1 6575 142 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 2 4137 46 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 3 5420 31 REGULATION OF HYPOXIA-INDUCIBLE FACTOR IN KIDNEY DISEASE. HYPOXIA PLAYS A CRUCIAL ROLE IN THE PATHOPHYSIOLOGY OF ACUTE KIDNEY INJURY (AKI) AND PRESUMABLY ALSO CHRONIC KIDNEY DISEASE (CKD). HYPOXIA-INDUCIBLE FACTOR (HIF) IS THE MASTER TRANSCRIPTION FACTOR THAT REGULATES ADAPTIVE RESPONSES AGAINST HYPOXIA. UNDER HYPOXIC CONDITIONS, HIF ACTIVATES TARGET GENES WITH HYPOXIA-RESPONSIVE ELEMENTS IN THEIR REGULATORY REGIONS. THE HIF ISOFORMS AND REGULATORS OF HIF (I.E. PROLYL HYDROXYLASES) SHOW CELL TYPE-SPECIFIC DISTRIBUTIONS. HYPOXIA IS OBSERVED IN BOTH ISCHAEMIC AND SO-CALLED NON-ISCHAEMIC FORMS OF AKI. IN ADDITION TO THE ACUTE PHASE, HYPOXIA MAY ENSUE DURING THE RECOVERY PHASE OF AKI, POSSIBLY DUE TO THE OXYGEN-CONSUMING PROCESSES OF CELL GROWTH AND PROLIFERATION FOR REPAIR. ALTHOUGH HIF PROTECTS THE KIDNEY AGAINST AKI, INTRINSIC HIF ACTIVATION IS SUBMAXIMAL IN AKI AND FURTHER AUGMENTATION OF HIF AMELIORATES DISEASE MANIFESTATIONS. THE KIDNEY IN CKD ALSO SUFFERS FROM HYPOXIA CAUSED BY MULTIPLE MECHANISMS, INCLUDING SUSTAINED OXYGEN DEMANDS IN THE REMAINING NEPHRONS DUE TO MALADAPTIVE TUBULOGLOMERULAR FEEDBACK. WHETHER HIF IS CHRONICALLY UPREGULATED IN CKD IS CONTENTIOUS. HYPOXIA-INDUCIBLE FACTOR ACTIVATION IS A PROMISING THERAPEUTIC APPROACH TO CKD, BUT EXCESSIVE ACTIVATION OF HIF MAY BE DELETERIOUS. IT IS LIKELY THAT THERE IS A THERAPEUTIC WINDOW OF HIF ACTIVATION IN CHRONIC CONDITIONS. UNDER CERTAIN CIRCUMSTANCES, ANIMALS WITH CKD ARE PROTECTED AGAINST AKI AND THIS MAY BE EXPLAINED BY NON-PHYSIOLOGICAL HYPOXIA OF THE KIDNEY AND SUBSEQUENT HIF EXPRESSION. IN ADDITION, AN ACUTE HYPOXIC INSULT MAY INDUCE LONG-LASTING CHANGES, POSSIBLY INCLUDING EPIGENETIC MODIFICATIONS INDUCED BY HIF. THESE OBSERVATIONS SUGGEST A COMPLEX INTERACTION BETWEEN AKI AND CKD VIA HYPOXIA AND HIF ACTIVATION. 2013 4 5363 29 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 5 6648 52 UPDATE ON DIAGNOSIS, PATHOPHYSIOLOGY, AND MANAGEMENT OF DIABETIC KIDNEY DISEASE. DIABETIC KIDNEY DISEASE (DKD) IS A CHRONIC COMPLICATION OF DIABETES MELLITUS WHICH MAY EVENTUALLY LEAD TO END-STAGE KIDNEY DISEASE (ESKD). DESPITE IMPROVEMENTS IN GLYCAEMIC CONTROL AND BLOOD PRESSURE MANAGEMENT WITH RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM (RAAS) BLOCKADE, THE CURRENT THERAPY CANNOT COMPLETELY HALT DKD PROGRESSION TO ESKD IN SOME PATIENTS. DKD IS A HETEROGENEOUS DISEASE ENTITY IN TERMS OF ITS CLINICAL MANIFESTATIONS, HISTOPATHOLOGY AND THE RATE OF PROGRESSION, WHICH MAKES IT DIFFICULT TO DEVELOP EFFECTIVE THERAPEUTICS. IT WAS FORMERLY CONSIDERED THAT ALBUMINURIA PRECEDED KIDNEY FUNCTION DECLINE IN DKD, BUT RECENT EPIDEMIOLOGICAL STUDIES REVEALED THAT A DISTINCT GROUP OF PATIENTS PRESENTED KIDNEY DYSFUNCTION WITHOUT DEVELOPING ALBUMINURIA. OTHER COMORBIDITIES, SUCH AS HYPERTENSION, OBESITY AND GOUT, ALSO AFFECT THE CLINICAL COURSE OF DKD. THE PATHOPHYSIOLOGY OF DKD IS COMPLEX AND MULTIFACTORIAL, INVOLVING BOTH METABOLIC AND HAEMODYNAMIC FACTORS. THESE INDUCE ACTIVATION OF INTRACELLULAR SIGNALLING PATHWAYS, OXIDATIVE STRESS, HYPOXIA, DYSREGULATED AUTOPHAGY AND EPIGENETIC CHANGES, WHICH RESULT IN KIDNEY INFLAMMATION AND FIBROSIS. RECENTLY, TWO GROUPS OF ANTIDIABETIC DRUGS, SODIUM-GLUCOSE COTRANSPORTER 2 (SGLT2) INHIBITORS AND GLUCAGON-LIKE PEPTIDE-1 (GLP-1) RECEPTOR AGONISTS, WERE DEMONSTRATED TO PROVIDE RENOPROTECTION ON TOP OF THEIR GLUCOSE-LOWERING EFFECTS. SEVERAL OTHER THERAPEUTIC AGENTS ARE ALSO BEING DEVELOPED AND EVALUATED IN CLINICAL TRIALS. 2021 6 4971 47 PATHOPHYSIOLOGIC MECHANISMS IN DIABETIC KIDNEY DISEASE: A FOCUS ON CURRENT AND FUTURE THERAPEUTIC TARGETS. DIABETIC KIDNEY DISEASE (DKD) IS THE PRIMARY CAUSE OF CHRONIC KIDNEY DISEASE AROUND THE GLOBE AND IS ONE OF THE MAIN COMPLICATIONS IN PATIENTS WITH TYPE 1 AND 2 DIABETES. THE STANDARD TREATMENT FOR DKD IS DRUGS CONTROLLING HYPERGLYCEMIA AND HIGH BLOOD PRESSURE. RENIN ANGIOTENSIN ALDOSTERONE SYSTEM BLOCKADE AND SODIUM GLUCOSE COTRANSPORTER 2 (SGLT2) INHIBITION HAVE YIELDED PROMISING RESULTS IN DKD, BUT MANY DIABETIC PATIENTS ON SUCH TREATMENTS NEVERTHELESS CONTINUE TO DEVELOP DKD, LEADING TO KIDNEY FAILURE AND CARDIOVASCULAR COMORBIDITIES. NEW THERAPEUTIC OPTIONS ARE URGENTLY REQUIRED. WE REVIEW HERE THE PROMISING THERAPEUTIC AVENUES BASED ON INSIGHTS INTO THE MECHANISMS OF DKD THAT HAVE RECENTLY EMERGED, INCLUDING MINERALOCORTICOID RECEPTOR ANTAGONISTS, SGLT2 INHIBITORS, GLUCAGON-LIKE PEPTIDE-1 RECEPTOR AGONIST, ENDOTHELIN RECEPTOR A INHIBITION, ANTI-INFLAMMATORY AGENTS, AUTOPHAGY ACTIVATORS AND EPIGENETIC REMODELLING. THE INVOLVEMENT OF SEVERAL MOLECULAR MECHANISMS IN DKD PATHOGENESIS, TOGETHER WITH THE GENETIC AND EPIGENETIC VARIABILITY OF THIS CONDITION, MAKES IT DIFFICULT TO TARGET THIS HETEROGENEOUS PATIENT POPULATION WITH A SINGLE DRUG. PERSONALIZED MEDICINE, TAKING INTO ACCOUNT THE GENETIC AND MECHANISTIC VARIABILITY, MAY THEREFORE IMPROVE RENAL AND CARDIOVASCULAR PROTECTION IN DIABETIC PATIENTS WITH DKD. 2020 7 2034 27 EPIGENETIC CHANGES IN THE ACUTE KIDNEY INJURY-TO-CHRONIC KIDNEY DISEASE TRANSITION. PREVIOUSLY ACUTE KIDNEY INJURY (AKI) HAD BEEN BELIEVED TO BE A TRANSIENT EVENT, AND RECOVERY FROM AKI HAD BEEN THOUGHT TO LEAD TO NO CONSEQUENCES. HOWEVER, RECENT EPIDEMIOLOGICAL STUDIES HAVE SHOWN THAT EVEN IF THERE IS COMPLETE RECOVERY OF THE KIDNEY FUNCTION, AKI CAN EVENTUALLY RESULT IN CHRONIC KIDNEY DISEASE (CKD) AND EVENTUALLY IN END-STAGE KIDNEY DISEASE IN THE LONG TERM. TRANSITION OF AKI TO CKD IS MEDIATED BY MULTIPLE MECHANISMS, INCLUDING ABERRANT CELL CYCLE ARREST AND HYPOXIA. HYPOXIA OF THE KIDNEY IS INDUCED BY RAREFACTION OF THE PERITUBULAR CAPILLARIES AFTER AKI EPISODES, AND INDUCES INFLAMMATION AND FIBROSIS. IT SHOULD ALSO BE NOTED THAT EPIGENETIC CHANGES ARE CLOSELY RELATED TO HYPOXIA, AND EPIGENETIC CHANGES INDUCED BY HYPOXIA, CALLED "HYPOXIC MEMORY" CAN EXPLAIN THE AKI-TO-CKD TRANSITION IN THE LONG TERM AFTER COMPLETE RECOVERY FROM THE INITIAL AKI EPISODE. TARGETING HYPOXIA AND SUBSEQUENT EPIGENETIC CHANGES ARE PROMISING STRATEGIES TO BLOCK THE TRANSITION FROM AKI TO CKD. 2017 8 3466 31 HYPOXIA AS A KEY PLAYER IN THE AKI-TO-CKD TRANSITION. RECENT CLINICAL AND ANIMAL STUDIES HAVE SHOWN THAT ACUTE KIDNEY INJURY (AKI), EVEN IF FOLLOWED BY COMPLETE RECOVERY OF RENAL FUNCTION, CAN EVENTUALLY RESULT IN CHRONIC KIDNEY DISEASE (CKD). RENAL HYPOXIA IS EMERGING AS A KEY PLAYER IN THE PATHOPHYSIOLOGY OF THE AKI-TO-CKD TRANSITION. CAPILLARY RAREFACTION AFTER AKI EPISODES INDUCES RENAL HYPOXIA, WHICH CAN IN TURN PROFOUNDLY AFFECT TUBULAR EPITHELIAL CELLS, (MYO)FIBROBLASTS, AND INFLAMMATORY CELLS, CULMINATING IN TUBULOINTERSTITIAL FIBROSIS, I.E., PROGRESSION TO CKD. DAMAGED TUBULAR EPITHELIAL CELLS THAT FAIL TO REDIFFERENTIATE MIGHT SUPPLY A DECREASED AMOUNT OF VASCULAR ENDOTHELIAL GROWTH FACTOR AND CONTRIBUTE TO CAPILLARY RAREFACTION, THUS AGGRAVATING HYPOXIA AND FORMING A VICIOUS CYCLE. MOUNTING EVIDENCE ALSO SHOWS THAT EPIGENETIC CHANGES ARE CLOSELY RELATED TO RENAL HYPOXIA IN THE PATHOPHYSIOLOGY OF CKD PROGRESSION. ANIMAL EXPERIMENTS SUGGEST THAT TARGETING HYPOXIA IS A PROMISING STRATEGY TO BLOCK THE TRANSITION FROM AKI TO CKD. HOWEVER, THE PRECISE MECHANISMS BY WHICH HYPOXIA INDUCES THE AKI-TO-CKD TRANSITION AND BY WHICH HYPOXIA-INDUCIBLE FACTOR ACTIVATION CAN EXERT A PROTECTIVE EFFECT IN THIS CONTEXT SHOULD BE CLARIFIED IN FURTHER STUDIES. 2014 9 2121 41 EPIGENETIC HISTONE MODIFICATIONS IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE. DIABETIC KIDNEY DISEASE (DKD), AS THE MAIN COMPLICATION OF DIABETES MELLITUS, IS THE PRIMARY CAUSE OF THE END-STAGE RENAL DISEASE (ESRD) AND THE MOST COMMON CHRONIC KIDNEY DISEASE. OVERALL, 30-40% OF PATIENTS WITH TYPE 1 AND TYPE 2 DIABETES EVENTUALLY DEVELOP DKD. ALTHOUGH SOME DIABETES PATIENTS HAVE INTENSIFIED GLYCEMIC CONTROL, THEY STILL DEVELOP DIABETIC KIDNEY DISEASE. CURRENT TREATMENT METHODS CAN ALLEVIATE BUT DO NOT MARKEDLY HALT DISEASE DEVELOPMENT, RESULTING IN RENAL FAILURE AND SEVERE COMPLICATIONS, EVEN CONTRIBUTING TO ELEVATED MORBIDITY AND MORTALITY RATES. DKD IS A DISEASE WITH INTERACTIONS OF GENES AND THE ENVIRONMENT. EMERGING EVIDENCE INDICATES THAT DKD-ASSOCIATED KEY GENES ARE ALSO REGULATED BY THE EPIGENETIC MECHANISM. RECENTLY, INCREASING RESEARCHES INVOLVING CELLS AND EXPERIMENTAL ANIMALS DEMONSTRATED THAT HISTONE POST-TRANSLATIONAL MODIFICATIONS CAN MEDIATE GENE EXPRESSION, WHICH CORRELATED WITH DIABETIC KIDNEY DISEASE. NOVEL THERAPEUTIC STRATEGIES FOR EPIGENETIC EVENTS COULD BE BENEFICIAL FOR THE EARLY DETECTION AND TREATMENT OF DKD TO PREVENT IT FROM DEVELOPING INTO END-STAGE RENAL DISEASE (ESRD). IN THIS REVIEW, WE DISCUSS PRIOR FINDINGS IN THE FIELD OF HISTONE MODIFICATIONS IN DKD, ESPECIALLY HISTONE ACETYLATION AND HISTONE METHYLATION. WE THEN FOCUS ON RECENT DEVELOPMENTS IN HISTONE ACETYLATION AND METHYLATION INVOLVED IN THE PATHOGENESIS OF DKD. 2021 10 3467 24 HYPOXIA, HIF, AND ASSOCIATED SIGNALING NETWORKS IN CHRONIC KIDNEY DISEASE. THE PATHOGENESIS OF CHRONIC KIDNEY DISEASE (CKD) IS COMPLEX AND APPARENTLY MULTIFACTORIAL. HYPOXIA OR DECREASE IN OXYGEN SUPPLY IN KIDNEY TISSUES HAS BEEN IMPLICATED IN CKD. HYPOXIA INDUCIBLE FACTORS (HIF) ARE A SMALL FAMILY OF TRANSCRIPTION FACTORS THAT ARE MAINLY RESPONSIVE TO HYPOXIA AND MEDIATE HYPOXIC RESPONSE. HIF PLAYS A CRITICAL ROLE IN RENAL FIBROSIS DURING CKD THROUGH THE MODULATION OF GENE TRANSCRIPTION, CROSSTALK WITH MULTIPLE SIGNALING PATHWAYS, EPITHELIAL-MESENCHYMAL TRANSITION, AND EPIGENETIC REGULATION. MOREOVER, HIF ALSO CONTRIBUTES TO THE DEVELOPMENT OF VARIOUS PATHOLOGICAL CONDITIONS ASSOCIATED WITH CKD, SUCH AS ANEMIA, INFLAMMATION, ABERRANT ANGIOGENESIS, AND VASCULAR CALCIFICATION. TREATMENTS TARGETING HIF AND RELATED SIGNALING PATHWAYS FOR CKD THERAPY ARE BEING DEVELOPED WITH PROMISING CLINICAL BENEFITS, ESPECIALLY FOR ANEMIA. THIS REVIEW PRESENTS AN UPDATED ANALYSIS OF HYPOXIA RESPONSE, HIF, AND THEIR ASSOCIATED SIGNALING NETWORK INVOLVED IN THE PATHOGENESIS OF CKD. 2017 11 5565 34 ROLE OF HYPOXIA IN PROGRESSIVE CHRONIC KIDNEY DISEASE AND IMPLICATIONS FOR THERAPY. PURPOSE OF REVIEW: CHRONIC HYPOXIA IN THE TUBULOINTERSTITIUM HAS BEEN RECOGNIZED AS A FINAL COMMON PATHWAY THAT LEADS TO THE DEVELOPMENT OF END-STAGE RENAL DISEASE. HYPOXIA-INDUCIBLE FACTOR (HIF), A MASTER REGULATOR OF THE ADAPTIVE RESPONSE AGAINST HYPOXIA, IS INVOLVED IN THE PATHOGENESIS OF CHRONIC KIDNEY DISEASE (CKD). THIS REVIEW FOCUSES ON HIF AND NOVEL THERAPEUTIC STRATEGIES TARGETING HIF. RECENT FINDINGS: ALTHOUGH HIF UPREGULATION IS BENEFICIAL AGAINST HYPOXIC KIDNEY INJURY, IT MAY BE HARMFUL UNDER CERTAIN PATHOLOGICAL CONDITIONS. RECENT ADVANCES IN EPIGENETIC CHANGES PROVIDE AN ADDITIONAL LAYER OF COMPLEXITY TO OUR UNDERSTANDING OF GENE REGULATION IN RESPONSE TO HYPOXIA, WHICH IS MOST LIKELY INVOLVED IN THE PROGRESSION OF CKD. ON THE BASIS OF THIS NOVEL KNOWLEDGE, THE PHARMACOLOGICAL ACTIVATION AND MODULATION OF HIF IS EMERGING AS A NOVEL THERAPEUTIC TARGET. SUMMARY: HIF PLAYS A CRUCIAL ROLE IN THE PATHOPHYSIOLOGY OF CKD. THE UNDERLYING MOLECULAR MECHANISMS, INCLUDING EPIGENETICS, HAVE BEEN THOROUGHLY INVESTIGATED. ON THE BASIS OF THE EXPERIMENTAL DATA AVAILABLE TO DATE, THE PHARMACOLOGICAL ACTIVATION OF HIF IS LIKELY A NOVEL PROMISING THERAPY FOR CKD. 2014 12 1832 40 EFFECTS OF METABOLIC MEMORY ON INFLAMMATION AND FIBROSIS ASSOCIATED WITH DIABETIC KIDNEY DISEASE: AN EPIGENETIC PERSPECTIVE. DIABETIC KIDNEY DISEASE (DKD) IS ONE OF THE MOST COMMON MICROVASCULAR COMPLICATION OF BOTH TYPE 1 (T1DM) AND TYPE 2 DIABETES MELLITUS (T2DM), AND THE LEADING CAUSE OF END-STAGE RENAL DISEASE (ESRD) WORLDWIDE. PERSISTENT INFLAMMATION AND SUBSEQUENT CHRONIC FIBROSIS ARE MAJOR CAUSES OF LOSS OF RENAL FUNCTION, WHICH IS ASSOCIATED WITH THE PROGRESSION OF DKD TO ESRD. IN FACT, DKD PROGRESSION IS AFFECTED BY A COMBINATION OF GENETIC AND ENVIRONMENTAL FACTORS. APPROXIMATELY, ONE-THIRD OF DIABETIC PATIENTS PROGRESS TO DEVELOP DKD DESPITE INTENSIVE GLYCEMIC CONTROL, WHICH PROPOSE AN ESSENTIAL CONCEPT "METABOLIC MEMORY." EPIGENETIC MODIFICATIONS, AN EXTENSIVELY STUDIED MECHANISM OF METABOLIC MEMORY, HAVE BEEN SHOWN TO CONTRIBUTE TO THE SUSCEPTIBILITY TO DEVELOP DKD. EPIGENETIC MODIFICATIONS ALSO PLAY A REGULATORY ROLE IN THE INTERACTIONS BETWEEN THE GENES AND THE ENVIRONMENTAL FACTORS. THE EPIGENETIC CONTRIBUTIONS TO THE PROCESSES OF INFLAMMATION AND FIBROGENESIS INVOLVED IN DKD OCCUR AT DIFFERENT REGULATORY LEVELS, INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND NON-CODING RNA MODULATION. COMPARED WITH GENETIC FACTORS, EPIGENETICS REPRESENTS A NEW THERAPEUTIC FRONTIER IN UNDERSTANDING THE DEVELOPMENT DKD AND MAY LEAD TO THERAPEUTIC BREAKTHROUGHS DUE TO THE POSSIBILITY TO REVERSE THESE MODIFICATIONS THERAPEUTICALLY. EARLY RECOGNITION OF EPIGENETIC EVENTS AND BIOMARKERS IS CRUCIAL FOR TIMELY DIAGNOSIS AND INTERVENTION OF DKD, AND FOR THE PREVENTION OF THE PROGRESSION OF DKD TO ESRD. HEREIN, WE WILL REVIEW THE LATEST EPIGENETIC MECHANISMS INVOLVED IN THE RENAL PATHOLOGY OF BOTH TYPE 1 (T1DN) AND TYPE 2 DIABETIC NEPHROPATHY (T2DN) AND HIGHLIGHT THE EMERGING ROLE AND POSSIBLE THERAPEUTIC STRATEGIES BASED ON THE UNDERSTANDING OF THE ROLE OF EPIGENETICS IN DKD-ASSOCIATED INFLAMMATION AND FIBROGENESIS. 2021 13 6075 30 THE DYNAMICS AND PLASTICITY OF EPIGENETICS IN DIABETIC KIDNEY DISEASE: THERAPEUTIC APPLICATIONS VIS-A-VIS. CHRONIC KIDNEY DISEASE (CKD) REFERS TO THE PHENOMENON OF PROGRESSIVE DECLINE IN THE GLOMERULAR FILTRATION RATE ACCOMPANIED BY ADVERSE CONSEQUENCES, INCLUDING FLUID RETENTION, ELECTROLYTE IMBALANCE, AND AN INCREASED CARDIOVASCULAR RISK COMPARED TO THOSE WITH NORMAL RENAL FUNCTION. THE TRIGGERS FOR THE IRREVERSIBLE RENAL FUNCTION DETERIORATION ARE MULTIFACTORIAL, AND DIABETES MELLITUS SERVES AS A MAJOR CONTRIBUTOR TO THE DEVELOPMENT OF CKD, NAMELY DIABETIC KIDNEY DISEASE (DKD). RECENTLY, EPIGENETIC DYSREGULATION EMERGED AS A PIVOTAL PLAYER STEERING THE PROGRESSION OF DKD, PARTLY RESULTING FROM HYPERGLYCEMIA-ASSOCIATED METABOLIC DISTURBANCES, RISING OXIDATIVE STRESS, AND/OR UNCONTROLLED INFLAMMATION. IN THIS REVIEW, WE DESCRIBE THE MAJOR EPIGENETIC MOLECULAR MECHANISMS, FOLLOWED BY SUMMARIZING CURRENT UNDERSTANDINGS OF THE EPIGENETIC ALTERATIONS PERTAINING TO DKD. WE HIGHLIGHT THE EPIGENETIC REGULATORY PROCESSES INVOLVED IN SEVERAL CRUCIAL RENAL CELL TYPES: MESANGIAL CELLS, PODOCYTES, TUBULAR EPITHELIA, AND GLOMERULAR ENDOTHELIAL CELLS. FINALLY, WE HIGHLIGHT EPIGENETIC BIOMARKERS AND RELATED THERAPEUTIC CANDIDATES THAT HOLD PROMISING POTENTIAL FOR THE EARLY DETECTION OF DKD AND THE AMELIORATION OF ITS PROGRESSION. 2022 14 6051 38 THE CONTRIBUTION OF HISTONE CROTONYLATION TO TISSUE HEALTH AND DISEASE: FOCUS ON KIDNEY HEALTH. ACUTE KIDNEY INJURY (AKI) AND CHRONIC KIDNEY DISEASE (CKD) ARE THE MOST SEVERE CONSEQUENCES OF KIDNEY INJURY. THEY ARE INTERCONNECTED SYNDROMES AS CKD PREDISPOSES TO AKI AND AKI MAY ACCELERATE CKD PROGRESSION. DESPITE THEIR GROWING IMPACT ON THE GLOBAL BURDEN OF DISEASE, THERE IS NO SATISFACTORY TREATMENT FOR AKI AND CURRENT THERAPEUTIC APPROACHES TO CKD REMAIN SUBOPTIMAL. RECENT RESEARCH HAS FOCUSED ON THE THERAPEUTIC TARGET POTENTIAL OF EPIGENETIC REGULATION OF GENE EXPRESSION, INCLUDING NON-CODING RNAS AND THE COVALENT MODIFICATIONS OF HISTONES AND DNA. INDEED, SEVERAL DRUGS TARGETING HISTONE MODIFICATIONS ARE IN CLINICAL USE OR UNDERGOING CLINICAL TRIALS. ACYL-LYSINE HISTONE MODIFICATIONS (E.G. METHYLATION, ACETYLATION, AND CROTONYLATION) HAVE MODULATED EXPERIMENTAL KIDNEY INJURY. MOST RECENTLY, INCREASED HISTONE LYSINE CROTONYLATION (KCR) WAS OBSERVED DURING EXPERIMENTAL AKI AND COULD BE REPRODUCED IN CULTURED TUBULAR CELLS EXPOSED TO INFLAMMATORY STRESS TRIGGERED BY THE CYTOKINE TWEAK. THE DEGREE OF KIDNEY HISTONE CROTONYLATION WAS MODULATED BY CROTONATE AVAILABILITY AND CROTONATE SUPPLEMENTATION PROTECTED FROM NEPHROTOXIC AKI. WE NOW REVIEW THE FUNCTIONAL RELEVANCE OF HISTONE CROTONYLATION IN KIDNEY DISEASE AND OTHER PATHOPHYSIOLOGICAL CONTEXTS, AS WELL AS THE IMPLICATIONS FOR THE DEVELOPMENT OF NOVEL THERAPEUTIC APPROACHES. THESE STUDIES PROVIDE INSIGHTS INTO THE OVERALL ROLE OF HISTONE CROTONYLATION IN HEALTH AND DISEASE. 2020 15 2972 35 GENETIC AND EPIGENETIC STUDIES IN DIABETIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE IS A WORLDWIDE HEALTH CRISIS, WHILE DIABETIC KIDNEY DISEASE (DKD) HAS BECOME THE LEADING CAUSE OF END-STAGE RENAL DISEASE (ESRD). DKD IS A MICROVASCULAR COMPLICATION AND OCCURS IN 30-40% OF DIABETES PATIENTS. EPIDEMIOLOGICAL INVESTIGATIONS AND CLINICAL OBSERVATIONS ON THE FAMILIAL CLUSTERING AND HERITABILITY IN DKD HAVE HIGHLIGHTED AN UNDERLYING GENETIC SUSCEPTIBILITY. FURTHERMORE, DKD IS A PROGRESSIVE AND LONG-TERM DIABETIC COMPLICATION, IN WHICH EPIGENETIC EFFECTS AND ENVIRONMENTAL FACTORS INTERACT WITH AN INDIVIDUAL'S GENETIC BACKGROUND. IN RECENT YEARS, RESEARCHERS HAVE UNDERTAKEN GENETIC AND EPIGENETIC STUDIES OF DKD IN ORDER TO BETTER UNDERSTAND ITS MOLECULAR MECHANISMS. IN THIS REVIEW, CLINICAL MATERIAL, RESEARCH APPROACHES AND EXPERIMENTAL DESIGNS THAT HAVE BEEN USED FOR GENETIC AND EPIGENETIC STUDIES OF DKD ARE DESCRIBED. CURRENT INFORMATION FROM GENETIC AND EPIGENETIC STUDIES OF DKD AND ESRD IN PATIENTS WITH DIABETES, INCLUDING THE APPROACHES OF GENOME-WIDE ASSOCIATION STUDY (GWAS) OR EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) AND CANDIDATE GENE ASSOCIATION ANALYSES, ARE SUMMARIZED. FURTHER INVESTIGATION OF MOLECULAR DEFECTS IN DKD WITH NEW APPROACHES SUCH AS NEXT GENERATION SEQUENCING ANALYSIS AND PHENOME-WIDE ASSOCIATION STUDY (PHEWAS) IS ALSO DISCUSSED. 2019 16 1384 44 DIABETES AND KIDNEY DISEASE: EMPHASIS ON TREATMENT WITH SGLT-2 INHIBITORS AND GLP-1 RECEPTOR AGONISTS. KIDNEY DISEASE IS A FREQUENT MICROVASCULAR COMPLICATION OF BOTH TYPE 1 AND TYPE 2 DIABETES. HISTORIC TRIALS HAVE DEMONSTRATED THAT A TIGHT GLYCAEMIC CONTROL IS THE MOST POWERFUL APPROACH TO DECREASE THE CHANCES OF DEVELOPING DIABETIC NEPHROPATHY. HOWEVER, HAVING AN HBA1C < 7% DOES NOT COMPLETELY SUPPRESS THE RISK OF KIDNEY DISEASE. THE OBSERVED RESIDUAL RISK IS LIKELY ASCRIBABLE TO TWO PHENOMENA: 1- THE PRESENCE OF RISK FACTORS AND ALTERATIONS ADDITIVE TO AND INDEPENDENT OF GLYCAEMIA, AND 2- THE ACTIVATION OF LONG-LASTING IMBALANCES BY PERIODS OF EXPOSURE TO UNCONTROLLED GLYCEMIA, A PHENOMENON REFERRED TO AS METABOLIC MEMORY OR LEGACY EFFECT. LONG-LASTING OXIDATIVE STRESS, EPIGENETIC ALTERATIONS, CELLULAR SENESCENCE, AND THE RESULTING CHRONIC LOW-GRADE INFLAMMATION ARE ALL CANDIDATE MECHANISMS EXPLAINING THE DEVELOPMENT OF NEPHROPATHY DESPITE PROPER CONTROL OF RISK FACTORS. RECENTLY, TWO CLASSES OF DRUGS, I.E. GLUCAGON-LIKE PEPTIDE (GLP) 1 RECEPTOR AGONISTS (RA) AND SODIUM-GLUCOSE TRANSPORTER 2 INHIBITORS (SGLT-I) HAVE CHANGED THIS SCENARIO. INDEED, CARDIOVASCULAR OUTCOME AND OTHER TRIALS HAVE CLEARLY SHOWN A RENOPROTECTIVE EFFECT FOR THESE DRUGS, WELL-BEYOND THEIR GLUCOSE-LOWERING PROPERTIES. IN THIS REVIEW, WE SUMMARIZE: 1- SELECTED KEY TRIALS AND MECHANISMS UNDERLYING THE DEVELOPMENT OF DIABETIC KIDNEY DISEASE AND 2- THE RESULTS RELATIVE TO RENAL ENDPOINTS IN CLINICAL TRIALS OF GLP-1 RA AND SGLT-2I. THEN, WE BRIEFLY DISCUSS SOME OF THE HYPOTHESES POSITED TO EXPLAIN THE MARKED RENOPROTECTIVE PROPERTIES OF THESE TWO CLASSES, EVIDENCING THE STILL EXISTING GAPS IN KNOWLEDGE AND PROPOSING FUTURE DIRECTIONS TO FURTHER IMPLEMENT THE USE OF THESE POWERFUL, DISEASE-MODIFYING DRUGS. 2021 17 2795 39 FATTY LIVER AND CHRONIC KIDNEY DISEASE: NOVEL MECHANISTIC INSIGHTS AND THERAPEUTIC OPPORTUNITIES. CHRONIC KIDNEY DISEASE (CKD) IS A RISK FACTOR FOR END-STAGE RENAL DISEASE (ESRD) AND CARDIOVASCULAR DISEASE (CVD). ESRD OR CVD DEVELOP IN A SUBSTANTIAL PROPORTION OF PATIENTS WITH CKD RECEIVING STANDARD-OF-CARE THERAPY, AND MORTALITY IN CKD REMAINS UNCHANGED. THESE DATA SUGGEST THAT KEY PATHOGENETIC MECHANISMS UNDERLYING CKD PROGRESSION GO UNAFFECTED BY CURRENT TREATMENTS. GROWING EVIDENCE SUGGESTS THAT NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) AND CKD SHARE COMMON PATHOGENETIC MECHANISMS AND POTENTIAL THERAPEUTIC TARGETS. COMMON NUTRITIONAL CONDITIONS PREDISPOSING TO BOTH NAFLD AND CKD INCLUDE EXCESSIVE FRUCTOSE INTAKE AND VITAMIN D DEFICIENCY. MODULATION OF NUCLEAR TRANSCRIPTION FACTORS REGULATING KEY PATHWAYS OF LIPID METABOLISM, INFLAMMATION, AND FIBROSIS, INCLUDING PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS AND FARNESOID X RECEPTOR, IS ADVANCING TO STAGE III CLINICAL DEVELOPMENT. THE RELEVANCE OF EPIGENETIC REGULATION IN THE PATHOGENESIS OF NAFLD AND CKD IS ALSO EMERGING, AND MODULATION OF MICRORNA21 IS A PROMISING THERAPEUTIC TARGET. ALTHOUGH SINGLE ANTIOXIDANT SUPPLEMENTATION HAS YIELDED VARIABLE RESULTS, MODULATION OF KEY EFFECTORS OF REDOX REGULATION AND MOLECULAR SENSORS OF INTRACELLULAR ENERGY, NUTRIENT, OR OXYGEN STATUS SHOW PROMISING PRECLINICAL RESULTS. OTHER EMERGING THERAPEUTIC APPROACHES TARGET KEY MEDIATORS OF INFLAMMATION, SUCH AS CHEMOKINES; FIBROGENESIS, SUCH AS GALECTIN-3; OR GUT DYSFUNCTION THROUGH GUT MICROBIOTA MANIPULATION AND INCRETIN-BASED THERAPIES. FURTHERMORE, NAFLD PER SE AFFECTS CKD THROUGH LIPOPROTEIN METABOLISM AND HEPATOKINE SECRETION, AND CONVERSELY, TARGETING THE RENAL TUBULE BY SODIUM-GLUCOSE COTRANSPORTER 2 INHIBITORS CAN IMPROVE BOTH CKD AND NAFLD. IMPLICATIONS FOR THE TREATMENT OF NAFLD AND CKD ARE DISCUSSED IN LIGHT OF THIS NEW THERAPEUTIC ARMAMENTARIUM. 2016 18 4016 26 LOW-DOSE HYDRALAZINE PREVENTS FIBROSIS IN A MURINE MODEL OF ACUTE KIDNEY INJURY-TO-CHRONIC KIDNEY DISEASE PROGRESSION. ACUTE KIDNEY INJURY (AKI) AND PROGRESSIVE CHRONIC KIDNEY DISEASE (CKD) ARE INTRINSICALLY TIED SYNDROMES. IN THIS REGARD, THE ACUTELY INJURED KIDNEY OFTEN DOES NOT ACHIEVE ITS FULL REGENERATIVE CAPACITY AND AKI DIRECTLY TRANSITIONS INTO PROGRESSIVE CKD ASSOCIATED WITH TUBULOINTERSTITIAL FIBROSIS. UNDERLYING MECHANISMS OF SUCH AKI-TO-CKD PROGRESSION ARE STILL INCOMPLETELY UNDERSTOOD AND SPECIFIC THERAPEUTIC INTERVENTIONS ARE STILL ELUSIVE. BECAUSE EPIGENETIC MODIFICATIONS PLAY A ROLE IN MAINTAINING TISSUE FIBROSIS, WE USED A MURINE MODEL OF ISCHEMIA-REPERFUSION INJURY TO DETERMINE WHETHER ABERRANT PROMOTER METHYLATION OF RASAL1 CONTRIBUTES CAUSALLY TO THE SWITCH BETWEEN PHYSIOLOGICAL REGENERATION AND TUBULOINTERSTITIAL FIBROGENESIS, A HALLMARK OF AKI-TO-CKD PROGRESSION. IT IS KNOWN THAT THE ANTIHYPERTENSIVE DRUG HYDRALAZINE HAS DEMETHYLATING ACTIVITY, AND THAT ITS OPTIMUM DEMETHYLATING ACTIVITY OCCURS AT CONCENTRATIONS BELOW BLOOD PRESSURE-LOWERING DOSES. ADMINISTRATION OF LOW-DOSE HYDRALAZINE EFFECTIVELY INDUCED EXPRESSION OF HYDROXYLASE TET3, WHICH CATALYZED RASAL1 HYDROXYMETHYLATION AND SUBSEQUENT RASAL1 PROMOTER DEMETHYLATION. HYDRALAZINE-INDUCED CPG PROMOTER DEMETHYLATION SUBSEQUENTLY ATTENUATED RENAL FIBROSIS AND PRESERVED EXCRETORY RENAL FUNCTION INDEPENDENT OF ITS BLOOD PRESSURE-LOWERING EFFECTS. IN COMPARISON, RASAL1 DEMETHYLATION AND INHIBITION OF TUBULOINTERSTITIAL FIBROSIS WAS NOT DETECTED UPON ADMINISTRATION OF THE ANGIOTENSIN-CONVERTING ENZYME INHIBITOR RAMIPRIL IN THIS MODEL. THUS, RASAL1 PROMOTER METHYLATION AND SUBSEQUENT TRANSCRIPTIONAL RASAL1 SUPPRESSION PLAYS A CAUSAL ROLE IN AKI-TO-CKD PROGRESSION. 2017 19 4513 22 MULTI-OMIC APPROACHES TO ACUTE KIDNEY INJURY AND REPAIR. THE KIDNEY HAS A REMARKABLE REGENERATIVE CAPACITY. IN RESPONSE TO ISCHEMIC OR TOXIC INJURY, PROXIMAL TUBULE CELLS CAN PROLIFERATE TO REBUILD DAMAGED TUBULES AND RESTORE KIDNEY FUNCTION. HOWEVER, SEVERE ACUTE KIDNEY INJURY (AKI) OR RECURRENT AKI EVENTS CAN LEAD TO MALADAPTIVE REPAIR AND DISEASE PROGRESSION FROM AKI TO CHRONIC KIDNEY DISEASE (CKD). THE APPLICATION OF SINGLE CELL TECHNOLOGIES HAS IDENTIFIED INJURED PROXIMAL TUBULE CELL STATES WEEKS AFTER AKI, DISTINGUISHED BY A PRO-INFLAMMATORY SENESCENT MOLECULAR SIGNATURE. EPIGENETIC STUDIES HIGHLIGHTED DYNAMIC CHANGES IN THE CHROMATIN LANDSCAPE OF THE KIDNEY FOLLOWING AKI AND DESCRIBED KEY TRANSCRIPTION FACTORS LINKED TO THE AKI RESPONSE. THE INTEGRATION OF MULTI-OMIC TECHNOLOGIES OPENS NEW POSSIBILITIES TO IMPROVE OUR UNDERSTANDING OF AKI AND THE DRIVING FORCES BEHIND THE AKI-TO-CKD TRANSITION, WITH THE ULTIMATE GOAL OF DESIGNING TAILORED DIAGNOSTIC AND THERAPEUTIC STRATEGIES TO IMPROVE AKI OUTCOMES AND PREVENT KIDNEY DISEASE PROGRESSION. 2021 20 5370 25 RECENT ADVANCES IN UNDERSTANDING OF CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS DEFINED AS ANY CONDITION THAT CAUSES REDUCED KIDNEY FUNCTION OVER A PERIOD OF TIME. FIBROSIS, TUBULAR ATROPHY AND INTERSTITIAL INFLAMMATION ARE THE HALLMARK OF PATHOLOGICAL FEATURES IN CKD. REGARDLESS OF INITIAL INSULT, CKD HAS SOME COMMON PATHWAYS LEADING CKD TO END-STAGE KIDNEY DISEASE, INCLUDING HYPOXIA IN THE TUBULOINTERSTITIUM AND PROTEINURIA. RECENT ADVANCES IN GENOME EDITING TECHNOLOGIES AND STEM CELL RESEARCH GIVE GREAT INSIGHTS TO UNDERSTAND THE PATHOGENESIS OF CKD, INCLUDING IDENTIFICATIONS OF THE ORIGINS OF RENAL MYOFIBROBLASTS AND TUBULAR EPITHELIAL CELLS UPON INJURY. ENVIRONMENTAL FACTORS SUCH AS HYPOXIA, OXIDATIVE STRESS, AND EPIGENETIC FACTORS IN RELATION TO CKD ARE ALSO DISCUSSED. 2015