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 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 3 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 4 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 5 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 6 3909 21 LIFE AFTER PANCREAS TRANSPLANTATION: REVERSAL OF DIABETIC LESIONS. PURPOSE OF REVIEW: RECIPIENTS OF PANCREAS TRANSPLANTATION BEAR THE BURDEN OF CHRONIC COMPLICATIONS OF DIABETES, BOTH MICROVASCULAR AND MACROVASCULAR. PANCREAS TRANSPLANTATION PROVIDES THE MOST EFFECTIVE METHOD OF GLYCEMIC AND METABOLIC CONTROL. AS TRANSPLANTATION PROVIDES IMMEDIATE RELIEF FROM ACUTE COMPLICATIONS OF DIABETES, THE IMPACT OF A SUCCESSFUL TRANSPLANT ON LONG-TERM COMPLICATIONS IS THE FOCUS OF THIS REVIEW. RECENT FINDINGS: IT IS INCREASINGLY RECOGNIZED THAT A SUCCESSFUL PANCREAS TRANSPLANT MAY SLOW, STABILIZE, OR AMELIORATE THE PROGRESSION OF MACROVASCULAR AND MICROVASCULAR COMPLICATIONS OF DIABETES. NEW UNDERSTANDING OF THE GENETIC AND EPIGENETIC MECHANISMS AND PATHOPHYSIOLOGY OF DIABETIC COMPLICATIONS HAS PROVIDED NEW DATA POTENTIALLY USEFUL FOR PROSPECTIVELY STUDYING THE EFFECT OF PANCREAS TRANSPLANT ON CHRONIC COMPLICATIONS OF DIABETES. SUMMARY: EARLIER CORRECTION OF DIABETES BY PANCREAS TRANSPLANTATION DECREASES CHRONIC COMPLICATIONS. REFINEMENTS IN THE UNDERSTANDING OF THE TISSUE TARGETS OF DIABETES COMPLICATIONS AND NEW DIAGNOSTIC AND IMAGING TOOLS TO MEASURE THEM MAY PROVE USEFUL IN FURTHER STUDYING THE IMPACT OF PANCREAS TRANSPLANTATION ON CHRONIC COMPLICATIONS OF DIABETES. 2014 7 599 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 8 4334 20 MICRORNAS: NOVEL DIAGNOSTIC AND THERAPEUTIC TOOLS FOR PANCREATIC DUCTAL ADENOCARCINOMA? PANCREATIC DUCTAL ADENOCARCINOMA (PDAC) IS KNOWN FOR ITS VERY POOR OVERALL PROGNOSIS, MAKING TOOLS FOR EARLY DIAGNOSIS AND NEW THERAPEUTIC MODALITIES URGENTLY NEEDED. MICRORNAS (MIRNAS), ENDOGENOUS NONCODING RNA MOLECULES OF APPROXIMATELY 22 NT, HAVE GAINED ATTENTION AS AN EPIGENETIC COMPONENT INVOLVED IN THE DEVELOPMENT OF MANY CANCERS, INCLUDING PDAC. MIRNA EXPRESSION PROFILES OF VARYING PANCREATIC TISSUES HAVE IDENTIFIED A NUMBER OF DIFFERENTIALLY EXPRESSED MIRNAS AND SEEM TO BE ABLE TO DIFFERENTIATE BETWEEN THREE TISSUES OF CLINICAL IMPORTANCE: NORMAL PANCREAS, CHRONIC PANCREATITIS, AND PDAC. THIS ARTICLE GATHERS OUR CURRENT KNOWLEDGE OF DIFFERENTIALLY EXPRESSED MIRNAS IN PANCREATIC TISSUES WITH RELEVANCE TO PDAC AND PRESENTS POTENTIAL DIAGNOSTIC AND THERAPEUTIC OPPORTUNITIES. 2009 9 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 10 241 35 ADIPOCYTE, IMMUNE CELLS, AND MIRNA CROSSTALK: A NOVEL REGULATOR OF METABOLIC DYSFUNCTION AND OBESITY. OBESITY IS CHARACTERIZED AS A COMPLEX AND MULTIFACTORIAL EXCESS ACCRETION OF ADIPOSE TISSUE (AT) ACCOMPANIED WITH ALTERATIONS IN THE IMMUNE RESPONSE THAT AFFECTS VIRTUALLY ALL AGE AND SOCIOECONOMIC GROUPS AROUND THE GLOBE. THE ABNORMAL ACCUMULATION OF AT LEADS TO SEVERAL METABOLIC DISEASES, INCLUDING NONALCOHOLIC FATTY LIVER DISORDER (NAFLD), LOW-GRADE INFLAMMATION, TYPE 2 DIABETES MELLITUS (T2DM), CARDIOVASCULAR DISORDERS (CVDS), AND CANCER. AT IS AN ENDOCRINE ORGAN COMPOSED OF ADIPOCYTES AND IMMUNE CELLS, INCLUDING B-CELLS, T-CELLS AND MACROPHAGES. THESE IMMUNE CELLS SECRETE VARIOUS CYTOKINES AND CHEMOKINES AND CROSSTALK WITH ADIPOKINES TO MAINTAIN METABOLIC HOMEOSTASIS AND LOW-GRADE CHRONIC INFLAMMATION. A NOVEL FORM OF ADIPOKINES, MICRORNA (MIRS), IS EXPRESSED IN MANY DEVELOPING PERIPHERAL TISSUES, INCLUDING ATS, T-CELLS, AND MACROPHAGES, AND MODULATES THE IMMUNE RESPONSE. MIRS ARE ESSENTIAL FOR INSULIN RESISTANCE, MAINTAINING THE TUMOR MICROENVIRONMENT, AND OBESITY-ASSOCIATED INFLAMMATION (OAI). THE ABNORMAL REGULATION OF AT, T-CELLS, AND MACROPHAGE MIRS MAY CHANGE THE FUNCTION OF DIFFERENT ORGANS INCLUDING THE PANCREAS, HEART, LIVER, AND SKELETAL MUSCLE. SINCE OBESITY AND INFLAMMATION ARE CLOSELY ASSOCIATED, THE DYSREGULATED EXPRESSION OF MIRS IN INFLAMMATORY ADIPOCYTES, T-CELLS, AND MACROPHAGES SUGGEST THE IMPORTANCE OF MIRS IN OAI. THEREFORE, IN THIS REVIEW ARTICLE, WE HAVE ELABORATED THE ROLE OF MIRS AS EPIGENETIC REGULATORS AFFECTING ADIPOCYTE DIFFERENTIATION, IMMUNE RESPONSE, AT BROWNING, ADIPOGENESIS, LIPID METABOLISM, INSULIN RESISTANCE (IR), GLUCOSE HOMEOSTASIS, OBESITY, AND METABOLIC DISORDERS. FURTHER, WE WILL DISCUSS A SET OF ALTERED MIRS AS NOVEL BIOMARKERS FOR METABOLIC DISEASE PROGRESSION AND THERAPEUTIC TARGETS FOR OBESITY. 2021 11 4263 36 MICRO(RNA) MANAGEMENT AND MISMANAGEMENT OF THE ISLET. PANCREATIC BETA-CELLS LOCATED WITHIN THE ISLETS OF LANGERHANS PLAY A CENTRAL ROLE IN METABOLIC CONTROL. THE MAIN FUNCTION OF THESE CELLS IS TO PRODUCE AND SECRETE INSULIN IN RESPONSE TO A RISE IN CIRCULATING LEVELS OF GLUCOSE AND OTHER NUTRIENTS. THE RELEASE OF INSUFFICIENT INSULIN TO COVER THE ORGANISM NEEDS RESULTS IN CHRONIC HYPERGLYCEMIA AND DIABETES DEVELOPMENT. BETA-CELLS INSURE A HIGHLY SPECIALIZED TASK AND TO EFFICIENTLY ACCOMPLISH THEIR FUNCTION THEY NEED TO EXPRESS A SPECIFIC SET OF GENES. MICRORNAS (MIRNAS) ARE SMALL NONCODING RNAS AND KEY REGULATORS OF GENE EXPRESSION. INDEED, BY PARTIALLY PAIRING TO SPECIFIC SEQUENCES IN THE 3' UNTRANSLATED REGIONS OF TARGET MRNAS, EACH OF THEM CAN CONTROL THE TRANSLATION OF HUNDREDS OF TRANSCRIPTS. IN THIS REVIEW, WE FOCUS ON FEW KEY MIRNAS CONTROLLING ISLET FUNCTION AND DISCUSS: THEIR DIFFERENTIAL EXPRESSION IN TYPE 2 DIABETES (T2D), THEIR REGULATION BY GENETIC AND ENVIRONMENTAL FACTORS, AND THEIR THERAPEUTIC POTENTIAL. GENETIC AND EPIGENETIC CHANGES OR PROLONGED EXPOSURE TO HYPERGLYCEMIA AND/OR HYPERLIPIDEMIA CAN AFFECT THE BETA-CELL MIRNA EXPRESSION PROFILE, RESULTING IN IMPAIRED BETA-CELL FUNCTION AND SURVIVAL LEADING TO THE DEVELOPMENT OF T2D. EXPERIMENTAL APPROACHES PERMITTING TO CORRECT THE LEVEL OF MISEXPRESSED MIRNAS HAVE BEEN SHOWN TO PREVENT OR TREAT T2D IN ANIMAL MODELS, SUGGESTING THAT THESE SMALL RNAS MAY BECOME INTERESTING THERAPEUTIC TARGETS. HOWEVER, TRANSLATION OF THESE EXPERIMENTAL FINDINGS TO THE CLINICS WILL NECESSITATE THE DEVELOPMENT OF INNOVATIVE STRATEGIES ALLOWING SAFE AND SPECIFIC DELIVERY OF COMPOUNDS MODULATING THE LEVEL OF THE RELEVANT MIRNAS TO THE BETA-CELLS. 2020 12 1974 41 EPIGENETIC ALTERATIONS CAUSED BY NUTRITIONAL STRESS DURING FETAL PROGRAMMING OF THE ENDOCRINE PANCREAS. NUTRITION DURING CRITICAL PERIODS OF DEVELOPMENT IS ONE OF THE PIVOTAL FACTORS IN ESTABLISHING A LIFELONG HEALTHY METABOLISM. DIFFERENT NUTRITIONAL DEFICIENCIES SUCH AS A LOW AVAILABILITY OF PROTEINS IN THE MATERNAL DIET PRODUCE ALTERATIONS IN OFFSPRING THAT INCLUDE CHANGES IN INSULIN AND GLUCOSE METABOLISM, A DECREASE IN THE SIZE AND NUMBER OF CELLS OF PANCREATIC ISLETS OF LANGERHANS, AND PREMATURE AGEING OF THE SECRETORY FUNCTION OF PANCREATIC BETA CELLS. MOREOVER, IT HAS BEEN REPORTED THAT CHRONIC NUTRITIONAL STRESS IS ASSOCIATED WITH EPIGENETIC ALTERATIONS IN MECHANISMS OF GENE REGULATION DURING PANCREATIC DEVELOPMENT AND FUNCTION. THESE ALTERATIONS CAN LEAD TO DYSFUNCTIONAL STATES IN PANCREATIC BETA CELLS, WHICH IN THE LONG RUN ARE RESPONSIBLE FOR THE ONSET OF METABOLIC DISEASES LIKE TYPE 2 DIABETES. THE PRESENT REVIEW SUMMARIZES THE MOST IMPORTANT EVIDENCE IN RELATION TO THE PARTICIPATION OF EPIGENETIC MECHANISMS IN THE REGULATION OF GENE EXPRESSION DURING THE INTRAUTERINE PROGRAMMING OF THE ENDOCRINE PANCREAS IN ANIMAL MODELS. SUCH MECHANISMS INCLUDE DNA METHYLATION AS WELL AS MODIFICATIONS OF HISTONES AND MICRORNAS (MIRNAS). 2015 13 6132 27 THE EPIGENETIC REGULATORS BMI1 AND RING1B ARE DIFFERENTIALLY REGULATED IN PANCREATITIS AND PANCREATIC DUCTAL ADENOCARCINOMA. CHRONIC PANCREATITIS AND PANCREATIC DUCTAL ADENOCARCINOMA (PDAC) ARE ASSOCIATED WITH MAJOR CHANGES IN CELL DIFFERENTIATION. THESE CHANGES MAY BE AT THE BASIS OF THE INCREASED RISK FOR PDAC AMONG PATIENTS WITH CHRONIC PANCREATITIS. POLYCOMB PROTEINS ARE EPIGENETIC SILENCERS EXPRESSED IN ADULT STEM CELLS; UP-REGULATION OF POLYCOMB PROTEINS HAS BEEN REPORTED TO OCCUR IN A VARIETY OF SOLID TUMOURS SUCH AS COLON AND BREAST CANCER. WE HYPOTHESIZED THAT POLYCOMB MIGHT PLAY A ROLE IN PRENEOPLASTIC STATES IN THE PANCREAS AND IN TUMOUR DEVELOPMENT/PROGRESSION. TO TEST THESE IDEAS, WE DETERMINED THE EXPRESSION OF PRC1 COMPLEX PROTEINS (BMI1 AND RING1B) DURING PANCREATIC DEVELOPMENT AND IN PANCREATIC TISSUE FROM MOUSE MODELS OF DISEASE: ACUTE AND CHRONIC PANCREATIC INJURY, DUCT LIGATION, AND IN K-RAS(G12V) CONDITIONAL KNOCK-IN AND CAERULEIN-TREATED K-RAS(G12V) MICE. THE STUDY WAS EXTENDED TO HUMAN PANCREATIC TISSUE SAMPLES. TO OBTAIN MECHANISTIC INSIGHTS, BMI1 EXPRESSION IN CELLS UNDERGOING IN VITRO EXOCRINE CELL METAPLASIA AND THE EFFECTS OF BMI1 DEPLETION IN AN ACINAR CANCER CELL LINE WERE STUDIED. WE FOUND THAT BMI1 AND RING1B ARE EXPRESSED IN PANCREATIC EXOCRINE PRECURSOR CELLS DURING EARLY DEVELOPMENT AND IN DUCTAL AND ISLET CELLS-BUT NOT ACINAR CELLS-IN THE ADULT PANCREAS. BMI1 EXPRESSION WAS INDUCED IN ACINAR CELLS DURING ACUTE INJURY, IN ACINAR-DUCTAL METAPLASTIC LESIONS, AS WELL AS IN PANCREATIC INTRAEPITHELIAL NEOPLASIA (PANIN) AND PDAC. IN CONTRAST, RING1B EXPRESSION WAS ONLY SIGNIFICANTLY AND PERSISTENTLY UP-REGULATED IN HIGH-GRADE PANINS AND IN PDAC. BMI1 KNOCKDOWN IN CULTURED ACINAR TUMOUR CELLS LED TO CHANGES IN THE EXPRESSION OF VARIOUS DIGESTIVE ENZYMES. OUR RESULTS SUGGEST THAT BMI1 AND RING1B ARE MODULATED IN PANCREATIC DISEASES AND COULD CONTRIBUTE DIFFERENTLY TO TUMOUR DEVELOPMENT. 2009 14 6318 24 THE RENIN-ANGIOTENSIN SYSTEM AND REACTIVE OXYGEN SPECIES: IMPLICATIONS IN PANCREATITIS. SIGNIFICANCE: THE RENIN-ANGIOTENSIN SYSTEM (RAS) IS A CIRCULATING HORMONAL SYSTEM INVOLVED IN THE REGULATION OF BLOOD PRESSURE AND CIRCULATING FLUID ELECTROLYTES. RECENT FINDINGS HAVE REVEALED THAT LOCALLY GENERATED ANGIOTENSIN (ANG) II PLAYS A PIVOTAL ROLE IN NORMAL PHYSIOLOGY AS WELL AS PATHOPHYSIOLOGY IN VARIOUS TISSUES AND ORGANS, INCLUDING THE PANCREAS. THIS REVIEW ARTICLE SUMMARIZES CURRENT PROGRESS THAT HAS BEEN MADE IN ELUCIDATING THE PUTATIVE ROLES OF ANG II IN BOTH ACUTE AND CHRONIC PANCREATITIS. RECENT ADVANCES: A CONVERGENCE OF EVIDENCE SUGGESTS THAT THE UNDERLYING MECHANISM MAY INVOLVE REACTIVE OXYGEN SPECIES (ROS)-GENERATING SYSTEMS, SUCH AS NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE OXIDASE, AND SUBSEQUENT ELEVATION OF PROINFLAMMATORY AND PROFIBROGENIC GENE EXPRESSION AS WELL AS PROTEIN ACTIVITY. MORE IMPORTANTLY, ANG II-INDUCED ROS INTERACTS WITH OTHER ROS-GENERATING SYSTEMS TO POSITIVELY FEED-FORWARD THE ROS-INDUCED SIGNALING. CRITICAL ISSUES AND FUTURE DIRECTIONS: ADVANCES IN BASIC RESEARCH INDICATE THAT RAS BLOCKERS MAY PROVIDE POTENTIAL THERAPEUTIC ROLE FOR THE MANAGEMENT OF PANCREATIC INFLAMMATION AND, MORE IMPORTANTLY, PANCREATITIS-ASSOCIATED COMPLICATIONS. GENETIC ALTERATIONS RESULTING FROM A MALFUNCTION IN THE EPIGENETIC CONTROL OF PANCREATIC RAS COULD BE A CAUSATIVE FACTOR IN THE DEVELOPMENT OF PANCREATITIS. 2011 15 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 16 6606 36 TYPE 2 DIABETES ACROSS GENERATIONS: FROM PATHOPHYSIOLOGY TO PREVENTION AND MANAGEMENT. TYPE 2 DIABETES IS NOW A PANDEMIC AND SHOWS NO SIGNS OF ABATEMENT. IN THIS SEMINAR WE REVIEW THE PATHOPHYSIOLOGY OF THIS DISORDER, WITH PARTICULAR ATTENTION TO EPIDEMIOLOGY, GENETICS, EPIGENETICS, AND MOLECULAR CELL BIOLOGY. EVIDENCE IS EMERGING THAT A SUBSTANTIAL PART OF DIABETES SUSCEPTIBILITY IS ACQUIRED EARLY IN LIFE, PROBABLY OWING TO FETAL OR NEONATAL PROGRAMMING VIA EPIGENETIC PHENOMENA. MATERNAL AND EARLY CHILDHOOD HEALTH MIGHT, THEREFORE, BE CRUCIAL TO THE DEVELOPMENT OF EFFECTIVE PREVENTION STRATEGIES. DIABETES DEVELOPS BECAUSE OF INADEQUATE ISLET BETA-CELL AND ADIPOSE-TISSUE RESPONSES TO CHRONIC FUEL EXCESS, WHICH RESULTS IN SO-CALLED NUTRIENT SPILLOVER, INSULIN RESISTANCE, AND METABOLIC STRESS. THE LATTER DAMAGES MULTIPLE ORGANS. INSULIN RESISTANCE, WHILE FORCING BETA CELLS TO WORK HARDER, MIGHT ALSO HAVE AN IMPORTANT DEFENSIVE ROLE AGAINST NUTRIENT-RELATED TOXIC EFFECTS IN TISSUES SUCH AS THE HEART. REVERSAL OF OVERNUTRITION, HEALING OF THE BETA CELLS, AND LESSENING OF ADIPOSE TISSUE DEFECTS SHOULD BE TREATMENT PRIORITIES. 2011 17 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 18 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 19 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 20 3817 32 INTRAUTERINE PROGRAMMING OF THE ENDOCRINE PANCREAS. EPIDEMIOLOGICAL STUDIES HAVE REVEALED STRONG RELATIONSHIPS BETWEEN POOR FOETAL GROWTH AND SUBSEQUENT DEVELOPMENT OF THE METABOLIC SYNDROME. PERSISTING EFFECTS OF EARLY MALNUTRITION BECOME TRANSLATED INTO PATHOLOGY, THEREBY DETERMINE CHRONIC RISK FOR DEVELOPING GLUCOSE INTOLERANCE AND DIABETES. THESE EPIDEMIOLOGICAL OBSERVATIONS IDENTIFY THE PHENOMENA OF FOETAL PROGRAMMING WITHOUT EXPLAINING THE UNDERLYING MECHANISMS THAT ESTABLISH THE CAUSAL LINK. ANIMAL MODELS HAVE BEEN ESTABLISHED AND STUDIES HAVE DEMONSTRATED THAT REDUCTION IN THE AVAILABILITY OF NUTRIENTS DURING FOETAL DEVELOPMENT PROGRAMS THE ENDOCRINE PANCREAS AND INSULIN-SENSITIVE TISSUES. WHATEVER THE TYPE OF FOETAL MALNUTRITION, WHETHER THERE ARE NOT ENOUGH CALORIES OR PROTEIN IN FOOD OR AFTER PLACENTAL DEFICIENCY, MALNOURISHED PUPS ARE BORN WITH A DEFECT IN THEIR BETA-CELL POPULATION THAT WILL NEVER COMPLETELY RECOVER, AND INSULIN-SENSITIVE TISSUES WILL BE DEFINITIVELY ALTERED. DESPITE THE SIMILAR ENDPOINT, DIFFERENT CELLULAR AND PHYSIOLOGICAL MECHANISMS ARE PROPOSED. HORMONES OPERATIVE DURING FOETAL LIFE LIKE INSULIN ITSELF, INSULIN-LIKE GROWTH FACTORS AND GLUCOCORTICOIDS, AS WELL AS SPECIFIC MOLECULES LIKE TAURINE, OR ISLET VASCULARIZATION WERE IMPLICATED AS POSSIBLE FACTORS AMPLIFYING THE DEFECT. THE MOLECULAR MECHANISMS RESPONSIBLE FOR INTRAUTERINE PROGRAMMING OF THE BETA CELLS ARE STILL ELUSIVE, BUT TWO HYPOTHESES RECENTLY EMERGED: THE FIRST ONE IMPLIES PROGRAMMING OF MITOCHONDRIA AND THE SECOND, EPIGENETIC REGULATION. 2007