE WAS NOT SUFFICIENT FOR CARCINOGENESIS. THIS CHANGE, HOWEVER, MAY BE NECESSARY FOR THE MECHANISM(S) OF TUMOR PROMOTION, SINCE CX32-POSITIVE AHF DID NOT PROLIFERATE AS READILY AS CX32-DEFICIENT AHF. 1990