Effect of Pentoxifylline on Staurosporine-Induced Neurite Elongation in PC12 Cells

The spatial activation of phosphoinositide 3-kinase (PI3-kinase) signaling at the axon growth cone generates phosphatidylinositol 3,4,5 trisphosphate (PtdIns(3,4,5)P3), which localizes and facilitates Akt activation and stimulates GSK-3β inactivation, promoting microtubule polymerization and axon elongation. However, the molecular mechanisms that govern the spatial down-regulation of PtdIns(3,4,5)P3 signaling at the growth cone remain undetermined. The inositol polyphosphate 5-phosphatases (5-phosphatase) hydrolyze the 5-position phosphate from phosphatidylinositol 4,5 bisphosphate (PtdIns(4,5)P2) and/or PtdIns(3,4,5)P3. We demonstrate here that PIPP, an uncharacterized 5-phosphatase, hydrolyzes PtdIns(3,4,5)P3 forming PtdIns(3,4)P2, decreasing Ser473-Akt phosphorylation. PIPP is expressed in PC12 cells, localizing to the plasma membrane of undifferentiated cells and the neurite shaft and growth cone of NGF-differentiated neurites. Overexpression of wild-type, but not catalytically inactive PIPP, in PC12 cells inhibited neurite elongation. Targeted depletion of PIPP using RNA interference (RNAi) resulted in enhanced neurite differentiation, associated with neurite hyperelongation. Inhibition of PI3-kinase activity prevented neurite hyperelongation in PIPP-deficient cells. PIPP targeted-depletion resulted in increased phospho-Ser473-Akt and phospho-Ser9-GSK-3β, specifically at the neurite growth cone, and accumulation of PtdIns(3,4,5)P3 at this site, associated with enhanced microtubule polymerization in the neurite shaft. PIPP therefore inhibits PI3-kinase-dependent neurite elongation in PC12 cells, via regulation of the spatial distribution of phospho-Ser473-Akt and phospho-Ser9-GSK-3β signaling.

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Neurite elongation is blocked if microtubule polymerization is inhibited in PC12 cells

Cell Motility and the Cytoskeleton ◽

10.1002/cm.970170205 ◽

1990 ◽

Vol 17 (2) ◽

pp. 95-105 ◽

Cited By ~ 23

Author(s):

Charles H. Keith

Keyword(s):

Pc12 Cells ◽

Neurite Elongation ◽

Microtubule Polymerization

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c-Fos Activated Phospholipid Synthesis Is Required for Neurite Elongation in Differentiating PC12 Cells

Molecular Biology of the Cell ◽

10.1091/mbc.e03-09-0705 ◽

2004 ◽

Vol 15 (4) ◽

pp. 1881-1894 ◽

Cited By ~ 47

Author(s):

Germán A. Gil ◽

Daniela F. Bussolino ◽

Maximiliano M. Portal ◽

Adolfo Alfonso Pecchio ◽

Marianne L. Renner ◽

...

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Neurite Outgrowth ◽

Pc12 Cells ◽

Dual Function ◽

Phospholipid Synthesis ◽

Nerve Growth ◽

Neurite Elongation ◽

Neurite Retraction ◽

Fos Expression

We have previously shown that c-Fos activates phospholipid synthesis through a mechanism independent of its genomic AP-1 activity. Herein, using PC12 cells induced to differentiate by nerve growth factor, the genomic effect of c-Fos in initiating neurite outgrowth is shown as distinct from its nongenomic effect of activating phospholipid synthesis and sustaining neurite elongation. Blocking c-Fos expression inhibited differentiation, phospholipid synthesis activation, and neuritogenesis. In cells primed to grow, blocking c-Fos expression determined neurite retraction. However, transfected cells expressing c-Fos or c-Fos deletion mutants with capacity to activate phospholipid synthesis sustain neurite outgrowth and elongation in the absence of nerve growth factor. Results disclose a dual function of c-Fos: it first releases the genomic program for differentiation and then associates to the endoplasmic reticulum and activates phospholipid synthesis. Because phospholipids are key membrane components, we hypothesize this latter phenomenon as crucial to support membrane genesis demands required for cell growth and neurite elongation.

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Rac is required for growth cone function but not neurite assembly

Journal of Cell Science ◽

10.1242/jcs.110.5.635 ◽

1997 ◽

Vol 110 (5) ◽

pp. 635-641 ◽

Cited By ~ 4

Author(s):

P. Lamoureux ◽

Z.F. Altun-Gultekin ◽

C. Lin ◽

J.A. Wagner ◽

S.R. Heidemann

Keyword(s):

Pc12 Cells ◽

Growth Cone ◽

Elongation Rate ◽

Dominant Negative ◽

Normal Density ◽

Spontaneous Growth ◽

Neurite Elongation ◽

Dominant Negative Form ◽

Applied Tension ◽

Negative Form

Recent work has suggested that rac1 and other members of the rho family of small GTP-binding proteins play an important role in the formation of neural processes. We have explored the mechanism of this effect by comparing the spontaneous, growth cone-mediated growth and experimental tension-induced growth of axons in normal PC12 cells and in mutant cells expressing a dominant negative form of rac. PC12 that have been primed by exposure to NGF, but not naive PC12 cells, initiate a microtubule-rich process de novo in response to tension applied to cell body. As in chick sensory neurons, neurite elongation rate is proportional to applied tension above a threshold. Addition of cyclic AMP, which has been shown to rapidly augment NGF-induced neurite outgrowth in PC12, causes a rapid increase in the rate of neurite elongation at a given tension level. Expression of a dominant negative form of rac1 inhibits spontaneous, growth cone-mediated neurite elongation in response to NGF, but does not substantially affect tension-induced neurite elongation. That is, rac-deficient cells show a normal linear relationship between applied tension and elongation rate and the elongations contain a normal density of axial microtubules by immunofluorescent assay. Thus, rac1 is apparently required for the mechanisms that normally generate tension in an elongating neurite, but if this tension is provided from an outside source, then axonal elongation can proceed normally in rac1-deficient cells. We conclude that rac1 is required for the adhesive and motile function of growth cones rather than the assembly of neurites per se.

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Dissociation of NGF Induced Signal Transduction from Neurite Elongation by Expression of a Mutant Adaptor Protein v-Crk in PC12 Cells

Molecular and Cellular Neuroscience ◽

10.1006/mcne.1996.0054 ◽

1996 ◽

Vol 8 (2-3) ◽

pp. 157-170 ◽

Cited By ~ 9

Author(s):

Kenneth K. Teng ◽

Jody C. Courtney ◽

Paul van Bergen en Henegouwen ◽

Raymond B. Birge ◽

Barbara L. Hempstead

Keyword(s):

Signal Transduction ◽

Pc12 Cells ◽

Adaptor Protein ◽

Neurite Elongation ◽

Induced Signal

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ProNGF derived from rat sciatic nerves downregulates neurite elongation and axon specification in PC12 cells

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2015.00364 ◽

2015 ◽

Vol 9 ◽

Cited By ~ 1

Author(s):

Anna Sofía Trigos ◽

Marines Longart ◽

Lisbeth García ◽

Cecilia Castillo ◽

Patricia Forsyth ◽

...

Keyword(s):

Pc12 Cells ◽

Neurite Elongation ◽

Sciatic Nerves ◽

Axon Specification

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Regulation of Growth Cone Extension by SNARE Proteins

Journal of Histochemistry & Cytochemistry ◽

10.1177/002215540305100404 ◽

2003 ◽

Vol 51 (4) ◽

pp. 429-433 ◽

Cited By ~ 46

Author(s):

Kazushi Kimura ◽

Akira Mizoguchi ◽

Chizuka Ide

Keyword(s):

Neurite Outgrowth ◽

Pc12 Cells ◽

The Other ◽

Snare Proteins ◽

Fusion System ◽

Surface Plasma ◽

Neurite Elongation ◽

Sensitive Factor ◽

Regulation Of Growth

Recent studies have suggested that the soluble N-ethylmaleimide-sensitive factor attached protein (SNAP) receptor (SNARE)-mediated membrane fusion system is involved in vesicle fusion with the surface plasma membrane, which leads to neurite elongation. There have been several reports analyzing the effects of neurite outgrowth by inhibition of SNAREs. We studied this mechanism by overexpressing GFP-fusion SNAREs including VAMP-2, SNAP-25A, and syntaxin1A in PC12 cells to investigate the role of SNAREs in neurite outgrowth. When overexpressed in PC12 cells, VAMP-2 promoted neurite elongation, whereas SNAP-25A stimulated neurite sprouting. On the other hand, overexpression of syntaxin1A neither promoted nor inhibited neurite outgrowth. Thus, VAMP-2 and SNAP-25A play different roles in neurite elongation and sprouting.

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