Chinese Medicine Induces Neurite Outgrowth in PC12 Mutant Cells Incapable of Differentiation

2002 ◽  
Vol 30 (02n03) ◽  
pp. 287-295 ◽  
Author(s):  
Yoshio Kano ◽  
Shinichiro Takaguchi ◽  
Tsutomu Nohno ◽  
Fukumi Hiragami ◽  
Kenji Kawamura ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Pc12 Cells ◽  
Mutant Cell ◽  
Mitogen Activated Protein Kinase ◽  
Chinese Medicines ◽  
Mapk Activity ◽  
Mitogen Activated Protein ◽  
Mutant Cells ◽  
Stimulation Of ◽  
Sustained Activation

During continuous culture of neural PC12 cells, we obtained a drug-hypersensitive PC12 mutant cell that showed high stimulation of neurite outgrowth by various drugs. When several Chinese medicines such as Shu-Jing-Huo-Xie-Tang and Wu-Ling-San were provided to these PC12 mutant cells, the frequency of nerve growth factor (NGF)-induced neurite outgrowth increased approximately 30-fold compared to NGF alone. Neurite outgrowth induced by NGF in PC12 cells is accompanied by sustained activation of mitogen-activated protein kinase (MAPK); however, these Chinese medicines did not induce MAPK activity. The findings thus indicate that certain Chinese medicines may induce neurite outgrowth by a novel mechanism which is distinct from the NGF-activated pathway in PC12 mutant cells.

scholarly journals Signals from the AT2 (Angiotensin Type 2) Receptor of Angiotensin II Inhibit p21ras and Activate MAPK (Mitogen-Activated Protein Kinase) to Induce Morphological Neuronal Differentiation in NG108–15 Cells

1999 ◽  
Vol 13 (9) ◽  
pp. 1615-1626 ◽  
Author(s):  
Louis Gendron∗ ◽  
Liette Laflamme∗ ◽  
Nathalie Rivard ◽  
Claude Asselin ◽  
Marcel D. Payet ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Morphological Differentiation ◽  
Mitogen Activated Protein Kinase ◽  
Ang Ii ◽  
Mapk Activity ◽  
Angiotensin Type 2 Receptor ◽  
Mitogen Activated Protein ◽  
Angiotensin Type ◽  
Stimulation Of

Abstract In a previous study, we had shown that activation of the AT2 (angiotensin type 2) receptor of angiotensin II (Ang II) induced morphological differentiation of the neuronal cell line NG108–15. In the present study, we investigated the nature of the possible intracellular mediators involved in the AT2 effect. We found that stimulation of AT2 receptors in NG108–15 cells resulted in time-dependent modulation of tyrosine phosphorylation of a number of cytoplasmic proteins. Stimulation of NG108–15 cells with Ang II induced a decrease in GTP-bound p21ras but a sustained increase in the activity of p42mapk and p44mapk as well as neurite outgrowth. Similarly, neurite elongation, increased polymerized tubulin levels, and increased mitogen-activated protein kinase (MAPK) activity were also observed in a stably transfected NG108–15 cell line expressing the dominant-negative mutant of p21ras, RasN17. These results support the observation that inhibition of p21ras did not impair the effect of Ang II on its ability to stimulate MAPK activity. While 10 μm of the MEK inhibitor, PD98059, only moderately affected elongation, 50 μm PD98059 completely blocked the Ang II- and the RasN17-mediated induction of neurite outgrowth. These results demonstrate that some of the events associated with the AT2 receptor-induced neuronal morphological differentiation of NG108–15 cells not only include inhibition of p21ras but an increase in MAPK activity as well, which is essential for neurite outgrowth.

scholarly journals The Insulin Receptor: A Potential Target of Amarogentin Isolated from Gentiana rigescens Franch That Induces Neurogenesis in PC12 Cells

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 581
Author(s):  
Lihong Cheng ◽  
Hiroyuki Osada ◽  
Tianyan Xing ◽  
Minoru Yoshida ◽  
Lan Xiang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Insulin Receptor ◽  
Signaling Pathways ◽  
Neurite Outgrowth ◽  
Pc12 Cells ◽  
Mitogen Activated Protein Kinase ◽  
Potential Target ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Gentiana Rigescens

Amarogentin (AMA) is a secoiridoid glycoside isolated from the traditional Chinese medicine, Gentiana rigescens Franch. AMA exhibits nerve growth factor (NGF)-mimicking and NGF-enhancing activities in PC12 cells and in primary cortical neuron cells. In this study, a possible mechanism was found showing the remarkable induction of phosphorylation of the insulin receptor (INSR) and protein kinase B (AKT). The potential target of AMA was predicted by using a small-interfering RNA (siRNA) and the cellular thermal shift assay (CETSA). The AMA-induced neurite outgrowth was reduced by the siRNA against the INSR and the results of the CETSA suggested that the INSR showed a significant thermal stability-shifted effect upon AMA treatment. Other neurotrophic signaling pathways in PC12 cells were investigated using specific inhibitors, Western blotting and PC12(rasN17) and PC12(mtGAP) mutants. The inhibitors of the glucocorticoid receptor (GR), phospholipase C (PLC) and protein kinase C (PKC), Ras, Raf and mitogen-activated protein kinase (MEK) significantly reduced the neurite outgrowth induced by AMA in PC12 cells. Furthermore, the phosphorylation reactions of GR, PLC, PKC and an extracellular signal-regulated kinase (ERK) were significantly increased after inducing AMA and markedly decreased after treatment with the corresponding inhibitors. Collectively, these results suggested that AMA-induced neuritogenic activity in PC12 cells potentially depended on targeting the INSR and activating the downstream Ras/Raf/ERK and PI3K/AKT signaling pathways. In addition, the GR/PLC/PKC signaling pathway was found to be involved in the neurogenesis effect of AMA.

Role of the PI3K/PKB signaling pathway in cAMP-mediated translocation of rat liver Ntcp

1999 ◽  
Vol 277 (6) ◽  
pp. G1165-G1172 ◽  
Author(s):  
Cynthia R. L. Webster ◽  
M. Sawkat Anwer
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Signaling Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Phosphatidylinositol 3 Kinase ◽  
Pi3k Inhibitors ◽  
Mapk Activity ◽  
Mitogen Activated Protein ◽  
Pi3k Signaling Pathway ◽  
Stimulation Of

cAMP stimulates Na+-taurocholate (TC) cotransport by translocating the Na+-TC-cotransporting peptide (Ntcp) to the plasma membrane. The present study was undertaken to determine whether the phosphatidylinositol-3-kinase (PI3K)-signaling pathway is involved in cAMP-mediated translocation of Ntcp. The ability of cAMP to stimulate TC uptake declined significantly when hepatocytes were pretreated with PI3K inhibitors wortmannin or LY-294002. Wortmannin inhibited cAMP-mediated translocation of Ntcp to the plasma membrane. cAMP stimulated protein kinase B (PKB) activity by twofold within 5 min, an effect inhibited by wortmannin. Neither basal mitogen-activated protein kinase (MAPK) activity nor cAMP-mediated inhibition of MAPK activity was affected by wortmannin. cAMP also stimulated p70S6K activity. However, rapamycin, an inhibitor of p70S6K, failed to inhibit cAMP-mediated stimulation of TC uptake, indicating that the effect of cAMP is not mediated via p70S6K. Cytochalasin D, an inhibitor of actin filament formation, inhibited the ability of cAMP to stimulate TC uptake and Ntcp translocation. Together, these results suggest that the stimulation of TC uptake and Ntcp translocation by cAMP may be mediated via the PI3K/PKB signaling pathway and requires intact actin filaments.

Insulin induces Ca2+ influx into isolated rat hepatocyte couplets

1997 ◽  
Vol 272 (6) ◽  
pp. G1425-G1432 ◽  
Author(s):  
K. Benzeroual ◽  
G. van de Werve ◽  
S. Meloche ◽  
L. Mathe ◽  
A. Romanelli ◽  
...  
Keyword(s):  
Peptide Hormone ◽  
Insulin Binding ◽  
Mitogen Activated Protein Kinase ◽  
Rat Hepatocyte ◽  
Mapk Activity ◽  
Mitogen Activated Protein ◽  
Insulin Dependent ◽  
Dose Dependent Increase ◽  
Isolated Rat ◽  
Stimulation Of

Isolated rat hepatocyte couplets were used to study the direct effect of insulin on intracellular Ca2+ homeostasis. Insulin induced a dose-dependent increase in hepatocellular Ca2+ that was gradual, generally monophasic, and reversible. Chelation of extracellular Ca2+ abolished the insulin-induced Ca2+ response, and this suppression was not related to an effect on insulin binding, as indicated by displacement studies. We thus tested the effect of several Ca2+ channel inhibitors on insulin-induced Ca2+ influx. Verapamil at 20 or 200 microM was without effect, whereas 500 microM nickel and 50 microM gadolinium strongly inhibited insulin-induced Ca2+ entry. Finally, we tested whether insulin-induced Ca2+ movements were implicated in the stimulation of mitogen-activated protein kinase (MAPK) activity, which we measured with the use of an immune-complex assay. Verapamil was without effect on the insulin-dependent stimulation of p44mapk activity, whereas addition of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, nickel, or gadolinium strongly inhibited the effect of the peptide hormone. Our results indicate that insulin triggers Ca2+ influx into hepatocytes, possibly through the opening of channels on the plasma membrane, and that this effect is important for insulin activation of MAPK.

scholarly journals Identification of B-KSR1, a Novel Brain-Specific Isoform of KSR1 That Functions in Neuronal Signaling

2000 ◽  
Vol 20 (15) ◽  
pp. 5529-5539 ◽  
Author(s):  
Jürgen Müller ◽  
Angela M. Cacace ◽  
W. Ernest Lyons ◽  
Carolyn B. McGill ◽  
Deborah K. Morrison
Keyword(s):  
Growth Factor ◽  
Neurite Outgrowth ◽  
Neuronal Differentiation ◽  
Catalytic Domain ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Loss Of Function ◽  
Mapk Activity ◽  
Kinase Suppressor Of Ras ◽  
Mitogen Activated Protein

ABSTRACT Kinase suppressor of Ras (KSR) is an evolutionarily conserved component of Ras-dependent signaling pathways. Here, we report the identification of B-KSR1, a novel splice variant of murine KSR1 that is highly expressed in brain-derived tissues. B-KSR1 protein is detectable in mouse brain throughout embryogenesis, is most abundant in adult forebrain neurons, and is complexed with activated mitogen-activated protein kinase (MAPK) and MEK in brain tissues. Expression of B-KSR1 in PC12 cells resulted in accelerated nerve growth factor (NGF)-induced neuronal differentiation and detectable epidermal growth factor (EGF)-induced neurite outgrowth. Sustained MAPK activity was observed in cells stimulated with either NGF or EGF, and all effects on neurite outgrowth could be blocked by the MEK inhibitor PD98059. In B-KSR1-expressing cells, the MAPK–B-KSR1 interaction was inducible and correlated with MAPK activation, while the MEK–B-KSR1 interaction was constitutive. Further examination of the MEK–B-KSR1 interaction revealed that all genetically identified loss-of-function mutations in the catalytic domain severely diminished MEK binding. Moreover, B-KSR1 mutants defective in MEK binding were unable to augment neurite outgrowth. Together, these findings demonstrate the functional importance of MEK binding and indicate that B-KSR1 may function to transduce Ras-dependent signals that are required for neuronal differentiation or that are involved in the normal functioning of the mature central nervous system.

scholarly journals Differential regulation of Raf-1 and B-Raf and Ras-dependent activation of mitogen-activated protein kinase by cyclic AMP in PC12 cells.

1995 ◽  
Vol 15 (10) ◽  
pp. 5524-5530 ◽  
Author(s):  
P Erhardt ◽  
J Troppmair ◽  
U R Rapp ◽  
G M Cooper
Keyword(s):  
Growth Factor ◽  
Cyclic Amp ◽  
Map Kinase ◽  
Pc12 Cells ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Map Kinase Pathway ◽  
Kinase Pathway ◽  
Stimulation Of

Growth factor stimulation of the mitogen-activated protein (MAP) kinase pathway in fibroblasts is inhibited by cyclic AMP (cAMP) as a result of inhibition of Raf-1. In contrast, cAMP inhibits neither nerve growth factor-induced MAP kinase activation nor differentiation in PC12 pheochromocytoma cells. Instead, in PC12 cells cAMP activates MAP kinase. Since one of the major differences between the Ras/Raf/MAP kinase cascades of these cell types is the expression of B-Raf in PC12 cells, we compared the effects of cAMP on Raf-1 and B-Raf. In PC12 cells maintained in serum-containing medium, B-Raf was refractory to inhibition by cAMP, whereas Raf-1 was effectively inhibited. In contrast, both B-Raf and Raf-1 were inhibited by cAMP in serum-starved PC12 cells. The effect of cAMP is thus dependent upon growth conditions, with B-Raf being resistant to cAMP inhibition in the presence of serum. These results were extended by studies of Rat-1 fibroblasts into which B-Raf had been introduced by transfection. As in PC12 cells, B-Raf was resistant to inhibition by cAMP in the presence of serum, whereas Raf-1 was effectively inhibited. In addition, the expression of B-Raf rendered Rat-1 cells resistant to the inhibitory effects of cAMP on both growth factor-induced activation of MAP kinase and mitogenesis. These results indicate that Raf-1 and B-Raf are differentially sensitive to inhibition by cAMP and that B-Raf expression can contribute to cell type-specific differences in the regulation of the MAP kinase pathway. In contrast to the situation in PC12 cells, cAMP by itself did not stimulate MAP kinase in B-Raf-expressing Rat-1 cells. The activation of MAP kinase by cAMP in PC12 cells was inhibited by the expression of a dominant negative Ras mutant, indicating that cAMP acts on a target upstream of Ras. Thus, it appears that a signaling component upstream of Ras is also require for cAMP stimulation of MAP kinase in PC12 cells.

scholarly journals Small GTPase Rin induces neurite outgrowth through Rac/Cdc42 and calmodulin in PC12 cells

2003 ◽  
Vol 163 (5) ◽  
pp. 1067-1076 ◽  
Author(s):  
Mitsunobu Hoshino ◽  
Shun Nakamura
Keyword(s):  
Neurite Outgrowth ◽  
Pc12 Cells ◽  
Small Gtpase ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Binding Motif ◽  
Mutant Proteins ◽  
Neuronal Signaling ◽  
Voltage Dependent ◽  
Mitogen Activated Protein

The novel Ras-like small GTPase Rin is expressed prominently in adult neurons, and binds calmodulin (CaM) through its COOH-terminal–binding motif. It might be involved in calcium/CaM-mediated neuronal signaling, but Rin-mediated signal transduction pathways have not yet been elucidated. Here, we show that expression of Rin induces neurite outgrowth without nerve growth factor or mitogen-activated protein kinase activation in rat pheochromocytoma PC12 cells. Rin-induced neurite outgrowth was markedly inhibited by coexpression with dominant negative Rac/Cdc42 protein or CaM inhibitor treatment. We also found that expression of Rin elevated the endogenous Rac/Cdc42 activity. Rin mutant proteins, in which the mutation disrupted association with CaM, failed to induce neurite outgrowth irrespective of Rac/Cdc42 activation. Disruption of endogenous Rin function inhibited the neurite outgrowth stimulated by forskolin and extracellular calcium entry through voltage-dependent calcium channel evoked by KCl. These findings suggest that Rin-mediated neurite outgrowth signaling requires not only endogenous Rac/Cdc42 activation but also Rin–CaM association, and that endogenous Rin is involved in calcium/CaM-mediated neuronal signaling pathways.

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