1 188 177 ACETYL TRANSFERASE EP300 DEFICIENCY LEADS TO CHRONIC REPLICATION STRESS MEDIATED BY DEFECTIVE FORK PROTECTION AT STALLED REPLICATION FORKS. MUTATIONS IN THE EPIGENETIC REGULATOR AND GLOBAL TRANSCRIPTIONAL ACTIVATOR, E1A BINDING PROTEIN (EP300), IS BEING INCREASINGLY REPORTED IN AGGRESSIVE HEMATOLOGICAL MALIGNANCIES INCLUDING ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL). HOWEVER, THE MECHANISTIC CONTRIBUTION OF EP300 DYSREGULATION TO CANCER INITIATION AND PROGRESSION ARE CURRENTLY UNKNOWN. INDEPENDENT INHIBITION OF EP300 IN HUMAN CELLS RESULTS IN THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN REGULATING THE CELL CYCLE, DNA REPLICATION AND DNA DAMAGE RESPONSE. NEVERTHELESS, SPECIFIC FUNCTION PLAYED BY EP300 IN DNA REPLICATION INITIATION, PROGRESSION AND REPLICATION FORK INTEGRITY HAS NOT BEEN STUDIED. HERE, USING ATLL CELLS AS A MODEL TO STUDY EP300 DEFICIENCY AND AN P300-SELECTIVE PROTAC DEGRADER, DEGRADER AS A PHARMACOLOGIC TOOL, WE REVEAL THAT EP300-MUTATED CELLS DISPLAY PROLONGED CELL CYCLE KINETICS, DUE TO PRONOUNCED DYSREGULATIONS IN DNA REPLICATION DYNAMICS LEADING TO PERSISTENT GENOMIC INSTABILITY. ABERRANT DNA REPLICATION IN EP300-MUTATED CELLS IS CHARACTERIZED BY ELEVATED REPLICATION ORIGIN FIRING DUE TO INCREASED REPLISOME PAUSING GENOME-WIDE. WE DEMONSTRATE THAT EP300 DEFICIENCY RESULTS IN NUCLEOLYTIC DEGRADATION OF NASCENTLY SYNTHESIZED DNA AT STALLED FORKS DUE TO A PROMINENT DEFECT IN FORK STABILIZATION AND PROTECTION. THIS IN TURN RESULTS IN THE ACCUMULATION OF SINGLE STRANDED DNA GAPS AT COLLAPSED REPLICATION FORKS, IN EP300-DEFICIENT CELLS. INHIBITION OF MRE11 NUCLEASE RESCUES THE SSDNA ACCUMULATION INDICATING A DYSREGULATION IN DOWNSTREAM MECHANISMS THAT RESTRAIN NUCLEASE ACTIVITY AT STALLED FORKS. IMPORTANTLY, WE FIND THAT THE ABSENCE OF EP300 RESULTS IN DECREASED EXPRESSION OF BRCA2 PROTEIN EXPRESSION AND A DEPENDENCY ON POLD3-MEDIATED ERROR-PRONE REPLICATION RESTART MECHANISMS. THE OVERALL S-PHASE ABNORMALITIES OBSERVED LEAD TO UNDER-REPLICATED DNA IN G2/M THAT INSTIGATES MITOTIC DNA SYNTHESIS. THIS IN TURN IS ASSOCIATED WITH MITOTIC SEGREGATION DEFECTS CHARACTERIZED BY ELEVATED MICRONUCLEI FORMATION, ACCUMULATION OF CYTOSOLIC DNA AND TRANSMISSION OF UNREPAIRED INHERITED DNA LESIONS IN THE SUBSEQUENT G1-PHASE IN EP300-DEFICIENT CELLS. WE DEMONSTRATE THAT THE DNA REPLICATION DYNAMICS OF EP300-MUTATED CELLS ATLL CELLS RECAPITULATE FEATURES OF BRCA-DEFICIENT CANCERS. ALTOGETHER THESE RESULTS SUGGEST THAT MUTATIONS IN EP300 CAUSE CHRONIC DNA REPLICATION STRESS AND DEFECTIVE REPLICATION FORK RESTART RESULTS IN PERSISTENT GENOMIC INSTABILITY THAT UNDERLIE AGGRESSIVE CHEMO-RESISTANT TUMORIGENESIS IN HUMANS. 2023 2 99 30 A PUTATIVE "HEPITYPE" IN THE ATM GENE ASSOCIATED WITH CHRONIC LYMPHOCYTIC LEUKEMIA RISK. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS ARE CHARACTERIZED BY SEVERAL CHROMOSOMAL LESIONS. SOME OF THESE ABERRATIONS IMPLY CHROMOSOME BREAKS AS A RESULT OF UNREPAIRED DOUBLE STRAND BREAKS (DSBS) IN THE DNA. THE ATM (ATAXIA TELANGIECTASIA-MUTATED) PROTEIN IS THE PRINCIPAL INTEGRATOR OF CELLULAR RESPONSES TO DSBS. ATM DELETION IS ALSO AN ADVERSE PROGNOSTIC FACTOR IN CLL. TAKING THIS INTO ACCOUNT, WE EVALUATED IF GENETIC AND/OR EPIGENETIC VARIATION IN THE ATM GENE MAY MODULATE THE INDIVIDUAL SUSCEPTIBILITY TO DEVELOP CLL. OUR CASE-CONTROL ASSOCIATION STUDY WAS PERFORMED IN A LARGE SPANISH POPULATION OF 1,503 INDIVIDUALS, INCLUDING 742 PATIENTS WITH CLL AND 761 CONTROLS. WE IDENTIFIED ONE HAPLOTYPE WITHIN THE ATM GENE THAT CONFERS AN INCREASED RISK OF CLL DEVELOPMENT (OR = 1.33; 95% CI: 1.10-1.60). TWO POLYMORPHISMS OF THIS ATM HAPLOTYPE ELIMINATED ONE CPG SITE EACH IN INTRONS 15 AND 61, CAUSING CHANGES IN DNA METHYLATION PATTERN. THESE DATA PROVIDE THE FIRST EVIDENCE FOR THE EXISTENCE OF A PUTATIVE "HEPITYPE" IN THE ATM GENE ASSOCIATED WITH CLL RISK. 2011 3 292 32 AGING AND SUSCEPTIBILITY TO PULMONARY DISEASE. THE LUNGS ARE CONTINUALLY SUBJECTED TO NOXIOUS AND INERT SUBSTANCES, ARE IMMUNOLOGICALLY ACTIVE, AND ARE IN A CONSTANT STATE OF DAMAGE AND REPAIR. THIS MAKES THE PULMONARY SYSTEM PARTICULARLY VULNERABLE TO DISEASES OF AGING. AGING CAN BE UNDERSTOOD AS RANDOM MOLECULAR DAMAGE THAT IS UNREPAIRED AND ACCUMULATES OVER TIME, RESULTING IN CELLULAR DEFECTS AND TISSUE DYSFUNCTION. THE BREAKDOWN OF CELLULAR MECHANISMS, INCLUDING STEM CELL EXHAUSTION, GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATION, LOSS OF PROTEOSTASIS, DEREGULATED NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, ALTERED INTERCELLULAR COMMUNICATION, AND CHANGES IN THE EXTRACELLULAR MATRIX IS THOUGHT TO ADVANCE THE AGING PROCESS ITSELF. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), IDIOPATHIC PULMONARY FIBROSIS (IPF), AND CANCERS ILLUSTRATE A PATHOLOGIC BREAKDOWN IN THESE MECHANISMS BEYOND NORMAL AGING. THE IMMUNE SYSTEM BECOMES LESS EFFECTIVE WITH ADVANCING AGE. THERE IS A LOW-LEVEL STATE OF CHRONIC INFLAMMATION TERMED INFLAMMAGING WHICH IS THOUGHT TO BE DRIVEN BY IMMUNOSENESCENCE, THE CHANGES IN THE INNATE AND ADAPTIVE IMMUNE SYSTEMS WITH ADVANCING AGE THAT LEAD TO DYSREGULATION AND DECREASED EFFECTIVENESS OF THE IMMUNE SYSTEM. THESE PROCESSES OF AGING LEAD TO EXPECTED CHANGES IN THE FORM AND FUNCTION OF THE RESPIRATORY SYSTEM, MOST NOTABLY A LOSS OF LUNG ELASTICITY, DECREASE IN RESPIRATORY MUSCLE STRENGTH, INCREASE IN VENTILATION-PERFUSION MISMATCHING, AND STIFFENING OF THE VASCULATURE. THE ASTUTE CLINICIAN IS AWARE OF THESE EXPECTED FINDINGS AND DOES NOT OFTEN ATTRIBUTE DYSPNEA TO AGING ALONE. MAINTAINING A LOW THRESHOLD TO INVESTIGATE FOR COMORBID DISEASE AND UNDERSTANDING HOW PULMONARY DISEASE PRESENTS DIFFERENTLY IN THE ELDERLY THAN IN YOUNGER ADULTS CAN IMPROVE CLINICAL OUTCOMES. (C) 2022 AMERICAN PHYSIOLOGICAL SOCIETY. COMPR PHYSIOL 12:3509-3522, 2022. 2022 4 389 30 AN INTEGRATIVE HYPOTHESIS LINKING CANCER, DIABETES AND ATHEROSCLEROSIS: THE ROLE OF MUTATIONS AND EPIGENETIC CHANGES. IT APPEARS THAT THE DISEASE STATES OF CANCER, ALTHEROSCLEROSIS AND DIABETES MIGHT SHARE A COMMON ETIOLOGY. THESE CHRONIC DISEASES APPEAR TO BE MULTI-STAGED IN THEIR PROGRESSION, WITH GENETIC, NUTRITIONAL, PSYCHO-SOCIAL, ENVIRONMENTAL AND VIRAL FACTORS INFLUENCING THEIR APPEARANCE. WE OFFERED A HYPOTHESIS (A "MUTATION THEORY OF DISEASE"), STATING THAT THESE DISEASES CAN BE DESCRIBED BY INITIATION AND PROMOTION PHASES; INITIATION BEING THE RESULT OF THE PRODUCTION OF MUTATED CELLS AFTER UNREPAIRED DAMAGED DNA IS REPLICATED; PROMOTION BEING THE SELECTIVE PROLIFERATION OF THE INITIATED CELLS TO FORM CLONES OF MUTATED CELLS. IT WAS FURTHER POSTULATED THAT PROMOTION AFFECTS CELL PROLIFERATION BY ALTERING A MEMBRANE-CA++ REGULATORY SYSTEM. DEPENDING ON THE NATURE OF THE MUTATION IN THE CLONE OF CELLS, SPECIFIC DISEASE STATES WOULD RESULT. THE ROLES OF RADIATIONS, CHEMICALS, VIRUSES, GENES, NUTRITION AND PSYCHO-SOCIAL STRESS WERE RELATED TO EITHER THE INITIATION (MUTATION PRODUCTION) OR THE PROMOTION (CELL PROLIFERATION) PHASE OF THESE DISEASES. 1980 5 5632 36 SENESCENT CELLS: SASPECTED DRIVERS OF AGE-RELATED PATHOLOGIES. THE PROGRESSION OF PHYSIOLOGICAL AGEING IS DRIVEN BY INTRACELLULAR ABERRATIONS INCLUDING TELOMERE ATTRITION, GENOMIC INSTABILITY, EPIGENETIC ALTERATIONS AND LOSS OF PROTEOSTASIS. THESE IN TURN DAMAGE CELLS AND COMPROMISE THEIR FUNCTIONALITY. CELLULAR SENESCENCE, A STABLE IRREVERSIBLE CELL-CYCLE ARREST, IS ELICITED IN DAMAGED CELLS AND PREVENTS THEIR PROPAGATION IN THE ORGANISM. UNDER NORMAL CONDITIONS, SENESCENT CELLS RECRUIT THE IMMUNE SYSTEM WHICH FACILITATES THEIR REMOVAL FROM TISSUES. NEVERTHELESS, DURING AGEING, TISSUE-RESIDING SENESCENT CELLS TEND TO ACCUMULATE, AND MIGHT NEGATIVELY IMPACT THEIR MICROENVIRONMENT VIA PROFOUND SECRETORY PHENOTYPE WITH PRO-INFLAMMATORY CHARACTERISTICS, TERMED SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). INDEED, SENESCENT CELLS ARE MOSTLY ABUNDANT AT SITES OF AGE-RELATED PATHOLOGIES, INCLUDING DEGENERATIVE DISORDERS AND MALIGNANCIES. INTERESTINGLY, STUDIES ON PROGEROID MICE INDICATE THAT SELECTIVE ELIMINATION OF SENESCENT CELLS CAN DELAY AGE-RELATED DETERIORATION. THIS SUGGESTS THAT CHRONIC INFLAMMATION INDUCED BY SENESCENT CELLS MIGHT BE A MAIN DRIVER OF THESE PATHOLOGIES. IMPORTANTLY, SENESCENT CELLS ACCUMULATE AS A RESULT OF DEFICIENT IMMUNE SURVEILLANCE, AND THEIR REMOVAL IS INCREASED UPON THE USE OF IMMUNE STIMULATORY AGENTS. INSIGHTS INTO MECHANISMS OF SENESCENCE SURVEILLANCE COULD BE COMBINED WITH CURRENT APPROACHES FOR CANCER IMMUNOTHERAPY TO PROPOSE NEW PREVENTIVE AND THERAPEUTIC STRATEGIES FOR AGE-RELATED DISEASES. 2014 6 787 27 CELLS OF ADULT T-CELL LEUKEMIA EVADE HTLV-1 TAX/NF-KAPPAB HYPERACTIVATION-INDUCED SENESCENCE. HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-1) IS THE ETIOLOGICAL AGENT OF ADULT T-CELL LEUKEMIA/LYMPHOMA (ATL). THE HTLV-1 VIRAL TRANS-ACTIVATOR/ONCOPROTEIN TAX IS A MAJOR DRIVER OF ATL, YET IT INDUCES RAPID P21(CIP1/WAF1) (P21)- AND P27(KIP1)-MEDIATED CELLULAR SENESCENCE THROUGH CONSTITUTIVE ACTIVATION (HYPERACTIVATION) OF NF-KAPPAB. ALTHOUGH CONSTITUTIVE NF-KAPPAB ACTIVATION IS A COMMON FEATURE OF T/B-CELL LEUKEMIA/LYMPHOMA, INCLUDING ATL, IT IS NOT KNOWN HOW ATL CELLS MAINTAIN CHRONIC NF-KAPPAB ACTIVATION WITHOUT UNDERGOING SENESCENCE. HERE, WE DEMONSTRATE THAT, IN CONTRAST TO HTLV-1(-) T-CELL LINES, ATL CELL LINES NO LONGER UNDERGO TAX-INDUCED SENESCENCE. ALTHOUGH TAX(+) AND TAX(-) ATL CELL LINES SHOWED SIGNATURES OF CONSTITUTIVE NF-KAPPAB ACTIVATION, THEIR ABILITY TO PROGRESS THROUGH THE CELL CYCLE WAS UNAFFECTED. IN SOME CASES, ATL CELL LINES CONTINUED TO PROLIFERATE DESPITE SIGNIFICANT UPREGULATION OF P21; ADDITIONALLY, MANY CELL LINES DISPLAYED ALTERED EXPRESSION OF G1 AND G1/S CYCLINS, PARTICULARLY OVEREXPRESSION OF CYCLIN D2. WE PROPOSE THAT, DURING THE COURSE OF ATL DEVELOPMENT, LEUKEMIA CELLS ACQUIRE GENETIC/EPIGENETIC CHANGES THAT CAN MITIGATE THE SENESCENCE RESPONSE TRIGGERED BY NF-KAPPAB HYPERACTIVATION. RESTORING THE NF-KAPPAB-INDUCED SENESCENCE RESPONSE WOULD LIKELY HELP TO CONTROL THE DEVELOPMENT AND PROGRESSION OF ATL AND SIMILAR LYMPHOID MALIGNANCIES. 2019 7 3181 20 HALLMARKS OF AGING: AN EXPANDING UNIVERSE. AGING IS DRIVEN BY HALLMARKS FULFILLING THE FOLLOWING THREE PREMISES: (1) THEIR AGE-ASSOCIATED MANIFESTATION, (2) THE ACCELERATION OF AGING BY EXPERIMENTALLY ACCENTUATING THEM, AND (3) THE OPPORTUNITY TO DECELERATE, STOP, OR REVERSE AGING BY THERAPEUTIC INTERVENTIONS ON THEM. WE PROPOSE THE FOLLOWING TWELVE HALLMARKS OF AGING: GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, DISABLED MACROAUTOPHAGY, DEREGULATED NUTRIENT-SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, ALTERED INTERCELLULAR COMMUNICATION, CHRONIC INFLAMMATION, AND DYSBIOSIS. THESE HALLMARKS ARE INTERCONNECTED AMONG EACH OTHER, AS WELL AS TO THE RECENTLY PROPOSED HALLMARKS OF HEALTH, WHICH INCLUDE ORGANIZATIONAL FEATURES OF SPATIAL COMPARTMENTALIZATION, MAINTENANCE OF HOMEOSTASIS, AND ADEQUATE RESPONSES TO STRESS. 2023 8 590 36 BET BROMODOMAIN PROTEIN INHIBITION REVERSES CHIMERIC ANTIGEN RECEPTOR EXTINCTION AND REINVIGORATES EXHAUSTED T CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA. CHIMERIC ANTIGEN RECEPTOR (CAR) T CELLS HAVE INDUCED REMARKABLE ANTITUMOR RESPONSES IN B CELL MALIGNANCIES. SOME PATIENTS DO NOT RESPOND BECAUSE OF T CELL DEFICIENCIES THAT HAMPER THE EXPANSION, PERSISTENCE, AND EFFECTOR FUNCTION OF THESE CELLS. WE USED LONGITUDINAL IMMUNE PROFILING TO IDENTIFY PHENOTYPIC AND PHARMACODYNAMIC CHANGES IN CD19-DIRECTED CAR T CELLS IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). CAR EXPRESSION MAINTENANCE WAS ALSO INVESTIGATED BECAUSE THIS CAN AFFECT RESPONSE DURABILITY. CAR T CELL FAILURE WAS ACCOMPANIED BY PREEXISTING T CELL-INTRINSIC DEFECTS OR DYSFUNCTION ACQUIRED AFTER INFUSION. IN A SMALL SUBSET OF PATIENTS, CAR SILENCING WAS OBSERVED COINCIDENT WITH LEUKEMIA RELAPSE. USING A SMALL MOLECULE INHIBITOR, WE DEMONSTRATED THAT THE BROMODOMAIN AND EXTRA-TERMINAL (BET) FAMILY OF CHROMATIN ADAPTERS PLAYS A ROLE IN DOWNREGULATING CAR EXPRESSION. BET PROTEIN BLOCKADE ALSO AMELIORATED CAR T CELL EXHAUSTION AS MANIFESTED BY INHIBITORY RECEPTOR REDUCTION, ENHANCED METABOLIC FITNESS, INCREASED PROLIFERATIVE CAPACITY, AND ENRICHED TRANSCRIPTOMIC SIGNATURES OF T CELL REINVIGORATION. BET INHIBITION DECREASED LEVELS OF THE TET2 METHYLCYTOSINE DIOXYGENASE, AND FORCED EXPRESSION OF THE TET2 CATALYTIC DOMAIN ELIMINATED THE POTENCY-ENHANCING EFFECTS OF BET PROTEIN TARGETING IN CAR T CELLS, PROVIDING A MECHANISM LINKING BET PROTEINS AND T CELL DYSFUNCTION. THUS, MODULATING BET EPIGENETIC READERS MAY IMPROVE THE EFFICACY OF CELL-BASED IMMUNOTHERAPIES. 2021 9 4386 28 MITOCHONDRIAL STRESS INDUCED BY CONTINUOUS STIMULATION UNDER HYPOXIA RAPIDLY DRIVES T CELL EXHAUSTION. CANCER AND CHRONIC INFECTIONS INDUCE T CELL EXHAUSTION, A HYPOFUNCTIONAL FATE CARRYING DISTINCT EPIGENETIC, TRANSCRIPTOMIC AND METABOLIC CHARACTERISTICS. HOWEVER, DRIVERS OF EXHAUSTION REMAIN POORLY UNDERSTOOD. AS INTRATUMORAL EXHAUSTED T CELLS EXPERIENCE SEVERE HYPOXIA, WE HYPOTHESIZED THAT METABOLIC STRESS ALTERS THEIR RESPONSES TO OTHER SIGNALS, SPECIFICALLY, PERSISTENT ANTIGENIC STIMULATION. IN VITRO, ALTHOUGH CD8(+) T CELLS EXPERIENCING CONTINUOUS STIMULATION OR HYPOXIA ALONE DIFFERENTIATED INTO FUNCTIONAL EFFECTORS, THE COMBINATION RAPIDLY DROVE T CELL DYSFUNCTION CONSISTENT WITH EXHAUSTION. CONTINUOUS STIMULATION PROMOTED BLIMP-1-MEDIATED REPRESSION OF PGC-1ALPHA-DEPENDENT MITOCHONDRIAL REPROGRAMMING, RENDERING CELLS POORLY RESPONSIVE TO HYPOXIA. LOSS OF MITOCHONDRIAL FUNCTION GENERATED INTOLERABLE LEVELS OF REACTIVE OXYGEN SPECIES (ROS), SUFFICIENT TO PROMOTE EXHAUSTED-LIKE STATES, IN PART THROUGH PHOSPHATASE INHIBITION AND THE CONSEQUENT ACTIVITY OF NUCLEAR FACTOR OF ACTIVATED T CELLS. REDUCING T CELL-INTRINSIC ROS AND LOWERING TUMOR HYPOXIA LIMITED T CELL EXHAUSTION, SYNERGIZING WITH IMMUNOTHERAPY. THUS, IMMUNOLOGIC AND METABOLIC SIGNALING ARE INTRINSICALLY LINKED: THROUGH MITIGATION OF METABOLIC STRESS, T CELL DIFFERENTIATION CAN BE ALTERED TO PROMOTE MORE FUNCTIONAL CELLULAR FATES. 2021 10 6590 40 TUMOR SUPPRESSOR INACTIVATION IN THE PATHOGENESIS OF ADULT T-CELL LEUKEMIA. TUMOR SUPPRESSOR FUNCTIONS ARE ESSENTIAL TO CONTROL CELLULAR PROLIFERATION, TO ACTIVATE THE APOPTOSIS OR SENESCENCE PATHWAY TO ELIMINATE UNWANTED CELLS, TO LINK DNA DAMAGE SIGNALS TO CELL CYCLE ARREST CHECKPOINTS, TO ACTIVATE APPROPRIATE DNA REPAIR PATHWAYS, AND TO PREVENT THE LOSS OF ADHESION TO INHIBIT INITIATION OF METASTASES. THEREFORE, TUMOR SUPPRESSOR GENES ARE INDISPENSABLE TO MAINTAINING GENETIC AND GENOMIC INTEGRITY. CONSEQUENTLY, INACTIVATION OF TUMOR SUPPRESSORS BY SOMATIC MUTATIONS OR EPIGENETIC MECHANISMS IS FREQUENTLY ASSOCIATED WITH TUMOR INITIATION AND DEVELOPMENT. IN CONTRAST, REACTIVATION OF TUMOR SUPPRESSOR FUNCTIONS CAN EFFECTIVELY REVERSE THE TRANSFORMED PHENOTYPE AND LEAD TO CELL CYCLE ARREST OR DEATH OF CANCEROUS CELLS AND BE USED AS A THERAPEUTIC STRATEGY. ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL) IS AN AGGRESSIVE LYMPHOPROLIFERATIVE DISEASE ASSOCIATED WITH INFECTION OF CD4 T CELLS BY THE HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-I). HTLV-I-ASSOCIATED T-CELL TRANSFORMATION IS THE RESULT OF A MULTISTEP ONCOGENIC PROCESS IN WHICH THE VIRUS INITIALLY INDUCES CHRONIC T-CELL PROLIFERATION AND ALTERS CELLULAR PATHWAYS RESULTING IN THE ACCUMULATION OF GENETIC DEFECTS AND THE DEREGULATED GROWTH OF VIRALLY INFECTED CELLS. THIS REVIEW WILL FOCUS ON THE CURRENT KNOWLEDGE OF THE GENETIC AND EPIGENETIC MECHANISMS REGULATING THE INACTIVATION OF TUMOR SUPPRESSORS IN THE PATHOGENESIS OF HTLV-I. 2015 11 2857 25 FROM PATHOGENESIS TO TREATMENT OF CHRONIC LYMPHOCYTIC LEUKAEMIA. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) HAS SEVERAL UNIQUE FEATURES THAT DISTINGUISH IT FROM OTHER CANCERS. MOST CLL TUMOUR CELLS ARE INERT AND ARRESTED IN G0/G1 OF THE CELL CYCLE AND THERE IS ONLY A SMALL PROLIFERATIVE COMPARTMENT; HOWEVER, THE PROGRESSIVE ACCUMULATION OF MALIGNANT CELLS WILL ULTIMATELY LEAD TO SYMPTOMATIC DISEASE. PATHOGENIC MECHANISMS HAVE BEEN ELUCIDATED THAT INVOLVE MULTIPLE EXTERNAL (FOR EXAMPLE, MICROENVIRONMENTAL STIMULI AND ANTIGENIC DRIVE) AND INTERNAL (GENETIC AND EPIGENETIC) EVENTS THAT ARE CRUCIAL IN THE TRANSFORMATION, PROGRESSION AND EVOLUTION OF CLL. OUR GROWING UNDERSTANDING OF CLL BIOLOGY IS ALLOWING THE TRANSLATION OF TARGETS AND BIOLOGICAL CLASSIFIERS INTO CLINICAL PRACTICE. 2010 12 293 38 AGING HALLMARKS AND THE ROLE OF OXIDATIVE STRESS. AGING IS A COMPLEX BIOLOGICAL PROCESS ACCOMPANIED BY A PROGRESSIVE DECLINE IN THE PHYSICAL FUNCTION OF THE ORGANISM AND AN INCREASED RISK OF AGE-RELATED CHRONIC DISEASES SUCH AS CARDIOVASCULAR DISEASES, CANCER, AND NEURODEGENERATIVE DISEASES. STUDIES HAVE ESTABLISHED THAT THERE EXIST NINE HALLMARKS OF THE AGING PROCESS, INCLUDING (I) TELOMERE SHORTENING, (II) GENOMIC INSTABILITY, (III) EPIGENETIC MODIFICATIONS, (IV) MITOCHONDRIAL DYSFUNCTION, (V) LOSS OF PROTEOSTASIS, (VI) DYSREGULATED NUTRIENT SENSING, (VII) STEM CELL EXHAUSTION, (VIII) CELLULAR SENESCENCE, AND (IX) ALTERED CELLULAR COMMUNICATION. ALL THESE ALTERATIONS HAVE BEEN LINKED TO SUSTAINED SYSTEMIC INFLAMMATION, AND THESE MECHANISMS CONTRIBUTE TO THE AGING PROCESS IN TIMING NOT CLEARLY DETERMINED YET. NEVERTHELESS, MITOCHONDRIAL DYSFUNCTION IS ONE OF THE MOST IMPORTANT MECHANISMS CONTRIBUTING TO THE AGING PROCESS. MITOCHONDRIA IS THE PRIMARY ENDOGENOUS SOURCE OF REACTIVE OXYGEN SPECIES (ROS). DURING THE AGING PROCESS, THERE IS A DECLINE IN ATP PRODUCTION AND ELEVATED ROS PRODUCTION TOGETHER WITH A DECLINE IN THE ANTIOXIDANT DEFENSE. ELEVATED ROS LEVELS CAN CAUSE OXIDATIVE STRESS AND SEVERE DAMAGE TO THE CELL, ORGANELLE MEMBRANES, DNA, LIPIDS, AND PROTEINS. THIS DAMAGE CONTRIBUTES TO THE AGING PHENOTYPE. IN THIS REVIEW, WE SUMMARIZE RECENT ADVANCES IN THE MECHANISMS OF AGING WITH AN EMPHASIS ON MITOCHONDRIAL DYSFUNCTION AND ROS PRODUCTION. 2023 13 1711 30 DYSFUNCTIONAL STATE OF T CELLS OR EXHAUSTION DURING CHRONIC VIRAL INFECTIONS AND COVID-19: A REVIEW. CORONAVIRUS DISEASE 2019 (COVID-19) CONTINUOUSLY AFFECTING THE LIVES OF MILLIONS OF PEOPLE. THE VIRUS IS SPREAD THROUGH THE RESPIRATORY ROUTE TO AN UNINFECTED PERSON, CAUSING MILD-TO-MODERATE RESPIRATORY DISEASE-LIKE SYMPTOMS THAT SOMETIMES PROGRESS TO SEVERE FORM AND CAN BE FATAL. WHEN THE HOST IS INFECTED WITH THE VIRUS, BOTH INNATE AND ADAPTIVE IMMUNITY COMES INTO PLAY. THE EFFECTOR T CELLS ACT AS THE MASTER PLAYER OF ADAPTIVE IMMUNE RESPONSE IN ERADICATING THE VIRUS FROM THE SYSTEM. BUT DURING CANCER AND CHRONIC VIRAL INFECTIONS, THE FATE OF AN EFFECTOR T CELL IS ALTERED, AND THE T CELL MAY ENTERS A STATE OF EXHAUSTION, WHICH IS MARKED BY LOSS OF EFFECTOR FUNCTION, DEPLETED PROLIFERATIVE CAPACITY AND CYTOTOXIC EFFECT ACCOMPLISHED BY AN INCREASED EXPRESSION OF NUMEROUS INHIBITORY RECEPTORS SUCH AS PROGRAMMED CELL DEATH PROTEIN 1 (PD-1), LYMPHOCYTE-ACTIVATION PROTEIN 3 (LAG-3), AND CYTOTOXIC T LYMPHOCYTE-ASSOCIATED ANTIGEN 4 (CTLA-4) ON THEIR SURFACE. VARIOUS OTHER TRANSCRIPTIONAL AND EPIGENETIC CHANGES TAKE PLACE INSIDE THE T CELL WHEN IT ENTERS INTO AN EXHAUSTED STATE. LATEST STUDIES POINT TOWARD THE INDUCTION OF AN ABNORMAL IMMUNE RESPONSE SUCH AS LYMPHOPENIA, CYTOKINE STORM, AND T CELL EXHAUSTION DURING SARS-COV-2 (SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2) INFECTION. THIS REVIEW SHEDS LIGHT ON THE DYSFUNCTIONAL STATE OF T CELLS DURING CHRONIC VIRAL INFECTION AND COVID-19. UNDERSTANDING THE CAUSE AND THE EFFECT OF T CELL EXHAUSTION OBSERVED DURING COVID-19 MAY HELP RESOLVE NEW THERAPEUTIC POTENTIALS FOR TREATING CHRONIC INFECTIONS AND OTHER DISEASES. 2022 14 5484 39 REVEALING THE PATHOGENIC AND AGING-RELATED MECHANISMS OF THE ENIGMATIC IDIOPATHIC PULMONARY FIBROSIS. AN INTEGRAL MODEL. A GROWING BODY OF EVIDENCE INDICATES THAT ABERRANT ACTIVATION OF ALVEOLAR EPITHELIAL CELLS AND FIBROBLASTS IN AN AGING LUNG PLAYS A CRITICAL ROLE IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS (IPF). HOWEVER, THE BIOPATHOLOGICAL PROCESSES LINKING AGING WITH IPF AND THE MECHANISMS RESPONSIBLE FOR THE ABNORMAL ACTIVATION OF EPITHELIAL CELLS AND FIBROBLASTS HAVE NOT BEEN ELUCIDATED. MANY OF THE HALLMARKS OF AGING (E.G., GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, MITOCHONDRIAL DYSFUNCTION, AND CELLULAR SENESCENCE) HAVE BEEN PROPOSED AS ESSENTIAL MECHANISMS FOR THE DEVELOPMENT OF IPF; HOWEVER, THESE DISTURBANCES ARE NOT RESTRICTED TO IPF AND ALSO OCCUR IN OTHER AGING-RELATED LUNG DISORDERS, PRIMARILY CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THEREFORE, AN UNANSWERED QUESTION IS WHY A CURRENT/FORMER SMOKER OF ABOUT 60 YEARS OF AGE WITH SHORTER TELOMERES, ALVEOLAR EPITHELIAL SENESCENCE, EXCESSIVE OXIDATIVE STRESS, AND MITOCHONDRIAL DYSFUNCTION DEVELOPS IPF AND NOT COPD; IN OTHER WORDS, WHAT MAKES OLD LUNGS SPECIFICALLY SUSCEPTIBLE TO DEVELOP IPF? IN THIS PERSPECTIVE, WE PROPOSE AN INTEGRAL MODEL IN WHICH THE COMBINATION OF SOME GENE VARIANTS AND/OR GENE EXPRESSION IN THE AGING LUNG RESULTS IN THE LOSS OF EPITHELIAL INTEGRITY AND CONSEQUENTLY IN THE FAILURE OF THE ALVEOLI TO CORRECTLY RESPOND TO INJURY AND TO FACE THE STRESS ASSOCIATED WITH MECHANICAL STRETCH. AFTERWARD, A DISTINCTIVE EPIGENETIC "REPROGRAMMING" THAT AFFECTS BOTH EPITHELIAL CELLS AND FIBROBLASTS PROVOKES, AMONG OTHERS, THE RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND THE ABERRANT ACTIVATION AND MISCOMMUNICATION BETWEEN BOTH CELL TYPES, RESULTING IN THE EXAGGERATED PRODUCTION AND ACCUMULATION OF EXTRACELLULAR MATRIX AND THE SUBSEQUENT DESTRUCTION OF THE LUNG ARCHITECTURE. 2014 15 5630 33 SENESCENCE IN PULMONARY FIBROSIS: BETWEEN AGING AND EXPOSURE. TO DATE, CHRONIC PULMONARY PATHOLOGIES REPRESENT THE THIRD LEADING CAUSE OF DEATH IN THE ELDERLY POPULATION. EVIDENCE-BASED PROJECTIONS SUGGEST THAT >65 (YEARS OLD) INDIVIDUALS WILL ACCOUNT FOR APPROXIMATELY A QUARTER OF THE WORLD POPULATION BEFORE THE TURN OF THE CENTURY. GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, DEREGULATED NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, AND ALTERED INTERCELLULAR COMMUNICATION, ARE DESCRIBED AS THE NINE "HALLMARKS" THAT GOVERN CELLULAR FITNESS. ANY DEVIATION FROM THE NORMAL PATTERN INITIATES A COMPLEX CASCADE OF EVENTS CULMINATING TO A DISEASE STATE. THIS BLUEPRINT, ORIGINALLY EMPLOYED TO DESCRIBE ABERRANT CHANGES IN CANCER CELLS, CAN BE ALSO USED TO DESCRIBE AGING AND FIBROSIS. PULMONARY FIBROSIS (PF) IS THE RESULT OF A PROGRESSIVE DECLINE IN INJURY RESOLUTION PROCESSES STEMMING FROM ENDOGENOUS (PHYSIOLOGICAL DECLINE OR SOMATIC MUTATIONS) OR EXOGENOUS STRESS. ENVIRONMENTAL, DIETARY OR OCCUPATIONAL EXPOSURE ACCELERATES THE PATHOGENESIS OF A SENESCENT PHENOTYPE BASED ON (1) WINDOW OF EXPOSURE; (2) DOSE, DURATION, RECURRENCE; AND (3) CELLS TYPE BEING TARGETED. AS THE LUNG AGES, THE THRESHOLD TO GENERATE AN IRREVERSIBLY SENESCENT PHENOTYPE IS LOWERED. HOWEVER, WE DO NOT HAVE SUFFICIENT KNOWLEDGE TO MAKE ACCURATE PREDICTIONS. IN THIS REVIEW, WE PROVIDE AN ASSESSMENT OF THE LITERATURE THAT INTERROGATES LUNG EPITHELIAL, MESENCHYMAL, AND IMMUNE SENESCENCE AT THE INTERSECTION OF AGING, ENVIRONMENTAL EXPOSURE AND PULMONARY FIBROSIS. 2020 16 5396 32 REDUCED HISTONE BIOSYNTHESIS AND CHROMATIN CHANGES ARISING FROM A DAMAGE SIGNAL AT TELOMERES. DURING REPLICATIVE AGING OF PRIMARY CELLS MORPHOLOGICAL TRANSFORMATIONS OCCUR, THE EXPRESSION PATTERN IS ALTERED AND CHROMATIN CHANGES GLOBALLY. HERE WE SHOW THAT CHRONIC DAMAGE SIGNALS, PROBABLY CAUSED BY TELOMERE PROCESSING, AFFECT EXPRESSION OF HISTONES AND LEAD TO THEIR DEPLETION. WE INVESTIGATED THE ABUNDANCE AND CELL CYCLE EXPRESSION OF HISTONES AND HISTONE CHAPERONES AND FOUND DEFECTS IN HISTONE BIOSYNTHESIS DURING REPLICATIVE AGING. SIMULTANEOUSLY, EPIGENETIC MARKS WERE REDISTRIBUTED ACROSS THE PHASES OF THE CELL CYCLE AND THE DNA DAMAGE RESPONSE (DDR) MACHINERY WAS ACTIVATED. THE AGE-DEPENDENT REPROGRAMMING AFFECTED TELOMERIC CHROMATIN ITSELF, WHICH WAS PROGRESSIVELY DESTABILIZED, LEADING TO A BOOST OF THE TELOMERE-ASSOCIATED DDR WITH EACH SUCCESSIVE CELL CYCLE. WE PROPOSE A MECHANISM IN WHICH CHANGES IN THE STRUCTURAL AND EPIGENETIC INTEGRITY OF TELOMERES AFFECT CORE HISTONES AND THEIR CHAPERONES, ENFORCING A SELF-PERPETUATING PATHWAY OF GLOBAL EPIGENETIC CHANGES THAT ULTIMATELY LEADS TO SENESCENCE. 2010 17 788 35 CELLULAR ALLOSTATIC LOAD IS LINKED TO INCREASED ENERGY EXPENDITURE AND ACCELERATED BIOLOGICAL AGING. STRESS TRIGGERS ANTICIPATORY PHYSIOLOGICAL RESPONSES THAT PROMOTE SURVIVAL, A PHENOMENON TERMED ALLOSTASIS. HOWEVER, THE CHRONIC ACTIVATION OF ENERGY-DEPENDENT ALLOSTATIC RESPONSES RESULTS IN ALLOSTATIC LOAD, A DYSREGULATED STATE THAT PREDICTS FUNCTIONAL DECLINE, ACCELERATES AGING, AND INCREASES MORTALITY IN HUMANS. THE ENERGETIC COST AND CELLULAR BASIS FOR THE DAMAGING EFFECTS OF ALLOSTATIC LOAD HAVE NOT BEEN DEFINED. HERE, BY LONGITUDINALLY PROFILING THREE UNRELATED PRIMARY HUMAN FIBROBLAST LINES ACROSS THEIR LIFESPAN, WE FIND THAT CHRONIC GLUCOCORTICOID EXPOSURE INCREASES CELLULAR ENERGY EXPENDITURE BY APPROXIMATELY 60%, ALONG WITH A METABOLIC SHIFT FROM GLYCOLYSIS TO MITOCHONDRIAL OXIDATIVE PHOSPHORYLATION (OXPHOS). THIS STATE OF STRESS-INDUCED HYPERMETABOLISM IS LINKED TO MTDNA INSTABILITY, NON-LINEARLY AFFECTS AGE-RELATED CYTOKINES SECRETION, AND ACCELERATES CELLULAR AGING BASED ON DNA METHYLATION CLOCKS, TELOMERE SHORTENING RATE, AND REDUCED LIFESPAN. PHARMACOLOGICALLY NORMALIZING OXPHOS ACTIVITY WHILE FURTHER INCREASING ENERGY EXPENDITURE EXACERBATES THE ACCELERATED AGING PHENOTYPE, POINTING TO TOTAL ENERGY EXPENDITURE AS A POTENTIAL DRIVER OF AGING DYNAMICS. TOGETHER, OUR FINDINGS DEFINE BIOENERGETIC AND MULTI-OMIC RECALIBRATIONS OF STRESS ADAPTATION, UNDERSCORING INCREASED ENERGY EXPENDITURE AND ACCELERATED CELLULAR AGING AS INTERRELATED FEATURES OF CELLULAR ALLOSTATIC LOAD. 2023 18 3183 28 HALLMARKS OF T CELL AGING. THE AGED ADAPTIVE IMMUNE SYSTEM IS CHARACTERIZED BY PROGRESSIVE DYSFUNCTION AS WELL AS INCREASED AUTOIMMUNITY. THIS DECLINE IS RESPONSIBLE FOR ELEVATED SUSCEPTIBILITY TO INFECTION AND CANCER, AS WELL AS DECREASED VACCINATION EFFICACY. RECENT EVIDENCE INDICATES THAT CD4(+) T CELL-INTRINSIC ALTERATINS CONTRIBUTE TO CHRONIC INFLAMMATION AND ARE SUFFICIENT TO ACCELERATE AN ORGANISM-WIDE AGING PHENOTYPE, SUPPORTING THE IDEA THAT T CELL AGING PLAYS A MAJOR ROLE IN BODY-WIDE DETERIORATION. IN THIS REVIEW, WE PROPOSE TEN MOLECULAR HALLMARKS TO REPRESENT COMMON DENOMINATORS OF T CELL AGING. THESE HALLMARKS ARE GROUPED INTO FOUR PRIMARY HALLMARKS (THYMIC INVOLUTION, MITOCHONDRIAL DYSFUNCTION, GENETIC AND EPIGENETIC ALTERATIONS, AND LOSS OF PROTEOSTASIS) AND FOUR SECONDARY HALLMARKS (REDUCTION OF THE TCR REPERTOIRE, NAIVE-MEMORY IMBALANCE, T CELL SENESCENCE, AND LACK OF EFFECTOR PLASTICITY), AND TOGETHER THEY EXPLAIN THE MANIFESTATION OF THE TWO INTEGRATIVE HALLMARKS (IMMUNODEFICIENCY AND INFLAMMAGING). A MAJOR CHALLENGE NOW IS WEIGHING THE RELATIVE IMPACT OF THESE HALLMARKS ON T CELL AGING AND UNDERSTANDING THEIR INTERCONNECTIONS, WITH THE FINAL GOAL OF DEFINING MOLECULAR TARGETS FOR INTERVENTIONS IN THE AGING PROCESS. 2021 19 930 40 CHRONIC IRRADIATION OF HUMAN CELLS REDUCES HISTONE LEVELS AND DEREGULATES GENE EXPRESSION. OVER THE PAST DECADES, THERE HAVE BEEN HUGE ADVANCES IN UNDERSTANDING CELLULAR RESPONSES TO IONISING RADIATION (IR) AND DNA DAMAGE. THESE STUDIES, HOWEVER, WERE MOSTLY EXECUTED WITH CELL LINES AND MICE USING SINGLE OR MULTIPLE ACUTE DOSES OF RADIATION. HENCE, RELATIVELY LITTLE IS KNOWN ABOUT HOW CONTINUOUS EXPOSURE TO LOW DOSE IONISING RADIATION AFFECTS NORMAL CELLS AND ORGANISMS, EVEN THOUGH OUR CELLS ARE CONSTANTLY EXPOSED TO LOW LEVELS OF RADIATION. WE ADDRESSED THIS ISSUE BY EXAMINING THE CONSEQUENCES OF EXPOSING HUMAN PRIMARY CELLS TO CONTINUOUS IONISING GAMMA-RADIATION DELIVERED AT 6-20 MGY/H. ALTHOUGH THESE DOSE RATES ARE ESTIMATED TO INFLICT FEWER THAN A SINGLE DNA DOUBLE-STRAND BREAK (DSB) PER HOUR PER CELL, THEY STILL CAUSED DOSE-DEPENDENT REDUCTIONS IN CELL PROLIFERATION AND INCREASED CELLULAR SENESCENCE. WE CONCOMITANTLY OBSERVED HISTONE PROTEIN LEVELS TO REDUCE BY UP TO 40%, WHICH IN CONTRAST TO PREVIOUS OBSERVATIONS, WAS NOT MAINLY DUE TO PROTEIN DEGRADATION BUT INSTEAD CORRELATED WITH REDUCED HISTONE GENE EXPRESSION. HISTONE REDUCTIONS WERE ACCOMPANIED BY ENLARGED NUCLEAR SIZE PARALLELED BY AN INCREASE IN GLOBAL TRANSCRIPTION, INCLUDING THAT OF PRO-INFLAMMATORY GENES. THUS, CHRONIC IRRADIATION, EVEN AT LOW DOSE-RATES, CAN INDUCE CELL SENESCENCE AND ALTER GENE EXPRESSION VIA A HITHERTO UNCHARACTERISED EPIGENETIC ROUTE. THESE FEATURES OF CHRONIC RADIATION REPRESENT A NEW ASPECT OF RADIATION BIOLOGY. 2020 20 182 20 ACCELERATED LUNG AGING AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. THE PREVALENCE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) INCREASES EXPONENTIALLY WITH AGING. ITS PATHOGENESIS, HOWEVER, IS NOT WELL KNOWN AND ASIDE FROM SMOKING CESSATION, THERE ARE NO DISEASE-MODIFYING TREATMENTS FOR THIS DISEASE. AREAS COVERED: COPD IS ASSOCIATED WITH ACCELERATING AGING AND AGING-RELATED DISEASES. IN THIS REVIEW, WE WILL DISCUSS THE HALLMARKS OF AGING INCLUDING GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATION, LOSS OF PROTEOSTASIS, MITOCHONDRIAL DYSFUNCTION, DEREGULATED NUTRIENT SENSING, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, AND ALTERED INTERCELLULAR COMMUNICATION, WHICH MAY BE INVOLVED IN COPD PATHOGENESIS. EXPERT COMMENTARY: COPD AND THE AGING PROCESS SHARE SIMILAR MOLECULAR AND CELLULAR CHANGES. AGING-RELATED MOLECULAR PATHWAYS MAY REPRESENT NOVEL THERAPEUTIC TARGETS AND BIOMARKERS FOR COPD. 2019