1 3859 138 ISLET STRUCTURE AND FUNCTION IN THE GK RAT. TYPE 2 DIABETES MELLITUS (T2D) ARISES WHEN THE ENDOCRINE PANCREAS FAILS TO SECRETE SUFFICIENT INSULIN TO COPE WITH THE METABOLIC DEMAND BECAUSE OF BETA-CELL SECRETORY DYSFUNCTION AND/OR DECREASED BETA-CELL MASS. DEFINING THE NATURE OF THE PANCREATIC ISLET DEFECTS PRESENT IN T2D HAS BEEN DIFFICULT, IN PART BECAUSE HUMAN ISLETS ARE INACCESSIBLE FOR DIRECT STUDY. THIS REVIEW IS AIMED TO ILLUSTRATE TO WHAT EXTENT THE GOTO-KAKIZAKI RAT, ONE OF THE BEST CHARACTERIZED ANIMAL MODELS OF SPONTANEOUS T2D, HAS PROVED TO BE A VALUABLE TOOL OFFERING SUFFICIENT COMMONALITIES TO STUDY THIS ASPECT. A COMPREHENSIVE COMPENDIUM OF THE MULTIPLE FUNCTIONAL GK ISLET ABNORMALITIES SO FAR IDENTIFIED IS PROPOSED IN THIS PERSPECTIVE. THE PATHOGENESIS OF DEFECTIVE BETA-CELL NUMBER AND FUNCTION IN THE GK MODEL IS ALSO DISCUSSED. IT IS PROPOSED THAT THE DEVELOPMENT OF T2D IN THE GK MODEL RESULTS FROM THE COMPLEX INTERACTION OF MULTIPLE EVENTS: (I) SEVERAL SUSCEPTIBILITY LOCI CONTAINING GENES RESPONSIBLE FOR SOME DIABETIC TRAITS (DISTINCT LOCI ENCODING IMPAIRMENT OF BETA-CELL METABOLISM AND INSULIN EXOCYTOSIS, BUT NO QUANTITATIVE TRAIT LOCUS FOR DECREASED BETA-CELL MASS); (II) GESTATIONAL METABOLIC IMPAIRMENT INDUCING AN EPIGENETIC PROGRAMMING OF THE OFFSPRING PANCREAS (DECREASED BETA-CELL NEOGENESIS AND PROLIFERATION) TRANSMITTED OVER GENERATIONS; AND (III) LOSS OF BETA-CELL DIFFERENTIATION RELATED TO CHRONIC EXPOSURE TO HYPERGLYCAEMIA/HYPERLIPIDAEMIA, ISLET INFLAMMATION, ISLET OXIDATIVE STRESS, ISLET FIBROSIS AND PERTURBED ISLET VASCULATURE. 2010 2 4433 26 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 3 1302 65 DEFECTIVE FUNCTIONAL BETA-CELL MASS AND TYPE 2 DIABETES IN THE GOTO-KAKIZAKI RAT MODEL. INCREASING EVIDENCE INDICATES THAT DECREASED FUNCTIONAL BETA-CELL MASS IS THE HALLMARK OF TYPE 2 DIABETES MELLITUS. THEREFORE, THE DEBATE FOCUSES ON THE POSSIBLE MECHANISMS RESPONSIBLE FOR ABNORMAL ISLET MICROENVIRONMENT, DECREASED BETA-CELL NUMBER, IMPAIRED BETA-CELL FUNCTION AND THEIR MULTIFACTORIAL ETIOLOGIES. THE INFORMATION AVAILABLE ON THE GOTO-KAKIZAKI/PAR RAT LINE, ONE OF THE BEST CHARACTERIZED ANIMAL MODELS OF SPONTANEOUS TYPE 2 DIABETES MELLITUS, ARE REVIEWED IN SUCH A PERSPECTIVE. WE PROPOSE THAT THE DEFECTIVE BETA-CELL MASS AND FUNCTION IN THE GOTO-KAKIZAKI/PAR MODEL REFLECT THE COMPLEX INTERACTIONS OF MULTIPLE PATHOGENIC PLAYERS, INCLUDING SEVERAL INDEPENDENT LOCI CONTAINING GENES RESPONSIBLE FOR SOME DIABETIC TRAITS (BUT NOT DECREASED BETA-CELL MASS), GESTATIONAL METABOLIC IMPAIRMENT INDUCING AN EPIGENETIC PROGRAMMING OF THE PANCREAS (DECREASED BETA-CELL NEOGENESIS), WHICH IS TRANSMITTED TO THE NEXT GENERATION, AND LOSS OF BETA-CELL DIFFERENTIATION DUE TO CHRONIC EXPOSURE TO HYPERGLYCEMIA, INFLAMMATORY MEDIATORS, OXIDATIVE STRESS AND PERTURBED ISLET MICROARCHITECTURE. 2007 4 6163 84 THE GK RAT BETA-CELL: A PROTOTYPE FOR THE DISEASED HUMAN BETA-CELL IN TYPE 2 DIABETES? INCREASING EVIDENCE INDICATES THAT DECREASED FUNCTIONAL BETA-CELL MASS IS THE HALLMARK OF TYPE 2 DIABETES (T2D) MELLITUS. NOWADAYS, THE DEBATE FOCUSES ON THE POSSIBLE MECHANISMS RESPONSIBLE FOR ABNORMAL ISLET MICROENVIRONMENT, DECREASED BETA-CELL NUMBER, IMPAIRED BETA-CELL FUNCTION, AND THEIR MULTIFACTORIAL AETIOLOGIES. THIS REVIEW IS AIMED TO ILLUSTRATE TO WHAT EXTEND THE GOTO-KAKIZAKI RAT, ONE OF THE BEST CHARACTERIZED ANIMAL MODELS OF SPONTANEOUS T2D, HAS PROVED BE A VALUABLE TOOL OFFERING SUFFICIENT COMMONALITIES TO STUDY THESE ASPECTS. WE PROPOSE THAT THE DEFECTIVE BETA-CELL MASS AND FUNCTION IN THE GK MODEL REFLECT THE COMPLEX INTERACTIONS OF MULTIPLE PATHOGENIC PLAYERS: (I) SEVERAL INDEPENDENT LOCI CONTAINING GENES RESPONSIBLE FOR SOME DIABETIC TRAITS (BUT NOT DECREASED BETA-CELL MASS); (II) GESTATIONAL METABOLIC IMPAIRMENT INDUCING AN EPIGENETIC PROGRAMMING OF THE PANCREAS (DECREASED BETA-CELL NEOGENESIS AND/OR PROLIFERATION) WHICH IS TRANSMITTED TO THE NEXT GENERATION; AND (III) LOSS OF BETA-CELL DIFFERENTIATION DUE TO CHRONIC EXPOSURE TO HYPERGLYCEMIA/HYPERLIPIDEMIA, INFLAMMATORY MEDIATORS, OXIDATIVE STRESS AND TO PERTURBED ISLET MICROARCHITECTURE. 2009 5 4459 33 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 6 5250 64 PROGRAMMED DISORDERS OF BETA-CELL DEVELOPMENT AND FUNCTION AS ONE CAUSE FOR TYPE 2 DIABETES? THE GK RAT PARADIGM. NOW THAT THE REDUCTION IN BETA-MASS HAS BEEN CLEARLY ESTABLISHED IN HUMANS WITH TYPE 2 DIABETES MELLITUS (T2DM) 1-4, THE DEBATE FOCUSES ON THE POSSIBLE MECHANISMS RESPONSIBLE FOR DECREASED BETA-CELL NUMBER AND IMPAIRED BETA-CELL FUNCTION AND THEIR MULTIFACTORIAL ETIOLOGY. APPROPRIATE INBRED RODENT MODELS ARE ESSENTIAL TOOLS FOR IDENTIFICATION OF GENES AND ENVIRONMENTAL FACTORS THAT INCREASE THE RISK OF ABNORMAL BETA-CELL FUNCTION AND OF T2DM. THE INFORMATION AVAILABLE IN THE GOTO-KAKIZAKI (GK) RAT, ONE OF THE BEST CHARACTERIZED ANIMAL MODELS OF SPONTANEOUS T2DM, ARE REVIEWED IN SUCH A PERSPECTIVE. WE PROPOSE THAT THE DEFECTIVE BETA-CELL MASS AND FUNCTION IN THE GK MODEL REFLECT THE COMPLEX INTERACTIONS OF THREE PATHOGENIC PLAYERS: (1) SEVERAL INDEPENDENT LOCI CONTAINING GENES CAUSING IMPAIRED INSULIN SECRETION; (2) GESTATIONAL METABOLIC IMPAIRMENT INDUCING A PROGRAMMING OF ENDOCRINE PANCREAS (DECREASED BETA-CELL NEOGENESIS) WHICH IS TRANSMITTED TO THE NEXT GENERATION; AND (3) SECONDARY (ACQUIRED) LOSS OF BETA-CELL DIFFERENTIATION DUE TO CHRONIC EXPOSURE TO HYPERGLYCEMIA (GLUCOTOXICITY). AN IMPORTANT MESSAGE IS THAT THE 'HERITABLE' DETERMINANTS OF T2DM ARE NOT SIMPLY DEPENDANT ON GENETIC FACTORS, BUT PROBABLY INVOLVE TRANSGENERATIONAL EPIGENETIC RESPONSES. 2005 7 6164 115 THE GK RAT: A PROTOTYPE FOR THE STUDY OF NON-OVERWEIGHT TYPE 2 DIABETES. TYPE 2 DIABETES MELLITUS (T2D) ARISES WHEN THE ENDOCRINE PANCREAS FAILS TO SECRETE SUFFICIENT INSULIN TO COPE WITH THE METABOLIC DEMAND BECAUSE OF BETA-CELL SECRETORY DYSFUNCTION AND/OR DECREASED BETA-CELL MASS. DEFINING THE NATURE OF THE PANCREATIC ISLET DEFECTS PRESENT IN T2D HAS BEEN DIFFICULT, IN PART BECAUSE HUMAN ISLETS ARE INACCESSIBLE FOR DIRECT STUDY. THIS REVIEW IS AIMED TO ILLUSTRATE TO WHAT EXTENT THE GOTO KAKIZAKI RAT, ONE OF THE BEST CHARACTERIZED ANIMAL MODELS OF SPONTANEOUS T2D, HAS PROVED TO BE A VALUABLE TOOL OFFERING SUFFICIENT COMMONALITIES TO STUDY THIS ASPECT. A COMPREHENSIVE COMPENDIUM OF THE MULTIPLE FUNCTIONAL GK ABNORMALITIES SO FAR IDENTIFIED IS PROPOSED IN THIS PERSPECTIVE, TOGETHER WITH THEIR TIME-COURSE AND INTERACTIONS. A SPECIAL FOCUS IS GIVEN TOWARD THE PATHOGENESIS OF DEFECTIVE BETA-CELL NUMBER AND FUNCTION IN THE GK MODEL. IT IS PROPOSED THAT THE DEVELOPMENT OF T2D IN THE GK MODEL RESULTS FROM THE COMPLEX INTERACTION OF MULTIPLE EVENTS: (1) SEVERAL SUSCEPTIBILITY LOCI CONTAINING GENES RESPONSIBLE FOR SOME DIABETIC TRAITS; (2) GESTATIONAL METABOLIC IMPAIRMENT INDUCING AN EPIGENETIC PROGRAMMING OF THE OFFSPRING PANCREAS AND THE MAJOR INSULIN TARGET TISSUES; AND (3) ENVIRONMENTALLY INDUCED LOSS OF BETA-CELL DIFFERENTIATION DUE TO CHRONIC EXPOSURE TO HYPERGLYCEMIA/HYPERLIPIDEMIA, INFLAMMATION, AND OXIDATIVE STRESS. 2012 8 2009 25 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 9 6341 24 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 4195 31 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 11 2171 29 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 12 599 37 BETA-CELL DIFFERENTIATION STATUS IN TYPE 2 DIABETES. TYPE 2 DIABETES (T2D) AFFECTS 415 MILLION PEOPLE WORLDWIDE AND IS CHARACTERIZED BY CHRONIC HYPERGLYCAEMIA AND INSULIN RESISTANCE, PROGRESSING TO INSUFFICIENT INSULIN PRODUCTION, AS A RESULT OF BETA-CELL FAILURE. OVER TIME, CHRONIC HYPERGLYCAEMIA CAN ULTIMATELY LEAD TO LOSS OF BETA-CELL FUNCTION, LEAVING PATIENTS INSULIN-DEPENDENT. UNTIL RECENTLY THE LOSS OF BETA-CELL MASS SEEN IN T2D WAS CONSIDERED TO BE THE RESULT OF INCREASED RATES OF APOPTOSIS; HOWEVER, IT HAS BEEN PROPOSED THAT APOPTOSIS ALONE CANNOT ACCOUNT FOR THE EXTENT OF BETA-CELL MASS LOSS SEEN IN THE DISEASE, AND THAT A LOSS OF FUNCTION MAY ALSO OCCUR AS A RESULT OF CHANGES IN BETA-CELL DIFFERENTIATION STATUS. IN THE PRESENT REVIEW, WE CONSIDER CURRENT KNOWLEDGE OF DETERMINANTS OF BETA-CELL FATE IN THE CONTEXT OF UNDERSTANDING ITS RELEVANCE TO DISEASE PROCESS IN T2D, AND ALSO THE IMPACT OF A DIABETOGENIC ENVIRONMENT (HYPERGLYCAEMIA, HYPOXIA, INFLAMMATION AND DYSLIPIDAEMIA) ON THE EXPRESSION OF GENES INVOLVED IN MAINTENANCE OF BETA-CELL IDENTITY. WE DESCRIBE CURRENT KNOWLEDGE OF THE IMPACT OF THE DIABETIC MICROENVIRONMENT ON GENE REGULATORY PROCESSES SUCH ALTERNATIVE SPLICING, THE EXPRESSION OF DISALLOWED GENES AND EPIGENETIC MODIFICATIONS. ELUCIDATING THE MOLECULAR MECHANISMS THAT UNDERPIN CHANGES TO BETA-CELL DIFFERENTIATION STATUS AND THE CONCOMITANT BETA-CELL FAILURE OFFERS POTENTIAL TREATMENT TARGETS FOR THE FUTURE MANAGEMENT OF PATIENTS WITH T2D. 2016 13 6357 34 THE ROLE OF HYPERGLYCAEMIA IN THE DEVELOPMENT OF DIABETIC CARDIOMYOPATHY. DIABETES MELLITUS IS A METABOLIC DISORDER WITH A CHRONIC HYPERGLYCAEMIC STATE. CARDIOVASCULAR DISEASES ARE THE PRIMARY CAUSE OF MORTALITY IN PATIENTS WITH DIABETES. INCREASING EVIDENCE SUPPORTS THE EXISTENCE OF DIABETIC CARDIOMYOPATHY, A CARDIAC DYSFUNCTION WITH IMPAIRED CARDIAC CONTRACTION AND RELAXATION, INDEPENDENT OF CORONARY AND/OR VALVULAR COMPLICATIONS. DIABETIC CARDIOMYOPATHY CAN LEAD TO HEART FAILURE. SEVERAL PRECLINICAL AND CLINICAL STUDIES HAVE AIMED TO DECIPHER THE UNDERLYING MECHANISMS OF DIABETIC CARDIOMYOPATHY. AMONG ALL THE CO-FACTORS, HYPERGLYCAEMIA SEEMS TO PLAY AN IMPORTANT ROLE IN THIS PATHOLOGY. HYPERGLYCAEMIA HAS BEEN SHOWN TO ALTER CARDIAC METABOLISM AND FUNCTION THROUGH SEVERAL DELETERIOUS MECHANISMS, SUCH AS OXIDATIVE STRESS, INFLAMMATION, ACCUMULATION OF ADVANCED GLYCATED END-PRODUCTS AND UPREGULATION OF THE HEXOSAMINE BIOSYNTHESIS PATHWAY. THESE MECHANISMS ARE RESPONSIBLE FOR THE ACTIVATION OF HYPERTROPHIC PATHWAYS, EPIGENETIC MODIFICATIONS, MITOCHONDRIAL DYSFUNCTION, CELL APOPTOSIS, FIBROSIS AND CALCIUM MISHANDLING, LEADING TO CARDIAC STIFFNESS, AS WELL AS CONTRACTILE AND RELAXATION DYSFUNCTION. THIS REVIEW AIMS TO DESCRIBE THE HYPERGLYCAEMIC-INDUCED ALTERATIONS THAT PARTICIPATE IN DIABETIC CARDIOMYOPATHY, AND THEIR CORRELATION WITH THE SEVERITY OF THE DISEASE AND PATIENT MORTALITY, AND TO PROVIDE AN OVERVIEW OF CARDIAC OUTCOMES OF GLUCOSE-LOWERING THERAPY. 2021 14 5363 22 RECENT ADVANCES IN DIABETIC KIDNEY DISEASES: FROM KIDNEY INJURY TO KIDNEY FIBROSIS. DIABETIC KIDNEY DISEASE (DKD) IS THE LEADING CAUSE OF CHRONIC KIDNEY DISEASE AND END-STAGE RENAL DISEASE. THE NATURAL HISTORY OF DKD INCLUDES GLOMERULAR HYPERFILTRATION, PROGRESSIVE ALBUMINURIA, DECLINING ESTIMATED GLOMERULAR FILTRATION RATE, AND, ULTIMATELY, KIDNEY FAILURE. IT IS KNOWN THAT DKD IS ASSOCIATED WITH METABOLIC CHANGES CAUSED BY HYPERGLYCEMIA, RESULTING IN GLOMERULAR HYPERTROPHY, GLOMERULOSCLEROSIS, AND TUBULOINTERSTITIAL INFLAMMATION AND FIBROSIS. HYPERGLYCEMIA IS ALSO KNOWN TO CAUSE PROGRAMMED EPIGENETIC MODIFICATION. HOWEVER, THE DETAILED MECHANISMS INVOLVED IN THE ONSET AND PROGRESSION OF DKD REMAIN ELUSIVE. IN THIS REVIEW, WE DISCUSS RECENT ADVANCES REGARDING THE PATHOGENIC MECHANISMS INVOLVED IN DKD. 2021 15 4137 23 MECHANISMS OF METABOLIC MEMORY AND RENAL HYPOXIA AS A THERAPEUTIC TARGET IN DIABETIC KIDNEY DISEASE. DIABETIC KIDNEY DISEASE (DKD) IS A WORLDWIDE PUBLIC HEALTH PROBLEM. THE DEFINITION OF DKD IS UNDER DISCUSSION. ALTHOUGH THE TERM DKD WAS ORIGINALLY DEFINED AS 'KIDNEY DISEASE SPECIFIC TO DIABETES,' DKD FREQUENTLY MEANS CHRONIC KIDNEY DISEASE WITH DIABETES MELLITUS AND INCLUDES NOT ONLY CLASSICAL DIABETIC NEPHROPATHY, BUT ALSO KIDNEY DYSFUNCTION AS A RESULT OF NEPHROSCLEROSIS AND OTHER CAUSES. METABOLIC MEMORY PLAYS A CRUCIAL ROLE IN THE PROGRESSION OF VARIOUS COMPLICATIONS OF DIABETES, INCLUDING DKD. THE MECHANISMS OF METABOLIC MEMORY IN DKD ARE SUPPOSED TO INCLUDE ADVANCED GLYCATION END-PRODUCTS, DEOXYRIBONUCLEIC ACID METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RIBONUCLEIC ACID INCLUDING MICRO RIBONUCLEIC ACID. REGARDLESS OF THE PRESENCE OF DIABETES MELLITUS, THE FINAL COMMON PATHWAY IN CHRONIC KIDNEY DISEASE IS CHRONIC KIDNEY HYPOXIA, WHICH INFLUENCES EPIGENETIC PROCESSES, INCLUDING DEOXYRIBONUCLEIC ACID METHYLATION, HISTONE MODIFICATION, AND CONFORMATIONAL CHANGES IN MICRO RIBONUCLEIC ACID AND CHROMATIN. THEREFORE, HYPOXIA AND OXIDATIVE STRESS ARE APPROPRIATE TARGETS OF THERAPIES AGAINST DKD. PROLYL HYDROXYLASE DOMAIN INHIBITOR ENHANCES THE DEFENSIVE MECHANISMS AGAINST HYPOXIA. BARDOXOLONE METHYL PROTECTS AGAINST OXIDATIVE STRESS, AND CAN EVEN REVERSE IMPAIRED RENAL FUNCTION; A PHASE 2 TRIAL WITH CONSIDERABLE ATTENTION TO HEART COMPLICATIONS IS CURRENTLY ONGOING IN JAPAN. 2017 16 4891 35 OXIDATIVE STRESS AND INFLAMMATORY MARKERS IN PREDIABETES AND DIABETES. PREDIABETES IS A STATE OF ELEVATED PLASMA GLUCOSE IN WHICH THE THRESHOLD FOR DIABETES HAS NOT YET BEEN REACHED AND CAN PREDISPOSE TO THE DEVELOPMENT OF TYPE 2 DIABETES AND CARDIOVASCULAR DISEASES. INSULIN RESISTANCE AND IMPAIRED BETA-CELL FUNCTION ARE OFTEN ALREADY PRESENT IN PREDIABETES. HYPERGLYCEMIA CAN UPREGULATE MARKERS OF CHRONIC INFLAMMATION AND CONTRIBUTE TO INCREASED REACTIVE OXYGEN SPECIES (ROS) GENERATION, WHICH ULTIMATELY CAUSE VASCULAR DYSFUNCTION. CONVERSELY, INCREASED OXIDATIVE STRESS AND INFLAMMATION CAN LEAD TO INSULIN RESISTANCE AND IMPAIRED INSULIN SECRETION. PROPER TREATMENT OF HYPERGLYCEMIA AND INHIBITION OF ROS OVERPRODUCTION IS CRUCIAL FOR DELAYING ONSET OF DIABETES AND FOR PREVENTION OF CARDIOVASCULAR COMPLICATIONS. THUS, IT IS IMPERATIVE TO DETERMINE THE MECHANISMS INVOLVED IN THE PROGRESSION FROM PREDIABETES TO DIABETES INCLUDING A CLARIFICATION OF HOW OLD AND NEW MEDICATIONS AFFECT OXIDATIVE AND IMMUNE MECHANISMS OF DIABETES. IN THIS REVIEW, WE DISCUSS THE RELATIONSHIP BETWEEN OXIDATIVE STRESS AND HYPERGLYCEMIA ALONG WITH LINKS BETWEEN INFLAMMATION AND PREDIABETES. ADDITIONALLY, THE EFFECTS OF HYPERGLYCEMIC MEMORY, MICROVESICLES, MICRO-RNA, AND EPIGENETIC REGULATION ON INFLAMMATION, OXIDATIVE STATE, AND GLYCEMIC CONTROL ARE HIGHLIGHTED. ADIPOSE TISSUE AND THEIR INFLUENCE ON CHRONIC INFLAMMATION ARE ALSO BRIEFLY REVIEWED. FINALLY, THE ROLE OF IMMUNE-TARGETED THERAPIES AND ANTI-DIABETIC MEDICATION ON GLYCEMIC CONTROL AND OXIDATIVE STRESS ARE DISCUSSED. 2019 17 6575 26 TREATMENT OF DIABETIC KIDNEY DISEASE: CURRENT AND FUTURE. DIABETIC KIDNEY DISEASE (DKD) IS THE MAJOR CAUSE OF END-STAGE KIDNEY DISEASE. HOWEVER, ONLY RENIN-ANGIOTENSIN SYSTEM INHIBITOR WITH MULTIDISCIPLINARY TREATMENTS IS EFFECTIVE FOR DKD. IN 2019, SODIUM-GLUCOSE COTRANSPORTER 2 (SGLT2) INHIBITOR SHOWED EFFICACY AGAINST DKD IN CANAGLIFLOZIN AND RENAL EVENTS IN DIABETES WITH ESTABLISHED NEPHROPATHY CLINICAL EVALUATION (CREDENCE) TRIAL, ADDING A NEW TREATMENT OPTION. HOWEVER, THE PROGRESSION OF DKD HAS NOT BEEN COMPLETELY CONTROLLED. THE PATIENTS WITH TRANSIENT EXPOSURE TO HYPERGLYCEMIA DEVELOP DIABETIC COMPLICATIONS, INCLUDING DKD, EVEN AFTER NORMALIZATION OF THEIR BLOOD GLUCOSE. TEMPORARY HYPERGLYCEMIA CAUSES ADVANCED GLYCATION END PRODUCT (AGE) ACCUMULATIONS AND EPIGENETIC CHANGES AS METABOLIC MEMORY. THE DRUGS THAT IMPROVE METABOLIC MEMORY ARE AWAITED, AND AGE INHIBITORS AND HISTONE MODIFICATION INHIBITORS ARE THE FOCUS OF CLINICAL AND BASIC RESEARCH. IN ADDITION, INCRETIN-RELATED DRUGS SHOWED A RENOPROTECTIVE ABILITY IN MANY CLINICAL TRIALS, AND THESE TRIALS WITH RENAL OUTCOME AS THEIR PRIMARY ENDPOINT ARE CURRENTLY ONGOING. HYPOXIA-INDUCIBLE FACTOR PROLYL HYDROXYLASE INHIBITORS RECENTLY APPROVED FOR RENAL ANEMIA MAY BE RENOPROTECTIVE SINCE THEY IMPROVE TUBULOINTERSTITIAL HYPOXIA. FURTHERMORE, NF-E2-RELATED FACTOR 2 ACTIVATORS IMPROVED THE GLOMERULAR FILTRATION RATE OF DKD PATIENTS IN BARDOXOLONE METHYL TREATMENT: RENAL FUNCTION IN CHRONIC KIDNEY DISEASE/TYPE 2 DIABETES (BEAM) TRIAL AND PHASE II STUDY OF BARDOXOLONE METHYL IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND TYPE 2 DIABETES (TSUBAKI) TRIAL. THUS, FOLLOWING SGLT2 INHIBITOR, NUMEROUS NOVEL DRUGS COULD BE UTILIZED IN TREATING DKD. FUTURE STUDIES ARE EXPECTED TO PROVIDE NEW INSIGHTS. 2021 18 6335 30 THE ROLE OF DNA METHYLATION IN THE PATHOGENESIS OF TYPE 2 DIABETES MELLITUS. DIABETES MELLITUS (DM) IS A CHRONIC CONDITION CHARACTERISED BY BETA CELL DYSFUNCTION AND PERSISTENT HYPERGLYCAEMIA. THE DISORDER CAN BE DUE TO THE ABSENCE OF ADEQUATE PANCREATIC INSULIN PRODUCTION OR A WEAK CELLULAR RESPONSE TO INSULIN SIGNALLING. AMONG THE THREE TYPES OF DM, NAMELY, TYPE 1 DM (T1DM), TYPE 2 DM (T2DM), AND GESTATIONAL DM (GDM); T2DM ACCOUNTS FOR ALMOST 90% OF DIABETES CASES WORLDWIDE.EPIGENETIC TRAITS ARE STABLY HERITABLE PHENOTYPES THAT RESULT FROM CERTAIN CHANGES THAT AFFECT GENE FUNCTION WITHOUT ALTERING THE GENE SEQUENCE. WHILE EPIGENETIC TRAITS ARE CONSIDERED REVERSIBLE MODIFICATIONS, THEY CAN BE INHERITED MITOTICALLY AND MEIOTICALLY. IN ADDITION, EPIGENETIC TRAITS CAN RANDOMLY ARISE IN RESPONSE TO ENVIRONMENTAL FACTORS OR CERTAIN GENETIC MUTATIONS OR LESIONS, SUCH AS THOSE AFFECTING THE ENZYMES THAT CATALYSE THE EPIGENETIC MODIFICATION. IN THIS REVIEW, WE FOCUS ON THE ROLE OF DNA METHYLATION, A TYPE OF EPIGENETIC MODIFICATION, IN THE PATHOGENESIS OF T2DM. 2020 19 2178 28 EPIGENETIC MECHANISMS OF MACROPHAGE ACTIVATION IN TYPE 2 DIABETES. THE ALARMING RISE OF OBESITY AND TYPE 2 DIABETES (T2D) HAS PUT A TREMENDOUS STRAIN ON GLOBAL HEALTHCARE SYSTEMS. OVER THE PAST DECADE EXTENSIVE RESEARCH HAS FOCUSED ON THE ROLE OF MACROPHAGES AS KEY MEDIATORS OF INFLAMMATION IN T2D. THE INFLAMMATORY ENVIRONMENT IN THE OBESE ADIPOSE TISSUE AND PANCREATIC BETA-CELL ISLETS CREATES AND PERPETUATES IMBALANCED INFLAMMATORY MACROPHAGE ACTIVATION. CONSEQUENCES OF THIS CHRONIC LOW-GRADE INFLAMMATION INCLUDE INSULIN RESISTANCE IN THE ADIPOSE TISSUE AND PANCREATIC BETA-CELL DYSFUNCTION. RECENTLY, THE EMERGING FIELD OF EPIGENETICS HAS PROVIDED NEW INSIGHTS INTO THE PATHOGENESIS OF T2D, WHILE ALSO AFFORDING POTENTIAL NEW OPPORTUNITIES FOR TREATMENT. IN MACROPHAGES, EPIGENETIC MECHANISMS ARE INCREASINGLY BEING RECOGNIZED AS CRUCIAL CONTROLLERS OF THEIR PHENOTYPE. HERE, WE FIRST DESCRIBE THE ROLE OF MACROPHAGES IN T2D. THEN WE ELABORATE ON EPIGENETIC MECHANISMS THAT REGULATE MACROPHAGE ACTIVATION, THEREBY FOCUSING ON T2D. NEXT, WE HIGHLIGHT HOW DIABETIC CONDITIONS SUCH AS HYPERLIPIDEMIA AND HYPERGLYCEMIA COULD INDUCE EPIGENETIC CHANGES THAT PROMOTE AN INFLAMMATORY MACROPHAGE PHENOTYPE. IN CONCLUSION WE DISCUSS POSSIBLE THERAPEUTIC INTERVENTIONS BY TARGETING MACROPHAGE EPIGENETICS AND SPECULATE ON FUTURE RESEARCH DIRECTIONS. 2017 20 2210 31 EPIGENETIC MODIFICATIONS AND POTENTIAL NEW TREATMENT TARGETS IN DIABETIC RETINOPATHY. RETINOPATHY IS A DEBILITATING VASCULAR COMPLICATION OF DIABETES. AS WITH OTHER DIABETIC COMPLICATIONS, DIABETIC RETINOPATHY (DR) IS CHARACTERIZED BY THE METABOLIC MEMORY, WHICH HAS BEEN OBSERVED BOTH IN DR PATIENTS AND IN DR ANIMAL MODELS. EVIDENCES HAVE PROVIDED THAT AFTER A PERIOD OF POOR GLUCOSE CONTROL INSULIN OR DIABETES DRUG TREATMENT FAILS TO PREVENT THE DEVELOPMENT AND PROGRESSION OF DR EVEN WHEN GOOD GLYCEMIC CONTROL IS REINSTITUTED (GLUCOSE NORMALIZATION), SUGGESTING A METABOLIC MEMORY PHENOMENON. RECENT STUDIES ALSO UNDERLINE THE ROLE OF EPIGENETIC CHROMATIN MODIFICATIONS AS MEDIATORS OF THE METABOLIC MEMORY. INDEED, EPIGENETIC CHANGES MAY LEAD TO STABLE MODIFICATION OF GENE EXPRESSION, PARTICIPATING IN DR PATHOGENESIS. MOREOVER, INCREASING EVIDENCES SUGGEST THAT ENVIRONMENTAL FACTORS SUCH AS CHRONIC HYPERGLYCEMIA ARE IMPLICATED DR PROGRESSION AND MAY ALSO AFFECT THE EPIGENETIC STATE. HERE WE REVIEW RECENT FINDINGS DEMONSTRATING THE KEY ROLE OF EPIGENETICS IN THE PROGRESSION OF DR. FURTHER ELUCIDATION OF EPIGENETIC MECHANISMS, ACTING BOTH AT THE CIS- AND TRANS-CHROMATIN STRUCTURAL ELEMENTS, WILL YIELD NEW INSIGHTS INTO THE PATHOGENESIS OF DR AND WILL OPEN THE WAY FOR THE DISCOVERY OF NOVEL THERAPEUTIC TARGETS TO PREVENT DR PROGRESSION. 2014