1 782 142 CELL-FREE MICRORNA-148A IS ASSOCIATED WITH RENAL ALLOGRAFT DYSFUNCTION: IMPLICATION FOR BIOMARKER DISCOVERY. BACKGROUND: CHRONIC ALLOGRAFT DYSFUNCTION (CAD), THE FOREMOST CAUSE OF RENAL GRAFT LOSS WORLDWIDE, IS A SERIOUS CHALLENGE FOR MOST OF THE RECIPIENTS. AS THE EPIGENETIC ERA IS EMERGING, EPIGENETIC BIOMARKERS ESPECIALLY MICRORNAS (MIRNAS) MAY REFLECT THE CURRENT STAGE OF THE DISEASE AND PATIENT'S THERAPY RESPONSE. THE CURRENT STUDY INVESTIGATED THE POTENTIAL SIGNIFICANCE OF CIRCULATING MIRNA-148A IN PREDICTING THE RENAL GRAFT FUNCTION. DESIGN AND METHODS: CIRCULATING MIRNAS WERE ISOLATED FROM 53 PLASMA SAMPLES OF RECIPIENTS WITH HISTOLOGICALLY VALIDATED INTERSTITIAL FIBROSIS AND TUBULAR ATROPHY (IFTA, N = 26), AND RECIPIENTS WITH STABLE GRAFT FUNCTION (SGF, N = 27), AND ALSO HEALTHY INDIVIDUALS ( N = 15). THE LEVEL OF MIRNA-148A WAS EVALUATED BY THE QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR) AND CORRELATED WITH CLINICAL AND HISTOLOGICAL PARAMETERS. RESULTS: SIGNIFICANTLY, MIRNA-148A DECREASED IN IFTA COMPARED WITH SGF SUBJECTS (P < 0.001). MIRNA-148A LEVELS INDICATED A SIGNIFICANT ASSOCIATION WITH SERUM CREATININE LEVELS ( R = 0.451, P = 0.021) AND GLOMERULAR FILTRATION RATE ( R = -0.520, P = 0.006). MIRNA-148A EXPRESSION LEVELS COULD DISCRIMINATE IFTA CASES FROM SGF INDIVIDUALS WITH AN AREA UNDER THE CURVE OF 0.89 ( P < 0.001), 97% SENSITIVITY, AND 72% SPECIFICITY. A NUMBER OF PREDICTED TARGETS THAT MIGHT BE INVOLVED IN CAD BY MIRNA-148A WERE PREDICTED. CONCLUSION: PLASMA CELL-FREE MIRNA-148A CORRELATED WITH RENAL FUNCTION AND HISTOLOGICAL GRADES; THEREFORE, IT MAY BE FURTHER INVESTIGATED AS A NOVEL NONINVASIVE MOLECULAR MARKER OF THE PROGRESSION TO IFTA IN RENAL TRANSPLANT RECIPIENTS; MOREOVER, THE EMERGING BIOMARKER MAY BECOME A THERAPEUTIC TARGET IN THE FUTURE CLINIC. 2019 2 177 32 ACCELERATED EPIGENETIC AGING AND INFLAMMATORY/IMMUNOLOGICAL PROFILE (IPAGE) IN PATIENTS WITH CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS DEFINED BY A REDUCED ESTIMATED GLOMERULAR FILTRATION RATE (EGFR). THIS FAILURE CAN BE RELATED TO A PHENOTYPE OF ACCELERATED AGING. IN THIS WORK, WE CONSIDERED 76 PATIENTS WITH END-STAGE RENAL DISEASE (ESRD) AND 83 HEALTHY CONTROLS. WE CONCOMITANTLY EVALUATED FOR THE FIRST TIME TWO MEASURES THAT CAN BE INFORMATIVE OF THE RATE OF AGING, I.E., WHOLE BLOOD DNA METHYLATION USING THE ILLUMINA INFINIUM EPIC ARRAY AND PLASMA LEVELS OF A SELECTION OF INFLAMMATORY/IMMUNOLOGICAL PROTEINS USING MULTIPLEX IMMUNOASSAYS. FIRST OF ALL, WE DEMONSTRATED ACCELERATED AGING IN TERMS OF THE MOST COMMON EPIGENETIC AGE ESTIMATORS IN CKD PATIENTS. MOREOVER, WE DEVELOPED A NEW CLOCK/PREDICTOR OF AGE BASED ON THE INFLAMMATORY/IMMUNOLOGICAL PROFILE (IPAGE) AND IDENTIFIED THE INFLAMMATORY/IMMUNOLOGICAL BIOMARKERS DIFFERENTIALLY EXPRESSED BETWEEN CASES AND CONTROLS. IPAGE APPEARED TO BE MORE SENSITIVE THAN EPIGENETIC CLOCKS IN QUANTIFYING THE ACCELERATED AGING PHENOTYPE OF ESRD PATIENTS. INTERESTINGLY, WE DID NOT FIND ANY CORRELATION BETWEEN THE AGE ACCELERATION EVALUATED ACCORDING TO THE EPIGENETIC CLOCKS AND IPAGE IN EITHER THE ESRD GROUP OR THE CONTROL GROUP. ON THE WHOLE, OUR DATA SHOW A CONSISTENT ACCELERATED AGING PHENOTYPE IN ESRD PATIENTS, WHICH IS BETTER APPRECIATED BY QUANTIFYING THE UNDERLYING INFLAMMATORY PROCESSES (INFLAMMAGING) BY IPAGE THAN BY USING EPIGENETIC CLOCKS. 2022 3 4024 33 LUNG ALLOGRAFT EPITHELIUM DNA METHYLATION AGE IS ASSOCIATED WITH GRAFT CHRONOLOGIC AGE AND PRIMARY GRAFT DYSFUNCTION. ADVANCED DONOR AGE IS A RISK FACTOR FOR POOR SURVIVAL FOLLOWING LUNG TRANSPLANTATION. HOWEVER, RECENT WORK IDENTIFYING EPIGENETIC DETERMINANTS OF AGING HAS SHOWN THAT BIOLOGIC AGE MAY NOT ALWAYS REFLECT CHRONOLOGIC AGE AND THAT STRESSORS CAN ACCELERATE BIOLOGIC AGING. WE HYPOTHESIZED THAT LUNG ALLOGRAFTS THAT EXPERIENCED PRIMARY GRAFT DYSFUNCTION (PGD), CHARACTERIZED BY POOR OXYGENATION IN THE FIRST THREE POST-TRANSPLANT DAYS, WOULD HAVE INCREASED BIOLOGIC AGE. WE CULTURED AIRWAY EPITHELIAL CELLS ISOLATED BY TRANSBRONCHIAL BRUSH AT 1-YEAR BRONCHOSCOPIES FROM 13 SUBJECTS WITH SEVERE PGD AND 15 CONTROLS MATCHED ON AGE AND TRANSPLANT INDICATION. WE MEASURED EPIGENETIC AGE USING THE HORVATH EPIGENETIC CLOCK. LINEAR MODELS WERE USED TO DETERMINE THE ASSOCIATION OF AIRWAY EPIGENETIC AGE WITH CHRONOLOGIC AGES AND PGD STATUS, ADJUSTED FOR RECIPIENT PGD RISK FACTORS. SURVIVAL MODELS ASSESSED THE ASSOCIATION WITH CHRONIC LUNG ALLOGRAFT DYSFUNCTION (CLAD) OR DEATH. DISTRIBUTIONS OF PROMOTER METHYLATION WITHIN PATHWAYS WERE COMPARED BETWEEN GROUPS. DNA METHYLTRANSFERASE (DNMT) ACTIVITY WAS QUANTIFIED IN AIRWAY EPITHELIAL CELLS UNDER HYPOXIC OR NORMOXIC CONDITIONS. AIRWAY EPIGENETIC AGE APPEARED YOUNGER BUT WAS STRONGLY ASSOCIATED WITH THE AGE OF THE ALLOGRAFT (SLOPE 0.38 PER YEAR, 95% CI 0.27-0.48). THERE WAS NO CORRELATION BETWEEN EPIGENETIC AGE AND RECIPIENT AGE (P = 0.96). EPIGENETIC AGE WAS 6.5 YEARS GREATER (95% CI 1.7-11.2) IN SUBJECTS WHO HAD EXPERIENCED PGD, AND THIS EFFECT REMAINED SIGNIFICANT AFTER ADJUSTING FOR DONOR AND RECIPIENT CHARACTERISTICS (P = 0.03). EPIGENETIC AGE WAS NOT ASSOCIATED WITH CLAD-FREE SURVIVAL RISK (P = 0.11). ANALYSIS OF DIFFERENTIAL METHYLATION OF PROMOTERS OF KEY BIOLOGIC PATHWAYS REVEALED HYPOMETHYLATION IN REGIONS RELATED TO HYPOXIA, INFLAMMATION, AND METABOLISM-ASSOCIATED PATHWAYS. ACCORDINGLY, AIRWAY EPITHELIAL CELLS CULTURED IN HYPOXIC CONDITIONS SHOWED SUPPRESSED DNMT ACTIVITY. WHILE AIRWAY METHYLATION AGE WAS PRIMARILY DETERMINED BY DONOR CHRONOLOGIC AGE, EARLY INJURY IN THE FORM OF PGD WAS ASSOCIATED WITH INCREASED ALLOGRAFT EPIGENETIC AGE. THESE DATA SHOW HOW PGD MIGHT SUPPRESS KEY PROMOTER METHYLATION RESULTING IN LONG-TERM IMPACTS ON THE ALLOGRAFT. 2021 4 3568 34 IMPACT OF INFLAMMATION ON EPIGENETIC DNA METHYLATION - A NOVEL RISK FACTOR FOR CARDIOVASCULAR DISEASE? OBJECTIVE: THE LIFESPAN OF DIALYSIS PATIENTS IS AS SHORT AS IN PATIENTS WITH METASTATIC CANCER DISEASE, MAINLY DUE TO CARDIOVASCULAR DISEASE (CVD). DNA METHYLATION IS AN IMPORTANT CELLULAR MECHANISM MODULATING GENE EXPRESSION ASSOCIATED WITH AGEING, INFLAMMATION AND ATHEROSCLEROTIC PROCESSES. DESIGN: DNA METHYLATION WAS ANALYSED IN PERIPHERAL BLOOD LEUCOCYTES FROM THREE DIFFERENT GROUPS OF CHRONIC KIDNEY DISEASE (CKD) POPULATIONS (37 CKD STAGES 3 AND 4 PATIENTS, 98 CKD STAGE 5 PATIENTS AND 20 PREVALENT HAEMODIALYSIS PATIENTS). THIRTY-SIX HEALTHY SUBJECTS SERVED AS CONTROLS. CLINICAL CHARACTERISTICS (DIABETES MELLITUS, NUTRITIONAL STATUS AND PRESENCE OF CLINICAL CVD), INFLAMMATION AND OXIDATIVE STRESS BIOMARKERS, HOMOCYSTEINE AND GLOBAL DNA METHYLATION IN PERIPHERAL BLOOD LEUCOCYTES (DEFINED AS HPAII/MSPI RATIO BY THE LUMINOMETRIC METHYLATION ASSAY METHOD) WERE EVALUATED. CKD STAGE 5 PATIENTS (N=98) STARTING DIALYSIS TREATMENT WERE FOLLOWED FOR A PERIOD OF 36 +/- 2 MONTHS. RESULTS: INFLAMED PATIENTS HAD LOWER RATIOS OF HPAII/MSPI, INDICATING GLOBAL DNA HYPERMETHYLATION. ANALYSIS BY THE COX REGRESSION MODEL DEMONSTRATED THAT DNA HYPERMETHYLATION (HPAII/MSPI RATIO