1 3887 58 KLOTHO METHYLATION IS LINKED TO UREMIC TOXINS AND CHRONIC KIDNEY DISEASE. EPIGENETIC REGULATION PLAYS A MAJOR ROLE IN UREMIC TOXIN-INDUCED CHRONIC KIDNEY DISEASE (CKD) PROGRESSION. THE KLOTHO PROTEIN IS A KEY MODULATOR OF HOMEOSTASIS IN RENAL FUNCTION. UREMIC TOXIN ACCUMULATION CAN INDUCE DNA METHYLTRANSFERASE (DNMT) PROTEIN EXPRESSION, WHICH IS INVOLVED IN THE SILENCING OF KLOTHO THROUGH HYPERMETHYLATION. TREATMENT WITH DNMT INHIBITORS CAN INDUCE A HYPERMETHYLATED STATUS OF KLOTHO AND SUPPRESS MRNA AND PROTEIN EXPRESSION. EPIGENETIC TARGETING OF SPECIFIC GENES MAY BECOME AN EFFECTIVE STRATEGY TO PREVENT PROGRESSION OF UREMIA-RELATED CKD. 2012 2 3654 27 INDOXYL SULFATE ACCELERATES VASCULAR SMOOTH MUSCLE CELL CALCIFICATION VIA MICRORNA-29B DEPENDENT REGULATION OF WNT/BETA-CATENIN SIGNALING. VASCULAR CALCIFICATION (VC) IS A VERY COMMON PHENOMENON IN PATIENTS WITH CHRONIC KIDNEY DISEASE(CKD) AND IT INCREASES THE INCIDENCE OF CARDIOVASCULAR DISEASE AND LEADS TO HIGH MORTALITY IN CKD PATIENTS. IT HAS BEEN REPORTED THAT SOME MICRORNAS (MIRS) PLAY ROLES IN VASCULAR CALCIFICATION AS AN EPIGENETIC REGULATOR. INDOXYL SULFATE (IS) IS A PROTEIN-BOUND UREMIC TOXIN WHICH HAS BEEN PROVEN AS ONE OF THE MAJOR RISK FACTORS OF CARDIOVASCULAR DISEASE IN CKD. HERE WE INVESTIGATED WHETHER MICRORNA-29B (MIR-29B) IS INVOLVED IN IS-INDUCED VASCULAR CALCIFICATION. WE FOUND THAT VASCULAR MIR-29B WAS DOWN-REGULATED IN RADIAL ARTERIES OF PATIENTS WITH END-STAGE RENAL DISEASE. CONSISTENTLY, IS ALSO DECREASED MIR-29B EXPRESSION IN HUMAN AORTIC SMOOTH MUSCLE CELLS (HASMCS) AND POTENTIATED THEIR CALCIFICATION. MIR-29B MIMICS SIGNIFICANTLY SUPPRESSED, WHILE MIR-29B ANTI-MIR MARKEDLY ENHANCED, IS-INDUCED RUNT-RELATED TRANSCRIPTION FACTOR 2 AND OSTEOPONTIN EXPRESSION. THE EXPRESSION OF WNT7B/BETA-CATENIN IN RADIAL ARTERIES WAS HIGHER IN END STAGE RENAL DISEASE THAN IN CONTROL GROUP, AND IS INCREASED WNT7B/BETA-CATENIN EXPRESSION IN HASMCS AS EARLY AS 3DAYS AFTER STIMULATION. FURTHERMORE, MIR-29B MIMICS POTENTLY REPRESSED WNT7B/BETA-CATENIN PROTEIN EXPRESSION IN HASMCS, WHEREAS MIR-29B ANTI-MIR INCREASED THEIR EXPRESSION, INDICATING MIR-29B INDEED NEGATIVELY REGULATES WNT7B/BETA-CATENIN SIGNALING. DICKKOPF-1 PROTEIN, THE WNT/BETA-CATENIN SIGNALING INHIBITOR, SUPPRESSED ANTI-MIR-29B-ENHANCED HASMCS CALCIFICATION. OUR DATA THUS INDICATE THAT MIR-29B DOWNREGULATION AND WNT/BETA-CATENIN SIGNALING ACTIVATION MAY BE THE KEY MECHANISM OF IS INDUCED VASCULAR CALCIFICATION IN CHRONIC KIDNEY DISEASE. 2018 3 6699 24 VASCULAR CALCIFICATION IN CKD: NEW INSIGHTS INTO ITS MECHANISMS. VASCULAR CALCIFICATION (VC) IS A COMMON COMPLICATION OF CHRONIC KIDNEY DISEASE (CKD) AND CONTRIBUTES TO AN INCREASED RISK OF CARDIOVASCULAR MORBIDITY AND MORTALITY. HOWEVER, EFFECTIVE THERAPIES ARE STILL UNAVAILABLE AT PRESENT. IT HAS BEEN WELL ESTABLISHED THAT VC ASSOCIATED WITH CKD IS NOT A PASSIVE PROCESS OF CALCIUM PHOSPHATE DEPOSITION, BUT AN ACTIVELY REGULATED AND CELL-MEDIATED PROCESS THAT SHARES MANY SIMILARITIES WITH BONE FORMATION. ADDITIONALLY, NUMEROUS STUDIES HAVE SUGGESTED THAT CKD PATIENTS HAVE SPECIFIC RISK FACTORS AND CONTRIBUTORS TO THE DEVELOPMENT OF VC, SUCH AS HYPERPHOSPHATEMIA, UREMIC TOXINS, OXIDATIVE STRESS AND INFLAMMATION. ALTHOUGH RESEARCH EFFORTS IN THE PAST DECADE HAVE GREATLY IMPROVED OUR KNOWLEDGE OF THE MULTIPLE FACTORS AND MECHANISMS INVOLVED IN CKD-RELATED VC, MANY QUESTIONS REMAIN UNANSWERED. MOREOVER, STUDIES FROM THE PAST DECADE HAVE DEMONSTRATED THAT EPIGENETIC MODIFICATIONS ABNORMALITIES, SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND NONCODING RNAS, PLAY AN IMPORTANT ROLE IN THE REGULATION OF VC. THIS REVIEW SEEKS TO PROVIDE AN OVERVIEW OF THE PATHOPHYSIOLOGICAL AND MOLECULAR MECHANISMS OF VC ASSOCIATED WITH CKD, MAINLY FOCUSING ON THE INVOLVEMENT OF EPIGENETIC MODIFICATIONS IN THE INITIATION AND PROGRESSION OF UREMIC VC, WITH THE AIM TO DEVELOP PROMISING THERAPIES FOR CKD-RELATED CARDIOVASCULAR EVENTS IN THE FUTURE. 2023 4 1648 19 DOES THE UREMIC MILIEU AFFECT THE EPIGENOTYPE? EPIGENETICS IS A DISCIPLINE THAT FOR MANY YEARS HAS LANGUISHED IN THE SHADOW OF ITS GENOMIC BIG BROTHER. BECAUSE OUR UNDERSTANDING OF THE ROLE PLAYED BY EPIGENETICS IN CHRONIC KIDNEY DISEASE REMAINS IN ITS INFANCY, FURTHER STUDIES ARE NEEDED TO UNDERSTAND THE ASSOCIATIONS, FOR INSTANCE, OF ABERRANT DNA METHYLATION IN RELATION TO UREMIC DYSMETABOLISM, AND ITS PRESUMABLY VERY COMPLEX INTERACTIONS IN THE DEVELOPMENT OF PREMATURE UREMIC VASCULAR DISEASE. FURTHER RESEARCH IS ALSO NEEDED TO STUDY THE ASSOCIATION BETWEEN ABERRANT GLOBAL DNA-METHYLATION, GENE-LEVEL METHYLATION STATUS, AND THE SILENCING (OR ACTIVATION) OF CANDIDATE GENES ASSOCIATED WITH ATHEROSCLEROSIS. INSOFAR AS IT SEEMS POSSIBLE TO MANIPULATE THE EPIGENOME, THE EFFECTS OF VARIOUS EPIGENETIC-TARGETED AND PATHWAY-TARGETED THERAPEUTIC APPROACHES ON UNBALANCED DNA METHYLATION, GENE SILENCING, AND VASCULAR HEALTH AND OUTCOMES SHOULD BE EXPLORED FURTHER IN UREMIA. 2009 5 4415 21 MOLECULAR AND CELLULAR MECHANISMS THAT INDUCE ARTERIAL CALCIFICATION BY INDOXYL SULFATE AND P-CRESYL SULFATE. THE PROTEIN-BOUND UREMIC TOXINS, INDOXYL SULFATE (IS) AND P-CRESYL SULFATE (PCS), ARE CONSIDERED TO BE HARMFUL VASCULAR TOXINS. ARTERIAL MEDIA CALCIFICATION, OR THE DEPOSITION OF CALCIUM PHOSPHATE CRYSTALS IN THE ARTERIES, CONTRIBUTES SIGNIFICANTLY TO CARDIOVASCULAR COMPLICATIONS, INCLUDING LEFT VENTRICULAR HYPERTROPHY, HYPERTENSION, AND IMPAIRED CORONARY PERFUSION IN THE ELDERLY AND PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) AND DIABETES. RECENTLY, WE REPORTED THAT BOTH IS AND PCS TRIGGER MODERATE TO SEVERE CALCIFICATION IN THE AORTA AND PERIPHERAL VESSELS OF CKD RATS. THIS REVIEW DESCRIBES THE MOLECULAR AND CELLULAR MECHANISMS BY WHICH THESE UREMIC TOXINS INDUCE ARTERIAL MEDIA CALCIFICATION. A COMPLEX INTERPLAY BETWEEN INFLAMMATION, COAGULATION, AND LIPID METABOLISM PATHWAYS, INFLUENCED BY EPIGENETIC FACTORS, IS CRUCIAL IN IS/PCS-INDUCED ARTERIAL MEDIA CALCIFICATION. HIGH LEVELS OF GLUCOSE ARE LINKED TO THESE EVENTS, SUGGESTING THAT A GOOD BALANCE BETWEEN GLUCOSE AND LIPID LEVELS MIGHT BE IMPORTANT. ON THE CELLULAR LEVEL, EFFECTS ON ENDOTHELIAL CELLS, WHICH ACT AS THE PRIMARY SENSORS OF CIRCULATING PATHOLOGICAL TRIGGERS, MIGHT BE AS IMPORTANT AS THOSE ON VASCULAR SMOOTH MUSCLE CELLS. ENDOTHELIAL DYSFUNCTION, PROVOKED BY IS AND PCS TRIGGERED OXIDATIVE STRESS, MAY BE CONSIDERED A KEY EVENT IN THE ONSET AND DEVELOPMENT OF ARTERIAL MEDIA CALCIFICATION. IN THIS REVIEW A NUMBER OF IMPORTANT OUTSTANDING QUESTIONS SUCH AS THE ROLE OF MIRNA'S, PHENOTYPIC SWITCHING OF BOTH ENDOTHELIAL AND VASCULAR SMOOTH MUSCLE CELLS AND NEW TYPES OF PROGRAMMED CELL DEATH IN ARTERIAL MEDIA CALCIFICATION RELATED TO PROTEIN-BOUND UREMIC TOXINS ARE PUT FORWARD AND DISCUSSED. 2020 6 3655 28 INDOXYL SULFATE ENHANCE THE HYPERMETHYLATION OF KLOTHO AND PROMOTE THE PROCESS OF VASCULAR CALCIFICATION IN CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS A STATE OF KLOTHO DEFICIENCY. THE KLOTHO EXPRESSION MAY BE SUPPRESSED DUE TO DNA HYPERMETHYLATION IN CANCER CELLS SO WE HAVE INVESTIGATED THE EFFECTS AND POSSIBLE MECHANISMS BY WHICH KLOTHO EXPRESSION IS REGULATED IN HUMAN AORTIC SMOOTH MUSCLE CELLS (HASMCS). THE VASCULAR KLOTHO HYPERMETHYLATION IN RADIAL ARTERIES OF PATIENTS WITH END-STAGE RENAL DISEASE WAS DESCRIBED. CULTURED HASMCS AND 5/6-NEPHRECTOMIZED SPRAGUE DAWLEY (SD) RATS TREATED WITH INDOXYL SULFATE (IS) WERE USED AS IN VITRO AND IN VIVO MODELS, RESPECTIVELY. IS INCREASED CPG HYPERMETHYLATION OF THE KLOTHO GENE AND DECREASED KLOTHO EXPRESSION IN HASMCS, AND POTENTIATED HASMCS CALCIFICATION. THE EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) 1 AND 3A IN HASMCS TREATED WITH IS WAS SIGNIFICANTLY INCREASED AND SPECIFIC INHIBITION OF DNA METHYLTRANSFERASE 1 BY 5-AZA-2'-DEOXYCYTIDINE(5AZA-2DC) CAUSED DEMETHYLATION OF THE KLOTHO GENE AND INCREASED KLOTHO EXPRESSION. IN RATS, INJECTION OF IS POTENTIATED VASCULAR CALCIFICATION, INCREASED CPG HYPERMETHYLATION OF THE KLOTHO GENE AND DECREASED KLOTHO EXPRESSION IN THE AORTIC MEDIAL LAYER AND ALL OF THESE CHANGES COULD BE REVERTED BY 5AZA-2DC TREATMENT. TRANSCRIPTIONAL SUPPRESSION OF VASCULAR KLOTHO GENE EXPRESSION BY IS AND EPIGENETIC MODIFICATION OF KLOTHO BY IS MAY BE AN IMPORTANT PATHOLOGICAL MECHANISM OF VASCULAR CALCIFICATION IN CKD. 2016 7 5363 14 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 8 6409 23 THE SIGNALING OF CELLULAR SENESCENCE IN DIABETIC NEPHROPATHY. DIABETIC NEPHROPATHY IS THE LEADING CAUSE OF CHRONIC KIDNEY DISEASE (CKD) IN WESTERN COUNTRIES. NOTABLY, IT HAS A RAPIDLY RISING PREVALENCE IN CHINA. THE PATIENTS, COMMONLY COMPLICATED WITH CARDIOVASCULAR DISEASES AND NEUROLOGIC DISORDERS, ARE AT HIGH RISK TO PROGRESS INTO END-STAGE RENAL DISEASE (ESRD) AND DEATH. HOWEVER, THE PATHOGENIC MECHANISMS OF DIABETIC NEPHROPATHY HAVE NOT BEEN DETERMINED. CELLULAR SENESCENCE, WHICH RECENTLY HAS GAINED BROAD ATTENTION, IS THOUGHT TO BE AN IMPORTANT PLAYER IN THE ONSET AND DEVELOPMENT OF DIABETIC NEPHROPATHY. IN THIS ISSUE, WE GENERALLY REVIEW THE MECHANISMS OF CELLULAR SENESCENCE IN DIABETIC NEPHROPATHY, WHICH INVOLVE TELOMERE ATTRITION, DNA DAMAGE, EPIGENETIC ALTERATIONS, MITOCHONDRIAL DYSFUNCTION, LOSS OF KLOTHO, WNT/BETA-CATENIN SIGNALING ACTIVATION, PERSISTENT INFLAMMATION, AND ACCUMULATION OF UREMIC TOXINS. MOREOVER, WE HIGHLIGHT THE POTENTIAL THERAPEUTIC TARGETS OF CELLULAR SENESCENCE IN DIABETIC NEPHROPATHY AND PROVIDE IMPORTANT CLUES FOR CLINICAL STRATEGIES. 2019 9 6700 23 VASCULAR CALCIFICATION MECHANISMS: UPDATES AND RENEWED INSIGHT INTO SIGNALING PATHWAYS INVOLVED IN HIGH PHOSPHATE-MEDIATED VASCULAR SMOOTH MUSCLE CELL CALCIFICATION. VASCULAR CALCIFICATION (VC) IS ASSOCIATED WITH AGING, CARDIOVASCULAR AND RENAL DISEASES AND RESULTS IN POOR MORBIDITY AND INCREASED MORTALITY. VC OCCURS IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD), A CONDITION THAT IS ASSOCIATED WITH HIGH SERUM PHOSPHATE (PI) AND SEVERE CARDIOVASCULAR CONSEQUENCES. HIGH SERUM PI LEVEL IS RELATED TO SOME PATHOLOGIES WHICH AFFECT THE BEHAVIOUR OF VASCULAR CELLS, INCLUDING PLATELETS, ENDOTHELIAL CELLS (ECS) AND SMOOTH MUSCLE CELLS (SMCS), AND PLAYS A CENTRAL ROLE IN PROMOTING VC. VC IS A COMPLEX, ACTIVE AND CELL-MEDIATED PROCESS INVOLVING THE TRANSDIFFERENTIATION OF VASCULAR SMCS TO A BONE-LIKE PHENOTYPE, SYSTEMIC INFLAMMATION, DECREASED ANTI-CALCIFIC EVENTS (LOSS OF CALCIFICATION INHIBITORS), LOSS IN SMC LINEAGE MARKERS AND ENHANCED PRO-CALCIFIC MICRORNAS (MIRS), AN INCREASED INTRACELLULAR CALCIUM LEVEL, APOPTOSIS, ABERRANT DNA DAMAGE RESPONSE (DDR) AND SENESCENCE OF VASCULAR SMCS. THIS REVIEW GIVES A BRIEF OVERVIEW OF THE CURRENT KNOWLEDGE OF VC MECHANISMS WITH A PARTICULAR FOCUS ON PI-INDUCED CHANGES IN THE VASCULAR WALL IMPORTANT IN PROMOTING CALCIFICATION. IN ADDITION TO REVIEWING THE MAIN FINDINGS, THIS REVIEW ALSO SHEDS LIGHT ON DIRECTIONS FOR FUTURE RESEARCH IN THIS AREA AND DISCUSSES EMERGING PATHWAYS SUCH AS PI-REGULATED INTRACELLULAR CALCIUM SIGNALING, EPIGENETICS, OXIDATIVE DNA DAMAGE AND SENESCENCE-MEDIATED MECHANISMS THAT MAY PLAY CRITICAL, YET TO BE EXPLORED, REGULATORY AND DRUGGABLE ROLES IN LIMITING VC. 2021 10 1665 26 DOWNREGULATION OF KIDNEY PROTECTIVE FACTORS BY INFLAMMATION: ROLE OF TRANSCRIPTION FACTORS AND EPIGENETIC MECHANISMS. CHRONIC KIDNEY DISEASE (CKD) IS ASSOCIATED TO AN INCREASED RISK OF DEATH, CKD PROGRESSION, AND ACUTE KIDNEY INJURY (AKI) EVEN FROM EARLY STAGES, WHEN GLOMERULAR FILTRATION RATE (GFR) IS PRESERVED. THE LINK BETWEEN EARLY CKD AND THESE RISKS IS UNCLEAR, SINCE THERE IS NO ACCUMULATION OF UREMIC TOXINS. HOWEVER, PATHOLOGICAL ALBUMINURIA AND KIDNEY INFLAMMATION ARE FREQUENT FEATURES OF EARLY CKD, AND THE PRODUCTION OF KIDNEY PROTECTIVE FACTORS MAY BE DECREASED. INDEED, KLOTHO EXPRESSION IS ALREADY DECREASED IN CKD CATEGORY G1 (NORMAL GFR). KLOTHO HAS ANTI-AGING AND NEPHROPROTECTIVE PROPERTIES, AND DECREASED KLOTHO LEVELS MAY CONTRIBUTE TO INCREASE THE RISK OF DEATH, CKD PROGRESSION, AND AKI. IN THIS REVIEW, WE DISCUSS THE DOWNREGULATION BY MEDIATORS OF INFLAMMATION OF MOLECULES WITH SYSTEMIC AND/OR RENAL LOCAL PROTECTIVE FUNCTIONS, EXEMPLIFIED BY KLOTHO AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA COACTIVATOR-1ALPHA (PGC-1ALPHA), A TRANSCRIPTION FACTOR THAT PROMOTES MITOCHONDRIAL BIOGENESIS. CYTOKINES SUCH AS TWEAK, TNF-ALPHA, OR TRANSFORMING GROWTH FACTOR -BETA1 PRODUCED LOCALLY DURING KIDNEY INJURY OR RELEASED FROM INFLAMMATORY SITES AT OTHER ORGANS MAY DECREASE KIDNEY EXPRESSION OF KLOTHO AND PGC-1ALPHA OR LEAD TO SUBOPTIMAL RECRUITMENT OF THESE NEPHROPROTECTIVE PROTEINS. TRANSCRIPTION FACTORS (E.G., SMAD3 AND NF-KAPPAB) AND EPIGENETIC MECHANISMS (E.G., HISTONE ACETYLATION OR METHYLATION) CONTRIBUTE TO DOWNREGULATE THE EXPRESSION OF KLOTHO AND/OR PGC-1ALPHA, WHILE HISTONE CROTONYLATION PROMOTES PGC-1ALPHA EXPRESSION. NF-KAPPABIZ FACILITATES THE REPRESSIVE EFFECT OF NF-KAPPAB ON KLOTHO EXPRESSION. A DETAILED UNDERSTANDING OF THESE MEDIATORS MAY CONTRIBUTE TO THE DEVELOPMENT OF NOVEL THERAPEUTIC APPROACHES TO PREVENT CKD PROGRESSION AND ITS NEGATIVE IMPACT ON MORTALITY AND AKI. 2016 11 2490 23 EPIGENETICALLY REGULATED INFLAMMATION IN VASCULAR SENESCENCE AND RENAL PROGRESSION OF CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) AND ITS COMPLICATIONS, INCLUDING VASCULAR SENESCENCE AND PROGRESSIVE RENAL FIBROSIS, ARE ASSOCIATED WITH INFLAMMATION. VASCULAR SENESCENCE, IN PARTICULAR, HAS EMERGED AS AN INSTRUMENTAL MEDIATOR OF VASCULAR INFLAMMATION THAT POTENTIALLY WORSENS RENAL FUNCTION. EPIGENETICALLY REGULATED INFLAMMATION INVOLVING HISTONE MODIFICATION, DNA METHYLATION, ACTIONS OF MICRORNAS AND OTHER NON-CODING RNAS, AND THEIR RECIPROCAL REACTIONS DURING VASCULAR SENESCENCE AND INFLAMMAGING ARE UNDERAPPRECIATED. THEIR SYNERGISTIC EFFECTS CAN CONTRIBUTE TO CKD PROGRESSION. VASCULAR SENOTHERAPEUTICS OR PHARMACOLOGICAL ANTI-SENESCENT THERAPIES BASED ON EPIGENETIC MACHINERIES CAN THEREFORE BE PLAUSIBLE OPTIONS FOR AMELIORATING VASCULAR AGING AND EVEN HALTING THE WORSENING OF RENAL FIBROSIS. THESE INCLUDE HISTONE DEACETYLASE MODULATORS, HISTONE METHYLTRANSFERASE MODULATORS, OTHER HISTONE MODIFICATION EFFECTORS, DNA METHYLTRANSFERASE INHIBITORS, TELOMERASE REVERSE TRANSCRIPTASE ENHANCERS, MICRORNA MIMIC DELIVERY, AND SMALL MOLECULES WITH MICRORNA-REGULATING POTENTIALS. SOME OF THESE MOLECULES HAVE ALREADY BEEN TESTED AND HAVE SHOWN ANECDOTAL EVIDENCE FOR TREATING UREMIC VASCULOPATHY AND RENAL FIBROSIS, SUPPORTING THE FEASIBILITY OF THIS APPROACH. 2022 12 5370 14 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 13 6717 29 VITAMIN B SUPPLEMENTATION AND NUTRITIONAL INTAKE OF METHYL DONORS IN PATIENTS WITH CHRONIC KIDNEY DISEASE: A CRITICAL REVIEW OF THE IMPACT ON EPIGENETIC MACHINERY. CARDIOVASCULAR MORBIDITY AND MORTALITY ARE SEVERAL-FOLD HIGHER IN PATIENTS WITH ADVANCED CHRONIC KIDNEY DISEASE (CKD) AND END-STAGE RENAL DISEASE (ESRD) THAN IN THE GENERAL POPULATION. HYPERHOMOCYSTEINEMIA HAS UNDOUBTEDLY A CENTRAL ROLE IN SUCH A PROMINENT CARDIOVASCULAR BURDEN. THE LEVELS OF HOMOCYSTEINE ARE REGULATED BY METHYL DONORS (FOLATE, METHIONINE, CHOLINE, BETAINE), AND COFACTORS (VITAMIN B6, VITAMIN B12,). UREMIA-INDUCED HYPERHOMOCYSTEINEMIA HAS AS ITS MAIN TARGETS DNA METHYLTRANSFERASES, AND THIS LEADS TO AN ALTERED EPIGENETIC CONTROL OF GENES REGULATED THROUGH METHYLATION. IN RENAL PATIENTS, THE EPIGENETIC LANDSCAPE IS STRICTLY CORRELATED WITH THE UREMIC PHENOTYPE AND DEPENDENT ON DIETARY INTAKE OF MICRONUTRIENTS, INFLAMMATION, GUT MICROBIOME, INFLAMMATORY STATUS, OXIDATIVE STRESS, AND LIFESTYLE HABITS. ALL THESE FACTORS ARE KEY CONTRIBUTORS IN METHYLOME MAINTENANCE AND IN THE MODULATION OF GENE TRANSCRIPTION THROUGH DNA HYPO- OR HYPERMETHYLATION IN CKD. THIS IS AN OVERVIEW OF THE EPIGENETIC CHANGES RELATED TO DNA METHYLATION IN PATIENTS WITH ADVANCED CKD AND ESRD. WE EXPLORED THE CURRENTLY AVAILABLE DATA ON THE MOLECULAR DYSREGULATIONS RESULTING FROM ALTERED GENE EXPRESSION IN UREMIA. SPECIAL ATTENTION WAS PAID TO THE EFFICACY OF B-VITAMINS SUPPLEMENTATION AND DIETARY INTAKE OF METHYL DONORS ON HOMOCYSTEINE LOWERING AND CARDIOVASCULAR PROTECTION. 2020 14 5596 20 ROLES OF HISTONE ACETYLATION MODIFIERS AND OTHER EPIGENETIC REGULATORS IN VASCULAR CALCIFICATION. VASCULAR CALCIFICATION (VC) IS CHARACTERIZED BY CALCIUM DEPOSITION INSIDE ARTERIES AND IS CLOSELY ASSOCIATED WITH THE MORBIDITY AND MORTALITY OF ATHEROSCLEROSIS, CHRONIC KIDNEY DISEASE, DIABETES, AND OTHER CARDIOVASCULAR DISEASES (CVDS). VC IS NOW WIDELY KNOWN TO BE AN ACTIVE PROCESS OCCURRING IN VASCULAR SMOOTH MUSCLE CELLS (VSMCS) INVOLVING MULTIPLE MECHANISMS AND FACTORS. THESE MECHANISMS SHARE FEATURES WITH THE PROCESS OF BONE FORMATION, SINCE THE PHENOTYPE SWITCHING FROM THE CONTRACTILE TO THE OSTEOCHONDROGENIC PHENOTYPE ALSO OCCURS IN VSMCS DURING VC. IN ADDITION, VC CAN BE REGULATED BY EPIGENETIC FACTORS, INCLUDING DNA METHYLATION, HISTONE MODIFICATION, AND NONCODING RNAS. ALTHOUGH VC IS COMMONLY OBSERVED IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND CVD, SPECIFIC DRUGS FOR VC HAVE NOT BEEN DEVELOPED. THUS, DISCOVERING NOVEL THERAPEUTIC TARGETS MAY BE NECESSARY. IN THIS REVIEW, WE SUMMARIZE THE CURRENT EXPERIMENTAL EVIDENCE REGARDING THE ROLE OF EPIGENETIC REGULATORS INCLUDING HISTONE DEACETYLASES AND PROPOSE THE THERAPEUTIC IMPLICATION OF THESE REGULATORS IN THE TREATMENT OF VC. 2020 15 6075 19 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 16 3913 19 LIFESTYLE MODIFICATIONS AND NUTRITIONAL AND THERAPEUTIC INTERVENTIONS IN DELAYING THE PROGRESSION OF CHRONIC KIDNEY DISEASE: A REVIEW. CHRONIC KIDNEY DISEASE (CKD) IS A DEBILITATING PROGRESSIVE ILLNESS THAT AFFECTS MORE THAN 10% OF THE WORLD'S POPULATION. IN THIS LITERATURE REVIEW, WE DISCUSSED THE ROLES OF NUTRITIONAL INTERVENTIONS, LIFESTYLE MODIFICATIONS, HYPERTENSION (HTN) AND DIABETES MELLITUS (DM) CONTROL, AND MEDICATIONS IN DELAYING THE PROGRESSION OF CKD. WALKING, WEIGHT LOSS, LOW-PROTEIN DIET (LPD), ADHERENCE TO THE ALTERNATE MEDITERRANEAN (AMED) DIET, AND ALTERNATIVE HEALTHY EATING INDEX (AHEI)-2010 SLOW THE PROGRESSION OF CKD. HOWEVER, SMOKING AND BINGE ALCOHOL DRINKING INCREASE THE RISK OF CKD PROGRESSION. IN ADDITION, HYPERGLYCEMIA, ALTERED LIPID METABOLISM, LOW-GRADE INFLAMMATION, OVER-ACTIVATION OF THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM (RAAS), AND OVERHYDRATION (OH) INCREASE DIABETIC CKD PROGRESSION. THE KIDNEY DISEASE: IMPROVING GLOBAL OUTCOMES (KDIGO) GUIDELINES RECOMMEND BLOOD PRESSURE (BP) CONTROL OF <140/90 MMHG IN PATIENTS WITHOUT ALBUMINURIA AND <130/80 MMHG IN PATIENTS WITH ALBUMINURIA TO PREVENT CKD PROGRESSION. MEDICAL THERAPIES AIM TO TARGET EPIGENETIC ALTERATIONS, FIBROSIS, AND INFLAMMATION. CURRENTLY, RAAS BLOCKADE, SODIUM-GLUCOSE COTRANSPORTER-2 (SGLT2) INHIBITORS, PENTOXIFYLLINE, AND FINERENONE ARE APPROVED FOR MANAGING CKD. IN ADDITION, ACCORDING TO THE COMPLETED STUDY OF DIABETIC NEPHROPATHY WITH ATRASENTAN (SONAR), ATRASENTAN, AN ENDOTHELIN RECEPTOR ANTAGONIST (ERA), DECREASED THE RISK OF RENAL EVENTS IN DIABETIC CKD PATIENTS. HOWEVER, ONGOING TRIALS ARE STUDYING THE ROLE OF OTHER AGENTS IN SLOWING THE PROGRESSION OF CKD. 2023 17 4381 24 MITOCHONDRIAL DYSFUNCTION AND THE AKI-TO-CKD TRANSITION. ACUTE KIDNEY INJURY (AKI) HAS BEEN WIDELY RECOGNIZED AS AN IMPORTANT RISK FACTOR FOR THE OCCURRENCE AND DEVELOPMENT OF CHRONIC KIDNEY DISEASE (CKD). EVEN MILDER AKI HAS ADVERSE CONSEQUENCES AND COULD PROGRESS TO RENAL FIBROSIS, WHICH IS THE ULTIMATE COMMON PATHWAY FOR VARIOUS TERMINAL KIDNEY DISEASES. THUS, IT IS URGENT TO DEVELOP A STRATEGY TO HINDER THE TRANSITION FROM AKI TO CKD. SOME MECHANISMS OF THE AKI-TO-CKD TRANSITION HAVE BEEN REVEALED, SUCH AS NEPHRON LOSS, CELL CYCLE ARREST, PERSISTENT INFLAMMATION, ENDOTHELIAL INJURY WITH VASCULAR RAREFACTION, AND EPIGENETIC CHANGES. PREVIOUS STUDIES HAVE ELUCIDATED THE PIVOTAL ROLE OF MITOCHONDRIA IN ACUTE INJURIES AND DEMONSTRATED THAT THE FITNESS OF THIS ORGANELLE IS A MAJOR DETERMINANT IN BOTH THE PATHOGENESIS AND RECOVERY OF ORGAN FUNCTION. RECENT RESEARCH HAS SUGGESTED THAT DAMAGE TO MITOCHONDRIAL FUNCTION IN EARLY AKI IS A CRUCIAL FACTOR LEADING TO TUBULAR INJURY AND PERSISTENT RENAL INSUFFICIENCY. DYSREGULATION OF MITOCHONDRIAL HOMEOSTASIS, ALTERATIONS IN BIOENERGETICS, AND ORGANELLE STRESS CROSS TALK CONTRIBUTE TO THE AKI-TO-CKD TRANSITION. IN THIS REVIEW, WE FOCUS ON THE PATHOPHYSIOLOGY OF MITOCHONDRIA IN RENAL RECOVERY AFTER AKI AND PROGRESSION TO CKD, CONFIRMING THAT TARGETING MITOCHONDRIA REPRESENTS A POTENTIALLY EFFECTIVE THERAPEUTIC STRATEGY FOR THE PROGRESSION OF AKI TO CKD. 2020 18 4513 19 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 19 2524 23 EPIGENETICS AND THE UREMIC PHENOTYPE: A MATTER OF BALANCE. EPIGENETICS, WHICH IS THE STUDY OF CHANGES IN GENE EXPRESSION THAT OCCUR WITHOUT CHANGES IN DNA SEQUENCE, IS A NOVEL DISCIPLINE THAT HAS LANGUISHED IN THE SHADOW OF ITS GENOMIC BIG BROTHER. SO FAR, STUDIES OF THE EPIGENOME HAVE ATTRACTED LITTLE INTEREST IN NEPHROLOGY. CHRONIC KIDNEY DISEASE IS AN EXAMPLE OF COMPLEX DISEASE IN WHICH THE PHENOTYPE ARISES FROM A COMBINATION OF ENVIRONMENTAL AND HERITABLE FACTORS. EVIDENCE SUGGESTS THAT THE CONTRIBUTION MADE BY THE ENVIRONMENT MAY BE MEDIATED VIA MODIFICATIONS OF THE EPIGENOME. IN THE UREMIC MILIEU, SEVERAL FEATURES SUCH AS INFLAMMATION, DYSLIPIDEMIA, HYPERHOMOCYSTEINEMA, OXIDATIVE STRESS AS WELL AS VITAMIN AND NUTRITIONAL DEFICIENCIES MAY AFFECT ABERRANT GLOBAL DNA METHYLATION. HOWEVER, AS HYPERHOMOCYSTEINEMIA SEEMS TO PROMOTE GLOBAL DNA HYPOMETHYLATION AND PERSISTENT INFLAMMATION DNA HYPERMETHYLATION, THE EFFECTS OF THE UREMIC MILIEU ON ABERRANT GLOBAL DNA METHYLATION MAY BE COMPLEX AND CONTEXT-SENSITIVE. IT SHOULD BE EMPHASIZED THAT IN ANALOGY TO THE UNSPECIFIC NATURE OF FEVER, ABERRANT GLOBAL DNA METHYLATION IS ONLY A SIGN OF A GENERALIZED EPIGENETIC DYSREGULATION. THUS, TO PROVIDE BETTER UNDERSTANDING OF THE EFFECTS OF ABERRANT DNA METHYLATION ON THE UREMIC PHENOTYPE, FURTHER STUDIES EVALUATING SITE-SPECIFIC INFORMATION ON METHYLATION IN VARIOUS CANDIDATE GENES ARE NEEDED. THE SCIENCE OF EPIGENETICS MAY NOT ONLY UNCOVER ETIOLOGIC AND PATHOGENIC MECHANISMS IN UREMIA, BUT MAY ALSO BE OF HELP TO DEVELOP NOVEL TREATMENT STRATEGIES TARGETING THE UNACCEPTABLE HIGH DEATH RISK IN CARDIOVASCULAR COMPLICATIONS IN THIS PATIENT POPULATION. 2008 20 5504 27 RHEIN REVERSAL OF DNA HYPERMETHYLATION-ASSOCIATED KLOTHO SUPPRESSION AMELIORATES RENAL FIBROSIS IN MICE. RENAL FIBROSIS IS THE HALLMARK OF CHRONIC KIDNEY DISEASES (CKD) AND ITS DEVELOPMENT AND PROGRESSION ARE SIGNIFICANTLY AFFECTED BY EPIGENETIC MODIFICATIONS. RHEIN, A PLANT-DERIVED ANTHRAQUINONE, DISPLAYS STRONG ANTI-FIBROSIS PROPERTIES, BUT ITS PROTECTIVE MODE OF ACTION REMAINS INCOMPLETELY UNDERSTOOD. HERE WE EXPLORE THE MECHANISM OF RHEIN ANTI-RENAL FIBROSIS BY INVESTIGATING ITS REGULATION OF KLOTHO, A KNOWN RENAL ANTI-FIBROTIC PROTEIN WHOSE SUPPRESSION AFTER RENAL INJURY REPORTEDLY INVOLVES ABERRANT DNA METHYLATION. WE REPORT THAT RHEIN IS AN IMPRESSIVE UP-REGULATOR OF KLOTHO AND IT MARKEDLY REVERSED KLOTHO DOWN-REGULATION IN UNILATERAL URETERAL OCCLUSION-INDUCED FIBROTIC KIDNEY. FURTHER EXAMINATIONS REVEALED THAT KLOTHO LOSS IN FIBROTIC KIDNEY IS ASSOCIATED WITH KLOTHO PROMOTER HYPERMETHYLATION DUE TO ABERRANT METHYLTRANSFERASE 1 AND 3A EXPRESSIONS. HOWEVER, RHEIN SIGNIFICANTLY CORRECTED ALL THESE EPIGENETIC ALTERATIONS AND SUBSEQUENTLY ALLEVIATED PRO-FIBROTIC PROTEIN EXPRESSION AND RENAL FIBROSIS, WHEREAS KLOTHO KNOCKDOWN VIA RNA INTERFERENCES LARGELY ABROGATED THE ANTI-RENAL FIBROTIC EFFECTS OF RHEIN, SUGGESTING THAT RHEIN EPIGENETIC REVERSAL OF KLOTHO LOSS REPRESENTS A CRITICAL MODE OF ACTION THAT CONFERS RHEIN'S ANTI- RENAL FIBROTIC FUNCTIONS. ALTOGETHER OUR STUDIES UNCOVER A NOVEL HYPOMETHYLATING CHARACTER OF RHEIN IN PREVENTING KLOTHO LOSS AND RENAL FIBROSIS, AND DEMONSTRATE THE EFFICACY OF KLOTHO-TARGETED EPIGENETIC INTERVENTION IN POTENTIAL TREATMENT OF RENAL FIBROSIS-ASSOCIATED KIDNEY DISEASES. 2016