1 3478 128 IDENTIFICATION OF ADPKD-RELATED GENES AND PATHWAYS IN CELLS OVEREXPRESSING PKD2. CONSISTENT WITH THE GENE DOSAGE EFFECT HYPOTHESIS, RENAL CYSTS CAN ARISE IN TRANSGENIC MURINE MODELS OVEREXPRESSING EITHER PKD1 OR PKD2, WHICH ARE CAUSAL GENES FOR AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE (ADPKD). TO DETERMINE WHETHER PKD GENE OVEREXPRESSION IS A UNIVERSAL MECHANISM DRIVING CYSTOGENESIS OR IS MERELY RESTRICTED TO RODENTS, OTHER ANIMAL MODELS ARE REQUIRED. PREVIOUSLY, WE FAILED TO OBSERVE ANY RENAL CYSTS IN A TRANSGENIC PORCINE MODEL OF PKD2 OVEREXPRESSION PARTIALLY DUE TO EPIGENETIC SILENCING OF THE TRANSGENE. THUS, TO EXPLORE THE FEASIBILITY OF PORCINE MODELS AND IDENTIFY POTENTIAL GENES/PATHWAYS AFFECTED IN ADPKD, LLC-PK1 CELLS WITH HIGH PKD2 EXPRESSION WERE GENERATED. MRNA SEQUENCING (RNA-SEQ) WAS PERFORMED, AND MYC, IER3, AND ADM WERE FOUND TO BE UPREGULATED GENES COMMON TO THE DIFFERENT PKD2 OVEREXPRESSION CELL MODELS. MYC IS A WELL-CHARACTERIZED FACTOR CONTRIBUTING TO CYSTOGENESIS, AND ADM IS A BIOMARKER FOR CHRONIC KIDNEY DISEASE. THUS, THESE GENES MIGHT BE INDICATORS OF DISEASE PROGRESSION. ADDITIONALLY, SOME ADPKD-ASSOCIATED PATHWAYS, E.G., THE MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) PATHWAY, WERE ENRICHED IN THE CELLS. MOREOVER, GENE ONTOLOGY (GO) ANALYSIS DEMONSTRATED THAT PROLIFERATION, APOPTOSIS, AND CELL CYCLE REGULATION, WHICH ARE HALLMARKS OF ADPKD, WERE ALTERED. THEREFORE, OUR EXPERIMENT IDENTIFIED SOME BIOMARKERS OR INDICATORS OF ADPKD, INDICATING THAT HIGH PKD2 EXPRESSION WOULD LIKELY DRIVE CYSTOGENESIS IN FUTURE PORCINE MODELS. 2020 2 5329 36 PURINERGIC SIGNALING IN THE LUMEN OF A NORMAL NEPHRON AND IN REMODELED PKD ENCAPSULATED CYSTS. THE NEPHRON IS THE FUNCTIONAL UNIT OF THE KIDNEY. BLOOD AND PLASMA ARE CONTINUALLY FILTERED WITHIN THE GLOMERULI THAT BEGIN EACH NEPHRON. ADENOSINE 5' TRIPHOSPHATE (ATP) AND ITS METABOLITES ARE FREELY FILTERED BY EACH GLOMERULUS AND ENTER THE LUMEN OF EACH NEPHRON BEGINNING AT THE PROXIMAL CONVOLUTED TUBULE (PCT). FLOW RATE, OSMOLALITY, AND OTHER MECHANICAL OR CHEMICAL STIMULI FOR ATP SECRETION ARE PRESENT IN EACH NEPHRON SEGMENT. THESE ATP-RELEASE STIMULI ARE ALSO DIFFERENT IN EACH NEPHRON SEGMENT DUE TO WATER OR SALT PERMEABILITY OR IMPERMEABILITY ALONG DIFFERENT LUMINAL MEMBRANES OF THE CELLS THAT LINE EACH NEPHRON SEGMENT. EACH OF THE ABOVE STIMULI CAN TRIGGER ADDITIONAL ATP RELEASE INTO THE LUMEN OF A NEPHRON SEGMENT. EACH NEPHRON-LINING EPITHELIAL CELL IS A POTENTIAL SOURCE OF SECRETED ATP. TOGETHER WITH FILTERED ATP AND ITS METABOLITES DERIVED FROM THE GLOMERULUS, SECRETED ATP AND ADENOSINE DERIVED FROM CELLS ALONG THE NEPHRON ARE LIKELY THE PRINCIPAL TWO OF SEVERAL NUCLEOTIDE AND NUCLEOSIDE CANDIDATES FOR RENAL AUTOCRINE AND PARACRINE LIGANDS WITHIN THE TUBULAR FLUID OF THE NEPHRON. THIS MINIREVIEW DISCUSSES THE FIRST PRINCIPLES OF PURINERGIC SIGNALING AS THEY RELATE TO THE NEPHRON AND THE URINARY BLADDER. THE REVIEW DISCUSSES HOW THE LUMEN OF A RENAL TUBULE PRESENTS AN IDEAL PURINERGIC SIGNALING MICROENVIRONMENT. THE REVIEW ALSO ILLUSTRATES HOW REMODELED AND ENCAPSULATED CYSTS IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE (ADPKD) AND REMODELED PSEUDOCYSTS IN AUTOSOMAL RECESSIVE PKD (ARPKD) OF THE RENAL COLLECTING DUCT LIKELY CREATE AN EVEN MORE IDEAL MICROENVIRONMENT FOR PURINERGIC SIGNALING. ONCE TRAPPED IN THESE CLOSED MICROENVIRONMENTS, PURINERGIC SIGNALING BECOMES CHRONIC AND LIKELY PLAYS A SIGNIFICANT EPIGENETIC AND DETRIMENTAL ROLE IN THE SECONDARY PROGRESSION OF PKD, ONCE THE REMODELING OF THE RENAL TISSUE HAS BEGUN. IN PKD CYSTIC MICROENVIRONMENTS, WE ARGUE THAT NORMAL PURINERGIC SIGNALING WITHIN THE LUMEN OF THE NEPHRON PROVIDES DETRIMENTAL ACCELERATION OF ADPKD ONCE REMODELING IS COMPLETE. 2008 3 5173 35 PREDICTING PROGRESSION OF AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE BY CHANGES IN THE TELOMERIC EPIGENOME. AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE (ADPKD) IS THE MOST COMMON INHERITED CAUSE OF CHRONIC KIDNEY DISEASE WITH POLYCYSTIN&NBSP;(PKD) 1 AND 2 GENE MUTATION. HOWEVER, THE INTRA-FAMILIAL VARIABILITY IN SYMPTOMS FURTHER SUGGESTS A NON-MENDELIAN CONTRIBUTION TO THE DISEASE. OUR GOAL WAS TO FIND A MARKER TO TRACK THE EPIGENETIC CHANGES COMMON TO RAPIDLY PROGRESSING FORMS OF THE DISEASE. THE RISK OF ADPKD INCREASES WITH AGE, AND AGING SHORTENS THE TELOMERE LENGTH (TL). TELOMERES ARE A NUCLEOPROTEIN STRUCTURE COMPOSED MAINLY OF THREE COMPLEXES, SHELTERIN, CST AND RNA-CONTAINING TELOMERE REPEAT(TERRA), WHICH PROTECTS THE ENDS OF CHROMOSOMES FROM DEGRADATION AND FUSION, AND PLAYS A ROLE IN MAINTAINING CELLULAR STABILITY AND IN THE REPAIR OF TELOMERIC DAMAGE. TERRAS ARE TRANSCRIBED FROM TELOMERIC REGIONS AND A PART OF THEM IS ENGAGED IN A DNA/RNA HYBRID (R-LOOP) AT EACH CHROMOSOME END. WE TRACKED TL AND TERRA LEVELS IN BLOOD SAMPLES OF 78 PATIENTS AND 20 HEALTHY CONTROL. OUR STUDY DEMONSTRATES THAT TL WAS SHORTENED AND TERRA EXPRESSION LEVELS IN THE DNA-ATTACHED FRACTION INCREASED IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY PATIENTS WITH MUTATIONS IN PKD1 AND PKD2 COMPARED TO THE CONTROL GROUP. MOREOVER, IT WAS OBSERVED THAT THE EXPRESSION OF TERRA ENGAGED IN THE R-LOOP WAS HIGHER AND THE LENGTH OF TELOMERES SHORTER IN PATIENTS WITH ADPKD WHO SHOWED RAPID DISEASE PROGRESSION. INTRAFAMILIAL VARIATION IN TL AND TERRA LEVELS WITH THE SAME MUTATION WOULD INDICATE RELIABLE EPIGENETIC POTENTIAL BIOMARKERS IN DISEASE MONITORING. 2022 4 1477 30 DIVERSE PHENOTYPIC EXPRESSION OF NPHP4 MUTATIONS IN FOUR SIBLINGS. NEPHRONOPHTHISIS (NPHP) IS AN AUTOSOMAL RECESSIVE DISEASE CHARACTERIZED BY RENAL TUBULAR BASEMENT MEMBRANE DISRUPTION, INTERSTITIAL FIBROSIS AND TUBULAR CYSTS THAT PROGRESSES TO END-STAGE KIDNEY DISEASE (ESKD). THERE ARE ALSO CHARACTERISTIC EXTRARENAL MANIFESTATIONS. MUTATIONS OF MORE THAN THIRTEEN GENES THAT CAN CAUSE NPHP HAVE BEEN IDENTIFIED. WE HEREIN REPORT FOUR SIBLINGS FROM A CONSANGUINEOUS FAMILY, WHO CARRIED THE SAME NPHP4 MUTATIONS BUT PRESENTED WITH DIFFERENT DISEASE PHENOTYPES RANGING FROM ENURESIS NOCTURNA TO ESKD. DILUTED URINE AND ECHOGENIC KIDNEYS IN ULTRASOUND EXAMINATION WERE CONSISTENT, WHICH IS TYPICAL FOR 100% OF THE NPHP CASES THAT HAVE BEEN DESCRIBED. CHRONIC KIDNEY DISEASE DEVELOPED IN THE OLDER TWO BROTHERS. THE OBSERVED PHENOTYPIC DIFFERENCES ARE LIKELY TO BE RELATED TO ENVIRONMENTAL AND EPIGENETIC FACTORS, OLIGOGENIC INHERITANCE AND MODIFIER GENES AFFECTING THE AGE OF PRESENTATION OF SIGNS AND SYMPTOMS. NPHP SHOULD BE CONSIDERED AS AN IMPORTANT CAUSE OF CKD IN CHILDREN, WHICH INSIDIOUSLY PROGRESSES TO ESKD, WITH NO SPECIFIC THERAPY AVAILABLE. 2014 5 5442 25 RENIN-ANGIOTENSIN BLOCKADE RESETS PODOCYTE EPIGENOME THROUGH KRUPPEL-LIKE FACTOR 4 AND ATTENUATES PROTEINURIA. PROTEINURIA IS A CENTRAL COMPONENT OF CHRONIC KIDNEY DISEASE AND AN INDEPENDENT RISK FACTOR FOR CARDIOVASCULAR DISEASE. KIDNEY PODOCYTES HAVE AN ESSENTIAL ROLE AS A FILTRATION BARRIER AGAINST PROTEINURIA. KRUPPEL-LIKE FACTOR 4 (KLF4) IS EXPRESSED IN PODOCYTES AND DECREASED IN GLOMERULAR DISEASES LEADING TO METHYLATION OF THE NEPHRIN PROMOTER, DECREASED NEPHRIN EXPRESSION AND PROTEINURIA. TREATMENT WITH AN ANGIOTENSIN RECEPTOR BLOCKER (ARB) REDUCED METHYLATION OF THE NEPHRIN PROMOTER IN MURINE GLOMERULI OF AN ADRIAMYCIN NEPHROPATHY MODEL WITH RECOVERY OF KLF4 EXPRESSION AND A DECREASE IN ALBUMINURIA. IN PODOCYTE-SPECIFIC KLF4 KNOCKOUT MICE, THE EFFECT OF ARB ON ALBUMINURIA AND THE NEPHRIN PROMOTER METHYLATION WAS ATTENUATED. IN CULTURED HUMAN PODOCYTES, ANGIOTENSIN II REDUCED KLF4 EXPRESSION AND CAUSED METHYLATION OF THE NEPHRIN PROMOTER WITH DECREASED NEPHRIN EXPRESSION. IN PATIENTS, NEPHRIN PROMOTER METHYLATION WAS INCREASED IN PROTEINURIC KIDNEY DISEASES WITH DECREASED KLF4 AND NEPHRIN EXPRESSION. KLF4 EXPRESSION IN ARB-TREATED PATIENTS WAS HIGHER IN PATIENTS WITH THAN WITHOUT ARB TREATMENT. THUS, ANGIOTENSIN II CAN MODULATE EPIGENETIC REGULATION IN PODOCYTES AND ARB INHIBITS THESE ACTIONS IN PART VIA KLF4 IN PROTEINURIC KIDNEY DISEASES. THIS STUDY PROVIDES A NEW CONCEPT THAT RENIN-ANGIOTENSIN SYSTEM BLOCKADE CAN EXERT THERAPEUTIC EFFECTS THROUGH EPIGENETIC MODULATION OF THE KIDNEY GENE EXPRESSION. 2015 6 3663 22 INDUCTION OF TET3-DEPENDENT EPIGENETIC REMODELING BY LOW-DOSE HYDRALAZINE ATTENUATES PROGRESSION OF CHRONIC KIDNEY DISEASE. PROGRESSION OF CHRONIC KIDNEY DISEASE REMAINS A PRINCIPAL PROBLEM IN CLINICAL NEPHROLOGY AND THERE IS A PRESSING NEED FOR NOVEL THERAPEUTICS AND BIOMARKERS. ABERRANT PROMOTER CPG ISLAND METHYLATION AND SUBSEQUENT TRANSCRIPTIONAL SILENCING OF SPECIFIC GENES HAVE EMERGED AS CONTRIBUTORS TO PROGRESSION OF CHRONIC KIDNEY DISEASE. HERE, WE REPORT THAT TRANSCRIPTIONAL SILENCING OF THE RAS-GTP SUPPRESSOR RASAL1 CONTRIBUTES CAUSALLY TO PROGRESSION OF KIDNEY FIBROSIS AND WE IDENTIFIED THAT CIRCULATING METHYLATED RASAL1 PROMOTER DNA FRAGMENTS IN PERIPHERAL BLOOD CORRESPOND WITH LEVELS OF INTRARENAL LEVELS OF RASAL1 PROMOTER METHYLATION AND DEGREE OF FIBROSIS IN KIDNEY BIOPSIES, ENABLING NON-INVASIVE LONGITUDINAL ANALYSIS OF INTRARENAL CPG ISLAND METHYLATION. 2015 7 4016 28 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 8 2444 29 EPIGENETIC STATES OF NEPHRON PROGENITORS AND EPITHELIAL DIFFERENTIATION. IN MAMMALS, FORMATION OF NEW NEPHRONS ENDS PERINATALLY DUE TO CONSUMPTION OF MESENCHYMAL PROGENITOR CELLS. PREMATURE DEPLETION OF PROGENITORS DUE TO PREMATURITY OR POSTNATAL LOSS OF NEPHRONS DUE TO INJURY CAUSES CHRONIC KIDNEY DISEASE AND HYPERTENSION. INTENSIVE EFFORTS ARE CURRENTLY INVESTED IN DESIGNING REGENERATIVE STRATEGIES TO FORM NEW NEPHRON PROGENITORS FROM PLURIPOTENT CELLS, WHICH UPON FURTHER DIFFERENTIATION PROVIDE A POTENTIAL SOURCE OF NEW NEPHRONS. TO KNOW IF REPROGRAMED RENAL CELLS CAN MAINTAIN THEIR IDENTITY AND FATE REQUIRES KNOWLEDGE OF THE EPIGENETIC STATES OF NATIVE NEPHRON PROGENITORS AND THEIR PROGENY. IN THIS ARTICLE, WE SUMMARIZE CURRENT KNOWLEDGE AND GAPS IN THE EPIGENOMIC LANDSCAPE OF THE DEVELOPING KIDNEY. WE NOW KNOW THAT PAX2/PTIP/H3K4 METHYLTRANSFERASE ACTIVITY PROVIDES THE INITIAL EPIGENETIC SPECIFICATION SIGNAL TO THE METANEPHRIC MESENCHYME. DURING NEPHROGENESIS, THE CAP MESENCHYME HOUSING NEPHRON PROGENITORS IS ENRICHED IN BIVALENT CHROMATIN MARKS; AS TUBULOGENESIS PROCEEDS, THE TUBULAR EPITHELIUM ACQUIRES H3K79ME2. THE LATTER MARK IS UNIQUELY INDUCED DURING EPITHELIAL DIFFERENTIATION. ANALYSIS OF HISTONE LANDSCAPES IN CLONAL METANEPHRIC MESENCHYME CELL LINES AND IN WILMS TUMOR AND NORMAL FETAL KIDNEY HAS REVEALED THAT PROMOTERS OF POISED NEPHROGENESIS GENES CARRY BIVALENT HISTONE SIGNATURES IN PROGENITORS. DIFFERENTIATION OR STIMULATION OF WNT SIGNALING PROMOTES RESOLUTION OF BIVALENCY; THIS DOES NOT OCCUR IN WILMS TUMOR CELLS CONSISTENT WITH THEIR DEVELOPMENTAL ARREST. THE USE OF SMALL CELL NUMBER CHIP-SEQ SHOULD FACILITATE THE CHARACTERIZATION OF THE CHROMATIN LANDSCAPE OF THE METANEPHRIC MESENCHYME AND VARIOUS NEPHRON COMPARTMENTS DURING NEPHROGENESIS. ONLY THEN WE WILL KNOW IF STEM AND SOMATIC CELL REPROGRAMMING INTO KIDNEY PROGENITORS RECAPITULATES NORMAL DEVELOPMENT. 2015 9 6299 28 THE PROXIMAL TUBULE IS THE PRIMARY TARGET OF INJURY AND PROGRESSION OF KIDNEY DISEASE: ROLE OF THE GLOMERULOTUBULAR JUNCTION. THERE IS AN ALARMING GLOBAL INCREASE IN THE INCIDENCE OF END-STAGE KIDNEY DISEASE, FOR WHICH EARLY BIOMARKERS AND EFFECTIVE TREATMENT OPTIONS ARE LACKING. LARGELY BASED ON THE HISTOLOGY OF THE END-STAGE KIDNEY AND ON THE MODEL OF UNILATERAL URETERAL OBSTRUCTION, CURRENT INVESTIGATION IS FOCUSED ON THE PATHOGENESIS OF RENAL INTERSTITIAL FIBROSIS AS A CENTRAL MECHANISM IN THE PROGRESSION OF CHRONIC KIDNEY DISEASE (CKD). IT IS NOW RECOGNIZED THAT CUMULATIVE EPISODES OF ACUTE KIDNEY INJURY (AKI) CAN LEAD TO CKD, AND, CONVERSELY, CKD IS A RISK FACTOR FOR AKI. BASED ON RECENT AND HISTORIC STUDIES, THIS REVIEW SHIFTS ATTENTION FROM THE GLOMERULUS AND INTERSTITIUM TO THE PROXIMAL TUBULE AS THE PRIMARY SENSOR AND EFFECTOR IN THE PROGRESSION OF CKD AS WELL AS AKI. PACKED WITH MITOCHONDRIA AND DEPENDENT ON OXIDATIVE PHOSPHORYLATION, THE PROXIMAL TUBULE IS PARTICULARLY VULNERABLE TO INJURY (OBSTRUCTIVE, ISCHEMIC, HYPOXIC, OXIDATIVE, METABOLIC), RESULTING IN CELL DEATH AND ULTIMATELY IN THE FORMATION OF ATUBULAR GLOMERULI. ANIMAL MODELS OF HUMAN GLOMERULAR AND TUBULAR DISORDERS HAVE PROVIDED EVIDENCE FOR A BROAD REPERTOIRE OF MORPHOLOGICAL AND FUNCTIONAL RESPONSES OF THE PROXIMAL TUBULE, REVEALING PROCESSES OF DEGENERATION AND REPAIR THAT MAY LEAD TO NEW THERAPEUTIC STRATEGIES. MOST PROMISING ARE STUDIES THAT ENCOMPASS THE ENTIRE LIFE CYCLE FROM FETUS TO SENESCENCE, RECOGNIZING EPIGENETIC FACTORS. THE APPLICATION OF TECHNIQUES IN MOLECULAR CHARACTERIZATION OF TUBULE SEGMENTS AND THE DEVELOPMENT OF HUMAN KIDNEY ORGANOIDS MAY PROVIDE NEW INSIGHTS INTO THE MAMMALIAN KIDNEY SUBJECTED TO STRESS OR INJURY, LEADING TO BIOMARKERS OF EARLY CKD AND NEW THERAPIES. 2016 10 4059 36 MASSIVE ANALYSIS OF CDNA ENDS (MACE) AND MIRNA EXPRESSION PROFILING IDENTIFIES PROATHEROGENIC PATHWAYS IN CHRONIC KIDNEY DISEASE. EPIGENETIC DYSREGULATION CONTRIBUTES TO THE HIGH CARDIOVASCULAR DISEASE BURDEN IN CHRONIC KIDNEY DISEASE (CKD) PATIENTS. ALTHOUGH MICRORNAS (MIRNAS) ARE CENTRAL EPIGENETIC REGULATORS, WHICH SUBSTANTIALLY AFFECT THE DEVELOPMENT AND PROGRESSION OF CARDIOVASCULAR DISEASE (CVD), NO DATA ON MIRNA DYSREGULATION IN CKD-ASSOCIATED CVD ARE AVAILABLE UNTIL NOW. WE NOW PERFORMED HIGH-THROUGHPUT MIRNA SEQUENCING OF PERIPHERAL BLOOD MONONUCLEAR CELLS FROM TEN CLINICALLY STABLE HEMODIALYSIS (HD) PATIENTS AND TEN HEALTHY CONTROLS, WHICH ALLOWED US TO IDENTIFY 182 DIFFERENTIALLY EXPRESSED MIRNAS (E.G., MIR-21, MIR-26B, MIR-146B, MIR-155). TO TEST BIOLOGICAL RELEVANCE, WE AIMED TO CONNECT MIRNA DYSREGULATION TO DIFFERENTIAL GENE EXPRESSION. GENOME-WIDE GENE EXPRESSION PROFILING BY MACE (MASSIVE ANALYSIS OF CDNA ENDS) IDENTIFIED 80 GENES TO BE DIFFERENTIALLY EXPRESSED BETWEEN HD PATIENTS AND CONTROLS, WHICH COULD BE LINKED TO CARDIOVASCULAR DISEASE (E.G., KLF6, DUSP6, KLF4), TO INFECTION / IMMUNE DISEASE (E.G., ZFP36, SOCS3, JUND), AND TO DISTINCT PROATHEROGENIC PATHWAYS SUCH AS THE TOLL-LIKE RECEPTOR SIGNALING PATHWAY (E.G., IL1B, MYD88, TICAM2), THE MAPK SIGNALING PATHWAY (E.G., DUSP1, FOS, HSPA1A), AND THE CHEMOKINE SIGNALING PATHWAY (E.G., RHOA, PAK1, CXCL5). FORMAL INTERACTION NETWORK ANALYSIS PROVED BIOLOGICAL RELEVANCE OF MIRNA DYSREGULATION, AS 68 DIFFERENTIALLY EXPRESSED MIRNAS COULD BE CONNECTED TO 47 RECIPROCALLY EXPRESSED TARGET GENES. OUR STUDY IS THE FIRST COMPREHENSIVE MIRNA ANALYSIS IN CKD THAT LINKS DYSREGULATED MIRNA EXPRESSION WITH DIFFERENTIAL EXPRESSION OF GENES CONNECTED TO INFLAMMATION AND CVD. AFTER RECENT ANIMAL DATA SUGGESTED THAT TARGETING MIRNAS IS BENEFICIAL IN EXPERIMENTAL CVD, OUR DATA MAY NOW SPUR FURTHER RESEARCH IN THE FIELD OF CKD-ASSOCIATED HUMAN CVD. 2014 11 1015 24 CIGARETTE SMOKING CAUSES EPIGENETIC CHANGES ASSOCIATED WITH CARDIORENAL FIBROSIS. CLINICAL STUDIES INDICATE THAT SMOKING COMBUSTIBLE CIGARETTES PROMOTES PROGRESSION OF RENAL AND CARDIAC INJURY, LEADING TO FUNCTIONAL DECLINE IN THE SETTING OF CHRONIC KIDNEY DISEASE (CKD). HOWEVER, BASIC STUDIES USING IN VIVO SMALL ANIMAL MODELS THAT MIMIC CLINICAL PATHOLOGY OF CKD ARE LACKING. TO ADDRESS THIS ISSUE, WE EVALUATED RENAL AND CARDIAC INJURY PROGRESSION AND FUNCTIONAL CHANGES INDUCED BY 4 WK OF DAILY COMBUSTIBLE CIGARETTE SMOKE EXPOSURE IN THE 5/6TH PARTIAL NEPHRECTOMY (PNX) CKD MODEL. MOLECULAR EVALUATIONS REVEALED THAT CIGARETTE SMOKE SIGNIFICANTLY (P < 0.05) DECREASED RENAL AND CARDIAC EXPRESSION OF THE ANTIFIBROTIC MICRORNA MIR-29B-3 AND INCREASED EXPRESSION OF MOLECULAR FIBROSIS MARKERS. IN TERMS OF CARDIAC AND RENAL ORGAN STRUCTURE AND FUNCTION, EXPOSURE TO CIGARETTE SMOKE LED TO SIGNIFICANTLY INCREASED SYSTOLIC BLOOD PRESSURE, CARDIAC HYPERTROPHY, CARDIAC AND RENAL FIBROSIS, AND DECREASED RENAL FUNCTION. THESE DATA INDICATE THAT DECREASED EXPRESSION OF MIR-29B-3P IS A NOVEL MECHANISM WHEREIN CIGARETTE SMOKE PROMOTES ACCELERATED CARDIAC AND RENAL TISSUE INJURY IN CKD. (155 WORDS). 2016 12 4819 26 OCCURRENCE OF TOXICITY AND CELL PROLIFERATION AFTER A SINGLE GAVAGE ADMINISTRATION OF CHLOROFORM TO MALE F344 RATS. CHLOROFORM, AN INDUSTRIAL SOLVENT AND ONE OF THE MOST COMMON ENVIRONMENTAL CONTAMINANTS WHICH PRODUCES CARCINOGENIC EFFECTS IN THE LIVER AND KIDNEY OF RODENTS, IS NOT GENOTOXIC IN MOST TRADITIONAL BACTERIAL AND MAMMALIAN TEST SYSTEMS. ITS CARCINOGENIC POTENTIAL APPEARS ATTRIBUTABLE TO THE SUSTAINED CELL TURNOVER (REGENERATIVE HYPERPLASIA) WHICH RESULTS FROM CHRONIC CHLOROFORM TOXICITY. IN THIS PRESENT STUDY, CELL PROLIFERATION (REPLICATIVE DNA SYNTHESIS, RDS) AND HISTOPATHOLOGICAL CHANGES IN HEPATOCYTES AND RENAL TUBULAR EPITHELIAL CELLS WERE ASSESSED IN MALE F344 RATS FOLLOWING A SINGLE GAVAGE CHLOROFORM EXPOSURE (50, 150 OR 500 MG/KG). IN ADDITION, BIOCHEMICAL PARAMETERS (BUN, GOT, LDH AND NAG) WERE EXAMINED USING PLASMA AND URINE SAMPLES. CELL PROLIFERATION AND HISTOPATHOLOGICAL CHANGES (E.G. HYPERTROPHY, NECROSIS, VACUOLATION) WERE ONLY SEEN AT THE DOSE OF 500 MG/KG IN THE LIVER AND KIDNEY. AT THE SAME DOSE, ALL BIOCHEMICAL MARKERS WERE INCREASED AT THE 24 TO 48 HR TIME POINTS. THESE RESULTS OBTAINED ARE THUS IN LINE WITH EARLIER FINDINGS POINTING TO EPIGENETIC CARCINOGENICITY. 1998 13 4513 20 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 14 4017 28 LOW-DOSE HYDRALAZINE REDUCES ALBUMINURIA AND GLOMERULOSCLEROSIS IN A MOUSE MODEL OF OBESITY-RELATED CHRONIC KIDNEY DISEASE. AIM: TO DETERMINE, USING A MOUSE MODEL OF OBESITY, WHETHER LOW-DOSE HYDRALAZINE PREVENTS OBESITY-RELATED CHRONIC KIDNEY DISEASE (CKD). METHODS: FROM 8 WEEKS OF AGE, MALE C57BL/6 MICE RECEIVED A HIGH-FAT DIET (HFD) OR CHOW, WITH OR WITHOUT LOW-DOSE HYDRALAZINE (25 MG/L) IN DRINKING WATER, FOR 24 WEEKS. BIOMETRIC AND METABOLIC VARIABLES, RENAL FUNCTION AND STRUCTURAL CHANGES, RENAL GLOBAL DNA METHYLATION, DNA METHYLATION PROFILE AND MARKERS OF RENAL FIBROSIS, INJURY, INFLAMMATION AND OXIDATIVE STRESS WERE ASSESSED. RESULTS: THE HFD-FED MICE DEVELOPED OBESITY, WITH GLUCOSE INTOLERANCE, HYPERINSULINAEMIA AND DYSLIPIDAEMIA. OBESITY INCREASED ALBUMINURIA AND GLOMERULOSCLEROSIS, WHICH WERE SIGNIFICANTLY AMELIORATED BY LOW-DOSE HYDRALAZINE IN THE ABSENCE OF A BLOOD PRESSURE-LOWERING EFFECT. OBESITY INCREASED RENAL GLOBAL DNA METHYLATION AND THIS WAS ATTENUATED BY LOW-DOSE HYDRALAZINE. HFD-INDUCED CHANGES IN METHYLATION OF INDIVIDUAL LOCI WERE ALSO SIGNIFICANTLY REVERSED BY LOW-DOSE HYDRALAZINE. OBESE MICE DEMONSTRATED INCREASED MARKERS OF KIDNEY FIBROSIS, INFLAMMATION AND OXIDATIVE STRESS, BUT THESE MARKERS WERE NOT SIGNIFICANTLY IMPROVED BY HYDRALAZINE. CONCLUSION: LOW-DOSE HYDRALAZINE AMELIORATED HFD-INDUCED ALBUMINURIA AND GLOMERULOSCLEROSIS, INDEPENDENT OF ALTERATIONS IN BIOMETRIC AND METABOLIC VARIABLES OR BLOOD PRESSURE REGULATION. ALTHOUGH THE PRECISE MECHANISM OF RENOPROTECTION IN OBESITY IS UNCLEAR, AN EPIGENETIC BASIS MAY BE IMPLICATED. THESE DATA SUPPORT REPURPOSING HYDRALAZINE AS A NOVEL THERAPY TO PREVENT CKD PROGRESSION IN OBESE PATIENTS. 2022 15 6368 31 THE ROLE OF MICRORNAS IN CHRONIC PSEUDOMONAS LUNG INFECTION IN CYSTIC FIBROSIS. BACKGROUND: CYSTIC FIBROSIS (CF) IS THE MOST COMMON LIFE LIMITING GENETIC DISORDER, CHARACTERIZED BY CHRONIC RESPIRATORY FAILURE SECONDARY TO INFLAMMATION AND CHRONIC BACTERIAL LUNG INFECTION. PSEUDOMONAS AERUGINOSA LUNG INFECTION IS ASSOCIATED WITH MORE SEVERE LUNG DISEASE AND RAPID PROGRESSION OF RESPIRATORY FAILURE WHEN COMPARED TO STAPHYLOCOCCUS AUREUS INFECTION. WE HYPOTHESIZED THAT A SPECIFIC SIGNATURE OF EPIGENETIC FACTORS TARGETING SPECIFIC GENE TRANSCRIPTS CONTRIBUTES TO THE INCREASED MORBIDITY SEEN IN CF PATIENTS WITH CHRONIC PSEUDOMONAS INFECTION. METHODS: WE COLLECTED EXHALED BREATH CONDENSATE (EBC) FROM 27 SUBJECTS AND EVALUATED MIRNA SIGNATURES IN THESE SAMPLES USING COMMERCIAL PCR ARRAY. WE IDENTIFIED PREDICTED MRNA TARGETS AND ASSOCIATED SIGNALING PATHWAYS USING INGENUITY PATHWAY ANALYSIS. RESULTS: WE FOUND 11 DIFFERENTIALLY EXPRESSED MIRNAS IN EBC OF PATIENTS INFECTED WITH PSEUDOMONAS AERUGINOSA COMPARED TO EBC FROM CF PATIENTS WHO WERE NOT CHRONICALLY INFECTED WITH PSEUDOMONAS AERUGINOSA (P < 0.05). SIX OF THESE MIRNAS (HSA-MIRNA-1247, HSA-MIRNA-1276, HSA-MIRNA-449C, HSA-MIRNA-3170, HSA-MIRNA-432-5P AND HSA-MIR-548) WERE SIGNIFICANTLY DIFFERENT IN THE CF PSEUDOMONAS POSITIVE GROUP WHEN COMPARED TO BOTH THE CF PSEUDOMONAS NEGATIVE GROUP AND HEALTHY CONTROL GROUP. INGENUITY PATHWAY ANALYSIS (IPA) REVEALED ORGANISMAL INJURY AND ABNORMALITIES, REPRODUCTIVE SYSTEM DISEASE AND CANCER AS THE TOP DISEASES AND BIO FUNCTIONS ASSOCIATED WITH THESE MIRNAS. IPA ALSO DETECTED RELA, JUN, TNF, IL-10, CTNNB1, IL-13, SERPINB8, CALM1, STARD3NL, SFI1, CD55, RPS6KA4, TTC36 AND HIST1H3D AS THE TOP TARGET GENES FOR THESE MIRNAS. CONCLUSION: OUR STUDY IDENTIFIED 6 MIRNAS AS EPIGENETIC FACTORS SPECIFICALLY ASSOCIATED WITH CHRONIC PSEUDOMONAS INFECTION IN PATIENTS WITH CF. 2019 16 818 22 CHARACTERISTICS OF THE SPECTRUM OF PROLIFERATIVE LESIONS OBSERVED IN THE KIDNEY AND URINARY BLADDER OF FISCHER 344 RATS AND B6C3F1 MICE. MANY RODENT RENAL AND BLADDER CARCINOGENS RELY UPON EPIGENETIC MECHANISMS OF CARCINOGENESIS; SUCH MECHANISMS ARE LIKELY TO INFLUENCE THE SPECTRUM OF URINARY TRACT TUMORS OBSERVED IN CONTROL AND TREATED ANIMALS. THIS IS REFLECTED IN SEVERAL FEATURES OF CHEMICALLY INDUCED RODENT URINARY TRACT NEOPLASMS, INCLUDING A LOW OVERALL TUMOR INCIDENCE, AN INCREASED PREVALENCE OF URINARY TRACT TUMORS IN RATS COMPARED TO MICE AND MALES COMPARED TO FEMALES, THE TENDENCY FOR EPITHELIAL TUMORS TO PREDOMINATE OVER NONEPITHELIAL TYPES, AND DEMONSTRATED LINKS TO CHRONIC PROGRESSIVE NEPHROPATHY AND UROLITHIASIS. SUCH TENDENCIES ARE ALSO CHARACTERISTIC OF SPONTANEOUS URINARY TRACT TUMORS IN RODENTS. DATA TO SUPPORT THESE OBSERVATIONS CAN BE DERIVED FROM LARGE HISTORICAL DATABASES SUCH AS THE TOXICOLOGY DATA MANAGEMENT SYSTEM, MAINTAINED BY NATIONAL TOXICOLOGY PROGRAM. 2002 17 1983 30 EPIGENETIC ALTERATIONS IN PODOCYTES IN DIABETIC NEPHROPATHY. RECENTLY, EPIGENETIC ALTERATIONS HAVE BEEN SHOWN TO BE INVOLVED IN THE PATHOGENESIS OF DIABETES AND ITS COMPLICATIONS. KIDNEY PODOCYTES, WHICH ARE GLOMERULAR EPITHELIAL CELLS, ARE IMPORTANT CELLS THAT FORM A SLIT MEMBRANE-A BARRIER FOR PROTEINURIA. PODOCYTES ARE TERMINALLY DIFFERENTIATED CELLS WITHOUT CELL DIVISION OR REPLENISHMENT ABILITIES. THEREFORE, PODOCYTE DAMAGE IS SUGGESTED TO BE ONE OF THE KEY FACTORS DETERMINING RENAL PROGNOSIS. RECENT STUDIES, INCLUDING OURS, SUGGEST THAT EPIGENETIC CHANGES IN PODOCYTES ARE ASSOCIATED WITH CHRONIC KIDNEY DISEASE, INCLUDING DIABETIC NEPHROPATHY. FURTHERMORE, THE ASSOCIATION BETWEEN DNA DAMAGE REPAIR AND EPIGENETIC CHANGES IN DIABETIC PODOCYTES HAS BEEN DEMONSTRATED. DETECTION OF PODOCYTE DNA DAMAGE AND EPIGENETIC CHANGES USING HUMAN SAMPLES, SUCH AS KIDNEY BIOPSY AND URINE-DERIVED CELLS, MAY BE A PROMISING STRATEGY FOR ESTIMATING KIDNEY DAMAGE AND RENAL PROGNOSES IN PATIENTS WITH DIABETES. TARGETING EPIGENETIC PODOCYTE CHANGES AND ASSOCIATED DNA DAMAGE MAY BECOME A NOVEL THERAPEUTIC STRATEGY FOR PREVENTING PROGRESSION TO END-STAGE RENAL DISEASE (ESRD) AND PROVIDE A POSSIBLE PROGNOSTIC MARKER IN DIABETIC NEPHROPATHY. THIS REVIEW SUMMARIZES RECENT ADVANCES REGARDING EPIGENETIC CHANGES, ESPECIALLY DNA METHYLATION, IN PODOCYTES IN DIABETIC NEPHROPATHY AND ADDRESSES DETECTION OF THESE ALTERATIONS IN HUMAN SAMPLES. ADDITIONALLY, WE FOCUSED ON DNA DAMAGE, WHICH IS INCREASED UNDER HIGH-GLUCOSE CONDITIONS AND ASSOCIATED WITH THE GENERATION OF EPIGENETIC CHANGES IN PODOCYTES. FURTHERMORE, EPIGENETIC MEMORY IN DIABETES IS DISCUSSED. UNDERSTANDING THE ROLE OF EPIGENETIC CHANGES IN PODOCYTES IN DIABETIC NEPHROPATHY MAY BE OF GREAT IMPORTANCE CONSIDERING THE INCREASING DIABETIC NEPHROPATHY PATIENT POPULATION IN AN AGING SOCIETY. 2021 18 5568 32 ROLE OF MARIJUANA COMPONENTS ON THE REGENERATIVE ABILITY OF STEM CELLS. STEM CELL THERAPY PROMOTES TISSUE REGENERATION AND WOUND HEALING. EFFORTS HAVE BEEN MADE TO PRIME STEM CELLS TO ENHANCE THEIR REGENERATIVE ABILITIES. CERTAIN MARIJUANA COMPONENTS, NAMELY THE NON-PSYCHOACTIVE CANNABIDIOL (CBD) AND PSYCHOACTIVE TETRAHYDROCANNABINOL (THC), ARE DEFINED AS IMMUNOMODULATORS.(9) WE TEST WHETHER TWO SOURCES OF STEM CELLS, PRIMED WITH CBD OR THC, WOULD DEMONSTRATE IMPROVED REGENERATIVE ABILITIES. HUMAN ADIPOSE-DERIVED STEM CELLS (ASCS) AND BONE MARROW-DERIVED STEM CELLS (BMDSCS), NOT OBTAINED FROM THE SAME INDIVIDUAL, WERE TREATED WITH LOW (300 NM) OR HIGH (3 MUM) CONCENTRATION CBD. PORCINE ASCS AND BMDSCS WERE ISOLATED FROM A SINGLE PIG, AND TREATED WITH EITHER LOW OR HIGH CONCENTRATIONS OF CBD OR THC. TRANSWELL MIGRATION AND MTT PROLIFERATION ASSAYS WERE PERFORMED ON THE HUMAN ASCS AND BMDSCS. ALSO, TRANSWELL MIGRATION ASSAY WAS PERFORMED ON THE PORCINE ASCS AND BMDSCS. FINALLY, A WOUND HEALING SCRATCH ASSAY IN PORCINE PRIMARY FIBROBLASTS (PFS) WAS PERFORMED, CO-CULTURED WITH THE CANNABINOID-TREATED ASCS. CBD PRIMING AT LOW CONCENTRATION INDUCES MIGRATION BY 180% (P < .01) IN PORCINE ASCS, AND BY ONLY 93% (P < .02) IN PORCINE BMDSCS. IN PORCINE STEM CELLS, THC PRIMING AT LOW CONCENTRATION INDUCES MIGRATION BY 91.6% (P < .01) IN ASCS BUT BY ONLY 44.3% (P < .03) IN BMDSCS. COMPARED TO PFS CO-CULTURED WITH UNTREATED ASCS, PFS CO-CULTURED WITH LOW CBD-PRIMED ASCS HAD 75% FASTER WOUND CLOSURE AT 18 HOURS (P < .01). CBD AND THC PRIMING OF ASCS AND BMDSCS, PARTICULARLY AT LOWER DOSES, ENHANCES A NUMBER OF REGENERATIVE PARAMETERS, SUGGESTING THAT THESE MAJOR MARIJUANA COMPONENTS MAY IMPROVE STEM CELL-BASED THERAPIES. SIGNIFICANCE OF THE STUDY: OUR STUDY DEMONSTRATES THAT CANNABINOIDS CAN ENHANCE THE REGENERATIVE CAPACITY OF TWO MAJOR SOURCES OF STEM CELLS, ADIPOSE- AND BONE MARROW-DERIVED, FROM HUMAN AND PORCINE DONORS. STEM CELL ISOLATION AND EXPANSION IS INVASIVE, COSTLY AND TIME CONSUMING. STEM CELLS WITH IMPROVED REGENERATIVE PROPERTIES MAY BE EFFECTIVE IN THE TREATMENT OF ACUTE OR CHRONIC WOUNDS. THIS IS THE FIRST STUDY TO COMPARE THE PRIMING POTENTIAL OF TWO SOURCES OF STEM CELLS FROM THE SAME ANIMAL, WITH THE SAME GENETIC AND EPIGENETIC PROFILE, AS WELL AS THE FIRST TO PRIME WITH THC. 2021 19 4963 35 PATHOGENESIS OF THYROID NODULES: HISTOLOGICAL CLASSIFICATION? THYROID NODULE GENESIS MAY BE CONSIDERED AS AN AMPLIFICATION OF THYROID HETEROGENEITY DUE TO GENETIC AND/OR EPIGENETIC MECHANISMS. WE CLASSIFIED THE THYROID NODULES IN FIVE TYPES WITH DISTINCT HISTOLOGICAL FEATURES: HYPERPLASTIC, NEOPLASTIC, COLLOID, CYSTIC AND THYROIDITIC NODULES. HYPERPLASTIC: THYROCYTE PROLIFERATION IS UNDER THE CONTROL OF TSH BUT SEVERAL OTHER PARACRINE AND AUTOCRINE FACTORS ARE SECRETED BY FOLLICULAR CELLS, THE STROMAL APPARATUS AND THE LYMPHOCYTES, WHICH ARE IMPLICATED IN INITIATION AND PERPETUATION OF THYROID HYPERPLASIA. GROWTH OCCURS MAINLY THROUGH TSHR, CAMP AND PKA. CONSTITUTIVE CAMP OVERPRODUCTION HAS BEEN SHOWN TO BE DUE TO POINT MUTATION OF THE TSHR OR GS PROTEIN, PRODUCING OVERGROWTH AND HYPERFUNCTION. NEOPLASTIC: SEVERAL ACTIVATED ONCOGENES HAVE BEEN IDENTIFIED IN THYROID MALIGNANCIES. ONCOGENES RELEVANT TO THE THYROID CARCINOGENESIS ARE: MUTATED TSHR AND GSP (CONSTITUTIVE ACTIVATION OF CAMP); TRK (RECEPTOR FOR NGF); RET/PTC (PHOSPHORYLATION OF TYROSINE KINASE RECEPTOR)--AN ISOFORM OF THIS ONCOGENE IS INDUCED BY RADIATION: RAS (IT ENCODES GS PROTEINS TRANSDUCING MITOGENIC SIGNALS); AND C-MET (RECEPTOR FOR HEPATOCYTE GROWTH FACTOR). THE EVOLUTION OF A DIFFERENTIATED THYROID CANCER TOWARDS AN UNDIFFERENTIATED CANCER IS DUE TO A MUTATION OF A FAMILY OF PROTEINS (I.E., P53), WHICH ACTS AS A BRAKE, PREVENTING THE GENOMIC INSTABILITY OF CANCER. IT IS SUGGESTED THAT A TUMOR INITIATES BY RET OR RAS AND POSSIBLY PROGRESSES--AS A RESULT OF ADDITIONAL MUTATIONS AND BY P53 MUTATION--TO ANAPLASTIC CARCINOMA. COLLOID: FLATTENING OF THE EPITHELIUM AND DILATATION OF FOLLICLES CONTAINING VISCOUS MATERIAL--MADE UP BY A CONCENTRATED SOLUTION OF THYROGLOBULIN (HTG)--IS THE CHARACTERISTIC OF THE COLLOID NODULE. A DEFECT OF INTRALUMINAL REABSORPTION OF HTG HAS BEEN SUGGESTED BUT NOT PROVEN. EXPERIMENTALLY, A LOAD OF IODINE IS ABLE TO CHANGE THYROID HYPERPLASIA TO A COLLOID FEATURE; HOWEVER, A LOAD OF IODINE IS RARELY FOUND IN THE CLINICAL HISTORY OF PATIENTS. A NEW CLUE TO THE PATHOGENESIS COMES FROM THE FINDING THAT A RELEVANT PART OF THE COLLOID (10-20%) IS MADE UP OF INSOLUBLE GLOBULES, WHERE HTG IS COMPACTED IN A POLYMERIC FORM. IT IS SUGGESTED THAT STOCKING HTG INTO GLOBULES IS DEFECTIVE IN COLLOID NODULES, LEADING TO ENORMOUS ENLARGEMENT OF THE FOLLICLE. CYSTIC: IT IS ESTIMATED THAT BETWEEN 15 AND 40% OF THYROID NODULES ARE PARTLY OR ENTIRELY CYSTIC. THE 'TRUE CYST' IS RARE; MOST OF THE SO-CALLED CYSTIC NODULES ARE 'PSEUDOCYSTS', WHICH FOLLOW NECROSIS AND COLLIQUATION. NECROSIS ISSUES AS AN IMBALANCE BETWEEN GROWTH AND THE PRECISELY REGULATED PROCESS OF ANGIOGENESIS. MORE RECENTLY, THE VEGF/VPF HAS BEEN FOUND TO BE AT THE ORIGIN OF RECENT AND RECURRENT CYSTS. IMMUNOTOXIC AND APOPTOTIC MECHANISMS HAVE ALSO BEEN SUGGESTED. CHEMICAL ANALYSIS OF CYSTIC FLUID SHOWED A 'DENATURED' AND 'SERUM-LIKE' PATTERN SUGGESTING DIFFERENT MECHANISMS IN THE PATHOGENESIS OF THE PSEUDOCYSTIC THYROID NODULES. THYROIDITIC: NODULAR LYMPHOCYTIC THYROIDITIS (NLT) INCLUDES TWO DIFFERENT ENTITIES: 1) LYMPHOCYTE THYROIDITIS GROWING AS A NODULE IN A HYPERPLASTIC OR NORMAL GLAND, AND 2) LYMPHOCYTE THYROIDITIS ASSOCIATED IN THE SAME NODULE WITH OTHER NODULAR DISEASES OF THE THYROID: PAPILLARY THYROID CARCINOMA AND LYMPHOMA HAVE BEEN FOUND TO BE ASSOCIATED TO CHRONIC LYMPHOCYTIC THYROIDITIS. 2001 20 4674 25 NEW INSIGHTS INTO THE ROLE AND MECHANISM OF PARTIAL EPITHELIAL-MESENCHYMAL TRANSITION IN KIDNEY FIBROSIS. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IS DESCRIBED AS THE PROCESS IN WHICH INJURED RENAL TUBULAR EPITHELIAL CELLS UNDERGO A PHENOTYPE CHANGE, ACQUIRING MESENCHYMAL CHARACTERISTICS AND MORPHING INTO FIBROBLASTS. INITIALLY, IT WAS WIDELY THOUGHT OF AS A CRITICAL MECHANISM OF FIBROGENESIS UNDERLYING CHRONIC KIDNEY DISEASE. HOWEVER, EVIDENCE THAT RENAL TUBULAR EPITHELIAL CELLS CAN CROSS THE BASEMENT MEMBRANE AND BECOME FIBROBLASTS IN THE RENAL INTERSTITIUM IS RARE, LEADING TO DEBATE ABOUT THE EXISTENCE OF EMT. RECENT RESEARCH HAS DEMONSTRATED THAT AFTER INJURY, RENAL TUBULAR EPITHELIAL CELLS ACQUIRE MESENCHYMAL CHARACTERISTICS AND THE ABILITY TO PRODUCE A VARIETY OF PROFIBROTIC FACTORS AND CYTOKINES, BUT REMAIN ATTACHED TO THE BASEMENT MEMBRANE. ON THIS BASIS, A NEW CONCEPT OF "PARTIAL EPITHELIAL-MESENCHYMAL TRANSITION (PEMT)" WAS PROPOSED TO EXPLAIN THE CONTRIBUTION OF RENAL EPITHELIAL CELLS TO RENAL FIBROGENESIS. IN THIS REVIEW, WE DISCUSS THE CONCEPT OF PEMT AND THE MOST RECENT FINDINGS RELATED TO THIS PROCESS, INCLUDING CELL CYCLE ARREST, METABOLIC ALTERNATION OF EPITHELIAL CELLS, INFILTRATION OF IMMUNE CELLS, EPIGENETIC REGULATION AS WELL AS THE NOVEL SIGNALING PATHWAYS THAT MEDIATE THIS DISTURBED EPITHELIAL-MESENCHYMAL COMMUNICATION. A DEEPER UNDERSTANDING OF THE ROLE AND THE MECHANISM OF PEMT MAY HELP IN DEVELOPING NOVEL THERAPIES TO PREVENT AND HALT FIBROSIS IN KIDNEY DISEASE. 2020