1 4749 98 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 2 2307 33 EPIGENETIC REGULATION OF CELLULAR FUNCTIONS IN WOUND HEALING. STRINGENT SPATIOTEMPORAL REGULATION OF THE WOUND HEALING PROCESS INVOLVING MULTIPLE CELL TYPES IS ASSOCIATED WITH EPIGENETIC MECHANISMS OF GENE REGULATION, SUCH AS DNA METHYLATION, HISTONE MODIFICATION AND CHROMATIN REMODELLING, AS WELL AS NON-CODING RNAS. HERE, WE DISCUSS THE EPIGENETIC CHANGES THAT OCCUR DURING WOUND HEALING AND THE RAPIDLY EXPANDING UNDERSTANDING OF HOW THESE MECHANISMS AFFECT HEALING RESOLUTION IN BOTH ACUTE AND CHRONIC WOUND MILIEU. WE PROVIDE A FOCUSSED OVERVIEW OF CURRENT RESEARCH INTO EPIGENETIC REGULATORS THAT CONTRIBUTE TO WOUND HEALING BY SPECIFIC CELL TYPE. WE HIGHLIGHT THE ROLE OF EPIGENETIC REGULATORS IN THE MOLECULAR PATHOPHYSIOLOGY OF CHRONIC WOUND CONDITIONS. THE UNDERSTANDING OF HOW EPIGENETIC REGULATORS CAN AFFECT CELLULAR FUNCTIONS DURING NORMAL AND IMPAIRED WOUND HEALING COULD LEAD TO NOVEL THERAPEUTIC APPROACHES, AND WE OUTLINE QUESTIONS THAT CAN PROVIDE GUIDANCE FOR FUTURE RESEARCH ON EPIGENETIC-BASED INTERVENTIONS TO PROMOTE HEALING. DISSECTING THE DYNAMIC INTERPLAY BETWEEN CELLULAR SUBTYPES INVOLVED IN WOUND HEALING AND EPIGENETIC PARAMETERS DURING BARRIER REPAIR WILL DEEPEN OUR UNDERSTANDING OF HOW TO IMPROVE HEALING OUTCOMES IN PATIENTS AFFECTED BY CHRONIC NON-HEALING WOUNDS. 2021 3 6181 35 THE IMMUNE FUNCTIONS OF KERATINOCYTES IN SKIN WOUND HEALING. AS THE MOST DOMINANT CELL TYPE IN THE SKIN, KERATINOCYTES PLAY CRITICAL ROLES IN WOUND REPAIR NOT ONLY AS STRUCTURAL CELLS BUT ALSO EXERTING IMPORTANT IMMUNE FUNCTIONS. THIS REVIEW FOCUSES ON THE COMMUNICATIONS BETWEEN KERATINOCYTES AND IMMUNE CELLS IN WOUND HEALING, WHICH ARE MEDIATED BY VARIOUS CYTOKINES, CHEMOKINES, AND EXTRACELLULAR VESICLES. KERATINOCYTES CAN ALSO DIRECTLY INTERACT WITH T CELLS VIA ANTIGEN PRESENTATION. MOREOVER, KERATINOCYTES PRODUCE ANTIMICROBIAL PEPTIDES THAT CAN DIRECTLY KILL THE INVADING PATHOGENS AND CONTRIBUTE TO WOUND REPAIR IN MANY ASPECTS. WE ALSO REVIEWED THE EPIGENETIC MECHANISMS KNOWN TO REGULATE KERATINOCYTE IMMUNE FUNCTIONS, INCLUDING HISTONE MODIFICATIONS, NON-PROTEIN-CODING RNAS (E.G., MICRORNAS, AND LONG NONCODING RNAS), AND CHROMATIN DYNAMICS. LASTLY, WE SUMMARIZED THE CURRENT EVIDENCE ON THE DYSREGULATED IMMUNE FUNCTIONS OF KERATINOCYTES IN CHRONIC NONHEALING WOUNDS. BASED ON THEIR CRUCIAL IMMUNE FUNCTIONS IN SKIN WOUND HEALING, WE PROPOSE THAT KERATINOCYTES SIGNIFICANTLY CONTRIBUTE TO THE PATHOGENESIS OF CHRONIC WOUND INFLAMMATION. WE HOPE THIS REVIEW WILL TRIGGER AN INTEREST IN INVESTIGATING THE IMMUNE ROLES OF KERATINOCYTES IN CHRONIC WOUND PATHOLOGY, WHICH MAY OPEN UP NEW AVENUES FOR DEVELOPING INNOVATIVE WOUND TREATMENTS. 2020 4 5922 30 TARGETING DNA METHYLATION AND DEMETHYLATION IN DIABETIC FOOT ULCERS. BACKGROUND: POOR WOUND HEALING IS A SIGNIFICANT COMPLICATION OF DIABETES, WHICH IS COMMONLY CAUSED BY NEUROPATHY, TRAUMA, DEFORMITIES, PLANTAR HYPERTENSION AND PERIPHERAL ARTERIAL DISEASE. DIABETIC FOOT ULCERS (DFU) ARE DIFFICULT TO HEAL, WHICH MAKES PATIENTS SUSCEPTIBLE TO INFECTIONS AND CAN ULTIMATELY CONDUCE TO LIMB AMPUTATION OR EVEN DEATH IN SEVERE CASES. AN INCREASING NUMBER OF STUDIES HAVE FOUND THAT EPIGENETIC ALTERATIONS ARE STRONGLY ASSOCIATED WITH POOR WOUND HEALING IN DIABETES. AIM OF REVIEW: THIS WORK PROVIDES SIGNIFICANT INSIGHTS INTO THE DEVELOPMENT OF THERAPEUTICS FOR IMPROVING CHRONIC DIABETIC WOUND HEALING, PARTICULARLY BY TARGETING AND REGULATING DNA METHYLATION AND DEMETHYLATION IN DFU. KEY SCIENTIFIC CONCEPTS OF REVIEW: DNA METHYLATION AND DEMETHYLATION PLAY AN IMPORTANT PART IN DIABETIC WOUND HEALING, VIA REGULATING CORRESPONDING SIGNALING PATHWAYS IN DIFFERENT BREEDS OF CELLS, INCLUDING MACROPHAGES, VASCULAR ENDOTHELIAL CELLS AND KERATINOCYTES. IN THIS REVIEW, WE DESCRIBE THE FOUR MAIN PHASES OF WOUND HEALING AND THEIR ABNORMALITY IN DIABETIC PATIENTS. FURTHERMORE, WE PROVIDED AN IN-DEPTH SUMMARY AND DISCUSSION ON HOW DNA METHYLATION AND DEMETHYLATION REGULATE DIABETIC WOUND HEALING IN DIFFERENT TYPES OF CELLS; AND GAVE A BRIEF SUMMARY ON RECENT ADVANCES IN APPLYING CELLULAR REPROGRAMMING TECHNIQUES FOR IMPROVING DIABETIC WOUND HEALING. 2023 5 5726 22 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 6 1713 29 DYSFUNCTIONAL WOUND HEALING IN DIABETIC FOOT ULCERS: NEW CROSSROADS. PURPOSE OF REVIEW: DIABETIC FOOT ULCERATIONS (DFU) AFFECT 25% OF PATIENTS WITH DIABETES MELLITUS DURING THEIR LIFETIME AND CONSTITUTE A MAJOR HEALTH PROBLEM AS THEY ARE OFTEN RECALCITRANT TO HEALING DUE TO A CONSTELLATION OF BOTH INTRINSIC AND EXTRINSIC FACTORS. THE PURPOSE OF THIS REVIEW IS TO (1) DETAIL THE CURRENT MECHANISTIC UNDERSTANDING OF DFU FORMATION AND (2) HIGHLIGHT FUTURE THERAPEUTIC TARGETS. RECENT FINDINGS: FROM A MOLECULAR PERSPECTIVE, DFUS EXHIBIT A CHRONIC INFLAMMATORY PREDISPOSITION. IN ADDITION, INCREASED LOCAL HYPOXIC CONDITIONS AND IMPAIRED CELLULAR RESPONSES TO HYPOXIA ARE PATHOGENIC FACTORS THAT CONTRIBUTE TO DELAYED WOUND HEALING. FINALLY, RECENT EVIDENCE SUGGESTS A ROLE FOR EPIGENETIC ALTERATIONS, INCLUDING MICRORNAS, IN DELAYED DFU HEALING DUE TO THE COMPLEX INTERPLAY BETWEEN GENES AND THE ENVIRONMENT. IN THIS REGARD, NOTABLE PROGRESS HAS BEEN MADE IN THE MOLECULAR AND GENETIC UNDERSTANDING OF DFU FORMATION. HOWEVER, FURTHER STUDIES ARE NEEDED TO TRANSLATE PRECLINICAL INVESTIGATIONS INTO CLINICAL THERAPIES. 2018 7 2953 27 GENETIC AND EPIGENETIC EVENTS IN DIABETIC WOUND HEALING. THE PREVALENCE OF THE CHRONIC METABOLIC DISORDER, DIABETES MELLITUS, IS EXPECTED TO INCREASE IN THE COMING YEARS AND WORLDWIDE PANDEMIC LEVELS ARE PREDICTED. INEVITABLY, THIS WILL BE ACCOMPANIED BY AN INCREASE IN THE PREVALENCE OF DIABETIC COMPLICATIONS, INCLUDING DIABETIC FOOT ULCERS. AT PRESENT, TREATMENT OPTIONS FOR DIABETIC FOOT ULCERS ARE IN MANY CASES INSUFFICIENT, AND PROGRESSION OF THE CONDITION RESULTS IN THE REQUIREMENT FOR LIMB AMPUTATION IN A PROPORTION OF PATIENTS. TO IMPROVE THERAPY, AN INCREASE IN OUR UNDERSTANDING OF THE PATHOBIOLOGY OF DIABETIC COMPLICATIONS SUCH AS IMPAIRED WOUND HEALING IS NECESSARY. IN THIS REVIEW, RECENT ADVANCES IN MOLECULAR ASPECTS OF NORMAL AND IMPAIRED DIABETIC WOUND HEALING ARE DISCUSSED. FURTHERMORE, INVESTIGATIONS OF THE ROLE OF EPIGENETIC PROCESSES IN THE PATHOGENESIS OF IMPAIRED DIABETIC WOUND HEALING ARE NOW EMERGING. INDEED, EPIGENETIC CHANGES HAVE ALREADY BEEN IDENTIFIED AS KEY FACTORS IN DIABETES AND RELATED COMPLICATIONS AND THESE ARE OVERVIEWED IN THIS REVIEW. 2011 8 630 25 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 9 2694 26 EVOLVING SPECTRUM OF DIABETIC WOUND: MECHANISTIC INSIGHTS AND THERAPEUTIC TARGETS. DIABETES MELLITUS IS A CHRONIC METABOLIC DISORDER RESULTING IN AN INCREASED BLOOD GLUCOSE LEVEL AND PROLONGED HYPERGLYCEMIA, CAUSES LONG TERM HEALTH CONSE-QUENCES. CHRONIC WOUND IS FREQUENTLY OCCURRING IN DIABETES PATIENTS DUE TO COMPROMISED WOUND HEALING CAPABILITY. MANAGEMENT OF WOUNDS IN DIABETIC PATIENTS REMAINS A CLINICAL CHALLENGE DESPITE MANY ADVANCEMENTS IN THE FIELD OF SCIENCE AND TECHNOLOGY. INCREASING EVIDENCE INDICATES THAT ALTERATION OF THE BIOCHEMICAL MILIEU RESULTING FROM ALTERATION IN INFLAMMATORY CYTOKINES AND MATRIX METALLOPROTEINASE, DECREASE IN FIBROBLAST AND KERATINOCYTE FUNCTIONING, NEUROPATHY, ALTERED LEUKOCYTE FUNCTIONING, INFECTION, ETC., PLAYS A SIGNIFICANT ROLE IN IMPAIRED WOUND HEALING IN DIABETIC PEOPLE. APART FROM THE CURRENT PHARMACOTHERAPY, DIFFERENT OTHER APPROACHES LIKE THE USE OF CONVENTIONAL DRUGS, ANTIDIABETIC MEDICATION, ANTIBIOTICS, DEBRIDEMENT, OFFLOADING, PLATELET-RICH PLASMA, GROWTH FACTOR, OXYGEN THERAPY, NEGATIVE PRESSURE WOUND THERAPY, LOW-LEVEL LASER, EXTRACORPOREAL SHOCK WAVE BIOENGINEERED SUBSTITUTE CAN BE CONSIDERED IN THE MANAGEMENT OF DIABETIC WOUNDS. DRUGS/THERAPEUTIC STRATEGY THAT INDUCE ANGIOGENESIS AND COLLAGEN SYNTHESIS, INHIBITION OF MMPS, REDUCTION OF OXIDATIVE STRESS, CONTROLLING HYPERGLYCEMIA, INCREASE GROWTH FACTORS, REGULATE INFLAMMATORY CYTOKINES, CAUSE NO INDUCTION, INDUCE FIBROBLAST AND KERATINOCYTE PROLIFERATION, CONTROL MICROBIAL INFECTIONS ARE CONSIDERED IMPORTANT IN CONTROLLING DIABETIC WOUND. FURTHER, MEDICINAL PLANTS AND/OR PHYTOCONSTITUENTS ALSO OFFER A VIABLE ALTERNATIVE IN THE TREATMENT OF DIABETIC WOUND. THE FOCUS OF THE PRESENT REVIEW IS TO HIGHLIGHT THE MOLECULAR AND CELLULAR MECHANISMS, AND DISCUSS THE DRUG TARGETS AND TREATMENT STRATEGIES INVOLVED IN THE DIABETIC WOUND. 2022 10 6284 31 THE POTENTIAL OF HUMAN INDUCED PLURIPOTENT STEM CELLS FOR MODELLING DIABETIC WOUND HEALING IN VITRO. IMPAIRED WOUND HEALING AND ULCERATION CAUSED BY DIABETES MELLITUS, IS A SIGNIFICANT HEALTHCARE BURDEN, MARKEDLY IMPAIRS QUALITY OF LIFE FOR PATIENTS, AND IS THE MAJOR CAUSE OF AMPUTATION WORLDWIDE. CURRENT EXPERIMENTAL APPROACHES USED TO INVESTIGATE THE COMPLEX WOUND HEALING PROCESS OFTEN INVOLVE CULTURES OF FIBROBLASTS AND/OR KERATINOCYTES IN VITRO, WHICH CAN BE LIMITED IN TERMS OF COMPLEXITY AND CAPACITY, OR UTILISATION OF RODENT MODELS IN WHICH THE MECHANISMS OF WOUND REPAIR DIFFER SUBSTANTIVELY FROM THAT IN HUMANS. HOWEVER, ADVANCES IN TISSUE ENGINEERING, AND THE DISCOVERY OF STRATEGIES TO REPROGRAMME ADULT SOMATIC CELLS TO PLURIPOTENCY, HAS LED TO THE POSSIBILITY OF DEVELOPING MODELS OF HUMAN SKIN ON A LARGE SCALE. GENERATION OF INDUCED PLURIPOTENT STEM CELLS (IPSCS) FROM TISSUES DONATED BY DIABETIC PATIENTS ALLOWS THE (EPI)GENETIC BACKGROUND OF THIS DISEASE TO BE STUDIED, AND THE ABILITY TO DIFFERENTIATE IPSCS TO MULTIPLE CELL TYPES FOUND WITHIN SKIN MAY FACILITATE THE DEVELOPMENT OF MORE COMPLEX SKIN MODELS; THESE ADVANCES OFFER KEY OPPORTUNITIES FOR IMPROVING MODELLING OF WOUND HEALING IN DIABETES, AND THE DEVELOPMENT OF EFFECTIVE THERAPEUTICS FOR TREATMENT OF CHRONIC WOUNDS. 2018 11 6282 35 THE POTENTIAL IMPACT OF SOCIAL GENOMICS ON WOUND HEALING. SIGNIFICANCE: HUMAN SKIN WOUNDS CARRY AN IMMENSE EPIDEMIOLOGIC AND FINANCIAL BURDEN, AND THEIR IMPACT WILL CONTINUE TO GROW WITH AN AGING POPULATION AND RISING INCIDENCE OF COMORBID CONDITIONS KNOWN TO AFFECT WOUND HEALING. TO COMPREHENSIVELY ADDRESS THIS GROWING CLINICAL ISSUE, PHYSICIANS SHOULD ALSO BE AWARE OF HOW CONDITIONS OF THE HUMAN SOCIAL ENVIRONMENT MAY AFFECT WOUND HEALING. HERE WE PROVIDE A REVIEW OF THE EMERGING FIELD OF SOCIAL GENOMICS AND ITS POTENTIAL IMPACT ON THE WOUND HEALING. RECENT ADVANCES: MULTIPLE STUDIES USING HUMAN AND ANIMAL MODELS HAVE CORRELATED SOCIAL INFLUENCES AND THEIR CONTRIBUTING EFFECTS TO ACUTE AND CHRONIC STRESS WITH DELAYS IN WOUND HEALING. FURTHERMORE, OBSERVATIONS BETWEEN NONGENETIC FACTORS SUCH AS NUTRITION, SOCIOECONOMIC, AND EDUCATIONAL STATUS HAVE ALSO SHOWN TO HAVE A DIRECT OR INDIRECT IMPACT ON CLINICAL OUTCOMES OF WOUND HEALING. CRITICAL ISSUES: NUTRITION, FINANCIAL BURDEN, SOCIOECONOMIC AND EDUCATION STATUS, AND ACUTE AND CHRONIC STRESS ARE VARIABLES THAT HAVE EITHER DIRECT (EPIGENETIC) OR INDIRECT IMPACT ON WOUND HEALING AND PATIENTS' QUALITY OF LIFE. WOUND CARE IS COSTLY AND REMAINS A CHALLENGE PLACING ECONOMIC BURDEN ON PATIENTS. FURTHERMORE, POOR CLINICAL OUTCOMES AND COMPLICATIONS INCLUDING LOSS OF MOBILITY AND DISABILITY MAY LEAD TO JOB LOSS, FURTHER CONTRIBUTING TO SOCIOECONOMIC RELATED STRESS. THUS, THE ECONOMIC BURDEN AND INADEQUATE WOUND HEALING ARE INTERTWINED, MAKING EACH OTHER WORSE. FUTURE DIRECTIONS: ALTHOUGH SOME EVIDENCE REGARDING THE SPECIFIC CHANGES IN GENETIC PATHWAYS IMPARTED BY CONDITIONS OF THE SOCIAL ENVIRONMENT EXISTS, FURTHER STUDIES ARE WARRANTED TO IDENTIFY POTENTIAL MECHANISMS, INTERVENTIONS, AND PREVENTION APPROACHES. 2020 12 2976 37 GENETIC AND MOLECULAR BASIS OF DIABETIC FOOT ULCERS: CLINICAL REVIEW. DIABETIC FOOT ULCERS (DFUS) ARE MAJOR COMPLICATIONS ASSOCIATED WITH DIABETES AND OFTEN CORRELATE WITH PERIPHERAL NEUROPATHY, TRAUMA AND PERIPHERAL VASCULAR DISEASE. IT IS NECESSARY TO UNDERSTAND THE MOLECULAR AND GENETIC BASIS OF DIABETIC FOOT ULCERS IN ORDER TO TAILOR PATIENT CENTRED CARE TOWARDS PARTICULAR PATIENT GROUPS. THIS REVIEW AIMED TO EVALUATE WHETHER CURRENT LITERATURE WAS INDICATIVE OF AN UNDERLYING MOLECULAR AND GENETIC BASIS FOR DFUS AND TO DISCUSS CLINICAL APPLICATIONS. FROM A MOLECULAR PERSPECTIVE, WOUND HEALING IS A PROCESS THAT TRANSPIRES FOLLOWING BREACH OF THE SKIN BARRIER AND IS USUALLY MEDIATED BY GROWTH FACTORS AND CYTOKINES RELEASED BY SPECIALISED CELLS ACTIVATED BY THE IMMUNE RESPONSE, INCLUDING FIBROBLASTS, ENDOTHELIAL CELLS, PHAGOCYTES, PLATELETS AND KERATINOCYTES. GROWTH FACTORS AND CYTOKINES ARE FUNDAMENTAL IN THE ORGANISATION OF THE MOLECULAR PROCESSES INVOLVED IN MAKING CUTANEOUS WOUND HEALING POSSIBLE. THERE IS A SIGNIFICANT ROLE FOR SINGLE NUCLEOTIDE POLYMORPHISM (SNPS) IN THE FLUCTUATION OF THESE GROWTH FACTORS AND CYTOKINES IN DFUS. FURTHERMORE, RECENT EVIDENCE SUGGESTS A KEY ROLE FOR EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION FROM LONG STANDING HYPERGLYCEMIA AND NON-CODING RNAS IN THE COMPLEX INTERPLAY BETWEEN GENES AND THE ENVIRONMENT. GENETIC FACTORS AND ETHNICITY CAN ALSO PLAY A SIGNIFICANT ROLE IN THE DEVELOPMENT OF DIABETIC NEUROPATHY LEADING TO DFUS. CLINICALLY, INTERVENTIONS WHICH HAVE IMPROVED OUTCOMES FOR PEOPLE WITH DFUS OR THOSE AT RISK OF DFUS INCLUDE SOME SYSTEMIC THERAPEUTIC DRUG INTERVENTIONS WHICH IMPROVE MICROVASCULAR BLOOD FLOW, SURGICAL INTERVENTIONS, HUMAN GROWTH FACTORS, AND HYPERBARIC OXYGEN THERAPY, NEGATIVE PRESSURE WOUND THERAPY, SKIN REPLACEMENT OR SHOCKWAVE THERAPY AND THE USE OF TOPICAL TREATMENTS. FUTURE TREATMENT MODALITIES INCLUDING STEM CELL AND GENE THERAPIES ARE PROMISING IN THE THERAPEUTIC APPROACH TO PREVENT THE PROGRESSION OF CHRONIC DIABETIC COMPLICATIONS. 2016 13 2381 39 EPIGENETIC REGULATION OF WOUND HEALING AND FIBROSIS. PURPOSE OF REVIEW: WOUND HEALING IS A NORMAL PHYSIOLOGICAL RESPONSE TO TISSUE INJURY WHICH CAN OCCUR IN ANY ORGAN. MECHANISMS THAT ORCHESTRATE WOUND HEALING IN DIFFERENT ORGANS ARE SURPRISINGLY GENERIC, INVOLVING GENERATION OF FIBROBLASTS AND MYOFIBROBLASTS BY DIFFERENTIATION PROCESSES THAT REQUIRE EXTENSIVE ALTERATIONS IN GENE EXPRESSION. THIS PROCESS AND INDEED PHENOTYPE OF CELLS ARE ORCHESTRATED BY THE COMBINED INFLUENCES OF MOLECULAR COMPONENTS OF EPIGENOME INCLUDING DNA METHYLATION, VAST ARRAY OF POSTTRANSLATIONAL MODIFICATIONS OF THE HISTONE PROTEIN CONSTITUENTS OF CHROMATIN AND REGULATORY NONCODING RNAS OF WHICH MICRORNAS (MIRS) ARE THE MOST EXTENSIVELY STUDIED. RECENT FINDINGS: NUMEROUS STUDIES FROM THE LAST 12 MONTHS SHOW ALL THE THREE EPIGENETIC MECHANISMS TO BE REGULATING GENERATION AND APOPTOSIS OF MYOFIBROBLASTS IN ORGANS AFFECTED BY PERTURBED WOUND HEALING. FURTHERMORE, THESE MECHANISMS ARE INVOLVED IN FIBROTIC DISEASE ITSELF, WITH SOME MIRS AND EPIGENETIC DRUGS BEING TESTED FOR THEIR THERAPEUTIC POTENTIAL. SUMMARY: FIELDS OF WOUND HEALING AND FIBROSIS WILL BE ENRICHED OVER THE NEXT DECADE BY PLETHORA OF NEW INFORMATION REGARDING EPIGENETIC CONTROL MECHANISMS WHICH WILL HOPEFULLY PROVIDE NEW ADVANCES IN DIAGNOSTICS AND PROGNOSTICS. WITH THE DESIGN OF EVER MORE SPECIFIC EPIGENETIC DRUGS, WE MAY IMPROVE OUR ABILITY TO THERAPEUTICALLY OPTIMIZE WOUND HEALING AND PREVENT FIBROSIS IN CHRONIC DISEASE AND AGEING. 2013 14 2248 29 EPIGENETIC MODULATION OF MACROPHAGE POLARIZATION- PERSPECTIVES IN DIABETIC WOUNDS. DIABETES IS A CHRONIC METABOLIC DISORDER THAT POSES A GLOBAL BURDEN TO HEALTHCARE. INCREASING INCIDENCE OF DIABETES-RELATED COMPLICATIONS IN THE AFFECTED POPULATION INCLUDES A DELAY IN WOUND HEALING THAT OFTEN RESULTS IN NON-TRAUMATIC LIMB AMPUTATIONS. OWING TO THE INTRICACIES OF THE HEALING PROCESS AND CROSSTALK BETWEEN THE MULTITUDE OF PARTICIPATING CELLS, THE IDENTIFICATION OF HYPERGLYCAEMIA-INDUCED CHANGES AT BOTH CELLULAR AND MOLECULAR LEVELS POSES A CHALLENGE. MACROPHAGES ARE ONE OF THE KEY PARTICIPANTS IN WOUND HEALING AND CONTINUE TO EXERT FUNCTIONAL CHANGES AT THE WOUND SITE SINCE THE TIME OF INJURY. IN THE PRESENT REVIEW, WE DISCUSS THE ROLE OF THESE CELLS AND THEIR ABERRANT FUNCTIONS IN DIABETIC WOUNDS. WE HAVE EXTENSIVELY STUDIED THE PROCESS OF MACROPHAGE POLARIZATION (MP) AND ITS MODULATION THROUGH EPIGENETIC MODIFICATIONS. DATA FROM BOTH PRE-CLINICAL AND CLINICAL STUDIES ON DIABETES HAVE CO-RELATED HYPERGLYCAEMIA INDUCED CHANGES IN GENE EXPRESSION TO AN INCREASED INCIDENCE OF DIABETIC COMPLICATIONS. HYPERGLYCAEMIA AND OXIDATIVE STRESS, CREATE AN ENVIRONMENT PRONE TO CHANGES IN THE EPIGENETIC CODE, THAT IS MANIFESTED AS AN ALTERED INFLAMMATORY GENE EXPRESSION. HERE, WE HAVE ATTEMPTED TO UNDERSTAND THE DIFFERENT EPIGENETIC MODULATIONS THAT POSSIBLY CONTRIBUTE TOWARDS DYSREGULATED MP, RESULTING IN DELAYED WOUND HEALING. 2018 15 5494 22 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 16 3931 24 LIVER INJURY AND THE ACTIVATION OF THE HEPATIC MYOFIBROBLASTS. LIVER FIBROSIS IS A WOUND HEALING PROCESS, THE END RESULT OF CHRONIC LIVER INJURY ELICITED BY DIFFERENT NOXIOUS STIMULI. ACTIVATED HEPATIC STELLATE CELLS OR MYOFIBROBLASTS AND PORTAL MYOFIBROBLASTS ARE CONSIDERED AS THE MAIN PRODUCERS OF THE EXTRACELLULAR MATRIX IN THE LIVER. UPON LIVER INJURY THE QUIESCENT STELLATE CELLS TRANSDIFFERENTIATE INTO MYOFIBROBLASTS A PROCESS HIGHLIGHTED BY THE LOSS OF VITAMIN A STORES, UPREGULATION OF INTERSTITIAL TYPE COLLAGENS, SMOOTH MUSCLE ALPHA ACTIN, MATRIX METALLOPROTEINASES, PROTEOGLYCANS, AND THE INDUCTION OF CELL SURVIVAL PATHWAYS. ACTIVATION OF HEPATIC STELLATE CELLS IS A RESULT OF A COMPLEX INTERPLAY BETWEEN THE PARENCHYMAL CELLS, IMMUNE CELLS, EXTRACELLULAR MATRIX MECHANICS AND EXTRAHEPATIC MILIEU SUCH AS THE GUT MICROBIOME. IN THIS REVIEW WE WILL FOCUS ON THE PATHOMECHANISM OF STELLATE CELL ACTIVATION FOLLOWING CHRONIC LIVER INJURY; WITH THE AIM OF IDENTIFYING POSSIBLE TREATMENT TARGETS FOR ANTI-FIBROGENIC AGENTS. 2013 17 2941 28 GENETIC AND EPIGENETIC ALTERATIONS IN TOLL LIKE RECEPTOR 2 AND WOUND HEALING IMPAIRMENT IN TYPE 2 DIABETES PATIENTS. AIM: PERSISTENT HYPERGLYCEMIC MICROENVIRONMENT IN TYPE 2 DIABETES MELLITUS (T2DM) LEADS TO THE DEVELOPMENT OF SECONDARY COMPLICATIONS LIKE WOUND HEALING IMPAIRMENT. PROPER CO-ORDINATION OF INNATE IMMUNE SYSTEM PLAYS AN INTEGRAL ROLE IN WOUND HEALING. TOLL LIKE RECEPTORS (TLRS) ARE PROMINENT CONTRIBUTORS FOR THE INDUCTION OF THE INNATE IMMUNE AND INFLAMMATION RESPONSE. TLR2 IS AN IMPORTANT EXTRACELLULAR MEMBER IN MAMMALIAN TLR FAMILY AND HAS BEEN SHOWN TO BE A POTENT PLAYER IN THE WOUND HEALING MECHANISM. METHODS: EXPRESSIONAL STATUS OF TLR2 WAS SEEN IN WOUNDS OF T2DM CASES WITH RESPECT TO THE SEVERITY OF WOUNDS IN 110 HUMAN LOWER EXTREMITY WOUNDS. THE METHYLATION STATUS OF TLR2 PROMOTER WAS ALSO EXAMINED. RESULTS: ALTHOUGH TLR2 TRANSCRIPTS WERE DOWNREGULATED IN T2DM WOUNDS COMPARED TO CONTROL, THEIR LEVELS TEND TO INCREASE WITH THE SEVERITY OF T2DM WOUNDS. THE METHYLATION STATUS OF TLR2 GENE PROMOTER WAS NOT SIGNIFICANTLY DIFFERENT AMONG DIFFERENT GRADES OF WOUNDS IN T2DM SUBJECTS. THE CPG SITES INVESTIGATED WERE TOTALLY OR PARTIALLY METHYLATED IN MAJORITY OF DFU CASES. CONCLUSION: TLR2 DOWN REGULATION IN WOUNDS OF T2DM PATIENTS COMPARED TO NON DIABETIC PATIENTS MAY LEAD TO DEVELOPMENT OF NON HEALING CHRONIC ULCERS IN THEM. 2015 18 2933 43 GENESIS OF THE MYOFIBROBLAST IN LUNG INJURY AND FIBROSIS. TISSUE INJURY INCITES A REPAIR RESPONSE WITH A KEY MESENCHYMAL COMPONENT THAT PROVIDES THE ESSENTIAL CONNECTIVE TISSUE FOR SUBSEQUENT REGENERATION OR PATHOLOGICAL FIBROSIS. THE FIBROBLAST IS THE MAJOR MESENCHYMAL CELL TYPE TO BE IMPLICATED IN THIS CONNECTIVE TISSUE RESPONSE, AND IT IS IN ITS ACTIVATED OR DIFFERENTIATED FORM THAT IT PARTICIPATES IN THE REPAIR PROCESS. THE MYOFIBROBLAST REPRESENTS SUCH AN ACTIVATED MESENCHYMAL CELL AND IS A KEY SOURCE OF EXTRACELLULAR MATRIX AND INFLAMMATORY/FIBROGENIC CYTOKINES AS WELL AS PARTICIPATING IN WOUND CONTRACTION. ALTHOUGH SUCCESSFUL HEALING RESULTS IN GRADUAL DISAPPEARANCE OF MYOFIBROBLASTS, THEIR PERSISTENCE IS ASSOCIATED WITH CHRONIC AND PROGRESSIVE FIBROSIS. THUS, ELUCIDATION OF THE MECHANISM INVOLVED IN THE GENESIS OF THE MYOFIBROBLAST SHOULD PROVIDE INSIGHT INTO BOTH PATHOGENESIS OF CHRONIC FIBROTIC DISEASES AND THERAPEUTIC STRATEGIES FOR THEIR MANAGEMENT AND CONTROL. ALTHOUGH THE FIBROBLAST IS A WELL-DOCUMENTED PROGENITOR CELL FOR THE MYOFIBROBLAST, RECENT STUDIES HAVE SUGGESTED ADDITIONAL PRECURSOR CELLS THAT HAVE THE POTENTIAL TO GIVE RISE TO THE MYOFIBROBLAST. MANY OF THE STUDIES FOCUSED ON MECHANISMS AND FACTORS THAT REGULATE INDUCTION OF ALPHA-SMOOTH MUSCLE ACTIN EXPRESSION, A KEY AND COMMONLY USED MARKER OF THE MYOFIBROBLAST. THESE REVEAL COMPLEX AND MULTIFACTORIAL MECHANISMS INVOLVING TRANSCRIPTIONAL AND EPIGENETIC REGULATION AND IMPLICATING DIVERSE CELL-SIGNALING PATHWAYS, INCLUDING THOSE ACTIVATED BY THE POTENT FIBROGENIC CYTOKINE TRANSFORMING GROWTH FACTOR BETA. DESPITE THESE EXTENSIVE STUDIES, MANY ASPECTS REMAIN POORLY UNDERSTOOD, WITH THE SUGGESTION THAT ADDITIONAL NOVEL MECHANISMS REMAIN TO BE DISCOVERED. FUTURE STUDIES WITH THE HELP OF NEWLY DEVELOPED TECHNICAL ADVANCEMENTS SHOULD EXPEDITE DISCOVERY IN THIS DIRECTION. 2012 19 1886 31 ENDOGENOUS BIOLOGICAL DRIVERS IN DIABETIC LOWER LIMB WOUNDS RECURRENCE: HYPOTHETICAL REFLECTIONS. AN IMPAIRED HEALING RESPONSE UNDERLIES DIABETIC FOOT WOUND CHRONICITY, FREQUENTLY TRANSLATING TO AMPUTATION, DISABILITY, AND MORTALITY. DIABETICS SUFFER FROM UNDERAPPRECIATED EPISODES OF POST-EPITHELIZATION ULCER RECURRENCE. RECURRENCE EPIDEMIOLOGICAL DATA ARE ALARMINGLY HIGH, SO THE ULCER IS CONSIDERED IN "REMISSION" AND NOT HEALED FROM THE TIME IT REMAINS EPITHELIALIZED. RECURRENCE MAY RESULT FROM THE COMBINED EFFECTS OF BEHAVIORAL AND ENDOGENOUS BIOLOGICAL FACTORS. ALTHOUGH THE DAMAGING ROLE OF BEHAVIORAL, CLINICAL PREDISPOSING FACTORS IS UNDEBATABLE, IT STILL REMAINS ELUSIVE IN THE IDENTIFICATION OF ENDOGENOUS BIOLOGICAL CULPRITS THAT MAY PRIME THE RESIDUAL SCAR TISSUE FOR RECURRENCE. FURTHERMORE, THE EVENT OF ULCER RECURRENCE STILL WAITS FOR THE IDENTIFICATION OF A MOLECULAR PREDICTOR. WE PROPOSE THAT ULCER RECURRENCE IS DEEPLY IMPINGED BY CHRONIC HYPERGLYCEMIA AND ITS DOWNSTREAM BIOLOGICAL EFFECTORS, WHICH ORIGINATE EPIGENETIC DRIVERS THAT ENFORCE ABNORMAL PATHOLOGIC PHENOTYPES TO DERMAL FIBROBLASTS AND KERATINOCYTES AS MEMORY CELLS. HYPERGLYCEMIA-DERIVED CYTOTOXIC REACTANTS ACCUMULATE AND MODIFY DERMAL PROTEINS, REDUCE SCAR TISSUE MECHANICAL TOLERANCE, AND DISRUPT FIBROBLAST-SECRETORY ACTIVITY. ACCORDINGLY, THE COMBINATION OF EPIGENETIC AND LOCAL AND SYSTEMIC CYTOTOXIC SIGNALERS INDUCE THE ONSET OF "AT-RISK PHENOTYPES" SUCH AS PREMATURE SKIN CELL AGING, DYSMETABOLISM, INFLAMMATORY, PRO-DEGRADATIVE, AND OXIDATIVE PROGRAMS THAT MAY ULTIMATELY CONVERGE TO SCAR CELL DEMISE. POST-EPITHELIALIZATION RECURRENCE RATE DATA ARE MISSING IN CLINICAL STUDIES OF REPUTED ULCER HEALING THERAPIES DURING FOLLOW-UP PERIODS. INTRA-ULCER INFILTRATION OF EPIDERMAL GROWTH FACTOR EXHIBITS THE MOST CONSISTENT REMISSION DATA WITH THE LOWEST RECURRENCES DURING 12-MONTH FOLLOW-UP. RECURRENCE DATA SHOULD BE REGARDED AS A VALUABLE CLINICAL ENDPOINT DURING THE INVESTIGATIONAL PERIOD FOR EACH EMERGENT HEALING CANDIDATE. 2023 20 3184 31 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