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Concerns have been raised regarding the potential adverse health effects of the ubiquitous herbicide glyphosate. Here, we investigated long-term effects of developmental exposure to a glyphosate-based herbicide (GBH) by analyzing serum melatonin levels and cellular changes in the striatum of adult male rats (90 days old). Pregnant and lactating rats were exposed to 3% GBH (0.36% glyphosate) through drinking water from gestational day 5 to postnatal day 15. The offspring showed reduced serum melatonin levels (43%) at the adult age compared with the control group. The perinatal exposure to GBH also induced long-term oxidative stress-related changes in the striatum demonstrated by increased lipid peroxidation (45%) and DNA/RNA oxidation (39%) together with increased protein levels of the antioxidant enzymes, superoxide dismutase (SOD1, 24%), glutamate-cysteine ligase (GCLC, 58%), and glutathione peroxidase 1 (GPx1, 31%). Moreover, perinatal GBH exposure significantly increased the total number of neurons (20%) and tyrosine hydroxylase (TH)-positive neurons (38%) in the adult striatum. Mechanistic in vitro studies with primary rat pinealocytes exposed to 50 mu M glyphosate demonstrated a decreased melatonin secretion partially through activation of metabotropic glutamate receptor 3 (mGluR3), while higher glyphosate levels (100 or 500 mu M) also reduced the pinealocyte viability. Since decreased levels of the important antioxidant and neuroprotector melatonin have been associated with an increased risk of developing neurodegenerative disorders, this demonstrates the need to consider the melatonin hormone system as a central endocrine-related target of glyphosate and other environmental contaminants.

Concerns have been raised regarding the potential adverse health effects of the ubiquitous herbicide glyphosate. Here, we investigated long-term effects of developmental exposure to a glyphosate-based herbicide (GBH) by analyzing serum melatonin levels and cellular changes in the striatum of adult male rats (90 days old). Pregnant and lactating rats were exposed to 3% GBH (0.36% glyphosate) through drinking water from gestational day 5 to postnatal day 15. The offspring showed reduced serum melatonin levels (43%) at the adult age compared with the control group. The perinatal exposure to GBH also induced long-term oxidative stress-related changes in the striatum demonstrated by increased lipid peroxidation (45%) and DNA/RNA oxidation (39%) together with increased protein levels of the antioxidant enzymes, superoxide dismutase (SOD1, 24%), glutamate-cysteine ligase (GCLC, 58%), and glutathione peroxidase 1 (GPx1, 31%). Moreover, perinatal GBH exposure significantly increased the total number of neurons (20%) and tyrosine hydroxylase (TH)-positive neurons (38%) in the adult striatum. Mechanistic in vitro studies with primary rat pinealocytes exposed to 50 mu M glyphosate demonstrated a decreased melatonin secretion partially through activation of metabotropic glutamate receptor 3 (mGluR3), while higher glyphosate levels (100 or 500 mu M) also reduced the pinealocyte viability. Since decreased levels of the important antioxidant and neuroprotector melatonin have been associated with an increased risk of developing neurodegenerative disorders, this demonstrates the need to consider the melatonin hormone system as a central endocrine-related target of glyphosate and other environmental contaminants.

Concerns have been raised regarding the potential adverse health effects of the ubiquitous herbicide glyphosate. Here, we investigated long-term effects of developmental exposure to a glyphosate-based herbicide (GBH) by analyzing serum melatonin levels and cellular changes in the striatum of adult male rats (90 days old). Pregnant and lactating rats were exposed to 3% GBH (0.36% glyphosate) through drinking water from gestational day 5 to postnatal day 15. The offspring showed reduced serum melatonin levels (43%) at the adult age compared with the control group. The perinatal exposure to GBH also induced long-term oxidative stress-related changes in the striatum demonstrated by increased lipid peroxidation (45%) and DNA/RNA oxidation (39%) together with increased protein levels of the antioxidant enzymes, superoxide dismutase (SOD1, 24%), glutamate–cysteine ligase (GCLC, 58%), and glutathione peroxidase 1 (GPx1, 31%). Moreover, perinatal GBH exposure significantly increased the total number of neurons (20%) and tyrosine hydroxylase (TH)-positive neurons (38%) in the adult striatum. Mechanistic in vitro studies with primary rat pinealocytes exposed to 50 µM glyphosate demonstrated a decreased melatonin secretion partially through activation of metabotropic glutamate receptor 3 (mGluR3), while higher glyphosate levels (100 or 500 µM) also reduced the pinealocyte viability. Since decreased levels of the important antioxidant and neuroprotector melatonin have been associated with an increased risk of developing neurodegenerative disorders, this demonstrates the need to consider the melatonin hormone system as a central endocrine-related target of glyphosate and other environmental contaminants.

Concerns have been raised regarding the potential adverse health effects of the ubiquitous herbicide glyphosate. Here, we investigated long-term effects of developmental exposure to a glyphosate-based herbicide (GBH) by analyzing serum melatonin levels and cellular changes in the striatum of adult male rats (90 days old). Pregnant and lactating rats were exposed to 3% GBH (0.36% glyphosate) through drinking water from gestational day 5 to postnatal day 15. The offspring showed reduced serum melatonin levels (43%) at the adult age compared with the control group. The perinatal exposure to GBH also induced long-term oxidative stress-related changes in the striatum demonstrated by increased lipid peroxidation (45%) and DNA/RNA oxidation (39%) together with increased protein levels of the antioxidant enzymes, superoxide dismutase (SOD1, 24%), glutamate-cysteine ligase (GCLC, 58%), and glutathione peroxidase 1 (GPx1, 31%). Moreover, perinatal GBH exposure significantly increased the total number of neurons (20%) and tyrosine hydroxylase (TH)-positive neurons (38%) in the adult striatum. Mechanistic in vitro studies with primary rat pinealocytes exposed to 50 mu M glyphosate demonstrated a decreased melatonin secretion partially through activation of metabotropic glutamate receptor 3 (mGluR3), while higher glyphosate levels (100 or 500 mu M) also reduced the pinealocyte viability. Since decreased levels of the important antioxidant and neuroprotector melatonin have been associated with an increased risk of developing neurodegenerative disorders, this demonstrates the need to consider the melatonin hormone system as a central endocrine-related target of glyphosate and other environmental contaminants.

Concerns have been raised regarding the potential adverse health effects of the ubiquitous herbicide glyphosate. Here, we investigated long-term effects of developmental exposure to a glyphosate-based herbicide (GBH) by analyzing serum melatonin levels and cellular changes in the striatum of adult male rats (90 days old). Pregnant and lactating rats were exposed to 3% GBH (0.36% glyphosate) through drinking water from gestational day 5 to postnatal day 15. The offspring showed reduced serum melatonin levels (43%) at the adult age compared with the control group. The perinatal exposure to GBH also induced long-term oxidative stress-related changes in the striatum demonstrated by increased lipid peroxidation (45%) and DNA/RNA oxidation (39%) together with increased protein levels of the antioxidant enzymes, superoxide dismutase (SOD1, 24%), glutamate-cysteine ligase (GCLC, 58%), and glutathione peroxidase 1 (GPx1, 31%). Moreover, perinatal GBH exposure significantly increased the total number of neurons (20%) and tyrosine hydroxylase (TH)-positive neurons (38%) in the adult striatum. Mechanistic in vitro studies with primary rat pinealocytes exposed to 50 mu M glyphosate demonstrated a decreased melatonin secretion partially through activation of metabotropic glutamate receptor 3 (mGluR3), while higher glyphosate levels (100 or 500 mu M) also reduced the pinealocyte viability. Since decreased levels of the important antioxidant and neuroprotector melatonin have been associated with an increased risk of developing neurodegenerative disorders, this demonstrates the need to consider the melatonin hormone system as a central endocrine-related target of glyphosate and other environmental contaminants.

Concerns have been raised regarding the potential adverse health effects of the ubiquitous herbicide glyphosate. Here, we investigated long-term effects of developmental exposure to a glyphosate-based herbicide (GBH) by analyzing serum melatonin levels and cellular changes in the striatum of adult male rats (90 days old). Pregnant and lactating rats were exposed to 3% GBH (0.36% glyphosate) through drinking water from gestational day 5 to postnatal day 15. The offspring showed reduced serum melatonin levels (43%) at the adult age compared with the control group. The perinatal exposure to GBH also induced long-term oxidative stress-related changes in the striatum demonstrated by increased lipid peroxidation (45%) and DNA/RNA oxidation (39%) together with increased protein levels of the antioxidant enzymes, superoxide dismutase (SOD1, 24%), glutamate-cysteine ligase (GCLC, 58%), and glutathione peroxidase 1 (GPx1, 31%). Moreover, perinatal GBH exposure significantly increased the total number of neurons (20%) and tyrosine hydroxylase (TH)-positive neurons (38%) in the adult striatum. Mechanistic in vitro studies with primary rat pinealocytes exposed to 50 mu M glyphosate demonstrated a decreased melatonin secretion partially through activation of metabotropic glutamate receptor 3 (mGluR3), while higher glyphosate levels (100 or 500 mu M) also reduced the pinealocyte viability. Since decreased levels of the important antioxidant and neuroprotector melatonin have been associated with an increased risk of developing neurodegenerative disorders, this demonstrates the need to consider the melatonin hormone system as a central endocrine-related target of glyphosate and other environmental contaminants.

Particulate matter (PM) is a major component of ambient air pollution (AAP), being widely associated with adverse health effects. Epidemiological and experimental studies point towards a clear implication of AAP on the development of central nervous system (CNS) diseases. In this sense, the period of most CNS susceptibility is early life, when the CNS is maturing. In humans the last trimester of gestation is crucial for brain maturation while in rodents, due to the shorter gestational period, the brain is still immature at birth, and early postnatal development plays a significant role. The present systematic review provides an updated overview and discusses the existing literature on the relationship between early exposure to PM and neurodevelopmental outcomes in experimental studies. We included 11 studies with postnatal exposure and 9 studies with both prenatal and postnatal exposure. Consistent results between studies suggest that PM exposure could alter normal develop-ment, triggering impairments in short-term memory, sociability, and impulsive-like behavior. This is also associated with alterations in synaptic plasticity and in the immune system. Interestingly, differences have been observed between sexes, although not all studies included females. Furthermore, the developmental window of exposure seems to be crucial for effects to be observed in the future. In summary, air pollution exposure during development affects subjects in a time-and sex-dependent manner, the postnatal period being more important and being males apparently more sensitive to exposure than females. Nevertheless, additional experimental investigations should prioritize the examination of learning, impulsivity, and biochemical parameters, with particular attention provided to disparities betwe

Polybrominated diphenyl ethers (PBDEs) are ubiquitous persistent organic pollutants (POPs) that are known neuroendocrine disrupting chemicals with adverse neurodevelopmental effects. PBDEs may act as risk factors for autism spectrum disorders (ASD), characterized by abnormal psychosocial functioning, although direct evidence is currently lacking. Using a translational exposure model, we tested the hypothesis that maternal transfer of a commercial mixture of PBDEs, DE-71, produces ASD-relevant behavioral and neurochemical deficits in female offspring. C57Bl6/N mouse dams (F0) were exposed to DE-71 via oral administration of 0 (VEH/CON), 0.1 (L-DE-71) or 0.4 (H-DE-71) mg/kg bw/d from 3 wk prior to gestation through end of lactation. Mass spectrometry analysis indicated in utero and lactational transfer of PBDEs (in ppb) to F1 female offspring brain tissue at postnatal day (PND) 15 which was reduced by PND 110. Neurobehavioral testing of social novelty preference (SNP) and social recognition memory (SRM) revealed that adult L-DE-71 F1 offspring display deficient short- and long-term SRM, in the absence of reduced sociability, and increased repetitive behavior. These effects were concomitant with reduced olfactory discrimination of social odors. Additionally, L-DE-71 exposure also altered short-term novel object recognition memory but not anxiety or depressive-like behavior. Moreover, F1 L-DE-71 displayed downregulated mRNA transcripts for oxytocin (Oxt) in the bed nucleus of the stria terminalis (BNST) and supraoptic nucleus, and vasopressin (Avp) in the BNST and upregulated Avp1ar in BNST, and Oxtr in the paraventricular nucleus. Our work demonstrates that developmental PBDE exposure produces ASD-relevant neurochemical, olfactory processing and behavioral phenotypes that may result from early neurodevelopmental reprogramming within central social and memory networks.

Polybrominated diphenyl ethers (PBDEs) are ubiquitous persistent organic pollutants (POPs) that are known neuroendocrine disrupting chemicals with adverse neurodevelopmental effects. PBDEs may act as risk factors for autism spectrum disorders (ASD), characterized by abnormal psychosocial functioning, although direct evidence is currently lacking. Using a translational exposure model, we tested the hypothesis that maternal transfer of a commercial mixture of PBDEs, DE-71, produces ASD-relevant behavioral and neurochemical deficits in female offspring. C57Bl6/N mouse dams (F0) were exposed to DE-71 via oral administration of 0 (VEH/CON), 0.1 (L-DE-71) or 0.4 (H-DE-71) mg/kg bw/d from 3 wk prior to gestation through end of lactation. Mass spectrometry analysis indicated in utero and lactational transfer of PBDEs (in ppb) to F1 female offspring brain tissue at postnatal day (PND) 15 which was reduced by PND 110. Neurobehavioral testing of social novelty preference (SNP) and social recognition memory (SRM) revealed that adult L-DE-71 F1 offspring display deficient short- and long-term SRM, in the absence of reduced sociability, and increased repetitive behavior. These effects were concomitant with reduced olfactory discrimination of social odors. Additionally, L-DE-71 exposure also altered short-term novel object recognition memory but not anxiety or depressive-like behavior. Moreover, F1 L-DE-71 displayed downregulated mRNA transcripts for oxytocin (Oxt) in the bed nucleus of the stria terminalis (BNST) and supraoptic nucleus, and vasopressin (Avp) in the BNST and upregulated Avp1ar in BNST, and Oxtr in the paraventricular nucleus. Our work demonstrates that developmental PBDE exposure produces ASD-relevant neurochemical, olfactory processing and behavioral phenotypes that may result from early neurodevelopmental reprogramming within central social and memory networks.

Studies have established associations between environmental and occupational manganese (Mn) exposure and executive and motor function deficits in children, adolescents, and adults. These health risks from elevated Mn exposure underscore the need for effective exposure biomarkers to improve exposure classification and help detect/diagnose Mn-related impairments. Here, neonate rats were orally exposed to 0, 25, or 50 mg Mn/kg/day during early life (PND 1-21) or lifelong through ∼ PND 500 to determine the relationship between oral Mn exposure and blood, brain, and bone Mn levels over the lifespan, whether Mn accumulates in bone, and whether elevated bone Mn altered the local atomic and mineral structure of bone, or its biomechanical properties. Additionally, we assessed levels of bone Mn compared to bone lead (Pb) in aged humans (age 41-91) living in regions impacted by historic industrial ferromanganese activity. The animal studies show that blood, brain, and bone Mn levels naturally decrease across the lifespan without elevated Mn exposure. With elevated exposure, bone Mn levels were strongly associated with blood Mn levels, bone Mn was more sensitive to elevated exposures than blood or brain Mn, and Mn did not accumulate with lifelong elevated exposure. Elevated early life Mn exposure caused some changes in bone mineral properties, including altered local atomic structure of hydroxyapatite, along with some biomechanical changes in bone stiffness in weanlings or young adult animals. In aged humans, blood Mn ranged from 5.4 to 23.5 ng/mL; bone Mn was universally low, and decreased with age, but did not vary based on sex or female parity history. Unlike Pb, bone Mn showed no evidence of accumulation over the lifespan, and may not be a biomarker of cumulative long-term exposure. Thus, bone may be a useful biomarker of recent ongoing Mn exposure in humans, and may be a relatively minor target of elevated exposure.

Epidemiological studies have reported associations between environmental manganese (Mn) exposure and attention-based learning and motor function deficits in children and adolescents. These studies have raised concerns about the increased vulnerability of children to the neurotoxic effects of elevated Mn exposure and underscore the need for effective exposure biomarkers to improve exposure classification, and to better detect Mn-related impairments across the lifespan. Recent animal model studies have established that elevated developmental Mn exposure can cause executive function and motor impairments, including deficits in focused and selective attention, but the specific neurobiological alterations responsible for these impairments are not well understood. Further, the impact of long-term Mn exposure on tissue accumulation of Mn in blood, brain, and bone as exposure biomarkers, and its effects on the skeleton as a potential target organ, is similarly not well understood. To address these knowledge gaps, I used an established rodent model of early life or lifelong childhood oral Mn exposure in Chapter 2 to determine 1) the relationship between oral Mn exposure and blood, brain, and bone Mn levels over the lifespan, 2) whether Mn accumulates in bone with lifelong exposure, 3) whether elevated bone Mn altered the mineral structure or physical properties of bone, and 4) bone Mn levels in aged humans (age 41-91; female, n=30; male, n=19) living in regions impacted by historic ferromanganese alloy plant activity. In Chapter 3, I used this same rodent model of early life or lifelong oral Mn exposure to determine whether Mn causes 1) lasting disruption to the catecholaminergic system of the medial prefrontal cortex (mPFC), using quantitative protein immunohistochemistry of catecholaminergic proteins, 2) alterations to the evoked release of dopamine (DA) and norepinephrine (NE) in the PFC, and 3) whether changes in the mPFC catecholaminergic system were associated with hei

Polybrominated diphenyl ethers (PBDEs) are ubiquitous persistent organic pollutants (POPs) that are known neuroendocrine disrupting chemicals with adverse neurodevelopmental effects. PBDEs may act as risk factors for autism spectrum disorders (ASD), characterized by abnormal psychosocial functioning, although direct evidence is currently lacking. Using a translational exposure model, we tested the hypothesis that maternal transfer of a commercial mixture of PBDEs, DE-71, produces ASD-relevant behavioral and neurochemical deficits in female offspring. C57Bl6/N mouse dams (F0) were exposed to DE-71 via oral administration of 0 (VEH/CON), 0.1 (L-DE-71) or 0.4 (H-DE-71) mg/kg bw/d from 3 wk prior to gestation through end of lactation. Mass spectrometry analysis indicated in utero and lactational transfer of PBDEs (in ppb) to F1 female offspring brain tissue at postnatal day (PND) 15 which was reduced by PND 110. Neurobehavioral testing of social novelty preference (SNP) and social recognition memory (SRM) revealed that adult L-DE-71 F1 offspring display deficient short- and long-term SRM, in the absence of reduced sociability, and increased repetitive behavior. These effects were concomitant with reduced olfactory discrimination of social odors. Additionally, L-DE-71 exposure also altered short-term novel object recognition memory but not anxiety or depressive-like behavior. Moreover, F1 L-DE-71 displayed downregulated mRNA transcripts for oxytocin (Oxt) in the bed nucleus of the stria terminalis (BNST) and supraoptic nucleus, and vasopressin (Avp) in the BNST and upregulated Avp1ar in BNST, and Oxtr in the paraventricular nucleus. Our work demonstrates that developmental PBDE exposure produces ASD-relevant neurochemical, olfactory processing and behavioral phenotypes that may result from early neurodevelopmental reprogramming within central social and memory networks.

Metbolic disorders such as obesity, type 2 diabetes, liver lipid disorders and metabolic syndrome are increasing rapidly and have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence showing that other environmental factors, including environmental chemicals, may contribute to the rapid increase in the incidence of these metabolic diseases. Of particular growing concern is low-dose developmental exposure to endocrine disrupting chemicals (EDCs). The developing period is an extremely sensitive window of exposure to environmental stressors, including EDCs, and early life exposure has been linked to metabolic disorders later in life. Consistent with hormones, EDCs can act at very low serum concentrations and even small changes in the endocrine system may lead to extensive effects. The overall aim of this thesis has been to investigate potential metabolic disruption following exposure to Bisphenol A (BPA), which is a known EDC. The experimental animal study demonstrated that male and female rat offspring generally exhibited differential susceptibility to developmental exposure to BPA (0.5 µg/kg BW/day or 50 µg/kg BW/day). The main results showed that the lowest dose of BPA induced increased plasma triglyceride levels and increased adipocyte cell density in inguinal white adipose tissue in female offspring. Further, this low dose increased fatty acid indices and altered the fatty acid composition in male offspring and enhanced insulin secretion in pancreatic islets from male and female offspring and dams. Contrastingly, the higher BPA-dose decreased insulin secretion in pancreatic islets from male and female offspring and dams. The increased fatty acid indices, and the altered fatty acid composition together with enhanced insulin secretion may be early risk factors for insulin resistance. Furthermore, depending on the tissue, dose and sex, BPA altered the expression of genes involved in lipid

Epidemiological studies have reported associations between environmental manganese (Mn) exposure and attention-based learning and motor function deficits in children and adolescents. These studies have raised concerns about the increased vulnerability of children to the neurotoxic effects of elevated Mn exposure and underscore the need for effective exposure biomarkers to improve exposure classification, and to better detect Mn-related impairments across the lifespan. Recent animal model studies have established that elevated developmental Mn exposure can cause executive function and motor impairments, including deficits in focused and selective attention, but the specific neurobiological alterations responsible for these impairments are not well understood. Further, the impact of long-term Mn exposure on tissue accumulation of Mn in blood, brain, and bone as exposure biomarkers, and its effects on the skeleton as a potential target organ, is similarly not well understood. To address these knowledge gaps, I used an established rodent model of early life or lifelong childhood oral Mn exposure in Chapter 2 to determine 1) the relationship between oral Mn exposure and blood, brain, and bone Mn levels over the lifespan, 2) whether Mn accumulates in bone with lifelong exposure, 3) whether elevated bone Mn altered the mineral structure or physical properties of bone, and 4) bone Mn levels in aged humans (age 41-91; female, n=30; male, n=19) living in regions impacted by historic ferromanganese alloy plant activity. In Chapter 3, I used this same rodent model of early life or lifelong oral Mn exposure to determine whether Mn causes 1) lasting disruption to the catecholaminergic system of the medial prefrontal cortex (mPFC), using quantitative protein immunohistochemistry of catecholaminergic proteins, 2) alterations to the evoked release of dopamine (DA) and norepinephrine (NE) in the PFC, and 3) whether changes in the mPFC catecholaminergic system were associated with hei

Metbolic disorders such as obesity, type 2 diabetes, liver lipid disorders and metabolic syndrome are increasing rapidly and have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence showing that other environmental factors, including environmental chemicals, may contribute to the rapid increase in the incidence of these metabolic diseases. Of particular growing concern is low-dose developmental exposure to endocrine disrupting chemicals (EDCs). The developing period is an extremely sensitive window of exposure to environmental stressors, including EDCs, and early life exposure has been linked to metabolic disorders later in life. Consistent with hormones, EDCs can act at very low serum concentrations and even small changes in the endocrine system may lead to extensive effects. The overall aim of this thesis has been to investigate potential metabolic disruption following exposure to Bisphenol A (BPA), which is a known EDC. The experimental animal study demonstrated that male and female rat offspring generally exhibited differential susceptibility to developmental exposure to BPA (0.5 µg/kg BW/day or 50 µg/kg BW/day). The main results showed that the lowest dose of BPA induced increased plasma triglyceride levels and increased adipocyte cell density in inguinal white adipose tissue in female offspring. Further, this low dose increased fatty acid indices and altered the fatty acid composition in male offspring and enhanced insulin secretion in pancreatic islets from male and female offspring and dams. Contrastingly, the higher BPA-dose decreased insulin secretion in pancreatic islets from male and female offspring and dams. The increased fatty acid indices, and the altered fatty acid composition together with enhanced insulin secretion may be early risk factors for insulin resistance. Furthermore, depending on the tissue, dose and sex, BPA altered the expression of genes involved in lipid

Metbolic disorders such as obesity, type 2 diabetes, liver lipid disorders and metabolic syndrome are increasing rapidly and have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence showing that other environmental factors, including environmental chemicals, may contribute to the rapid increase in the incidence of these metabolic diseases. Of particular growing concern is low-dose developmental exposure to endocrine disrupting chemicals (EDCs). The developing period is an extremely sensitive window of exposure to environmental stressors, including EDCs, and early life exposure has been linked to metabolic disorders later in life. Consistent with hormones, EDCs can act at very low serum concentrations and even small changes in the endocrine system may lead to extensive effects. The overall aim of this thesis has been to investigate potential metabolic disruption following exposure to Bisphenol A (BPA), which is a known EDC. The experimental animal study demonstrated that male and female rat offspring generally exhibited differential susceptibility to developmental exposure to BPA (0.5 µg/kg BW/day or 50 µg/kg BW/day). The main results showed that the lowest dose of BPA induced increased plasma triglyceride levels and increased adipocyte cell density in inguinal white adipose tissue in female offspring. Further, this low dose increased fatty acid indices and altered the fatty acid composition in male offspring and enhanced insulin secretion in pancreatic islets from male and female offspring and dams. Contrastingly, the higher BPA-dose decreased insulin secretion in pancreatic islets from male and female offspring and dams. The increased fatty acid indices, and the altered fatty acid composition together with enhanced insulin secretion may be early risk factors for insulin resistance. Furthermore, depending on the tissue, dose and sex, BPA altered the expression of genes involved in lipid

Metbolic disorders such as obesity, type 2 diabetes, liver lipid disorders and metabolic syndrome are increasing rapidly and have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence showing that other environmental factors, including environmental chemicals, may contribute to the rapid increase in the incidence of these metabolic diseases. Of particular growing concern is low-dose developmental exposure to endocrine disrupting chemicals (EDCs). The developing period is an extremely sensitive window of exposure to environmental stressors, including EDCs, and early life exposure has been linked to metabolic disorders later in life. Consistent with hormones, EDCs can act at very low serum concentrations and even small changes in the endocrine system may lead to extensive effects. The overall aim of this thesis has been to investigate potential metabolic disruption following exposure to Bisphenol A (BPA), which is a known EDC. The experimental animal study demonstrated that male and female rat offspring generally exhibited differential susceptibility to developmental exposure to BPA (0.5 µg/kg BW/day or 50 µg/kg BW/day). The main results showed that the lowest dose of BPA induced increased plasma triglyceride levels and increased adipocyte cell density in inguinal white adipose tissue in female offspring. Further, this low dose increased fatty acid indices and altered the fatty acid composition in male offspring and enhanced insulin secretion in pancreatic islets from male and female offspring and dams. Contrastingly, the higher BPA-dose decreased insulin secretion in pancreatic islets from male and female offspring and dams. The increased fatty acid indices, and the altered fatty acid composition together with enhanced insulin secretion may be early risk factors for insulin resistance. Furthermore, depending on the tissue, dose and sex, BPA altered the expression of genes involved in lipid

Metbolic disorders such as obesity, type 2 diabetes, liver lipid disorders and metabolic syndrome are increasing rapidly and have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence showing that other environmental factors, including environmental chemicals, may contribute to the rapid increase in the incidence of these metabolic diseases. Of particular growing concern is low-dose developmental exposure to endocrine disrupting chemicals (EDCs). The developing period is an extremely sensitive window of exposure to environmental stressors, including EDCs, and early life exposure has been linked to metabolic disorders later in life. Consistent with hormones, EDCs can act at very low serum concentrations and even small changes in the endocrine system may lead to extensive effects. The overall aim of this thesis has been to investigate potential metabolic disruption following exposure to Bisphenol A (BPA), which is a known EDC. The experimental animal study demonstrated that male and female rat offspring generally exhibited differential susceptibility to developmental exposure to BPA (0.5 µg/kg BW/day or 50 µg/kg BW/day). The main results showed that the lowest dose of BPA induced increased plasma triglyceride levels and increased adipocyte cell density in inguinal white adipose tissue in female offspring. Further, this low dose increased fatty acid indices and altered the fatty acid composition in male offspring and enhanced insulin secretion in pancreatic islets from male and female offspring and dams. Contrastingly, the higher BPA-dose decreased insulin secretion in pancreatic islets from male and female offspring and dams. The increased fatty acid indices, and the altered fatty acid composition together with enhanced insulin secretion may be early risk factors for insulin resistance. Furthermore, depending on the tissue, dose and sex, BPA altered the expression of genes involved in lipid

In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health.

Studies have reported associations between environmental manganese (Mn) exposure and impaired cognition, attention, impulse control, and fine motor function in children. Our recent rodent studies established that elevated Mn exposure causes these impairments. Here, rats were exposed orally to 0, 25, or 50 mg Mn kg-1  day-1 during early postnatal life (PND 1-21) or lifelong to determine whether early life Mn exposure causes heightened behavioral reactivity in the open field, lasting changes in the catecholaminergic systems in the medial prefrontal cortex (mPFC), altered dendritic spine density, and whether lifelong exposure exacerbates these effects. We also assessed astrocyte reactivity (glial fibrillary acidic protein, GFAP), and astrocyte complement C3 and S100A10 protein levels as markers of A1 proinflammatory or A2 anti-inflammatory reactive astrocytes. Postnatal Mn exposure caused heightened behavioral reactivity during the first 5-10 min intervals of daily open field test sessions, consistent with impairments in arousal regulation. Mn exposure reduced the evoked release of norepinephrine (NE) and caused decreased protein levels of tyrosine hydroxylase (TH), dopamine (DA) and NE transporters, and DA D1 receptors, along with increased DA D2 receptors. Mn also caused a lasting increase in reactive astrocytes (GFAP) exhibiting increased A1 and A2 phenotypes, with a greater induction of the A1 proinflammatory phenotype. These results demonstrate that early life Mn exposure causes broad lasting hypofunctioning of the mPFC catecholaminergic systems, consistent with the impaired arousal regulation, attention, impulse control, and fine motor function reported in these animals, suggesting that mPFC catecholaminergic dysfunction may underlie similar impairments reported in Mn-exposed children.

Alterations in attention and inhibitory control are common features in several neurological disorders. Environmental factors such as exposure to pesticides have been linked to their appearance. Chlorpyrifos (CPF) is the most widely used organophosphate compound in the world. CPF exposure during development seems to be critical for later behavioral and molecular disruptions during adult ages, although this depends on the specific period of development, where the preweaning period is the least studied. Despite the abundant empirical work made in the last decades on developmental CPF exposure, the systematic study of this on attention is sparse, and nonexistent concerning inhibitory control, without a single study on preweaning developmental stages. The present research explored the effects of the exposure to low doses of CPF that do not elicit a significant inhibition of the Cholinesterases during this developmental period on rats' behavior in the five-choice serial reaction time task. Behavioral manipulations (inter-trial interval and stimulus duration), pharmacological manipulations (cholinergic and GABAergic drugs) and brain gene expression analyses were also conducted. Exposure to CPF decreased the locomotor activity and enhanced the learning profile of the female rats, increased the impulsive rates, unmasked by a longer inter-trial interval, hypo-sensitized the cholinergic system and down-regulated the mRNA expression levels of the brain-derived neurotrophic factor in the dorsal striatum of the male rats. This happened without significant inhibition of the brain Acetylcholinesterase. All this new information corroborates that the exposure to a common pesticide at low doses during a key, but under-explored developmental period importantly affects different behaviors

The synthetic estrogen 17α-ethinylestradiol (EE2), ubiquitous in the aquatic environment and commonly detected in sewage effluents, interferes with the endocrine system in multiple ways. Exposure during sensitive windows of development causes persistent effects on fertility, reproductive and non-reproductive behavior in mammals and fish. In the present study, three-spined stickleback (Gasterosteus aculeatus) were exposed to nominal 0 and 20 ng/L EE2 from fertilization to 7 weeks post-hatch. After 8 months of remediation in clean water three non-reproductive behaviors, not previously analyzed in developmentally EE2-exposed progeny of wild-caught fish, were evaluated. Chemical analysis revealed that the nominal 0 and 20 ng/L exposure contained 5 and 30 ng/L EE2, respectively. Therefore, the use of control fish from previous experiments was necessary for comparisons. Fish exposed during development showed significant concentration-dependent reduction in anxiety-like behavior in the scototaxis (light/dark preference) test by means of shorter latency to first entrance to the white compartment, more visits in white, and longer total time in white compared to unexposed fish. In the novel tank test, developmental exposure significantly increased the number of transitions to the upper half of the aquaria. Exposure to EE2 during development did not alter shoal cohesion in the shoaling test compared with unexposed fish but fish exposed to 30 ng/L EE2 had significantly longer latency to leave the shoal and fewer transitions away from the shoal compared to fish exposed to 5 ng/L EE2. Skewed sex ratio with more females, sex reversal in genetic males as well as intersex in males was observed after exposure to 30, but not 5 ng/L EE2. In conclusion, EE2 exposure during development in three-spined stickleback resulted in persistent effects on anxiety-like behaviors. These long-term effects from developmental exposure are likely to be of higher relevance for natural populations than a, As manuscript in dissertation.

© 2019 Elsevier Inc. To date, we have shown that apolipoprotein E (APOE) polymorphisms differentially modulate the neurobehavioral and metabolic effects of chlorpyrifos (CPF), a widely used pesticide, which is detected as residue in food. We previously reported that, after being exposed to CPF, APOE3 subjects exhibit metabolic dysfunctions while APOE4 subjects undergo changes in behavior. In the current study, we investigated the effects of a double exposure to CPF on social behavior and hypothalamic gene expression in apoE-targeted replacement (TR) mice. Male apoE3-and apoE4-TR mice were exposed to CPF at 0 or 1 mg/kg/day on postnatal days 10–15 and then, during adulthood (5 months of age), fed a CPF-supplemented diet (0 or 2 mg/kg/day) for 15 days. During adult exposure to CPF, body weight gain and food intake were monitored. At the end of the adult exposure period, we evaluated social behavior in a three-chamber test, as well as mRNA levels of hypothalamic neuropeptides and receptors related to social behavior and feeding control. Adult CPF exposure increased food intake in general, but only apoE4 mice increased their body weight. Postnatal CPF exposure improved preference for the social contexts in apoE4 mice while adult CPF exposure did the same in apoE3 mice. Anorexigenic-peptide and social-related behavior gene expression decreased as a result of adult CPF exposure in apoE4 mice, and neuropeptide Y was more expressed in apoE4 mice. These results indicate that CPF exposure produces orexigenic and metabolic effects and enlarges individual differences in social behavior, especially in apoE3 mice.

Low doses of Bisphenol A (BPA) during development may affect reproduction. In this study, Fischer 344 rats were exposed to 0.5 or 50 μg BPA/kg bw/day via drinking water from gestational day 3.5 to postnatal day 22. Anogenital distance, organ weight, histopathology of reproductive organs, hormone analysis and sperm morphology were evaluated in male offspring. In this study no major effects of BPA on male reproduction in midpubertal (postnatal day 35) or adult (12-month-old) rats were revealed, apart from a higher prevalence of mild inflammatory cell infiltrate in cauda epididymis in adult rats exposed to 50 μg BPA/kg bw/day. No BPA-related effects on sexual development were seen but care should be taken when evaluating histopathology in midpuberty testis due to large morphological variation. Results from the present study show no major signs of altered male reproduction in rats exposed to low doses of BPA during gestation and lactation., De två sista författarna delar sistaförfattarskapet.

The environmental neurotoxin beta-N-methylamino-L-alanine (BMAA) is a glutamate receptor agonist that can induce oxidative stress and has been implicated as a possible risk factor for neurodegenerative disease. Detection of BMAA in mussels, crustaceans, and fish illustrates that the sources of human exposure to this toxin are more abundant than previously anticipated. The aim of this study was to determine uptake of BMAA in the pineal gland and subsequent effects on melatonin production in primary pinealocyte cultures and a rat model. Autoradiographic imaging of 10-day-old male rats revealed a high and selective uptake in the pineal gland at 30minutes to 24hours after C-14-L-BMAA administration (0.68mg/kg). Primary pinealocyte cultures exposed to 0.05-3mmol/L BMAA showed a 57%-93% decrease in melatonin synthesis in vitro. Both the metabotropic glutamate receptor 3 (mGluR3) antagonist Ly341495 and the protein kinase C (PKC) activator phorbol-12-myristate-13-acetate prevented the decrease in melatonin secretion, suggesting that BMAA inhibits melatonin synthesis by mGluR3 activation and PKC inhibition. Serum analysis revealed a 45% decrease in melatonin concentration in neonatal rats assessed 2weeks after BMAA administration (460mg/kg) and confirmed an inhibition of melatonin synthesis in vivo. Given that melatonin is a most important neuroprotective molecule in the brain, the etiology of BMAA-induced neurodegeneration may include mechanisms beyond direct excitotoxicity and oxidative stress.

The role of sex as an effect modifier of developmental lead (Pb) exposure has until recently received little attention. Lead exposure in early life can affect brain development with persisting influences on cognitive and behavioral functioning, as well as, elevated risks for developing a variety of diseases and disorders in later life. Although both sexes are affected by Pb exposure, the incidence, manifestation, and severity of outcomes appears to differ in males and females. Results from epidemiologic and animal studies indicate significant effect modification by sex, however, the results are not consistent across studies. Unfortunately, only a limited number of human epidemiological studies have included both sexes in independent outcome analyses limiting our ability to draw definitive conclusions regarding sex-differentiated outcomes. Additionally, due to various methodological differences across studies, there is still not a good mechanistic understanding of the molecular effects of lead on the brain and the factors that influence differential responses to Pb based on sex. In this review, focused on prenatal and postnatal Pb exposures in humans and animal models, we discuss current literature supporting sex differences in outcomes in response to Pb exposure and explore some of the ideas regarding potential molecular mechanisms that may contribute to sex-related differences in outcomes from developmental Pb exposure. The sex-dependent variability in outcomes from developmental Pb exposure may arise from a combination of complex factors, including, but not limited to, intrinsic sex-specific molecular/genetic mechanisms and external risk factors including sex-specific responses to environmental stressors which may act through shared epigenetic pathways to influence the genome and behavioral output. © 2018 Singh, Singh, Sobolewski, Cory-Slechta and Schneider.

Atrazine is a commonly used herbicide in the Midwestern United States. Currently, Indiana uses about 26% of its land to grow corn, and atrazine is used in ample amounts, resulting in contamination of drinking water supplies. The U.S. Environmental Protection Agency (EPA) has set the Maximum Contaminant Level (MCL) at 3 parts per billion (ppb) in drinking water, but the herbicide is often found at higher concentrations. However, data suggests that atrazine can cause adverse health impacts even at 3 ppb. Previous studies from our laboratory in the zebrafish model system have shown atrazine alters gene expression associated with neuroendocrine and reproductive system function, carcinogenesis, and cell cycle regulation and an increase in head size following an embryonic atrazine exposure at 0.3, 3, or 30 ppb. From these studies, it was shown that at 72 hours postfertilization (hpf; the end of embryogenesis), atrazine elicits alterations of the gene, tumor protein D52-like 1 (tpd52l1). Previous studies have identified Tpd52l1 in cell proliferation and calcium signaling, along with regulating expression at the G2-M transition in breast cancer cells. The goal of this project was to characterize the expression of tpd52l1 during development of the zebrafish, as well as determine developmental time-point specific gene alterations caused by the embryonic atrazine exposure. To characterize the expression of tpd52l1 throughout embryogenesis, zebrafish embryos were bred and embryos were collected at 24, 36, 48, 60, and 72 hpf for RNA isolation. In addition, alteration in tpd52l1 gene expression following atrazine exposure was assessed at the same developmental time points. Analysis by quantitative polymerase chain reaction (qPCR) showed consistent levels of gene expression throughout embryonic development (p > 0.05), but a significant increase at 36 hpf in the 0.3 and 3 ppb treatments and a significant decrease at 60 hpf was observed in all three atrazine treatments (p < 0.05). T

BACKGROUND: Bisphenol A (BPA) is a component of polycarbonate plastics to which humans are regularly exposed at low levels, and an endocrine disruptor with effects on several hormonal systems. Bone is a sensitive hormone target tissue, and we have recently shown that in utero and lactational exposure to 25µg BPA/kg BW/day alters femoral geometry in rat offspring. OBJECTIVE: To investigate bone effects in rat offspring after developmental exposure to a BPA dose in the range of human daily exposure (0.1-1.5µg/kg BW/day) as well as a dose to corroborate previous findings. METHODS: Pregnant Fischer 344 rats were exposed to BPA via drinking water corresponding to 0.5µg/kg BW/day: [0.5], (n=21) or 50µg/kg BW/day: [50], (n = 16) from gestational day 3.5 until postnatal day 22, while controls were given only vehicle (n = 25). The offspring was sacrificed at 5 weeks of age. Bone effects were analyzed using peripheral quantitative computed tomography (pQCT), the 3-point bending test, plasma markers of bone turnover, and gene expression in cortical bone and bone marrow. RESULTS: Compared to controls, male offspring developmentally exposed to BPA had shorter femurs. pQCT analysis revealed effects in the [0.5] group, but not in the [50] group; BPA reduced both trabecular area (-3.9%, p < 0.01) and total cross sectional area (-4.1%, p < 0.01) of femurs in the [0.5] group, whereas no effects were seen on bone density. Conversely, bone length and size were not affected in female offspring. However, the procollagen type I N-terminal propeptide (P1NP), a peptide formed during type 1 collagen synthesis, was increased in plasma (42%: p < 0.01) in female offspring exposed to [0.5] of BPA, although collagen gene expression was not increased in bone. The biomechanical properties of the bones were not altered in either sex. Bone marrow mRNA expression was only affected in male offspring. CONCLUSIONS: Developmental low-dose exposure to BPA resulted in sex-specific bone effects in r

The synthetic estrogen 17 alpha-ethinylestradiol (EE2) is an endocrine disrupting compound of concern due to its persistence and widespread presence in the aquatic environment. Effects of developmental exposure to low concentrations of EE2 in fish on reproduction and behavior not only persisted to adulthood, but have also been observed to be transmitted to several generations of unexposed progeny. To investigate the possible biological mechanisms of the persistent anxiogenic phenotype, we exposed zebrafish embryos for 80 days post fertilization to 0, 3, and 10 ng/L EE2 (measured concentrations 2.14 and 7.34 ng/L). After discontinued exposure, the animals were allowed to recover for 120 days in clean water. Adult males and females were later tested for changes in stress response and shoal cohesion, and whole-brain gene expression was analyzed with RNA sequencing. The results show increased anxiety in the novel tank and scototaxis tests, and increased shoal cohesion in fish exposed during development to EE2. RNA sequencing revealed 34 coding genes differentially expressed in male brains and 62 in female brains as a result of EE2 exposure. Several differences were observed between males and females in differential gene expression, with only one gene, sv2b, coding for a synaptic vesicle protein, that was affected by EE2 in both sexes. Functional analyses showed that in female brains, EE2 had significant effects on pathways connected to the circadian rhythm, cytoskeleton and motor proteins and synaptic proteins. A large number of non-coding sequences including 19 novel miRNAs were also differentially expressed in the female brain. The largest treatment effect in male brains was observed in pathways related to cholesterol biosynthesis and synaptic proteins. Circadian rhythm and cholesterol biosynthesis, previously implicated in anxiety behavior, might represent possible candidate pathways connecting the transcriptome changes to the alterations to behavior. Further the obs

The synthetic estrogen 17 alpha-ethinylestradiol (EE2) is an endocrine disrupting compound of concern due to its persistence and widespread presence in the aquatic environment. Effects of developmental exposure to low concentrations of EE2 in fish on reproduction and behavior not only persisted to adulthood, but have also been observed to be transmitted to several generations of unexposed progeny. To investigate the possible biological mechanisms of the persistent anxiogenic phenotype, we exposed zebrafish embryos for 80 days post fertilization to 0, 3, and 10 ng/L EE2 (measured concentrations 2.14 and 7.34 ng/L). After discontinued exposure, the animals were allowed to recover for 120 days in clean water. Adult males and females were later tested for changes in stress response and shoal cohesion, and whole-brain gene expression was analyzed with RNA sequencing. The results show increased anxiety in the novel tank and scototaxis tests, and increased shoal cohesion in fish exposed during development to EE2. RNA sequencing revealed 34 coding genes differentially expressed in male brains and 62 in female brains as a result of EE2 exposure. Several differences were observed between males and females in differential gene expression, with only one gene, sv2b, coding for a synaptic vesicle protein, that was affected by EE2 in both sexes. Functional analyses showed that in female brains, EE2 had significant effects on pathways connected to the circadian rhythm, cytoskeleton and motor proteins and synaptic proteins. A large number of non-coding sequences including 19 novel miRNAs were also differentially expressed in the female brain. The largest treatment effect in male brains was observed in pathways related to cholesterol biosynthesis and synaptic proteins. Circadian rhythm and cholesterol biosynthesis, previously implicated in anxiety behavior, might represent possible candidate pathways connecting the transcriptome changes to the alterations to behavior. Further the obs

The synthetic estrogen 17 alpha-ethinylestradiol (EE2) is an endocrine disrupting compound of concern due to its persistence and widespread presence in the aquatic environment. Effects of developmental exposure to low concentrations of EE2 in fish on reproduction and behavior not only persisted to adulthood, but have also been observed to be transmitted to several generations of unexposed progeny. To investigate the possible biological mechanisms of the persistent anxiogenic phenotype, we exposed zebrafish embryos for 80 days post fertilization to 0, 3, and 10 ng/L EE2 (measured concentrations 2.14 and 7.34 ng/L). After discontinued exposure, the animals were allowed to recover for 120 days in clean water. Adult males and females were later tested for changes in stress response and shoal cohesion, and whole-brain gene expression was analyzed with RNA sequencing. The results show increased anxiety in the novel tank and scototaxis tests, and increased shoal cohesion in fish exposed during development to EE2. RNA sequencing revealed 34 coding genes differentially expressed in male brains and 62 in female brains as a result of EE2 exposure. Several differences were observed between males and females in differential gene expression, with only one gene, sv2b, coding for a synaptic vesicle protein, that was affected by EE2 in both sexes. Functional analyses showed that in female brains, EE2 had significant effects on pathways connected to the circadian rhythm, cytoskeleton and motor proteins and synaptic proteins. A large number of non-coding sequences including 19 novel miRNAs were also differentially expressed in the female brain. The largest treatment effect in male brains was observed in pathways related to cholesterol biosynthesis and synaptic proteins. Circadian rhythm and cholesterol biosynthesis, previously implicated in anxiety behavior, might represent possible candidate pathways connecting the transcriptome changes to the alterations to behavior. Further the obs

The synthetic estrogen 17 alpha-ethinylestradiol (EE2) is an endocrine disrupting compound of concern due to its persistence and widespread presence in the aquatic environment. Effects of developmental exposure to low concentrations of EE2 in fish on reproduction and behavior not only persisted to adulthood, but have also been observed to be transmitted to several generations of unexposed progeny. To investigate the possible biological mechanisms of the persistent anxiogenic phenotype, we exposed zebrafish embryos for 80 days post fertilization to 0, 3, and 10 ng/L EE2 (measured concentrations 2.14 and 7.34 ng/L). After discontinued exposure, the animals were allowed to recover for 120 days in clean water. Adult males and females were later tested for changes in stress response and shoal cohesion, and whole-brain gene expression was analyzed with RNA sequencing. The results show increased anxiety in the novel tank and scototaxis tests, and increased shoal cohesion in fish exposed during development to EE2. RNA sequencing revealed 34 coding genes differentially expressed in male brains and 62 in female brains as a result of EE2 exposure. Several differences were observed between males and females in differential gene expression, with only one gene, sv2b, coding for a synaptic vesicle protein, that was affected by EE2 in both sexes. Functional analyses showed that in female brains, EE2 had significant effects on pathways connected to the circadian rhythm, cytoskeleton and motor proteins and synaptic proteins. A large number of non-coding sequences including 19 novel miRNAs were also differentially expressed in the female brain. The largest treatment effect in male brains was observed in pathways related to cholesterol biosynthesis and synaptic proteins. Circadian rhythm and cholesterol biosynthesis, previously implicated in anxiety behavior, might represent possible candidate pathways connecting the transcriptome changes to the alterations to behavior. Further the obs

The synthetic estrogen 17 alpha-ethinylestradiol (EE2) is an endocrine disrupting compound of concern due to its persistence and widespread presence in the aquatic environment. Effects of developmental exposure to low concentrations of EE2 in fish on reproduction and behavior not only persisted to adulthood, but have also been observed to be transmitted to several generations of unexposed progeny. To investigate the possible biological mechanisms of the persistent anxiogenic phenotype, we exposed zebrafish embryos for 80 days post fertilization to 0, 3, and 10 ng/L EE2 (measured concentrations 2.14 and 7.34 ng/L). After discontinued exposure, the animals were allowed to recover for 120 days in clean water. Adult males and females were later tested for changes in stress response and shoal cohesion, and whole-brain gene expression was analyzed with RNA sequencing. The results show increased anxiety in the novel tank and scototaxis tests, and increased shoal cohesion in fish exposed during development to EE2. RNA sequencing revealed 34 coding genes differentially expressed in male brains and 62 in female brains as a result of EE2 exposure. Several differences were observed between males and females in differential gene expression, with only one gene, sv2b, coding for a synaptic vesicle protein, that was affected by EE2 in both sexes. Functional analyses showed that in female brains, EE2 had significant effects on pathways connected to the circadian rhythm, cytoskeleton and motor proteins and synaptic proteins. A large number of non-coding sequences including 19 novel miRNAs were also differentially expressed in the female brain. The largest treatment effect in male brains was observed in pathways related to cholesterol biosynthesis and synaptic proteins. Circadian rhythm and cholesterol biosynthesis, previously implicated in anxiety behavior, might represent possible candidate pathways connecting the transcriptome changes to the alterations to behavior. Further the obs

Atrazine is a commonly used herbicide in the Midwestern United States. Currently, Indiana uses about 26% of its land to grow corn, and atrazine is used in ample amounts, resulting in contamination of drinking water supplies. The U.S. Environmental Protection Agency (EPA) has set the Maximum Contaminant Level (MCL) at 3 parts per billion (ppb) in drinking water, but the herbicide is often found at higher concentrations. However, data suggests that atrazine can cause adverse health impacts even at 3 ppb. Previous studies from our laboratory in the zebrafish model system have shown atrazine alters gene expression associated with neuroendocrine and reproductive system function, carcinogenesis, and cell cycle regulation and an increase in head size following an embryonic atrazine exposure at 0.3, 3, or 30 ppb. From these studies, it was shown that at 72 hours postfertilization (hpf; the end of embryogenesis), atrazine elicits alterations of the gene, tumor protein D52-like 1 (tpd52l1). Previous studies have identified Tpd52l1 in cell proliferation and calcium signaling, along with regulating expression at the G2-M transition in breast cancer cells. The goal of this project was to characterize the expression of tpd52l1 during development of the zebrafish, as well as determine developmental time-point specific gene alterations caused by the embryonic atrazine exposure. To characterize the expression of tpd52l1 throughout embryogenesis, zebrafish embryos were bred and embryos were collected at 24, 36, 48, 60, and 72 hpf for RNA isolation. In addition, alteration in tpd52l1 gene expression following atrazine exposure was assessed at the same developmental time points. Analysis by quantitative polymerase chain reaction (qPCR) showed consistent levels of gene expression throughout embryonic development (p > 0.05), but a significant increase at 36 hpf in the 0.3 and 3 ppb treatments and a significant decrease at 60 hpf was observed in all three atrazine treatments (p < 0.05). T

Background: Bisphenol A (BPA) is a chemical produced in large volumes for use in manufacturing of consumer products and industrial applications, and an endocrine disruptor known to affect several hormonal systems. Bone produces hormones and is additionally a sensitive hormone target tissue, and is thus potentially sensitive to low doses of endocrine disruptors such as BPA, especially during development. Methods: 110 pregnant Wistar rats were gavaged with 0; 25 mu g; 250 mu g; 5000 mu g or 50,000 mu g BPA/kg bodyweight (bw)/day from gestational day 7 until weaning at postnatal day 22. The three-month-old offspring were sacrificed and right femurs collected for length measurements, geometrical measurements by peripheral quantitative computed tomography (pQCT), as well as for analyses of biomechanical properties using the three-point-bending method. Results: The femur was elongated in female offspring of dams exposed to 25 or 5000 mu g BPA/kg bw/day (1.8% and 2.1%, respectively), and increased cortical thickness (4.7%) was observed in male offspring of dams exposed to 25 mu g BPA/kg bw/day, compared to controls (p < 0.005). The biomechanical properties of the bone were not significantly altered. Conclusions: In utero and lactational exposure to the lowest BPA dose used in this study altered femoral geometry in both male and female offspring. This was observed at 25 mu g BPA/kg bw/day, a dose lower than the Human Equivalent Dose (HED) applied by EFSA to set a temporary TDI (609 mu g BPA/kg bw/day), and far lower than the No-Observed-Adverse-Effect-Level (NOAEL) (5000 mu g BPA/kg bw/day) on which the US FDA TDI is based.

Thesis (Ph.D.)--University of Rochester. School of Medicine & Dentistry. Dept. of Microbiology and Immunology, 2015., Developmental exposures have been shown to alter immune-mediated processes later in life, yet the mechanism by which this occurs is unknown. In fact, in most cases it is unclear which cell types and molecular machinery are affected. Many studies have examined early life exposures to chemicals that activate the aryl hydrocarbon receptor (AhR). Cells of the immune system express this receptor, and AhR activation in the fully mature immune system (i.e., non-developmental exposure) alters CD4+ T cell-dependent immune responses. However, little is known about how activation of the AhR during development changes the function of CD4+ T cells in adult offspring. Therefore, using mouse models of human disease, we determined whether developmental exposure to the prototypical AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) affects CD4+ T cell responses in adult offspring. For the majority of work in this project, we used influenza A virus infection to initiate an immune response. Developmentally exposed adult mice infected with influenza virus had fewer conventional effector CD4+ T cells in draining lymph nodes of the lung, yet an increase in regulatory CD4+ T cells (Tregs). In contrast, the lungs of these mice had an increase in all CD4+ T cell subsets. Using a combination of tools, including adoptive transfers and the cre-loxP system, we determined that the altered CD4+ T cell response to infection in developmentally exposed mice reflects a combination of intrinsic and extrinsic changes in CD4+ T cells, which are revealed in a tissue-specific manner. While the extrinsic factors triggered by developmental exposure that influence CD4+ T cell function later in life remain to be elucidated, we determined that these changes require live, replicating virus in the lung, suggesting a novel effect of developmental exposure on the structural cells of the lung. The implications of this work extend beyond influenza virus infection, as we observe changes in disease progression in d

The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine disrupting chemical (EDC) of concern due to its persistent nature and widespread presence in the aquatic environment. In mammals, effects of developmental EDC exposure on reproduction and behavior not only persist to adulthood after discontinued exposure, but are also inherited by several consecutive unexposed generations. The results presented in this thesis demonstrate that non-reproductive behavior in fish is highly sensitive to the influence of EE2 during development and the effects do not appear to be restored after a long recovery period in clean water. We have shown that exposure to low doses of EE2 during development results in increased anxiety in two fish species (zebrafish and guppy) and their offspring. We have also demonstrated that the effects of EE2 on anxiety are apparent in both sexes and are transgenerationally transmitted to two consecutive generations of unexposed offspring in the guppy. In order to investigate the possible biological mechanisms of the observed persistent effects on non-reproductive behavior, we also performed an RNA sequencing analysis of the whole-brain transcriptome in developmentally exposed zebrafish after remediation in clean water until adulthood. Differential expression of 33 genes in males and 62 genes in females were observed as a result of EE2 exposure, with only one gene affected in both sexes. Functional analysis revealed cholesterol biosynthesis and circadian rhythm to be the top two affected pathways in males and females, respectively. Both pathways have previously been implicated in anxiety behavior and represent possible candidates connecting the transcriptome alterations to the observed behavioral phenotype. The study represents an initial survey of the fish brain transcriptome by means of RNA sequencing after long-term recovery from developmental exposure to an estrogenic compound.

The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine disrupting chemical (EDC) of concern due to its persistent nature and widespread presence in the aquatic environment. In mammals, effects of developmental EDC exposure on reproduction and behavior not only persist to adulthood after discontinued exposure, but are also inherited by several consecutive unexposed generations. The results presented in this thesis demonstrate that non-reproductive behavior in fish is highly sensitive to the influence of EE2 during development and the effects do not appear to be restored after a long recovery period in clean water. We have shown that exposure to low doses of EE2 during development results in increased anxiety in two fish species (zebrafish and guppy) and their offspring. We have also demonstrated that the effects of EE2 on anxiety are apparent in both sexes and are transgenerationally transmitted to two consecutive generations of unexposed offspring in the guppy. In order to investigate the possible biological mechanisms of the observed persistent effects on non-reproductive behavior, we also performed an RNA sequencing analysis of the whole-brain transcriptome in developmentally exposed zebrafish after remediation in clean water until adulthood. Differential expression of 33 genes in males and 62 genes in females were observed as a result of EE2 exposure, with only one gene affected in both sexes. Functional analysis revealed cholesterol biosynthesis and circadian rhythm to be the top two affected pathways in males and females, respectively. Both pathways have previously been implicated in anxiety behavior and represent possible candidates connecting the transcriptome alterations to the observed behavioral phenotype. The study represents an initial survey of the fish brain transcriptome by means of RNA sequencing after long-term recovery from developmental exposure to an estrogenic compound.

The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine disrupting chemical (EDC) of concern due to its persistent nature and widespread presence in the aquatic environment. In mammals, effects of developmental EDC exposure on reproduction and behavior not only persist to adulthood after discontinued exposure, but are also inherited by several consecutive unexposed generations. The results presented in this thesis demonstrate that non-reproductive behavior in fish is highly sensitive to the influence of EE2 during development and the effects do not appear to be restored after a long recovery period in clean water. We have shown that exposure to low doses of EE2 during development results in increased anxiety in two fish species (zebrafish and guppy) and their offspring. We have also demonstrated that the effects of EE2 on anxiety are apparent in both sexes and are transgenerationally transmitted to two consecutive generations of unexposed offspring in the guppy. In order to investigate the possible biological mechanisms of the observed persistent effects on non-reproductive behavior, we also performed an RNA sequencing analysis of the whole-brain transcriptome in developmentally exposed zebrafish after remediation in clean water until adulthood. Differential expression of 33 genes in males and 62 genes in females were observed as a result of EE2 exposure, with only one gene affected in both sexes. Functional analysis revealed cholesterol biosynthesis and circadian rhythm to be the top two affected pathways in males and females, respectively. Both pathways have previously been implicated in anxiety behavior and represent possible candidates connecting the transcriptome alterations to the observed behavioral phenotype. The study represents an initial survey of the fish brain transcriptome by means of RNA sequencing after long-term recovery from developmental exposure to an estrogenic compound.

The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine disrupting chemical (EDC) of concern due to its persistent nature and widespread presence in the aquatic environment. In mammals, effects of developmental EDC exposure on reproduction and behavior not only persist to adulthood after discontinued exposure, but are also inherited by several consecutive unexposed generations. The results presented in this thesis demonstrate that non-reproductive behavior in fish is highly sensitive to the influence of EE2 during development and the effects do not appear to be restored after a long recovery period in clean water. We have shown that exposure to low doses of EE2 during development results in increased anxiety in two fish species (zebrafish and guppy) and their offspring. We have also demonstrated that the effects of EE2 on anxiety are apparent in both sexes and are transgenerationally transmitted to two consecutive generations of unexposed offspring in the guppy. In order to investigate the possible biological mechanisms of the observed persistent effects on non-reproductive behavior, we also performed an RNA sequencing analysis of the whole-brain transcriptome in developmentally exposed zebrafish after remediation in clean water until adulthood. Differential expression of 33 genes in males and 62 genes in females were observed as a result of EE2 exposure, with only one gene affected in both sexes. Functional analysis revealed cholesterol biosynthesis and circadian rhythm to be the top two affected pathways in males and females, respectively. Both pathways have previously been implicated in anxiety behavior and represent possible candidates connecting the transcriptome alterations to the observed behavioral phenotype. The study represents an initial survey of the fish brain transcriptome by means of RNA sequencing after long-term recovery from developmental exposure to an estrogenic compound.

Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and nonreproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17 alpha-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6 ng/L EE2. After remediation for 82 days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2 ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 12 and 1.6 ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2 ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects., Funding Agency:Swedish Baltic Sea Foundation 1742/42/2008 1556/42/2011

BACKGROUND: Immune suppression may be a critical effect associated with exposure to perfluorinated compounds (PFCs), as indicated by recent data on vaccine antibody responses in children. Therefore, this information may be crucial when deciding on exposure limits. METHODS: Results obtained from follow-up of a Faroese birth cohort were used. Serum-PFC concentrations were measured at age 5 years, and serum antibody concentrations against tetanus and diphtheria toxoids were obtained at ages 7 years. Benchmark dose results were calculated in terms of serum concentrations for 431 children with complete data using linear and logarithmic curves, and sensitivity analyses were included to explore the impact of the low-dose curve shape. RESULTS: Under different linear assumptions regarding dose-dependence of the effects, benchmark dose levels were about 1.3 ng/mL serum for perfluorooctane sulfonic acid and 0.3 ng/mL serum for perfluorooctanoic acid at a benchmark dose response of 5%. These results are below average serum concentrations reported in recent population studies. Even lower results were obtained using logarithmic dose--response curves. Assumption of no effect below the lowest observed dose resulted in higher benchmark dose results, as did a benchmark response of 10%. CONCLUSIONS: The benchmark dose results obtained are in accordance with recent data on toxicity in experimental models. When the results are converted to approximate exposure limits for drinking water, current limits appear to be several hundred fold too high. Current drinking water limits therefore need to be reconsidered.

BACKGROUND: Immune suppression may be a critical effect associated with exposure to perfluorinated compounds (PFCs), as indicated by recent data on vaccine antibody responses in children. Therefore, this information may be crucial when deciding on exposure limits. METHODS: Results obtained from follow-up of a Faroese birth cohort were used. Serum-PFC concentrations were measured at age 5 years, and serum antibody concentrations against tetanus and diphtheria toxoids were obtained at ages 7 years. Benchmark dose results were calculated in terms of serum concentrations for 431 children with complete data using linear and logarithmic curves, and sensitivity analyses were included to explore the impact of the low-dose curve shape. RESULTS: Under different linear assumptions regarding dose-dependence of the effects, benchmark dose levels were about 1.3 ng/mL serum for perfluorooctane sulfonic acid and 0.3 ng/mL serum for perfluorooctanoic acid at a benchmark dose response of 5%. These results are below average serum concentrations reported in recent population studies. Even lower results were obtained using logarithmic dose--response curves. Assumption of no effect below the lowest observed dose resulted in higher benchmark dose results, as did a benchmark response of 10%. CONCLUSIONS: The benchmark dose results obtained are in accordance with recent data on toxicity in experimental models. When the results are converted to approximate exposure limits for drinking water, current limits appear to be several hundred fold too high. Current drinking water limits therefore need to be reconsidered.

Effects of continuous low-dose maternal methylmercury intoxication on the induction and propagation of ictal epileptiform activity induced by 3-aminopyridine, were investigated on the neocortex of 4-weeks-old offspring rats. Epileptogenicity was significantly increased in offspring of mercury-treated animals compared to those of controls, characterized by more frequent occurrence of periodic ictal activity, a facilitated propagation of epileptiform discharges and a strong tendency to generalization. The latency of first ictal event was slightly shorter and the average duration of individual ictal periods slightly longer in treated animals. However, the amplitude of seizure discharges was significantly smaller in treated animals than in controls.We conclude, that the synaptic and membrane mechanisms responsible for initiation and propagation of paroxysmal activity were probably facilitated, while the efficacy of cortical inhibition, in preventing initiation and spread of epileptiform discharges was reduced by mercury treatment in the developing nervous system. The smaller amplitude of paroxysmal discharges could be a sign of a remarkable loss of cortical neurons. Copyright (C) 1999 ISDN., SCOPUS: ar.j, info:eu-repo/semantics/published

Effects of continuous low-dose maternal methylmercury intoxication on the induction and propagation of ictal epileptiform activity induced by 3-aminopyridine, were investigated on the neocortex of 4-weeks-old offspring rats. Epileptogenicity was significantly increased in offspring of mercury-treated animals compared to those of controls, characterized by more frequent occurrence of periodic ictal activity, a facilitated propagation of epileptiform discharges and a strong tendency to generalization. The latency of first ictal event was slightly shorter and the average duration of individual ictal periods slightly longer in treated animals. However, the amplitude of seizure discharges was significantly smaller in treated animals than in controls.We conclude, that the synaptic and membrane mechanisms responsible for initiation and propagation of paroxysmal activity were probably facilitated, while the efficacy of cortical inhibition, in preventing initiation and spread of epileptiform discharges was reduced by mercury treatment in the developing nervous system. The smaller amplitude of paroxysmal discharges could be a sign of a remarkable loss of cortical neurons. Copyright (C) 1999 ISDN., SCOPUS: ar.j, info:eu-repo/semantics/published