scholarly journals Depletion of 43-kD growth-associated protein in primary sensory neurons leads to diminished formation and spreading of growth cones.

1993 ◽  
Vol 123 (2) ◽  
pp. 417-429 ◽  
Author(s):  
L Aigner ◽  
P Caroni
Keyword(s):  
Neurite Outgrowth ◽  
Growth Cone ◽  
Growth Cones ◽  
Major Protein ◽  
Nerve Terminals ◽  
Drg Neurons ◽  
Process Formation ◽  
Neurite Formation ◽  
Cone Formation ◽  
External Signals

The 43-kD growth-associated protein (GAP-43) is a major protein kinase C (PKC) substrate of growing axons, and of developing nerve terminals and glial cells. It is a highly hydrophilic protein associated with the cortical cytoskeleton and membranes. In neurons it is rapidly transported from the cell body to growth cones and nerve terminals, where it accumulates. To define the role of GAP-43 in neurite outgrowth, we analyzed neurite regeneration in cultured dorsal root ganglia (DRG) neurons that had been depleted of GAP-43 with any of three nonoverlapping antisense oligonucleotides. The GAP-43 depletion procedure was specific for this protein and an antisense oligonucleotide to the related PKC substrate MARCKS did not detectably affect GAP-43 immunoreactivity. We report that neurite outgrowth and morphology depended on the levels of GAP-43 in the neurons in a substrate-specific manner. When grown on a laminin substratum, GAP-43-depleted neurons extended longer, thinner and less branched neurites with strikingly smaller growth cones than their GAP-43-expressing counterparts. In contrast, suppression of GAP-43 expression prevented growth cone and neurite formation when DRG neurons were plated on poly-L-ornithine. These findings indicate that GAP-43 plays an important role in growth cone formation and neurite outgrowth. It may be involved in the potentiation of growth cone responses to external signals affecting process formation and guidance.

scholarly journals Absence of persistent spreading, branching, and adhesion in GAP-43-depleted growth cones.

1995 ◽  
Vol 128 (4) ◽  
pp. 647-660 ◽  
Author(s):  
L Aigner ◽  
P Caroni
Keyword(s):  
Growth Factor ◽  
Neurite Outgrowth ◽  
Growth Cone ◽  
Growth Cones ◽  
Culture Conditions ◽  
Major Protein ◽  
Kinase C ◽  
Competence Factor ◽  
Cone Activity

The growth-associated protein GAP-43 is a major protein kinase C substrate of growth cones and developing nerve terminals. In the growth cone, it accumulates near the plasma membrane, where it associates with the cortical cytoskeleton and membranes. The role of GAP-43 in neurite outgrowth is not yet clear, but recent findings suggest that it may be a crucial competence factor in this process. To define the role of GAP-43 in growth cone activity, we have analyzed neurite outgrowth and growth cone activity in primary sensory neurons depleted of GAP-43 by a specific antisense oligonucleotide procedure. Under optimal culture conditions, but in the absence of GAP-43, growth cones adhered poorly, displayed highly dynamic but unstable lamellar extensions, and were strikingly devoid of local f-actin concentrations. Upon stimulation, they failed to produce NGF-induced spreading or insulin-like growth factor-1-induced branching, whereas growth factor-induced phosphotyrosine immunoreactivity and acceleration of neurite elongation were not impaired. Unlike their GAP-43-expressing counterparts, they readily retracted when exposed to inhibitory central nervous system myelin-derived liposomes. Frequency and extent of induced retraction were attenuated by NGF. Our results indicate that GAP-43 can promote f-actin accumulation, evoked morphogenic activity, and resistance to retraction of the growth cone, suggesting that it may promote regulated neurite outgrowth during development and regeneration.

scholarly journals Suppression of Radixin and Moesin Alters Growth Cone Morphology, Motility, and Process Formation In Primary Cultured Neurons

1998 ◽  
Vol 143 (2) ◽  
pp. 443-455 ◽  
Author(s):  
Gabriela Paglini ◽  
Patricia Kunda ◽  
Santiago Quiroga ◽  
Kenneth Kosik ◽  
Alfredo Cáceres
Keyword(s):  
Growth Cone ◽  
Temporal Correlation ◽  
Growth Cones ◽  
Morphological Development ◽  
Cellular Functions ◽  
Erm Proteins ◽  
Process Formation ◽  
Neurite Formation ◽  
Developing Neurons ◽  
Key Aspects

In this study we have examined the cellular functions of ERM proteins in developing neurons. The results obtained indicate that there is a high degree of spatial and temporal correlation between the expression and subcellular localization of radixin and moesin with the morphological development of neuritic growth cones. More importantly, we show that double suppression of radixin and moesin, but not of ezrin–radixin or ezrin–moesin, results in reduction of growth cone size, disappearance of radial striations, retraction of the growth cone lamellipodial veil, and disorganization of actin filaments that invade the central region of growth cones where they colocalize with microtubules. Neuritic tips from radixin–moesin suppressed neurons displayed high filopodial protrusive activity; however, its rate of advance is 8–10 times slower than the one of growth cones from control neurons. Radixin–moesin suppressed neurons have short neurites and failed to develop an axon-like neurite, a phenomenon that appears to be directly linked with the alterations in growth cone structure and motility. Taken collectively, our data suggest that by regulating key aspects of growth cone development and maintenance, radixin and moesin modulate neurite formation and the development of neuronal polarity.

Neuronal calcium sensor-1 in nerve growth cones independently regulates both the neurite outgrowth and growth cone morphology

2007 ◽  
Vol 58 ◽  
pp. S204
Author(s):  
Masumi Iketani ◽  
Chihiro Imaizumi ◽  
Andreas Jeromin ◽  
Fumio Nakamura ◽  
Katsuhiko Mikoshiba ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Growth Cone ◽  
Growth Cones ◽  
Calcium Sensor ◽  
Nerve Growth ◽  
Neuronal Calcium Sensor ◽  
Cone Morphology ◽  
Nerve Growth Cones

scholarly journals Involvement of advillin in somatosensory neuron subtype-specific axon regeneration and neuropathic pain

2018 ◽  
Vol 115 (36) ◽  
pp. E8557-E8566 ◽  
Author(s):  
Yu-Chia Chuang ◽  
Cheng-Han Lee ◽  
Wei-Hsin Sun ◽  
Chih-Cheng Chen
Keyword(s):  
Neuropathic Pain ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Focal Adhesion ◽  
Growth Cone ◽  
Axon Regeneration ◽  
Spinal Cord Dorsal Horn ◽  
Drg Neurons ◽  
Autoimmune Encephalomyelitis ◽  
Cone Formation ◽  
Experimental Autoimmune

Advillin is a sensory neuron-specific actin-binding protein expressed at high levels in all types of somatosensory neurons in early development. However, the precise role of advillin in adulthood is largely unknown. Here we reveal advillin expression restricted to isolectin B4-positive (IB4+) neurons in the adult dorsal root ganglia (DRG). Advillin knockout (KO) specifically impaired axonal regeneration in adult IB4+ DRG neurons. During axon regeneration, advillin was expressed at the very tips of filopodia and modulated growth cone formation by interacting with and regulating focal-adhesion–related proteins. The advillin-containing focal-adhesion protein complex was shed from neurite tips during neurite retraction and was detectable in cerebrospinal fluid in experimental autoimmune encephalomyelitis, oxaliplatin-induced peripheral neuropathy, and chronic constriction injury of the sciatic nerve. In addition, advillin KO disturbed experimental autoimmune encephalomyelitis-induced neural plasticity in the spinal-cord dorsal horn and aggravated neuropathic pain. Our study highlights a role for advillin in growth cone formation, axon regeneration, and neuropathic pain associated with IB4+ DRG neurons in adulthood.

scholarly journals Process formation results from the imbalance between motor-mediated forces

2001 ◽  
Vol 114 (21) ◽  
pp. 3899-3904 ◽  
Author(s):  
Lotfi Ferhat ◽  
Guillaume Rami ◽  
Igor Medina ◽  
Yehezkel Ben-Ari ◽  
Alfonso Represa
Keyword(s):  
Motor Activity ◽  
Neurite Outgrowth ◽  
Cell Lines ◽  
Molecular Basis ◽  
Neuronal Cell ◽  
Cytoplasmic Dynein ◽  
Process Formation ◽  
Neurite Formation ◽  
Neuronal Cell Lines

Several reports have suggested that neurite outgrowth is mediated by opposing forces generated on microtubules and microfilaments but the molecular basis underlying these forces have not been determined. Here, we show that in non-neuronal cell lines, the inhibition of actomyosin activity by acidic calponin promotes the formation of processes. This effect is blocked by inhibition of the motor activity of cytoplasmic dynein. Therefore, neurite formation is due to an imbalance between tensile and compressive forces mediated by myosins and dyneins, respectively. We propose a mechanism that involves the motor-mediated forces in a tight regulation of the process formation.

scholarly journals Induction of Growth Cone Formation by Transient and Localized Increases of Intracellular Proteolytic Activity

1998 ◽  
Vol 140 (1) ◽  
pp. 223-232 ◽  
Author(s):  
Noam E. Ziv ◽  
Micha E. Spira
Keyword(s):  
Proteolytic Activity ◽  
Growth Cone ◽  
Growth Cones ◽  
Membrane Properties ◽  
Carrier Solution ◽  
External Application ◽  
Aplysia Neurons ◽  
Cone Formation ◽  
Subsequent Regeneration ◽  
Passive Membrane Properties

The formation of a growth cone at the tip of a transected axon is a crucial step in the subsequent regeneration of the amputated axon. During this process, the transected axon is transformed from a static segment into a motile growth cone. Despite the importance of this process for regeneration of the severed axon, little is known about the mechanisms underlying this transformation. Recent studies have suggested that Ca2+-activated proteinases underlay the morphological remodeling of neurons after injury. However, this hypothesis was never tested directly. Here we tested the ability of transient and localized increases in intracellular proteolytic activity to induce growth cone formation and neuritogenesis. Minute amounts of the proteinase trypsin were microinjected into intact axonal segments or somata of cultured Aplysia neurons, transiently elevating the intracellular protease concentration to 13–130 nM in the vicinity of the injection site. Such microinjections were followed by the formation of ectopic growth cones and irreversible neuritogenesis. Growth cones were not formed after external application of trypsin, microinjection of the carrier solution, or inactivated trypsin. Growth cone formation was not preceded by increases in free intracellular Ca2+ or changes in passive membrane properties, and was blocked by inhibitors of actin and tubulin polymerization. Trypsin-induced neuritogenesis was associated with ultrastructural alterations similar to those observed by us after axotomy. We conclude that local and transient elevations of cytoplasmic proteolytic activity can induce growth cone formation and neuritogenesis, and suggest that localized proteolytic activity plays a role in growth cone formation after axotomy.

scholarly journals Myosin 1c and myosin IIB serve opposing roles in lamellipodial dynamics of the neuronal growth cone

2002 ◽  
Vol 158 (7) ◽  
pp. 1207-1217 ◽  
Author(s):  
Thomas J. Diefenbach ◽  
Vaughan M. Latham ◽  
Dean Yimlamai ◽  
Canwen A. Liu ◽  
Ira M. Herman ◽  
...  
Keyword(s):  
Dorsal Root Ganglion ◽  
Neurite Outgrowth ◽  
Growth Cone ◽  
Dorsal Root ◽  
Myosin Ii ◽  
Growth Cones ◽  
Neuronal Growth ◽  
Rapid Reduction ◽  
Neuronal Growth Cone

The myosin family of motor proteins is implicated in mediating actin-based growth cone motility, but the roles of many myosins remain unclear. We previously implicated myosin 1c (M1c; formerly myosin Iβ) in the retention of lamellipodia (Wang et al., 1996). Here we address the role of myosin II (MII) in chick dorsal root ganglion neuronal growth cone motility and the contribution of M1c and MII to retrograde F-actin flow using chromophore-assisted laser inactivation (CALI). CALI of MII reduced neurite outgrowth and growth cone area by 25%, suggesting a role for MII in lamellipodial expansion. Micro-CALI of MII caused a rapid reduction in local lamellipodial protrusion in growth cones with no effects on filopodial dynamics. This is opposite to micro-CALI of M1c, which caused an increase in lamellipodial protrusion. We used fiduciary beads (Forscher et al., 1992) to observe retrograde F-actin flow during the acute loss of M1c or MII. Micro-CALI of M1c reduced retrograde bead flow by 76%, whereas micro-CALI of MII or the MIIB isoform did not. Thus, M1c and MIIB serve opposite and nonredundant roles in regulating lamellipodial dynamics, and M1c activity is specifically required for retrograde F-actin flow.

scholarly journals Cdc42 and Actin Control Polarized Expression of TI-VAMP Vesicles to Neuronal Growth Cones and Their Fusion with the Plasma Membrane

2006 ◽  
Vol 17 (3) ◽  
pp. 1194-1203 ◽  
Author(s):  
Philipp Alberts ◽  
Rachel Rudge ◽  
Theano Irinopoulou ◽  
Lydia Danglot ◽  
Cécile Gauthier-Rouvière ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Neurite Outgrowth ◽  
Growth Cone ◽  
Membrane Trafficking ◽  
Hippocampal Neurons ◽  
Membrane Vesicles ◽  
Growth Cones ◽  
Network Control ◽  
Dependent Manner ◽  
Actin Remodeling

Tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP)-mediated fusion of intracellular vesicles with the plasma membrane is crucial for neurite outgrowth, a pathway not requiring synaptobrevin-dependent exocytosis. Yet, it is not known how the TI-VAMP membrane trafficking pathway is regulated or how it is coordinated with cytoskeletal dynamics within the growth cone that guide neurite outgrowth. Here, we demonstrate that TI-VAMP, but not synaptobrevin 2, concentrates in the peripheral, F-actin-rich region of the growth cones of hippocampal neurons in primary culture. Its accumulation correlates with and depends upon the presence of F-actin. Moreover, acute stimulation of actin remodeling by homophilic activation of the adhesion molecule L1 induces a site-directed, actin-dependent recruitment of the TI-VAMP compartment. Expression of a dominant-positive mutant of Cdc42, a key regulator of cell polarity, stimulates formation of F-actin- and TI-VAMP-rich filopodia outside the growth cone. Furthermore, we report that Cdc42 activates exocytosis of pHLuorin tagged TI-VAMP in an actin-dependent manner. Collectively, our data suggest that Cdc42 and regulated assembly of the F-actin network control the accumulation and exocytosis of TI-VAMP-containing membrane vesicles in growth cones to coordinate membrane trafficking and actin remodeling during neurite outgrowth.

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