1 1300 105 DEDIFFERENTIATION AND IN VIVO REPROGRAMMING OF COMMITTED CELLS IN WOUND REPAIR (REVIEW). ACCUMULATING EVIDENCE HAS SHOWN THAT CELL DEDIFFERENTIATION OR REPROGRAMMING IS A PIVOTAL PROCEDURE FOR ANIMALS TO DEAL WITH INJURY AND PROMOTE ENDOGENOUS TISSUE REPAIR. TISSUE DAMAGE IS A CRITICAL FACTOR THAT TRIGGERS CELL DEDIFFERENTIATION OR REPROGRAMMING IN VIVO. BY CONTRAST, MICROENVIRONMENTAL CHANGES, INCLUDING THE LOSS OF STEM CELLS, HYPOXIA, CELL SENESCENCE, INFLAMMATION AND IMMUNITY, CAUSED BY TISSUE DAMAGE CAN RETURN CELLS TO AN UNSTABLE STATE. IF THE WOUND PERSISTS IN THE LONG?TERM DUE TO CHRONIC DAMAGE, THEN DEDIFFERENTIATION OR REPROGRAMMING OF THE SURROUNDING CELLS MAY LEAD TO CARCINOGENESIS. IN RECENT YEARS, EXTENSIVE RESEARCH HAS BEEN PERFORMED INVESTIGATING CELL DEDIFFERENTIATION OR REPROGRAMMING IN VIVO, WHICH CAN HAVE SIGNIFICANT IMPLICATIONS FOR WOUND REPAIR, TREATMENT AND PREVENTION OF CANCER IN THE FUTURE. THE CURRENT REVIEW SUMMARIZES THE MOLECULAR EVENTS THAT ARE KNOWN TO DRIVE CELL DEDIFFERENTIATION DIRECTLY FOLLOWING TISSUE INJURY AND THE EFFECTS OF EPIGENETIC MODIFICATION ON DEDIFFERENTIATION OR REPROGRAMMING IN VIVO. IN ADDITION, THE PRESENT REVIEW EXPLORES THE INTRACELLULAR MECHANISM OF ENDOGENOUS TISSUE REPAIR AND ITS RELATIONSHIP WITH CANCER, WHICH IS ESSENTIAL FOR BALANCING THE RISK BETWEEN TISSUE REPAIR AND MALIGNANT TRANSFORMATION AFTER INJURY. 2022 2 5857 30 SUBSTRATE-SPECIFIC BINDING OF 8-OXOGUANINE DNA GLYCOSYLASE 1 (OGG1) REPROGRAMS MUCOSAL ADAPTATIONS TO CHRONIC AIRWAY INJURY. RECENT ADVANCES HAVE UNCOVERED THE NON-RANDOM DISTRIBUTION OF 7, 8-DIHYDRO-8-OXOGUANINE (8-OXOGUA) INDUCED BY REACTIVE OXYGEN SPECIES, WHICH IS BELIEVED TO HAVE EPIGENETIC EFFECTS. ITS COGNATE REPAIR PROTEIN, 8-OXOGUANINE DNA GLYCOSYLASE 1 (OGG1), READS OXIDATIVE SUBSTRATES AND PARTICIPATES IN TRANSCRIPTIONAL INITIATION. WHEN REDOX SIGNALING IS ACTIVATED IN SMALL AIRWAY EPITHELIAL CELLS, THE DNA REPAIR FUNCTION OF OGG1 IS REPURPOSED TO TRANSMIT ACUTE INFLAMMATORY SIGNALS ACCOMPANIED BY CELL STATE TRANSITIONS AND MODIFICATION OF THE EXTRACELLULAR MATRIX. EPITHELIAL-MESENCHYMAL AND EPITHELIAL-IMMUNE INTERACTIONS ACT COOPERATIVELY TO ESTABLISH A LOCAL NICHE THAT INSTRUCTS THE MUCOSAL IMMUNE LANDSCAPE. IF THE TRANSITIONAL CELL STATE GOVERNED BY OGG1 REMAINS RESPONSIVE TO INFLAMMATORY MEDIATORS INSTEAD OF DIFFERENTIATION, THE COLLATERAL DAMAGE PROVIDES POSITIVE FEEDBACK TO INFLAMMATION, ASCRIBING INFLAMMATORY REMODELING TO ONE OF THE DRIVERS IN CHRONIC PATHOLOGIES. IN THIS REVIEW, WE DISCUSS THE SUBSTRATE-SPECIFIC READ THROUGH OGG1 HAS EVOLVED IN REGULATING THE INNATE IMMUNE RESPONSE, CONTROLLING ADAPTATIONS OF THE AIRWAY TO ENVIRONMENTAL AND INFLAMMATORY INJURY, WITH A FOCUS ON THE READER FUNCTION OF OGG1 IN INITIATION AND PROGRESSION OF EPITHELIAL TO MESENCHYMAL TRANSITIONS IN CHRONIC PULMONARY DISEASE. 2023 3 4524 32 MULTIFACETED CONTROL OF DNA REPAIR PATHWAYS BY THE HYPOXIC TUMOR MICROENVIRONMENT. HYPOXIA, AS A PERVASIVE FEATURE IN THE MICROENVIRONMENT OF SOLID TUMORS, PLAYS A SIGNIFICANT ROLE IN CANCER PROGRESSION, METASTASIS, AND ULTIMATELY CLINICAL OUTCOME. ONE KEY CELLULAR CONSEQUENCE OF HYPOXIC STRESS IS THE REGULATION OF DNA REPAIR PATHWAYS, WHICH CONTRIBUTES TO THE GENOMIC INSTABILITY AND MUTATOR PHENOTYPE OBSERVED IN HUMAN CANCERS. TUMOR HYPOXIA CAN VARY IN SEVERITY AND DURATION, RANGING FROM ACUTE FLUCTUATING HYPOXIA ARISING FROM TEMPORARY BLOCKAGES IN THE IMMATURE MICROVASCULATURE, TO CHRONIC MODERATE HYPOXIA DUE TO SPARSE VASCULATURE, TO COMPLETE ANOXIA AT DISTANCES MORE THAN 150 MUM FROM THE NEAREST BLOOD VESSEL. PARALLELING THE INTRA-TUMOR HETEROGENEITY OF HYPOXIA, THE EFFECTS OF HYPOXIA ON DNA REPAIR OCCUR THROUGH DIVERSE MECHANISMS. ACUTELY, HYPOXIA ACTIVATES DNA DAMAGE SIGNALING PATHWAYS, PRIMARILY VIA POST-TRANSLATIONAL MODIFICATIONS. ON A LONGER TIMESCALE, HYPOXIA LEADS TO TRANSCRIPTIONAL AND/OR TRANSLATIONAL DOWNREGULATION OF MOST DNA REPAIR PATHWAYS INCLUDING DNA DOUBLE-STRAND BREAK REPAIR, MISMATCH REPAIR, AND NUCLEOTIDE EXCISION REPAIR. FURTHERMORE, EXTENDED HYPOXIA CAN LEAD TO LONG-TERM PERSISTENT SILENCING OF CERTAIN DNA REPAIR GENES, INCLUDING BRCA1 AND MLH1, REVEALING A MECHANISM BY WHICH TUMOR SUPPRESSOR GENES CAN BE INACTIVATED. THE DISCOVERIES OF THE HYPOXIC MODULATION OF DNA REPAIR PATHWAYS HAVE HIGHLIGHTED MANY POTENTIAL WAYS TO TARGET SUSCEPTIBILITIES OF HYPOXIC CANCER CELLS. IN THIS REVIEW, WE WILL DISCUSS THE MULTIFACETED HYPOXIC CONTROL OF DNA REPAIR AT THE TRANSCRIPTIONAL, POST-TRANSCRIPTIONAL, AND EPIGENETIC LEVELS, AND WE WILL OFFER PERSPECTIVE ON THE FUTURE OF ITS CLINICAL IMPLICATIONS. 2015 4 4116 36 MECHANISMS OF AIRWAY EPITHELIAL INJURY AND ABNORMAL REPAIR IN ASTHMA AND COPD. THE AIRWAY EPITHELIUM COMPRISES OF DIFFERENT CELL TYPES AND ACTS AS A PHYSICAL BARRIER PREVENTING PATHOGENS, INCLUDING INHALED PARTICLES AND MICROBES, FROM ENTERING THE LUNGS. GOBLET CELLS AND SUBMUCOSAL GLANDS PRODUCE MUCUS THAT TRAPS PATHOGENS, WHICH ARE EXPELLED FROM THE RESPIRATORY TRACT BY CILIATED CELLS. BASAL CELLS ACT AS PROGENITOR CELLS, DIFFERENTIATING INTO DIFFERENT EPITHELIAL CELL TYPES, TO MAINTAIN HOMEOSTASIS FOLLOWING INJURY. ADHERENS AND TIGHT JUNCTIONS BETWEEN CELLS MAINTAIN THE EPITHELIAL BARRIER FUNCTION AND REGULATE THE MOVEMENT OF MOLECULES ACROSS IT. IN THIS REVIEW WE DISCUSS HOW ABNORMAL EPITHELIAL STRUCTURE AND FUNCTION, CAUSED BY CHRONIC INJURY AND ABNORMAL REPAIR, DRIVES AIRWAY DISEASE AND SPECIFICALLY ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN BOTH DISEASES, INHALED ALLERGENS, POLLUTANTS AND MICROBES DISRUPT JUNCTIONAL COMPLEXES AND PROMOTE CELL DEATH, IMPAIRING THE BARRIER FUNCTION AND LEADING TO INCREASED PENETRATION OF PATHOGENS AND A CONSTANT AIRWAY IMMUNE RESPONSE. IN ASTHMA, THE INFLAMMATORY RESPONSE PRECIPITATES THE EPITHELIAL INJURY AND DRIVES ABNORMAL BASAL CELL DIFFERENTIATION. THIS LEADS TO REDUCED CILIATED CELLS, GOBLET CELL HYPERPLASIA AND INCREASED EPITHELIAL MESENCHYMAL TRANSITION, WHICH CONTRIBUTE TO IMPAIRED MUCOCILIARY CLEARANCE AND AIRWAY REMODELLING. IN COPD, CHRONIC OXIDATIVE STRESS AND INFLAMMATION TRIGGER PREMATURE EPITHELIAL CELL SENESCENCE, WHICH CONTRIBUTES TO LOSS OF EPITHELIAL INTEGRITY AND AIRWAY INFLAMMATION AND REMODELLING. INCREASED NUMBERS OF BASAL CELLS SHOWING DEREGULATED DIFFERENTIATION, CONTRIBUTES TO CILIARY DYSFUNCTION AND MUCOUS HYPERPRODUCTION IN COPD AIRWAYS. DEFECTIVE ANTIOXIDANT, ANTIVIRAL AND DAMAGE REPAIR MECHANISMS, POSSIBLY DUE TO GENETIC OR EPIGENETIC FACTORS, MAY CONFER SUSCEPTIBILITY TO AIRWAY EPITHELIAL DYSFUNCTION IN THESE DISEASES. THE CURRENT EVIDENCE SUGGESTS THAT A CONSTANT CYCLE OF INJURY AND ABNORMAL REPAIR OF THE EPITHELIUM DRIVES CHRONIC AIRWAY INFLAMMATION AND REMODELLING IN ASTHMA AND COPD. MECHANISTIC UNDERSTANDING OF INJURY SUSCEPTIBILITY AND DAMAGE RESPONSE MAY LEAD TO IMPROVED THERAPIES FOR THESE DISEASES. 2023 5 866 29 CHRONIC ACTIVATION OF MUC1-C IN WOUND REPAIR PROMOTES PROGRESSION TO CANCER STEM CELLS. THE MUCIN 1 (MUC1) GENE EMERGED IN MAMMALS TO AFFORD PROTECTION OF BARRIER EPITHELIAL TISSUES FROM THE EXTERNAL ENVIRONMENT. MUC1 ENCODES A TRANSMEMBRANE C-TERMINAL (MUC1-C) SUBUNIT THAT IS ACTIVATED BY LOSS OF HOMEOSTASIS AND INDUCES INFLAMMATORY, PROLIFERATIVE, AND REMODELING PATHWAYS ASSOCIATED WITH WOUND REPAIR. AS A CONSEQUENCE, CHRONIC ACTIVATION OF MUC1-C PROMOTES LINEAGE PLASTICITY, EPIGENETIC REPROGRAMMING, AND CARCINOGENESIS. IN DRIVING CANCER PROGRESSION, MUC1-C IS IMPORTED INTO THE NUCLEUS, WHERE IT INDUCES NF-KAPPAB INFLAMMATORY SIGNALING AND THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). MUC1-C REPRESSES GENE EXPRESSION BY ACTIVATING (I) DNA METHYLTRANSFERASE 1 (DNMT1) AND DNMT3B, (II) POLYCOMB REPRESSIVE COMPLEX 1 (PRC1) AND PRC2, AND (III) THE NUCLEOSOME REMODELING AND DEACETYLASE (NURD) COMPLEX. PRC1/2-MEDIATED GENE REPRESSION IS COUNTERACTED BY THE SWI/SNF CHROMATIN REMODELING COMPLEXES. MUC1-C ACTIVATES THE SWI/SNF BAF AND PBAF COMPLEXES IN CANCER STEM CELL (CSC) MODELS WITH THE INDUCTION OF GENOME-WIDE DIFFERENTIALLY ACCESSIBLE REGIONS AND EXPRESSED GENES. MUC1-C REGULATES CHROMATIN ACCESSIBILITY OF ENHANCER-LIKE SIGNATURES IN ASSOCIATION WITH THE INDUCTION OF THE YAMANAKA PLURIPOTENCY FACTORS AND RECRUITMENT OF JUN AND BAF, WHICH PROMOTE INCREASES IN HISTONE ACTIVATION MARKS AND OPENING OF CHROMATIN. THESE AND OTHER FINDINGS DESCRIBED IN THIS REVIEW HAVE UNCOVERED A PIVOTAL ROLE FOR MUC1-C IN INTEGRATING LINEAGE PLASTICITY AND EPIGENETIC REPROGRAMMING, WHICH ARE TRANSIENT IN WOUND REPAIR AND SUSTAINED IN PROMOTING CSC PROGRESSION. 2022 6 4512 26 MUC1-C IN CHRONIC INFLAMMATION AND CARCINOGENESIS; EMERGENCE AS A TARGET FOR CANCER TREATMENT. CHRONIC INFLAMMATION IS A HIGHLY PREVALENT CONSEQUENCE OF CHANGES IN ENVIRONMENTAL AND LIFESTYLE FACTORS THAT CONTRIBUTE TO THE DEVELOPMENT OF CANCER. THE BASIS FOR THIS CRITICAL ASSOCIATION HAS LARGELY REMAINED UNCLEAR. THE MUC1 GENE EVOLVED IN MAMMALS TO PROTECT EPITHELIA FROM THE EXTERNAL ENVIRONMENT. THE MUC1-C SUBUNIT PROMOTES RESPONSES FOUND IN WOUND HEALING AND CANCER. MUC1-C INDUCES EMT, EPIGENETIC REPROGRAMMING, DEDIFFERENTIATION AND PLURIPOTENCY FACTOR EXPRESSION, WHICH WHEN PROLONGED IN CHRONIC INFLAMMATION PROMOTE CANCER PROGRESSION. AS DISCUSSED IN THIS REVIEW, MUC1-C ALSO DRIVES DRUG RESISTANCE AND IMMUNE EVASION, AND IS AN IMPORTANT TARGET FOR CANCER THERAPEUTICS NOW UNDER DEVELOPMENT. 2020 7 5631 37 SENESCENCE-INFLAMMATORY REGULATION OF REPARATIVE CELLULAR REPROGRAMMING IN AGING AND CANCER. THE INABILITY OF ADULT TISSUES TO TRANSITORILY GENERATE CELLS WITH FUNCTIONAL STEM CELL-LIKE PROPERTIES IS A MAJOR OBSTACLE TO TISSUE SELF-REPAIR. NUCLEAR REPROGRAMMING-LIKE PHENOMENA THAT INDUCE A TRANSIENT ACQUISITION OF EPIGENETIC PLASTICITY AND PHENOTYPE MALLEABILITY MAY CONSTITUTE A REPARATIVE ROUTE THROUGH WHICH HUMAN TISSUES RESPOND TO INJURY, STRESS, AND DISEASE. HOWEVER, TISSUE REJUVENATION SHOULD INVOLVE NOT ONLY THE TRANSIENT EPIGENETIC REPROGRAMMING OF DIFFERENTIATED CELLS, BUT ALSO THE COMMITTED RE-ACQUISITION OF THE ORIGINAL OR ALTERNATIVE COMMITTED CELL FATE. CHRONIC OR UNRESTRAINED EPIGENETIC PLASTICITY WOULD DRIVE AGING PHENOTYPES BY IMPAIRING THE REPAIR OR THE REPLACEMENT OF DAMAGED CELLS; SUCH UNCONTROLLED PHENOMENA OF IN VIVO REPROGRAMMING MIGHT ALSO GENERATE CANCER-LIKE CELLULAR STATES. WE HEREIN PROPOSE THAT THE ABILITY OF SENESCENCE-ASSOCIATED INFLAMMATORY SIGNALING TO REGULATE IN VIVO REPROGRAMMING CYCLES OF TISSUE REPAIR OUTLINES A THRESHOLD MODEL OF AGING AND CANCER. THE DEGREE OF SENESCENCE/INFLAMMATION-ASSOCIATED DEVIATION FROM THE HOMEOSTATIC STATE MAY DELINEATE A TYPE OF THRESHOLDING ALGORITHM DISTINGUISHING BENEFICIAL FROM DELETERIOUS EFFECTS OF IN VIVO REPROGRAMMING. FIRST, TRANSIENT ACTIVATION OF NF-KAPPAB-RELATED INNATE IMMUNITY AND SENESCENCE-ASSOCIATED INFLAMMATORY COMPONENTS (E.G., IL-6) MIGHT FACILITATE REPARATIVE CELLULAR REPROGRAMMING IN RESPONSE TO ACUTE INFLAMMATORY EVENTS. SECOND, PARA-INFLAMMATION SWITCHES MIGHT PROMOTE LONG-LASTING BUT REVERSIBLE REFRACTORINESS TO REPARATIVE CELLULAR REPROGRAMMING. THIRD, CHRONIC SENESCENCE-ASSOCIATED INFLAMMATORY SIGNALING MIGHT LOCK CELLS IN HIGHLY PLASTIC EPIGENETIC STATES DISABLED FOR REPARATIVE DIFFERENTIATION. THE CONSIDERATION OF A CELLULAR REPROGRAMMING-CENTERED VIEW OF EPIGENETIC PLASTICITY AS A FUNDAMENTAL ELEMENT OF A TISSUE'S CAPACITY TO UNDERGO SUCCESSFUL REPAIR, AGING DEGENERATION OR MALIGNANT TRANSFORMATION SHOULD PROVIDE CHALLENGING STOCHASTIC INSIGHTS INTO THE CURRENT DETERMINISTIC GENETIC PARADIGM FOR MOST CHRONIC DISEASES, THEREBY INCREASING THE SPECTRUM OF THERAPEUTIC APPROACHES FOR PHYSIOLOGICAL AGING AND CANCER. 2017 8 3184 33 HARNESSING METABOLISM OF HEPATIC MACROPHAGES TO AID LIVER REGENERATION. LIVER REGENERATION IS A DYNAMIC AND REGULATED PROCESS THAT INVOLVES INFLAMMATION, GRANULATION, AND TISSUE REMODELING. HEPATIC MACROPHAGES, ABUNDANTLY DISTRIBUTED IN THE LIVER, ARE ESSENTIAL COMPONENTS THAT ACTIVELY PARTICIPATE IN EACH STEP TO ORCHESTRATE LIVER REGENERATION. IN THE HOMEOSTATIC LIVER, RESIDENT MACROPHAGES (KUPFFER CELLS) ACQUIRE A TOLEROGENIC PHENOTYPE AND CONTRIBUTE TO IMMUNOLOGICAL TOLERANCE. FOLLOWING TOXICITY-INDUCED DAMAGE OR PHYSICAL RESECTION, KUPFFER CELLS AS WELL AS MONOCYTE-DERIVED MACROPHAGES CAN BE ACTIVATED AND PROMOTE AN INFLAMMATORY PROCESS THAT SUPPORTS THE SURVIVAL AND ACTIVATION OF HEPATIC MYOFIBROBLASTS AND THUS PROMOTES SCAR TISSUE FORMATION. SUBSEQUENTLY, THESE MACROPHAGES, IN TURN, EXHIBIT THE ANTI-INFLAMMATORY EFFECTS CRITICAL TO EXTRACELLULAR MATRIX REMODELING DURING THE RESOLUTION STAGE. HOWEVER, CONTINUOUS DAMAGE-INDUCED CHRONIC INFLAMMATION GENERALLY LEADS TO HEPATIC MACROPHAGE DYSFUNCTION, WHICH EXACERBATES HEPATOCELLULAR INJURY AND TRIGGERS FURTHER LIVER FIBROSIS AND EVEN CIRRHOSIS. EMERGING MACROPHAGE-TARGETING STRATEGIES HAVE SHOWN EFFICACY IN BOTH PRECLINICAL AND CLINICAL STUDIES. INCREASING EVIDENCE INDICATES THAT METABOLIC REWIRING PROVIDES SUBSTRATES FOR EPIGENETIC MODIFICATION, WHICH ENDOWS MONOCYTES/MACROPHAGES WITH PROLONGED "INNATE IMMUNE MEMORY". THEREFORE, IT IS REASONABLE TO CONCEIVE NOVEL THERAPEUTIC STRATEGIES FOR METABOLICALLY REPROGRAMMING MACROPHAGES AND THUS MEDIATE A HOMEOSTATIC OR REPARATIVE PROCESS FOR HEPATIC INFLAMMATION MANAGEMENT AND LIVER REGENERATION. 2023 9 5494 19 REVIEW OF THE MOLECULAR MECHANISMS IN WOUND HEALING: NEW THERAPEUTIC TARGETS? THE RESTORATION OF THE SKIN BARRIER IN ACUTE AND CHRONIC WOUNDS IS CONTROLLED BY SEVERAL MOLECULAR MECHANISMS THAT SYNERGISTICALLY REGULATE CELL KINETICS, ENZYMATIC FUNCTIONS, AND NEUROVASCULAR ACTIVATION. THESE PATHWAYS INCLUDE GENETIC AND EPIGENETIC ACTIVATION, WHICH MODULATE PHYSIOLOGICAL WOUND HEALING. OUR REVIEW DESCRIBES THE GENETIC BACKGROUND OF SKIN REPAIR, NAMELY TRANSCRIPTION-INDEPENDENT DIFFUSIBLE DAMAGE SIGNALS, INDIVIDUAL VARIABILITY, EPIGENETIC MECHANISM, CONTROLLED QUALITATIVE TRAITS, POST-TRANSLATIONAL MECHANISMS, ANTIOXIDANTS, NUTRIENTS, DNA MODIFICATIONS, BACTERIA ACTIVATION, MITOCHONDRIAL ACTIVITY, AND OXIDATIVE STRESS. THE DNA BACKGROUND MODULATING SKIN RESTORATION COULD BE USED TO PLAN NEW DIAGNOSTICS AND THERAPEUTICS. 2017 10 3688 40 INFLAMMATION: GEARING THE JOURNEY TO CANCER. CHRONIC INFLAMMATION PLAYS A MULTIFACETED ROLE IN CARCINOGENESIS. MOUNTING EVIDENCE FROM PRECLINICAL AND CLINICAL STUDIES SUGGESTS THAT PERSISTENT INFLAMMATION FUNCTIONS AS A DRIVING FORCE IN THE JOURNEY TO CANCER. THE POSSIBLE MECHANISMS BY WHICH INFLAMMATION CAN CONTRIBUTE TO CARCINOGENESIS INCLUDE INDUCTION OF GENOMIC INSTABILITY, ALTERATIONS IN EPIGENETIC EVENTS AND SUBSEQUENT INAPPROPRIATE GENE EXPRESSION, ENHANCED PROLIFERATION OF INITIATED CELLS, RESISTANCE TO APOPTOSIS, AGGRESSIVE TUMOR NEOVASCULARIZATION, INVASION THROUGH TUMOR-ASSOCIATED BASEMENT MEMBRANE AND METASTASIS, ETC. INFLAMMATION-INDUCED REACTIVE OXYGEN AND NITROGEN SPECIES CAUSE DAMAGE TO IMPORTANT CELLULAR COMPONENTS (E.G., DNA, PROTEINS AND LIPIDS), WHICH CAN DIRECTLY OR INDIRECTLY CONTRIBUTE TO MALIGNANT CELL TRANSFORMATION. OVEREXPRESSION, ELEVATED SECRETION, OR ABNORMAL ACTIVATION OF PROINFLAMMATORY MEDIATORS, SUCH AS CYTOKINES, CHEMOKINES, CYCLOOXYGENASE-2, PROSTAGLANDINS, INDUCIBLE NITRIC OXIDE SYNTHASE, AND NITRIC OXIDE, AND A DISTINCT NETWORK OF INTRACELLULAR SIGNALING MOLECULES INCLUDING UPSTREAM KINASES AND TRANSCRIPTION FACTORS FACILITATE TUMOR PROMOTION AND PROGRESSION. WHILE INFLAMMATION PROMOTES DEVELOPMENT OF CANCER, COMPONENTS OF THE TUMOR MICROENVIRONMENT, SUCH AS TUMOR CELLS, STROMAL CELLS IN SURROUNDING TISSUE AND INFILTRATED INFLAMMATORY/IMMUNE CELLS GENERATE AN INTRATUMORAL INFLAMMATORY STATE BY ABERRANT EXPRESSION OR ACTIVATION OF SOME PROINFLAMMATORY MOLECULES. MANY OF PROINFLAMMATORY MEDIATORS, ESPECIALLY CYTOKINES, CHEMOKINES AND PROSTAGLANDINS, TURN ON THE ANGIOGENIC SWITCHES MAINLY CONTROLLED BY VASCULAR ENDOTHELIAL GROWTH FACTOR, THEREBY INDUCING INFLAMMATORY ANGIOGENESIS AND TUMOR CELL-STROMA COMMUNICATION. THIS WILL END UP WITH TUMOR ANGIOGENESIS, METASTASIS AND INVASION. MOREOVER, CELLULAR MICRORNAS ARE EMERGING AS A POTENTIAL LINK BETWEEN INFLAMMATION AND CANCER. THE PRESENT ARTICLE HIGHLIGHTS THE ROLE OF VARIOUS PROINFLAMMATORY MEDIATORS IN CARCINOGENESIS AND THEIR PROMISE AS POTENTIAL TARGETS FOR CHEMOPREVENTION OF INFLAMMATION-ASSOCIATED CARCINOGENESIS. 2008 11 4374 29 MISMATCH REPAIR PROTEINS RECRUIT DNA METHYLTRANSFERASE 1 TO SITES OF OXIDATIVE DNA DAMAGE. AT SITES OF CHRONIC INFLAMMATION, EPITHELIAL CELLS ARE EXPOSED TO HIGH LEVELS OF REACTIVE OXYGEN SPECIES AND UNDERGO CANCER-ASSOCIATED DNA METHYLATION CHANGES, SUGGESTING THAT INFLAMMATION MAY INITIATE EPIGENETIC ALTERATIONS. PREVIOUSLY, WE DEMONSTRATED THAT OXIDATIVE DAMAGE CAUSES EPIGENETIC SILENCING PROTEINS TO BECOME PART OF A LARGE COMPLEX THAT IS LOCALIZED TO GC-RICH REGIONS OF THE GENOME, INCLUDING PROMOTER CPG ISLANDS THAT ARE EPIGENETICALLY SILENCED IN CANCER. HOWEVER, WHETHER THESE PROTEINS WERE RECRUITED DIRECTLY TO DAMAGED DNA OR DURING THE DNA REPAIR PROCESS WAS UNKNOWN. HERE WE DEMONSTRATE THAT THE MISMATCH REPAIR PROTEIN HETERODIMER MSH2-MSH6 PARTICIPATES IN THE OXIDATIVE DAMAGE-INDUCED RECRUITMENT OF DNA METHYLTRANSFERASE 1 (DNMT1) TO CHROMATIN. HYDROGEN PEROXIDE TREATMENT INDUCES THE INTERACTION OF MSH2-MSH6 WITH DNMT1, SUGGESTING THAT THE RECRUITMENT IS THROUGH A PROTEIN-PROTEIN INTERACTION. IMPORTANTLY, THE REDUCTION IN TRANSCRIPTION FOR GENES WITH CPG ISLAND-CONTAINING PROMOTERS CAUSED BY OXIDATIVE DAMAGE IS ABROGATED BY KNOCKDOWN OF MSH6 AND/OR DNMT1. OUR FINDINGS PROVIDE EVIDENCE THAT THE ROLE OF DNMT1 AT SITES OF OXIDATIVE DAMAGE IS TO REDUCE TRANSCRIPTION, POTENTIALLY PREVENTING TRANSCRIPTION FROM INTERFERING WITH THE REPAIR PROCESS. THIS STUDY UNIQUELY BRINGS TOGETHER SEVERAL FACTORS THAT ARE KNOWN TO CONTRIBUTE TO COLON CANCER, NAMELY INFLAMMATION, MISMATCH REPAIR PROTEINS, AND EPIGENETIC CHANGES. 2016 12 3678 36 INFLAMMATION AND REGENERATION IN THE DENTIN-PULP COMPLEX: A DOUBLE-EDGED SWORD. DENTAL TISSUE INFECTION AND DISEASE RESULT IN ACUTE AND CHRONIC ACTIVATION OF THE INNATE IMMUNE RESPONSE, WHICH IS MEDIATED BY MOLECULAR AND CELLULAR SIGNALING. DIFFERENT CELL TYPES WITHIN THE DENTIN-PULP COMPLEX ARE ABLE TO DETECT INVADING BACTERIA AT ALL STAGES OF THE INFECTION. INDEED, AT RELATIVELY EARLY DISEASE STAGES, ODONTOBLASTS WILL RESPOND TO BACTERIAL COMPONENTS, AND AS THE DISEASE PROGRESSES, CORE PULPAL CELLS INCLUDING FIBROBLASTS, STEMS CELLS, ENDOTHELIAL CELLS, AND IMMUNE CELLS WILL BECOME INVOLVED. PATTERN RECOGNITION RECEPTORS, SUCH AS TOLL-LIKE RECEPTORS EXPRESSED ON THESE CELL TYPES, ARE RESPONSIBLE FOR DETECTING BACTERIAL COMPONENTS, AND THEIR LIGAND BINDING LEADS TO THE ACTIVATION OF THE NUCLEAR FACTOR-KAPPA B AND P38 MITOGEN-ACTIVATED PROTEIN (MAP) KINASE INTRACELLULAR SIGNALING CASCADES. SUBSEQUENT NUCLEAR TRANSLOCATION OF THE TRANSCRIPTION FACTOR SUBUNITS FROM THESE PATHWAYS WILL LEAD TO PROINFLAMMATORY MEDIATOR EXPRESSION, INCLUDING INCREASES IN CYTOKINES AND CHEMOKINES, WHICH TRIGGER HOST CELLULAR DEFENSE MECHANISMS. THE COMPLEX MOLECULAR SIGNALING WILL RESULT IN THE RECRUITMENT OF IMMUNE SYSTEM CELLS TARGETED AT COMBATING THE INVADING MICROBES; HOWEVER, THE TRAFFICKING AND ANTIBACTERIAL ACTIVITY OF THESE CELLS CAN LEAD TO COLLATERAL TISSUE DAMAGE. RECENT EVIDENCE SUGGESTS THAT IF INFLAMMATION IS RESOLVED RELATIVELY LOW LEVELS OF PROINFLAMMATORY MEDIATORS MAY PROMOTE TISSUE REPAIR, WHEREAS IF CHRONIC INFLAMMATION ENSUES REPAIR MECHANISMS BECOME INHIBITED. THUS, THE EFFECTS OF MEDIATORS ARE TEMPORAL CONTEXT DEPENDENT. ALTHOUGH CONTAINMENT AND REMOVAL OF THE INFECTION ARE KEYS TO ENABLE DENTAL TISSUE REPAIR, IT IS FEASIBLE THAT THE DEVELOPMENT OF ANTI-INFLAMMATORY AND IMMUNOMODULATORY APPROACHES, BASED ON MOLECULAR, EPIGENETIC, AND PHOTOBIOMODULATORY TECHNOLOGIES, MAY ALSO BE BENEFICIAL FOR FUTURE ENDODONTIC TREATMENTS. 2014 13 6151 31 THE FIRE WITHIN: CELL-AUTONOMOUS MECHANISMS IN INFLAMMATION-DRIVEN CANCER. INFLAMMATORY CELLS ARE IMPORTANT FOR TUMOR INITIATION AND PROMOTION, PROVIDING CANCER CELLS WITH CYTOKINES THAT ENHANCE CELL PROLIFERATION AND SURVIVAL. ALTHOUGH MALIGNANT EPITHELIAL CELLS WERE TRADITIONALLY CONSIDERED TO BE ON THE RECEIVING END OF THESE MICROENVIRONMENTAL INTERACTIONS, RECENT STUDIES SHOW THAT EPITHELIAL CELLS CAN UNDERGO INFLAMMATORY REPROGRAMMING ON THEIR OWN. SUCH EPIGENETIC SWITCHES ARE OFTEN TRIGGERED BY CHRONIC TISSUE INJURY AND PLAY IMPORTANT ROLES IN TISSUE REPAIR. BY CONVERTING TERMINALLY DIFFERENTIATED CELLS THAT HARBOR EVEN A SINGLE ONCOGENIC MUTATION TO A LESS DIFFERENTIATED STATE WITH A HIGHER PROLIFERATIVE POTENTIAL, CELL-AUTONOMOUS INFLAMMATION IS AN IMPORTANT CONTRIBUTOR TO TUMOR INITIATION. 2019 14 2950 20 GENETIC AND EPIGENETIC DAMAGE INDUCED BY REACTIVE NITROGEN SPECIES: IMPLICATIONS IN CARCINOGENESIS. CHRONIC INFECTION AND INFLAMMATION ARE RECOGNIZED RISK FACTORS FOR HUMAN CANCER AT VARIOUS SITES. INFECTION AND INFLAMMATION CAN ACTIVATE AND INDUCE A VARIETY OF OXIDANT-GENERATING ENZYMES, INCLUDING NADPH OXIDASE AND INDUCIBLE NITRIC OXIDE SYNTHASE. REACTIVE OXYGEN AND NITROGEN SPECIES PRODUCED BY SUCH ENZYMES REACT WITH EACH OTHER TO GENERATE NEW AND MORE POTENT REACTIVE SPECIES. THESE OXIDANTS NOT ONLY CAN DAMAGE DNA AND INDUCE MUTATIONS, BUT ALSO CAN ACTIVATE ONCOGENE PRODUCTS AND/OR INACTIVATE TUMOR-SUPPRESSOR PROTEINS, THUS CONTRIBUTING TO MOST PROCESSES OF CARCINOGENESIS. APPROPRIATE TREATMENT OF INFLAMMATION SHOULD BE FURTHER EXPLORED FOR CHEMOPREVENTION OF HUMAN CANCERS, ESPECIALLY THOSE ASSOCIATED WITH CHRONIC INFLAMMATION. 2003 15 5726 25 SKIN WELL-BEING IN DIABETES: ROLE OF MACROPHAGES. MACROPHAGES ARE KEY PLAYERS IN WOUND HEALING- ALONG WITH MEDIATING THE ACUTE INFLAMMATORY RESPONSE, MACROPHAGES ACTIVATE CUTANEOUS EPITHELIAL CELLS AND PROMOTE TISSUE REPAIR. DIABETES COMPLICATIONS, INCLUDING DIABETIC CHRONIC WOUNDS, ARE ACCOMPANIED BY PERSISTENT INFLAMMATION AND MACROPHAGE MALFUNCTION. SEVERAL STUDIES INDICATE THAT HYPERGLYCEMIA INDUCES VARIOUS ALTERATIONS THAT AFFECT MACROPHAGE FUNCTION IN WOUND HEALING INCLUDING EPIGENETIC CHANGES, IMBALANCE BETWEEN PRO- AND ANTI-INFLAMMATORY MODULATORS, AND INSENSITIVITY TO PROLIFERATIVE STIMULI. IN THIS REVIEW, WE BRIEFLY SUMMARIZE RECENT STUDIES REGARDING THOSE ALTERATIONS AND THEIR IMPLICATIONS ON SKIN WELL-BEING IN DIABETES. 2020 16 4749 33 NOVEL PROSPECTS FOR SCARLESS WOUND HEALING: THE ROLES OF MYOFIBROBLASTS AND ADIPOCYTES. DISTURBANCES OR DEFECTS IN THE PROCESS OF WOUND REPAIR CAN DISRUPT THE DELICATE BALANCE OF CELLS AND MOLECULES NECESSARY FOR COMPLETE WOUND HEALING, THUS LEADING TO CHRONIC WOUNDS OR FIBROTIC SCARS. MYOFIBROBLASTS ARE ONE OF THE MOST IMPORTANT CELLS INVOLVED IN FIBROTIC SCARS, AND REPROGRAMMING PROVIDES A POTENTIAL AVENUE TO INCREASE MYOFIBROBLAST CLEARANCE. ALTHOUGH MYOFIBROBLASTS HAVE LONG BEEN RECOGNIZED AS TERMINALLY DIFFERENTIATED CELLS, RECENT STUDIES HAVE SHOWN THAT MYOFIBROBLASTS HAVE THE CAPACITY TO BE REPROGRAMMED INTO ADIPOCYTES. THIS REVIEW INTENDS TO SUMMARIZE THE POTENTIAL OF REPROGRAMMING MYOFIBROBLASTS INTO ADIPOCYTES. WE WILL DISCUSS MYOFIBROBLAST LINEAGE TRACING, AS WELL AS THE KNOWN MECHANISMS UNDERLYING ADIPOCYTE REGENERATION FROM MYOFIBROBLASTS. IN ADDITION, WE INVESTIGATED DIFFERENT CHANGES IN MYOFIBROBLAST GENE EXPRESSION, TRANSCRIPTIONAL REGULATORS, SIGNALLING PATHWAYS AND EPIGENETIC REGULATORS DURING SKIN WOUND HEALING. IN THE FUTURE, MYOFIBROBLAST REPROGRAMMING IN WOUND HEALING WILL BE BETTER UNDERSTOOD AND APPRECIATED, WHICH MAY PROVIDE NEW IDEAS FOR THE TREATMENT OF SCARLESS WOUND HEALING. 2022 17 6100 31 THE EMERGING ROLE OF EPIGENETIC MODIFIERS IN REPAIR OF DNA DAMAGE ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES. AT SITES OF CHRONIC INFLAMMATION EPITHELIAL CELLS ARE EXPOSED TO HIGH LEVELS OF REACTIVE OXYGEN SPECIES (ROS), WHICH CAN CONTRIBUTE TO THE INITIATION AND DEVELOPMENT OF MANY DIFFERENT HUMAN CANCERS. ABERRANT EPIGENETIC ALTERATIONS THAT CAUSE TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES ARE ALSO IMPLICATED IN MANY DISEASES ASSOCIATED WITH INFLAMMATION, INCLUDING CANCER. HOWEVER, IT IS NOT CLEAR HOW ALTERED EPIGENETIC GENE SILENCING IS INITIATED DURING CHRONIC INFLAMMATION. THE HIGH LEVEL OF ROS AT SITES OF INFLAMMATION IS KNOWN TO INDUCE OXIDATIVE DNA DAMAGE IN SURROUNDING EPITHELIAL CELLS. FURTHERMORE, DNA DAMAGE IS KNOWN TO TRIGGER SEVERAL RESPONSES, INCLUDING RECRUITMENT OF DNA REPAIR PROTEINS, TRANSCRIPTIONAL REPRESSION, CHROMATIN MODIFICATIONS AND OTHER CELL SIGNALING EVENTS. RECRUITMENT OF EPIGENETIC MODIFIERS TO CHROMATIN IN RESPONSE TO DNA DAMAGE RESULTS IN TRANSIENT COVALENT MODIFICATIONS TO CHROMATIN SUCH AS HISTONE UBIQUITINATION, ACETYLATION AND METHYLATION AND DNA METHYLATION. DNA DAMAGE ALSO ALTERS NON-CODING RNA EXPRESSION. ALL OF THESE ALTERATIONS HAVE THE POTENTIAL TO ALTER GENE EXPRESSION AT SITES OF DAMAGE. TYPICALLY, THESE MODIFICATIONS AND GENE TRANSCRIPTION ARE RESTORED BACK TO NORMAL ONCE THE REPAIR OF THE DNA DAMAGE IS COMPLETED. HOWEVER, CHRONIC INFLAMMATION MAY INDUCE SUSTAINED DNA DAMAGE AND DNA DAMAGE RESPONSES THAT RESULT IN THESE TRANSIENT COVALENT CHROMATIN MODIFICATIONS BECOMING MITOTICALLY STABLE EPIGENETIC ALTERATIONS. UNDERSTANDING HOW EPIGENETIC ALTERATIONS ARE INITIATED DURING CHRONIC INFLAMMATION WILL ALLOW US TO DEVELOP PHARMACEUTICAL STRATEGIES TO PREVENT OR TREAT CHRONIC INFLAMMATION-INDUCED CANCER. THIS REVIEW WILL FOCUS ON TYPES OF DNA DAMAGE AND EPIGENETIC ALTERATIONS ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES, THE TYPES OF DNA DAMAGE AND TRANSIENT COVALENT CHROMATIN MODIFICATIONS INDUCED BY INFLAMMATION AND OXIDATIVE DNA DAMAGE AND HOW THESE MODIFICATIONS MAY RESULT IN EPIGENETIC ALTERATIONS. 2019 18 5493 22 REVIEW OF IN VITRO TEST SYSTEMS USING DNA DAMAGE AND REPAIR FOR SCREENING OF CHEMICAL CARCINOGENS. CHEMICAL CARCINOGENS ARE MECHANISTICALLY CLASSIFIED AS GENOTOXIC WHICH INTERACT DIRECTLY WITH DNA, AND EPIGENETIC WHICH CAUSE CHRONIC TISSUE INJURY, HORMONAL IMBALANCE, AND PROMOTIONAL EFFECTS. THIS REVIEW EVALUATES IN VITRO TESTS FOR THEIR CONTRIBUTION TO A BATTERY FOR IDENTIFYING GENOTOXIC CHEMICAL CARCINOGENS. IN ADDITION TO BACTERIAL MUTAGENIC ASSAYS, NONSPECIFIC DNA DAMAGE/REPAIR TESTS ARE RECOMMENDED FOR SCREENING CHEMICALS, IN PARTICULAR THE HEPATOCYTE PRIMARY CULTURE/DNA REPAIR TEST. 1979 19 5816 31 STRESS AND STEM CELLS. THE UNIQUE PROPERTIES AND FUNCTIONS OF STEM CELLS MAKE THEM PARTICULARLY SUSCEPTIBLE TO STRESSES AND ALSO LEAD TO THEIR REGULATION BY STRESS. STEM CELL DIVISION MUST RESPOND TO THE DEMAND TO REPLENISH CELLS DURING NORMAL TISSUE TURNOVER AS WELL AS IN RESPONSE TO DAMAGE. OXIDATIVE STRESS, MECHANICAL STRESS, GROWTH FACTORS, AND CYTOKINES SIGNAL STEM CELL DIVISION AND DIFFERENTIATION. MANY OF THE CONSERVED PATHWAYS REGULATING STEM CELL SELF-RENEWAL AND DIFFERENTIATION ARE ALSO STRESS-RESPONSE PATHWAYS. THE LONG LIFE SPAN AND DIVISION POTENTIAL OF STEM CELLS CREATE A PROPENSITY FOR TRANSFORMATION (CANCER) AND SPECIFIC STRESS RESPONSES SUCH AS APOPTOSIS AND SENESCENCE ACT AS ANTITUMOR MECHANISMS. QUIESCENCE REGULATED BY CDK INHIBITORS AND A HYPOXIC NICHE REGULATED BY FOXO TRANSCRIPTION FACTOR FUNCTION TO REDUCE STRESS FOR SEVERAL TYPES OF STEM CELLS TO FACILITATE LONG-TERM MAINTENANCE. AGING IS A PARTICULARLY RELEVANT STRESS FOR STEM CELLS, BECAUSE REPEATED DEMANDS ON STEM CELL FUNCTION OVER THE LIFE SPAN CAN HAVE CUMULATIVE CELL-AUTONOMOUS EFFECTS INCLUDING EPIGENETIC DYSREGULATION, MUTATIONS, AND TELOMERE EROSION. IN ADDITION, AGING OF THE ORGANISM IMPAIRS FUNCTION OF THE STEM CELL NICHE AND SYSTEMIC SIGNALS, INCLUDING CHRONIC INFLAMMATION AND OXIDATIVE STRESS. 2012 20 3245 22 HEPATIC STELLATE CELLS AS KEY TARGET IN LIVER FIBROSIS. PROGRESSIVE LIVER FIBROSIS, INDUCED BY CHRONIC VIRAL AND METABOLIC DISORDERS, LEADS TO MORE THAN ONE MILLION DEATHS ANNUALLY VIA DEVELOPMENT OF CIRRHOSIS, ALTHOUGH NO ANTIFIBROTIC THERAPY HAS BEEN APPROVED TO DATE. TRANSDIFFERENTIATION (OR "ACTIVATION") OF HEPATIC STELLATE CELLS IS THE MAJOR CELLULAR SOURCE OF MATRIX PROTEIN-SECRETING MYOFIBROBLASTS, THE MAJOR DRIVER OF LIVER FIBROGENESIS. PARACRINE SIGNALS FROM INJURED EPITHELIAL CELLS, FIBROTIC TISSUE MICROENVIRONMENT, IMMUNE AND SYSTEMIC METABOLIC DYSREGULATION, ENTERIC DYSBIOSIS, AND HEPATITIS VIRAL PRODUCTS CAN DIRECTLY OR INDIRECTLY INDUCE STELLATE CELL ACTIVATION. DYSREGULATED INTRACELLULAR SIGNALING, EPIGENETIC CHANGES, AND CELLULAR STRESS RESPONSE REPRESENT CANDIDATE TARGETS TO DEACTIVATE STELLATE CELLS BY INDUCING REVERSION TO INACTIVATED STATE, CELLULAR SENESCENCE, APOPTOSIS, AND/OR CLEARANCE BY IMMUNE CELLS. CELL TYPE- AND TARGET-SPECIFIC PHARMACOLOGICAL INTERVENTION TO THERAPEUTICALLY INDUCE THE DEACTIVATION WILL ENABLE MORE EFFECTIVE AND LESS TOXIC PRECISION ANTIFIBROTIC THERAPIES. 2017