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Chen Z, Chen F, Fang Z, Zhao H, Zhan C, Li C, He Y, Huang C, Long L, Lai K. Glial activation and inflammation in the NTS in a rat model after exposure to diesel exhaust particles. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2021; 83:103584. [PMID: 33460804 DOI: 10.1016/j.etap.2021.103584] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 01/03/2021] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
Airway pollution can affect the central nervous system, but whether this causes glial activation and inflammation in the nucleus of solitary tract (NTS) remains unclear. We used a rat model with exposure to diesel exhaust particulate matter (DEP) at 200 μg/m3 (low exposure) and 1000 μg/m3 (high exposure) for 14 days. Activation of microglia and astrocytes in the NTS was assessed using Iba-1 and glial fibrillary acidic protein (GFAP) staining. The expression of neurotrophic factors including brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and nerve growth factor (NGF) in the NTS were evaluated by immunofluorescence. Changes in the intracellular structure of NTS neurons were observed via electron microscopy. Inflammatory cytokines and oxidant stress levels in the medulla were also measured. Exposure to DEP can cause NTS inflammation as well as airway inflammation, especially in the H-exposure group. We showed that the numbers of microglia and astrocytes in the NTS, as well as NGF expression in the NTS, were significantly higher in both exposure groups than in controls, but BDNF or GDNF expression was not detected. Exposure to DEP induced ultrastructural changes in NTS neurons as reflected by endoplasmic reticulum dilation, ribosomal loss, mitochondrial vacuolization, and a sparse myelin sheath. Medulla inflammation and an imbalance of oxidants and antioxidants also resulted from exposure to DEP. The H-exposure group showed an imbalance of oxidants and antioxidants with decreased levels of SOD and GSH and increased levels of MDA and ROS compared to the control group (both p < 0.01) in the medulla. Inflammatory cytokines (IL-1β, IL-6, and TNF-α) were also significantly increased in the H-exposure group. Fourteen days of exposure to DEP can affect the NTS neurons in rat. Glial activation and inflammation may play important roles in the response of the NTS to DEP.
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Affiliation(s)
- Zhe Chen
- Department of Pulmonary and Critical Care Medicine, Laboratory of Immunology, Affiliated Kunshan Hospital of Jiangsu University, Suzhou, Jiangsu, 215300, China; State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Fagui Chen
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China; Department of Pulmonary and Critical Care Medicine, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou, Guangdong, 515031, China
| | - Zhangfu Fang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Huasi Zhao
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China; Department of Pulmonary and Critical Care Medicine, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China
| | - Chen Zhan
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Chenhui Li
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Yaowei He
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Chuqin Huang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Li Long
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Kefang Lai
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China.
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McCant D, Lange S, Haney J, Honeycutt M. The perpetuation of the misconception that rats receive a 3-5 times lower lung tissue dose than humans at the same ozone concentration. Inhal Toxicol 2017; 29:187-196. [PMID: 28697635 DOI: 10.1080/08958378.2017.1323982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This paper highlights the pervasive misconception concerning 1994 findings from Hatch et al. about ozone (O3) tissue dose in humans versus rats. That study exposed humans to 0.4 ppm and rats to 2 ppm 18O-labeled O3 and found comparable incorporation of 18O into bronchoalveolar lavage constituents. However, during O3 exposure humans were exercising, which increased their ventilation rate five-fold, while rats were at rest. This resulted in similar O3 tissue doses between the two species, and predominantly explained the comparable 18O incorporation at five-fold different concentrations. The five-times higher exercising human inhalation rate offset the five-times lower concentration, producing the same human dose expected at rest at 2 ppm (i.e. 0.4 ppm × 4686 L/2 hour ≈ 2 ppm × 998 L/2 hour). In 2013, Hatch et al. showed that resting humans and resting rats experienced fairly comparable 18O incorporation at the same O3 exposure concentration and activity state into BALF cells. Despite these findings, we show here that in the peer-reviewed literature a substantial proportion of researchers continue to perpetuate the misunderstanding that human lung tissue doses of O3 are simply 3-5 times greater than rat doses at the same O3 concentration, due to interspecies differences, and not considering activity state. It is important to correct this misconception to ensure an appropriate understanding of the implications of O3 studies by the scientific community and policy experts making regulatory decisions (e.g. the US Environmental Protection Agency's National Ambient Air Quality Standards for O3).
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Affiliation(s)
- Darrell McCant
- a Toxicology Division , Texas Commission on Environmental Quality , Austin , TX , USA
| | - Sabine Lange
- a Toxicology Division , Texas Commission on Environmental Quality , Austin , TX , USA
| | - Joseph Haney
- a Toxicology Division , Texas Commission on Environmental Quality , Austin , TX , USA
| | - Michael Honeycutt
- a Toxicology Division , Texas Commission on Environmental Quality , Austin , TX , USA
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McGinnis WR, Audhya T, Edelson SM. Proposed toxic and hypoxic impairment of a brainstem locus in autism. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:6955-7000. [PMID: 24336025 PMCID: PMC3881151 DOI: 10.3390/ijerph10126955] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/07/2013] [Accepted: 11/11/2013] [Indexed: 01/15/2023]
Abstract
Electrophysiological findings implicate site-specific impairment of the nucleus tractus solitarius (NTS) in autism. This invites hypothetical consideration of a large role for this small brainstem structure as the basis for seemingly disjointed behavioral and somatic features of autism. The NTS is the brain's point of entry for visceral afference, its relay for vagal reflexes, and its integration center for autonomic control of circulatory, immunological, gastrointestinal, and laryngeal function. The NTS facilitates normal cerebrovascular perfusion, and is the seminal point for an ascending noradrenergic system that modulates many complex behaviors. Microvascular configuration predisposes the NTS to focal hypoxia. A subregion--the "pNTS"--permits exposure to all blood-borne neurotoxins, including those that do not readily transit the blood-brain barrier. Impairment of acetylcholinesterase (mercury and cadmium cations, nitrates/nitrites, organophosphates, monosodium glutamate), competition for hemoglobin (carbon monoxide, nitrates/nitrites), and higher blood viscosity (net systemic oxidative stress) are suggested to potentiate microcirculatory insufficiency of the NTS, and thus autism.
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Affiliation(s)
- Woody R. McGinnis
- Autism Research Institute, 4182 Adams Avenue, San Diego, CA 92116, USA; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-541-326-8822; Fax: +1-619-563-6840
| | - Tapan Audhya
- Division of Endocrinology, Department of Medicine, New York University Medical School, New York, NY 10016, USA; E-Mail:
| | - Stephen M. Edelson
- Autism Research Institute, 4182 Adams Avenue, San Diego, CA 92116, USA; E-Mail:
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Genc S, Zadeoglulari Z, Fuss SH, Genc K. The adverse effects of air pollution on the nervous system. J Toxicol 2012; 2012:782462. [PMID: 22523490 PMCID: PMC3317189 DOI: 10.1155/2012/782462] [Citation(s) in RCA: 344] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 11/15/2011] [Indexed: 12/20/2022] Open
Abstract
Exposure to ambient air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. In the last decades, the adverse effects of air pollution on the pulmonary and cardiovascular systems have been well established in a series of major epidemiological and observational studies. In the recent past, air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer's disease, Parkinson's disease, and neurodevelopmental disorders. It has been demonstrated that various components of air pollution, such as nanosized particles, can easily translocate to the CNS where they can activate innate immune responses. Furthermore, systemic inflammation arising from the pulmonary or cardiovascular system can affect CNS health. Despite intense studies on the health effects of ambient air pollution, the underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests that air pollution-induced neuroinflammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. A better understanding of the mediators and mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system and mental health.
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Affiliation(s)
- Sermin Genc
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| | - Zeynep Zadeoglulari
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| | - Stefan H. Fuss
- Department of Molecular Biology and Genetics, Bogazici University, 34342 Istanbul, Turkey
| | - Kursad Genc
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
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Auten RL, Foster WM. Biochemical effects of ozone on asthma during postnatal development. Biochim Biophys Acta Gen Subj 2011; 1810:1114-9. [PMID: 21276837 DOI: 10.1016/j.bbagen.2011.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 01/05/2011] [Accepted: 01/21/2011] [Indexed: 01/07/2023]
Abstract
BACKGROUND Ozone exposure during early life has the potential to contribute to the development of asthma as well as to exacerbate underlying allergic asthma. SCOPE OF REVIEW Developmentally regulated aspects of sensitivity to ozone exposure and downstream biochemical and cellular responses. MAJOR CONCLUSIONS Developmental differences in antioxidant defense responses, respiratory physiology, and vulnerabilities to cellular injury during particular developmental stages all contribute to disparities in the health effects of ozone exposure between children and adults. GENERAL SIGNIFICANCE Ozone exposure has the capacity to affect multiple aspects of the "effector arc" of airway hyperresponsiveness, ranging from initial epithelial damage and neural excitation to neural reprogramming during infancy. This article is part of a Special Issue entitled: Biochemistry of Asthma.
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Affiliation(s)
- Richard L Auten
- Department of Pediatrics (Neonatal Medicine), Duke University, DUMC Box 3373, Durham, NC 27710, USA.
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