• Title/Summary/Keyword: Phosphorylated protein

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Protective effect of Citrus unshiu peel on the cadmium-induced apoptosis in HepG2 cells (카드뮴으로 유발한 간세포 자멸사에서 진피의 보호효과)

  • Noh, Gyu Pyo;Byun, Sung Hui;Lee, Jong Rok;Park, Sook Jahr;Kim, Sang Chan
    • The Korea Journal of Herbology
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    • v.36 no.1
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    • pp.41-49
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    • 2021
  • Objective : Citrus unshiu peel (Citri Unshius Pericarpium) has been prescribed to suppress coughing and phlegm in Korean medicine. In this study, the effect of ethanol extract of Citrus unshiu peel (CEE) on apoptosis was investigated using cadmium chloride (CdCl2) treated HepG2 cells. Methods : CEE was prepared by extracting 300 g of Citri Unshius Pericarpium in 3 L of ethanol for 72 h. Apoptosis was determined by the TUNEL assay. The mitochondrial membrane potential (MMP) was monitored using the membrane-permeable fluorescent dye Rh123. The expression level of each protein was monitored by Western blot analysis. Results : CEE protected HepG2 cells from apoptosis as determined by the TUNEL assay. A decrease in MMP was observed in cells exposed to cadmium, indicating that mitochondria are involved in the induction of apoptosis. However, CEE recovered the reduction in MMP caused by cadmium. In addition, decreased expression of B-cell lymphoma 2 (Bcl-2), procaspase, and poly(ADP-ribose) polymerase (PARP) by cadmium was increased by CEE. The anti-apoptotic effect of CEE was found to be associated with inhibition of JNK and p38 phosphorylation when examining the expression of phosphorylated MAPK by Western blot. Conclusion : This study showed that CEE exerted anti-apoptotic effects in cadmium-induced HepG2 cells by inhibiting the reduction of MMP and changes in the expression level of apoptotic proteins. These results suggest the potential for CEE to be used for heavy metal-induced liver damage.

Toll-like receptor 4/nuclear factor-kappa B pathway is involved in radicular pain by encouraging spinal microglia activation and inflammatory response in a rat model of lumbar disc herniation

  • Zhu, Lirong;Huang, Yangliang;Hu, Yuming;Tang, Qian;Zhong, Yi
    • The Korean Journal of Pain
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    • v.34 no.1
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    • pp.47-57
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    • 2021
  • Background: Lumbar disc herniation (LDH) is a common cause of radicular pain, but the mechanism is not clear. In this study, we investigated the engagement of toll-like receptor 4 (TLR4) and the nuclear factor-kappa B (NF-κB) in radicular pain and its possible mechanisms. Methods: An LDH model was induced by autologous nucleus pulposus (NP) implantation, which was obtained from coccygeal vertebra, then relocated in the lumbar 4/5 spinal nerve roots of rats. Mechanical and thermal pain behaviors were assessed by using von Frey filaments and hotplate test respectively. The protein level of TLR4 and phosphorylated-p65 (p-p65) was evaluated by western blotting analysis and immunofluorescence staining. Spinal microglia activation was evaluated by immunofluorescence staining of specific relevant markers. The expression of proand anti-inflammatory cytokines in the spinal dorsal horn was measured by enzyme linked immunosorbent assay. Results: Spinal expression of TLR4 and p-NF-κB (p-p65) was significantly increased after NP implantation, lasting up to 14 days. TLR4 was mainly expressed in spinal microglia, but not astrocytes or neurons. TLR4 antagonist TAK242 decreased spinal expression of p-p65. TAK242 or NF-κB inhibitor pyrrolidinedithiocarbamic acid alleviated mechanical and thermal pain behaviors, inhibited spinal microglia activation, moderated spinal inflammatory response manifested by decreasing interleukin (IL)-1β, IL-6, tumor necrosis factor-α expression and increasing IL-10 expression in the spinal dorsal horn. Conclusions: The study revealed that TLR4/NF-κB pathway participated in radicular pain by encouraging spinal microglia activation and inflammatory response.

Effects of alpha-linolenic acid and essential amino acids on the proliferation and differentiation of C2C12 myoblasts

  • Zhou, Dongjie;Li, Xiao-Han;Lee, Song‑Hee;Heo, Geun;Cui, Xiang-Shun
    • Journal of Animal Reproduction and Biotechnology
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    • v.37 no.1
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    • pp.17-26
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    • 2022
  • Alpha-linolenic acid is an important polyunsaturated fatty acid that exhibits anticancer, anti-inflammatory, and antioxidative effects. In this study, we investigated the protective effects of alpha-linolenic acid on the cell proliferation and differentiation of C2C12 cells under essential amino acid-deficient conditions. Different concentrations of alpha-linolenic acid and essential amino acids were added to the growth and differentiation media. The concentrations of 10 µM of alpha-linolenic acid and 2% essential amino acid were chosen for subsequent experiments. Supplementation with alpha-linolenic acid and essential amino acids improved the proliferation and differentiation of C2C12 cells and significantly increased the mRNA levels of catalase, superoxide dismutase, B-cell lymphoma-2, and beclin-1 as well as the protein levels of PPARγ coactivator-1α compared to those in the controls. Moreover, supplementation with alpha-linolenic acid and essential amino acids reduced the levels of phosphorylated H2A.X variant histone, Bcl-2-associated X, p53, and light chain 3 during C2C12 cell proliferation, and increased the expression levels of myogenic factors 4 (myogenin) and 5 during C2C12 cell differentiation. Overall, we determined that alpha-linolenic acid and essential amino acids maintained the cell proliferation and differentiation of C2C12 cells via their anti-oxidative, anti-apoptotic, and anti-autophagic effects.

High fat diet-induced brain damaging effects through autophagy-mediated senescence, inflammation and apoptosis mitigated by ginsenoside F1-enhanced mixture

  • Hou, Jingang;Jeon, Byeongmin;Baek, Jongin;Yun, Yeejin;Kim, Daeun;Chang, Boyoon;Kim, Sungyeon;Kim, Sunchang
    • Journal of Ginseng Research
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    • v.46 no.1
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    • pp.79-90
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    • 2022
  • Background: Herbal medicines are popular approaches to capably prevent and treat obesity and its related diseases. Excessive exposure to dietary lipids causes oxidative stress and inflammation, which possibly induces cellular senescence and contribute the damaging effects in brain. The potential roles of selective enhanced ginsenoside in regulating high fat diet (HFD)-induced brain damage remain unknown. Methods: The protection function of Ginsenoside F1-enhanced mixture (SGB121) was evaluated by in vivo and in vitro experiments. Human primary astrocytes and SH-SY5Y cells were treated with palmitic acid conjugated Bovine Serum Albumin, and the effects of SGB121 were determined by MTT and lipid uptake assays. For in vivo tests, C57BL/6J mice were fed with high fat diet for 3 months with or without SGB121 administration. Thereafter, immunohistochemistry, western blot, PCR and ELISA assays were conducted with brain tissues. Results and conclusion: SGB121 selectively suppressed HFD-induced oxidative stress and cellular senescence in brain, and reduced subsequent inflammation responses manifested by abrogated secretion of IL-6, IL-1β and TNFα via NF-κB signaling pathway. Interestingly, SGB121 protects against HFD-induced damage by improving mitophagy and endoplasmic reticulum-stress associated autophagy flux and inhibiting apoptosis. In addition, SGB121 regulates lipid uptake and accumulation by FATP4 and PPARα. SGB121 significantly abates excessively phosphorylated tau protein in the cortex and GFAP activation in corpus callosum. Together, our results suggest that SGB121 is able to favor the resistance of brain to HFD-induced damage, therefore provide explicit evidence of the potential to be a functional food.

Auranofin accelerates spermidine-induced apoptosis via reactive oxygen species generation and suppression of PI3K/Akt signaling pathway in hepatocellular carcinoma

  • Hyun Hwangbo;Da Hye Kim;Min Yeong Kim;Seon Yeong Ji;EunJin Bang;Su Hyun Hong;Yung Hyun Choi;JaeHun Cheong
    • Fisheries and Aquatic Sciences
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    • v.26 no.2
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    • pp.133-144
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    • 2023
  • Auranofin is a US Food and Drug Administration (FDA)-approved anti-arthritis medication that functions as a thioredoxin reductase inhibitor. Spermidine, a polyamine present in marine algae, can exert various physiological functions. Herein, we examined the synergistic anticancer activity of auranofin and spermidine in hepatocellular carcinoma (HCC). Combined treatment with auranofin and spermidine suppressed cell viability more efficiently than either treatment alone in HCC Hep3B cells. The isobologram plotted by calculating the half maximal inhibitory concentration (IC50) values of each drug indicated that the two drugs exhibited a synergistic effect. Based on the analysis of annexin V and cell cycle distribution, auranofin and spermidine markedly induced apoptosis in Hep3B cells. Moreover, auranofin and spermidine increased mitochondria-mediated apoptosis by promoting mitochondrial membrane potential (Δψm) loss. Auranofin and spermidine significantly increased reactive oxygen species (ROS) production in Hep3B cells, and the blocking ROS suppressed apoptosis induced by spermidine and auranofin. In addition, auranofin and spermidine reduced the expression of phosphorylated phosphatidylinositol-3 kinase (PI3K) and protein kinase B (Akt), and PI3K inhibitor accelerated auranofin- and spermidine-induced apoptosis. Using ROS scavenger and PI3K inhibitor, we revealed that ROS acts upstream of auranofin- and spermidine-induced apoptosis. Collectively, our study suggests that combination treatment with auranofin and spermidine could afford synergistic anticancer activity via ROS overproduction and reduced PI3K/Akt signaling pathway.

The Effect of Treadmill Exercise on Tau Hyperphosphorylayion in an Aged Transgenic Mouse Model of Taupathies

  • Wang, Seong-Hwan;Kang, Eun-Bum;Kwon, In-Su;Koo, Jung-Hoon;Shin, Kwang-O;Jang, Yong-Chul;Um, Hyun-Sub;Oh, Yoo-Sung;Kim, Chul-Hyun;Cho, In-Ho;Cho, Joon-Yong
    • Korean Journal of Exercise Nutrition
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    • v.16 no.2
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    • pp.93-100
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    • 2012
  • Alzheimer's disease (AD) is the most common cause of dementia in adults. Microtubule associated protein tau is abnormally phosphorylated in AD and aggregates as paired helical filaments (PHFs) in neurofibrillary tangles (NFTs). NFTs are the most common intraneuronal inclusion in the brains of patients with AD and have been implicated in mediating neuronal cell death and cognitive deficit. Aberrant phosphorylation of tau is an early pathological event in AD, but the underlying mechanisms are unclear. MAP kinases are a family of Serine/Threonine (Ser/Thr) kinases that involved hyper - phosphorylation of tau in AD. The purpose of this study was to investigate the effect of treadmill exercise on phosphorylation of tau level and activation of MAPKs including JNK, ERK, p38-MAPK. To address this, Tg mouse model of AD, Tg-NSE/hTau 23, which expresses human tau 23 in the brain, was chosen. Animals were subjected to treadmill exercise for 12 weeks from 24 months of age. Treadmill exercise in Tg group improved cognitive function compared with Tg-SED group in watermaze test. In addition, treadmill exercised Tg mice significantly reduced the activation of JNK54/46, p38-MAPK and tau (Ser404, Ser202, Thr231), and increased activation of ERK44/42 in cerebral cortex. These results suggest that treadmill exercise may provide a therapeutic potential to alleviate the tau pathology like AD.

Regulation of Tumor Neceosis Factor-${\alpha}$ Receptors and Signal Transduction Pathways

  • Han, Hyung-Mee
    • Toxicological Research
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    • v.8 no.2
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    • pp.343-357
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    • 1992
  • Tumor necrosis factor-${\alpha}$(TNF), a polypeptide hormone secreted primarily by activated macrophages, was originally identified on the basis of its ability to cause hemorrhagic necrosis and tumor regression in vivo. Subsequently, TNF has been shown to be an important component of the host responses to infection and cancer and may mediate the wasting syndrome known as cachexia. These systemic actions of TNF are reflected in its diverse effects on target cells in vitro. TNF initiates its diverse cellular actions by binding to specific cell surface receptors. Although TNF receptors have been identified on most of animal cells, regulation of these receptors and the mechanisms which transduce TNF receptor binding into cellular responses are not well understood. Therefore, in the present study, the mechanisms how TNF receptors are being regulated and how TNF receptor binding is being transduced into cellular responses were investigated in rat liver plasma membranes (PM) and ME-180 human cervical carcinoma cell lines. $^{125}I$-TNF bound to high ($K_d=1.51{\pm}0.35nM$)affinity receptors in rat liver PM. Solubilization of PM with 1% Triton X-100 increased both high affinity (from $0.33{\pm}0.04\;to\;1.67{\pm}0.05$ pmoles/mg protein) and low affinity (from $1.92{\pm}0.16\;to\;7.57{\pm}0.50$ pmoles/mg protein) TNF binding without affecting the affinities for TNF, suggesting the presence of a large latent pool of TNF receptors. Affinity labeling of receptors whether from PM or solubilized PM resulted in cross-linking of $^{125}I$-TNF into $M_r$ 130 kDa, 90 kDa and 66kDa complexes. Thus, the properties of the latent TNF receptors were similar to those initially accessible to TNF. To determine if exposure of latent receptors is regulated by TNF, $^{125}I$-TNF binding to control and TNF-pretreated membranes were assayed. Specific binding was increased by pretreatment with TNF (P<0.05), demonstrating that hepatic PM contains latent TNF receptors whose exposure is promoted by TNF. Homologous up-regulation of TNF receptors may, in part, be responsible for sustained hepatic responsiveness during chronic exposure to TNF. As a next step, the post-receptor events induced by TNF were examined. Although the signal transduction pathways for TNF have not been delineated clearly, the actions of many other hormones are mediated by the reversible phosphorylation of specific enzymes or target proteins. The present study demonstrated that TNF induces phosphorylation of 28 kDa protein (p28). Two dimensional soidum dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) resolved the 28kDa phosphoprotein into two isoforms having pIs of 6.2 and 6.1. The pIs and relative molecular weight of p28 were consistent with those of a previously characterized mRNA cap binding protein. mRNA cap binding proteins are a class of translation initiation factors that recognize the 7-methylguanosine cap structure found on the 5' end of eukaryotic mRNAs. In vitro, these proteins are defined by their specific elution from affinity columns composed of 7-methylguanosine 5'-triphosphate($m^7$GTP)-Sepharose. Affinity purification of mRNA cap binding proteins from control and TNF treated ME-180 cells proved that TNF rapidly stimulates phosphorylation of an mRNA cap binding protein. Phosphorylation occurred in several cell types that are important in vitro models of TNF action. The mRNA cap binding protein phosphorylated in response to TNF treatment was purifice, sequenced, and identified as the proto-oncogene product eukaryotic initiation factor-4E(eIF-4E). These data show that phosphorylation of a key component of the cellular translational machinery is a common early event in the diverse cellular actions of TNF.

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Inhibition of Inducible Nitric Oxide Synthase Expression by YS 49, a Synthetic Isoquinoline Alkaloid, in ROS 17/2.8 Cells Activated with $TNF-{\alpha},\;IFN-{\gamma}$ and LPS

  • Kang, Young-Jin;Kang, Sun-Young;Lee, Young-Soo;Park, Min-Kyu;Kim, Hye-Jung;Seo, Han-Geuk;Lee, Jae-Heun;YunChoi, Hye-Sook;Chang, Ki-Churl
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.5
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    • pp.273-280
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    • 2004
  • Nitric oxide (NO) has been suggested to act as a mediator of cytokine-induced effects of turn over of bone. Activation of the inducible nitric oxide synthase (iNOS) by inflammation has been related with apoptotic cell death in osteoblast. YS 49, a synthetic isoquinoline alkaloid, inhibits NO production in macrophages activated with cytokines. In the present study, we investigated the molecular mechanism of YS 49 to inhibit iNOS expression in ROS 17/2.8 cells, which were activated with combined treatment of inflammatory cytokines $(TNF-{\alpha},\;IFN-{\gamma})$ and lipopolysaccharide (LPS). Results indicated that YS 49 concentration-dependently reduced iNOS mRNA and protein expression, as evidenced by Northern and Western blot analysis, respectively. The underlying mechanism by which YS 49 suppressed iNOS expression was not to affect iNOS mRNA stability but to inhibit activation and translocation of $NF-_kB$ by preventing the degradation of its inhibitory protein $I_kB_{\alpha}$. As expected, YS 49 prevented NO-induced apoptotic cell death by sodium nitroprusside. Taken together, it is concluded that YS 49 inhibits iNOS expression by interfering with degradation of phosphorylated inhibitory $_kB_{\alpha}\;(p-I_kB_{\alpha})$. These actions may be beneficial for the treatment of inflammation of the joint, such as rheumatoid arthritis.

Role of ghrelin in the pancreatic exocrine secretion via mitogen-activated protein kinase signaling in rats

  • Lee, Kyung-Hoon;Lee, Jae-Sung;Wang, Tao;Oh, Jin-Ju;Roh, Sanggun;Lee, Hong-Gu
    • Journal of Animal Science and Technology
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    • v.59 no.7
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    • pp.16.1-16.6
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    • 2017
  • Background: This study was performed to investigate the impact of exogenous ghrelin on the pancreatic ${\alpha}$-amylase outputs and responses of pancreatic proteins to ghrelin that may relate to pancreatic exocrine. Methods: Sprague-Dawley male rats (9 weeks old, $300{\pm}10g$) were injected with ghrelin via intraperitoneal (i.p.) infusion at dosage of 0, 0.1, 1.0 and $10.0{\mu}g/kg$ body weight (BW), respectively. The plasma ghrelin and cholecystokinin (CCK) level were determined using enzyme immunoassay kit; the mRNA expression of ghrelin receptor ($GHSR-1{\alpha}$) and growth hormone (GH) receptor were assessed by reverse transcription PCR; the expressions of pancreatic ${\alpha}$-amylase activity, extracellular-signal-regulated kinases (ERK), phosphorylated extracellular-signal-regulated kinases (pERK) and c-Jun N-terminal kinase (JNK) were evaluated by western blotting; moreover the responses of pancreatic proteins to ghrelin were analyzed using the two-dimensional gel electrophoresis system. Results: The exogenous ghrelin (1.0 and $10.0{\mu}g/kg\;BW$) elevated the level of plasma ghrelin (p < 0.05), and suppressed the expression of pancreatic ${\alpha}$-amylase at a dose of $10.0{\mu}g/kg\;BW$ (p < 0.05). No difference in the level of plasma CCK was observed, even though rats were exposed to any dose of exogenous ghrelin. In addition, a combination of western blot and proteomic analysis revealed exogenous ghrelin ($10.0{\mu}g/kg\;BW$) induced increasing the JNK and ERK expressions (p < 0.05) and four proteins such as Destrin, Anionic trypsin-1, Trypsinogen, and especially eukaryotic translation initiation factor 3 in rat pancreas. Conclusions: Taken together, exogenous ghrelin by i.p. infusion plays a role in the pancreatic exocrine secretion via mitogen-activated protein kinase signaling pathway.

Anti-Obese Activity of HPJ Extract on High Fat Diet-Induced Obese Mice (고지방 식이로 유도된 비만 쥐에서 HPJ 추출물의 항비만 효과)

  • Yuan, Hai-Dan;Quan, Hai-Yan;Zhang, Ya;Kim, Sung-Jib;Shin, Dae-Hee;Lim, Bang-Ho;Chung, Sung-Hyun
    • YAKHAK HOEJI
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    • v.53 no.5
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    • pp.286-292
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    • 2009
  • In this study, we investigated the anti-obese activity of HPJ extract in C57BL/6J mice. The C57BL/6J mice were randomly divided into five groups: normal control group (Con), high fat diet control group (HFD), treatment groups with HPJ at 125 mg/kg (HPJ125), 250 mg/kg (HPJ250), or 500 mg/kg (HPJ500). To induce an obesity, mice were fed by a high fat diet for 6 weeks, and mice were administered with HPJ extract once a day for 8 weeks. At the end of treatment, we examined the effect of HPJ extract on body weight, plasma lipid, and lipogenic enzymes. HPJ extract was found to lower whole body and epididymal adipose tissue weights and lowered plasma levels of glucose, insulin, triglyceride (TG), total cholesterol (TC), non-esterified fatty acid (NEFA) and leptin, compared to those in HFD group. Histological analyses of the liver and fat tissues of mice treated with HPJ extract revealed significantly decreased number of lipid droplets and decreased size of adipocytes compared to the HFD group. In addition, HPJ extract preserved the morphological integrity of pancreatic islets. To elucidate an action mechanism of HPJ extract, Western blot and RT-PCR were performed using epididymal adipose tissues. HPJ extract up-regulated the levels of phosphorylated adenosine monophosphate-activated protein kinase (AMPK) and its substrate, acetyl-CoA carboxylasse (ACC). HPJ extract also attenuated lipogenic gene expressions of sterol regulatory element-binding protein $1{\alpha}$ (SREBP$1{\alpha}$), fatty acid synthase (FAS), sterol-CoA desaturase 1 (SCD1) and glycerol-3-phosphate acyltransferase (GPAT) in dose-dependent manners. In contrast, expressions of lipolytic genes such as peroxisome proliferator-activated receptor-$\alpha$ (PPAR-${\alpha}$) and CD36, and fatty acid $\beta$-oxidation gene, carnitine palmitoyltransferase-1 (CPT-1) were increased. These results suggest that HPJ extract ameliorates obesity through inhibiting synthesis of lipogenic enzymes as well as stimulating fatty acid oxidation resulting from activation of AMPK, and HPJ extract could be developed as a potential therapeutic agent for obese patients.