Selenazoles (selenium compounds) facilitate survival of cultured rat pheochromocytoma PC12 cells after serum-deprivation and stimulate their neuronal differentiation via activation of Akt and mitogen-activated protein kinase, respectively

2007 ◽  
Vol 352 (2) ◽  
pp. 360-365 ◽  
Author(s):  
Atsuyoshi Nishina ◽  
Akihiro Sekiguchi ◽  
Ryo-hei Fukumoto ◽  
Mamoru Koketsu ◽  
Shoei Furukawa
2010 ◽  
Vol 7 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Noriko Hattori ◽  
Hiroshi Nomoto ◽  
Hidefumi Fukumitsu ◽  
Satoshi Mishima ◽  
Shoei Furukawa

Earlier we identified adenosine monophosphate (AMP)N1-oxide as a unique compound of royal jelly (RJ) that induces neurite outgrowth (neuritegenesis) from cultured rat pheochromocytoma PC12 cells via the adenosine A2Areceptor. Now, we found that AMPN1-oxide stimulated the phosphorylation of not only mitogen-activated protein kinase (MAPK) but also that of cAMP/calcium-response element-binding protein (CREB) in a dose-dependent manner. Inhibition of MAPK activation by a MEK inhibitor, PD98059, did not influence the AMPN1-oxide-induced neuritegenesis, whereas that of protein kinase A (PKA) by a selective inhibitor, KT5720, significantly reduced neurite outgrowth. AMPN1-oxide also had the activity of suppressing the growth of PC12 cells, which correlated well with the neurite outgrowth-promoting activity. KT5720 restored the growth of AMPN1-oxide-treated PC12 cells. It is well known that nerve growth factor suppresses proliferation of PC12 cells before causing stimulation of neuronal differentiation. Thus, AMPN1-oxide elicited neuronal differentiation of PC12 cells, as evidenced by generation of neurites, and inhibited cell growth through adenosine A2Areceptor-mediated PKA signaling, which may be responsible for characteristic actions of RJ.


2002 ◽  
Vol 22 (16) ◽  
pp. 5946-5961 ◽  
Author(s):  
Alec C. Kimmelman ◽  
Nelson Nuñez Rodriguez ◽  
Andrew M.-L. Chan

ABSTRACT R-Ras3/M-Ras is a novel member of the Ras subfamily of GTP-binding proteins which has a unique expression pattern highly restricted to the mammalian central nervous system. In situ hybridization using an R-Ras3 cRNA probe revealed high levels of R-Ras3 transcripts in the hippocampal region of the mouse brain as well as a pattern of expression in the cerebellum that was distinct from that of H-Ras. We found that R-Ras3 was activated by nerve growth factor (NGF) and basic fibroblast growth factor as well as by the guanine nucleotide exchange factor GRP but not by epidermal growth factor. Ectopic expression of either R-Ras3 or GRP in PC12 cells induced efficient neuronal differentiation. The ability of NGF as well as GRP to promote differentiation of PC12 cells was attenuated by an R-Ras3 dominant-negative mutant. Furthermore, the biological action of R-Ras3 in PC12 cells was dependent on the mitogen-activated protein kinase (MAPK). Interestingly, whereas R-Ras3 was unable to mediate efficient activation of MAPK activity in NIH 3T3 cells, it was able to do so in PC12 cells. This cell-type specificity is in stark contrast to that of H-Ras, which can stimulate the MAPK pathway in both cell types. Indeed, this pattern of MAPK activation could be explained by the fact that R-Ras3 was unable to activate c-Raf, while it bound and stimulated the neuronal Raf isoform, B-Raf, in PC12 cells. Thus, R-Ras3 is implicated in a novel pathway of neuronal differentiation by coupling specific trophic factors to the MAPK cascade through the activation of B-Raf.


Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 581
Author(s):  
Lihong Cheng ◽  
Hiroyuki Osada ◽  
Tianyan Xing ◽  
Minoru Yoshida ◽  
Lan Xiang ◽  
...  

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.


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