scholarly journals The Use of Myelinating Cultures as a Screen of Glycomolecules for CNS Repair

Biology ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 52 ◽  
Author(s):  
George A. McCanney ◽  
Susan L. Lindsay ◽  
Michael A. McGrath ◽  
Hugh J. Willison ◽  
Claire Moss ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Neurite Outgrowth ◽  
Normal Process ◽  
Drug Candidates ◽  
Receptor Complexes ◽  
Modern Drug ◽  
Over Time

In vitro cell-based assays have been fundamental in modern drug discovery and have led to the identification of novel therapeutics. We have developed complex mixed central nervous system (CNS) cultures, which recapitulate the normal process of myelination over time and allow the study of several parameters associated with CNS damage, both during development and after injury or disease. In particular, they have been used as a reliable screen to identify drug candidates that may promote (re)myelination and/or neurite outgrowth. Previously, using these cultures, we demonstrated that a panel of low sulphated heparin mimetics, with structures similar to heparan sulphates (HSs), can reduce astrogliosis, and promote myelination and neurite outgrowth. HSs reside in either the extracellular matrix or on the surface of cells and are thought to modulate cell signaling by both sequestering ligands, and acting as co-factors in the formation of ligand-receptor complexes. In this study, we have used these cultures as a screen to address the repair potential of numerous other commercially available sulphated glycomolecules, namely heparosans, ulvans, and fucoidans. These compounds are all known to have certain characteristics that mimic cellular glycosaminoglycans, similar to heparin mimetics. We show that the N-sulphated heparosans promoted myelination. However, O-sulphated heparosans did not affect myelination but promoted neurite outgrowth, indicating the importance of structure in HS function. Moreover, neither highly sulphated ulvans nor fucoidans had any effect on remyelination but CX-01, a low sulphated porcine intestinal heparin, promoted remyelination in vitro. These data illustrate the use of myelinating cultures as a screen and demonstrate the potential of heparin mimetics as CNS therapeutics.

scholarly journals Thrombospondin-4, an extracellular matrix protein expressed in the developing and adult nervous system promotes neurite outgrowth.

1995 ◽  
Vol 131 (4) ◽  
pp. 1083-1094 ◽  
Author(s):  
S Arber ◽  
P Caroni
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Neuromuscular Junction ◽  
Neurite Outgrowth ◽  
Adult Skeletal Muscle ◽  
Wide Range ◽  
Thrombospondin 4

Extracellular matrix (ECM) molecules are involved in multiple aspects of cell-to-cell signaling during development and in the adult. In nervous system development, specific recognition processes, e.g., during axonal pathfinding and synaptogenesis involve modulation and signaling by ECM components. Much less is known about their presence and possible roles in the adult nervous system. We now report that thrombospondin-4 (TSP-4), a recently discovered member of the TSP gene family is expressed by neurons, promotes neurite outgrowth, and accumulates at the neuromuscular junction and at certain synapse-rich structures in the adult. To search for muscle genes that may be involved in neuromuscular signaling, we isolated cDNAs induced in adult skeletal muscle by denervation. One of these cDNAs coded for the rat homologue of TSP-4. In skeletal muscle, it was expressed by muscle interstitial cells. The transcript was further detected in heart and in the developing and adult nervous system, where it was expressed by a wide range of neurons. An antiserum to the unique carboxyl-terminal end of the protein allowed to specifically detect TSP-4 in transfected cells in vitro and on cryostat sections in situ. TSP-4 associated with ECM structures in vitro and in vivo. In the adult, it accumulated at the neuromuscular junction and at synapse-rich structures in the cerebellum and retina. To analyze possible activities of TSP-4 towards neurons, we carried out coculture experiments with stably transfected COS cells and motor, sensory, or retina neurons. These experiments revealed that TSP-4 was a preferred substrate for these neurons, and promoted neurite outgrowth. The results establish TSP-4 as a neuronal ECM protein associated with certain synapse-rich structures in the adult. Its activity towards embryonic neurons in vitro and its distribution in vivo suggest that it may be involved in local signaling in the developing and adult nervous system.

scholarly journals Tenascin expression in the mouse: in situ localization and induction in vitro by bFGF

1993 ◽  
Vol 104 (1) ◽  
pp. 69-76 ◽  
Author(s):  
R.P. Tucker ◽  
J.A. Hammarback ◽  
D.A. Jenrath ◽  
E.J. Mackie ◽  
Y. Xu
Keyword(s):  
Central Nervous System ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Growth Factors ◽  
Growth Factor ◽  
Blot Analysis ◽  
Tgf Beta ◽  
The Central Nervous System ◽  
Swiss 3T3

The glycoprotein tenascin is found in the extracellular matrix in regions of cell motility, cell proliferation, and tissue modelling. We have used novel tenascin cDNA probes to localize tenascin transcripts in the developing mouse and to study the regulation of tenascin expression by growth factors in vitro. At postnatal day 1 tenascin mRNAs are abundant in regions of bone and cartilage formation, as well as in the ependymal layer of the central nervous system. Previous studies have demonstrated that transforming growth factor-beta type 1 (TGF-beta 1) can induce tenascin expression in vitro. As TGF-beta 1 is absent or scarce in the developing brain, it is likely that other growth factors, alone or in addition to TGF-beta 1, may regulate tenascin expression during development. Therefore, we have compared the effects of TGF-beta 1 and a growth factor that is found in both developing connective tissue and the central nervous system, basic fibroblast growth factor (bFGF), on tenascin expression in a mouse embryo fibroblast cell line (Swiss 3T3 cells). Immuno-slot blot analysis of Swiss 3T3 cell-conditioned culture medium demonstrates that bFGF is a more potent inducer of tenascin expression than TGF-beta 1. Furthermore, bFGF and TGF-beta 1 have an additive effect on levels of tenascin, but not fibronectin, in the conditioned medium. Western blots revealed that different forms of tenascin are induced by bFGF and TGF-beta 1: the tenascin induced by the former has a molecular mass of approximately 250 kDa, the latter induces an approximately 200 kDa form of tenascin. The induction of large tenascin by bFGF was confirmed by northern blot analysis, which revealed increased levels of an 8 kb tenascin transcript after 24 h by as little as 4 ng/ml of bFGF in serum-free medium. Thus bFGF, alone or in combination with TGF-beta 1, is a potential regulator of tenascin expression in vitro. bFGF may alter not only the relative abundance of tenascin and fibronectin in the extracellular matrix, but also the splice variant of tenascin expressed by a given cell type.

Influence of extracellular matrix proteins on the expression of neuronal polarity

Development ◽  
1989 ◽  
Vol 106 (3) ◽  
pp. 483-491 ◽  
Author(s):  
B. Chamak ◽  
A. Prochiantz
Keyword(s):  
Central Nervous System ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Growth Inhibition ◽  
Physical Properties ◽  
Neuronal Morphology ◽  
Matrix Proteins ◽  
Neuronal Polarity ◽  
Neuronal Adhesion

The influence of laminin (LN) and fibronectin (FN) on the differentiation of individual neurones from the embryonic rat central nervous system was studied in vitro. In control cultures or in the presence of soluble FN, most neurones had several dendrite-like and one axon-like processes. On substratum-bound LN, multipolar and unipolar cells were present. Soluble LN and bound FN induced a very simple neuronal morphology, most neurones having only one axon-like neurite as defined by morphological and immunocytochemical characteristics. The significant reduction of neuronal adhesion and spreading in conditions leading to the growth inhibition of dendrite-like processes suggests that, contrary to that of axons, dendrite growth strongly depends on neuronal adhesion. We propose a model in which the different dependency of axonal and dendritic outgrowth towards adhesion and spreading is explained by the respective physical properties of the two types of neurites.

scholarly journals THAP1 modulates oligodendrocyte maturation by regulating ECM degradation in lysosomes

2021 ◽  
Vol 118 (31) ◽  
pp. e2100862118
Author(s):  
Dhananjay Yellajoshyula ◽  
Samuel S. Pappas ◽  
Abigail E. Rogers ◽  
Biswa Choudhury ◽  
Xylena Reed ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Oligodendrocyte Progenitor Cells ◽  
Gene Encoding ◽  
A Cell ◽  
Ecm Degradation ◽  
Oligodendrocyte Development

Mechanisms controlling myelination during central nervous system (CNS) maturation play a pivotal role in the development and refinement of CNS circuits. The transcription factor THAP1 is essential for timing the inception of myelination during CNS maturation through a cell-autonomous role in the oligodendrocyte lineage. Here, we demonstrate that THAP1 modulates the extracellular matrix (ECM) composition by regulating glycosaminoglycan (GAG) catabolism within oligodendrocyte progenitor cells (OPCs). Thap1−/− OPCs accumulate and secrete excess GAGs, inhibiting their maturation through an autoinhibitory mechanism. THAP1 controls GAG metabolism by binding to and regulating the GusB gene encoding β-glucuronidase, a GAG-catabolic lysosomal enzyme. Applying GAG-degrading enzymes or overexpressing β-glucuronidase rescues Thap1−/− OL maturation deficits in vitro and in vivo. Our studies establish lysosomal GAG catabolism within OPCs as a critical mechanism regulating oligodendrocyte development.

Tissue plasminogen activator as a modulator of neuronal survival and function

2002 ◽  
Vol 30 (2) ◽  
pp. 222-225 ◽  
Author(s):  
S. E. Tsirka
Keyword(s):  
Central Nervous System ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Neurite Outgrowth ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Cell Surface Receptor ◽  
Mammalian Brain ◽  
Tissue Plasminogen ◽  
Surface Receptor

The tissue plasminogen activator (tPA)/plasmin proteolytic system has been implicated in both physiological and pathological processes in the mammalian brain. The physiological roles include facilitating neurite outgrowth and pathfinding. The pathological role involves mediating a critical step in the progression of excitotoxin-induced neurodegeneration. Mechanistically, tPA appears to function through two pathways. The first pathway proceeds via its well established ability to convert plasminogen into plasmin. Plasmin then either promotes neuronal death via both the degradation of the extracellular matrix and the establishment of chemoattractant gradients for microglia, or facilitates neurite outgrowth through the processing of extracellular matrix proteoglycans. The second pathway for tPA does not involve its proteolytic activity: rather tPA functions as an agonist to stimulate a cell-surface receptor on microglia (the macrophage-like immunocompetent cells of the central nervous system) and results in their activation. Once activated after neuronal injury, microglia contribute to the ensuing neurodegeneration. Using tPA as a link between neurons and microglia, we are focusing on understanding their communication and interactions in the normal and diseased central nervous system.

scholarly journals Preferential outgrowth of central nervous system neurites on astrocytes and Schwann cells as compared with nonglial cells in vitro.

1985 ◽  
Vol 100 (1) ◽  
pp. 198-207 ◽  
Author(s):  
J R Fallon
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurite Outgrowth ◽  
Schwann Cells ◽  
Glial Cells ◽  
Conditioned Media ◽  
Cell Type ◽  
Transmission Electron ◽  
Promote Neurite Outgrowth

I have compared central nervous system (CNS) neurite outgrowth on glial and nonglial cells. Monolayers of glial cells (astrocytes and Schwann cells) or nonglial cells (e.g., fibroblasts) were prepared and were shown to be greater than 95% pure as judged by cell type-specific markers. These monolayers were then tested for their ability to support neurite outgrowth from various CNS explants. While CNS neurites grew vigorously on the glial cells, most showed little growth on nonglial cell monolayers. Neurites grew singly or in fine fascicles on the glial cells at rates greater than 0.5 mm/d. The neurite outgrowth on astrocytes was investigated in detail. Scanning and transmission electron microscopy showed that the neurites were closely apposed to the astrocyte surface and that the growth cones were well spread with long filopodia. There was no evidence of significant numbers of explant-derived cells migrating onto the monolayers. Two types of experiments indicated that factors associated with the astrocyte surface were primarily responsible for the vigorous neurite outgrowth seen on these cells: (a) Conditioned media from either astrocytes or fibroblasts had no effect on the pattern of outgrowth on fibroblasts and astrocytes, and conditioned media factors from either cell type did not promote neurite outgrowth when bound to polylysine-coated dishes. (b) When growing CNS neurites encountered a boundary between astrocytes and fibroblasts, they stayed on the astrocytes and did not encroach onto the fibroblasts. These experiments strongly suggest that molecules specific to the surfaces of astrocytes make these cells particularly attractive substrates for CNS neurite outgrowth, and they raise the possibility that similar molecules on embryonic glial cells may play a role in guiding axonal growth during normal CNS development.

Neural Stem Cells to Glial Cells an Important Factor for Brain Injury

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Glial Cells ◽  
Brain Injuries ◽  
The Body ◽  
The Central Nervous System ◽  
Near Future

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.

scholarly journals Beyond Oncological Hyperthermia: Physically Drivable Magnetic Nanobubbles as Novel Multipurpose Theranostic Carriers in the Central Nervous System

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2104 ◽  
Author(s):  
Eleonora Ficiarà ◽  
Shoeb Anwar Ansari ◽  
Monica Argenziano ◽  
Luigi Cangemi ◽  
Chiara Monge ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tumors ◽  
Ad Hoc ◽  
Superparamagnetic Iron Oxide ◽  
Conventional Radiotherapy ◽  
The Central Nervous System ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Magnetic Oxygen-Loaded Nanobubbles (MOLNBs), manufactured by adding Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on the surface of polymeric nanobubbles, are investigated as theranostic carriers for delivering oxygen and chemotherapy to brain tumors. Physicochemical and cyto-toxicological properties and in vitro internalization by human brain microvascular endothelial cells as well as the motion of MOLNBs in a static magnetic field were investigated. MOLNBs are safe oxygen-loaded vectors able to overcome the brain membranes and drivable through the Central Nervous System (CNS) to deliver their cargoes to specific sites of interest. In addition, MOLNBs are monitorable either via Magnetic Resonance Imaging (MRI) or Ultrasound (US) sonography. MOLNBs can find application in targeting brain tumors since they can enhance conventional radiotherapy and deliver chemotherapy being driven by ad hoc tailored magnetic fields under MRI and/or US monitoring.

scholarly journals Effects of Platelet-Rich Plasma on Cellular Populations of the Central Nervous System: The Influence of Donor Age

2021 ◽  
Vol 22 (4) ◽  
pp. 1725
Author(s):  
Diego Delgado ◽  
Ane Miren Bilbao ◽  
Maider Beitia ◽  
Ane Garate ◽  
Pello Sánchez ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cellular Response ◽  
Platelet Rich Plasma ◽  
Biological Response ◽  
In Vitro Models ◽  
Molecular Composition ◽  
Cellular Models ◽  
The Central Nervous System

Platelet-rich plasma (PRP) is a biologic therapy that promotes healing responses across multiple medical fields, including the central nervous system (CNS). The efficacy of this therapy depends on several factors such as the donor’s health status and age. This work aims to prove the effect of PRP on cellular models of the CNS, considering the differences between PRP from young and elderly donors. Two different PRP pools were prepared from donors 65–85 and 20–25 years old. The cellular and molecular composition of both PRPs were analyzed. Subsequently, the cellular response was evaluated in CNS in vitro models, studying proliferation, neurogenesis, synaptogenesis, and inflammation. While no differences in the cellular composition of PRPs were found, the molecular composition of the Young PRP showed lower levels of inflammatory molecules such as CCL-11, as well as the presence of other factors not found in Aged PRP (GDF-11). Although both PRPs had effects in terms of reducing neural progenitor cell apoptosis, stabilizing neuronal synapses, and decreasing inflammation in the microglia, the effect of the Young PRP was more pronounced. In conclusion, the molecular composition of the PRP, conditioned by the age of the donors, affects the magnitude of the biological response.

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