1 328 107 ALPHA-KETOGLUTARIC ACID AMELIORATES INTERVERTEBRAL DISC DEGENERATION BY BLOCKING THE IL-6/JAK2/STAT3 PATHWAY. INTERVERTEBRAL DISC DEGENERATION (IVDD) IS THE MAJOR CAUSE OF LOW BACK PAIN. ALPHA-KETOGLUTARIC ACID (ALPHA-KG), AN IMPORTANT INTERMEDIATE IN ENERGY METABOLISM, HAS VARIOUS FUNCTIONS, INCLUDING EPIGENETIC REGULATION, MAINTENANCE OF REDOX HOMEOSTASIS, AND ANTI-AGING, BUT WHETHER IT CAN AMELIORATE IVDD HAS NOT BEEN REPORTED. HERE, WE EXAMINED THE IMPACTS OF LONG-TERM ADMINISTRATION OF A-KG ON AGING-ASSOCIATED IVDD IN ADULT RATS. IN VIVO AND IN VITRO EXPERIMENTS SHOWED THAT ALPHA-KG SUPPLEMENTATION EFFECTIVELY AMELIORATED IVDD IN RATS AND THE SENESCENCE OF NUCLEUS PULPOSUS CELLS (NPCS). ALPHA-KG SUPPLEMENTATION SIGNIFICANTLY ATTENUATED SENESCENCE, APOPTOSIS AND MMP-13 PROTEIN EXPRESSION, AND IT INCREASED THE SYNTHESIS OF AGGRECAN AND COLLAGEN II IN IL-1BETA-TREATED NPCS. IN ADDITION, ALPHA-KG SUPPLEMENTATION REDUCED THE LEVELS OF IL-6, PHOSPHORYLATED JAK2 AND STAT3, AND THE NUCLEAR TRANSLOCATION OF P-STAT3 IN IL-1BETA-INDUCED DEGENERATING NPCS. THE EFFECTS OF ALPHA-KG WERE ENHANCED BY AG490 IN NPCS. THE UNDERLYING MECHANISM MAY INVOLVE THE INHIBITION OF JAK2/STAT3 PHOSPHORYLATION AND THE REDUCTION OF IL-6 EXPRESSION. OUR FINDINGS MAY HELP IN THE DEVELOPMENT OF NEW THERAPEUTIC STRATEGIES FOR IVDD. 2023 2 2041 29 EPIGENETIC CHANGES WITHIN THE ANNULUS FIBROSUS BY DNA METHYLATION IN RAT INTERVERTEBRAL DISC DEGENERATION MODEL. INTERVERTEBRAL DISC DEGENERATION (IDD) IS AN AGE-DEPENDENT PROGRESSIVE SPINAL DISEASE THAT CAUSES CHRONIC BACK OR NECK PAIN. ALTHOUGH AGING HAS LONG BEEN PRESENTED AS THE MAIN RISK FACTOR, THE EXACT CAUSE IS NOT FULLY KNOWN. DNA METHYLATION IS ASSOCIATED WITH CHRONIC PAIN, SUGGESTING THAT EPIGENETIC MODULATION MAY AMELIORATE DISC DEGENERATION. WE EXAMINED HISTOLOGICAL CHANGES IN THE DNA METHYLATION WITHIN THE DISCS AND THEIR ASSOCIATION WITH PAIN-RELATED TRANSIENT RECEPTOR POTENTIAL VANILLOID SUBTYPE 1 (TRPV1) EXPRESSION IN RATS SUBJECTED TO IDD. EPIGENETIC MARKERS (5-HYDROXYMETHYLCYTOSINE (5HMC), 5-METHYLCYTOSINE (5MC)), DNA METHYLTRANSFERASES (DNMTS), AND TEN-ELEVEN TRANSLOCATIONS (TETS) WERE ANALYZED USING IMMUNOHISTOCHEMISTRY, REAL-TIME PCR, AND DNA DOT-BLOT FOLLOWING IDD. RESULTS REVEALED HIGH 5MC LEVELS IN THE ANNULUS FIBROSUS (AF) REGION WITHIN THE DISC AFTER IDD AND AN ASSOCIATION WITH TRPV1 EXPRESSION. DNMT1 IS MAINLY INVOLVED IN 5MC CONVERSION IN DEGENERATED DISCS. HOWEVER, 5HMC LEVELS DID NOT DIFFER BETWEEN GROUPS. A DEGENERATED DISC CAN LEAD TO LOCOMOTOR DEFECTS AS ASSESSED BY LADDER AND TAIL SUSPENSION TESTS, NO PAIN SIGNALS IN THE VON FREY TEST, UPREGULATED MATRIX METALLOPROTEINASE-3, AND DOWNREGULATED AGGRECAN LEVELS WITHIN THE DISC. THUS, WE FOUND THAT THE DNA METHYLATION STATUS IN THE AF REGION OF THE DISC WAS MAINLY CHANGED AFTER IDD AND ASSOCIATED WITH ABERRANT TRPV1 EXPRESSION IN DEGENERATED DISCS. 2022 3 3816 28 INTRAUTERINE PROGRAMMING OF CARTILAGINOUS 11BETA-HSD2 INDUCED BY CORTICOSTERONE AND CAFFEINE MEDIATED SUSCEPTIBILITY TO ADULT OSTEOARTHRITIS. OUR PREVIOUS STUDY REPORTED THAT PRENATAL CAFFEINE EXPOSURE (PCE) COULD INDUCE CHONDRODYSPLASIA AND INCREASE THE SUSCEPTIBILITY TO OSTEOARTHRITIS IN OFFSPRING RATS. HOWEVER, THE POTENTIAL MECHANISMS AND INITIATING FACTORS REMAIN UNKNOWN. THIS STUDY AIMS TO INVESTIGATE WHETHER 11BETA-HSD2, A GLUCOCORTICOID-METABOLIZING ENZYME, IS INVOLVED IN THE SUSCEPTIBILITY OF OSTEOARTHRITIS INDUCED BY PCE AND TO FURTHER EXPLORE ITS POTENTIAL MECHANISMS AND INITIATING FACTORS. FIRSTLY, WE FOUND THAT PCE REDUCED CARTILAGE MATRIX SYNTHESIS (AGGRECAN/COL2A1 EXPRESSION) IN MALE ADULT OFFSPRING RATS AND EXHIBITED AN OSTEOARTHRITIS PHENOTYPE FOLLOWING CHRONIC STRESS, WHICH WAS ASSOCIATED WITH PERSISTENTLY REDUCED H3K9AC AND H3K27AC LEVELS AT THE PROMOTER OF 11BETA-HSD2 AS WELL AS ITS EXPRESSION IN THE CARTILAGE FROM FETUS TO ADULTHOOD. THE EXPRESSION OF 11BETA-HSD2, AGGRECAN AND COL2A1 WERE ALL DECREASED BY CORTICOSTERONE IN THE FETAL CHONDROCYTES, WHILE OVEREXPRESSION OF 11BETA-HSD2 COULD PARTIALLY ALLEVIATE THE DECREASE OF MATRIX SYNTHESIS INDUCED BY CORTICOSTERONE IN VITRO. FURTHERMORE, THE GLUCOCORTICOID RECEPTOR (GR) ACTIVATED BY GLUCOCORTICOIDS DIRECTLY BONDED TO THE PROMOTER REGION OF 11BETA-HSD2 TO INHIBIT ITS EXPRESSION. MEANWHILE, THE ACTIVATED GR REDUCED THE H3K9AC AND H3K27AC LEVELS OF 11BETA-HSD2 BY RECRUITING HDAC4 AND PROMOTING GR-HDAC4 PROTEIN INTERACTION TO INHIBIT THE 11BETA-HSD2 EXPRESSION. MOREOVER, CAFFEINE COULD REDUCE THE EXPRESSION OF 11BETA-HSD2 BY INHIBITING THE CAMP/PKA SIGNALING PATHWAY BUT WITHOUT REDUCING THE H3K9AC AND H3K27AC LEVELS OF 11BETA-HSD2, THEREBY SYNERGISTICALLY ENHANCING THE CORTICOSTERONE EFFECT. IN CONCLUSION, THE PERSISTENTLY REDUCED H3K9AC AND H3K27AC LEVELS OF 11BETA-HSD2 FROM FETUS TO ADULTHOOD MEDIATED THE INHIBITION OF CARTILAGE MATRIX SYNTHESIS AND THE INCREASED SUSCEPTIBILITY TO OSTEOARTHRITIS. THIS EPIGENETIC PROGRAMMING CHANGE IN UTERO WAS INDUCED BY GLUCOCORTICOIDS WITH SYNERGISTIC EFFECT OF CAFFEINE. 2022 4 3724 35 INHIBITION OF EZH2 AMELIORATES CARTILAGE ENDPLATE DEGENERATION AND ATTENUATES THE PROGRESSION OF INTERVERTEBRAL DISC DEGENERATION VIA DEMETHYLATION OF SOX-9. BACKGROUND: CARTILAGINOUS ENDPLATE (CEP) DEGENERATION IS CONSIDERED AS ONE OF THE MAJOR CAUSES OF INTERVERTEBRAL DISC DEGENERATION (IVDD) WHICH CAUSES LOW BACK PAIN. RECENT STUDIES HAVE PROVED THAT EPIGENETIC ALTERATION IS INVOLVED IN A VARIETY OF DISEASES. THIS WORK EXPLORED THE ROLE OF HISTONE METHYLTRANSFERASE ENHANCER OF ZESTE HOMOLOGUE 2 (EZH2) IN CEP DEGENERATION, AS WELL AS ITS UNDERLYING EPIGENETIC MECHANISMS, AND CONFIRMED THE EFFECT OF EZH2 KNOCKDOWN ON DELAYING IVDD DEVELOPMENT. METHODS: WESTERN BLOTTING, IMMUNOFLUORESCENCE STAINING, AND CHIP ASSAY WERE APPLIED TO DEMONSTRATE THE MOLECULAR MECHANISM OF EZH2 IN CEP TISSUE. THE THERAPEUTIC POTENTIAL OF EZH2 WAS INVESTIGATED USING PUNCTURE-INDUCED RAT MODELS. FINDINGS: THE EZH2 EXPRESSION WAS UPREGULATED IN HUMAN AND RAT CEP TISSUE. IT WAS ALSO FOUND THAT THE OVEREXPRESSION OF EZH2 SUPPRESSED THE EXPRESSION OF COLLAGEN II, AGGRECAN AND SOX-9, AND PROMOTED THE EXPRESSION OF ADTAMTS5 AND MMP13 IN RAT ENDPLATE CHONDROCYTES (EPCS), WHICH COULD BE REVERSED BY EZH2 SILENCING. THE CORRELATION BETWEEN EZH2 AND SOX-9 WAS FURTHER EXPLORED, WHILE OVEREXPRESSION OF SOX-9 COULD REVERSE THE EFFECT OF EZH2 IN RAT EPCS. MOREOVER, INHIBITION OF EZH2 UPREGULATED THE LEVEL OF SOX-9 BY DEMETHYLATING H3K27ME3 AT SOX-9 PROMOTER SITES, REVEALING THE REGULATORY MECHANISM OF EZH2 ON SOX-9. MEANWHILE, PUNCTURE-INDUCED RAT MODELS SHOWED THAT EZH2 KNOCKDOWN EXERTED A PROTECTIVE EFFECT ON CEP AND DISC DEGENERATION. INTERPRETATION: THIS STUDY REVEALS THAT EZH2 INHIBITION IS A PROMISING STRATEGY FOR MITIGATING THE SYMPTOMS AND PROGRESSION OF IVDD. FUNDING: THIS STUDY WAS FUNDED BY THE NATURAL SCIENCE FOUNDATION OF ZHEJIANG PROVINCE (Y16H060034). AUTHORS DECLARE THAT THE FUNDERS HAD NO INVOLVEMENT IN THE STUDY DESIGN, DATA ANALYSIS AND INTERPRETATION OF THE RESULTS. 2019 5 4880 22 OVERVIEW OF MMP-13 AS A PROMISING TARGET FOR THE TREATMENT OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A COMMON DEGENERATIVE DISEASE CHARACTERIZED BY THE DESTRUCTION OF ARTICULAR CARTILAGE AND CHRONIC INFLAMMATION OF SURROUNDING TISSUES. MATRIX METALLOPROTEINASE-13 (MMP-13) IS THE PRIMARY MMP INVOLVED IN CARTILAGE DEGRADATION THROUGH ITS PARTICULAR ABILITY TO CLEAVE TYPE II COLLAGEN. HENCE, IT IS AN ATTRACTIVE TARGET FOR THE TREATMENT OF OA. HOWEVER, THE DETAILED MOLECULAR MECHANISMS OF OA INITIATION AND PROGRESSION REMAIN ELUSIVE, AND, CURRENTLY, THERE ARE NO INTERVENTIONS AVAILABLE TO RESTORE DEGRADED CARTILAGE. THIS REVIEW FULLY ILLUSTRATES THE INVOLVEMENT OF MMP-13 IN THE INITIATION AND PROGRESSION OF OA THROUGH THE REGULATION OF MMP-13 ACTIVITY AT THE MOLECULAR AND EPIGENETIC LEVELS, AS WELL AS THE STRATEGIES THAT HAVE BEEN EMPLOYED AGAINST MMP-13. THE AIM OF THIS REVIEW IS TO IDENTIFY MMP-13 AS AN ATTRACTIVE TARGET FOR INHIBITOR DEVELOPMENT IN THE TREATMENT OF OA. 2021 6 2284 19 EPIGENETIC REGULATION IN INTERVERTEBRAL DISC DEGENERATION. INTERVERTEBRAL DISC (IVD) DEGENERATION IS THE LEADING CAUSE OF LOW BACK PAIN, WHICH HAS A STRIKING IMPACT ON NUMEROUS PATIENTS. THEREFORE, COMPREHENSIVELY ILLUMINATING THE REGULATORY MECHANISMS OF IVD DEGENERATION IS OF GREAT SIGNIFICANCE. HERE, WE DISCUSS THE LATEST ADVANCES IN UNDERSTANDING THE MAIN EPIGENETIC MECHANISMS REGULATING IVD DEGENERATION. 2022 7 3355 24 HISTONE EXTRACTION FROM HUMAN ARTICULAR CARTILAGE FOR THE STUDY OF EPIGENETIC REGULATION IN OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A CHRONIC DISEASE THAT AFFECTS ARTICULAR CARTILAGE, CAUSING ITS DEGENERATION. ALTHOUGH OA IS ONE OF THE MOST PREVALENT PATHOLOGIES GLOBALLY, THERE ARE NO DEFINITIVE TREATMENTS AVAILABLE. RECENTLY, RESEARCH HAS FOCUSED ON ELUCIDATING THE COMPLEX INTERPLAY THAT TAKES PLACE BETWEEN INFLAMMATORY PROCESSES AND EPIGENETIC REGULATION, SHOWING THAT HISTONE POST-TRANSLATIONAL MODIFICATIONS (PTMS) CAN EXERT A PRONOUNCED EFFECT ON THE EXPRESSION OF OA-RELATED GENES. OA CHONDROCYTES ENHANCE THE PRODUCTION OF INTERLEUKIN 1BETA (IL-1BETA) AND INTERLEUKIN 8 (IL-8), WHICH ARE EPIGENETICALLY REGULATED. THESE CYTOKINES UPREGULATE THE SYNTHESIS OF MATRIX METALLOPROTEINASES (MMPS) AND AGGRECANASES, WHICH PROMOTE THE EXTRACELLULAR MATRIX (ECM) DESTRUCTION. THIS MOTIVATES THE STUDY OF HISTONE PTMS TO INVESTIGATE THE EPIGENETIC REGULATION OF PROINFLAMMATORY MOLECULES, BUT THE ABSENCE OF SPECIFIC PROTOCOLS TO EXTRACT HISTONES FROM HUMAN ARTICULAR CARTILAGE HAS COMPLICATED THIS TASK. THE LACK OF EFFECTIVE METHODS CAN BE EXPLAINED BY THE STRUCTURAL COMPLEXITY AND LOW CELLULARITY OF THIS TISSUE, WHICH ARE RESPONSIBLE FOR THE BIOMECHANICAL PROPERTIES THAT ALLOW THE MOVEMENT OF THE JOINT BUT ALSO COMPLICATE HISTONE ISOLATION. HERE, WE PROVIDE A HISTONE EXTRACTION PROCEDURE SPECIFICALLY ADAPTED FOR CRYOPRESERVED HUMAN ARTICULAR CARTILAGE THAT CAN BE USEFUL TO UNDERSTAND EPIGENETIC REGULATION IN OA AND ACCELERATE THE SEARCH FOR NOVEL STRATEGIES. 2022 8 814 23 CHANGES IN SMALL NONCODING RNA EXPRESSION DURING CHONDROCYTE SENESCENCE. OBJECTIVE: OSTEOARTHRITIS (OA) IS CHARACTERIZED BY THE CHRONIC AND PROGRESSIVE DETERIORATION OF ARTICULAR CARTILAGE. CHONDROCYTE SENESCENCE COULD LEAD TO A SHIFT IN THE BALANCE BETWEEN EXTRACELLULAR MATRIX (ECM) COMPONENT SYNTHESIS AND DEGRADATION. SMALL NONCODING RNAS (SNCRNAS), INCLUDING MICRORNAS (MIRNAS), P-ELEMENT-INDUCED WIMPY TESTIS-(PIWI-) INTERACTING RNAS (PIRNAS), SMALL NUCLEOLAR RNAS (SNORNAS), SMALL NUCLEAR RNAS (SNRNAS), AND REPEAT-ASSOCIATED SIRNAS (RASIRNAS), ARE A CLASS OF IMPORTANT EPIGENETIC MOLECULES. WE AIMED TO GAIN INSIGHTS INTO THE CHANGES AND ROLES OF SNCRNA IN CHONDROCYTE SENESCENCE. DESIGN: HEALTHY MOUSE POSTNATAL CHONDROCYTES WERE ISOLATED, AND A REPLICATIVE AGING MODEL WAS CONSTRUCTED. WE USED SMALL RNA SEQUENCING (SMALL RNA-SEQ) TO GENERATE EXTENSIVE SMALL RNA DATA. WE IDENTIFIED DIFFERENTIALLY EXPRESSED SNCRNAS AND PERFORMED TISSUE-SPECIFIC ANALYSIS USING REAL-TIME QUANTITATIVE POLYMERASE CHAIN REACTION (QRT-PCR). BETA-GALACTOSIDASE STAINING WAS USED TO DETECT CHONDROCYTE SENESCENCE. THE RESULTS SHOWED THAT THE EXPRESSION PROFILES OF SNCRNA IN PASSAGE 5 CHONDROCYTES WERE SIGNIFICANTLY DIFFERENT FROM THOSE IN PASSAGE 0 CHONDROCYTES. THE EXPRESSION OF SNCRNA WAS TISSUE SPECIFIC. WE FOUND THAT 40 MIRNAS WERE UPREGULATED AND 70 MIRNAS WERE DOWNREGULATED DURING CHONDROCYTE SENESCENCE, AND THAT MIR-132-5P EXPRESSION INHIBITION PREVENTED CHONDROCYTE SENESCENCE. WE FOUND THAT 8 PIRNAS WERE UPREGULATED AND 17 PIRNAS WERE DOWNREGULATED DURING CHONDROCYTE SENESCENCE, AND THAT PIRNA PIR_025576 OVEREXPRESSION DELAYED CHONDROCYTE SENESCENCE. WE FOUND THAT 24 SNORNAS WERE UPREGULATED AND 28 SNORNAS WERE DOWNREGULATED DURING CHONDROCYTE SENESCENCE, AND THAT SNORNA ENSMUSG00000087935 OVEREXPRESSION DELAYED CHONDROCYTE SENESCENCE. WE FOUND THAT 5 SNRNAS WERE UPREGULATED AND 6 SNRNAS WERE DOWNREGULATED DURING CHONDROCYTE SENESCENCE, AND THAT SNRNA ENSMUSG00000064682 OVEREXPRESSION DELAYED CHONDROCYTE SENESCENCE. WE FOUND THAT 1 RASIRNA WAS UPREGULATED AND 4 RASIRNAS WERE DOWNREGULATED DURING CHONDROCYTE SENESCENCE. CONCLUSIONS: THESE FINDINGS MIGHT PROVIDE NOVEL INSIGHTS INTO OA PATHOGENESIS AND CONTRIBUTE TO THE DEVELOPMENT OF CANDIDATES FOR TARGETED THERAPEUTICS IN OA. 2022 9 1724 16 DYSREGULATION OF EPIGENETIC RELATED GENES IN DIABETIC TRIGGER FINGER PATIENTS; PRELIMINARY ANALYSIS OF PATIENT-DERIVED SAMPLES. BACKGROUND: TRIGGER FINGER (TF), A PAINFUL CONDITION INVOLVING A FINGER FLEXOR TENDON, IS A COMMON PROBLEM WITH A PREVALENCE OF ~2-3% IN THE GENERAL POPULATION. HOWEVER, THE TF PREVALENCE IS HIGHER AMONG DIABETIC PATIENTS-RANGES FROM 6.7% TO 10%. WE HAVE ANALYZED THE EXPRESSION OF THE EXTRACELLULAR MATRIX, INFLAMMATION, AND EPIGENETIC RELATED GENES IN DIABETIC AND NON-DIABETES TF. WE HYPOTHESIZED THAT DIABETES CONDITION INDUCES ALTER THE EXPRESSION OF EPIGENETIC MODIFICATION GENES IN DIABETIC PATIENTS AND ONE OF THE UNDERLYING DETERMINANTS FOR MORE PREVALENCE OF TF IN DIABETIC PATIENTS. METHOD: TISSUES FROM THE FINGERS OF PATIENTS WITH SYMPTOMATIC TRIGGER FINGERS WERE COLLECTED. WE HAD THREE GROUPS: CARPAL TUNNEL SYNDROME (AS A CONTROL), TRIGGER FINGER, AND DIABETIC TRIGGER FINGER. A QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION WAS PERFORMED. THE GENE EXPRESSION OF EXTRACELLULAR MATRIX (ECM) COMPONENTS [COL-I, COL-II, COL-X, AGGRECAN], DNA METHYLTRANSFERASES ENZYMES (DNMT1, DNMT3), GROWTH FACTORS (TGF-B, IGF), AND HISTONE DEACETYLASE ENZYMES (HDAC1, HDAC2) WERE EVALUATED IN ALL GROUPS. RESULTS: THE MRNA EXPRESSION OF COL-I, COL-II, AGGRECAN WAS SIGNIFICANTLY HIGHER IN THE PULLY A1 OF DIABETIC PATIENTS (P= 0.0164, P=0.0351, P=0.0399, RESPECTIVELY) AS COMPARED TO NON-DIABETIC TF PATIENTS. DIABETES WAS ASSOCIATED WITH A SIGNIFICANT INCREASE IN THE DNMT3 EXPRESSION COMPARED TO NON-DIABETIC TF PATIENTS (P=0.0485). HDAC1 AND HDAC2 GENE EXPRESSION WERE UP-REGULATED IN DIABETIC TF THAN NON-DIABETIC TF. CONCLUSION: THE CHRONIC STATE OF HYPERGLYCEMIA INDUCES EPIGENETIC MODIFICATION OF GENE EXPRESSIONS IN TRIGGER FINGERS. THIS SEEMS TO HAVE A SIGNIFICANT IMPACT ON THE DEVELOPMENT, RECURRENCE, AND PROGRESSION OF TRIGGER FINGER IN DIABETIC PATIENTS. 2020 10 4033 40 M6A HYPOMETHYLATION OF DNMT3B REGULATED BY ALKBH5 PROMOTES INTERVERTEBRAL DISC DEGENERATION VIA E4F1 DEFICIENCY. BACKGROUND: THE INTERVERTEBRAL DISC (IVD) DEGENERATION IS THE LEADING CAUSE OF LOW BACK PAIN, WHICH ACCOUNTS FOR A MAIN CAUSE OF DISABILITY. N6-METHYLADENOSINE (M6A) IS THE MOST ABUNDANT INTERNAL MODIFICATION IN EUKARYOTIC MESSENGER RNAS AND IS INVOLVED IN VARIOUS DISEASES AND CELLULAR PROCESSES BY MODULATING MRNA FATE. HOWEVER, THE CRITICAL ROLE OF M6A REGULATION IN IVD DEGENERATION REMAINS UNCLEAR. NUCLEUS PULPOSUS CELL (NPC) SENESCENCE IS CRITICAL FOR THE PROGRESSION OF IVD DEGENERATION. HERE, WE UNCOVERED THE ROLE AND EXPLORED THE REGULATORY MECHANISM OF M6A IN NPC SENESCENCE DURING IVD DEGENERATION. METHODS: IDENTIFICATION OF NPC SENESCENCE DURING IVD DEGENERATION WAS BASED ON THE ANALYSIS OF TISSUE SAMPLES AND THE CELLULAR MODEL. ALKBH5 UPREGULATION INDUCING CELLULAR SENESCENCE WAS CONFIRMED BY FUNCTIONAL EXPERIMENTS IN VIVO AND IN VITRO. CHIP-QPCR AND DNA-PULLDOWN WERE USED TO REVEAL INCREASED ALKBH5 WAS REGULATED BY KDM4A-MEDIATED H3K9ME3. FURTHERMORE, ME-RIP-SEQ WAS PERFORMED TO IDENTIFY M6A HYPOMETHYLATION OF DNMT3B TRANSCRIPTS IN SENESCENT NPCS. STABILITY ANALYSIS SHOWED THAT DNMT3B EXPRESSION WAS ENHANCED FOR LESS YTHDF2 RECOGNITION AND INCREASED DNMT3B PROMOTED NPC SENESCENCE AND IVD DEGENERATION VIA E4F1 METHYLATION BY IN VIVO AND IN VITRO ANALYSES. RESULTS: EXPRESSION OF ALKBH5 IS ENHANCED DURING IVD DEGENERATION AND NPC SENESCENCE, DUE TO DECREASED KDM4A-MEDIATED H3K9ME3 MODIFICATION. FUNCTIONALLY, ALKBH5 CAUSES NPC SENESCENCE BY DEMETHYLATING DNMT3B TRANSCRIPTS AND IN TURN PROMOTING ITS EXPRESSION VIA LESS YTHDF2 RECOGNITION AND FOLLOWING DEGRADATION DUE TO TRANSCRIPT HYPOMETHYLATION IN VITRO AND IN VIVO. INCREASED DNMT3B PROMOTES THE DEVELOPMENT OF IVD DEGENERATION AND NPC SENESCENCE, MECHANISTICALLY BY METHYLATING CPG ISLANDS OF E4F1 AT THE PROMOTER REGION AND THUS RESTRAINING ITS TRANSCRIPTION AND EXPRESSION. CONCLUSIONS: COLLECTIVELY, OUR FINDINGS REVEAL AN EPIGENETIC INTERPLAY MECHANISM IN NPC SENESCENCE AND IVD DEGENERATION, PRESENTING A CRITICAL PRO-SENESCENCE ROLE OF ALKBH5 AND M6A HYPOMETHYLATION, HIGHLIGHTING THE THERAPEUTIC POTENTIAL OF TARGETING THE M6A/DNMT3B/E4F1 AXIS FOR TREATING IVD DEGENERATION. 2022 11 1826 30 EFFECTS OF HISTONE DEACETYLASE INHIBITOR ON EXTRACELLULAR MATRIX PRODUCTION IN HUMAN NASAL POLYP ORGAN CULTURES. BACKGROUND: NASAL POLYPOSIS IS ASSOCIATED WITH A CHRONIC INFLAMMATORY CONDITION OF THE SINONASAL MUCOSA AND INVOLVES MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION. EPIGENETIC MODULATION BY HISTONE DEACETYLASE (HDAC) INHIBITORS INCLUDING TRICHOSTATIN A (TSA) HAS BEEN REPORTED TO HAVE INHIBITORY EFFECTS ON MYOFIBROBLAST DIFFERENTIATION IN LUNG AND RENAL FIBROBLASTS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE THE INHIBITORY EFFECT OF TSA ON MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION IN NASAL POLYP ORGAN CULTURES. METHODS: NASAL POLYP TISSUES FROM 18 PATIENTS WERE ACQUIRED DURING ENDOSCOPIC SINUS SURGERY. AFTER ORGAN CULTURE, NASAL POLYPS WERE STIMULATED WITH TGF-BETA1 AND THEN TREATED WITH TSA. ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), FIBRONECTIN, AND COLLAGEN TYPE I EXPRESSION LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (PCR), REAL-TIME PCR, WESTERN BLOT, AND IMMUNOFLUORESCENT STAINING. HDAC2, HDAC4, AND ACETYLATED H4 EXPRESSION LEVELS WERE ASSAYED BY WESTERN BLOT. CYTOTOXICITY WAS ANALYZED BY THE TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE BIOTIN-DUTP NICK END LABELING ASSAY. RESULTS: THE EXPRESSION LEVELS OF ALPHA-SMA, FIBRONECTIN, AND COLLAGEN TYPE 1 WERE INCREASED IN NASAL POLYP AFTER TRANSFORMING GROWTH FACTOR (TGF) BETA1 TREATMENT. TSA-INHIBITED TGF-BETA1 INDUCED THESE GENE AND PROTEIN EXPRESSION LEVELS. FURTHERMORE, TSA SUPPRESSED PROTEIN EXPRESSION LEVELS OF HDAC2 AND HDAC4. HOWEVER, TSA INDUCED HYPERACETYLATION OF HISTONES H4. TREATMENT WITH TGF-BETA1 WITH OR WITHOUT TSA DID NOT HAVE CYTOTOXIC EFFECT. CONCLUSION: THESE FINDINGS PROVIDE NOVEL INSIGHTS INTO THE EPIGENETIC REGULATION IN MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION OF NASAL POLYP. TSA COULD BE A CANDIDATE OF A THERAPEUTIC AGENT FOR REVERSING THE TGF-BETA1-INDUCED ECM SYNTHESIS THAT LEADS TO NASAL POLYP DEVELOPMENT. 2013 12 4296 34 MICRORNA-1 MODULATES CHONDROCYTE PHENOTYPE BY REGULATING FZD7 OF WNT/ BETA-CATENIN SIGNALING PATHWAY. OBJECTIVE: OSTEOARTHRITIS (OA) IS AN INCURABLE JOINT DISEASE CHARACTERIZED BY PRONOUNCED PAIN. MICRORNAS CONSTITUTE EPIGENETIC MECHANISMS THAT MAY AFFECT OA PROGRESSION BY CONTRIBUTING TO CHANGES IN CHONDROCYTE PHENOTYPE. THIS STUDY INVESTIGATES FOR THE FIRST TIME WHETHER THERE IS A LINK BETWEEN MIRNA-1 (MIR-1) AND OA PATHOGENESIS, AND THE MOLECULAR MECHANISMS INVOLVED. DESIGN: OA-ASSOCIATED GENE EXPRESSION, INCLUDING MMP-13, ADAMTS5, AND COL2A1 WAS COMPARED IN CHONDROCYTES FROM NON-OA AND OA CARTILAGE, AND IN SW1353 CELLS OVER- AND UNDEREXPRESSING MIR-1. BIOINFORMATICS AND LUCIFERASE REPORTER ASSAY WERE CONDUCTED TO CONFIRM WHETHER FZD7 WAS A TARGET OF MIR-1. THE EFFECTS OF MIR-1 ON FZD7 EXPRESSION AND DOWNSTREAM WNT/BETA-CATENIN SIGNALLING WERE INVESTIGATED. RESULTS: NON-OA AND OA CHONDROCYTES DIFFERED SIGNIFICANTLY IN THE EXPRESSION OF MIR-1 AND OA-ASSOCIATED GENES. MIR-1 OVER- AND UNDEREXPRESSION IN SW1353 CELLS, RESPECTIVELY, REDUCED AND ENHANCED GENE EXPRESSION ASSOCIATED WITH CARTILAGE CATABOLISM. FZD7, WHICH HAS AN IMPORTANT ROLE IN THE WNT/BETA-CATENIN SIGNALING PATHWAY, WAS SHOWN TO BE A POTENTIAL TARGET OF MIR-1. MIR-1 BINDING TO FZD7 INCREASED THE LEVELS OF PHOSPHORYLATED (INACTIVATED) BETA-CATENIN, THEREBY PREVENTING DOWNSTREAM BETA-CATENIN SIGNALING. CONCLUSIONS: INHIBITION OF WNT/BETA-CATENIN SIGNALING BY MIR-1 IN CHONDROCYTES MAY ATTENUATE THE EXPRESSION OF GENES THAT REGULATE THE ACTIVITY OF CATABOLIC ENZYMES. THIS FINDING MAY BE USEFUL FOR FUTURE INVESTIGATIONS OF MOLECULAR TARGETS FOR OA TREATMENT. 2021 13 4347 31 MIR-140 ATTENUATES THE PROGRESSION OF EARLY-STAGE OSTEOARTHRITIS BY RETARDING CHONDROCYTE SENESCENCE. OSTEOARTHRITIS (OA) IS A MAJOR CAUSE OF JOINT PAIN AND DISABILITY, AND CHONDROCYTE SENESCENCE IS A KEY PATHOLOGICAL PROCESS IN OA AND MAY BE A TARGET OF NEW THERAPEUTICS. MICRORNA-140 (MIR-140) PLAYS A PROTECTIVE ROLE IN OA, BUT LITTLE IS KNOWN ABOUT ITS EPIGENETIC EFFECT ON CHONDROCYTE SENESCENCE. IN THIS STUDY, WE FIRST VALIDATED THE FEATURES OF CHONDROCYTE SENESCENCE CHARACTERIZED BY INCREASED CELL CYCLE ARREST IN THE G0/G1 PHASE AND THE EXPRESSION OF SENESCENCE-ASSOCIATED BETA-GALACTOSIDASE (SA-BETAGAL), P16(INK4A), P21, P53, AND GAMMAH2AX IN HUMAN KNEE OA. THEN, WE REVEALED IN INTERLEUKIN 1BETA (IL-1BETA)-INDUCED OA CHONDROCYTES IN VITRO THAT PRETRANSFECTION WITH MIR-140 EFFECTIVELY INHIBITED THE EXPRESSION OF SA-BETAGAL, P16(INK4A), P21, P53, AND GAMMAH2AX. FURTHERMORE, IN VIVO RESULTS FROM TRAUMA-INDUCED EARLY-STAGE OA RATS SHOWED THAT INTRA-ARTICULARLY INJECTED MIR-140 COULD RAPIDLY REACH THE CHONDROCYTE CYTOPLASM AND INDUCE MOLECULAR CHANGES SIMILAR TO THE IN VITRO RESULTS, RESULTING IN A NOTICEABLE ALLEVIATION OF OA PROGRESSION. FINALLY, BIOINFORMATICS ANALYSIS PREDICTED THE POTENTIAL TARGETS OF MIR-140 AND A MECHANISTIC NETWORK BY WHICH MIR-140 REGULATES CHONDROCYTE SENESCENCE. COLLECTIVELY, MIR-140 CAN EFFECTIVELY ATTENUATE THE PROGRESSION OF EARLY-STAGE OA BY RETARDING CHONDROCYTE SENESCENCE, CONTRIBUTING NEW EVIDENCE OF THE INVOLVEMENT OF MIR-MEDIATED EPIGENETIC REGULATION OF CHONDROCYTE SENESCENCE IN OA PATHOGENESIS. 2020 14 630 15 BIOLOGICAL AND MECHANICAL FACTORS AND EPIGENETIC REGULATION INVOLVED IN TENDON HEALING. TENDONS ARE AN IMPORTANT PART OF THE MUSCULOSKELETAL SYSTEM. CONNECTING MUSCLES TO BONES, TENDONS CONVERT FORCE INTO MOVEMENT. TENDON INJURY CAN BE ACUTE OR CHRONIC. NOTICEABLY, TENDON HEALING REQUIRES A LONG TIME SPAN AND INCLUDES INFLAMMATION, PROLIFERATION, AND REMODELING PROCESSES. THE MISMATCH BETWEEN ENDOGENOUS AND EXOGENOUS HEALING MAY LEAD TO ADHESION CAUSING FURTHER NEGATIVE EFFECTS. MANAGEMENT OF TENDON INJURIES AND COMPLICATIONS SUCH AS SUBSEQUENT ADHESION FORMATION ARE STILL CHALLENGES FOR CLINICIANS. DUE TO NUMEROUS FACTORS, TENDON HEALING IS A COMPLEX PROCESS. THIS REVIEW INTRODUCES THE ROLE OF VARIOUS BIOLOGICAL AND MECHANICAL FACTORS AND EPIGENETIC REGULATION PROCESSES INVOLVED IN TENDON HEALING. 2023 15 5850 25 SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) REDUCES FIBROSIS MARKERS AND DEACTIVATES HUMAN STELLATE CELLS VIA THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). HEPATIC FIBROSIS IS KNOWN AS THE ACCUMULATION OF CONNECTIVE TISSUE SECONDARY TO CHRONIC DAMAGE TO THE LIVER. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) CORRESPONDING INCREASE IN LIVER FIBROGENESIS WAS SHOWN WITH IMMUNOHISTOCHEMISTRY AND PCR-BASED STUDIES. SUBEROYLANILIDE HYDROXAMIC ACID (SAHA), A SYNTHETIC COMPOUND APPROVED AS A HISTONE DEACETYLASE INHIBITOR (HDAC) BY THE FDA TO TREAT CUTANEOUS T-CELL LYMPHOMA IS UNDER INVESTIGATION FOR THE TREATMENT OF LUNG AND RENAL FIBROSIS. EXPERIMENTAL MODELING FOR HEPATIC FIBROSIS CAN BE CONSTRUCTED WITH AN LX2 CELL LINE ISOLATED FROM HUMAN HEPATIC STELLATE CELLS (HSCS). IN THIS STUDY, WE AIMED TO INVESTIGATE THE MODULATION OF SAHA IN THE PATHOGENESIS OF LIVER FIBROSIS BY DETECTING THE LEVELS OF PROTEINS; (E-CADHERIN (E-CAD), N-CADHERIN (N-CAD), VIMENTIN (VIM), AND GENES; E-CAD, N-CAD, VIM, TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA), ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), TYPE 1 COLLAGEN (COL1A1), TYPE 3 COLLAGEN (COL3A1)) THAT PLAY A SIGNIFICANT ROLE IN EMT WITH THE LX2 CELL LINE. WE ALSO EVALUATED THE ACTION OF SAHA WITH CELL PROLIFERATION, CLONOGENIC, AND MIGRATION ASSAY. CELL PROLIFERATION WAS PERFORMED BY FLOW CYTOMETRY. ALL THE PROTEIN LEVELS WERE DETERMINED BY WESTERN BLOT ANALYSIS, AND GENE EXPRESSION LEVELS WERE MEASURED BY REAL-TIME PCR. OUR STUDY OBSERVED THAT SAHA TREATMENT DECREASED CELL VIABILITY, COLONY FORMATION AND MIGRATION IN LX2 CELLS. WE FOUND THAT SAHA INCREASED E-CAD EXPRESSION LEVEL, WHILE IT DECREASED N-CAD, VIM, COL1A1, COL3A1, ALPHA-SMA TGF-BETA GENES EXPRESSION LEVELS. SAHA DECREASED THE LEVEL OF E-CAD, N-CAD, AND VIM PROTEIN LEVELS. WE THOUGHT THAT SAHA POSSESSES POTENT ANTIFIBROTIC AND ANTI-EMT PROPERTIES IN LX2. 2021 16 2784 24 EZH2 PROMOTES EXTRACELLULAR MATRIX DEGRADATION VIA NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND P38 SIGNALING PATHWAYS IN PULPITIS. PULPITIS IS A COMPLICATED CHRONIC INFLAMMATORY PROCESS WHICH CAN BE IN A DYNAMIC BALANCE BETWEEN DAMAGE AND REPAIR. THE EXTRACELLULAR MATRIX PLAYS AN IMPORTANT REGULATORY ROLE IN WOUND HEALING AND TISSUE REPAIR. THE AIM OF THIS STUDY WAS TO EXPLORE THE ROLE OF THE EPIGENETIC MARK, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) ON THE DEGRADATION OF EXTRACELLULAR MATRIX DURING PULPITIS. QUANTITATIVE POLYMERASE CHAIN REACTION WAS USED TO ASSESS THE EXPRESSION OF MATRIX METALLOPROTEINASES (MMPS) AND TYPE I COLLAGEN IN HUMAN DENTAL PULP CELLS (HDPCS) UPON EZH2 AND EI1 (EZH2 INHIBITOR) STIMULATION. THE MECHANISM OF EZH2 AFFECTING EXTRACELLULAR MATRIX WAS EXPLORED THROUGH QUANTITATIVE POLYMERASE CHAIN REACTION AND WESTERN BLOT. A RAT MODEL OF DENTAL PULP INFLAMMATION WAS ESTABLISHED, AND THE EXPRESSION OF TYPE I COLLAGEN IN DENTAL PULP UNDER EZH2 STIMULATION WAS DETECTED BY IMMUNOHISTOCHEMICAL STAINING. EZH2 UPREGULATED THE EXPRESSION OF MMP-1, MMP-3, MMP-8, AND MMP-10 AND DECREASED THE PRODUCTION OF TYPE I COLLAGEN IN HDPCS, WHILE EI1 HAD THE OPPOSITE EFFECT. EZH2 ACTIVATED THE NUCLEAR FACTOR-KAPPA B (NF-KAPPAB) AND P38 SIGNALING PATHWAYS IN HDPCS, THE INHIBITION OF WHICH REVERSED THE INDUCTION OF MMPS AND THE SUPPRESSION OF TYPE I COLLAGEN. EZH2 CAN DOWNREGULATE THE TYPE I COLLAGEN LEVELS IN AN EXPERIMENTAL MODEL OF DENTAL PULPITIS IN RATS. EZH2 PROMOTES EXTRACELLULAR MATRIX DEGRADATION VIA NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND P38 SIGNALING PATHWAYS IN PULPITIS. EZH2 CAN DECREASE THE TYPE I COLLAGEN LEVELS IN VIVO AND IN VITRO. 2021 17 2349 24 EPIGENETIC REGULATION OF MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX PRODUCTION IN NASAL POLYP-DERIVED FIBROBLASTS. BACKGROUND: NASAL POLYPOSIS IS A MULTI-FACTORIAL DISEASE ASSOCIATED WITH CHRONIC INFLAMMATORY CONDITION OF THE PARANASAL SINUSES. MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION ARE INVOLVED IN THE PATHOGENESIS OF NASAL POLYPOSIS. OBJECTIVE: THE AIM OF THIS STUDY WAS TO STUDY THE EFFECT OF TRICHOSTATIN A (TSA), A HISTONE DEACETYLASE (HDAC) INHIBITOR, ON TRANSFORMING GROWTH FACTOR (TGF)-BETA1-INDUCED MYOFIBROBLAST DIFFERENTIATION AND ECM ACCUMULATION IN NASAL POLYP-DERIVED FIBROBLASTS (NPDFS). METHODS: NASAL POLYP-DERIVED FIBROBLASTS WERE ISOLATED FROM NASAL POLYPS OF PATIENTS WHO HAVE CHRONIC RHINOSINUSITIS WITH NASAL POLYP. TSA WAS TREATED IN TGF-BETA1-INDUCED NPDFS. EXPRESSION LEVELS OF HDAC2, ALPHA-SMOOTH MUSCLE ACTIN (SMA), TGF-BETA1, COLLAGEN TYPE I, ACETYLATED HISTONE H3, ACETYLATED HISTONE H4, PHOSPHORYLATED SMAD2/3 AND SMAD7 WERE DETERMINED BY RT-PCR, WESTERN BLOT AND/OR IMMUNOFLUORESCENT STAINING. THE TOTAL COLLAGEN AMOUNT PRODUCTION WAS ANALYSED BY SIRCOL SOLUBLE COLLAGEN ASSAY AND CONTRACTILE ACTIVITY WAS MEASURED BY COLLAGEN GEL CONTRACTION ASSAY. HDAC2 INHIBITION BY TSA OR HDAC2 SILENCING WAS ESTABLISHED BY RT-PCR AND WESTERN BLOT. THE EPIGENETIC EFFECT ON ALPHA-SMA GENE INACTIVATION WAS EXAMINED BY CHROMATIN IMMUNOPRECIPITATION ASSAY. PROLIFERATION WAS DETERMINED BY KI67-POSITIVE CELL STAINING AND CYTOTOXICITY WAS ASSESSED BY 3-(4,5- DIMETHYLTHIAZOL-2YL)-2,5-DIPHENYL-2H-TETRAZOLIUM BROMIDE (MTT) ASSAY. RESULTS: THE EXPRESSION LEVELS OF HDAC2, ALPHA-SMA AND TGF-BETA1 WERE INCREASED IN NASAL POLYP TISSUES COMPARED TO NORMAL INFERIOR TURBINATE TISSUES. TSA AND HDAC2 SILENCING INHIBITED EXPRESSION LEVELS ALPHA-SMA, COLLAGEN AND HDAC2. TSA INDUCED HYPERACETYLATION OF HISTONE AND SUPPRESSED OPENING OF ALPHA-SMA GENE PROMOTER IN TGF-BETA1-INDUCED NPDFS. TSA INHIBITED TGF-BETA1-INDUCED SMAD 2/3 AND RESCUED TGF-BETA1-SUPPRESSED SMAD7 SIGNALLING PATHWAY. FINALLY, TSA BLOCKED PROLIFERATION IN TGF-BETA1-INDUCED NPDFS AND HAS NO CYTOTOXIC EFFECT IN NPDFS. CONCLUSIONS AND CLINICAL RELEVANCE: THESE RESULTS SUGGEST THAT HDAC INHIBITION IS ASSOCIATED WITH MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLUAR MATRIX ACCUMULATION IN NASAL POLYPOSIS. TSA MAY BE USEFUL AS AN INHIBITOR OF NASAL POLYP GROWTH, AND THUS HAS POTENTIAL TO BE USED AS A NOVEL TREATMENT OPTION FOR NASAL POLYPOSIS. 2012 18 3729 29 INHIBITION OF TET1 PREVENTS THE DEVELOPMENT OF OSTEOARTHRITIS AND REVEALS THE 5HMC LANDSCAPE THAT ORCHESTRATES PATHOGENESIS. OSTEOARTHRITIS (OA) IS A DEGENERATIVE DISEASE OF THE JOINT, WHICH RESULTS IN PAIN, LOSS OF MOBILITY, AND, EVENTUALLY, JOINT REPLACEMENT. CURRENTLY, NO DISEASE-MODIFYING DRUGS EXIST, PARTLY BECAUSE OF THE MULTIPLE LEVELS AT WHICH CARTILAGE HOMEOSTASIS IS DISRUPTED. RECENT STUDIES HAVE HIGHLIGHTED THE IMPORTANCE OF EPIGENETIC DYSREGULATION IN OA, SPARKING INTEREST IN THE EPIGENETIC MODULATION FOR THIS DISEASE. IN OUR PREVIOUS WORK, WE CHARACTERIZED A FIVEFOLD INCREASE IN CYTOSINE HYDROXYMETHYLATION (5HMC), AN OXIDIZED DERIVATIVE OF CYTOSINE METHYLATION (5MC) ASSOCIATED WITH GENE ACTIVATION, ACCUMULATING AT OA-ASSOCIATED GENES. TO TEST THE ROLE OF 5HMC IN OA, HERE, WE USED A MOUSE MODEL OF SURGICALLY INDUCED OA AND FOUND THAT OA ONSET WAS ACCOMPANIED BY A GAIN OF ~40,000 DIFFERENTIALLY HYDROXYMETHYLATED SITES BEFORE THE NOTABLE HISTOLOGICAL APPEARANCE OF DISEASE. WE DEMONSTRATED THAT TEN-ELEVEN-TRANSLOCATION ENZYME 1 (TET1) MEDIATES THE 5HMC DEPOSITION BECAUSE 98% OF SITES ENRICHED FOR 5HMC IN OA WERE LOST IN TET1(-/-) MICE. LOSS OF TET1-MEDIATED 5HMC PROTECTED THE TET1(-/-) MICE FROM OA DEVELOPMENT, INCLUDING DEGENERATION OF THE CARTILAGE SURFACE AND OSTEOPHYTE FORMATION, BY DIRECTLY PREVENTING THE ACTIVATION OF MULTIPLE OA PATHWAYS. LOSS OF TET1 IN HUMAN OA CHONDROCYTES REDUCED THE EXPRESSION OF THE MATRIX METALLOPROTEINASES MMP3 AND MMP13 AND MULTIPLE INFLAMMATORY CYTOKINES. INTRA-ARTICULAR INJECTIONS OF A DIOXYGENASES INHIBITOR, 2-HYDROXYGLUTARATE, ON MICE AFTER SURGICAL INDUCTION OF OA STALLED DISEASE PROGRESSION. TREATMENT OF HUMAN OA CHONDROCYTES WITH THE SAME INHIBITOR ALSO PHENOCOPIED TET1 LOSS. COLLECTIVELY, THESE DATA DEMONSTRATE THAT TET1-MEDIATED 5HMC DEPOSITION REGULATES MULTIPLE OA PATHWAYS AND CAN BE MODULATED FOR THERAPEUTIC INTERVENTION. 2020 19 854 30 CHONDROPROTECTIVE EFFECTS OF A HISTONE DEACETYLASE INHIBITOR, PANOBINOSTAT, ON PAIN BEHAVIOR AND CARTILAGE DEGRADATION IN ANTERIOR CRUCIATE LIGAMENT TRANSECTION-INDUCED EXPERIMENTAL OSTEOARTHRITIC RATS. OSTEOARTHRITIS (OA) IS THE MOST COMMON ARTICULAR DEGENERATIVE DISEASE CHARACTERIZED BY CHRONIC PAIN, JOINT INFLAMMATION, AND MOVEMENT LIMITATIONS, WHICH ARE SIGNIFICANTLY INFLUENCED BY ABERRANT EPIGENETIC MODIFICATIONS OF NUMEROUS OA-SUSCEPTIBLE GENES. RECENT STUDIES REVEALED THAT BOTH THE ABNORMAL ACTIVATION AND DIFFERENTIAL EXPRESSION OF HISTONE DEACETYLASES (HDACS) MIGHT CONTRIBUTE TO OA PATHOGENESIS. IN THIS STUDY, WE INVESTIGATED THE CHONDROPROTECTIVE EFFECTS OF A MARINE-DERIVED HDAC INHIBITOR, PANOBINOSTAT, ON ANTERIOR CRUCIATE LIGAMENT TRANSECTION (ACLT)-INDUCED EXPERIMENTAL OA RATS. THE INTRA-ARTICULAR ADMINISTRATION OF 2 OR 10 MICROG OF PANOBINOSTAT (EACH GROUP, N = 7) PER WEEK FROM THE 6TH TO 17TH WEEK ATTENUATES ACLT-INDUCED NOCICEPTIVE BEHAVIORS, INCLUDING SECONDARY MECHANICAL ALLODYNIA AND WEIGHT-BEARING DISTRIBUTION. HISTOPATHOLOGICAL AND MICROCOMPUTED TOMOGRAPHY ANALYSIS SHOWED THAT PANOBINOSTAT SIGNIFICANTLY PREVENTS CARTILAGE DEGENERATION AFTER ACLT. MOREOVER, INTRA-ARTICULAR PANOBINOSTAT EXERTS HYPERTROPHIC EFFECTS IN THE CHONDROCYTES OF ARTICULAR CARTILAGE BY REGULATING THE PROTEIN EXPRESSIONS OF HDAC4, HDAC6, HDAC7, RUNT-DOMAIN TRANSCRIPTION FACTOR-2, AND MATRIX METALLOPROTEINASE-13. THE STUDY INDICATED THAT HDACS MIGHT HAVE DIFFERENT MODULATIONS ON THE CHONDROCYTE PHENOTYPE IN THE EARLY STAGES OF OA DEVELOPMENT. THESE RESULTS PROVIDE NEW EVIDENCE THAT PANOBINOSTAT MAY BE A POTENTIAL THERAPEUTIC DRUG FOR OA. 2021 20 6235 22 THE M(6)A DEMETHYLASE FTO PROMOTES RENAL EPITHELIAL-MESENCHYMAL TRANSITION BY REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. BACKGROUND: RENAL INTERSTITIAL FIBROSIS (RIF) IS THE MAIN PATHOLOGICAL CHANGE OF A VARIETY OF CHRONIC KIDNEY DISEASES (CKD). EPIGENETIC MODIFICATIONS OF FIBROSIS-PRONE GENES REGULATE RIF PROGRESSION. THIS STUDY AIMED TO INVESTIGATE LONG NON-CODING RNA (LNCRNA) N6-METHYLADENOSINE (M(6)A) MODIFICATION AND ITS ROLE IN REGULATING RIF PROGRESSION. METHODS: UNILATERAL URETERAL OCCLUSION (UUO) WAS EMPLOYED TO CONSTRUCT THE RIF IN VIVO MODEL; AND TGF-BETA1-TREATED HK-2 AND HKC-8 CELLS WERE USED FOR IN VITRO EXPERIMENTS. THE MRNA AND PROTEIN EXPRESSIONS WERE ASSESSED USING QRT-PCR AND WESTERN BLOT. THE PROLIFERATION AND MIGRATION WERE EVALUATED BY EDU ASSAY AND TRANSWELL ASSAY, RESPECTIVELY. IN ADDITION, LEVELS OF INFLAMMATORY CYTOKINES WERE DETERMINED BY ELISA ASSAY AND QRT-PCR. MOREOVER, LNCRNA GAS5 M(6)A LEVEL WAS DETECTED USING ME-RIP ASSAY. HE AND MASSON STAINING WERE EMPLOYED TO EVALUATE FIBROTIC LESIONS OF THE KIDNEY. RESULTS: FTO EXPRESSION WAS ELEVATED IN HK-2 AND HKC-8 CELLS AFTER TGF-BETA1 TREATMENT AND MOUSE KIDNEY TISSUE FOLLOWING UUO, AND LNCRNA GAS5 WAS DOWNREGULATED. LNCRNA GAS5 OVEREXPRESSION OR FTO SILENCING SUPPRESSED TGF-BETA1-INDUCED THE INCREASE OF EMT-RELATED PROTEINS (VIMENTIN, SNAIL AND N-CADHERIN) AND INFLAMMATORY CYTOKINES (IL-6, IL-1BETA AND TNF-ALPHA) LEVELS IN HK-2 CELLS. FTO SUPPRESSED LNCRNA GAS5 EXPRESSION BY REDUCING THE M6A MODIFICATION OF LNCRNA GAS5. ADDITIONALLY, FTO KNOCKDOWN COULD SUPPRESS EMT PROCESS AND INFLAMMATION RESPONSE INDUCED BY TGF-BETA1 AND UUO IN VITRO AND IN VIVO. AS EXPECTED, FTO KNOCKDOWN ABROGATED THE PROMOTION EFFECTS OF LNCRNA GAS5 SILENCING ON TGF-BETA1-INDUCED EMT PROCESS AND INFLAMMATION RESPONSE IN HK-2 AND HKC-8 CELLS. CONCLUSION: FTO PROMOTED EMT PROCESS AND INFLAMMATION RESPONSE THROUGH REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. 2022