1 3744 123 INSIGHTS INTO THE CRYSTAL STRUCTURE OF BRD2-BD2 - PHENANTHRIDINONE COMPLEX AND THEORETICAL STUDIES ON PHENANTHRIDINONE ANALOGS. BROMODOMAIN AND EXTRA-TERMINAL FAMILY PROTEINS RECOGNIZE THE ACETYLATED HISTONE CODE ON CHROMATIN AND PARTICIPATE IN DOWNSTREAM PROCESSES LIKE DNA REPLICATION, MODIFICATION, AND REPAIR. AS PART OF EPIGENETIC APPROACHES, BRD2 AND BRD4 WERE IDENTIFIED AS PUTATIVE TARGETS, FOR THE MANAGEMENT OF CHRONIC DISEASES. WE HAVE RECENTLY REPORTED THE DISCOVERY OF A NEW SCAFFOLD OF THE PHENANTHRIDINONE-BASED INHIBITOR (L10) OF THE SECOND BROMODOMAIN OF BRD2 (BRD2-BD2). HERE, WE PRESENT THE CRYSTAL STRUCTURE OF THE BRD2-BD2, REFINED TO 1.4 A RESOLUTION, IN COMPLEX WITH BETA-MERCAPTOETHANOL (A COMPONENT OF THE PROTEIN BUFFER). THE BETA-MERCAPTOETHANOL COVALENTLY LINKS TO C425 OF BD2 IN THE ACETYL-LYSINE BINDING POCKET, TO FORM A MODIFIED CYSTEINE MERCAPTOETHANOL (CME). THE CME MODIFICATION SIGNIFICANTLY HINDERS THE ENTRY OF LIGANDS INTO THE BD2 BINDING POCKET, SUGGESTING THAT BETA-MERCAPTOETHANOL SHOULD BE REMOVED DURING PROTEIN PRODUCTION PROCESS. NEXT, TO CONFIRM WHETHER PHENANTHRIDIONONE SCAFFOLD IS A NEW INHIBITOR FAMILY OF BRD2-BD2, WE HAVE DETERMINED THE CRYSTAL STRUCTURE OF BD2 IN COMPLEX WITH 6(5H)-PHENANTHRIDINONE (A CORE MOIETY OF L10), REFINED TO 1.28 A RESOLUTION. IT CONFIRMED THAT THE PHENANTHRIDINONE MOLECULE, UNAMBIGUOUSLY, BINDS TO BD2. MOREOVER, WE PERFORMED MOLECULAR DOCKING AND MOLECULAR DYNAMIC STUDIES ON SELECTED PHENANTHRIDINONE ANALOGS. THE PREDICTED L10 ANALOGS ARE STABLE WITH ESSENTIAL HYDROPHOBIC AND HYDROPHILIC INTERACTIONS WITH BD2 DURING MOLECULAR DYNAMIC SIMULATIONS. WE PROPOSE THAT THE PREDICTED PHENANTHRIDINONE ANALOGS MAY BE POTENTIAL MOLECULES FOR INHIBITING THE BD2 FUNCTION OF ACETYLATED HISTONE RECOGNITION. 2018 2 595 31 BET PROTEINS REGULATE EXPRESSION OF OSR1 IN EARLY KIDNEY DEVELOPMENT. IN UTERO RENAL DEVELOPMENT IS SUBJECT TO MATERNAL METABOLIC AND ENVIRONMENTAL INFLUENCES AFFECTING LONG-TERM RENAL FUNCTION AND THE RISK OF DEVELOPING CHRONIC KIDNEY FAILURE AND CARDIOVASCULAR DISEASE. EPIGENETIC PROCESSES HAVE BEEN IMPLICATED IN THE ORCHESTRATION OF RENAL DEVELOPMENT AND PRENATAL PROGRAMMING OF NEPHRON NUMBER. HOWEVER, THE ROLE OF MANY EPIGENETIC MODIFIERS FOR KIDNEY DEVELOPMENT IS STILL UNCLEAR. BROMODOMAIN AND EXTRA-TERMINAL DOMAIN (BET) PROTEINS ACT AS HISTONE ACETYLATION READER MOLECULES AND PROMOTE GENE TRANSCRIPTION. BET FAMILY MEMBERS BRD2, BRD3 AND BRD4 ARE EXPRESSED IN THE NEPHROGENIC ZONE DURING KIDNEY DEVELOPMENT. HERE, THE EFFECT OF THE BET INHIBITOR JQ1 ON RENAL DEVELOPMENT IS EVALUATED. INHIBITION OF BET PROTEINS VIA JQ1 LEADS TO REDUCED GROWTH OF METANEPHRIC KIDNEY CULTURES, LOSS OF THE NEPHRON PROGENITOR CELL POPULATION, AND PREMATURE AND DISTURBED NEPHRON DIFFERENTIATION. GENE EXPRESSION OF KEY NEPHRON PROGENITOR TRANSCRIPTION FACTOR OSR1 IS DOWNREGULATED AFTER 24 H BET INHIBITION, WHILE LHX1 AND PAX8 EXPRESSION IS INCREASED. MINING OF BRD4 CHIP-SEQ AND GENE EXPRESSION DATA IDENTIFY OSR1 AS A KEY FACTOR REGULATED BY BRD4-CONTROLLED GENE ACTIVATION. INHIBITION OF BRD4 BY BET INHIBITOR JQ1 LEADS TO DOWNREGULATION OF OSR1, THEREBY CAUSING A DISTURBANCE IN THE BALANCE OF NEPHRON PROGENITOR CELL SELF-RENEWAL AND PREMATURE DIFFERENTIATION OF THE NEPHRON, WHICH ULTIMATELY LEADS TO KIDNEY HYPOPLASIA AND DISTURBED NEPHRON DEVELOPMENT. THIS RAISES QUESTIONS ABOUT THE POTENTIAL TERATOGENIC EFFECTS OF BET INHIBITORS FOR EMBRYONIC DEVELOPMENT. IN SUMMARY, OUR WORK HIGHLIGHTS THE ROLE OF BET PROTEINS FOR PRENATAL PROGRAMMING OF NEPHROGENESIS AND IDENTIFIES OSR1 AS A POTENTIAL TARGET OF BET PROTEINS. 2021 3 6059 31 THE DEVELOPMENT OF A SENSITIVE FLUORESCENT PROTEIN-BASED TRANSCRIPT REPORTER FOR HIGH THROUGHPUT SCREENING OF NEGATIVE MODULATORS OF LNCRNAS. WHILE THE HUMAN GENOME IS PERVASIVELY TRANSCRIBED, <2% OF THE HUMAN GENOME IS TRANSCRIBED INTO PROTEIN-CODING MRNAS, LEAVING MOST OF THE TRANSCRIPTS AS NONCODING RNAS, SUCH AS MICRORNAS AND LONG-NONCODING RNAS (LNCRNAS), WHICH ARE CRITICAL COMPONENTS OF EPIGENETIC REGULATION. LNCRNAS ARE EMERGING AS CRITICAL REGULATORS OF GENE EXPRESSION AND GENOMIC STABILITY. HOWEVER, IT REMAINS LARGELY UNKNOWN ABOUT HOW LNCRNAS ARE REGULATED. HERE, WE DEVELOP A HIGHLY SENSITIVE AND DYNAMIC REPORTER THAT ALLOWS US TO IDENTIFY AND/OR MONITOR NEGATIVE MODULATORS OF LNCRNA TRANSCRIPT LEVELS IN A HIGH THROUGHPUT FASHION. SPECIFICALLY, WE ENGINEER A FLUORESCENT FUSION PROTEIN BY FUSING THREE COPIES OF THE PEST DESTRUCTION DOMAIN OF MOUSE ORNITHINE DECARBOXYLASE (MODC) TO THE C-TERMINAL END OF THE CODON-OPTIMIZED BILIRUBIN-INDUCIBLE FLUORESCENT PROTEIN, DESIGNATED AS DBIFP, AND SHOW THAT THE DBIFP PROTEIN IS HIGHLY DESTABILIZED, COMPARED WITH THE COMMONLY-USED EGFP PROTEIN. WE FURTHER DEMONSTRATE THAT THE DBIFP SIGNAL IS EFFECTIVELY DOWN-REGULATED WHEN THE DBIFP AND MOUSE LNCRNA H19 CHIMERIC TRANSCRIPT IS SILENCED BY MOUSE H19-SPECIFIC SIRNAS. THEREFORE, OUR RESULTS STRONGLY SUGGEST THAT THE DBIFP FUSION PROTEIN MAY SERVE AS A SENSITIVE AND DYNAMIC TRANSCRIPT REPORTER TO MONITOR THE INHIBITION OF LNCRNAS BY MICRORNAS, SYNTHETIC REGULATORY RNA MOLECULES, RNA BINDING PROTEINS, AND/OR SMALL MOLECULE INHIBITORS SO THAT NOVEL AND EFFICACIOUS INHIBITORS TARGETING THE EPIGENETIC CIRCUIT CAN BE DISCOVERED TO TREAT HUMAN DISEASES SUCH AS CANCER AND OTHER CHRONIC DISORDERS. 2018 4 26 36 A 6-ALKYLSALICYLATE HISTONE ACETYLTRANSFERASE INHIBITOR INHIBITS HISTONE ACETYLATION AND PRO-INFLAMMATORY GENE EXPRESSION IN MURINE PRECISION-CUT LUNG SLICES. LYSINE ACETYLATIONS ARE POST-TRANSLATIONAL MODIFICATIONS OF CELLULAR PROTEINS, THAT ARE CRUCIAL IN THE REGULATION OF MANY CELLULAR PROCESSES. LYSINE ACETYLATIONS ON HISTONE PROTEINS ARE PART OF THE EPIGENETIC CODE REGULATING GENE EXPRESSION AND ARE INSTALLED BY HISTONE ACETYLTRANSFERASES. OBSERVATIONS THAT INFLAMMATORY LUNG DISEASES, SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE, ARE CHARACTERIZED BY INCREASED HISTONE ACETYLTRANSFERASE ACTIVITY INDICATE THAT DEVELOPMENT OF SMALL MOLECULE INHIBITORS FOR THESE ENZYMES MIGHT BE A VALUABLE APPROACH TOWARDS NEW THERAPIES FOR THESE DISEASES. THE 6-ALKYLSALICYLATE MG149 IS A CANDIDATE TO EXPLORE THIS HYPOTHESIS BECAUSE IT HAS BEEN DEMONSTRATED TO INHIBIT THE MYST TYPE HISTONE ACETYLTRANSFERASES. IN THIS STUDY, WE DETERMINED THE K(I) VALUE FOR INHIBITION OF THE MYST TYPE HISTONE ACETYLTRANSFERASE KAT8 BY MG149 TO BE 39 +/- 7.7 MUM. UPON INVESTIGATING WHETHER THE INHIBITION OF HISTONE ACETYLTRANSFERASES BY MG149 CORRELATES WITH INHIBITION OF HISTONE ACETYLATION IN MURINE PRECISION-CUT LUNG SLICES, INHIBITION OF ACETYLATION WAS OBSERVED USING AN LC-MS/MS BASED ASSAY ON HISTONE H4 RES 4-17, WHICH CONTAINS THE TARGET LYSINE OF KAT8. FOLLOWING UP ON THIS, UPON TREATMENT WITH MG149, REDUCED PRO-INFLAMMATORY GENE EXPRESSION WAS OBSERVED IN LIPOPOLYSACCHARIDE AND INTERFERON GAMMA STIMULATED MURINE PRECISION-CUT LUNG SLICES. BASED ON THIS, WE PROPOSE THAT 6-ALKYLSALICYLATES SUCH AS MG149 HAVE POTENTIAL FOR DEVELOPMENT TOWARDS APPLICATIONS IN THE TREATMENT OF INFLAMMATORY LUNG DISEASES. 2017 5 691 31 BRD4 PROFILING IDENTIFIES CRITICAL CHRONIC LYMPHOCYTIC LEUKEMIA ONCOGENIC CIRCUITS AND REVEALS SENSITIVITY TO PLX51107, A NOVEL STRUCTURALLY DISTINCT BET INHIBITOR. BROMODOMAIN AND EXTRA-TERMINAL (BET) FAMILY PROTEINS ARE KEY REGULATORS OF GENE EXPRESSION IN CANCER. HEREIN, WE UTILIZE BRD4 PROFILING TO IDENTIFY CRITICAL PATHWAYS INVOLVED IN PATHOGENESIS OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). BRD4 IS OVEREXPRESSED IN CLL AND IS ENRICHED PROXIMAL TO GENES UPREGULATED OR DE NOVO EXPRESSED IN CLL WITH KNOWN FUNCTIONS IN DISEASE PATHOGENESIS AND PROGRESSION. THESE GENES, INCLUDING KEY MEMBERS OF THE B-CELL RECEPTOR (BCR) SIGNALING PATHWAY, PROVIDE A RATIONALE FOR THIS THERAPEUTIC APPROACH TO IDENTIFY NEW TARGETS IN ALTERNATIVE TYPES OF CANCER. ADDITIONALLY, WE DESCRIBE PLX51107, A STRUCTURALLY DISTINCT BET INHIBITOR WITH NOVEL IN VITRO AND IN VIVO PHARMACOLOGIC PROPERTIES THAT EMULATES OR EXCEEDS THE EFFICACY OF BCR SIGNALING AGENTS IN PRECLINICAL MODELS OF CLL. HEREIN, THE DISCOVERY OF THE INVOLVEMENT OF BRD4 IN THE CORE CLL TRANSCRIPTIONAL PROGRAM PROVIDES A COMPELLING RATIONALE FOR CLINICAL INVESTIGATION OF PLX51107 AS EPIGENETIC THERAPY IN CLL AND APPLICATION OF BRD4 PROFILING IN OTHER CANCERS.SIGNIFICANCE: TO DATE, FUNCTIONAL STUDIES OF BRD4 IN CLL ARE LACKING. THROUGH INTEGRATED GENOMIC, FUNCTIONAL, AND PHARMACOLOGIC ANALYSES, WE UNCOVER THE EXISTENCE OF BRD4-REGULATED CORE CLL TRANSCRIPTIONAL PROGRAMS AND PRESENT PRECLINICAL PROOF-OF-CONCEPT STUDIES VALIDATING BET INHIBITION AS AN EPIGENETIC APPROACH TO TARGET BCR SIGNALING IN CLL. CANCER DISCOV; 8(4); 458-77. (C)2018 AACR.THIS ARTICLE IS HIGHLIGHTED IN THE IN THIS ISSUE FEATURE, P. 371. 2018 6 5474 22 RESTORATION OF HISTONE ACETYLATION AMELIORATES DISEASE AND METABOLIC ABNORMALITIES IN A FUS MOUSE MODEL. DYSREGULATION OF EPIGENETIC MECHANISMS IS EMERGING AS A CENTRAL EVENT IN NEURODEGENERATIVE DISORDERS, INCLUDING AMYOTROPHIC LATERAL SCLEROSIS (ALS). IN MANY MODELS OF NEURODEGENERATION, GLOBAL HISTONE ACETYLATION IS DECREASED IN THE AFFECTED NEURONAL TISSUES. HISTONE ACETYLATION IS CONTROLLED BY THE ANTAGONISTIC ACTIONS OF TWO PROTEIN FAMILIES -THE HISTONE ACETYLTRANSFERASES (HATS) AND THE HISTONE DEACETYLASES (HDACS). DRUGS INHIBITING HDAC ACTIVITY ARE ALREADY USED IN THE CLINIC AS ANTI-CANCER AGENTS. THE AIM OF THIS STUDY WAS TO EXPLORE THE THERAPEUTIC POTENTIAL OF HDAC INHIBITION IN THE CONTEXT OF ALS. WE DISCOVERED THAT TRANSGENIC MICE OVEREXPRESSING WILD-TYPE FUS ("TG FUS+/+"), WHICH RECAPITULATE MANY ASPECTS OF HUMAN ALS, SHOWED REDUCED GLOBAL HISTONE ACETYLATION AND ALTERATIONS IN METABOLIC GENE EXPRESSION, RESULTING IN A DYSREGULATED METABOLIC HOMEOSTASIS. CHRONIC TREATMENT OF TG FUS+/+ MICE WITH ACY-738, A POTENT HDAC INHIBITOR THAT CAN CROSS THE BLOOD-BRAIN BARRIER, AMELIORATED THE MOTOR PHENOTYPE AND SUBSTANTIALLY EXTENDED THE LIFE SPAN OF THE TG FUS+/+ MICE. AT THE MOLECULAR LEVEL, ACY-738 RESTORED GLOBAL HISTONE ACETYLATION AND METABOLIC GENE EXPRESSION, THEREBY RE-ESTABLISHING METABOLITE LEVELS IN THE SPINAL CORD. TAKEN TOGETHER, OUR FINDINGS LINK EPIGENETIC ALTERATIONS TO METABOLIC DYSREGULATION IN ALS PATHOLOGY, AND HIGHLIGHT ACY-738 AS A POTENTIAL THERAPEUTIC STRATEGY TO TREAT THIS DEVASTATING DISEASE. 2019 7 2340 29 EPIGENETIC REGULATION OF LEUKOCYTE INFLAMMATORY MEDIATOR PRODUCTION DICTATES STAPHYLOCOCCUS AUREUS CRANIOTOMY INFECTION OUTCOME. STAPHYLOCOCCUS AUREUS IS A COMMON CAUSE OF SURGICAL-SITE INFECTIONS, INCLUDING THOSE ARISING AFTER CRANIOTOMY, WHICH IS PERFORMED TO ACCESS THE BRAIN FOR THE TREATMENT OF TUMORS, EPILEPSY, OR HEMORRHAGE. CRANIOTOMY INFECTION IS CHARACTERIZED BY COMPLEX SPATIAL AND TEMPORAL DYNAMICS OF LEUKOCYTE RECRUITMENT AND MICROGLIAL ACTIVATION. WE RECENTLY IDENTIFIED UNIQUE TRANSCRIPTIONAL PROFILES OF THESE IMMUNE POPULATIONS DURING S. AUREUS CRANIOTOMY INFECTION. EPIGENETIC PROCESSES ALLOW RAPID AND REVERSIBLE CONTROL OVER GENE TRANSCRIPTION; HOWEVER, LITTLE IS KNOWN ABOUT HOW EPIGENETIC PATHWAYS INFLUENCE IMMUNITY TO LIVE S. AUREUS. AN EPIGENETIC COMPOUND LIBRARY SCREEN IDENTIFIED BROMODOMAIN AND EXTRATERMINAL DOMAIN-CONTAINING (BET) PROTEINS AND HISTONE DEACETYLASES (HDACS) AS CRITICAL FOR REGULATING TNF, IL-6, IL-10, AND CCL2 PRODUCTION BY PRIMARY MOUSE MICROGLIA, MACROPHAGES, NEUTROPHILS, AND GRANULOCYTIC MYELOID-DERIVED SUPPRESSOR CELLS IN RESPONSE TO LIVE S. AUREUS. CLASS I HDACS (C1HDACS) WERE INCREASED IN THESE CELL TYPES IN VITRO AND IN VIVO DURING ACUTE DISEASE IN A MOUSE MODEL OF S. AUREUS CRANIOTOMY INFECTION. HOWEVER, SUBSTANTIAL REDUCTIONS IN C1HDACS WERE OBSERVED DURING CHRONIC INFECTION, HIGHLIGHTING TEMPORAL REGULATION AND THE IMPORTANCE OF THE TISSUE MICROENVIRONMENT FOR DICTATING C1HDAC EXPRESSION. MICROPARTICLE DELIVERY OF HDAC AND BET INHIBITORS IN VIVO CAUSED WIDESPREAD DECREASES IN INFLAMMATORY MEDIATOR PRODUCTION, WHICH SIGNIFICANTLY INCREASED BACTERIAL BURDEN IN THE BRAIN, GALEA, AND BONE FLAP. THESE FINDINGS IDENTIFY HISTONE ACETYLATION AS AN IMPORTANT MECHANISM FOR REGULATING CYTOKINE AND CHEMOKINE PRODUCTION ACROSS DIVERSE IMMUNE CELL LINEAGES THAT IS CRITICAL FOR BACTERIAL CONTAINMENT. ACCORDINGLY, ABERRANT EPIGENETIC REGULATION MAY BE IMPORTANT FOR PROMOTING S. AUREUS PERSISTENCE DURING CRANIOTOMY INFECTION. 2023 8 222 22 ACUTE LIVER STEATOSIS TRANSLATIONALLY CONTROLS THE EPIGENETIC REGULATOR MIER1 TO PROMOTE LIVER REGENERATION IN A STUDY WITH MALE MICE. THE EARLY PHASE LIPID ACCUMULATION IS ESSENTIAL FOR LIVER REGENERATION. HOWEVER, WHETHER THIS ACUTE LIPID ACCUMULATION CAN SERVE AS SIGNALS TO DIRECT LIVER REGENERATION RATHER THAN SIMPLY PROVIDING BUILDING BLOCKS FOR CELL PROLIFERATION REMAINS UNCLEAR. THROUGH IN VIVO CRISPR SCREENING, WE IDENTIFY MIER1 (MESODERM INDUCTION EARLY RESPONSE 1) AS A KEY EPIGENETIC REGULATOR THAT BRIDGES THE ACUTE LIPID ACCUMULATION AND CELL CYCLE GENE EXPRESSION DURING LIVER REGENERATION IN MALE ANIMALS. PHYSIOLOGICALLY, LIVER ACUTE LIPID ACCUMULATION INDUCES THE PHOSPHORYLATION OF EIF2S1(EUKARYOTIC TRANSLATION INITIATION FACTOR 2), WHICH CONSEQUENTLY ATTENUATED MIER1 TRANSLATION. MIER1 DOWNREGULATION IN TURN PROMOTES CELL CYCLE GENE EXPRESSION AND REGENERATION THROUGH CHROMATIN REMODELING. IMPORTANTLY, THE LIPIDS-EIF2S1-MIER1 PATHWAY IS IMPAIRED IN ANIMALS WITH CHRONIC LIVER STEATOSIS; WHEREAS MIER1 DEPLETION SIGNIFICANTLY IMPROVES REGENERATION IN THESE ANIMALS. TAKEN TOGETHER, OUR STUDIES IDENTIFY AN EPIGENETIC MECHANISM BY WHICH THE EARLY PHASE LIPID REDISTRIBUTION FROM ADIPOSE TISSUE TO LIVER DURING REGENERATION IMPACTS HEPATOCYTE PROLIFERATION, AND SUGGEST A POTENTIAL STRATEGY TO BOOST LIVER REGENERATION. 2023 9 1902 27 ENHANCED EXPRESSION OF THE NUCLEAR ENVELOPE LAP2 TRANSCRIPTIONAL REPRESSORS IN NORMAL AND MALIGNANT ACTIVATED LYMPHOCYTES. EXTENSIVE RESEARCH IN RECENT YEARS HAS BROADENED THE FUNCTIONS OF NUCLEAR ENVELOPE PROTEINS BEYOND SIMPLY STABILIZING THE NUCLEUS ARCHITECTURE. PARTICULARLY, INTEGRAL NUCLEAR MEMBRANE PROTEINS, SUCH AS THE ALTERNATIVE SPLICED ISOFORMS OF LAMINA-ASSOCIATED POLYPEPTIDE 2 (LAP2), HAVE BEEN SHOWN TO BE IMPORTANT FOR THE INITIATION OF REPLICATION AND REPRESSION OF TRANSCRIPTION. THE LATTER IS REGULATED BY EPIGENETIC CHANGES, INDUCED BY THE BINDING OF LAP2BETA TO HISTONE DEACETYLASE-3 (HDAC3), RESULTING IN HISTONE H4 DEACETYLATION. INVOLVEMENT OF NUCLEAR ENVELOPE PROTEINS IN PATHOLOGICAL PROLIFERATIVE CONDITIONS, MAINLY THOSE INVOLVING ABNORMAL RECRUITMENT AND ACTIVATION OF HDACS, IS STILL UNKNOWN. IN THIS PAPER, WE SHOW THAT VARIOUS NUCLEAR ENVELOPE PROTEINS ARE HIGHLY EXPRESSED IN NORMAL AND MALIGNANT ACTIVATED LYMPHOCYTES. SPECIFICALLY, RAPIDLY REPLICATING CELLS OF VARIOUS HEMATOLOGICAL MALIGNANCIES HIGHLY EXPRESS LAP2BETA, WHILE SLOWLY PROLIFERATING MALIGNANT CELLS OF CHRONIC MALIGNANT HEMATOLOGICAL DISEASES DO NOT. TAKING TOGETHER THE ELEVATED EXPRESSION OF LAP2BETA IN HIGHLY PROLIFERATIVE MALIGNANT CELLS WITH ITS KNOWN ABILITY TO MODIFY HISTONES THROUGH BINDING WITH HDAC3 RAISES THE POSSIBILITY OF ITS ROLE IN HEMATOLOGICAL MALIGNANCIES INVOLVING ABERRANT ACTIVITY OF HDAC3. BASED ON OUR PRESENTED RESULTS, WE BELIEVE THAT THE LAP2-HDAC REGULATORY PATHWAY SHOULD BE STUDIED AS A NEW TARGET FOR RATIONAL THERAPY. 2007 10 984 21 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022 11 6230 23 THE LONG NONCODING RNA LANDSCAPE IN HYPOXIC AND INFLAMMATORY RENAL EPITHELIAL INJURY. LONG NONCODING RNAS (LNCRNAS) ARE EMERGING AS KEY SPECIES-SPECIFIC REGULATORS OF CELLULAR AND DISEASE PROCESSES. TO IDENTIFY POTENTIAL LNCRNAS RELEVANT TO ACUTE AND CHRONIC RENAL EPITHELIAL INJURY, WE PERFORMED UNBIASED WHOLE TRANSCRIPTOME PROFILING OF HUMAN PROXIMAL TUBULAR EPITHELIAL CELLS (PTECS) IN HYPOXIC AND INFLAMMATORY CONDITIONS. RNA SEQUENCING REVEALED THAT THE PROTEIN-CODING AND NONCODING TRANSCRIPTOMIC LANDSCAPE DIFFERED BETWEEN HYPOXIA-STIMULATED AND CYTOKINE-STIMULATED HUMAN PTECS. HYPOXIA- AND INFLAMMATION-MODULATED LNCRNAS WERE PRIORITIZED FOR FOCUSED FOLLOWUP ACCORDING TO THEIR DEGREE OF INDUCTION BY THESE STRESS STIMULI, THEIR EXPRESSION IN HUMAN KIDNEY TISSUE, AND WHETHER EXPOSURE OF HUMAN PTECS TO PLASMA OF CRITICALLY ILL SEPSIS PATIENTS WITH ACUTE KIDNEY INJURY MODULATED THEIR EXPRESSION. FOR THREE LNCRNAS (MIR210HG, LINC-ATP13A4-8, AND LINC-KIAA1737-2) THAT FULFILLED OUR CRITERIA, WE VALIDATED THEIR EXPRESSION PATTERNS, EXAMINED THEIR LOCI FOR CONSERVATION AND SYNTENY, AND DEFINED THEIR ASSOCIATED EPIGENETIC MARKS. THE LNCRNA LANDSCAPE CHARACTERIZED HERE PROVIDES INSIGHTS INTO NOVEL TRANSCRIPTOMIC VARIATIONS IN THE RENAL EPITHELIAL CELL RESPONSE TO HYPOXIC AND INFLAMMATORY STRESS. 2015 12 2246 23 EPIGENETIC MODULATION OF INFLAMMATION AND SYNAPTIC PLASTICITY PROMOTES RESILIENCE AGAINST STRESS IN MICE. MAJOR DEPRESSIVE DISORDER IS ASSOCIATED WITH ABNORMALITIES IN THE BRAIN AND THE IMMUNE SYSTEM. CHRONIC STRESS IN ANIMALS SHOWED THAT EPIGENETIC AND INFLAMMATORY MECHANISMS PLAY IMPORTANT ROLES IN MEDIATING RESILIENCE AND SUSCEPTIBILITY TO DEPRESSION. HERE, THROUGH A HIGH-THROUGHPUT SCREENING, WE IDENTIFY TWO PHYTOCHEMICALS, DIHYDROCAFFEIC ACID (DHCA) AND MALVIDIN-3'-O-GLUCOSIDE (MAL-GLUC) THAT ARE EFFECTIVE IN PROMOTING RESILIENCE AGAINST STRESS BY MODULATING BRAIN SYNAPTIC PLASTICITY AND PERIPHERAL INFLAMMATION. DHCA/MAL-GLUC ALSO SIGNIFICANTLY REDUCES DEPRESSION-LIKE PHENOTYPES IN A MOUSE MODEL OF INCREASED SYSTEMIC INFLAMMATION INDUCED BY TRANSPLANTATION OF HEMATOPOIETIC PROGENITOR CELLS FROM STRESS-SUSCEPTIBLE MICE. DHCA REDUCES PRO-INFLAMMATORY INTERLEUKIN 6 (IL-6) GENERATIONS BY INHIBITING DNA METHYLATION AT THE CPG-RICH IL-6 SEQUENCES INTRONS 1 AND 3, WHILE MAL-GLUC MODULATES SYNAPTIC PLASTICITY BY INCREASING HISTONE ACETYLATION OF THE REGULATORY SEQUENCES OF THE RAC1 GENE. PERIPHERAL INFLAMMATION AND SYNAPTIC MALADAPTATION ARE IN LINE WITH NEWLY HYPOTHESIZED CLINICAL INTERVENTION TARGETS FOR DEPRESSION THAT ARE NOT ADDRESSED BY CURRENTLY AVAILABLE ANTIDEPRESSANTS. 2018 13 3465 32 HYPOTHESIS: REGULATION OF NEUROPLASTICITY MAY INVOLVE I-MOTIF AND G-QUADRUPLEX DNA FORMATION MODULATED BY EPIGENETIC MECHANISMS. RECENT STUDIES DEMONSTRATED THE EXISTENCE IN VIVO OF VARIOUS FUNCTIONAL DNA STRUCTURES THAT DIFFER FROM THE DOUBLE HELIX. THE G-QUADRUPLEX (G4) AND INTERCALATED MOTIF (I-MOTIF OR IM) DNA STRUCTURES ARE FORMED AS KNOTS WHERE, CORRESPONDINGLY, GUANINES OR CYTOSINES ON THE SAME STRAND OF DNA BIND TO EACH OTHER. THERE ARE GROUNDS TO BELIEVE THAT G4 AND IM SEQUENCES PLAY A SIGNIFICANT ROLE IN REGULATING GENE EXPRESSION CONSIDERING THEIR TENDENCY TO BE FOUND IN OR NEAR REGULATORY SITES (SUCH AS PROMOTERS, ENHANCERS, AND TELOMERES) AS WELL AS THE CORRELATION BETWEEN THE PREVALENCE OF G4 OR IM CONFORMATIONS AND SPECIFIC PHASES OF CELL CYCLE. NOTABLY, G4 AND IM CAPABLE SEQUENCES TEND TO BE FOUND ON THE OPPOSITE STRANDS OF THE SAME DNA SITE WITH AT MOST ONE OF THE TWO STRUCTURES FORMED AT ANY GIVEN TIME. THE RECENT EVIDENCE THAT K(+), MG(2+) CONCENTRATIONS DIRECTLY AFFECT IM FORMATION (AND LIKELY G4 FORMATION INDIRECTLY) LEAD US TO BELIEVE THAT THESE STRUCTURES MAY PLAY A MAJOR ROLE IN SYNAPTIC PLASTICITY OF NEURONS, AND, THEREFORE, IN A VARIETY OF CENTRAL NERVOUS SYSTEM (CNS) FUNCTIONS INCLUDING MEMORY, LEARNING, HABITUAL BEHAVIORS, PAIN PERCEPTION AND OTHERS. FURTHERMORE, EPIGENETIC MECHANISMS, WHICH HAVE AN IMPORTANT ROLE IN SYNAPTIC PLASTICITY AND MEMORY FORMATION, WERE ALSO SHOWN TO INFLUENCE FORMATION AND STABILITY OF G4S AND IMS. OUR HYPOTHESIS IS THAT NON-CANONICAL DNA AND RNA STRUCTURES COULD BE AN INTEGRAL PART OF NEUROPLASTICITY CONTROL VIA GENE EXPRESSION REGULATION AT THE LEVEL OF TRANSCRIPTION, TRANSLATION AND SPLICING. WE PROPOSE THAT THE REGULATORY ACTIVITY OF DNA IM AND G4 STRUCTURES IS MODULATED BY DNA METHYLATION/DEMETHYLATION OF THE IM AND/OR G4 SEQUENCES, WHICH FACILITATES THE SWITCH BETWEEN CANONICAL AND NON-CANONICAL CONFORMATION. OTHER NEURONAL MECHANISMS INTERACTING WITH THE FORMATION AND REGULATORY ACTIVITY OF NON-CANONICAL DNA AND RNA STRUCTURES, PARTICULARLY G4, IM AND TRIPLEXES, MAY INVOLVE MICRORNAS AS WELL AS ION AND PROTON FLUXES. WE ARE PROPOSING EXPERIMENTS IN ACUTE BRAIN SLICES AND IN VIVO TO TEST OUR HYPOTHESIS. THE PROPOSED STUDIES WOULD PROVIDE NEW INSIGHTS INTO FUNDAMENTAL NEURONAL MECHANISMS IN HEALTH AND DISEASE AND POTENTIALLY OPEN NEW AVENUES FOR TREATING MENTAL HEALTH DISORDERS. 2019 14 6421 30 THE THERAPEUTIC PROPERTIES OF RESMINOSTAT FOR HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON FORM OF PRIMARY LIVER CANCER WITH INCREASES IN NEW CASES BEING REPORTED ANNUALLY. HISTOPATHOLOGISTS HAVE IDENTIFIED HEPATIC STEATOSIS AS A CHARACTERISTIC OF A BROAD RANGE OF CHRONIC LIVER DISEASES THAT ARE ASSOCIATED WITH THE ONSET AND DEVELOPMENT OF HCC. IN THIS CONTEXT, EPIGENETIC MODIFICATIONS MAY SERVE AS PRECANCEROUS FACTORS PREDISPOSING NORMAL CELLS TO THE INITIATION OF CARCINOGENESIS. THIS STUDY DEMONSTRATED THAT HEPATIC TUMORIGENESIS AND DIFFERENTIATED ADIPOCYTES MAY MODULATE BOTH GLOBAL HISTONE DEACETYLASE (HDAC) EXPRESSION AND SPECIFIC CLASS I HDAC GENES IN THE TUMOUR MICROENVIRONMENT. THE NOVEL CLASS I HDAC INHIBITOR RESMINOSTAT WAS SHOWN TO REDUCE THE PROLIFERATION OF HCC CELLS ALONG WITH ITS SPECIFICITY IN TARGETING CLASS I HDACS AND ONCOGENES. THE COMBINED EFFECT OF RESMINOSTAT WITH SEVERAL PHARMACEUTICAL AGENTS SUCH AS SORAFENIB, CISPLATIN AND DOXORUBICIN WAS ALSO DEMONSTRATED. THE INHIBITION OF HEAT SHOCK PROTEIN 90 (HSP90) HAS BEEN DEMONSTRATED AS A POTENTIAL THERAPEUTIC OPTION FOR HCC. IN LINE WITH THIS, THE SPECIFIC HSP90 INHIBITOR 17-(ALLYLAMINO)-17-DEMETHOXYGELDANAMYCIN (17-AAG) WAS SELECTED AND IT WAS FOUND THAT THE COMBINATION OF RESMINOSTAT AND 17-AAG MAY PROVIDE A "SMART" CLINICAL STRATEGY FOR HCC PATIENTS BY TARGETING CELLULAR COMMUNICATION WITHIN THE TUMOUR MICROENVIRONMENT. THIS STUDY PROVIDES AN INSIGHT INTO THE USE OF RESMINOSTAT AS AN EPIGENETIC BASED THERAPEUTIC FOR HCC ALONG WITH OTHER PHARMACEUTICAL OPTIONS, IN PARTICULAR BY TARGETING THE CELL-TO-CELL COMMUNICATION THAT OCCURS BETWEEN HEPATOMA AND ADIPOCYTES. 2018 15 4507 17 MRTF: BASIC BIOLOGY AND ROLE IN KIDNEY DISEASE. A LESSER KNOWN BUT CRUCIALLY IMPORTANT DOWNSTREAM EFFECT OF RHO FAMILY GTPASES IS THE REGULATION OF GENE EXPRESSION. THIS MAJOR ROLE IS MEDIATED VIA THE CYTOSKELETON, THE ORGANIZATION OF WHICH DICTATES THE NUCLEOCYTOPLASMIC SHUTTLING OF A SET OF TRANSCRIPTION FACTORS. CENTRAL AMONG THESE IS MYOCARDIN-RELATED TRANSCRIPTION FACTOR (MRTF), WHICH UPON ACTIN POLYMERIZATION TRANSLOCATES TO THE NUCLEUS AND BINDS TO ITS COGNATE PARTNER, SERUM RESPONSE FACTOR (SRF). THE MRTF/SRF COMPLEX THEN DRIVES A LARGE COHORT OF GENES INVOLVED IN CYTOSKELETON REMODELING, CONTRACTILITY, EXTRACELLULAR MATRIX ORGANIZATION AND MANY OTHER PROCESSES. ACCORDINGLY, MRTF, ACTIVATED BY A VARIETY OF MECHANICAL AND CHEMICAL STIMULI, AFFECTS A PLETHORA OF FUNCTIONS WITH PHYSIOLOGICAL AND PATHOLOGICAL RELEVANCE. THESE INCLUDE CELL MOTILITY, DEVELOPMENT, METABOLISM AND THUS METASTASIS FORMATION, INFLAMMATORY RESPONSES AND-PREDOMINANTLY-ORGAN FIBROSIS. THE AIM OF THIS REVIEW IS TWOFOLD: TO PROVIDE AN UP-TO-DATE SUMMARY ABOUT THE BASIC BIOLOGY AND REGULATION OF THIS VERSATILE TRANSCRIPTIONAL COACTIVATOR; AND TO HIGHLIGHT ITS PRINCIPAL INVOLVEMENT IN THE PATHOBIOLOGY OF KIDNEY DISEASE. ACTING THROUGH BOTH DIRECT TRANSCRIPTIONAL AND EPIGENETIC MECHANISMS, MRTF PLAYS A KEY (YET NOT FULLY APPRECIATED) ROLE IN THE INDUCTION OF A PROFIBROTIC EPITHELIAL PHENOTYPE (PEP) AS WELL AS IN FIBROBLAST-MYOFIBROBLAST TRANSITION, PRIME PATHOMECHANISMS IN CHRONIC KIDNEY DISEASE AND RENAL FIBROSIS. 2021 16 102 24 A REGULATORY ROLE FOR CHD2 IN MYELOPOIESIS. THE TRANSCRIPTIONAL PROGRAM THAT DICTATES HAEMATOPOIETIC CELL FATE AND DIFFERENTIATION REQUIRES AN EPIGENETIC REGULATORY AND MEMORY FUNCTION, PROVIDED BY A NETWORK OF EPIGENETIC FACTORS THAT REGULATE DNA METHYLATION, POST-TRANSLATIONAL HISTONE MODIFICATIONS AND CHROMATIN STRUCTURE. DISTURBED EPIGENETIC REGULATION CAUSES PERTURBATIONS IN THE BLOOD CELL DIFFERENTIATION PROGRAM THAT RESULTS IN VARIOUS TYPES OF HAEMATOPOIETIC DISORDERS. THUS, ACCURATE EPIGENETIC REGULATION IS ESSENTIAL FOR FUNCTIONAL HAEMATOPOIESIS. IN THIS STUDY, WE USED A CRISPR-CAS9 SCREENING APPROACH TO IDENTIFY NEW EPIGENETIC REGULATORS IN MYELOID DIFFERENTIATION. WE DESIGNED A CHROMATIN-UMI CRISPR GUIDE LIBRARY TARGETING 1092 EPIGENETIC REGULATORS. PHORBOL 12-MYRISTATE 13-ACETATE (PMA) TREATMENT OF THE CHRONIC MYELOID LEUKAEMIA CELL LINE K-562 WAS USED AS A MEGAKARYOCYTIC MYELOID DIFFERENTIATION MODEL. BOTH PREVIOUSLY DESCRIBED DEVELOPMENTAL EPIGENETIC REGULATORS AND NOVEL FACTORS WERE IDENTIFIED IN OUR SCREEN. IN THIS STUDY, WE VALIDATED AND CHARACTERIZED A ROLE FOR THE CHROMATIN REMODELLER CHD2 IN MYELOID PROLIFERATION AND MEGAKARYOCYTIC DIFFERENTIATION. 2020 17 6000 28 THE ACTIVATION OF HISTONE DEACETYLASES 4 PREVENTED ENDOTHELIAL DYSFUNCTION: A CRUCIAL MECHANISM OF HUANGQIGUIZHIWUWU DECOCTION IN IMPROVING MICROCIRCULATION DYSFUNCTION IN DIABETES. ETHNOPHARMACOLOGICAL RELEVANCE: THE REGULATION OF EPIGENETIC FACTORS IS CONSIDERED A CRUCIAL TARGET FOR SOLVING COMPLEX CHRONIC DISEASES SUCH AS CARDIO-CEREBROVASCULAR DISEASES. HUANGQIGUIZHIWUWU DECOCTION (HGWWD), A CLASSIC CHINESE PRESCRIPTION, IS MAINLY USED TO TREAT VARIOUS VASCULAR DISEASES. ALTHOUGH OUR PREVIOUS STUDIES REPORTED THAT HGWWD COULD EFFECTIVELY PREVENT VASCULAR DYSFUNCTION IN DIABETIC RODENT MODELS, THE PRECISE MECHANISM IS STILL ELUSIVE. AIM OF THE STUDY: IN THIS STUDY, WE INVESTIGATED THE EPIGENETIC MECHANISMS OF MODULATING THE DAMAGE OF VASCULAR ENDOTHELIAL CELLS IN DIABETES BY HGWWD. METHODS: WE FIRST ANALYZED COMMON ACTIVE COMPONENTS OF HGWWD BY USING HPLC-Q-TOF-MS/MS ANALYSIS, AND PREDICTED THE ISOFORMS OF HISTONE DEACETYLASE (HDAC) THAT CAN POTENTIALLY COMBINE THE ABOVE ACTIVE COMPONENTS BY SYSTEMS PHARMACOLOGY. NEXT, WE SCREENED THE INVOLVEMENT OF SPECIFIC HDAC ISOFORMS IN THE PROTECTIVE EFFECT OF HGWWD ON VASCULAR INJURY BY USING PHARMACOLOGICAL BLOCKADE COMBINED WITH THE EVALUATION OF VASCULAR FUNCTION IN VIVO AND IN VITRO. RESULTS: FIRSTLY, HDAC1, HDAC2, HDAC3, HDAC4, HDAC6, HDAC7, SIRT2, AND SIRT3 HAVE BEEN IMPLICATED WITH THE POSSIBILITY OF BINDING TO THE THIRTY-ONE COMMON ACTIVE COMPONENTS IN HGWWD. FURTHERMORE, THE PROTECTIVE EFFECT OF HGWWD IS REVERSED BY BOTH TSA (HDAC INHIBITOR) AND MC1568 (CLASS II HDAC INHIBITOR) ON VASCULAR IMPAIRMENT ACCOMPANIED BY REDUCED AORTIC HDAC ACTIVITY IN STZ MICE. FINALLY, INHIBITION OF HDAC4 BLOCKED THE PROTECTIVE EFFECT OF HGWWD ON MICROVASCULAR AND ENDOTHELIAL DYSFUNCTION IN DIABETIC MICE. CONCLUSIONS: THESE RESULTS PROVE THE KEY ROLE OF HDAC4 IN DIABETES-INDUCED MICROVASCULAR DYSFUNCTION AND UNDERLYING EPIGENETIC MECHANISMS FOR THE PROTECTIVE EFFECT OF HGWWD IN DIABETES. 2023 18 195 23 ACF CHROMATIN-REMODELING COMPLEX MEDIATES STRESS-INDUCED DEPRESSIVE-LIKE BEHAVIOR. IMPROVED TREATMENT FOR MAJOR DEPRESSIVE DISORDER (MDD) REMAINS ELUSIVE BECAUSE OF THE LIMITED UNDERSTANDING OF ITS UNDERLYING BIOLOGICAL MECHANISMS. IT IS LIKELY THAT STRESS-INDUCED MALADAPTIVE TRANSCRIPTIONAL REGULATION IN LIMBIC NEURAL CIRCUITS CONTRIBUTES TO THE DEVELOPMENT OF MDD, POSSIBLY THROUGH EPIGENETIC FACTORS THAT REGULATE CHROMATIN STRUCTURE. WE ESTABLISH THAT PERSISTENT UPREGULATION OF THE ACF (ATP-UTILIZING CHROMATIN ASSEMBLY AND REMODELING FACTOR) ATP-DEPENDENT CHROMATIN-REMODELING COMPLEX, OCCURRING IN THE NUCLEUS ACCUMBENS OF STRESS-SUSCEPTIBLE MICE AND DEPRESSED HUMANS, IS NECESSARY FOR STRESS-INDUCED DEPRESSIVE-LIKE BEHAVIORS. WE FOUND THAT ALTERED ACF BINDING AFTER CHRONIC STRESS WAS CORRELATED WITH ALTERED NUCLEOSOME POSITIONING, PARTICULARLY AROUND THE TRANSCRIPTION START SITES OF AFFECTED GENES. THESE ALTERATIONS IN ACF BINDING AND NUCLEOSOME POSITIONING WERE ASSOCIATED WITH REPRESSED EXPRESSION OF GENES IMPLICATED IN SUSCEPTIBILITY TO STRESS. TOGETHER, OUR FINDINGS IDENTIFY THE ACF CHROMATIN-REMODELING COMPLEX AS A CRITICAL COMPONENT IN THE DEVELOPMENT OF SUSCEPTIBILITY TO DEPRESSION AND IN REGULATING STRESS-RELATED BEHAVIORS. 2015 19 2373 31 EPIGENETIC REGULATION OF THE N-TERMINAL TRUNCATED ISOFORM OF MATRIX METALLOPROTEINASE-2 (NTT-MMP-2) AND ITS PRESENCE IN RENAL AND CARDIAC DISEASES. SEVERAL CLINICAL AND EXPERIMENTAL STUDIES HAVE DOCUMENTED A COMPELLING AND CRITICAL ROLE FOR THE FULL-LENGTH MATRIX METALLOPROTEINASE-2 (FL-MMP-2) IN ISCHEMIC RENAL INJURY, PROGRESSIVE RENAL FIBROSIS, AND DIABETIC NEPHROPATHY. A NOVEL N-TERMINAL TRUNCATED ISOFORM OF MMP-2 (NTT-MMP-2) WAS RECENTLY DISCOVERED, WHICH IS INDUCED BY HYPOXIA AND OXIDATIVE STRESS BY THE ACTIVATION OF A LATENT PROMOTER LOCATED IN THE FIRST INTRON OF THE MMP2 GENE. THIS NTT-MMP-2 ISOFORM IS ENZYMATICALLY ACTIVE BUT REMAINS INTRACELLULAR IN OR NEAR THE MITOCHONDRIA. IN THIS PERSPECTIVE ARTICLE, WE FIRST PRESENT THE FINDINGS ABOUT THE DISCOVERY OF THE NTT-MMP-2 ISOFORM, AND ITS FUNCTIONAL AND STRUCTURAL DIFFERENCES AS COMPARED WITH THE FL-MMP-2 ISOFORM. BASED ON PUBLICLY AVAILABLE EPIGENOMICS DATA FROM THE ENCYCLOPEDIA OF DNA ELEMENTS (ENCODE) PROJECT, WE PROVIDE INSIGHTS INTO THE EPIGENETIC REGULATION OF THE LATENT PROMOTER LOCATED IN THE FIRST INTRON OF THE MMP2 GENE, WHICH SUPPORT THE ACTIVATION OF THE NTT-MMP-2 ISOFORM. WE THEN FOCUS ON ITS FUNCTIONAL ASSESSMENT BY COVERING THE ALTERATIONS FOUND IN THE KIDNEY OF TRANSGENIC MICE EXPRESSING THE NTT-MMP-2 ISOFORM. NEXT, WE HIGHLIGHT RECENT FINDINGS REGARDING THE PRESENCE OF THE NTT-MMP-2 ISOFORM IN RENAL DYSFUNCTION, IN KIDNEY AND CARDIAC DISEASES, INCLUDING DAMAGE OBSERVED IN AGING, ACUTE ISCHEMIA-REPERFUSION INJURY (IRI), CHRONIC KIDNEY DISEASE, DIABETIC NEPHROPATHY, AND HUMAN RENAL TRANSPLANTS WITH DELAYED GRAFT FUNCTION. FINALLY, WE BRIEFLY DISCUSS HOW OUR INSIGHTS MAY GUIDE FURTHER EXPERIMENTAL AND CLINICAL STUDIES THAT ARE NEEDED TO ELUCIDATE THE UNDERLYING MECHANISMS AND THE ROLE OF THE NTT-MMP-2 ISOFORM IN RENAL DYSFUNCTION, WHICH MAY HELP TO ESTABLISH IT AS A POTENTIAL THERAPEUTIC TARGET IN KIDNEY DISEASES. 2021 20 3002 21 GENETIC, EPIGENETIC AND POSTTRANSCRIPTIONAL MECHANISMS FOR TREATMENT OF MAJOR DEPRESSION: THE 5-HT1A RECEPTOR GENE AS A PARADIGM. MAJOR DEPRESSION AND ANXIETY ARE HIGHLY PREVALENT AND INVOLVE CHRONIC DYSREGULATION OF SEROTONIN, BUT THEY REMAIN POORLY UNDERSTOOD. HERE, WE REVIEW NOVEL TRANSCRIPTIONAL (GENETIC, EPIGENETIC) AND POSTTRANSCRIPTIONAL (MICRORNA, ALTERNATIVE SPLICING) MECHANISMS IMPLICATED IN MENTAL ILLNESS, FOCUSING ON A KEY SEROTONIN-RELATED REGULATOR, THE SEROTONIN 1A (5-HT1A) RECEPTOR. FUNCTIONAL SINGLE-NUCLEOTIDE POLYMORPHISMS AND STRESS-INDUCED DNA METHYLATION OF THE 5-HT1A PROMOTER CONVERGE TO DIFFERENTIALLY ALTER PRE- AND POSTSYNAPTIC 5-HT1A RECEPTOR EXPRESSION ASSOCIATED WITH MAJOR DEPRESSION AND REDUCED THERAPEUTIC RESPONSE TO SEROTONERGIC ANTIDEPRESSANTS. MAJOR DEPRESSION IS ALSO ASSOCIATED WITH ALTERED LEVELS OF SPLICE FACTORS AND MICRORNA, POSTTRANSCRIPTIONAL MECHANISMS THAT REGULATE RNA STABILITY. THE HUMAN 5-HT1A 3'-UNTRANSLATED REGION IS ALTERNATIVELY SPLICED, REMOVING MICRORNA SITES AND INCREASING 5-HT1A EXPRESSION, WHICH IS REDUCED IN MAJOR DEPRESSION AND MAY BE GENOTYPE-DEPENDENT. THUS, THE 5-HT1A RECEPTOR GENE ILLUSTRATES THE CONVERGENCE OF GENETIC, EPIGENETIC AND POSTTRANSCRIPTIONAL MECHANISMS IN GENE EXPRESSION, NEURODEVELOPMENT AND NEUROPLASTICITY, AND MAJOR DEPRESSION. UNDERSTANDING GENE REGULATORY MECHANISMS COULD ENHANCE THE DETECTION, CATEGORIZATION AND PERSONALIZED TREATMENT OF MAJOR DEPRESSION. 2019