1 2301 109 EPIGENETIC REGULATION OF BEIGE ADIPOCYTE FATE BY HISTONE METHYLATION. ADIPOSE TISSUE HARBORS PLASTICITY TO ADAPT TO ENVIRONMENTAL THERMAL CHANGES. WHILE BROWN ADIPOCYTE IS A THERMOGENIC CELL WHICH PRODUCES HEAT ACUTELY IN RESPONSE TO COLD STIMULI, BEIGE (OR BRITE) ADIPOCYTE IS AN INDUCIBLE FORM OF THERMOGENIC ADIPOCYTES WHICH EMERGES IN THE WHITE ADIPOSE DEPOTS IN RESPONSE TO CHRONIC COLD EXPOSURE. SUCH ADAPTABILITY OF ADIPOCYTES IS REGULATED BY EPIGENETIC MECHANISMS. AMONG THEM, HISTONE METHYLATION IS CHEMICALLY STABLE AND THUS IS AN APPROPRIATE EPIGENETIC MARK FOR MEDIATING CELLULAR MEMORY TO INDUCE AND MAINTAIN THE BEIGE ADIPOCYTE CHARACTERISTICS. THE ENZYMES THAT CATALYZE THE METHYLATION OR DEMETHYLATION OF H3K27 AND H3K9 REGULATE BROWN ADIPOCYTE BIOGENESIS THROUGH THEIR CATALYTIC ACTIVITY-DEPENDENT AND -INDEPENDENT MECHANISMS. RESOLVING THE BIVALENCY OF H3K4ME3 AND H3K27ME3 AS WELL AS "OPENING" THE CHROMATIN STRUCTURE BY DEMETHYLATION OF H3K9 BOTH MEDIATE BEIGE ADIPOGENESIS. IN ADDITION, IT IS RECENTLY REPORTED THAT MAINTENANCE OF BEIGE ADIPOCYTE, BEIGE-TO-WHITE TRANSITION, AND CELLULAR MEMORY OF PRIOR COLD EXPOSURE IN BEIGE ADIPOCYTE ARE ALSO REGULATED BY HISTONE METHYLATION. A FURTHER UNDERSTANDING OF THE EPIGENETIC MECHANISM OF BEIGE ADIPOCYTE BIOGENESIS WOULD UNRAVEL THE MECHANISM OF THE CELLULAR MEMORY OF ENVIRONMENTAL STIMULI AND PROVIDE A NOVEL THERAPEUTICS FOR THE METABOLIC DISORDERS SUCH AS OBESITY AND DIABETES THAT ARE INFLUENCED BY ENVIRONMENTAL FACTORS. 2019 2 384 20 AN EVOLUTIONARY PERSPECTIVE ON CHRONIC MYELOMONOCYTIC LEUKEMIA. CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) SHARES WITH OTHER MYELOID DISEASES A NUMBER OF SOMATIC GENE MUTATIONS. THESE MUTATIONS CAN NOW BE INTEGRATED WITHIN THE FRAMEWORK OF EVOLUTION THEORY TO ADDRESS THE MECHANISMS OF THE DISEASE. SEVERAL EVIDENCES INDICATE THAT THE DISEASE EMERGES IN ADULT HEMATOPOIETIC STEM CELLS (HSC) THROUGH THE AGE-DEPENDENT ACCUMULATION OF DNA DAMAGE, LEADING STOCHASTICALLY TO A DRIVER MUTATION THAT CONFERS A COMPETITIVE ADVANTAGE TO THE CELL. A MUTATION IN TET2 GENE COULD BE ONE OF THESE DRIVER MUTATIONS PROVOKING THE EMERGENCE OF CLONALITY. AFTER A LONG LATENCY, SECONDARY LESIONS, SUCH AS MUTATIONS IN THE SRSF2 GENE, CONTRIBUTE TO PROGRESSION TO FULL-BLOWN MALIGNANCY, WITH ABNORMAL DIFFERENTIATION. ADDITIONAL MUTATIONS ACCUMULATE AND BRANCHING ARISING MOSTLY THROUGH MITOTIC RECOMBINATION GENERATES CLONAL HETEROGENEITY. MODIFICATIONS IN THE MICROENVIRONMENT PROBABLY AFFECT THIS CLONAL DYNAMICS, WHEREAS EPIGENETIC ALTERATIONS, SUCH AS HYPERMETHYLATION OF THE TIF1GAMMA GENE PROMOTER, MAY GENERATE PHENOTYPIC DIVERSIFICATION OF OTHERWISE CLONAL POPULATIONS. THE PRESERVED ALTHOUGH DEREGULATED MYELOID DIFFERENTIATION THAT CHARACTERIZES CMML, WITH GRANULOMONOCYTE EXPANSION AND VARIOUS CYTOPENIAS, MAY DEPEND ON EARLY CLONAL DOMINANCE IN THE HEMATOPIETIC CELL HIERARCHY. PROGRESSION TO ACUTE MYELOID LEUKEMIA OBSERVED IN 25-30% OF THE PATIENTS MAY ARISE FROM THE MASSIVE EXPANSION OF A CLONE WITH NOVEL GENETIC LESIONS, PROVIDING A HIGH FITNESS TO PREVIOUSLY MINOR SUBCLONES WHEN IN CHRONIC PHASE OF THE DISEASE. THIS REVIEW DISCUSSES THE VARIOUS MODELS OF DISEASE EMERGENCE AND PROGRESSION AND HOW THIS RECENT KNOWLEDGE COULD DRIVE RATIONAL THERAPEUTIC STRATEGIES. 2013 3 1489 26 DNA DAMAGE SIGNALLING GUARDS AGAINST ACTIVATED ONCOGENES AND TUMOUR PROGRESSION. DNA DAMAGE RESPONSE (DDR), THE GUARDIAN OF GENOMIC INTEGRITY, EMERGES AS AN ONCOGENE-INDUCIBLE BIOLOGICAL BARRIER AGAINST PROGRESSION OF CANCER BEYOND ITS EARLY STAGES. RECENT EVIDENCE FROM BOTH CELL CULTURE AND ANIMAL MODELS AS WELL AS ANALYSES OF CLINICAL SPECIMENS SHOW THAT ACTIVATION OF NUMEROUS ONCOGENES AND LOSS OF SOME TUMOUR SUPPRESSORS RESULT IN DNA REPLICATION STRESS AND DNA DAMAGE THAT ALARM THE CELLULAR DDR MACHINERY, A MULTIFACETED RESPONSE ORCHESTRATED BY THE ATR-CHK1 AND ATM-CHK2 KINASE SIGNALLING PATHWAYS. SUCH ACTIVATION OF THE DDR NETWORK LEADS TO CELLULAR SENESCENCE OR DEATH OF ONCOGENE-TRANSFORMED CELLS, RESULTING IN DELAY OR PREVENTION OF TUMORIGENESIS. AT THE SAME TIME, THE ONGOING CHRONIC DDR ACTIVATION CREATES SELECTIVE PRESSURE THAT EVENTUALLY FAVOURS OUTGROWTH OF MALIGNANT CLONES WITH GENETIC OR EPIGENETIC DEFECTS IN THE GENOME MAINTENANCE MACHINERY, SUCH AS ABERRATIONS IN THE ATM-CHK2-P53 CASCADE AND OTHER DDR COMPONENTS. FURTHERMORE, THE EXECUTIVE DDR MACHINERY IS SHARED BY AT LEAST TWO ANTICANCER BARRIERS, AS BOTH THE ONCOGENE-INDUCED DNA REPLICATION STRESS AND TELOMERE SHORTENING IMPACT THE CELL FATE DECISIONS THROUGH CONVERGENCE ON DNA DAMAGE SIGNALLING. IN THIS STUDY, WE HIGHLIGHT RECENT ADVANCES IN THIS RAPIDLY EVOLVING AREA OF CANCER RESEARCH, WITH PARTICULAR EMPHASIS ON MECHANISTIC INSIGHTS, EMERGING ISSUES OF SPECIAL CONCEPTUAL SIGNIFICANCE AND DISCUSSION OF MAJOR REMAINING CHALLENGES AND IMPLICATIONS OF THE CONCEPT OF DDR AS A TUMORIGENESIS BARRIER FOR EXPERIMENTAL AND CLINICAL ONCOLOGY. 2007 4 3621 20 IN VIVO AND IN VITRO MODELS OF HEPATOCELLULAR CARCINOMA: CURRENT STRATEGIES FOR TRANSLATIONAL MODELING. HEPATOCELLULAR CARCINOMA (HCC) IS THE SIXTH MOST COMMON CANCER WORLDWIDE AND THE THIRD LEADING CAUSE OF CANCER-RELATED DEATH GLOBALLY. HCC IS A COMPLEX MULTISTEP DISEASE AND USUALLY EMERGES IN THE SETTING OF CHRONIC LIVER DISEASES. THE MOLECULAR PATHOGENESIS OF HCC VARIES ACCORDING TO THE ETIOLOGY, MAINLY CAUSED BY CHRONIC HEPATITIS B AND C VIRUS INFECTIONS, CHRONIC ALCOHOL CONSUMPTION, AFLATOXIN-CONTAMINATED FOOD, AND NON-ALCOHOLIC FATTY LIVER DISEASE ASSOCIATED WITH METABOLIC SYNDROME OR DIABETES MELLITUS. THE ESTABLISHMENT OF HCC MODELS HAS BECOME ESSENTIAL FOR BOTH BASIC AND TRANSLATIONAL RESEARCH TO IMPROVE OUR UNDERSTANDING OF THE PATHOPHYSIOLOGY AND UNRAVEL NEW MOLECULAR DRIVERS OF THIS DISEASE. THE IDEAL MODEL SHOULD RECAPITULATE KEY EVENTS OBSERVED DURING HEPATOCARCINOGENESIS AND HCC PROGRESSION IN VIEW OF ESTABLISHING EFFECTIVE DIAGNOSTIC AND THERAPEUTIC STRATEGIES TO BE TRANSLATED INTO CLINICAL PRACTICE. DESPITE CONSIDERABLE EFFORTS CURRENTLY DEVOTED TO LIVER CANCER RESEARCH, ONLY A FEW ANTI-HCC DRUGS ARE AVAILABLE, AND PATIENT PROGNOSIS AND SURVIVAL ARE STILL POOR. THE PRESENT PAPER PROVIDES A STATE-OF-THE-ART OVERVIEW OF IN VIVO AND IN VITRO MODELS USED FOR TRANSLATIONAL MODELING OF HCC WITH A SPECIFIC FOCUS ON THEIR KEY MOLECULAR HALLMARKS. 2021 5 6713 35 VISCERAL ADIPOSITY SYNDROME. THE ASSOCIATION OF ANTHROPOMETRIC (WAIST CIRCUMFERENCE) AND HEMODYNAMIC (BLOOD PRESSURE) CHANGES WITH ABNORMALITIES IN GLUCOSE AND LIPID METABOLISM HAS BEEN MOTIVATION FOR A LOT OF DISCUSSIONS IN THE LAST 30 YEARS. NOWADAYS, BLOOD PRESSURE, BODY MASS INDEX/ABDOMINAL CIRCUMFERENCE, GLYCEMIA, TRIGLYCERIDEMIA, AND HDL-CHOLESTEROL CONCENTRATIONS ARE CONSIDERED IN THE DEFINITION OF METABOLIC SYNDROME, REFERRED AS VISCERAL ADIPOSITY SYNDROME (VAS) IN THE PRESENT REVIEW. HOWEVER, MORE THAN 250 YEARS AGO AN ASSOCIATION BETWEEN VISCERAL AND MEDIASTINAL OBESITY WITH HYPERTENSION, GOUT, AND OBSTRUCTIVE APNEA HAD ALREADY BEEN RECOGNIZED. EXPANSION OF VISCERAL ADIPOSE TISSUE SECONDARY TO CHRONIC OVER-CONSUMPTION OF CALORIES STIMULATES THE RECRUITMENT OF MACROPHAGES, WHICH ASSUME AN INFLAMMATORY PHENOTYPE AND PRODUCE CYTOKINES THAT DIRECTLY INTERFERE WITH INSULIN SIGNALING, RESULTING IN INSULIN RESISTANCE. IN TURN, INSULIN RESISTANCE (IR) MANIFESTS ITSELF IN VARIOUS TISSUES, CONTRIBUTING TO THE OVERALL PHENOTYPE OF VAS. FOR EXAMPLE, IN WHITE ADIPOSE TISSUE, IR RESULTS IN LIPOLYSIS, INCREASED FREE FATTY ACIDS RELEASE AND WORSENING OF INFLAMMATION, SINCE FATTY ACIDS CAN BIND TO TOLL-LIKE RECEPTORS. IN THE LIVER, IR RESULTS IN INCREASED HEPATIC GLUCOSE PRODUCTION, CONTRIBUTING TO HYPERGLYCEMIA; IN THE VASCULAR ENDOTHELIUM AND KIDNEY, IR RESULTS IN VASOCONSTRICTION, SODIUM RETENTION AND, CONSEQUENTLY, ARTERIAL HYPERTENSION. OTHER PLAYERS HAVE BEEN RECOGNIZED IN THE DEVELOPMENT OF VAS, SUCH AS GENETIC PREDISPOSITION, EPIGENETIC FACTORS ASSOCIATED WITH EXPOSURE TO AN UNFAVOURABLE INTRAUTERINE ENVIRONMENT AND THE GUT MICROBIOTA. MORE RECENTLY, EXPERIMENTAL AND CLINICAL STUDIES HAVE SHOWN THE AUTONOMIC NERVOUS SYSTEM PARTICIPATES IN MODULATING VISCERAL ADIPOSE TISSUE. THE SYMPATHETIC NERVOUS SYSTEM IS RELATED TO ADIPOSE TISSUE FUNCTION AND DIFFERENTIATION THROUGH BETA1, BETA2, BETA3, ALPHA1, AND ALPHA2 ADRENERGIC RECEPTORS. THE RELATION IS BIDIRECTIONAL: SYMPATHETIC DENERVATION OF ADIPOSE TISSUE BLOCKS LIPOLYSIS TO A VARIETY OF LIPOLYTIC STIMULI AND ADIPOSE TISSUE SEND INPUTS TO THE BRAIN. AN IMBALANCE OF SYMPATHETIC/PARASYMPATHETIC AND ALPHA2 ADRENERGIC/BETA3 RECEPTOR IS RELATED TO VISCERAL ADIPOSE TISSUE STORAGE AND INSULIN SENSITIVITY. THUS, IN ADDITION TO THE WELL-KNOWN FACTORS CLASSICALLY ASSOCIATED WITH VAS, ABNORMAL AUTONOMIC ACTIVITY ALSO EMERGES AS AN IMPORTANT FACTOR REGULATING WHITE ADIPOSE TISSUE, WHICH HIGHLIGHTS COMPLEX ROLE OF ADIPOSE TISSUE IN THE VAS. 2016 6 5633 17 SENESCENT REMODELING OF THE INNATE AND ADAPTIVE IMMUNE SYSTEM IN THE ELDERLY MEN WITH PROSTATE CANCER. DESPITE YEARS OF INTENSIVE INVESTIGATION THAT HAS BEEN MADE IN UNDERSTANDING PROSTATE CANCER, IT REMAINS A MAJOR CAUSE OF DEATH IN MEN WORLDWIDE. PROSTATE CANCER EMERGES FROM MULTIPLE ALTERATIONS THAT INDUCE CHANGES IN EXPRESSION PATTERNS OF GENES AND PROTEINS THAT FUNCTION IN NETWORKS CONTROLLING CRITICAL CELLULAR EVENTS. BASED ON THE EXPONENTIAL AGING OF THE POPULATION AND THE INCREASING LIFE EXPECTANCY IN INDUSTRIALIZED WESTERN COUNTRIES, PROSTATE CANCER IN THE ELDERLY MEN IS BECOMING A DISEASE OF INCREASING SIGNIFICANCE. AGING IS A PROGRESSIVE DEGENERATIVE PROCESS STRICTLY INTEGRATED WITH INFLAMMATION. SEVERAL THEORIES HAVE BEEN PROPOSED THAT ATTEMPT TO DEFINE THE ROLE OF CHRONIC INFLAMMATION IN AGING INCLUDING REDOX STRESS, MITOCHONDRIAL DAMAGE, IMMUNOSENESCENCE, AND EPIGENETIC MODIFICATIONS. HERE, WE REVIEW THE INNATE AND ADAPTIVE IMMUNE SYSTEMS AND THEIR SENESCENT REMODELING IN ELDERLY MEN WITH PROSTATE CANCER. 2014 7 2914 28 GENE REGULATORY NETWORK UNDERLYING THE IMMORTALIZATION OF EPITHELIAL CELLS. BACKGROUND: TUMORIGENIC TRANSFORMATION OF HUMAN EPITHELIAL CELLS IN VITRO HAS BEEN DESCRIBED EXPERIMENTALLY AS THE POTENTIAL RESULT OF SPONTANEOUS IMMORTALIZATION. THIS PROCESS IS CHARACTERIZED BY A SERIES OF CELL-STATE TRANSITIONS, IN WHICH NORMAL EPITHELIAL CELLS ACQUIRE FIRST A SENESCENT STATE WHICH IS LATER SURPASSED TO ATTAIN A MESENCHYMAL STEM-LIKE PHENOTYPE WITH A POTENTIALLY TUMORIGENIC BEHAVIOR. IN THIS PAPER WE AIM TO PROVIDE A SYSTEM-LEVEL MECHANISTIC EXPLANATION TO THE EMERGENCE OF THESE CELL TYPES, AND TO THE TIME-ORDERED TRANSITION PATTERNS THAT ARE COMMON TO NEOPLASIAS OF EPITHELIAL ORIGIN. TO THIS END, WE FIRST INTEGRATE PUBLISHED FUNCTIONAL AND WELL-CURATED MOLECULAR DATA OF THE COMPONENTS AND INTERACTIONS THAT HAVE BEEN FOUND TO BE INVOLVED IN SUCH CELL STATES AND TRANSITIONS INTO A NETWORK OF 41 MOLECULAR COMPONENTS. WE THEN REDUCE THIS INITIAL NETWORK BY REMOVING SIMPLE MEDIATORS (I.E., LINEAR PATHWAYS), AND FORMALIZE THE RESULTING REGULATORY CORE INTO LOGICAL RULES THAT GOVERN THE DYNAMICS OF EACH OF THE NETWORK COMPONENTS AS A FUNCTION OF THE STATES OF ITS REGULATORS. RESULTS: COMPUTATIONAL DYNAMIC ANALYSIS SHOWS THAT OUR PROPOSED GENE REGULATORY NETWORK MODEL RECOVERS EXACTLY THREE ATTRACTORS, EACH OF THEM DEFINED BY A SPECIFIC GENE EXPRESSION PROFILE THAT CORRESPONDS TO THE EPITHELIAL, SENESCENT, AND MESENCHYMAL STEM-LIKE CELLULAR PHENOTYPES, RESPECTIVELY. WE SHOW THAT ALTHOUGH A MESENCHYMAL STEM-LIKE STATE CAN BE ATTAINED EVEN UNDER UNPERTURBED PHYSIOLOGICAL CONDITIONS, THE LIKELIHOOD OF CONVERGING TO THIS STATE IS INCREASED WHEN PRO-INFLAMMATORY CONDITIONS ARE SIMULATED, PROVIDING A SYSTEMS-LEVEL MECHANISTIC EXPLANATION FOR THE CARCINOGENIC ROLE OF CHRONIC INFLAMMATORY CONDITIONS OBSERVED IN THE CLINIC. WE ALSO FOUND THAT THE REGULATORY CORE YIELDS AN EPIGENETIC LANDSCAPE THAT RESTRICTS TEMPORAL PATTERNS OF PROGRESSION BETWEEN THE STEADY STATES, SUCH THAT RECOVERED PATTERNS RESEMBLE THE TIME-ORDERED TRANSITIONS OBSERVED DURING THE SPONTANEOUS IMMORTALIZATION OF EPITHELIAL CELLS, BOTH IN VIVO AND IN VITRO. CONCLUSION: OUR STUDY STRONGLY SUGGESTS THAT THE IN VITRO TUMORIGENIC TRANSFORMATION OF EPITHELIAL CELLS, WHICH STRONGLY CORRELATES WITH THE PATTERNS OBSERVED DURING THE PATHOLOGICAL PROGRESSION OF EPITHELIAL CARCINOGENESIS IN VIVO, EMERGES FROM UNDERLYING REGULATORY NETWORKS INVOLVED IN EPITHELIAL TRANS-DIFFERENTIATION DURING DEVELOPMENT. 2017 8 4022 29 LSD1 FOR THE TARGETED REGULATION OF ADIPOSE TISSUE. WHITE AND THERMAL (BROWN AND BEIGE) ADIPOSE TISSUE ENERGY STORAGE AND OXIDATIVE REGULATION PATHWAYS PLAY A CENTRAL ROLE IN MAINTAINING THE ENERGY BALANCE THROUGHOUT THE BODY, AND THE DYSREGULATION OF THESE PATHWAYS IS CLOSELY RELATED TO GLUCOSE AND LIPID METABOLISM DISORDERS AND ADIPOSE TISSUE DYSFUNCTION, INCLUDING OBESITY, CHRONIC INFLAMMATION, INSULIN RESISTANCE, MITOCHONDRIAL DYSFUNCTION, AND FIBROSIS. RECENT EPIGENETIC STUDIES HAVE IDENTIFIED THE NOVEL REGULATORY ELEMENT LSD1, WHICH CONTROLS THE ABOVE PARAMETERS, AND HAVE PROVIDED NEW MECHANISTIC POSSIBILITIES FOR RE-ENCODING THE FATE AND FUNCTION OF ADIPOCYTES. IN THIS REVIEW, WE OUTLINE THE CURRENT ADVANCES IN ADIPOCYTE METABOLISM IN PHYSIOLOGY AND DISEASE AND DISCUSS POSSIBLE STRATEGIES FOR LSD1 TO ALTER THE PHENOTYPE OF ADIPOSE TISSUE AND THUS INFLUENCE ENERGY UTILIZATION TO IMPROVE METABOLIC HEALTH. 2022 9 4914 18 PAIN VULNERABILITY: A NEUROBIOLOGICAL PERSPECTIVE. THERE ARE MANY KNOWN RISK FACTORS FOR CHRONIC PAIN CONDITIONS, YET THE BIOLOGICAL UNDERPINNINGS THAT LINK THESE FACTORS TO ABNORMAL PROCESSING OF PAINFUL SIGNALS ARE ONLY JUST BEGINNING TO BE EXPLORED. THIS REVIEW WILL DISCUSS THE POTENTIAL MECHANISMS THAT HAVE BEEN PROPOSED TO UNDERLIE VULNERABILITY AND RESILIENCE TOWARD DEVELOPING CHRONIC PAIN. PARTICULAR FOCUS WILL BE GIVEN TO GENETIC AND EPIGENETIC PROCESSES, PRIMING EFFECTS ON A CELLULAR LEVEL, AND ALTERATIONS IN BRAIN NETWORKS CONCERNED WITH REWARD, MOTIVATION/LEARNING AND DESCENDING MODULATORY CONTROL. ALTHOUGH RESEARCH IN THIS AREA IS STILL IN ITS INFANCY, A BETTER UNDERSTANDING OF HOW PAIN VULNERABILITY EMERGES HAS THE POTENTIAL TO HELP IDENTIFY INDIVIDUALS AT RISK AND MAY OPEN UP NEW THERAPEUTIC AVENUES. 2014 10 6042 26 THE COLON REVISITED OR THE KEY TO WELLNESS, HEALTH AND DISEASE. THE HYPOTHESIS BEING ADVANCED IN THIS PAPER IS THAT THERE IS A NEW MEDICAL PARADIGM EMERGING FROM THE BIOMEDICAL RESEARCH CARRIED OUT IN THIS CENTURY, MAINLY DUE TO THE EXPLOSION OF THE SO CALLED "OMICS" AND ASSOCIATED TECHNIQUES. THE MAIN IDEA IS THAT THERE IS A COMMON PATHWAY FROM WELLBEING AND HEALTH TO CHRONIC DISEASE ("CHRONOPATHY") AND EVEN TO DEATH, WHICH COMPRISES FOLLOWING STEPS: 1) UNHEALTHY DIET, SEDENTARY LIFE STYLE AND PERMANENT EXPOSITION TO XENOBIOTICS AND ALL KINDS OF NOXIOUS STIMULI;-->2) INTESTINAL DYSBIOSIS;-->3) ALTERATION OF THE INTESTINAL MUCUS LAYER (ESPECIALLY THAT OF THE COLON);-->4) DISRUPTION OF THE ENDOTHELIAL TIGHT JUNCTIONS;-->5) METABOLIC ENDOTOXEMIA+BACTERIAL TRANSLOCATION;-->6) INFLAMMATION;-->7) EXACERBATION OF THE ENTERIC NERVOUS SYSTEM (ENS) AND CONSEQUENT MALADAPTATION AND MALFUNCTIONING OF THE COLON;-->8) EPIGENETIC MANIFESTATIONS;-->9) "CHRONOPATHY" AND PREMATURE DEATH. THEREFORE, IN ORDER TO MAINTAIN A GOOD HEALTH OR TO IMPROVE OR EVEN REVERSE CHRONIC DISEASES IN A PERSON, THE MAIN OUTCOME TO LOOK FOR IS A HOMEOSTATIC BALANCE OF THE INTESTINAL MICROBIOTA (EUBIOSIS), MOST OF WHICH IS LOCATED IN THE COLON. LYNN MARGULIS WAS ONE OF THE MAIN SCIENTISTS TO HIGHLIGHT THE IMPORTANCE OF THE ROLE PLAYED BY BACTERIA NOT ONLY IN THE ORIGIN OF ALL BIOLOGICAL SPECIES NOW PRESENT ON EARTH, BUT ALSO ON THEIR ROLE IN GLOBAL HOMEOSTASIS. BACTERIA DO NOT RELY ON OTHER LIVING BEINGS FOR THEIR EXISTENCE, WHILE THE LATTER DEPEND COMPLETELY ON THE FORMER. HUMANS ARE NO EXEMPTION, AND NEW EVIDENCE EMERGES EACH DAY ABOUT THE PIVOTAL ROLE OF INTESTINAL MICROBIOTA IN HUMAN HEALTH, DISEASE AND, IN GENERAL, IN ITS WELLBEING. THE FOLLOWING FACTS ABOUT INTESTINAL MICROBIOTA ARE NOWADAYS GENERALLY ACCEPTED: THERE ARE ABOUT 10 TIMES MORE BACTERIA IN THE GUT THAN HUMAN CELLS IN EVERY HUMAN BEING; THE MICROBIOMA IS ABOUT 100-150 TIMES BIGGER THAT THE HUMAN GENOME, AND THERE IS A CLEAR LINK BETWEEN INTESTINAL MICROBIOTA AND MANY OF THE MOST COMMON CHRONIC DISEASES, FROM OBESITY AND DIABETES TO DEPRESSION AND PARKINSON DISEASE AND DIFFERENT KINDS OF CANCER. THE MAIN IMPLICATION OF THIS THEORY IS THAT WE SHOULD BECOME A SORT OF MICROBIOTA FARMERS, THAT IS, WE OUGHT TO BE MORE CONSCIOUS OF OUR INTESTINAL MICROBIOTA, TAKE CARE OF IT AND MONITOR IT PERMANENTLY. THUS, AS PART OF OUR GOOD LIFE HABITS (HEALTHY EATING, PHYSICAL EXERCISE), WE SHOULD PROBABLY UNDERGO PERIODIC SEASONS OF FASTING AND COLON CLEANSING, AS IT WAS COMMON IN OLDER TIMES. 2017 11 2991 22 GENETIC INSTABILITY IN INHERITED AND SPORADIC LEUKEMIAS. GENETIC INSTABILITY DUE TO INCREASED DNA DAMAGE AND ALTERED DNA REPAIR IS OF CENTRAL SIGNIFICANCE IN THE INITIATION AND PROGRESSION OF INHERITED AND SPORADIC HUMAN LEUKEMIAS. ALTHOUGH VERY RARE, SOME INHERITED DNA REPAIR INSUFFICIENCY SYNDROMES (E.G., FANCONI ANEMIA, BLOOM'S SYNDROME) HAVE ADDED SUBSTANTIALLY TO OUR UNDERSTANDING OF CRUCIAL MECHANISMS OF LEUKEMOGENESIS IN RECENT YEARS. CONVERSELY, SPORADIC LEUKEMIAS ACCOUNT FOR THE MAIN PROPORTION OF LEUKEMIAS AND HERE DNA DAMAGING REACTIVE OXYGEN SPECIES (ROS) PLAY A CENTRAL ROLE. ALTHOUGH THE EXACT MECHANISMS OF INCREASED ROS PRODUCTION REMAIN LARGELY UNKNOWN AND NO SINGLE PATHWAY HAS BEEN DETECTED THUS FAR, SOME ONCOGENIC PROTEINS (E.G., THE ACTIVATED TYROSINE KINASES BCR-ABL1 AND FLT3-ITD) SEEM TO PLAY A KEY ROLE IN DRIVING GENETIC INSTABILITY BY INCREASED ROS GENERATION WHICH INFLUENCES THE DISEASE COURSE (E.G., BLAST CRISIS IN CHRONIC MYELOID LEUKEMIA OR RELAPSE IN FLT3-ITD POSITIVE ACUTE MYELOID LEUKEMIA). OF COURSE OTHER MECHANISMS, WHICH PROMOTE GENETIC INSTABILITY IN LEUKEMIA ALSO EXIST. A NEWLY EMERGING MECHANISM IS THE GENOME-WIDE ALTERATION OF EPIGENETIC MARKS (E.G., HYPOMETHYLATION OF HISTONE H3K79), WHICH PROMOTES CHROMOSOMAL INSTABILITY. TAKEN TOGETHER GENETIC INSTABILITY PLAYS A CRITICAL ROLE BOTH IN INHERITED AND SPORADIC LEUKEMIAS AND EMERGES AS A COMMON THEME IN BOTH INHERITED AND SPORADIC LEUKEMIAS. BEYOND ITS THEORETICAL IMPACT, THE ANALYSIS OF GENETIC INSTABILITY MAY LEAD THE WAY TO THE DEVELOPMENT OF INNOVATIVE THERAPY STRATEGIES. 2010 12 82 28 A NON-GENETIC BASIS FOR CANCER PROGRESSION AND METASTASIS: SELF-ORGANIZING ATTRACTORS IN CELL REGULATORY NETWORKS. IT IS COMMONLY ASSUMED THAT SOMATIC EVOLUTION DRIVES THE MULTI-STEP PROCESS THAT PRODUCES METASTATIC CANCER. BUT IT IS DIFFICULT TO RECONCILE THE INEXORABLE PROGRESSION TOWARDS METASTASIS IN VIRTUALLY ALL CARCINOMAS AND THE ASSOCIATED COMPLEX CHANGE OF CANCER CELL PHENOTYPE, CHARACTERIZED BY AN EPITHELIAL-TO-MESENCHYMAL TRANSITION, WITH THE RANDOM NATURE OF GENE MUTATIONS. GIVEN THEIR IRREVERSIBLE NATURE, IT IS ALSO DIFFICULT TO EXPLAIN WHY CERTAIN METASTATIC CARCINOMAS CAN REFORM NORMAL TISSUE BOUNDARIES AND REMAIN DORMANT FOR YEARS AT DISTANT SITES. HERE WE PROPOSE AN ENCOMPASSING CONCEPTUAL FRAMEWORK BASED ON SYSTEM-LEVEL DYNAMICS OF GENE REGULATORY NETWORKS THAT MAY HELP RECONCILE THESE INCONSISTENCIES. THE CONCEPTS OF GENE EXPRESSION STATE SPACE AND ATTRACTORS ARE INTRODUCED WHICH PROVIDE A MATHEMATICAL AND MOLECULAR BASIS FOR AN "EPIGENETIC LANDSCAPE". WE THEN DESCRIBE HOW CANCER CELLS ARE TRAPPED IN "EMBRYONIC ATTRACTORS" BECAUSE OF DISTORTIONS OF THIS LANDSCAPE CAUSED BY MUTATIONAL REWIRING OF THE REGULATORY NETWORK. THE IMPLICATIONS OF THIS CONCEPT FOR A NEW INTEGRATIVE UNDERSTANDING OF TUMOR FORMATION AND METASTATIC PROGRESSION ARE DISCUSSED. THIS FORMAL FRAMEWORK OF CANCER PROGRESSION UNITES MAINSTREAM GENETIC DETERMINISM WITH ALTERNATIVE IDEAS THAT EMPHASIZE NON-GENETIC INFLUENCES, INCLUDING CHRONIC GROWTH STIMULATION,EXTRACELLULAR MATRIX REMODELING, ALTERATION OF CELL MECHANICS AND DISRUPTION OF TISSUE ARCHITECTURE. 2006 13 1229 27 CRITICAL WINDOWS: EXPLORING THE ASSOCIATION BETWEEN PERINATAL TRAUMA, EPIGENETICS, AND CHRONIC PAIN. CHRONIC PAIN IS HIGHLY PREVALENT AND BURDENSOME, AFFECTING MILLIONS OF PEOPLE WORLDWIDE. ALTHOUGH IT EMERGES AT ANY POINT IN LIFE, IT OFTEN MANIFESTS IN ADOLESCENCE. GIVEN THAT ADOLESCENCE IS A UNIQUE DEVELOPMENTAL PERIOD, ADDITIONAL STRAINS ASSOCIATED WITH PERSISTENT AND OFTEN IDIOPATHIC PAIN LEAD TO SIGNIFICANT LONG-TERM CONSEQUENCES. WHILE THERE IS NO SINGULAR CAUSE FOR THE CHRONIFICATION OF PAIN, EPIGENETIC MODIFICATIONS THAT LEAD TO NEURAL REORGANIZATION MAY UNDERPIN CENTRAL SENSITIZATION AND SUBSEQUENT MANIFESTATION OF PAIN HYPERSENSITIVITY. EPIGENETIC PROCESSES ARE PARTICULARLY ACTIVE DURING THE PRENATAL AND EARLY POSTNATAL YEARS. WE DEMONSTRATE HOW EXPOSURE TO VARIOUS TRAUMAS, SUCH AS INTIMATE PARTNER VIOLENCE WHILE IN UTERO OR ADVERSE CHILDHOOD EXPERIENCES, CAN SIGNIFICANTLY INFLUENCE EPIGENETIC REGULATION WITHIN THE BRAIN AND IN TURN MODIFY PAIN-RELATED PROCESSES. WE PROVIDE COMPELLING EVIDENCE THAT THE BURDEN OF CHRONIC PAIN IS LIKELY INITIATED EARLY IN LIFE, OFTEN BEING TRANSMITTED FROM MOTHER TO OFFSPRING. WE ALSO HIGHLIGHT TWO PROMISING PROPHYLACTIC STRATEGIES, OXYTOCIN ADMINISTRATION AND PROBIOTIC USE, THAT HAVE THE POTENTIAL TO ATTENUATE THE EPIGENETIC CONSEQUENCES OF EARLY ADVERSITY. OVERALL, WE ADVANCE UNDERSTANDING OF THE CAUSAL RELATIONSHIP BETWEEN TRAUMA AND ADOLESCENT CHRONIC PAIN BY HIGHLIGHTING EPIGENETIC MECHANISMS THAT UNDERLIE THIS TRANSMISSION OF RISK, ULTIMATELY INFORMING HOW TO PREVENT THIS RISING EPIDEMIC. 2023 14 3811 22 INTRATUMORAL HETEROGENEITY: CLONAL COOPERATION IN EPITHELIAL-TO-MESENCHYMAL TRANSITION AND METASTASIS. ALTHOUGH PHENOTYPIC INTRATUMORAL HETEROGENEITY WAS FIRST DESCRIBED MANY DECADES AGO, THE ADVENT OF NEXT-GENERATION SEQUENCING HAS PROVIDED CONCLUSIVE EVIDENCE THAT IN ADDITION TO PHENOTYPIC DIVERSITY, SIGNIFICANT GENOTYPIC DIVERSITY EXISTS WITHIN TUMORS. TUMOR HETEROGENEITY LIKELY ARISES BOTH FROM CLONAL EXPANSIONS, AS WELL AS FROM DIFFERENTIATION HIERARCHIES EXISTENT IN THE TUMOR, SUCH AS THAT ESTABLISHED BY CANCER STEM CELLS (CSCS) AND NON-CSCS. THESE DIFFERENTIATION HIERARCHIES MAY ARISE DUE TO GENETIC MUTATIONS, EPIGENETIC ALTERATIONS, OR MICROENVIRONMENTAL INFLUENCES. AN ADDITIONAL DIFFERENTIATION HIERARCHY WITHIN EPITHELIAL TUMORS MAY ARISE WHEN ONLY A FEW TUMOR CELLS TRANS-DIFFERENTIATE INTO MESENCHYMAL-LIKE CELLS, A PROCESS KNOWN AS EPITHELIAL-TO-MESENCHYMAL TRANSITION (EMT). AGAIN, THIS PROCESS CAN BE INFLUENCED BY BOTH GENETIC AND NON-GENETIC FACTORS. IN THIS REVIEW WE DISCUSS THE EVIDENCE FOR CLONAL INTERACTION AND COOPERATION FOR TUMOR MAINTENANCE AND PROGRESSION, PARTICULARLY WITH RESPECT TO EMT, AND FURTHER ADDRESS THE FAR-REACHING EFFECTS THAT TUMOR HETEROGENEITY MAY HAVE ON CANCER THERAPY. 2015 15 4477 23 MOLECULAR PATHOGENESIS OF HUMAN HEPATOCELLULAR CARCINOMA. HEPATOCARCINOGENESIS IS A SLOW PROCESS DURING WHICH GENOMIC CHANGES PROGRESSIVELY ALTER THE HEPATOCELLULAR PHENOTYPE TO PRODUCE CELLULAR INTERMEDIATES THAT EVOLVE INTO HEPATOCELLULAR CARCINOMA. DURING THE LONG PRENEOPLASTIC STAGE, IN WHICH THE LIVER IS OFTEN THE SITE OF CHRONIC HEPATITIS, CIRRHOSIS, OR BOTH, HEPATOCYTE CYCLING IS ACCELERATED BY UPREGULATION OF MITOGENIC PATHWAYS, IN PART THROUGH EPIGENETIC MECHANISMS. THIS LEADS TO THE PRODUCTION OF MONOCLONAL POPULATIONS OF ABERRANT AND DYSPLASTIC HEPATOCYTES THAT HAVE TELOMERE EROSION AND TELOMERASE RE-EXPRESSION, SOMETIMES MICROSATELLITE INSTABILITY, AND OCCASIONALLY STRUCTURAL ABERRATIONS IN GENES AND CHROMOSOMES. DEVELOPMENT OF DYSPLASTIC HEPATOCYTES IN FOCI AND NODULES AND EMERGENCE OF HEPATOCELLULAR CARCINOMA ARE ASSOCIATED WITH THE ACCUMULATION OF IRREVERSIBLE STRUCTURAL ALTERATIONS IN GENES AND CHROMOSOMES, BUT THE GENOMIC BASIS OF THE MALIGNANT PHENOTYPE IS HETEROGENEOUS. THE MALIGNANT HEPATOCYTE PHENOTYPE MAY BE PRODUCED BY THE DISRUPTION OF A NUMBER OF GENES THAT FUNCTION IN DIFFERENT REGULATORY PATHWAYS, PRODUCING SEVERAL MOLECULAR VARIANTS OF HEPATOCELLULAR CARCINOMA. NEW STRATEGIES SHOULD ENABLE THESE VARIANTS TO BE CHARACTERIZED. 2002 16 6151 19 THE FIRE WITHIN: CELL-AUTONOMOUS MECHANISMS IN INFLAMMATION-DRIVEN CANCER. INFLAMMATORY CELLS ARE IMPORTANT FOR TUMOR INITIATION AND PROMOTION, PROVIDING CANCER CELLS WITH CYTOKINES THAT ENHANCE CELL PROLIFERATION AND SURVIVAL. ALTHOUGH MALIGNANT EPITHELIAL CELLS WERE TRADITIONALLY CONSIDERED TO BE ON THE RECEIVING END OF THESE MICROENVIRONMENTAL INTERACTIONS, RECENT STUDIES SHOW THAT EPITHELIAL CELLS CAN UNDERGO INFLAMMATORY REPROGRAMMING ON THEIR OWN. SUCH EPIGENETIC SWITCHES ARE OFTEN TRIGGERED BY CHRONIC TISSUE INJURY AND PLAY IMPORTANT ROLES IN TISSUE REPAIR. BY CONVERTING TERMINALLY DIFFERENTIATED CELLS THAT HARBOR EVEN A SINGLE ONCOGENIC MUTATION TO A LESS DIFFERENTIATED STATE WITH A HIGHER PROLIFERATIVE POTENTIAL, CELL-AUTONOMOUS INFLAMMATION IS AN IMPORTANT CONTRIBUTOR TO TUMOR INITIATION. 2019 17 1942 22 EPIDEMIOLOGY OF LIVER CANCER IN AFRICA: CURRENT AND FUTURE TRENDS. HEPATOCELLULAR CARCINOMA (HCC) IS A DISEASE OF GLOBAL PUBLIC HEALTH SIGNIFICANCE WITH MORTALITY ON THE RISE, DESPITE THE PREVENTABLE NATURE OF ITS RISK FACTORS ESPECIALLY IN AFRICA. IT IS NOW THE SIXTH MOST COMMON CANCER WORLDWIDE, FIFTH IN MALES, AND NINTH IN FEMALES. HCC INCIDENCE AND MORTALITY ARE PREDICTED TO INCREASE IN AFRICAN COUNTRIES CONSTRAINED BY LIMITED RESOURCES TO COMBAT ENDEMIC LEVELS OF VIRAL INFECTION AND SYNERGISTIC ENVIRONMENTAL RISK FACTORS. THE CHANGING NATURE OF HCC ETIOLOGY IS PARTICULARLY ILLUSTRATED HERE WITH THE TRADITIONAL RISK FACTORS LIKE VIRAL HEPATITIS COEXISTING ALONGSIDE HIGH HUMAN IMMUNODEFICIENCY VIRUS (HIV) PREVALENCE AND RAPIDLY INCREASING URBANIZATION THAT HAVE PROMOTED A SHARP INCREASE IN ADDITIONAL RISK FACTORS LIKE COINFECTION, TYPE 2 DIABETES MELLITUS, AND OBESITY. ALTHOUGH THERE ARE SOME DIFFERENCES IN ETIOLOGY BETWEEN NORTH AFRICA AND SUB-SAHARAN AFRICA, RISK FACTORS LIKE CHRONIC VIRAL HEPATITIS B AND C, AFLATOXIN EXPOSURE, AND IRON OVERLOAD PREDOMINATE. AGGRESSIVE HEPATITIS B GENOTYPES, COMBINED WITH HEPATITIS B VIRUS/HEPATITIS C VIRUS/HIV COINFECTIONS AND AFLATOXIN EXPOSURE, PROMOTE A MORE AGGRESSIVE MOLECULAR PHENOTYPE. IN PARALLEL TO A BETTER UNDERSTANDING OF THE MOLECULAR ETIOLOGY OF HCC, POLICY AND PLANNING INITIATIVES TO ADDRESS THE BURDEN OF HCC MUST BE ANCHORED WITHIN THE REALITY OF THE LIMITED RESOURCES AVAILABLE. ESTABLISHMENT AND COORDINATION OF CANCER REGISTRIES ACROSS AFRICA IS NEEDED TO IMPROVE THE QUALITY OF DATA NECESSARY TO GALVANIZE ACTION. PREVENTIVE MEASURES INCLUDING HEPATITIS B VACCINATION PROGRAMS, MEASURES TO PREVENT MATERNAL-TO-CHILD AND CHILD-TO-CHILD TRANSMISSION, DELIVERY OF UNIVERSALLY ACCESSIBLE ANTIRETROVIRAL AND ANTIVIRAL TREATMENTS, AND REDUCTION OF DIETARY AFLATOXIN EXPOSURE CAN CONTRIBUTE MARKEDLY TO REDUCE HCC INCIDENCE. FINALLY, THE DEVELOPMENT OF BIOMARKERS AND NEW THERAPEUTIC INTERVENTIONS WILL NEED A BETTER UNDERSTANDING OF THE UNIQUE GENETIC AND EPIGENETIC CHARACTERISTICS OF HCC ON THE CONTINENT. WE PRESENT A NARRATIVE REVIEW OF HCC IN AFRICA, DISCUSSING PRESENT AND FUTURE TRENDS. 2020 18 5631 29 SENESCENCE-INFLAMMATORY REGULATION OF REPARATIVE CELLULAR REPROGRAMMING IN AGING AND CANCER. THE INABILITY OF ADULT TISSUES TO TRANSITORILY GENERATE CELLS WITH FUNCTIONAL STEM CELL-LIKE PROPERTIES IS A MAJOR OBSTACLE TO TISSUE SELF-REPAIR. NUCLEAR REPROGRAMMING-LIKE PHENOMENA THAT INDUCE A TRANSIENT ACQUISITION OF EPIGENETIC PLASTICITY AND PHENOTYPE MALLEABILITY MAY CONSTITUTE A REPARATIVE ROUTE THROUGH WHICH HUMAN TISSUES RESPOND TO INJURY, STRESS, AND DISEASE. HOWEVER, TISSUE REJUVENATION SHOULD INVOLVE NOT ONLY THE TRANSIENT EPIGENETIC REPROGRAMMING OF DIFFERENTIATED CELLS, BUT ALSO THE COMMITTED RE-ACQUISITION OF THE ORIGINAL OR ALTERNATIVE COMMITTED CELL FATE. CHRONIC OR UNRESTRAINED EPIGENETIC PLASTICITY WOULD DRIVE AGING PHENOTYPES BY IMPAIRING THE REPAIR OR THE REPLACEMENT OF DAMAGED CELLS; SUCH UNCONTROLLED PHENOMENA OF IN VIVO REPROGRAMMING MIGHT ALSO GENERATE CANCER-LIKE CELLULAR STATES. WE HEREIN PROPOSE THAT THE ABILITY OF SENESCENCE-ASSOCIATED INFLAMMATORY SIGNALING TO REGULATE IN VIVO REPROGRAMMING CYCLES OF TISSUE REPAIR OUTLINES A THRESHOLD MODEL OF AGING AND CANCER. THE DEGREE OF SENESCENCE/INFLAMMATION-ASSOCIATED DEVIATION FROM THE HOMEOSTATIC STATE MAY DELINEATE A TYPE OF THRESHOLDING ALGORITHM DISTINGUISHING BENEFICIAL FROM DELETERIOUS EFFECTS OF IN VIVO REPROGRAMMING. FIRST, TRANSIENT ACTIVATION OF NF-KAPPAB-RELATED INNATE IMMUNITY AND SENESCENCE-ASSOCIATED INFLAMMATORY COMPONENTS (E.G., IL-6) MIGHT FACILITATE REPARATIVE CELLULAR REPROGRAMMING IN RESPONSE TO ACUTE INFLAMMATORY EVENTS. SECOND, PARA-INFLAMMATION SWITCHES MIGHT PROMOTE LONG-LASTING BUT REVERSIBLE REFRACTORINESS TO REPARATIVE CELLULAR REPROGRAMMING. THIRD, CHRONIC SENESCENCE-ASSOCIATED INFLAMMATORY SIGNALING MIGHT LOCK CELLS IN HIGHLY PLASTIC EPIGENETIC STATES DISABLED FOR REPARATIVE DIFFERENTIATION. THE CONSIDERATION OF A CELLULAR REPROGRAMMING-CENTERED VIEW OF EPIGENETIC PLASTICITY AS A FUNDAMENTAL ELEMENT OF A TISSUE'S CAPACITY TO UNDERGO SUCCESSFUL REPAIR, AGING DEGENERATION OR MALIGNANT TRANSFORMATION SHOULD PROVIDE CHALLENGING STOCHASTIC INSIGHTS INTO THE CURRENT DETERMINISTIC GENETIC PARADIGM FOR MOST CHRONIC DISEASES, THEREBY INCREASING THE SPECTRUM OF THERAPEUTIC APPROACHES FOR PHYSIOLOGICAL AGING AND CANCER. 2017 19 6182 33 THE IMPACT OF ADIPOSE TISSUE-DERIVED MIRNAS IN METABOLIC SYNDROME, OBESITY, AND CANCER. OBESITY IS A MULTIFACTORIAL AND COMPLEX CONDITION THAT IS CHARACTERIZED BY ABNORMAL AND EXCESSIVE WHITE ADIPOSE TISSUE ACCUMULATION, WHICH CAN LEAD TO THE DEVELOPMENT OF METABOLIC DISEASES, SUCH AS TYPE 2 DIABETES MELLITUS, NONALCOHOLIC FATTY LIVER DISEASE, CARDIOVASCULAR DISEASES, AND SEVERAL TYPES OF CANCER. OBESITY IS CHARACTERIZED BY EXCESSIVE ADIPOSE TISSUE ACCUMULATION AND ASSOCIATED WITH ALTERATIONS IN IMMUNITY, DISPLAYING A CHRONIC LOW-GRADE INFLAMMATION PROFILE. ADIPOSE TISSUE IS A DYNAMIC AND COMPLEX ENDOCRINE ORGAN COMPOSED NOT ONLY BY ADIPOCYTES, BUT SEVERAL IMMUNOLOGICAL CELLS, WHICH CAN SECRETE HORMONES, CYTOKINES AND MANY OTHER FACTORS CAPABLE OF REGULATING METABOLIC HOMEOSTASIS AND SEVERAL CRITICAL BIOLOGICAL PATHWAYS. REMARKABLY, ADIPOSE TISSUE IS A MAJOR SOURCE OF CIRCULATING MICRORNAS (MIRNAS), RECENTLY DESCRIBED AS A NOVEL FORM OF ADIPOKINES. SEVERAL ADIPOSE TISSUE-DERIVED MIRNAS ARE DEEPLY ASSOCIATED WITH ADIPOCYTES DIFFERENTIATION AND HAVE BEEN IDENTIFIED WITH AN ESSENTIAL ROLE IN OBESITY-ASSOCIATED INFLAMMATION, INSULIN RESISTANCE, AND TUMOR MICROENVIRONMENT. DURING OBESITY, ADIPOSE TISSUE CAN COMPLETELY CHANGE THE PROFILE OF THE SECRETED MIRNAS, INFLUENCING CIRCULATING MIRNAS AND IMPACTING THE DEVELOPMENT OF DIFFERENT PATHOLOGICAL CONDITIONS, SUCH AS OBESITY, METABOLIC SYNDROME, AND CANCER. IN THIS REVIEW, WE DISCUSS HOW MIRNAS CAN ACT AS EPIGENETIC REGULATORS AFFECTING ADIPOGENESIS, ADIPOCYTE DIFFERENTIATION, LIPID METABOLISM, BROWNING OF THE WHITE ADIPOSE TISSUE, GLUCOSE HOMEOSTASIS, AND INSULIN RESISTANCE, IMPACTING DEEPLY OBESITY AND METABOLIC DISEASES. MOREOVER, WE CHARACTERIZE HOW MIRNAS CAN OFTEN ACT AS ONCOGENIC AND TUMOR SUPPRESSOR MOLECULES, SIGNIFICANTLY MODULATING CANCER ESTABLISHMENT AND PROGRESSION. FURTHERMORE, WE HIGHLIGHT IN THIS MANUSCRIPT HOW ADIPOSE TISSUE-DERIVED MIRNAS CAN FUNCTION AS IMPORTANT NEW THERAPEUTIC TARGETS. 2020 20 6365 26 THE ROLE OF METABOLIC DYSFUNCTION IN T-CELL EXHAUSTION DURING CHRONIC VIRAL INFECTION. T CELLS ARE IMPORTANT COMPONENTS OF ADAPTIVE IMMUNITY THAT PROTECT THE HOST AGAINST INVADING PATHOGENS DURING INFECTION. UPON RECOGNIZING THE ACTIVATION SIGNALS, NAIVE AND/OR MEMORY T CELLS WILL INITIATE CLONAL EXPANSION, TRIGGER DIFFERENTIATION INTO EFFECTOR POPULATIONS AND TRAFFIC TO THE INFLAMED SITES TO ELIMINATE PATHOGENS. HOWEVER, IN CHRONIC VIRAL INFECTIONS, SUCH AS THOSE CAUSED BY HUMAN IMMUNODEFICIENCY VIRUS (HIV), HEPATITIS B AND C (HBV AND HCV), T CELLS EXHIBIT IMPAIRED FUNCTION AND BECOME DIFFICULT TO CLEAR PATHOGENS IN A STATE KNOWN AS T-CELL EXHAUSTION. THE ACTIVATION AND FUNCTION PERSISTENCE OF T CELLS DEMAND FOR DYNAMIC CHANGES IN CELLULAR METABOLISM TO MEET THEIR BIOENERGETIC AND BIOSYNTHETIC DEMANDS, ESPECIALLY THE AUGMENTATION OF AEROBIC GLYCOLYSIS, WHICH NOT ONLY PROVIDE EFFICIENT ENERGY GENERATION, BUT ALSO FUEL MULTIPLE BIOCHEMICAL INTERMEDIATES THAT ARE ESSENTIAL FOR NUCLEOTIDE, AMINO ACID, FATTY ACID SYNTHESIS AND MITOCHONDRIA FUNCTION. CHANGES IN CELLULAR METABOLISM ALSO AFFECT THE FUNCTION OF EFFECTORS T CELLS THROUGH MODIFYING EPIGENETIC SIGNATURES. IT IS WIDELY ACCEPTED THAT THE DYSFUNCTION OF T CELL METABOLISM CONTRIBUTES GREATLY TO T-CELL EXHAUSTION. HERE, WE REVIEWED RECENT FINDINGS ON T CELLS METABOLISM UNDER CHRONIC VIRAL INFECTION, SEEKING TO REVEAL THE ROLE OF METABOLIC DYSFUNCTION PLAYED IN T-CELL EXHAUSTION. 2022