1
|
Harkins D, Harvey TJ, Atterton C, Miller I, Currey L, Oishi S, Kasherman M, Davila RA, Harris L, Green K, Piper H, Parton RG, Thor S, Cooper HM, Piper M. Hydrocephalus in Nfix−/− Mice Is Underpinned by Changes in Ependymal Cell Physiology. Cells 2022; 11:cells11152377. [PMID: 35954220 PMCID: PMC9368351 DOI: 10.3390/cells11152377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 02/04/2023] Open
Abstract
Nuclear factor one X (NFIX) is a transcription factor required for normal ependymal development. Constitutive loss of Nfix in mice (Nfix−/−) is associated with hydrocephalus and sloughing of the dorsal ependyma within the lateral ventricles. Previous studies have implicated NFIX in the transcriptional regulation of genes encoding for factors essential to ependymal development. However, the cellular and molecular mechanisms underpinning hydrocephalus in Nfix−/− mice are unknown. To investigate the role of NFIX in hydrocephalus, we examined ependymal cells in brains from postnatal Nfix−/− and control (Nfix+/+) mice using a combination of confocal and electron microscopy. This revealed that the ependymal cells in Nfix−/− mice exhibited abnormal cilia structure and disrupted localisation of adhesion proteins. Furthermore, we modelled ependymal cell adhesion using epithelial cell culture and revealed changes in extracellular matrix and adherens junction gene expression following knockdown of NFIX. Finally, the ablation of Nfix from ependymal cells in the adult brain using a conditional approach culminated in enlarged ventricles, sloughing of ependymal cells from the lateral ventricles and abnormal localisation of adhesion proteins, which are phenotypes observed during development. Collectively, these data demonstrate a pivotal role for NFIX in the regulation of cell adhesion within ependymal cells of the lateral ventricles.
Collapse
Affiliation(s)
- Danyon Harkins
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Tracey J. Harvey
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Cooper Atterton
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Ingrid Miller
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Laura Currey
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Sabrina Oishi
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Maria Kasherman
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Raul Ayala Davila
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Lucy Harris
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane 4072, Australia; (L.H.); (K.G.); (R.G.P.)
| | - Kathryn Green
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane 4072, Australia; (L.H.); (K.G.); (R.G.P.)
| | - Hannah Piper
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Robert G. Parton
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane 4072, Australia; (L.H.); (K.G.); (R.G.P.)
- Institute for Molecular Biosciences, The University of Queensland, Brisbane 4072, Australia
| | - Stefan Thor
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
| | - Helen M. Cooper
- Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia;
| | - Michael Piper
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; (D.H.); (T.J.H.); (C.A.); (I.M.); (L.C.); (S.O.); (M.K.); (R.A.D.); (H.P.); (S.T.)
- Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia;
- Correspondence:
| |
Collapse
|
2
|
Deng S, Gan L, Liu C, Xu T, Zhou S, Guo Y, Zhang Z, Yang GY, Tian H, Tang Y. Roles of Ependymal Cells in the Physiology and Pathology of the Central Nervous System. Aging Dis 2022; 14:468-483. [PMID: 37008045 PMCID: PMC10017161 DOI: 10.14336/ad.2022.0826-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/26/2022] [Indexed: 11/18/2022] Open
Abstract
Ependymal cells are indispensable components of the central nervous system (CNS). They originate from neuroepithelial cells of the neural plate and show heterogeneity, with at least three types that are localized in different locations of the CNS. As glial cells in the CNS, accumulating evidence demonstrates that ependymal cells play key roles in mammalian CNS development and normal physiological processes by controlling the production and flow of cerebrospinal fluid (CSF), brain metabolism, and waste clearance. Ependymal cells have been attached to great importance by neuroscientists because of their potential to participate in CNS disease progression. Recent studies have demonstrated that ependymal cells participate in the development and progression of various neurological diseases, such as spinal cord injury and hydrocephalus, raising the possibility that they may serve as a potential therapeutic target for the disease. This review focuses on the function of ependymal cells in the developmental CNS as well as in the CNS after injury and discusses the underlying mechanisms of controlling the functions of ependymal cells.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Yaohui Tang
- Correspondence should be addressed to: Dr. Yaohui Tang, Med-X Research Institute and School of Biomedical Engineering Shanghai Jiao Tong University, Shanghai, China. .
| |
Collapse
|
3
|
Harkins D, Cooper HM, Piper M. The role of lipids in ependymal development and the modulation of adult neural stem cell function during aging and disease. Semin Cell Dev Biol 2020; 112:61-68. [PMID: 32771376 DOI: 10.1016/j.semcdb.2020.07.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/24/2020] [Accepted: 07/29/2020] [Indexed: 01/10/2023]
Abstract
Within the adult mammalian central nervous system, the ventricular-subventricular zone (V-SVZ) lining the lateral ventricles houses neural stem cells (NSCs) that continue to produce neurons throughout life. Developmentally, the V-SVZ neurogenic niche arises during corticogenesis following the terminal differentiation of telencephalic radial glial cells (RGCs) into either adult neural stem cells (aNSCs) or ependymal cells. In mice, these two cellular populations form rosettes during the late embryonic and early postnatal period, with ependymal cells surrounding aNSCs. These aNSCs and ependymal cells serve a number of key purposes, including the generation of neurons throughout life (aNSCs), and acting as a barrier between the CSF and the parenchyma and promoting CSF bulk flow (ependymal cells). Interestingly, the development of this neurogenic niche, as well as its ongoing function, has been shown to be reliant on different aspects of lipid biology. In this review we discuss the developmental origins of the rodent V-SVZ neurogenic niche, and highlight research which has implicated a role for lipids in the physiology of this part of the brain. We also discuss the role of lipids in the maintenance of the V-SVZ niche, and discuss new research which has suggested that alterations to lipid biology could contribute to ependymal cell dysfunction in aging and disease.
Collapse
Affiliation(s)
- Danyon Harkins
- School of Biomedical Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - Helen M Cooper
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia
| | - Michael Piper
- School of Biomedical Sciences, The University of Queensland, Brisbane, 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia.
| |
Collapse
|
4
|
Hagiwara T, Hagino H, Ueda K, Nakama M, Minami T. Maternal exposure to methylmercury causes an impairment in ependymal cilia motility in the third ventricle and dilation of lateral ventricles in mice offspring. Birth Defects Res 2020; 112:1253-1259. [PMID: 32648687 DOI: 10.1002/bdr2.1750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 05/25/2020] [Accepted: 06/09/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND Although maternal MeHg-exposure causes hydrocephalus in the offspring of mice, its pathogenesis has not been fully explained. In the present study, we examined the issue of how maternal MeHg-exposure in mice affects ependymal ciliary movement in the offspring and whether the lateral ventricles in offspring show dilation. METHODS Pregnant mice were given drinking water containing 0, 10, or 20 mg/L MeHg, or a single dose of 2 mg/kg MeHg. Brain slices were prepared from the offspring and the ependymal ciliary movement of ependymal cells in the third ventricle were observed by a high-speed digital camera. The dilation of the lateral ventricles in the offspring was assessed by histological examination. RESULTS The administration of MeHg in the drinking water of pregnant mice at levels of 10 mg/L and 20 mg/L MeHg from GD10 to birth caused a significant decrease of ciliary beating frequency (CBF) in ependymal cells of the third ventricle in the weaned offspring. The ependymal ciliary movement of the weaned offspring was particularly sensitive in the case of the administration of MeHg at GD10. Moreover, there was a significant dilation of cross-sectional areas of lateral ventricles in weaned offspring from the pregnant mice that had been administered MeHg. The CBF and the cross-sectional areas of the lateral ventricles improved with time. CONCLUSIONS These results suggest that the impairment of ependymal ciliary movement by maternal MeHg-exposure contributes to the development of hydrocephalus in the offspring.
Collapse
Affiliation(s)
- Teruki Hagiwara
- Department of Life Science, School of Science & Engineering, Kindai University, Higashiosaka, Japan
| | - Hajime Hagino
- Department of Science, Interdisciplinary Graduate School of Science and Engineering, Kindai University, Higashiosaka, Japan
| | - Kaho Ueda
- Department of Science, Interdisciplinary Graduate School of Science and Engineering, Kindai University, Higashiosaka, Japan
| | - Mina Nakama
- Department of Science, Interdisciplinary Graduate School of Science and Engineering, Kindai University, Higashiosaka, Japan.,Division of Clinical Genetics, Gifu University Hospital, Gifu, Japan
| | - Takeshi Minami
- Department of Life Science, School of Science & Engineering, Kindai University, Higashiosaka, Japan.,Department of Science, Interdisciplinary Graduate School of Science and Engineering, Kindai University, Higashiosaka, Japan
| |
Collapse
|
5
|
Dórea JG. Multiple low-level exposures: Hg interactions with co-occurring neurotoxic substances in early life. Biochim Biophys Acta Gen Subj 2018; 1863:129243. [PMID: 30385391 DOI: 10.1016/j.bbagen.2018.10.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/01/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022]
Abstract
All chemical forms of Hg can affect neurodevelopment; however, low levels of organic Hg (methylmercury-MeHg and ethylmercury-EtHg in Thimerosal-containing vaccines, hereafter 'TCV') exposures during early life (pregnancy and lactation) co-occur with other environmental neurotoxic substances. These neurotoxicants may act in parallel, synergistically, or antagonistically to Hg. Nevertheless, the risks of neurotoxicity associated with multiple neuro-toxicants depend on type, time, combinations of exposure, and environmental and/or genetic-associated factors. Neurological developmental disorders, delays in cognition and behavioral outcomes associated with multiple exposures (which include Hg) may show transient or lasting outcomes depending on constitutional and/or environmental factors that can interact to neutralize, aggravate or attenuate these effects; often these studies are challenging to interpret. During pregnancy and lactation, fish-MeHg exposure is frequently confounded with the opposing effects of neuroactive nutrients (in fish) that lead to positive, negative, or no effects on neurobehavioral tests. In infancy, exposures to acute binary mixtures (TCV- EtHg and Al-adjuvants in infant immunizations) are associated with increased risks of tics and other developmental disorders. Despite the certitude that promulgates single environmental neurotoxicants, empirical comparisons of combined exposures indicate that Hg-related outcome is uneven. Hg in combination with other neurotoxic mixtures may elevate risks of neurotoxicity, but these risks arise in circumstances that are not yet predictable. Therefore, to achieve the goals of the Minamata treaty and to safeguard the health of children, low levels of mercury exposure (in any chemical form) needs to be further reduced whether the source is environmental (air- and food-borne) or iatrogenic (pediatric TCVs).
Collapse
Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília 70919-970, DF, Brazil..
| |
Collapse
|
6
|
Dórea JG. Low-dose Thimerosal in pediatric vaccines: Adverse effects in perspective. ENVIRONMENTAL RESEARCH 2017; 152:280-293. [PMID: 27816865 DOI: 10.1016/j.envres.2016.10.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/26/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
Vaccines are prophylactics used as the first line of intervention to prevent, control and eradicate infectious diseases. Young children (before the age of six months) are the demographic group most exposed to recommended/mandatory vaccines preserved with Thimerosal and its metabolite ethylmercury (EtHg). Particularly in the less-developed countries, newborns, neonates, and young children are exposed to EtHg because it is still in several of their pediatric vaccines and mothers are often immunized with Thimerosal-containing vaccines (TCVs) during pregnancy. While the immunogenic component of the product has undergone more rigorous testing, Thimerosal, known to have neurotoxic effects even at low doses, has not been scrutinized for the limit of tolerance alone or in combination with adjuvant-Al during immaturity or developmental periods (pregnant women, newborns, infants, and young children). Scientific evidence has shown the potential hazards of Thimerosal in experiments that modeled vaccine-EtHg concentrations. Observational population studies have revealed uncertainties related to neurological effects. However, consistently, they showed a link of EtHg with risk of certain neurodevelopment disorders, such as tic disorder, while clearly revealing the benefits of removing Thimerosal from children's vaccines (associated with immunological reactions) in developed countries. So far, only rich countries have benefited from withdrawing the risk of exposing young children to EtHg. Regarding Thimerosal administered to the very young, we have sufficient studies that characterize a state of uncertainty: the collective evidence strongly suggests that Thimerosal exposure is associated with adverse neurodevelopmental outcomes. It is claimed that the continued use of Thimerosal in the less-developed countries is due to the cost to change to another preservative, such as 2-phenoxyethanol. However, the estimated cost increase per child in the first year of life is lower than estimated lifetime cost of caring for a child with a neurodevelopmental disorder, such tic disorder. The evidence indicates that Thimerosal-free vaccine options should be made available in developing countries.
Collapse
Affiliation(s)
- José G Dórea
- Professor Emeritus, Faculty of Health Sciences, Universidade de Brasilia, 70919-970 Brasilia, DF, Brazil.
| |
Collapse
|