scholarly journals A Novel Mechanism of S-equol Action in Neurons and Astrocytes: The Possible Involvement of GPR30/GPER1

2019 ◽  
Vol 20 (20) ◽  
pp. 5178 ◽  
Author(s):  
Winda Ariyani ◽  
Wataru Miyazaki ◽  
Noriyuki Koibuchi

S-equol is a major bacterial metabolite of the soy isoflavone daidzein. It is known to be a phytoestrogen that acts by binding to the nuclear estrogen receptors (ERs) that are expressed in various brain regions, including the cerebellum. However, the effects of S-equol on cerebellar development and function have not yet been extensively studied. In this study, the effects of S-equol were evaluated using a mouse primary cerebellar culture, Neuro-2A clonal cells, and an astrocyte-enriched culture. S-equol augmented the dendrite arborization of Purkinje cells induced by triiodothyronine (T3) and the neurite growth of Neuro-2A cell differentiation. Such augmentation was suppressed by G15, a selective G-protein coupled ER (GPR30) antagonist, and ICI 182,780, an antagonist for ERs in both cultures. On the other hand, in astrocytes, S-equol induced cell proliferation and cell migration with an increase in the phosphorylated extracellular-signal-regulated kinase 1/2 and F-actin rearrangements. Such effects were suppressed by G15, but not by ICI. These findings indicated that S-equol may enhanced cerebellar development by affecting both neurons and astrocytes through several signaling pathways, including GPR30 and ERs. We here report a novel mechanism of S-equol in cerebellar development that may provide a novel possibility to use S-equol supplementation during development.

2010 ◽  
Vol 30 (12) ◽  
pp. 2918-2932 ◽  
Author(s):  
Laure Voisin ◽  
Marc K. Saba-El-Leil ◽  
Catherine Julien ◽  
Christophe Frémin ◽  
Sylvain Meloche

ABSTRACT The extracellular signal-regulated kinase 1 and 2 (ERK1/2) mitogen-activated protein (MAP) kinase signaling pathway plays an important role in the proliferative response of mammalian cells to mitogens. However, the individual contribution of the isoforms ERK1 and ERK2 to cell proliferation control is unclear. The two ERK isoforms have similar biochemical properties and recognize the same primary sequence determinants on substrates. On the other hand, analysis of mice lacking individual ERK genes suggests that ERK1 and ERK2 may have evolved unique functions. In this study, we used a robust genetic approach to analyze the individual functions of ERK1 and ERK2 in cell proliferation using genetically matched primary embryonic fibroblasts. We show that individual loss of either ERK1 or ERK2 slows down the proliferation rate of fibroblasts to an extent reflecting the expression level of the kinase. Moreover, RNA interference-mediated silencing of ERK1 or ERK2 expression in cells genetically disrupted for the other isoform similarly reduces cell proliferation. We generated fibroblasts genetically deficient in both Erk1 and Erk2. Combined loss of ERK1 and ERK2 resulted in a complete arrest of cell proliferation associated with G1 arrest and premature replicative senescence. Together, our findings provide compelling genetic evidence for a redundant role of ERK1 and ERK2 in promoting cell proliferation.


2021 ◽  
Vol 11 (11) ◽  
pp. 2137-2145
Author(s):  
Xuejuan Zhu ◽  
Danqian Lu

Background: Sulfiredoxin (Srx) has been identified to play important roles in the development of various cancers. However, the precise effects and underlying mechanism of Srx on the progression of HCC are far from being fully understood. Materials and Methods: The abundances of Srx in THLE-2 cell and HCC cell lines were determined by western blot and RT-qPCR. Next, SK-Hep-1 cells were transfected with shRNA-Srx or shRNA-NC and treated with TBHQ (an extracellular signal-regulated kinase (ERK) activator) for functional experiments. Then, CCK8 and colony formation assays were used to determine cell proliferation and clone-forming abilities in vitro. Cell migration and invasion were assessed via wound healing and transwell assays. The expression of MMP2, MMP9 and key members in ERK/nuclear factor E2 related factor (Nrf2) signaling pathway was detected by performing western blot analysis. Results: We reported evidence that Srx was frequently up-regulated in HCC cell lines. Srx interference constrained cell proliferation, colony formation rate, migration and invasion of SK-Hep-1 cells. Moreover, mechanistic investigations indicated that Srx interference significantly inhibited the activation of ERK/Nrf2 signaling pathway, and ERK activator TBHQ can reverse the functions of Srx interference in SK-Hep-1 cells. Conclusion: Overall, Downregulation of Srx might impede HCC progression by suppressing ERK/Nrf2 signaling pathway. Findings in the current study reported the functional involvement and molecular mechanism of Srx in HCC, suggesting that Srx might have a potential therapeutic value in HCC treatment.


Cancers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 439 ◽  
Author(s):  
Vanessa Delcroix ◽  
Olivier Mauduit ◽  
Nolwenn Tessier ◽  
Anaïs Montillaud ◽  
Tom Lesluyes ◽  
...  

By inhibiting Insulin-Like Growth Factor-1-Receptor (IGF-1R) signaling, Klotho (KL) acts like an aging- and tumor-suppressor. We investigated whether KL impacts the aggressiveness of liposarcomas, in which IGF-1R signaling is frequently upregulated. Indeed, we observed that a higher KL expression in liposarcomas is associated with a better outcome for patients. Moreover, KL is downregulated in dedifferentiated liposarcomas (DDLPS) compared to well-differentiated tumors and adipose tissue. Because DDLPS are high-grade tumors associated with poor prognosis, we examined the potential of KL as a tool for overcoming therapy resistance. First, we confirmed the attenuation of IGF-1-induced calcium (Ca2+)-response and Extracellular signal-Regulated Kinase 1/2 (ERK1/2) phosphorylation in KL-overexpressing human DDLPS cells. KL overexpression also reduced cell proliferation, clonogenicity, and increased apoptosis induced by gemcitabine, thapsigargin, and ABT-737, all of which are counteracted by IGF-1R-dependent signaling and activate Ca2+-dependent endoplasmic reticulum (ER) stress. Then, we monitored cell death and cytosolic Ca2+-responses and demonstrated that KL increases the reticular Ca2+-leakage by maintaining TRPC6 at the ER and opening the translocon. Only the latter is necessary for sensitizing DDLPS cells to reticular stressors. This was associated with ERK1/2 inhibition and could be mimicked with IGF-1R or MEK inhibitors. These observations provide a new therapeutic strategy in the management of DDLPS.


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