scholarly journals T-type Ca 2+ channels are required for enhanced sympathetic axon growth by TNFα reverse signalling

Open Biology ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 160288 ◽  
Author(s):  
Lilian Kisiswa ◽  
Clara Erice ◽  
Laurent Ferron ◽  
Sean Wyatt ◽  
Catarina Osório ◽  
...  
Keyword(s):  
Sympathetic Neurons ◽  
Sympathetic Innervation ◽  
Axon Growth ◽  
Tumour Necrosis Factor Receptor ◽  
Kinase C ◽  
Cultured Sympathetic Neurons ◽  
Sympathetic Axon ◽  
Pkc Activation ◽  
Cell Somata ◽  
Necrosis Factor

Tumour necrosis factor receptor 1 (TNFR1)-activated TNFα reverse signalling, in which membrane-integrated TNFα functions as a receptor for TNFR1, enhances axon growth from developing sympathetic neurons and plays a crucial role in establishing sympathetic innervation. Here, we have investigated the link between TNFα reverse signalling and axon growth in cultured sympathetic neurons. TNFR1-activated TNFα reverse signalling promotes Ca 2+ influx, and highly selective T-type Ca 2+ channel inhibitors, but not pharmacological inhibitors of L-type, N-type and P/Q-type Ca 2+ channels, prevented enhanced axon growth. T-type Ca 2+ channel-specific inhibitors eliminated Ca 2+ spikes promoted by TNFα reverse signalling in axons and prevented enhanced axon growth when applied locally to axons, but not when applied to cell somata. Blocking action potential generation did not affect the effect of TNFα reverse signalling on axon growth, suggesting that propagated action potentials are not required for enhanced axon growth. TNFα reverse signalling enhanced protein kinase C (PKC) activation, and pharmacological inhibition of PKC prevented the axon growth response. These results suggest that TNFα reverse signalling promotes opening of T-type Ca 2+ channels along sympathetic axons, which is required for enhanced axon growth.

Vascular-derived artemin: a determinant of vascular sympathetic innervation?

2007 ◽  
Vol 293 (1) ◽  
pp. H266-H273 ◽  
Author(s):  
Deborah H. Damon ◽  
Jaclyn A. teRiele ◽  
Stephen B. Marko
Keyword(s):  
Important Determinant ◽  
Sympathetic Neurons ◽  
Sympathetic Innervation ◽  
Axon Growth ◽  
Neurite Growth ◽  
Sympathetic Ganglia ◽  
Neonatal Rat ◽  
Rt Pcr ◽  
Adult Rats ◽  
Sympathetic Axon

Vascular sympathetic innervation is an important determinant of blood pressure and blood flow. The mechanisms that determine vascular sympathetic innervation are not well understood. The present study tests the hypothesis that vascular-derived artemin promotes the development of sympathetic innervation to blood vessels by promoting sympathetic axon growth. RT-PCR and Western analyses indicate that artemin is expressed by cultured vascular smooth muscle and arteries, and artemin coreceptors, glial cell-derived neurotrophic factor family receptor α3 and ret, are expressed by postganglionic sympathetic neurons. The effects of artemin on axon growth were assessed on explants of neonatal rat sympathetic ganglia. In the presence, but not in the absence, of nerve growth factor, exogenous artemin stimulated neurite growth. Femoral arteries (FA) from adult rats contain artemin, and these arteries stimulated sympathetic neurite growth. Growth in the presence of FA was 92.2 ± 11.9 mm, and that in the absence of FA was 26.3 ± 5.4 mm ( P < 0.05). FA stimulation of axon growth was reduced by an antibody that neutralized the activity of artemin ( P < 0.05). These data indicate that artemin is expressed in arteries, and its receptors are expressed and functional in the postganglionic sympathetic neurons that innervate them. This suggests that artemin may be a determinant of vascular sympathetic innervation.

Protein kinase C blocks somatostatin-induced modulation of calcium current in chick sympathetic neurons

1993 ◽  
Vol 70 (4) ◽  
pp. 1639-1643 ◽  
Author(s):  
A. Golard ◽  
L. W. Role ◽  
S. A. Siegelbaum
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Current ◽  
Phorbol Esters ◽  
Sympathetic Neurons ◽  
Somatostatin Receptor ◽  
Kinase C ◽  
Voltage Dependent ◽  
Ganglion Neurons ◽  
Pkc Activation

1. Somatostatin produces a voltage-dependent inhibition of N-type Ca2+ current in chick sympathetic neurons. Pretreatment of chick sympathetic ganglion neurons with protein kinase C (PKC) activators has no effect on calcium current (ICa) but reduces the inhibition of ICa by somatostatin. 2. The effects of the alkaloid PKC activator (-)-indolactam V were indistinguishable from those of 4 beta-phorbol-12-myristate-13-acetate (4 beta-PMA). The inactive isomers (+)-indolactam V and 4 alpha-PMA did not alter the modulation of ICa by somatostatin. 3. Modulation of ICa by somatostatin desensitizes, with a time for half desensitization of approximately 3 min. PKC activation mimics the normal desensitization process in that responses to 30 nM somatostatin are inhibited to a greater extent than are responses to 1 microM somatostatin. 4. PKC appears to act at the level of the somatostatin receptor or receptor-G protein interaction because PKC activation does not alter Ca2+ current inhibition in response to a nonhydrolyzable analog of GTP, GTP-gamma-S, which directly activates G proteins. 5. The specific PKC inhibitor calphostin C largely reverses the effects of phorbol esters, but does not slow the normal rate of desensitization of somatostatin responses. This indicates that PKC is not involved in the homologous desensitization of the somatostatin receptor. 6. Neither substance P, which activates PKC in these cells, nor arachidonic acid, another PKC activator, altered the action of somatostatin on ICa.

scholarly journals Neurotrophin-regulated signalling pathways

2006 ◽  
Vol 361 (1473) ◽  
pp. 1545-1564 ◽  
Author(s):  
Louis F Reichardt
Keyword(s):  
Nervous System ◽  
Map Kinases ◽  
Sympathetic Neurons ◽  
Axon Growth ◽  
Synaptic Function ◽  
Neurotrophin Receptor ◽  
Signalling Pathways ◽  
Tumour Necrosis Factor Receptor ◽  
Trk Receptors ◽  
Cell Fate Decisions

Neurotrophins are a family of closely related proteins that were identified initially as survival factors for sensory and sympathetic neurons, and have since been shown to control many aspects of survival, development and function of neurons in both the peripheral and the central nervous systems. Each of the four mammalian neurotrophins has been shown to activate one or more of the three members of the tropomyosin-related kinase (Trk) family of receptor tyrosine kinases (TrkA, TrkB and TrkC). In addition, each neurotrophin activates p75 neurotrophin receptor (p75NTR), a member of the tumour necrosis factor receptor superfamily. Through Trk receptors, neurotrophins activate Ras, phosphatidyl inositol-3 (PI3)-kinase, phospholipase C-γ1 and signalling pathways controlled through these proteins, such as the MAP kinases. Activation of p75NTR results in activation of the nuclear factor-κB (NF-κB) and Jun kinase as well as other signalling pathways. Limiting quantities of neurotrophins during development control the number of surviving neurons to ensure a match between neurons and the requirement for a suitable density of target innervation. The neurotrophins also regulate cell fate decisions, axon growth, dendrite growth and pruning and the expression of proteins, such as ion channels, transmitter biosynthetic enzymes and neuropeptide transmitters that are essential for normal neuronal function. Continued presence of the neurotrophins is required in the adult nervous system, where they control synaptic function and plasticity, and sustain neuronal survival, morphology and differentiation. They also have additional, subtler roles outside the nervous system. In recent years, three rare human genetic disorders, which result in deleterious effects on sensory perception, cognition and a variety of behaviours, have been shown to be attributable to mutations in brain-derived neurotrophic factor and two of the Trk receptors.

The role of ubiquitin in neurotrophin receptor signalling and sorting

2006 ◽  
Vol 34 (5) ◽  
pp. 757-760 ◽  
Author(s):  
M.W. Wooten ◽  
T. Geetha
Keyword(s):  
Neurotrophin Receptor ◽  
Tumour Necrosis Factor Receptor ◽  
Receptor Kinase ◽  
Polyubiquitin Chains ◽  
Receptor Signalling ◽  
Kinase C ◽  
Ubiquitin Conjugating Enzyme ◽  
P75 Receptor ◽  
Necrosis Factor

NGF (nerve growth factor) binding to TrkA (tropomyosin receptor kinase A) induces dimerization, autophosphorylation and internalization of the receptor to signalling vesicles for delivery of differentiation signals. TrkA interacts with p75 receptor through the p62–TRAF-6 (tumour-necrosis-factor-receptor-associated factor 6) complex bridging the two receptors. The atypical protein kinase C is activated and recruited to the receptor complex as well. TrkA is Lys63-polyubiquitinated on Lys485 by the E3 (ubiquitin ligase), TRAF-6, and E2 (ubiquitin-conjugating enzyme), UbcH7. Inhibition of polyubiquitination has been observed to interrupt signalling and internalization. Furthermore, an absence of p62 prevents endosomal localization and signalling. Altogether, these findings reveal Lys63-linked polyubiquitin chains and the shuttling protein p62 co-ordinately regulate TrkA internalization, trafficking and sorting.

Vascular endothelial-derived semaphorin 3 inhibits sympathetic axon growth

2006 ◽  
Vol 290 (3) ◽  
pp. H1220-H1225 ◽  
Author(s):  
Deborah H. Damon
Keyword(s):  
Axon Guidance ◽  
Vascular Endothelial Cells ◽  
Sympathetic Innervation ◽  
Axon Growth ◽  
Sympathetic Ganglia ◽  
Vascular Endothelial ◽  
Semaphorin 3A ◽  
Rt Pcr ◽  
Guidance Cue ◽  
Sympathetic Axon

Vascular sympathetic innervation is an important determinant of blood pressure and blood flow. The mechanisms that determine vascular sympathetic innervation are not well understood. Recent studies indicate that vascular endothelial cells (EC) express semaphorin 3A, a repulsive axon guidance cue. This suggests that EC would inhibit the growth of axons to blood vessels. The present study tests this hypothesis. RT-PCR and Western analyses confirmed that rat aortic vascular ECs expressed semaphorin 3A as well as other class 3 semaphorins (sema 3s). To determine the effects of EC-derived sema 3 on sympathetic axons, axon outgrowth was assessed in cultures of neonatal sympathetic ganglia grown for 72 h in the absence and presence of vascular EC. Nerve growth factor-induced axon growth in the presence of ECs was 50 ± 4% ( P < 0.05) of growth in the absence of ECs. ECs did not inhibit axon growth in the presence of an antibody that neutralized the activity of sema 3 ( P > 0.05). RT-PCR and Western analyses also indicated that sema 3s were expressed in ECs of intact arteries. To assess the function of sema 3s in arteries, sympathetic ganglia were grown in the presence of arteries for 72 h, and the percentage of axons that grew toward the artery was determined: 44 ± 4% of axons grew toward neonatal carotid arteries. Neutralization of sema 3s or removal of EC increased the percentage of axons that grew toward the artery (71 ± 8% and 72 ± 8%, respectively). These data indicate that vascular EC-derived sema 3s inhibit sympathetic axon growth and may thus be a determinant of vascular sympathetic innervation.

TNF-alpha induces peroxynitrite-mediated depletion of lung endothelial glutathione via protein kinase C

1995 ◽  
Vol 269 (4) ◽  
pp. L551-L559 ◽  
Author(s):  
D. T. Phelps ◽  
T. J. Ferro ◽  
P. J. Higgins ◽  
R. Shankar ◽  
D. M. Parker ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Necrosis Factor Alpha ◽  
Endothelial Monolayers ◽  
Kinase C ◽  
Factor Alpha ◽  
Oxide Synthase ◽  
Pkc Activation ◽  
Necrosis Factor ◽  
Dependent Mechanism

We tested the hypothesis that tumor necrosis factor-alpha (TNF) induces a peroxynitrite (ONOO-)-mediated depletion of glutathione via a protein kinase C (PKC)-dependent mechanism in pulmonary artery endothelial monolayers (PAEM). PAEM were incubated with TNF (1,000 U/ml) for 6 and 18 h. The PAEM were assayed for ONOO(-)-dependent changes in the concentration of luminol, free glutathione [Gfree; i.e., reduced glutathione and oxidized glutathione (GSSG)] and GSSG. TNF treatment decreased luminol and Gfree, and increased GSSG and GSSG/Gfree, compared with treatment with control media. The TNF-induced effects were prevented by co-incubation with the nitric oxide synthase inhibitors NG-monomethyl-L-arginine (1 mM), NG-nitro-L-arginine methyl ester (1 mM), or NG-nitro-L-arginine (1 mM). In addition, the TNF-induced effects were prevented by superoxide dismutase (10 U/ml), which removes O2-, and by urate (0.5 mM) and L-cysteine (3 mM), putative scavengers of ONOO-. The treatment of PAEM with the PKC activator phorbol 12-myristate 13-acetate (PMA, 1 microM) induced similar alterations in luminol and glutathione as TNF. TNF and PMA induced a protein of similar molecular weight (approximately 90 kDa) in the focal contact-rich fraction of PAEM lysate. TNF- and PMA-induced effects were prevented with the specific PKC inhibitor calphostin C (1 microM). The data indicate that TNF-induced PKC activation mediates ONOO- generation, which results in the oxidation and depletion of glutathione in PAEM.

Activation of protein kinase C mediates altered pulmonary vasoreactivity induced by tumor necrosis factor-alpha

1994 ◽  
Vol 267 (3) ◽  
pp. L282-L290 ◽  
Author(s):  
G. Serfilippi ◽  
T. J. Ferro ◽  
A. Johnson
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Necrosis Factor Alpha ◽  
Calphostin C ◽  
Kinase C ◽  
Factor Alpha ◽  
Pkc Activation ◽  
Necrosis Factor

We postulated that tumor necrosis factor-alpha (TNF) "primes" the lung for the development of pulmonary vasoconstriction and edema by activating protein kinase C (PKC). Guinea pigs were injected with TNF (1.6 x 10(5) U/kg i.p.), and the lungs were isolated 4 h later. Compared with controls, TNF pretreatment resulted in greater increases in pulmonary vascular resistance and pressure and lung weight, in response to the thromboxane A2 mimetic, U-46619 (122 pmol/min). Treatment with TNF resulted in 1) pulmonary arterial endothelial PKC activation, 2) increased lung polymorphonuclear neutrophil (PMN) sequestration, 3) increased levels of superoxide radical (O2.) in lung effluent, and 4) decreased nitrite levels (NO2-, oxidation product of nitric oxide) in lung effluent. Intraperitoneal treatment with calphostin C (3 microM, 15 min prior to treatment with TNF) prevented the effects of TNF on 1) PKC activation, 2) the hemodynamic responses to U-46619, and 3) the levels of NO2- and O2(.). PKC activation does not mediate TNF-induced lung sequestration of PMN, since calphostin C had no effect on lung myeloperoxidase activity. The data suggest that PKC activation mediates TNF-induced 1) increases in O2., 2) decreases in NO2-, and 3) increases in vasoreactivity and edema in response to U-46619.

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