1 4443 126 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 2 35 31 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 3 1668 36 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 26 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 5 768 30 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 6 238 25 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 7 2316 44 EPIGENETIC REGULATION OF FRUCTOSE-1,6-BISPHOSPHATASE 1 BY HOST TRANSCRIPTION FACTOR SPECKLED 110 KDA DURING HEPATITIS B VIRUS INFECTION. HEPATITIS B VIRUS (HBV) IS THE LEADING CAUSE OF LIVER DISEASE RANGING FROM ACUTE AND CHRONIC HEPATITIS TO LIVER CIRRHOSIS AND HEPATOCELLULAR CARCINOMA (HCC). STUDIES HAVE REVEALED THAT HBV INFECTION BROADLY REPROGRAMMES THE HOST CELLULAR METABOLIC PROCESSES FOR VIRAL PATHOGENESIS. PREVIOUS REPORTS HAVE SHOWN THAT GLYCOLYSIS AND GLUCONEOGENESIS ARE AMONG THE MOST DEREGULATED PATHWAYS DURING HBV INFECTION. WE NOTED THAT DESPITE BEING ONE OF THE RATE-LIMITING ENZYMES OF GLUCONEOGENESIS, THE ROLE AND REGULATION OF FRUCTOSE-1,6-BISPHOSPHATASE 1 (FBP1) DURING HBV INFECTION IS NOT MUCH EXPLORED. IN THIS STUDY, WE REPORT FBP1 UPREGULATION UPON HBV INFECTION AND UNRAVEL A NOVEL MECHANISM OF EPIGENETIC REPROGRAMMING OF FBP1 BY HBV VIA UTILIZING HOST FACTOR SPECKLED 110 KDA (SP110). HERE, WE IDENTIFIED ACETYLATED LYSINE 18 OF HISTONE H3 (H3K18AC) AS A SELECTIVE INTERACTOR OF SP110 BROMODOMAIN. FURTHERMORE, WE FOUND THAT SP110 GETS RECRUITED ON H3K18AC-ENRICHED FBP1 PROMOTER, AND FACILITATES RECRUITMENT OF DEACETYLASE SIRTUIN 2 (SIRT2) ON THAT SITE IN THE PRESENCE OF HBV. SIRT2 IN TURN BRINGS ITS INTERACTOR AND TRANSCRIPTIONAL ACTIVATOR HEPATOCYTE NUCLEAR FACTOR 4-ALPHA TO THE PROMOTER, WHICH ULTIMATELY LEADS TO A LOSS OF DNA METHYLATION NEAR THE COGNATE SITE. INTERESTINGLY, THIS SP110 DRIVEN FBP1 REGULATION DURING INFECTION WAS FOUND TO PROMOTE VIRAL-BORNE HCC PROGRESSION. MOREOVER, SP110 CAN BE USED AS A PROGNOSTIC MARKER FOR THE HEPATITIS-MEDIATED HCC PATIENTS, WHERE HIGH SP110 EXPRESSION SIGNIFICANTLY LOWERED THEIR SURVIVAL. THUS, THE EPIGENETIC READER PROTEIN SP110 HAS POTENTIAL TO BE A THERAPEUTIC TARGET TO CHALLENGE HBV-INDUCED HCCS. 2022 8 1806 31 EFFECT OF TRANSCRIPTION INHIBITION AND GENERATION OF SUPPRESSIVE VIRAL NON-CODING RNAS. BACKGROUND: HIV-1 PATIENTS RECEIVING COMBINATION ANTIRETROVIRAL THERAPY (CART) SURVIVE INFECTION BUT REQUIRE LIFE-LONG ADHERENCE AT HIGH EXPENSE. IN CHRONIC CART-TREATED PATIENTS WITH UNDETECTABLE VIRAL TITERS, CELL-ASSOCIATED VIRAL RNA IS STILL DETECTABLE, POINTING TO LOW-LEVEL VIRAL TRANSCRIPTIONAL LEAKINESS. TO DATE, THERE ARE NO FDA-APPROVED DRUGS AGAINST HIV-1 TRANSCRIPTION. WE HAVE PREVIOUSLY SHOWN THAT F07#13, A THIRD GENERATION TAT PEPTIDE MIMETIC WITH COMPETITIVE ACTIVITY AGAINST CDK9/T1-TAT BINDING SITES, INHIBITS HIV-1 TRANSCRIPTION IN VITRO AND IN VIVO. RESULTS: HERE, WE DEMONSTRATE THAT INCREASING CONCENTRATIONS OF F07#13 (0.01, 0.1, 1 MICROM) CAUSE A DECREASE IN TAT LEVELS IN A DOSE-DEPENDENT MANNER BY INHIBITING THE CDK9/T1-TAT COMPLEX FORMATION AND SUBSEQUENT UBIQUITIN-MEDIATED TAT SEQUESTRATION AND DEGRADATION. OUR DATA INDICATE THAT COMPLEXES I AND IV CONTAIN DISTINCT PATTERNS OF UBIQUITINATED TAT AND THAT TRANSCRIPTIONAL INHIBITION INDUCED BY F07#13 CAUSES AN OVERALL REDUCTION IN TAT LEVELS. THIS REDUCTION MAY BE TRIGGERED BY F07#13 BUT ULTIMATELY IS MEDIATED BY TAR-GAG VIRAL RNAS THAT BIND SUPPRESSIVE TRANSCRIPTION FACTORS (SIMILAR TO 7SK, NRON, HOTAIR, AND XIST LNCRNAS) TO ENHANCE TRANSCRIPTIONAL GENE SILENCING AND LATENCY. THESE RNAS COMPLEX WITH PRC2, SIN3A, AND CUL4B, RESULTING IN EPIGENETIC MODIFICATIONS. FINALLY, WE OBSERVED AN F07#13-MEDIATED DECREASE OF VIRAL BURDEN BY TARGETING THE R REGION OF THE LONG TERMINAL REPEAT (HIV-1 PROMOTER REGION, LTR), PROMOTING BOTH PAUSED POLYMERASES AND INCREASED EFFICIENCY OF CRISPR/CAS9 EDITING IN INFECTED CELLS. THIS IMPLIES THAT GENE EDITING MAY BE BEST PERFORMED UNDER A REPRESSED TRANSCRIPTIONAL STATE. CONCLUSIONS: COLLECTIVELY, OUR RESULTS INDICATE THAT F07#13, WHICH CAN TERMINATE RNA POLYMERASE II AT DISTINCT SITES, CAN GENERATE SCAFFOLD RNAS, WHICH MAY ASSEMBLE INTO SPECIFIC SETS OF "RNA MACHINES" THAT CONTRIBUTE TO GENE REGULATION. IT REMAINS TO BE SEEN WHETHER THESE EFFECTS CAN ALSO BE SEEN IN VARIOUS CLADES THAT HAVE VARYING PROMOTER STRENGTH, MUTANT LTRS, AND IN PATIENT SAMPLES. 2019 9 5601 29 RORALPHA IS CRUCIAL FOR ATTENUATED INFLAMMATORY RESPONSE TO MAINTAIN INTESTINAL HOMEOSTASIS. RETINOIC ACID-RELATED ORPHAN RECEPTOR ALPHA (RORALPHA) FUNCTIONS AS A TRANSCRIPTION FACTOR FOR VARIOUS BIOLOGICAL PROCESSES, INCLUDING CIRCADIAN RHYTHM, CANCER, AND METABOLISM. HERE, WE GENERATE INTESTINAL EPITHELIAL CELL (IEC)-SPECIFIC RORALPHA-DEFICIENT (RORALPHA(DELTAIEC)) MICE AND FIND THAT RORALPHA IS CRUCIAL FOR MAINTAINING INTESTINAL HOMEOSTASIS BY ATTENUATING NUCLEAR FACTOR KAPPAB (NF-KAPPAB) TRANSCRIPTIONAL ACTIVITY. RORALPHA(DELTAIEC) MICE EXHIBIT EXCESSIVE INTESTINAL INFLAMMATION AND HIGHLY ACTIVATED INFLAMMATORY RESPONSES IN THE DEXTRAN SULFATE SODIUM (DSS) MOUSE COLITIS MODEL. TRANSCRIPTOME ANALYSIS REVEALS THAT DELETION OF RORALPHA LEADS TO UP-REGULATION OF NF-KAPPAB TARGET GENES IN IECS. CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALS CORECRUITMENT OF RORALPHA AND HISTONE DEACETYLASE 3 (HDAC3) ON NF-KAPPAB TARGET PROMOTERS AND SUBSEQUENT DISMISSAL OF CREB BINDING PROTEIN (CBP) AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) FOR TRANSCRIPTIONAL REPRESSION. TOGETHER, WE DEMONSTRATE THAT RORALPHA/HDAC3-MEDIATED ATTENUATION OF NF-KAPPAB SIGNALING CONTROLS THE BALANCE OF INFLAMMATORY RESPONSES, AND THERAPEUTIC STRATEGIES TARGETING THIS EPIGENETIC REGULATION COULD BE BENEFICIAL TO THE TREATMENT OF CHRONIC INFLAMMATORY DISEASES, INCLUDING INFLAMMATORY BOWEL DISEASE (IBD). 2019 10 5017 24 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 11 5004 29 PERIPHERAL B CELLS FROM PATIENTS WITH HEPATITIS C VIRUS-ASSOCIATED LYMPHOMA EXHIBIT CLONAL EXPANSION AND AN ANERGIC-LIKE TRANSCRIPTIONAL PROFILE. CHRONIC HCV INFECTION REMAINS A GLOBAL HEALTH CONCERN DUE TO ITS INVOLVEMENT IN HEPATIC AND EXTRAHEPATIC DISEASES, INCLUDING B CELL NON-HODGKIN LYMPHOMA (BNHL). CLINICAL AND EPIDEMIOLOGICAL EVIDENCE SUPPORT A CAUSAL ROLE FOR HCV IN BNHL DEVELOPMENT, ALTHOUGH MECHANISTIC INSIGHT IS LACKING. WE PERFORMED RNA-SEQUENCING ON PERIPHERAL B CELLS FROM PATIENTS WITH HCV ALONE, BNHL ALONE, AND HCV-ASSOCIATED BNHL TO IDENTIFY UNIQUE AND SHARED TRANSCRIPTIONAL PROFILES ASSOCIATED WITH TRANSFORMATION. IN PATIENTS WITH HCV-ASSOCIATED BNHL, WE OBSERVED THE ENRICHMENT OF AN ANERGIC-LIKE GENE SIGNATURE AND EVIDENCE OF CLONAL EXPANSION THAT WAS CORRELATED WITH THE EXPRESSION OF EPIGENETIC REGULATORY GENES. OUR DATA SUPPORT A ROLE FOR VIRAL-MEDIATED CLONAL EXPANSION OF ANERGIC-LIKE B CELLS IN HCV-ASSOCIATED BNHL DEVELOPMENT AND SUGGEST EPIGENETIC DYSREGULATION AS A POTENTIAL MECHANISM DRIVING EXPANSION. WE PROPOSE EPIGENETIC MECHANISMS MAY BE INVOLVED IN BOTH HCV-ASSOCIATED LYMPHOMA AND REGULATION OF B CELL ANERGY, REPRESENTING AN ATTRACTIVE TARGET FOR CLINICAL INTERVENTIONS. 2023 12 5511 22 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 13 1067 30 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 14 1843 23 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 15 3945 34 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 1950 29 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 17 1016 25 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 18 2818 17 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 19 4867 22 OSSIFYING FIBROMA TUMOR STEM CELLS ARE MAINTAINED BY EPIGENETIC REGULATION OF A TSP1/TGF-BETA/SMAD3 AUTOCRINE LOOP. ABNORMAL STEM CELL FUNCTION MAKES A KNOWN CONTRIBUTION TO MANY MALIGNANT TUMORS, BUT THE ROLE OF STEM CELLS IN BENIGN TUMORS IS NOT WELL UNDERSTOOD. HERE, WE SHOW THAT OSSIFYING FIBROMA (OF) CONTAINS A STEM CELL POPULATION THAT RESEMBLES MESENCHYMAL STEM CELLS (OFMSCS) AND IS CAPABLE OF GENERATING OF-LIKE TUMOR XENOGRAFTS. MECHANISTICALLY, OFMSCS SHOW ENHANCED TGF-BETA SIGNALING THAT INDUCES ABERRANT PROLIFERATION AND DEFICIENT OSTEOGENESIS VIA NOTCH AND BMP SIGNALING PATHWAYS, RESPECTIVELY. THE ELEVATED TGF-BETA ACTIVITY IS TIGHTLY REGULATED BY JHDM1D-MEDIATED EPIGENETIC REGULATION OF THROMBOSPONDIN-1 (TSP1), FORMING A JHDM1D/TSP1/TGF-BETA/SMAD3 AUTOCRINE LOOP. INHIBITION OF TGF-BETA SIGNALING IN OFMSCS CAN RESCUE THEIR ABNORMAL OSTEOGENIC DIFFERENTIATION AND ELEVATED PROLIFERATION RATE. FURTHERMORE, CHRONIC ACTIVATION OF TGF-BETA CAN CONVERT NORMAL MSCS INTO OF-LIKE MSCS VIA ESTABLISHMENT OF THIS JHDM1D/TSP1/TGF-BETA/SMAD3 AUTOCRINE LOOP. THESE RESULTS REVEAL THAT EPIGENETIC REGULATION OF TGF-BETA SIGNALING IN MSCS GOVERNS THE BENIGN TUMOR PHENOTYPE IN OF AND HIGHLIGHT TGF-BETA SIGNALING AS A CANDIDATE THERAPEUTIC TARGET. 2013 20 460 33 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