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Koshko L, Scofield S, Debarba L, Stilgenbauer L, Fakhoury P, Jayarathne H, Perez-Mojica JE, Griggs E, Lempradl A, Sadagurski M. Prenatal benzene exposure in mice alters offspring hypothalamic development predisposing to metabolic disease in later life. Chemosphere 2023; 330:138738. [PMID: 37084897 DOI: 10.1016/j.chemosphere.2023.138738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/10/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
Maternal exposure to environmental contaminants during pregnancy poses a significant threat to a developing fetus, as these substances can easily cross the placenta and disrupt the neurodevelopment of offspring. Specifically, the hypothalamus is essential in the regulation of metabolism, notably during critical windows of development. An abnormal hormonal and inflammatory milieu during development can trigger persistent changes in the function of hypothalamic circuits, leading to long-lasting effects on the body's energy homeostasis and metabolism. We recently demonstrated that gestational exposure to clinically relevant levels of benzene induces severe metabolic dysregulation in the offspring. Given the central role of the hypothalamus in metabolic control, we hypothesized that prenatal exposure to benzene impacts hypothalamic development, contributing to the adverse metabolic effects in the offspring. C57BL/6JB dams were exposed to benzene at 50 ppm in the inhalation chambers exclusively during pregnancy (from E0.5 to E19). Transcriptomic analysis of the exposed offspring at postnatal day 21 (P21) revealed hypothalamic changes in genes related to metabolic regulation, inflammation, and neurodevelopment exclusively in males. Moreover, the hypothalamus of prenatally benzene-exposed male offspring displayed alterations in orexigenic and anorexigenic projections, impairments in leptin signaling, and increased microgliosis. Additional exposure to benzene during lactation did not promote further microgliosis or astrogliosis in the offspring, while the high-fat diet (HFD) challenge in adulthood exacerbated glucose metabolism and hypothalamic inflammation in benzene-exposed offspring of both sexes. These findings reveal the persistent adverse effects of prenatal benzene exposure on hypothalamic circuits and neuroinflammation, predisposing the offspring to long-lasting metabolic health conditions.
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Affiliation(s)
- Lisa Koshko
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA
| | - Sydney Scofield
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA
| | - Lucas Debarba
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA
| | - Lukas Stilgenbauer
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA
| | - Patrick Fakhoury
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA
| | - Hashan Jayarathne
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA
| | | | - Ellen Griggs
- Van Andel Research Institute, Grand Rapids, MI, USA
| | | | - Marianna Sadagurski
- Department of Biological Sciences, Institute of Environmental Health Sciences, Integrative Biosciences Center (IBio), Wayne State University, Detroit, MI, USA.
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Yacawych WT, Palmer AL, Doczi MA. Insulin receptor localization in the embryonic avian hypothalamus. Neurosci Lett 2019; 698:126-132. [PMID: 30615976 DOI: 10.1016/j.neulet.2019.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 12/17/2018] [Accepted: 01/04/2019] [Indexed: 11/26/2022]
Abstract
The hypothalamus is a brain region critical for the homeostatic regulation of appetite and energy expenditure. Hypothalamic neuronal activity that is altered during development can produce permanent physiological changes later in life. For example, circulating hormones such as insulin have been shown to influence hypothalamic neuronal projections, leading to altered metabolism in adult rodents. While insulin signaling in the post-hatch chicken has been shown to mirror that of mammals, the developmental role of insulin in the avian embryonic hypothalamus remains largely unexplored. Here we present the earliest known evidence for insulin receptor (InsR) expression in embryonic avian hypothalamic nuclei governing energy homeostasis. RT-PCR analysis reveals InsR mRNA in E8, E10, and E12 neurons while western blot data demonstrate protein expression in E12 avian whole brain and hypothalamic lysates. Immunohistochemical analysis of avian hypothalamic brain slices demonstrates a shift in InsR localization from paraventricular expression in E8 to a more defined concentration of InsR in developmental regions resembling the ventromedial hypothalamus (VMH) and arcuate nucleus (ARC) in E12 time points. In addition, InsR expression appears in a heterogeneous pattern, suggesting receptor localization to subpopulations of avian hypothalamic neurons as early as E8. With increasing evidence suggesting energy homeostasis pathways may be altered via the gestational environment, it is important to understand how insulin signaling may affect embryogenesis. Our research provides evidence for the earliest known embryonic expression of InsR protein in the avian hypothalamus and may suggest a developmental role for insulin signaling in the early patterning of metabolic pathways in the central nervous system.
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Affiliation(s)
- Warren T Yacawych
- Department of Biology, Norwich University, 158 Harmon Drive, Northfield, VT, 05663, USA
| | - Alexandra L Palmer
- Department of Biology, Norwich University, 158 Harmon Drive, Northfield, VT, 05663, USA
| | - Megan A Doczi
- Department of Biology, Norwich University, 158 Harmon Drive, Northfield, VT, 05663, USA.
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Nesan D, Kurrasch DM. Genetic programs of the developing tuberal hypothalamus and potential mechanisms of their disruption by environmental factors. Mol Cell Endocrinol 2016; 438:3-17. [PMID: 27720896 DOI: 10.1016/j.mce.2016.09.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/22/2016] [Accepted: 09/29/2016] [Indexed: 12/15/2022]
Abstract
The hypothalamus is a critical regulator of body homeostasis, influencing the autonomic nervous system and releasing trophic hormones to modulate the endocrine system. The developmental mechanisms that govern formation of the mature hypothalamus are becoming increasingly understood as research in this area grows, leading us to gain appreciation for how these developmental programs are susceptible to disruption by maternal exposure to endocrine disrupting chemicals or other environmental factors in utero. These vulnerabilities, combined with the prominent roles of the various hypothalamic nuclei in regulating appetite, reproductive behaviour, mood, and other physiologies, create a window whereby early developmental disruption can have potent long-term effects. Here we broadly outline our current understanding of hypothalamic development, with a particular focus on the tuberal hypothalamus, including what is know about nuclear coalescing and maturation. We finish by discussing how exposure to environmental or maternally-derived factors can perhaps disrupt these hypothalamic developmental programs, and potentially lead to neuroendocrine disease states.
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Affiliation(s)
- Dinushan Nesan
- Department of Medical Genetics, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Deborah M Kurrasch
- Department of Medical Genetics, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.
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Abstract
The hypothalamus is composed of many heterogeneous nuclei that control distinct physiological functions. Investigating molecular mechanisms that regulate the specification of these nuclei and specific neuronal subtypes, and their contribution to diverse hypothalamic functions, is an exciting research focus. Here, we begin by summarizing the hypothalamic functions of feeding regulation, sleep-wake cycles, stress responses, and circadian rhythm, and describing their anatomical bases. Next, we review the molecular regulation of formation of hypothalamic territories, specification of nuclei and subnuclei, and generation of specific neurons. Finally, we highlight physiological and behavioral consequences of altered hypothalamic development. Identifying molecules that regulate hypothalamic development and function will increase our understanding of hypothalamus-related disorders, such as obesity and diabetes, and aid in the development of therapies aimed specifically at their etiologies.
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Affiliation(s)
- Yanxia Gao
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Tao Sun
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, Box 60, New York, NY, 10065, USA.
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Abstract
The hypothalamus contains a core circuitry that communicates with the brainstem and spinal cord to regulate energy balance. Because metabolic phenotype is influenced by environmental variables during perinatal development, it is important to understand how these neural pathways form in order to identify key signaling pathways that are responsible for metabolic programming. Recent progress in defining gene expression events that direct early patterning and cellular specification of the hypothalamus, as well as advances in our understanding of hormonal control of central neuroendocrine pathways, suggest several key regulatory nodes that may represent targets for metabolic programming of brain structure and function. This review focuses on components of central circuitry known to regulate various aspects of energy balance and summarizes what is known about their developmental neurobiology within the context of metabolic programming.
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Affiliation(s)
- Amanda E Elson
- The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA
| | - Richard B Simerly
- The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA.
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Bilella A, Alvarez-Bolado G, Celio MR. Coaxiality of Foxb1- and parvalbumin-expressing neurons in the lateral hypothalamic PV1-nucleus. Neurosci Lett 2014; 566:111-4. [PMID: 24576653 DOI: 10.1016/j.neulet.2014.02.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 12/25/2022]
Abstract
In the ventrolateral hypothalamus, the PV1-nucleus is defined by its population of parvalbumin-expressing neurons. During embryogenesis, the ventrolateral hypothalamus is colonized also by Foxb1-expressing neurons. In adult Foxb1-EGFP mice, many immunofluorescent neurons were found within the region that is occupied by the PV1-nucleus. They formed a cloud around the axial cord of the parvalbumin-immunopositive cells, which they greatly outnumber (3:1). Only a small proportion of the neurons in the PV1-nucleus co-expressed both parvalbumin and Foxb1. In the light of these findings, a redesignation of this lateral hypothalamic structure as the PV1-Foxb1 nucleus would more accurately reflect its specific biochemical properties.
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Affiliation(s)
- Alessandro Bilella
- Anatomy Unit, Department of Medicine and Program in Neuroscience, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Gonzalo Alvarez-Bolado
- Institute of Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Marco R Celio
- Anatomy Unit, Department of Medicine and Program in Neuroscience, University of Fribourg, CH-1700 Fribourg, Switzerland.
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