1 2484 151 EPIGENETIC, TRANSCRIPTIONAL AND PHENOTYPIC RESPONSES IN TWO GENERATIONS OF DAPHNIA MAGNA EXPOSED TO THE DNA METHYLATION INHIBITOR 5-AZACYTIDINE. THE WATER FLEA DAPHNIA MAGNA IS A KEYSTONE SPECIES IN FRESHWATER ECOSYSTEMS AND HAS BEEN WIDELY USED AS A MODEL ORGANISM IN ENVIRONMENTAL ECOTOXICOLOGY. THIS AQUATIC CRUSTACEAN IS SENSITIVE TO ENVIRONMENTAL STRESSORS AND DISPLAYS CONSIDERABLE PLASTICITY IN ADAPTING TO CHANGING ENVIRONMENTAL CONDITIONS. PART OF THIS PLASTICITY MAY BE DUE TO EPIGENETIC REGULATION OF GENE EXPRESSION, INCLUDING CHANGES TO DNA METHYLATION AND HISTONE MODIFICATIONS. BECAUSE OF THE GENERALLY HYPOMETHYLATED GENOME OF THIS SPECIES, WE HYPOTHESIZED THAT THE HISTONE CODE MAY HAVE AN ESSENTIAL ROLE IN THE EPIGENETIC CONTROL AND THAT HISTONE MODIFICATIONS MIGHT BE AN EARLY MARKER FOR STRESS. THIS STUDY AIMS TO CHARACTERIZE THE EPIGENETIC, TRANSCRIPTIONAL AND PHENOTYPIC RESPONSES AND THEIR CAUSAL LINKAGES IN DIRECTLY EXPOSED ADULT (F0) DAPHNIA AND PERITONEAL EXPOSED NEONATES (F1) AFTER A CHRONIC (7-DAY) EXPOSURE TO A SUBLETHAL CONCENTRATION (10 MG/L) OF 5-AZACYTIDINE, A WELL-STUDIED VERTEBRATE DNA METHYLATION INHIBITOR. EXPOSURE OF THE F0 GENERATION SIGNIFICANTLY REDUCED THE CUMULATIVE FECUNDITY, ACCOMPANIED WITH DIFFERENTIAL EXPRESSION OF GENES IN THE ONE-CARBON-CYCLE METABOLIC PATHWAY. IN THE EPIGENOME OF THE F0 GENERATION, A DECREASE IN GLOBAL DNA METHYLATION, BUT NO SIGNIFICANT CHANGES ON H3K4ME3 OR H3K27ME3, WERE OBSERVED. IN THE F1 OFFSPRING GENERATION, CHANGES IN GENE EXPRESSION, A SIGNIFICANT REDUCTION IN GLOBAL DNA METHYLATION AND CHANGES IN HISTONE MODIFICATIONS WERE IDENTIFIED. THE RESULTS INDICATE THAT EXPOSURE DURING ADULTHOOD MAY RESULT IN MORE PRONOUNCED EFFECTS ON EARLY DEVELOPMENT IN THE OFFSPRING GENERATION, THOUGH INTERPRETATION OF THE DATA SHOULD BE CAREFULLY DONE SINCE BOTH THE EXPOSURE REGIME AND DEVELOPMENTAL PERIOD IS DIFFERENT IN THE TWO GENERATIONS EXAMINED. THE OBTAINED RESULTS IMPROVE OUR UNDERSTANDING OF CRUSTACEAN EPIGENETICS AND THE TOOLS DEVELOPED MAY PROMOTE USE OF EPIGENETIC MARKERS IN HAZARD ASSESSMENT OF ENVIRONMENTAL STRESSORS. 2019 2 4923 47 PARENTAL DIURON EXPOSURE CAUSES LOWER HATCHABILITY AND ABNORMAL OVARIAN DEVELOPMENT IN OFFSPRING OF MEDAKA (ORYZIAS MELASTIGMA). DIURON IS ONE OF THE MOST WIDELY USED HERBICIDES WORLDWIDE. IT HAS BEEN WIDELY DETECTED IN VARIOUS AQUATIC ENVIRONMENTS, ESPECIALLY IN MARINE ECOSYSTEMS. ALTHOUGH DIRECT EFFECTS OF DIURON EXPOSURE ON VARIOUS ORGANISMS HAVE BEEN REPORTED, LITTLE IS KNOWN ABOUT ITS EFFECTS ON MARINE FISHES INCLUDING MULTIGENERATIONAL EFFECTS. HEREIN, THE FILIAL GENERATION (F1) OF DIURON-EXPOSED MARINE MEDAKA (ORYZIAS MELASTIGMA) (F0) WAS RAISED IN CLEAN SEAWATER FROM FERTILIZED EGGS TO ADULTHOOD AND USED AS A MARINE FISH MODEL TO STUDY THE POTENTIAL MULTIGENERATIONAL EFFECTS OF DIURON. WE FOUND THAT THE SUCCESSFUL HATCHING OF F1 LARVAE WAS SIGNIFICANTLY REDUCED AND THAT OVARIAN DEVELOPMENT IN F1 FEMALES WAS RETARDED. A SIGNIFICANT INCREASE IN THE PERCENTAGE OF PREVITELLOGENIC OOCYTES, ALONG WITH A VISUAL DECREASE IN THE PERCENTAGE OF VITELLOGENIC AND MATURE OOCYTES IN THE F1 OVARY, WERE OBSERVED. THE HORMONE LEVELS OF THE HYPOTHALAMUS-PITUITARY-GONAD-LIVER AXIS AND VITELLOGENIN-RELATED TRANSCRIPTION WERE DOWNREGULATED. IN ADDITION, THE MRNA LEVELS OF DNA METHYLTRANSFERASE IN THE BRAIN, OVARY AND LIVER OF F1 ADULT FISH EXHIBITED SIGNIFICANT UPREGULATION, SUGGESTING THAT THE PROBABLE UNDERLYING MULTIGENERATIONAL MECHANISM MIGHT BE ASSOCIATED WITH EPIGENETIC MODIFICATIONS. TAKEN TOGETHER, THESE RESULTS DEMONSTRATED THAT CHRONIC ENVIRONMENTAL DIURON EXPOSURE IN F0 MARINE MEDAKA CAN INHIBIT F1 OVARY DEVELOPMENT AND SUGGESTED THAT DIURON MAY AFFECT MARINE FISH THRIVING IN THE OCEAN. 2022 3 3109 46 GENOTOXIC AND EPIGENETIC EFFECTS OF DIURON IN THE PACIFIC OYSTER: IN VITRO EVIDENCE OF INTERACTION BETWEEN DNA DAMAGE AND DNA METHYLATION. RECENTLY, RESEARCH HAS CONTRIBUTED TO BETTER KNOWLEDGE ON THE OCCURRENCE OF PESTICIDES IN COASTAL WATER BY IDENTIFYING FREQUENTLY DETECTED SUBSTANCES, THEIR CONCENTRATION RANGE AND THEIR ACUTE AND CHRONIC TOXICITY FOR ORGANISMS. PESTICIDE POLLUTION IS OF PARTICULAR CONCERN IN FRANCE DUE TO IMPORTANT AGRICULTURAL ACTIVITIES AND PRESENCE OF SEVERAL EXOREIC CATCHMENT AREAS THAT VEHICLE PESTICIDES UP TO COASTAL WATERS, IMPACTING NON-TARGET MARINE SPECIES. SEVERAL ECOTOXICOLOGY QUESTIONS REMAIN TO BE ADDRESSED CONCERNING THE LONG-TERM EFFECTS OF CHRONIC PESTICIDE EXPOSURE AND THE MECHANISMS INVOLVED IN ADAPTATION TO CHEMICAL STRESS. IN THE PRESENT STUDY, WE BROUGHT NEW INSIGHTS ON THE GENETIC AND EPIGENETIC EFFECTS OF THE HERBICIDE DIURON IN OYSTER GENITORS. DURING GAMETOGENESIS, WE EXPOSED CRASSOSTREA GIGAS TO ENVIRONMENTALLY REALISTIC HERBICIDE CONCENTRATIONS (0.2-0.3 MUG L(-1) DURING TWO 7-DAY PERIODS AT HALF-COURSE AND END OF GAMETOGENESIS). DIURON EXPOSURE WAS SHOWN TO DECREASE GLOBAL DNA METHYLATION AND TOTAL METHYLTRANSFERASE ACTIVITY IN WHOLE OYSTER TISSUE; THIS IS CONSISTENT WITH THE PREVIOUS OBSERVATION OF A SIGNIFICANT DECREASE IN DNMT1 GENE EXPRESSION. DIURON EFFECT SEEMED TO BE TISSUE-SPECIFIC; HYPERMETHYLATION WAS DETECTED IN THE DIGESTIVE GLAND, WHEREAS DIURON EXPOSURE HAD NO EFFECT ON GILL AND GONAD TISSUE. THE GENOTOXICITY OF DIURON WAS CONFIRMED BY THE DETECTION OF ONE ADDUCT IN GONAD DNA. BY USING IN VITRO APPROACHES AND HUMAN DNMT1 (DNMT1 HAS NOT BEEN PURIFIED YET IN BIVALVES), THE PRESENCE OF DNA LESIONS (ADDUCT, 8-OXODGUO) WAS SHOWN TO INTERFERE WITH DNMT1 ACTIVITY, INDICATING A COMPLEX INTERACTION BETWEEN DNA DAMAGE AND DNA METHYLATION. BASED ON OUR RESULTS, WE PROPOSE MECHANISMS TO EXPLAIN THE EFFECT OF DIURON EXPOSURE ON DNA METHYLATION, A WIDESPREAD EPIGENETIC MARK. 2021 4 166 37 ABNORMAL OVARIAN DNA METHYLATION PROGRAMMING DURING GONAD MATURATION IN WILD CONTAMINATED FISH. THERE IS INCREASING EVIDENCE THAT POLLUTANTS MAY CAUSE DISEASES VIA EPIGENETIC MODIFICATIONS. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION PARTICIPATE IN THE REGULATION OF GENE TRANSCRIPTION. SURPRISINGLY, EPIGENETICS RESEARCH IS STILL LIMITED IN ECOTOXICOLOGY. IN THIS STUDY, WE INVESTIGATED WHETHER CHRONIC EXPOSURE TO CONTAMINANTS EXPERIENCED BY WILD FEMALE FISH (ANGUILLA ANGUILLA) THROUGHOUT THEIR JUVENILE PHASE CAN AFFECT THE DNA METHYLATION STATUS OF THEIR OOCYTES DURING GONAD MATURATION. THUS, FISH WERE SAMPLED IN TWO LOCATIONS PRESENTING A LOW OR A HIGH CONTAMINATION LEVEL. THEN, FISH WERE TRANSFERRED TO THE LABORATORY AND ARTIFICIALLY MATURED. BEFORE HORMONAL TREATMENT, THE DNA METHYLATION LEVELS OF THE GENES ENCODING FOR THE AROMATASE AND THE RECEPTOR OF THE FOLLICLE STIMULATING HORMONE WERE HIGHER IN CONTAMINATED FISH THAN IN FISH FROM THE CLEAN SITE. FOR THE HORMONE RECEPTOR, THIS HYPERMETHYLATION WAS POSITIVELY CORRELATED WITH THE CONTAMINATION LEVEL OF FISH AND WAS ASSOCIATED WITH A DECREASE IN ITS TRANSCRIPTION LEVEL. IN ADDITION, WHEREAS GONAD GROWTH WAS ASSOCIATED WITH AN INCREASE IN DNA METHYLATION IN FISH FROM THE CLEAN SITE, NO CHANGES WERE OBSERVED IN CONTAMINATED FISH IN RESPONSE TO HORMONAL TREATMENT. FINALLY, A HIGHER GONAD GROWTH WAS OBSERVED IN FISH FROM THE REFERENCE SITE IN COMPARISON TO CONTAMINATED FISH. 2014 5 3632 37 INCORPORATING TRANSGENERATIONAL EPIGENETIC INHERITANCE INTO ECOLOGICAL RISK ASSESSMENT FRAMEWORKS. CHRONIC EXPOSURE TO ENVIRONMENTAL CONTAMINANTS CAN INDUCE HERITABLE "TRANSGENERATIONAL" MODIFICATIONS TO ORGANISMS, POTENTIALLY AFFECTING FUTURE ECOSYSTEM HEALTH AND FUNCTIONALITY. INCORPORATING TRANSGENERATIONAL EPIGENETIC HERITABILITY INTO RISK ASSESSMENT PROCEDURES HAS BEEN PREVIOUSLY SUGGESTED. HOWEVER, A CRITICAL REVIEW OF EXISTING LITERATURE YIELDED NUMEROUS STUDIES CLAIMING TRANSGENERATIONAL IMPACTS, WITH LITTLE COMPELLING EVIDENCE. THEREFORE, CONTAMINANT-INDUCED EPIGENETIC INHERITANCE MAY BE LESS COMMON THAN IS REPORTED IN THE LITERATURE. WE IDENTIFIED A NEED FOR MULTIGENERATION EPIGENETIC STUDIES THAT EXTEND BEYOND WHAT COULD BE DEEMED "DIRECT EXPOSURE" TO F1 AND F2 GAMETES AND ALSO INCLUDE SUBSEQUENT MULTIPLE NONEXPOSED GENERATIONS TO ADEQUATELY EVALUATE TRANSGENERATIONAL RECOVERY TIMES. ALSO, INCREASED EXPERIMENTAL REPLICATION IS REQUIRED TO ACCOUNT FOR THE HIGHLY VARIABLE NATURE OF EPIGENETIC RESPONSES AND APPARENT IRREPRODUCIBILITY OF CURRENT STUDIES. FURTHER, EPIGENETIC END POINTS NEED TO BE CORRELATED WITH OBSERVABLE DETRIMENTAL ORGANISM CHANGES BEFORE A NEED FOR RISK MANAGEMENT CAN BE PROPERLY DETERMINED. WE SUGGEST THAT EPIGENETIC-BASED CONTAMINANT STUDIES INCLUDE CONCENTRATIONS LOWER THAN CURRENT "EC(10-20)" OR "LOWEST OBSERVABLE EFFECT CONCENTRATIONS" FOR THE ORGANISM'S MOST SENSITIVE PHENOTYPIC END POINT, AS HIGHER CONCENTRATIONS ARE LIKELY ALREADY REGULATED. FINALLY, WE PROPOSE A REGULATORY FRAMEWORK AND OPTIMAL EXPERIMENTAL DESIGN THAT ENABLES TRANSGENERATIONAL EPIGENETIC EFFECTS TO BE ASSESSED AND INCORPORATED INTO CONVENTIONAL ECOTOXICOLOGICAL TESTING. 2017 6 1352 38 DEVELOPMENT AND APPLICATION OF THE ADVERSE OUTCOME PATHWAY FRAMEWORK FOR UNDERSTANDING AND PREDICTING CHRONIC TOXICITY: I. CHALLENGES AND RESEARCH NEEDS IN ECOTOXICOLOGY. TO ELUCIDATE THE EFFECTS OF CHEMICALS ON POPULATIONS OF DIFFERENT SPECIES IN THE ENVIRONMENT, EFFICIENT TESTING AND MODELING APPROACHES ARE NEEDED THAT CONSIDER MULTIPLE STRESSORS AND ALLOW RELIABLE EXTRAPOLATION OF RESPONSES ACROSS SPECIES. AN ADVERSE OUTCOME PATHWAY (AOP) IS A CONCEPT THAT PROVIDES A FRAMEWORK FOR ORGANIZING KNOWLEDGE ABOUT THE PROGRESSION OF TOXICITY EVENTS ACROSS SCALES OF BIOLOGICAL ORGANIZATION THAT LEAD TO ADVERSE OUTCOMES RELEVANT FOR RISK ASSESSMENT. IN THIS PAPER, WE FOCUS ON EXPLORING HOW THE AOP CONCEPT CAN BE USED TO GUIDE RESEARCH AIMED AT IMPROVING BOTH OUR UNDERSTANDING OF CHRONIC TOXICITY, INCLUDING DELAYED TOXICITY AS WELL AS EPIGENETIC AND TRANSGENERATIONAL EFFECTS OF CHEMICALS, AND OUR ABILITY TO PREDICT ADVERSE OUTCOMES. A BETTER UNDERSTANDING OF THE INFLUENCE OF SUBTLE TOXICITY ON INDIVIDUAL AND POPULATION FITNESS WOULD SUPPORT A BROADER INTEGRATION OF SUBLETHAL ENDPOINTS INTO RISK ASSESSMENT FRAMEWORKS. DETAILED MECHANISTIC KNOWLEDGE WOULD FACILITATE THE DEVELOPMENT OF ALTERNATIVE TESTING METHODS AS WELL AS HELP PRIORITIZE HIGHER TIER TOXICITY TESTING. WE ARGUE THAT TARGETED DEVELOPMENT OF AOPS SUPPORTS BOTH OF THESE ASPECTS BY PROMOTING THE ELUCIDATION OF MOLECULAR MECHANISMS AND THEIR CONTRIBUTION TO RELEVANT TOXICITY OUTCOMES ACROSS BIOLOGICAL SCALES. WE FURTHER DISCUSS INFORMATION REQUIREMENTS AND CHALLENGES IN APPLICATION OF AOPS FOR CHEMICAL- AND SITE-SPECIFIC RISK ASSESSMENT AND FOR EXTRAPOLATION ACROSS SPECIES. WE PROVIDE RECOMMENDATIONS FOR POTENTIAL EXTENSION OF THE AOP FRAMEWORK TO INCORPORATE INFORMATION ON EXPOSURE, TOXICOKINETICS AND SITUATION-SPECIFIC ECOLOGICAL CONTEXTS, AND DISCUSS COMMON INTERFACES THAT CAN BE EMPLOYED TO COUPLE AOPS WITH COMPUTATIONAL MODELING APPROACHES AND WITH EVOLUTIONARY LIFE HISTORY THEORY. THE EXTENDED AOP FRAMEWORK CAN SERVE AS A VENUE FOR INTEGRATION OF KNOWLEDGE DERIVED FROM VARIOUS SOURCES, INCLUDING EMPIRICAL DATA AS WELL AS MOLECULAR, QUANTITATIVE AND EVOLUTIONARY-BASED MODELS DESCRIBING SPECIES RESPONSES TO TOXICANTS. THIS WILL ALLOW A MORE EFFICIENT APPLICATION OF AOP KNOWLEDGE FOR QUANTITATIVE CHEMICAL- AND SITE-SPECIFIC RISK ASSESSMENT AS WELL AS FOR EXTRAPOLATION ACROSS SPECIES IN THE FUTURE. 2015 7 1247 47 CURRENT EVIDENCE FOR A ROLE OF EPIGENETIC MECHANISMS IN RESPONSE TO IONIZING RADIATION IN AN ECOTOXICOLOGICAL CONTEXT. THE ISSUE OF POTENTIAL LONG-TERM OR HEREDITARY EFFECTS FOR BOTH HUMANS AND WILDLIFE EXPOSED TO LOW DOSES (OR DOSE RATES) OF IONISING RADIATION IS A MAJOR CONCERN. CHRONIC EXPOSURE TO IONISING RADIATION, DEFINED AS AN EXPOSURE OVER A LARGE FRACTION OF THE ORGANISM'S LIFESPAN OR EVEN OVER SEVERAL GENERATIONS, CAN POSSIBLY HAVE CONSEQUENCES IN THE PROGENY. RECENT WORK HAS BEGUN TO SHOW THAT EPIGENETICS PLAYS AN IMPORTANT ROLE IN ADAPTATION OF ORGANISMS CHALLENGED TO ENVIRONMENTAL STIMULAE. CHANGES TO SO-CALLED EPIGENETIC MARKS SUCH AS HISTONE MODIFICATIONS, DNA METHYLATION AND NON-CODING RNAS RESULT IN ALTERED TRANSCRIPTOMES AND PROTEOMES, WITHOUT DIRECTLY CHANGING THE DNA SEQUENCE. MOREOVER, SOME OF THESE ENVIRONMENTALLY-INDUCED EPIGENETIC CHANGES TEND TO PERSIST OVER GENERATIONS, AND THUS, EPIGENETIC MODIFICATIONS ARE REGARDED AS THE CONDUITS FOR ENVIRONMENTAL INFLUENCE ON THE GENOME. HERE, WE REVIEW THE CURRENT KNOWLEDGE OF POSSIBLE INVOLVEMENT OF EPIGENETICS IN THE CASCADE OF RESPONSES RESULTING FROM ENVIRONMENTAL EXPOSURE TO IONISING RADIATION. IN ADDITION, FROM A COMPARISON OF LAB AND FIELD OBTAINED DATA, WE INVESTIGATE EVIDENCE ON RADIATION-INDUCED CHANGES IN THE EPIGENOME AND IN PARTICULAR THE TOTAL OR LOCUS SPECIFIC LEVELS OF DNA METHYLATION. THE CHALLENGES FOR FUTURE RESEARCH AND POSSIBLE USE OF CHANGES AS AN EARLY WARNING (BIOMARKER) OF RADIOSENSITIVITY AND INDIVIDUAL EXPOSURE IS DISCUSSED. SUCH A BIOMARKER COULD BE USED TO DETECT AND BETTER UNDERSTAND THE MECHANISMS OF TOXIC ACTION AND INTER/INTRA-SPECIES SUSCEPTIBILITY TO RADIATION WITHIN AN ENVIRONMENTAL RISK ASSESSMENT AND MANAGEMENT CONTEXT. 2019 8 1817 37 EFFECTS OF CHRONIC METAL EXPOSURE ON WILD FISH POPULATIONS REVEALED BY HIGH-THROUGHPUT CDNA SEQUENCING. GIVEN THE INHERENT VARIABILITY OF AQUATIC SYSTEMS, PREDICTING THE IN SITU EFFECTS OF CONTAMINANTS ON SUCH ECOSYSTEMS STILL REPRESENTS A MAJOR CHALLENGE FOR ECOTOXICOLOGY. IN THIS CONTEXT, TRANSCRIPTOMIC TOOLS CAN HELP IDENTIFY AND INVESTIGATE THE MECHANISMS OF TOXICITY BEYOND THE TRADITIONAL MORPHOMETRIC, PHYSIOLOGICAL AND POPULATION-LEVEL ENDPOINTS. IN THIS STUDY, WE USED THE 454 SEQUENCING TECHNOLOGY TO EXAMINE THE IN SITU EFFECTS OF CHRONIC METAL (CD, CU) EXPOSURE ON THE YELLOW PERCH (PERCA FLAVESCENS) TRANSCRIPTOME. TOTAL HEPATIC MRNA FROM FISH SAMPLED ALONG A POLYMETALLIC GRADIENT WAS EXTRACTED, REVERSE TRANSCRIBED, LABELED WITH UNIQUE BARCODE SEQUENCES AND SEQUENCED. THIS APPROACH ALLOWED US TO IDENTIFY CORRELATIONS BETWEEN THE TRANSCRIPTION LEVEL OF SINGLE GENES AND THE HEPATIC CONCENTRATIONS OF INDIVIDUAL METALS; 71% OF THE CORRELATIONS ESTABLISHED WERE NEGATIVE. CHRONIC METAL EXPOSURE WAS THUS ASSOCIATED WITH A DECREASE IN THE TRANSCRIPTION LEVELS OF NUMEROUS GENES INVOLVED IN PROTEIN BIOSYNTHESIS, IN THE IMMUNE SYSTEM, AND IN LIPID AND ENERGY METABOLISM. OUR RESULTS SUGGEST THAT THIS MARKED DECREASE COULD RESULT FROM AN IMPAIRMENT OF BILE ACID METABOLISM BY CD AND ENERGY RESTRICTION BUT ALSO FROM THE RECRUITMENT OF SEVERAL GENES INVOLVED IN EPIGENETIC MODIFICATIONS OF HISTONES AND DNA THAT LEAD TO GENE SILENCING. 2011 9 5113 27 POPULATION-LEVEL IMPACTS OF PESTICIDE-INDUCED CHRONIC EFFECTS ON INDIVIDUALS DEPEND MORE ON ECOLOGY THAN TOXICOLOGY. THE CURRENT METHOD FOR ASSESSING LONG-TERM RISK OF PESTICIDES TO MAMMALS IN THE EU IS BASED ON THE INDIVIDUAL RATHER THAN THE POPULATION-LEVEL AND LACKS ECOLOGICAL REALISM. HENCE THERE IS LITTLE POSSIBILITY FOR REGULATORY AUTHORITIES TO INCREASE ECOLOGICAL REALISM AND UNDERSTANDING OF RISKS AT THE POPULATION-LEVEL. HERE WE DEMONSTRATE HOW, USING ABM MODELLING, ASSESSMENTS AT THE POPULATION-LEVEL CAN BE OBTAINED EVEN FOR A PESTICIDE WITH COMPLEX LONG-TERM EFFECTS SUCH AS EPIGENETIC TRANSMISSION OF REPRODUCTIVE DEPRESSION. BY OBJECTIVELY FITTING NONLINEAR MODELS TO THE SIMULATION OUTPUTS IT WAS POSSIBLE TO COMPARE POPULATION DEPRESSION AND RECOVERY RATES FOR A RANGE OF SCENARIOS IN WHICH TOXICITY AND EXPOSURE FACTORS WERE VARIED. THE SYSTEM WAS DIFFERENTIALLY SENSITIVE TO THE VARIOUS FACTORS, BUT VOLE ECOLOGY AND BEHAVIOUR WERE AT LEAST AS IMPORTANT PREDICTORS OF POPULATION-LEVEL EFFECTS AS TOXICOLOGY. THIS EMPHASISES THE NEED FOR GREATER FOCUS ON ANIMAL ECOLOGY IN RISK ASSESSMENTS. 2009 10 6553 43 TRANSGENERATIONAL EFFECTS IN DNA METHYLATION, GENOTOXICITY AND REPRODUCTIVE PHENOTYPE BY CHRONIC ARSENIC EXPOSURE. AN EMERGING CONCERN IS THE INFLUENCES OF EARLY LIFE EXPOSURE TO ENVIRONMENTAL TOXICANTS ON OFFSPRING CHARACTERISTICS IN LATER LIFE. SINCE RECENT EVIDENCE SUGGESTS A TRANSGENERATIONAL TRANSFERENCE OF ABERRANT PHENOTYPES FROM EXPOSED-PARENTS TO NON-EXPOSED OFFSPRING RELATED TO ADULT-ONSET DISEASES INCLUDING REPRODUCTIVE PHENOTYPE. THE TRANSGENERATIONAL POTENTIAL OF ARSENIC A WELL KNOW GENOTOXIC AND EPIGENETIC MODIFIER AGENT HAS NOT BEEN ASSESSED IN MAMMALS UNTIL NOW. IN THIS EXPERIMENTAL STUDY, WE EVALUATED THE TRANSGENERATIONAL EFFECTS OF ARSENIC IN A RAT MODEL WITH CHRONIC EXPOSURE TO ARSENIC. RATS CHRONICALLY EXPOSED TO ARSENIC IN DRINKING WATER (1 MG AS(2)O(3)/ML) (F0) WERE MATED TO PRODUCE THE ARSENIC LINEAGE (F1, F2, AND F3). THE ARSENIC TOXIC EFFECTS ON WERE EVALUATED OVER THE FOUR GENERATIONS BY ANALYZING THE DNA METHYLATION PERCENTAGE, GENOTOXICITY IN WBC AND PHYSICAL AND REPRODUCTIVE PARAMETERS, INCLUDING SPERM QUALITY PARAMETERS AND HISTOPATHOLOGICAL EVALUATION OF THE GONADS. CHRONIC EXPOSURE TO ARSENIC CAUSED GENOTOXIC DAMAGE (F0-F3) DIFFERENT METHYLATION PATTERNS, ALTERATIONS IN PHYSICAL AND REPRODUCTIVE PARAMETERS, ABERRANT MORPHOLOGY IN THE OVARIES (F0 AND F1) AND TESTICLES (F1-F3), AND A DECREASE IN THE QUALITY OF SPERM (F0-F3, EXCEPT F2). PARENTAL CHRONIC ARSENIC EXPOSURE CAUSES TRANSGENERATIONAL GENOTOXICITY AND CHANGES IN GLOBAL DNA METHYLATION WHICH MIGHT BE ASSOCIATED WITH REPRODUCTIVE DEFECTS IN RATS. COMBINED WITH RECENT STUDIES REVEAL THAT DISTURBANCES IN THE EARLY LIFE OF AN INDIVIDUAL CAN AFFECT THE HEALTH OF LATER GENERATIONS. 2021 11 1885 46 ENDOCRINE DISRUPTORS IN SOIL: EFFECTS OF BISPHENOL A ON GENE EXPRESSION OF THE EARTHWORM EISENIA FETIDA. XENOBIOTICS SUCH AS BISPHENOL A (BPA), ARE PRESENT IN BIOSOLIDS, WHICH ARE APPLIED AS ORGANIC FERTILIZERS IN AGRICULTURAL FIELDS. THEIR EFFECTS ON SOIL LIFE HAVE BEEN POORLY ASSESSED, AND THIS IS PARTICULARLY IMPORTANT IN THE CASE OF EARTHWORMS, WHICH REPRESENT THE MAIN ANIMAL BIOMASS IN THIS MEDIUM. IN THE PRESENT WORK WE STUDY THE IMPACTS OF BPA ON GENE EXPRESSION OF EISENIA FETIDA, A WIDELY USED ECOTOXICOLOGICAL MODEL. CHRONIC SOIL TESTS AND ACUTE CONTACT TESTS WERE PERFORMED, AND GENE EXPRESSION WAS ANALYZED IN TOTAL TISSUE AND IN MASCULINE REPRODUCTIVE ORGANS OF THE EARTHWORMS. THE GENES STUDIED IN THIS RESEARCH PLAYED A ROLE IN ENDOCRINE PATHWAYS, DETOXIFICATION MECHANISMS, STRESS RESPONSE, EPIGENETICS, AND GENOTOXICITY. MOST OF THE GENES WERE IDENTIFIED FOR THE FIRST TIME, PROVIDING POTENTIALLY USEFUL BIOMARKERS FOR FUTURE ASSESSMENTS. FOR CHRONIC EXPOSURES, NO CHANGES WERE DETECTED IN WHOLE-BODY TISSUE; HOWEVER, MASCULINE REPRODUCTIVE ORGANS SHOWED CHANGES IN THE EXPRESSION OF GENES RELATED TO ENDOCRINE FUNCTION (ECR, MAPR, ADIPOR), EPIGENETIC MECHANISMS (DNMTS), GENOTOXICITY (PARP1), AND STRESS RESPONSES (HSC70 4). FOR ACUTE EXPOSURES, THE EXPRESSION OF ONE EPIGENETIC-RELATED GENE WAS ALTERED FOR BOTH WHOLE-BODY TISSUES AND MALE REPRODUCTIVE ORGANS (PIWI2). FURTHER CHANGES WERE DETECTED FOR WHOLE-BODY TISSUES INVOLVED IN DETOXIFICATION (METALLOTHIONEIN), STRESS (HSC70 4), AND GENOTOXICITY (PARP1) MECHANISMS. ACUTE EXPOSURE EFFECTS WERE ALSO TESTED IN WHOLE-BODY TISSUES OF JUVENILES, SHOWING CHANGES IN THE EXPRESSION OF METALLOTHIONEIN AND PIWI2. THE MOLECULAR CHANGES FOUND IN THE ANALYZED EARTHWORMS INDICATE THAT EXPOSURE TO BPA MAY HAVE NEGATIVE IMPLICATIONS IN THEIR POPULATIONS. PARTICULARLY INTERESTING ARE THE ALTERATIONS RELATED TO EPIGENETIC MECHANISMS, WHICH SUGGEST THAT FUTURE GENERATIONS MAY BE IMPACTED. THIS STUDY IS THE FIRST TO EVALUATE THE MOLECULAR EFFECTS OF BPA ON SOIL ORGANISMS, AND FURTHER ASSAYS WILL BE NECESSARY TO BETTER CHARACTERIZE THE TRUE ENVIRONMENTAL REPERCUSSIONS. CAPSULE: LEVELS OF GENE EXPRESSION IN TOTAL-BODY TISSUES AND MASCULINE REPRODUCTIVE ORGANS WERE ANALYZED IN EARTHWORMS AFTER EXPOSURE TO BISPHENOL A AND WE OBSERVED ASSOCIATED CHANGES IN DETOXIFICATION, ENDOCRINE, EPIGENETIC, GENOTOXIC AND STRESS PATHWAYS. 2018 12 73 35 A MULTI-GENERATIONAL STUDY ON LOW-DOSE BPA EXPOSURE IN WISTAR RATS: EFFECTS ON MATERNAL BEHAVIOR, FLAVOR INTAKE AND DEVELOPMENT. BISPHENOL A (BPA) IS A COMMON ENDOCRINE DISRUPTOR FOUND AS AN ENVIRONMENTAL AND FOOD CONTAMINANT. IT EXERTS BOTH DEVELOPMENTAL AND BEHAVIORAL EFFECTS, MAINLY WHEN EXPOSURE OCCURS IN EARLY LIFE. THE AIM OF THIS STUDY WAS TO DETERMINE THE MULTI-GENERATIONAL EFFECTS OF CHRONIC, HUMAN-RELEVANT LOW-DOSE EXPOSURE TO BPA ON DEVELOPMENT, MATERNAL BEHAVIOR AND FLAVOR PREFERENCE IN WISTAR RATS. BPA WAS ORALLY ADMINISTERED AT A DAILY DOSE OF 5 MUG/KG BODY WEIGHT TO F0 PREGNANT DAMS FROM THE FIRST DAY OF GESTATION (GD 1) UNTIL THE LAST DAY OF LACTATION (LD 21), AND THEN TO F1 OFFSPRING FROM WEANING (PND 21) TO ADULTHOOD (PND 100). F2 OFFSPRING WERE NOT EXPOSED. DEVELOPMENT AND CLINICAL SIGNS OF TOXICITY WERE ASSESSED DAILY. MATERNAL BEHAVIOR WAS EVALUATED BY OBSERVING NURSING AND PUP-CARING ACTIONS, AS WELL AS "NON-MATERNAL" BEHAVIORS IN F0 AND F1 DAMS FROM PARTURITION UNTIL LD 8. THE FLAVOR PREFERENCES OF F1 AND F2 OFFSPRING WERE EVALUATED BASED ON THE INTAKE OF SWEET, SALT AND FAT SOLUTIONS USING THE TWO-BOTTLE CHOICE TEST ON PND 21-34 AND PND 86-99. BPA EXPOSURE: 1) DECREASED MATERNAL BEHAVIOR IN F1 DAMS, 2) CAUSED DEVELOPMENTAL DEFECTS IN BOTH F1 AND F2 OFFSPRING, WITH A NOTICEABLE DECREASE IN ANOGENITAL DISTANCE IN MALE RATS, AND 3) DID NOT AFFECT FLAVORED SOLUTION INTAKE IN F1, BUT INDUCED CHANGES IN SWEET PREFERENCE IN F2 JUVENILES AND IN SALT AND FAT SOLUTION INTAKES IN F2 ADULTS, AND 4) INDUCED A BODY WEIGHT INCREASE IN THE F2 GENERATION ONLY, WHEREAS FOOD INTAKE AND WATER CONSUMPTION DID NOT CHANGE. TAKEN AS A WHOLE, OUR FINDINGS SHOWED THAT BOTH GESTATIONAL (F0) AND LIFELONG (F1) EXPOSURES TO A HUMAN-RELEVANT DOSE OF BPA COULD INDUCE MULTI-GENERATIONAL EFFECTS ON BOTH DEVELOPMENT AND BEHAVIOR. THESE RESULTS SUGGEST POSSIBLE SELECTIVE NEUROENDOCRINE DEFECTS AND/OR EPIGENETIC CHANGES CAUSED BY BPA EXPOSURE. 2014 13 4009 39 LOW LEVELS OF CD INDUCE PERSISTING EPIGENETIC MODIFICATIONS AND ACCLIMATION MECHANISMS IN THE EARTHWORM LUMBRICUS TERRESTRIS. TOXIC EFFECTS OF CADMIUM (CD), A COMMON SOIL POLLUTANT, ARE STILL NOT VERY WELL UNDERSTOOD, PARTICULARLY IN REGARD TO ITS EPIGENETIC IMPACT. THEREFORE, THE AIM OF THIS STUDY WAS TO ASSESS DNA METHYLATION CHANGES AND THEIR PERSISTENCE IN THE EARTHWORM LUMBRICUS TERRESTRIS UPON CHRONIC LOW DOSE CD EXPOSURE USING METHYLATION SENSITIVE AMPLIFICATION POLYMORPHISM (MSAP). MOREOVER, THE BIOMARKER RESPONSE AND FITNESS OF THE EARTHWORMS, AS WELL AS THE EXPRESSION OF DETOXIFICATION-RELATED GENES (METALLOTHIONEIN (MT) AND PHYTOCHELATIN SYNTHASE (PCS)) WAS EVALUATED. LOW LEVELS OF CD CAUSED AN INCREASE IN GENOME-WIDE DNA METHYLATION, WHICH REMAINED PARTLY MODIFIED, EVEN AFTER SEVERAL MONTHS OF RECOVERY IN UNPOLLUTED SOIL. INCREASED CELLULAR STRESS SEEMED TO DECREASE AFTER TWO WEEKS OF EXPOSURE WHEREAS FITNESS PARAMETERS REMAINED UNAFFECTED BY CD, PROBABLY AS A RESULT FROM THE ACTIVATION OF DETOXIFICATION MECHANISMS LIKE THE EXPRESSION OF MTS. INTERESTINGLY, EVEN THOUGH THE LEVEL OF CD EXPOSURE WAS VERY LOW, MT EXPRESSION LEVELS INDICATE THE DEVELOPMENT OF ACCLIMATION MECHANISMS. TAKEN TOGETHER, THIS STUDY DEMONSTRATES THAT ACCLIMATION, AS WELL AS EPIGENETIC MODIFICATIONS CAN OCCUR ALREADY IN MODERATELY POLLUTED ENVIRONMENTS. IN ADDITION, THESE EFFECTS CAN HAVE LONG-LASTING IMPACTS ON KEY SPECIES OF SOIL INVERTEBRATES AND MIGHT PERSIST LONG AFTER THE ACTUAL HEAVY METAL CHALLENGE HAS PASSED. 2017 14 6552 42 TRANSGENERATIONAL DNA METHYLATION CHANGES IN DAPHNIA MAGNA EXPOSED TO CHRONIC GAMMA IRRADIATION. OUR AIM WAS TO INVESTIGATE EPIGENETIC CHANGES IN DAPHNIA MAGNA AFTER A 25-DAY CHRONIC EXTERNAL GAMMA IRRADIATION (GENERATION F0 EXPOSED TO 6.5 MUGY.H(-1) OR 41.3 MGY.H(-1)) AND THEIR POTENTIAL INHERITANCE BY SUBSEQUENT RECOVERING GENERATIONS, NAMELY, F2 (EXPOSED AS GERMLINE CELLS IN F1 EMBRYOS) AND F3 (THE FIRST TRULY UNEXPOSED GENERATION). EFFECTS ON SURVIVAL, GROWTH, AND REPRODUCTION WERE OBSERVED AND DNA WAS EXTRACTED FOR WHOLE-GENOME BISULFITE SEQUENCING IN ALL GENERATIONS. RESULTS SHOWED EFFECTS ON REPRODUCTION IN F0 BUT NO EFFECT IN THE SUBSEQUENT GENERATIONS F1, F2, AND F3. IN CONTRAST, WE OBSERVED SIGNIFICANT METHYLATION CHANGES AT SPECIFIC CPG POSITIONS IN EVERY GENERATION INDEPENDENT OF DOSE RATE, WITH A MAJORITY OF HYPOMETHYLATION. SOME OF THESE CHANGES WERE SHARED BETWEEN DOSE RATES AND BETWEEN GENERATIONS. ASSOCIATED GENE FUNCTIONS INCLUDED GENE FAMILIES AND GENES THAT WERE PREVIOUSLY SHOWN TO PLAY ROLES DURING EXPOSURE TO IONIZING RADIATION. COMMON METHYLATION CHANGES DETECTED BETWEEN GENERATIONS F2 AND F3 CLEARLY SHOWED THAT EPIGENETIC MODIFICATIONS CAN BE TRANSMITTED TO UNEXPOSED GENERATIONS, MOST LIKELY THROUGH THE GERMLINE, WITH POTENTIAL IMPLICATIONS FOR ENVIRONMENTAL RISK. 2018 15 5450 37 REPRODUCTIVE TOXICITY OF COMBINED EFFECTS OF ENDOCRINE DISRUPTORS ON HUMAN REPRODUCTION. CONFLUENCE OF ENVIRONMENTAL, GENETIC, AND LIFESTYLE VARIABLES IS RESPONSIBLE FOR DETERIORATION OF HUMAN FECUNDITY. ENDOCRINE DISRUPTORS OR ENDOCRINE DISRUPTING CHEMICALS (EDCS) MAY BE FOUND IN A VARIETY OF FOODS, WATER, AIR, BEVERAGES, AND TOBACCO SMOKE. IT HAS BEEN DEMONSTRATED IN EXPERIMENTAL INVESTIGATIONS THAT A WIDE RANGE OF ENDOCRINE DISRUPTING CHEMICALS HAVE NEGATIVE EFFECTS ON HUMAN REPRODUCTIVE FUNCTION. HOWEVER, EVIDENCE ON THE REPRODUCTIVE CONSEQUENCES OF HUMAN EXPOSURE TO ENDOCRINE DISRUPTING CHEMICALS IS SPARSE AND/OR CONFLICTING IN THE SCIENTIFIC LITERATURE. THE COMBINED TOXICOLOGICAL ASSESSMENT IS A PRACTICAL METHOD FOR ASSESSING THE HAZARDS OF COCKTAILS OF CHEMICALS, CO-EXISTING IN THE ENVIRONMENT. THE CURRENT REVIEW PROVIDES A COMPREHENSIVE OVERVIEW OF STUDIES EMPHASIZING THE COMBINED TOXICITY OF ENDOCRINE DISRUPTING CHEMICALS ON HUMAN REPRODUCTION. ENDOCRINE DISRUPTING CHEMICALS INTERACT WITH EACH OTHER TO DISRUPT THE DIFFERENT ENDOCRINE AXES, RESULTING IN SEVERE GONADAL DYSFUNCTIONS. TRANSGENERATIONAL EPIGENETIC EFFECTS HAVE ALSO BEEN INDUCED IN GERM CELLS, MOSTLY THROUGH DNA METHYLATION AND EPIMUTATIONS. SIMILARLY, AFTER ACUTE OR CHRONIC EXPOSURE TO ENDOCRINE DISRUPTING CHEMICALS COMBINATIONS, INCREASED OXIDATIVE STRESS (OS), ELEVATED ANTIOXIDANT ENZYMATIC ACTIVITY, DISRUPTED REPRODUCTIVE CYCLE, AND REDUCED STEROIDOGENESIS ARE OFTEN REPORTED CONSEQUENCES. THE ARTICLE ALSO DISCUSSES THE CONCENTRATION ADDITION (CA) AND INDEPENDENT ACTION (IA) PREDICTION MODELS, WHICH REVEAL THE IMPORTANCE OF VARIOUS SYNERGISTIC ACTIONS OF ENDOCRINE DISRUPTING CHEMICALS MIXTURES. MORE CRUCIALLY, THIS EVIDENCE-BASED STUDY ADDRESSES THE RESEARCH LIMITATIONS AND INFORMATION GAPS, AS WELL AS PARTICULARLY PRESENTS THE FUTURE RESEARCH VIEWS ON COMBINED ENDOCRINE DISRUPTING CHEMICALS TOXICITY ON HUMAN REPRODUCTION. 2023 16 3119 40 GESTATIONAL EXPOSURE TO PARTICULATE AIR POLLUTION EXACERBATES THE GROWTH PHENOTYPES INDUCED BY PRECONCEPTION PATERNAL ALCOHOL USE: A MULTIPLEX MODEL OF EXPOSURE. IT IS NOW CLEAR THAT PARENTAL HISTORIES OF DRUG USE, TOXICANT EXPOSURE, AND SOCIAL STRESS ALL HAVE A SIGNIFICANT INFLUENCE ON THE HEALTH AND DEVELOPMENT OF THE NEXT GENERATION. HOWEVER, THE ABILITY OF EPIGENETIC PARENTAL LIFE MEMORIES TO INTERACT WITH SUBSEQUENT GESTATIONAL EXPOSURES AND CUMULATIVELY MODIFY THE DEVELOPMENTAL TRAJECTORY OF THE OFFSPRING REMAINS AN UNEXPLORED PERSPECTIVE IN TOXICOLOGY. STUDIES FROM OUR LABORATORY HAVE IDENTIFIED MALE-SPECIFIC POSTNATAL GROWTH RESTRICTION IN A MOUSE MODEL OF CHRONIC, PRECONCEPTION PATERNAL ALCOHOL EXPOSURE. THE GOAL OF THE CURRENT STUDY WAS TO DETERMINE IF PATERNAL ALCOHOL USE, BEFORE CONCEPTION, COULD MODIFY THE SUSCEPTIBILITY OF THE OFFSPRING TO A COMPLETELY SEPARATE EXPOSURE ENCOUNTERED BY THE MOTHER DURING PREGNANCY. IN INDEPENDENT EXPERIMENTS, WE PREVIOUSLY IDENTIFIED ALTERED DEVELOPMENTAL PROGRAMMING AND INCREASED MARKERS OF SEVERE ASTHMA INDUCED BY GESTATIONAL EXPOSURE TO PARTICULATE AIR POLLUTION. IN THIS STUDY, MALE MICE WERE EXPOSED TO EITHER THE CONTROL OR ALCOHOL PRECONCEPTION TREATMENTS, THEN MATED TO NAIVE FEMALES, WHICH WE SUBSEQUENTLY EXPOSED TO AN ULTRAFINE MIXTURE OF PARTICULATE MATTER VIA INHALATION. INDIVIDUALLY, NEITHER PRECONCEPTION PATERNAL DRINKING NOR GESTATIONAL EXPOSURES TO PARTICULATE AIR POLLUTION IMPACTED THE POSTNATAL GROWTH OF FEMALE OFFSPRING. HOWEVER, WHEN BOTH EXPOSURES WERE COMBINED, FEMALES DISPLAYED A 30% REDUCTION IN WEIGHT GAIN. UNEXPECTEDLY, THIS EXPOSURE PARADIGM RESULTED IN A DRAMATIC POSTNATAL INCREASE IN LITTER LOSS DUE TO MATERNAL CANNIBALISM, WHICH PREVENTED ADDITIONAL MEASURES OF OFFSPRING HEALTH. THESE PRELIMINARY STUDIES PROVIDE EVIDENCE OF A COMPLEX INTERPLAY BETWEEN PRECONCEPTION LIFE HISTORY AND INTRAUTERINE ENVIRONMENTAL FACTORS IN THE CONTROL OF POSTNATAL GROWTH. 2020 17 1106 39 COMBINED TOXICITY OF ENDOCRINE-DISRUPTING CHEMICALS: A REVIEW. THE COMBINED TOXICOLOGICAL ASSESSMENT PROVIDES A REALISTIC APPROACH FOR HAZARD EVALUATION OF CHEMICAL COCKTAILS THAT CO-EXISTED IN THE ENVIRONMENT. THIS REVIEW PROVIDES A HOLISTIC INSIGHT INTO THE STUDIES HIGHLIGHTING THE MIXTURE TOXICITY OF THE ENDOCRINE-DISRUPTING CHEMICALS (EDCS), ESPECIALLY FOCUSING ON THE SCREENING OF BIOCHEMICAL PATHWAYS AND OTHER TOXICOGENETIC ENDPOINTS. REVIEWED LITERATURE SHOWED THAT NUMEROUS MULTIPLEXED TOXICOGENOMIC TECHNIQUES WERE APPLIED TO DETERMINE REPRODUCTIVE EFFECTS IN VERTEBRATES, BUT LIMITED STUDIES WERE FOUND IN NON-MAMMALIAN SPECIES AFTER MIXTURE CHEMICAL EXPOSURE. FURTHER, WE FOUND THAT THE EXPERIMENTAL DESIGN AND CONCENTRATION SELECTION ARE THE TWO IMPORTANT PARAMETERS IN MIXTURE TOXICITY STUDIES THAT SHOULD BE TIME- AND COST-EFFECTIVE, HIGHLY PRECISE, AND ENVIRONMENTALLY RELEVANT. A SUMMARY OF EDC MIXTURES AFFECTING THE THYROID AXIS, ESTROGEN AXIS, ANDROGEN AXIS, GROWTH STRESS, AND IMMUNE SYSTEM VIA IN VIVO BIOASSAYS WAS ALSO PRESENTED. IT IS INTERESTING TO MENTION THAT MAJORITY OF ESTROGENIC EFFECTS OF THE MIXTURES WERE SEX-DEPENDENT, PARTICULARLY OBSERVED IN MALE FISH AS COMPARED TO FEMALE FISH. FURTHER, THE ANDROGEN AXIS WAS PERTURBED WITH SERIOUS MALFORMATIONS IN MALE RAT TESTIS (EPIDIDYMAL OR GUBERNACULAR LESIONS, AND DECIDUOUS SPERMATIDS). ALSO, TRANSGENERATIONAL EPIGENETIC EFFECTS WERE PROMOTED IN THE F(3) AND F(4) GENERATIONS IN THE FORM OF DNA METHYLATION EPIMUTATIONS IN SPERM, INCREASING POLYCYSTIC OVARIES AND REDUCING THE OFFSPRING. SIMILARLY, INCREASED OXIDATIVE STRESS, HIGH ANTIOXIDANT ENZYMATIC ACTIVITIES, DISTURBED ESTROUS CYCLE, AND DECREASED STEROIDOGENESIS WERE THE COMMONLY FOUND EFFECTS AFTER ACUTE OR CHRONIC EXPOSURE TO EDC MIXTURES. IMPORTANTLY, THE CONCENTRATION ADDITION (CA) AND INDEPENDENT ACTION (IA) MODELS BECAME MORE PREVALENT AND SUITABLE PREDICTIVE MODELS TO UNVEIL THE PROMINENCE OF SYNERGISTIC ESTROGENIC AND ANTI-ANDROGENIC EFFECTS OF CHEMICAL MIXTURES. MORE IMPORTANTLY, THIS REVIEW ENCOMPASSES THE RESEARCH CHALLENGES AND GAPS IN THE EXISTING KNOWLEDGE AND SPECIFIC FUTURE RESEARCH PERSPECTIVES ON COMBINED TOXICITY. 2021 18 4008 41 LOW DOSE OF URANIUM INDUCES MULTIGENERATIONAL EPIGENETIC EFFECTS IN RAT KIDNEY. PURPOSE: A PROTOCOL OF CHRONIC EXPOSURE TO LOW DOSE OF URANIUM WAS ESTABLISHED IN ORDER TO DISTINGUISH THE SEXUAL DIFFERENCES AND THE DEVELOPMENTAL PROCESS THAT ARE CRITICAL WINDOWS FOR EPIGENETIC EFFECTS OVER GENERATIONS. METHODS: BOTH MALE AND FEMALE RATS WERE CONTAMINATED THROUGH THEIR DRINKING WATER WITH A NON-TOXIC SOLUTION OF URANYL NITRATE FOR 9 MONTHS. THE EXPOSED GENERATION (F0) AND THE FOLLOWING TWO GENERATIONS (F1 AND F2) WERE EXAMINED. CLINICAL MONITORING, GLOBAL DNA METHYLATION PROFILE AND DNA METHYLTRANSFERASES (DNMTS) GENE EXPRESSION WERE ANALYZED IN KIDNEYS. RESULTS: WHILE THE BODY WEIGHT OF F1 MALES INCREASED, A SMALL DECREASE IN KIDNEY AND BODY WEIGHT WAS OBSERVED IN F2 MALES. IN ADDITION, GLOBAL DNA HYPERMETHYLATION PROFILE IN KIDNEY CELLS WAS OBSERVED IN F1 AND F2 MALES. QPCR RESULTS REVEAL A SIGNIFICANT INCREASE OF METHYLTRANSFERASE GENES EXPRESSION (DNMT1 AND DNMT3A) FOR F2 FEMALES. CONCLUSIONS: IN THE FIELD OF PUBLIC HEALTH POLICY AND TO RAISE ATTENTION TO GENERATIONAL EFFECTS FOR THE RISK ASSESSMENT OF THE ENVIRONMENTAL EXPOSURES, LOW DOSES OF URANIUM DO NOT IMPLY CLINICAL EFFECTS ON ADULT EXPOSED RATS. HOWEVER, OUR RESULTS CONFIRM THE IMPORTANCE OF THE DEVELOPMENTAL WINDOWS' SENSITIVITY IN ADDITION TO THE SEXUAL DIMORPHISMS OF THE OFFSPRING. 2018 19 3566 27 IMPACT OF HEAVY METALS ON THE FEMALE REPRODUCTIVE SYSTEM. INTRODUCTION: IT HAS BEEN RECOGNIZED THAT ENVIRONMENTAL POLLUTION CAN AFFECT THE QUALITY OF HEALTH OF THE HUMAN POPULATION. HEAVY METALS ARE AMONG THE GROUP OF HIGHLY EMITTED CONTAMINANTS AND THEIR ADVERSE EFFECT OF LIVING ORGANISMS HAS BEEN WIDELY STUDIED IN RECENT DECADES. LIFESTYLE AND QUALITY OF THE AMBIENT ENVIRONMENT ARE AMONG THESE FACTORS WHICH CAN MAINLY CONTRIBUTE TO THE HEAVY METALS EXPOSURE IN HUMANS. OBJECTIVE: A REVIEW OF LITERATURE LINKING HEAVY METALS AND THE FEMALE REPRODUCTIVE SYSTEM AND DESCRIPTION OF THE POSSIBLE ASSOCIATIONS WITH EMISSION AND EXPOSURE OF HEAVY METALS AND IMPAIRMENTS OF FEMALE REPRODUCTIVE SYSTEM ACCORDING TO CURRENT KNOWLEDGE. RESULTS: THE POTENTIAL HEALTH DISORDERS CAUSED BY CHRONIC OR ACUTE HEAVY METALS TOXICITY INCLUDE IMMUNODEFICIENCY, OSTEOPOROSIS, NEURODEGENERATION AND ORGAN FAILURES. POTENTIAL LINKAGES OF HEAVY METALS CONCENTRATION FOUND IN DIFFERENT HUMAN ORGANS AND BLOOD WITH OESTROGEN-DEPENDENT DISEASES SUCH AS BREAST CANCER, ENDOMETRIAL CANCER, ENDOMETRIOSIS AND SPONTANEOUS ABORTIONS, AS WELL AS PRE-TERM DELIVERIES, STILLBIRTHS AND HYPOTROPHY, HAVE ALSO BEEN REPORTED. CONCLUSIONS: ENVIRONMENTAL DETERIORATION CAN LEAD TO THE ELEVATED RISK OF HUMAN EXPOSURE TO HEAVY METALS, AND CONSEQUENTLY, HEALTH IMPLICATIONS INCLUDING DISTURBANCES IN REPRODUCTION. IT IS THEREFORE IMPORTANT TO CONTINUE THE INVESTIGATIONS ON METAL-INDUCED MECHANISMS OF FERTILITY IMPAIRMENT ON THE GENETIC, EPIGENETIC AND BIOCHEMICAL LEVEL. 2015 20 1767 39 EARLY-LIFE EXPOSURE TO ENDOCRINE DISRUPTING CHEMICALS AND LATER-LIFE HEALTH OUTCOMES: AN EPIGENETIC BRIDGE? A GROWING BODY OF EVIDENCE DEMONSTRATES THAT ADVERSE EVENTS EARLY IN DEVELOPMENT, AND PARTICULARLY DURING INTRAUTERINE LIFE, MAY PROGRAM RISKS FOR DISEASES IN ADULT LIFE. INCREASING EVIDENCE HAS BEEN ACCUMULATED INDICATING THE IMPORTANT ROLE OF EPIGENETIC REGULATION INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND MIRNAS IN DEVELOPMENTAL PROGRAMMING. AMONG THE ENVIRONMENTAL FACTORS WHICH PLAY AN IMPORTANT ROLE IN PROGRAMMING OF CHRONIC PATHOLOGIES, THE ENDOCRINE-DISRUPTING CHEMICALS (EDCS) THAT HAVE ESTROGENIC, ANTI-ESTROGENIC, AND ANTI-ANDROGENIC ACTIVITY ARE OF SPECIFIC CONCERN BECAUSE THE DEVELOPING ORGANISM IS EXTREMELY SENSITIVE TO PERTURBATION BY SUBSTANCES WITH HORMONE-LIKE ACTIVITY. AMONG EDCS, THERE ARE MANY SUBSTANCES THAT ARE CONSTANTLY PRESENT IN THE MODERN HUMAN ENVIRONMENT OR ARE IN WIDESPREAD USE, INCLUDING DIOXIN AND DIOXIN-LIKE COMPOUNDS, PHTHALATES, AGRICULTURAL PESTICIDES, POLYCHLORINATED BIPHENYLS, INDUSTRIAL SOLVENTS, PHARMACEUTICALS, AND HEAVY METALS. APART FROM THEIR COMMON ENDOCRINE ACTIVE PROPERTIES, SEVERAL EDCS HAVE BEEN SHOWN TO DISRUPT DEVELOPMENTAL EPIGENOMIC PROGRAMMING. THE PURPOSE OF THIS REVIEW IS TO PROVIDE A SUMMARY OF RECENT RESEARCH FINDINGS WHICH INDICATE THAT EXPOSURE TO EDCS DURING IN-UTERO AND/OR NEONATAL DEVELOPMENT CAN CAUSE LONG-TERM HEALTH OUTCOMES VIA MECHANISMS OF EPIGENETIC MEMORY. 2014