1 5017 150 PERSISTENT INFECTION OF CULTURED CELLS WITH MOUSE HEPATITIS VIRUS (MHV) RESULTS FROM THE EPIGENETIC EXPRESSION OF THE MHV RECEPTOR. THE A59 STRAIN OF MURINE CORONAVIRUS MOUSE HEPATITIS VIRUS (MHV) CAN CAUSE PERSISTENT INFECTION OF 17C1-1 CELLS AND OTHER MURINE CELL LINES. PERSISTENTLY INFECTED CULTURES RELEASED LARGE AMOUNTS OF VIRUS (10(7) TO 10(8) PFU/ML) AND WERE RESISTANT TO SUPERINFECTION WITH MHV BUT NOT TO INFECTION WITH UNRELATED SEMLIKI FOREST AND VESICULAR STOMATITIS VIRUSES. THE CULTURE MEDIUM FROM PERSISTENTLY INFECTED CULTURES DID NOT CONTAIN A SOLUBLE INHIBITOR SUCH AS INTERFERON THAT PROTECTED UNINFECTED CELLS FROM INFECTION BY MHV OR VESICULAR STOMATITIS VIRUS. THE PERSISTENT INFECTION WAS CURED IF FEWER THAN 100 CELLS WERE TRANSFERRED DURING SUBCULTURING, AND SUCH CURED CULTURES WERE SUSCEPTIBLE TO REINFECTION AND THE REESTABLISHMENT OF PERSISTENT INFECTION. CULTURES OF 17C1-1 CELLS THAT HAD BEEN NEWLY CLONED FROM SINGLE CELLS CONSISTED OF A MIXTURE OF MHV-RESISTANT AND -SUSCEPTIBLE CELLS. 17C1-1/#97 CELLS, WHICH WERE CURED BY SUBCLONING AFTER 97 PASSAGES OF A PERSISTENTLY INFECTED CULTURE OVER A 1-YEAR PERIOD, CONTAINED 5 TO 10% OF THEIR POPULATION AS SUSCEPTIBLE CELLS, WHILE 17C1-1/#402 CELLS, WHICH WERE CURED BY SUBCLONING AFTER 402 PASSAGES OVER A 3-YEAR PERIOD, HAD LESS THAN 1% SUSCEPTIBLE CELLS. SUSCEPTIBILITY TO INFECTION CORRELATED WITH THE EXPRESSION OF MHV RECEPTOR GLYCOPROTEIN (MHVR [BGP1A]). FLUORESCENCE-ACTIVATED CELL SORTER ANALYSIS WITH ANTIBODY TO MHVR SHOWED THAT 17C1-1/#97 CELLS CONTAINED A SMALL FRACTION OF MHVR-EXPRESSING CELLS. THESE MHVR-EXPRESSING CELLS WERE SELECTIVELY ELIMINATED WITHIN 24 H AFTER CHALLENGE WITH MHV-A59, AND PRETREATMENT OF 17C1-1/#97 CELLS WITH MONOCLONAL ANTIBODY CC1, WHICH BINDS TO THE N-TERMINAL DOMAIN OF MHVR, BLOCKED INFECTION. WE CONCLUDE THAT THE SUBPOPULATION OF MHVR-EXPRESSING CELLS WERE INFECTED AND KILLED IN ACUTELY OR PERSISTENTLY INFECTED CULTURES, WHILE THE SUBPOPULATION OF MHVR-NONEXPRESSING CELLS SURVIVED AND PROLIFERATED. THE SUBPOPULATION OF MHVR-NEGATIVE CELLS PRODUCED A SMALL PROPORTION OF PROGENY CELLS THAT EXPRESSED MHVR AND BECAME INFECTED, THEREBY MAINTAINING THE PERSISTENT INFECTION AS A STEADY-STATE CARRIER CULTURE. THUS, IN 17C1-1 CELL CULTURES, THE UNSTABLE OR EPIGENETIC EXPRESSION OF MHVR PERMITTED THE ESTABLISHMENT OF A PERSISTENT, CHRONIC INFECTION. 1995 2 1843 25 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 3 1668 27 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 4 2080 27 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 5 1951 27 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 6 1016 24 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 7 1950 23 EPIGENETIC ACTIVATION OF TENSIN 4 PROMOTES GASTRIC CANCER PROGRESSION. GASTRIC CANCER (GC) IS A COMPLEX DISEASE INFLUENCED BY MULTIPLE GENETIC AND EPIGENETIC FACTORS. CHRONIC INFLAMMATION CAUSED BY HELICOBACTER PYLORI INFECTION AND DIETARY RISK FACTORS CAN RESULT IN THE ACCUMULATION OF ABERRANT DNA METHYLATION IN GASTRIC MUCOSA, WHICH PROMOTES GC DEVELOPMENT. TENSIN 4 (TNS4), A MEMBER OF THE TENSIN FAMILY OF PROTEINS, IS LOCALIZED TO FOCAL ADHESION SITES, WHICH CONNECT THE EXTRACELLULAR MATRIX AND CYTOSKELETAL NETWORK. WE IDENTIFIED UPREGULATION OF TNS4 IN GC USING QUANTITATIVE REVERSE TRANSCRIPTION PCR WITH 174 PAIRED SAMPLES OF GC TUMORS AND ADJACENT NORMAL TISSUES. TRANSCRIPTIONAL ACTIVATION OF TNS4 OCCURRED EVEN DURING THE EARLY STAGE OF TUMOR DEVELOPMENT. TNS4 DEPLETION IN GC CELL LINES THAT EXPRESSED HIGH TO MODERATE LEVELS OF TNS4, I.E., SNU-601, KATO III, AND MKN74, REDUCED CELL PROLIFERATION AND MIGRATION, WHEREAS ECTOPIC EXPRESSION OF TNS4 IN THOSE LINES THAT EXPRESSED LOWER LEVELS OF TNS4, I.E., SNU-638, MKN1, AND MKN45 INCREASED COLONY FORMATION AND CELL MIGRATION. THE PROMOTER REGION OF TNS4 WAS HYPOMETHYLATED IN GC CELL LINES THAT SHOWED UPREGULATION OF TNS4. WE ALSO FOUND A SIGNIFICANT NEGATIVE CORRELATION BETWEEN TNS4 EXPRESSION AND CPG METHYLATION IN 250 GC TUMORS BASED ON THE CANCER GENOME ATLAS (TCGA) DATA. THIS STUDY ELUCIDATES THE EPIGENETIC MECHANISM OF TNS4 ACTIVATION AND FUNCTIONAL ROLES OF TNS4 IN GC DEVELOPMENT AND PROGRESSION AND SUGGESTS A POSSIBLE APPROACH FOR FUTURE GC TREATMENTS. 2023 8 768 23 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 9 5775 25 SPERMIDINE/SPERMINE N(1)-ACETYLTRANSFERASE ACTIVITY ASSOCIATES WITH WHITE BLOOD CELL COUNT IN MYELOID LEUKEMIAS. THE METABOLISM OF POLYAMINES, THE CATIONIC SMALL MOLECULES ESSENTIAL FOR CELL PROLIFERATION AND DIFFERENTIATION, IS ALTERED IN CANCER CELLS AND CAN BE EXPLOITED IN CANCER DIAGNOSIS AND THERAPY. SPERMIDINE/SPERMINE N(1)-ACETYLTRANSFERASE (SSAT), WHICH REGULATES INTRACELLULAR LEVELS OF POLYAMINES BY CATABOLIZING SPERMIDINE AND SPERMINE, HAS A CONTROVERSIAL ROLE IN THE DEVELOPMENT OF CANCERS. IN THIS STUDY, THE POLYAMINE METABOLISM AND FUNCTION OF SSAT WERE CHARACTERIZED IN ACUTE MYELOID LEUKEMIA (AML), CHRONIC MYELOID LEUKEMIA (CML), AND ACUTE LYMPHOID LEUKEMIA PATIENT SAMPLES. ALSO, MICE OVEREXPRESSING SSAT AND HAVING A MYELOPROLIFERATIVE PHENOTYPE WERE ANALYZED FOR THEIR RESPONSE TO DECITABINE AND HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A. THE PRESENCE OF EPIGENETIC FACTORS IN THE BONE MARROW CELLS OF SSAT MICE WAS ANALYZED. ELEVATED LEVELS OF SPERMIDINE AND SPERMINE, AS WELL AS INCREASED ACTIVITY OF SSAT, WERE DETECTED IN AML, CML, AND ACUTE LYMPHOID LEUKEMIA PATIENTS COMPARED WITH THE CONTROLS. HOWEVER, WE FOUND SSAT ACTIVITY TO BE ASSOCIATED WITH WHITE BLOOD CELL COUNT ONLY IN AML AND CML PATIENTS. DECITABINE TREATMENT BROUGHT THE PERIPHERAL BLOOD AND BONE MARROW CELL COUNTS OF SSAT MICE TO THE LEVEL OF WILD-TYPE MICE. SPERMIDINE/SPERMINE N(1)-ACETYLTRANSFERASE MICE HAD INCREASED HISTONE METHYLATION AND AN INCREASED LEVEL OF HISTONE DEACETYLASE 1 IN THEIR BONE MARROW CELLS. THE STUDY SUGGESTS THAT SSAT INFLUENCES THE DEVELOPMENT OF MYELOID MALIGNANCIES, AND EPIGENETIC FACTORS PARTLY CONTRIBUTE TO THE SSAT OVEREXPRESSION-INDUCED MYELOPROLIFERATIVE DISEASE IN MICE. 2014 10 35 17 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 11 1067 28 CLINICAL UTILITY OF PDSS2 EXPRESSION TO STRATIFY PATIENTS AT RISK FOR RECURRENCE OF HEPATOCELLULAR CARCINOMA. IDENTIFICATION OF NOVEL GENETIC AND EPIGENETIC ALTERATIONS IS REQUIRED FOR OPTIMAL STRATIFICATION OF PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC) AT RISK FOR RECURRENCE AND ADVERSE PROGNOSIS. COENZYME Q10 (COQ10), WHICH MEDIATES APOPTOSIS, IS SYNTHESIZED BY PRENYL DIPHOSPHATE SYNTHASE SUBUNIT 2 (PDSS2). IN THE PRESENT STUDY WE EVALUATED THE CLINICAL SIGNIFICANCE AND REGULATORY MECHANISMS OF PDSS2 EXPRESSION IN HCC. PDSS2 EXPRESSION LEVELS AND THOSE OF GENES ENCODING POTENTIALLY INTERACTING PROTEINS AS WELL AS THE METHYLATION STATUS OF THE PDSS2 PROMOTER REGION WERE ANALYZED IN HCC CELL LINES. PDSS2 MRNA LEVELS IN 151 PAIRS OF RESECTED SPECIMENS WERE DETERMINED TO EVALUATE THE ASSOCIATION OF PDSS2 EXPRESSION AND CLINICOPATHOLOGICAL FACTORS. THE EXPRESSION AND DISTRIBUTION OF PDSS2 WERE DETERMINED USING IMMUNOHISTOCHEMISTRY. PDSS2 MRNA EXPRESSION WAS DECREASED IN SIX OF NINE HCC CELL LINES AND SIGNIFICANTLY CORRELATED WITH THOSE OF HEPATOCYTE NUCLEAR FACTOR 4ALPHA. PDSS2 TRANSCRIPTION IN HCC CELLS WITH DECREASED PDSS2 EXPRESSION ACCOMPANYING HYPERMETHYLATION WAS REACTIVATED AFTER TREATING THESE CELLS WITH A METHYLATION INHIBITOR. MEAN EXPRESSION LEVELS OF PDSS2 MRNA RELATIVE TO THAT OF UNINVOLVED LIVER DIMINISHED GRADUALLY IN THE ORDER OF CHRONIC HEPATITIS TO CIRRHOSIS, AND EACH WAS SIGNIFICANTLY HIGHER THAN THOSE OF HCCS. PDSS2 AND PDSS2 MRNA LEVELS WERE CONSISTENT. DECREASED PDSS2 MRNA LEVELS WERE DETECTED IN HCC TISSUES OF 56 PATIENTS, CORRELATED WITH SHORTER DISEASE-SPECIFIC SURVIVAL, AND WAS IDENTIFIED AS AN INDEPENDENT PROGNOSTIC FACTOR. PDSS2 IS A PUTATIVE TUMOR SUPPRESSOR, AND PROMOTER HYPERMETHYLATION IS A KEY REGULATORY MECHANISM IN HCC. DECREASED LEVELS OF PDSS2 MRNA EXPRESSION MAY REPRESENT A NOVEL BIOMARKER OF HCC. 2014 12 5487 35 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 13 6636 28 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 14 368 27 AMYLOID BETA-MEDIATED EPIGENETIC ALTERATION OF INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN 3 CONTROLS CELL SURVIVAL IN ALZHEIMER'S DISEASE. SWEDISH DOUBLE MUTATION (KM670/671NL) OF AMYLOID PRECURSOR PROTEIN (APP) IS REPORTED TO INCREASE TOXIC AMYLOID BETA (ABETA) PRODUCTION VIA ABERRANT CLEAVAGE AT THE BETA-SECRETASE SITE AND THEREBY CAUSE EARLY-ONSET ALZHEIMER'S DISEASE (AD). HOWEVER, THE UNDERLYING MOLECULAR MECHANISMS LEADING TO AD PATHOGENESIS REMAINS LARGELY UNKNOWN. PREVIOUSLY, OUR TRANSCRIPTOME SEQUENCE ANALYSES REVEALED GLOBAL EXPRESSIONAL MODIFICATIONS OF OVER 600 GENES IN APP-SWEDISH MUTANT-EXPRESSING H4 (H4-SW) CELLS COMPARED TO WILD TYPE H4 CELLS. INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN 3 (IGFBP3) IS ONE GENE THAT SHOWED SIGNIFICANTLY DECREASED MRNA EXPRESSION IN H4-SW CELLS. IN THIS STUDY, WE INVESTIGATED THE FUNCTIONAL ROLE OF IGFBP3 IN AD PATHOGENESIS AND ELUCIDATED THE MECHANISMS REGULATING ITS EXPRESSION. WE OBSERVED DECREASED IGFBP3 EXPRESSION IN THE H4-SW CELL LINE AS WELL AS THE HIPPOCAMPUS OF AD MODEL TRANSGENIC MICE. TREATMENT WITH EXOGENOUS IGFBP3 PROTEIN INHIBITED ABETA1-42- INDUCED CELL DEATH AND CASPASE-3 ACTIVITY, WHEREAS SIRNA-MEDIATED SUPPRESSION OF IGFBP3 EXPRESSION INDUCED CELL DEATH AND CASPASE-3 CLEAVAGE. IN PRIMARY HIPPOCAMPAL NEURONS, ADMINISTRATION OF IGFBP3 PROTEIN BLOCKED APOPTOTIC CELL DEATH DUE TO ABETA1-42 TOXICITY. THESE DATA IMPLICATE A PROTECTIVE ROLE FOR IGFBP3 AGAINST ABETA1-42-MEDIATED APOPTOSIS. NEXT, WE INVESTIGATED THE REGULATORY MECHANISMS OF IGFBP3 EXPRESSION IN AD PATHOGENESIS. WE OBSERVED ABNORMAL IGFBP3 HYPERMETHYLATION WITHIN THE PROMOTER CPG ISLAND IN H4-SW CELLS. TREATMENT WITH THE DNA METHYLTRANSFERASE INHIBITOR 5-AZA-2'-DEOXYCYTIDINE RESTORED IGFBP3 EXPRESSION AT BOTH THE MRNA AND PROTEIN LEVELS. CHRONIC EXPOSURE TO ABETA1-42 INDUCED IGFBP3 HYPERMETHYLATION AT CPGS, PARTICULARLY AT LOCI -164 AND -173, AND SUBSEQUENTLY SUPPRESSED IGFBP3 EXPRESSION. THEREFORE, WE DEMONSTRATE THAT EXPRESSION OF ANTI-APOPTOTIC IGFBP3 IS REGULATED BY EPIGENETIC DNA METHYLATION, SUGGESTING A MECHANISM THAT CONTRIBUTES TO AD PATHOGENESIS. 2014 15 3945 25 LNCRNA IL21-AS1 INTERACTS WITH HNRNPU PROTEIN TO PROMOTE IL21 OVEREXPRESSION AND ABERRANT DIFFERENTIATION OF TFH CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS. BACKGROUND: THE ABERRANT DIFFERENTIATION OF T FOLLICULAR HELPER (TFH) CELLS PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF SYSTEMIC LUPUS ERYTHEMATOSUS (SLE). HOWEVER, THE MECHANISM OF REGULATING TFH CELLS DIFFERENTIATION REMAINS UNCLEAR. LONG NONCODING RNAS (LNCRNAS) ACT AS IMPORTANT REGULATORS IN THE PROCESSES OF INNATE AND ADAPTIVE IMMUNE RESPONSE. WHETHER LNCRNAS ARE INVOLVED IN REGULATING TFH CELL DIFFERENTIATION AND AUTOIMMUNE RESPONSES NEED TO BE FURTHER IDENTIFIED. METHODS: THE CHARACTERS AND FUNCTIONS OF HUMAN IL21-AS1 AND ITS MOUSE HOMOLOGOUS LNCRNA (MIL21-AS) WERE INVESTIGATED BY A SERIES OF BIOCHEMICAL ASSAYS AND CELL TRANSFECTION ASSAY. MIL21-AS1 REGULATING HUMORAL IMMUNE RESPONSE IN VIVO WAS EXPLORED BY KEYHOLE LIMPET HAEMOCYANIN (KLH) AND CHRONIC GRAFT VERSUS HOST DISEASE (CGVHD) MODEL. RESULTS: HUMAN IL21-AS1 AND ITS MOUSE HOMOLOGOUS LNCRNA (MIL21-AS) WERE IDENTIFIED AND CLONED. WE UNCOVERED THAT IL21-AS1 WAS HIGHLY EXPRESSED IN CD4(+) T CELLS OF SLE PATIENTS AND TFH CELLS, WHICH PROMOTED DIFFERENTIATION OF TFH CELLS. MECHANISTICALLY, IL21-AS1 BOUND HETEROGENEOUS NUCLEAR RIBONUCLEOPROTEIN U AND RECRUITED ACETYLTRANSFERASES CREB-BINDING PROTEIN TO THE PROMOTER OF IL21, LEADING TO THE TRANSCRIPTIONAL ACTIVATION OF IL21 AND TFH CELLS DIFFERENTIATION THROUGH INCREASING HISTONE H3 ACETYLATION LEVEL ON IL21 PROMOTER. MOREOVER, TFH PROPORTION AND ANTIBODIES PRODUCTION WERE SIGNIFICANTLY INCREASED IN MIL21-AS KNOCK-IN MICE IMMUNIZED WITH KLH. MIL21-AS1 OVEREXPRESSION ALSO EXACERBATED THE LUPUS-LIKE PHENOTYPE IN CGVHD MICE MODEL. CONCLUSIONS: OUR RESULTS DEMONSTRATE THAT IL21-AS1 ACTIVATES IL21 TRANSCRIPTION VIA EPIGENETIC MECHANISM TO PROMOTE GERMINAL CENTRE RESPONSE, ADDING INSIGHT INTO THE MOLECULAR REGULATION OF AUTOIMMUNE PATHOGENESIS AND PROVIDING A NOVEL TARGET FOR SLE TREATMENT. 2022 16 5340 28 QUORUM SENSING AND VIRULENCE OF PSEUDOMONAS AERUGINOSA DURING LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. PSEUDOMONAS AERUGINOSA IS THE PREDOMINANT MICROORGANISM IN CHRONIC LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. THE CHRONIC LUNG INFECTION IS PRECEDED BY INTERMITTENT COLONIZATION. WHEN THE CHRONIC INFECTION BECOMES ESTABLISHED, IT IS WELL ACCEPTED THAT THE ISOLATED STRAINS DIFFER PHENOTYPICALLY FROM THE INTERMITTENT STRAINS. DOMINATING CHANGES ARE THE SWITCH TO MUCOIDITY (ALGINATE OVERPRODUCTION) AND LOSS OF EPIGENETIC REGULATION OF VIRULENCE SUCH AS THE QUORUM SENSING (QS). TO ELUCIDATE THE DYNAMICS OF P. AERUGINOSA QS SYSTEMS DURING LONG TERM INFECTION OF THE CF LUNG, WE HAVE INVESTIGATED 238 ISOLATES OBTAINED FROM 152 CF PATIENTS AT DIFFERENT STAGES OF INFECTION RANGING FROM INTERMITTENT TO LATE CHRONIC. ISOLATES WERE CHARACTERIZED WITH REGARD TO QS SIGNAL MOLECULES, ALGINATE, RHAMNOLIPID AND ELASTASE PRODUCTION AND MUTANT FREQUENCY. THE GENETIC BASIS FOR CHANGE IN QS REGULATION WERE INVESTIGATED AND IDENTIFIED BY SEQUENCE ANALYSIS OF LASR, RHLR, LASI AND RHLI. THE FIRST QS SYSTEM TO BE LOST WAS THE ONE ENCODED BY LAS SYSTEM 12 YEARS (MEDIAN VALUE) AFTER THE ONSET OF THE LUNG INFECTION WITH SUBSEQUENT LOSS OF THE RHL ENCODED SYSTEM AFTER 17 YEARS (MEDIAN VALUE) SHOWN AS DEFICIENCIES IN PRODUCTION OF THE 3-OXO-C12-HSL AND C4-HSL QS SIGNAL MOLECULES RESPECTIVELY. THE CONCOMITANT DEVELOPMENT OF QS MALFUNCTION SIGNIFICANTLY CORRELATED WITH THE REDUCED PRODUCTION OF RHAMNOLIPIDS AND ELASTASE AND WITH THE OCCURRENCE OF MUTATIONS IN THE REGULATORY GENES LASR AND RHLR. ACCUMULATION OF MUTATIONS IN BOTH LASR AND RHLR CORRELATED WITH DEVELOPMENT OF HYPERMUTABILITY. INTERESTINGLY, A HIGHER NUMBER OF MUCOID ISOLATES WERE FOUND TO PRODUCE C4-HSL SIGNAL MOLECULES AND RHAMNOLIPIDS COMPARED TO THE NON-MUCOID ISOLATES. AS SEEN FROM THE PRESENT DATA, WE CAN CONCLUDE THAT P. AERUGINOSA AND PARTICULARLY THE MUCOID STRAINS DO NOT LOSE THE QS REGULATION OR THE ABILITY TO PRODUCE RHAMNOLIPIDS UNTIL THE LATE STAGE OF THE CHRONIC INFECTION. 2010 17 1622 28 DNA METHYLTRANSFERASES IN MALAR MELASMA AND THEIR MODIFICATION BY SUNSCREEN IN COMBINATION WITH 4% NIACINAMIDE, 0.05% RETINOIC ACID, OR PLACEBO. BACKGROUND: MALAR MELASMA HAS A CHRONIC AND RECURRENT CHARACTER THAT MAY BE RELATED TO EPIGENETIC CHANGES. OBJECTIVE: TO RECOGNIZE THE EXPRESSION AND DNA METHYLATION OF DNA METHYLTRANSFERASES (DNMTS) IN MALAR MELASMA AND PERILESIONAL SKIN, AS WELL AS THE CHANGES IN DNMTS AFTER THEIR TREATMENT WITH SUNSCREEN IN COMBINATION WITH 4% NIACINAMIDE, 0.05% RETINOIC ACID, OR PLACEBO. METHODS: THIRTY FEMALE PATIENTS WERE CLINICALLY EVALUATED FOR THE EXPRESSION OF DNMT1 AND DNMT3B USING REAL-TIME PCR AND IMMUNOFLUORESCENCE. THESE INITIAL RESULTS WERE COMPARED TO RESULTS AFTER EIGHT WEEKS OF TREATMENT WITH SUNSCREEN IN COMBINATION WITH NIACINAMIDE, RETINOIC ACID, OR PLACEBO. RESULTS: THE RELATIVE EXPRESSION OF DNMT1 WAS SIGNIFICANTLY ELEVATED IN MELASMA COMPARED WITH UNAFFECTED SKIN IN ALL SUBJECTS, INDICATING DNA HYPERMETHYLATION. AFTER TREATMENT, IT WAS DECREASED IN ALL GROUPS: NIACINAMIDE (7 VERSUS 1; P<0.01), RETINOIC ACID (7 VERSUS 2; P<0.05), AND PLACEBO (7 VERSUS 3; P<0.05), WHICH CORRELATES WITH CLINICAL IMPROVEMENT. DNMT3B WAS NOT OVEREXPRESSED IN LESIONAL SKIN BUT REDUCED IN ALL GROUPS. CONCLUSIONS: WE FOUND DNA HYPERMETHYLATION IN MELASMA LESIONS. ENVIRONMENTAL FACTORS SUCH AS SOLAR RADIATION MAY INDUCE CELLULAR CHANGES THAT TRIGGER HYPERPIGMENTATION THROUGH THE ACTIVATION OF PATHWAYS REGULATED BY EPIGENETIC MODIFICATIONS. HOWEVER, LIMITING OR DECREASING DNA METHYLATION THROUGH SUNSCREEN, NIACINAMIDE, AND RETINOIC ACID TREATMENTS THAT PROVIDE PHOTOPROTECTION AND GENETIC TRANSCRIPTION CAN COUNTERACT THIS. 2019 18 1421 21 DIFFERENTIAL BRAIN ADRA2A AND ADRA2C GENE EXPRESSION AND EPIGENETIC REGULATION IN SCHIZOPHRENIA. EFFECT OF ANTIPSYCHOTIC DRUG TREATMENT. POSTSYNAPTIC ALPHA(2A)-ADRENOCEPTOR DENSITY IS ENHANCED IN THE DORSOLATERAL PREFRONTAL CORTEX (DLPFC) OF ANTIPSYCHOTIC-TREATED SCHIZOPHRENIA SUBJECTS. THIS ALTERATION MIGHT BE DUE TO TRANSCRIPTIONAL ACTIVATION, AND COULD BE REGULATED BY EPIGENETIC MECHANISMS SUCH AS HISTONE POSTTRANSLATIONAL MODIFICATIONS (PTMS). THE AIM OF THIS STUDY WAS TO EVALUATE ADRA2A AND ADRA2C GENE EXPRESSION (CODIFYING FOR ALPHA(2)-ADRENOCEPTOR SUBTYPES), AND PERMISSIVE AND REPRESSIVE HISTONE PTMS AT GENE PROMOTER REGIONS IN THE DLPFC OF SUBJECTS WITH SCHIZOPHRENIA AND MATCHED CONTROLS (N = 24 PAIRS). WE STUDIED THE EFFECT OF ANTIPSYCHOTIC (AP) TREATMENT IN AP-FREE (N = 12) AND AP-TREATED (N = 12) SUBGROUPS OF SCHIZOPHRENIA SUBJECTS AND IN RATS ACUTELY AND CHRONICALLY TREATED WITH TYPICAL AND ATYPICAL ANTIPSYCHOTICS. ADRA2A MRNA EXPRESSION WAS SELECTIVELY UPREGULATED IN AP-TREATED SCHIZOPHRENIA SUBJECTS (+93%) WHEREAS ADRA2C MRNA EXPRESSION WAS UPREGULATED IN ALL SCHIZOPHRENIA SUBJECTS (+53%) REGARDLESS OF ANTIPSYCHOTIC TREATMENT. ACUTE AND CHRONIC CLOZAPINE TREATMENT IN RATS DID NOT ALTER BRAIN CORTEX ADRA2A MRNA EXPRESSION BUT INCREASED ADRA2C MRNA EXPRESSION. BOTH ADRA2A AND ADRA2C PROMOTER REGIONS SHOWED EPIGENETIC MODIFICATION BY HISTONE METHYLATION AND ACETYLATION IN HUMAN DLPFC. THE UPREGULATION OF ADRA2A EXPRESSION IN AP-TREATED SCHIZOPHRENIA SUBJECTS MIGHT BE RELATED TO OBSERVED BIVALENT CHROMATIN AT ADRA2A PROMOTER REGION IN SCHIZOPHRENIA (DEPICTED BY INCREASED PERMISSIVE H3K4ME3 AND REPRESSIVE H3K27ME3) AND COULD BE TRIGGERED BY THE ENHANCED H4K16AC AT ADRA2A PROMOTER. IN CONCLUSION, EPIGENETIC PREDISPOSITION DIFFERENTIALLY MODULATED ADRA2A AND ADRA2C MRNA EXPRESSION IN DLPFC OF SCHIZOPHRENIA SUBJECTS. 2021 19 4443 24 MOLECULAR INSIGHTS INTO SPINDLIN1-HBX INTERPLAY AND ITS IMPACT ON HBV TRANSCRIPTION FROM CCCDNA MINICHROMOSOME. MOLECULAR INTERPLAY BETWEEN HOST EPIGENETIC FACTORS AND VIRAL PROTEINS CONSTITUTES AN INTRIGUING MECHANISM FOR SUSTAINING HEPATITIS B VIRUS (HBV) LIFE CYCLE AND ITS CHRONIC INFECTION. HBV ENCODES A REGULATORY PROTEIN, HBX, WHICH ACTIVATES TRANSCRIPTION AND REPLICATION OF HBV GENOME ORGANIZED AS COVALENTLY CLOSED CIRCULAR (CCC) DNA MINICHROMOSOME. HERE WE ILLUSTRATE HOW HBX ACCOMPLISHES ITS TASK BY HIJACKING SPINDLIN1, AN EPIGENETIC READER COMPRISING THREE CONSECUTIVE TUDOR DOMAINS. OUR BIOCHEMICAL AND STRUCTURAL STUDIES HAVE REVEALED THAT THE HIGHLY CONSERVED N-TERMINAL 2-21 SEGMENT OF HBX (HBX(2-21)) ASSOCIATES INTIMATELY WITH TUDOR 3 OF SPINDLIN1, ENHANCING HISTONE H3 "K4ME3-K9ME3" READOUT BY TUDORS 2 AND 1. FUNCTIONALLY, SPINDLIN1-HBX ENGAGEMENT PROMOTES GENE EXPRESSION FROM THE CHROMATINIZED CCCDNA, ACCOMPANIED BY AN EPIGENETIC SWITCH FROM AN H3K9ME3-ENRICHED REPRESSIVE STATE TO AN H3K4ME3-MARKED ACTIVE STATE, AS WELL AS A CONFORMATIONAL SWITCH OF HBX THAT MAY OCCUR IN COORDINATION WITH OTHER HBX-BINDING FACTORS, SUCH AS DDB1. DESPITE A PROPOSED TRANSREPRESSION ACTIVITY OF HBX(2-21), OUR STUDY REVEALS A KEY ROLE OF SPINDLIN1 IN DEREPRESSING THIS CONSERVED MOTIF, THEREBY PROMOTING HBV TRANSCRIPTION FROM ITS CHROMATINIZED GENOME. 2023 20 5511 18 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