1 5343 146 RADIATION-STIMULATED EPIGENETIC REPROGRAMMING OF ADAPTIVE-RESPONSE GENES IN THE LUNG: AN EVOLUTIONARY GIFT FOR MOUNTING ADAPTIVE PROTECTION AGAINST LUNG CANCER. HUMANS ARE CONTINUOUSLY EXPOSED TO LOW-LEVEL IONIZING RADIATION FROM NATURAL SOURCES. HOWEVER, HARSHER RADIATION ENVIRONMENTS PERSISTED DURING OUR PLANET'S EARLY YEARS AND MAMMALS SURVIVED VIA AN EVOLUTIONARY GIFT--A SYSTEM OF RADIATION-INDUCED NATURAL PROTECTIVE MEASURES (ADAPTIVE PROTECTION). THIS SYSTEM INCLUDES ANTIOXIDANTS, DNA REPAIR, APOPTOSIS OF SEVERELY DAMAGED CELLS, EPIGENETICALLY REGULATED APOPTOSIS (EPIAPOPTOSIS) PATHWAYS THAT SELECTIVELY REMOVE PRECANCEROUS AND OTHER ABERRANT CELLS, AND IMMUNITY AGAINST CANCER. WE PROPOSE A NOVEL MODEL IN WHICH THE PROTECTIVE SYSTEM IS REGULATED AT LEAST IN PART VIA RADIATION-STRESS-STIMULATED EPIGENETIC REPROGRAMMING (EPIREPROGRAMMING) OF ADAPTIVE-RESPONSE GENES. HIGH-DOSE RADIATION CAN PROMOTE EPIGENETICALLY SILENCING OF ADAPTIVE-RESPONSE GENES (EPISILENCING), FOR EXAMPLE VIA PROMOTER-ASSOCIATED DNA AND/OR HISTONE METHYLATION AND/OR HISTONE DEACETYLATION. EVIDENCE IS PROVIDED FOR LOW LINEAR-ENERGY-TRANSFER (LET) RADIATION-ACTIVATED NATURAL PROTECTION (ANP) AGAINST HIGH-LET ALPHA-RADIATION-INDUCED LUNG CANCER IN PLUTONIUM-239 EXPOSED RATS AND RADON-PROGENY-EXPOSED HUMANS. USING A REVISED HORMETIC RELATIVE RISK MODEL FOR CANCER INDUCTION THAT ACCOUNTS FOR BOTH EPIGENETIC ACTIVATION (EPIACTIVATION) AND EPISILENCING OF GENES, WE DEMONSTRATE THAT, ON AVERAGE, >80% OF ALPHA-RADIATION-INDUCED RAT LUNG CANCERS WERE PREVENTED BY CHRONIC, LOW-RATE GAMMA-RAY ANP. INTERESTINGLY, LIFETIME EXPOSURE TO RESIDENTIAL RADON AT THE ENVIRONMENTAL PROTECTION AGENCY'S ACTION LEVEL OF 4 PCI L(-1) APPEARS TO BE ASSOCIATED WITH ON AVERAGE A > 60% REDUCTION IN LUNG CANCER CASES, RATHER THAN AN INCREASE. WE HAVE USED UNDERLINED ITALICS TO INDICATE NEWLY INTRODUCED TERMINOLOGY. 2009 2 5341 61 RADIATION-HORMESIS PHENOTYPES, THE RELATED MECHANISMS AND IMPLICATIONS FOR DISEASE PREVENTION AND THERAPY. HUMANS ARE CONTINUOUSLY EXPOSED TO IONIZING RADIATION THROUGHOUT LIFE FROM NATURAL SOURCES THAT INCLUDE COSMIC, SOLAR, AND TERRESTRIAL. MUCH HARSHER NATURAL RADIATION AND CHEMICAL ENVIRONMENTS EXISTED DURING OUR PLANET'S EARLY YEARS. MAMMALS SURVIVED THE HARSHER ENVIRONMENTS VIA EVOLUTIONARILY-CONSERVED GIFTS ? A CONTINUOUSLY EVOLVING SYSTEM OF STRESS-INDUCED NATURAL PROTECTIVE MEASURES (I.E., ACTIVATED NATURAL PROTECTION [ANP]). THE CURRENT PROTECTIVE SYSTEM IS DIFFERENTIALLY ACTIVATED BY STOCHASTIC (I.E., VARIABLE) LOW-RADIATION-DOSE THRESHOLDS AND WHEN OPTIMALLY ACTIVATED IN MAMMALS INCLUDES ANTIOXIDANTS, DNA DAMAGE REPAIR, P53-RELATED APOPTOSIS OF SEVERELY-DAMAGED CELLS, REACTIVE-OXYGEN-SPECIES (ROS)/REACTIVE-NITROGEN-SPECIES (RNS)- AND CYTOKINE-REGULATED AUXILIARY APOPTOSIS THAT SELECTIVELY REMOVES ABERRANT CELLS (E.G., PRECANCEROUS CELLS), SUPPRESSION OF DISEASE PROMOTING INFLAMMATION, AND IMMUNITY AGAINST CANCER CELLS. THE INTERCELLULAR-SIGNALING-BASED PROTECTIVE SYSTEM IS REGULATED AT LEAST IN PART VIA EPIGENETIC REPROGRAMMING OF ADAPTIVE-RESPONSE GENES. WHEN THE SYSTEM IS OPTIMALLY ACTIVATED, IT PROTECTS AGAINST CANCER AND SOME OTHER DISEASES, THEREBY LEADING TO HORMETIC PHENOTYPES (E.G., REDUCED DISEASE INCIDENCE TO BELOW THE BASELINE LEVEL; REDUCED PAIN FROM INFLAMMATION-RELATED PROBLEMS). HERE, SOME EXPRESSED RADIATION HORMESIS PHENOTYPES AND RELATED MECHANISMS ARE DISCUSSED ALONG WITH THEIR IMPLICATIONS FOR DISEASE PREVENTION AND THERAPY. 2014 3 1162 37 CONTRASTING EFFECTS OF ACUTE AND CHRONIC STRESS ON THE TRANSCRIPTOME, EPIGENOME, AND IMMUNE RESPONSE OF ATLANTIC SALMON. STRESS EXPERIENCED DURING EARLY LIFE MAY HAVE LASTING EFFECTS ON THE IMMUNE SYSTEM, WITH IMPACTS ON HEALTH AND DISEASE DEPENDENT ON THE NATURE AND DURATION OF THE STRESSOR. THE EPIGENOME IS ESPECIALLY SENSITIVE TO ENVIRONMENTAL STIMULI DURING EARLY LIFE AND REPRESENTS A POTENTIAL MECHANISM THROUGH WHICH STRESS MAY CAUSE LONG-LASTING HEALTH EFFECTS. HOWEVER, THE EXTENT TO WHICH THE EPIGENOME RESPONDS DIFFERENTLY TO CHRONIC VS ACUTE STRESSORS IS UNCLEAR, ESPECIALLY FOR NON-MAMMALIAN SPECIES. WE EXAMINED THE EFFECTS OF ACUTE STRESS (COLD-SHOCK DURING EMBRYOGENESIS) AND CHRONIC STRESS (ABSENCE OF TANK ENRICHMENT DURING LARVAL-STAGE) ON GLOBAL GENE EXPRESSION (USING RNA-SEQ) AND DNA METHYLATION (USING RRBS) IN THE GILLS OF ATLANTIC SALMON (SALMO SALAR) FOUR MONTHS AFTER HATCHING. CHRONIC STRESS INDUCED PRONOUNCED TRANSCRIPTIONAL DIFFERENCES, WHILE ACUTE STRESS CAUSED FEW LASTING TRANSCRIPTIONAL EFFECTS. HOWEVER, BOTH ACUTE AND CHRONIC STRESS CAUSED LASTING AND CONTRASTING CHANGES IN THE METHYLOME. CRUCIALLY, WE FOUND THAT ACUTE STRESS ENHANCED TRANSCRIPTIONAL IMMUNE RESPONSE TO A PATHOGENIC CHALLENGE (BACTERIAL LIPOPOLYSACCHARIDE, LPS), WHILE CHRONIC STRESS SUPPRESSED IT. WE IDENTIFIED STRESS-INDUCED CHANGES IN PROMOTER AND GENE-BODY METHYLATION THAT WERE ASSOCIATED WITH ALTERED EXPRESSION FOR A SMALL PROPORTION OF IMMUNE-RELATED GENES, AND EVIDENCE OF WIDER EPIGENETIC REGULATION WITHIN SIGNALLING PATHWAYS INVOLVED IN IMMUNE RESPONSE. OUR RESULTS SUGGEST THAT STRESS CAN AFFECT IMMUNO-COMPETENCE THROUGH EPIGENETIC MECHANISMS, AND HIGHLIGHT THE MARKEDLY DIFFERENT EFFECTS OF CHRONIC LARVAL AND ACUTE EMBRYONIC STRESS. THIS KNOWLEDGE COULD BE USED TO HARNESS THE STIMULATORY EFFECTS OF ACUTE STRESS ON IMMUNITY, PAVING THE WAY FOR IMPROVED STRESS AND DISEASE MANAGEMENT THROUGH EPIGENETIC CONDITIONING. 2018 4 5468 32 RESISTANCE TRAINING AND REDOX HOMEOSTASIS: CORRELATION WITH AGE-ASSOCIATED GENOMIC CHANGES. REGULAR PHYSICAL ACTIVITY IS EFFECTIVE AS PREVENTION AND TREATMENT FOR DIFFERENT CHRONIC CONDITIONS RELATED TO THE AGEING PROCESSES. IN FACT, A SEDENTARY LIFESTYLE HAS BEEN LINKED TO A WORSENING OF CELLULAR AGEING BIOMARKERS SUCH AS TELOMERE LENGTH (TL) AND/OR SPECIFIC EPIGENETIC CHANGES (E.G. DNA METHYLATION), WITH INCREASE OF THE PROPENSITY TO AGING-RELATED DISEASES AND PREMATURE DEATH. EXTENDING OUR PREVIOUS FINDINGS, WE AIMED TO TEST THE HYPOTHESIS THAT 12 WEEKS OF LOW FREQUENCY, MODERATE INTENSITY, EXPLOSIVE-TYPE RESISTANCE TRAINING (EMRT) MAY ATTENUATE AGE-ASSOCIATED GENOMIC CHANGES. TO THIS AIM, TL, GLOBAL DNA METHYLATION, TRF2, KU80, SIRT1, SIRT2 AND GLOBAL PROTEIN ACETYLATION, AS WELL AS OTHER PROTEINS INVOLVED IN APOPTOTIC PATHWAY (BCL-2, BAX AND CASPASE-3), ANTIOXIDANT RESPONSE (TRXR1 AND MNSOD) AND OXIDATIVE DAMAGE (MYELOPEROXIDASE) WERE EVALUATED BEFORE AND AFTER EMRT IN WHOLE BLOOD OR PERIPHERAL MONONUCLEAR CELLS (PBMCS) OF ELDERLY SUBJECTS. OUR FINDINGS CONFIRM THE POTENTIAL OF EMRT TO INDUCE AN ADAPTIVE CHANGE IN THE ANTIOXIDANT PROTEIN SYSTEMS AT SYSTEMIC LEVEL AND SUGGEST A PUTATIVE ROLE OF RESISTANCE TRAINING IN THE REDUCTION OF GLOBAL DNA METHYLATION. MOREOVER, WE OBSERVED THAT EMRT COUNTERACTS THE TELOMERES' SHORTENING IN A MANNER THAT PROVED TO BE DIRECTLY CORRELATED WITH THE AMELIORATION OF REDOX HOMEOSTASIS AND EFFICACY OF TRAINING REGIME, EVALUATED AS IMPROVEMENT OF BOTH MUSCLE'S POWER/STRENGTH AND FUNCTIONAL PARAMETERS. 2016 5 4019 28 LOW-DOSE OR LOW-DOSE-RATE IONIZING RADIATION-INDUCED BIOEFFECTS IN ANIMAL MODELS. ANIMAL EXPERIMENTAL STUDIES INDICATE THAT ACUTE OR CHRONIC LOW-DOSE IONIZING RADIATION (LDIR) (