scholarly journals Induction of neuron-specific tropomyosin mRNAs by nerve growth factor is dependent on morphological differentiation.

1993 ◽  
Vol 120 (1) ◽  
pp. 205-215 ◽  
Author(s):  
R P Weinberger ◽  
R C Henke ◽  
O Tolhurst ◽  
P L Jeffrey ◽  
P Gunning
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Critical Role ◽  
Morphological Differentiation ◽  
Mrna Levels ◽  
Neuronal Phenotype ◽  
Nerve Growth ◽  
Cellular Expression

We have examined the expression of brain-specific tropomyosins during neuronal differentiation. Both TmBr-1 and TmBr-3 were shown to be neuron specific. TmBr-1 and TmBr-3 mRNA levels increased during the most active phase of neurite outgrowth in the developing rat cerebellum. In PC12 cells stimulated by nerve growth factor (NGF) to differentiate to the neuronal phenotype, TmBr-1 and TmBr-3 levels increased with an increasing degree of morphological differentiation. Induction of TmBr-1 and TmBr-3 expression only occurred under conditions where PC12 cells were permitted to extend neurites. NGF was unable to maintain levels of TmBr-1 and TmBr-3 with the loss of neuronal phenotype by resuspension of differentiated PC12 cells. The unique cellular expression and regulation in vivo and in vitro of TmBr-1 and TmBr-3 strongly suggests a critical role of these tropomyosins in neuronal microfilament function. The findings reveal that the induction and maintenance of the neuronal tropomyosins is dependent on morphological differentiation and the maintenance of the neuronal phenotype.

scholarly journals Critical Role for Kalirin in Nerve Growth Factor Signaling through TrkA

2005 ◽  
Vol 25 (12) ◽  
pp. 5106-5118 ◽  
Author(s):  
Kausik Chakrabarti ◽  
Rong Lin ◽  
Noraisha I. Schiller ◽  
Yanping Wang ◽  
David Koubi ◽  
...  
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Critical Role ◽  
Neuronal Morphology ◽  
Neurotrophin Receptor ◽  
General Mechanism ◽  
Pleckstrin Homology Domain ◽  
Pleckstrin Homology ◽  
Nerve Growth

ABSTRACT Kalirin is a multidomain guanine nucleotide exchange factor (GEF) that activates Rho proteins, inducing cytoskeletal rearrangement in neurons. Although much is known about the effects of Kalirin on Rho GTPases and neuronal morphology, little is known about the association of Kalirin with the receptor/signaling systems that affect neuronal morphology. Our experiments demonstrate that Kalirin binds to and colocalizes with the TrkA neurotrophin receptor in neurons. In PC12 cells, inhibition of Kalirin expression using antisense RNA decreased nerve growth factor (NGF)-induced TrkA autophosphorylation and process extension. Kalirin overexpression potentiated neurotrophin-stimulated TrkA autophosphorylation and neurite outgrowth in PC12 cells at a low concentration of NGF. Furthermore, elevated Kalirin expression resulted in catalytic activation of TrkA, as demonstrated by in vitro kinase assays and increased NGF-stimulated cellular activation of Rac, Mek, and CREB. Domain mapping demonstrated that the N-terminal Kalirin pleckstrin homology domain mediates the interaction with TrkA. The effects of Kalirin on TrkA provide a molecular basis for the requirement of Kalirin in process extension from PC12 cells and for previously observed effects on axonal extension and dendritic maintenance. The interaction of TrkA with the pleckstrin homology domain of Kalirin may be one example of a general mechanism whereby receptor/Rho GEF pairings play an important role in receptor tyrosine kinase activation and signal transduction.

scholarly journals The role of cAMP in nerve growth factor-promoted neurite outgrowth in PC12 cells.

1986 ◽  
Vol 102 (3) ◽  
pp. 821-829 ◽  
Author(s):  
C Richter-Landsberg ◽  
B Jastorff
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Neurite Outgrowth ◽  
Pc12 Cells ◽  
Morphological Differentiation ◽  
Intracellular Camp ◽  
Nerve Growth ◽  
Process Formation ◽  
Dependent Protein

Nerve growth factor (NGF)-mediated neurite outgrowth in rat pheochromocytoma PC12 cells has been described to be synergistically potentiated by the simultaneous addition of dibutyryl cAMP. To elucidate further the role of cAMP in NGF-induced neurite outgrowth we have used the adenylate cyclase activator forskolin, cAMP, and a set of chemically modified cAMP analogues, including the adenosine cyclic 3',5'-phosphorothioates (cAMPS) (Rp)-cAMPS and (Sp)-cAMPS. These diastereomers have differential effects on the activation of cAMP-dependent protein kinases, i.e., (Sp)-cAMPS behaves as a cAMP agonist and (Rp)-cAMPS behaves as a cAMP antagonist. Our data show that the establishment of a neuritic network, as observed from PC12 cells treated with NGF alone, could not be induced by either forskolin, cAMP, or cAMP analogues alone. The presence of NGF in combination with forskolin or cAMP or its agonistic analogues potentiated the initiation of neurite outgrowth from PC12 cells. The (Sp)-cAMPS-induced stimulation of NGF-mediated process formation was successfully blocked by the (Rp)-cAMPS diastereomer. On the other hand, NGF-stimulated neurite outgrowth was not inhibited by the presence of the cAMP antagonist (Rp)-cAMPS. We conclude that the morphological differentiation of PC12 cells stimulated by NGF does not require cAMP as a second messenger. The constant increase of intracellular cAMP, caused by either forskolin or cAMP and the analogues, in combination with NGF, not only rapidly stimulated early neurite outgrowth but also exerted a maintaining effect on the neuronal network established by NGF.

scholarly journals Nerve growth factor-induced neurite outgrowth in PC12 cells involves the coordinate induction of microtubule assembly and assembly-promoting factors.

1985 ◽  
Vol 101 (5) ◽  
pp. 1799-1807 ◽  
Author(s):  
D G Drubin ◽  
S C Feinstein ◽  
E M Shooter ◽  
M W Kirschner
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Neurite Outgrowth ◽  
Pc12 Cells ◽  
Time Course ◽  
Microtubule Assembly ◽  
Nerve Growth ◽  
Peripheral Neurons ◽  
Associated Proteins

Nerve growth factor (NGF) regulates the microtubule-dependent extension and maintenance of axons by some peripheral neurons. We show here that one effect of NGF is to promote microtubule assembly during neurite outgrowth in PC12 cells. Though NGF causes an increase in total tubulin levels, the formation of neurites and the assembly of microtubules follow a time course completely distinct from that of the tubulin induction. The increases in microtubule mass and neurite extension closely parallel 10- and 20-fold inductions of tau and MAP1, proteins shown previously to promote microtubule assembly in vitro. When NGF is removed from PC12 cells, neurites disappear, microtubule mass decreases, and both microtubule-associated proteins return to undifferentiated levels. These data suggest that the induction of tau and MAP1 in response to NGF promotes microtubule assembly and that these factors are therefore key regulators of neurite outgrowth.

Short- and long-term mechanisms of tau regulation in PC12 cells

1995 ◽  
Vol 108 (8) ◽  
pp. 2857-2864 ◽  
Author(s):  
E. Sadot ◽  
J. Barg ◽  
D. Rasouly ◽  
P. Lazarovici ◽  
I. Ginzburg
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Tau Protein ◽  
Immunoblot Analysis ◽  
Term Treatment ◽  
Mrna Levels ◽  
Short Term Treatment ◽  
Nerve Growth ◽  
Protein Levels

Induction by nerve growth factor of neurite outgrowth in PC12 cells is transcription-dependent and is associated with the accumulation of tau protein. It was recently shown that short-term treatment with staurosporine, a protein kinase alkaloid inhibitor, induced an elevation of tau protein levels and outgrowth of stable neurites. In this study, we analyzed the mechanism(s) by which nerve growth factor and staurosporine exert their effects on tau levels. We demonstrate that nerve growth factor affects tau mRNA stability, thus contributing to the observed increase in tau mRNA levels. On the other hand, tau mRNA levels were not affected by the treatment with staurosporine. We also demonstrate that the phosphorylation of tau protein was reduced after treatment of PC12 cells with nerve growth factor or staurosporine, as shown by immunoblot analysis using specific antibodies and alkaline phosphatase treatment. Thus, regulation of tau levels by nerve growth factor appears to be mediated by transcriptional, post-transcriptional and posttranslational steps, whereas the effect of staurosporine on tau levels may be attributed to its effect on the state of phosphorylation of the protein.

Effect of protein synthesis inhibitors on growth factor activation of c-fos, c-myc, and actin gene transcription

1986 ◽  
Vol 6 (4) ◽  
pp. 1050-1057
Author(s):  
M E Greenberg ◽  
A L Hermanowski ◽  
E B Ziff
Keyword(s):  
Protein Synthesis ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Gene Transcription ◽  
Actin Gene ◽  
Mrna Levels ◽  
Protein Synthesis Inhibitors ◽  
3T3 Cells ◽  
Nerve Growth

Stimulation of quiescent 3T3 cells with purified growth factors or of the pheochromocytoma cell line PC12 with nerve growth factor results in the rapid transient induction of c-fos, c-myc, and actin gene transcription (M.E. Greenberg and E.B. Ziff, Nature [London] 312:711-716; M.E. Greenberg, L.A. Greene, and E.B. Ziff, J. Biol. Chem. 26:14101-14110). We used protein synthesis inhibitors to investigate whether synthesis of new proteins plays a role in the rapid induction and subsequent repression of the transcription of these genes. Pretreatment of quiescent 3T3 cells with the inhibitor anisomycin before growth factor stimulation caused a superinduction of c-fos and c-myc mRNA levels upon growth factor addition. Nuclear runoff transcription analyses of 3T3 cells indicated that anisomycin potentiated c-fos, c-myc, and also actin expression at the transcriptional level, possibly by inhibiting transcriptional repression. Somewhat different results were obtained when PC12 cells were incubated with either anisomycin or cycloheximide. In PC12 cells protein synthesis inhibitors superinduced nerve growth factor activation of c-fos mRNA production but completely abolished the activation of c-myc. The results suggest that in PC12 cells c-fos transcription is activated by a protein-synthesis-independent mechanism, whereas c-myc stimulation requires new protein synthesis. The difference in the effect of anisomycin on growth factor activation of c-myc expression in 3T3 versus PC12 cells may be due to differential stringency of protein synthesis inhibition in the two cells or could reflect cell type differences in c-myc regulation.

Treatment of PC12 cells with nerve growth factor increases iron uptake

2001 ◽  
Vol 357 (3) ◽  
pp. 881-886 ◽  
Author(s):  
James MWANJEWE ◽  
Betsy King HUI ◽  
Michael D. COUGHLIN ◽  
Ashok K. GROVER
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Iron Uptake ◽  
Iron Concentration ◽  
Neuronal Phenotype ◽  
Nerve Growth ◽  
And Control ◽  
Iron Chelating Agents ◽  
Ca2 Channels

Phaeochromocytoma PC12 cells treated with nerve growth factor (NGF) differentiate into a neuronal phenotype. Here we compare the uptake of transferrin-bound and non-transferrin-bound iron in NGF-treated (neuronal phenotype) and control (proliferating) PC12 cells. The non-transferrin-bound iron uptake was greater in the NGF-treated cells than in the control, independently of the uptake time, the iron-chelating agents used, the oxidation state of iron (Fe2+ or Fe3+) and the iron concentration tested. The NGF-treated cells expressed L-type and N-type voltage-operated Ca2+ channels. Nitrendipine (an L-type inhibitor) and possibly ω-conotoxin (an N-type inhibitor) inhibited the iron uptake by 20%. Thapsigargin inhibits the endoplasmic reticulum Ca2+ pump and allowed Mn2+ entry into cells. Preincubating PC12 cells with thapsigargin increased the iron uptake. The rate of transferrin-bound iron uptake was less than 1% of the non-transferrin-bound iron uptake and the maximum transferrin-bound iron uptake was also very low. We conclude that an increase in the iron uptake by multiple pathways accompanies the transition of PC12 cells from the proliferating to the neuronal phenotype.

scholarly journals Effect of protein synthesis inhibitors on growth factor activation of c-fos, c-myc, and actin gene transcription.

1986 ◽  
Vol 6 (4) ◽  
pp. 1050-1057 ◽  
Author(s):  
M E Greenberg ◽  
A L Hermanowski ◽  
E B Ziff
Keyword(s):  
Protein Synthesis ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Gene Transcription ◽  
Actin Gene ◽  
Mrna Levels ◽  
Protein Synthesis Inhibitors ◽  
3T3 Cells ◽  
Nerve Growth

Stimulation of quiescent 3T3 cells with purified growth factors or of the pheochromocytoma cell line PC12 with nerve growth factor results in the rapid transient induction of c-fos, c-myc, and actin gene transcription (M.E. Greenberg and E.B. Ziff, Nature [London] 312:711-716; M.E. Greenberg, L.A. Greene, and E.B. Ziff, J. Biol. Chem. 26:14101-14110). We used protein synthesis inhibitors to investigate whether synthesis of new proteins plays a role in the rapid induction and subsequent repression of the transcription of these genes. Pretreatment of quiescent 3T3 cells with the inhibitor anisomycin before growth factor stimulation caused a superinduction of c-fos and c-myc mRNA levels upon growth factor addition. Nuclear runoff transcription analyses of 3T3 cells indicated that anisomycin potentiated c-fos, c-myc, and also actin expression at the transcriptional level, possibly by inhibiting transcriptional repression. Somewhat different results were obtained when PC12 cells were incubated with either anisomycin or cycloheximide. In PC12 cells protein synthesis inhibitors superinduced nerve growth factor activation of c-fos mRNA production but completely abolished the activation of c-myc. The results suggest that in PC12 cells c-fos transcription is activated by a protein-synthesis-independent mechanism, whereas c-myc stimulation requires new protein synthesis. The difference in the effect of anisomycin on growth factor activation of c-myc expression in 3T3 versus PC12 cells may be due to differential stringency of protein synthesis inhibition in the two cells or could reflect cell type differences in c-myc regulation.

scholarly journals Sputa nerve growth factor forms a preferable substitute to mouse 7S-β nerve growth factor

2004 ◽  
Vol 383 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Dawn C.-I. KOH ◽  
A. ARMUGAM ◽  
K. JEYASEELAN
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Gel Filtration ◽  
Nuclear Factor Κb ◽  
Reversed Phase ◽  
Protein Profiling ◽  
Nerve Growth

The NGF (nerve growth factor) from Naja sputatrix has been purified by gel filtration followed by reversed-phase HPLC. The protein showed a very high ability to induce neurite formation in PC12 cells relative to the mouse NGF. Two cDNAs encoding isoforms of NGF have been cloned and an active recombinant NGF, sputa NGF, has been produced in Escherichia coli as a His-tagged fusion protein. Sputa NGF has been found to be non-toxic under both in vivo and in vitro conditions. The induction of neurite outgrowth by this NGF has been found to involve the high-affinity trkA–p75NTR complex of receptors. The pro-survival mechanism of p75NTR has been mediated by the activation of nuclear factor κB gene by a corresponding down-regulation of inhibitory κB gene. Real-time PCR and protein profiling (by surface-enhanced laser-desorption–ionization time-of-flight) have confirmed that sputa NGF up-regulates the expression of the endogenous NGF in PC12 cells. Preliminary microarray analysis has also shown that sputa NGF is capable of promoting additional beneficial effects such as the up-regulation of arginine vasopressin receptor 1A, voltage-dependent T-type calcium channel. Hence, sputa NGF forms a new and useful NGF.

Sign in / Sign up

Export Citation Format

Share Document