Ependymal Research Articles

The Matrix Receptor CD44 Is Present in Astrocytes throughout the Human Central Nervous System and Accumulates in Hypoxia and Seizures.

In the mammalian isocortex, CD44, a cell surface receptor for extracellular matrix molecules, is present in pial-based and fibrous astrocytes of white matter but not in protoplasmic astrocytes. In the hominid isocortex, CD44+ astrocytes comprise the subpial "interlaminar" astrocytes, sending long processes into the cortex. The hippocampus also contains similar astrocytes. We have examined all levels of the human central nervous system and found CD44+ astrocytes in every region. Astrocytes in white matter and astrocytes that interact with large blood vessels but not with capillaries in gray matter are CD44+, the latter extending long processes into the parenchyma. Motor neurons in the brainstem and spinal cord, such as oculomotor, facial, hypoglossal, and in the anterior horn of the spinal cord, are surrounded by CD44+ processes, contrasting with neurons in the cortex, basal ganglia, and thalamus. We found CD44+ processes that intercalate between ependymal cells to reach the ventricle. We also found CD44+ astrocytes in the molecular layer of the cerebellar cortex. Protoplasmic astrocytes, which do not normally contain CD44, acquire it in pathologies like hypoxia and seizures. The pervasive and inducible expression of CD44 in astrocytes is a novel finding that lays the foundations for functional studies into the significance of CD44 in health and disease.

History of research concerning the ependyma: a view from inside the human brain.

The history of research concerning ependymal cells is reviewed. Cilia were identified along the surface of the cerebral ventricles c1835. Numerous anatomical and histopathological studies in the late 1800's showed irregularities in the ependymal surface that were thought to be indicative of specific pathologies such as syphilis; this was subsequently disproven. The evolution of thoughts about functions of cilia, the possible role of ependyma in the brain-cerebrospinal fluid barrier, and the relationship of ependyma to the subventricular zone germinal cells is discussed. How advances in light and electron microscopy and cell culture contributed to our understanding of the ependyma is described. Discoveries of the supraependymal serotoninergic axon network and supraependymal macrophages are recounted. Finally, the consequences of loss of ependymal cells from different regions of the central nervous system are considered.

The role of glial cells in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) has traditionally been considered a neuron-centric disease. This view is now outdated, with increasing recognition of cell autonomous and non-cell autonomous contributions of central and peripheral nervous system glia to ALS pathomechanisms. With glial research rapidly accelerating, we comprehensively interrogate the roles of astrocytes, microglia, oligodendrocytes, ependymal cells, Schwann cells and satellite glia in nervous system physiology and ALS-associated pathology. Moreover, we highlight the inter-glial, glial-neuronal and inter-system polylogue which constitutes the healthy nervous system and destabilises in disease. We also propose classification based on function for complex glial reactive phenotypes and discuss the pre-requisite for integrative modelling to advance translation. Given the paucity of life-enhancing therapies currently available for ALS patients, we discuss the promising potential of harnessing glia in driving ALS therapeutic discovery.

Isolated lumbar myxopapillary ependymoma Case-report

INTRODUCTION Spinal ependymoma is described typically as an intramedullary tumor arising from ependymal cells lining the ventricles and the central spinal canal. Intradural extramedullary (IDEM) ependymomas subtype are extremely rare. (1) Case-report: It’s about a 32-year-old patient with no past medical history who was admitted to our neurosurgical department for non-systematized bilateral lumbocrural pain set on upon an intense sport activity limiting his ability of walking with a perimeter reduced to 50 meters deteriorating progressively over 6 months.

Convergent differentiation of multiciliated cells

Multiciliated cells (MCCs) are epithelial cells that control body fluid flow and contribute to the clearance of pathogenic microbes and other particles from the airways, egg transport in oviducts, and circulation of cerebrospinal fluid in the central nervous system. Although MCCs have shared functions to control fluid flow via coordinated motility of multiple ciliary structures, they are found in multiple mammalian tissues originating from distinct germ layers and differentiate via distinct developmental pathways. To understand the similarities and differences of MCCs in multiple tissues, we investigated single-cell transcriptome data of nasal epithelial cells, bronchial tubes, fallopian tubes, and ependymal cells in the subventricular zone from humans and mice by cross-species data integration. Expression of cilia-associated genes was indistinguishable between these MCCs, although cell populations had unique properties by the species and tissue, demonstrating that they share the same final differentiation status for ciliary functions. We further analyzed the final differentiation step of MCCs from their distinctive progenitors and confirmed their convergent gene set expression for ciliogenesis at the final step. These results may provide new insight into understanding ciliogenesis during the developmental process.

The origins and dynamic changes of C3- and S100A10-positive reactive astrocytes after spinal cord injury.

Accaumulating studies focus on the effects of C3-positive A1-like phenotypes and S100A10-positive A2-like phenotypes of reactive astrocytes on spinal cord injury (SCI), however the origins and dynamic changes of C3- and S100A10-positive reactive astrocytes after SCI remain poorly understood. Through transgenic mice and lineage tracing, we aimed to determine the origins of C3- and S100A10-positive reactive astrocytes. Meanwhile, the distribution and dynamic changes in C3- and S100A10-positive reactive astrocytes were also detected in juvenile and adult SCI mice models and cultured astrocytes. Combing with bulk RNA sequencing (RNA-seq), single-cell RNA sequencing (scRNA-seq) and bioinformatic analysis, we further explored the dynamic transcripts changes of C3- and S100A10-positive reactive astrocytes after SCI. We confirmed that resident astrocytes produced both C3- and S100A10-positive reactive astrocytes, whereas ependymal cells regenerated only S100A10-positive reactive astrocytes in lesion area. Importantly, C3-positive reactive astrocytes were predominantly activated in adult SCI mice, while S100A10-positive reactive astrocytes were hyperactivated in juvenile mice. Furthermore, we observed that C3- and S100A10-positive reactive astrocytes had a dynamic transformation process at different time in vitro and vivo, and a majority of intermediate states of C3- and S100A10-positive reactive astrocytes were found during transformation. RNA-seq and scRNA-seq results further confirmed that the transcripts of C3-positive reactive astrocytes and their lipid toxicity were gradually increased with time and age. In contrast, S100A10-positive reactive astrocytes transcripts increased at early time and then gradually decreased after SCI. Our results provide insight into the origins and dynamic changes of C3- and S100A10-positive reactive astrocytes after SCI, which would be valuable resources to further target C3- and S100A10-positive reactive astrocytes after SCI.

The Surgical Histopathology of the Filum Terminale: Findings from a Large Series of Patients with Tethered Cord Syndrome.

This study investigated the prevalence of embryonic and connective tissue elements in the filum terminale (FT) of patients with tethered cord syndrome (TCS), examining both typical and pathological histology. The FT specimens from 288 patients who underwent spinal cord detethering from 2013 to 2021 were analyzed. The histopathological examination involved routine hematoxylin and eosin staining and specific immunohistochemistry when needed. The patient details were extracted from electronic medical records. The study found that 97.6% of the FT specimens had peripheral nerves, and 70.8% had regular ependymal cell linings. Other findings included ependymal cysts and canals, ganglion cells, neuropil, and prominent vascular features. Notably, 41% showed fatty infiltration, and 7.6% had dystrophic calcification. Inflammatory infiltrates, an underreported finding, were observed in 3.8% of the specimens. The research highlights peripheral nerves and ganglion cells as natural components of the FT, with ependymal cell overgrowth and other tissues potentially linked to TCS. Enlarged vessels may suggest venous congestion due to altered FT mechanics. The presence of lymphocytic infiltrations and calcifications provides new insights into structural changes and mechanical stress in the FT, contributing to our understanding of TCS pathology.

P2X7 receptor activation awakes a dormant stem cell niche in the adult spinal cord.

The ependyma of the spinal cord is a latent stem cell niche that is reactivated by injury, generating new cells that migrate to the lesion site to limit the damage. The mechanisms by which ependymal cells are reactivated after injury remain poorly understood. ATP has been proposed to act as a diffusible "danger signal" to alert about damage and start repair. Indeed, spinal cord injury (SCI) generates an increase in extracellular ATP around the lesion epicenter that lasts for several hours and affects the functional outcome after the damage. The P2X7 receptor (P2X7r) has functional properties (e.g., low sensitivity for ATP, high permeability for Ca2+) that makes it a suitable candidate to act as a detector of tissue damage. Because ependymal cells express functional P2X7r that generate an inward current and regenerative Ca2+ waves, we hypothesize that the P2X7r has a main role in the mechanisms by which progenitor-like cells in the ependyma react to tissue damage. To test this possibility, we simulated the P2X7r activation that occurs after SCI by in vivo intraspinal injection of the selective agonist BzATP nearby the central canal. We found that BzATP rescued ependymal cells from quiescence by triggering a proliferative response similar to that generated by injury. In addition, P2X7r activation by BzATP induced a shift of ependymal cells to a glial fibrillary acidic protein (GFAP) phenotype similar to that induced by injury. However, P2X7r activation did not trigger the migration of ependyma-derived cells as occurs after tissue damage. Injection of BzATP induced the expression of connexin 26 (Cx26) in ependymal cells, an event needed for the proliferative reaction after injury. BzATP did not induce these changes in ependymal cells of P2X7-/- mice supporting a specific action on P2X7r. In vivo blockade of P2X7r with the potent antagonist AZ10606120 reduced significantly the injury-induced proliferation of ependymal cells. Our data indicate that P2X7r has a key role in the "awakening" of the ependymal stem cell niche after injury and suggest purinergic signaling is an interesting target to improve the contribution of endogenous progenitors to repair.

A role for mutations in AK9 and other genes affecting ependymal cells in idiopathic normal pressure hydrocephalus.

Idiopathic normal pressure hydrocephalus (iNPH) is an enigmatic neurological disorder that develops after age 60 and is characterized by gait difficulty, dementia, and incontinence. Recently, we reported that heterozygous CWH43 deletions may cause iNPH. Here, we identify mutations affecting nine additional genes (AK9, RXFP2, PRKD1, HAVCR1, OTOG, MYO7A, NOTCH1, SPG11, and MYH13) that are statistically enriched among iNPH patients. The encoded proteins are all highly expressed in choroid plexus and ependymal cells, and most have been associated with cilia. Damaging mutations in AK9, which encodes an adenylate kinase, were detected in 9.6% of iNPH patients. Mice homozygous for an iNPH-associated AK9 mutation displayed normal cilia structure and number, but decreased cilia motility and beat frequency, communicating hydrocephalus, and balance impairment. AK9+/- mice displayed normal brain development and behavior until early adulthood, but subsequently developed communicating hydrocephalus. Together, our findings suggest that heterozygous mutations that impair ventricular epithelial function may contribute to iNPH.

Abstract C156: Dasatinib targets an upregulated SRC family kinase gene in extramedullary leukemia, improving prognosis in these patients

Abstract Purpose: To review outcomes of pts with extramedullary leukemic tumors (EMLT) treated with the second-generation tryrosine kinase inhibitor (TKI) dasatinib. Procedures: Reported cases of extramedullary leukemic tumors in patients treated with TKIs were reviewed and survivals elicited from authors. RNA seq and RT-PCR for lymphocyte-specific kinase (LCK) mRNA were performed on cases of EMLT in breast. Summary: Leukemic cells growing as tumors in any organ lead to treatment failure and death, even if marrow is in remission. Median survival of patients with EMLT is 5 months, unchanged for the last 50 years. Like solid cancers, EMLT are invasive and metastatic, showing desmoplastic fibrosis and invasion of adipose tissue. Traditional anti-leukemia chemo has not reliably cured EMLT in any site, but excision of primary tumors followed by adjuvant chemo has achieved remissions of > 20 yrs. This suggests the benefit of removing tumor microenvironment (TME) containing cytokines and immune cells influencing tumor growth and resistance. TME is a logical target to ablate EMLT; TME is not affected by agents that kill replicating leukemia cells. RNAseq of very long-stored samples of EMLT in breast found upregulation of LCK compared to normal breast, confirmed by LCK RT-PCR analysis in 3 of 5 ALL tumors (2 Ph+ALL, 1 B-ALL) and 1 of 8 AML tumors. LCK is a target of DAS, a second-generation TKI that, like first-generation imatinab (IM), effectively controls BCR-ABL+ (Ph+) chronic myeloid leukemia (CML) marrow. However, IM cannot prevent or treat EM relapse, documented in 90 reported cases, mostly in CNS sites, with or without blastic marrow. CNS leukemia can lead to blindness, deafness, and paralysis. Responses to routine CNS therapy with RT and intrathecal or high-dose chemo +/- transplant, occur but lengthy DFS is rare. Since 2004, DAS +/- routine therapy has cleared CNS sites (meninges, brain, optic nerve) for up to 7+ yrs in Ph+ and T lymphoid leukemias. LCK is expressed diffusely in the CNS within neurons and ependymal cells. Tumors in non-CNS sites have also been cleared by DAS +/- routine therapy in pts with CML, Ph+ALL, T-ALL, and Ph+ B lymphoblastic lymphoma. Sites include skin, pancreas, stomach, testis, and epidural space, with DFS up to 9+ yrs. Among 137 of 153 DAS-treated pts with EMLT with followup after response, 23 have had progression in EM sites, while 47 were disease-free for 1 to 10 yrs (29 pts > 2 yrs). Conclusions: DAS appears to be an effective agent for treatment of EMLT. LCK is a potential DAS target in both Ph+ and non-Ph+ hematologic malignancies (HM), as EM tumors occur in leukemias, lymphomas, and myeloma. DAS combined with other therapies may benefit some HM patients and improve survival. Prospective clinical studies are needed to define which patients might benefit from DAS and the role of LCK. Routine scanning by PET/CT should be conducted in HM to find clinically unrecognized EMLT and to document response. Citation Format: Isabel Cunningham, Jianqi Yang, Herbert B Newton, Rory A Fisher. Dasatinib targets an upregulated SRC family kinase gene in extramedullary leukemia, improving prognosis in these patients [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C156.

ANKS1A-Deficiency Aberrantly Increases the Entry of the Protein Transport Machinery into the Ependymal Cilia.

In this study, we examine whether a change in the protein levels for FOP in Ankyrin repeat and SAM domain-containing protein 1A (ANKS1A)-deficient ependymal cells affects the intraflagellar transport (IFT) protein transport system in the multicilia. Three distinct abnormalities are observed in the multicilia of ANKS1A-deficient ependymal cells. First, there were a greater number of IFT88-positive trains along the cilia from ANKS1A deficiency. The results are similar to each isolated cilium as well. Second, each isolated cilium contains a significant increase in the number of extracellular vesicles (ECVs) due to the lack of ANKS1A. Third, Van Gogh-like 2 (Vangl2), a ciliary membrane protein, is abundantly detected along the cilia and in the ECVs attached to them for ANKS1A-deficient cells. We also use primary ependymal culture systems to obtain the ECVs released from the multicilia. Consequently, we find that ECVs from ANKS1A-deficient cells contain more IFT machinery and Vangl2. These results indicate that ANKS1A deficiency increases the entry of the protein transport machinery into the multicilia and as a result of these abnormal protein transports, excessive ECVs form along the cilia. We conclude that ependymal cells make use of the ECV-based disposal system in order to eliminate excessively transported proteins from basal bodies.

Truncated radial glia as a common precursor in the late corticogenesis of gyrencephalic mammals.

The diversity of neural stem cells is a hallmark of the cerebral cortex development in gyrencephalic mammals, such as Primates and Carnivora. Among them, ferrets are a good model for mechanistic studies. However, information on their neural progenitor cells (NPC), termed radial glia (RG), is limited. Here, we surveyed the temporal series of single-cell transcriptomes of progenitors regarding ferret corticogenesis and found a conserved diversity and temporal trajectory between human and ferret NPC, despite the large timescale difference. We found truncated RG (tRG) in ferret cortical development, a progenitor subtype previously described in humans. The combination of in silico and in vivo analyses identified that tRG differentiate into both ependymal and astrogenic cells. Via transcriptomic comparison, we predict that this is also the case in humans. Our findings suggest that tRG plays a role in the formation of adult ventricles, thereby providing the architectural bases for brain expansion.

Truncated radial glia as a common precursor in the late corticogenesis of gyrencephalic mammals

The diversity of neural stem cells is a hallmark of the cerebral cortex development in gyrencephalic mammals, such as Primates and Carnivora. Among them, ferrets are a good model for mechanistic studies. However, information on their neural progenitor cells (NPC), termed radial glia (RG), is limited. Here, we surveyed the temporal series of single-cell transcriptomes of progenitors regarding ferret corticogenesis and found a conserved diversity and temporal trajectory between human and ferret NPC, despite the large timescale difference. We found truncated RG (tRG) in ferret cortical development, a progenitor subtype previously described in humans. The combination of in silico and in vivo analyses identified that tRG differentiate into both ependymal and astrogenic cells. Via transcriptomic comparison, we predict that this is also the case in humans. Our findings suggest that tRG plays a role in the formation of adult ventricles, thereby providing the architectural bases for brain expansion.

Spinal Ependymomas: An Updated WHO Classification and a Narrative Review.

Ependymomas are neuroepithelial tumors that develop from ependymal cells found in the brain parenchyma and can spread to any part of the spinal cord. Three to six percent of all malignanciesaffecting the central nervous system (CNS) are ependymomas. Even the most talented surgeons are challenged by spinal cord ependymomas; as a result, research into this clinical phenomenon should continue. Since 1979, the World Health Organization (WHO) has published a classification and grading system for CNS malignancies to ensure consistent diagnostic standards worldwide. The WHO prepared an update on these tumors, paying particular attention to molecular techniques to categorize the therapeutic management of each patient with greater accuracy and clarity.We thoroughly reviewedthe literature on the epidemiology, etiology, diagnosis, and treatment of spinal ependymomas since there has not been a recent review of these tumors. This included modifications to the 2021 WHO Classification of Tumors of the Central Nervous System.

Age-related anatomical variation and morphometric studies on the optic tectum in post-hatch broiler chicken.

In this investigation the morphological and morphometrical features of the optic tectum in post-hatch broiler chicken were studied macroscopically and microscopically. The present study was conducted on 70 day old broiler chicks which were reared up to 42 days. The whole experimental period of study was divided into seven groups (from group I to VII) at weekly interval (days 0, 7, 14, 21, 28, 35 and 42). The optic lobes were paired and spherical to oval eminences located on the ventro-lateral part of the midbrain in broiler chicken. There was significant increase in length and width of the optic lobes with the advancement of age. Histological analysis of optic tectum shows six basic layers from the external surface to internal one towards the optic ventricle. Different layers of optic tectum were identified as stratum opticum, stratum griseum superficial, stratum griseum central, stratum album central, stratum griseum periventriculare and stratum fibrosum periventriculare with several types of neurons. Among all six layers of the optic tectum the stratum griseum superficial layer showed very high degree of secondry differentiation and evolved into nine sub- layers in all age groups of broiler chickens. Three main cell types had been identified that is, small to medium sized stellate shaped neuron, pyramidal neuron and fusiform neuron, beside these multipolar neuron were also evident. The thickness of all layers of optic tectum significantly increases with the advancement of age of the birds. The optic ventricle was lined with a layer of cuboidal ependymal cells.

Multifocal thoracic intradural extramedullary anaplastic ependymoma: case report and review of the literature

BackgroundEpendymomas are neuroectodermal tumors that grow from the ependymal cells of the ventricles or the central canal of the spinal cord. When the ependymoma is anaplastic, extramedullary, intradural and multifocal, it is a very rare anatomical entity, same as case described by us.Case presentationA 44-year-old man had been admitted to our hospital for progressive paralysis of both legs over the past 5 weeks. Contrast-enhanced MRI showed intradural extramedullary tumor at T11 with cord compression and an other more little tumor at T6 level, also intradural and extramedullary. The largest lesion was completely removed by laminectomy. Histology documented an anaplastic ependymoma. Contrast-enhanced brain and spinal MRI showed the results of the previous surgery.ConclusionMultifocal intradural extramedullary anaplastic ependymomas are very rare entity. Surgery is the main treatment that can improve prognosis, while radiotherapy is useful, after surgery, in the treatment of residues, recurrences, anaplastic transformations, metastases and multifocal lesions.

Shifting from ependyma to choroid plexus epithelium and the changing expressions of aquaporin-1 and aquaporin-4.

The cells of the choroid plexus (CP) epithelium are specialized ependymal cells (ECs) but have distinct properties. The CP cells and ECs form single-cell sheets contiguous to each other at a transitional zone. The CP is underlined by a basal lamina and has barrier properties, whereas the ECs do not. The basal lamina of the CP is continuous with the glia limitans superficialis and, consequently, the CP stroma is continuous with the meninges along entering blood vessels. The CP has previously been reported to express aquaporin-1 (AQP1) mostly apically, and ECs show mostly basolateral aquaporin-4 (AQP4) expression. Recent evidence in various systems has shown that in changing conditions the expression and distribution of AQP4 can be modified, involving phosphorylation and calmodulin-triggered translocation. Studies on the human CP revealed that AQP4 is also expressed in some CP cells, which is likely to be increased during ageing based on mouse data. Moreover, subependymal astrocytic processes in the ependyma-CP transition, forming a glial plate around blood vessels and facing the CP stroma, were strongly positive for AQP4. We propose that the increased AQP4 expression might be a compensatory mechanism for the observed reduction in CSF production in the ageing human brain. The high AQP4 density in the transition zone might facilitate the transport of water into and out of the CP stroma and serve as a drainage and clearing pathway for metabolites in the CNS.

A Review of the Occurrence of Intraventricular Hemorrhage in Preterm Newborns and its Future Neurodevelopmental Consequences.

Intraventricular hemorrhage (IVH) is a type of bleeding that occurs through the germinal matrix and comes through the ependymal cells into the ventricular cavity. It is mostly seen in preterm neonates but can also be seen sometimes in term neonates. Various factors predispose to preterm delivery; it can be spontaneous or medically induced. Spontaneous IVH occurs in cases of intrauterine infections in the mother, and it can be induced in cases of medical emergencies such as preeclampsia and eclampsia. The brain of a preterm newborn is not fully developed as it does not have pericytes and proteins, so it can bleed very quickly, which can cause IVH. Also, the vessels supplying the germinal matrix are immature and highly vascularized. IVH has four grades based on findings detected on cranial ultrasound and MRI. Management includes medical and surgical management; medical management includes phenobarbitone used for seizures and prophylaxis. Surgical management includes drainage, irrigation, and fibrinolytic therapy (DRIFT), and neuro-endoscopic lavage. IVH causes various short-term and long-term neurodevelopmental consequences. Long-term complications include cerebral palsy and intellectual disability, which hamperthe life of the child. It mainly presents with seizures, flaccidity, decerebrate posture, etc. Various preventive measures can be taken to tackle IVH in newborns. First of all, preterm delivery should be avoided, and intrauterine infections in mothers should be treated. The administration of corticosteroids should be done for all preterm deliveries as it helps in the maturation of organs. The administration of magnesium sulfate should be done as it is neuroprotective and reduces cerebral palsy in the future. Delayed cord clamping is to be done to reduce recurrent blood transfusions and decrease the risk of IVH. This article explains the pathogenesis, management, prevention, and future outcomes of IVH.

DDEL-13. CILIA INHIBITORS SYNERGIZE WITH TEMOZOLOMIDE TO DRAMATICALLY IMPROVE SURVIVAL IN ORTHOTOPIC MURINE MODELS OF GLIOBLASTOMA

Abstract Patients with malignant brain tumors such as glioblastoma face a poor prognosis with a median survival of less than two years. Recent glymphatic studies demonstrate the interconnectivity between the fluid in the brain parenchymal and ventricular spaces. We reasoned enhancing the accumulation of a drug in the cerebral spinal fluid (CSF) of the ventricular space will also enhance the accumulation of the drug in the parenchyma where a GBM resides. To improve drug accumulation in the CSF, we modulated the motility of ependymal cell cilia. Ependymal cells coat the ventricles and display motile cilia that mechanically propel CSF through the ventricular space. Impairing ciliary motion could slow down CSF turnover without affecting the overall amount of CSF in the brain and central nervous system. To test these hypotheses, we identified FDA-approved therapeutics that are known to impair airway cilia as a “side effect.” Seven candidate drugs were administered into the ventricle of mice bearing orthotopic GBM in combination with systemic temozolomide. Five of the seven cilia-inhibiting drugs significantly improved overall survival when combined with temozolomide compared to controls. The lead candidate, lidocaine, demonstrated a synergistic relationship with temozolomide, and 100% of animals treated with the combination survived to the study endpoint tumor free. We demonstrate lidocaine can impair cilia motility in vitro and in vivo. Combining intraventricular lidocaine with temozolomide is well tolerated and results in a 2.8-fold increase in brain temozolomide concentration per dose compared to controls. Finally, we validate these data in two human PDX orthotopic xenograft GBM murine models, including an un-methylated MGMT GBM that became sensitive to temozolomide with the combination treatment. These studies offer a new concept for treating malignant brain tumors and potentially a scheme to improve the treatment of additional encephalopathies in the future.

Deup1 Expression Interferes with Multiciliated Differentiation.

A recent study revealed that the loss of Deup1 expression does not affect either centriole amplification or multicilia formation. Therefore, the deuterosome per se is not a platform for amplification of centrioles. In this study, we examine whether gain-of-function of Deup1 affects the development of multiciliated ependymal cells. Our time-lapse study reveals that deuterosomes with an average diameter of 300 nm have two different fates during ependymal differentiation. In the first instance, deuterosomes are scattered and gradually disappear as cells become multiciliated. In the second instance, deuterosomes self-organize into a larger aggregate, called a deuterosome cluster (DC). Unlike scattered deuterosomes, DCs possess centriole components primarily within their large structure. A characteristic of DC-containing cells is that they tend to become primary ciliated rather than multiciliated. Our in utero electroporation study shows that DCs in ependymal tissue are mostly observed at early postnatal stages, but are scarce at late postnatal stages, suggesting the presence of DC antagonists within the differentiating cells. Importantly, from our bead flow assay, ectopic expression of Deup1 significantly impairs cerebrospinal fluid flow. Furthermore, we show that expression of mouse Deup1 in Xenopus embryos has an inhibitory effect on differentiation of multiciliated cells in the epidermis. Taken together, we conclude that the DC formation of Deup1 in multiciliated cells inhibits production of multiple centrioles.