1 5590 114 ROLE OF THE BICARBONATE-RESPONSIVE SOLUBLE ADENYLYL CYCLASE IN CHOLANGIOCYTE APOPTOSIS IN PRIMARY BILIARY CHOLANGITIS; A NEW HYPOTHESIS. PRIMARY BILIARY CHOLANGITIS (PBC) IS A CHRONIC FIBROSING CHOLANGIOPATHY CHARACTERIZED BY AN AUTOIMMUNE STEREOTYPE AND DEFECTIVE BILIARY BICARBONATE SECRETION DUE TO DOWN-REGULATION OF ANION EXCHANGER 2 (AE2). DESPITE THE AUTOIMMUNE FEATURES, IMMUNOSUPPRESSANTS ARE INEFFECTIVE WHILE TWO BILE ACID-BASED THERAPIES (URSODEOXYCHOLIC ACID AND OBETICHOLIC ACID) HAVE BEEN SHOWN TO IMPROVE BIOCHEMICAL AND HISTOLOGICAL FEATURES OF CHOLESTASIS AND LONG-TERM PROGNOSIS. HOWEVER, THE ETIOLOGY AND PATHOGENESIS OF PBC IS LARGELY UNKNOWN. RECENTLY, IT HAS BEEN SHOWN THAT MICRORNA-506 (MIR-506) ON CHROMOSOME X IS UP-REGULATED IN PBC CHOLANGIOCYTES AND SUPPRESSES AE2 EXPRESSION, WHICH SENSITIZES CHOLANGIOCYTES TO BILE SALT-INDUCED APOPTOSIS BY ACTIVATING SOLUBLE ADENYLYL CYCLASE (SAC), AN EVOLUTIONARILY CONSERVED BICARBONATE SENSOR. IN THIS REVIEW, WE DISCUSS THE EXPERIMENTAL EVIDENCE FOR THE EMERGING ROLE OF THE MIR-506-AE2-SAC AXIS IN PBC PATHOGENESIS. WE FURTHER HYPOTHESIZE THAT THE INITIAL DISEASE TRIGGER INDUCES AN X-LINKED EPIGENETIC CHANGE, LEADING TO A FEMALE-BIASED ACTIVATION OF THE MIR-506-AE2-SAC AXIS. THIS ARTICLE IS PART OF A SPECIAL ISSUE ENTITLED: CHOLANGIOCYTES IN HEALTH AND DISEASEEDITED BY JESUS BANALES, MARCO MARZIONI AND PETER JANSEN. 2018 2 1637 27 DOES DYSREGULATION OF KEY EPIGENETIC AND BIOCHEMICAL PATHWAYS OCCUR IN POSTULATED VASOACTIVE NEUROPEPTIDE AUTOIMMUNE DISORDERS? AUTOIMMUNE DYSFUNCTION OF CERTAIN VASOACTIVE NEUROPEPTIDES (VNS) HAS BEEN POSTULATED AS A CONTRIBUTING CAUSE OF SUDDEN INFANT DEATH SYNDROME (SIDS), CHRONIC FATIGUE SYNDROME (CFS), GULF WAR SYNDROME (GWS) AND OTHER FATIGUE-RELATED DISORDERS. THIS FAMILY OF VNS INCLUDES PITUITARY ADENYLATE CYCLASE ACTIVATING POLYPEPTIDE (PACAP), VASOACTIVE INTESTINAL PEPTIDE (VIP) AND CALCITONIN GENE RELATED PEPTIDE (CGRP). THE POSTULATED MECHANISM IS COMPROMISE OF ADENYLATE CYCLASE ACTIVATION, A VITAL AND UNIQUE STEP IN CYCLIC AMP PRODUCTION FROM ATP, THROUGH AUTOIMMUNE DYSFUNCTION OF VNS, THEIR RECEPTORS OR THEIR GENES POSSIBLY INVOLVING CYTOSINE-PHOSPHATE-GUANINE (CPG) FRAGMENTS. CPG FRAGMENTS ARE IMMUNOMODULATORY DINUCLEOTIDES SERVING AS 'FRIEND OR FOE' RECOGNITION SYSTEMS TO DIFFERENTIATE BACTERIAL AND VIRAL (HYPOMETHYLATED CPG) FROM MAMMALIAN (METHYLATED CPG) DNA. HOWEVER HYPOMETHYLATION DISORDERS AFFECTING THESE FRAGMENTS IN MAMMALS MAY CONVERT THEM TO DYSFUNCTIONAL STATES BY PROMOTING AUTOIMMUNE INFLAMMATORY REACTIONS. EPIGENETIC MECHANISMS ACTING ON GENE PROMOTER REGIONS MAY CONTRIBUTE TO THE DEVELOPMENT OF VN AUTOIMMUNE FATIGUE-RELATED DISORDERS THROUGH CPG FRAGMENTS LOCATED IN VITAL SEGMENTS OF VN/RECEPTOR GENES BY CAUSING SIGNALLING DEFECTS WITH PROFOUND IMPLICATIONS FOR VN FUNCTION. NEUROTRANSMITTER DYSFUNCTION PARTICULARLY GLUTAMATERGIC TRANSMISSION COULD ALSO RESULT WITH DISRUPTION OF NEURONAL CELLULAR BIOCHEMICAL FUNCTIONS SUCH AS AMMONIA REGULATION. ENDOSOMAL ACIDITY AND MITOCHONDRIAL MEMBRANE POTENTIAL MODIFIERS SUCH AS CHLOROQUINE, TOGETHER WITH IMMUNOREGULATORY THERAPIES, MAY HAVE THERAPEUTIC IMPLICATIONS IN PROTECTING AGAINST THESE APPARENT AUTOIMMUNE DISORDERS. THIS PAPER EXAMINES SPECIFIC EPIGENETIC AND BIOCHEMICAL MECHANISMS POSSIBLY MEDIATED BY VN OR RECEPTOR GENES RESULTING IN POSTULATED VN AUTOIMMUNE FATIGUE-RELATED DISORDERS. THESE MECHANISMS MAY HAVE IMPLICATIONS FOR TREATMENT AND PREVENTION OPTIONS FOR VN AUTOIMMUNE DISORDERS. VN AUTOIMMUNE PROCESSES HAVE IMPLICATIONS FOR MILITARY MEDICINE WHERE RADIOLOGICAL, CHEMICAL AND BIOLOGICAL AGENTS MAY PLAY AN IMPORTANT ROLE IN PATHOGENESIS. 2005 3 6438 18 THERAPEUTIC AND PREVENTIVE INTERVENTIONS FOR POSTULATED VASOACTIVE NEUROPEPTIDE AUTOIMMUNE FATIGUE-RELATED DISORDERS. MAJOR ADVANCES HAVE BEEN MADE IN UNDERSTANDING THE RELATIVELY NOVEL GROUP OF VASOACTIVE (VASODILATORY) NEUROPEPTIDES (VNS) IN HUMANS. VNS COMPRISE A NOVEL BUT EXPANDING GROUP OF SUBSTANCES HAVING IMMUNOREGULATION, INFLAMMATION MODULATION, NEUROTRANSMITTER, NEUROTROPHIC, HORMONAL AND METABOLIC FUNCTIONS. THESE SUBSTANCES MAY CONTROL GENE EXPRESSION FOR MRNA FOR THEMSELVES AND THEIR RECEPTORS. THEY HAVE COMPLEX RELATIONSHIPS WITH GASEOUS AND OTHER NEUROTRANSMITTERS AND XENOBIOTIC SUBSTANCES. THEORETICAL ARGUMENTS HAVE IMPLICATED THESE SUBSTANCES IN AUTOIMMUNE PHENOMENA RESULTING IN FATIGUE-RELATED CONDITIONS SUCH AS CHRONIC FATIGUE SYNDROME (CFS), SUDDEN INFANT DEATH SYNDROME (SIDS), FIBROMYALGIA (FM) AND GULF WAR SYNDROME (GWS) BUT REMAIN UNPROVEN. AS WELL AS POSSIBLY SPONTANEOUS ONSET, THE PRECIPITATING CAUSES OF VN AUTOIMMUNE DYSFUNCTION ARE LIKELY TO BE A COMBINATION OF GENETIC PREDISPOSITION, INFECTION AND XENOBIOTIC SUBSTANCES. THERAPEUTIC AND PREVENTIVE POSSIBILITIES FOR POSTULATED VN AUTOIMMUNE CONDITIONS WILL BE INFLUENCED BY THE COMPLEX PATHOLOPHYSIOLOGY UNDERPINNING THEM. SOME SPECULATIVE POSSIBILITIES ARE VN SUBSTITUTION/REPLACEMENT, PRESERVATION OF BIOLOGICAL EFFECT, EPIGENETIC DNA MODIFICATIONS, PLASMA EXCHANGE, ANTI-CHOLINESTERASES, E.G., PYRIDOSTIGMINE, CORTICOSTEROIDS AND OTHER DRUG TREATMENTS, THYMECTOMY, INTRAVENOUS IMMUNOGLOBULIN AND ANTI-IDIOTYPE ANTIBODIES, AND CPG/DNA VACCINES. PREVENTION AND TREATMENT OF POSSIBLE VN AUTOIMMUNE FATIGUE-RELATED DISORDERS MAY PROVE TO BE IMPORTANT AREAS FOR FUTURE RESEARCH AND DEVELOPMENT. 2005 4 6009 24 THE ANTI-INFLAMMATORY MEDIATOR, VASOACTIVE INTESTINAL PEPTIDE, MODULATES THE DIFFERENTIATION AND FUNCTION OF TH SUBSETS IN RHEUMATOID ARTHRITIS. GENETIC BACKGROUND, EPIGENETIC MODIFICATIONS, AND ENVIRONMENTAL FACTORS TRIGGER AUTOIMMUNE RESPONSE IN RHEUMATOID ARTHRITIS (RA). SEVERAL PATHOGENIC INFECTIONS HAVE BEEN RELATED TO THE ONSET OF RA AND MAY CAUSE AN INADEQUATE IMMUNOLOGICAL TOLERANCE TOWARDS CRITICAL SELF-ANTIGENS LEADING TO CHRONIC JOINT INFLAMMATION AND AN IMBALANCE BETWEEN DIFFERENT T HELPER (TH) SUBSETS. VASOACTIVE INTESTINAL PEPTIDE (VIP) IS A MEDIATOR THAT MODULATES ALL THE STAGES COMPRISED BETWEEN THE ARRIVAL OF PATHOGENS AND TH CELL DIFFERENTIATION IN RA THROUGH ITS KNOWN ANTI-INFLAMMATORY AND IMMUNOMODULATORY ACTIONS. THIS "NEUROIMMUNOPEPTIDE" MODULATES THE PATHOGENIC ACTIVITY OF DIVERSE CELL SUBPOPULATIONS INVOLVED IN RA AS LYMPHOCYTES, FIBROBLAST-LIKE SYNOVIOCYTES (FLS), OR MACROPHAGES. IN ADDITION, VIP DECREASES THE EXPRESSION OF PATTERN RECOGNITION RECEPTOR (PRR) SUCH AS TOLL-LIKE RECEPTORS (TLRS) IN FLS FROM RA PATIENTS. THESE RECEPTORS ACT AS SENSORS OF PATHOGEN-ASSOCIATED MOLECULAR PATTERN (PAMP) AND DAMAGE-ASSOCIATED MOLECULAR PATTERN (DAMP) CONNECTING THE INNATE AND ADAPTIVE IMMUNE SYSTEM. MOREOVER, VIP MODULATES THE IMBALANCE BETWEEN TH SUBSETS IN RA, DECREASING PATHOGENIC TH1 AND TH17 SUBSETS AND FAVORING TH2 OR TREG PROFILE DURING THE DIFFERENTIATION/POLARIZATION OF NAIVE OR MEMORY TH CELLS. FINALLY, VIP REGULATES THE PLASTICITY BETWEEN THESES SUBSETS. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF VIP EFFECTS ON THE AFOREMENTIONED FEATURES OF RA PATHOLOGY. 2018 5 5220 29 PRIMARY BILIARY CHOLANGITIS: A TALE OF EPIGENETICALLY-INDUCED SECRETORY FAILURE? PRIMARY BILIARY CHOLANGITIS (PBC) IS A CHRONIC CHOLESTATIC LIVER DISEASE ASSOCIATED WITH AUTOIMMUNE-RELATED DESTRUCTION OF SMALL TO MEDIUM SIZE INTRAHEPATIC BILE DUCTS. THE AETIOLOGY OF PBC IS UNKNOWN AND ITS PATHOGENESIS REMAINS OBSCURE. BOTH GENETIC VARIANTS AND ENVIRONMENTAL FACTORS HAVE BEEN LINKED TO INCREASED PBC SUSCEPTIBILITY, WITH OTHER ALTERATIONS KNOWN TO COOPERATE IN DISEASE PATHOBIOLOGY. INCREASING EVIDENCE INDICATES THE PRESENCE OF EPIGENETIC ABNORMALITIES IN PBC, PARTICULARLY ALTERATIONS OF CHOLANGIOCELLULAR MICRORNAS (MIRNAS OR MIRS). THIS REVIEW HIGHLIGHTS AND DISCUSSES THE MOST RELEVANT EPIGENETIC ALTERATIONS FOUND IN PATIENTS WITH PBC, FOCUSING ON THE ROLE OF MIR-506 IN THE PROMOTION OF CHOLESTASIS AND IMMUNE ACTIVATION. 2018 6 3012 34 GENETICS AND EPIGENETICS IN THE PATHOGENESIS OF PRIMARY BILIARY CHOLANGITIS. PRIMARY BILIARY CHOLANGITIS (PBC) IS A CHRONIC, SLOWLY PROGRESSIVE CHOLESTATIC AUTOIMMUNE LIVER DISEASE PREDOMINANTLY AFFLICTING WOMEN. PBC IS CHARACTERIZED BY THE PRESENCE OF DISEASE-SPECIFIC ANTIMITOCHONDRIAL ANTIBODIES AND THE HISTOLOGICAL DESTRUCTION OF INTRAHEPATIC BILE DUCTS, WHICH EVENTUALLY LEAD TO CIRRHOSIS AND HEPATIC FAILURE. FORTUNATELY, URSODEOXYCHOLIC ACID THERAPY HAS IMPROVED THE OUTCOME OF THE VAST MAJORITY OF PBC CASES. ALTHOUGH THE ETIOLOGY OF PBC HAS NOT YET BEEN ELUCIDATED, HUMAN LEUKOCYTE ANTIGEN (HLA) CLASS II ALLELES HAVE BEEN CONSISTENTLY ASSOCIATED WITH DISEASE ONSET FOR DECADES. PBC PATIENTS MAY ALSO HAVE GENETICALLY DETERMINED RISK FACTORS IN NON-HLA REGIONS. MEANWHILE, EXPOSURE TO ENVIRONMENTAL FACTORS, SUCH AS INFECTIOUS DISEASES AND HARMFUL CHEMICALS, CAN PRODUCE EPIGENETIC ALTERATIONS IN SOME INDIVIDUALS AND SUBSEQUENT PBC ONSET. IN THIS REVIEW, WE DESCRIBE THE INFLUENCE OF HLA ALLELES AND OTHER GENE POLYMORPHISMS ON PBC ALONG WITH THE RESULTS OF GENOME-WIDE ASSOCIATION STUDIES ON THIS DISEASE AND ITS FUTURE PROSPECTS IN TERMS OF EPIGENETICS. 2018 7 5221 30 PRIMARY BILIARY CHOLANGITIS: PATHOGENESIS AND THERAPEUTIC OPPORTUNITIES. PRIMARY BILIARY CHOLANGITIS IS A CHRONIC, SEROPOSITIVE AND FEMALE-PREDOMINANT INFLAMMATORY AND CHOLESTATIC LIVER DISEASE, WHICH HAS A VARIABLE RATE OF PROGRESSION TOWARDS BILIARY CIRRHOSIS. SUBSTANTIAL PROGRESS HAS BEEN MADE IN PATIENT RISK STRATIFICATION WITH THE GOAL OF PERSONALIZED CARE, INCLUDING EARLY ADOPTION OF NEXT-GENERATION THERAPY WITH LICENSED USE OF OBETICHOLIC ACID OR OFF-LABEL FIBRATE DERIVATIVES FOR THOSE WITH INSUFFICIENT BENEFIT FROM URSODEOXYCHOLIC ACID, THE CURRENT FIRST-LINE DRUG. THE DISEASE BIOLOGY SPANS GENETIC RISK, EPIGENETIC CHANGES, DYSREGULATED MUCOSAL IMMUNITY AND ALTERED BILIARY EPITHELIAL CELL FUNCTION, ALL OF WHICH INTERACT AND ARISE IN THE CONTEXT OF ILL-DEFINED ENVIRONMENTAL TRIGGERS. A CURRENT FOCUS OF RESEARCH ON NUCLEAR RECEPTOR PATHWAY MODULATION THAT SPECIFICALLY AND POTENTLY IMPROVES BILIARY EXCRETION, REDUCES INFLAMMATION AND ATTENUATES FIBROSIS IS REDEFINING THERAPY. PATIENTS ARE BENEFITING FROM PHARMACOLOGICAL AGONISTS OF FARNESOID X RECEPTOR AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS. IMMUNOTHERAPY REMAINS A CHALLENGE, WITH A LACK OF TARGET DEFINITION, PLEIOTROPIC IMMUNE PATHWAYS AND AN INTERPLAY BETWEEN HEPATIC IMMUNE RESPONSES AND CHOLESTASIS, WHEREIN BILE ACID-INDUCED INFLAMMATION AND FIBROSIS ARE DOMINANT CLINICALLY. THE MANAGEMENT OF PATIENT SYMPTOMS, PARTICULARLY PRURITUS, IS A NOTABLE GOAL REFLECTED IN THE DEVELOPMENT OF RATIONAL THERAPY WITH APICAL SODIUM-DEPENDENT BILE ACID TRANSPORTER INHIBITORS. 2020 8 5272 33 PROMOTER HYPERMETHYLATION OF THE AE2/SLC4A2 GENE IN PBC. BACKGROUND & AIMS: PATIENTS WITH PRIMARY BILIARY CHOLANGITIS (PBC) EXHIBIT REDUCED AE2/SLC4A2 GENE EXPRESSION IN THE LIVER AND PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS). AE2 ENCODES A CL(-)/HCO(3) (-) EXCHANGER INVOLVED IN BILIARY BICARBONATE SECRETION AND INTRACELLULAR PH REGULATION. REDUCED AE2 EXPRESSION IN PBC MAY BE PATHOGENIC, AS AE2-KNOCKOUT MICE REPRODUCE CHARACTERISTIC PBC FEATURES. HEREIN, WE AIMED TO IDENTIFY CPG-METHYLATION ABNORMALITIES IN AE2 PROMOTER REGIONS THAT MIGHT CONTRIBUTE TO THE REDUCED GENE TRANSCRIPTION IN PBC LIVERS AND PBMCS. METHODS: CPG-CYTOSINE METHYLATION RATES WERE INTERROGATED AT 1-BASE PAIR RESOLUTION IN UPSTREAM AND ALTERNATE AE2 PROMOTER REGIONS THROUGH PYROSEQUENCING OF BISULPHITE-MODIFIED GENOMIC DNA FROM LIVER SPECIMENS AND PBMCS. AE2A AND ALTERNATIVE AE2B1 AND AE2B2 MRNA LEVELS WERE MEASURED BY REAL-TIME PCR. HUMAN LYMPHOBLASTOID-T2 CELLS WERE TREATED WITH 5-AZA-2 -DEOXYCYTIDINE FOR DEMETHYLATION ASSAYS. RESULTS: AE2 PROMOTERS WERE FOUND TO BE HYPERMETHYLATED IN PBC LIVERS COMPARED TO NORMAL AND DISEASED LIVER SPECIMENS. RECEIVER OPERATING CHARACTERISTIC (ROC) CURVE ANALYSIS SHOWED THAT MINIMAL CPG-HYPERMETHYLATION CLUSTERS OF 3 AE2A-CPG SITES AND 4 ALTERNATE-AE2B2-CPG SITES SPECIFICALLY DIFFERENTIATED PBC FROM NORMAL AND DISEASED CONTROLS, WITH MEAN METHYLATION RATES INVERSELY CORRELATING WITH RESPECTIVE TRANSCRIPT LEVELS. ADDITIONALLY, IN PBMCS A MINIMAL CLUSTER OF 3 HYPERMETHYLATED AE2A-CPG SITES DISTINGUISHED PBC FROM CONTROLS, AND MEAN METHYLATION RATES CORRELATED NEGATIVELY WITH AE2A MRNA LEVELS IN THESE IMMUNE CELLS. ALTERNATE AE2B2/AE2B1 PROMOTERS IN PBMCS WERE CONSTITUTIVELY HYPERMETHYLATED, IN LINE WITH ABSENT ALTERNATIVE MRNA EXPRESSION IN DISEASED AND HEALTHY PBMCS. DEMETHYLATION ASSAYS TREATING LYMPHOBLASTOID-T2 CELLS WITH 5-AZA-2 -DEOXYCYTIDINE TRIGGERED AE2B2/AE2B1 EXPRESSION AND UPREGULATED AE2A-PROMOTER EXPRESSION. CONCLUSIONS: DISEASE-SPECIFIC HYPERMETHYLATION OF AE2 PROMOTER REGIONS AND SUBSEQUENT DOWNREGULATION OF AE2-GENE EXPRESSION IN THE LIVER AND PBMCS OF PATIENTS WITH PBC MIGHT BE CRITICALLY INVOLVED IN THE PATHOGENESIS OF THIS COMPLEX DISEASE. LAY SUMMARY: PRIMARY BILIARY CHOLANGITIS (PBC) IS A CHRONIC IMMUNE-ASSOCIATED CHOLESTATIC LIVER DISEASE WITH UNCLEAR COMPLEX/MULTIFACTORIAL ETIOPATHOGENESIS AFFECTING MOSTLY MIDDLE-AGED WOMEN. PATIENTS WITH PBC EXHIBIT REDUCED EXPRESSION OF THE AE2/SLC4A2 GENE. HEREIN, WE FOUND THAT AE2 PROMOTER REGIONS ARE HYPERMETHYLATED IN THE LIVER AND PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH PBC. THIS INCREASED METHYLATION IS ASSOCIATED WITH DOWNREGULATED AE2-GENE EXPRESSION, WHICH MIGHT CONTRIBUTE TO THE PATHOGENESIS OF PBC. THEREFORE, NOVEL EPIGENETIC TARGETS MAY IMPROVE TREATMENT IN PATIENTS WITH PBC WHO RESPOND POORLY TO CURRENT PHARMACOLOGICAL THERAPIES. 2019 9 5506 29 RHEUMATOID ARTHRITIS AND PRIMARY BILIARY CIRRHOSIS: CAUSE, CONSEQUENCE, OR COINCIDENCE? PRIMARY BILIARY CIRRHOSIS (PBC) IS A PROGRESSIVE CHOLESTATIC LIVER DISEASE CHARACTERIZED SEROLOGICALLY BY CHOLESTASIS AND THE PRESENCE OF HIGH-TITRE ANTIMITOCHONDRIAL ANTIBODIES AND HISTOLOGICALLY BY CHRONIC NONSUPPURATIVE CHOLANGITIS AND GRANULOMATA. PBC PATIENTS OFTEN HAVE CONCOMITANT AUTOIMMUNE DISEASES, INCLUDING ARTHROPATHIES. THIS RAISES THE QUESTION AS TO WHETHER THERE ARE SHARED FEATURES IN THE PATHOGENESIS OF THOSE DISEASES WITH THE PATHOGENESIS OF PBC. EPIDEMIOLOGICAL AND LARGE CASE STUDIES HAVE INDICATED THAT ALTHOUGH THE INCIDENCE OF RHEUMATOID ARTHRITIS (RA) IS NOT SIGNIFICANTLY RAISED IN PBC PATIENTS, THERE APPEARS TO BE A HIGHER RATE OF RA IN PBC PATIENTS AND THEIR RELATIVES. GENETIC STUDIES HAVE DEMONSTRATED THAT SEVERAL GENES IMPLICATED IN PBC HAVE ALSO BEEN IMPLICATED IN RA. EPIGENETIC STUDIES PROVIDED A WEALTH OF DATA REGARDING RA, BUT THE FINDINGS ON EPIGENETIC CHANGES IN PBC ARE VERY LIMITED. AS WELL, CERTAIN INFECTIOUS AGENTS IDENTIFIED IN THE PATHOGENESIS OF PBC MAY ALSO PLAY A ROLE IN THE PATHOGENESIS OF RA. THESE DATA SUGGEST THAT ALTHOUGH RA IS NOT SIGNIFICANTLY PRESENT IN PBC, SOME INDIVIDUALS WITH CERTAIN GENETIC TRAITS AND ENVIRONMENTAL EXPOSURES MAY DEVELOP BOTH CONDITIONS. THIS CONCEPT MAY ALSO APPLY TO OTHER CONCOMITANT DISEASES FOUND IN PBC PATIENTS. 2012 10 4175 26 MELATONIN PROTECTS CHOLANGIOCYTES FROM OXIDATIVE STRESS-INDUCED PROAPOPTOTIC AND PROINFLAMMATORY STIMULI VIA MIR-132 AND MIR-34. BIOSYNTHESIS OF MELATONIN BY CHOLANGIOCYTES IS ESSENTIAL FOR MAINTAINING THE FUNCTION OF BILIARY EPITHELIUM. HOWEVER, THIS CYTOPROTECTIVE MECHANISM APPEARS TO BE IMPAIRED IN PRIMARY BILIARY CHOLANGITIS (PBC). MIR-132 HAS EMERGED AS A MEDIATOR OF INFLAMMATION IN CHRONIC LIVER DISEASES. THE EFFECT OF MELATONIN ON OXIDATIVE STRESS AND BILE ACID-INDUCED APOPTOSIS WAS ALSO EXAMINED IN CHOLANGIOCYES OVEREXPRESSING MIR506, AS A PBC-LIKE CELLULAR MODEL. IN PBC PATIENTS THE SERUM LEVELS OF MELATONIN WERE FOUND INCREASED IN COMPARISON TO HEALTHY CONTROLS. WHEREAS, IN CHOLANGIOCYTES WITHIN CIRRHOTIC PBC LIVERS THE MELATONIN BIOSYNTHETIC PATHWAY WAS SUBSTANTIALLY SUPPRESSED EVEN THOUGH THE EXPRESSIONS OF MELATONIN RATE-LIMITING ENZYME ARALKYLAMINE N-ACETYLTRANSFERASE (AANAT), AND CK-19 (MARKER OF CHOLANGIOCYTES) WERE ENHANCED. IN CHOLANGIOCYTES EXPOSED TO MITOCHONDRIAL OXIDATIVE STRESS MELATONIN DECREASED THE EXPRESSION OF PROAPOPTOTIC STIMULI (PTEN, BAX, MIR-34), WHICH WAS ACCOMPANIED BY THE INHIBITION OF A PIVOTAL MEDIATOR OF INFLAMMATORY RESPONSE NF-KAPPAB-P65 AND THE ACTIVATION OF ANTIAPOPTOTIC SIGNALING (MIR-132, BCL2). SIMILARLY, MELATONIN REDUCED BILE ACID-INDUCED PROAPOPTOTIC CASPASE 3 AND BIM LEVELS. IN SUMMARY, THE INSUFFICIENT HEPATIC EXPRESSION OF MELATONIN IN PBC PATIENTS MAY PREDISPOSE CHOLANGIOCYTES TO OXIDATIVE STRESS-RELATED DAMAGE. MELATONIN, VIA EPIGENETIC MODULATION, WAS ABLE TO SUPPRESS NF-KAPPAB SIGNALING ACTIVATION AND PROTECT AGAINST BILIARY CELLS APOPTOTIC SIGNALING. 2020 11 4964 27 PATHOGENETIC AND CLINICAL ASPECTS OF ANTI-NEUTROPHIL CYTOPLASMIC AUTOANTIBODY-ASSOCIATED VASCULITIDES. ANTI-NEUTROPHIL CYTOPLASMIC AUTOANTIBODIES (ANCA) TARGETING PROTEINASE 3 (PR3) AND MYELOPEROXIDASE EXPRESSED BY INNATE IMMUNE CELLS (NEUTROPHILS AND MONOCYTES) ARE SALIENT DIAGNOSTIC AND PATHOGENIC FEATURES OF SMALL VESSEL VASCULITIS, COMPRISING GRANULOMATOSIS WITH POLYANGIITIS (GPA), MICROSCOPIC POLYANGIITIS, AND EOSINOPHILIC GPA. GENETIC STUDIES SUGGEST THAT ANCA-ASSOCIATED VASCULITIDES (AAV) CONSTITUTE SEPARATE DISEASES, WHICH SHARE COMMON IMMUNOLOGICAL AND PATHOLOGICAL FEATURES, BUT ARE OTHERWISE HETEROGENEOUS. THE SUCCESSFUL THERAPEUTIC USE OF ANTI-CD20 ANTIBODIES EMPHASIZES THE PROMINENT ROLE OF ANCA AND POSSIBLY OTHER AUTOANTIBODIES IN THE PATHOGENESIS OF AAV. HOWEVER, TO ELUCIDATE CAUSAL EFFECTS IN AAV, A BETTER UNDERSTANDING OF THE COMPLEX INTERPLAY LEADING TO THE EMERGENCE OF B LYMPHOCYTES THAT PRODUCE PATHOGENIC ANCA REMAINS A CHALLENGE. DIFFERENT SCENARIOS SEEM POSSIBLE; E.G., THE BREAK OF TOLERANCE INDUCED BY A SHIFT FROM NON-PATHOGENIC TOWARD PATHOGENIC AUTOANTIGEN EPITOPES IN INFLAMED TISSUE. THIS REVIEW GIVES A BRIEF OVERVIEW ON CURRENT KNOWLEDGE ABOUT GENETIC AND EPIGENETIC FACTORS, BARRIER DYSFUNCTION AND CHRONIC NON-RESOLVING INFLAMMATION, NECRO-INFLAMMATORY AUTO-AMPLIFICATION OF CELLULAR DEATH AND INFLAMMATION, ALTERED AUTOANTIGEN PRESENTATION, ALTERNATIVE COMPLEMENT PATHWAY ACTIVATION, ALTERATIONS WITHIN PERIPHERAL AND INFLAMED TISSUE-RESIDING T- AND B-CELL POPULATIONS, ECTOPIC LYMPHOID TISSUE NEOFORMATION, THE CHARACTERIZATION OF PR3-SPECIFIC T-CELLS, PROPERTIES OF ANCA, LINKS BETWEEN AUTOIMMUNE DISEASE AND INFECTION-TRIGGERED PATHOLOGY, AND ANIMAL MODELS IN AAV. 2018 12 6650 28 UPDATE ON ETIOLOGY AND PATHOGENESIS OF BILIARY ATRESIA. BILIARY ATRESIA IS A RARE INFLAMMATORY SCLEROSING OBSTRUCTIVE CHOLANGIOPATHY THAT INITIATES IN INFANCY AS COMPLETE CHOLEDOCHAL BLOCKAGE AND PROGRESSES TO THE INVOLVEMENT OF INTRAHEPATIC BILIARY EPITHELIUM. GROWING EVIDENCE SHOWS THAT BILIARY ATRESIA IS NOT A SINGLE ENTITY WITH A SINGLE ETIOLOGY BUT A PHENOTYPE RESULTING FROM MULTIFACTORIAL EVENTS WHOSE COMMON PATH IS OBLITERATIVE CHOLANGIOPATHY. THE ETIOLOGY OF BILIARY ATRESIA HAS BEEN EXPLAINED AS RESULTING FROM GENETIC VARIANTS, TOXINS, VIRAL INFECTION, CHRONIC INFLAMMATION OR BILE DUCT LESIONS MEDIATED BY AUTOIMMUNITY, ABNORMALITIES IN THE DEVELOPMENT OF THE BILE DUCTS, AND DEFECTS IN EMBRYOGENESIS, ABNORMAL FETAL OR PRENATAL CIRCULATION AND SUSCEPTIBILITY FACTORS. IT IS INCREASINGLY EVIDENT THAT THE GENETIC AND EPIGENETIC PREDISPOSITION COMBINED WITH THE ENVIRONMENTAL FACTORS TO WHICH THE MOTHER IS EXPOSED ARE POTENTIAL TRIGGERS FOR BILIARY ATRESIA. THERE IS ALSO AN INDICATION THAT A PROGRESSIVE THICKENING OF THE ARTERIAL MIDDLE LAYER OCCURS IN THIS DISEASE, SUGGESTIVE OF VASCULAR REMODELING AND DISAPPEARANCE OF THE INTERLOBULAR BILE DUCTS. IT IS SUGGESTED THAT THE HYPOXIA/ISCHEMIA PROCESS CAN AFFECT PORTAL STRUCTURES IN BILIARY ATRESIA AND IS ASSOCIATED WITH BOTH THE EXTENT OF BILIARY PROLIFERATION AND THE THICKENING OF THE MEDIAL LAYER. 2022 13 740 29 CANCER/TESTIS ANTIGENS: EXPRESSION, REGULATION, TUMOR INVASION, AND USE IN IMMUNOTHERAPY OF CANCERS. CANCER/TESTIS ANTIGENS (CTAS) ARE NAMED BASED ON THEIR EXPRESSION PATTERN THAT IS RESTRICTED IN A NUMBER OF NORMAL AND ABNORMAL TISSUES. TUMOR CELLS FREQUENTLY EXPRESS ANTIGENS WHOSE EXPRESSION IS TYPICALLY RESTRICTED TO GERM CELLS. THEIR UNIQUE EXPRESSION PATTERN IS GUARANTEED BY PRECISE EPIGENETIC REGULATORY MECHANISMS. BECAUSE OF THEIR TUMOR-LIMITED, HIGH IMMUNOGENICITY, AND BIASED EXPRESSION, DISCOVERY OF THESE MOLECULES PROVIDES UNPRECEDENTED OPPORTUNITIES FOR FURTHER RESEARCH AND CLINICAL DEVELOPMENT IN THE FIELD OF CANCER DIAGNOSIS AND IMMUNOTHERAPY. EVOLVING EVIDENCE REVEALS THAT A NUMBER OF CTAS STIMULATE EPITHELIAL MESENCHYMAL TRANSITION (EMT) AND GENERATION OF CANCER STEM-LIKE CELLS, INTENSIFYING METASTASIS, INVASION, AND TUMORIGENESIS. BASED ON THESE FEATURES, CTAS ATTRACT ATTENTION TO BE CONSIDERED AS IDEAL TARGETS FOR DEVELOPING SEVERAL CLINICAL TRIALS, MANY OF THEM CONCENTRATING ON CTA VACCINE THERAPY. ACCORDING TO RECENT PRACTICAL CLINICAL INTEREST, MORE CHARACTERIZATIONS OF CTA REGULATION ARE IDENTIFIED. CTA EXPRESSION HAS BEEN DEMONSTRATED IN A VARIETY OF HUMAN CANCER TISSUES, AND SOME OF THEM HAVE BEEN FOUND TO ELICIT HUMORAL AND/OR CELLULAR IMMUNE RESPONSES IN CANCER PATIENTS. CTAS ARE BRILLIANT TARGETS FOR ANTICANCER DRUG DISCOVERY, TARGETED TUMOR THERAPY, AND DIAGNOSTIC BIOMARKERS, FURTHERMORE, VALUED GENES IN THE STUDY OF IMMUNOTHERAPY, PROMOTING TUMORIGENESIS, AND MALIGNANT PROGRESSION. THIS REVIEW OUTLINES AND CATEGORIZES OUR CURRENT UNDERSTANDING OF THE COMPLEX AND BIASED PROCESS OF CTAS MRNA AND PROTEIN EXPRESSION IN CANCER, AND SUPPLIES THE MOST RECENT INFORMATION ON THEIR REGULATION AND FUNCTION. BESIDES, A CONCISE SYNOPSIS OF THE MAJOR CLINICAL TRIALS INVOLVING CTAS, AS THERAPEUTIC AVENUES, IS DISCUSSED. ABBREVIATIONS: AIRE: AUTOIMMUNE REGULATOR; CAMP: CYCLIC ADENOSINE 3',5'-CYCLIC MONOPHOSPHATE; CEA: CARCINOEMBRYONIC ANTIGEN; CML: CHRONIC MYELOID LEUKEMIA; CREB: CYCLICAMP RESPONSE ELEMENT BINDING; CSCS: CANCER STEM CELLS; CTAS: CANCER/TESTIS ANTIGENS; CTL: CYTOTOXIC T LYMPHOCYTE; DCS: DENDRITIC CELLS; EMT: EPITHELIAL-MESENCHYMAL TRANSITION; ERK: EXTRACELLULAR SIGNAL-REGULATED KINASE; ESCC: ESOPHAGEAL SQUAMOUS CELL CARCINOMA; ETS: E26 TRANSFORMATION-SPECIFIC; HIS: HISTIDINE; HLA: HUMAN LEUKOCYTE ANTIGEN; HNSCC: HEAD AND NECK SQUAMOUS CELL CARCINOMA; IFN-GAMMA: INTERFERON-GAMMA; IHC: IMMUNOHISTOCHEMISTRY; IL-7: INTERLEUKIN7; MHC: MAJOR HISTOCOMPATIBILITY COMPLEX; MMP2: MATRIX METALLOPROTEINASE 2; MTECS: MEDULLARY THYMUS EPITHELIAL CELLS; MUC1: MUCIN 1; NSCLC: NON-SMALL CELL LUNG CANCER; PRAME: PREFERENTIALLY EXPRESSED ANTIGEN IN MELANOMA; RDA: REPRESENTATIONAL DIFFERENCE ANALYSIS; SEREX: SEROLOGICAL ANALYSIS OF CDNA EXPRESSION; SSX: SYNOVIAL SARCOMA X CHROMOSOME; TAAS: TUMOR-ASSOCIATED ANTIGENS; TCR: T-CELL RECEPTOR; TCGA: THE CANCER GENOME ATLAS; TGF-BETA: TRANSFORMING GROWTH FACTOR-BETA. 2016 14 5222 24 PRIMARY BILIARY CIRRHOSIS: FAMILY STORIES. PRIMARY BILIARY CIRRHOSIS (PBC) IS A CHRONIC IMMUNE-MEDIATED CHOLESTATIC LIVER DISEASE OF UNKNOWN AETIOLOGY WHICH AFFECTS MOSTLY WOMEN IN MIDDLE AGE. FAMILIAL PBC IS WHEN PBC AFFECTS MORE THAN ONE MEMBER OF THE SAME FAMILY, AND DATA SUGGEST THAT FIRST-DEGREE RELATIVES OF PBC PATIENTS HAVE AN INCREASED RISK OF DEVELOPING THE DISEASE. MOST OFTEN, THESE FAMILIAL CLUSTERS INVOLVE MOTHER-DAUGHTER PAIRS, WHICH IS CONSISTENT WITH THE FEMALE PREPONDERANCE OF THE DISEASE. THESE CLUSTERS PROVIDE EVIDENCE TOWARDS A GENETIC BASIS UNDERLYING PBC. HOWEVER, CLUSTERS OF NONRELATED INDIVIDUALS HAVE ALSO BEEN REPORTED, GIVING STRENGTH TO AN ENVIRONMENTAL COMPONENT. TWIN STUDIES HAVE DEMONSTRATED A HIGH CONCORDANCE FOR PBC IN MONOZYGOTIC TWINS AND A LOW CONCORDANCE AMONG DIZYGOTIC TWINS. IN CONCLUSION, STUDIES OF PBC IN FAMILIES CLEARLY DEMONSTRATE THAT GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS PLAY A ROLE IN THE DEVELOPMENT OF THE DISEASE. 2011 15 6476 23 TOLL-LIKE RECEPTORS, INFECTIONS, AND RHEUMATOID ARTHRITIS. TOLL-LIKE RECEPTORS (TLR) THAT BELONG TO THE GROUP OF PROTEIN RECOGNITION RECEPTOR (PPR) PROVIDE AN INNATE IMMUNE RESPONSE FOLLOWING THE SENSING OF CONSERVED PATHOGEN-ASSOCIATED MICROBIAL PATTERNS (PAMPS) AND CHANGES IN DANGER-ASSOCIATED MOLECULAR PATTERNS (DAMPS) THAT ARE GENERATED AS A CONSEQUENCE OF CELLULAR INJURY. ANALYSIS OF THE TLR PATHWAY HAS MOREOVER OFFERED NEW INSIGHTS INTO THE PATHOGENESIS OF RHEUMATOID ARTHRITIS (RA). INDEED, A DYSFUNCTIONAL TLR-MEDIATED RESPONSE CHARACTERIZES RA PATIENTS AND PARTICIPATES IN ESTABLISHMENT OF A CHRONIC INFLAMMATORY STATE. SUCH AN INAPPROPRIATE TLR RESPONSE HAS BEEN ATTRIBUTED (I) TO THE REPORT OF IMPORTANT ALTERATIONS IN THE MICROBIOTA AND ABNORMAL RESPONSES TO INFECTIOUS AGENTS AS PART OF RA; (II) TO THE ABNORMAL PRESENCE OF TLR-LIGANDS IN THE SERUM AND SYNOVIAL FLUID OF RA PATIENTS; (III) TO THE OVEREXPRESSION OF TLR MOLECULES; (IV) TO THE PRODUCTION OF A LARGE PANEL OF PRO-INFLAMMATORY CYTOKINES DOWNSTREAM OF THE TLR PATHWAY; AND (V) TO GENETIC VARIANTS AND EPIGENETIC FACTORS IN SUSCEPTIBLE RA PATIENTS PROMOTING A HYPER TLR RESPONSE. AS A CONSEQUENCE, THE DEVELOPMENT OF PROMISING THERAPEUTIC STRATEGIES TARGETING TLRS FOR THE TREATMENT AND PREVENTION OF RA IS EMERGING. 2020 16 2588 32 EPIGENETICS OF PRIMARY BILIARY CHOLANGITIS. PRIMARY BILIARY CHOLANGITIS (PBC) IS A CHRONIC CHOLESTATIC LIVER DISEASE WITH NON-SUPPURATIVE DESTRUCTION OF THE INTRAHEPATIC BILE DUCTS. THE INTERPLAY OF GENETICS AND ENVIRONMENTAL TRIGGERS CONTRIBUTES TO THE ONSET OF THE DISEASE AND SUBSEQUENTLY RESULTS IN CHOLESTASIS AND PROGRESSIVE FIBROSIS. RECENTLY, GENOME-WIDE ASSOCIATION STUDIES (GWAS) HAVE IDENTIFIED MULTIPLE GENES INFLUENCING THE SUSCEPTIBILITY TO PBC IN HLA AND NON-HLA LOCI. HOWEVER, IT IS ESTIMATED THAT THE KNOWN RISK VARIANTS MERELY ACCOUNT FOR NO MORE THAN 20% OF THE HERITABILITY OF PBC AND CAUSES OF THE REMAINING HERITABILITY REMAIN UNCERTAIN. INCREASING EVIDENCE SUGGESTS THAT THE PRESENCE OF EPIGENETIC ABNORMALITIES MAY EXPLAIN THE "MISSING HERITABILITY" THAT CANNOT BE CAPTURED BY GWAS. AMONG THESE EPIGENETIC MECHANISMS, DNA METHYLATION, HISTONE MODIFICATION, AND NONCODING RNAS (I.E. MIRNA AND LNCRNA) ARE INVOLVED IN THE PATHOGENESIS OF PBC. ADDITIONALLY, TELOMERE DYSREGULATION IN BILIARY EPITHELIAL CELLS (BECS) MAY PLAY A ROLE IN DISEASE ONSET, WHEREAS A DEFICIENCY IN SEX CHROMOSOME AND SKEWED GENE EXPRESSION IN THE X CHROMOSOME MAY TO SOME EXTENT EXPLAIN THE FEMALE DOMINANCE IN PBC. 2020 17 5856 23 SUBSTRATE UTILISATION OF CULTURED SKELETAL MUSCLE CELLS IN PATIENTS WITH CFS. CHRONIC FATIGUE SYNDROME (CFS) PATIENTS OFTEN SUFFER FROM SEVERE MUSCLE PAIN AND AN INABILITY TO EXERCISE DUE TO MUSCLE FATIGUE. IT HAS PREVIOUSLY BEEN SHOWN THAT CFS SKELETAL MUSCLE CELLS HAVE LOWER LEVELS OF ATP AND HAVE AMP-ACTIVATED PROTEIN KINASE DYSFUNCTION. THIS STUDY OUTLINES EXPERIMENTS LOOKING AT THE UTILISATION OF DIFFERENT SUBSTRATES BY SKELETAL MUSCLE CELLS FROM CFS PATIENTS (N = 9) AND HEALTHY CONTROLS (N = 11) USING EXTRACELLULAR FLUX ANALYSIS. RESULTS SHOW THAT CFS SKELETAL MUSCLE CELLS ARE UNABLE TO UTILISE GLUCOSE TO THE SAME EXTENT AS HEALTHY CONTROL CELLS. CFS SKELETAL MUSCLE CELLS WERE SHOWN TO OXIDISE GALACTOSE AND FATTY ACIDS NORMALLY, INDICATING THAT THE BIOENERGETIC DYSFUNCTION LIES UPSTREAM OF THE TCA CYCLE. THE DYSFUNCTION IN GLUCOSE OXIDATION IS SIMILAR TO WHAT HAS PREVIOUSLY BEEN SHOWN IN BLOOD CELLS FROM CFS PATIENTS. THE CONSISTENCY OF CELLULAR BIOENERGETIC DYSFUNCTION IN DIFFERENT CELL TYPES SUPPORTS THE HYPOTHESIS THAT CFS IS A SYSTEMIC DISEASE. THE RETENTION OF BIOENERGETIC DEFECTS IN CULTURED CELLS INDICATES THAT THERE IS A GENETIC OR EPIGENETIC COMPONENT TO THE DISEASE. THIS IS THE FIRST STUDY TO USE CELLS DERIVED FROM SKELETAL MUSCLE BIOPSIES IN CFS PATIENTS AND HEALTHY CONTROLS TO LOOK AT CELLULAR BIOENERGETIC FUNCTION IN WHOLE CELLS. 2020 18 6869 20 [PATHOGENESIS OF RHEUMATOID ARTHRITIS]. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE SYSTEMIC DISEASE THAT PRIMARILY AFFECTS JOINTS. ETIOLOGY AND THE PATHOGENESIS OF RA ARE COMPLEX, INVOLVING MANY TYPES OF CELLS, AMONG OTHERS MACROPHAGES, T AND B CELLS, FIBRO- BLASTS, CHONDROCYTES AND DENDRITIC CELLS. DESPITE WELL DOCUMENTED ROLE OF MANY GENES AND EPIGENETIC MODIFICATIONS IN THE DEVELOPMENT AND EVOLUTION OF THE DISEASE, IN MOST RA PATIENTS THERE IS NO CLEAR PREDISPOSING FACTOR PRESENT. ENVIRONMENTAL FACTORS INVOLVED IN RA PATHOGENESIS ARE CIGARETTE SMOKE, INDUSTRIAL POLLUTANTS LIKE SILICA CRYSTALS, DISTURBANCES OF INTESTINAL, LUNG, AND ORAL MICROBIOTA AND SOME SPECIFIC BACTERIAL AND VIRAL INFECTIOUS AGENTS AND THEIR COMPONENTS. IN THE INITIAL DISEASE STAGE THERE ARE QUALITATIVE AND QUANTITATIVE DISTURBANCES OFPEPTIDE CITRULINATION AS WELL AS OTHER PROTEIN MODIFICATIONS, FOLLOWED BY ANTIGEN PRESENTING CELL (APC) (MACROPHAGES AND DENDRITIC CELLS) AND FIBROBLAST LIKE SYNOVIOCYTES (FLS) ACTIVATION. SOME MICROBES FOSTER THIS PROCESSES BY APC AND FLS DIRECT AND INDIRECT ACTIVATION. IN THE SECOND STAGE APC'S ELICIT SPECIFIC HUMORAL B CELL RE- SPONSE RESULTING IN SPECIFIC ANTIBODIES PRODUCTION AND T CELL AUTOREACTIVITY. INHERITED AND ACQUIRED DEFECTS IN T AND B CELL RESPONSES CAUSED BY REPEATED ACTIVATION OF INNATE IMMUNITY AS WELL AS LOSS OF TOLERANCE, ELICIT CHRONIC AUTOIMMUNE INFLAMMATION, PRIMARILY OF SYNOVIAL MEMBRANES, AND DEVELOPMENT OF CELLULAR PANUS. PATHOLOGIC ACTIVATION OF THE OSTEOCLASTS AND RELEASE OF THE IMMUNE SYSTEM EFFECTOR MOLECULES AND THE PROTEOLYTIC ENZYMES DAMAGE THE CARTILAGE, BONE AND TENDONS COMPOSITION AND STRUCTURE. PERSISTENT INFLAMMATION THROUGH ITS COMPLEX MECHANISMS RESULTS IN MANY SYSTEMIC AND EXTRAARTICULAR RA MANIFESTATIONS OF ALMOST ALL ORGAN SYSTEMS, RESULTING IN SEVERE COMPLICATIONS AND COMORBIDITIES SUCH AS RHEUMATOID LUNG, CARDITIS, VASCULITIS, CAHEXIA, ANEMIA, ACCELERATED ATHEROSCLEROSIS, MYOCARDIAL AND CEREBROVASCULAR VASCULAR DISEASE, LYMPHOMA, OSTEOPOROSIS, DEPRESSION ETC. ACCUMULATED COMPLICATIONS AND COMORBIDITIES FINALLY RESULT IN HANDICAP, SOCIAL DYSFUNCTION AND PREMATURE DEATH. 2014 19 4764 22 NRF2: FRIEND OR FOE FOR CHEMOPREVENTION? HEALTH REFLECTS THE ABILITY OF AN ORGANISM TO ADAPT TO STRESS. STRESSES--METABOLIC, PROTEOTOXIC, MITOTIC, OXIDATIVE AND DNA-DAMAGE STRESSES--NOT ONLY CONTRIBUTE TO THE ETIOLOGY OF CANCER AND OTHER CHRONIC DEGENERATIVE DISEASES BUT ARE ALSO HALLMARKS OF THE CANCER PHENOTYPE. ACTIVATION OF THE KELCH-LIKE ECH-ASSOCIATED PROTEIN 1 (KEAP1)-NF-E2-RELATED FACTOR 2 (NRF2)-SIGNALING PATHWAY IS AN ADAPTIVE RESPONSE TO ENVIRONMENTAL AND ENDOGENOUS STRESSES AND SERVES TO RENDER ANIMALS RESISTANT TO CHEMICAL CARCINOGENESIS AND OTHER FORMS OF TOXICITY, WHILST DISRUPTION OF THE PATHWAY EXACERBATES THESE OUTCOMES. THIS PATHWAY CAN BE INDUCED BY THIOL-REACTIVE SMALL MOLECULES THAT DEMONSTRATE PROTECTIVE EFFICACY IN PRECLINICAL CHEMOPREVENTION MODELS AND IN CLINICAL TRIALS. HOWEVER, MUTATIONS AND EPIGENETIC MODIFICATIONS AFFECTING THE REGULATION AND FATE OF NRF2 CAN LEAD TO CONSTITUTIVE DOMINANT HYPERACTIVATION OF SIGNALING THAT PRESERVES RATHER THAN ATTENUATES CANCER PHENOTYPES BY PROVIDING SELECTIVE RESISTANCE TO STRESSES. THIS REVIEW PROVIDES A SYNOPSIS OF KEAP1-NRF2 SIGNALING, COMPARES THE IMPACT OF GENETIC VERSUS PHARMACOLOGIC ACTIVATION AND CONSIDERS BOTH THE ATTRIBUTES AND CONCERNS OF TARGETING THE PATHWAY IN CHEMOPREVENTION. 2010 20 3025 29 GENETICS AND PATHOPHYSIOLOGY OF GRANULOMATOSIS WITH POLYANGIITIS (GPA) AND ITS MAIN AUTOANTIGEN PROTEINASE 3. GRANULOMATOSIS WITH POLYANGIITIS (GPA) IS A SEVERE AUTOIMMUNE DISEASE AND ONE OF THE SMALL VESSEL ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY (ANCA)-ASSOCIATED VASCULITIDES. ALTHOUGH ITS ETIOLOGY AND PATHOPHYSIOLOGY ARE STILL WIDELY UNKNOWN, IT IS ACCEPTED THAT INFECTIONS, ENVIRONMENTAL FACTORS, EPIGENETIC MODIFICATIONS, AND A GENETIC PREDISPOSITION PROVIDE THE BASIS FOR THIS SYSTEMIC DISORDER. GPA TYPICALLY EVOLVES INTO TWO PHASES: AN INITIAL PHASE CHARACTERIZED BY EAR, NOSE AND THROAT (ENT) MANIFESTATIONS, SUCH AS CHRONIC SINUSITIS AND OTITIS, ULCERATION OF THE ORAL CAVITY AND PHARYNX, AS WELL AS PULMONARY NODULES AND A SEVERE GENERALIZED PHASE, DEFINED BY THE OCCURRENCE OF RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS, PULMONARY HEMORRHAGE, AND ARTHRITIS. ANCAS, DIRECTED AGAINST THE NEUTROPHILIC ENZYMES PROTEINASE 3 AND MYELOPEROXIDASE, ARE PRESENT IN UP TO 90% OF THE AFFECTED PATIENTS IN THE SYSTEMIC PHASE. AS THE HUMORAL IMMUNITY IS PREDOMINANTLY DIRECTED AGAINST NEUTROPHILIC ANTIGENS, IT IS APPARENT THAT NEUTROPHILS PLAY A CRITICAL ROLE IN GPA BOTH AS TARGET AND EFFECTOR CELLS. ALTHOUGH GPA PATHOGENESIS IS NOT WELL KNOWN, SOME SUSCEPTIBILITY GENES AND LOCI HAVE BEEN IDENTIFIED BY CANDIDATE GENE APPROACHES, GENOME-WIDE ASSOCIATION STUDIES, AND META-ANALYSES, AS WELL AS FAMILIAL ASSOCIATION STUDIES. SUCH GENES ARE CTLA4, PTPN22, COL11A2, SERPINA1, AND THE MHC CLASS II GENE CLUSTER. THIS REVIEW HIGHLIGHTS THE CLINICAL, PATHOPHYSIOLOGICAL, AND GENETIC BACKGROUND OF GPA AND AIMS TO GIVE AN OVERVIEW OF RECENT EFFORTS TO IDENTIFY GPA SUSCEPTIBILITY GENES. WE POINT OUT THE GENETIC BASIS OF THE MAIN AUTOANTIGEN PR3 AND WHY IT IS SO DIFFICULT TO ESTABLISH A MURINE GPA MODEL. 2016