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Morera H, Dave P, Kolinko Y, Alahmari S, Anderson A, Denham G, Davis C, Riano J, Goldgof D, Hall LO, Harry GJ, Mouton PR. A novel deep learning-based method for automatic stereology of microglia cells from low magnification images. Neurotoxicol Teratol 2024; 102:107336. [PMID: 38402997 DOI: 10.1016/j.ntt.2024.107336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/31/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
Microglial cells mediate diverse homeostatic, inflammatory, and immune processes during normal development and in response to cytotoxic challenges. During these functional activities, microglial cells undergo distinct numerical and morphological changes in different tissue volumes in both rodent and human brains. However, it remains unclear how these cytostructural changes in microglia correlate with region-specific neurochemical functions. To better understand these relationships, neuroscientists need accurate, reproducible, and efficient methods for quantifying microglial cell number and morphologies in histological sections. To address this deficit, we developed a novel deep learning (DL)-based classification, stereology approach that links the appearance of Iba1 immunostained microglial cells at low magnification (20×) with the total number of cells in the same brain region based on unbiased stereology counts as ground truth. Once DL models are trained, total microglial cell numbers in specific regions of interest can be estimated and treatment groups predicted in a high-throughput manner (<1 min) using only low-power images from test cases, without the need for time and labor-intensive stereology counts or morphology ratings in test cases. Results for this DL-based automatic stereology approach on two datasets (total 39 mouse brains) showed >90% accuracy, 100% percent repeatability (Test-Retest) and 60× greater efficiency than manual stereology (<1 min vs. ∼ 60 min) using the same tissue sections. Ongoing and future work includes use of this DL-based approach to establish clear neurodegeneration profiles in age-related human neurological diseases and related animal models.
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Affiliation(s)
- Hunter Morera
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA.
| | - Palak Dave
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - Yaroslav Kolinko
- Department of Histology and Embryology & Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Saeed Alahmari
- Department of Computer Science, Najran University, Najran 66462, Saudi Arabia
| | | | | | | | | | - Dmitry Goldgof
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - Lawrence O Hall
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - G Jean Harry
- Mechanistic Toxicology Branch, Division of Translational Toxicology, NIEHS/NIH, Research Triangle Park, NC 27709, USA
| | - Peter R Mouton
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA; SRC Biosciences, Tampa, FL 33606, USA.
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Gilbert ME, O'Shaughnessy KL, Thomas SE, Riutta C, Wood CR, Smith A, Oshiro WO, Ford RL, Hotchkiss MG, Hassan I, Ford JL. Thyroid Disruptors: Extrathyroidal Sites of Chemical Action and Neurodevelopmental Outcome-An Examination Using Triclosan and Perfluorohexane Sulfonate. Toxicol Sci 2021; 183:195-213. [PMID: 34460931 PMCID: PMC9038230 DOI: 10.1093/toxsci/kfab080] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Many xenobiotics are identified as potential thyroid disruptors due to their action to reduce circulating levels of thyroid hormone, most notably thyroxine (T4). Developmental neurotoxicity is a primary concern for thyroid disrupting chemicals yet correlating the impact of chemically induced changes in serum T4 to perturbed brain development remains elusive. A number of thyroid-specific neurodevelopmental assays have been proposed, based largely on the model thyroid hormone synthesis inhibitor propylthiouracil (PTU). This study examined whether thyroid disrupting chemicals acting distinct from synthesis inhibition would result in the same alterations in brain as expected with PTU. The perfluoroalkyl substance perfluorohexane sulfonate (50 mg/kg/day) and the antimicrobial Triclosan (300 mg/kg/day) were administered to pregnant rats from gestational day 6 to postnatal day (PN) 21, and a number of PTU-defined assays for neurotoxicity evaluated. Both chemicals reduced serum T4 but did not increase thyroid stimulating hormone. Both chemicals increased expression of hepatic metabolism genes, while thyroid hormone-responsive genes in the liver, thyroid gland, and brain were largely unchanged. Brain tissue T4 was reduced in newborns, but despite persistent T4 reductions in serum, had recovered in the PN6 pup brain. Neither treatment resulted in a low dose PTU-like phenotype in either brain morphology or neurobehavior, raising questions for the interpretation of serum biomarkers in regulatory toxicology. They further suggest that reliance on serum hormones as prescriptive of specific neurodevelopmental outcomes may be too simplistic and to understand thyroid-mediated neurotoxicity we must expand our thinking beyond that which follows thyroid hormone synthesis inhibition.
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Affiliation(s)
- Mary E Gilbert
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Katherine L O'Shaughnessy
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Susan E Thomas
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Cal Riutta
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Carmen R Wood
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Alicia Smith
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Wendy O Oshiro
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Richard L Ford
- Oak Ridge Institute for Science Education, Oak Ridge, Tennesse 37830, USA
| | - Michelle Gatien Hotchkiss
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Iman Hassan
- Center for Public Health and Environmental Assessment, Public Health Integrated Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
| | - Jermaine L Ford
- Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27709, USA
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Latchney SE, Majewska AK. Persistent organic pollutants at the synapse: Shared phenotypes and converging mechanisms of developmental neurotoxicity. Dev Neurobiol 2021; 81:623-652. [PMID: 33851516 DOI: 10.1002/dneu.22825] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 02/27/2021] [Accepted: 04/09/2021] [Indexed: 12/18/2022]
Abstract
The developing nervous system is sensitive to environmental and physiological perturbations in part due to its protracted period of prenatal and postnatal development. Epidemiological and experimental studies link developmental exposures to persistent organic pollutants (POPs) including polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polybrominated diphenyl ethers, and benzo(a)pyrene to increased risk for neurodevelopmental disorders in children. Mechanistic studies reveal that many of the complex cellular processes that occur during sensitive periods of rapid brain development are cellular targets for developmental neurotoxicants. One area of research interest has focused on synapse formation and plasticity, processes that involve the growth and retraction of dendrites and dendritic spines. For each chemical discussed in this review, we summarize the morphological and electrophysiological data that provide evidence that developmental POP exposure produces long-lasting effects on dendritic morphology, spine formation, glutamatergic and GABAergic signaling systems, and synaptic transmission. We also discuss shared intracellular mechanisms, with a focus on calcium and thyroid hormone homeostasis, by which these chemicals act to modify synapses. We conclude our review highlighting research gaps that merit consideration when characterizing synaptic pathology elicited by chemical exposure. These gaps include low-dose and nonmonotonic dose-response effects, the temporal relationship between dendritic growth, spine formation, and synaptic activity, excitation-inhibition balance, hormonal effects, and the need for more studies in females to identify sex differences. By identifying converging pathological mechanisms elicited by POP exposure at the synapse, we can define future research directions that will advance our understanding of these chemicals on synapse structure and function.
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Affiliation(s)
- Sarah E Latchney
- Department of Biology, St. Mary's College of Maryland, St. Mary's City, MD, USA.,Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, USA
| | - Ania K Majewska
- Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Center for Visual Science, University of Rochester Medical Center, Rochester, NY, USA
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4
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Bowen C, Childers G, Perry C, Martin N, McPherson CA, Lauten T, Santos J, Harry GJ. Mitochondrial-related effects of pentabromophenol, tetrabromobisphenol A, and triphenyl phosphate on murine BV-2 microglia cells. CHEMOSPHERE 2020; 255:126919. [PMID: 32402876 PMCID: PMC8439439 DOI: 10.1016/j.chemosphere.2020.126919] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/18/2020] [Accepted: 04/27/2020] [Indexed: 05/02/2023]
Abstract
The predominant reliance on bromated flame retardants (BFRs) is diminishing with expanded use of alternative organophosphate flame retardants. However, exposure related issues for susceptible populations, the developing, infirmed, or aged, remain given environmental persistence and home-environment detection. In this regard, reports of flame retardant (FR)-related effects on the innate immune system suggest process by which a spectrum of adverse health effects could manifest across the life-span. As representative of the nervous system innate immune system, the current study examined changes in microglia following exposure to representative FRs, pentabromophenol (PBP), tetrabromobisphenol A (2,2',6,6',-tetrabromo-4,4'-isopropylidine diphenol; TBBPA) and triphenyl phosphate (TPP). Following 18hr exposure of murine BV-2 cells, at dose levels resulting in ≥80% viability (10 and 40 μM), limited alterations in pro-inflammatory responses were observed however, changes were observed in mitochondrial respiration. Basal respiration was altered by PBP; ATP-linked respiration by PBP and TBBPA, and maximum respiration by all three FRs. Basal glycolytic rate was altered by PBP and TBBPA and compensatory glycolysis by all three. Phagocytosis was decreased for PBP and TBBPA. NLRP3 inflammasome activation was assessed using BV-2-ASC (apoptosis-associated speck-like protein containing a CARD) reporter cells to visualize aggregate formation. PBP, showed a direct stimulation of aggregate formation and properties as a NLRP3 inflammasome secondary trigger. TBBPA showed indications of possible secondary triggering activity while no changes were seen with TPP. Thus, the data suggests an effect of all three FRs on mitochondria metabolism yet, different functional outcomes including, phagocytic capability and NLRP3 inflammasome activation.
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Affiliation(s)
| | | | | | - Negin Martin
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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Ramhøj L, Hass U, Gilbert ME, Wood C, Svingen T, Usai D, Vinggaard AM, Mandrup K, Axelstad M. Evaluating thyroid hormone disruption: investigations of long-term neurodevelopmental effects in rats after perinatal exposure to perfluorohexane sulfonate (PFHxS). Sci Rep 2020; 10:2672. [PMID: 32060323 PMCID: PMC7021709 DOI: 10.1038/s41598-020-59354-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/24/2020] [Indexed: 12/17/2022] Open
Abstract
Thyroid hormones are critical for mammalian brain development. Thus, chemicals that can affect thyroid hormone signaling during pregnancy are of great concern. Perfluorohexane sulfonate (PFHxS) is a widespread environmental contaminant found in human serum, breastmilk, and other tissues, capable of lowering serum thyroxine (T4) in rats. Here, we investigated its effects on the thyroid system and neurodevelopment following maternal exposure from early gestation through lactation (0.05, 5 or 25 mg/kg/day PFHxS), alone or in combination with a mixture of 12 environmentally relevant endocrine disrupting compounds (EDmix). PFHxS lowered thyroid hormone levels in both dams and offspring in a dose-dependent manner, but did not change TSH levels, weight, histology, or expression of marker genes of the thyroid gland. No evidence of thyroid hormone-mediated neurobehavioral disruption in offspring was observed. Since human brain development appear very sensitive to low T4 levels, we maintain that PFHxS is of potential concern to human health. It is our view that current rodent models are not sufficiently sensitive to detect adverse neurodevelopmental effects of maternal and perinatal hypothyroxinemia and that we need to develop more sensitive brain-based markers or measurable metrics of thyroid hormone-dependent perturbations in brain development.
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Affiliation(s)
- Louise Ramhøj
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark
| | - Ulla Hass
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark
| | - Mary E Gilbert
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Carmen Wood
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Terje Svingen
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark
| | - Diana Usai
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark
| | - Anne Marie Vinggaard
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark
| | - Karen Mandrup
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark
| | - Marta Axelstad
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, DK-2800,, Denmark.
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Edwards CM, Small D, Bell T, David-Drori J, Hansen C, Morris-Schaffer K, Canale C, Ng J, Markowski VP. Early postnatal decabromodiphenyl ether exposure reduces thyroid hormone and astrocyte density in the juvenile mouse dentate gyrus. Physiol Behav 2020; 216:112798. [PMID: 31926943 DOI: 10.1016/j.physbeh.2020.112798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/03/2020] [Accepted: 01/03/2020] [Indexed: 12/15/2022]
Abstract
Decabromodiphenyl ether (decaBDE) is a flame retardant that was widely-applied to many consumer products for decades. Consequently, decaBDE and other members of its class have become globally-distributed environmental contaminants. Epidemiological and animal studies indicate that decaBDE exposure during critical periods of brain development produces long-term behavioral impairments. The current study was designed to identify potential neuroendocrine mechanisms for learning and response inhibition deficits observed by our lab in a previous study. C57BL6/J mouse pups were given a single daily oral dose of 0 or 20 mg/kg decaBDE from day 1 to 21. Serum thyroid hormone levels and astrocyte-specific staining in three regions of the hippocampus were measured on day 22. DecaBDE exposure significantly reduced serum triiodothyronine, thyroxine, and astrocyte density in the subgranular zone but not the hilus or granular layer in both male and female mice. The reduction of thyroid hormone and/or glia activity could impair hippocampal development, leading to behavior dysfunction.
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Affiliation(s)
- Caitlyn M Edwards
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Deena Small
- Department of Biochemistry, University of New England, Biddeford, ME 04005, United States
| | - Tyler Bell
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Julian David-Drori
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Christina Hansen
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Keith Morris-Schaffer
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Charlene Canale
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - John Ng
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Vincent P Markowski
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States.
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Baş O, Çankaya S, Enginyurt Ö, Aslan A, Uydu HA, Odaci E, Yılmaz A, Demir A, Gul T. The effect of acute organophosphate intoxication on female rat hippocampus cornu ammonis region pyramidal neuron numbers, biochemistry and morphology. J Chem Neuroanat 2019; 100:101652. [DOI: 10.1016/j.jchemneu.2019.101652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 04/03/2019] [Accepted: 05/24/2019] [Indexed: 12/27/2022]
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Beekhuijzen M, Rijk JCW, Meijer M, de Raaf MA, Pelgrom S. A critical evaluation of thyroid hormone measurements in OECD test guideline studies: Is there any added value? Reprod Toxicol 2019; 88:56-66. [PMID: 31348994 DOI: 10.1016/j.reprotox.2019.07.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/28/2019] [Accepted: 07/19/2019] [Indexed: 01/14/2023]
Abstract
Recently several OECD test guidelines were updated to include thyroid hormone measurements for assessing endocrine disruptor potency, which led to an imperative need to align interpretation of these results by the different stakeholders. We therefore evaluated 124 repro screening studies, which showed in 38% of the studies a statistical significant finding for T4 in at least one treatment group, probably due to disturbances of normal homeostasis causing high variation. Consequently, for a thorough evaluation it is extremely important to take the historical control range into account. In conclusion, the current testing approach is not providing specific information needed to assess endocrine disruption, as too often a statistical significant finding is noted and as down-stream adverse effects are not evaluated. Therefore, major modifications are urgently needed. Instead of extending the in vivo experiments, it should be investigated if in vitro assessments will provide more relevant information on human endocrine disruptor potential.
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Age-Related Decrease in Tyrosine Hydroxylase Immunoreactivity in the Substantia Nigra and Region-Specific Changes in Microglia Morphology in HIV-1 Tg Rats. Neurotox Res 2019; 36:563-582. [PMID: 31286433 DOI: 10.1007/s12640-019-00077-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/28/2019] [Accepted: 06/14/2019] [Indexed: 12/12/2022]
Abstract
Animal models have been used to study cellular processes related to human immunodeficiency virus-1 (HIV-1)-associated neurocognitive disorders (HAND). The HIV-1 transgenic (Tg) rat expresses HIV viral genes except the gag-pol replication genes and exhibits neuropathological features similar to HIV patients receiving combined antiretroviral therapy (cART). Using this rat, alterations in dopaminergic function have been demonstrated; however, the data for neuroinflammation and glial reactivity is conflicting. Differences in behavior, tyrosine hydroxylase (TH) immunoreactivity, neuroinflammation, and glia reactivity were assessed in HIV-1 Tg male rats. At 6 and 12 weeks of age, rotarod performance was diminished, motor activity was not altered, and active avoidance latency performance and memory were diminished in HIV-1 Tg rats. TH+ immunoreactivity in the substantia nigra (SN) was decreased at 8 months but not at 2-5 months. At 5 months, astrocyte and microglia morphology was not altered in the cortex, hippocampus, or SN. In the striatum, astrocytes were unaltered, microglia displayed slightly thickened proximal processes, mRNA levels for Iba1 and Cd11b were elevated, and interleukin (Il)1α,Cxcr3, and cell adhesion molecule, Icam, decreased. In the hippocampus, mRNA levels for Tnfa and Cd11b were slightly elevated. No changes were observed in the cortex or SN. The data support an age-related effect of HIV proteins upon the nigrostriatal dopaminergic system and suggest an early response of microglia in the terminal synaptic region with little evidence of an associated neuroinflammatory response across brain regions.
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Adlimoghaddam A, Snow WM, Stortz G, Perez C, Djordjevic J, Goertzen AL, Ko JH, Albensi BC. Regional hypometabolism in the 3xTg mouse model of Alzheimer's disease. Neurobiol Dis 2019; 127:264-277. [PMID: 30878533 DOI: 10.1016/j.nbd.2019.03.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 02/22/2019] [Accepted: 03/12/2019] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive age-related neurodegenerative disease. Although neurofibrillary tangles and amyloid beta are classic hallmarks of AD, the earliest deficits in AD progression may be caused by unknown factors. One suspected factor has to do with brain energy metabolism. To investigate this factor, brain metabolic activity in 3xTg-AD mice and age-matched controls were measured with FDG-PET. Significant hypometabolic changes (p < .01) in brain metabolism were detected in the cortical piriform and insular regions of AD brains relative to controls. These regions are associated with olfaction, which is a potential clinical marker for AD progression as well as neurogenesis. The activity of the terminal component of the mitochondrial respiratory chain (complex IV) and the expression of complex I-V were significantly decreased (p < .05), suggesting that impaired metabolic activity coupled with impaired oxidative phosphorylation leads to decreased mitochondrial bioenergetics and subsequent Neurodegeneration. Although there is an association between neuroinflammatory pathological markers (microglial) and hypometabolism in AD, there was no association found between neuropathological (Aβ, tau, and astrocytes) and functional changes in AD sensitive brain regions, also suggesting that brain hypometabolism occurs prior to AD pathology. Therefore, targeting metabolic mechanisms in cortical piriform and insular regions at early stages may be a promising approach for preventing, slowing, and/or blocking the onset of AD and preserving neurogenesis.
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Affiliation(s)
- Aida Adlimoghaddam
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada.
| | | | | | - Claudia Perez
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada
| | - Jelena Djordjevic
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada
| | | | - Ji Hyun Ko
- Dept. of Human Anatomy and Cell Science, University of Manitoba, Canada; Health Sciences Centre, Canada
| | - Benedict C Albensi
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada.
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Wang Y, Han J, Chen X, Zeng X, Wang Y, Dong J, Chen J. Maternal iodine supplementation improves motor coordination in offspring by modulating the mGluR1 signaling pathway in mild iodine deficiency-induced hypothyroxinemia rats. J Nutr Biochem 2018; 58:80-89. [DOI: 10.1016/j.jnutbio.2018.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/17/2018] [Accepted: 04/22/2018] [Indexed: 02/02/2023]
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12
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Physiological approaches to assess diminished sympathetic activity in the conscious rat. J Pharmacol Toxicol Methods 2017; 88:64-71. [PMID: 28658603 DOI: 10.1016/j.vascn.2017.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/16/2017] [Accepted: 06/24/2017] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to evaluate functional measures of diminished sympathetic activity after postganglionic neuronal loss in the conscious rat. To produce variable degrees of sympathetic postganglionic neuronal loss, adult rats were treated daily with toxic doses of guanethidine (100mg/kg) for either 5days or 11days, followed by a recovery period of at least 18days. Heart rate, blood pressure, cardiac baroreflex responsiveness, urinalysis (for catecholamine metabolite, 3-methoxy-4-hydroxyphenylethylenglycol; MHPG), and pupillometry were performed during the recovery period. At the end of the recovery period stereology of superior cervical ganglia (SCG) was performed to determine the degree of neuronal loss. Total number of SCG neurons was correlated to physiological outcomes using regression analysis. Whereas guanethidine treatment for 11days caused significant reduction in the number of neurons (15,646±1460 vs. 31,958±1588), guanethidine treatment for 5days caused variable levels of neuronal depletion (26,009±3518). Regression analysis showed that only changes in urinary MHPG levels and systolic blood pressure significantly correlated with reduction of SCG neurons (r2=0.45 and 0.19, both p<0.05). Although cardiac baroreflex-induced reflex tachycardia (345.7±19.6 vs. 449.7±20.3) and pupil/iris ratio (0.50±0.03% vs. 0.61±0.02%) were significantly attenuated in the 11-day guanethidine treated rats there was no significant relationship between these measurements and the number of remaining SCG neurons after treatment (p>0.05). These data suggest that basal systolic blood pressure and urinary MHPG levels predict drug-induced depletion of sympathetic activity in vivo.
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Trumpff C, De Schepper J, Vanderfaeillie J, Vercruysse N, Van Oyen H, Moreno-Reyes R, Tafforeau J, Vandevijvere S. Neonatal thyroid-stimulating hormone concentration and psychomotor development at preschool age. Arch Dis Child 2016; 101:1100-1106. [PMID: 27402733 PMCID: PMC5256416 DOI: 10.1136/archdischild-2015-310006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 06/14/2016] [Accepted: 06/16/2016] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Thyroid hormones are essential for normal brain development. The aim of this study is to assess if high concentration of thyroid stimulating hormone (TSH) that is below the clinical threshold (5-15 mIU/L) at neonatal screening is linked to psychomotor development impairments in the offspring at preschool age. DESIGN A total of 284 Belgian preschool children 4-6 years old and their mothers were included in the study. The children were randomly selected from the total list of neonates screened in 2008, 2009 and 2010 by the Brussels newborn screening centre. The sampling was stratified by gender and TSH range (0.45-15 mIU/L). Infants with congenital hypothyroidism (>15 mIU/L), low birth weight and/or prematurity were excluded. Psychomotor development was assessed using the Charlop-Atwell scale of motor coordination. The iodine status of children was determined using median urinary iodine concentration. Socioeconomic, parental and child potential confounding factors were measured through a self-administered questionnaire. RESULTS TSH level was not significantly associated with total motor score (average change in z-score per unit increase in TSH is 0.02 (-0.03, 0.07), p=0.351), objective motor score (p=0.794) and subjective motor score (p=0.124). No significant associations were found using multivariate regression model to control confounding factors. CONCLUSIONS Mild thyroid dysfunction in the newborn-reflected by an elevation of TSH that is below the clinical threshold (5-15 mIU/L)-was not associated with impaired psychomotor development at preschool age.
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Affiliation(s)
- Caroline Trumpff
- Unit of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium
| | - Jean De Schepper
- Department of Paediatric Endocrinology, UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Johan Vanderfaeillie
- Faculty of Psychology and Educational Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Nathalie Vercruysse
- Faculty of Psychology and Educational Sciences, Université Libre de Bruxelles, Brussels, Belgium
| | - Herman Van Oyen
- Unit of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium
| | - Rodrigo Moreno-Reyes
- Department of Nuclear Medicine, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean Tafforeau
- Unit of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium
| | - Stefanie Vandevijvere
- Unit of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium
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Xiao H, Kuckelkorn J, Nüßer LK, Floehr T, Hennig MP, Roß-Nickoll M, Schäffer A, Hollert H. The metabolite 3,4,3',4'-tetrachloroazobenzene (TCAB) exerts a higher ecotoxicity than the parent compounds 3,4-dichloroaniline (3,4-DCA) and propanil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 551-552:304-316. [PMID: 26878642 DOI: 10.1016/j.scitotenv.2016.02.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/02/2016] [Accepted: 02/02/2016] [Indexed: 06/05/2023]
Abstract
3,4,3',4'-tetrachloroazobenzene (TCAB) is not commercially manufactured but formed as an unwanted by-product in the manufacturing of 3,4-dichloroaniline (3,4-DCA) or metabolized from the degradation of chloranilide herbicides, like propanil. While a considerable amount of research has been done concerning the toxicological and ecotoxicological effects of propanil and 3,4-DCA, limited information is available on TCAB. Our study examined the toxicity of TCAB in comparison to its parent compounds propanil and 3,4-DCA, using a battery of bioassays including in vitro with aryl hydrocarbon receptor (AhR) mediated activity by the 7-ethoxyresorufin-O-deethylase (EROD) assay and micro-EROD, endocrine-disrupting activity with chemically activated luciferase gene expression (CALUX) as well as in vivo with fish embryo toxicity (FET) assays with Danio rerio. Moreover, the quantitative structure activity response (QSAR) concepts were applied to simulate the binding affinity of TCAB to certain human receptors. It was shown that TCAB has a strong binding affinity to the AhR in EROD and micro-EROD induction assay, with the toxic equivalency factor (TEF) of 8.7×10(-4) and 1.2×10(-5), respectively. TCAB presented to be a weak endocrine disrupting compound with a value of estradiol equivalence factor (EEF) of 6.4×10(-9) and dihydrotestosterone equivalency factor (DEF) of 1.1×10(-10). No acute lethal effects of TCAB were discovered in FET test after 96h of exposure. Major sub-lethal effects detected were heart oedema, yolk malformation, as well as absence of blood flow and tail deformation. QSAR modelling suggested an elevated risk to environment, particularly with respect to binding to the AhR. An adverse effect potentially triggering ERβ, mineralocorticoid, glucocorticoid and progesterone receptor activities might be expected. Altogether, the results obtained suggest that TCAB exerts a higher toxicity than both propanil and 3,4-DCA. This should be considered when assessing the impact of these compounds for the environment and also for regulatory decisions.
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Affiliation(s)
- Hongxia Xiao
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Jochen Kuckelkorn
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Leonie Katharina Nüßer
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Tilman Floehr
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Michael Patrick Hennig
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Martina Roß-Nickoll
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; College of Resources and Environmental Science, Chongqing University, Tiansheng Road Beibei 1, Chongqing 400715, People's Republic of China.
| | - Andreas Schäffer
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, Nanjing 210023, People's Republic of China; College of Resources and Environmental Science, Chongqing University, Tiansheng Road Beibei 1, Chongqing 400715, People's Republic of China.
| | - Henner Hollert
- Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, Nanjing 210023, People's Republic of China; College of Resources and Environmental Science, Chongqing University, Tiansheng Road Beibei 1, Chongqing 400715, People's Republic of China; Key Laboratory of Yangtze Water Environment, Ministry of Education, Tongji University, Siping Road 1239, Shanghai 200092, People's Republic of China.
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15
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Zahner MR, Liu CN, Okerberg CV, Opsahl AC, Bobrowski WF, Somps CJ. Neurophysiological assessment of sympathetic cardiovascular activity after loss of postganglionic neurons in the anesthetized rat. J Pharmacol Toxicol Methods 2016; 80:59-67. [PMID: 27085835 DOI: 10.1016/j.vascn.2016.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 03/29/2016] [Accepted: 04/11/2016] [Indexed: 12/18/2022]
Abstract
The goal of this study was to determine the degree of sympathetic postganglionic neuronal loss required to impair cardiovascular-related sympathetic activity. To produce neuronal loss separate groups of rats were treated daily with guanethidine for either 5days or 11days, followed by a recovery period. Sympathetic activity was measured by renal sympathetic nerve activity (RSNA). Stereology of thoracic (T13) ganglia was performed to determine neuronal loss. Despite loss of more than two thirds of neurons in T13 ganglia in both treated groups no effect on resting blood pressure (BP) or heart rate (HR) was detected. Basal RSNA in rats treated for 5days (0.61±0.10μV∗s) and 11days (0.37±0.08μV∗s) was significantly less than vehicle-treated rats (0.99±0.13μV∗s, p<0.05). Increases in RSNA by baroreceptor unloading were significantly lower in 5-day (1.09±0.19μV∗s) and 11-day treated rats (0.59±0.11μV∗s) compared with vehicle-treated rats (1.82±0.19μV∗s, p<0.05). Increases in RSNA to chemoreceptor stimulation were significantly lower in 5-day treated rats (1.54±0.25μV∗s) compared with vehicle-treated rats (2.69±0.23μV∗s, p<0.05). Increases in RSNA in 11-day treated rats were significantly lower (0.75±0.15μV∗s, p<0.05) compared with both vehicle-treated and 5-day treated rats. A positive correlation of neurons to sympathetic responsiveness but not basal activity was detected. These data suggest that diminished capacity for reflex sympathetic responsiveness rather than basal activity alone must be assessed for complete detection of neurophysiological cardiovascular impairment.
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Affiliation(s)
- Matthew R Zahner
- Drug Safety Research & Development, Pfizer Worldwide Research and Development, Groton, CT 06340, United States.
| | - Chang-Ning Liu
- Drug Safety Research & Development, Pfizer Worldwide Research and Development, Groton, CT 06340, United States
| | - Carlin V Okerberg
- Drug Safety Research & Development, Pfizer Worldwide Research and Development, Groton, CT 06340, United States
| | - Alan C Opsahl
- Drug Safety Research & Development, Pfizer Worldwide Research and Development, Groton, CT 06340, United States
| | - Walter F Bobrowski
- Drug Safety Research & Development, Pfizer Worldwide Research and Development, Groton, CT 06340, United States
| | - Chris J Somps
- Drug Safety Research & Development, Pfizer Worldwide Research and Development, Groton, CT 06340, United States
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16
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Association Between Microglia, Inflammatory Factors, and Complement with Loss of Hippocampal Mossy Fiber Synapses Induced by Trimethyltin. Neurotox Res 2016; 30:53-66. [PMID: 26892644 DOI: 10.1007/s12640-016-9606-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/16/2022]
Abstract
Complement-associated factors are implicated in pathogen presentation, neurodegeneration, and microglia resolution of tissue injury. To characterize complement activation with microglial clearance of degenerating mossy fiber boutons, hippocampal dentate granule neurons were ablated in CD-1 mice with trimethyltin (TMT; 2.2 mg/kg, i.p.). Neuronal apoptosis was accompanied by amoeboid microglia and elevations in tumor necrosis factor [Tnfa], interleukin 1β [Il1b], and Il6 mRNA and C1q protein. Inos mRNA levels were unaltered. Silver degeneration and synaptophysin staining indicated loss of synaptic innervation to CA3 pyramidal neurons. Reactive microglia with thickened bushy morphology showed co-localization of synaptophysin+ fragments. The initial response at 2 days post-TMT included transient elevations in Tnfa, Il1b, Il6, and Inos mRNA levels. A concurrent increase at 2 days was observed in arginase-1 [Arg1], Il10, transforming growth factor β1 [Tgfb1], and chitinase 3 like-3 [Ym1] mRNA levels. At 2 days, C1q protein was evident in the CA3 with elevated C1qa, C1qb, C3, Cr3a, and Cr3b mRNA levels. mRNA levels remained elevated at 5 days, returning to control by 14 days, corresponding to silver degeneration. mRNA levels for pentraxin3 (Ptx3) were elevated on day 2 and Ptx1 was not altered. Our data suggest an association between microglia reactivity, the induction of anti-inflammatory genes concurrent with pro-inflammatory genes and the expression of complement-associated factors with the degeneration of synapses following apoptotic neuronal loss.
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17
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Wallace DR. Current State of Developmental Neurotoxicology Research. TOXICS 2015; 3:370-372. [PMID: 29051469 PMCID: PMC5606643 DOI: 10.3390/toxics3040370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 09/29/2015] [Accepted: 09/29/2015] [Indexed: 12/11/2022]
Affiliation(s)
- David R Wallace
- Department of Pharmacology & Physiology, Oklahoma State University Center for Health Sciences, 1111 West 17th Street, Tulsa, OK, USA.
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18
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Min H, Dong J, Wang Y, Wang Y, Teng W, Xi Q, Chen J. Maternal Hypothyroxinemia-Induced Neurodevelopmental Impairments in the Progeny. Mol Neurobiol 2015; 53:1613-1624. [PMID: 25666160 DOI: 10.1007/s12035-015-9101-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/15/2015] [Indexed: 12/16/2022]
Abstract
Maternal hypothyroxinemia can induce neurodevelopmental impairments in the developing fetus. We here review recent studies on the epidemiology and molecular mechanisms associated with this important public health issue. In 2011, the American Thyroid Association defined maternal hypothyroxinemia as low serum free thyroxine (FT4) levels (<5th or <10th percentile) existing in conjunction with normal serum free triiodothyronine (FT3) or thyroid stimulating hormone (TSH) levels during pregnancy. Compared to clinical or subclinical hypothyroidism, hypothyroxinemia is more commonly found in pregnant women. Hypothyroxinemia usually ensues in response to several factors, such as mild iodine deficiency, environmental endocrine disrupters, or certain thyroid diseases. Unequivocal evidence demonstrates that maternal hypothyroxinemia leads to negative effects on fetal brain development, increasing the risks for cognitive deficits and poor psychomotor development in resulting progeny. In support of this, rodent models provide direct evidence of neurodevelopmental damage induced by maternal hypothyroxinemia, including dendritic and axonal growth limitation, neural abnormal location, and synaptic function alteration. The neurodevelopmental impairments induced by hypothyroxinemia suggest an independent role of T4. Increasing evidence indicates that adequate thyroxine is required for the mothers in order to protect against the abnormal brain development in their progeny.
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Affiliation(s)
- Hui Min
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110013, People's Republic of China
- Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Jing Dong
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110013, People's Republic of China
- Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Yi Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110013, People's Republic of China
- Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Yuan Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110013, People's Republic of China
- Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Weiping Teng
- Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Qi Xi
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
| | - Jie Chen
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110013, People's Republic of China.
- Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, People's Republic of China.
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