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Dawes WJ, Grant O, Reitemeier SC, Tetlow S, Lee D, Hirst RA, O'Callaghan C. High-Speed Video Microscopy of Ependymal Cilia in Brain Organotypic and Cell Culture Models. Methods Mol Biol 2024; 2725:239-250. [PMID: 37856029 DOI: 10.1007/978-1-0716-3507-0_15] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
The wall of the ventricular system within the neuraxis is lined almost entirely by E1 ependymal cells, each of which projects multiple motile cilia from their apical surface into the cerebrospinal fluid (CSF). This specialized layer of E1 cells constitutes the border between the CSF and the brain interstitial fluid (BIF), and by controlling influx and efflux across the CSF to BIF interface, it is increasingly recognized to play an integral role in modulating and maintaining the brain microenvironment. The motile cilia have been shown to be responsive to changes in the CSF microenvironment, and while the physiological role of this mechanism remains incompletely understood, manipulating this control mechanism may influence the brain microenvironment potentially opening a new frontier in therapeutic intervention.In this paper, we describe our techniques for preparing organotypic slices from the murine brain parenchyma and establishing cell cultures of multiciliated ependymal cells from mouse and rat neonatal brain tissue. Our methodology generates a functional readout of ciliary function, specifically high-speed video microscopy (HSVM) enables the quantification of ciliary beat frequency (CBF), and characterization of ciliary beat pattern.
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Affiliation(s)
- William J Dawes
- Alder Hey Children's Hospital, University of Liverpool, Liverpool, UK.
- UCL Great Ormond Street Hospital, London, UK.
| | | | | | - Sarah Tetlow
- Alder Hey Children's Hospital, University of Liverpool, Liverpool, UK
| | - Dani Lee
- UCL Great Ormond Street Institute of Child Health & GOSH UCL BRC, London, UK
| | - Robert A Hirst
- Centre for PCD Diagnosis and Research, Department of Respiratory Sciences, University of Leicester, Leicester, UK
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Jiang C, Wang X, Lu C, Li Q, Ma L, Li W, Cui S, Li K, Wang X, Feng Y, Jian F. The Physiological Occlusion of the Central Canal May Be a Prerequisite for Syringomyelia Formation. Neurospine 2023; 20:1346-1357. [PMID: 38171302 PMCID: PMC10762419 DOI: 10.14245/ns.2346834.417] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 01/05/2024] Open
Abstract
OBJECTIVE Syringomyelia is a common central nervous system disease characterized by the dilation of the central canal (CC). Regarding the pathogenesis of syringomyelia, cerebrospinal fluid (CSF) circulation obstruction in the subarachnoid space (SAS) of the spinal cord has been widely accepted. However, clinical and animal studies on obstructing the CSF in SAS failed to form syringomyelia, challenging the theory of SAS obstruction. The precise pathogenesis remains unknown. METHODS We utilized an extradural compression rat model to investigate the pathogenesis underlying syringomyelia. Magnetic resonance imaging enabled detection of syringomyelia formation. To assess CSF flow within the SAS, Evans blue was infused into the cisterna magna. Histological analysis allowed morphological examination of the CC. Furthermore, CSF flow through the CC was traced using Ovalbumin Alexa-Flour 647 conjugate (OAF-647). Scanning electron microscopy (SEM) enabled visualization of ependymal cilia. RESULTS The findings showed that the dura mater below the compression segment exhibited lighter coloration relative to the region above the compression, indicative of partial obstruction within the SAS. However, the degree of SAS occlusion did not significantly differ between syringomyelia (SM-Y group) and those without (SM-N group). Intriguingly, hematoxylin and eosin staining and CSF tracing revealed occlusion of the CC accompanied by reduced CSF flow in the SM-Y group compared to SM-N and control groups. SEM images uncovered impairment of ependymal cilia inside the syringomyelia. CONCLUSION CC occlusion may represent a physiological prerequisite for syringomyelia formation, while SAS obstruction serves to initiate disease onset. The impairment of ependymal cilia appears to facilitate progression of syringomyelia.
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Affiliation(s)
- Chuan Jiang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xinyu Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Chunli Lu
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Qian Li
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Longbing Ma
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Wei Li
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Shengyu Cui
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Kang Li
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiang Wang
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yuxin Feng
- Capital Medical University, Beijing, China
| | - Fengzeng Jian
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China
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Umlauf BJ, Frampton G, Cooper A, Greene HF. A novel strategy to increase the therapeutic potency of GBM chemotherapy via altering parenchymal/cerebral spinal fluid clearance rate. J Control Release 2023; 364:195-205. [PMID: 37865172 DOI: 10.1016/j.jconrel.2023.10.024] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/04/2023] [Accepted: 10/16/2023] [Indexed: 10/23/2023]
Abstract
Patients with glioblastoma (GBM) face a poor prognosis with a median survival of less than two years. Escalating the dose of chemotherapy is often impossible due to patient comorbidities; thus, we focused on modulating brain clearance as a mechanism to enhance drug accumulation. Given the recently identified interconnectivity between brain parenchymal fluid and cerebral spinal fluid (CSF), we reasoned enhancing drug concentration in the CSF also increases drug concentration in the parenchyma where a GBM resides. To improve drug accumulation in the CSF, we impair the motility of ependymal cell cilia. We identified FDA-approved therapeutics that interact with cilia as a "side effect." Therapeutics that inhibit airway cilia also inhibit ependymal cilia. Multiple cilia-inhibiting drugs, when administered in combination with GBM chemotherapy temozolomide (TMZ), significantly improved the overall survival of mice bearing orthotopic GBM. Combining TMZ with lidocaine results in 100% of animals surviving tumor-free to the study endpoint. This treatment results in a ~ 40-fold increase in brain TMZ levels and is well-tolerated. Mice bearing MGMT methylated, human PDX orthotopic GBM also responded with 100% of animals surviving tumor-free to the study endpoint. Finally, even mice bearing TMZ-resistant, orthotopic GBM responded to the combination treatment with 40% of animals surviving tumor-free to the study endpoint, implying this strategy can sensitize TMZ-resistant GBM. These studies offer a new concept for treating malignant brain tumors by improving the accumulation of TMZ in the CNS. In the future, this regimen may also improve the treatment of additional encephalopathies treated by brain-penetrating therapeutics. SIGNIFICANCE: We exploit the interconnectivity of parenchymal and cerebral spinal fluid to enhance the amount of temozolomide that accumulates in the central nervous system to improve the survival of mice bearing brain tumors.
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Affiliation(s)
- Benjamin J Umlauf
- Department of Neurosurgery, Dell Medical School, The University of Texas at Austin, 1601 Trinity St. Bldg B., Austin, USA; Mulva Clinic for the Neurosciences, The University of Texas at Austin, 1601 Trinity St. Bldg A., Austin, USA.
| | - Gabriel Frampton
- Department of Neurosurgery, Dell Medical School, The University of Texas at Austin, 1601 Trinity St. Bldg B., Austin, USA
| | - Alexis Cooper
- Department of Neurosurgery, Dell Medical School, The University of Texas at Austin, 1601 Trinity St. Bldg B., Austin, USA
| | - Hannah-Faith Greene
- Department of Neurosurgery, Dell Medical School, The University of Texas at Austin, 1601 Trinity St. Bldg B., Austin, USA
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Dur AH, Tang T, Viviano S, Sekuri A, Willsey HR, Tagare HD, Kahle KT, Deniz E. In Xenopus ependymal cilia drive embryonic CSF circulation and brain development independently of cardiac pulsatile forces. Fluids Barriers CNS 2020; 17:72. [PMID: 33308296 PMCID: PMC7731788 DOI: 10.1186/s12987-020-00234-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/28/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Hydrocephalus, the pathological expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles, is a common, deadly disease. In the adult, cardiac and respiratory forces are the main drivers of CSF flow within the brain ventricular system to remove waste and deliver nutrients. In contrast, the mechanics and functions of CSF circulation in the embryonic brain are poorly understood. This is primarily due to the lack of model systems and imaging technology to study these early time points. Here, we studied embryos of the vertebrate Xenopus with optical coherence tomography (OCT) imaging to investigate in vivo ventricular and neural development during the onset of CSF circulation. METHODS Optical coherence tomography (OCT), a cross-sectional imaging modality, was used to study developing Xenopus tadpole brains and to dynamically detect in vivo ventricular morphology and CSF circulation in real-time, at micrometer resolution. The effects of immobilizing cilia and cardiac ablation were investigated. RESULTS In Xenopus, using OCT imaging, we demonstrated that ventriculogenesis can be tracked throughout development until the beginning of metamorphosis. We found that during Xenopus embryogenesis, initially, CSF fills the primitive ventricular space and remains static, followed by the initiation of the cilia driven CSF circulation where ependymal cilia create a polarized CSF flow. No pulsatile flow was detected throughout these tailbud and early tadpole stages. As development progressed, despite the emergence of the choroid plexus in Xenopus, cardiac forces did not contribute to the CSF circulation, and ciliary flow remained the driver of the intercompartmental bidirectional flow as well as the near-wall flow. We finally showed that cilia driven flow is crucial for proper rostral development and regulated the spatial neural cell organization. CONCLUSIONS Our data support a paradigm in which Xenopus embryonic ventriculogenesis and rostral brain development are critically dependent on ependymal cilia-driven CSF flow currents that are generated independently of cardiac pulsatile forces. Our work suggests that the Xenopus ventricular system forms a complex cilia-driven CSF flow network which regulates neural cell organization. This work will redirect efforts to understand the molecular regulators of embryonic CSF flow by focusing attention on motile cilia rather than other forces relevant only to the adult.
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Affiliation(s)
- A H Dur
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
- Acibadem Mehmet Ali Aydinlar University School of Medicine, Istanbul, Turkey
| | - T Tang
- Department of Radiology and Biomedical Imaging, Yale University, 300 Cedar St, New Haven, CT, 06510, USA
| | - S Viviano
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
| | - A Sekuri
- Acibadem Mehmet Ali Aydinlar University School of Medicine, Istanbul, Turkey
| | - H R Willsey
- Department of Psychiatry and Behavioral Sciences, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - H D Tagare
- Department of Radiology and Biomedical Imaging, Yale University, 300 Cedar St, New Haven, CT, 06510, USA
| | - K T Kahle
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
- Department of Neurosurgery and Cellular & Molecular Physiology, and Centers for Mendelian Genomics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
| | - E Deniz
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA.
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA.
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