scholarly journals The NC1 domain of type IV collagen promotes axonal growth in sympathetic neurons through interaction with the alpha 1 beta 1 integrin.

1991 ◽  
Vol 113 (2) ◽  
pp. 417-428 ◽  
Author(s):  
P J Lein ◽  
D Higgins ◽  
D C Turner ◽  
L A Flier ◽  
V P Terranova
Keyword(s):  
Sympathetic Neurons ◽  
Axon Growth ◽  
Axonal Growth ◽  
Collagen Iv ◽  
Morphological Development ◽  
Neuritic Outgrowth ◽  
Beta 1 Integrin ◽  
Process Outgrowth ◽  
Nc1 Domain

We have examined the effects of collagen IV on the morphological development of embryonic rat sympathetic neurons in vitro. In short-term (less than or equal to 24 h) culture, collagen IV accelerated process outgrowth, causing increases in the number of neurites and total neuritic length. Analysis of proteolytic fragments of collagen IV indicated that the NC1 domain was nearly as active as the intact molecule in stimulating process outgrowth; in contrast, the 7S domain and triple helix-rich fragments of collagen IV were inactive. Moreover, anti-NC1 antiserum inhibited neuritic outgrowth on collagen IV by 79%. In long-term (up to 28 d) cultures, neurons chronically exposed to collagen IV maintained a single axon but failed to form dendrites. Thus, the NC1 domain of collagen IV can alter neuronal development by selectively stimulating axonal growth. Comparison of collagen IV's effects to those of laminin revealed that these molecules exert quantitatively different effects on the rate of initial axon growth and the number of axons extended by sympathetic neurons. Moreover, neuritic outgrowth on collagen IV, but not laminin, was blocked by cycloheximide. We also observed differences in the receptors mediating the neurite-promoting activity of these proteins. Two different antisera that recognize beta 1 integrins each blocked neuritic outgrowth on both collagen IV and laminin; however, an mAb (3A3) specific for the alpha 1 beta 1 integrin inhibited collagen IV but not laminin-induced process growth in cultures of both sympathetic and dorsal root neurons. These data suggest that immunologically distinct integrins mediate the response of peripheral neurons to collagen IV and laminin.

Altered synthesis of laminin 1 and absence of basement membrane component deposition in (beta)1 integrin-deficient embryoid bodies

2000 ◽  
Vol 113 (2) ◽  
pp. 259-268 ◽  
Author(s):  
M. Aumailley ◽  
M. Pesch ◽  
L. Tunggal ◽  
F. Gaill ◽  
R. Fassler
Keyword(s):  
Basement Membrane ◽  
Collagen Iv ◽  
Basement Membranes ◽  
Mouse Genetics ◽  
Embryoid Bodies ◽  
Membrane Formation ◽  
Beta 1 Integrin ◽  
Laminin 1

Basement membranes are the earliest extracellular matrices produced during embryogenesis. They result from synthesis and assembly into a defined supramolecular architecture of several components, including laminins, collagen IV, nidogen, and proteoglycans. In vitro studies have allowed us to propose an assembly model based on the polymerisation of laminin and collagen IV in two separate networks associated together by nidogen. How nucleation of polymers and insolubilisation of the different components into a basement membrane proceed in vivo is, however, unknown. A most important property of several basement membrane components is to provide signals controling the activity of adjacent cells. The transfer of information is mediated by interactions with cell surface receptors, among them integrins. Mouse genetics has demonstrated that the absence of these interactions is not compatible with development as deletion of either laminin (gamma)1 chain or integrin (beta)1 chain lead to lethality of mouse embryos at the peri-implantation stage. We have used embyoid bodies as a model system recapitulating the early steps of embryogenesis to unravel the respective roles of laminin and (beta)1 integrins in basement membrane formation. Our data show that there is formation of a basal lamina in wild-type, but not in (beta)1-integrin deficient, embryoid bodies. Surprisingly, in the absence of (beta)1 integrins, laminin 1 was not secreted in the extracellular space due to a rapid switch off of laminin (alpha)1 chain synthesis which normally drives the secretion of laminin heterotrimers. These results indicate that (beta)1 integrins are required for the initiation of basement membrane formation, presumably by applying a feed-back regulation on the expression of laminin (alpha)1 chain and other components of basement membranes.

RET signaling is essential for migration, axonal growth and axon guidance of developing sympathetic neurons

Development ◽  
2001 ◽  
Vol 128 (20) ◽  
pp. 3963-3974 ◽  
Author(s):  
Hideki Enomoto ◽  
Peter A. Crawford ◽  
Alexander Gorodinsky ◽  
Robert O. Heuckeroth ◽  
Eugene M. Johnson ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Blood Vessels ◽  
Sympathetic Neurons ◽  
Sympathetic Innervation ◽  
Axonal Growth ◽  
Initial Contact ◽  
Neuronal Precursors ◽  
Sympathetic Nervous ◽  
Deficient Mice

Sympathetic axons use blood vessels as an intermediate path to reach their final target tissues. The initial contact between differentiating sympathetic neurons and blood vessels occurs following the primary sympathetic chain formation, where precursors of sympathetic neurons migrate and project axons along or toward blood vessels. We demonstrate that, in Ret-deficient mice, neuronal precursors throughout the entire sympathetic nervous system fail to migrate and project axons properly. These primary deficits lead to mis-routing of sympathetic nerve trunks and accelerated cell death of sympathetic neurons later in development. Artemin is expressed in blood vessels during periods of early sympathetic differentiation, and can promote and attract axonal growth of the sympathetic ganglion in vitro. This analysis identifies RET and artemin as central regulators of early sympathetic innervation.

scholarly journals Fidgetin-like 2 is a novel negative regulator of axonal growth and can be targeted to promote functional nerve regeneration after injury

2020 ◽  
Author(s):  
Lisa Baker ◽  
Moses Tar ◽  
Guillermo Villegas ◽  
Rabab Charafeddine ◽  
Adam Kramer ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Critical Role ◽  
Axon Growth ◽  
Axonal Growth ◽  
Negative Regulator ◽  
Neural Regeneration

AbstractThe microtubule (MT) cytoskeleton plays a critical role in axon growth and guidance. Here, we identify the MT severing enzyme fidgetin-like 2 (FL2) as a negative regulator of axonal regeneration and a potential therapeutic target for promoting neural regeneration after injury. Genetic knockout of FL2 in cultured adult dorsal root ganglion (DRG) neurons resulted in longer axons and attenuated growth cone retraction in response to inhibitory molecules. Given the axonal growth-promoting effects of FL2 depletion in vitro, we tested whether the enzyme could be targeted to promote regeneration in a rodent model of peripheral nerve injury. In the model used in our experiments, the cavernous nerves (CN) are either crushed or transected, mimicking nerve injury caused by radical prostatectomy (RP). As with patients, CN injury results in erectile dysfunction, for which there are presently poor treatment options. At the time of injury, FL2-siRNA or control-siRNA was applied to the site using nanoparticles or chondroitin sulfate microgels as delivery agents. Treatment significantly enhanced functional nerve recovery, as determined by cavernosometry (measurements of corporal blood pressure in response to electrostimulation of the nerve). Remarkably, following complete bilateral nerve transection, visible and functional nerve regeneration was observed in 7 out of 8 animals treated with FL2-siRNA. In contrast, no control-siRNA treated animals showed regeneration. These observations suggest a novel therapeutic approach to treat peripheral nerve injury, particularly injuries resulting from surgical procedures such as RP, where treatments depleting FL2 could be applied locally at the time of injury.

scholarly journals Depolarization and electrical stimulation enhance in vitro and in vivo sensory axon growth after spinal cord injury

2018 ◽  
Vol 300 ◽  
pp. 247-258 ◽  
Author(s):  
Ioana Goganau ◽  
Beatrice Sandner ◽  
Norbert Weidner ◽  
Karim Fouad ◽  
Armin Blesch
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Stimulation ◽  
Axon Growth ◽  
Sensory Axon ◽  
Cord Injury

scholarly journals CP30, a Cysteine Proteinase Involved inTrichomonas vaginalis Cytoadherence

2000 ◽  
Vol 68 (9) ◽  
pp. 4907-4912 ◽  
Author(s):  
M. Remedios Mendoza-López ◽  
Cecilia Becerril-Garcia ◽  
Loriz V. Fattel-Facenda ◽  
Leticia Avila-Gonzalez ◽  
Martha E. Ruíz-Tachiquín ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Hela Cell ◽  
Trichomonas Vaginalis ◽  
Cysteine Proteinase ◽  
Collagen Iv ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cell Monolayers ◽  
Thiol Proteinase

ABSTRACT We describe here the participation of a Trichomonas vaginalis 30-kDa proteinase (CP30) with affinity to the HeLa cell surface in attachment of this parasite to host epithelial cells. The CP30 band is a cysteine proteinase because its activity was inhibited by E-64, a thiol proteinase inhibitor. In two-dimensional substrate gel electrophoresis of total extracts of the trichomonad isolate CNCD 147, three spots with proteolytic activity were detected in the 30-kDa region, in the pI range from 4.5 to 5.5. Two of the spots (pI 4.5 and 5.0) bound to the surfaces of fixed HeLa cells corresponding to the CP30 band. The immunoglobulin G fraction of the rabbit anti-CP30 antiserum that recognized a 30-kDa band by Western blotting and immunoprecipitated CP30 specifically inhibited trichomonal cytoadherence to HeLa cell monolayers in a concentration-dependent manner and reacted with CP30 at the parasite surface. CP30 degraded proteins found on the female urogenital tract, including fibronectin, collagen IV, and hemoglobin. Interestingly, CP30 digested fibronectin and collagen IV only at pH levels between 4.5 and 5.0. Moreover, trichomonosis patients whose diagnosis was confirmed by in vitro culture possessed antibody to CP30 in both sera and vaginal washes, and CP30 activity was found in vaginal washes. Our results suggest that surface CP30 is a cysteine proteinase necessary for trichomonal adherence to human epithelial cells.

The preimplantation pig embryo: cell number and allocation to trophectoderm and inner cell mass of the blastocyst in vivo and in vitro

Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 793-803 ◽  
Author(s):  
V.E. Papaioannou ◽  
K.M. Ebert
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Staining Technique ◽  
Cell Number ◽  
Total Cell ◽  
Differential Staining ◽  
Morphological Development ◽  
Total Cell Number

Total cell number as well as differential cell numbers representing the inner cell mass (ICM) and trophectoderm were determined by a differential staining technique for preimplantation pig embryos recovered between 5 and 8 days after the onset of oestrus. Total cell number increased rapidly over this time span and significant effects were found between embryos of the same chronological age from different females. Inner cells could be detected in some but not all embryos of 12–16 cells. The proportion of inner cells was low in morulae but increased during differentiation of ICM and trophectoderm in early blastocysts. The proportion of ICM cells then decreased as blastocysts expanded and hatched. Some embryos were cultured in vitro and others were transferred to the oviducts of immature mice as a surrogate in vivo environment and assessed for morphology and cell number after several days. Although total cell number did not reach in vivo levels, morphological development and cell number increase was sustained better in the immature mice than in vitro. The proportion of ICM cells in blastocysts formed in vitro was in the normal range.

Contrasting migratory response of astrocytoma cells to tenascin mediated by different integrins

1996 ◽  
Vol 109 (8) ◽  
pp. 2161-2168 ◽  
Author(s):  
A. Giese ◽  
M.A. Loo ◽  
S.A. Norman ◽  
S. Treasurywala ◽  
M.E. Berens
Keyword(s):  
Cell Adhesion ◽  
Matrix Protein ◽  
Glioma Cells ◽  
Extracellular Matrix Protein ◽  
Integrin Receptors ◽  
Migration Assay ◽  
Dose Dependent Fashion ◽  
Beta 1 Integrin

Tenascin, an extracellular matrix protein, is expressed in human gliomas in vitro and in vivo. The distribution of tenascin at the invasive edge of these tumors, even surrounding solitary invading cells, suggests a role for this protein as a regulator of glioma cell migration. We tested whether purified tenascin, passively deposited on surfaces, influenced the adhesion or migration of a human gliomaderived cell line, SF-767. Adhesion of glioma cells to tenascin increased in a dose-dependent fashion up to a coating concentration of 10 micrograms/ml. Higher coating concentrations resulted in progressively fewer cells attaching. Cell adhesion could be blocked to basal levels using anti-beta 1 integrin antibodies. In contrast, when anti-alpha v antibodies were added to the medium of cells on tenascin, cell adhesion was enhanced slightly. Using a microliter scale migration assay, we found that cell motility on tenascin was dose dependently stimulated at coating concentrations of 1 and 3 micrograms/ml, but migration was inhibited below levels of non-specific motility when tested at coating concentrations of 30 and 100 micrograms/ml. Migration on permissive concentrations of tenascin could be reversibly inhibited with anti-beta 1, while treatment with anti-alpha v antibodies increased migration rates. We conclude that SF-767 glioma cells express two separate integrin receptors that mediate contrasting adhesive and migratory responses to tenascin.

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