• Biomolecules & Therapeutics
• /
• v.24 no.3
• /
• pp.268-282
• /
• 2016

In the present study, we investigated the anti-inflammatory properties of Eucommia ulmoides Oliv. Bark. (EUE) in lipopolysaccharide (LPS)-stimulated microglial BV-2 cells and found that EUE inhibited LPS-mediated up-regulation of pro-inflammatory response factors. In addition, EUE inhibited the elevated production of pro-inflammatory cytokines, mediators, and reactive oxygen species (ROS) in LPS-stimulated BV-2 microglial cells. Subsequent mechanistic studies revealed that EUE suppressed LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs), phosphoinositide-3-kinase (PI3K)/Akt, glycogen synthase $kinase-3{\beta}$ ($GSK-3{\beta}$), and their downstream transcription factor, nuclear factor-kappa B ($NF-{\kappa}B$). EUE also blocked the nuclear translocation of $NF-{\kappa}B$ and inhibited its binding to DNA. We next demonstrated that EUE induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated heme oxygenase-1 (HO-1) expression. We determined that the significant up-regulation of HO-1 expression by EUE was a consequence of Nrf2 nuclear translocation; furthermore, EUE increased the DNA binding of Nrf2. In contrast, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, blocked the ability of EUE to inhibit NO and $PGE_2$ production, indicating the vital role of HO-1. Overall, our results indicate that EUE inhibits pro-inflammatory responses by modulating MAPKs, PI3K/Akt, and $GSK-3{\beta}$, consequently suppressing $NF-{\kappa}B$ activation and inducing Nrf2-dependent HO-1 activation.

• The Korean Journal of Physiology and Pharmacology
• /
• v.16 no.1
• /
• pp.43-48
• /
• 2012

Glutamate excitotoxicity is emerging as a contributor to degeneration of spinal cord motoneurons in amyotrophic lateral sclerosis (ALS). Recently, we have reported that ghrelin protects motoneurons against chronic glutamate excitotoxicity through the activation of extracellular signal-regulated kinase 1/2 and phosphatidylinositol-3-kinase/Akt/glycogen synthase kinase-$3{\beta}$ pathways. Previous studies suggest that activated microglia actively participate in the pathogenesis of ALS motoneuron degeneration. However, it is still unknown whether ghrelin exerts its protective effect on motoneurons via inhibition of microglial activation. In this study, we investigate organotypic spinal cord cultures (OSCCs) exposed to threohydroxyaspartate (THA), as a model of excitotoxic motoneuron degeneration, to determine if ghrelin prevents microglial activation. Exposure of OSCCs to THA for 3 weeks produced typical motoneuron death, and treatment of ghrelin significantly attenuated THA-induced motoneuron loss, as previously reported. Ghrelin prevented THA-induced microglial activation in the spinal cord and the expression of pro-inflammatory cytokines tumor necrosis factor-${\alpha}$ and interleukin-$1{\beta}$. Our data indicate that ghrelin may act as a survival factor for motoneurons by functioning as a microglia-deactivating factor and suggest that ghrelin may have therapeutic potential for the treatment of ALS and other neurodegenerative disorders where inflammatory responses play a critical role.

• Journal of Pharmacopuncture
• /
• v.22 no.4
• /
• pp.248-252
• /
• 2019

Objectives: The aim of the present work is evaluating the special effects of Urtica Dioica and Lamium Album on the serum level of K-Ras and GSK-3 beta in diabetic rats. Methods: In the present experimental study, 32 male Wistar rats randomly divided into 4 groups (Group I: normal control rats; receiving daily PBS, Group 2: diabetic control rats; receiving single dose of streptozotocin (60 mg/kg) and daily PBS, Group 3: Diabetic rats treated with 100 mg/kg of hydroalcoholic extract of the U. dioica, Group 4: Diabetic rats treated with 100 mg/kg of hydroalcoholic extract of L. Album. Diabetes-induced by an intraperitoneal injection of streptozotocin (60 mg/ kg). On the 14 th day of treatment, the weight, fasting blood sugar (FBS) and on 28 th day blood glucose, K-Ras and GSK3 beta was measured. Results: In diabetic group blood GSK- 3 beta increase in comparison to control group (P < 0.05), also blood K-Ras decrease in the diabetic group (P < 0.05). Both extracts reduced GSK-3 beta level, however, this reduction was only statistically significant by U.dioica (P < 0.05). Compared to diabetic group, blood K-Ras level increased by both extract (P < 0.05). Also diabetes induction increase blood glucose levels and both extracts decrease its level significantly (P < 0.05).there is no significant differences among both extract effects on blood glucose, and K-Ras. Conclusion: For the first time shown that both extracts by regulating GSK-3 beta and K-Ras improve blood glucose level. More studies are needed to determine all the effects of these herbs.

• Journal of the Korean Magnetic Resonance Society
• /
• v.9 no.1
• /
• pp.38-47
• /
• 2005

Axin is a scaffold protein of the APC/axin/GSK complex, binding to all of the other signalling components. Axin interacts with Glycogen synthase kinase 3$\beta$ (GSK 3$\beta$) and functions as a negative regulator of Wnt signalling pathways. To determine the solution structure of the GSK3$\beta$ binding regions of the axin, we initiated NMR study of axin fragment comprising residues 3$Val^{388} - Arg^{401}$using circular dichroism (CD) and two-dimensional NMR spectroscopy. The CD spectra of 3$axin^{pep}$ in the presence of 30% TFE displayed a standard 3$\alpha$-helical conformation, exhibiting the bound structure of 3$axin^{pep}$ to GSK3$\bata$. On the basis of experimental restraints including $NOE_s$, and $^3J_{HN\alpha} $ coupling constants, the solution conformation of $axin^{pep}$ was determined with program CNS. The 20 lowest energy structures were selected out of 50 final simulated-annealing structures in both water and TFE environment, respectively. The $RMSD_s$ for the 20 structures in TFE solution were 0.086 nm for backbone atoms and 0.195 nm for all heavy atoms, respectively. The Ramachandran plot indicates that the $\varphi$, $\psi$ angles of the 20 final structures is properly distributed in energetically acceptable regions. $Axin^pep$ in aqueous solutions consists of a stable $\alpha$-helix spanning residues form $Glu^{391}$ to $Val^{391} $, which is an interacting motif with GSK3$\beta$.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.6197-6201
• /
• 2012

Although enhancer of zeste homolog 2 (EZH2) has been reported as an independent prognostic factor in renal cell carcinoma (RCC), little is known about the exact mechanism of EZH2 in promoting the genesis of RCC. However, several studies have shown that dysregulation of the Wnt/${\beta}$-catenin signaling pathway plays a crucial role. Therefore, we determined whether EZH2 could affect ACHN human RCC cell proliferation and invasion via the Wnt/${\beta}$-catenin pathway. In the present study, we investigated the effects of short interfering RNA (siRNA)-mediated EZH2 gene silencing on Wnt/${\beta}$-catenin signaling in ACHN cells. EZH2-siRNA markedly inhibited the proliferation and invasion capabilities of ACHN, while also reducing the expression of EZH2, Wnt3a and ${\beta}$-catenin. In contrast, cellular expression of GSK-$3{\beta}$ (glycogen synthase kinase-$3{\beta}$), an inhibitor of the Wnt/${\beta}$-catenin pathway, was conspicuously higher after transfection of EZH2 siRNA. These preliminary findings suggest EZH2 may promote proliferation and invasion of ACHN cells via action on the Wnt/${\beta}$-catenin signaling pathway.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.29 no.1
• /
• pp.18-26
• /
• 2015

Akebiae Caulis is a galenical originated from Akebia quinata Decaisne species. It is commonly used in the treatment of oposiuria, inflammation, nociceptive and fever. Here, we investigated the effect of Akebiae Caulis extract (ACE) to protect hepatocyte against the malfunction of mitochondria and apoptosis. Arachidonic acid (AA)+iron promoted excessive reactive oxygen species (ROS) production and exerted a deleterious effect on mitochondria. Treatment with ACE protected hepatocytes from AA+iron-induced cytotoxicity, as shown by alterations in the protein levels related with apoptosis such as poly(ADP-ribose) polymerase, pro-caspase 3, Bcl-XL and Bcl-2. Moreover, AA+iron-induced $H_2O_2$ production, GSH depletion and mitochondrial dysfunction were alleviated by ACE pretreatment. As a potential molecular mechanism for the ACE-mediated cytoprotection, phosphorylation of AMP-activated protein kinase (AMPK), a key regulator in determining cell survival or death, was increased by ACE. Moreover, ACE treatment enhanced inactive phosphorylation of glycogen synthase kinase-$3{\beta}$ ($GSK3{\beta}$), downstream substrate kinase of AMPK. More importantly, ACE prevented a decrease in the $GSK3{\beta}$ phosphorylation derived by AA+iron, which might contribute to mitohondiral protection and cell survival. To further identify essential compounds in Akebiae Caulis for the protection of AA+iron-mediated cytotoxicity, we found that betulin in combination with hederagenin protected from AA+iron-induced mitochondrial dysfunction. Betulin+hederagenin treatment also increased inactive phosphorylation of $GSK3{\beta}$ in common with ACE. These results suggest that ACE protected hepatocytes against oxidative stress and mitochondrial dysfunction, which is mediated with inactive $GSK3{\beta}$ phosphorylation downstream of AMPK.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.6
• /
• pp.2015-2020
• /
• 2011

A series of isoxazol-indolin-2-one was designed for GSK-3${\beta}$ inhibitors as novel anticancer agents based on their binding mode analysis in GSK-3${\beta}$ crystal structure. Total 21 compounds were synthesized and evaluated for their inhibitory activity against two tumor cell lines (DU145 and HT29). Most of the synthesized compounds were potent with above 80% inhibitory activity at 100 ${\mu}M$, and several compounds were examined for inhibitory activity against GSK-3${\beta}$. Among them, 15(Z) ($R_1$=H, $R_2$=3-Cl-phenyl) was most active with 78% inhibition of tumor cell line (HT29) at 20 ${\mu}M$ and 72% inhibition of GSK-3${\beta}$ at 20 ${\mu}M$.

• Biomedical Science Letters
• /
• v.9 no.2
• /
• pp.59-65
• /
• 2003

When cells are exposed to proteotoxic stresses such as heat shock, amino acid analogs, and heavy metals, they increase the synthesis of the heat shock proteins (HSPs) by activating the heat shock transcription factor 1 (HSF1), whose activity is controlled via multiple steps including homotrimerization, nuclear translocation, DNA binding, and hyperphosphorylation. Under unstressed conditions, the HSF1 activity is repressed through its constitutive phosphorylation by glycogen synthase kinase 3$\beta$ (GSK3$\beta$), extracellular regulated kinase 1/2 (ERK1/2), and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). However, the protein kinase (s) responsible for HSF1 hyperphosphorylation and activation is not yet identified. In the present study, we observed that profile of p38 mitogen-activated protein kinase (p38MAPK) activation in response to heat shock was very similar to those of HSF1 hyperphosphorylation and nuclear translocation. Therefore, we investigated whether p38MAPK is involved in the heat shock-induced HSF1 activation and HSP expression. Here we show that the p38MAPK inhibitors, SB202190 and SB203580, but not other inhibitors including the MEK1/2 inhibitor PD98059 and the PI3-K inhibitor LY294002 and wortmannin, suppress HSF1 hyperphosphorylation in response to heat shock and L-azetidine 2-carboxylic acid (Azc), but not to heavy metals. Furthermore, heat shock-induced HSF1-DNA binding and HSP72 expression was specifically prevented by the p38MAPK inhibitors, but not by the MEK1/2 inhibitor and the PI3-K inhibitors. These results suggest that SB202190- and SB203580-sensitive p38MAPK may positively regulate HSP gene regulation in response to heat shock and amino acid analogs.

• The Korean Journal of Physiology and Pharmacology
• /
• v.20 no.6
• /
• pp.613-619
• /
• 2016

Diabetic cardiomyopathy (DCM), a serious complication of diabetes mellitus, is associated with changes in myocardial structure and function. This study sought to explore the ability of insulin-like growth factor-1 (IGF-1) to modulate DCM and its related mechanisms. Twenty-four male Wistar rats were injected with streptozotocin (STZ, 60 mg/kg) to mimic diabetes mellitus. Myocardial fibrosis and apoptosis were evaluated by histopathologic analyses, and relevant proteins were analyzed by Western blotting. Inflammatory factors were assessed by ELISA. Markers of oxidative stress were tested by colorimetric analysis. Rats with DCM displayed decreased body weight, metabolic abnormalities, elevated apoptosis (as assessed by the bcl-2/bax ratio and TUNEL assays), increased fibrosis, increased markers of oxidative stress (MDA and SOD) and inflammatory factors (TNF-${\alpha}$ and IL-$1{\beta}$), and decreased phosphorylation of Akt and glycogen synthase kinase (GSK-$3{\beta}$). IGF-1 treatment, however, attenuated the metabolic abnormalities and myocardial apoptosis, interstitial fibrosis, oxidative stress and inflammation seen in diabetic rats, while also increasing the phosphorylation levels of Akt and GSK-$3{\beta}$. These findings suggest that IGF-1 ameliorates the pathophysiological progress of DCM along with an activation of the Akt/GSK-$3{\beta}$ signaling pathway. Our findings suggest that IGF-1 could be a potential therapeutic choice for controlling DCM.

• Journal of Veterinary Science
• /
• v.23 no.1
• /
• pp.4.1-4.15
• /
• 2022

Background: Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the antiadipogenic effects of flavonoids are unclear. Objectives: The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells. Methods: The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis. Results: The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators. Conclusion: The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.