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Scanning electron microscope images of Listeria on ciliated ependymal cells. (A) low magnification of rat ciliated ependymal cells in vitro. Scale bar represents 70 µm, (B) high magnification of a rat ciliated ependymal cell in vitro. Scale bar represents 5 µm, (C) L. monocytogenes strain 10403S on ciliated ependymal cell. The arrow shows areas of extracellular material. Scale bar represents 4 µm, (D) L. monocytogenes strain 10403S aggregate (arrow) on ciliated ependymal cells. No extracellular material is visible. Scale bar represents 2 µm, (E) presence of a thick layer of extracellular material on ciliated ependymal cells after incubation with L. monocytogenes strain EGDe. The arrow is pointing to an area with extracellular material. Scale bar represents 5 µm, (F) L. monocytogenes EGDe aggregate in the presence of extracellular material. The arrow is pointing to an area of extracellular material. Scale bar represents 5 µm.
Source publication
Ciliated ependymal cells line the cerebral ventricles and aqueducts separating the infected CSF from the brain parenchyma in meningitis.
Investigation of the interaction of Listeria monocytogenes with cultured rat brain ependymal cells showed that certain strains reduced the beat frequency of the cilia but all the strains studied significantly redu...
Citations
... Indeed, genetic mutations inducing cilia defects in ependymal cells contribute to neurological disorders such as hydrocephalus (Fliegauf et al., 2007). Cilia defects in ependymal cells are also found in the context of bacterial infections (Hirst et al., 2003;Fadaee-Shohada et al., 2010). Ependymal cells incur DNA damage after traumatic brain injury and have been implicated in major neurological disorders like Alzheimer's disease, where defects could contribute to neurodegeneration if toxic waste clearance and CSF circulation is reduced (Luca et al., 2018). ...
Ependymal cells make up the epithelial monolayer that lines the brain ventricles and the spinal cord central canal that are filled with cerebrospinal fluid. The ependyma has several functions, including regulating solute exchange between the cerebrospinal fluid and parenchyma, controlling microcirculation of cerebrospinal fluid via coordinated ciliary beating, and acting as a partial barrier. Dysregulation of these functions can lead to waste clearance impairment, cerebrospinal fluid accumulation, hydrocephalus, and more. A role for ependymal cells in a variety of neurological disorders has been proposed, including in neuromyelitis optica and multiple sclerosis, two autoimmune demyelinating diseases of the central nervous system, where periventricular damage is common. What is not known is the mechanisms behind how ependymal cells become dysregulated in these diseases. In neuromyelitis optica, it is well established that autoantibodies directed against Aquaporin-4 are drivers of disease, and it has been shown recently that these autoantibodies can drive ependymal cell dysregulation. We propose a similar mechanism is at play in multiple sclerosis, where autoantibodies targeting a glial cell protein called GlialCAM on ependymal cells are contributing to disease. GlialCAM shares high molecular similarities with the Epstein-Barr virus (EBV) protein EBNA1. EBV has recently been shown to be necessary for multiple sclerosis initiation, yet how EBV mediates pathogenesis, especially in the periventricular area, remains elusive. In this perspective article, we discuss how ependymal cells could be targeted by antibody-related autoimmune mechanisms in autoimmune demyelinating diseases and how this is implicated in ventricular/periventricular pathology.
... There is a lack of agreement concerning the CBA definition. 11,25,116,130 CBA has been defined as the distance travelled between the maximum forward and backwards movements of the cilia tip, 130 or as the angle between the cilium body in the end position of an effective stroke and a recovery stroke 116 (which is only an indicator of the CBA, due to the flexible nature of the beat). 11 ...
... There is a lack of agreement concerning the CBA definition. 11,25,116,130 CBA has been defined as the distance travelled between the maximum forward and backwards movements of the cilia tip, 130 or as the angle between the cilium body in the end position of an effective stroke and a recovery stroke 116 (which is only an indicator of the CBA, due to the flexible nature of the beat). 11 ...
Primary ciliary dyskinesia is an inherited disorder in which respiratory cilia are stationary, or beat in a slow or dyskinetic manner, leading to impaired mucociliary clearance and significant sinopulmonary disease. One diagnostic test is ciliary functional analysis using digital high‐speed video microscopy (DHSV), which allows real‐time analysis of complete ciliary function, comprising ciliary beat frequency (CBF) and ciliary beat pattern (CBP). However, DHSV lacks standardization. In this paper, the current knowledge of DHSV ciliary functional analysis is presented, and recommendations given for a standardized protocol for ciliary sample collection and processing. A proposal is presented for a quantitative and qualitative CBP evaluation system, to be used to develop international consensus agreement, and future DHSV research areas are identified.
... Human erythrocytes exhibit a smooth, spherical shape, while ependymal cells demonstrate a long, slender shape. 45,46 These differences produce different cellular responses when internalizing foreign matter, such as nanoparticles. Second, plasma membranes from different cell types have different lipid compositions, which influence the physical properties of membranes and make them function differently. ...
A recently reported incident of severe pulmonary fibrosis caused by inhaled polymer nanoparticles in seven female workers obtained much attention. In addition to the release of ENM waste from industrial sites, a major release of ENMs to environmental water occurs due to home and personal use of appliances, cosmetics, and personal products, such as shampoo and sunscreen. Airborne and aqueous ENMs pose immediate danger to the human respiratory and gastrointestinal systems. ENMs may enter other human organs after they are absorbed into the bloodstream through the gastrointestinal and respiratory systems. Practically, a thorough understanding of the fundamental chemical interactions between nanoparticles and biological systems has two direct impacts. First, this knowledge will encourage and assist experimental approaches to chemically modify nanoparticle surfaces for various industrial or medicinal applications.
... Thus, the initial harvesting of the partner along mucociliary membranes may also be the period of the first molecular interactions underlying partner recognition. Whereas the interface of beneficial or benign bacteria with host cilia is more common than the interaction with pathogenic microbes, the cilia-microbe relationship has been studied in depth principally in cell or tissue culture models of interactions with bacterial pathogens, such as Pseudomonas aeruginosa (Bajolet-Laudinat et al., 1994;Adam et al., 1997;Mewe et al., 2005), Listeria monocytogenes (Fadaee-Shohada et al., 2010), Moraxella catarrhalis (Balder et al., 2009) and Bordetella spp. (Soane et al., 2000;Groathouse et al., 2003;Anderton et al., 2004;Edwards et al., 2005). ...
We studied the Euprymna scolopes-Vibrio fischeri symbiosis to characterize, in vivo and in real time, the transition between the bacterial partner's free-living and symbiotic life styles. Previous studies using high inocula demonstrated that environmental V. fischeri cells aggregate during a 3 h period in host-shed mucus along the light organ's superficial ciliated epithelia. Under lower inoculum conditions, similar to the levels of symbiont cells in the environment, this interaction induces haemocyte trafficking into these tissues. Here, in experiments simulating natural conditions, microscopy revealed that at 3 h following first exposure, only ∼ 5 V. fischeri cells aggregated on the organ surface. These cells associated with host cilia and induced haemocyte trafficking. Symbiont viability was essential and mutants defective in symbiosis initiation and/or production of certain surface features, including the Mam7 protein, which is implicated in host cell attachment of V. cholerae, associated normally with host cilia. Studies with exopolysaccharide mutants, which are defective in aggregation, suggest a two-step process of V. fischeri cell engagement: association with host cilia followed by aggregation, i.e. host cell-symbiont interaction with subsequent symbiont-symbiont cell interaction. Taken together, these data provide a new model of early partner engagement, a complex model of host-symbiont interaction with exquisite sensitivity.
... Also, a method to obtain a primary culture of spinal cord ependymal cells from axolotl was developed by Chernoff et al. (1990). All these methods of culturing ependymal cells have led to the publication of more than 50 articles dealing with ultrastructure (Araki et al. 1983;Rieke et al. 1987), cell biology Tritschler et al. 2007), electrophysiology (Hild et al. 1965), metabolism (Prothmann et al. 2001;Verleysdonk et al. 2004aVerleysdonk et al. , b, 2005Murin et al. 2009), ciliogenesis (Hirota et al. 2010;Guirao et al. 2010;Monkkonen et al. 2008), ciliary beating physiology (Fadaee-Shohada et al. 2010;Monkkonen et al. 2007) and differentiation capacity (Chernoff et al. 1998;Laabich et al. 1991) of ependymal cells. One disadvantage of all these cultures is the use of foetal or neonatal nervous tissue making necessary a 2-3 week period for the ependymal cells to differentiate. ...
Ependymal cells form an epithelium lining the ventricular cavities of the vertebrate brain. Numerous methods to obtain primary culture ependymal cells have been developed. Most of them use foetal or neonatal rat brain and the few that utilize adult brain hardly achieve purity. Here, we describe a simple and novel method to obtain a pure non-adherent ependymal cell culture from explants of the striatal and septal walls of the lateral ventricles. The combination of a low incubation temperature followed by a gentle enzymatic digestion allows the detachment of most of the ependymal cells from the ventricular wall in a period of 6 h. Along with ependymal cells, a low percentage (less than 6 %) of non-ependymal cells also detaches. However, they do not survive under two restrictive culture conditions: (1) a simple medium (alpha-MEM with glucose) without any supplement; and (2) a low density of 1 cell/µl. This purification method strategy does not require cell labelling with antibodies and cell sorting, which makes it a simpler and cheaper procedure than other methods previously described. After a period of 48 h, only ependymal cells survive such conditions, revealing the remarkable survival capacity of ependymal cells. Ependymal cells can be maintained in culture for up to 7-10 days, with the best survival rates obtained in Neurobasal supplemented with B27 among the tested media. After 7 days in culture, ependymal cells lose most of the cilia and therefore the mobility, while acquiring radial glial cell markers (GFAP, BLBP, GLAST). This interesting fact might indicate a reprogramming of the cell identity.
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.
Impact statement:
Cilia play an important role in the airway defense mechanism. So far, studies on ciliary function have mainly been based on in vitro methods. Images of in vivo ciliary motion are very difficult to capture. In this study, we describe a novel approach to observe and analyze nasal ciliary motion in living animals with comparison to in vitro observation. Such images of ciliary motion from living animals have not been reported to date. The result of the study indicates that in vivo ciliary physiological function differs from ex vivo and in vitro conditions in many ways, such as the stability over time and response to temperature variation. This is a good foundation for further in vivo analysis of airway ciliary physiological function in animals as well as humans.
