1 1896 76 ENDOTHELIAL-TO-MESENCHYMAL TRANSITION: AN UNDERAPPRECIATED MEDIATOR OF DIABETIC COMPLICATIONS. DIABETES AND ITS COMPLICATIONS REPRESENT A GREAT BURDEN ON THE GLOBAL HEALTHCARE SYSTEM. DIABETIC COMPLICATIONS ARE FUNDAMENTALLY DISEASES OF THE VASCULATURE, WITH ENDOTHELIAL CELLS BEING THE CENTERPIECE OF EARLY HYPERGLYCEMIA-INDUCED CHANGES. ENDOTHELIAL-TO-MESENCHYMAL TRANSITION IS A TIGHTLY REGULATED PROCESS THAT RESULTS IN ENDOTHELIAL CELLS LOSING ENDOTHELIAL CHARACTERISTICS AND DEVELOPING MESENCHYMAL TRAITS. ALTHOUGH ENDOTHELIAL-TO-MESENCHYMAL TRANSITION HAS BEEN FOUND TO OCCUR WITHIN MOST OF THE MAJOR COMPLICATIONS OF DIABETES, IT HAS NOT BEEN A MAJOR FOCUS OF STUDY OR A COMMON TARGET IN THE TREATMENT OR PREVENTION OF DIABETIC COMPLICATIONS. IN THIS REVIEW WE SUMMARIZE THE IMPORTANCE OF ENDOTHELIAL-TO-MESENCHYMAL TRANSITION IN EACH MAJOR DIABETIC COMPLICATION, EXAMINE SPECIFIC MECHANISMS AT PLAY, AND HIGHLIGHT POTENTIAL MECHANISMS TO PREVENT ENDOTHELIAL-TO-MESENCHYMAL TRANSITION IN EACH OF THE MAJOR CHRONIC COMPLICATIONS OF DIABETES. 2023 2 2163 27 EPIGENETIC MECHANISMS IN DIABETIC VASCULAR COMPLICATIONS. THERE HAS BEEN A RAPID INCREASE IN THE INCIDENCE OF DIABETES AS WELL THE ASSOCIATED VASCULAR COMPLICATIONS. BOTH GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN IMPLICATED IN THESE PATHOLOGIES. INCREASING EVIDENCE SUGGESTS THAT EPIGENETIC FACTORS PLAY A KEY ROLE IN THE COMPLEX INTERPLAY BETWEEN GENES AND THE ENVIRONMENT. ACTIONS OF MAJOR PATHOLOGICAL MEDIATORS OF DIABETES AND ITS COMPLICATIONS SUCH AS HYPERGLYCAEMIA, OXIDANT STRESS, AND INFLAMMATORY FACTORS CAN LEAD TO DYSREGULATED EPIGENETIC MECHANISMS THAT AFFECT CHROMATIN STRUCTURE AND GENE EXPRESSION. FURTHERMORE, PERSISTENCE OF THIS ALTERED STATE OF THE EPIGENOME MAY BE THE UNDERLYING MECHANISM CONTRIBUTING TO A 'METABOLIC MEMORY' THAT RESULTS IN CHRONIC INFLAMMATION AND VASCULAR DYSFUNCTION IN DIABETES EVEN AFTER ACHIEVING GLYCAEMIC CONTROL. FURTHER EXAMINATION OF EPIGENETIC MECHANISMS BY ALSO TAKING ADVANTAGE OF RECENTLY DEVELOPED NEXT-GENERATION SEQUENCING TECHNOLOGIES CAN PROVIDE NOVEL INSIGHTS INTO THE PATHOLOGY OF DIABETES AND ITS COMPLICATIONS AND LEAD TO THE DISCOVERY OF MUCH NEEDED NEW DRUG TARGETS FOR THESE DISEASES. IN THIS REVIEW, WE HIGHLIGHT THE ROLE OF EPIGENETICS IN DIABETES AND ITS VASCULAR COMPLICATIONS, AND RECENT TECHNOLOGICAL ADVANCES THAT HAVE SIGNIFICANTLY ACCELERATED THE FIELD. 2011 3 2491 29 EPIGENETICS AND CARDIOVASCULAR DISEASE IN DIABETES. TYPE 2 DIABETES HAS BECOME A MAJOR HEALTH ISSUE WORLDWIDE. CHRONIC HYPERGLYCEMIA INDUCES A LOW-GRADE INFLAMMATION THAT, ON TOP OF OTHER MECHANISMS, LEADS TO ENDOTHELIAL DYSFUNCTION. MOUNTING EVIDENCE SUGGESTS THAT DNA METHYLATION, POST-TRANSLATIONAL MODIFICATIONS OF HISTONES, AND LONG NON-CODING RNAS PLAY AN IMPORTANT ROLE IN THE INITIATION, MAINTENANCE, AND PROGRESSION OF BOTH MACRO- AND MICRO-VASCULAR COMPLICATIONS OF DIABETES. LONG-TERM EXPOSURE TO HYPERGLYCEMIA INDUCES EPIGENETIC CHANGES THAT COULD BECOME IRREVERSIBLE, A PHENOMENON KNOWN AS THE 'METABOLIC MEMORY.' WHETHER EPIGENETIC-BASED THERAPIES COULD BE USED TO SLOW OR LIMIT THE PROGRESSION OF CARDIOVASCULAR DISEASE REMAINS UNCLEAR. WHILE NON-CODING RNAS ARE CURRENTLY INVESTIGATED AS POTENTIAL BIOMARKERS THAT PREDICT DIABETIC CARDIOVASCULAR DISEASE INCIDENCE AND PROGRESSION, THEIR THERAPEUTIC ROLE IS ONLY HYPOTHETICAL. IN THIS REVIEW, WE HIGHLIGHT THE LATEST FINDINGS IN EXPERIMENTAL AND CLINICAL STUDIES RELEVANT TO EPIGENETICS AND CARDIOVASCULAR DISEASE IN DIABETES. 2015 4 2613 31 EPIGENETICS: DECIPHERING ITS ROLE IN DIABETES AND ITS CHRONIC COMPLICATIONS. 1. INCREASING EVIDENCE SUGGESTS THAT EPIGENETIC FACTORS MIGHT REGULATE THE COMPLEX INTERPLAY BETWEEN GENES AND THE ENVIRONMENT, AND AFFECT HUMAN DISEASES, SUCH AS DIABETES AND ITS COMPLICATIONS. 2. CLINICAL TRIALS HAVE UNDERSCORED THE LONG LASTING BENEFICIAL EFFECTS OF STRICT GLYCAEMIC CONTROL FOR REDUCING THE PROGRESSION OF DIABETIC COMPLICATIONS. THEY HAVE ALSO SHOWN THAT DIABETIC COMPLICATIONS, SUCH AS DIABETIC NEPHROPATHY, A CHRONIC KIDNEY DISORDER, CAN CONTINUE EVEN AFTER BLOOD GLUCOSE NORMALIZATION, SUGGESTING A METABOLIC MEMORY OF THE PRIOR GLYCAEMIC STATE. 3. DYSREGULATION OF EPIGENETIC POST-TRANSCRIPTIONAL MODIFICATIONS OF HISTONES IN CHROMATIN, INCLUDING HISTONE LYSINE METHYLATION, HAS BEEN IMPLICATED IN ABERRANT GENE REGULATION ASSOCIATED WITH THE PATHOLOGY OF DIABETES AND ITS COMPLICATIONS. GENOME-WIDE STUDIES HAVE SHOWN CELL-TYPE SPECIFIC CHANGES IN HISTONE METHYLATION PATTERNS UNDER DIABETIC CONDITIONS. IN ADDITION, STUDIES IN VASCULAR CELLS HAVE SHOWN LONG LASTING CHANGES IN EPIGENETIC MODIFICATIONS AT KEY INFLAMMATORY GENE PROMOTERS AFTER PRIOR EXPOSURE TO DIABETIC CONDITIONS, SUGGESTING A POSSIBLE MECHANISM FOR METABOLIC MEMORY. 4. RECENT STUDIES HAVE SHOWN ROLES FOR HISTONE METHYLATION, DNA METHYLATION, AS WELL AS MICRORNA IN DIABETIC NEPHROPATHY. WHETHER THESE EPIGENETIC FACTORS PLAY A ROLE IN METABOLIC MEMORY OF DIABETIC KIDNEY DISEASE IS LESS WELL UNDERSTOOD. 5. THE INCIDENCE OF DIABETES IS GROWING RAPIDLY, AS ALSO THE COST OF TREATING THE RESULTING COMPLICATIONS. A BETTER UNDERSTANDING OF METABOLIC MEMORY AND THE POTENTIAL INVOLVEMENT OF EPIGENETIC MECHANISMS IN THIS PHENOMENON COULD ENABLE THE DEVELOPMENT OF NEW THERAPEUTIC TARGETS FOR THE TREATMENT AND/OR PREVENTION OF SUSTAINED DIABETIC COMPLICATIONS. 2011 5 3156 30 GLYCEMIC MEMORIES AND THE EPIGENETIC COMPONENT OF DIABETIC NEPHROPATHY. A STRONG CASE FOR THE DEREGULATION OF EPIGENETIC CHROMATIN MODIFICATIONS IN THE DEVELOPMENT AND PROGRESSION OF VARIOUS CHRONIC COMPLICATIONS OF DIABETES HAS EMERGED FROM RECENT EXPERIMENTAL OBSERVATIONS. CLINICAL TRIALS OF TYPE 1 AND TYPE 2 DIABETES PATIENTS HIGHLIGHT THE IMPORTANCE OF EARLY AND INTENSIVE TREATMENT AND THE PROLONGED DAMAGE OF HYPERGLYCEMIA ON ORGANS SUCH AS THE KIDNEY. THE FUNCTIONAL RELATIONSHIP BETWEEN THE REGULATION OF CHROMATIN ARCHITECTURE AND PERSISTENT GENE EXPRESSION CHANGES CONFERRED BY PRIOR HYPERGLYCEMIA REPRESENTS AN IMPORTANT AVENUE OF INVESTIGATION FOR EXPLAINING DIABETIC NEPHROPATHY. WHILE SEVERAL STUDIES IMPLICATE EPIGENETIC CHANGES AT THE CHROMATIN TEMPLATE IN THE DEREGULATED GENE EXPRESSION ASSOCIATED WITH DIABETIC NEPHROPATHY, THE MOLECULAR DETERMINANTS OF METABOLIC MEMORY IN RENAL CELLS REMAIN POORLY UNDERSTOOD. THERE IS NOW STRONG EVIDENCE FROM EXPERIMENTAL ANIMALS AND CELL CULTURE OF PERSISTENT GLUCOSE-DRIVEN CHANGES IN VASCULAR ENDOTHELIAL GENE EXPRESSION THAT MAY ALSO HAVE RELEVANCE FOR THE MICROVASCULATURE OF THE KIDNEY. EXPLORATION OF EPIGENETIC MECHANISMS UNDERLYING THE HYPERGLYCEMIC CUE MEDIATING PERSISTENT TRANSCRIPTIONAL CHANGES IN RENAL CELLS HOLDS NOVEL THERAPEUTIC POTENTIAL FOR DIABETIC NEPHROPATHY. 2013 6 2190 30 EPIGENETIC MECHANISMS. THE INCIDENCE OF DIABETES AND RELATED COMPLICATIONS LIKE NEPHROPATHY IS GROWING RAPIDLY AND HAS BECOME A MAJOR HEALTH CARE ISSUE. CHANGES IN THE ENVIRONMENT AND NUTRITIONAL HABITS HAVE BEEN IMPLICATED AS MAJOR PLAYERS. FURTHERMORE, IT IS BECOMING INCREASINGLY CLEAR THAT EPIGENETIC FACTORS MAY MODULATE THE CONNECTIONS BETWEEN GENES AND THE ENVIRONMENT. WHILE DIABETES IN ITSELF IS TREATABLE TO A LARGE EXTENT, IT IS STILL ASSOCIATED WITH SIGNIFICANTLY INCREASED RISK FOR COMPLICATIONS INCLUDING CHRONIC KIDNEY AND CARDIOVASCULAR DISEASES. CURRENT TREATMENTS HAVE ADDED PREVENTATIVE APPROACHES SO AS TO AVOID FUTURE DIABETIC COMPLICATIONS. UNFORTUNATELY, DIABETIC PATIENTS ARE OFTEN PLAGUED WITH THE CONTINUED DEVELOPMENT OF VARIOUS COMPLICATIONS EVEN AFTER ACHIEVING GLUCOSE CONTROL. THIS HAS BEEN SUGGESTED TO BE ATTRIBUTABLE TO A MYSTERIOUS PHENOMENON TERMED 'METABOLIC MEMORY' OF THE PRIOR GLYCEMIC STATE. RECENT STUDIES HAVE SUGGESTED THAT EPIGENETIC CHANGES TO CHROMATIN CAN AFFECT GENE EXPRESSION IN RESPONSE TO VARIOUS STIMULI, AND CHANGES IN KEY BIOCHEMICAL PATHWAYS AND EPIGENETIC HISTONE AND DNA METHYLATION PATTERNS IN CHROMATIN HAVE BEEN OBSERVED IN A DIABETIC MILIEU. THESE ACCUMULATING DATA SUGGEST THAT METABOLIC OR HYPERGLYCEMIC MEMORY MAY BE DUE TO EPIGENETIC CHANGES IN SPECIFIC TARGET TISSUES ALTERING GENE EXPRESSION WITHOUT CHANGING THE GENETIC CODE ITSELF. WHILE THE GENETICS OF DIABETES HAS LONG BEEN THE FOCUS OF SCIENTIFIC RESEARCH, MUCH LESS IS KNOWN ABOUT THE ROLE OF EPIGENETICS AND THE RELATED MOLECULAR PATHWAYS THAT MIGHT AFFECT THE DEVELOPMENT OF DIABETES AND THE ASSOCIATED COMPLICATIONS. FURTHER STUDIES OF EPIGENETIC MECHANISMS ARE THEREFORE TIMELY AND COULD PROVIDE VALUABLE NEW INSIGHTS INTO THE PATHOLOGY OF DIABETIC COMPLICATIONS AND ALSO UNCOVER MUCH NEEDED NEW THERAPEUTIC TARGETS. 2011 7 4459 30 MOLECULAR MECHANISMS OF DIABETIC VASCULAR COMPLICATIONS. DIABETIC COMPLICATIONS ARE THE MAJOR CAUSES OF MORBIDITY AND MORTALITY IN PATIENTS WITH DIABETES. MICROVASCULAR COMPLICATIONS INCLUDE RETINOPATHY, NEPHROPATHY AND NEUROPATHY, WHICH ARE LEADING CAUSES OF BLINDNESS, END-STAGE RENAL DISEASE AND VARIOUS PAINFUL NEUROPATHIES; WHEREAS MACROVASCULAR COMPLICATIONS INVOLVE ATHEROSCLEROSIS RELATED DISEASES, SUCH AS CORONARY ARTERY DISEASE, PERIPHERAL VASCULAR DISEASE AND STROKE. DIABETIC COMPLICATIONS ARE THE RESULT OF INTERACTIONS AMONG SYSTEMIC METABOLIC CHANGES, SUCH AS HYPERGLYCEMIA, LOCAL TISSUE RESPONSES TO TOXIC METABOLITES FROM GLUCOSE METABOLISM, AND GENETIC AND EPIGENETIC MODULATORS. CHRONIC HYPERGLYCEMIA IS RECOGNIZED AS A MAJOR INITIATOR OF DIABETIC COMPLICATIONS. MULTIPLE MOLECULAR MECHANISMS HAVE BEEN PROPOSED TO MEDIATE HYPERGLYCEMIA'S ADVERSE EFFECTS ON VASCULAR TISSUES. THESE INCLUDE INCREASED POLYOL PATHWAY, ACTIVATION OF THE DIACYLGLYCEROL/PROTEIN KINASE C PATHWAY, INCREASED OXIDATIVE STRESS, OVERPRODUCTION AND ACTION OF ADVANCED GLYCATION END PRODUCTS, AND INCREASED HEXOSAMINE PATHWAY. IN ADDITION, THE ALTERATIONS OF SIGNAL TRANSDUCTION PATHWAYS INDUCED BY HYPERGLYCEMIA OR TOXIC METABOLITES CAN ALSO LEAD TO CELLULAR DYSFUNCTIONS AND DAMAGE VASCULAR TISSUES BY ALTERING GENE EXPRESSION AND PROTEIN FUNCTION. LESS STUDIED THAN THE TOXIC MECHANISMS, HYPERGLYCEMIA MIGHT ALSO INHIBIT THE ENDOGENOUS VASCULAR PROTECTIVE FACTORS SUCH AS INSULIN, VASCULAR ENDOTHELIAL GROWTH FACTOR, PLATELET-DERIVED GROWTH FACTOR AND ACTIVATED PROTEIN C, WHICH PLAY IMPORTANT ROLES IN MAINTAINING VASCULAR HOMEOSTASIS. THUS, EFFECTIVE THERAPIES FOR DIABETIC COMPLICATIONS NEED TO INHIBIT MECHANISMS INDUCED BY HYPERGLYCEMIA'S TOXIC EFFECTS AND ALSO ENHANCE THE ENDOGENOUS PROTECTIVE FACTORS. THE PRESENT REVIEW SUMMARIZES THESE MULTIPLE BIOCHEMICAL PATHWAYS ACTIVATED BY HYPERGLYCEMIA AND THE POTENTIAL THERAPEUTIC INTERVENTIONS THAT MIGHT PREVENT DIABETIC COMPLICATIONS. (J DIABETES INVEST, DOI: 10.1111/J.2040-1124.2010.00018.X, 2010). 2010 8 6377 31 THE ROLE OF NON-CODING RNAS IN DIABETIC NEPHROPATHY: POTENTIAL APPLICATIONS AS BIOMARKERS FOR DISEASE DEVELOPMENT AND PROGRESSION. DIABETIC NEPHROPATHY, A PROGRESSIVE KIDNEY DISEASE THAT DEVELOPS SECONDARY TO DIABETES, IS THE MAJOR CAUSE OF CHRONIC KIDNEY DISEASE IN DEVELOPED COUNTRIES, AND CONTRIBUTES SIGNIFICANTLY TO INCREASED MORBIDITY AND MORTALITY AMONG INDIVIDUALS WITH DIABETES. ALTHOUGH THE CAUSES OF DIABETIC NEPHROPATHY ARE NOT FULLY UNDERSTOOD, RECENT STUDIES DEMONSTRATE A ROLE FOR EPIGENETIC FACTORS IN THE DEVELOPMENT OF THE DISEASE. FOR EXAMPLE, NON-CODING RNA (NCRNA) MOLECULES, INCLUDING MICRORNAS (MIRNAS), HAVE BEEN SHOWN TO BE FUNCTIONALLY IMPORTANT IN MODULATING RENAL RESPONSE TO HYPERGLYCEMIA AND PROGRESSION OF DIABETIC NEPHROPATHY. CHARACTERIZATION OF MIRNA EXPRESSION IN DIABETIC NEPHROPATHY FROM STUDIES OF ANIMAL MODELS OF DIABETES, AND IN VITRO INVESTIGATIONS USING DIFFERENT TYPES OF KIDNEY CELLS ALSO SUPPORT THIS ROLE. THE GOAL OF THIS REVIEW, THEREFORE, IS TO SUMMARIZE THE CURRENT STATE OF KNOWLEDGE OF SPECIFIC NCRNAS INVOLVED IN THE DEVELOPMENT OF DIABETIC NEPHROPATHY, WITH A FOCUS ON THE POTENTIAL ROLE OF MIRNAS TO SERVE AS SENSITIVE, NON-INVASIVE BIOMARKERS OF KIDNEY DISEASE AND PROGRESSION. NON-CODING RNAS ARE CURRENTLY RECOGNIZED AS POTENTIALLY IMPORTANT REGULATORS OF GENES INVOLVED IN PROCESSES RELATED TO THE DEVELOPMENT OF DIABETIC NEPHROPATHY, AND AS SUCH, REPRESENT VIABLE TARGETS FOR BOTH CLINICAL DIAGNOSTIC STRATEGIES AND THERAPEUTIC INTERVENTION. 2013 9 6341 29 THE ROLE OF EPIGENETIC MODIFICATIONS IN LATE COMPLICATIONS IN TYPE 1 DIABETES. TYPE 1 DIABETES IS A CHRONIC AUTOIMMUNE DISEASE IN WHICH THE DESTRUCTION OF PANCREATIC BETA CELLS LEADS TO HYPERGLYCEMIA. THE PREVENTION OF HYPERGLYCEMIA IS VERY IMPORTANT TO AVOID OR AT LEAST POSTPONE THE DEVELOPMENT OF MICRO- AND MACROVASCULAR COMPLICATIONS, ALSO KNOWN AS LATE COMPLICATIONS. THESE INCLUDE DIABETIC RETINOPATHY, CHRONIC RENAL FAILURE, DIABETIC NEUROPATHY, AND CARDIOVASCULAR DISEASES. THE IMPACT OF LONG-TERM HYPERGLYCEMIA HAS BEEN SHOWN TO PERSIST LONG AFTER THE NORMALIZATION OF BLOOD GLUCOSE LEVELS, A PHENOMENON KNOWN AS METABOLIC MEMORY. IT IS BELIEVED THAT EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, AND MICRORNAS, PLAY AN IMPORTANT ROLE IN METABOLIC MEMORY. THE AIM OF THIS REVIEW IS TO ADDRESS THE IMPACT OF LONG-TERM HYPERGLYCEMIA ON EPIGENETIC MARKS IN LATE COMPLICATIONS OF TYPE 1 DIABETES. 2022 10 2965 34 GENETIC AND EPIGENETIC MODIFICATIONS IN THE PATHOGENESIS OF DIABETIC RETINOPATHY: A MOLECULAR LINK TO REGULATE GENE EXPRESSION. INTENSIFICATION IN THE FREQUENCY OF DIABETES AND THE ASSOCIATED VASCULAR COMPLICATIONS HAS BEEN A ROOT CAUSE OF BLINDNESS AND VISUAL IMPAIRMENT WORLDWIDE. ONE SUCH VASCULAR COMPLICATION WHICH HAS BEEN THE PROMINENT CAUSE OF BLINDNESS; RETINAL VASCULATURE, NEURONAL AND GLIAL ABNORMALITIES IS DIABETIC RETINOPATHY (DR), A CHRONIC COMPLICATED OUTCOME OF TYPE 1 AND TYPE 2 DIABETES. IT HAS ALSO BECOME CLEAR THAT "GENETIC" VARIATIONS IN POPULATION ALONE CAN'T EXPLAIN THE DEVELOPMENT AND PROGRESSION OF DIABETES AND ITS COMPLICATIONS INCLUDING DR. DR EXPERIENCES ENGAGEMENT OF FOREMOST MEDIATORS OF DIABETES SUCH AS HYPERGLYCEMIA, OXIDANT STRESS, AND INFLAMMATORY FACTORS THAT LEAD TO THE DYSREGULATION OF "EPIGENETIC" MECHANISMS INVOLVING HISTONE ACETYLATION AND HISTONE AND DNA METHYLATION, CHROMATIN REMODELING AND EXPRESSION OF A COMPLEX SET OF STRESS-REGULATED AND DISEASE-ASSOCIATED GENES. IN ADDITION, BOTH ELEVATED GLUCOSE CONCENTRATION AND INSULIN RESISTANCE LEAVE A ROBUST EFFECT ON EPIGENETIC REPROGRAMMING OF THE ENDOTHELIAL CELLS TOO, SINCE ENDOTHELIUM ASSOCIATED WITH THE EYE AIDS IN MAINTAINING THE VASCULAR HOMEOSTASIS. FURTHERMORE, SEVERAL STUDIES CONDUCTED ON THE DISEASE SUGGEST THAT THE MODIFICATIONS OF THE EPIGENOME MIGHT BE THE FUNDAMENTAL MECHANISM(S) FOR THE PROPOSED METABOLIC MEMORY' RESULTING INTO PROLONGED GENE EXPRESSION FOR INFLAMMATION AND CELLULAR DYSFUNCTION EVEN AFTER ATTAINING THE GLYCEMIC CONTROL IN DIABETICS. HENCEFORTH, THE PRESENT REVIEW FOCUSES ON THE ASPECTS OF GENETIC AND EPIGENETIC ALTERATIONS IN GENES SUCH AS VASCULAR ENDOTHELIAL GROWTH FACTOR AND ALDOSE REDUCTASE CONSIDERED BEING ASSOCIATED WITH DR. IN ADDITION, WE DISCUSS BRIEFLY THE ROLE OF THE THIOREDOXIN-INTERACTING PROTEIN TXNIP, WHICH IS STRONGLY INDUCED BY HIGH GLUCOSE AND DIABETES, IN CELLULAR OXIDATIVE STRESS AND MITOCHONDRIAL DYSFUNCTION POTENTIALLY LEADING TO CHROMATIN REMODELING AND OCULAR COMPLICATIONS OF DIABETES. THE IDENTIFICATION OF DISEASE-ASSOCIATED GENES AND THEIR EPIGENETIC REGULATIONS WILL LEAD TO POTENTIAL NEW DRUGS AND GENE THERAPIES AS WELL AS PERSONALIZED MEDICINE TO PREVENT OR SLOW DOWN THE PROGRESSION OF DR. 2016 11 4433 27 MOLECULAR COMPLEXITIES UNDERLYING THE VASCULAR COMPLICATIONS OF DIABETES MELLITUS - A COMPREHENSIVE REVIEW. DIABETES IS A CHRONIC DISEASE, CHARACTERIZED BY HYPERGLYCEMIA, WHICH REFERS TO THE ELEVATED LEVELS OF GLUCOSE IN THE BLOOD, DUE TO THE INABILITY OF THE BODY TO PRODUCE OR USE INSULIN EFFECTIVELY. CHRONIC HYPERGLYCEMIA LEVELS LEAD TO MACROVASCULAR AND MICROVASCULAR COMPLICATIONS. THE MACROVASCULAR COMPLICATIONS CONSIST OF PERIPHERAL ARTERY DISEASE (PAD), CARDIOVASCULAR DISEASES (CVD) AND CEREBROVASCULAR DISEASES, WHILE THE MICROVASCULAR COMPLICATIONS COMPRISE OF DIABETIC MICROANGIOPATHY, DIABETIC NEPHROPATHY, DIABETIC RETINOPATHY AND DIABETIC NEUROPATHY. VASCULAR ENDOTHELIAL DYSFUNCTION PLAYS A CRUCIAL ROLE IN MEDIATING BOTH MACROVASCULAR AND MICROVASCULAR COMPLICATIONS UNDER HYPERGLYCEMIC CONDITIONS. IN DIABETIC MICROVASCULATURE, THE INTRACELLULAR HYPERGLYCEMIA CAUSES DAMAGE TO THE VASCULAR ENDOTHELIUM THROUGH - (I) ACTIVATION OF FOUR BIOCHEMICAL PATHWAYS, NAMELY THE POLYOL PATHWAY, PROTEIN KINASE C (PKC) PATHWAY, ADVANCED GLYCATION END PRODUCTS (AGE) PATHWAY AND HEXOSAMINE PATHWAY, ALL OF WHICH COMMUTES GLUCOSE AND ITS INTERMEDIATES LEADING TO OVERPRODUCTION OF REACTIVE OXYGEN SPECIES, (II) DYSREGULATION OF GROWTH FACTORS AND CYTOKINES, (III) EPIGENETIC CHANGES WHICH CONCERN THE CHANGES IN DNA AS A RESPONSE TO INTRACELLULAR CHANGES, AND (IV) ABNORMALITIES IN NON-CODING RNAS, SPECIFICALLY MICRORNAS. THIS REVIEW WILL FOCUS ON GAINING AN UNDERSTANDING OF THE MOLECULAR COMPLEXITIES UNDERLYING THE VASCULAR COMPLICATIONS IN DIABETES MELLITUS, TO INCREASE OUR UNDERSTANDING TOWARDS THE DEVELOPMENT OF NEW MECHANISTIC THERAPEUTIC STRATEGIES TO PREVENT OR TREAT DIABETES-INDUCED VASCULAR COMPLICATIONS. 2020 12 2953 20 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 13 4151 25 MECHANISTIC INSIGHTS INTO GLUCOSE INDUCED VASCULAR EPIGENETIC REPROGRAMMING IN TYPE 2 DIABETES. ENDOTHELIAL CELLS LINING THE VESSEL WALL REGULATE THROMBOSIS, INFLAMMATION, ANGIOGENESIS AND BALANCE BETWEEN VASOCONSTRICTION AND VASODILATORY FUNCTIONS. SUBJECTS WITH TYPE 2 DIABETES (T2D) ACCRUE A MULTITUDE OF VASCULOPATHIES CAUSING HIGH MORBIDITY AND MORTALITY ACROSS THE GLOBE. HIGH GLUCOSE AND ITS MODIFIED PRODUCTS SUCH AS ADVANCED GLYCATION END PRODUCTS LEAD TO A BIDIRECTIONAL ACTIVATION OF INFLAMMATORY AND EPIGENETIC MACHINERY IN ENDOTHELIAL CELLS RESULTING IN A STATE OF CHRONIC INFLAMMATORY MILIEU AND EVENTUALLY INTO VASCULAR COMPLICATIONS. CLINICAL AND EXPERIMENTAL STUDIES HAVE SHOWN THAT DESPITE THE THERAPEUTIC NORMALIZATION OF GLUCOSE LEVELS, SUBJECTS WITH T2D OVERT TO VASCULAR COMPLICATIONS THROUGH A PROCESS OF METABOLIC MEMORY WHICH IS ASSOCIATED WITH SIGNIFICANT EPIGENETIC REPROGRAMMING IN ENDOTHELIAL CELLS. IN NORMAL PHYSIOLOGICAL CONDITIONS, VASCULAR ENDOTHELIAL CELLS DISPLAY A QUIESCENT STATE AND ONLY IN RESPONSE TO EITHER PHYSIOLOGICAL OR PATHOLOGICAL RESPONSE, ENDOTHELIAL CELLS UNDERGO PROLIFERATION. DURING THE PATHOGENESIS OF T2D, DNA METHYLATION, HISTONE MARKS AND NON-CODING RNAS FORMING THE EPIGENETIC LANDSCAPE ARE DYSREGULATED AND ACTIVATE QUIESCENT ENDOTHELIAL CELLS TO SWITCH ON A DIVERSE SET OF MOLECULAR ACTIVITIES AND LEAD TO ENDOTHELIAL DYSFUNCTION. IN THE PRESENT REVIEW, WE PROVIDE A COMPREHENSIVE OVERVIEW OF HOW HYPERGLYCEMIA IN T2D REPROGRAMS ENDOTHELIAL EPIGENOME AND LEAD TO FUNCTIONAL CONSEQUENCES IN THE PATHOGENESIS OF VASCULAR COMPLICATIONS. FURTHER, WE CATALOGUE AND DISCUSS EPI-DRUGS THAT MAY AMELIORATE ENDOTHELIAL FUNCTIONS DURING T2D. 2022 14 2171 26 EPIGENETIC MECHANISMS IN THE PATHOGENESIS OF DIABETIC FOOT ULCERS. THE INCIDENCE OF DIABETES MELLITUS, A CHRONIC METABOLIC DISEASE ASSOCIATED WITH BOTH PREDISPOSING GENETIC AND ENVIRONMENTAL FACTORS, IS INCREASING GLOBALLY. AS A RESULT, IT IS EXPECTED THAT THERE WILL ALSO BE AN INCREASING INCIDENCE OF DIABETIC COMPLICATIONS WHICH ARISE AS A RESULT OF POOR GLYCEMIC CONTROL. COMPLICATIONS INCLUDE CARDIOVASCULAR DISEASES, NEPHROPATHY, RETINOPATHY AND DIABETIC FOOT ULCERS. THE FINDINGS OF SEVERAL MAJOR CLINICAL TRIALS HAVE IDENTIFIED THAT DIABETIC COMPLICATIONS MAY ARISE EVEN AFTER MANY YEARS OF PROPER GLYCEMIC CONTROL. THIS HAS LED TO THE CONCEPT OF PERSISTENT EPIGENETIC CHANGES. VARIOUS EPIGENETIC MECHANISMS HAVE BEEN IDENTIFIED AS IMPORTANT CONTRIBUTORS TO THE PATHOGENESIS OF DIABETES AND DIABETIC COMPLICATIONS. THE AIM OF THIS REVIEW IS TO PROVIDE AN OVERVIEW OF THE PATHOBIOLOGY OF TYPE 2 DIABETES WITH AN EMPHASIS ON COMPLICATIONS, PARTICULARLY DIABETIC FOOT ULCERS. AN OVERVIEW OF EPIGENETIC MECHANISMS IS PROVIDED AND THE FOCUS IS ON THE EMERGING EVIDENCE FOR ABERRANT EPIGENETIC MECHANISMS IN DIABETIC FOOT ULCERS. 2012 15 2009 21 EPIGENETIC BASIS OF DIABETIC VASCULOPATHY. TYPE 2 DIABETES MELLITUS (T2DM) CAUSES PERIPHERAL VASCULAR DISEASE BECAUSE OF WHICH SEVERAL BLOOD-BORNE FACTORS, INCLUDING VITAL NUTRIENTS FAIL TO REACH THE AFFECTED TISSUE. TISSUE EPIGENOME IS SENSITIVE TO CHRONIC HYPERGLYCEMIA AND IS KNOWN TO CAUSE PATHOGENESIS OF MICRO- AND MACROVASCULAR COMPLICATIONS. THESE VASCULAR COMPLICATIONS OF T2DM MAY PERPETUATE THE ONSET OF ORGAN DYSFUNCTION. THE BURDEN OF DIABETES IS PRIMARILY BECAUSE OF A WIDE RANGE OF COMPLICATIONS OF WHICH NONHEALING DIABETIC ULCERS REPRESENT A MAJOR COMPONENT. THUS, IT IS IMPERATIVE THAT CURRENT RESEARCH HELP RECOGNIZE MORE EFFECTIVE METHODS FOR THE DIAGNOSIS AND MANAGEMENT OF EARLY VASCULAR INJURIES. THIS REVIEW ADDRESSES THE SIGNIFICANCE OF EPIGENETIC PROCESSES SUCH AS DNA METHYLATION AND HISTONE MODIFICATIONS IN THE EVOLUTION OF MACROVASCULAR AND MICROVASCULAR COMPLICATIONS OF T2DM. 2022 16 2195 26 EPIGENETIC MODIFICATION MECHANISMS INVOLVED IN INFLAMMATION AND FIBROSIS IN RENAL PATHOLOGY. THE GROWING INCIDENCE OF OBESITY, HYPERTENSION, AND DIABETES, COUPLED WITH THE AGING OF THE POPULATION, IS INCREASING THE PREVALENCE OF RENAL DISEASES IN OUR SOCIETY. CHRONIC KIDNEY DISEASE (CKD) IS CHARACTERIZED BY PERSISTENT INFLAMMATION, FIBROSIS, AND LOSS OF RENAL FUNCTION LEADING TO END-STAGE RENAL DISEASE. NOWADAYS, CKD TREATMENT HAS LIMITED EFFECTIVENESS UNDERSCORING THE IMPORTANCE OF THE DEVELOPMENT OF INNOVATIVE THERAPEUTIC OPTIONS. RECENT STUDIES HAVE IDENTIFIED HOW EPIGENETIC MODIFICATIONS PARTICIPATE IN THE SUSCEPTIBILITY TO CKD AND HAVE EXPLAINED HOW THE ENVIRONMENT INTERACTS WITH THE RENAL CELL EPIGENOME TO CONTRIBUTE TO RENAL DAMAGE. EPIGENETIC MECHANISMS REGULATE CRITICAL PROCESSES INVOLVED IN GENE REGULATION AND DOWNSTREAM CELLULAR RESPONSES. THE MOST RELEVANT EPIGENETIC MODIFICATIONS THAT PLAY A CRITICAL ROLE IN RENAL DAMAGE INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND CHANGES IN MIRNA LEVELS. IMPORTANTLY, THESE EPIGENETIC MODIFICATIONS ARE REVERSIBLE AND, THEREFORE, A SOURCE OF POTENTIAL THERAPEUTIC TARGETS. HERE, WE WILL EXPLAIN HOW EPIGENETIC MECHANISMS MAY REGULATE ESSENTIAL PROCESSES INVOLVED IN RENAL PATHOLOGY AND HIGHLIGHT SOME POSSIBLE EPIGENETIC THERAPEUTIC STRATEGIES FOR CKD TREATMENT. 2018 17 4195 33 METABOLIC MEMORY: MECHANISMS AND IMPLICATIONS FOR DIABETIC RETINOPATHY. CHRONIC HYPERGLYCEMIA OF DIABETES LEADS TO MICROVASCULAR COMPLICATIONS THAT SEVERELY IMPACT QUALITY OF LIFE. DIABETIC RETINOPATHY (DR) MAY BE THE MOST COMMON OF THESE AND IS A LEADING CAUSE OF VISUAL IMPAIRMENT AND BLINDNESS AMONG WORKING AGE ADULTS IN DEVELOPED NATIONS. MANY LARGE-SCALE TYPE 1 AND TYPE 2 DIABETES CLINICAL TRIALS HAVE DEMONSTRATED THAT EARLY INTENSIVE GLYCEMIC CONTROL CAN REDUCE THE INCIDENCE AND PROGRESSION OF MICRO AND MACROVASCULAR COMPLICATIONS. ON THE OTHER HAND, EPIDEMIOLOGICAL AND PROSPECTIVE DATA HAVE REVEALED THAT THE STRESSORS OF DIABETIC VASCULATURE PERSIST BEYOND THE POINT WHEN GLYCEMIC CONTROL HAS BEEN ACHIEVED. THESE KINDS OF PERSISTENT ADVERSE EFFECTS OF HYPERGLYCEMIA ON THE DEVELOPMENT AND PROGRESSION OF COMPLICATIONS HAS BEEN DEFINED AS "METABOLIC MEMORY", AND OXIDATIVE STRESS, ADVANCED GLYCATION END PRODUCTS AND EPIGENETIC CHANGES HAVE BEEN IMPLICATED IN THE PROCESS. RECENT STUDIES HAVE INDICATED THAT SUCH "HYPERGLYCEMIC MEMORY" MAY ALSO INFLUENCE DR, SUGGESTING THAT MANIPULATION OF HYPERGLYCEMIC MEMORY MAY PROVE A BENEFICIAL APPROACH TO PREVENTION AND TREATMENT. THIS REVIEW SUMMARIZES THE EVIDENCE FROM DR-RELATED CLINICAL TRIALS AND MECHANISTIC STUDIES TO INVESTIGATE THE SIGNIFICANCE OF METABOLIC MEMORY IN DR AND UNDERSTAND ITS POTENTIAL AS A TARGET OF MOLECULAR THERAPEUTICS AIMED AT REVERSING HYPERGLYCEMIC MEMORY. 2012 18 6067 32 THE DIABETES MELLITUS-ATHEROSCLEROSIS CONNECTION: THE ROLE OF LIPID AND GLUCOSE METABOLISM AND CHRONIC INFLAMMATION. DIABETES MELLITUS COMPRISES A GROUP OF CARBOHYDRATE METABOLISM DISORDERS THAT SHARE A COMMON MAIN FEATURE OF CHRONIC HYPERGLYCEMIA THAT RESULTS FROM DEFECTS OF INSULIN SECRETION, INSULIN ACTION, OR BOTH. INSULIN IS AN IMPORTANT ANABOLIC HORMONE, AND ITS DEFICIENCY LEADS TO VARIOUS METABOLIC ABNORMALITIES IN PROTEINS, LIPIDS, AND CARBOHYDRATES. ATHEROSCLEROSIS DEVELOPS AS A RESULT OF A MULTISTEP PROCESS ULTIMATELY LEADING TO CARDIOVASCULAR DISEASE ASSOCIATED WITH HIGH MORBIDITY AND MORTALITY. ALTERATION OF LIPID METABOLISM IS A RISK FACTOR AND CHARACTERISTIC FEATURE OF ATHEROSCLEROSIS. POSSIBLE LINKS BETWEEN THE TWO CHRONIC DISORDERS DEPENDING ON ALTERED METABOLIC PATHWAYS HAVE BEEN INVESTIGATED IN NUMEROUS STUDIES. IT WAS SHOWN THAT BOTH TYPES OF DIABETES MELLITUS CAN ACTUALLY INDUCE ATHEROSCLEROSIS DEVELOPMENT OR FURTHER ACCELERATE ITS PROGRESSION. ELEVATED GLUCOSE LEVEL, DYSLIPIDEMIA, AND OTHER METABOLIC ALTERATIONS THAT ACCOMPANY THE DISEASE DEVELOPMENT ARE TIGHTLY INVOLVED IN THE PATHOGENESIS OF ATHEROSCLEROSIS AT ALMOST EVERY STEP OF THE ATHEROGENIC PROCESS. CHRONIC INFLAMMATION IS CURRENTLY CONSIDERED AS ONE OF THE KEY FACTORS IN ATHEROSCLEROSIS DEVELOPMENT AND IS PRESENT STARTING FROM THE EARLIEST STAGES OF THE PATHOLOGY INITIATION. IT MAY ALSO BE REGARDED AS ONE OF THE POSSIBLE LINKS BETWEEN ATHEROSCLEROSIS AND DIABETES MELLITUS. HOWEVER, THE DATA AVAILABLE SO FAR DO NOT ALLOW FOR DEVELOPING EFFECTIVE ANTI-INFLAMMATORY THERAPEUTIC STRATEGIES THAT WOULD STOP ATHEROSCLEROTIC LESION PROGRESSION OR INDUCE LESION REDUCTION. IN THIS REVIEW, WE SUMMARIZE THE MAIN ASPECTS OF DIABETES MELLITUS THAT POSSIBLY AFFECT THE ATHEROGENIC PROCESS AND ITS RELATIONSHIP WITH CHRONIC INFLAMMATION. WE ALSO DISCUSS THE ESTABLISHED PATHOPHYSIOLOGICAL FEATURES THAT LINK ATHEROSCLEROSIS AND DIABETES MELLITUS, SUCH AS OXIDATIVE STRESS, ALTERED PROTEIN KINASE SIGNALING, AND THE ROLE OF CERTAIN MIRNA AND EPIGENETIC MODIFICATIONS. 2020 19 4336 25 MICRORNAS: THE UNDERLYING MEDIATORS OF PATHOGENETIC PROCESSES IN VASCULAR COMPLICATIONS OF DIABETES. DIABETES MELLITUS CAUSES CHRONIC COMPLICATIONS PRIMARILY AFFECTING THE VASCULATURE OF VARIOUS ORGANS, RISKING PATIENTS FOR RENAL FAILURE, VISION LOSS AND HEART FAILURE. A NEWLY DISCOVERED CLASS OF MOLECULES, MICRORNAS, MAY BE IMPORTANT IN THE GENESIS OF THESE PATHOLOGIC PROCESSES. MICRORNAS REGULATE GENE EXPRESSION AT THE POST-TRANSCRIPTIONAL LEVEL BY INHIBITING TARGET MESSENGER RNA TRANSLATION. IN DISEASE STATES, HOWEVER, THE EXPRESSION OF MICRORNAS OFTEN IS ALTERED, RESULTING IN FURTHER ALTERED EXPRESSION (MOSTLY OVEREXPRESSION) OF DOWNSTREAM TARGET GENES. INTERESTINGLY, RESTORING MICRORNA EXPRESSION TO NORMAL LEVELS CAN CORRECT DOWNSTREAM EFFECTS AND PREVENT DIABETES-ASSOCIATED CHANGES. INVESTIGATIONS INTO MICRORNA INVOLVED IN VARIOUS PATHOGENETIC PROCESSES MEDIATING DIABETIC NEPHROPATHY, RETINOPATHY AND CARDIOMYOPATHY ARE HIGHLIGHTED IN THIS REVIEW. FUTURE DIRECTIONS OF MICRORNA IN THERAPEUTICS AND DIAGNOSTICS ARE ALSO DISCUSSED. IT IS OUR INTENT TO HELP THE READER APPRECIATE THE DIVERSE INTERACTIONS MICRORNAS HAVE IN CELLULAR SIGNALLING AND HOW UNDERSTANDING EPIGENETIC ELEMENTS, SUCH AS MICRORNAS, POTENTIALLY CAN YIELD NEW THERAPEUTIC STRATEGIES. 2013 20 607 22 BEYOND GENETICS: EPIGENETIC CODE IN CHRONIC KIDNEY DISEASE. EPIGENETICS REFERS TO A HERITABLE CHANGE IN THE PATTERN OF GENE EXPRESSION THAT IS MEDIATED BY A MECHANISM SPECIFICALLY NOT DUE TO ALTERATIONS IN THE PRIMARY NUCLEOTIDE SEQUENCE. WELL-KNOWN EPIGENETIC MECHANISMS ENCOMPASS DNA METHYLATION, CHROMATIN REMODELING (HISTONE MODIFICATIONS), AND RNA INTERFERENCE. FUNCTIONALLY, EPIGENETICS PROVIDES AN EXTRA LAYER OF TRANSCRIPTIONAL CONTROL AND PLAYS A CRUCIAL ROLE IN NORMAL PHYSIOLOGICAL DEVELOPMENT, AS WELL AS IN PATHOLOGICAL CONDITIONS. ABERRANT DNA METHYLATION IS IMPLICATED IN IMMUNE DYSFUNCTION, INFLAMMATION, AND INSULIN RESISTANCE. EPIGENETIC CHANGES MAY BE RESPONSIBLE FOR 'METABOLIC MEMORY' AND DEVELOPMENT OF MICRO- AND MACROVASCULAR COMPLICATIONS OF DIABETES. MICRORNAS ARE CRITICAL IN THE MAINTENANCE OF GLOMERULAR HOMEOSTASIS AND HENCE RNA INTERFERENCE MAY BE IMPORTANT IN THE PROGRESSION OF RENAL DISEASE. RECENT STUDIES HAVE SHOWN THAT EPIGENETIC MODIFICATIONS ORCHESTRATE THE EPITHELIAL-MESENCHYMAL TRANSITION AND EVENTUALLY FIBROSIS OF THE RENAL TISSUE. OXIDATIVE STRESS, INFLAMMATION, HYPERHOMOCYSTEINEMIA, AND UREMIC TOXINS COULD INDUCE EPIMUTATIONS IN CHRONIC KIDNEY DISEASE. EPIGENETIC ALTERATIONS ARE ASSOCIATED WITH INFLAMMATION AND CARDIOVASCULAR DISEASE IN PATIENTS WITH CHRONIC KIDNEY DISEASE. REVERSIBLE NATURE OF THE EPIGENETIC CHANGES GIVES A UNIQUE OPPORTUNITY TO HALT OR EVEN REVERSE THE DISEASE PROCESS THROUGH TARGETED THERAPEUTIC STRATEGIES. 2011