Loss of catalase increases malignant mouse keratinocyte cell growth through activation of the stress activated JNK pathway.

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Hanke, Neale T; Finch, Joanne S; Bowden, G Timothy

2008-05-01

A cell line that produces mouse squamous cell carcinoma (6M90) was modified to develop a cell line with an introduced Tet-responsive catalase transgene (MTOC2). We have previously reported that the overexpressed catalase in the MTOC2 cells reverses the malignant phenotype in part by decreasing epidermal growth factor receptor (EGFR) signaling. With this work we expanded the investigation into the differences between these two cell lines. We found that the decreased EGFR pathway activity of the MTOC2 cells is not because of reduced autocrine secretion of an epidermal growth factor (EGF) ligand but rather because of lower basal receptor activity. Phosphorylated levels of the mitogen-activated protein kinase (MAPK) members JNK and p38 were both higher in the 6M90 cells with low catalase when compared with the MTOC2 cell line. Although treatment with an EGFR inhibitor, AG1478, blocked the increased activity of JNK in the 6M90 cells, a similar effect was not observed for p38. Basal levels of downstream c-jun transcription were also found to be higher in the 6M90 cells versus MTOC2 cells. Activated p38 was found to down-regulate the JNK MAPK pathway in the 6M90 cells. However, the 6M90 cells contain constitutively high levels of phosphorylated JNK, generating higher levels of phosphorylated c-jun and total c-jun than those in the MTOC2 cells. Inhibition of JNK activity in the 6M90 cells reduced AP-1 transcription and cell proliferation. The data confirm the inhibitory effects of catalase on tumor cell growth, specifically through a ligand-independent decrease in the stress activated JNK pathway. (c) 2007 Wiley-Liss, Inc.

[Curcumin alleviates early brain injury following subarachnoid hemorrhage in rats by inhibiting JNK/c-Jun signal pathway].

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Li, Xia; Zhu, Ji

2018-03-01

Objective To investigate the inhibitory effect of curcumin on early brain injury following subarachnoid hemorrhage (SAH) by inhibiting JNK/ c-Jun signal pathway. Methods Sixty adult male SD rats were randomly divided into four groups: sham operation group (sham group), SAH group, SAH group treated with 100 mg/(kg.d) curcumin and SAH group treated with 200 mg/(kg.d) curcumin, with 15 rats in each group. Endovascular puncture was used to induce SAH model. Nissl staining was used to test whether neurons were broken. TUNEL staining was used to detect apoptosis. Immunohistochemistry was used to investigate the expression of caspase-3. Western blot analysis was used to detect the expressions of p-JNK, JNK, p-c-Jun, c-Jun, and caspase-3. Results Nissl staining indicated the decrease of Nissl bodies in SAH group, but increase of Nissl bodies in SAH group treated with curcumin. TUNEL staining showed that there were more apoptotic neurons in SAH group compared with sham group, while apoptotic neurons decreased after the treatment with curcumin, more obviously in the group treated with 200 mg/(kg.d) curcumin. The expressions of p-JNK, JNK, p-c-Jun, c-Jun, and caspase-3 were up-regulated in SAH group compared with sham group. However, the expressions of those proteins were down-regulated after the treatment with curcumin, especially by higher-dose curcumin treatment. Conclusion Curcumin might suppress early brain injury after SAH by inhibiting JNK/c-Jun signal pathway and neuron apoptosis.

Low Dose Cadmium Inhibits Proliferation of Human Renal Mesangial Cells via Activation of the JNK Pathway

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Chen, Xiaocui; Li, Jing; Cheng, Zuowang; Xu, Yinghua; Wang, Xia; Li, Xiaorui; Xu, Dongmei; Kapron, Carolyn M.; Liu, Ju

2016-01-01

Cadmium (Cd) is a heavy metal and environmental pollutant. The kidney is the principal target organ of Cd exposure. Previously, we found that low concentration of Cd damages the integrity of the glomerular filtration barrier. However, little is known about the effects of Cd on renal mesangial cells, which provide structural support for the glomerular capillary loops and regulate intraglomerular blood flow. In this study, human renal mesangial cells (HRMCs) were cultured in the presence of serum and treated with 4 μM Cd. We found that Cd activates the c-Jun N-terminal kinase (JNK) pathway, and increases the protein levels of c-Jun and c-Fos. Cd treatment also induces a decrease in proliferation and an increase in apoptosis of HRMCs, but only the decrease in HRMC proliferation was reversed by pretreatment with SP600125, an inhibitor of the JNK pathway. In addition, Cd does not change the expression of α-smooth muscle actin and platelet-derived growth factor receptor-β, the markers of mesangial cells, or the alignment of the filamentous actin (F-actin) cytoskeleton of HRMCs. Our data indicate that the JNK pathway mediates the inhibitory effects of Cd on HRMC proliferation. PMID:27739415

Huaier Aqueous Extract Induces Hepatocellular Carcinoma Cells Arrest in S Phase via JNK Signaling Pathway

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Chengshuo Zhang

2015-01-01

Full Text Available Huaier aqueous extract, the main active constituent of Huaier proteoglycan, has antihepatocarcinoma activity in experimental and clinical settings. However, the potential and associated antihepatoma mechanisms of Huaier extract are not yet fully understood. Therefore, in this study, we aimed to elucidate the inhibitory proliferation effect of Huaier extract on apoptosis and cycle of HepG2 and Bel-7402 cells. Our data demonstrated that incubation with Huaier extract resulted in a marked decrease in cell viability dose-dependently. Flow cytometric analysis showed that a 48 h treatment of Huaier extract caused cell apoptosis. Typical apoptotic nucleus alterations were observed with fluorescence microscope after Hoechst staining. Immunoblot analysis further demonstrated that Huaier extract activated caspase 3 and PARP. Additionally, Huaier extract inhibited the activity of p-ERK, p-p38, and p-JNK in terms of MAPK. Furthermore, Huaier extract induced HCC cells arrest in S phase and decreased the cycle related protein expression of β-catenin and cyclin D1. Studies with JNK specific inhibitor, SP600125, showed that Huaier extract induced S phase arrest and decreased β-catenin and cyclin D1 expression via JNK signaling pathway. In conclusion, we verify that Huaier extract causes cell apoptosis and induces hepatocellular carcinoma cells arrest in S phase via JNK pathway, which advances our understanding on the molecular mechanisms of Huaier extract in hepatocarcinoma management.

JNK-associated scattered growth of YD-10B oral squamous carcinoma cells while maintaining the epithelial phenotype

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Lee, Gayoung; Kim, Hyun-Man

2017-01-01

Cell scattering of epithelial carcinoma cancer cells is one of the critical event in tumorigenesis. Cells losing epithelial cohesion detach from aggregated epithelial cell masses and may migrate to fatal organs through metastasis. The present study investigated the molecular mechanism by which squamous cell carcinoma cells grow scattered at the early phase of transformation while maintaining the epithelial phenotype. We studied YD-10B cells, which are established from human oral squamous cell carcinoma, because the cells grow scattered without the development of E-cadherin junctions (ECJs) under routine culture conditions despite the high expression of functional E-cadherin. The functionality of their E-cadherin was demonstrated in that YD-10B cells developed ECJs, transiently or persistently, when they were cultured on substrates coated with a low amount of fibronectin or to confluence. The phosphorylation of JNK was up-regulated in YD-10B cells compared with that in human normal oral keratinocyte cells or human squamous cell carcinoma cells, which grew aggregated along with well-organized ECJs. The suppression of JNK activity induced the aggregated growth of YD-10B cells concomitant with the development of ECJs. These results indicate for the first time that inherently up-regulated JNK activity induces the scattered growth of the oral squamous cell carcinoma cells through down-regulating the development of ECJ despite the expression of functional E-cadherin, a hallmark of the epithelial phenotype. - Highlights: • JNK dissociates YD-10B oral squamous cell carcinoma cells. • JNK suppresses the development of E-cadherin junctions of oral carcinoma cells. • Suppression of JNK activity reverses the scattered growth of oral carcinoma cells.

ShenFu Preparation Protects AML12 Cells Against Palmitic Acid-Induced Injury Through Inhibition of Both JNK/Nox4 and JNK/NFκB Pathways

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Jia-Fu Ji

2018-02-01

Full Text Available Background/Aims: Nonalcoholic steatohepatitis includes steatosis along with liver inflammation, hepatocyte injury and fibrosis. In this study, we investigated the protective role and the potential mechanisms of a traditional Chinese medicine ShenFu (SF preparation in an in vitro hepatic steatosis model. Methods: In palmitic acid (PA-induced murine hepatic AML12 cell injury, effects of SF preparation on cellular apoptosis and intracellular triglyceride (iTG level were assessed using TUNEL and TG Colorimetric Assay. Reactive oxygen species (ROS and mitochondrial membrane potential (MMP levels were measured using DCF and JC-1 assay. Cytokine levels were evaluated using ELISA assay. Immunoblot was used to compare the activation level of c-Jun N terminal kinase (JNK, NADPH oxidase (Nox4, and NFκB pathways. Results: Addition of SF preparation prevented PA-mediated increase of apoptosis and iTG as well as IL-8 and IL-6. In PA-treated cell, SF preparation reduced the level of Nox4 and ROS, while increasing the level of MMP and the expression of manganese superoxide dismutase (MnSOD and catalase, indicating emendation of mitochondrial dysfunction. Nox4 inhibitor GKT137381 prevented PA-induced increase of ROS and apoptosis, while decreasing iTG slightly and not influencing the level of IL-8 and IL-6. SF preparation prevented PA-induced upregulation of phospho-JNK. JNK inhibitor SP600125 prevented PA-mediated increase of Nox4, IL-8, IL-6 and iTG. Nuclear translocation of NFκB/p65 was detected in PA-treated cells, which was prevented by SF preparation. An IκB degradation inhibitor, BAY11-7082, prevented PA-induced increase of IL-8 and IL-6 as well as iTG, whereas it only decreased ROS levels slightly and showed no influence on cellular apoptosis. Conclusion: SF preparation shows a beneficial role in prevention of hepatocyte injury by attenuating oxidative stress and cytokines production at least partially through inhibition of JNK/Nox4 and JNK

Balanites aegyptiaca ameliorates insulin secretion and decreases pancreatic apoptosis in diabetic rats: Role of SAPK/JNK pathway.

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Hassanin, Kamel M A; Mahmoud, Mohamed O; Hassan, Hossam M; Abdel-Razik, Abdel-Razik H; Aziz, Lourin N; Rateb, Mostafa E

2018-06-01

SAPK-JNK pathway performs a significant role in the pathogenesis of type 2 diabetes. Balanites aegyptiaca (BA) is used as an anti-diabetic agent in folk medicine however its hypoglycemic mechanism is not fully elucidated. The current study aimed to evaluate the effect of crude extract, butanol, and dichloromethane fractions from BA on the stress-activated protein kinase/c-Jun N-terminal kinase (SAPK-JNK) pathway in experimental diabetic rats. Six groups of male Wistar rats were included: normal control, diabetic, diabetic rats treated with crude, butanol or dichloromethane fraction from BA (50 mg/kg BW) and diabetic rats treated with gliclazide as a reference drug for one month. Our results suggested a protective role of treatment of diabetic rats with BA against oxidative stress-induced SAPK-JNK pathway. Moreover, BA treatment produced a reduction in plasma glucose, HbA 1c , lactic acid, lipid profile, malondialdehyde levels and produced an increase in insulin, reduced glutathione levels, catalase and superoxide dismutase activities compared with untreated diabetic rats. Moreover, it decreased apoptosis signal-regulating kinase 1, c-Jun N-terminal kinase 1, protein 53 and increased insulin receptor substrate 1 in rat pancreas while it increased glucose transporter 4 in rat muscle. Analysis of BA extracts by LC-HRMS revealed the presence of different saponins with reported hypoglycemic effect. In conclusion, BA exerted hypoglycemic, hypolipidemic, insulinotropic and antioxidant effects. Additionally, it reduced apoptosis in pancreatic β-cells and increased glucose uptake in muscle. These results suggest that the hypoglycemic effect of BA is due to the inhibition of the SAPK-JNK pathway. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

PDGF stimulation of Mueller cell proliferation: Contributions of c-JNK and the PI3K/Akt pathway

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Moon, Sang Woong; Chung, Eun Jee; Jung, Sun-Ah; Lee, Joon H.

2009-01-01

Platelet-derived growth factor (PDGF) has a critical role in proliferative vitreoretinopathy (PVR) as a chemoattractant and mitogen for retinal pigment epithelial cells and retinal glial cells. Here, we investigated the potential effects of PDGF on the proliferation of Mueller cells and the intracellular signaling pathway mediating these changes. PDGF induced Mueller cell proliferation and increased phosphorylation of the PDGF receptor (PDGFR), as shown by an MTT assay and immunoprecipitation analyses. Both effects were blocked by JNJ, a PDGFR-selective tyrosine kinase inhibitor. PDGF also stimulated phosphorylation of c-JNK and Akt. PDGF-induced Mueller cell proliferation was significantly reduced by pre-treatment with SP600125 and LY294002, inhibitors of c-JNK and Akt phosphorylation, respectively. Our findings collectively indicate that PDGF-stimulated Mueller cell proliferation occurs via activation of the c-JNK and PI3K/Akt signaling pathways. These data provide useful information in establishing the role of Mueller cells in the development of proliferative vitreoretinopathy.

Activation of Erk and JNK MAPK pathways by acute swim stress in rat brain regions

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Salvadore Christopher

2004-09-01

Full Text Available Abstract Background The mitogen-activated protein kinases (MAPKs have been shown to participate in a wide array of cellular functions. A role for some MAPKs (e.g., extracellular signal-regulated kinase, Erk1/2 has been documented in response to certain physiological stimuli, such as ischemia, visceral pain and electroconvulsive shock. We recently demonstrated that restraint stress activates the Erk MAPK pathway, but not c-Jun-N-terminal kinase/stress-activated protein kinase (JNK/SAPK or p38MAPK, in several rat brain regions. In the present study, we investigated the effects of a different stressor, acute forced swim stress, on the phosphorylation (P state of these MAPKs in the hippocampus, neocortex, prefrontal cortex, amygdala and striatum. In addition, effects on the phosphorylation state of the upstream activators of the MAPKs, their respective MAPK kinases (MAPKKs; P-MEK1/2, P-MKK4 and P-MKK3/6, were determined. Finally, because the Erk pathway can activate c-AMP response element (CRE binding (CREB protein, and swim stress has recently been reported to enhance CREB phosphorylation, changes in P-CREB were also examined. Results A single 15 min session of forced swimming increased P-Erk2 levels 2–3-fold in the neocortex, prefrontal cortex and striatum, but not in the hippocampus or amygdala. P-JNK levels (P-JNK1 and/or P-JNK2/3 were increased in all brain regions about 2–5-fold, whereas P-p38MAPK levels remained essentially unchanged. Surprisingly, levels of the phosphorylated MAPKKs, P-MEK1/2 and P-MKK4 (activators of the Erk and JNK pathways, respectively were increased in all five brain regions, and much more dramatically (P-MEK1/2, 4.5 to > 100-fold; P-MKK4, 12 to ~300-fold. Consistent with the lack of forced swim on phosphorylation of p38MAPK, there appeared to be no change in levels of its activator, P-MKK3/6. P-CREB was increased in all but cortical (prefrontal, neocortex areas. Conclusions Swim stress specifically and markedly

Curcumin Induced Human Gastric Cancer BGC-823 Cells Apoptosis by ROS-Mediated ASK1-MKK4-JNK Stress Signaling Pathway

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Tao Liang

2014-09-01

Full Text Available The signaling mediated by stress-activated MAP kinases (MAPK, c-Jun N-terminal kinase (JNK has well-established importance in cancer. In the present report, we investigated the effects of curcumin on the signaling pathway in human gastric cancer BGC-823 cells. Curcumin induced reactive oxygen species (ROS production and BGC-823 cells apoptosis. Inhibition of ROS generation by antioxidant (NAC or Trion significantly prevented curcumin-mediated apoptosis. Notably, we observed that curcumin activated ASK1, a MAPKKK that is oxidative stress sensitive and responsible to phosphorylation of JNK via triggering cascades, up-regulated an upstream effector of the JNK, MKK4, and phosphorylated JNK protein expression in BGC-823 cells. However, curcumin induced ASK1-MKK4-JNK signaling was attenuated by NAC. All the findings confirm the possibility that oxidative stress-activated ASK1-MKK4-JNK signaling cascade promotes the apoptotic response in curcumin-treated BGC-823 cells.

A Fat-Facets-Dscam1-JNK Pathway Enhances Axonal Growth in Development and after Injury

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Marta Koch

2018-02-01

Full Text Available Injury to the adult central nervous systems (CNS can result in severe long-term disability because damaged CNS connections fail to regenerate after trauma. Identification of regulators that enhance the intrinsic growth capacity of severed axons is a first step to restore function. Here, we conducted a gain-of-function genetic screen in Drosophila to identify strong inducers of axonal growth after injury. We focus on a novel axis the Down Syndrome Cell Adhesion Molecule (Dscam1, the de-ubiquitinating enzyme Fat Facets (Faf/Usp9x and the Jun N-Terminal Kinase (JNK pathway transcription factor Kayak (Kay/Fos. Genetic and biochemical analyses link these genes in a common signaling pathway whereby Faf stabilizes Dscam1 protein levels, by acting on the 3′-UTR of its mRNA, and Dscam1 acts upstream of the growth-promoting JNK signal. The mammalian homolog of Faf, Usp9x/FAM, shares both the regenerative and Dscam1 stabilizing activities, suggesting a conserved mechanism.

JNK2 promotes endothelial cell alignment under flow.

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Cornelia Hahn

Full Text Available Endothelial cells in straight, unbranched segments of arteries elongate and align in the direction of flow, a feature which is highly correlated with reduced atherosclerosis in these regions. The mitogen-activated protein kinase c-Jun N-terminal kinase (JNK is activated by flow and is linked to inflammatory gene expression and apoptosis. We previously showed that JNK activation by flow is mediated by integrins and is observed in cells plated on fibronectin but not on collagen or basement membrane proteins. We now show thatJNK2 activation in response to laminar shear stress is biphasic, with an early peak and a later peak. Activated JNK localizes to focal adhesions at the ends of actin stress fibers, correlates with integrin activation and requires integrin binding to the extracellular matrix. Reducing JNK2 activation by siRNA inhibits alignment in response to shear stress. Cells on collagen, where JNK activity is low, align slowly. These data show that an inflammatory pathway facilitates adaptation to laminar flow, thereby revealing an unexpected connection between adaptation and inflammatory pathways.

Stathmin Mediates Hepatocyte Resistance to Death from Oxidative Stress by down Regulating JNK

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Zhao, Enpeng; Amir, Muhammad; Lin, Yu; Czaja, Mark J.

2014-01-01

Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth. PMID:25285524

Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK.

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Enpeng Zhao

Full Text Available Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK. The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

Interleukin-1 Acts via the JNK-2 Signaling Pathway to Induce Aggrecan Degradation by Human Chondrocytes.

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Ismail, Heba M; Yamamoto, Kazuhiro; Vincent, Tonia L; Nagase, Hideaki; Troeberg, Linda; Saklatvala, Jeremy

2015-07-01

Aggrecan enables articular cartilage to bear load and resist compression. Aggrecan loss occurs early in osteoarthritis and rheumatoid arthritis and can be induced by inflammatory cytokines such as interleukin-1 (IL-1). IL-1 induces cleavage of specific aggrecans characteristic of the ADAMTS proteinases. The aim of this study was to identify the intracellular signaling pathways by which IL-1 causes aggrecan degradation by human chondrocytes and to investigate how aggrecanase activity is controlled by chondrocytes. We developed a cell-based assay combining small interfering RNA (siRNA)-induced knockdown with aggrecan degradation assays. Human articular chondrocytes were overlaid with bovine aggrecan after transfection with siRNAs against molecules of the IL-1 signaling pathway. After IL-1 stimulation, released aggrecan fragments were detected with AGEG and ARGS neoepitope antibodies. Aggrecanase activity and tissue inhibitor of metalloproteinases 3 levels were measured by enzyme-linked immunosorbent assay. Low-density lipoprotein receptor-related protein 1 (LRP-1) shedding was analyzed by Western blotting. ADAMTS-5 is a major aggrecanase in human chondrocytes, regulating aggrecan degradation in response to IL-1. The tumor necrosis factor receptor-associated 6 (TRAF-6)/transforming growth factor β-activated kinase 1 (TAK-1)/MKK-4 signaling axis is essential for IL-1-induced aggrecan degradation, while NF-κB is not. Of the 3 MAPKs (ERK, p38, and JNK), only JNK-2 showed a significant role in aggrecan degradation. Chondrocytes constitutively secreted aggrecanase, which was continuously endocytosed by LRP-1, keeping the extracellular level of aggrecanase low. IL-1 induced aggrecanase activity in the medium in a JNK-2-dependent manner, possibly by reducing aggrecanase endocytosis, because IL-1 caused JNK-2-dependent shedding of LRP-1. The signaling axis TRAF-6/TAK-1/MKK-4/JNK-2 mediates IL-1-induced aggrecanolysis. The level of aggrecanase is controlled by its

Arsenic trioxide mediates HAPI microglia inflammatory response and subsequent neuron apoptosis through p38/JNK MAPK/STAT3 pathway

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Mao, Jiamin; Yang, Jianbing; Zhang, Yan; Li, Ting; Wang, Cheng; Xu, Lingfei; Hu, Qiaoyun; Wang, Xiaoke; Jiang, Shengyang; Nie, Xiaoke; Chen, Gang

2016-01-01

Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1β in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1β caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 and P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1β and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons. - Highlights: • Arsenic trioxide exposure induced expression of IL-β in HAPI microglia. • Arsenic trioxide exposure induced activation of MAPK pathways in HAPI microglia. • Arsenic trioxide exposure induced activation of STAT3 pathways in HAPI microglia. • The expression of IL-β though P38/JNK MAPK/STAT3 pathways in HAPI microglia.

Arsenic trioxide mediates HAPI microglia inflammatory response and subsequent neuron apoptosis through p38/JNK MAPK/STAT3 pathway

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Mao, Jiamin [Department of Environmental Health, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Yang, Jianbing [Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001 (China); Zhang, Yan [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Li, Ting [Department of Environmental Health, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Wang, Cheng [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Xu, Lingfei; Hu, Qiaoyun; Wang, Xiaoke; Jiang, Shengyang [Department of Environmental Health, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Nie, Xiaoke [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Chen, Gang, E-mail: chengang@ntu.edu.cn [Department of Environmental Health, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China)

2016-07-15

Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1β in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1β caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 and P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1β and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons. - Highlights: • Arsenic trioxide exposure induced expression of IL-β in HAPI microglia. • Arsenic trioxide exposure induced activation of MAPK pathways in HAPI microglia. • Arsenic trioxide exposure induced activation of STAT3 pathways in HAPI microglia. • The expression of IL-β though P38/JNK MAPK/STAT3 pathways in HAPI microglia.

Protective properties of sesamin against fluoride-induced oxidative stress and apoptosis in kidney of carp (Cyprinus carpio) via JNK signaling pathway.

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Cao, Jinling; Chen, Jianjie; Xie, Lingtian; Wang, Jundong; Feng, Cuiping; Song, Jing

2015-10-01

Sesamin, a major lignan derived from sesame seeds, has been reported to have many benefits and medicinal properties. However, its protective effects against fluoride-induced injury in kidney of fish have not been clarified. Previously we found that fluoride exposure caused damage and apoptosis in the kidneys of the common carp, Cyprinus carpio. In this study, the effects of sesamin on renal oxidative stress and apoptosis in fluoride-exposed fish were determined. The results showed that sesamin alleviated significantly fluoride-induced renal damage and apoptosis of carp in a dose-dependent manner, indicated by the histopathological examination and ultrastructural observation. Moreover, treatment with sesamin also inhibited significantly fluoride-induced remarkable enhancement of reactive oxygen species (ROS) production and oxidative stress, such as the increase of lipid peroxidation level and the depletion of intracellular reduced glutathione (GSH) level in kidney. To explore the underlying mechanisms of sesamin action, we found that activities of caspase-3 were notably inhibited by treatment with sesamin in the kidney of fluoride-exposed fish. Sesamin decreased the levels of p-JNK protein in kidney, which in turn inactivated pro-apoptotic signaling events by restoring the balance between mitochondrial pro- and anti-apoptotic Bcl-2 and Bax proteins and by decreasing the release of mitochondrial cytochrome c in kidney of fluoride-exposed fish. JNK was also involved in the mitochondrial extrinsic apoptotic pathways of sesamin effects against fluoride-induced renal injury by regulating the levels of p-c-Jun, necrosis factor-alpha (TNF-α) and Bak proteins. These findings indicated that sesamin could protect kidney against fluoride-induced apoptosis by the oxidative stress downstream-mediated change in the inactivation of JNK signaling pathway. Taken together, sesamin plays an important role in maintaining renal health and preventing kidney from toxic damage induced by

Eicosapentaenoic acid (EPA) induced apoptosis in HepG2 cells through ROS–Ca{sup 2+}–JNK mitochondrial pathways

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuanyuan; Han, Lirong [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China); Qi, Wentao [Academy of State Administration of Grain, No.11 Baiwanzhuang Avenue, Xicheng District, Beijing, 100037 (China); Cheng, Dai; Ma, Xiaolei; Hou, Lihua [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China); Cao, Xiaohong, E-mail: caoxh@tust.edu.cn [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China); Wang, Chunling, E-mail: wangchunling@tust.edu.cn [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China)

2015-01-24

Highlights: • EPA evoked ROS formation, [Ca{sup 2+}]{sub c} accumulation, the opening of MPTP and the phosphorylation of JNK. • EPA-induced [Ca{sup 2+}]{sub c} elevation was depended on production of ROS. • EPA-induced ROS generation, [Ca{sup 2+}]{sub c} increase, and JNK activated caused MPTP opening. • The apoptosis induced by EPA was related to release of cytochrome C through the MPTP. • EPA induced HepG2 cells apoptosis through ROS–Ca{sup 2+}–JNK mitochondrial pathways. - Abstract: Eicosapentaenoic acid (EPA), a well-known dietary n−3 PUFAS, has been considered to inhibit proliferation of tumor cells. However, the molecular mechanism related to EPA-induced liver cancer cells apoptosis has not been reported. In this study, we investigated the effect of EPA on HepG2 cells proliferation and apoptosis mechanism through mitochondrial pathways. EPA inhibited proliferation of HepG2 cells in a dose-dependent manner and had no significant effect on the cell viability of humor normal liver L-02 cells. It was found that EPA initially evoked ROS formation, leading to [Ca{sup 2+}]{sub c} accumulation and the mitochondrial permeability transition pore (MPTP) opening; EPA-induced HepG2 cells apoptosis was inhibited by N-acetylcysteine (NAC, an inhibitor of ROS), 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium) and CsA (inhibitor of MPTP). The relationship between ROS production, the increase of cytoplasmic Ca and MPTP opening was detected. It seems that ROS may act as an upstream regulator of EPA-induced [Ca{sup 2+}]{sub c} generation, moreover, generation of ROS, overload of mitochondrial [Ca{sup 2+}]{sub c}, and JNK activated cause the opening of MPTP. Western blotting results showed that EPA elevated the phosphorylation status of JNK, processes associated with the ROS generation. Simultaneously, the apoptosis induced by EPA was related to release of cytochrome C from mitochondria to cytoplasm through the MPTP

Acrolein induces Hsp72 via both PKCdelta/JNK and calcium signaling pathways in human umbilical vein endothelial cells.

Science.gov (United States)

Misonou, Yoshiko; Takahashi, Motoko; Park, Yong Seek; Asahi, Michio; Miyamoto, Yasuhide; Sakiyama, Haruhiko; Cheng, Xinyao; Taniguchi, Naoyuki

2005-05-01

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehydes to which humans are exposed in a variety of environment situations and is also a product of lipid peroxidation. Increased levels of unsaturated aldehydes play an important role in the pathogenesis of a number of human diseases such as Alzheimer's disease, atherosclerosis and diabetes. A number of studies have reported that acrolein evokes downstream signaling via an elevation in cellular oxidative stress. Here, we report that low concentrations of acrolein induce Hsp72 in human umbilical vein endothelial cells (HUVEC) and that both the PKCdelta/JNK pathway and calcium pathway were involved in the induction. The findings confirm that the production of reactive oxygen species (ROS) is not directly involved in the pathway. The induction of Hsp72 was not observed in other cells such as smooth muscle cells (SMC) or COS-1 cells. The results suggest that HUVEC have a unique defense system against cell damage by acrolein in which Hsp72 is induced via activation of both the PKCd/JNK and the calcium pathway.

Drosophila MOF regulates DIAP1 and induces apoptosis in a JNK dependent pathway.

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Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Koteswara Rao, G; Bag, Indira; Bhadra, Utpal; Pal-Bhadra, Manika

2016-03-01

Histone modulations have been implicated in various cellular and developmental processes where in Drosophila Mof is involved in acetylation of H4K16. Reduction in the size of larval imaginal discs is observed in the null mutants of mof with increased apoptosis. Deficiency involving Hid, Reaper and Grim [H99] alleviated mof (RNAi) induced apoptosis in the eye discs. mof (RNAi) induced apoptosis leads to activation of caspases which is suppressed by over expression of caspase inhibitors like P35 and Diap1 clearly depicting the role of caspases in programmed cell death. Also apoptosis induced by knockdown of mof is rescued by JNK mutants of bsk and tak1 indicating the role of JNK in mof (RNAi) induced apoptosis. The adult eye ablation phenotype produced by ectopic expression of Hid, Rpr and Grim, was restored by over expression of Mof. Accumulation of Mof at the Diap1 promoter 800 bp upstream of the transcription start site in wild type larvae is significantly higher (up to twofolds) compared to mof (1) mutants. This enrichment coincides with modification of histone H4K16Ac indicating an induction of direct transcriptional up regulation of Diap1 by Mof. Based on these results we propose that apoptosis triggered by mof (RNAi) proceeds through a caspase-dependent and JNK mediated pathway.

Wnt-11 signaling leads to down-regulation of the Wnt/β-catenin, JNK/AP-1 and NF-κB pathways and promotes viability in the CHO-K1 cells

International Nuclear Information System (INIS)

Railo, Antti; Nagy, Irina I.; Kilpelaeinen, Pekka; Vainio, Seppo

2008-01-01

The Wnt family of glycoprotein growth factors controls a number of central cellular processes such as proliferation, differentiation and ageing. All the Wnt proteins analyzed so far either activate or inhibit the canonical β-catenin signaling pathway that regulates transcription of the target genes. In addition, some of them activate noncanonical signaling pathways that involve components such as the JNK, heterotrimeric G proteins, protein kinase C, and calmodulin-dependent protein kinase II, although the precise signaling mechanisms are only just beginning to be revealed. We demonstrate here that Wnt-11 signaling is sufficient to inhibit not only the canonical β-catenin mediated Wnt signaling but also JNK/AP-1 and NF-κB signaling in the CHO cells, thus serving as a noncanonical Wnt ligand in this system. Inhibition of the JNK/AP-1 pathway is mediated in part by the MAPK kinase MKK4 and Akt. Moreover, protein kinase C is involved in the regulation of JNK/AP-1 by Wnt-11, but not of the NF-κB pathway. Consistent with the central role of Akt, JNK and NF-κB in cell survival and stress responses, Wnt-11 signaling promotes cell viability. Hence Wnt-11 is involved in coordination of key signaling pathways

3-MCPD 1-palmitate induced renal tubular cell apoptosis in vivo via JNK/p53 pathway

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Fatty acid esters of 3-chloro-1, 2-propanediol (3-MCPD esters) are a group of processing-induced food contaminants with nephrotoxicity, but the molecular mechanism(s) remains unclear. This study investigated whether and how the JNK/p53 pathway may play a role in the nephrotoxic effect of 3-MCPD este...

DISTINCT FUNCTIONS OF JNK AND C-JUN IN OXIDANT-INDUCED HEPATOCYTE DEATH

Science.gov (United States)

Amir, Muhammad; Liu, Kun; Zhao, Enpeng; Czaja, Mark J.

2013-01-01

Overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling is a central mechanism of hepatocyte injury and death including that from oxidative stress. However, the functions of JNK and c-Jun are still unclear, and this pathway also inhibits hepatocyte death. Previous studies of menadione-induced oxidant stress demonstrated that toxicity resulted from sustained JNK/c-Jun activation as death was blocked by the c-Jun dominant negative TAM67. To further delineate the function of JNK/c-Jun signaling in hepatocyte injury from oxidant stress, the effects of direct JNK inhibition on menadione-induced death were examined. In contrast to the inhibitory effect of TAM67, pharmacological JNK inhibition by SP600125 sensitized the rat hepatocyte cell line RALA255-10G to death from menadione. SP600125 similarly sensitized mouse primary hepatocytes to menadione toxicity. Death from SP600125/menadione was c-Jun dependent as it was blocked by TAM67, but independent of c-Jun phosphorylation. Death occurred by apoptosis and necrosis and activation of the mitochondrial death pathway. Short hairpin RNA knockdowns of total JNK or JNK2 sensitized to death from menadione, whereas a jnk1 knockdown was protective. Jnk2 null mouse primary hepatocytes were also sensitized to menadione death. JNK inhibition magnified decreases in cellular ATP content and β-oxidation induced by menadione. This effect mediated cell death as chemical inhibition of β-oxidation also sensitized cells to death from menadione, and supplementation with the β-oxidation substrate oleate blocked death. Components of the JNK/c-Jun signaling pathway have opposing functions in hepatocyte oxidant stress with JNK2 mediating resistance to cell death and c-Jun promoting death. PMID:22644775

β3-adrenergic receptor activation induces TGFβ1 expression in cardiomyocytes via the PKG/JNK/c-Jun pathway.

Science.gov (United States)

Xu, Zhongcheng; Wu, Jimin; Xin, Junzhou; Feng, Yenan; Hu, Guomin; Shen, Jing; Li, Mingzhe; Zhang, Youyi; Xiao, Han; Wang, Li

2018-06-05

In heart failure, the expression of cardiac β 3 -adrenergic receptors (β 3 -ARs) increases. However, the precise role of β 3 -AR signaling within cardiomyocytes remains unclear. Transforming growth factor β1 (TGFβ1) is a crucial cytokine mediating the cardiac remodeling that plays a causal role in the progression of heart failure. Here, we set out to determine the effect of β 3 -AR activation on TGFβ1 expression in rat cardiomyocytes and examine the underlying mechanism. The selective β 3 -AR agonist BRL37344 induced an increase in TGFβ1 expression and the phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun in β 3 -AR-overexpressing cardiomyocytes. Those effects of BRL37344 were suppressed by a β 3 -AR antagonist. Moreover, the inhibition of JNK and c-Jun activity by a JNK inhibitor and c-Jun siRNA blocked the increase in TGFβ1 expression upon β 3 -AR activation. A protein kinase G (PKG) inhibitor also attenuated β 3 -AR-agonist-induced TGFβ1 expression and the phosphorylation of JNK and c-Jun. In conclusion, the β 3 -AR activation in cardiomyocytes increases the expression of TGFβ1 via the PKG/JNK/c-Jun pathway. These results help us further understand the role of β 3 -AR signaling in heart failure. Copyright © 2018 Elsevier Inc. All rights reserved.

Proteomics and pathway analysis identifies JNK signaling as critical for high linear energy transfer radiation-induced apoptosis in non-small lung cancer cells.

Science.gov (United States)

Ståhl, Sara; Fung, Eva; Adams, Christopher; Lengqvist, Johan; Mörk, Birgitta; Stenerlöw, Bo; Lewensohn, Rolf; Lehtiö, Janne; Zubarev, Roman; Viktorsson, Kristina

2009-05-01

During the past decade, we have witnessed an explosive increase in generation of large proteomics data sets, not least in cancer research. There is a growing need to extract and correctly interpret information from such data sets to generate biologically relevant hypotheses. A pathway search engine (PSE) has recently been developed as a novel tool intended to meet these requirements. Ionizing radiation (IR) is an anticancer treatment modality that triggers multiple signal transduction networks. In this work, we show that high linear energy transfer (LET) IR induces apoptosis in a non-small cell lung cancer cell line, U-1810, whereas low LET IR does not. PSE was applied to study changes in pathway status between high and low LET IR to find pathway candidates of importance for high LET-induced apoptosis. Such pathways are potential clinical targets, and they were further validated in vitro. We used an unsupervised shotgun proteomics approach where high resolution mass spectrometry coupled to nanoflow liquid chromatography determined the identity and relative abundance of expressed proteins. Based on the proteomics data, PSE suggested the JNK pathway (p = 6.10(-6)) as a key event in response to high LET IR. In addition, the Fas pathway was found to be activated (p = 3.10(-5)) and the p38 pathway was found to be deactivated (p = 0.001) compared with untreated cells. Antibody-based analyses confirmed that high LET IR caused an increase in phosphorylation of JNK. Moreover pharmacological inhibition of JNK blocked high LET-induced apoptotic signaling. In contrast, neither an activation of p38 nor a role for p38 in high LET IR-induced apoptotic signaling was found. We conclude that, in contrast to conventional low LET IR, high LET IR can trigger activation of the JNK pathway, which in turn is critical for induction of apoptosis in these cells. Thus PSE predictions were largely confirmed, and PSE was proven to be a useful hypothesis-generating tool.

A Quantitative RNAi Screen for JNK Modifiers Identifies Pvr as a Novel Regulator of Drosophila Immune Signaling

Science.gov (United States)

Bond, David; Foley, Edan

2009-01-01

Drosophila melanogaster responds to gram-negative bacterial challenges through the IMD pathway, a signal transduction cassette that is driven by the coordinated activities of JNK, NF-κB and caspase modules. While many modifiers of NF-κB activity were identified in cell culture and in vivo assays, the regulatory apparatus that determines JNK inputs into the IMD pathway is relatively unexplored. In this manuscript, we present the first quantitative screen of the entire genome of Drosophila for novel regulators of JNK activity in the IMD pathway. We identified a large number of gene products that negatively or positively impact on JNK activation in the IMD pathway. In particular, we identified the Pvr receptor tyrosine kinase as a potent inhibitor of JNK activation. In a series of in vivo and cell culture assays, we demonstrated that activation of the IMD pathway drives JNK-dependent expression of the Pvr ligands, Pvf2 and Pvf3, which in turn act through the Pvr/ERK MAP kinase pathway to attenuate the JNK and NF-κB arms of the IMD pathway. Our data illuminate a poorly understood arm of a critical and evolutionarily conserved innate immune response. Furthermore, given the pleiotropic involvement of JNK in eukaryotic cell biology, we believe that many of the novel regulators identified in this screen are of interest beyond immune signaling. PMID:19893628

Protection of Momordica charantia polysaccharide against intracerebral hemorrhage-induced brain injury through JNK3 signaling pathway.

Science.gov (United States)

Duan, Zhen-Zhen; Zhou, Xiao-Ling; Li, Yi-Hang; Zhang, Feng; Li, Feng-Ying; Su-Hua, Qi

2015-01-01

It has been well documented that Momordica charantia polysaccharide (MCP) has multiple biological effects such as immune enhancement, anti-oxidation and anti-cancer. However, the potential protective effects of MCP on stroke damage and its relative mechanisms remain unclear. Our present study demonstrated that MCP could scavenge reactive oxygen species (ROS) in intra-cerebral hemorrhage damage, significantly attenuating the neuronal death induced by thrombin in primary hippocampal neurons. Furthermore, we found that MCP prevented the activation of the c-Jun N-terminal protein kinase (JNK3), c-Jun and caspase-3, which was caused by the intra-cerebral hemorrhage injury. Taken together, our study demonstrated that MCP had a neuroprotective effect in response to intra-cerebral hemorrhage and its mechanisms involved the inhibition of JNK3 signaling pathway.

Vitamin K2 Induces Mitochondria-Related Apoptosis in Human Bladder Cancer Cells via ROS and JNK/p38 MAPK Signal Pathways.

Science.gov (United States)

Duan, Fengsen; Yu, Yuejin; Guan, Rijian; Xu, Zhiliang; Liang, Huageng; Hong, Ling

2016-01-01

The effects of vitamin K2 on apoptosis in a variety of cancer cells have been well established in previous studies. However, the apoptotic effect of vitamin K2 on bladder cancer cells has not been evaluated. The aim of this study is to examine the apoptotic activity of Vitamin K2 in bladder cancer cells and investigate the underlying mechanism. In this study, Vitamin K2 induced apoptosis in bladder cancer cells through mitochondria pathway including loss of mitochondria membrane potential, cytochrome C release and caspase-3 cascade. Furthermore, the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK was detected in Vitamin K2-treated cells and both SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38 MAPK) completely abolished the Vitamin K2-induced apoptosis and loss of mitochondria membrane potential. Moreover, the generation of reactive oxygen species (ROS) was detected in bladder cancer cells, upon treatment of vitamin K2 and the anti-oxidant N-acetyl cysteine (NAC) almost blocked the Vitamin K2-triggered apoptosis, loss of mitochondria membrane potential and activation of JNK and p38 MAPK. Taken together, these findings revealed that Vitamin K2 induces apoptosis in bladder cancer cells via ROS-mediated JNK/p38 MAPK and Mitochondrial pathways.

Proteomics and Pathway Analysis Identifies JNK Signaling as Critical for High Linear Energy Transfer Radiation-induced Apoptosis in Non-small Lung Cancer Cells*S⃞

Science.gov (United States)

Ståhl, Sara; Fung, Eva; Adams, Christopher; Lengqvist, Johan; Mörk, Birgitta; Stenerlöw, Bo; Lewensohn, Rolf; Lehtiö, Janne; Zubarev, Roman; Viktorsson, Kristina

2009-01-01

During the past decade, we have witnessed an explosive increase in generation of large proteomics data sets, not least in cancer research. There is a growing need to extract and correctly interpret information from such data sets to generate biologically relevant hypotheses. A pathway search engine (PSE) has recently been developed as a novel tool intended to meet these requirements. Ionizing radiation (IR) is an anticancer treatment modality that triggers multiple signal transduction networks. In this work, we show that high linear energy transfer (LET) IR induces apoptosis in a non-small cell lung cancer cell line, U-1810, whereas low LET IR does not. PSE was applied to study changes in pathway status between high and low LET IR to find pathway candidates of importance for high LET-induced apoptosis. Such pathways are potential clinical targets, and they were further validated in vitro. We used an unsupervised shotgun proteomics approach where high resolution mass spectrometry coupled to nanoflow liquid chromatography determined the identity and relative abundance of expressed proteins. Based on the proteomics data, PSE suggested the JNK pathway (p = 6·10−6) as a key event in response to high LET IR. In addition, the Fas pathway was found to be activated (p = 3·10−5) and the p38 pathway was found to be deactivated (p = 0.001) compared with untreated cells. Antibody-based analyses confirmed that high LET IR caused an increase in phosphorylation of JNK. Moreover pharmacological inhibition of JNK blocked high LET-induced apoptotic signaling. In contrast, neither an activation of p38 nor a role for p38 in high LET IR-induced apoptotic signaling was found. We conclude that, in contrast to conventional low LET IR, high LET IR can trigger activation of the JNK pathway, which in turn is critical for induction of apoptosis in these cells. Thus PSE predictions were largely confirmed, and PSE was proven to be a useful hypothesis-generating tool. PMID:19168796

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

International Nuclear Information System (INIS)

Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming

2016-01-01

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

Energy Technology Data Exchange (ETDEWEB)

Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming, E-mail: zengshenming@gmail.com

2016-04-22

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

Effect of JNK inhibitor SP600125 on hair cell regeneration in zebrafish (Danio rerio) larvae

Science.gov (United States)

Sun, Shaoyang; Wang, Xu; Li, Wenyan; Li, Huawei

2016-01-01

The c-Jun amino-terminal kinase (JNK) proteins are a subgroup of the mitogen-activated protein kinase family. They play a complex role in cell proliferation, survival, and apoptosis. Here, we report a novel role of JNK signalling in hair cell regeneration. We eliminated hair cells of 5-day post-fertilization zebrafish larvae using neomycin followed by JNK inhibition with SP600125. JNK inhibition strongly decreased the number of regenerated hair cells in response to neomycin damage. These changes were associated with reduced proliferation. JNK inhibition also increased cleaved caspase-3 activity and induced apoptosis in regenerating neuromasts. Finally, JNK inhibition with SP600125 decreased the expression of genes related to Wnt. Over-activation of the Wnt signalling pathway partly rescued the hair cell regeneration defects induced by JNK inhibition. Together, our findings provide novel insights into the function of JNK and show that JNK inhibition blocks hair cell regeneration by controlling the Wnt signalling pathway. PMID:27438150

Mineral trioxide aggregate upregulates odonto/osteogenic capacity of bone marrow stromal cells from craniofacial bones via JNK and ERK MAPK signalling pathways.

Science.gov (United States)

Wang, Y; Li, J; Song, W; Yu, J

2014-06-01

The aim of this study was to investigate effects of mineral trioxide aggregate (MTA) on odonto/osteogenic differentiation of bone marrow stromal cells (BMSCs) from craniofacial bones. Craniofacial BMSCs were isolated from rat mandible and effects of MTA on their proliferation, differentiation and MAPK pathway involvement were subsequently investigated, in vitro. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2,5-tetrazoliumbromide) assay was performed to evaluate proliferation of the MTA-treated cells. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time reverse transcription polymerase chain reaction and western blot assays were used to assess differentiation capacity as well as MAPK pathway involvement. 0.02 mg/ml MTA-treated BMSCs had significantly higher ALP activity and formed more mineralized nodules than the untreated group. Odonto/osteoblastic marker genes/proteins (Alp, Runx2/RUNX2, Osx/OSX, Ocn/OCN and Dspp/DSP respectively) in MTA-treated cells were remarkably upregulated compared to untreated ones. Mechanistically, phosphorylated Jun N-terminal kinase (P-JNK) and phosphorylated extracellular regulated protein kinases (P-ERK) in MTA-treated BMSCs increased significantly in a time-dependent manner, while inhibition of JNK and ERK MAPK pathways dramatically blocked MTA-induced odonto/osteoblastic differentiation, as indicated by reduced ALP levels, weakened mineralization capacity and downregulated levels of odonto/osteoblastic marker genes (Alp, Runx2, Osx, Ocn and Dspp). Mineral trioxide aggregate promoted odonto/osteogenic capacity of craniofacial BMSCs via JNK and ERK MAPK signalling pathways. © 2014 John Wiley & Sons Ltd.

Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

International Nuclear Information System (INIS)

Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng; Shi, Xianglin; Kim, Jong-Ghee; Heo, Jung Sun; Choe, Youngji; Jeon, Young-Mi; Lee, Jeong-Chae

2012-01-01

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G 2 /M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

Energy Technology Data Exchange (ETDEWEB)

Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2012-03-15

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

RhoA/ROCK signaling regulates smooth muscle phenotypic modulation and vascular remodeling via the JNK pathway and vimentin cytoskeleton.

Science.gov (United States)

Tang, Lian; Dai, Fan; Liu, Yan; Yu, Xiaoqiang; Huang, Chao; Wang, Yuqin; Yao, Wenjuan

2018-05-20

The RhoA/ROCK signaling pathway regulates cell morphology, adhesion, proliferation, and migration. In this study, we investigated the regulatory role of RhoA/ROCK signaling on PDGF-BB-mediated smooth muscle phenotypic modulation and vascular remodeling and clarified the molecular mechanisms behind these effects. PDGF-BB treatment induced the activation of RhoA, ROCK, PDGF-Rβ, and the expression of PDGF-Rβ in HA-VSMCs (human aortic vascular smooth muscle cells). PDGF-Rβ inhibition and RhoA suppression blocked PDGF-BB-induced RhoA activation and ROCK induction. In addition, PDGF-BB-mediated cell proliferation and migration were suppressed by PDGF-Rβ inhibition, RhoA suppression, and ROCK inhibition, suggesting that PDGF-BB promotes phenotypic modulation of HA-VSMCs by activating the RhoA/ROCK pathway via the PDGF receptor. Moreover, suppressing both ROCK1 and ROCK2 blocked cell cycle progression from G0/G1 to S phase by decreasing the transcription and protein expression of cyclin D1, CDK2, and CDK4 via JNK/c-Jun pathway, thus reducing cell proliferation in PDGF-BB-treated HA-VSMCs. ROCK1 deletion, rather than ROCK2 suppression, significantly inhibited PDGF-BB-induced migration by reducing the expression of vimentin and preventing the remodeling of vimentin and phospho-vimentin. Furthermore, ROCK1 deletion suppressed vimentin by inhibiting the phosphorylation of Smad2/3 and the nuclear translocation of Smad4. These findings suggested that ROCK1 and ROCK2 might play different roles in PDGF-BB-mediated cell proliferation and migration in HA-VSMCs. In addition, PDGF-BB and its receptor participated in neointima formation and vascular remodeling by promoting cell cycle protein expression via the JNK pathway and enhancing vimentin expression in a rat balloon injury model; effects that were inhibited by treatment with fasudil. Together, the results of this study reveal a novel mechanism through which RhoA/ROCK signaling regulates smooth muscle phenotypic modulation and

Taurine prevents arsenic-induced cardiac oxidative stress and apoptotic damage: Role of NF-κB, p38 and JNK MAPK pathway

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Ghosh, Jyotirmoy; Das, Joydeep; Manna, Prasenjit; Sil, Parames C.

2009-01-01

Cardiac dysfunction is a major cause of morbidity and mortality worldwide due to its complex pathogenesis. However, little is known about the mechanism of arsenic-induced cardiac abnormalities and the use of antioxidants as the possible protective agents in this pathophysiology. Conditionally essential amino acid, taurine, accounts for 25% to 50% of the amino acid pool in myocardium and possesses antioxidant properties. The present study has, therefore, been carried out to investigate the underlying mechanism of the beneficial role of taurine in arsenic-induced cardiac oxidative damage and cell death. Arsenic reduced cardiomyocyte viability, increased reactive oxygen species (ROS) production and intracellular calcium overload, and induced apoptotic cell death by mitochondrial dependent caspase-3 activation and poly-ADP ribose polymerase (PARP) cleavage. These changes due to arsenic exposure were found to be associated with increased IKK and NF-κB (p65) phosphorylation. Pre-exposure of myocytes to an IKK inhibitor (PS-1145) prevented As-induced caspase-3 and PARP cleavage. Arsenic also markedly increased the activity of p38 and JNK MAPKs, but not ERK to that extent. Pre-treatment with SP600125 (JNK inhibitor) and SB203580 (p38 MAPK inhibitor) attenuated NF-κB and IKK phosphorylation indicating that p38 and JNK MAPKs are mainly involved in arsenic-induced NF-κB activation. Taurine treatment suppressed these apoptotic actions, suggesting that its protective role in arsenic-induced cardiomyocyte apoptosis is mediated by attenuation of p38 and JNK MAPK signaling pathways. Similarly, arsenic intoxication altered a number of biomarkers related to cardiac oxidative stress and other apoptotic indices in vivo and taurine supplementation could reduce it. Results suggest that taurine prevented arsenic-induced myocardial pathophysiology, attenuated NF-κB activation via IKK, p38 and JNK MAPK signaling pathways and could possibly provide a protection against As

High sugar diet disrupts gut homeostasis though JNK and STAT pathways in Drosophila.

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Zhang, Xiaoyue; Jin, Qiuxia; Jin, Li Hua

2017-06-10

The incidence of diseases associated with a high sugar diet has increased in the past years, and numerous studies have focused on the effect of high sugar intake on obesity and metabolic syndrome. However, how a high sugar diet influences gut homeostasis is still poorly understood. In this study, we used Drosophila melanogaster as a model organism and supplemented a culture medium with 1 M sucrose to create a high sugar condition. Our results indicate that a high sugar diet promoted differentiation of intestinal stem cells through upregulation of the JNK pathway and downregulation of the JAK/STAT pathway. Moreover, the number of commensal bacteria decreased in the high sugar group. Our data suggests that the high caloric diet disrupts gut homeostasis and highlights Drosophila as an ideal model system to explore gastrointestinal disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Fibroblast Growth Factor 21 Mediates Glycemic Regulation by Hepatic JNK

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Santiago Vernia

2016-03-01

Full Text Available The cJun NH2-terminal kinase (JNK-signaling pathway is implicated in metabolic syndrome, including dysregulated blood glucose concentration and insulin resistance. Fibroblast growth factor 21 (FGF21 is a target of the hepatic JNK-signaling pathway and may contribute to the regulation of glycemia. To test the role of FGF21, we established mice with selective ablation of the Fgf21 gene in hepatocytes. FGF21 deficiency in the liver caused marked loss of FGF21 protein circulating in the blood. Moreover, the protective effects of hepatic JNK deficiency to suppress metabolic syndrome in high-fat diet-fed mice were not observed in mice with hepatocyte-specific FGF21 deficiency, including reduced blood glucose concentration and reduced intolerance to glucose and insulin. Furthermore, we show that JNK contributes to the regulation of hepatic FGF21 expression during fasting/feeding cycles. These data demonstrate that the hepatokine FGF21 is a key mediator of JNK-regulated metabolic syndrome.

JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships

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Zeke, András; Misheva, Mariya

2016-01-01

SUMMARY The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states. PMID:27466283

Metformin and pioglitazone combination therapy ameliorate polycystic ovary syndrome through AMPK/PI3K/JNK pathway

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Wu, Yuanyuan; Li, Pengfen; Zhang, Dan; Sun, Yingpu

2018-01-01

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder, which results in health problems such as menstrual disorders, hyperandrogenism and persistent anovulation. Hyperandrogenism and insulin resistance are the basic characteristics of PCOS. To investigate the combined effect of metformin and pioglitazone on POCS and the potential mechanisms, a rat model of PCOS was established by intramuscular injection of estradiol valerate (EV). The effect of metformin and pioglitazone monotherapy or combination therapy in control rats and PCOS rats was evaluated, involving the testosterone level, follicular development and insulin resistance. The potential mechanism for the therapeutic effect of metformin and pioglitazone on POCS was explored through using three inhibitors of the 5′adenosine monophosphate-activated protein kinase (AMPK)/phosphoinositide-3 kinase (PI3K)/c-Jun N-terminal kinase (JNK) pathway (Compound C, Wortmannin and SP600125). The results showed that EV-induced PCOS rats demonstrated hyperandrogenemia, hyperinsulinemia and follicular dysplasia. Metformin or pioglitazone monotherapy significantly suppressed the high level of testosterone, reduced the raised percentage of cystic follicles and primary follicles, promoted the number of early antral follicles, and markedly decreased the high concentration of fasting insulin and homeostatic model assessment for insulin resistance index in PCOS rats. In addition, metformin and pioglitazone combination therapy demonstrated greater efficacy than its individual components. Furthermore, individual or joint treatment with metformin and pioglitazone affected the phosphorylation level of JNK in PCOS rats. Compound C and Wortmannin eliminated the effect of metformin and pioglitazone combination therapy on improving the follicular growth in PCOS rats, whereas SP600125 treatment enhanced this combination therapy effect. These data suggested that metformin and pioglitazone combination therapy

Catalpol ameliorates high-fat diet-induced insulin resistance and adipose tissue inflammation by suppressing the JNK and NF-κB pathways

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Zhou, Jun, E-mail: hustzhj@hust.edu.cn; Xu, Gang; Ma, Shuai; Li, Fen; Yuan, Miao; Xu, Huibi; Huang, Kaixun

2015-11-27

Catalpol, a bioactive component from the root of Rehmannia glutinosa, has been shown to possess hypoglycemic effects in type 2 diabetic animal models, however, the underlying mechanisms remain poorly understood. Here we investigated the effect of catalpol on high-fat diet (HFD)-induced insulin resistance and adipose tissue inflammation in mice. Oral administration of catalpol at 100 mg/kg for 4 weeks had no effect on body weight of HFD-induced obese mice, but it significantly improved fasting glucose and insulin levels, glucose tolerance and insulin tolerance. Moreover, macrophage infiltration into adipose tissue was markedly reduced by catalpol. Intriguingly, catalpol also significantly reduced mRNA expressions of M1 pro-inflammatory cytokines, but increased M2 anti-inflammatory gene expressions in adipose tissue. Concurrently, catalpol significantly suppressed the c-Jun NH2-terminal kinase (JNK) and nuclear factor-kappa B (NF-κB) signaling pathways in adipose tissue. Collectively, these results suggest that catalpol may ameliorate HFD-induced insulin resistance in mice by attenuating adipose tissue inflammation and suppressing the JNK and NF-κB pathways, and thus provide important new insights into the underlying mechanisms of the antidiabetic effect of catalpol. - Highlights: • Catalpol ameliorates high-fat diet (HFD)-induced insulin resistance in mice. • Catalpol reduces adipose tissue macrophage infiltration in HFD-fed mice. • Catalpol regulates M1 and M2 inflammatory gene expression in obese adipose tissue. • Catalpol suppresses the JNK and NF-κB signaling pathways in obese adipose tissue.

Catalpol ameliorates high-fat diet-induced insulin resistance and adipose tissue inflammation by suppressing the JNK and NF-κB pathways

International Nuclear Information System (INIS)

Zhou, Jun; Xu, Gang; Ma, Shuai; Li, Fen; Yuan, Miao; Xu, Huibi; Huang, Kaixun

2015-01-01

Catalpol, a bioactive component from the root of Rehmannia glutinosa, has been shown to possess hypoglycemic effects in type 2 diabetic animal models, however, the underlying mechanisms remain poorly understood. Here we investigated the effect of catalpol on high-fat diet (HFD)-induced insulin resistance and adipose tissue inflammation in mice. Oral administration of catalpol at 100 mg/kg for 4 weeks had no effect on body weight of HFD-induced obese mice, but it significantly improved fasting glucose and insulin levels, glucose tolerance and insulin tolerance. Moreover, macrophage infiltration into adipose tissue was markedly reduced by catalpol. Intriguingly, catalpol also significantly reduced mRNA expressions of M1 pro-inflammatory cytokines, but increased M2 anti-inflammatory gene expressions in adipose tissue. Concurrently, catalpol significantly suppressed the c-Jun NH2-terminal kinase (JNK) and nuclear factor-kappa B (NF-κB) signaling pathways in adipose tissue. Collectively, these results suggest that catalpol may ameliorate HFD-induced insulin resistance in mice by attenuating adipose tissue inflammation and suppressing the JNK and NF-κB pathways, and thus provide important new insights into the underlying mechanisms of the antidiabetic effect of catalpol. - Highlights: • Catalpol ameliorates high-fat diet (HFD)-induced insulin resistance in mice. • Catalpol reduces adipose tissue macrophage infiltration in HFD-fed mice. • Catalpol regulates M1 and M2 inflammatory gene expression in obese adipose tissue. • Catalpol suppresses the JNK and NF-κB signaling pathways in obese adipose tissue.

JNK signaling pathway regulates sorbitol-induced Tau proteolysis and apoptosis in SH-SY5Y cells by targeting caspase-3.

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Olivera Santa-Catalina, Marta; Caballero Bermejo, Montaña; Argent, Ricardo; Alonso, Juan C; Centeno, Francisco; Lorenzo, María J

2017-12-15

Growing evidence suggests that Diabetes Mellitus increases the risk of developing Alzheimer's disease. It is well known that hyperglycemia, a key feature of Diabetes Mellitus, may induce plasma osmolarity disturbances. Both hyperglycemia and hyperosmolarity promote the altered post-translational regulation of microtubule-associated protein Tau. Interestingly, abnormal hyperphosphorylation and cleavage of Tau have been proven to lead to the genesis of filamentous structures referred to as neurofibrillary tangles, the main pathological hallmark of Alzheimer's disease. We have previously described that hyperosmotic stress induced by sorbitol promotes Tau proteolysis and apoptosis in SH-SY5Y cells via caspase-3 activation. In order to gain insights into the regulatory mechanisms of such processes, in this work we explored the intracellular signaling pathways that regulate these events. We found that sorbitol treatment significantly enhanced the activation of conventional families of MAPK in SH-SY5Y cells. Tau proteolysis was completely prevented by JNK inhibition but not affected by either ERK1/2 or p38 MAPK blockade. Moreover, inhibition of JNK, but not ERK1/2 or p38 MAPK, efficiently prevented sorbitol-induced apoptosis and caspase-3 activation. In summary, we provide evidence that JNK signaling pathway is an upstream regulator of hyperosmotic stress-induced Tau cleavage and apoptosis in SH-SY5Y through the control of caspase-3 activation. Copyright © 2017 Elsevier Inc. All rights reserved.

Iron overload may promote alteration of NK cells and hematopoietic stem/progenitor cells by JNK and P38 pathway in myelodysplastic syndromes.

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Hua, Yanni; Wang, Chaomeng; Jiang, Huijuan; Wang, Yihao; Liu, Chunyan; Li, Lijuan; Liu, Hui; Shao, Zonghong; Fu, Rong

2017-08-01

The objective of the study was to examine levels of intracellular iron, reactive oxygen species (ROS) and the expression of JNK and p38MAPK in NK cells and hematopoietic stem/progenitor cells (HSPCs) in MDS patients, and explore potential mechanisms by which iron overload (IOL) promotes MDS progression. Thirty-four cases of MDS and six cases of AML transformed from MDS (MDS/AML) were included. HSPCs and NK cells were isolated by magnetic absorption cell sorting. We used flow cytometry to detect the levels of ROS and intracellular JNK and P38 in NK cells and HSPCs. Total RNA and protein were extracted from NK cells and CD34 + cells to examine the expression of JNK and p38MAPK using RT-PCR and Western blotting. Intracellular iron concentration was detected. Data were analyzed by SPSS 21 statistical software. Intracellular iron concentration and ROS were increased in both NK cells and HSPCs in MDS patients with iron overload (P overload had higher JNK expression and lower p38 expression in NK cells, and higher p38 expression in HSPCs compared with non-iron overload group. IOL may cause alterations in NK cells and HSPCs through the JNK and p38 pathways, and play a role in the transformation to AML from MDS.

Cambogin Induces Caspase-Independent Apoptosis through the ROS/JNK Pathway and Epigenetic Regulation in Breast Cancer Cells.

Science.gov (United States)

Shen, Kaikai; Xie, Jianling; Wang, Hua; Zhang, Hong; Yu, Mengyuan; Lu, Fangfang; Tan, Hongsheng; Xu, Hongxi

2015-07-01

Cambogin is a polycyclic polyprenylated acylphoroglucinol (PPAP) from the Garcinia genus, which has been used traditionally for cancer treatment across Southeastern Asia. In this study, we found that cambogin inhibited breast cancer cell proliferation and induced cell apoptosis in vitro. Cambogin induced the activation of the caspase-independent mitochondrial apoptotic pathway, as indicated by an increase in the ratio of Bax/Bcl-2 and the nuclear translocation of apoptosis inducing factor (AIF). Two-dimensional gel electrophoresis and mass spectrometry revealed that the expression of proteins involving in the radical oxygen species (ROS) pathway was among the most affected upon cambogin treatment. Cambogin enhanced cellular ROS production, and induced the activation of the ASK1-MKK4/MKK7-JNK/SAPK signaling pathway. Pretreatment with ROS scavenger N-acetylcysteine (NAC), an antioxidant, or the JNK inhibitor SP600125 was able to restore cell viability in the presence of cambogin. Importantly, cambogin treatment led to the activation of activating transcription factor-2 (ATF-2) and the trimethylation of histone H3K9 in the activator protein 1 (AP-1) binding region of the Bcl-2 gene promoter. Finally, cambogin exhibited a potential antitumor effect in MCF-7 breast cancer xenografts without apparent toxicity. Taken in conjunction, the present study indicates that cambogin can induce breast adenocarcinoma cell apoptosis and therefore represents therapeutic potential for cancer treatment. ©2015 American Association for Cancer Research.

Lycium barbarum (wolfberry reduces secondary degeneration and oxidative stress, and inhibits JNK pathway in retina after partial optic nerve transection.

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Hongying Li

Full Text Available Our group has shown that the polysaccharides extracted from Lycium barbarum (LBP are neuroprotective for retinal ganglion cells (RGCs in different animal models. Protecting RGCs from secondary degeneration is a promising direction for therapy in glaucoma management. The complete optic nerve transection (CONT model can be used to study primary degeneration of RGCs, while the partial optic nerve transection (PONT model can be used to study secondary degeneration of RGCs because primary degeneration of RGCs and secondary degeneration can be separated in location in the same retina in this model; in other situations, these types of degeneration can be difficult to distinguish. In order to examine which kind of degeneration LBP could delay, both CONT and PONT models were used in this study. Rats were fed with LBP or vehicle daily from 7 days before surgery until sacrifice at different time-points and the surviving numbers of RGCs were evaluated. The expression of several proteins related to inflammation, oxidative stress, and the c-jun N-terminal kinase (JNK pathways were detected with Western-blot analysis. LBP did not delay primary degeneration of RGCs after either CONT or PONT, but it did delay secondary degeneration of RGCs after PONT. We found that LBP appeared to exert these protective effects by inhibiting oxidative stress and the JNK/c-jun pathway and by transiently increasing production of insulin-like growth factor-1 (IGF-1. This study suggests that LBP can delay secondary degeneration of RGCs and this effect may be linked to inhibition of oxidative stress and the JNK/c-jun pathway in the retina.

Lycium Barbarum (Wolfberry) Reduces Secondary Degeneration and Oxidative Stress, and Inhibits JNK Pathway in Retina after Partial Optic Nerve Transection

Science.gov (United States)

Li, Hongying; Liang, Yuxiang; Chiu, Kin; Yuan, Qiuju; Lin, Bin; Chang, Raymond Chuen-Chung; So, Kwok-Fai

2013-01-01

Our group has shown that the polysaccharides extracted from Lycium barbarum (LBP) are neuroprotective for retinal ganglion cells (RGCs) in different animal models. Protecting RGCs from secondary degeneration is a promising direction for therapy in glaucoma management. The complete optic nerve transection (CONT) model can be used to study primary degeneration of RGCs, while the partial optic nerve transection (PONT) model can be used to study secondary degeneration of RGCs because primary degeneration of RGCs and secondary degeneration can be separated in location in the same retina in this model; in other situations, these types of degeneration can be difficult to distinguish. In order to examine which kind of degeneration LBP could delay, both CONT and PONT models were used in this study. Rats were fed with LBP or vehicle daily from 7 days before surgery until sacrifice at different time-points and the surviving numbers of RGCs were evaluated. The expression of several proteins related to inflammation, oxidative stress, and the c-jun N-terminal kinase (JNK) pathways were detected with Western-blot analysis. LBP did not delay primary degeneration of RGCs after either CONT or PONT, but it did delay secondary degeneration of RGCs after PONT. We found that LBP appeared to exert these protective effects by inhibiting oxidative stress and the JNK/c-jun pathway and by transiently increasing production of insulin-like growth factor-1 (IGF-1). This study suggests that LBP can delay secondary degeneration of RGCs and this effect may be linked to inhibition of oxidative stress and the JNK/c-jun pathway in the retina. PMID:23894366

A Protein Scaffold Coordinates SRC-Mediated JNK Activation in Response to Metabolic Stress.

Science.gov (United States)

Kant, Shashi; Standen, Claire L; Morel, Caroline; Jung, Dae Young; Kim, Jason K; Swat, Wojciech; Flavell, Richard A; Davis, Roger J

2017-09-19

Obesity is a major risk factor for the development of metabolic syndrome and type 2 diabetes. How obesity contributes to metabolic syndrome is unclear. Free fatty acid (FFA) activation of a non-receptor tyrosine kinase (SRC)-dependent cJun NH 2 -terminal kinase (JNK) signaling pathway is implicated in this process. However, the mechanism that mediates SRC-dependent JNK activation is unclear. Here, we identify a role for the scaffold protein JIP1 in SRC-dependent JNK activation. SRC phosphorylation of JIP1 creates phosphotyrosine interaction motifs that bind the SH2 domains of SRC and the guanine nucleotide exchange factor VAV. These interactions are required for SRC-induced activation of VAV and the subsequent engagement of a JIP1-tethered JNK signaling module. The JIP1 scaffold protein, therefore, plays a dual role in FFA signaling by coordinating upstream SRC functions together with downstream effector signaling by the JNK pathway. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

A Protein Scaffold Coordinates SRC-Mediated JNK Activation in Response to Metabolic Stress

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Shashi Kant

2017-09-01

Full Text Available Obesity is a major risk factor for the development of metabolic syndrome and type 2 diabetes. How obesity contributes to metabolic syndrome is unclear. Free fatty acid (FFA activation of a non-receptor tyrosine kinase (SRC-dependent cJun NH2-terminal kinase (JNK signaling pathway is implicated in this process. However, the mechanism that mediates SRC-dependent JNK activation is unclear. Here, we identify a role for the scaffold protein JIP1 in SRC-dependent JNK activation. SRC phosphorylation of JIP1 creates phosphotyrosine interaction motifs that bind the SH2 domains of SRC and the guanine nucleotide exchange factor VAV. These interactions are required for SRC-induced activation of VAV and the subsequent engagement of a JIP1-tethered JNK signaling module. The JIP1 scaffold protein, therefore, plays a dual role in FFA signaling by coordinating upstream SRC functions together with downstream effector signaling by the JNK pathway.

Molybdenum induces pancreatic β-cell dysfunction and apoptosis via interdependent of JNK and AMPK activation-regulated mitochondria-dependent and ER stress-triggered pathways

International Nuclear Information System (INIS)

Yang, Tsung-Yuan; Yen, Cheng-Chieh; Lee, Kuan-I; Su, Chin-Chuan; Yang, Ching-Yao; Wu, Chin-Ching; Hsieh, Shang-Shu; Ueng, Kwo-Chang; Huang, Chun-Fa

2016-01-01

Molybdenum (Mo), a well-known toxic environmental and industrial pollutant, causes adverse health effects and diseases in humans and has received attention as a potential risk factor for DM. However, the roles of Mo in the mechanisms of the toxicological effects in pancreatic β-cells are mostly unclear. In this study, the results revealed dysfunction of insulin secretion and apoptosis in the pancreatic β-cell-derived RIN-m5F cells and the isolated mouse islets in response to Mo. These effects were accompanied by a mitochondria-dependent apoptotic signals including a decreased in the MMP, an increase in cytochrome c release, and the activation of caspase cascades and PARP. In addition, ER stress was triggered as indicated by several key molecules of the UPR. Furthermore, exposure to Mo induced the activation of ERK1/2, JNK, AMPKα, and GSK3-α/β. Pretreatment with specific pharmacological inhibitors (in RIN-m5F cells and isolated mouse islets) of JNK (SP600125) and AMPK (Compound C) or transfection with si-RNAs (in RIN-m5F cells) specific to JNK and AMPKα effectively prevented the Mo-induced apoptosis and related signals, but inhibitors of ERK1/2 and GSK3-α/β (PD98059 and LiCl, respectively) did not reverse the Mo-induced effects. Additionally, both the inhibitors and specific si-RNAs could suppress the Mo-induced phosphorylation of JNK and AMPKα each other. Taken together, these results suggest that Mo exerts its cytotoxicity on pancreatic β-cells by inducing dysfunction and apoptosis via interdependent JNK and AMPK activation downstream-regulated mitochondrial-dependent and ER stress-triggered apoptosis pathways. - Highlights: • Molybdenum (Mo) induces pancreatic β-cell dysfunction and apoptosis. • Mo causes β-cell death via mitochondria-dependent caspase cascades signals. • ER stress-triggered apoptotic pathway also regulates Mo-induced β-cell death. • Interdependent of JNK and AMPK activation involves in Mo-induced β-cell apoptosis.

Molybdenum induces pancreatic β-cell dysfunction and apoptosis via interdependent of JNK and AMPK activation-regulated mitochondria-dependent and ER stress-triggered pathways

Energy Technology Data Exchange (ETDEWEB)

Yang, Tsung-Yuan [Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Yen, Cheng-Chieh [Department of Occupational Safety and Health, College of Health Care and Management, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Lee, Kuan-I [Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan (China); Su, Chin-Chuan [Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua County 500, Taiwan (China); Graduate Institute of Basic Medical Science, School of Medicine, College of Medicine, China Medical University, Taichung 404, Taiwan (China); Yang, Ching-Yao [Department of Surgery, National Taiwan University Hospital, Taipei 100, Taiwan (China); Department of Surgery, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Wu, Chin-Ching [Department of Public Health, China Medical University, Taichung 404, Taiwan (China); Hsieh, Shang-Shu, E-mail: gile1123@yahoo.com.tw [Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan (China); Ueng, Kwo-Chang, E-mail: kcueng@gmail.com [Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Huang, Chun-Fa, E-mail: cfhuang@mail.cmu.edu.tw [School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan (China)

2016-03-01

Molybdenum (Mo), a well-known toxic environmental and industrial pollutant, causes adverse health effects and diseases in humans and has received attention as a potential risk factor for DM. However, the roles of Mo in the mechanisms of the toxicological effects in pancreatic β-cells are mostly unclear. In this study, the results revealed dysfunction of insulin secretion and apoptosis in the pancreatic β-cell-derived RIN-m5F cells and the isolated mouse islets in response to Mo. These effects were accompanied by a mitochondria-dependent apoptotic signals including a decreased in the MMP, an increase in cytochrome c release, and the activation of caspase cascades and PARP. In addition, ER stress was triggered as indicated by several key molecules of the UPR. Furthermore, exposure to Mo induced the activation of ERK1/2, JNK, AMPKα, and GSK3-α/β. Pretreatment with specific pharmacological inhibitors (in RIN-m5F cells and isolated mouse islets) of JNK (SP600125) and AMPK (Compound C) or transfection with si-RNAs (in RIN-m5F cells) specific to JNK and AMPKα effectively prevented the Mo-induced apoptosis and related signals, but inhibitors of ERK1/2 and GSK3-α/β (PD98059 and LiCl, respectively) did not reverse the Mo-induced effects. Additionally, both the inhibitors and specific si-RNAs could suppress the Mo-induced phosphorylation of JNK and AMPKα each other. Taken together, these results suggest that Mo exerts its cytotoxicity on pancreatic β-cells by inducing dysfunction and apoptosis via interdependent JNK and AMPK activation downstream-regulated mitochondrial-dependent and ER stress-triggered apoptosis pathways. - Highlights: • Molybdenum (Mo) induces pancreatic β-cell dysfunction and apoptosis. • Mo causes β-cell death via mitochondria-dependent caspase cascades signals. • ER stress-triggered apoptotic pathway also regulates Mo-induced β-cell death. • Interdependent of JNK and AMPK activation involves in Mo-induced β-cell apoptosis.

Selenite exacerbates hepatic insulin resistance in mouse model of type 2 diabetes through oxidative stress-mediated JNK pathway

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jun, E-mail: hustzhj@hust.edu.cn; Xu, Gang; Bai, Zhaoshuai; Li, Kaicheng; Yan, Junyan; Li, Fen; Ma, Shuai; Xu, Huibi; Huang, Kaixun, E-mail: hxxzrf@hust.edu.cn

2015-12-15

Recent evidence suggests a potential pro-diabetic effect of selenite treatment in type 2 diabetics; however, the underlying mechanisms remain elusive. Here we investigated the effects and the underlying mechanisms of selenite treatment in a nongenetic mouse model of type 2 diabetes. High-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice were orally gavaged with selenite at 0.5 or 2.0 mg/kg body weight/day or vehicle for 4 weeks. High-dose selenite treatment significantly elevated fasting plasma insulin levels and insulin resistance index, in parallel with impaired glucose tolerance, insulin tolerance and pyruvate tolerance. High-dose selenite treatment also attenuated hepatic IRS1/Akt/FoxO1 signaling and pyruvate kinase gene expressions, but elevated the gene expressions of phosphoenolpyruvate carboxyl kinase (PEPCK), glucose 6-phosphatase (G6Pase), peroxisomal proliferator-activated receptor-γ coactivator 1α (PGC-1α) and selenoprotein P (SelP) in the liver. Furthermore, high-dose selenite treatment caused significant increases in MDA contents, protein carbonyl contents, and a decrease in GSH/GSSG ratio in the liver, concurrent with enhanced ASK1/MKK4/JNK signaling. Taken together, these findings suggest that high-dose selenite treatment exacerbates hepatic insulin resistance in mouse model of type 2 diabetes, at least in part through oxidative stress-mediated JNK pathway, providing new mechanistic insights into the pro-diabetic effect of selenite in type 2 diabetes. - Highlights: • Selenite exacerbates hepatic insulin resistance in HFD/STZ-induced diabetic mice. • Selenite elevates hepatic gluconeogenesis and reduces glycolysis in diabetic mice. • Selenite exacerbates hepatic oxidative stress and triggers JNK signaling pathway. • Selenite elevates hepatic selenoprotein P expression in diabetic mice.

Selenite exacerbates hepatic insulin resistance in mouse model of type 2 diabetes through oxidative stress-mediated JNK pathway

International Nuclear Information System (INIS)

Zhou, Jun; Xu, Gang; Bai, Zhaoshuai; Li, Kaicheng; Yan, Junyan; Li, Fen; Ma, Shuai; Xu, Huibi; Huang, Kaixun

2015-01-01

Recent evidence suggests a potential pro-diabetic effect of selenite treatment in type 2 diabetics; however, the underlying mechanisms remain elusive. Here we investigated the effects and the underlying mechanisms of selenite treatment in a nongenetic mouse model of type 2 diabetes. High-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice were orally gavaged with selenite at 0.5 or 2.0 mg/kg body weight/day or vehicle for 4 weeks. High-dose selenite treatment significantly elevated fasting plasma insulin levels and insulin resistance index, in parallel with impaired glucose tolerance, insulin tolerance and pyruvate tolerance. High-dose selenite treatment also attenuated hepatic IRS1/Akt/FoxO1 signaling and pyruvate kinase gene expressions, but elevated the gene expressions of phosphoenolpyruvate carboxyl kinase (PEPCK), glucose 6-phosphatase (G6Pase), peroxisomal proliferator-activated receptor-γ coactivator 1α (PGC-1α) and selenoprotein P (SelP) in the liver. Furthermore, high-dose selenite treatment caused significant increases in MDA contents, protein carbonyl contents, and a decrease in GSH/GSSG ratio in the liver, concurrent with enhanced ASK1/MKK4/JNK signaling. Taken together, these findings suggest that high-dose selenite treatment exacerbates hepatic insulin resistance in mouse model of type 2 diabetes, at least in part through oxidative stress-mediated JNK pathway, providing new mechanistic insights into the pro-diabetic effect of selenite in type 2 diabetes. - Highlights: • Selenite exacerbates hepatic insulin resistance in HFD/STZ-induced diabetic mice. • Selenite elevates hepatic gluconeogenesis and reduces glycolysis in diabetic mice. • Selenite exacerbates hepatic oxidative stress and triggers JNK signaling pathway. • Selenite elevates hepatic selenoprotein P expression in diabetic mice.

Apoptosis induced by penta-acetyl geniposide in C6 glioma cells is associated with JNK activation and Fas ligand induction

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Peng, C.-H.; Tseng, T.-H.; Huang, C.-N.; Hsu, S.-P.; Wang, C.-J.

2005-01-01

In our previous study, penta-acetyl geniposide ((AC) 5 GP) is suggested to induce tumor cell apoptosis through the specific activation of PKCδ. However, the downstream signal pathway of PKCδ has not yet been investigated. It was shown that JNK may play an important role in the regulation of apoptosis and could be a possible downstream signal of PKCδ isoforms. In the present study, we investigate whether JNK is involved in (AC) 5 GP induced apoptosis. The result reveals that (AC) 5 GP induces JNK activation and c-Jun phosphorylation thus stimulating the expression of Fas-L and Fas. Using SP600125 to block JNK activation shows that (AC) 5 GP-mediated apoptosis and related proteins expression are attenuated. Furthermore, we find that the (AC) 5 GP induces apoptosis through the activation of JNK/Jun/Fas L/Fas/caspase 8/caspase 3, a mitochondria-independent pathway. The JNK pathway is suggested to be the downstream signal of PKCδ, since rottlerin impedes (AC) 5 GP-induced JNK activation. Therefore, (AC) 5 GP mediates cell death via activation of PKCδ/JNK/FasL cascade signaling

Suppression of Hepatic Epithelial-to-Mesenchymal Transition by Melittin via Blocking of TGFβ/Smad and MAPK-JNK Signaling Pathways.

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Park, Ji-Hyun; Park, Byoungduck; Park, Kwan-Kyu

2017-04-13

Transforming growth factor (TGF)-β1 plays a crucial role in the epithelial-to-mesenchymal transition (EMT) in hepatocytes and hepatic stellate cells (HSC), which contributes to the pathogenesis of liver fibrosis. Melittin (MEL) is a major component of bee venom and is effective in rheumatoid arthritis, pain relief, cancer cell proliferation, fibrosis and immune modulating activity. In this study, we found that MEL inhibits hepatic EMT in vitro and in vivo, regulating the TGFβ/Smad and TGFβ/nonSmad signaling pathways. MEL significantly inhibited TGF-β1-induced expression of EMT markers (E-cadherin reduction and vimentin induction) in vitro. These results were confirmed in CCl₄-induced liver in vivo. Treatment with MEL almost completely blocked the phosphorylation of Smad2/3, translocation of Smad4 and phosphorylation of JNK in vitro and in vivo. Taken together, these results suggest that MEL suppresses EMT by inhibiting the TGFβ/Smad and TGFβ/nonSmad-c-Jun N-terminal kinase (JNK)/Mitogen-activated protein kinase (MAPK) signaling pathways. These results indicated that MEL possesses potent anti-fibrotic and anti-EMT properties, which may be responsible for its effects on liver diseases.

Antimony trioxide-induced apoptosis is dependent on SEK1/JNK signaling.

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Mann, Koren K; Davison, Kelly; Colombo, Myrian; Colosimo, April L; Diaz, Zuanel; Padovani, Alessandra M S; Guo, Qi; Scrivens, P James; Gao, Wenli; Mader, Sylvie; Miller, Wilson H

2006-01-05

Very little is known concerning the toxicity of antimony, despite its commercial use as a flame retardant and medical use as a treatment for parasitic infections. Our previous studies show that antimony trioxide (Sb(2)O(3)) induces growth inhibition in patient-derived acute promyelocytic leukemia (APL) cell lines, a disease in which a related metal, arsenic trioxide (As(2)O(3)), is used clinically. However, signaling pathways initiated by Sb(2)O(3) treatment remain undefined. Here, we show that Sb(2)O(3) treatment of APL cells is associated with increased apoptosis as well as differentiation markers. Sb(2)O(3)-induced reactive oxygen species (ROS) correlated with increased apoptosis. In addition, when we decreased the buffering capacity of the cell by depleting glutathione, ROS production and apoptosis was enhanced. Arsenic-resistant APL cells with increased glutathione levels exhibited increased cross-resistance to Sb(2)O(3). Based on studies implicating c-jun kinase (JNK) in the mediation of the response to As(2)O(3), we investigated the role for JNK in Sb(2)O(3)-induced apoptosis. Sb(2)O(3) activates JNK and its downstream target, AP-1. In fibroblasts with a genetic deletion in SEK1, an upstream regulator of JNK, Sb(2)O(3)-induced growth inhibition as well as JNK activation was decreased. These data suggest roles for ROS and the SEK1/JNK pathway in the cytotoxicity associated with Sb(2)O(3) exposure.

A non-redundant role for Drosophila Mkk4 and hemipterous/Mkk7 in TAK1-mediated activation of JNK.

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Peter Geuking

Full Text Available BACKGROUND: The JNK pathway is a mitogen-activated protein (MAP kinase pathway involved in the regulation of numerous physiological processes during development and in response to environmental stress. JNK activity is controlled by two MAPK kinases (MAPKK, Mkk4 and Mkk7. Mkk7 plays a prominent role upon Tumor Necrosis Factor (TNF stimulation. Eiger, the unique TNF-superfamily ligand in Drosophila, potently activates JNK signaling through the activation of the MAPKKK Tak1. METHODOLOGY/PRINCIPAL FINDINGS: In a dominant suppressor screen for new components of the Eiger/JNK-pathway in Drosophila, we have identified an allelic series of the Mkk4 gene. Our genetic and biochemical results demonstrate that Mkk4 is dispensable for normal development and host resistance to systemic bacterial infection but plays a non-redundant role as a MAPKK acting in parallel to Hemipterous/Mkk7 in dTAK1-mediated JNK activation upon Eiger and Imd pathway activation. CONCLUSIONS/SIGNIFICANCE: In contrast to mammals, it seems that in Drosophila both MAPKKs, Hep/Mkk7 and Mkk4, are required to induce JNK upon TNF or pro-inflammatory stimulation.

Melatonin inhibits the migration of human lung adenocarcinoma A549 cell lines involving JNK/MAPK pathway.

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Qiaoyun Zhou

Full Text Available OBJECTIVE: Melatonin, an indolamine produced and secreted predominately by the pineal gland, exhibits a variety of physiological functions, possesses antioxidant and antitumor properties. But, the mechanisms for the anti-cancer effects are unknown. The present study explored the effects of melatonin on the migration of human lung adenocarcinoma A549 cells and its mechanism. METHODS: MTT assay was employed to measure the viability of A549 cells treated with different concentrations of melatonin. The effect of melatonin on the migration of A549 cells was analyzed by wound healing assay. Occludin location was observed by immunofluorescence. The expression of occludin, osteopontin (OPN, myosin light chain kinase (MLCK and phosphorylation of myosin light chain (MLC, JNK were detected by western blots. RESULTS: After A549 cells were treated with melatonin, the viability and migration of the cells were inhibited significantly. The relative migration rate of A549 cells treated with melatonin was only about 20% at 24 h. The expression level of OPN, MLCK and phosphorylation of MLC of A549 cells were reduced, while the expression of occludin was conversely elevated, and occludin located on the cell surface was obviously increased. The phosphorylation status of JNK in A549 cells was also reduced when cells were treated by melatonin. CONCLUSIONS: Melatonin significantly inhibits the migration of A549 cells, and this may be associated with the down-regulation of the expression of OPN, MLCK, phosphorylation of MLC, and up-regulation of the expression of occludin involving JNK/MAPK pathway.

Fucoidan extract induces apoptosis in MCF-7 cells via a mechanism involving the ROS-dependent JNK activation and mitochondria-mediated pathways.

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Zhongyuan Zhang

Full Text Available BACKGROUND: Fucoidan extract (FE, an enzymatically digested compound with a low molecular weight, is extracted from brown seaweed. As a natural compound with various actions, FE is attractive, especially in Asian countries, for improving the therapeutic efficacy and safety of cancer treatment. The present study was carried out to investigate the anti-tumor properties of FE in human carcinoma cells and further examine the underlying mechanisms of its activities. METHODOLOGY/PRINCIPAL FINDING: FE inhibits the growth of MCF-7, MDA-MB-231, HeLa, and HT1080 cells. FE-mediated apoptosis in MCF-7 cancer cells is accompanied by DNA fragmentation, nuclear condensation, and phosphatidylserine exposure. FE induces mitochondrial membrane permeabilization (MMP through loss of mitochondrial membrane potential (ΔΨm and regulation of the expression of Bcl-2 family members. Release of apoptosis-inducing factor (AIF and cytochrome c precedes MMP. AIF release causes DNA fragmentation, the final stage of apoptosis, via a caspase-independent mitochondrial pathway. Additionally, FE was found to induce phosphorylation of c-Jun N-terminal kinase (JNK, p38, and extracellular signal-regulated kinase (ERK 1/2, and apoptosis was found to be attenuated by inhibition of JNK. Furthermore, FE-mediated apoptosis was found to involve the generation of reactive oxygen species (ROS, which are responsible for the decrease of ΔΨm and phosphorylation of JNK, p38, and ERK1/2 kinases. CONCLUSIONS/SIGNIFICANCE: These data suggest that FE activates a caspase-independent apoptotic pathway in MCF-7 cancer cells through activation of ROS-mediated MAP kinases and regulation of the Bcl-2 family protein-mediated mitochondrial pathway. They also provide evidence that FE deserves further investigation as a natural anticancer and cancer preventive agent.

Blockage of JNK pathway enhances arsenic trioxide-induced apoptosis in human keratinocytes

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Huang, H.-S.; Liu, Z.-M.; Hong, D.-Y.

2010-01-01

Arsenic is well known as a carcinogen predisposing humans to some severe diseases and also as an effective medicine for treating acute promyelocytic leukemia, syphilis, and psoriasis. Multiple active mechanisms, including cell cycle arrest and apoptosis, have been proposed in therapy; however, the opposing effects of arsenic remain controversial. Our previous study found that arsenic trioxide (ATO)-induced activation of p21 WAF1/CIP1 (p21) led to A431 cell death through the antagonistic effects of the signaling of ERK1/2 and JNK1. In the current study, the inhibitory effects of JNK1 on ATO-induced p21 expression were explored. Over-expression of JNK1 in A431 cells could inhibit p21 expression, which was associated with HDAC1 and TGIF. Using the GST pull-down assay and fluorescence resonance energy transfer analysis, N-terminal domain (amino acids 1-108) of TGIF, critical to its binding with c-Jun, was found. Using reporter assays, requirement of the C-terminal domain (amino acids 138-272) of TGIF to suppress ATO-induced p21 expression was observed. Thus, the domains of TGIF that carried out its inhibitory effects on p21 were identified. Finally, treatment with JNK inhibitor SP600125 could enhance ATO-induced apoptosis of HaCaT keratinocytes by using flow cytometry.

miR-138 protects cardiomyocytes from hypoxia-induced apoptosis via MLK3/JNK/c-jun pathway

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He, Siyi; Liu, Peng; Jian, Zhao; Li, Jingwei; Zhu, Yun; Feng, Zezhou; Xiao, Yingbin, E-mail: xiaoyb@vip.sina.com

2013-11-29

Highlights: •First time to find miR-138 is up-regulated in hypoxic cardiomyocytes. •First time to find miR-138 targets MLK3 and regulates JNK/c-jun pathway. •Rare myocardial biopsy of patients with CHD were collected. •Both silence and overexpression of miR-138 were implemented. •Various methods were used to detect cell function. -- Abstract: Cardiomyocytes experience a series of complex endogenous regulatory mechanisms against apoptosis induced by chronic hypoxia. MicroRNAs are a class of endogenous small non-coding RNAs that regulate cellular pathophysiological processes. Recently, microRNA-138 (miR-138) has been found related to hypoxia, and beneficial for cell proliferation. Therefore, we intend to study the role of miR-138 in hypoxic cardiomyocytes and the main mechanism. Myocardial samples of patients with congenital heart disease (CHD) were collected to test miR-138 expression. Agomir or antagomir of miR-138 was transfected into H9C2 cells to investigate its effect on cell apoptosis. Higher miR-138 expression was observed in patients with cyanotic CHD, and its expression gradually increased with prolonged hypoxia time in H9C2 cells. Using MTT and LDH assays, cell growth was significantly greater in the agomir group than in the negative control (NC) group, while antagomir decreased cell survival. Dual luciferase reporter gene and Western-blot results confirmed MLK3 was a direct target of miR-138. It was found that miR-138 attenuated hypoxia-induced apoptosis using TUNEL, Hoechst staining and Annexin V-PE/7-AAD flow cytometry analysis. We further detected expression of apoptosis-related proteins. In the agomir group, the level of pro-apoptotic proteins such as cleaved-caspase-3, cleaved-PARP and Bad significantly reduced, while Bcl-2 and Bcl-2/Bax ratio increased. Opposite changes were observed in the antagomir group. Downstream targets of MLK3, JNK and c-jun, were also suppressed by miR-138. Our study demonstrates that up-regulation of miR-138 plays

JNK inhibition sensitizes tumor cells to radiation-induced premature senescence via Bcl-2/ROS/DDR signaling pathway

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Lee, Jae Seon; Lee, Je Jung

2009-01-01

Premature senescence is considered as a cellular defense mechanism to prevent tumorigenesis. Although recent evidences demonstrate that c-Jun N-terminal kinase (JNK) is involved in the senescence process, the target and exact mechanism of JNK signaling in the regulation of cell proliferation has yet to be defined. In this study, we investigated the role of JNK in premature senescence and demonstrated JNK inhibition sensitized tumor cells to radiation-induced premature senescence

JNK Promotes Epithelial Cell Anoikis by Transcriptional and Post-translational Regulation of BH3-Only Proteins

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Nomeda Girnius

2017-11-01

Full Text Available Summary: Developmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis. While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here, we tested the role of the cJUN NH2-terminal kinase (JNK signaling pathway using murine models with compound JNK deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that JNK acts through a BAK/BAX-dependent apoptotic pathway by increasing BIM expression and phosphorylating BMF, leading to death of detached epithelial cells. : Developmental morphogenesis, tissue injury, and oncogenic transformation can cause epithelial cell detachment. These cells are eliminated by a specialized form of apoptosis termed anoikis. Girnius and Davis show that anoikis is mediated by the cJUN NH2-terminal kinase (JNK, which increases BIM expression and phosphorylates BMF to engage BAK/BAX-dependent apoptosis. Keywords: apoptosis, anoikis, epithelial cell, mammary gland, JNK, BAX, BAK, BH3-only protein, BIM, BMF

A novel missense mutation in CCDC88C activates the JNK pathway and causes a dominant form of spinocerebellar ataxia.

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Tsoi, Ho; Yu, Allen C S; Chen, Zhefan S; Ng, Nelson K N; Chan, Anne Y Y; Yuen, Liz Y P; Abrigo, Jill M; Tsang, Suk Ying; Tsui, Stephen K W; Tong, Tony M F; Lo, Ivan F M; Lam, Stephen T S; Mok, Vincent C T; Wong, Lawrence K S; Ngo, Jacky C K; Lau, Kwok-Fai; Chan, Ting-Fung; Chan, H Y Edwin

2014-09-01

Spinocerebellar ataxias (SCAs) are a group of clinically and genetically diverse and autosomal-dominant disorders characterised by neurological deficits in the cerebellum. At present, there is no cure for SCAs. Of the different distinct subtypes of autosomal-dominant SCAs identified to date, causative genes for only a fraction of them are currently known. In this study, we investigated the cause of an autosomal-dominant SCA phenotype in a family that exhibits cerebellar ataxia and pontocerebellar atrophy along with a global reduction in brain volume. Whole-exome analysis revealed a missense mutation c.G1391A (p.R464H) in the coding region of the coiled-coil domain containing 88C (CCDC88C) gene in all affected individuals. Functional studies showed that the mutant form of CCDC88C activates the c-Jun N-terminal kinase (JNK) pathway, induces caspase 3 cleavage and triggers apoptosis. This study expands our understanding of the cause of autosomal-dominant SCAs, a group of heterogeneous congenital neurological conditions in humans, and unveils a link between the JNK stress pathway and cerebellar atrophy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Insulin resistance in non-obese subjects is associated with activation of the JNK pathway and impaired insulin signaling in skeletal muscle.

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Umesh B Masharani

2011-05-01

Full Text Available The pathogenesis of insulin resistance in the absence of obesity is unknown. In obesity, multiple stress kinases have been identified that impair the insulin signaling pathway via serine phosphorylation of key second messenger proteins. These stress kinases are activated through various mechanisms related to lipid oversupply locally in insulin target tissues and in various adipose depots.To explore whether specific stress kinases that have been implicated in the insulin resistance of obesity are potentially contributing to insulin resistance in non-obese individuals, twenty healthy, non-obese, normoglycemic subjects identified as insulin sensitive or resistant were studied. Vastus lateralis muscle biopsies obtained during euglycemic, hyperinsulinemic clamp were evaluated for insulin signaling and for activation of stress kinase pathways. Total and regional adipose stores and intramyocellular lipids (IMCL were assessed by DXA, MRI and (1H-MRS. In muscle of resistant subjects, phosphorylation of JNK was increased (1.36±0.23 vs. 0.78±0.10 OD units, P<0.05, while there was no evidence for activation of p38 MAPK or IKKβ. IRS-1 serine phosphorylation was increased (1.30±0.09 vs. 0.22±0.03 OD units, P<0.005 while insulin-stimulated tyrosine phosphorylation decreased (10.97±0.95 vs. 0.89±0.50 OD units, P<0.005. IMCL levels were twice as high in insulin resistant subjects (3.26±0.48 vs. 1.58±0.35% H(2O peak, P<0.05, who also displayed increased total fat and abdominal fat when compared to insulin sensitive controls.This is the first report demonstrating that insulin resistance in non-obese, normoglycemic subjects is associated with activation of the JNK pathway related to increased IMCL and higher total body and abdominal adipose stores. While JNK activation is consistent with a primary impact of muscle lipid accumulation on metabolic stress, further work is necessary to determine the relative contributions of the various mediators of impaired

Pattern of MAP kinases p44/42 and JNK activation by non-lethal doses of tributyltin in human natural killer cells

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Aluoch, Aloice O. [Tennessee State University, Department of Biological Sciences, Nashville, TN (United States); Odman-Ghazi, Sabah O.; Whalen, Margaret M. [Tennessee State University, Department of Chemistry, Nashville, TN (United States)

2007-04-15

Tributyltin (TBT) has been shown to disrupt the ability of natural killer (NK) cells to destroy tumor targets in vitro even at exposures of 25 nM for 24 h, but cell viability was not significantly impacted. Thus, evaluation of intracellular molecular events that regulate cell viability in TBT exposed NK cells are of interest. It has been suggested that activation of the mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), may promote apoptosis while activation of the MAPK p44/42 may be crucial in mediating anti-apoptotic stimuli. However, it is well established that increases in pro-apoptotic BCL-2 family members, such as Bax, results in cell death. We have set out to study the effects of a range of TBT concentrations on the MAPKs, JNK and p44/42. Additionally, we examined the effects of TBT on the levels of pro-apoptotic proteins Bax and p53 as well as anti-apoptotic protein Bcl-2. The results show that 300-25 nM TBT activated JNK within 10 min. MAPK p44/42 was also activated by 300-50 nM TBT within 10 min. These data show that while 300-200 nM TBT activates p44/42 significantly more than JNK, the pattern of 100-25 nM TBT activation of these MAPKs may be similar. TBT exposure alters neither pro-apoptotic proteins Bax and p53 nor anti-apoptotic protein Bcl-2 levels at any exposure studied. The results suggest that exposure to TBT activated the anti-apoptotic regulatory p44/42 pathway to a greater extent than the pro-apoptotic JNK pathway, which may explain to some extent how NK cell viability is maintained. (orig.)

Atorvastatin attenuates contrast-induced nephropathy by modulating inflammatory responses through the regulation of JNK/p38/Hsp27 expression

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Xuyu He

2016-05-01

Our study demonstrates that high-dosage atorvastatin treatment attenuates both the inflammatory processes and apoptosis in contrast-induced acute kidney injury, and that the JNK/p38 MAPK pathway participates in the contrast-induced apoptosis of renal tubular cells. Finally, atorvastatin reduces CIN by suppression of apoptosis, which may be through inhibition of JNK/p38 MAPK pathways.

Synaptic and genomic responses to JNK and AP-1 signaling in Drosophila neurons

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Bohmann Dirk

2005-06-01

Full Text Available Abstract Background The transcription factor AP-1 positively controls synaptic plasticity at the Drosophila neuromuscular junction. Although in motor neurons, JNK has been shown to activate AP-1, a positive regulator of growth and strength at the larval NMJ, the consequences of JNK activation are poorly studied. In addition, the downstream transcriptional targets of JNK and AP-1 signaling in the Drosophila nervous system have yet to be identified. Here, we further investigated the role of JNK signaling at this model synapse employing an activated form of JNK-kinase; and using Serial Analysis of Gene Expression and oligonucleotide microarrays, searched for candidate early targets of JNK or AP-1 dependent transcription in neurons. Results Temporally-controlled JNK induction in postembryonic motor neurons triggers synaptic growth at the NMJ indicating a role in developmental plasticity rather than synaptogenesis. An unexpected observation that JNK activation also causes a reduction in transmitter release is inconsistent with JNK functioning solely through AP-1 and suggests an additional, yet-unidentified pathway for JNK signaling in motor neurons. SAGE profiling of mRNA expression helps define the neural transcriptome in Drosophila. Though many putative AP-1 and JNK target genes arose from the genomic screens, few were confirmed in subsequent validation experiments. One potentially important neuronal AP-1 target discovered, CG6044, was previously implicated in olfactory associative memory. In addition, 5 mRNAs regulated by RU486, a steroid used to trigger conditional gene expression were identified. Conclusion This study demonstrates a novel role for JNK signaling at the larval neuromuscular junction and provides a quantitative profile of gene transcription in Drosophila neurons. While identifying potential JNK/AP-1 targets it reveals the limitations of genome-wide analyses using complex tissues like the whole brain.

The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways.

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Bruno A Cardoso

Full Text Available The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi, albeit with poorer tolerance. Here, we show that bone marrow (BM stromal cells (HS-5 protected MPN-derived cell lines (SET-2; HEL and UKE-1 and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN.

The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways

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Cardoso, Bruno A.; Belo, Hélio; Barata, João T.; Almeida, António M.

2015-01-01

The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN) are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi), albeit with poorer tolerance. Here, we show that bone marrow (BM) stromal cells (HS-5) protected MPN-derived cell lines (SET-2; HEL and UKE-1) and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN. PMID:26623653

SP600125 Induces Src and Type I IGF Receptor Phosphorylation Independent of JNK

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Qingbin Kong

2014-09-01

Full Text Available c-Jun N-terminal kinases (JNK are members of the mitogen-activated protein kinase (MAPK family that have important roles in signal transduction. The small molecule SP600125 is widely used in biochemical studies as a JNK inhibitor. However, recent studies indicate that SP600125 may also act independent of JNK. Here, we report that SP600125 can induce Src, type I insulin-like growth factor receptor (IGF-IR, Akt and Erk1/2 phosphorylation. Notably, these effects are independent of its inhibition of JNK. Inhibition of Src abrogates the stimulation of IGF-IR, Akt and Erk1/2 phosphorylation. IGF-IR knockdown blunts the induction of both Akt and Erk1/2 phosphorylation by SP600125. Moreover, combination of SP600125 and the Src inhibitor saracatinib synergistically inhibits cell proliferation. We conclude that SP600125 can activate Src-IGF-IR-Akt/Erk1/2 signaling pathways independent of JNK.

The reverse-mode NCX1 activity inhibitor KB-R7943 promotes prostate cancer cell death by activating the JNK pathway and blocking autophagic flux.

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Long, Zhou; Chen, BaiJun; Liu, Qian; Zhao, Jiang; Yang, ZhenXing; Dong, XingYou; Xia, LiuBin; Huang, ShengQuan; Hu, XiaoYan; Song, Bo; Li, LongKun

2016-07-05

We explored the effects of KB-R7943, an inhibitor of reverse-mode NCX1 activity, in prostate cancer (PCa). NCX1 was overexpressed in PCa tissues and cell lines, and higher NCX1 levels were associated higher PCa grades. At concentrations greater than 10 μM, KB-R7943 dose-dependently decreased PC3 and LNCaP cell viability. KB-R7943 also increased cell cycle G1/S phase arrest and induced apoptosis in PC3 cells. KB-R7943 increased autophagosome accumulation in PCa cells as indicated by increases in LC3-II levels and eGFP-LC3 puncta. Combined treatment with chloroquine (CQ) and KB-R7943 decreased P62 and increased LC3-II protein levels in PC3 cells, indicating that KB-R7943 blocked autophagic flux. KB-R7943 induced autophagosome accumulation mainly by downregulating the PI3K/AKT/m-TOR pathway and upregulating the JNK pathway. In xenograft experiments, KB-R7943 inhibited tumor growth. Combined treatment with KB-R7943 and an autophagy inhibitor inhibited growth and increased apoptosis. These results indicate that KB-R7943 promotes cell death in PCa by activating the JNK signaling pathway and blocking autophagic flux.

Transforming growth factor-β1 induces expression of human coagulation factor XII via Smad3 and JNK signaling pathways in human lung fibroblasts.

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Jablonska, Ewa; Markart, Philipp; Zakrzewicz, Dariusz; Preissner, Klaus T; Wygrecka, Malgorzata

2010-04-09

Coagulation factor XII (FXII) is a liver-derived serine protease involved in fibrinolysis, coagulation, and inflammation. The regulation of FXII expression is largely unknown. Transforming growth factor-beta1 (TGF-beta1) is a multifunctional cytokine that has been linked to several pathological processes, including tissue fibrosis by modulating procoagulant and fibrinolytic activities. This study investigated whether TGF-beta1 may regulate FXII expression in human lung fibroblasts. Treatment of human lung fibroblasts with TGF-beta1 resulted in a time-dependent increase in FXII production, activation of p44/42, p38, JNK, and Akt, and phosphorylation and translocation into the nucleus of Smad3. However, TGF-beta1-induced FXII expression was repressed only by the JNK inhibitor and JNK and Smad3 antisense oligonucleotides but not by MEK, p38, or phosphoinositide 3-kinase blockers. JNK inhibition had no effect on TGF-beta1-induced Smad3 phosphorylation, association with Smad4, and its translocation into the nucleus but strongly suppressed Smad3-DNA complex formation. FXII promoter analysis revealed that the -299/+1 region was sufficient for TGF-beta1 to induce FXII expression. Sequence analysis of this region detected a potential Smad-binding element at position -272/-269 (SBE-(-272/-269)). Chromatin immunoprecipitation and streptavidin pulldown assays demonstrated TGF-beta1-dependent Smad3 binding to SBE-(-272/-269). Mutation or deletion of SBE-(-272/-269) substantially reduced TGF-beta1-mediated activation of the FXII promoter. Clinical relevance was demonstrated by elevated FXII levels and its co-localization with fibroblasts in the lungs of patients with acute respiratory distress syndrome. Our results show that JNK/Smad3 pathway plays a critical role in TGF-beta1-induced FXII expression in human lung fibroblasts and implicate its possible involvement in pathological conditions characterized by elevated TGF-beta1 levels.

Stimulation of JNK Phosphorylation by the PTTH in Prothoracic Glands of the Silkworm, Bombyx mori

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Shi-Hong Gu

2018-02-01

Full Text Available In this study, phosphorylation of c-Jun N-terminal kinase (JNK by the prothoracicotropic hormone (PTTH was investigated in prothoracic glands (PGs of the silkworm, Bombyx mori. Results showed that JNK phosphorylation was stimulated by the PTTH in time- and dose-dependent manners. In vitro activation of JNK phosphorylation in PGs by the PTTH was also confirmed in an in vivo experiment, in which a PTTH injection greatly increased JNK phosphorylation in PGs of day-6 last instar larvae. JNK phosphorylation caused by PTTH stimulation was greatly inhibited by U73122, a potent and specific inhibitor of phospholipase C (PLC and an increase in JNK phosphorylation was also detected when PGs were treated with agents (either A23187 or thapsigargin that directly elevated the intracellular Ca2+ concentration, thereby indicating involvement of PLC and Ca2+. Pretreatment with an inhibitor (U0126 of mitogen-activated protein kinase (MAPK/extracellular signal-regulated kinase (ERK kinase (MEK and an inhibitor (LY294002 of phosphoinositide 3-kinase (PI3K failed to significantly inhibit PTTH-stimulated JNK phosphorylation, indicating that ERK and PI3K were not related to JNK. We further investigated the effect of modulation of the redox state on JNK phosphorylation. In the presence of either an antioxidant (N-acetylcysteine, NAC or diphenylene iodonium (DPI, PTTH-stimulated JNK phosphorylation was blocked. The JNK kinase inhibitor, SP600125, markedly inhibited PTTH-stimulated JNK phosphorylation and ecdysteroid synthesis. The kinase assay of JNK in PGs confirmed its stimulation by PTTH and inhibition by SP600125. Moreover, PTTH treatment did not affect JNK or Jun mRNA expressions. Based on these findings, we concluded that PTTH stimulates JNK phosphorylation in Ca2+- and PLC-dependent manners and that the redox-regulated JNK signaling pathway is involved in PTTH-stimulated ecdysteroid synthesis in B. mori PGs.

Involvement of JNK and NF-κB pathways in lipopolysaccharide (LPS)-induced BAG3 expression in human monocytic cells.

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Wang, Hua-Qin; Meng, Xin; Liu, Bao-Qin; Li, Chao; Gao, Yan-Yan; Niu, Xiao-Fang; Li, Ning; Guan, Yifu; Du, Zhen-Xian

2012-01-01

Lipopolysaccharide (LPS) is an outer-membrane glycolipid component of Gram-negative bacteria known for its fervent ability to activate monocytic cells and for its potent proinflammatory capabilities. Bcl-2-associated athanogene 3 (BAG3) is a survival protein that has been shown to be stimulated during cell response to stressful conditions, such as exposure to high temperature, heavy metals, proteasome inhibition, and human immunodeficiency virus 1 (HIV-1) infection. In addition, BAG3 regulates replication of Varicella-Zoster Virus (VZV) and Herpes Simplex Virus (HSV) replication, suggesting that BAG3 could participate in the host response to infection. In the current study, we found that LPS increased the expression of BAG3 in a dose- and time-dependent manner. Actinomycin D completely blocked the LPS-induced BAG3 accumulation, as well as LPS activated the proximal promoter of BAG3 gene, supported that the induction by LPS occurred at the level of gene transcription. LPS-induced BAG3 expression was blocked by JNK or NF-κB inhibition, suggesting that JNK and NF-κB pathways participated in BAG3 induction by LPS. In addition, we also found that induction of BAG3 was implicated in monocytic cell adhesion to extracellular matrix induced by LPS. Overall, the data support that BAG3 is induced by LPS via JNK and NF-κB-dependent signals, and involved in monocytic cell-extracellular matrix interaction, suggesting that BAG3 may have a role in the host response to LPS stimulation. Copyright © 2011 Elsevier Inc. All rights reserved.

JNK1 Controls Dendritic Field Size in L2/3 and L5 of the Motor Cortex, Constrains Soma Size and Influences Fine Motor Coordination

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Emilia eKomulainen

2014-09-01

Full Text Available Genetic anomalies on the JNK pathway confer susceptibility to autism spectrum disorders, schizophrenia and intellectual disability. The mechanism whereby a gain or loss of function in JNK signaling predisposes to these prevalent dendrite disorders, with associated motor dysfunction, remains unclear. Here we find that JNK1 regulates the dendritic field of L2/3 and L5 pyramidal neurons of the mouse motor cortex (M1, the main excitatory pathway controlling voluntary movement. In Jnk1-/- mice, basal dendrite branching of L5 pyramidal neurons is increased in M1, as is cell soma size, whereas in L2/3, dendritic arborization is decreased. We show that JNK1 phosphorylates rat HMW-MAP2 on T1619, T1622 and T1625 (Uniprot P15146 corresponding to mouse T1617, T1620, T1623, to create a binding motif, that is critical for MAP2 interaction with and stabilization of microtubules, and dendrite growth control. Targeted expression in M1 of GFP-HMW-MAP2 that is pseudo-phosphorylated on T1619, T1622 and T1625 increases dendrite complexity in L2/3 indicating that JNK1 phosphorylation of HMW-MAP2 regulates the dendritic field. Consistent with the morphological changes observed in L2/3 and L5, Jnk1-/- mice exhibit deficits in limb placement and motor coordination, while stride length is reduced in older animals. In summary, JNK1 phosphorylates HMW-MAP2 to increase its stabilization of microtubules while at the same time controlling dendritic fields in the main excitatory pathway of M1. Moreover, JNK1 contributes to normal functioning of fine motor coordination. We report for the first time, a quantitative sholl analysis of dendrite architecture, and of motor behavior in Jnk1-/- mice. Our results illustrate the molecular and behavioral consequences of interrupted JNK1 signaling and provide new ground for mechanistic understanding of those prevalent neuropyschiatric disorders where genetic disruption of the JNK pathway is central.

Low humidity environmental challenge causes barrier disruption and cornification of the mouse corneal epithelium via a c-jun N-terminal kinase 2 (JNK2) pathway.

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Pelegrino, F S A; Pflugfelder, S C; De Paiva, C S

2012-01-01

Patients with tear dysfunction often experience increased irritation symptoms when subjected to drafty and/or low humidity environmental conditions. The purpose of this study was to investigate the effects of low humidity stress (LHS) on corneal barrier function and expression of cornified envelope (CE) precursor proteins in the epithelium of C57BL/6 and c-jun N-terminal kinase 2 (JNK2) knockout (KO) mice. LHS was induced in both strains by exposure to an air draft for 15 (LHS15D) or 30 days (LHS30D) at a relative humidity LHS15D showed corneal barrier dysfunction, decreased apical corneal epithelial cell area, higher MMP-9 expression and gelatinase activity and increased involucrin and SPRR-2 immunoreactivity in the corneal epithelium compared to NS mice. JNK2KO mice were resistant to LHS-induced corneal barrier disruption. MMP-3,-9,-13, IL-1α, IL-1β, involucrin and SPRR-2a RNA transcripts were significantly increased in C57BL/6 mice at LHS15D, while no change was noted in JNK2KO mice. LHS is capable of altering corneal barrier function, promoting pathologic alteration of the TJ complex and stimulating production of CE proteins by the corneal epithelium. Activation of the JNK2 signaling pathway contributes to corneal epithelial barrier disruption in LHS. Copyright © 2011 Elsevier Ltd. All rights reserved.

JNK-induced MCP-1 production in spinal cord astrocytes contributes to central sensitization and neuropathic pain.

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Gao, Yong-Jing; Zhang, Ling; Samad, Omar Abdel; Suter, Marc R; Yasuhiko, Kawasaki; Xu, Zhen-Zhong; Park, Jong-Yeon; Lind, Anne-Li; Ma, Qiufu; Ji, Ru-Rong

2009-04-01

Our previous study showed that activation of c-jun-N-terminal kinase (JNK) in spinal astrocytes plays an important role in neuropathic pain sensitization. We further investigated how JNK regulates neuropathic pain. In cultured astrocytes, tumor necrosis factor alpha (TNF-alpha) transiently activated JNK via TNF receptor-1. Cytokine array indicated that the chemokine CCL2/MCP-1 (monocyte chemoattractant protein-1) was strongly induced by the TNF-alpha/JNK pathway. MCP-1 upregulation by TNF-alpha was dose dependently inhibited by the JNK inhibitors SP600125 (anthra[1,9-cd]pyrazol-6(2H)-one) and D-JNKI-1. Spinal injection of TNF-alpha produced JNK-dependent pain hypersensitivity and MCP-1 upregulation in the spinal cord. Furthermore, spinal nerve ligation (SNL) induced persistent neuropathic pain and MCP-1 upregulation in the spinal cord, and both were suppressed by D-JNKI-1. Remarkably, MCP-1 was primarily induced in spinal cord astrocytes after SNL. Spinal administration of MCP-1 neutralizing antibody attenuated neuropathic pain. Conversely, spinal application of MCP-1 induced heat hyperalgesia and phosphorylation of extracellular signal-regulated kinase in superficial spinal cord dorsal horn neurons, indicative of central sensitization (hyperactivity of dorsal horn neurons). Patch-clamp recordings in lamina II neurons of isolated spinal cord slices showed that MCP-1 not only enhanced spontaneous EPSCs but also potentiated NMDA- and AMPA-induced currents. Finally, the MCP-1 receptor CCR2 was expressed in neurons and some non-neuronal cells in the spinal cord. Together, we have revealed a previously unknown mechanism of MCP-1 induction and action. MCP-1 induction in astrocytes after JNK activation contributes to central sensitization and neuropathic pain facilitation by enhancing excitatory synaptic transmission. Inhibition of the JNK/MCP-1 pathway may provide a new therapy for neuropathic pain management.

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye.

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Wu, Yue; Zhuang, Yuan; Han, Min; Xu, Tian; Deng, Kejing

2009-10-20

Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the Drosophila eye. Here we report the isolation of a new loss-of-function ras allele, rasKP, which causes excessive apoptosis in the Drosophila eye. This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress rasKP-induced apoptosis, whereas the removal of hid only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the rasKP cell death. In addition, we find a strong correlation between rasKP-induced apoptosis in the eye disc and the activation of JNK signalling. In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.

The Ste20 Family Kinases MAP4K4, MINK1, and TNIK Converge to Regulate Stress-Induced JNK Signaling in Neurons.

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Larhammar, Martin; Huntwork-Rodriguez, Sarah; Rudhard, York; Sengupta-Ghosh, Arundhati; Lewcock, Joseph W

2017-11-15

The c-Jun- N -terminal kinase (JNK) signaling pathway regulates nervous system development, axon regeneration, and neuronal degeneration after acute injury or in chronic neurodegenerative disease. Dual leucine zipper kinase (DLK) is required for stress-induced JNK signaling in neurons, yet the factors that initiate DLK/JNK pathway activity remain poorly defined. In the present study, we identify the Ste20 kinases MAP4K4, misshapen-like kinase 1 (MINK1 or MAP4K6) and TNIK Traf2- and Nck-interacting kinase (TNIK or MAP4K7), as upstream regulators of DLK/JNK signaling in neurons. Using a trophic factor withdrawal-based model of neurodegeneration in both male and female embryonic mouse dorsal root ganglion neurons, we show that MAP4K4, MINK1, and TNIK act redundantly to regulate DLK activation and downstream JNK-dependent phosphorylation of c-Jun in response to stress. Targeting MAP4K4, MINK1, and TNIK, but not any of these kinases individually, is sufficient to protect neurons potently from degeneration. Pharmacological inhibition of MAP4Ks blocks stabilization and phosphorylation of DLK within axons and subsequent retrograde translocation of the JNK signaling complex to the nucleus. These results position MAP4Ks as important regulators of the DLK/JNK signaling pathway. SIGNIFICANCE STATEMENT Neuronal degeneration occurs in disparate circumstances: during development to refine neuronal connections, after injury to clear damaged neurons, or pathologically during disease. The dual leucine zipper kinase (DLK)/c-Jun- N -terminal kinase (JNK) pathway represents a conserved regulator of neuronal injury signaling that drives both neurodegeneration and axon regeneration, yet little is known about the factors that initiate DLK activity. Here, we uncover a novel role for a subfamily of MAP4 kinases consisting of MAP4K4, Traf2- and Nck-interacting kinase (TNIK or MAP4K7), and misshapen-like kinase 1 (MINK1 or MAP4K6) in regulating DLK/JNK signaling in neurons. Inhibition of

TGF-β1 is Involved in Vitamin D-Induced Chondrogenic Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells by Regulating the ERK/JNK Pathway

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Xiaorui Jiang

2017-08-01

Full Text Available Background/Aims: Osteoarthritis (OA is characterized by degradation of cartilage, sole cell type of which is chondrocytes. Bone marrow-derived mesenchymal stem cells (BMSCs possess multipotency and can be directionally differentiated into chondrocytes under stimulation. This study was aimed to explore the possible roles of vitamin D and transforming growth factor-β1 (TGF-β1 in the chondrogenic differentiation of BMSCs. Methods: BMSCs were isolated from femurs and tibias of rats and characterized by flow cytometry. After stimulation with vitamin D, BMSC proliferation and migration were measured by Cell Counting Kit-8 (CCK-8 and Transwell assays, respectively. Chondrogenic differentiation was estimated through expression levels of specific markers by qRT-PCR and Western blot analysis. After stable transfection, the effects of aberrantly expressed TGF-β1 on vitamin D-induced alterations, including BMSC viability, migration and chondrogenic differentiation, were all evaluated utilizing CCK-8 assay, Transwell assay, qRT-PCR and Western blot analysis. Finally, the phosphorylation levels of key kinases in the extracellular signal-regulated kinase (ERK and c-Jun N-terminal kinase (JNK pathways were determined by Western blot analysis. Results: Vitamin D remarkably promoted BMSC viability, migration and chondrogenic differentiation. These alterations of BMSCs induced by vitamin D were reinforced by TGF-β1 overexpression while were reversed by TGF-β1 silencing. Additionally, the phosphorylation levels of ERK, JNK and c-Jun were enhanced by TGF-β1 overexpression but were reduced by TGF-β1 knockdown. Conclusion: Vitamin D promoted BMSC proliferation, migration and chondrogenic differentiation. TGF-β1 might be implicated in the vitamin D-induced alterations of BMSCs through regulating ERK/JNK pathway.

Overexpressed DNA polymerase iota regulated by JNK/c-Jun contributes to hypermutagenesis in bladder cancer.

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Yuan, Fang; Xu, Zhigang; Yang, Mingzhen; Wei, Quanfang; Zhang, Yi; Yu, Jin; Zhi, Yi; Liu, Yang; Chen, Zhiwen; Yang, Jin

2013-01-01

Human DNA polymerase iota (pol ι) possesses high error-prone DNA replication features and performs translesion DNA synthesis. It may be specialized and strictly regulated in normal mammalian cells. Dysregulation of pol ι may contribute to the acquisition of a mutator phenotype. However, there are few reports describing the transcription regulatory mechanism of pol ι, and there is controversy regarding its role in carcinogenesis. In this study, we performed the deletion and point-mutation experiment, EMSA, ChIP, RNA interference and western blot assay to prove that c-Jun activated by c-Jun N-terminal kinase (JNK) regulates the transcription of pol ι in normal and cancer cells. Xeroderma pigmentosum group C protein (XPC) and ataxia-telangiectasia mutated related protein (ATR) promote early JNK activation in response to DNA damage and consequently enhance the expression of pol ι, indicating that the novel role of JNK signal pathway is involved in DNA damage response. Furthermore, associated with elevated c-Jun activity, the overexpression of pol ι is positively correlated with the clinical tumor grade in 97 bladder cancer samples and may contribute to the hypermutagenesis. The overexpressed pol ι-involved mutagenesis is dependent on JNK/c-Jun pathway in bladder cancer cells identifying by the special mutation spectra. Our results support the conclusion that dysregulation of pol ι by JNK/c-Jun is involved in carcinogenesis and offer a novel understanding of the role of pol ι or c-Jun in mutagenesis.

JNK and NADPH Oxidase Involved in Fluoride-Induced Oxidative Stress in BV-2 Microglia Cells

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Ling Yan

2013-01-01

Full Text Available Excessive fluoride may cause central nervous system (CNS dysfunction, and oxidative stress is a recognized mode of action of fluoride toxicity. In CNS, activated microglial cells can release more reactive oxygen species (ROS, and NADPH oxidase (NOX is the major enzyme for the production of extracellular superoxide in microglia. ROS have been characterized as an important secondary messenger and modulator for various mammalian intracellular signaling pathways, including the MAPK pathways. In this study we examined ROS production and TNF-α, IL-1β inflammatory cytokines releasing, and the expression of MAPKs in BV-2 microglia cells treated with fluoride. We found that fluoride increased JNK phosphorylation level of BV-2 cells and pretreatment with JNK inhibitor SP600125 markedly reduced the levels of intracellular and NO. NOX inhibitor apocynin and iNOS inhibitor SMT dramatically decreased NaF-induced ROS and NO generations, respectively. Antioxidant melatonin (MEL resulted in a reduction in JNK phosphorylation in fluoride-stimulated BV-2 microglia. The results confirmed that NOX and iNOS played an important role in fluoride inducing oxidative stress and NO production and JNK took part in the oxidative stress induced by fluoride and meanwhile also could be activated by ROS in fluoride-treated BV-2 cells.

JNK and NADPH Oxidase Involved in Fluoride-Induced Oxidative Stress in BV-2 Microglia Cells

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Yan, Ling; Liu, Shengnan; Wang, Chen; Wang, Fei; Song, Yingli; Yan, Nan; Xi, Shuhua; Liu, Ziyou; Sun, Guifan

2013-01-01

Excessive fluoride may cause central nervous system (CNS) dysfunction, and oxidative stress is a recognized mode of action of fluoride toxicity. In CNS, activated microglial cells can release more reactive oxygen species (ROS), and NADPH oxidase (NOX) is the major enzyme for the production of extracellular superoxide in microglia. ROS have been characterized as an important secondary messenger and modulator for various mammalian intracellular signaling pathways, including the MAPK pathways. In this study we examined ROS production and TNF-α, IL-1β inflammatory cytokines releasing, and the expression of MAPKs in BV-2 microglia cells treated with fluoride. We found that fluoride increased JNK phosphorylation level of BV-2 cells and pretreatment with JNK inhibitor SP600125 markedly reduced the levels of intracellular O2 ·− and NO. NOX inhibitor apocynin and iNOS inhibitor SMT dramatically decreased NaF-induced ROS and NO generations, respectively. Antioxidant melatonin (MEL) resulted in a reduction in JNK phosphorylation in fluoride-stimulated BV-2 microglia. The results confirmed that NOX and iNOS played an important role in fluoride inducing oxidative stress and NO production and JNK took part in the oxidative stress induced by fluoride and meanwhile also could be activated by ROS in fluoride-treated BV-2 cells. PMID:24072958

Amitriptyline induces early growth response-1 gene expression via ERK and JNK mitogen-activated protein kinase pathways in rat C6 glial cells.

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Chung, Eun Young; Shin, Soon Young; Lee, Young Han

2007-07-05

Astrocytes play important roles in guiding the construction of the nervous system, controlling extracellular ions and neurotransmitters, and regulating CNS synaptogenesis. Egr-1 is a transcription factor involved in neuronal differentiation and astrocyte cell proliferation. In this study, we investigated whether the tricyclic antidepressant (TCA) amitriptyline induces Egr-1 expression in astrocytes using rat C6 glioma cells as a model. We found that amitriptyline increased the expression of Egr-1 in a dose- and time-dependent manner. The amitriptyline-induced Egr-1 expression was mediated through serum response elements (SREs) in the Egr-1 promoter. SREs were activated by the Ets-domain transcription factor Elk-1 through the ERK and JNK mitogen-activated protein (MAP) kinase pathways. The inhibition of the ERK and JNK MAP kinase signals attenuated amitriptyline-induced transactivation of Gal4-Elk-1 and Egr-1 promoter activity. Our findings suggest that the induction of Egr-1 expression in astrocytes may be required to attain the therapeutic effects of antidepressant drugs.

Cantharidin Induced Oral Squamous Cell Carcinoma Cell Apoptosis via the JNK-Regulated Mitochondria and Endoplasmic Reticulum Stress-Related Signaling Pathways.

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Chin-Chuan Su

Full Text Available Oral cancer is a subtype of head and neck cancer which represents 2.65% of all human malignancies. Most of oral cancer is histopathologically diagnosed as oral squamous cell carcinoma (OSCC. OSCC is characterized by a high degree of local invasion and a high rate of metastasis to the cervical lymph nodes. How to prevention and treatment of OSCC is important and imperative. Here, we investigated the therapeutic effect and molecular mechanism of cantharidin, an active compound isolated from blister beetles, on OSCC in vitro. Results showed that cantharidin significantly decreased cell viability in human tongue squamous carcinoma-derived SAS, CAL-27, and SCC-4 cell lines. The further mechanistic studies were carried out in SAS cells. Cantharidin also significantly increased apoptosis-related signals, including caspase-9, caspase-7 and caspase-3 proteins. Besides, cantharidin decreased mitochondrial transmembrane potential (MMP and induced cytochrome c and apoptosis inducing factor (AIF release. Cantharidin also increased Bax, Bid, and Bak protein expressions and decreased Bcl-2 protein expression. Cantharidin could also increase the endoplasmic reticulum (ER stress signals, including the expressions of phosphorylated eIF-2α and CHOP, but not Grp78 and Grp94. Furthermore, cantharidin reduced pro-caspase-12 protein expression. In signals of mitogen-activated protein kinases, cantharidin increased the phosphorylation of JNK, but not ERK and p38. Transfection of shRNA-JNK to OSCC cells effectively reversed the cantharidin-induced cell apoptotic signals, including the mitochondrial and ER stress-related signaling molecules. Taken together, these findings suggest that cantharidin induces apoptosis in OSCC cells via the JNK-regulated mitochondria and ER stress-related signaling pathways.

Nucleolin and YB-1 are required for JNK-mediated interleukin-2 mRNA stabilization during T-cell activation

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Chen, C Y; Gherzi, R; Andersen, Jens S.

2000-01-01

Regulated mRNA turnover is a highly important process, but its mechanism is poorly understood. Using interleukin-2 (IL-2) mRNA as a model, we described a role for the JNK-signaling pathway in stabilization of IL-2 mRNA during T-cell activation, acting via a JNK response element (JRE) in the 5' un...

Lycium barbarum Polysaccharides Protect Rat Corneal Epithelial Cells against Ultraviolet B-Induced Apoptosis by Attenuating the Mitochondrial Pathway and Inhibiting JNK Phosphorylation

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Shaobo Du

2017-01-01

Full Text Available Lycium barbarum polysaccharides (LBPs have been shown to play a key role in protecting the eyes by reducing the apoptosis induced by certain types of damage. However, it is not known whether LBPs can protect damaged corneal cells from apoptosis. Moreover, no reports have focused on the role of LBPs in guarding against ultraviolet B- (UVB- induced apoptosis. The present study aimed to investigate the protective effect and underlying mechanism of LBPs against UVB-induced apoptosis in rat corneal epithelial (RCE cells. The results showed that LBPs significantly prevented the loss of cell viability and inhibited cell apoptosis induced by UVB in RCE cells. LBPs also inhibited UVB-induced loss of mitochondrial membrane potential, downregulation of Bcl-2, and upregulation of Bax and caspase-3. Finally, LBPs attenuated the phosphorylation of c-Jun NH2-terminal kinase (JNK triggered by UVB. In summary, LBPs protect RCE cells against UVB-induced damage and apoptosis, and the underlying mechanism involves the attenuation of the mitochondrial apoptosis pathway and the inhibition of JNK phosphorylation.

B7-H4 Treatment of T Cells Inhibits ERK, JNK, p38, and AKT Activation.

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Xiaojie Wang

Full Text Available B7-H4 is a newly identified B7 homolog that plays an important role in maintaining T-cell homeostasis by inhibiting T-cell proliferation and lymphokine-secretion. In this study, we investigated the signal transduction pathways inhibited by B7-H4 engagement in mouse T cells. We found that treatment of CD3(+ T cells with a B7-H4.Ig fusion protein inhibits anti-CD3 elicited T-cell receptor (TCR/CD28 signaling events, including phosphorylation of the MAP kinases, ERK, p38, and JNK. B7-H4.Ig treatment also inhibited the phosphorylation of AKT kinase and impaired its kinase activity as assessed by the phosphorylation of its endogenous substrate GSK-3. Expression of IL-2 is also reduced by B7-H4. In contrast, the phosphorylation state of the TCR proximal tyrosine kinases ZAP70 and lymphocyte-specific protein tyrosine kinase (LCK are not affected by B7-H4 ligation. These results indicate that B7-H4 inhibits T-cell proliferation and IL-2 production through interfering with activation of ERK, JNK, and AKT, but not of ZAP70 or LCK.

Soluble Receptor for Advanced Glycation End Product Ameliorates Chronic Intermittent Hypoxia Induced Renal Injury, Inflammation, and Apoptosis via P38/JNK Signaling Pathways

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Xu Wu

2016-01-01

Full Text Available Obstructive sleep apnea (OSA associated chronic kidney disease is mainly caused by chronic intermittent hypoxia (CIH triggered tissue damage. Receptor for advanced glycation end product (RAGE and its ligand high mobility group box 1 (HMGB1 are expressed on renal cells and mediate inflammatory responses in OSA-related diseases. To determine their roles in CIH-induced renal injury, soluble RAGE (sRAGE, the RAGE neutralizing antibody, was intravenously administered in a CIH model. We also evaluated the effect of sRAGE on inflammation and apoptosis. Rats were divided into four groups: (1 normal air (NA, (2 CIH, (3 CIH+sRAGE, and (4 NA+sRAGE. Our results showed that CIH accelerated renal histological injury and upregulated RAGE-HMGB1 levels involving inflammatory (NF-κB, TNF-α, and IL-6, apoptotic (Bcl-2/Bax, and mitogen-activated protein kinases (phosphorylation of P38, ERK, and JNK signal transduction pathways, which were abolished by sRAGE but p-ERK. Furthermore, sRAGE ameliorated renal dysfunction by attenuating tubular endothelial apoptosis determined by immunofluorescence staining of CD31 and TUNEL. These findings suggested that RAGE-HMGB1 activated chronic inflammatory transduction cascades that contributed to the pathogenesis of the CIH-induced renal injury. Inhibition of RAGE ligand interaction by sRAGE provided a therapeutic potential for CIH-induced renal injury, inflammation, and apoptosis through P38 and JNK pathways.

The anti-apoptotic and cardioprotective effects of salvianolic acid a on rat cardiomyocytes following ischemia/reperfusion by DUSP-mediated regulation of the ERK1/2/JNK pathway.

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Tongda Xu

Full Text Available The purpose of this study was to observe the effects of salvianolic acid A (SAA pretreatment on the myocardium during ischemia/reperfusion (I/R and to illuminate the interrelationships among dual specificity protein phosphatase (DUSP 2/4/16, ERK1/2 and JNK pathways during myocardial I/R, with the ultimate goal of elucidating how SAA exerts cardioprotection against I/R injury (IRI. Wistar rats were divided into the following six groups: control group (CON, I/R group, SAA+I/R group, ERK1/2 inhibitor PD098059+I/R group (PD+I/R, PD+SAA+I/R group, and JNK inhibitor SP600125+I/R group (SP+I/R. The cardioprotective effects of SAA on the myocardium during I/R were investigated with a Langendorff device. Heart rate (HR, left ventricular systolic pressure (LVSP, left ventricular end-diastolic pressure (LVEDP, maximum rate of ventricular pressure rise and fall (±dp/dtmax, myocardial infarction areas (MIA, lactate dehydrogenase (LDH, and cardiomyocytes apoptosis were monitored. To determine the crosstalk betwee JNK and ERK1/2 via DUSP2/4/16 with SAA pretreatment, siRNA-DUSP2/4/16 were performed. The expression levels of Bcl-2, Bax, caspase 3, p-JNK, p-ERK1/2 and DUSP2/4/16 in cardiomyocytes were assayed by Western blot. Our results showed that LDH, MIA and cell apoptosis were decreased, and various parameters of heart function were improved by SAA pretreatment and SP application. In the I/R group, the expression levels of p-ERK1/2 and DUSP4/16 were not significantly different compared with the CON group, however, the protein expression levels of p-ERK1/2, Bcl-2 and DUSP4/16 were higher, while p-JNK, Bax, caspase 3 and DUSP2 levels were reduced among the SAA+I/R, PD+SAA+I/R and SP+I/R groups. The above indices were not significantly different between the SAA+I/R and SP+I/R groups. Compared with the SAA+I/R group, p-ERK1/2 was increased and p-JNK was decreased in the SAA+si-DUSP2+I/R, however, p-ERK was downregulated and p-JNK was upregulated in SAA+si-DUSP4

Inhibition of Spinal Interlukin-33/ST2 Signaling and Downstream ERK and JNK Pathways in Electroacupuncture Analgesia in Formalin Mice.

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Ping Han

Full Text Available Although acupuncture is widely used to manage pain, it remains highly controversial, largely due to the lack of a clear mechanism for its benefits. Here, we investigated the role of IL-33, a novel interleukin (IL-1 family member, and its receptor ST2 in the analgesic effects of electroacupuncture (EA on formalin-induced inflammatory pain. The results showed that 1 EA stimulation of ipsilateral Zusanli (ST 36 and Yanglingquan (GB 34 acupoints for 30 min remarkably suppressed the two phases of formalin-induced spontaneous pain; 2 subcutaneous or intrathecal administration of recombinant IL-33 (rIL-33 significantly inhibited the analgesic effect of EA, whereas the ST2 antibody potentiated EA analgesia in formalin mice; 3 EA treatment decreased the up-regulation of IL-33 and ST2 protein following formalin injection; and 4 the suppression of the formalin-induced expression of spinal phosphorylated ERK and JNK induced by EA treatment was significantly attenuated following subcutaneous rIL-33 delivery, and was further decreased by the ST2 antibody. These data suggest that EA alleviates formalin-induced inflammatory pain, at least partially, by inhibiting of spinal IL-33/ST2 signaling and the downstream ERK and JNK pathways.

Inhibition of Spinal Interlukin-33/ST2 Signaling and Downstream ERK and JNK Pathways in Electroacupuncture Analgesia in Formalin Mice

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Zhao, Jing; Wang, Yanqing; Wu, Gencheng; Mi, Wenli

2015-01-01

Although acupuncture is widely used to manage pain, it remains highly controversial, largely due to the lack of a clear mechanism for its benefits. Here, we investigated the role of IL-33, a novel interleukin (IL)-1 family member, and its receptor ST2 in the analgesic effects of electroacupuncture (EA) on formalin-induced inflammatory pain. The results showed that 1) EA stimulation of ipsilateral Zusanli (ST 36) and Yanglingquan (GB 34) acupoints for 30 min remarkably suppressed the two phases of formalin-induced spontaneous pain; 2) subcutaneous or intrathecal administration of recombinant IL-33 (rIL-33) significantly inhibited the analgesic effect of EA, whereas the ST2 antibody potentiated EA analgesia in formalin mice; 3) EA treatment decreased the up-regulation of IL-33 and ST2 protein following formalin injection; and 4) the suppression of the formalin-induced expression of spinal phosphorylated ERK and JNK induced by EA treatment was significantly attenuated following subcutaneous rIL-33 delivery, and was further decreased by the ST2 antibody. These data suggest that EA alleviates formalin-induced inflammatory pain, at least partially, by inhibiting of spinal IL-33/ST2 signaling and the downstream ERK and JNK pathways. PMID:26067287

Reactive oxygen species mediate nitric oxide production through ERK/JNK MAPK signaling in HAPI microglia after PFOS exposure

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Wang, Cheng; Nie, Xiaoke; Zhang, Yan [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Li, Ting; Mao, Jiamin [Department of Labor and Environmental Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Liu, Xinhang [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Gu, Yiyang; Shi, Jiyun [Department of Labor and Environmental Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Xiao, Jing [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Wan, Chunhua [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China); Wu, Qiyun, E-mail: wqy@ntu.edu.cn [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu 226001 (China)

2015-10-15

Perfluorooctane sulfonate (PFOS), an emerging persistent contaminant that is commonly encountered during daily life, has been shown to exert toxic effects on the central nervous system (CNS). However, the molecular mechanisms underlying the neurotoxicity of PFOS remain largely unknown. It has been widely acknowledged that the inflammatory mediators released by hyper-activated microglia play vital roles in the pathogenesis of various neurological diseases. In the present study, we examined the impact of PFOS exposure on microglial activation and the release of proinflammatory mediators, including nitric oxide (NO) and reactive oxidative species (ROS). We found that PFOS exposure led to concentration-dependent NO and ROS production by rat HAPI microglia. We also discovered that there was rapid activation of the ERK/JNK MAPK signaling pathway in the HAPI microglia following PFOS treatment. Moreover, the PFOS-induced iNOS expression and NO production were attenuated after the inhibition of ERK or JNK MAPK by their corresponding inhibitors, PD98059 and SP600125. Interestingly, NAC, a ROS inhibitor, blocked iNOS expression, NO production, and activation of ERK and JNK MAPKs, which suggested that PFOS-mediated microglial NO production occurs via a ROS/ERK/JNK MAPK signaling pathway. Finally, by exposing SH-SY5Y cells to PFOS-treated microglia-conditioned medium, we demonstrated that NO was responsible for PFOS-mediated neuronal apoptosis. - Highlights: • PFOS exposure induced expression of iNOS and production of NO in HAPI microglia. • PFOS induced the production of ROS in HAPI microglia. • ERK/JNK MAPK pathways were activated following PFOS exposure in HAPI microglia. • NO released by HAPI microglia participated in the apoptosis of SH-SY5Y cells.

Reactive oxygen species mediate nitric oxide production through ERK/JNK MAPK signaling in HAPI microglia after PFOS exposure

International Nuclear Information System (INIS)

Wang, Cheng; Nie, Xiaoke; Zhang, Yan; Li, Ting; Mao, Jiamin; Liu, Xinhang; Gu, Yiyang; Shi, Jiyun; Xiao, Jing; Wan, Chunhua; Wu, Qiyun

2015-01-01

Perfluorooctane sulfonate (PFOS), an emerging persistent contaminant that is commonly encountered during daily life, has been shown to exert toxic effects on the central nervous system (CNS). However, the molecular mechanisms underlying the neurotoxicity of PFOS remain largely unknown. It has been widely acknowledged that the inflammatory mediators released by hyper-activated microglia play vital roles in the pathogenesis of various neurological diseases. In the present study, we examined the impact of PFOS exposure on microglial activation and the release of proinflammatory mediators, including nitric oxide (NO) and reactive oxidative species (ROS). We found that PFOS exposure led to concentration-dependent NO and ROS production by rat HAPI microglia. We also discovered that there was rapid activation of the ERK/JNK MAPK signaling pathway in the HAPI microglia following PFOS treatment. Moreover, the PFOS-induced iNOS expression and NO production were attenuated after the inhibition of ERK or JNK MAPK by their corresponding inhibitors, PD98059 and SP600125. Interestingly, NAC, a ROS inhibitor, blocked iNOS expression, NO production, and activation of ERK and JNK MAPKs, which suggested that PFOS-mediated microglial NO production occurs via a ROS/ERK/JNK MAPK signaling pathway. Finally, by exposing SH-SY5Y cells to PFOS-treated microglia-conditioned medium, we demonstrated that NO was responsible for PFOS-mediated neuronal apoptosis. - Highlights: • PFOS exposure induced expression of iNOS and production of NO in HAPI microglia. • PFOS induced the production of ROS in HAPI microglia. • ERK/JNK MAPK pathways were activated following PFOS exposure in HAPI microglia. • NO released by HAPI microglia participated in the apoptosis of SH-SY5Y cells.

Genetic variants of JNK and p38α pathways and risk of non-small cell lung cancer in an Eastern Chinese population.

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Jia, Ming; Zhu, Meiling; Zhou, Fei; Wang, Mengyun; Sun, Menghong; Yang, Yajun; Wang, Xiaofeng; Wang, Jiucun; Jin, Li; Xiang, Jiaqing; Zhang, Yawei; Chang, Jianhua; Wei, Qingyi

2017-02-15

The JNK and p38α pathways play an important role in carcinogenesis. Therefore, we hypothesize that single nucleotide polymorphisms (SNPs) of genes involved in these pathways are associated with risk of lung cancer. We first selected and genotyped 11 independent SNPs of the JNK and p38α pathway-related genes in a discovery set of 1,002 non-small cell lung cancer (NSCLC) cases and 1,025 cancer-free controls of Eastern Chinese. Then, we validated those significant SNPs in a replication set of 1,333 NSCLC cases and 1,339 cancer-free controls of Eastern Chinese. Multifactor dimensionality reduction (MDR) and classification and regression tree (CART) analyses were used to identify interactions between significant SNPs and other covariates. In both discovery and replication as well as their pooled analysis, carriers of GADD45G rs8252T variant genotypes had a significantly lower risk of NSCLC (adjusted OR = 0.81 and 0.79, 95% CI = 0.72-0.92 and 0.64-0.99 and p = 0.001 and 0.040 for dominant and recessive genetic models, respectively) and carriers of MAP2K7 rs3679T variant genotypes had an increased risk of NSCLC (adjusted OR = 1.19 and 1.29, 95% CI = 1.05-1.34 and 1.09-1.54 and p = 0.005 and 0.004 for dominant and recessive genetic models, respectively). Furthermore, rs8252 variant CT/TT carriers showed significantly higher levels of GADD45G mRNA expression than CC carriers in the target tissues. We observed some evidence of interactions between rs8252 genotypes and sex in NSCLC risk. These results indicate that GADD45G rs8252 and MAP2K7 rs3679 SNPs may be susceptibility biomarkers for NSCLC in Eastern Chinese populations. © 2016 UICC.

Iodine-131 treatment of thyroid cancer cells leads to suppression of cell proliferation followed by induction of cell apoptosis and cell cycle arrest by regulation of B-cell translocation gene 2-mediated JNK/NF-κB pathways

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Zhao, L.M.; Pang, A.X., E-mail: zhaoliming515@126.com [Department of Nuclear Medicine, Linyi People' s Hospital, Linyi (China); Department of Urology, Linyi People' s Hospital, Linyi (China)

2017-10-01

Iodine-131 ({sup 131}I) is widely used for the treatment of thyroid-related diseases. This study aimed to investigate the expression of p53 and BTG2 genes following {sup 131}I therapy in thyroid cancer cell line SW579 and the possible underlying mechanism. SW579 human thyroid squamous carcinoma cells were cultured and treated with {sup 131}I. They were then assessed for {sup 131}I uptake, cell viability, apoptosis, cell cycle arrest, p53 expression, and BTG2 gene expression. SW579 cells were transfected with BTG2 siRNA, p53 siRNA and siNC and were then examined for the same aforementioned parameters. When treated with a JNK inhibitor of SP600125 and {sup 131}I or with a NF-kB inhibitor of BMS-345541 and {sup 131}I, non-transfected SW579 cells were assessed in JNK/NFkB pathways. It was observed that {sup 131}I significantly inhibited cell proliferation, promoted cell apoptosis and cell cycle arrest. Both BTG2 and p53 expression were enhanced in a dose-dependent manner. An increase in cell viability by up-regulation in Bcl2 gene, a decrease in apoptosis by enhanced CDK2 gene expression and a decrease in cell cycle arrest at G{sub 0}/G{sub 1} phase were also observed in SW579 cell lines transfected with silenced BTG2 gene. When treated with SP600125 and {sup 131}I, the non transfected SW579 cell lines significantly inhibited JNK pathway, NF-kB pathway and the expression of BTG2. However, when treated with BMS-345541 and {sup 131}I, only the NF-kB pathway was suppressed. {sup 131}I suppressed cell proliferation, induced cell apoptosis, and promoted cell cycle arrest of thyroid cancer cells by up-regulating B-cell translocation gene 2-mediated activation of JNK/NF--κB pathways. (author)

Leflunomide or A77 1726 protect from acetaminophen-induced cell injury through inhibition of JNK-mediated mitochondrial permeability transition in immortalized human hepatocytes

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Latchoumycandane, Calivarathan; Seah, Quee Ming; Tan, Rachel C.H.; Sattabongkot, Jetsumon; Beerheide, Walter; Boelsterli, Urs A.

2006-01-01

Leflunomide, a disease-modifying anti-rheumatic drug, protects against T-cell-mediated liver injury by poorly understood mechanisms. The active metabolite of leflunomide, A77 1726 (teriflunomide) has been shown to inhibit stress-activated protein kinases (JNK pathway), which are key regulators of mitochondria-mediated cell death. Therefore, we hypothesized that leflunomide may protect from drugs that induce the mitochondrial permeability transition (mPT) by blocking the JNK signaling pathway. To this end, we exposed cultured immortalized human hepatocytes (HC-04) to the standard protoxicant drug acetaminophen (APAP), which induces CsA-sensitive mPT-mediated cell death. We determined the effects of leflunomide on the extent of APAP-induced hepatocyte injury and the upstream JNK-mediated mitochondrial signaling pathways. We found that leflunomide or A77 1726 concentration-dependently protected hepatocytes from APAP (1 mM)-induced mitochondrial permeabilization and lethal cell injury. This was not due to proximal inhibition of CYP-catalyzed APAP bioactivation to its thiol-reactive metabolite. Instead, we demonstrate that leflunomide (20 μM) inhibited the APAP-induced early (3 h) activation (phosphorylation) of JNK1/2, thus inhibiting phosphorylation of the anti-apoptotic protein Bcl-2 and preventing P-Bcl-2-mediated induction of the mPT. This greatly attenuated mitochondrial cytochrome c release, which we used as a marker for mitochondrial permeabilization. The specific JNK2 inhibitor SP600125 similarly protected from APAP-induced cell death. In conclusion, these findings are consistent with our hypothesis that leflunomide protects from protoxicant-induced hepatocyte injury by inhibiting JNK signaling and preventing mPT induction

TRX-ASK1-JNK signaling regulation of cell density-dependent cytotoxicity in cigarette smoke-exposed human bronchial epithelial cells.

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Lee, Yong Chan; Chuang, Chun-Yu; Lee, Pak-Kei; Lee, Jin-Soo; Harper, Richart W; Buckpitt, Alan B; Wu, Reen; Oslund, Karen

2008-05-01

Cigarette smoke is a major environmental air pollutant that injures airway epithelium and incites subsequent diseases including chronic obstructive pulmonary disease. The lesion that smoke induces in airway epithelium is still incompletely understood. Using a LIVE/DEAD cytotoxicity assay, we observed that subconfluent cultures of bronchial epithelial cells derived from both human and monkey airway tissues and an immortalized normal human bronchial epithelial cell line (HBE1) were more susceptible to injury by cigarette smoke extract (CSE) and by direct cigarette smoke exposure than cells in confluent cultures. Scraping confluent cultures also caused an enhanced cell injury predominately in the leading edge of the scraped confluent cultures by CSE. Cellular ATP levels in both subconfluent and confluent cultures were drastically reduced after CSE exposure. In contrast, GSH levels were significantly reduced only in subconfluent cultures exposed to smoke and not in confluent cultures. Western blot analysis demonstrated ERK activation in both confluent and subconfluent cultures after CSE. However, activation of apoptosis signal-regulating kinase 1 (ASK1), JNK, and p38 were demonstrated only in subconfluent cultures and not in confluent cultures after CSE. Using short interfering RNA (siRNA) to JNK1 and JNK2 and a JNK inhibitor, we attenuated CSE-mediated cell death in subconfluent cultures but not with an inhibitor of the p38 pathway. Using the tetracycline (Tet)-on inducible approach, overexpression of thioredoxin (TRX) attenuated CSE-mediated cell death and JNK activation in subconfluent cultures. These results suggest that the TRX-ASK1-JNK pathway may play a critical role in mediating cell density-dependent CSE cytotoxicity.

The anti-epidermal growth factor receptor (EGFR) monoclonal antibody, C225, enhances radiation-induced apoptosis in primary glioma cell lines through mediation of MAPK/JNK/p38 signaling pathways

International Nuclear Information System (INIS)

Chakravarti, A.; Noll, E.; Black, P.M.; Loeffler, J.S.

2001-01-01

Purpose: Increasing evidence suggests that signaling mediated by the epidermal growth factor receptor (EGFR) pathway contributes to radiation resistance. The anti-EGFR monoclonal antibody, C225, has been shown to enhance radiation response for several tumor types in preclinical models. Malignant gliomas are known to express, and quite frequently overexpress, EGFR. Our objectives in this study were to 1) Evaluate the efficacy of C225 as a radiation response modifier in EGFR-expressing glioma cell lines and to 2) Investigate the underlying molecular mechanisms mediating C225-induced enhancement of radiation response. Materials and Methods: Twelve EGFR-expressing glioma cells lines, established from patient tumors, were used for this study. Cells were incubated with C225, irradiated, and then evaluated for radiation response. Assays used to evaluate efficacy of C225-mediated radiosensitization included time-course apoptosis assays (Annexin V and TUNEL), viability assays (MTT), and clonogenic survival assays. The changes along MAPK (p44/p42)/JNK/p38-MAPK signal transduction pathways were then investigated using quantitative Western analysis with phospho-specific antibodies to determine the molecular mechanisms by which C225 mediates a given response. Results: C225 clearly enhanced radiation response for 7 of the 12 primary glioma cell lines studied. Enhancement of both immediate and delayed apoptotic responses was evident in these 7 responsive cell lines after C225 administration. The average apoptosis index at 6 hours post-RT+C225 for the 7 responsive lines was 9.5%, compared to 1.2% for the RT-only controls. A pattern of delayed apoptosis was evident in these 7 lines, with secondary apoptotic peaks (∼ 8.0%) occurring at 24 hours post-RT+C225. Time course viability measurements revealed a steady decrease in viable tumor cells in these responsive cell lines from 75% at 6 hours post-RT+C225 to 20% at 7 days. Clonogenic survival was also diminished in these 7 lines

Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways

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Young Hyun Yoo

2012-11-01

Full Text Available Diallyl disulfide (DADS, a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound's anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4 and Fas ligand (FasL proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs, including extracellular-signal regulating kinase (ERK, p38 MAPK and c-Jun N-terminal kinase (JNK. A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059 and p38 MAPK (SB203580 had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.

GADD45a Regulates Olaquindox-Induced DNA Damage and S-Phase Arrest in Human Hepatoma G2 Cells via JNK/p38 Pathways

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Daowen Li

2017-01-01

Full Text Available Olaquindox, a quinoxaline 1,4-dioxide derivative, is widely used as a feed additive in many countries. The potential genotoxicity of olaquindox, hence, is of concern. However, the proper mechanism of toxicity was unclear. The aim of the present study was to investigate the effect of growth arrest and DNA damage 45 alpha (GADD45a on olaquindox-induced DNA damage and cell cycle arrest in HepG2 cells. The results showed that olaquindox could induce reactive oxygen species (ROS-mediated DNA damage and S-phase arrest, where increases of GADD45a, cyclin A, Cdk 2, p21 and p53 protein expression, decrease of cyclin D1 and the activation of phosphorylation-c-Jun N-terminal kinases (p-JNK, phosphorylation-p38 (p-p38 and phosphorylation-extracellular signal-regulated kinases (p-ERK were involved. However, GADD45a knockdown cells treated with olaquindox could significantly decrease cell viability, exacerbate DNA damage and increase S-phase arrest, associated with the marked activation of p-JNK, p-p38, but not p-ERK. Furthermore, SP600125 and SB203580 aggravated olaquindox-induced DNA damage and S-phase arrest, suppressed the expression of GADD45a. Taken together, these findings revealed that GADD45a played a protective role in olaquindox treatment and JNK/p38 pathways may partly contribute to GADD45a regulated olaquindox-induced DNA damage and S-phase arrest. Our findings increase the understanding on the molecular mechanisms of olaquindox.

Oxygen-Glucose-Deprivation/Reoxygenation-Induced Autophagic Cell Death Depends on JNK-Mediated Phosphorylation of Bcl-2

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Jin Fan

2016-03-01

Full Text Available Background/Aims: The purpose of this study was to investigate the role of autophagy in oxygen-glucose-deprivation/reoxygenation (OGD/R injury in rat neurons. Methods and results: Cortical neurons were isolated from Sprague-Dawley rats and identified by immunofluorescence. The cortical neurons were randomly assigned to one of four groups: control group (I, experimental group (OGD/R group, II, JNK inhibitor pretreatment group (III and JNK inhibitor pretreatment + OGD/R group (IV. Neuronal cell viability significantly decreased after 6h and 12h of reoxygenation in Group IV (P P Conclusion: The regulation of the JNK/Bcl-2/Beclin-1 signaling pathway may be one of the mechanisms underlying the OGD/R-induced autophagic cell death of neurons.

TNF-α decreases VEGF secretion in highly polarized RPE cells but increases it in non-polarized RPE cells related to crosstalk between JNK and NF-κB pathways.

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Hiroto Terasaki

Full Text Available Asymmetrical secretion of vascular endothelial growth factor (VEGF by retinal pigment epithelial (RPE cells in situ is critical for maintaining the homeostasis of the retina and choroid. VEGF is also involved in the development and progression of age-related macular degeneration (AMD. We studied the effect of tumor necrosis factor-α (TNF-α on the secretion of VEGF in polarized and non-polarized RPE cells (P-RPE cells and N-RPE cells, respectively in culture and in situ in rats. A subretinal injection of TNF-α caused a decrease in VEGF expression and choroidal atrophy. Porcine RPE cells were seeded on Transwell™ filters, and their maturation and polarization were confirmed by the asymmetrical VEGF secretion and trans electrical resistance. Exposure to TNF-α decreased the VEGF secretion in P-RPE cells but increased it in N-RPE cells in culture. TNF-α inactivated JNK in P-RPE cells but activated it in N-RPE cells, and TNF-α activated NF-κB in P-RPE cells but not in N-RPE cells. Inhibition of NF-κB activated JNK in both types of RPE cells indicating crosstalk between JNK and NF-κB. TNF-α induced the inhibitory effects of NF-κB on JNK in P-RPE cells because NF-κB is continuously inactivated. In N-RPE cells, however, it was not evident because NF-κB was already activated. The basic activation pattern of JNK and NF-κB and their crosstalk led to opposing responses of RPE cells to TNF-α. These results suggest that VEGF secretion under inflammatory conditions depends on cellular polarization, and the TNF-α-induced VEGF down-regulation may result in choroidal atrophy in polarized physiological RPE cells. TNF-α-induced VEGF up-regulation may cause neovascularization by non-polarized or non-physiological RPE cells.

Protective Effects of Green Tea Polyphenol Against Renal Injury Through ROS-Mediated JNK-MAPK Pathway in Lead Exposed Rats.

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Wang, Haidong; Li, Deyuan; Hu, Zhongze; Zhao, Siming; Zheng, Zhejun; Li, Wei

2016-06-30

To investigate the potential therapeutic effects of polyphenols in treating Pb induced renal dysfunction and intoxication and to explore the detailed underlying mechanisms. Wistar rats were divided into four groups: control groups (CT), Pb exposure groups (Pb), Pb plus Polyphenols groups (Pb+PP) and Polyphenols groups (PP). Animals were kept for 60 days and sacrificed for tests of urea, serum blood urea nitrogen (BUN) and creatinine. Histological evaluations were then performed. In vitro studies were performed using primary kidney mesangial cells to reveal detailed mechanisms. Cell counting kit-8 (CCK-8) was used to evaluate cell viability. Pb induced cell apoptosis was measured by flow cytometry. Reactive oxygen species (ROS) generation and scavenging were tested by DCFH-DA. Expression level of tumor necrosis factor-α (TNF-α), interleukin-1-β (IL-1-β) and IL-6 were assayed by ELISA. Western blot and qPCR were used to measure the expression of ERK1/2, JNK1/2 and p38. Polyphenols have obvious protective effects on Pb induced renal dysfunction and intoxication both in vivo and in vitro. Polyphenols reduced Pb concentration and accumulation in kidney. Polyphenols also protected kidney mesangial cells from Pb induced apoptosis. Polyphenols scavenged Pb induced ROS generation and suppressed ROS-mediated ERK/JNK/p38 pathway. Downstream pro-inflammatory cytokines were inhibited in consistency. Polyphenol is protective in Pb induced renal intoxication and inflammatory responses. The underlying mechanisms lie on the antioxidant activity and ROS scavenging activity of polyphenols.

Allergen-Removed Rhus verniciflua Extract Induces Ovarian Cancer Cell Death via JNK Activation.

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Kang, Se-Hui; Hwang, In-Hu; Son, Eunju; Cho, Chong-Kwan; Choi, Jong-Soon; Park, Soo-Jung; Jang, Byeong-Churl; Lee, Kyung-Bok; Lee, Zee-Won; Lee, Jong Hoon; Yoo, Hwa-Seung; Jang, Ik-Soon

2016-01-01

Nuclear factor-[Formula: see text]B (NF-[Formula: see text]B)/Rel transcription factors are best known for their central roles in promoting cell survival in cancer. NF-[Formula: see text]B antagonizes tumor necrosis factor (TNF)-[Formula: see text]-induced apoptosis through a process involving attenuation of the c-Jun-N-terminal kinase (JNK). However, the role of JNK activation in apoptosis induced by negative regulation of NF-[Formula: see text]B is not completely understood. We found that allergen-removed Rhus verniciflua Stokes (aRVS) extract-mediated NF-[Formula: see text]B inhibition induces apoptosis in SKOV-3 ovarian cancer cells via the serial activation of caspases and SKOV-3 cells are most specifically suppressed by aRVS. Here, we show that in addition to activating caspases, aRVS extract negatively modulates the TNF-[Formula: see text]-mediated I[Formula: see text]B/NF-[Formula: see text]B pathway to promote JNK activation, which results in apoptosis. When the cytokine TNF-[Formula: see text] binds to the TNF receptor, I[Formula: see text]B dissociates from NF-[Formula: see text]B. As a result, the active NF-[Formula: see text]B translocates to the nucleus. aRVS extract (0.5[Formula: see text]mg/ml) clearly prevented NF-[Formula: see text]B from mobilizing to the nucleus, resulting in the upregulation of JNK phosphorylation. This subsequently increased Bax activation, leading to marked aRVS-induced apoptosis, whereas the JNK inhibitor SP600125 in aRVS extract treated SKOV-3 cells strongly inhibited Bax. Bax subfamily proteins induced apoptosis through caspase-3. Thus, these results indicate that aRVS extract contains components that inhibit NF-[Formula: see text]B signaling to upregulate JNK activation in ovarian cancer cells and support the potential of aRVS as a therapeutic agent for ovarian cancer.

Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase

International Nuclear Information System (INIS)

Chitnis, Nilesh S.; D'Costa, Susan M.; Paul, Eric R.; Bilimoria, Shaen L.

2008-01-01

Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIV XS ; 400 μg/ml), UV-irradiated virus (CIV UV ; 10 μg/ml) and CVPE (CIV protein extract; 10 μg/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 μg/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i. CIV UV or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIV UV particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV UV , CIV XS or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family Iridoviridae, apoptosis: (i) requires entry and

LPS-Induced Low-Grade Inflammation Increases Hypothalamic JNK Expression and Causes Central Insulin Resistance Irrespective of Body Weight Changes.

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Rorato, Rodrigo; Borges, Beatriz de Carvalho; Uchoa, Ernane Torres; Antunes-Rodrigues, José; Elias, Carol Fuzeti; Elias, Lucila Leico Kagohara

2017-07-04

Metabolic endotoxemia contributes to low-grade inflammation in obesity, which causes insulin resistance due to the activation of intracellular proinflammatory pathways, such as the c-Jun N-terminal Kinase (JNK) cascade in the hypothalamus and other tissues. However, it remains unclear whether the proinflammatory process precedes insulin resistance or it appears because of the development of obesity. Hypothalamic low-grade inflammation was induced by prolonged lipopolysaccharide (LPS) exposure to investigate if central insulin resistance is induced by an inflammatory stimulus regardless of obesity. Male Wistar rats were treated with single (1 LPS) or repeated injections (6 LPS) of LPS (100 μg/kg, IP) to evaluate the phosphorylation of the insulin receptor substrate-1 (IRS1), Protein kinase B (AKT), and JNK in the hypothalamus. Single LPS increased the expression of pIRS1, pAKT, and pJNK, whereas the repeated LPS treatment failed to recruit pIRS1 and pAKT. The 6 LPS treated rats showed increased total JNK and pJNK. The 6 LPS rats became unresponsive to the hypophagic effect induced by central insulin administration (12 μM/5 μL, ICV). Prolonged exposure to LPS (24 h) impaired the insulin-induced AKT phosphorylation and the translocation of the transcription factor forkhead box protein O1 (FoxO1) from the nucleus to the cytoplasm of the cultured hypothalamic GT1-7 cells. Central administration of the JNK inhibitor (20 μM/5 μL, ICV) restored the ability of insulin to phosphorylate IRS1 and AKT in 6 LPS rats. The present data suggest that an increased JNK activity in the hypothalamus underlies the development of insulin resistance during prolonged exposure to endotoxins. Our study reveals that weight gain is not mandatory for the development of hypothalamic insulin resistance and the blockade of proinflammatory pathways could be useful for restoring the insulin signaling during prolonged low-grade inflammation as seen in obesity.

Membrane-Type 1 Matrix Metal loproteinase Is Regulated by Sp1 through the Differential Activation of AKT, JNK, and ERK Pathways in Human Prostate Tumor Cells

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Isis C. Sroka

2007-05-01

Full Text Available We and other investigators have previously shown that membrane-type 1 matrix metalloproteinase (MT1-MMP is overexpressed in invasive prostate cancer cells. However, the mechanism for this expression is not known. Here, we show that MT1-MMP is minimally expressed in nonmalignant primary prostate cells, moderately expressed in DU-145 cells, and highly expressed in invasive PC-3 and PC-3N cells. Using human MT1-MMP promoter reporter plasmids and mobility shift assays, we show that Spi regulates MT1-MMP expression in DU-145, PC-3, and PC-3N cells and in PC3-N cells using chromatin immunoprecipitation analysis and silencing RNA. Investigation of signaling pathway showed that DU-145 cells express constitutively phosphorylated extracellular stress-regulated kinase (ERK, whereas PC-3 and PC-3N cells express constitutively phosphorylated AKT/PKB and c-Jun NH2 terminal kinase (JNK. We show that MT1-MMP and Spi levels are decreased in PC-3 and PC-3N cells when phosphatidylinositol-3 kinase and JNK are inhibited, and that MT1-MMP levels are decreased in DU-145 cells when MEK is inhibited. Transient transfection of PC-3 and PC-3N cells with a dominant-negative JNK or p85, and of DU-145 cells with a dominant negative ERK, reduces MT1-MMP promoter activity. These results indicate differential signaling control of Spi-mediated transcriptional regulation of MT1-MMP in prostate cancer cell lines.

Hyperoside Downregulates the Receptor for Advanced Glycation End Products (RAGE and Promotes Proliferation in ECV304 Cells via the c-Jun N-Terminal Kinases (JNK Pathway Following Stimulation by Advanced Glycation End-Products In Vitro

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Zhengyu Zhang

2013-11-01

Full Text Available Hyperoside is a major active constituent in many medicinal plants which are traditionally used in Chinese medicines for their neuroprotective, anti-inflammatory and antioxidative effects. The molecular mechanisms underlying these effects are unknown. In this study, quiescent ECV304 cells were treated in vitro with advanced glycation end products (AGEs in the presence or absence of hyperoside. The results demonstrated that AGEs induced c-Jun N-terminal kinases (JNK activation and apoptosis in ECV304 cells. Hyperoside inhibited these effects and promoted ECV304 cell proliferation. Furthermore, hyperoside significantly inhibited RAGE expression in AGE-stimulated ECV304 cells, whereas knockdown of RAGE inhibited AGE-induced JNK activation. These results suggested that AGEs may promote JNK activation, leading to viability inhibition of ECV304 cells via the RAGE signaling pathway. These effects could be inhibited by hyperoside. Our findings suggest a novel role for hyperoside in the treatment and prevention of diabetes.

KFC, a Ste20-like kinase with mitogenic potential and capability to activate the SAPK/JNK pathway.

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Yustein, J T; Li, D; Robinson, D; Kung, H J

2000-02-03

The Sterile-20 (Ste20) family of serine-threonine kinases has been implicated in the activation of the stress-activated protein kinase pathways. However, the physiological role has remained ambiguous for most of the investigated mammalian Ste20's. Here we report the cloning of a novel Ste20-like kinase, from chicken embryo fibroblast (CEF) cells, which we have named KFC, for Kinase From Chicken. The 898 amino acid full-length KFC protein contains an amino-terminal kinase domain, an adjacent downstream serine-rich region, and a C-terminal tail containing a coiled-coil domain. Here we show that the coiled-coil domain of KFC negatively regulates the intrinsic kinase activity. We have also identified a splice variant of KFC in which there is a 207 nucleotide in-frame deletion. This deletion of 69 amino acids encompasses the serine-rich region. These two isoforms, called KFCL, for full-length, and KFCS for spliced (or short) form, not only differ in structure, but also in biological properties. Stable CEF cells overexpressing KFCL, but not KFCS, have a significant increase in growth rate when compared to parental cells. This mitogenic effect is the first such reported for this family of kinases. Finally, we found that KFC, when activated by truncation of the regulatory C-terminus, has a specific activation of the stress-activated protein kinase (SAPK/JNK) pathway.

Chrysin inhibits tumor promoter-induced MMP-9 expression by blocking AP-1 via suppression of ERK and JNK pathways in gastric cancer cells.

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Yong Xia

Full Text Available Cell invasion is a crucial mechanism of cancer metastasis and malignancy. Matrix metalloproteinase-9 (MMP-9 is an important proteolytic enzyme involved in the cancer cell invasion process. High expression levels of MMP-9 in gastric cancer positively correlate with tumor aggressiveness and have a significant negative correlation with patients' survival times. Recently, mechanisms suppressing MMP-9 by phytochemicals have become increasingly investigated. Chrysin, a naturally occurring chemical in plants, has been reported to suppress tumor metastasis. However, the effects of chrysin on MMP-9 expression in gastric cancer have not been well studied. In the present study, we tested the effects of chrysin on MMP-9 expression in gastric cancer cells, and determined its underlying mechanism. We examined the effects of chrysin on MMP-9 expression and activity via RT-PCR, zymography, promoter study, and western blotting in human gastric cancer AGS cells. Chrysin inhibited phorbol-12-myristate 13-acetate (PMA-induced MMP-9 expression in a dose-dependent manner. Using AP-1 decoy oligodeoxynucleotides, we confirmed that AP-1 was the crucial transcriptional factor for MMP-9 expression. Chrysin blocked AP-1 via suppression of the phosphorylation of c-Jun and c-Fos through blocking the JNK1/2 and ERK1/2 pathways. Furthermore, AGS cells pretreated with PMA showed markedly enhanced invasiveness, which was partially abrogated by chrysin and MMP-9 antibody. Our results suggest that chrysin may exert at least part of its anticancer effect by controlling MMP-9 expression through suppression of AP-1 activity via a block of the JNK1/2 and ERK1/2 signaling pathways in gastric cancer AGS cells.

Genetic Correction of SOD1 Mutant iPSCs Reveals ERK and JNK Activated AP1 as a Driver of Neurodegeneration in Amyotrophic Lateral Sclerosis

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Akshay Bhinge

2017-04-01

Full Text Available Summary: Although mutations in several genes with diverse functions have been known to cause amyotrophic lateral sclerosis (ALS, it is unknown to what extent causal mutations impinge on common pathways that drive motor neuron (MN-specific neurodegeneration. In this study, we combined induced pluripotent stem cells-based disease modeling with genome engineering and deep RNA sequencing to identify pathways dysregulated by mutant SOD1 in human MNs. Gene expression profiling and pathway analysis followed by pharmacological screening identified activated ERK and JNK signaling as key drivers of neurodegeneration in mutant SOD1 MNs. The AP1 complex member JUN, an ERK/JNK downstream target, was observed to be highly expressed in MNs compared with non-MNs, providing a mechanistic insight into the specific degeneration of MNs. Importantly, investigations of mutant FUS MNs identified activated p38 and ERK, indicating that network perturbations induced by ALS-causing mutations converge partly on a few specific pathways that are drug responsive and provide immense therapeutic potential. : In this article, Bhinge, Stanton, and colleagues use genome editing of patient-derived iPSCs to model ALS phenotypic defects in vitro. Transcriptomic analysis of disease MNs reveals activation of MAPK, AP1, WNT, cell-cycle, and p53 signaling in ALS MNs. Pharmacological screening uncovers activated ERK and JNK signaling as therapeutic targets in ALS. Keywords: ALS, SOD1, FUS, CRISPR-Cas9, p38, ERK, JNK, WNT, TP53, JUN

JNK1 protects against glucolipotoxicity-mediated beta-cell apoptosis

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Prause, Michala; Christensen, Dan Ploug; Billestrup, Nils

2014-01-01

Pancreatic β-cell dysfunction is central to type 2 diabetes pathogenesis. Prolonged elevated levels of circulating free-fatty acids and hyperglycemia, also termed glucolipotoxicity, mediate β-cell dysfunction and apoptosis associated with increased c-Jun N-terminal Kinase (JNK) activity. Endoplas......Pancreatic β-cell dysfunction is central to type 2 diabetes pathogenesis. Prolonged elevated levels of circulating free-fatty acids and hyperglycemia, also termed glucolipotoxicity, mediate β-cell dysfunction and apoptosis associated with increased c-Jun N-terminal Kinase (JNK) activity....... Endoplasmic reticulum (ER) and oxidative stress are elicited by palmitate and high glucose concentrations further potentiating JNK activity. Our aim was to determine the role of the JNK subtypes JNK1, JNK2 and JNK3 in palmitate and high glucose-induced β-cell apoptosis. We established insulin-producing INS1...... INS1 cells showed increased apoptosis and cleaved caspase 9 and 3 compared to non-sense shRNA expressing control INS1 cells when exposed to palmitate and high glucose associated with increased CHOP expression, ROS formation and Puma mRNA expression. JNK2 shRNA expressing INS1 cells did not affect...

Vitamin E and Lycopene Reduce Coal Burning Fluorosis-induced Spermatogenic Cell Apoptosis via Oxidative Stress-mediated JNK and ERK Signaling Pathways.

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Tian, Yuan; Xiao, Yuehai; Wang, Bolin; Sun, Chao; Tang, Kaifa; Sun, Fa

2017-12-22

Although fluoride has been widely used in toothpaste, mouthwash, and drinking water to prevent dental caries, the excessive intake of fluoride can cause fluorosis which is associated with dental, skeletal, and soft tissue fluorosis. Recent evidences have drawn the attention to its adverse effects on male reproductive system that include spermatogenesis defect, sperm count loss, and sperm maturation impairment. Fluoride induces oxidative stress through the activation of mitogen activated protein kinase (MAPK) cascade which can lead to cell apoptosis. Vitamin E (VE) and lycopene are two common anti-oxidants, being protective to reactive oxygen species (ROS)-induced toxic effects. However, whether and how these two anti-oxidants prevent fluoride-induced spermatogenic cell apoptosis are largely unknown. In the present study, a male rat model for coal burning fluorosis was established and the histological lesions and spermatogenic cell apoptosis in rat testes were observed. The decreased expression of clusterin, a heterodimeric glycoprotein reported to regulate spermatogenic cell apoptosis, is detected in fluoride-treated rat testes. Interestingly, the co-administration with VE or lycopene reduced fluorosis-mediated testicular toxicity and rescued clusterin expression. Further, fluoride caused the enhanced Jun N-terminal kinase (JNK) and extracellular signal-regulated protein kinase (ERK) phosphorylation, which was reduced by VE or lycopene. Thus, VE and lycopene prevent coal burning fluorosis-induced spermatogenic cell apoptosis through the suppression of oxidative stress-mediated JNK and ERK signaling pathway, which could be an alternative therapeutic strategy for the treatment of fluorosis. ©2017 The Author(s).

The effect of menadione on glutathione S-transferase A1 (GSTA1): c-Jun N-terminal kinase (JNK) complex dissociation in human colonic adenocarcinoma Caco-2 cells.

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Adnan, Humaira; Antenos, Monica; Kirby, Gordon M

2012-10-02

Glutathione S-transferases (GSTs) act as modulators of mitogen-activated protein kinase signal transduction pathways via a mechanism involving protein-protein interactions. We have demonstrated that GSTA1 forms complexes with JNK and modifies JNK activation during cellular stress, but the factors that influence complex association and dissociation are unknown. We hypothesized that menadione causes dissociation of GSTA1-JNK complexes, activates JNK, and the consequences of menadione exposure depend on GSTA1 expression. We demonstrate that menadione causes GSTA1-JNK dissociation and JNK activation in preconfluent Caco-2 cells, whereas postconfluent cells are resistant to this effect. Moreover, preconfluent cells are more sensitive than postconfluent cells to menadione-induced cytotoxicity. Activation of JNK is transient since removal of menadione causes GSTA1 to re-associate with JNK reducing cytotoxicity. Over-expression and knockdown of GSTA1 did not alter JNK activation by menadione or sensitivity to menadione-induced cytotoxicity. These results indicate that GSTA1-JNK complex integrity does not affect the ability of menadione to activate JNK. N-acetyl cysteine prevents GSH depletion and blocks menadione-induced complex dissociation, JNK activation and inhibits menadione-induced cytotoxicity. JNK activation and inhibits menadione-induced cytotoxicity. The data suggest that the mechanism of menadione-induced JNK activation involves the production of reactive oxygen species, likely superoxide anion, and intracellular GSH levels play an important role in preventing GSTA1-JNK complex dissociation, subsequent JNK activation and induction of cytotoxicity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

UVC-induced apoptosis in Dubca cells is independent of JNK activation and p53Ser-15 phosphorylation

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Chathoth, Shahanas; Thayyullathil, Faisal; Hago, Abdulkader; Shahin, Allen; Patel, Mahendra; Galadari, Sehamuddin

2009-01-01

Ultraviolet C (UVC) irradiation in mammalian cell lines activates a complex signaling network that leads to apoptosis. By using Dubca cells as a model system, we report the presence of a UVC-induced apoptotic pathway that is independent of c-Jun N-terminal kinases (JNKs) activation and p53 phosphorylation at Ser 15 . Irradiation of Dubca cells with UVC results in a rapid JNK activation and phosphorylation of its downstream target c-Jun, as well as, phosphorylation of activating transcription factor 2 (ATF2). Pre-treatment with JNK inhibitor, SP600125, inhibited UVC-induced c-Jun phosphorylation without preventing UVC-induced apoptosis. Similarly, inhibition of UVC-induced p53 phosphorylation did not prevent Dubca cell apoptosis, suggesting that p53 Ser-15 phosphorylation is not associated with UVC-induced apoptosis signaling. The pan-caspase inhibitor z-VAD-fmk inhibited UVC-induced PARP cleavage, DNA fragmentation, and ultimately apoptosis of Dubca cells. Altogether, our study clearly indicates that UVC-induced apoptosis is independent of JNK and p53 activation in Dubca cells, rather, it is mediated through a caspase dependent pathway. Our findings are not in line with the ascribed critical role for JNKs activation, and downstream phosphorylation of targets such as c-Jun and ATF2 in UVC-induced apoptosis.

Mesenchymal Stem Cell Conditioned Medium Promotes Proliferation and Migration of Alveolar Epithelial Cells under Septic Conditions In Vitro via the JNK-P38 Signaling Pathway

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Jie Chen

2015-11-01

Full Text Available Background/Aims: Mesenchymal stem cell (MSC based therapies may be useful for treating acute respiratory distress syndrome (ARDS, but the underlying mechanisms are incompletely understood. We investigated the impact of human umbilical cord Wharton's jelly-derived MSC (hUC-MSC secreted factors on alveolar epithelial cells under septic conditions and determined the relevant intracellular signaling pathways. Methods: Human alveolar epithelial cells (AEC and primary human small airway epithelial cells (SAEC were subjected to lipopolysaccharide (LPS with or without the presence of hUC-MSC-conditioned medium (CM. Proliferation and migration of AEC and SAEC were determined via an MTT assay, a wound healing assay and a transwell migration assay (only for AEC. Protein phosphorylation was determined by western blot and the experiments were repeated in presence of small-molecule inhibitors. The hMSC-secretory proteins were identified by LC-MS/MS mass spectrometry. Results: MSC-CM enhanced proliferation and migration. Activation of JNK and P38, but not ERK, was required for the proliferation and migration of AEC and SAEC. Pretreatment of AEC or SAEC with SP600125, an inhibitor of JNK1 or SB200358, an inhibitor of P38, significantly reduced cell proliferation and migration. An array of proteins including TGF-beta receptor type-1, TGF-beta receptor type-2, Ras-related C3 botulinum toxin substrate 1 and Ras-related C3 botulinum toxin substrate 2 which influencing the proliferation and migration of AEC and SAEC were detected in MSC-CM. Conclusion: Our data suggest MSC promote epithelial cell repair through releasing a repertoire of paracrine factors via activation of JNK and P38 MAPK.

Heat shock instructs hESCs to exit from the self-renewal program through negative regulation of OCT4 by SAPK/JNK and HSF1 pathway.

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Byun, Kyunghee; Kim, Taek-Kyun; Oh, Jeehyun; Bayarsaikhan, Enkhjargal; Kim, Daesik; Lee, Min Young; Pack, Chan-Gi; Hwang, Daehee; Lee, Bonghee

2013-11-01

Environmental factors affect self-renewal of stem cells by modulating the components of self-renewal networks. Heat shock, an environmental factor, induces heat shock factors (HSFs), which up-regulate stress response-related genes. However, the link of heat shock to self-renewal of stem cells has not been elucidated yet. Here, we present the direct link of heat shock to a core stem cell regulator, OCT4, in the self-renewal network through SAPK/JNK and HSF1 pathway. We first showed that heat shock initiated differentiation of human embryonic stem cells (hESCs). Gene expression analysis revealed that heat shock increased the expression of many genes involved in cellular processes related to differentiation of stem cells. We then examined the effects of HSFs induced by heat shock on core self-renewal factors. Among HSFs, heat shock induced mainly HSF1 in hESCs. The HSF1 repressed the expression of OCT4, leading to the differentiation of hESCs and the above differentiation-related gene expression change. We further examined the effects of the upstream MAP (mitogen-activated protein) kinases of HSF1 on the repression of OCT4 expression by HSF1. Among the MAP kinases, SAPK/JNK controlled predominantly the repression of the OCT4 expression by HSF1. The direct link of heat shock to the core self-renewal regulator through SAPK/JNK and HSF1 provides a fundamental basis for understanding the effect of heat and other stresses involving activation of HSF1 on the self-renewal program and further controlling differentiation of hESCs in a broad spectrum of stem cell applications using these stresses. © 2013.

Protective effect of sauchinone against regional myocardial ischemia/reperfusion injury: inhibition of p38 MAPK and JNK death signaling pathways.

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Kim, Seok Jai; Jeong, Cheol Won; Bae, Hong Beom; Kwak, Sang Hyun; Son, Jong-Keun; Seo, Chang-Seob; Lee, Hyun-Jung; Lee, JongUn; Yoo, Kyung Yeon

2012-05-01

Sauchinone has been known to have anti-inflammatory and antioxidant effects. We determined whether sauchinone is beneficial in regional myocardial ischemia/reperfusion (I/R) injury. Rats were subjected to 20 min occlusion of the left anterior descending coronary artery, followed by 2 hr reperfusion. Sauchinone (10 mg/kg) was administered intraperitoneally 30 min before the onset of ischemia. The infarct size was measured 2 hr after resuming the perfusion. The expression of cell death kinases (p38 and JNK) and reperfusion injury salvage kinases (phosphatidylinositol-3-OH kinases-Akt, extra-cellular signal-regulated kinases [ERK1/2])/glycogen synthase kinase (GSK)-3β was determined 5 min after resuming the perfusion. Sauchinone significantly reduced the infarct size (29.0% ± 5.3% in the sauchinone group vs 44.4% ± 6.1% in the control, P death signaling pathways.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

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Nie, Shaobo [Department of Orthopaedics, PLA General Hospital, Beijing 100853 (China); Xu, Jiawei [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhang, Chenghua [Department of Orthopaedics, Changle County Hospital of Traditional Chinese Medicine, Weifang 262400 (China); Xu, Chen [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Liu, Ming, E-mail: ming_li4717@sina.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yu, Degang, E-mail: ydg163@126.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China)

2016-01-29

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

International Nuclear Information System (INIS)

Nie, Shaobo; Xu, Jiawei; Zhang, Chenghua; Xu, Chen; Liu, Ming; Yu, Degang

2016-01-01

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Suppression of cadmium-induced JNK/p38 activation and HSP70 family gene expression by LL-Z1640-2 in NIH3T3 cells

International Nuclear Information System (INIS)

Sugisawa, Nobusuke; Matsuoka, Masato; Okuno, Takeo; Igisu, Hideki

2004-01-01

When NIH3T3 cells were exposed to CdCl 2 , the three major mitogen-activated protein kinases (MAPKs), extracellular signal-regulated protein kinase (ERK), c-Jun NH 2 -terminal kinase (JNK), and p38, were phosphorylated in a time (1-9 h)- and dose (1-20 μM)-dependent manner. Treatment with a macrocyclic nonaketide compound, LL-Z1640-2 (10-100 ng/ml), suppressed the phosphorylation of MAPKs without affecting the total protein level in cells exposed to 10 μM CdCl 2 for 6 h. CdCl 2 -induced phosphorylation of c-Jun on Ser63 and that on Ser73, and resultant accumulation of total c-Jun protein were also suppressed by LL-Z1640-2 treatment. The in vitro kinase assays also showed significant inhibitory effects of LL-Z1640-2 (at 10 or 25 ng/ml) on JNK and p38 but less markedly. In contrast to JNK and p38, ERK activity was inhibited moderately only at 50 or 100 ng/ml LL-Z1640-2. On the other hand, other JNK inhibitors, SP600125 and L-JNKI1, failed to suppress CdCl 2 -induced activation of the JNK pathway. Among the mouse stress response genes upregulated in response to CdCl 2 exposure, the expressions of hsp68 (encoding for heat shock 70 kDa protein 1; Hsp70-1) and grp78 (encoding for 78 kDa glucose-regulated protein; Grp78) genes were suppressed by treatment with 25 ng/ml LL-Z1640-2. Thus, LL-Z1640-2 could suppress CdCl 2 -induced activation of JNK/p38 pathways and expression of HSP70 family genes in NIH3T3 cells. LL-Z1640-2 seems to be useful to analyze functions of toxic metal-induced JNK/p38 activation

The c-Jun N-terminal kinase pathway is critical for cell transformation by the latent membrane protein 1 of Epstein-Barr virus

International Nuclear Information System (INIS)

Kutz, Helmut; Reisbach, Gilbert; Schultheiss, Ute; Kieser, Arnd

2008-01-01

The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) transforms cells activating signal transduction pathways such as NF-κB, PI3-kinase, or c-Jun N-terminal kinase (JNK). Here, we investigated the functional role of the LMP1-induced JNK pathway in cell transformation. Expression of a novel dominant-negative JNK1 allele caused a block of proliferation in LMP1-transformed Rat1 fibroblasts. The JNK-specific inhibitor SP600125 reproduced this effect in Rat1-LMP1 cells and efficiently interfered with proliferation of EBV-transformed lymphoblastoid cells (LCLs). Inhibition of the LMP1-induced JNK pathway in LCLs caused the downregulation of c-Jun and Cdc2, the essential G2/M cell cycle kinase, which was accompanied by a cell cycle arrest of LCLs at G2/M phase transition. Moreover, SP600125 retarded tumor growth of LCLs in a xenograft model in SCID mice. Our data support a critical role of the LMP1-induced JNK pathway for proliferation of LMP1-transformed cells and characterize JNK as a potential target for intervention against EBV-induced malignancies

Inhibition of Phosphodiesterase 4 by FCPR03 Alleviates Lipopolysaccharide-Induced Depressive-Like Behaviors in Mice: Involvement of p38 and JNK Signaling Pathways

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Hui Yu

2018-02-01

Full Text Available Inflammatory responses induced by peripheral administration of lipopolysaccharide (LPS triggers depressive-like behavioral syndrome in rodents. Inhibition of phosphodiesterase 4 (PDE4 produces a robust anti-inflammatory effect in inflammatory cells. Unfortunately, archetypal PDE4 inhibitors cause intolerable gastrointestinal side-effects, such as vomiting and nausea. N-isopropyl-3-(cyclopropylmethoxy-4-difluoromethoxy benzamide (FCPR03 is a novel, selective PDE4 inhibitor with little, or no, emetic potency. Our previous studies show that FCPR03 is effective in attenuating neuroinflammation in mice treated with LPS. However, whether FCPR03 could exert antidepressant-like effect induced by LPS is largely unknown. In the present study, mice injected intraperitoneally (i.p. with LPS was established as an in vivo animal model of depression. The antidepressant-like activities of FCPR03 were evaluated using a tail suspension test, forced swimming test, and sucrose preference test. We demonstrated that administration of FCPR03 (1 mg/kg produced antidepressant-like effects in mice challenged by LPS, as evidenced by decreases in the duration of immobility in the forced swim and tail suspension tests, while no significant changes in locomotor activity were observed. FCPR03 also increased sucrose preference in mice treated with LPS. In addition, treatment with FCPR03 abolished the downregulation of brain-derived neurotrophic factor induced by LPS and decreased the level of corticosterone in plasma. Meanwhile, periphery immune challenge by LPS induced enhanced phosphorylation of p38-mitogen activated protein kinase (p38 and c-Jun N-terminal kinase (JNK in both the cerebral cortex and hippocampus in mice. Interestingly, treatment with FCPR03 significantly blocked the role of LPS and reduced the levels of phosphorylated p38 and JNK. Collectively, these results indicate that FCPR03 shows antidepressant-like effects in mice challenged by LPS, and the p38/JNK

Caffeic Acid Phenethyl Ester (Propolis Extract) Ameliorates Insulin Resistance by Inhibiting JNK and NF-κB Inflammatory Pathways in Diabetic Mice and HepG2 Cell Models.

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Nie, Jiarui; Chang, Yaning; Li, Yujia; Zhou, Yingjun; Qin, Jiawen; Sun, Zhen; Li, Haibin

2017-10-18

Caffeic acid phenethyl ester (CAPE), extracted from propolis, was evaluated for the ameliorative effects on insulin resistance and the mechanisms were identified, using non-insulin-dependent diabetes mellitus (NIDDM) model mice and insulin resistance (IR) model cells. After 5 weeks of CAPE supplementation, insulin sensitivity, hyperlipidemia, and peroxisome proliferator-activated receptor-α (PPAR-α) levels were improved in mice. Proinflammatory cytokines in serum and the expressions of tumor necrosis factor-alpha (TNF-α) mRNA in tissues were markedly downregulated from CAPE-treated mice. In vitro, CAPE supplement significantly improved glucose consumption, glucose uptake, glycogen content, and oxidative stress and decreased expression of glucose-6-phosphatase (G6Pase) mRNA in cells. Both in vivo and in vitro, CAPE enhanced p-Akt (Ser473) and p-insulin receptor substrate (IRS)-1 (Tyr612), but inhibited p-JNK (Thr183/Tyr185), p-NF-κB p65 (Ser536), and nuclear translocation of p-NF-κB p65 (Ser536). In summary, CAPE can ameliorate insulin resistance through modulation of JNK and NF-κB signaling pathway in mice and HepG2 cells.

Oral administration of curcumin suppresses production of matrix metalloproteinase (MMP)-1 and MMP-3 to ameliorate collagen-induced arthritis: inhibition of the PKCdelta/JNK/c-Jun pathway.

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Mun, Se Hwan; Kim, Hyuk Soon; Kim, Jie Wan; Ko, Na Young; Kim, Do Kyun; Lee, Beob Yi; Kim, Bokyung; Won, Hyung Sik; Shin, Hwa-Sup; Han, Jeung-Whan; Lee, Hoi Young; Kim, Young Mi; Choi, Wahn Soo

2009-09-01

We investigated whether oral administration of curcumin suppressed type II collagen-induced arthritis (CIA) in mice and its effect and mechanism on matrix metalloproteinase (MMP)-1 and MMP-3 production in CIA mice, RA fibroblast-like synoviocytes (FLS), and chondrocytes. CIA in mice was suppressed by oral administration of curcumin in a dose-dependent manner. Macroscopic observations were confirmed by histological examinations. Histological changes including infiltration of immune cells, synovial hyperplasia, cartilage destruction, and bone erosion in the hind paw sections were extensively suppressed by curcumin. The histological scores were consistent with clinical arthritis indexes. Production of MMP-1 and MMP-3 were inhibited by curcumin in CIA hind paw sections and tumor necrosis factor (TNF)-alpha-stimulated FLS and chondrocytes in a dose-dependent manner. As for the mechanism, curcumin inhibited activating phosphorylation of protein kinase Cdelta (PKCdelta) in CIA, FLS, and chondrocytes. Curcumin also suppressed the JNK and c-Jun activation in those cells. This study suggests that the suppression of MMP-1 and MMP-3 production by curcumin in CIA is mediated through the inhibition of PKCdelta and the JNK/c-Jun signaling pathway.

Outer Membrane Protein 25 of Brucella Activates Mitogen-Activated Protein Kinase Signal Pathway in Human Trophoblast Cells

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Jing Zhang

2017-12-01

Full Text Available Outer membrane protein 25 (OMP25, a virulence factor from Brucella, plays an important role in maintaining the structural stability of Brucella. Mitogen-activated protein kinase (MAPK signal pathway widely exists in eukaryotic cells. In this study, human trophoblast cell line HPT-8 and BALB/c mice were infected with Brucella abortus 2308 strain (S2308 and 2308ΔOmp25 mutant strain. The expression of cytokines and activation of MAPK signal pathway were detected. We found that the expressions of tumor necrosis factor-α, interleukin-1, and interleukin-10 (IL-10 were increased in HPT-8 cells infected with S2308 and 2308ΔOmp25 mutant. S2308 also activated p38 phosphorylation protein, extracellular-regulated protein kinases (ERK, and Jun-N-terminal kinase (JNK from MAPK signal pathway. 2308ΔOmp25 could not activate p38, ERK, and JNK branches. Immunohistochemistry experiments showed that S2308 was able to activate phosphorylation of p38 and ERK in BABL/c mice. However, 2308ΔOmp25 could weakly activate phosphorylation of p38 and ERK. These results suggest that Omp25 played an important role in the process of Brucella activation of the MAPK signal pathway.

Autophagy Stimulus Promotes Early HuR Protein Activation and p62/SQSTM1 Protein Synthesis in ARPE-19 Cells by Triggering Erk1/2, p38MAPK, and JNK Kinase Pathways

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Nicoletta Marchesi

2018-01-01

Full Text Available RNA-binding protein dysregulation and altered expression of proteins involved in the autophagy/proteasome pathway play a role in many neurodegenerative disease onset/progression, including age-related macular degeneration (AMD. HuR/ELAVL1 is a master regulator of gene expression in human physiopathology. In ARPE-19 cells exposed to the proteasomal inhibitor MG132, HuR positively affects at posttranscriptional level p62 expression, a stress response gene involved in protein aggregate clearance with a role in AMD. Here, we studied the early effects of the proautophagy AICAR + MG132 cotreatment on the HuR-p62 pathway. We treated ARPE-19 cells with Erk1/2, AMPK, p38MAPK, PKC, and JNK kinase inhibitors in the presence of AICAR + MG132 and evaluated HuR localization/phosphorylation and p62 expression. Two-hour AICAR + MG132 induces both HuR cytoplasmic translocation and threonine phosphorylation via the Erk1/2 pathway. In these conditions, p62 mRNA is loaded on polysomes and its translation in de novo protein is favored. Additionally, for the first time, we report that JNK can phosphorylate HuR, however, without modulating its localization. Our study supports HuR’s role as an upstream regulator of p62 expression in ARPE-19 cells, helps to understand better the early events in response to a proautophagy stimulus, and suggests that modulation of the autophagy-regulating kinases as potential therapeutic targets for AMD may be relevant.

Non-Smad signaling pathways.

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Mu, Yabing; Gudey, Shyam Kumar; Landström, Maréne

2012-01-01

Transforming growth factor-beta (TGFβ) is a key regulator of cell fate during embryogenesis and has also emerged as a potent driver of the epithelial-mesenchymal transition during tumor progression. TGFβ signals are transduced by transmembrane type I and type II serine/threonine kinase receptors (TβRI and TβRII, respectively). The activated TβR complex phosphorylates Smad2 and Smad3, converting them into transcriptional regulators that complex with Smad4. TGFβ also uses non-Smad signaling pathways such as the p38 and Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways to convey its signals. Ubiquitin ligase tumor necrosis factor (TNF)-receptor-associated factor 6 (TRAF6) and TGFβ-associated kinase 1 (TAK1) have recently been shown to be crucial for the activation of the p38 and JNK MAPK pathways. Other TGFβ-induced non-Smad signaling pathways include the phosphoinositide 3-kinase-Akt-mTOR pathway, the small GTPases Rho, Rac, and Cdc42, and the Ras-Erk-MAPK pathway. Signals induced by TGFβ are tightly regulated and specified by post-translational modifications of the signaling components, since they dictate the subcellular localization, activity, and duration of the signal. In this review, we discuss recent findings in the field of TGFβ-induced responses by non-Smad signaling pathways.

Prolonged duration of isoflurane anesthesia impairs spatial recognition memory through the activation of JNK1/2 in the hippocampus of mice.

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Jiang, Shan; Miao, Bei; Chen, Ying

2017-05-03

Postoperative cognitive dysfunction is a frequent complication with surgery and anesthesia, and the underlying mechanism is unclear. Our aim was to investigate the effect of different durations of isoflurane anesthesia on spatial recognition memory and activation of JNK1/2 in the hippocampus of mice. In the present study, adult male mice were anesthetized with isoflurane for different durations (1.5% isoflurane for 1, 2, and 4 h). Spatial recognition memory was determined using spontaneous alternation and two-trial recognition memory in Y-maze at 24 h after anesthesia. The activation of JNK1/2 in the hippocampus was tested using western blot. Mice treated with isoflurane for 4 h showed significantly decreased spontaneous alternations and decreased exploration parameters compared with the no anesthesia group, but this was not observed in mice treated with isoflurane for 1 or 2 h. The protein levels of p-JNK1/2 in the hippocampus were significantly increased at 10 min after isoflurane anesthesia for 1, 2, and 4 h compared with no anesthesia. However, only isoflurane anesthesia for 4 h still increased JNK1/2 and p-JNK1/2 levels at 24 h after anesthesia. We concluded that prolonged duration of isoflurane anesthesia maintained the activation of JNK1/2, which led to memory impairment at 24 h after anesthesia.

The Fanconi anemia pathway sensitizes to DNA alkylating agents by inducing JNK-p53-dependent mitochondrial apoptosis in breast cancer cells.

Science.gov (United States)

Zhao, Lin; Li, Yanlin; He, Miao; Song, Zhiguo; Lin, Shu; Yu, Zhaojin; Bai, Xuefeng; Wang, Enhua; Wei, Minjie

2014-07-01

The Fanconi anemia/BRCA (FA/BRCA) DNA damage repair pathway plays a pivotal role in the cellular response to DNA alkylating agents and greatly influences drug response in cancer treatment. However, the molecular mechanisms underlying the FA/BRCA pathway reversed resistance have received limited attention. In the present study, we investigated the effect of Fanconi anemia complementation group F protein (FANCF), a critical factor of the FA/BRCA pathway, on cancer cell apoptosis induced by DNA alkylating agents such as mitomycin c (MMC). We found that FANCF shRNA potentiated MMC-induced cytotoxicity and apoptosis in MCF-7 and MDA-MB-231 breast cancer cells. At a mechanistic level, FANCF shRNA downregulated the anti-apoptotic protein Bcl-2 and upregulated the pro-apoptotic protein Bax, accompanied by release of cyt-c and smac into the cytosol in MMC-treated cells. Furthermore, activation of caspase-3 and -9, other than caspase-8, cleavage of poly(ADP ribose) polymerase (PARP), and a decrease of mitochondrial membrane potential (MMP) indicated that involvement of the mitochondrial apoptotic pathway in FANCF silencing of MMC-treated breast cancer cells. A decrease in IAP family proteins XIAP and survivin were also observed following FANCF silencing in MMC-treated breast cancer cells. Notably, FANCF shRNA was able to increase p53 levels through activation of the JNK pathway in MMC-treated breast cancer cells. Furthermore, p53 inhibition using pifithrin-α abolished the induction of caspase-3 and PARP by FANCF shRNA and MMC, indicating that MMC-induced apoptosis is substantially enhanced by FANCF shRNA via p53-dependent mechanisms. To our knowledge, we provide new evidence for the potential application of FANCF as a chemosensitizer in breast cancer therapy.

Ionizing radiation induces PI3K-dependent JNK activation for amplifying mitochondrial dysfunction in human cervical cancer cells

International Nuclear Information System (INIS)

Kim, Min Jung; Choi, Soon Young; Bae, Sang Woo; Kang, Chang Mo; Lee, Yun Sil; Lee, Su Jae

2005-01-01

Ionizing radiation is one of the most commonly used treatments for a wide variety of tumors. Exposure of cells to ionizing radiation results in the simultaneous activation or down regulation of multiple signaling pathways, which play critical role in controlling cell death and cell survival after irradiation in a cell type specific manner. The molecular mechanism by which apoptotic cell death occurs in response to ionizing radiation has been widely explored but not precisely deciphered. Therefore an improved understanding of the mechanisms involved in radiation-induced apoptosis may ultimately provide novel strategies of intervention in specific signal transduction pathways to favorably alter the therapeutic ratio in the treatment of human malignancies. The aim of our investigation was to elucidate molecular mechanisms of the mitochondrial dysfunction mediated apoptotic cell death triggered by ionizing radiation in human cervical cancer cells. We demonstrated that ionizing radiation utilizes PI3K-JNK signaling pathway for amplifying mitochondrial dysfunction and susequent apoptotic cell death: We showed that PI3K-dependent JNK activation leads to transcriptional upregulation of Fas and the phosphorylation/inactivation of Bcl-2, resulting in mitochondrial dysfunction-mediated apoptotic cell death in response to ionizing radiation

Predicting pathway cross-talks in ankylosing spondylitis through investigating the interactions among pathways.

Science.gov (United States)

Gu, Xiang; Liu, Cong-Jian; Wei, Jian-Jie

2017-11-13

Given that the pathogenesis of ankylosing spondylitis (AS) remains unclear, the aim of this study was to detect the potentially functional pathway cross-talk in AS to further reveal the pathogenesis of this disease. Using microarray profile of AS and biological pathways as study objects, Monte Carlo cross-validation method was used to identify the significant pathway cross-talks. In the process of Monte Carlo cross-validation, all steps were iterated 50 times. For each run, detection of differentially expressed genes (DEGs) between two groups was conducted. The extraction of the potential disrupted pathways enriched by DEGs was then implemented. Subsequently, we established a discriminating score (DS) for each pathway pair according to the distribution of gene expression levels. After that, we utilized random forest (RF) classification model to screen out the top 10 paired pathways with the highest area under the curve (AUCs), which was computed using 10-fold cross-validation approach. After 50 bootstrap, the best pairs of pathways were identified. According to their AUC values, the pair of pathways, antigen presentation pathway and fMLP signaling in neutrophils, achieved the best AUC value of 1.000, which indicated that this pathway cross-talk could distinguish AS patients from normal subjects. Moreover, the paired pathways of SAPK/JNK signaling and mitochondrial dysfunction were involved in 5 bootstraps. Two paired pathways (antigen presentation pathway and fMLP signaling in neutrophil, as well as SAPK/JNK signaling and mitochondrial dysfunction) can accurately distinguish AS and control samples. These paired pathways may be helpful to identify patients with AS for early intervention.

Wound-Induced Polyploidization: Regulation by Hippo and JNK Signaling and Conservation in Mammals.

Science.gov (United States)

Losick, Vicki P; Jun, Albert S; Spradling, Allan C

2016-01-01

Tissue integrity and homeostasis often rely on the proliferation of stem cells or differentiated cells to replace lost, aged, or damaged cells. Recently, we described an alternative source of cell replacement- the expansion of resident, non-dividing diploid cells by wound-induced polyploidization (WIP). Here we show that the magnitude of WIP is proportional to the extent of cell loss using a new semi-automated assay with single cell resolution. Hippo and JNK signaling regulate WIP; unexpectedly however, JNK signaling through AP-1 limits rather than stimulates the level of Yki activation and polyploidization in the Drosophila epidermis. We found that polyploidization also quantitatively compensates for cell loss in a mammalian tissue, mouse corneal endothelium, where increased cell death occurs with age in a mouse model of Fuchs Endothelial Corneal Dystrophy (FECD). Our results suggest that WIP is an evolutionarily conserved homeostatic mechanism that maintains the size and synthetic capacity of adult tissues.

Efavirenz and 8-hydroxyefavirenz induce cell death via a JNK- and BimEL-dependent mechanism in primary human hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Bumpus, Namandje N., E-mail: nbumpus1@jhmi.edu

2011-12-15

Chronic use of efavirenz (EFV) has been linked to incidences of hepatotoxicity in patients receiving EFV to treat HIV-1. While recent studies have demonstrated that EFV stimulates hepatic cell death a role for the metabolites of efavirenz in this process has yet to be examined. In the present study, incubation of primary human hepatocytes with synthetic 8-hydroxyEFV (8-OHEFV), which is the primary metabolite of EFV, resulted in cell death, caspase-3 activation and reactive oxygen species formation. The metabolite exerted these effects at earlier time points and using lower concentrations than were required for the parent compound. In addition, pharmacological inhibition of cytochrome P450-dependent metabolism of EFV using 1-aminobenzotriazole markedly decreased reactive oxygen species formation and cell death. Treatment of primary human hepatocytes with EFV and 8-OHEFV also stimulated phosphorylation of c-Jun N-terminal kinase (JNK) as well as phosphorylation of the JNK substrate c-Jun. Further, the mRNA and protein expression of an isoform of Bim (Bcl-2 interacting mediator of cell death) denoted as BimEL, which is proapoptotic and has been shown to be modulated by JNK, was increased. Inhibition of JNK using SP600125 prevented the EFV- and 8-OHEFV-mediated cell death. Silencing of Bim using siRNA transfected into hepatocytes also prevented cell death resulting from 8-OHEFV-treatment. These data suggest that the oxidative metabolite 8-OHEFV is a more potent inducer of hepatic cell death than the parent compound EFV. Further, activation of the JNK signaling pathway and BimEL mRNA expression appear to be required for EFV- and 8-OHEFV-mediated hepatocyte death. -- Highlights: Black-Right-Pointing-Pointer 8-Hydroxyefavirenz is a more potent stimulator of cell death than efavirenz. Black-Right-Pointing-Pointer Efavirenz and 8-hydroxyefavirenz increase JNK activity and BimEL mRNA expression. Black-Right-Pointing-Pointer JNK and Bim are required for efavirenz- and 8

JNK Controls the Onset of Mitosis in Planarian Stem Cells and Triggers Apoptotic Cell Death Required for Regeneration and Remodeling

Science.gov (United States)

Almuedo-Castillo, María; Crespo, Xenia; Seebeck, Florian; Bartscherer, Kerstin; Salò, Emili; Adell, Teresa

2014-01-01

Regeneration of lost tissues depends on the precise interpretation of molecular signals that control and coordinate the onset of proliferation, cellular differentiation and cell death. However, the nature of those molecular signals and the mechanisms that integrate the cellular responses remain largely unknown. The planarian flatworm is a unique model in which regeneration and tissue renewal can be comprehensively studied in vivo. The presence of a population of adult pluripotent stem cells combined with the ability to decode signaling after wounding enable planarians to regenerate a complete, correctly proportioned animal within a few days after any kind of amputation, and to adapt their size to nutritional changes without compromising functionality. Here, we demonstrate that the stress-activated c-jun–NH2–kinase (JNK) links wound-induced apoptosis to the stem cell response during planarian regeneration. We show that JNK modulates the expression of wound-related genes, triggers apoptosis and attenuates the onset of mitosis in stem cells specifically after tissue loss. Furthermore, in pre-existing body regions, JNK activity is required to establish a positive balance between cell death and stem cell proliferation to enable tissue renewal, remodeling and the maintenance of proportionality. During homeostatic degrowth, JNK RNAi blocks apoptosis, resulting in impaired organ remodeling and rescaling. Our findings indicate that JNK-dependent apoptotic cell death is crucial to coordinate tissue renewal and remodeling required to regenerate and to maintain a correctly proportioned animal. Hence, JNK might act as a hub, translating wound signals into apoptotic cell death, controlled stem cell proliferation and differentiation, all of which are required to coordinate regeneration and tissue renewal. PMID:24922054

TNF{alpha} and IL-1{beta} are mediated by both TLR4 and Nod1 pathways in the cultured HAPI cells stimulated by LPS

Energy Technology Data Exchange (ETDEWEB)

Zheng, Wenwen; Zheng, Xuexing [College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province (China); Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136 (United States); Liu, Shue [Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136 (United States); Ouyang, Hongsheng [College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province (China); Levitt, Roy C.; Candiotti, Keith A. [Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136 (United States); Hao, Shuanglin, E-mail: shao@med.miami.edu [Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136 (United States)

2012-04-20

Highlights: Black-Right-Pointing-Pointer LPS induces proinflammatory cytokine release in HAPI cells. Black-Right-Pointing-Pointer JNK pathway is dependent on TLR4 signaling to release cytokines. Black-Right-Pointing-Pointer NF-{kappa}B pathway is dependent on Nod1 signaling to release cytokines. -- Abstract: A growing body of evidence recently suggests that glial cell activation plays an important role in several neurodegenerative diseases and neuropathic pain. Microglia in the central nervous system express toll-like receptor 4 (TLR4) that is traditionally accepted as the primary receptor of lipopolysaccharide (LPS). LPS activates TLR4 signaling pathways to induce the production of proinflammatory molecules. In the present studies, we verified the LPS signaling pathways using cultured highly aggressively proliferating immortalized (HAPI) microglial cells. We found that HAPI cells treated with LPS upregulated the expression of TLR4, phospho-JNK (pJNK) and phospho-NF-{kappa}B (pNF-{kappa}B), TNF{alpha} and IL-1{beta}. Silencing TLR4 with siRNA reduced the expression of pJNK, TNF{alpha} and IL-1{beta}, but not pNF-{kappa}B in the cells. Inhibition of JNK with SP600125 (a JNK inhibitor) decreased the expression of TNF{alpha} and IL-1{beta}. Unexpectedly, we found that inhibition of Nod1 with ML130 significantly reduced the expression of pNF-{kappa}B. Inhibition of NF-{kappa}B also reduced the expression of TNF{alpha} and IL-1{beta}. Nod1 ligand, DAP induced the upregulation of pNF-{kappa}B which was blocked by Nod1 inhibitor. These data indicate that LPS-induced pJNK is TLR4-dependent, and that pNF-{kappa}B is Nod1-dependent in HAPI cells treated with LPS. Either TLR4-JNK or Nod1-NF-{kappa}B pathways is involved in the expression of TNF{alpha} and IL-1{beta}.

The involvement of calcium and MAP kinase signaling pathways in the production of radiation-induced bystander effects.

LENUS (Irish Health Repository)

Lyng, F M

2006-04-01

Much evidence now exists regarding radiation-induced bystander effects, but the mechanisms involved in the transduction of the signal are still unclear. The mitogen-activated protein kinase (MAPK) pathways have been linked to growth factor-mediated regulation of cellular events such as proliferation, senescence, differentiation and apoptosis. Activation of multiple MAPK pathways such as the ERK, JNK and p38 pathways have been shown to occur after exposure of cells to radiation and a variety of other toxic stresses. Previous studies have shown oxidative stress and calcium signaling to be important in radiation-induced bystander effects. The aim of the present study was to investigate MAPK signaling pathways in bystander cells exposed to irradiated cell conditioned medium (ICCM) and the role of oxidative metabolism and calcium signaling in the induction of bystander responses. Human keratinocytes (HPV-G cell line) were irradiated (0.005-5 Gy) using a cobalt-60 teletherapy unit. The medium was harvested 1 h postirradiation and transferred to recipient HPV-G cells. Phosphorylated forms of p38, JNK and ERK were studied by immunofluorescence 30 min-24 h after exposure to ICCM. Inhibitors of the ERK pathway (PD98059 and U0126), the JNK pathway (SP600125), and the p38 pathway (SB203580) were used to investigate whether bystander-induced cell death could be blocked. Cells were also incubated with ICCM in the presence of superoxide dismutase, catalase, EGTA, verapamil, nifedipine and thapsigargin to investigate whether bystander effects could be inhibited because of the known effects on calcium homeostasis. Activated forms of JNK and ERK proteins were observed after exposure to ICCM. Inhibition of the ERK pathway appeared to increase bystander-induced apoptosis, while inhibition of the JNK pathway appeared to decrease apoptosis. In addition, reactive oxygen species, such as superoxide and hydrogen peroxide, and calcium signaling were found to be important modulators of

Expression and proliferation profiles of PKC, JNK and p38MAPK in physiologically stretched human bladder smooth muscle cells

International Nuclear Information System (INIS)

Wazir, Romel; Luo, De-Yi; Dai, Yi; Yue, Xuan; Tian, Ye; Wang, Kun-Jie

2013-01-01

Highlights: •Stretch induces proliferation in human bladder smooth muscle cells (HBSMC). •5% Equibiaxial elongation produces maximum proliferation. •Physiologic stretch decreases apoptotic cell death. •PKC is involved in functional modulation of bladder. •JNK and p38 are not involved in proliferating HBSMC. -- Abstract: Objective: To determine protein kinase C (PKC), c-Jun NH2-Terminal Kinase (JNK) and P38 mitogen-activated protein kinases (p38MAPK) expression levels and effects of their respective inhibitors on proliferation of human bladder smooth muscle cells (HBSMCs) when physiologically stretched in vitro. Materials and methods: HBSMCs were grown on silicone membrane and stretch was applied under varying conditions; (equibiaxial elongation: 2.5%, 5%, 10%, 15%, 20%, 25%), (frequency: 0.05, 0.1, 0.2, 0.5, 1 Hz). Optimal physiological stretch was established by assessing proliferation with 5-Bromo-2-deoxyuridine (BrdU) assay and flow cytometry. PKC, JNK and p38 expression levels were analyzed by Western blot. Specificity was maintained by employing specific inhibitors; (GF109203X for PKC, SP600125 for JNK and SB203580 for p38MAPK), in some experiments. Results: Optimum proliferation was observed at 5% equibiaxial stretch (BrdU: 0.837 ± 0.026 (control) to 1.462 ± 0.023)%, (P 0.05 SP600125) and (1.461 ± 0.01, P > 0.05 SB203580). These findings show that mechanical stretch can promote magnitude-dependent proliferative modulation through PKC and possibly JNK but not via p38MAPK in hBSMCs

Activation of the HMGB1-RAGE axis upregulates TH expression in dopaminergic neurons via JNK phosphorylation.

Science.gov (United States)

Kim, Soo Jeong; Ryu, Min Jeong; Han, Jeongsu; Jang, Yunseon; Kim, Jungim; Lee, Min Joung; Ryu, Ilhwan; Ju, Xianshu; Oh, Eungseok; Chung, Woosuk; Kweon, Gi Ryang; Heo, Jun Young

2017-11-04

The derangement of tyrosine hydroxylase (TH) activity reduces dopamine synthesis and is implicated in the pathogenesis of Parkinson's disease. However, the extracellular modulator and intracellular regulatory mechanisms of TH have yet to be identified. Recently, high-mobility group box 1 (HMGB1) was reported to be actively secreted from glial cells and is regarded as a mediator of dopaminergic neuronal loss. However, the mechanism for how HMGB1 affects TH expression, particularly through the receptor for advanced glycation endproducts (RAGE), has not yet been investigated. We found that recombinant HMGB1 (rHMGB1) upregulates TH mRNA expression via simultaneous activation of JNK phosphorylation, and this induction of TH expression is blocked by inhibitors of RAGE and JNK. To investigate how TH expression levels change through the HMGB1-RAGE axis as a result of MPP + toxicity, we co-treated SN4741 dopaminergic cells with MPP + and rHMGB1. rHMGB1 blocked the reduction of TH mRNA following MPP + treatment without altering cell survival rates. Our results suggest that HMGB1 upregulates TH expression to maintain dopaminergic neuronal function via activating RAGE, which is dependent on JNK phosphorylation. Copyright © 2017 Elsevier Inc. All rights reserved.

miR-181a regulates multiple pathways in hypopharyngeal ...

African Journals Online (AJOL)

Expression of four pathway reporters were significantly increased (p53/DNA damage, TGFβ, MAPK/ERK and MAPK/JNK), while expression of two pathway reporters were decreased (Wnt and NFkB) upon miR-181a down-regulation. Notch, Myc/Max, hypoxia and cell cycle/pRB-E2F pathways were not significantly affected ...

Asthmatic airway smooth muscle CXCL10 production: mitogen-activated protein kinase JNK involvement

Science.gov (United States)

Alrashdan, Yazan A.; Alkhouri, Hatem; Chen, Emily; Lalor, Daniel J.; Poniris, Maree; Henness, Sheridan; Brightling, Christopher E.; Burgess, Janette K.; Armour, Carol L.; Ammit, Alaina J.

2012-01-01

CXCL10 (IP10) is involved in mast cell migration to airway smooth muscle (ASM) bundles in asthma. We aimed to investigate the role of cytokine-induced MAPK activation in CXCL10 production by ASM cells from people with and without asthma. Confluent growth-arrested ASM cells were treated with inhibitors of the MAPKs ERK, p38, and JNK and transcription factor NF-κB, or vehicle, and stimulated with IL-1β, TNF-α, or IFN-γ, alone or combined (cytomix). CXCL10 mRNA and protein, JNK, NF-κB p65 phosphorylation, and Iκ-Bα protein degradation were assessed using real-time PCR, ELISA, and immunoblotting, respectively. Cytomix, IL-1β, and TNF-α induced CXCL10 mRNA expression more rapidly in asthmatic than nonasthmatic ASM cells. IL-1β and/or TNF-α combined with IFN-γ synergistically increased asthmatic ASM cell CXCL10 release. Inhibitor effects were similar in asthmatic and nonasthmatic cells, but cytomix-induced release was least affected, with only JNK and NF-κB inhibitors halving it. Notably, JNK phosphorylation was markedly less in asthmatic compared with nonasthmatic cells. However, in both, the JNK inhibitor SP600125 reduced JNK phosphorylation and CXCL10 mRNA levels but did not affect CXCL10 mRNA stability or Iκ-Bα degradation. Together, the JNK and NF-κB inhibitors completely inhibited their CXCL10 release. We concluded that, in asthmatic compared with nonasthmatic ASM cells, JNK activation was reduced and CXCL10 gene expression was more rapid following cytomix stimulation. However, in both, JNK activation did not regulate early events leading to NF-κB activation. Thus JNK and NF-κB provide independent therapeutic targets for limiting CXCL10 production and mast cell migration to the ASM in asthma. PMID:22387292

Bex2 regulates cell proliferation and apoptosis in malignant glioma cells via the c-Jun NH2-terminal kinase pathway

International Nuclear Information System (INIS)

Zhou, Xiuping; Meng, Qingming; Xu, Xuebin; Zhi, Tongle; Shi, Qiong; Wang, Yong; Yu, Rutong

2012-01-01

Highlights: ► The expression levels of Bex2 markedly increased in glioma tissues. ► Bex2 over-expression promoted cell proliferation, while its down-regulation inhibited cell growth. ► Bex2 down-regulation promoted cell apoptosis via JNK/c-Jun signaling pathway. -- Abstract: The function of Bex2, a member of the Brain Expressed X-linked gene family, in glioma is controversial and its mechanism is largely unknown. We report here that Bex2 regulates cell proliferation and apoptosis in malignant glioma cells via the c-Jun NH2-terminal kinase (JNK) pathway. The expression level of Bex2 is markedly increased in glioma tissues. We observed that Bex2 over-expression promotes cell proliferation, while down-regulation of Bex2 inhibits cell growth. Furthermore, Bex2 down-regulation promotes cell apoptosis and activates the JNK pathway; these effects were abolished by administration of the JNK specific inhibitor, (SP600125). Thus, Bex2 may be an important player during the development of glioma.

Fucoidan/FGF-2 induces angiogenesis through JNK- and p38-mediated activation of AKT/MMP-2 signalling

Energy Technology Data Exchange (ETDEWEB)

Kim, Beom Su [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-dong, Seo-gu, Daejeon 302-830 (Korea, Republic of); Park, Ji-Yun [Bonecell Biotech Inc., 77, Dunsan-dong, Seo-gu, Daejeon 302-830 (Korea, Republic of); Kang, Hyo-Jin [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kim, Hyung-Jin [Department of Microbiology, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Lee, Jun, E-mail: omslee@wku.ac.kr [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-dong, Seo-gu, Daejeon 302-830 (Korea, Republic of)

2014-08-08

Graphical abstract: Schematic diagram of the angiogenic activity mechanism by FGF-2/fucoidan treatment in HUVECs. Fucoidan enhances the FGF-2-induced phosphorylation of p38, JNK, and ERK MAPKs. However, p38 and JNK were involved in AKT phosphorylation and MMP-2 activation and resulted in enhanced angiogenic activity, such as tube formation and migration, in HUVECs. - Highlights: • The angiogenic activity of fucoidan in HUVECs was explored. • Fucoidan enhanced HUVEC proliferation, migration, and tube formation. • Fucoidan enhanced angiogenesis through p38 and JNK but not ERK in HUVECs. • Fucoidan targeted angiogenesis-mediated AKT/MMP-2 signalling in HUVECs. - Abstract: Angiogenesis is an important biological process in tissue development and repair. Fucoidan has previously been shown to potentiate in vitro tube formation in the presence of basic fibroblast growth factor (FGF-2). However, the underlying molecular mechanism remains largely unknown. This study was designed to investigate the action of fucoidan in angiogenesis in human umbilical vein endothelial cells (HUVECs) and to explore fucoidan-signalling pathways. First, we evaluated the effect of fucoidan on cell proliferation. Matrigel-based tube formation and wound healing assays were performed to investigate angiogenesis. Matrix metalloproteinase-2 (MMP-2) mRNA expression and activity levels were analysed by reverse transcription polymerase chain reaction (RT-PCR) and zymography, respectively. Additionally, phosphorylation of mitogen-activated protein kinases (MAPKs) and protein kinase B (AKT) was detected by Western blot. The results indicate that fucoidan treatment significantly increased cell proliferation in the presence of FGF-2. Moreover, compared to the effect of FGF-2 alone, fucoidan and FGF-2 had a greater effect on tube formation and cell migration, and this effect was found to be synergistic. Furthermore, fucoidan enhanced the phosphorylation of extracellular signal-regulated kinase (ERK

Fucoidan/FGF-2 induces angiogenesis through JNK- and p38-mediated activation of AKT/MMP-2 signalling

International Nuclear Information System (INIS)

Kim, Beom Su; Park, Ji-Yun; Kang, Hyo-Jin; Kim, Hyung-Jin; Lee, Jun

2014-01-01

Graphical abstract: Schematic diagram of the angiogenic activity mechanism by FGF-2/fucoidan treatment in HUVECs. Fucoidan enhances the FGF-2-induced phosphorylation of p38, JNK, and ERK MAPKs. However, p38 and JNK were involved in AKT phosphorylation and MMP-2 activation and resulted in enhanced angiogenic activity, such as tube formation and migration, in HUVECs. - Highlights: • The angiogenic activity of fucoidan in HUVECs was explored. • Fucoidan enhanced HUVEC proliferation, migration, and tube formation. • Fucoidan enhanced angiogenesis through p38 and JNK but not ERK in HUVECs. • Fucoidan targeted angiogenesis-mediated AKT/MMP-2 signalling in HUVECs. - Abstract: Angiogenesis is an important biological process in tissue development and repair. Fucoidan has previously been shown to potentiate in vitro tube formation in the presence of basic fibroblast growth factor (FGF-2). However, the underlying molecular mechanism remains largely unknown. This study was designed to investigate the action of fucoidan in angiogenesis in human umbilical vein endothelial cells (HUVECs) and to explore fucoidan-signalling pathways. First, we evaluated the effect of fucoidan on cell proliferation. Matrigel-based tube formation and wound healing assays were performed to investigate angiogenesis. Matrix metalloproteinase-2 (MMP-2) mRNA expression and activity levels were analysed by reverse transcription polymerase chain reaction (RT-PCR) and zymography, respectively. Additionally, phosphorylation of mitogen-activated protein kinases (MAPKs) and protein kinase B (AKT) was detected by Western blot. The results indicate that fucoidan treatment significantly increased cell proliferation in the presence of FGF-2. Moreover, compared to the effect of FGF-2 alone, fucoidan and FGF-2 had a greater effect on tube formation and cell migration, and this effect was found to be synergistic. Furthermore, fucoidan enhanced the phosphorylation of extracellular signal-regulated kinase (ERK

Axon Regeneration Is Regulated by Ets-C/EBP Transcription Complexes Generated by Activation of the cAMP/Ca2+ Signaling Pathways.

Directory of Open Access Journals (Sweden)

Chun Li

2015-10-01

Full Text Available The ability of specific neurons to regenerate their axons after injury is governed by cell-intrinsic regeneration pathways. In Caenorhabditis elegans, the JNK and p38 MAPK pathways are important for axon regeneration. Axonal injury induces expression of the svh-2 gene encoding a receptor tyrosine kinase, stimulation of which by the SVH-1 growth factor leads to activation of the JNK pathway. Here, we identify ETS-4 and CEBP-1, related to mammalian Ets and C/EBP, respectively, as transcriptional activators of svh-2 expression following axon injury. ETS-4 and CEBP-1 function downstream of the cAMP and Ca2+-p38 MAPK pathways, respectively. We show that PKA-dependent phosphorylation of ETS-4 promotes its complex formation with CEBP-1. Furthermore, activation of both cAMP and Ca2+ signaling is required for activation of svh-2 expression. Thus, the cAMP/Ca2+ signaling pathways cooperatively activate the JNK pathway, which then promotes axon regeneration.

C-Jun N-terminal kinase signalling pathway in response to cisplatin.

Science.gov (United States)

Yan, Dong; An, GuangYu; Kuo, Macus Tien

2016-11-01

Cisplatin (cis diamminedichloroplatinum II, cDDP) is one of the most effective cancer chemotherapeutic agents and is used in the treatment of many types of human malignancies. However, inherent tumour resistance is a major barrier to effective cisplatin therapy. So far, the mechanism of cDDP resistance has not been well defined. In general, cisplatin is considered to be a cytotoxic drug, for damaging DNA and inhibiting DNA synthesis, resulting in apoptosis via the mitochondrial death pathway or plasma membrane disruption. cDDP-induced DNA damage triggers signalling pathways that will eventually decide between cell life and death. As a member of the mitogen-activated protein kinases family, c-Jun N-terminal kinase (JNK) is a signalling pathway in response to extracellular stimuli, especially drug treatment, to modify the activity of numerous proteins locating in the mitochondria or the nucleus. Recent studies suggest that JNK signalling pathway plays a major role in deciding the fate of the cell and inducing resistance to cDDP-induced apoptosis in human tumours. c-Jun N-terminal kinase regulates several important cellular functions including cell proliferation, differentiation, survival and apoptosis while activating and inhibiting substrates for phosphorylation transcription factors (c-Jun, ATF2: Activating transcription factor 2, p53 and so on), which subsequently induce pro-apoptosis and pro-survival factors expression. Therefore, it is suggested that JNK signal pathway is a double-edged sword in cDDP treatment, simultaneously being a significant pro-apoptosis factor but also being associated with increased resistance to cisplatin-based chemotherapy. This review focuses on current knowledge concerning the role of JNK in cell response to cDDP, as well as their role in cisplatin resistance. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Ultrafine particles from diesel engines induce vascular oxidative stress via JNK activation.

Science.gov (United States)

Li, Rongsong; Ning, Zhi; Cui, Jeffery; Khalsa, Bhavraj; Ai, Lisong; Takabe, Wakako; Beebe, Tyler; Majumdar, Rohit; Sioutas, Constantinos; Hsiai, Tzung

2009-03-15

Exposure to particulate air pollution is linked to increased incidences of cardiovascular diseases. Ambient ultrafine particles (UFP) from diesel vehicle engines have been shown to be proatherogenic in ApoE knockout mice and may constitute a major cardiovascular risk in humans. We posited that circulating nano-sized particles from traffic pollution sources induce vascular oxidative stress via JNK activation in endothelial cells. Diesel UFP were collected from a 1998 Kenworth truck. Intracellular superoxide assay revealed that these UFP dose-dependently induced superoxide (O(2)(-)) production in human aortic endothelial cells (HAEC). Flow cytometry showed that UFP increased MitoSOX red intensity specific for mitochondrial superoxide. Protein carbonyl content was increased by UFP as an indication of vascular oxidative stress. UFP also up-regulated heme oxygenase-1 (HO-1) and tissue factor (TF) mRNA expression, and pretreatment with the antioxidant N-acetylcysteine significantly decreased their expression. Furthermore, UFP transiently activated JNK in HAEC. Treatment with the JNK inhibitor SP600125 and silencing of both JNK1 and JNK2 with siRNA inhibited UFP-stimulated O(2)(-) production and mRNA expression of HO-1 and TF. Our findings suggest that JNK activation plays an important role in UFP-induced oxidative stress and stress response gene expression.

JNK1 induces hedgehog signaling from stellate cells to accelerate liver regeneration in mice.

Science.gov (United States)

Langiewicz, Magda; Graf, Rolf; Humar, Bostjan; Clavien, Pierre A

2018-04-27

To improve outcomes of two-staged hepatectomies for large/multiple liver tumors, portal vein ligation (PVL) has been combined with parenchymal transection (coined ALPPS; Associated Liver Partition and Portal vein ligation for Staged hepatectomy) to greatly accelerate liver regeneration. In a novel ALPPS mouse model, we have reported paracrine Indian hedgehog (IHH) signaling from stellate cells as an early contributor to augmented regeneration. Here, we sought to identify upstream regulators of IHH. ALPPS in mice was compared against PVL and additional control surgeries. Potential IHH regulators were identified through in silico mining of transcriptomic data. JNK1 activity was reduced through SP600125 to evaluate its effects on IHH signaling. Recombinant IHH was injected after JNK diminution to substantiate their relationship during accelerated liver regeneration. Mining linked Ihh to Mapk8. JNK1 upregulation after ALPPS was validated and preceded the IHH peak. On immunofluorescence, JNK1 and IHH co-localized in ASMA-positive non-parenchymal cells. Inhibition of JNK1 prior to ALPPS surgery reduced liver weight gain to PVL levels and was accompanied by downregulation of hepatocellular proliferation and the IHH-GLI1-CCND1 axis. In JNK1-inhibited mice, recombinant IHH restored ALPPS-like acceleration of regeneration and re-elevated JNK1 activity, suggesting the presence of a positive IHH-JNK1 feedback loop. JNK1-mediated induction of IHH paracrine signaling from HSCs is essential for accelerated regeneration of parenchymal mass. The JNK1-IHH axis is a mechanism unique to ALPPS surgery and may point to therapeutic alternatives for patients with insufficient regenerative capacity. ALPPS, a novel two-staged hepatectomy, induces an unprecedented acceleration of liver regeneration to enable treatment of unresectable liver tumors. Here, we demonstrate JNK1-IHH signaling as a mechanism underlying the regenerative acceleration induced by ALPPS. Copyright © 2018 European

Neural Differentiation of Human Adipose Tissue-Derived Stem Cells Involves Activation of the Wnt5a/JNK Signalling

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Sujeong Jang

2015-01-01

Full Text Available Stem cells are a powerful resource for cell-based transplantation therapies, but understanding of stem cell differentiation at the molecular level is not clear yet. We hypothesized that the Wnt pathway controls stem cell maintenance and neural differentiation. We have characterized the transcriptional expression of Wnt during the neural differentiation of hADSCs. After neural induction, the expressions of Wnt2, Wnt4, and Wnt11 were decreased, but the expression of Wnt5a was increased compared with primary hADSCs in RT-PCR analysis. In addition, the expression levels of most Fzds and LRP5/6 ligand were decreased, but not Fzd3 and Fzd5. Furthermore, Dvl1 and RYK expression levels were downregulated in NI-hADSCs. There were no changes in the expression of ß-catenin and GSK3ß. Interestingly, Wnt5a expression was highly increased in NI-hADSCs by real time RT-PCR analysis and western blot. Wnt5a level was upregulated after neural differentiation and Wnt3, Dvl2, and Naked1 levels were downregulated. Finally, we found that the JNK expression was increased after neural induction and ERK level was decreased. Thus, this study shows for the first time how a single Wnt5a ligand can activate the neural differentiation pathway through the activation of Wnt5a/JNK pathway by binding Fzd3 and Fzd5 and directing Axin/GSK-3ß in hADSCs.

Cyr61/CCN1 induces CCL20 production by keratinocyte via activating p38 and JNK/AP-1 pathway in psoriasis.

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Li, Huidan; Li, Haichuan; Huo, Rongfen; Wu, Pinru; Shen, Zhengyu; Xu, Hui; Shen, Baihua; Li, Ningli

2017-10-01

Psoriasis is a common chronic skin disease characterized by epidermal hyperplasia and inflammation. Cysteine-rich angiogenic inducer 61 (Cyr61/CCN1) has recently been implicated in psoriasis pathogenesis by promoting keratinocyte activation. However, the mechanisms by which CCN1 enhances cutaneous inflammation are not fully understood. In this study, we investigated the role of CCN1 on the expression of CCL20 in human keratinocyte. By double-label immunofluorescence staining, we first identified that the expression of CCN1 colocalized well with CCL20 production in the epidermis of psoriasis skin lesion. Furthermore, in vivo, blocking or knockdown CCN1 expression ameliorated skin inflammation and reduced the expression of CCL20 in both imiquimod and IL-23-induced psoriasis-like mouse models, which indicated that CCN1 might be involved in the regulation of CCL20 production in psoriasis. Next, in vitro, we stimulated primary normal human epidermal keratinocyte (NHEK) with exogenous protein CCN1 and found that CCN1 directly upregulated CCL20 production independent of TNF-α, IL-22 and IL-17 pathway. Lastly, the signaling pathway study showed that CCN1 enhanced the binding of AP-1 to the CCL20 promoter via crosstalk with p38 and JNK. Our study demonstrates that CCN1 stimulates CCL20 production in vitro and in vivo, and thus supports the notion that overexpressed CCN1 in hyperproliferating keratinocyte is functionally involved in the recruitment of inflammatory cells to skin lesions affected by psoriasis. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Interference of silibinin with IGF-1R signalling pathways protects human epidermoid carcinoma A431 cells from UVB-induced apoptosis

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Liu, Weiwei; Otkur, Wuxiyar; Li, Lingzhi; Wang, Qiong; He, Hao; Zang, Linghe; Hayashi, Toshihiko; Tashiro, Shin-ichi; Onodera, Satoshi; Xia, Mingyu; Ikejima, Takashi

2013-01-01

Highlights: ► Silibinin protects A431 cells from UVB irradiation-induced apoptosis. ► Up-regulation of the IGF-1R-JNK/ERK pathways by UVB induces cell apoptosis. ► Silibinin inhibits IGF-1R pathways to repress caspase-8-mediated apoptosis. -- Abstract: Ultraviolet B (UVB) from sunlight is a major cause of cutaneous lesion. Silibinin, a traditional hepatic protectant, elicits protective effects against UVB-induced cellular damage. In A431 cells, the insulin-like growth factor-1 receptor (IGF-1R) was markedly up-regulated by UVB irradiation. The activation of the IGF-1R signalling pathways contributed to apoptosis of the cells rather than rescuing the cells from death. Up-regulated IGF-1R stimulated downstream mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinases (JNK) and extracellular signal-regulated protein kinases 1/2 (ERK1/2). The subsequent activation of caspase-8 and caspase-3 led to apoptosis. The activation of IGF-1R signalling pathways is the cause of A431 cell death. The pharmacological inhibitors and the small interfering RNA (siRNA) targeting IGF-1R suppressed the downstream activation of JNK/ERK-caspases to help the survival of the UVB-irradiated A431 cells. Indeed, silibinin treatment suppressed the IGF-1R-JNK/ERK pathways and thus protected the cells from UVB-induced apoptosis

Oxidative stress by layered double hydroxide nanoparticles via an SFK-JNK and p38-NF-κB signaling pathway mediates induction of interleukin-6 and interleukin-8 in human lung epithelial cells

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Choi SJ

2015-04-01

Full Text Available Soo-Jin Choi, Hee-Jeong Paek, Jin YuDepartment of Food Science and Technology, Seoul Women’s University, Seoul, Republic of KoreaAbstract: Anionic nanoclays are layered double hydroxide nanoparticles (LDH-NPs that have been shown to exhibit toxicity by inducing reactive oxidative species and a proinflammatory mediator in human lung epithelial A549 cells. However, the molecular mechanism responsible for this LDH-NP-induced toxicity and the relationship between oxidative stress and inflammatory events remains unclear. In this study, we focused on intracellular signaling pathways and transcription factors induced in response to oxidative stress caused by exposure to LDH-NPs in A549 cells. Mitogen-activated protein kinase (MAPK cascades, such as extracellular signal-regulated kinase, c-Jun-N-terminal kinase (JNK, and p38, were investigated as potential signaling mechanisms responsible for regulation of oxidative stress and cytokine release. Src family kinases (SFKs, which are known to mediate activation of MAPK, together with redox-sensitive transcription factors, including nuclear factor kappa B and nuclear factor-erythroid 2-related factor-2, were also investigated as downstream events of MAPK signaling. The results obtained suggest that LDH-NP exposure causes oxidative stress, leading to expression of antioxidant enzymes, such as catalase, glucose reductase, superoxide dismutase, and heme oxygenase-1, via a SFK-JNK and p38-nuclear factor kappa B signaling pathway. Further, activation of this signaling was also found to regulate release of inflammatory cytokines, including interleukin-6 and interleukin-8, demonstrating the inflammatory potential of LDH-NP.Keywords: layered double hydroxide, mitogen-activated protein kinases, Src family kinases, nuclear factor kappa B, oxidative stress, inflammatory cytokine

Nitric oxide-induced eosinophil apoptosis is dependent on mitochondrial permeability transition (mPT, JNK and oxidative stress: apoptosis is preceded but not mediated by early mPT-dependent JNK activation

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Ilmarinen-Salo Pinja

2012-08-01

Full Text Available Abstract Background Eosinophils are critically involved in the pathogenesis of asthma. Nitric oxide (NO is produced in high amounts in asthmatic lungs and has an important role as a regulator of lung inflammation. NO was previously shown to induce eosinophil apoptosis mediated via c-jun N-terminal kinase (JNK and caspases. Our aim was to clarify the cascade of events leading to NO-induced apoptosis in granulocyte macrophage-colony stimulating factor (GM-CSF-treated human eosinophils concentrating on the role of mitochondria, reactive oxygen species (ROS and JNK. Methods Apoptosis was determined by flow cytometric analysis of relative DNA content, by Annexin-V labelling and/or morphological analysis. Immunoblotting was used to study phospho-JNK (pJNK expression. Mitochondrial membrane potential was assessed by JC-1-staining and mitochondrial permeability transition (mPT by loading cells with calcein acetoxymethyl ester (AM and CoCl2 after which flow cytometric analysis was conducted. Statistical significance was calculated by repeated measures analysis of variance (ANOVA or paired t-test. Results NO-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP induced late apoptosis in GM-CSF-treated eosinophils. SNAP-induced apoptosis was suppressed by inhibitor of mPT bongkrekic acid (BA, inhibitor of JNK SP600125 and superoxide dismutase-mimetic AEOL 10150. Treatment with SNAP led to late loss of mitochondrial membrane potential. Additionally, we found that SNAP induces early partial mPT (1 h that was followed by a strong increase in pJNK levels (2 h. Both events were prevented by BA. However, these events were not related to apoptosis because SNAP-induced apoptosis was prevented as efficiently when BA was added 16 h after SNAP. In addition to the early and strong rise, pJNK levels were less prominently increased at 20–30 h. Conclusions Here we demonstrated that NO-induced eosinophil apoptosis is mediated via ROS, JNK and late mPT. Additionally

Endothelial Dysfunction in Human Diabetes Is Mediated by Wnt5a-JNK Signaling.

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Bretón-Romero, Rosa; Feng, Bihua; Holbrook, Monika; Farb, Melissa G; Fetterman, Jessica L; Linder, Erika A; Berk, Brittany D; Masaki, Nobuyuki; Weisbrod, Robert M; Inagaki, Elica; Gokce, Noyan; Fuster, Jose J; Walsh, Kenneth; Hamburg, Naomi M

2016-03-01

Endothelial dysfunction is linked to insulin resistance, inflammatory activation, and increased cardiovascular risk in diabetes mellitus; however, the mechanisms remain incompletely understood. Recent studies have identified proinflammatory signaling of wingless-type family member (Wnt) 5a through c-jun N-terminal kinase (JNK) as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in 85 subjects with type 2 diabetes mellitus (n=42) and age- and sex-matched nondiabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Endothelial cells from patients with diabetes mellitus displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes mellitus. In endothelial cells from nondiabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In human aortic endothelial cells, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. Our findings demonstrate that noncanonical Wnt5a signaling and JNK activity contribute to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes mellitus. © 2016 American Heart

The HIV-1 Vpu protein induces apoptosis in Drosophila via activation of JNK signaling.

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Christelle Marchal

Full Text Available The genome of the human immunodeficiency virus type 1 (HIV-1 encodes the canonical retroviral proteins, as well as additional accessory proteins that enhance the expression of viral genes, the infectivity of the virus and the production of virions. The accessory Viral Protein U (Vpu, in particular, enhances viral particle production, while also promoting apoptosis of HIV-infected human T lymphocytes. Some Vpu effects rely on its interaction with the ubiquitin-proteasome protein degradation system, but the mechanisms responsible for its pro-apoptotic effects in vivo are complex and remain largely to be elucidated.We took advantage of the Drosophila model to study the effects of Vpu activity in vivo. Expression of Vpu in the developing Drosophila wing provoked tissue loss due to caspase-dependent apoptosis. Moreover, Vpu induced expression of the pro-apoptotic gene reaper, known to down-regulate Inhibitor of Apoptosis Proteins (IAPs which are caspase-antagonizing E3 ubiquitin ligases. Indeed, Vpu also reduced accumulation of Drosophila IAP1 (DIAP1. Though our results demonstrate a physical interaction between Vpu and the proteasome-addressing SLIMB/β-TrCP protein, as in mammals, both SLIMB/βTrCP-dependent and -independent Vpu effects were observed in the Drosophila wing. Lastly, the pro-apoptotic effect of Vpu in this tissue was abrogated upon inactivation of the c-Jun N-terminal Kinase (JNK pathway. Our results in the fly thus provide the first functional evidence linking Vpu pro-apoptotic effects to activation of the conserved JNK pathway.

Gardenia jasminoides extracts and gallic acid inhibit lipopolysaccharide-induced inflammation by suppression of JNK2/1 signaling pathways in BV-2 cells

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Wen-Hung Lin

2015-06-01

Conclusion:Taken together, these results indicate that the protective mechanism of the GJ extract involves an antioxidant effect and inhibition of JNK2/1 MAP kinase and COX-2 expressions in LPS-induced inflammation of BV-2 cells.

Data on the phosphorylation of p38MAPK and JNK induced by chlorpyrifos in Drosophila melanogaster

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J.E.S. Batista

2016-12-01

Full Text Available Exposure to organophosphate compounds, such as chlorpyrifos, has been linked to disturbances on cell signaling pathways. Mitogen activated protein kinases (MAPK are a family of protein kinases involved in a range of cellular processes, including stress response, apoptosis and survival. Therefore, changes in the activation state of these kinases may characterize key mechanisms of toxicity elicited by xenobiotics. Here we report data on the phosphorylation of p38MAPK and JNK, members of the MAPK family, in Drosophila melanogaster exposed to chlorpyrifos, as characterized by western blotting assays.

A role for protein phosphatase-2A in p38 mitogen-activated protein kinase-mediated regulation of the c-Jun NH(2)-terminal kinase pathway in human neutrophils.

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Avdi, Natalie J; Malcolm, Kenneth C; Nick, Jerry A; Worthen, G Scott

2002-10-25

Human neutrophil accumulation in inflammatory foci is essential for the effective control of microbial infections. Although exposure of neutrophils to cytokines such as tumor necrosis factor-alpha (TNFalpha), generated at sites of inflammation, leads to activation of MAPK pathways, mechanisms responsible for the fine regulation of specific MAPK modules remain unknown. We have previously demonstrated activation of a TNFalpha-mediated JNK pathway module, leading to apoptosis in adherent human neutrophils (Avdi, N. J., Nick, J. A., Whitlock, B. B., Billstrom, M. A., Henson, P. M., Johnson, G. L., and Worthen, G. S. (2001) J. Biol. Chem. 276, 2189-2199). Herein, evidence is presented linking regulation of the JNK pathway to p38 MAPK and the Ser/Thr protein phosphatase-2A (PP2A). Inhibition of p38 MAPK by SB 203580 and M 39 resulted in significant augmentation of TNFalpha-induced JNK and MKK4 (but not MKK7 or MEKK1) activation, whereas prior exposure to a p38-activating agent (platelet-activating factor) diminished the TNFalpha-induced JNK response. TNFalpha-induced apoptosis was also greatly enhanced upon p38 inhibition. Studies with a reconstituted cell-free system indicated the absence of a direct inhibitory effect of p38 MAPK on the JNK module. Neutrophil exposure to the Ser/Thr phosphatase inhibitors okadaic acid and calyculin A induced JNK activation. Increased phosphatase activity following TNFalpha stimulation was shown to be PP2A-associated and p38-dependent. Furthermore, PP2A-induced dephosphorylation of MKK4 resulted in its inactivation. Thus, in neutrophils, p38 MAPK, through a PP2A-mediated mechanism, regulates the JNK pathway, thus determining the extent and nature of subsequent responses such as apoptosis.

MAPK/JNK1 activation protects cells against cadmium-induced autophagic cell death via differential regulation of catalase and heme oxygenase-1 in oral cancer cells.

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So, Keum-Young; Kim, Sang-Hun; Jung, Ki-Tae; Lee, Hyun-Young; Oh, Seon-Hee

2017-10-01

Antioxidant enzymes are related to oral diseases. We investigated the roles of heme oxygenase-1 (HO-1) and catalase in cadmium (Cd)-induced oxidative stress and the underlying molecular mechanism in oral cancer cells. Exposing YD8 cells to Cd reduced the expression levels of catalase and superoxide dismutase 1/2 and induced the expression of HO-1 as well as autophagy and apoptosis, which were reversed by N-acetyl-l-cysteine (NAC). Cd-exposed YD10B cells exhibited milder effects than YD8 cells, indicating that Cd sensitivity is associated with antioxidant enzymes and autophagy. Autophagy inhibition via pharmacologic and genetic modulations enhanced Cd-induced HO-1 expression, caspase-3 cleavage, and the production of reactive oxygen species (ROS). Ho-1 knockdown increased autophagy and apoptosis. Hemin treatment partially suppressed Cd-induced ROS production and apoptosis, but enhanced autophagy and CHOP expression, indicating that autophagy induction is associated with cellular stress. Catalase inhibition by pharmacological and genetic modulations increased Cd-induced ROS production, autophagy, and apoptosis, but suppressed HO-1, indicating that catalase is required for HO-1 induction. p38 inhibition upregulated Cd-induced phospho-JNK and catalase, but suppressed HO-1, autophagy, apoptosis. JNK suppression exhibited contrary results, enhancing the expression of phospho-p38. Co-suppression of p38 and JNK1 failed to upregulate catalase and procaspase-3, which were upregulated by JNK1 overexpression. Overall, the balance between the responses of p38 and JNK activation to Cd appears to have an important role in maintaining cellular homeostasis via the regulation of antioxidant enzymes and autophagy induction. In addition, the upregulation of catalase by JNK1 activation can play a critical role in cell protection against Cd-induced oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

CPT-11 activates NLRP3 inflammasome through JNK and NF-κB signalings

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Li, Qian [Department of Oncology, The First Affiliated Hospital with Nanjing Medical University, 300, Guangzhou Road, Nanjing 210029 (China); Zhang, Xiong [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210046 (China); Wang, Weicheng; Li, LeLe [Department of Oncology, The First Affiliated Hospital with Nanjing Medical University, 300, Guangzhou Road, Nanjing 210029 (China); Xu, Qiang, E-mail: molpharm@163.com [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210046 (China); Wu, Xudong, E-mail: xudongwu@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210046 (China); Gu, Yanhong, E-mail: guluer@163.com [Department of Oncology, The First Affiliated Hospital with Nanjing Medical University, 300, Guangzhou Road, Nanjing 210029 (China)

2015-12-01

CPT-11 is widely used for cancer therapy as a chemotherapeutic agent. Despite its good efficacy, a large number of side effects appeared during decades of clinical application. Delayed diarrhea, at dose limiting toxicity, happens after 24 h of treatment and the rate of occurrence is up to 90%. Although many investments have been made on this negative impact, the real molecular mechanism of delayed diarrhea is poorly understood. In this study, we have discovered that CPT-11 promotes macrophage infiltration into intestinal tissues and activates the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome, resulting in a robust IL-1β response and colonic inflammation similar to DSS (dextran sodium sulfate) induced experimental colitis. CPT-11 plus LPS primed mouse bone marrow-derived macrophages (BMDMs) and human acute monocytic leukemia cells (THP-1 cells) staying in a highly activated status, showing increased caspase-1 activity and releasing great amounts of IL-1β and IL-18 as detected by ELISA and western blot. A further mechanism showed that JNK and NF-κB signaling pathways participated in inflammatory responses activated by CPT-11. These results prompted us to suggest that the NLRP3-IL-1β signaling pathway might play an important role in CPT11-induced colitis. Our findings provide a basis for developing novel strategies that improve clinical implications of CPT-11. - Highlights: • CPT-11 induced experimental colitis in vivo. • CPT-11 induced intestine injury and macrophage infiltration. • CPT-11 significantly elevated levels of macrophage derived inflammatory cytokines in mice intestines. • CPT-11 activated NLRP3 inflammasome in vitro and in vivo. • CPT-11 activated JNK and NF-κB signalings in THP-1 and BMDMs.

Black Rice Anthocyanins Suppress Metastasis of Breast Cancer Cells by Targeting RAS/RAF/MAPK Pathway.

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Chen, Xiang-Yan; Zhou, Jie; Luo, Li-Ping; Han, Bin; Li, Fei; Chen, Jing-Yao; Zhu, Yan-Feng; Chen, Wei; Yu, Xiao-Ping

2015-01-01

Overexpression of human epidermal growth factor receptor 2 (HER2) drives the biology of 30% of breast cancer cases. As a transducer of HER2 signaling, RAS/RAF/MAPK pathway plays a pivotal role in the development of breast cancer. In this study, we examined the molecular mechanisms underlying the chemopreventive effects of black rice anthocyanins (BRACs) extract and identified their molecular targets in HER2(+) breast cancer cells. Treatment of MDA-MB-453 cells (HER2(+)) with BRACs inhibited cell migration and invasion, suppressed the activation of mitogen-activated protein kinase kinase kinase (RAF), mitogen-activated protein kinase kinase (MEK), and c-Jun N-terminal kinase (JNK), and downregulated the secretion of matrix metalloproteinase 2 (MMP2) and MMP9. BRACs also weakened the interactions of HER2 with RAF, MEK, and JNK proteins, respectively, and decreased the mRNA expression of raf, mek, and jnk. Further, we found combined treatment with BRACs and RAF, MEK, or JNK inhibitors could enhance the antimetastatic activity, compared with that of each treatment. Transient transfection with small interfering RNAs (siRNAs) specific for raf, mek, and jnk inhibited their mRNA expression in MDA-MB-453 cells. Moreover, cotreatment with BRACs and siRNA induces a more remarkable inhibitory effect than that by either substance alone. In summary, our study suggested that BRACs suppress metastasis in breast cancer cells by targeting the RAS/RAF/MAPK pathway.

Biphasic effect of arsenite on cell proliferation and apoptosis is associated with the activation of JNK and ERK1/2 in human embryo lung fibroblast cells

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He Xiaoqing; Chen Rui; Yang Ping; Li Aiping; Zhou Jianwei; Liu Qizhan

2007-01-01

Biphasic dose-response relationship induced by environmental agents is often characterized with the effect of low-dose stimulation and high-dose inhibition. Some studies showed that arsenite may induce cell proliferation and apoptosis via biphasic dose-response relationship in human cells; however, mechanisms underlying this phenomenon are not well understood. In the present study, we aimed at investigating the relationship between biphasic effect of arsenite on cell proliferation and apoptosis and activation of JNK and ERK1/2 in human embryo lung fibroblast (HELF) cells. Our results demonstrated that cell proliferation may be stimulated at lower concentrations (0.1 and 0.5 μM) arsenite but inhibited at higher concentrations (5 and 10 μM). When cell apoptosis was used as the endpoint, the concentration-response curves were changed to U-shapes. During stimulation phospho-JNK levels were significantly increased at 3, 6, and 12 h after 0.1 or 0.5 μM arsenite exposure. Phospho-ERK1/2 levels were increased with different concentrations (0.1-10 μM) of arsenite at 6, 12, and 24 h. Blocking of JNK pathway with 20 μM SP600125 or ERK1/2 by 100 μM PD98059 significantly inhibited biphasic effect of arsenite in cells. Data in the present study suggest that activation of JNK and ERK1/2 may be involved in biphasic effect of arsenite when measuring cell proliferation and apoptosis in HELF cells. JNK activation seems to play a more critical role than ERK1/2 activation in the biphasic process

Loss of the HPV-infection resistance EVER2 protein impairs NF-κB signaling pathways in keratinocytes.

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Françoise Vuillier

Full Text Available Homozygous mutations in EVER genes cause epidermodysplasia verruciformis (EV, characterized by an immune defect and the development of skin cancers associated with β-human papillomavirus (HPV infections. The effects of EVER protein loss on the keratinocyte immune response remain unknown. We show here that EVER2 plays a critical role in the interplay between the NF-κB and JNK/AP-1 signaling pathways. EVER2-deficient cells overproduce IL-6 following the upregulation of JNK activation. They respond poorly to phorbol ester and TNF via the NF-κB pathway. They have lower levels of IKKα subunit, potentially accounting for impairments of p100 processing and the alternative NF-κB pathway. The loss of EVER2 is associated with an unusual TRAF protein profile. We demonstrate that EVER2 deficiency sustains TRAF2 ubiquitination and decreases the pool of TRAF2 available in the detergent-soluble fraction of the cell. Finally, we demonstrate that EVER2 loss induces constitutive PKCα-dependent c-jun phosphorylation and facilitates activation of the HPV5 long control region through a JNK-dependent pathway. These findings indicate that defects of the EVER2 gene may create an environment conducive to HPV replication and the persistence of lesions with the potential to develop into skin cancer.

Jnk2 effects on tumor development, genetic instability and replicative stress in an oncogene-driven mouse mammary tumor model.

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Peila Chen

2010-05-01

Full Text Available Oncogenes induce cell proliferation leading to replicative stress, DNA damage and genomic instability. A wide variety of cellular stresses activate c-Jun N-terminal kinase (JNK proteins, but few studies have directly addressed the roles of JNK isoforms in tumor development. Herein, we show that jnk2 knockout mice expressing the Polyoma Middle T Antigen transgene developed mammary tumors earlier and experienced higher tumor multiplicity compared to jnk2 wildtype mice. Lack of jnk2 expression was associated with higher tumor aneuploidy and reduced DNA damage response, as marked by fewer pH2AX and 53BP1 nuclear foci. Comparative genomic hybridization further confirmed increased genomic instability in PyV MT/jnk2-/- tumors. In vitro, PyV MT/jnk2-/- cells underwent replicative stress and cell death as evidenced by lower BrdU incorporation, and sustained chromatin licensing and DNA replication factor 1 (CDT1 and p21(Waf1 protein expression, and phosphorylation of Chk1 after serum stimulation, but this response was not associated with phosphorylation of p53 Ser15. Adenoviral overexpression of CDT1 led to similar differences between jnk2 wildtype and knockout cells. In normal mammary cells undergoing UV induced single stranded DNA breaks, JNK2 localized to RPA (Replication Protein A coated strands indicating that JNK2 responds early to single stranded DNA damage and is critical for subsequent recruitment of DNA repair proteins. Together, these data support that JNK2 prevents replicative stress by coordinating cell cycle progression and DNA damage repair mechanisms.

Gallic acid prevents isoproterenol-induced cardiac hypertrophy and fibrosis through regulation of JNK2 signaling and Smad3 binding activity

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Ryu, Yuhee; Jin, Li; Kee, Hae Jin; Piao, Zhe Hao; Cho, Jae Yeong; Kim, Gwi Ran; Choi, Sin Young; Lin, Ming Quan; Jeong, Myung Ho

2016-01-01

Gallic acid, a type of phenolic acid, has been shown to have beneficial effects in inflammation, vascular calcification, and metabolic diseases. The present study was aimed at determining the effect and regulatory mechanism of gallic acid in cardiac hypertrophy and fibrosis. Cardiac hypertrophy was induced by isoproterenol (ISP) in mice and primary neonatal cardiomyocytes. Gallic acid pretreatment attenuated concentric cardiac hypertrophy. It downregulated the expression of atrial natriuretic peptide, brain natriuretic peptide, and beta-myosin heavy chain in vivo and in vitro. Moreover, it prevented interstitial collagen deposition and expression of fibrosis-associated genes. Upregulation of collagen type I by Smad3 overexpression was observed in cardiac myoblast H9c2 cells but not in cardiac fibroblasts. Gallic acid reduced the DNA binding activity of phosphorylated Smad3 in Smad binding sites of collagen type I promoter in rat cardiac fibroblasts. Furthermore, it decreased the ISP-induced phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal regulated kinase (ERK) protein in mice. JNK2 overexpression reduced collagen type I and Smad3 expression as well as GATA4 expression in H9c2 cells and cardiac fibroblasts. Gallic acid might be a novel therapeutic agent for the prevention of cardiac hypertrophy and fibrosis by regulating the JNK2 and Smad3 signaling pathway. PMID:27703224

JNK mitogen-activated protein kinase limits calcium-dependent chloride secretion across colonic epithelial cells.

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Donnellan, Fergal

2010-01-01

Neuroimmune agonists induce epithelial Cl(-) secretion through elevations in intracellular Ca2+ or cAMP. Previously, we demonstrated that epidermal growth factor receptor (EGFR) transactivation and subsequent ERK MAPK activation limits secretory responses to Ca2+-dependent, but not cAMP-dependent, agonists. Although JNK MAPKs are also expressed in epithelial cells, their role in regulating transport function is unknown. Here, we investigated the potential role for JNK in regulating Cl(-) secretion in T(84) colonic epithelial cells. Western blot analysis revealed that a prototypical Ca2+-dependent secretagogue, carbachol (CCh; 100 microM), induced phosphorylation of both the 46-kDa and 54-kDa isoforms of JNK. This effect was mimicked by thapsigargin (TG), which specifically elevates intracellular Ca2+, but not by forskolin (FSK; 10 microM), which elevates cAMP. CCh-induced JNK phosphorylation was attenuated by the EGFR inhibitor, tyrphostin-AG1478 (1 microM). Pretreatment of voltage-clamped T(84) cells with SP600125 (2 microM), a specific JNK inhibitor, potentiated secretory responses to both CCh and TG but not to FSK. The effects of SP600125 on CCh-induced secretion were not additive with those of the ERK inhibitor, PD98059. Finally, in apically permeabilized T(84) cell monolayers, SP600125 potentiated CCh-induced K+ conductances but not Na+\\/K+ATPase activity. These data demonstrate a novel role for JNK MAPK in regulating Ca2+ but not cAMP-dependent epithelial Cl(-) secretion. JNK activation is mediated by EGFR transactivation and exerts its antisecretory effects through inhibition of basolateral K+ channels. These data further our understanding of mechanisms regulating epithelial secretion and underscore the potential for exploitation of MAPK-dependent signaling in treatment of intestinal transport disorders.

The accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in biphasic effects induced by different levels of arsenite in human bronchial epithelial cells

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Xu, Yuan; Li, Yuan; Li, Huiqiao; Pang, Ying; Zhao, Yue; Jiang, Rongrong; Shen, Lu; Zhou, Jianwei; Wang, Xinru; Liu, Qizhan

2013-01-01

The biphasic effects of arsenite, in which low levels of arsenite induce cell proliferation and high levels of arsenite induce DNA damage and apoptosis, apparently contribute to arsenite-induced carcinogenesis. However, the mechanisms underlying this phenomenon are not well understood. In this study, we investigated the effects of different levels of arsenite on cell proliferation, DNA damage and apoptosis as well as on signal transduction pathways in human bronchial epithelial (HBE) cells. Our results show that a low level of arsenite activates extracellular signal-regulated kinases (ERK), which probably mediate arsenite-inhibited degradation of ubiquitinated hypoxia-inducible factor-2α (HIF-2α) in HBE cells. ERK inhibition blocks cell proliferation induced by a low level of arsenite, in part via HIF-2α. In contrast, a high level of arsenite activates c-Jun N-terminal kinases (JNK), which provoke a response to suppress ubiquitinated HIF-1α degradation. Down-regulation of HIF-1α by inhibiting JNK, however, increases the DNA damage but decreases the apoptosis induced by a high level of arsenite. Thus, data in the present study suggest that the accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in different levels of arsenite-induced biphasic effects, with low levels of arsenite inducing cell proliferation and high levels of arsenite inducing DNA damage and apoptosis in HBE cells. -- Highlights: ► Biphasic effects induced by different concentrations of arsenite. ► Different regulation of ERK or JNK signal pathway by arsenite. ► Different regulation of HIF1α or HIF 2α by arsenite.

Synergistic apoptosis of CML cells by buthionine sulfoximine and hydroxychavicol correlates with activation of AIF and GSH-ROS-JNK-ERK-iNOS pathway.

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Avik Acharya Chowdhury

expression of inducible nitric oxide synthase (iNOS. iNOS- mediated production of NO was identified as an effector molecule causing apoptosis of CML cells. CONCLUSION/SIGNIFICANCE: BSO synergizes with HCH in inducing apoptosis of CML cells through the GSH-ROS-JNK-ERK-iNOS pathway.

Apelin-13 upregulates Egr-1 expression in rat vascular smooth muscle cells through the PI3K/Akt and PKC signaling pathways

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Liu, Qi-Feng [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Yu, Hong-Wei [Department of Cardiology, Jinzhou Central Hospital, Jinzhou 121001 (China); Sun, Li-Li [Department of Ophthalmology, The Third Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); You, Lu; Tao, Gui-Zhou [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Qu, Bao-Ze, E-mail: qubaoze1971@hotmail.com [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China)

2015-12-25

Previous studies have shown that Apelin-13 upregulates early growth response factor-1 (Egr-1) via the extracellular signal-regulated protein kinase (ERK) signaling pathway. Apelin-13 induces proliferation and migration of vascular smooth muscle cells (VSMCs) as well as the upregulation of osteopontin (OPN) via the upregulation of Egr-1. This study was designed to further explore the activity of Apelin-13 in VSMCs by investigating members of the mitogen-activated protein kinase (MAPK) family, in particular Jun kinase (JNK) and p38 mitogen-activated protein kinase (P38). We also examined whether the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) signaling pathways were involved in the regulation of Egr-1 by Apelin-13. We treated rat aortic VSMCs with Apelin-13 and examined the expression of JNK, p-JNK, P38, and p-P38 to investigate whether Apelin-13-mediated increases in Egr-1 occurred through the JNK and P38 signaling pathways. We then pretreated VSMCs with the Gi protein inhibitor pertussis toxin (PTX) and the Gq inhibitor YM254890, added Apelin-13 and looked for changes in Egr-1 expression. Finally, we pretreated with the PI3K inhibitor LY294002 and the PKC inhibitor GF109203X, and treated with Apelin-13. Our results showed that JNK and P38 did not participate in Apelin-13-mediated increase in Egr-1. Instead, Apelin-13 upregulation of Egr-1 was mediated by a PTX-sensitive Gi protein. Apelin-13 did increase ERK phosphorylation through the PI3K/Akt and PKC signaling pathways, resulting in changes in Egr-1 expression. These data provide important targets for future studies to modulate vascular remodeling. - Highlights: • Apelin-13 mediates Egr-1 upregulation in vascular smooth muscle cells via ERK1/2. • The underlying mechanisms are unknown, but exclude Jnk or p38 pathway activation. • Apelin-13 binds to Gi, activating the PI3K/Akt and PKC signaling cascades. • Consequent ERK phosphorylation results in increased Egr-1

Apelin-13 upregulates Egr-1 expression in rat vascular smooth muscle cells through the PI3K/Akt and PKC signaling pathways

International Nuclear Information System (INIS)

Liu, Qi-Feng; Yu, Hong-Wei; Sun, Li-Li; You, Lu; Tao, Gui-Zhou; Qu, Bao-Ze

2015-01-01

Previous studies have shown that Apelin-13 upregulates early growth response factor-1 (Egr-1) via the extracellular signal-regulated protein kinase (ERK) signaling pathway. Apelin-13 induces proliferation and migration of vascular smooth muscle cells (VSMCs) as well as the upregulation of osteopontin (OPN) via the upregulation of Egr-1. This study was designed to further explore the activity of Apelin-13 in VSMCs by investigating members of the mitogen-activated protein kinase (MAPK) family, in particular Jun kinase (JNK) and p38 mitogen-activated protein kinase (P38). We also examined whether the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) signaling pathways were involved in the regulation of Egr-1 by Apelin-13. We treated rat aortic VSMCs with Apelin-13 and examined the expression of JNK, p-JNK, P38, and p-P38 to investigate whether Apelin-13-mediated increases in Egr-1 occurred through the JNK and P38 signaling pathways. We then pretreated VSMCs with the Gi protein inhibitor pertussis toxin (PTX) and the Gq inhibitor YM254890, added Apelin-13 and looked for changes in Egr-1 expression. Finally, we pretreated with the PI3K inhibitor LY294002 and the PKC inhibitor GF109203X, and treated with Apelin-13. Our results showed that JNK and P38 did not participate in Apelin-13-mediated increase in Egr-1. Instead, Apelin-13 upregulation of Egr-1 was mediated by a PTX-sensitive Gi protein. Apelin-13 did increase ERK phosphorylation through the PI3K/Akt and PKC signaling pathways, resulting in changes in Egr-1 expression. These data provide important targets for future studies to modulate vascular remodeling. - Highlights: • Apelin-13 mediates Egr-1 upregulation in vascular smooth muscle cells via ERK1/2. • The underlying mechanisms are unknown, but exclude Jnk or p38 pathway activation. • Apelin-13 binds to Gi, activating the PI3K/Akt and PKC signaling cascades. • Consequent ERK phosphorylation results in increased Egr-1

TIPE attenuates the apoptotic effect of radiation and cisplatin and promotes tumor growth via JNK and p38 activation in Raw264.7 and EL4 cells.

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Liu, Yao; Ni, Xiao Yan; Chen, Rui Ling; Li, Juan; Gao, Feng Guang

2018-06-01

Tumor necrosis factor α‑induced protein 8 (TIPE) is highly expressed in many types of malignancies. Apoptosis is the process of programmed cell death which maintains the balance of cell survival and death. TIPE is involved in the carcinogenesis of many tumor types, yet the exact role of TIPE in defective apoptosis‑associated carcinogenesis remains uncertain. In the present study, TIPE‑overexpressing Raw264.7 and EL4 cells and vector control cells were treated with 4 mJ/cm2 ultraviolet radiation or 2 µg/ml cisplatin. Following ultraviolet irradiation, TIPE overexpression decreased the percentage of apoptotic cells as detected by flow cytometric and reversed the cisplatin‑mediated decrease in mitochondrial membrane potential by JC‑1 assay. Western blot analyses also revealed that TIPE overexpression inhibited cisplatin‑induced activation of caspase‑3 and ‑9 and PARP. Secondly, TIPE overexpression increased the levels of phosphorylated JNK, MEK and p38. Moreover, inhibition of JNK and p38, but not MEK, efficiently abolished the cell pro‑survival effect of TIPE. Most importantly, an in vivo tumor implantation model revealed that TIPE overexpression augmented the volume and weight of the implanted tumors, indicating that TIPE facilitated tumor formation. We found that TIPE exhibited an anti‑apoptotic effect via JNK and p38 activation, which ultimately promoted tumor. Hence, the present study revealed that activation of JNK and p38 kinases contribute to the TIPE‑mediated anti‑apoptotic effect, indicating that JNK and p38 may be potential therapeutic molecules for TIPE overexpression‑associated diseases.

WNT5A-JNK regulation of vascular insulin resistance in human obesity.

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Farb, Melissa G; Karki, Shakun; Park, Song-Young; Saggese, Samantha M; Carmine, Brian; Hess, Donald T; Apovian, Caroline; Fetterman, Jessica L; Bretón-Romero, Rosa; Hamburg, Naomi M; Fuster, José J; Zuriaga, María A; Walsh, Kenneth; Gokce, Noyan

2016-12-01

Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m 2 ) and five metabolically normal non-obese (BMI 26±2 kg/m 2 ) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (p<0.001), but preserved in non-obese individuals. Visceral adiposity was associated with increased JNK activation and elevated expression of WNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p<0.001), while endothelial cells exposed to recombinant WNT5A developed insulin resistance and impaired eNOS phosphorylation (p<0.05). We observed profound vascular insulin resistance in the visceral adipose tissue arterioles of obese subjects that was associated with up-regulated WNT5A-JNK signaling and impaired endothelial eNOS activation. Pharmacological JNK antagonism markedly improved vascular endothelial function, and may represent a potential therapeutic target in obesity-related vascular disease. © The Author(s) 2016.

Sex determination in honeybees: two separate mechanisms induce and maintain the female pathway

DEFF Research Database (Denmark)

Gempe, Tanja; Hasselmann, Martin; Schiøtt, Morten

2009-01-01

Organisms have evolved a bewildering diversity of mechanisms to generate the two sexes. The honeybee (Apis mellifera) employs an interesting system in which sex is determined by heterozygosity at a single locus (the Sex Determination Locus) harbouring the complementary sex determiner (csd) gene....... Bees heterozygous at Sex Determination Locus are females, whereas bees homozygous or hemizygous are males. Little is known, however, about the regulation that links sex determination to sexual differentiation. To investigate the control of sexual development in honeybees, we analyzed the functions...... and the regulatory interactions of genes involved in the sex determination pathway. We show that heterozygous csd is only required to induce the female pathway, while the feminizer (fem) gene maintains this decision throughout development. By RNAi induced knockdown we show that the fem gene is essential for entire...

Role of the Mixed-Lineage Protein Kinase Pathway in the Metabolic Stress Response to Obesity

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Shashi Kant

2013-08-01

Full Text Available Saturated free fatty acid (FFA is implicated in the metabolic response to obesity. In vitro studies indicate that FFA signaling may be mediated by the mixed-lineage protein kinase (MLK pathway that activates cJun NH2-terminal kinase (JNK. Here, we examined the role of the MLK pathway in vivo using a mouse model of diet-induced obesity. The ubiquitously expressed MLK2 and MLK3 protein kinases have partially redundant functions. We therefore compared wild-type and compound mutant mice that lack expression of MLK2 and MLK3. MLK deficiency protected mice against high-fat-diet-induced insulin resistance and obesity. Reduced JNK activation and increased energy expenditure contribute to the metabolic effects of MLK deficiency. These data confirm that the MLK pathway plays a critical role in the metabolic response to obesity.

Inhibiting Src family tyrosine kinase activity blocks glutamate signalling to ERK1/2 and Akt/PKB but not JNK in cultured striatal neurones.

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Crossthwaite, Andrew J; Valli, Haseeb; Williams, Robert J

2004-03-01

Glutamate receptor activation of mitogen-activated protein (MAP) kinase signalling cascades has been implicated in diverse neuronal functions such as synaptic plasticity, development and excitotoxicity. We have previously shown that Ca2+-influx through NMDA receptors in cultured striatal neurones mediates the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt/protein kinase B (PKB) through a phosphatidylinositol 3-kinase (PI 3-kinase)-dependent pathway. Exposing neurones to the Src family tyrosine kinase inhibitor PP2, but not the inactive analogue PP3, inhibited NMDA receptor-induced phosphorylation of ERK1/2 and Akt/PKB in a concentration-dependent manner, and reduced cAMP response element-binding protein (CREB) phosphorylation. To establish a link between Src family tyrosine kinase-mediated phosphorylation and PI 3-kinase signalling, affinity precipitation experiments were performed with the SH2 domains of the PI 3-kinase regulatory subunit p85. This revealed a Src-dependent phosphorylation of a focal adhesion kinase (FAK)-p85 complex on glutamate stimulation. Demonstrating that PI3-kinase is not ubiquitously involved in NMDA receptor signal transduction, the PI 3-kinase inhibitors wortmannin and LY294002 did not prevent NMDA receptor Ca2+-dependent phosphorylation of c-Jun N-terminal kinase 1/2 (JNK1/2). Further, inhibiting Src family kinases increased NMDA receptor-dependent JNK1/2 phosphorylation, suggesting that Src family kinase-dependent cascades may physiologically limit signalling to JNK. These results demonstrate that Src family tyrosine kinases and PI3-kinase are pivotal regulators of NMDA receptor signalling to ERK/Akt and JNK in striatal neurones.

Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

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Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

2010-06-15

CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation. 2010 Elsevier Ltd. All rights reserved.

ICOS and Bcl6-dependent pathways maintain a CD4 T cell population with memory-like properties during tuberculosis

Science.gov (United States)

Moguche, Albanus O.; Shafiani, Shahin; Clemons, Corey; Larson, Ryan P.; Dinh, Crystal; Higdon, Lauren E.; Cambier, C.J.; Sissons, James R.; Gallegos, Alena M.; Fink, Pamela J.

2015-01-01

Immune control of persistent infection with Mycobacterium tuberculosis (Mtb) requires a sustained pathogen-specific CD4 T cell response; however, the molecular pathways governing the generation and maintenance of Mtb protective CD4 T cells are poorly understood. Using MHCII tetramers, we show that Mtb-specific CD4 T cells are subject to ongoing antigenic stimulation. Despite this chronic stimulation, a subset of PD-1+ cells is maintained within the lung parenchyma during tuberculosis (TB). When transferred into uninfected animals, these cells persist, mount a robust recall response, and provide superior protection to Mtb rechallenge when compared to terminally differentiated Th1 cells that reside preferentially in the lung-associated vasculature. The PD-1+ cells share features with memory CD4 T cells in that their generation and maintenance requires intrinsic Bcl6 and intrinsic ICOS expression. Thus, the molecular pathways required to maintain Mtb-specific CD4 T cells during ongoing infection are similar to those that maintain memory CD4 T cells in scenarios of antigen deprivation. These results suggest that vaccination strategies targeting the ICOS and Bcl6 pathways in CD4 T cells may provide new avenues to prevent TB. PMID:25918344

Calcineurin inhibitors recruit protein kinases JAK2 and JNK, TLR signaling and the UPR to activate NF-κB-mediated inflammatory responses in kidney tubular cells

International Nuclear Information System (INIS)

González-Guerrero, Cristian; Ocaña-Salceda, Carlos; Berzal, Sergio; Carrasco, Susana; Fernández-Fernández, Beatriz

2013-01-01

The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus are key drugs in current immunosuppressive regimes for solid organ transplantation. However, they are nephrotoxic and promote death and profibrotic responses in tubular cells. Moreover, renal inflammation is observed in CNI nephrotoxicity but the mechanisms are poorly understood. We have now studied molecular pathways leading to inflammation elicited by the CNIs in cultured and kidney tubular cells. Both CsA and tacrolimus elicited a proinflammatory response in tubular cells as evidenced by a transcriptomics approach. Transcriptomics also suggested several potential pathways leading to expression of proinflammatory genes. Validation and functional studies disclosed that in tubular cells, CNIs activated protein kinases such as the JAK2/STAT3 and TAK1/JNK/AP-1 pathways, TLR4/Myd88/IRAK signaling and the Unfolded Protein Response (UPR) to promote NF-κB activation and proinflammatory gene expression. CNIs also activated an Nrf2/HO-1-dependent compensatory response and the Nrf2 activator sulforaphane inhibited JAK2 and JNK activation and inflammation. A murine model of CsA nephrotoxicity corroborated activation of the proinflammatory pathways identified in cell cultures. Human CNIs nephrotoxicity was also associated with NF-κB, STAT3 and IRE1α activation. In conclusion, CNIs recruit several intracellular pathways leading to previously non-described proinflammatory actions in renal tubular cells. Identification of these pathways provides novel clues for therapeutic intervention to limit CNIs nephrotoxicity. - Highlights: • Molecular mechanisms modulating CNI renal inflammation were investigated. • Kinases, immune receptors and ER stress mediate the inflammatory response to CNIs. • Several intracellular pathways activate NF-κB in CNIs-treated tubular cells. • A NF-κB-dependent cytokine profile characterizes CNIs-induced inflammation. • CNI nephrotoxicity was associated to inflammatory

TGFβ1 induces apoptosis in invasive prostate cancer and bladder cancer cells via Akt-independent, p38 MAPK and JNK/SAPK-mediated activation of caspases

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Al-Azayzih, Ahmad; Gao, Fei; Goc, Anna; Somanath, Payaningal R.

2012-01-01

Highlights: ► TGFβ induced apoptosis in invasive prostate cancer and bladder cancer cells. ► TGFβ inhibited prostate/bladder cancer cell proliferation and colony/foci formation. ► TGFβ induced prostate/bladder cancer cell apoptosis independent of Akt inhibition. ► TGFβ inhibited ERK1/2 phosphorylation in prostate/bladder cancer cells. ► TGFβ induced p38 MAPK and JNK-mediated activation of caspases-9, -8 and -3. -- Abstract: Recent findings indicate that advanced stage cancers shun the tumor suppressive actions of TGFβ and inexplicably utilize the cytokine as a tumor promoter. We investigated the effect of TGFβ1 on the survival and proliferation of invasive prostate (PC3) and bladder (T24) cancer cells. Our study indicated that TGFβ1 decreased cell viability and induced apoptosis in invasive human PC3 and T24 cells via activation of p38 MAPK-JNK-Caspase9/8/3 pathway. Surprisingly, no change in the phosphorylation of pro-survival Akt kinase was observed. We postulate that TGFβ1 pathway may be utilized for specifically targeting urological cancers without inflicting side effects on normal tissues.

Chlorpromazine-induced hepatotoxicity during inflammation is mediated by TIRAP-dependent signaling pathway in mice

International Nuclear Information System (INIS)

Gandhi, Adarsh; Guo, Tao; Shah, Pranav; Moorthy, Bhagavatula; Ghose, Romi

2013-01-01

Inflammation is a major component of idiosyncratic adverse drug reactions (IADRs). To understand the molecular mechanism of inflammation-mediated IADRs, we determined the role of the Toll-like receptor (TLR) signaling pathway in idiosyncratic hepatotoxicity of the anti-psychotic drug, chlorpromazine (CPZ). Activation of TLRs recruits the first adaptor protein, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to the TIR domain of TLRs leading to the activation of the downstream kinase, c-Jun-N-terminal kinase (JNK). Prolonged activation of JNK leads to cell-death. We hypothesized that activation of TLR2 by lipoteichoic acid (LTA) or TLR4 by lipopolysaccharide (LPS) will augment the hepatotoxicity of CPZ by TIRAP-dependent mechanism involving prolonged activation of JNK. Adult male C57BL/6, TIRAP +/+ and TIRAP −/− mice were pretreated with saline, LPS (2 mg/kg) or LTA (6 mg/kg) for 30 min or 16 h followed by CPZ (5 mg/kg) or saline (vehicle) up to 24 h. We found that treatment of mice with CPZ in presence of LPS or LTA leads to ∼ 3–4 fold increase in serum ALT levels, a marked reduction in hepatic glycogen content, significant induction of serum tumor necrosis factor (TNF) α and prolonged JNK activation, compared to LPS or LTA alone. Similar results were observed in TIRAP +/+ mice, whereas the effects of LPS or LTA on CPZ-induced hepatotoxicity were attenuated in TIRAP −/− mice. For the first time, we show that inflammation-mediated hepatotoxicity of CPZ is dependent on TIRAP, and involves prolonged JNK activation in vivo. Thus, TIRAP-dependent pathways may be targeted to predict and prevent inflammation-mediated IADRs. -- Highlights: ► Inflammation augments the toxicity of an idiosyncratic hepatotoxin chlorpromazine. ► Activation of Toll-like receptors by LPS or LTA induces chlorpromazine toxicity. ► Sustained stress kinase (JNK) activation is associated with chlorpromazine toxicity. ► These studies provide novel mechanistic

Chlorpromazine-induced hepatotoxicity during inflammation is mediated by TIRAP-dependent signaling pathway in mice

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Gandhi, Adarsh, E-mail: adarsh.gandhi@nih.gov [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Guo, Tao, E-mail: tguo4@jhu.edu [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Shah, Pranav [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Moorthy, Bhagavatula [Baylor College of Medicine, Department of Pediatrics, 1102 Bates Avenue, Suite 530, Houston, TX 77030 (United States); Ghose, Romi, E-mail: rghose@uh.edu [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States)

2013-02-01

Inflammation is a major component of idiosyncratic adverse drug reactions (IADRs). To understand the molecular mechanism of inflammation-mediated IADRs, we determined the role of the Toll-like receptor (TLR) signaling pathway in idiosyncratic hepatotoxicity of the anti-psychotic drug, chlorpromazine (CPZ). Activation of TLRs recruits the first adaptor protein, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to the TIR domain of TLRs leading to the activation of the downstream kinase, c-Jun-N-terminal kinase (JNK). Prolonged activation of JNK leads to cell-death. We hypothesized that activation of TLR2 by lipoteichoic acid (LTA) or TLR4 by lipopolysaccharide (LPS) will augment the hepatotoxicity of CPZ by TIRAP-dependent mechanism involving prolonged activation of JNK. Adult male C57BL/6, TIRAP{sup +/+} and TIRAP{sup −/−} mice were pretreated with saline, LPS (2 mg/kg) or LTA (6 mg/kg) for 30 min or 16 h followed by CPZ (5 mg/kg) or saline (vehicle) up to 24 h. We found that treatment of mice with CPZ in presence of LPS or LTA leads to ∼ 3–4 fold increase in serum ALT levels, a marked reduction in hepatic glycogen content, significant induction of serum tumor necrosis factor (TNF) α and prolonged JNK activation, compared to LPS or LTA alone. Similar results were observed in TIRAP{sup +/+} mice, whereas the effects of LPS or LTA on CPZ-induced hepatotoxicity were attenuated in TIRAP{sup −/−} mice. For the first time, we show that inflammation-mediated hepatotoxicity of CPZ is dependent on TIRAP, and involves prolonged JNK activation in vivo. Thus, TIRAP-dependent pathways may be targeted to predict and prevent inflammation-mediated IADRs. -- Highlights: ► Inflammation augments the toxicity of an idiosyncratic hepatotoxin chlorpromazine. ► Activation of Toll-like receptors by LPS or LTA induces chlorpromazine toxicity. ► Sustained stress kinase (JNK) activation is associated with chlorpromazine toxicity. ► These studies

Inhibition of spinal astrocytic c-Jun N-terminal kinase (JNK activation correlates with the analgesic effects of ketamine in neuropathic pain

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Wang Wen

2011-01-01

Full Text Available Abstract Background We have previously reported that inhibition of astrocytic activation contributes to the analgesic effects of intrathecal ketamine on spinal nerve ligation (SNL-induced neuropathic pain. However, the underlying mechanisms are still unclear. c-Jun N-terminal kinase (JNK, a member of mitogen-activated protein kinase (MAPK family, has been reported to be critical for spinal astrocytic activation and neuropathic pain development after SNL. Ketamine can decrease lipopolysaccharide (LPS-induced phosphorylated JNK (pJNK expression and could thus exert its anti-inflammatory effect. We hypothesized that inhibition of astrocytic JNK activation might be involved in the suppressive effect of ketamine on SNL-induced spinal astrocytic activation. Methods Immunofluorescence histochemical staining was used to detect SNL-induced spinal pJNK expression and localization. The effects of ketamine on SNL-induced mechanical allodynia were confirmed by behavioral testing. Immunofluorescence histochemistry and Western blot were used to quantify the SNL-induced spinal pJNK expression after ketamine administration. Results The present study showed that SNL induced ipsilateral pJNK up-regulation in astrocytes but not microglia or neurons within the spinal dorsal horn. Intrathecal ketamine relieved SNL-induced mechanical allodynia without interfering with motor performance. Additionally, intrathecal administration of ketamine attenuated SNL-induced spinal astrocytic JNK activation in a dose-dependent manner, but not JNK protein expression. Conclusions The present results suggest that inhibition of JNK activation may be involved in the suppressive effects of ketamine on SNL-induced spinal astrocyte activation. Therefore, inhibition of spinal JNK activation may be involved in the analgesic effects of ketamine on SNL-induced neuropathic pain.

Inhibition of spinal astrocytic c-Jun N-terminal kinase (JNK) activation correlates with the analgesic effects of ketamine in neuropathic pain

Science.gov (United States)

2011-01-01

Background We have previously reported that inhibition of astrocytic activation contributes to the analgesic effects of intrathecal ketamine on spinal nerve ligation (SNL)-induced neuropathic pain. However, the underlying mechanisms are still unclear. c-Jun N-terminal kinase (JNK), a member of mitogen-activated protein kinase (MAPK) family, has been reported to be critical for spinal astrocytic activation and neuropathic pain development after SNL. Ketamine can decrease lipopolysaccharide (LPS)-induced phosphorylated JNK (pJNK) expression and could thus exert its anti-inflammatory effect. We hypothesized that inhibition of astrocytic JNK activation might be involved in the suppressive effect of ketamine on SNL-induced spinal astrocytic activation. Methods Immunofluorescence histochemical staining was used to detect SNL-induced spinal pJNK expression and localization. The effects of ketamine on SNL-induced mechanical allodynia were confirmed by behavioral testing. Immunofluorescence histochemistry and Western blot were used to quantify the SNL-induced spinal pJNK expression after ketamine administration. Results The present study showed that SNL induced ipsilateral pJNK up-regulation in astrocytes but not microglia or neurons within the spinal dorsal horn. Intrathecal ketamine relieved SNL-induced mechanical allodynia without interfering with motor performance. Additionally, intrathecal administration of ketamine attenuated SNL-induced spinal astrocytic JNK activation in a dose-dependent manner, but not JNK protein expression. Conclusions The present results suggest that inhibition of JNK activation may be involved in the suppressive effects of ketamine on SNL-induced spinal astrocyte activation. Therefore, inhibition of spinal JNK activation may be involved in the analgesic effects of ketamine on SNL-induced neuropathic pain. PMID:21255465

The mechanism by which MEK/ERK regulates JNK and p38 activity in polyamine depleted IEC-6 cells during apoptosis

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Bavaria, Mitul N.; Jin, Shi; Ray, Ramesh M.; Johnson, Leonard R.

2014-01-01

Polyamine-depletion inhibited apoptosis by activating ERK1/2, while, preventing JNK1/2 activation. MKP-1 knockdown by SiRNA increased ERK1/2, JNK1/2, and p38 phosphorylation and apoptosis. Therefore, we predicted that polyamines might regulate MKP1 via MEK/ERK and thereby apoptosis. We examined the role of MEK/ERK in the regulation of MKP1 and JNK, and p38 activities and apoptosis. Inhibition of MKP-1 activity with a pharmacological inhibitor, sanguinarine (SA), increased JNK1/2, p38, and ERK1/2 activities without causing apoptosis. However, pre-activation of these kinases by SA significantly increased camptothecin (CPT)-induced apoptosis suggesting different roles for MAPKs during survival and apoptosis. Inhibition of MEK1 activity prevented the expression of MKP-1 protein and augmented CPT-induced apoptosis, which correlated with increased activities of JNK1/2, caspases, and DNA fragmentation. Polyamine depleted cells had higher levels of MKP-1 protein and decreased JNK1/2 activity and apoptosis. Inhibition of MEK1 prevented MKP-1 expression and increased JNK1/2 and apoptosis. Phospho-JNK1/2, phospho-ERK2, MKP-1, and the catalytic subunit of protein phosphatase 2A (PP2Ac) formed a complex in response to TNF/CPT. Inactivation of PP2Ac had no effect on the association of MKP-1 and JNK1. However, inhibition of MKP-1 activity decreased the formation of the MKP-1, PP2Ac and JNK complex. Following inhibition by SA, MKP-1 localized in the cytoplasm, while basal and CPT-induced MKP-1 remained in the nuclear fraction. These results suggest that nuclear MKP-1 translocates to the cytoplasm, binds phosphorylated JNK and p38 resulting in dephosphorylation and decreased activity. Thus, MEK/ERK activity controls the levels of MKP-1 and, thereby, regulates JNK activity in polyamine-depleted cells. PMID:24253595

Sodium Octanoate Modulates the Innate Immune Response of Bovine Mammary Epithelial Cells through the TLR2/P38/JNK/ERK1/2 Pathway: Implications during Staphylococcus aureus Internalization.

Science.gov (United States)

Alva-Murillo, Nayeli; Ochoa-Zarzosa, Alejandra; López-Meza, Joel E

2017-01-01

Bovine mammary epithelial cells (bMECs) contribute to mammary gland defense against invading pathogens, such as Staphylococcus aureus (intracellular facultative), which is recognized by TLR2. In a previous report, we showed that sodium octanoate [NaO, a medium chain fatty acid (C8)] induces (0.25 mM) or inhibits (1 mM) S. aureus internalization into bMECs and differentially regulates the innate immune response (IIR). However, the molecular mechanisms have not been described, which was the aim of this study. The results showed that α5β1 integrin membrane abundance (MA) was increased in 0.25 mM NaO-treated cells, but TLR2 or CD36 MA was not modified. When these receptors were blocked individually, 0.25 mM NaO-increased S. aureus internalization was notably reduced. Interestingly, in this condition, the IIR of the bMECs was impaired because MAPK (p38, JNK, and ERK1/2) phosphorylation and the activation of transcription factors related to these pathways were decreased. In addition, the 1 mM NaO treatment induced TLR2 MA, but neither the integrin nor CD36 MA was modified. The reduction in S. aureus internalization induced by 1 mM NaO was increased further when TLR2 was blocked. In addition, the phosphorylation levels of the MAPKs increased, and 13 transcriptional factors related to the IIR were slightly activated (CBF, CDP, c-Myb, AP-1, Ets-1/Pea-3, FAST-1, GAS/ISRE, AP-2, NFAT-1, OCT-1, RAR/DR-5, RXR/DR-1, and Stat-3). Moreover, the 1 mM NaO treatment up-regulated gene expression of IL-8 and RANTES and secretion of IL-1β. Notably, when 1 mM NaO-treated bMECs were challenged with S. aureus , the gene expression of IL-8 and IL-10 increased, while IL-1β secretion was reduced. In conclusion, our results showed that α5β1 integrin, TLR2 and CD36 are involved in 0.25 mM NaO-increased S. aureus internalization in bMECs. In addition, 1 mM NaO activates bMECs via the TLR2 signaling pathways (p38, JNK, and ERK1/2), which improves IIR before S. aureus invasion. Additionally

Adiponectin stimulates human osteoblasts proliferation and differentiation via the MAPK signaling pathway

International Nuclear Information System (INIS)

Luo Xianghang; Guo Lijuan; Yuan Lingqing; Xie Hui; Zhou Houde; Wu Xianping; Liao Eryuan

2005-01-01

Adipocytes can highly and specifically express adiponectin, and the adiponectin receptor (AdipoR) has been detected in bone-forming cells. The present study was undertaken to investigate the action of adiponectin on osteoblast proliferation and differentiation. AdipoR1 protein was detected in human osteoblasts. Adiponectin promoted osteoblast proliferation and resulted in a dose- and time-dependent increase in alkaline phosphatase (ALP) activity, osteocalcin and type I collagen production, and an increase in mineralized matrix. Suppression of AdipoR1 with small-interfering RNA (siRNA) abolished the adiponectin-induced cell proliferation and ALP expression. Adiponectin induces activation of p38 mitogen-activated protein kinase (MAPK) and c-jun N-terminal Kinase (JNK), but not ERK1/2 in osteoblasts, and these effects were blocked by suppression of AdipoR1 with siRNA. Furthermore, pretreatment of osteoblasts with the JNK inhibitor SP600125 abolished the adiponectin-induced cell proliferation. p38 inhibitor SB203580 blocked the adiponectin-induced ALP activity. These data indicate that adiponectin induces human osteoblast proliferation and differentiation, and the proliferation response is mediated by the AdipoR/JNK pathway, while the differentiation response is mediated via the AdipoR/p38 pathway. These findings suggest that osteoblasts are the direct targets of adiponectin

Fentanyl induces autophagy via activation of the ROS/MAPK pathway and reduces the sensitivity of cisplatin in lung cancer cells.

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Yao, Jiaqi; Ma, Chi; Gao, Wei; Liang, Jinxiao; Liu, Chang; Yang, Hongfang; Yan, Qiu; Wen, Qingping

2016-12-01

Cancer pain is the most common complication of lung carcinoma. Opioid agonist fentanyl is widely used for relieving pain in cancer patients, and cisplatin (DDP)‑based chemotherapy is commonly used for the treatment of advanced lung cancer; these two drugs are always used together in lung carcinoma patients. However, the mechanisms and related biological pathways by which fentanyl influences cisplatin sensitivity are relatively poorly reported. Here, we found that fentanyl reduces the sensitivity of cisplatin in human lung cancer cells and induces autophagy. Fentanyl induced reactive oxygen species (ROS) generation and JNK activation. N-acetyl‑L‑cysteine is a ROS scavenger and antioxidant, and the inhibition of JNK with SP600125 prevented fentanyl‑induced autophagy. We also found that 3-methyladenine (3-MA; an autophagy inhibitor) increased the sensitivity of DDP and weakened the inhibition of fentanyl. In conclusion, fentanyl reduces the sensitivity of cisplatin in lung cancer cells through the ROS-JNK-autophagy pathway, whereas the autophagy inhibitor 3-MA may weaken this effect.

Regulation of Schistosoma mansoni development and reproduction by the mitogen-activated protein kinase signaling pathway.

Science.gov (United States)

Andrade, Luiza Freire de; Mourão, Marina de Moraes; Geraldo, Juliana Assis; Coelho, Fernanda Sales; Silva, Larissa Lopes; Neves, Renata Heisler; Volpini, Angela; Machado-Silva, José Roberto; Araujo, Neusa; Nacif-Pimenta, Rafael; Caffrey, Conor R; Oliveira, Guilherme

2014-06-01

Protein kinases are proven targets for drug development with an increasing number of eukaryotic Protein Kinase (ePK) inhibitors now approved as drugs. Mitogen-activated protein kinase (MAPK) family members connect cell-surface receptors to regulatory targets within cells and influence a number of tissue-specific biological activities such as cell proliferation, differentiation and survival. However, the contributions of members of the MAPK pathway to schistosome development and survival are unclear. We employed RNA interference (RNAi) to elucidate the functional roles of five S. mansoni genes (SmCaMK2, SmJNK, SmERK1, SmERK2 and SmRas) involved in MAPK signaling pathway. Mice were injected with post-infective larvae (schistosomula) subsequent to RNAi and the development of adult worms observed. The data demonstrate that SmJNK participates in parasite maturation and survival of the parasites, whereas SmERK are involved in egg production as infected mice had significantly lower egg burdens with female worms presenting underdeveloped ovaries. Furthermore, it was shown that the c-fos transcription factor was overexpressed in parasites submitted to RNAi of SmERK1, SmJNK and SmCaMK2 indicating its putative involvement in gene regulation in this parasite's MAPK signaling cascade. We conclude that MAPKs proteins play important roles in the parasite in vivo survival, being essential for normal development and successful survival and reproduction of the schistosome parasite. Moreover SmERK and SmJNK are potential targets for drug development.

Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes

International Nuclear Information System (INIS)

Yoshida, Ikuma; Ibuki, Yuko

2014-01-01

Graphical abstract: - Highlights: • Formaldehyde modified histones. • The phosphorylation of H3S10 was increased at the promoter regions of proto-oncogenes. • The phosphorylation of H2AXS139 was attributed to FA-induced DNA damage. • The FA-induced initiation and promotion of cancer could be judged by these modifications. - Abstract: Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications

Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Ikuma; Ibuki, Yuko, E-mail: ibuki@u-shizuoka-ken.ac.jp

2014-12-15

Graphical abstract: - Highlights: • Formaldehyde modified histones. • The phosphorylation of H3S10 was increased at the promoter regions of proto-oncogenes. • The phosphorylation of H2AXS139 was attributed to FA-induced DNA damage. • The FA-induced initiation and promotion of cancer could be judged by these modifications. - Abstract: Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications.

CR3 and Dectin-1 Collaborate in Macrophage Cytokine Response through Association on Lipid Rafts and Activation of Syk-JNK-AP-1 Pathway.

Directory of Open Access Journals (Sweden)

Juin-Hua Huang

2015-07-01

Full Text Available Collaboration between heterogeneous pattern recognition receptors (PRRs leading to synergistic coordination of immune response is important for the host to fight against invading pathogens. Although complement receptor 3 (CR3 and Dectin-1 are major PRRs to detect fungi, crosstalk between these two receptors in antifungal immunity is largely undefined. Here we took advantage of Histoplasma capsulatum which is known to interact with both CR3 and Dectin-1 and specific particulate ligands to study the collaboration of CR3 and Dectin-1 in macrophage cytokine response. By employing Micro-Western Array (MWA, genetic approach, and pharmacological inhibitors, we demonstrated that CR3 and Dectin-1 act collaboratively to trigger macrophage TNF and IL-6 response through signaling integration at Syk kinase, allowing subsequent enhanced activation of Syk-JNK-AP-1 pathway. Upon engagement, CR3 and Dectin-1 colocalize and form clusters on lipid raft microdomains which serve as a platform facilitating their cooperation in signaling activation and cytokine production. Furthermore, in vivo studies showed that CR3 and Dectin-1 cooperatively participate in host defense against disseminated histoplasmosis and instruct adaptive immune response. Taken together, our findings define the mechanism of receptor crosstalk between CR3 and Dectin-1 and demonstrate the importance of their collaboration in host defense against fungal infection.

Pentraxin 3 Activates JNK Signaling and Regulates the Epithelial-To-Mesenchymal Transition in Renal Fibrosis

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Tung-Wei Hung

2016-12-01

Full Text Available Background/Aims: Tubulointerstitial fibrosis can lead to end-stage renal disease. Pentraxin 3 (PTX3 is an acute phase protein produced by resident and innate immunity cells. We investigated the effect of PTX3 on cultured human proximal tubular epithelial (HK-2 cells and a rat unilateral ureteral obstruction (UUO model of renal fibrosis. Methods: Gain-of-function experiments were used to examine the effect of recombinant human PTX3 (Rh-PTX3 on HK-2 cells. Cell proliferation (MTT assay and in vitro cell migration were measured. The levels of PTX3, p-JNK, and EMT markers were measured using immunohistochemistry, RT-PCR, and western blotting in UUO rats and HK-2 cells. Results: HK-2 cells treated with Rh PTX3 did not affect cell viability, but significantly increased cell migration. Moreover, Rh-PTX3 increased the expression of snail, slug, N-cadherin, and vimentin, decreased the expression of E-cadherin, and increased the phosphorylation of JNK. SP600126 (a specific JNK inhibitor enhanced the effects of Rh-PTX3. Rats with UUO exhibited time-dependent increased levels of PTX3, p-JNK, and vimentin, and decreased expression of E-cadherin. Conclusions: Our results suggest that PTX3 induces cell migration via upregulation of EMT in a JNK-dependent mechanism, and highlight the role of PTX3 in the pathogenesis renal fibrosis.

Optical angular constancy is maintained as a navigational control strategy when pursuing robots moving along complex pathways.

Science.gov (United States)

Wang, Wei; McBeath, Michael K; Sugar, Thomas G

2015-03-24

The optical navigational control strategy used to intercept moving targets was explored using a real-world object that travels along complex, evasive pathways. Fielders ran across a gymnasium attempting to catch a moving robot that varied in speed and direction, while ongoing position was measured using an infrared motion-capture system. Fielder running paths were compared with the predictions of three lateral control models, each based on maintaining a particular optical angle relative to the robotic target: (a) constant alignment angle (CAA), (b) constant eccentricity angle (CEA), and (c) linear optical trajectory (LOT). Findings reveal that running pathways were most consistent with maintenance of LOT and least consistent with CEA. This supports that fielders use the same optical control strategy of maintaining angular constancy using a LOT when navigating toward targets moving along complex pathways as when intercepting simple ballistic trajectories. In those cases in which a target dramatically deviates from its optical path, fielders appear to simply reset LOT parameters using a new constant angle value. Maintenance of such optical angular constancy has now been shown to work well with ballistic, complex, and evasive moving targets, confirming the LOT strategy as a robust, general-purpose optical control mechanism for navigating to intercept catchable targets, both airborne and ground based. © 2015 ARVO.

JNK1/2 Activation by an Extract from the Roots of Morus alba L. Reduces the Viability of Multidrug-Resistant MCF-7/Dox Cells by Inhibiting YB-1-Dependent MDR1 Expression

Directory of Open Access Journals (Sweden)

Youn Kyung Choi

2013-01-01

Full Text Available Cancer cells acquire anticancer drug resistance during chemotherapy, which aggravates cancer disease. MDR1 encoded from multidrug resistance gene 1 mainly causes multidrug resistance phenotypes of different cancer cells. In this study, we demonstrate that JNK1/2 activation by an extract from the root of Morus alba L. (White mulberry reduces doxorubicin-resistant MCF-7/Dox cell viability by inhibiting YB-1 regulation of MDR1 gene expression. When MCF-7 or MCF-7/Dox cells, where MDR1 is highly expressed were treated with an extract from roots or leaves of Morus alba L., respectively, the root extract from the mulberry (REM but not the leaf extract (LEM reduced cell viabilities of both MCF-7 and MCF-7/Dox cells, which was enhanced by cotreatment with doxorubicin. REM but not LEM further inhibited YB-1 nuclear translocation and its regulation of MDR1 gene expression. Moreover, REM promoted phosphorylation of c-Jun NH2-terminal kinase 1/2 (JNK1/2 and JNK1/2 inhibitor, SP600125 and rescued REM inhibition of both MDR1 expression and viabilities in MCF-7/Dox cells. Consistently, overexpression of JNK1, c-Jun, or c-Fos inhibited YB-1-dependent MDR1 expression and reduced viabilities in MCF-7/Dox cells. In conclusion, our data indicate that REM-activated JNK-cJun/c-Fos pathway decreases the viability of MCF-7/Dox cells by inhibiting YB-1-dependent MDR1 gene expression. Thus, we suggest that REM may be useful for treating multidrug-resistant cancer cells.

The p75NTR mediates a bifurcated signal transduction cascade through the NFκB and JNK pathways to inhibit cell survival

International Nuclear Information System (INIS)

Allen, Jeffrey; Khwaja, Fatima; Byers, Stephen; Djakiew, Daniel

2005-01-01

p75 NTR is most abundantly expressed in the nervous system, but is also widely expressed in many other organs and tissues where it primarily functions as a negative regulator of cell survival. In the prostate, p75 NTR functions as an inhibitory protein capable of slowing proliferation and inducing apoptosis. It has been shown that p75 NTR is expressed in the normal prostate, progressively lost from malignant tumor cells in vivo, and largely absent from prostate cancer cell lines derived from metastases. Although the role of p75 NTR in prostate cancer has been well established, the signal transduction pathway that mediates its inhibitory activity has only been partially elucidated. This study demonstrates that exogenous expression of p75 NTR down-regulates, in a dose-dependent manner, a bifurcated signaling cascade that results in reduced expression of potent transcription effectors. This two-arm signal transduction cascade was directly linked to the upstream receptor by using dominant-negative deletion constructs of p75 NTR that rescued tumor cells from p75 NTR -induced loss of survival and promotion of apoptosis. Furthermore, the dominant negatives rescued alterations in the levels of signal transduction intermediates. Conversely, the use of kinase-inactive intermediates that are downstream of the receptor further reduced expression of involved transcription effectors and reduced survival of the cells. These results provide a definitive link between the proximate p75 NTR and signal transduction intermediates leading to the transcription effectors NFκB and JNK, with associated growth suppression and induction of apoptosis

SCM-198 inhibits microglial overactivation and attenuates Aβ(1-40)-induced cognitive impairments in rats via JNK and NF-кB pathways.

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Hong, Zhen-Yi; Shi, Xue-Ru; Zhu, Kai; Wu, Ting-Ting; Zhu, Yi-Zhun

2014-08-19

Neuroinflammation mediated by overactivated microglia plays a key role in many neurodegenerative diseases, including Alzheimer's disease (AD). In this study, we investigated for the first time the anti-neuroinflammatory effects and possible mechanisms of SCM-198 (an alkaloid extracted from Herbaleonuri), which was previously found highly cardioprotective, both in vitro and in vivo. For in vitro experiments, lipopolysaccharide (LPS) or β-amyloid(1-40) (Aβ(1-40)) was applied to induce microglial overactivation. Proinflammatory mediators were measured and activations of NF-κB and mitogen-activated protein kinases' (MAPKs) pathways were investigated. Further protective effect of SCM-198 was evaluated in microglia-neuron co-culture assay and Sprague-Dawley (SD) rats intrahippocampally-injected with Aβ(1-40). SCM-198 reduced expressions of nitric oxide (NO), TNF-α, IL-1β and IL-6 possibly via, at least partially, inhibiting c-Jun N-terminal kinase (JNK) and NF-κB signaling pathways in microglia. Co-culture assay showed that activated microglia pretreated with SCM-198 led to less neuron loss and decreased phosphorylation of tau and extracellular signal-regulated kinase (ERK) in neurons. Besides, SCM-198 also directly protected against Aβ(1-40)-induced neuronal death and lactate dehydrogenase (LDH) release in primary cortical neurons. For in vivo studies, SCM-198 significantly enhanced cognitive performances of rats 12 days after intrahippocampal injections of aged Aβ(1-40) peptides in the Morris water maze (MWM), accompanied by less hippocampal microglial activation, decreased synaptophysin loss and phosphorylation of ERK and tau. Co-administration of donepezil and SCM-198 resulted in a slight cognitive improvement in SD rats 50 days after intrahippocampal injections of aged Aβ(1-40) peptides as compared to only donepezil or SCM-198 treated group. Our findings are the first to report that SCM-198 has considerable anti-neuroinflammatory effects on inhibiting

JNK inhibition reduces apoptosis and neovascularization in a murine model of age-related macular degeneration.

Science.gov (United States)

Du, Hongjun; Sun, Xufang; Guma, Monica; Luo, Jing; Ouyang, Hong; Zhang, Xiaohui; Zeng, Jing; Quach, John; Nguyen, Duy H; Shaw, Peter X; Karin, Michael; Zhang, Kang

2013-02-05

Age-related macular degeneration (AMD) is the leading cause of registered blindness among the elderly and affects over 30 million people worldwide. It is well established that oxidative stress, inflammation, and apoptosis play critical roles in pathogenesis of AMD. In advanced wet AMD, although, most of the severe vision loss is due to bleeding and exudation of choroidal neovascularization (CNV), and it is well known that vascular endothelial growth factor (VEGF) plays a pivotal role in the growth of the abnormal blood vessels. VEGF suppression therapy improves visual acuity in AMD patients. However, there are unresolved issues, including safety and cost. Here we show that mice lacking c-Jun N-terminal kinase 1 (JNK1) exhibit decreased inflammation, reduced CNV, lower levels of choroidal VEGF, and impaired choroidal macrophage recruitment in a murine model of wet AMD (laser-induced CNV). Interestingly, we also detected a substantial reduction in choroidal apoptosis of JNK1-deficient mice. Intravitreal injection of a pan-caspase inhibitor reduced neovascularization in the laser-induced CNV model, suggesting that apoptosis plays a role in laser-induced pathological angiogenesis. Intravitreal injection of a specific JNK inhibitor decreased choroidal VEGF expression and reduced pathological CNV. These results suggest that JNK1 plays a key role in linking oxidative stress, inflammation, macrophage recruitment apoptosis, and VEGF production in wet AMD and pharmacological JNK inhibition offers a unique and alternative avenue for prevention and treatment of AMD.

c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis

Science.gov (United States)

2015-03-01

1 AWARD NUMBER: W81XWH-12-1-0431 TITLE: “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis ” PRINCIPAL...TITLE AND SUBTITLE “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Scelerosis” 5a. CONTRACT NUMBER 5b. GRANT NUMBER... Lateral   Sclerosis ”   Final  Report:  Project  Period  Sept  2012-­‐Dec  2014     Personnel  List:     Feng,  Yangbo

Histamine acting on H1 receptor promotes inhibition of proliferation via PLC, RAC, and JNK-dependent pathways

International Nuclear Information System (INIS)

Notcovich, Cintia; Diez, Federico; Tubio, Maria Rosario; Baldi, Alberto; Kazanietz, Marcelo G.; Davio, Carlos; Shayo, Carina

2010-01-01

It is well established that histamine modulates cell proliferation through the activation of the histamine H1 receptor (H1R), a G protein-coupled receptor (GPCR) that is known to couple to phospholipase C (PLC) activation via Gq. In the present study, we aimed to determine whether H1R activation modulates Rho GTPases, well-known effectors of Gq/G 11 -coupled receptors, and whether such modulation influences cell proliferation. Experiments were carried out in CHO cells stably expressing H1R (CHO-H1R). By using pull-down assays, we found that both histamine and a selective H1R agonist activated Rac and RhoA in a time- and dose-dependent manner without significant changes in the activation of Cdc42. Histamine response was abolished by the H1R antagonist mepyramine, RGS2 and the PLC inhibitor U73122, suggesting that Rac and RhoA activation is mediated by H1R via Gq coupling to PLC stimulation. Histamine caused a marked activation of serum response factor activity via the H1R, as determined with a serum-responsive element (SRE) luciferase reporter, and this response was inhibited by RhoA inactivation with C3 toxin. Histamine also caused a significant activation of JNK which was inhibited by expression of the Rac-GAP β2-chimaerin. On the other hand, H1R-induced ERK1/2 activation was inhibited by U73122 but not affected by C3 or β2-chimaerin, suggesting that ERK1/2 activation was dependent on PLC and independent of RhoA or Rac. [ 3 H]-Thymidine incorporation assays showed that both histamine and the H1R agonist inhibited cell proliferation in a dose-dependent manner and that the effect was independent of RhoA but partially dependent on JNK and Rac. Our results reveal that functional coupling of the H1R to Gq-PLC leads to the activation of RhoA and Rac small GTPases and suggest distinct roles for Rho GTPases in the control of cell proliferation by histamine.

Resveratrol Ameliorates Palmitate-Induced Inflammation in Skeletal Muscle Cells by Attenuating Oxidative Stress and JNK/NF-κB Pathway in a SIRT1-Independent Mechanism.

Science.gov (United States)

Sadeghi, Asie; Seyyed Ebrahimi, Shadi Sadat; Golestani, Abolfazl; Meshkani, Reza

2017-09-01

Resveratrol has been shown to exert anti-inflammatory and anti-oxidant effects in a variety of cell types, however, its role in prevention of inflammatory responses mediated by palmitate in skeletal muscle cells remains unexplored. In the present study, we investigated the effects of resveratrol on palmitate-induced inflammation and elucidated the underlying mechanisms in skeletal muscle cells. The results showed that palmitate significantly enhanced TNF-α and IL-6 mRNA expression and protein secretion from C2C12 cells at 12, 24, and 36 h treatments. Increased expression of cytokines was accompanied by an enhanced phosphorylation of JNK, P38, ERK1/2, and IKKα/IKKβ. In addition, JNK and P38 inhibitors could significantly attenuate palmitate-induced mRNA expression of TNF-α and IL-6, respectively, whereas NF-κB inhibitor reduced the expression of both cytokines in palmitate-treated cells. Resveratrol pretreatment significantly prevented palmitate-induced TNF-α and IL-6 mRNA expression and protein secretion in C2C12 cells. Importantly, pre-treatment of the cells with resveratrol completely abrogated the phosphorylation of ERK1/2, JNK, and IKKα/IKKβ in palmitate treated cells. The protection from palmitate-induced inflammation by resveratrol was accompanied by a decrease in the generation of reactive oxygen species (ROS). N-acetyl cysteine (NAC), a known scavenger of ROS, could protect palmitate-induced expression of TNF-α and IL-6. Furthermore, inhibition of SIRT1 by shRNA or sirtinol demonstrated that the anti-inflammatory effect of resveratrol in muscle cells is mediated through a SIRT1-independent mechanism. Taken together, these findings suggest that resveratrol may represent a promising therapy for prevention of inflammation in skeletal muscle cells. J. Cell. Biochem. 118: 2654-2663, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Dietary influence on MAPK-signaling pathways and risk of colon and rectal cancer.

Science.gov (United States)

Slattery, Martha L; Lundgreen, Abbie; Wolff, Roger K

2013-01-01

Mitogen-activated protein kinase (MAPK) pathways regulate cellular functions including cell proliferation, differentiation, migration, and apoptosis. Associations between genes in the DUSP, ERK1/2, JNK, and p38 MAPK-signaling pathways and dietary factors associated with growth factors, inflammation, and oxidative stress and risk of colon and rectal cancer were evaluated. Data include colon cases (n = 1555) and controls (n = 1956) and rectal cases (n = 754) and controls (n = 959). Statistically significant interactions were observed for the MAPK-signaling pathways after adjustment for multiple comparisons. DUSP genes interacted with carbohydrates, mutagen index, calories, calcium, vitamin D, lycopene, dietary fats, folic acid, and selenium. MAPK1, MAPK3, MAPK1, and RAF1 within the ERK1/2 MAPK-signaling pathway interacted with dietary fats and cruciferous vegetables. Within the JNK MAPK-signaling pathway, interactions between MAP3K7 and protein, vitamin C, iron, folic acid, carbohydrates, and cruciferous vegetables; MAP3K10 and folic acid; MAP3K9 and lutein/zeaxanthin; MAPK8 and calcium; MAP3K3 and calcium and lutein; MAP3K1 and cruciferous vegetables. Interaction within the p38-signaling pathway included MAPK14 with calories, carbohydrates saturated fat, selenium, vitamin C; MAP3K2 and carbohydrates, and folic acid. These data suggest that dietary factors involved in inflammation and oxidative stress interact with MAPK-signaling genes to alter risk of colorectal cancer.

IL33 Promotes Colon Cancer Cell Stemness via JNK Activation and Macrophage Recruitment

Science.gov (United States)

Fang, Min; Li, Yongkui; Huang, Kai; Qi, Shanshan; Zhang, Jian; Zgodzinski, Witold; Majewski, Marek; Wallner, Grzegorz; Gozdz, Stanislaw; Macek, Pawel; Kowalik, Artur; Pasiarski, Marcin; Grywalska, Ewelina; Vatan, Linda; Nagarsheth, Nisha; Li, Wei; Zhao, Lili; Kryczek, Ilona; Wang, Guobin; Wang, Zheng; Zou, Weiping; Wang, Lin

2018-01-01

The expression and biological role of IL33 in colon cancer is poorly understood. In this study, we show that IL33 is expressed by vascular endothelial cells and tumor cells in the human colon cancer microenvironment. Administration of human IL33 and overexpression of murine IL33 enhanced human and murine colon cancer cell growth in vivo, respectively. IL33 stimulated cell sphere formation and prevented chemotherapy-induced tumor apoptosis. Mechanistically, IL33 activated core stem cell genes NANOG, NOTCH3, and OCT3/4 via the ST2 signaling pathway, and induced phosphorylation of c-Jun N terminal kinase (JNK) activation and enhanced binding of c-Jun to the promoters of the core stem cell genes. Moreover, IL33 recruited macrophages into the cancer microenvironment and stimulated them to produce prostaglandin E2, which supported colon cancer stemness and tumor growth. Clinically, tumor IL33 expression associated with poor survival in patients with metastatic colon cancer. Thus, IL33 dually targets tumor cells and macrophages and endows stem-like qualities to colon cancer cells to promote carcinogenesis. Collectively, our work reveals an immune-associated mechanism that extrinsically confers cancer cell stemness properties. Targeting the IL33 signaling pathway may offer an opportunity to treat patients with metastatic cancer. PMID:28249897

Insulin stimulates the expression of the SHARP-1 gene via multiple signaling pathways.

Science.gov (United States)

Takagi, K; Asano, K; Haneishi, A; Ono, M; Komatsu, Y; Yamamoto, T; Tanaka, T; Ueno, H; Ogawa, W; Tomita, K; Noguchi, T; Yamada, K

2014-06-01

The rat enhancer of split- and hairy-related protein-1 (SHARP-1) is a basic helix-loop-helix transcription factor. An issue of whether SHARP-1 is an insulin-inducible transcription factor was examined. Insulin rapidly increased the level of SHARP-1 mRNA both in vivo and in vitro. Then, signaling pathways involved with the increase of SHARP-1 mRNA by insulin were determined in H4IIE rat hepatoma cells. Pretreatments with LY294002, wortmannin, and staurosporine completely blocked the induction effect, suggesting the involvement of both phosphoinositide 3-kinase (PI 3-K) and protein kinase C (PKC) pathways. In fact, overexpression of a dominant negative form of atypical protein kinase C lambda (aPKCλ) significantly decreased the induction of the SHARP-1 mRNA. In addition, inhibitors for the small GTPase Rac or Jun N-terminal kinase (JNK) also blocked the induction of SHARP-1 mRNA by insulin. Overexpression of a dominant negative form of Rac1 prevented the activation by insulin. Furthermore, actinomycin D and cycloheximide completely blocked the induction of SHARP-1 mRNA by insulin. Finally, when a SHARP-1 expression plasmid was transiently transfected with various reporter plasmids into H4IIE cells, the promoter activity of PEPCK reporter plasmid was specifically decreased. Thus, we conclude that insulin induces the SHARP-1 gene expression at the transcription level via a both PI 3-K/aPKCλ/JNK- and a PI 3-K/Rac/JNK-signaling pathway; protein synthesis is required for this induction; and that SHARP-1 is a potential repressor of the PEPCK gene expression. © Georg Thieme Verlag KG Stuttgart · New York.

JNK1ß1 is phosphorylated during expression in E. coli and in vitro by MKK4 at three identical novel sites

CSIR Research Space (South Africa)

Owen, GR

2013-03-01

Full Text Available JNK1 is activated by phosphorylation of the canonical T183 and Y185 residues, modifications that are catalysed typically by the upstream eukaryotic kinases MKK4 and MKK7. Nonetheless, the exact sites at which the most abundant JNK variant, JNK1ß1...

Fisetin attenuates cerulein-induced acute pancreatitis through down regulation of JNK and NF-κB signaling pathways.

Science.gov (United States)

Jo, Il-Joo; Bae, Gi-Sang; Choi, Sun Bok; Kim, Dong-Goo; Shin, Joon-Yeon; Seo, Seung-Hee; Choi, Mee-Ok; Kim, Tae-Hyeon; Song, Ho-Joon; Park, Sung-Joo

2014-08-15

Acute pancreatitis (AP) is a complicated disease which is largely undiscovered. Fisetin, a natural flavonoid from fruits and vegetables, has been shown to have anti-inflammatory, antioxidant, and anti-cancer activities in various disease models. However, the effects of fisetin on AP have not been determined. Pre- and post- treatment of mice with fisetin reduced the severity of AP and pancreatitis-associated lung injury and inhibited several biochemical parameters (pancreatic weight to body weight ratio, amylase, lipase, and myeloperoxidase activity) and production of inflammatory cytokines. In pancreatic acinar cells, fisetin also inhibited cell death and production of inflammatory cytokines. In addition, fisetin inhibited activation of c-Jun NH2-terminal kinase (JNK) and nuclear factor (NF)-κB in vivo and in vitro. In conclusion, these results suggest that fisetin exhibits anti-inflammatory effect on AP and could be a beneficial agent in the treatment of AP and its pulmonary complications. Copyright © 2014 Elsevier B.V. All rights reserved.

JNK1 ablation in mice confers long-term metabolic protection from diet-induced obesity at the cost of moderate skin oxidative damage.

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Becattini, Barbara; Zani, Fabio; Breasson, Ludovic; Sardi, Claudia; D'Agostino, Vito Giuseppe; Choo, Min-Kyung; Provenzani, Alessandro; Park, Jin Mo; Solinas, Giovanni

2016-09-01

Obesity and insulin resistance are associated with oxidative stress, which may be implicated in the progression of obesity-related diseases. The kinase JNK1 has emerged as a promising drug target for the treatment of obesity and type 2 diabetes. JNK1 is also a key mediator of the oxidative stress response, which can promote cell death or survival, depending on the magnitude and context of its activation. In this article, we describe a study in which the long-term effects of JNK1 inactivation on glucose homeostasis and oxidative stress in obese mice were investigated for the first time. Mice lacking JNK1 (JNK1(-/-)) were fed an obesogenic high-fat diet (HFD) for a long period. JNK1(-/-) mice fed an HFD for the long term had reduced expression of antioxidant genes in their skin, more skin oxidative damage, and increased epidermal thickness and inflammation compared with the effects in control wild-type mice. However, we also observed that the protection from obesity, adipose tissue inflammation, steatosis, and insulin resistance, conferred by JNK1 ablation, was sustained over a long period and was paralleled by decreased oxidative damage in fat and liver. We conclude that compounds targeting JNK1 activity in brain and adipose tissue, which do not accumulate in the skin, may be safer and most effective.-Becattini, B., Zani, F., Breasson, L., Sardi, C., D'Agostino, V. G., Choo, M.-K., Provenzani, A., Park, J. M., Solinas, G. JNK1 ablation in mice confers long-term metabolic protection from diet-induced obesity at the cost of moderate skin oxidative damage. © FASEB.

Modulation of Apoptosis Pathways by Oxidative Stress and Autophagy in β Cells

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Maorong Wang

2012-01-01

Full Text Available Human islets isolated for transplantation are exposed to multiple stresses including oxidative stress and hypoxia resulting in significant loss of functional β cell mass. In this study we examined the modulation of apoptosis pathway genes in islets exposed to hydrogen peroxide, peroxynitrite, hypoxia, and cytokines. We observed parallel induction of pro- and antiapoptotic pathways and identified several novel genes including BFAR, CARD8, BNIP3, and CIDE-A. As BNIP3 is an inducer of autophagy, we examined this pathway in MIN6 cells, a mouse beta cell line and in human islets. Culture of MIN6 cells under low serum conditions increased the levels of several proteins in autophagy pathway, including ATG4, Beclin 1, LAMP-2, and UVRAG. Amino acid deprivation led to induction of autophagy in human islets. Preconditioning of islets with inducers of autophagy protected them from hypoxia-induced apoptosis. However, induction of autophagy during hypoxia exacerbated apoptotic cell death. ER stress led to induction of autophagy and apoptosis in β cells. Overexpression of MnSOD, an enzyme that scavenges free radicals, resulted in protection of MIN6 cells from cytokine-induced apoptosis. Ceramide, a mediator of cytokine-induced injury, reduced the active phosphorylated form of Akt and downregulated the promoter activity of the antiapoptotic gene bcl-2. Furthermore, cytokine-stimulated JNK pathway downregulated the bcl-2 promoter activity which was reversed by preincubation with SP600125, a JNK inhibitor. Our findings suggest that β cell apoptosis by multiple stresses in islets isolated for transplantation is the result of orchestrated gene expression in apoptosis pathway.

Puerarin reduces apoptosis in rat hippocampal neurons culturea in high glucose medium by modulating the p38 mitogen activated protein kinase and c-Jun N-terminal kinase signaling pathways.

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Xu, Xiaohan; Wang, Jingbo; Zhang, Hong; Tian, Guoqing; Liu, Yuqin

2016-02-01

To investigate the neuroprotective etfect of puerarin on rat hippocampal neurons cultured in high glucose medium, and to examine the role of the p38 mitogen activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) signaling pathways in this effect. Primary cultures of hippocampal neurons were prepared from newborn Sprague Dawley rats. Neuron-specific enolase immunocytochemistry was used to identify neurons. The neurons were cultured with normal medium (control group) or with high-glucose medium (high-glucose group), and puerarin (puerarin group), a p38 MAPK inhibitor (SB239063; p38 MAPK inhibitor group) or a JNK inhibitor (SP600125; JNK inhibitor group) were added. After 72 h of treatment, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was performed to detect apoptosis, and western blotting was used to assess protein levels of p-p38, p38, p-JNK and JNK. In the high-glucose group, the neuronal apoptosis rate and the p-p38/p38 and p-JNK/JNK ratios were higher than in the control group. The p38 MAPK and JNK inhibitors prevented this increase in the apoptosis rate. The apoptosis rates in the puerarin group, the p38 MAPK inhibitor group and the JNK inhibitor group were significantly decreased compared with the high-glucose group. Moreover, protein levels of p-p38 and p-JNK were significantly reduced, and the p-p38/p38 and p-JNK/JNK ratios were decreased in the puerarin group compared with the high-glucose group. In addition, compared with the high-glucose group, p-p38 levels and the p-p38/p38 ratio were reduced in the p38 MAPK inhibitor group, and p-JNK levels and the p-JNK/JNK ratio were decreased in the JNK inhibitor group. Puerarin attenuates neuronal apoptosis induced by high glucose by reducing the phosphorylation of p38 and JNK.

MicroRNA-155 attenuates late sepsis-induced cardiac dysfunction through JNK and β-arrestin 2.

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Zhou, Yu; Song, Yan; Shaikh, Zahir; Li, Hui; Zhang, Haiju; Caudle, Yi; Zheng, Shouhua; Yan, Hui; Hu, Dan; Stuart, Charles; Yin, Deling

2017-07-18

Cardiac dysfunction is correlated with detrimental prognosis of sepsis and contributes to a high risk of mortality. After an initial hyperinflammatory reaction, most patients enter a protracted state of immunosuppression (late sepsis) that alters both innate and adaptive immunity. The changes of cardiac function in late sepsis are not yet known. MicroRNA-155 (miR-155) is previously found to play important roles in both regulations of immune activation and cardiac function. In this study, C57BL/6 mice were operated to develop into early and late sepsis phases, and miR-155 mimic was injected through the tail vein 48 h after cecal ligation and puncture (CLP). The effect of miR-155 on CLP-induced cardiac dysfunction was explored in late sepsis. We found that increased expression of miR-155 in the myocardium protected against cardiac dysfunction in late sepsis evidenced by attenuating sepsis-reduced cardiac output and enhancing left ventricular systolic function. We also observed that miR-155 markedly reduced the infiltration of macrophages and neutrophils into the myocardium and attenuated the inflammatory response via suppression of JNK signaling pathway. Moreover, overexpression of β-arrestin 2 (Arrb2) exacerbated the mice mortality and immunosuppression in late sepsis. Furthermore, transfection of miR-155 mimic reduced Arrb2 expression, and then restored immunocompetence and improved survival in late septic mice. We conclude that increased miR-155 expression through systemic administration of miR-155 mimic attenuates cardiac dysfunction and improves late sepsis survival by targeting JNK associated inflammatory signaling and Arrb2 mediated immunosuppression.

Overweight worsens apoptosis, neuroinflammation and blood-brain barrier damage after hypoxic ischemia in neonatal brain through JNK hyperactivation

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Wu Hsin-Chieh

2011-04-01

Full Text Available Abstract Background Apoptosis, neuroinflammation and blood-brain barrier (BBB damage affect the susceptibility of the developing brain to hypoxic-ischemic (HI insults. c-Jun N-terminal kinase (JNK is an important mediator of insulin resistance in obesity. We hypothesized that neonatal overweight aggravates HI brain damage through JNK hyperactivation-mediated upregulation of neuronal apoptosis, neuroinflammation and BBB leakage in rat pups. Methods Overweight (OF pups were established by reducing the litter size to 6, and control (NF pups by keeping the litter size at 12 from postnatal (P day 1 before HI on P7. Immunohistochemistry and immunoblotting were used to determine the TUNEL-(+ cells and BBB damage, cleaved caspase-3 and poly (ADP-ribose polymerase (PARP, and phospho-JNK and phospho-BimEL levels. Immunofluorescence was performed to determine the cellular distribution of phospho-JNK. Results Compared with NF pups, OF pups had a significantly heavier body-weight and greater fat deposition on P7. Compared with the NF-HI group, the OF-HI group showed significant increases of TUNEL-(+ cells, cleaved levels of caspase-3 and PARP, and ED1-(+ activated microglia and BBB damage in the cortex 24 hours post-HI. Immunofluorescence of the OF-HI pups showed that activated-caspase 3 expression was found mainly in NeuN-(+ neurons and RECA1-(+ vascular endothelial cells 24 hours post-HI. The OF-HI group also had prolonged escape latency in the Morris water maze test and greater brain-volume loss compared with the NF-HI group when assessed at adulthood. Phospho-JNK and phospho-BimEL levels were higher in OF-HI pups than in NF-HI pups immediately post-HI. JNK activation in OF-HI pups was mainly expressed in neurons, microglia and vascular endothelial cells. Inhibiting JNK activity by AS601245 caused more attenuation of cleaved caspase-3 and PARP, a greater reduction of microglial activation and BBB damage post-HI, and significantly reduced brain damage in

NADPH oxidase 2-derived reactive oxygen species mediate FFAs-induced dysfunction and apoptosis of β-cells via JNK, p38 MAPK and p53 pathways.

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Huiping Yuan

2010-12-01

Full Text Available Dysfunction of β-cell is one of major characteristics in the pathogenesis of type 2 diabetes. The combination of obesity and type 2 diabetes, characterized as 'diabesity', is associated with elevated plasma free fatty acids (FFAs. Oxidative stress has been implicated in the pathogenesis of FFA-induced β-cell dysfunction. However, molecular mechanisms linking between reactive oxygen species (ROS and FFA-induced β-cell dysfunction and apoptosis are less clear. In the present study, we test the hypothesis that NOX2-derived ROS may play a critical role in dysfunction and apoptosis of β-cells induced by FFA. Our results show that palmitate and oleate (0.5 mmol/L, 48 h induced JNK activation and AKT inhibition which resulted in decreased phosphorylation of FOXO1 following nuclear localization and the nucleocytoplasmic translocation of PDX-1, leading to the reducing of insulin and ultimately dysfunction of pancreatic NIT-1 cells. We also found that palmitate and oleate stimulated apoptosis of NIT-1 cells through p38MAPK, p53 and NF-κB pathway. More interestingly, our data suggest that suppression of NOX2 may restore FFA-induced dysfunction and apoptosis of NIT-1 cells. Our findings provide a new insight of the NOX2 as a potential new therapeutic target for preservation of β-cell mass and function.

Multiple Signaling Pathways Coordinately Regulate Forgetting of Olfactory Adaptation through Control of Sensory Responses in Caenorhabditis elegans.

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Kitazono, Tomohiro; Hara-Kuge, Sayuri; Matsuda, Osamu; Inoue, Akitoshi; Fujiwara, Manabi; Ishihara, Takeshi

2017-10-18

Forgetting memories is important for animals to properly respond to continuously changing environments. To elucidate the mechanisms of forgetting, we used one of the behavioral plasticities of Caenorhabditis elegans hermaphrodite, olfactory adaptation to an attractive odorant, diacetyl, as a simple model of learning. In C. elegans, the TIR-1/JNK-1 pathway accelerates forgetting of olfactory adaptation by facilitating neural secretion from AWC sensory neurons. In this study, to identify the downstream effectors of the TIR-1/JNK-1 pathway, we conducted a genetic screen for suppressors of the gain-of-function mutant of tir-1 ( ok1052 ), which shows excessive forgetting. Our screening showed that three proteins-a membrane protein, MACO-1; a receptor tyrosine kinase, SCD-2; and its putative ligand, HEN-1-regulated forgetting downstream of the TIR-1/JNK-1 pathway. We further demonstrated that MACO-1 and SCD-2/HEN-1 functioned in parallel genetic pathways, and only MACO-1 regulated forgetting of olfactory adaptation to isoamyl alcohol, which is an attractive odorant sensed by different types of sensory neurons. In olfactory adaptation, odor-evoked Ca 2+ responses in olfactory neurons are attenuated by conditioning and recovered thereafter. A Ca 2+ imaging study revealed that this attenuation is sustained longer in maco-1 and scd-2 mutant animals than in wild-type animals like the TIR-1/JNK-1 pathway mutants. Furthermore, temporal silencing by histamine-gated chloride channels revealed that the neuronal activity of AWC neurons after conditioning is important for proper forgetting. We propose that distinct signaling pathways, each of which has a specific function, may coordinately and temporally regulate forgetting by controlling sensory responses. SIGNIFICANCE STATEMENT Active forgetting is an important process to understand the whole mechanisms of memories. Recent papers have reported that the noncell autonomous regulations are required for proper forgetting in

Curcumin Enhances Cytotoxic Effects of Bortezomib in Human Multiple Myeloma H929 Cells: Potential Roles of NF-κB/JNK

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Qing-Xian Bai

2012-04-01

Full Text Available Combined curcumin and PS-341 treatment has been reported to enhance cytotoxicity and minimize adverse effects through ERK and p38MAPK mechanisms in human multiple myeloma cells. However, whether JNK plays similar role in this process remains unclear. In the present study, we found combined treatment altered NF-κB p65 expressions and distributions in multiple myeloma H929 cells. Western blot analysis showed combined treatment inactivated NF-κB while activated JNK signaling. Pre-treatment with JNK inhibitor SP600125 could attenuate NF-κB inactivation and restored H929 cells’ survival. These results suggested that curcumin might enhance the cytotoxicity of PS-341 by interacting with NF-κB, at least in part, through JNK mechanism.

Nuclear movement regulated by non-Smad Nodal signaling via JNK is associated with Smad signaling during zebrafish endoderm specification.

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Hozumi, Shunya; Aoki, Shun; Kikuchi, Yutaka

2017-11-01

Asymmetric nuclear positioning is observed during animal development, but its regulation and significance in cell differentiation remain poorly understood. Using zebrafish blastulae, we provide evidence that nuclear movement towards the yolk syncytial layer, which comprises extraembryonic tissue, occurs in the first cells fated to differentiate into the endoderm. Nodal signaling is essential for nuclear movement, whereas nuclear envelope proteins are involved in movement through microtubule formation. Positioning of the microtubule-organizing center, which is proposed to be crucial for nuclear movement, is regulated by Nodal signaling and nuclear envelope proteins. The non-Smad JNK signaling pathway, which is downstream of Nodal signaling, regulates nuclear movement independently of the Smad pathway, and this nuclear movement is associated with Smad signal transduction toward the nucleus. Our study provides insight into the function of nuclear movement in Smad signaling toward the nucleus, and could be applied to the control of TGFβ signaling. © 2017. Published by The Company of Biologists Ltd.

Hypothalamic AMPK-ER Stress-JNK1 Axis Mediates the Central Actions of Thyroid Hormones on Energy Balance.

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Martínez-Sánchez, Noelia; Seoane-Collazo, Patricia; Contreras, Cristina; Varela, Luis; Villarroya, Joan; Rial-Pensado, Eva; Buqué, Xabier; Aurrekoetxea, Igor; Delgado, Teresa C; Vázquez-Martínez, Rafael; González-García, Ismael; Roa, Juan; Whittle, Andrew J; Gomez-Santos, Beatriz; Velagapudi, Vidya; Tung, Y C Loraine; Morgan, Donald A; Voshol, Peter J; Martínez de Morentin, Pablo B; López-González, Tania; Liñares-Pose, Laura; Gonzalez, Francisco; Chatterjee, Krishna; Sobrino, Tomás; Medina-Gómez, Gema; Davis, Roger J; Casals, Núria; Orešič, Matej; Coll, Anthony P; Vidal-Puig, Antonio; Mittag, Jens; Tena-Sempere, Manuel; Malagón, María M; Diéguez, Carlos; Martínez-Chantar, María Luz; Aspichueta, Patricia; Rahmouni, Kamal; Nogueiras, Rubén; Sabio, Guadalupe; Villarroya, Francesc; López, Miguel

2017-07-05

Thyroid hormones (THs) act in the brain to modulate energy balance. We show that central triiodothyronine (T3) regulates de novo lipogenesis in liver and lipid oxidation in brown adipose tissue (BAT) through the parasympathetic (PSNS) and sympathetic nervous system (SNS), respectively. Central T3 promotes hepatic lipogenesis with parallel stimulation of the thermogenic program in BAT. The action of T3 depends on AMP-activated protein kinase (AMPK)-induced regulation of two signaling pathways in the ventromedial nucleus of the hypothalamus (VMH): decreased ceramide-induced endoplasmic reticulum (ER) stress, which promotes BAT thermogenesis, and increased c-Jun N-terminal kinase (JNK) activation, which controls hepatic lipid metabolism. Of note, ablation of AMPKα1 in steroidogenic factor 1 (SF1) neurons of the VMH fully recapitulated the effect of central T3, pointing to this population in mediating the effect of central THs on metabolism. Overall, these findings uncover the underlying pathways through which central T3 modulates peripheral metabolism. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Hydrogen sulfide (H2S)/cystathionine γ-lyase (CSE) pathway contributes to the proliferation of hepatoma cells

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Pan, Yan; Ye, Shuang; Yuan, Dexiao; Zhang, Jianghong; Bai, Yang; Shao, Chunlin

2014-01-01

Highlights: • Inhibition of H 2 S/CSE pathway strongly stimulates cellular apoptosis. • Inhibition of H 2 S/CSE pathway suppresses cell growth by blocking EGFR pathway. • H 2 S/CSE pathway is critical for maintaining the proliferation of hepatoma cells. - Abstract: Hydrogen sulfide (H 2 S)/cystathionine γ-lyase (CSE) pathway has been demonstrated to play vital roles in physiology and pathophysiology. However, its role in tumor cell proliferation remains largely unclear. Here we found that CSE over-expressed in hepatoma HepG2 and PLC/PRF/5 cells. Inhibition of endogenous H 2 S/CSE pathway drastically decreased the proliferation of HepG2 and PLC/PRF/5 cells, and it also enhanced ROS production and mitochondrial disruption, pronounced DNA damage and increased apoptosis. Moreover, this increase of apoptosis was associated with the activation of p53 and p21 accompanied by a decreased ratio of Bcl-2/Bax and up-regulation of phosphorylated c-Jun N-terminal kinase (JNK) and caspase-3 activity. In addition, the negative regulation of cell proliferation by inhibition of H 2 S/CSE system correlated with the blockage of cell mitogenic and survival signal transduction of epidermal growth factor receptor (EGFR) via down-regulating the extracellular-signal-regulated kinase 1/2 (ERK1/2) activation. These results demonstrate that H 2 S/CSE and its downstream pathway contribute to the proliferation of hepatoma cells, and inhibition of this pathway strongly suppress the excessive growth of hepatoma cells by stimulating mitochondrial apoptosis and suppressing cell growth signal transduction

STATE OF JNK AND P38 MAP-KINASE SYSTEM IN BLOOD monon uclea r le ucocytes DUR ING INFLAMMATION

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N. Y. Chasovskih

2009-01-01

Full Text Available Abstract. Pogrammed cell death of peripheral blood mononuclear leucocytes from patients with acute inflammatory diseases (non-nosocomial pneumonia, acute appendicitis was investigated under ex vivo conditions, upon cultivation of the cells with selective inhibitors of JNK (SP600125 and р38 МАРК (ML3403. In vitro addition of SP600125 and ML3403 under oxidative stress conditions prevents increase of annexinpositive mononuclear cells numbers, thus suggesting JNK and р38 МАР-kinases to be involved into oxidative mechanisms of apoptosis deregulation. A role of JNK in IL-8 production by mononuclear leucocytes was revealed in cases of acute inflammation. Regulatory effect of JNK and p38 MAP-kinases can be mediated through activation of redox-sensitive apoptogenic signal transduction systems, as well as due to changes in cellular cytokine-producing function.

Gα12/13 signaling promotes cervical cancer invasion through the RhoA/ROCK-JNK signaling axis

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Yuan, Bo; Cui, Jinquan; Wang, Wuliang; Deng, Kehong

2016-01-01

Several reports have indicated a role for the members of the G12 family of heterotrimeric G proteins (Gα12 and Gα13) in oncogenesis and tumor cell growth. The aims of the present study were to evaluate the role of G12 signaling in cervical cancer. We demonstrated that expression of the G12 proteins was highly upregulated in cervical cancer cells. Additionally, expression of the activated forms of Gα12/Gα13 but not expression of activated Gαq induced cell invasion through the activation of the RhoA family of G proteins, but had no effect on cell proliferation in the cervical cancer cells. Inhibition of G12 signaling by expression of the RGS domain of the p115-Rho-specific guanine nucleotide exchange factor (p115-RGS) blocked thrombin-stimulated cell invasion, but did not inhibit cell proliferation in cervical cells, whereas the inhibition of Gαq (RGS2) had no effect. Furthermore, G12 signaling was able to activate Rho proteins, and this stimulation was inhibited by p115-RGS, and Gα12-induced invasion was blocked by an inhibitor of RhoA/B/C (C3 toxin). Pharmacological inhibition of JNK remarkably decreased G12-induced JNK activation. Both a JNK inhibitor (SP600125) and a ROCK inhibitor (Y27632) reduced G12-induced JNK and c-Jun activation, and markedly inhibited G12-induced cellular invasion. Collectively, these findings demonstrate that stimulation of G12 proteins is capable of promoting invasion through RhoA/ROCK-JNK activation. -- Highlights: •Gα12/Gα13 is upregulated in cervical cancer cell lines. •Gα12/Gα13 is not involved in cervical cancer cell proliferation. •Gα12/Gα13 promotes cervical cancer cell invasion. •The role of Rho G proteins in G12-promoted cervical cancer cell invasion. •G12 promotes cell invasion through activation of the ROCK-JNK signaling axis.

Distinct Roles for JNK and IKK Activation in Agouti-Related Peptide Neurons in the Development of Obesity and Insulin Resistance

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Eva Tsaousidou

2014-11-01

Full Text Available Activation of c-Jun N-terminal kinase 1 (JNK1- and inhibitor of nuclear factor kappa-B kinase 2 (IKK2-dependent signaling plays a crucial role in the development of obesity-associated insulin and leptin resistance not only in peripheral tissues but also in the CNS. Here, we demonstrate that constitutive JNK activation in agouti-related peptide (AgRP-expressing neurons of the hypothalamus is sufficient to induce weight gain and adiposity in mice as a consequence of hyperphagia. JNK activation increases spontaneous action potential firing of AgRP cells and causes both neuronal and systemic leptin resistance. Similarly, activation of IKK2 signaling in AgRP neurons also increases firing of these cells but fails to cause obesity and leptin resistance. In contrast to JNK activation, IKK2 activation blunts insulin signaling in AgRP neurons and impairs systemic glucose homeostasis. Collectively, these experiments reveal both overlapping and nonredundant effects of JNK- and IKK-dependent signaling in AgRP neurons, which cooperate in the manifestation of the metabolic syndrome.

Cadmium induces matrix metalloproteinase-9 expression via ROS-dependent EGFR, NF-kB, and AP-1 pathways in human endothelial cells

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Lian, Sen; Xia, Yong; Khoi, Pham Ngoc; Ung, Trong Thuan; Yoon, Hyun Joong; Kim, Nam Ho; Kim, Kyung Keun; Jung, Young Do

2015-01-01

Highlights: • Cadmium induces MMP-9 expression through NADPH oxidase-derived ROS. • Cadmium induces MMP-9 through EGFR-mediated Akt, Erk1/2 and JNK1/2 signaling pathways. • Akt, MAPKs (Erk1/2 and JNK1/2) functioned as upstream signals of NF-kB and AP-1 respectively, in cadmium-induced MMP-9 in endothelial cells. • ROS production by NADPH oxidase is the furthest upstream signal in MMP-9 expression in ECV304 cells. - Abstract: Cadmium (Cd), a widespread cumulative pollutant, is a known human carcinogen, associated with inflammation and tumors. Matrix metalloproteinase-9 (MMP-9) plays a pivotal role in tumor metastasis; however, the mechanisms underlying the MMP-9 expression induced by Cd remain obscure in human endothelial cells. Here, Cd elevated MMP-9 expression in dose- and time-dependent manners in human endothelial cells. Cd increased ROS production and the ROS-producing NADPH oxidase. Cd translocates p47 phox , a key subunit of NADPH oxidase, to the cell membrane. Cd also activated the phosphorylation of EGFR, Akt, Erk1/2, and JNK1/2 in addition to promoting NF-kB and AP-1 binding activities. Specific inhibitor and mutagenesis studies showed that EGFR, Akt, Erk1/2, JNK1/2 and transcription factors NF-κB and AP-1 were related to Cd-induced MMP-9 expression in endothelial cells. Akt, Erk1/2, and JNK1/2 functioned as upstream signals in the activation of NF-κB and AP-1, respectively. In addition, N-acetyl-L-cystein (NAC), diphenyleneiodonium chloride (DPI) and apocynin (APO) inhibited the Cd-induced activation of EGFR, Akt, Erk1/2, JNK1/2, and p38 MAPK, indicating that ROS production by NADPH oxidase is the furthest upstream signal in MMP-9 expression. At present, it states that Cd displayed marked invasiveness in ECV304 cells, which was partially abrogated by MMP-9 neutralizing antibodies. These results demonstrated that Cd induces MMP-9 expression via ROS-dependent EGFR- > Erk1/2, JNK1/2- > AP-1 and EGFR- > Akt- > NF-κB signaling pathways and, in turn

CD274 promotes cell cycle entry of leukemia-initiating cells through JNK/Cyclin D2 signaling

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Xia Fang

2016-11-01

. The CD274/JNK/Cyclin D2 pathway promotes the cell cycle entry of LICs, which may serve as a novel therapeutic target for the treatment of leukemia.

Identification of ASK1, MKK4, JNK, c-Jun, and caspase-3 as a signaling cascade involved in cadmium-induced neuronal cell apoptosis

International Nuclear Information System (INIS)

Kim, Sun Don; Moon, Chang Kyu; Eun, Su-Yong; Ryu, Pan Dong; Jo, Sangmee Ahn

2005-01-01

Cd induces oxidative stress and apoptosis in various cells by activating mitogen-activated protein kinases (MAPKs), but the precise signaling components of the MAPK cascade and their role in neuronal apoptosis are still unclear. Here, we report that Cd treatment of SH-SY5Y cells caused apoptosis through sequential phosphorylation of the apoptosis signal regulating kinase 1, MAPK kinase 4, c-Jun N-terminal kinase (JNK), and c-Jun as determined by overexpression of dominant negative (DN) constructs of these genes or using a specific JNK inhibitor SP600125. Both Cd-induced JNK and c-Jun phosphorylation and apoptosis were inhibited dramatically by N-acetyl-L-cysteine, a free radical scavenger. In addition, caspase inhibitors, zDEVD and zVAD, reduced apoptosis but not JNK and c-Jun phosphorylation induced by Cd, while overexpression of DN JNK1 inhibited caspase-3 activity. Taken together, our data suggested that the JNK/c-Jun signaling cascade plays a crucial role in Cd-induced neuronal cell apoptosis and provides a molecular linkage between oxidative stress and neuronal apoptosis

PKCη confers protection against apoptosis by inhibiting the pro-apoptotic JNK activity in MCF-7 cells

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Rotem-Dai, Noa; Oberkovitz, Galia; Abu-Ghanem, Sara; Livneh, Etta

2009-01-01

Apoptosis is frequently regulated by different protein kinases including protein kinase C family enzymes. Both inhibitory and stimulatory effects were demonstrated for several of the different PKC isoforms. Here we show that the novel PKC isoform, PKCη, confers protection against apoptosis induced by the DNA damaging agents, UVC irradiation and the anti-cancer drug - Camptothecin, of the breast epithelial adenocarcinoma MCF-7 cells. The induced expression of PKCη in MCF-7 cells, under the control of the tetracycline-responsive promoter, resulted in increased cell survival and inhibition of cleavage of the apoptotic marker PARP-1. Activation of caspase-7 and 9 and the release of cytochrome c were also inhibited by the inducible expression of PKCη. Furthermore, JNK activity, required for apoptosis in MCF-7, as indicated by the inhibition of both caspase-7 cleavage and cytochrome c release from the mitochondria in the presence of the JNK inhibitor SP600125, was also suppressed by PKCη expression. Hence, in contrast to most PKC isoforms enhancing JNK activation, our studies show that PKCη is an anti-apoptotic protein, acting as a negative regulator of JNK activity. Thus, PKCη could represent a target for intervention aimed to reduce resistance to anti-cancer treatments.

Adhesion- and stress-related adaptation of glioma radiochemoresistance is circumvented by β1 integrin/JNK co-targeting.

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Vehlow, Anne; Klapproth, Erik; Storch, Katja; Dickreuter, Ellen; Seifert, Michael; Dietrich, Antje; Bütof, Rebecca; Temme, Achim; Cordes, Nils

2017-07-25

Resistance of cancer stem-like and cancer tumor bulk cells to radiochemotherapy and destructive infiltration of the brain fundamentally influence the treatment efficiency to cure of patients suffering from Glioblastoma (GBM). The interplay of adhesion and stress-related signaling and activation of bypass cascades that counteract therapeutic approaches remain to be identified in GBM cells. We here show that combined inhibition of the adhesion receptor β1 integrin and the stress-mediator c-Jun N-terminal kinase (JNK) induces radiosensitization and blocks invasion in stem-like and patient-derived GBM cultures as well as in GBM cell lines. In vivo, this treatment approach not only significantly delays tumor growth but also increases median survival of orthotopic, radiochemotherapy-treated GBM mice. Both, in vitro and in vivo, effects seen with β1 integrin/JNK co-inhibition are superior to the monotherapy. Mechanistically, the in vitro radiosensitization provoked by β1 integrin/JNK targeting is caused by defective DNA repair associated with chromatin changes, enhanced ATM phosphorylation and prolonged G2/M cell cycle arrest. Our findings identify a β1 integrin/JNK co-dependent bypass signaling for GBM therapy resistance, which might be therapeutically exploitable.

Cap-n-Collar Promotes Tissue Regeneration by Regulating ROS and JNK Signaling in the Drosophila melanogaster Wing Imaginal Disc.

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Brock, Amanda R; Seto, Mabel; Smith-Bolton, Rachel K

2017-07-01

Regeneration is a complex process that requires an organism to recognize and repair tissue damage, as well as grow and pattern new tissue. Here, we describe a genetic screen to identify novel regulators of regeneration. We ablated the Drosophila melanogaster larval wing primordium by inducing apoptosis in a spatially and temporally controlled manner and allowed the tissue to regenerate and repattern. To identify genes that regulate regeneration, we carried out a dominant-modifier screen by assessing the amount and quality of regeneration in adult wings heterozygous for isogenic deficiencies. We have identified 31 regions on the right arm of the third chromosome that modify the regenerative response. Interestingly, we observed several distinct phenotypes: mutants that regenerated poorly, mutants that regenerated faster or better than wild-type, and mutants that regenerated imperfectly and had patterning defects. We mapped one deficiency region to cap-n-collar ( cnc ), the Drosophila Nrf2 ortholog, which is required for regeneration. Cnc regulates reactive oxygen species levels in the regenerating epithelium, and affects c-Jun N-terminal protein kinase (JNK) signaling, growth, debris localization, and pupariation timing. Here, we present the results of our screen and propose a model wherein Cnc regulates regeneration by maintaining an optimal level of reactive oxygen species to promote JNK signaling. Copyright © 2017 by the Genetics Society of America.

PDK2 promotes chondrogenic differentiation of mesenchymal stem cells by upregulation of Sox6 and activation of JNK/MAPK/ERK pathway

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H. Wang

Full Text Available This study was undertaken to clarify the role and mechanism of pyruvate dehydrogenase kinase isoform 2 (PDK2 in chondrogenic differentiation of mesenchymal stem cells (MSCs. MSCs were isolated from femurs and tibias of Sprague-Dawley rats, weighing 300-400 g (5 females and 5 males. Overexpression and knockdown of PDK2 were transfected into MSCs and then cell viability, adhesion and migration were assessed. Additionally, the roles of aberrant PDK2 in chondrogenesis markers SRY-related high mobility group-box 6 (Sox6, type ΙΙ procollagen gene (COL2A1, cartilage oligomeric matrix protein (COMP, aggrecan (AGC1, type ΙX procollagen gene (COL9A2 and collagen type 1 alpha 1 (COL1A1 were measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR. The expressions of c-Jun N-terminal kinase (JNK, p38 mitogen-activated protein kinase (MAPK and extracellular regulated protein kinase (ERK were measured. Overexpressing PDK2 promoted cell viability, adhesion and inhibited cell migration in MSCs (all P<0.05. qRT-PCR assay showed a potent increase in the mRNA expressions of all chondrogenesis markers in response to overexpressing PDK2 (P<0.01 or P<0.05. PDK2 overexpression also induced a significant accumulation in mRNA and protein expressions of JNK, p38MAPK and ERK in MSCs compared to the control (P<0.01 or P<0.05. Meanwhile, silencing PDK2 exerted the opposite effects on MSCs. This study shows a preliminary positive role and potential mechanisms of PDK2 in chondrogenic differentiation of MSCs. It lays the theoretical groundwork for uncovering the functions of PDK2 and provides a promising basis for repairing cartilage lesions in osteoarthritis.

Differential gene expressions of the MAPK signaling pathway in enterovirus 71-infected rhabdomyosarcoma cells

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Weifeng Shi

Full Text Available BACKGROUND: Mitogen-activated protein kinase (MAPK signaling pathway plays an important role in response to viral infection. The aim of this study was to explore the function and mechanism of MAPK signaling pathway in enterovirus 71 (EV71 infection of human rhabdomyosarcoma (RD cells. METHODS: Apoptosis of RD cells was observed using annexin V-FITC/PI binding assay under a fluorescence microscope. Cellular RNA was extracted and transcribed to cDNA. The expressions of 56 genes of MAPK signaling pathway in EV71-infected RD cells at 8 h and 20 h after infection were analyzed by PCR array. The levels of IL-2, IL-4, IL-10, and TNF-α in the supernatant of RD cells infected with EV71 at different time points were measured by ELISA. RESULTS: The viability of RD cells decreased obviously within 48 h after EV71 infection. Compared with the control group, EV71 infection resulted in the significantly enhanced releases of IL-2, IL-4, IL-10 and TNF-α from infected RD cells (p < 0.05. At 8 h after infection, the expressions of c-Jun, c-Fos, IFN-i, MEKK1, MLK3 and NIK genes in EV71-infected RD cells were up-regulated by 2.08-6.12-fold, whereas other 19 genes (e.g. AKT1, AKT2, E2F1, IKK and NF-κB1 exhibited down-regulation. However, at 20 h after infection, those MAPK signaling molecules including MEKK1, ASK1, MLK2, MLK3, NIK, MEK1, MEK2, MEK4, MEK7, ERK1, JNK1 and JNK2 were up-regulated. In addition, the expressions of AKT2, ELK1, c-Jun, c-Fos, NF-κB p65, PI3K and STAT1 were also increased. CONCLUSION: EV71 infection induces the differential gene expressions of MAPK signaling pathway such as ERK, JNK and PI3K/AKT in RD cells, which may be associated with the secretions of inflammatory cytokines and host cell apoptosis.

Interplay among Drosophila transcription factors Ets21c, Fos and Ftz-F1 drives JNK-mediated tumor malignancy

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Eva Külshammer

2015-10-01

Full Text Available Cancer initiation and maintenance of the transformed cell state depend on altered cellular signaling and aberrant activities of transcription factors (TFs that drive pathological gene expression in response to cooperating genetic lesions. Deciphering the roles of interacting TFs is therefore central to understanding carcinogenesis and for designing cancer therapies. Here, we use an unbiased genomic approach to define a TF network that triggers an abnormal gene expression program promoting malignancy of clonal tumors, generated in Drosophila imaginal disc epithelium by gain of oncogenic Ras (RasV12 and loss of the tumor suppressor Scribble (scrib1. We show that malignant transformation of the rasV12scrib1 tumors requires TFs of distinct families, namely the bZIP protein Fos, the ETS-domain factor Ets21c and the nuclear receptor Ftz-F1, all acting downstream of Jun-N-terminal kinase (JNK. Depleting any of the three TFs improves viability of tumor-bearing larvae, and this positive effect can be enhanced further by their combined removal. Although both Fos and Ftz-F1 synergistically contribute to rasV12scrib1 tumor invasiveness, only Fos is required for JNK-induced differentiation defects and Matrix metalloprotease (MMP1 upregulation. In contrast, the Fos-dimerizing partner Jun is dispensable for JNK to exert its effects in rasV12scrib1 tumors. Interestingly, Ets21c and Ftz-F1 are transcriptionally induced in these tumors in a JNK- and Fos-dependent manner, thereby demonstrating a hierarchy within the tripartite TF network, with Fos acting as the most upstream JNK effector. Of the three TFs, only Ets21c can efficiently substitute for loss of polarity and cooperate with RasV12 in inducing malignant clones that, like rasV12scrib1 tumors, invade other tissues and overexpress MMP1 and the Drosophila insulin-like peptide 8 (Dilp8. While rasV12ets21c tumors require JNK for invasiveness, the JNK activity is dispensable for their growth. In conclusion, our

Postprandial triglyceride-rich lipoproteins promote invasion of human coronary artery smooth muscle cells in a fatty-acid manner through PI3k-Rac1-JNK signaling.

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Varela, Lourdes M; Bermúdez, Beatriz; Ortega-Gómez, Almudena; López, Sergio; Sánchez, Rosario; Villar, Jose; Anguille, Christelle; Muriana, Francisco J G; Roux, Pierre; Abia, Rocío

2014-06-01

The aim was to investigate the effect of postprandial triglyceride-rich lipoproteins (TRLs) with different fatty acid compositions on human coronary artery smooth muscle cell (hCASMC) invasion and to identify the molecular pathways involved. TRLs were isolated from the plasma of healthy volunteers after the ingestion of single meals enriched in MUFAs, saturated fatty acids (SFAs), or PUFAs. hCASMC invasion was analyzed using transwell chambers with Matrigel. TRLs-SFAs provoked the highest invasion, followed by TRLs-MUFAs and TRLs-PUFAs. Inhibition studies with Orlistat showed that invasion was dependent on the fatty acid composition of the TRLs. Fatty acids incorporated into the cell membranes strongly associated with cell invasion. Pull-down assays showed that TRLs-SFAs were able to increase Rac1 activity via inhibition of RhoA-dependent signaling. Chemical inhibition and siRNA studies showed that Rac1, PI3k, JNK, and MMP2 regulates TRL-SFA-induced hCASMC invasion. We demonstrate for the first time that TRLs induce hCASMCs invasion in a fatty acid dependent manner. This effect in TRLs-SFAs is mediated by the PI3k-Rac1-JNK, RhoA, and Rac1-MMP2 pathways. The ingestion of MUFA, compared to other dietary fatty acids such as SFA, could be considered as a nutritional strategy to reduce the atherosclerotic plaque formation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The experience of seeking, gaining and maintaining employment after traumatic spinal cord injury and the vocational pathways involved.

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Hilton, Gillean; Unsworth, Carolyn A; Stuckey, Ruth; Murphy, Gregory C

2018-01-01

Vocational potential in people with spinal cord injury (SCI) are unrealised with rates of employment substantially lower than in the labour force participation of the general population and the pre-injury employment rates. To understand the experience and pathway of people achieving employment outcome after traumatic spinal cord injury by; classifying participants into employment outcome groups of stable, unstable and without employment; identifying pre and post-injury pathways for participants in each group and, exploring the experiences of people of seeking, gaining and maintaining employment. Thirty-one participants were interviewed. Mixed methods approach including interpretive phenomenological analysis and vocational pathway mapping of quantitative data. The most common pathway identified was from study and work pre-injury to stable employment post-injury. Four super-ordinate themes were identified from the interpretive phenomenological analysis; expectations of work, system impacts, worker identity and social supports. Implications for clinical practice include fostering cultural change, strategies for system navigation, promotion of worker identity and optimal use of social supports. The findings increase insight and understanding of the complex experience of employment after spinal cord injury. There is opportunity to guide experimental research, policy development and education concerning the complexity of the return to work experience and factors that influence pathways.

MAPK inhibitors, particularly the JNK inhibitor, increase cell death effects in H2O2-treated lung cancer cells via increased superoxide anion and glutathione depletion.

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Park, Woo Hyun

2018-02-01

Reactive oxygen species (ROS), especially hydrogen peroxide (H2O2), induce apoptosis in cancer cells by regulating mitogen-activated protein kinase (MAPK) signaling pathways. The present study investigated the effects of MAPK inhibitors on cell growth and death as well as changes in ROS and glutathione (GSH) levels in H2O2-treated Calu-6 and A549 lung cancer cells. H2O2 inhibited growth and induced death of Calu-6 and A549 lung cancer cells. All MAPK inhibitors appeared to enhance growth inhibition in H2O2-treated Calu-6 and A549 lung cancer cells and increased the percentage of Annexin V-FITC-positive cells in these cancer cells. Among the MAPK inhibitors, a JNK inhibitor significantly augmented the loss of mitochondrial membrane potential (MMP; ΔΨm) in H2O2-treated Calu-6 and A549 lung cancer cells. Intracellular ROS levels were significantly increased in the H2O2-treated cells at 1 and 24 h. Only the JNK inhibitor increased ROS levels in the H2O2-treated cells at 1 h and all MAPK inhibitors raised superoxide anion levels in these cells at 24 h. In addition, H2O2 induced GSH depletion in Calu-6 and A549 cells and the JNK inhibitor significantly enhanced GSH depletion in H2O2‑treated cells. Each of the MAPK inhibitors altered ROS and GSH levels differently in the Calu-6 and A549 control cells. In conclusion, H2O2 induced growth inhibition and death in lung cancer cells through oxidative stress and depletion of GSH. The enhanced effect of MAPK inhibitors, especially the JNK inhibitor, on cell death in H2O2-treated lung cancer cells was correlated with increased O2•- levels and GSH depletion.

JWA gene regulates PANC-1 pancreatic cancer cell behaviors through MEK-ERK1/2 of the MAPK signaling pathway.

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Wu, Yuan-Yuan; Ma, Tie-Liang; Ge, Zhi-Jun; Lin, Jie; Ding, Wei-Liang; Feng, Jia-Ke; Zhou, Su-Jun; Chen, Guo-Chang; Tan, Yong-Fei; Cui, Guo-Xing

2014-10-01

The present study aimed to investigate the role of JWA gene in the proliferation, apoptosis, invasion and migration of PANC-1 pancreatic cancer cells and the effect on the MAPK signaling pathway. Human PANC-1 pancreatic cancer cells were cultured in vitro , and small interfering RNA (siRNA) was designed for the JWA gene. The siRNA was transfected into PANC-1 cells. Subsequently, the cell proliferation was measured by MTT assay; cell apoptosis was detected by analyzing BAX and Bcl-2 protein expression; cell migration and invasion were measured using Transwell ® chambers; and the protein expression of JWA and ERK1/2, JNK and p38 and their phosphorylated forms were measured by western blotting. By utilizing the MTT assay, the results showed that when JWA protein expression was inhibited, the proliferation of PANC-1 cells was enhanced. In addition, the expression of apoptosis-associated protein (AAP) BAX was substantially decreased, while the expression of the apoptosis inhibitor gene, Bcl-2 , was significantly enhanced. Using Transwell chambers, it was found that the number of penetrating PANC-1 cells was significantly increased after transfection with JWA siRNA, suggesting that the migration and invasion of the cells was substantially increased. By studying the association between JWA and the MAPK pathway in PANC-1 cells, it was found that the expression of p-ERK1/2 of the MAPK pathway was significantly downregulated following JWA siRNA transfection. However, the expression levels of ERK1/2, JNK, p38, p-JNK and p-p38 showed no significant differences. In conclusion, it was shown that JWA affects the proliferation, apoptosis, invasion and migration of PANC-1 pancreatic cancer cells which could be attributed to effects on the expression of ERK1/2 in the MAPK pathway.

The natural triterpene maslinic acid induces apoptosis in HT29 colon cancer cells by a JNK-p53-dependent mechanism

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Reyes-Zurita, Fernando J; Pachón-Peña, Gisela; Lizárraga, Daneida; Rufino-Palomares, Eva E; Cascante, Marta; Lupiáñez, José A

2011-01-01

Maslinic acid, a pentacyclic triterpene found in the protective wax-like coating of the leaves and fruit of Olea europaea L., is a promising agent for the prevention of colon cancer. We have shown elsewhere that maslinic acid inhibits cell proliferation to a significant extent and activates mitochondrial apoptosis in colon cancer cells. In our latest work we have investigated further this compound's apoptotic molecular mechanism. We used HT29 adenocarcinoma cells. Changes genotoxicity were analyzed by single-cell gel electrophoresis (comet assay). The cell cycle was determined by flow cytometry. Finally, changes in protein expression were examined by western blotting. Student's t-test was used for statistical comparison. HT29 cells treated with maslinic acid showed significant increases in genotoxicity and cell-cycle arrest during the G0/G1 phase after 72 hours' treatment and an apoptotic sub-G0/G1 peak after 96 hours. Nevertheless, the molecular mechanism for this cytotoxic effect of maslinic acid has never been properly explored. We show here that the anti-tumoral activity of maslinic acid might proceed via p53-mediated apoptosis by acting upon the main signaling components that lead to an increase in p53 activity and the induction of the rest of the factors that participate in the apoptotic pathway. We found that in HT29 cells maslinic acid activated the expression of c-Jun NH2-terminal kinase (JNK), thus inducing p53. Treatment of tumor cells with maslinic acid also resulted in an increase in the expression of Bid and Bax, repression of Bcl-2, release of cytochrome-c and an increase in the expression of caspases -9, -3, and -7. Moreover, maslinic acid produced belated caspase-8 activity, thus amplifying the initial mitochondrial apoptotic signaling. All these results suggest that maslinic acid induces apoptosis in human HT29 colon-cancer cells through the JNK-Bid-mediated mitochondrial apoptotic pathway via the activation of p53. Thus we propose

Hydrogen sulfide (H{sub 2}S)/cystathionine γ-lyase (CSE) pathway contributes to the proliferation of hepatoma cells

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Pan, Yan; Ye, Shuang; Yuan, Dexiao; Zhang, Jianghong; Bai, Yang; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

2014-05-15

Highlights: • Inhibition of H{sub 2}S/CSE pathway strongly stimulates cellular apoptosis. • Inhibition of H{sub 2}S/CSE pathway suppresses cell growth by blocking EGFR pathway. • H{sub 2}S/CSE pathway is critical for maintaining the proliferation of hepatoma cells. - Abstract: Hydrogen sulfide (H{sub 2}S)/cystathionine γ-lyase (CSE) pathway has been demonstrated to play vital roles in physiology and pathophysiology. However, its role in tumor cell proliferation remains largely unclear. Here we found that CSE over-expressed in hepatoma HepG2 and PLC/PRF/5 cells. Inhibition of endogenous H{sub 2}S/CSE pathway drastically decreased the proliferation of HepG2 and PLC/PRF/5 cells, and it also enhanced ROS production and mitochondrial disruption, pronounced DNA damage and increased apoptosis. Moreover, this increase of apoptosis was associated with the activation of p53 and p21 accompanied by a decreased ratio of Bcl-2/Bax and up-regulation of phosphorylated c-Jun N-terminal kinase (JNK) and caspase-3 activity. In addition, the negative regulation of cell proliferation by inhibition of H{sub 2}S/CSE system correlated with the blockage of cell mitogenic and survival signal transduction of epidermal growth factor receptor (EGFR) via down-regulating the extracellular-signal-regulated kinase 1/2 (ERK1/2) activation. These results demonstrate that H{sub 2}S/CSE and its downstream pathway contribute to the proliferation of hepatoma cells, and inhibition of this pathway strongly suppress the excessive growth of hepatoma cells by stimulating mitochondrial apoptosis and suppressing cell growth signal transduction.

Kaempferol Sensitizes Human Ovarian Cancer Cells-OVCAR-3 and SKOV-3 to Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)-Induced Apoptosis via JNK/ERK-CHOP Pathway and Up-Regulation of Death Receptors 4 and 5.

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Zhao, Yingmei; Tian, Binqiang; Wang, Yong; Ding, Haiying

2017-10-26

BACKGROUND Ovarian cancer is the most common gynecological malignancies in women, with high mortality rates worldwide. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) superfamily which preferentially induces apoptosis of cancer cells. However, acquired resistance to TRAIL hampers its therapeutic application. Identification of compounds that sensitize cancer cells to TRAIL is vital in combating resistance to TRAIL. The effect of kaempferol, a flavonoid enhancing TRAIL-induced apoptosis in ovarian cancer cells, was investigated in this study. MATERIAL AND METHODS The cytotoxic effects of TRAIL (25 ng/mL) and kaempferol (20-100 µM) on human ovarian cancer cells OVCAR-3 and SKOV-3 were assessed. Effect of kaempferol on the expression patterns of cell survival proteins (Bcl-xL, Bcl-2, survivin, XIAP, c-FLIP) and apoptotic proteins (caspase-3, caspase-8, caspase-9, Bax) were studied. The influence of kaempferol on expression of DR4 and DR5 death receptors on the cell surface and protein and mRNA levels was also analyzed. Apoptosis following silencing of DR5 and CHOP by small interfering RNA (siRNA), and activation of MAP kinases were analyzed as well. RESULTS Kaempferol enhanced apoptosis and drastically up-regulated DR4, DR5, CHOP, JNK, ERK1/2, p38 and apoptotic protein expression with decline in the expression of anti-apoptotic proteins. Further transfection with siRNA specific to CHOP and DR5 indicated the involvement of CHOP in DR5 up-regulation and also the contribution of DR5 in kaempferol-enhanced TRAIL-induced apoptosis. CONCLUSIONS Kaempferol sensitized ovarian cancer cells to TRAIL-induced apoptosis via up-regulation of DR4 and DR5 through ERK/JNK/CHOP pathways.

Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47phox pathway

International Nuclear Information System (INIS)

Tsai, Ming-Horng; Lin, Zih-Chan; Liang, Chan-Jung; Yen, Feng-Lin; Chiang, Yao-Chang; Lee, Chiang-Wen

2014-01-01

Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phox activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases. - Highlights: • LPS activates the Nox2/p47 phox /JNK/AP-1 and induces COX2 expression in Hs68 cells. • Eupafolin inhibits LPS-induced COX-2 expression via Nox2/p47 phox inhibition. • Eupafolin may be used in the treatment of skin diseases involving inflammation

Role of the mixed-lineage protein kinase pathway in the metabolic stress response to obesity

OpenAIRE

Kant, Shashi; Barrett, Tamera; Vertii, Anastassiia; Noh, Yun Hee; Jung, Dae Young; Kim, Jason K.; Davis, Roger J.

2013-01-01

Saturated free fatty acid (FFA) is implicated in the metabolic response to obesity. In vitro studies indicate that FFA signaling may be mediated by the mixed-lineage protein kinase (MLK) pathway that activates cJun NH2-terminal kinase (JNK). Here, we examined the role of the MLK pathway in vivo using a mouse model of diet-induced obesity. The ubiquitously expressed MLK2 and MLK3 protein kinases have partially redundant functions. We therefore compared wild-type and compound mutant mice that l...

MAPK Signal Transduction Pathway Regulation: A Novel Mechanism of Rat HSC-T6 Cell Apoptosis Induced by FUZHENGHUAYU Tablet

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Qi Wang

2013-01-01

Full Text Available FUZHENGHUAYU Tablets have been widely used in the treatment of liver fibrosis in China. Here, we investigate the apoptotic effect of FUZHENGHUAYU Tablet in rat liver stellate cell line HSC-T6. HSC-T6 cells were incubated with control serum or drug serum from rats fed with 0.9% NaCl or FUZHENGHUAYU Tablet, respectively. Cells exposed to drug serum showed higher proportions of early and late apoptotic cells than controls. The mRNA levels of collagens I and III, TGF-β1 and α-SMA were reduced by drug serum compared to control serum. Differentially expressed mRNAs and miRNAs were analyzed by microarray and sequencing, respectively. We identified 334 differentially expressed mRNAs and also 60 GOs and two pathways related to the mRNAs. Seventy-five differentially expressed miRNAs were down-regulated by drug serum and 1963 target genes were predicted. 134 GOs up-regulated in drug serum group were linked to miRNA targets, and drug serum also regulated 43 miRNA signal transduction pathways. Protein levels were evaluated by Western blot. Drug serum down-regulated (phospho-SAPK/JNK/(SAPK/JNK and up-regulated phospho-p38/p38 ratios. The study showed that FUZHENGHUAYU Tablet induced apoptosis in rat HSC-T6 cells possibly in part by activating p38 and inhibiting SAPK/JNK.

Bee venom suppresses PMA-mediated MMP-9 gene activation via JNK/p38 and NF-kappaB-dependent mechanisms.

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Cho, Hyun-Ji; Jeong, Yun-Jeong; Park, Kwan-Kyu; Park, Yoon-Yub; Chung, Il-Kyung; Lee, Kwang-Gill; Yeo, Joo-Hong; Han, Sang-Mi; Bae, Young-Seuk; Chang, Young-Chae

2010-02-17

Bee venom has been used for the treatment of inflammatory diseases such as rheumatoid arthritis and for the relief of pain in traditional oriental medicine. The purpose of this study is to elucidate the effects of bee venom on MMP-9 expression and determine possible mechanisms by which bee venom relieves or prevents the expression of MMP-9 during invasion and metastasis of breast cancer cells. We examined the expression and activity of MMP-9 and possible signaling pathway affected in PMA-induced MCF-7 cells. Bee venom was obtained from the National Institute of Agricultural Science and Technology of Korea. Matrigel invasion assay, wound-healing assay, zymography assay, western blot assay, electrophoretic mobility shift assay and luciferase gene assay were used for assessment. Bee venom inhibited cell invasion and migration, and also suppressed MMP-9 activity and expression, processes related to tumor invasion and metastasis, in PMA-induced MCF-7 cells. Bee venom specifically suppressed the phosphorylation of p38/JNK and at the same time, suppressed the protein expression, DNA binding and promoter activity of NF-kappaB. The levels of phosphorylated ERK1/2 and c-Jun did not change. We also investigated MMP-9 inhibition by melittin, apamin and PLA(2), representative single component of bee venom. We confirmed that PMA-induced MMP-9 activity was significantly decreased by melittin, but not by apamin and phospholipase A(2). These data demonstrated that the expression of MMP-9 was abolished by melittin, the main component of bee venom. Bee venom inhibits PMA-induced MMP-9 expression and activity by inhibition of NF-kappaB via p38 MAPK and JNK signaling pathways in MCF-7 cells. These results indicate that bee venom can be a potential anti-metastatic and anti-invasive agent. This useful effect may lead to future clinical research on the anti-cancer properties of bee venom. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Propolis augments apoptosis induced by butyrate via targeting cell survival pathways.

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Eric Drago

Full Text Available Diet is one of the major lifestyle factors affecting incidence of colorectal cancer (CC, and despite accumulating evidence that numerous diet-derived compounds modulate CC incidence, definitive dietary recommendations are not available. We propose a strategy that could facilitate the design of dietary supplements with CC-preventive properties. Thus, nutrient combinations that are a source of apoptosis-inducers and inhibitors of compensatory cell proliferation pathways (e.g., AKT signaling may produce high levels of programmed death in CC cells. Here we report the combined effect of butyrate, an apoptosis inducer that is produced through fermentation of fiber in the colon, and propolis, a honeybee product, on CC cells. We established that propolis increases the apoptosis of CC cells exposed to butyrate through suppression of cell survival pathways such as the AKT signaling. The programmed death of CC cells by combined exposure to butyrate and propolis is further augmented by inhibition of the JNK signaling pathway. Analyses on the contribution of the downstream targets of JNK signaling, c-JUN and JAK/STAT, to the apoptosis of butyrate/propolis-treated CC cells ascertained that JAK/STAT signaling has an anti-apoptotic role; whereas, the role of cJUN might be dependent upon regulatory cell factors. Thus, our studies ascertained that propolis augments apoptosis of butyrate-sensitive CC cells and re-sensitizes butyrate-resistant CC cells to apoptosis by suppressing AKT signaling and downregulating the JAK/STAT pathway. Future in vivo studies should evaluate the CC-preventive potential of a dietary supplement that produces high levels of colonic butyrate, propolis, and diet-derived JAK/STAT inhibitors.

Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47{sup phox} pathway

Energy Technology Data Exchange (ETDEWEB)

Tsai, Ming-Horng [Department of Pediatrics, Division of Neonatology and Pediatric Hematology/Oncology, Chang Gung Memorial Hospital, Yunlin, Taiwan (China); Lin, Zih-Chan [Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Liang, Chan-Jung [Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Yen, Feng-Lin [Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Institute of Biomedical Sciences, Sun Yat-Sen University, 70 Lienhai Rd., Kaohsiung, Taiwan (China); Chiang, Yao-Chang [Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan (China); China Medical University, Taichung, Taiwan (China); Lee, Chiang-Wen, E-mail: cwlee@gw.cgust.edu.tw [Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi, Taiwan (China); Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chia-Yi, Taiwan (China); Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan (China)

2014-09-01

Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phox activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases. - Highlights: • LPS activates the Nox2/p47{sup phox}/JNK/AP-1 and induces COX2 expression in Hs68 cells. • Eupafolin inhibits LPS-induced COX-2 expression via Nox2/p47{sup phox} inhibition. • Eupafolin may be used in the treatment of skin diseases involving inflammation.

Dioscorin isolated from Dioscorea alata activates TLR4-signaling pathways and induces cytokine expression in macrophages.

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Fu, Shu-Ling; Hsu, Ya-Hui; Lee, Pei-Yeh; Hou, Wen-Chi; Hung, Ling-Chien; Lin, Chao-Hsiung; Chen, Chiu-Ming; Huang, Yu-Jing

2006-01-06

The Toll-like receptor 4 (TLR4)-signaling pathway is crucial for activating both innate and adaptive immunity. TLR4 is a promising molecular target for immune-modulating drugs, and TLR4 agonists are of therapeutic potential for treating immune diseases and cancers. Several medicinal herb-derived components have recently been reported to act via TLR4-dependent pathways, suggesting that medicinal plants are potential resources for identifying TLR4 activators. We have applied a screening procedure to systematically identify herbal constituents that activate TLR4. To exclude possible LPS contamination in these plant-derived components, a LPS inhibitor, polymyxin B, was added during screening. One of the plant components we identified from the screening was dioscorin, the glycoprotein isolated from Dioscorea alata. It induced TLR4-downstream cytokine expression in bone marrow cells isolated from TLR4-functional C3H/HeN mice but not from TLR4-defective C3H/HeJ mice. Dioscorin also stimulated multiple signaling molecules (NF-kappaB, ERK, JNK, and p38) and induced the expression of cytokines (TNF-alpha, IL-1beta, and IL-6) in murine RAW 264.7 macrophages. Furthermore, the ERK, p38, JNK, and NF-kappaB-mediated pathways are all involved in dioscorin-mediated TNF-alpha production. In summary, our results demonstrate that dioscorin is a novel TLR4 activator and induces macrophage activation via typical TLR4-signaling pathways.

Cordyceps militaris Fraction induces apoptosis and G2/M Arrest via c-Jun N-Terminal kinase signaling pathway in oral squamous carcinoma KB Cells.

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Xie, Wangshi; Zhang, Zhang; Song, Liyan; Huang, Chunhua; Guo, Zhongyi; Hu, Xianjing; Bi, Sixue; Yu, Rongmin

2018-01-01

Cordyceps militaris fraction (CMF) has been shown to possess in vitro antitumor activity against human chronic myeloid leukemia K562 cells in our previous research. The in vitro inhibitory activities of CMF on the growth of KB cells were evaluated by viability assay. The apoptotic and cell cycle influences of CMF were detected by 4',6-diamidino-2-phenylindole staining and flow cytometry assay. The expression of different apoptosis-associated proteins and cell cycle regulatory proteins was examined by Western blot assay. The nuclear localization of c-Jun was observed by fluorescence staining. The objective of this study was to investigate the antiproliferative effect of CMF as well as the mechanism underlying the apoptosis and cell cycle arrest it induces in KB cells. CMF suppressed KB cells' proliferation in a dose- and time-dependent manner. Flow cytometric analysis indicated that CMF induced G2/M cell cycle arrest and apoptosis. Western blot analysis revealed that CMF induced caspase-3, caspase-9, and PARP cleavages, and increased the Bax/Bcl-2 ratio. CMF also led to increased expression of p21, decreased expression of cyclin B1, mitotic phosphatase cdc25c, and mitotic kinase cdc2, as well as unchanged expression of p53. In addition, CMF stimulated c-Jun N-terminal kinases (JNK) protein phosphorylations, resulting in upregulated expression of c-Jun and nuclear localization of c-Jun. Pretreatment with JNK inhibitor SP600125 suppressed CMF-induced apoptosis and G2/M arrest. CMF is capable of modulating c-Jun caspase and Bcl-2 family proteins through JNK-dependent apoptosis, which results in G2/M phase arrest in KB cells. CMF could be developed as a promising candidate for the new antitumor agents. CMF exhibited strong anticancer activity against oral squamous carcinoma KB cellsCMF inhibited KB cells' proliferation via induction of apoptosis and G2/M cell cycle arrestCMF activated JNK signaling pathway and promoted the nuclear localization of c-JunCMF regulated the

MAP kinase pathways and calcitonin influence CD44 alternate isoform expression in prostate cancer cells

International Nuclear Information System (INIS)

Robbins, Eric W; Travanty, Emily A; Yang, Kui; Iczkowski, Kenneth A

2008-01-01

Dysregulated expression and splicing of cell adhesion marker CD44 is found in many types of cancer. In prostate cancer (PC) specifically, the standard isoform (CD44s) has been found to be downregulated compared with benign tissue whereas predominant variant isoform CD44v7-10 is upregulated. Mitogen-activated protein kinase pathways and paracrine calcitonin are two common factors linked to dysregulated expression and splicing of CD44 in cancer. Calcitonin has been found to increase proliferation and invasion in PC acting through the protein kinase A pathway. In androgen-independent PC with known high CD44v7-10 expression, CD44 total and CD44v7-10 RNA or protein were assessed in response to exogenous and endogenous calcitonin and to inhibitors of protein kinase A, MEK, JNK, or p38 kinase. Benign cells and calcitonin receptor-negative PC cells were also tested. MEK or p38 but not JNK reduced CD44 total RNA by 40%–65% in cancer and benign cells. Inhibition of protein kinase A reduced CD44 total and v7-10 protein expression. In calcitonin receptor-positive cells only, calcitonin increased CD44 variant RNA and protein by 3 h and persisting to 48 h, apparently dependent on an uninhibited p38 pathway. Cells with constitutive CT expression showed an increase in CD44v7-10 mRNA but a decrease in CD44 total RNA. The MEK pathway increases CD44 RNA, while calcitonin, acting through the protein kinase A and p38 pathway, facilitates variant splicing. These findings could be used in the formulation of therapeutic methods for PC targeting CD44 alternate splicing

Low-dose radiation induces drosophila innate immunity through toll pathway activation

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Seong, Ki Moon; Kim, Cha Soon; Lee, Byung-Sub; Nam, Seon Young; Yang, Kwang Hee; Kim, Ji-Young; Jin, Young-Woo; Park, Joong-Jean; Min, Kyung-Jin

2012-01-01

Numerous studies report that exposing certain organisms to low-dose radiation induces beneficial effects on lifespan, tumorigenesis, and immunity. By analyzing survival after bacterial infection and antimicrobial peptide gene expression in irradiated flies, we demonstrate that low-dose irradiation of Drosophila enhances innate immunity. Low-dose irradiation of flies significantly increased resistance against gram-positive and gram-negative bacterial infections, as well as expression of several antimicrobial peptide genes. Additionally, low-dose irradiation also resulted in a specific increase in expression of key proteins of the Toll signaling pathway and phosphorylated forms of p38 and N-terminal kinase (JNK). These results indicate that innate immunity is activated after low-dose irradiation through Toll signaling pathway in Drosophila. (author)

MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

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Yu, Teng; Ji, Jiang; Guo, Yong-li

2013-01-01

Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

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Yu, Teng, E-mail: tengyu33@yahoo.com [Department of Dermatology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China); Ji, Jiang [Department of Dermatology, The Second Hospital Affiliated of Soochow University, SuZhou, Jiangsu Province 215000 (China); Guo, Yong-li [Department of Oncology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China)

2013-11-08

Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells.

Acquired tolerance in cadmium-adapted lung epithelial cells: Roles of the c-Jun N-terminal kinase signaling pathway and basal level of metallothionein

International Nuclear Information System (INIS)

Lau, Andy T.Y.; Zhang Jian; Chiu, J.-F.

2006-01-01

Cadmium-resistant cells were developed in our laboratory with rat lung epithelial cells (LECs) by stepwise exposure of LECs to cadmium chloride from 1 μM to 20 μM after 20 passages. To investigate the Cd-resistant phenotype in a long-term perspective, cadmium-resistant cells adapted to 20 μM cadmium (Cd R ) were then cultured in the absence of cadmium for various passages [Cd R (-n)]. All these adapted cells were significantly protected from cadmium toxicity as compared to parental cadmium-sensitive LECs (Cd S ). The cadmium-resistant phenotype of adapted cells was relatively stable in the absence of cadmium for as long as 40 passages. Basal mRNA level of metallothionein-1 (MT-1) was dramatically higher in Cd R than in Cd R (-), which may account for the higher Cd-resistance of Cd R than Cd R (-). MT-1 mRNA level decreased drastically in Cd R after cadmium removal, suggesting that the high basal level of MT-1 in Cd R may be only partially responsible for cadmium-resistance. Treatment of cells with high levels of cadmium resulted in decreased phosphorylation of c-Jun N-terminal kinase (JNK1/2) in adapted cells than in sensitive cells and this cadmium-induced JNK activity was blocked by JNK inhibitor II, SP600125. Ro318220, a strong activator of JNK, reverted cadmium-sensitive phenotype in adapted cells. Taken together, our results suggest that during cadmium adaptation, cells develop tolerance to cell death, generally due to perturbation of the JNK signaling pathway and the nonresponsiveness of JNK phosphorylation is critical for the Cd-tolerance in these cells

The nitric oxide-sensitive p21Ras-ERK pathway mediates S-nitrosoglutathione-induced apoptosis

International Nuclear Information System (INIS)

Tsujita, Maristela; Batista, Wagner L.; Ogata, Fernando T.; Stern, Arnold; Monteiro, Hugo P.; Arai, Roberto J.

2008-01-01

p21Ras protein plays a critical role in cellular signaling that induces either cell cycle progression or apoptosis. Nitric oxide (NO) has been consistently reported to activate p21Ras through the redox sensitive cysteine residue (118). In this study, we demonstrated that the p21Ras-ERK pathway regulates THP-1 monocyte/macrophage apoptosis induced by S-nitrosoglutathione (SNOG). This was apparent from studies in THP-1 cells expressing NO-insensitive p21Ras (p21Ras C118S ) where the pro-apoptotic action of SNOG was almost abrogated. Three major MAP kinase pathways (ERK, JNK, and p38) that are downstream to p21Ras were investigated. It was observed that only the activation of ERK1/2 MAP kinases by SNOG in THP-1 cells was attributable to p21Ras. The inhibition of the ERK pathway by PD98059 markedly attenuated apoptosis in SNOG-treated THP-1 cells, but had a marginal effect on SNOG-treated THP-1 cells expressing NO-insensitive p21Ras. The inhibition of the JNK and p38 pathways by selective inhibitors had no marked effects on the percentage of apoptosis. The induction of p21Waf1 expression by SNOG was observed in THP-1 cells harboring mutant and wild-type p21Ras, however in cells expressing mutant Ras, the expression of p21Waf1 was significantly attenuated. The treatment of THP-1 cells expressing wild-type p21Ras with PD98059 resulted in significant attenuation of p21Waf1 expression. These results indicate that the redox sensitive p21Ras-ERK pathway plays a critical role in sensing and delivering the pro-apoptotic signaling mediated by SNOG

Apoptosis of bone marrow mesenchymal stem cells caused by homocysteine via activating JNK signal.

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Benzhi Cai

Full Text Available Bone marrow mesenchymal stem cells (BMSCs are capable of homing to and repair damaged myocardial tissues. Apoptosis of BMSCs in response to various pathological stimuli leads to the attenuation of healing ability of BMSCs. Plenty of evidence has shown that elevated homocysteine level is a novel independent risk factor of cardiovascular diseases. The present study was aimed to investigate whether homocysteine may induce apoptosis of BMSCs and its underlying mechanisms. Here we uncovered that homocysteine significantly inhibited the cellular viability of BMSCs. Furthermore, TUNEL, AO/EB, Hoechst 333342 and Live/Death staining demonstrated the apoptotic morphological appearance of BMSCs after homocysteine treatment. A distinct increase of ROS level was also observed in homocysteine-treated BMSCs. The blockage of ROS by DMTU and NAC prevented the apoptosis of BMSCs induced by homocysteine, indicating ROS was involved in the apoptosis of BMSCs. Moreover, homocysteine also caused the depolarization of mitochondrial membrane potential of BMSCs. Furthermore, apoptotic appearance and mitochondrial membrane potential depolarization in homocysteine-treated BMSCs was significantly reversed by JNK inhibitor but not p38 MAPK and ERK inhibitors. Western blot also confirmed that p-JNK was significantly activated after exposing BMSCs to homocysteine. Homocysteine treatment caused a significant reduction of BMSCs-secreted VEGF and IGF-1 in the culture medium. Collectively, elevated homocysteine induced the apoptosis of BMSCs via ROS-induced the activation of JNK signal, which provides more insight into the molecular mechanisms of hyperhomocysteinemia-related cardiovascular diseases.

Effects of sodium fluoride on MAPKs signaling pathway in the gills of a freshwater teleost, Cyprinus carpio.

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Cao, Jinling; Chen, Jianjie; Wang, Jundong; Klerks, Paul; Xie, Lingtian

2014-07-01

Exposure to elevated levels of fluoride can cause a variety of adverse effects in fish. Previously we showed that fluoride causes injuries and apoptosis in the gills of Cyprinus carpio. In this study, the effects of fluoride on caspase-3 activity and on accumulation of proteins in the MAPKs pathways were evaluated using Western blotting and immunohistochemistry methods in vivo and in vitro. In vivo experiments showed that the caspase-3 activity increased with fluoride exposure level in a dose-dependent pattern Western blotting and immunohistochemistry results indicated that ERK relative activation tended to decrease as a function of fluoride exposure concentration. In contrast, relative activation of JNK increased with fluoride exposure level. Fluoride exposure did not appear to affect p38 activation. Furthermore, pretreatment of branchial cells with MAPK-specific inhibitors effectively prevented JNK induction and ERK inhibition, respectively, as well as reversed caspase-3 activity in fluoride-treated branchial cells. Our results indicate that activation of JNK and inactivation of ERK were caused by increased ROS and decreased antioxidant capacity in the gills of chronically exposed C. carpio described previously, which eventually caused the observed apoptosis in the fluoride-exposed gills and cells in C. carpio. JNK activation and ERK inactivation mechanism play a crucial role in gill impairment induced by chronic fluorosis. These findings contribute to a better understanding of the initial molecular and cellular events in the gill of fish chronically exposed to fluoride. Copyright © 2014 Elsevier B.V. All rights reserved.

How Do Positive Views Maintain Life Satisfaction?

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Wu, Chia-Huei; Tsai, Ying-Mei; Chen, Lung Hung

2009-01-01

This study proposes three mediation pathways to explain how the positive views (perceived control, optimism and self-enhancement) proposed by Cummins and Nistico (Journal of Happiness Studies 3:37-69 2002) maintain life satisfaction. The three pathways were enhancing self-esteem, reducing have-want discrepancy and changing importance perceptions.…

Fluid shear promotes chondrosarcoma cell invasion by activating matrix metalloproteinase 12 via IGF-2 and VEGF signaling pathways

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Wang, P; Chen, S-H; Hung, W-C; Paul, C; Zhu, F; Guan, P-P; Huso, DL; Kontrogianni-Konstantopoulos, A; Konstantopoulos, K

2015-01-01

Interstitial fluid flow in and around the tumor tissue is a physiologically relevant mechanical signal that regulates intracellular signaling pathways throughout the tumor. Yet, the effects of interstitial flow and associated fluid shear stress on the tumor cell function have been largely overlooked. Using in vitro bioengineering models in conjunction with molecular cell biology tools, we found that fluid shear (2 dyn/cm2) markedly upregulates matrix metalloproteinase 12 (MMP-12) expression and its activity in human chondrosarcoma cells. MMP-12 expression is induced in human chondrocytes during malignant transformation. However, the signaling pathway regulating MMP-12 expression and its potential role in human chondrosarcoma cell invasion and metastasis have yet to be delineated. We discovered that fluid shear stress induces the synthesis of insulin growth factor-2 (IGF-2) and vascular endothelial growth factor (VEGF) B and D, which in turn transactivate MMP-12 via PI3-K, p38 and JNK signaling pathways. IGF-2-, VEGF-B- or VEGF-D-stimulated chondrosarcoma cells display markedly higher migratory and invasive potentials in vitro, which are blocked by inhibiting MMP-12, PI3-K, p38 or JNK activity. Moreover, recombinant human MMP-12 or MMP-12 overexpression can potentiate chondrosarcoma cell invasion in vitro and the lung colonization in vivo. By reconstructing and delineating the signaling pathway regulating MMP-12 activation, potential therapeutic strategies that interfere with chondrosarcoma cell invasion may be identified. PMID:25435370

Insulin regulates multiple signaling pathways leading to monocyte/macrophage chemotaxis into the wound tissue

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Yan Liu

2018-01-01

Full Text Available Wound healing is a complex process that involves sequential phases that overlap in time and space and affect each other dynamically at the gene and protein levels. We previously showed that insulin accelerates wound healing by stimulating faster and regenerative healing. One of the processes that insulin stimulates is an increase in monocyte/macrophage chemotaxis. In this study, we performed experiments in vivo and in vitro to elucidate the signaling transduction pathways that are involved in insulin-induced monocyte/macrophage chemotaxis. We found that insulin stimulates THP-1 cell chemotaxis in a dose-dependent and insulin receptor-dependent manner. We also show that the kinases PI3K-Akt, SPAK/JNK, and p38 MAPK are key molecules in the insulin-induced signaling pathways that lead to chemoattraction of the THP-1 cell. Furthermore, both PI3K-Akt and SPAK/JNK signaling involve Rac1 activation, an important molecule in regulating cell motility. Indeed, topical application of Rac1 inhibitor at an early stage during the healing process caused delayed and impaired healing even in the presence of insulin. These results delineate cell and molecular mechanisms involved in insulin-induced chemotaxis of monocyte/macrophage, cells that are critical for proper healing.

The flavonoid quercetin induces apoptosis and inhibits JNK activation in intimal vascular smooth muscle cells

International Nuclear Information System (INIS)

Perez-Vizcaino, Francisco; Bishop-Bailley, David; Lodi, Federica; Duarte, Juan; Cogolludo, Angel; Moreno, Laura; Bosca, Lisardo; Mitchell, Jane A.; Warner, Timothy D.

2006-01-01

Quercetin, the most abundant dietary flavonol, exerts vasodilator, anti-hypertensive, and anti-atherogenic effects and reduces the vascular remodelling associated with elevated blood pressure. Here, we have compared the effects of quercetin in intimal- and medial-type rat vascular smooth muscle cells (VSMC) in culture. After 48 h, quercetin reduced the viability of a polyclonal intimal-type cell line derived from neonatal aorta but not of a medial-type cell line derived from adult aorta. These differential effects were similar in both proliferating and quiescent VSMC. Quercetin also preferentially reduced the viability of intimal-type over medial-type VSMC in primary cultures derived from balloon-injured carotid arteries. The effects of quercetin on cell viability were mainly dependent upon induction of apoptosis, as demonstrated by nuclear condensation and fragmentation, and were unrelated to PPARγ, pro-oxidant effects or nitric oxide. The expression of MAPKs (ERK, p38, and JNK) and ERK phosphorylation were not different between intimal- and medial-type VSMC. p38 phosphorylation was negligible in both cell types. Medial-type showed a weak JNK phosphorylation while this was markedly increased in intimal-type cells. Quercetin reduced JNK phosphorylation but had no consistent effect on ERK phosphorylation. In conclusion, quercetin preferentially produced apoptosis in intimal-type compared to medial-type VSMC. This might play a role in the anti-atherogenic and anti-hypertensive effects of quercetin

Induction of matrix metalloproteinase-2 by tenascin-X deficiency is mediated through the c-Jun N-terminal kinase and protein tyrosine kinase phosphorylation pathway

International Nuclear Information System (INIS)

Matsumoto, Ken-ichi; Minamitani, Takeharu; Orba, Yasuko; Sato, Mami; Sawa, Hirofumi; Ariga, Hiroyoshi

2004-01-01

The results of our previous study showed that tumor invasion and metastasis are promoted in extracellular matrix (ECM) tenascin-X-deficient (TNX-/-) mice via increased expression of matrix metalloproteinases (MMPs). However, little is known about the relationship between TNX deficiency and activation of MMP genes. In this study, we investigated the molecular mechanism by which TNX deficiency activates the MMP-2 gene. We examined the intracellular signaling pathways that regulate gene expression of the proteinase in isolated fibroblasts. Results of gelatin zymography showed that MMP-2 was induced to a greater extent in TNX-/- fibroblasts embedded in type I collagen than in wild-type fibroblasts. RT-PCR analysis revealed that the increased level of MMP-2 expression was caused at the transcription level. Conversely, stable overexpression of TNX in a fibroblast cell line reduced MMP-2 expression and suppressed MMP-2 promoter activity. In addition, treatment of TNX-/- fibroblasts with SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and genistein, a tyrosine kinase inhibitor, suppressed the increased level of proMMP-2 and increased MMP-2 promoter activity in TNX-/- fibroblasts. Furthermore, increased activation of JNK and tyrosine phosphorylation of certain proteins were observed in TNX-/- fibroblasts. These findings suggest that induction of MMP-2 by TNX deficiency is mediated, at least in part, through the JNK and protein tyrosine kinase phosphorylation pathway

Cadmium induces apoptosis in pancreatic β-cells through a mitochondria-dependent pathway: the role of oxidative stress-mediated c-Jun N-terminal kinase activation.

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Kai-Chih Chang

Full Text Available Cadmium (Cd, one of well-known highly toxic environmental and industrial pollutants, causes a number of adverse health effects and diseases in humans. The growing epidemiological studies have suggested a possible link between Cd exposure and diabetes mellitus (DM. However, the toxicological effects and underlying mechanisms of Cd-induced pancreatic β-cell injury are still unknown. In this study, we found that Cd significantly decreased cell viability, and increased sub-G1 hypodiploid cells and annexin V-Cy3 binding in pancreatic β-cell-derived RIN-m5F cells. Cd also increased intracellular reactive oxygen species (ROS generation and malondialdehyde (MDA production and induced mitochondrial dysfunction (the loss of mitochondrial membrane potential (MMP and the increase of cytosolic cytochrome c release, the decreased Bcl-2 expression, increased p53 expression, poly (ADP-ribose polymerase (PARP cleavage, and caspase cascades, which accompanied with intracellular Cd accumulation. Pretreatment with the antioxidant N-acetylcysteine (NAC effectively reversed these Cd-induced events. Furthermore, exposure to Cd induced the phosphorylations of c-jun N-terminal kinases (JNK, extracellular signal-regulated kinases (ERK1/2, and p38-mitogen-activated protein kinase (MAPK, which was prevented by NAC. Additionally, the specific JNK inhibitor SP600125 or JNK-specific small interference RNA (si-RNA transfection suppressed Cd-induced β-cell apoptosis and related signals, but not ERK1/2 and p38-MAPK inhibitors (PD98059 and SB203580 did not. However, the JNK inhibitor or JNK-specific si-RNA did not suppress ROS generation in Cd-treated cells. These results indicate that Cd induces pancreatic β-cell death via an oxidative stress downstream-mediated JNK activation-triggered mitochondria-regulated apoptotic pathway.

Effects of Lutein on Hyperosmoticity-Induced Upregulation of IL-6 in Cultured Corneal Epithelial Cells and Its Relevant Signal Pathways

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Shih-Chun Chao

2016-01-01

Full Text Available Dry eye is a common disorder characterized by deficiency of tear. Hyperosmoticity of tear stimulates inflammation and damage of ocular surface tissues and plays an essential role in the pathogenesis of dry eye. Cultured human corneal epithelial (CE cells were used for the study of effects of lutein and hyperosmoticity on the secretion of IL-6 by CE cells. Cell viability of CE cells was not affected by lutein at 1–10 μM as determined by MTT assay. Hyperosmoticity significantly elevated the secretion of IL-6 by CE cells as measured by ELISA analysis. The constitutive secretion of IL-6 was not affected by lutein. Lutein significantly and dose-dependently inhibited hyperosmoticity-induced secretion of IL-6. Phosphorylated- (p- p38 MAPK, p-JNK levels in cell lysates and NF-κB levels in cell nuclear extracts were increased by being exposed to hyperosmotic medium. JNK, p38, and NF-κB inhibitors decreased hyperosmoticity-induced secretion of IL-6. Lutein significantly inhibited hyperosmoticity-induced elevation of NF-κB, p38, and p-JNK levels. We demonstrated that lutein inhibited hyperosmoticity-induced secretion of IL-6 in CE cells through the deactivation of p38, JNK, and NF-κB pathways. Lutein may be a promising agent to be explored for the treatment of dry eye.

Anti-influenza A virus activity of rhein through regulating oxidative stress, TLR4, Akt, MAPK, and NF-κB signal pathways.

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Qian-Wen Wang

Full Text Available Rhein, an anthraquinone compound existing in many traditional herbal medicines, has anti-inflammatory, antioxidant, antitumor, antiviral, hepatoprotective, and nephroprotective activities, but its anti-influenza A virus (IAV activity is ambiguous. In the present study, through plaque inhibition assay, time-of-addition assay, antioxidant assay, qRT-PCR, ELISA, and western blotting assays, we investigated the anti-IAV effect and mechanism of action of rhein in vitro and in vivo. The results showed that rhein could significantly inhibit IAV adsorption and replication, decrease IAV-induced oxidative stress, activations of TLR4, Akt, p38, JNK MAPK, and NF-κB pathways, and production of inflammatory cytokines and matrix metalloproteinases in vitro. Oxidant H2O2 and agonists of TLR4, Akt, p38/JNK and IKK/NF-κB could significantly antagonize the inhibitory effects of rhein on IAV-induced cytopathic effect (CPE and IAV replication. Through an in vivo test in mice, we also found that rhein could significantly improve the survival rate, lung index, pulmonary cytokines, and pulmonary histopathological changes. Rhein also significantly decreased pulmonary viral load at a high dose. In conclusion, rhein can inhibit IAV adsorption and replication, and the mechanism of action to inhibit IAV replication may be due to its ability to suppress IAV-induced oxidative stress and activations of TLR4, Akt, p38, JNK MAPK, and NF-κB signal pathways.

Tumor necrosis factor-α induces MMP-9 expression via p42/p44 MAPK, JNK, and nuclear factor-κB in A549 cells

International Nuclear Information System (INIS)

Lin, C.-C.; Tseng, Hsiao-Wei; Hsieh, Hsi-Lung; Lee, Chiang-Wen; Wu, C.-Y.; Cheng, C.-Y.; Yang, C.-M.

2008-01-01

Matrix metalloproteinases (MMPs), in particular MMP-9, have been shown to be induced by cytokines including tumor necrosis factor-α (TNF-α) and contributes to airway inflammation. However, the mechanisms underlying MMP-9 expression induced by TNF-α in human A549 cells remain unclear. Here, we showed that TNF-α induced production of MMP-9 protein and mRNA is determined by zymographic, Western blotting, RT-PCR and ELISA assay, which were attenuated by inhibitors of MEK1/2 (U0126), JNK (SP600125), and NF-κB (helenalin), and transfection with dominant negative mutants of ERK2 (ΔERK) and JNK (ΔJNK), and siRNAs for MEK1, p42 and JNK2. TNF-α-stimulated phosphorylation of p42/p44 MAPK and JNK were attenuated by pretreatment with the inhibitors U0126 and SP600125 or transfection with dominant negative mutants of ΔERK and ΔJNK. Furthermore, the involvement of NF-κB in TNF-α-induced MMP-9 production was consistent with that TNF-α-stimulated degradation of IκB-α and translocation of NF-κB into the nucleus which were blocked by helenalin, but not by U0126 and SP600125, revealed by immunofluorescence staining. The regulation of MMP-9 gene transcription by MAPKs and NF-κB was further confirmed by gene luciferase activity assay. MMP-9 promoter activity was enhanced by TNF-α in A549 cells transfected with wild-type MMP-9-Luc, which was inhibited by helenalin, U0126, or SP600125. In contrast, TNF-α-stimulated MMP-9 luciferase activity was totally lost in cells transfected with mutant-NF-κB MMP-9-luc. Moreover, pretreatment with actinomycin D and cycloheximide attenuated TNF-α-induced MMP-9 expression. These results suggest that in A549 cells, phosphorylation of p42/p44 MAPK, JNK, and transactivation of NF-κB are essential for TNF-α-induced MMP-9 gene expression

Egr-1 activation by cancer-derived extracellular vesicles promotes endothelial cell migration via ERK1/2 and JNK signaling pathways.

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Yae Jin Yoon

Full Text Available Various mammalian cells, including cancer cells, shed extracellular vesicles (EVs, also known as exosomes and microvesicles, into surrounding tissues. These EVs play roles in tumor growth and metastasis by promoting angiogenesis. However, the detailed mechanism of how cancer-derived EVs elicit endothelial cell activation remains unknown. Here, we provide evidence that early growth response-1 (Egr-1 activation in endothelial cells is involved in the angiogenic activity of colorectal cancer cell-derived EVs. Both RNA interference-mediated downregulation of Egr-1 and ERK1/2 or JNK inhibitor significantly blocked EV-mediated Egr-1 activation and endothelial cell migration. Furthermore, lipid raft-mediated endocytosis inhibitor effectively blocked endothelial Egr-1 activation and migration induced by cancer-derived EVs. Our results suggest that Egr-1 activation in endothelial cells may be a key mechanism involved in the angiogenic activity of cancer-derived EVs. These findings will improve our understanding regarding the proangiogenic activities of EVs in diverse pathological conditions including cancer, cardiovascular diseases, and neurodegenerative diseases.

The Effect of Bee Venom on COX-2, P38, ERK and JNK in RAW 264.7 Cells

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Jae-Young Sim

2003-06-01

Full Text Available Objectives : The purpose of this study was to investigate the effect of Bee Venom on the lipopolysaccharide(LPS, sodium nitroprusside(SNP, hydrogen peroxide(H2O2-induced expressions of cyclooxygenase-2(COX-2, p38, jun N-terminal Kinase(JNK and extra-signal response kinase(ERK in RAW 264.7 cells, a murine macrophage cell line. Methods : The expressions of COX-2, p38, JNK and ERK were determined by western blotting with corresponding antibodies.\\ Results : 1. The 0.5, 1 and 5 ㎍/㎖ of bee venom inhibited significantly LPS and SNP-induced expression of COX-2 compared with control, respectively. The 0.5, 1 and 5 ㎍/㎖ of bee venom inhibited insignificantly H2O2-induced expression of COX-2 compared with control, respectively. 2. The 0.5, 1 and 5 ㎍/㎖ of bee venom inhibited significantly LPS, SNP and H2O2-induced expression of p38 compared with control, respectively. 3. The 1 and 5 ㎍/㎖ of bee venom inhibited significantly SNP-induced expression of JNK compared with control, respectively. All of bee venom inhibited insignificantly LPS and H2O2-induced expression of JNK compared with control, respectively. 4. The 5 ㎍/㎖ of bee venom inhibited significantly SNP-induced expression of ERK, the 0.5 ㎍/㎖ of bee venom increased significantly H2O2-induced expression of ERK compared with control. The 0.5, 1 and 5 ㎍/㎖ of bee venom inhibited insignificantly LPS-induced expression of ERK compared with control, respectively.

Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation.

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Marsolier, J; Perichon, M; DeBarry, J D; Villoutreix, B O; Chluba, J; Lopez, T; Garrido, C; Zhou, X Z; Lu, K P; Fritsch, L; Ait-Si-Ali, S; Mhadhbi, M; Medjkane, S; Weitzman, J B

2015-04-16

Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PIN1 in T. annulata (TaPIN1) that is secreted into the host cell and modulates oncogenic signalling pathways. Here we show that TaPIN1 is a bona fide prolyl isomerase and that it interacts with the host ubiquitin ligase FBW7, leading to its degradation and subsequent stabilization of c-JUN, which promotes transformation. We performed in vitro and in silico analysis and in vivo zebrafish xenograft experiments to demonstrate that TaPIN1 is directly inhibited by the anti-parasite drug buparvaquone (and other known PIN1 inhibitors) and is mutated in a drug-resistant strain. Prolyl isomerization is thus a conserved mechanism that is important in cancer and is used by Theileria parasites to manipulate host oncogenic signalling.

Calcium Hydroxide-induced Proliferation, Migration, Osteogenic Differentiation, and Mineralization via the Mitogen-activated Protein Kinase Pathway in Human Dental Pulp Stem Cells.

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Chen, Luoping; Zheng, Lisha; Jiang, Jingyi; Gui, Jinpeng; Zhang, Lingyu; Huang, Yan; Chen, Xiaofang; Ji, Jing; Fan, Yubo

2016-09-01

Calcium hydroxide has been extensively used as the gold standard for direct pulp capping in clinical dentistry. It induces proliferation, migration, and mineralization in dental pulp stem cells (DPSCs), but the underlying mechanisms are still unclear. The aim of this study was to investigate the role of the mitogen-activated protein (MAP) kinase pathway in calcium hydroxide-induced proliferation, migration, osteogenic differentiation, and mineralization in human DPSCs. Human DPSCs between passages 3 and 6 were used. DPSCs were preincubated with inhibitors of MAP kinases and cultured with calcium hydroxide. The phosphorylated MAP kinases were detected by Western blot analysis. Cell viability was analyzed via the methylthiazol tetrazolium assay. Cell migration was estimated using the wound healing assay. Alkaline phosphatase (ALP) expression was analyzed using the ALP staining assay. Mineralization was studied by alizarin red staining analysis. Calcium hydroxide significantly promoted the phosphorylation of the c-Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase. The inhibition of JNK and p38 signaling abolished calcium hydroxide-induced proliferation of DPSCs. The inhibition of JNK, p38, and extracellular signal-regulated kinase signaling suppressed the migration, ALP expression, and mineralization of DPSCs. Our study showed that the MAP kinase pathway was involved in calcium hydroxide-induced proliferation, migration, osteogenic differentiation, and mineralization in human DPSCs. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Momordica charantia polysaccharides could protect against cerebral ischemia/reperfusion injury through inhibiting oxidative stress mediated c-Jun N-terminal kinase 3 signaling pathway.

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Gong, Juanjuan; Sun, Fumou; Li, Yihang; Zhou, Xiaoling; Duan, Zhenzhen; Duan, Fugang; Zhao, Lei; Chen, Hansen; Qi, Suhua; Shen, Jiangang

2015-04-01

Momordica charantia (MC) is a medicinal plant for stroke treatment in Traditional Chinese Medicine, but its active compounds and molecular targets are unknown yet. M. charantia polysaccharide (MCP) is one of the important bioactive components in MC. In the present study, we tested the hypothesis that MCP has neuroprotective effects against cerebral ischemia/reperfusion injury through scavenging superoxide (O2(-)), nitric oxide (NO) and peroxynitrite (ONOO(-)) and inhibiting c-Jun N-terminal protein kinase (JNK3) signaling cascades. We conducted experiments with in vivo global and focal cerebral ischemia/reperfusion rat models and in vitro oxygen glucose deprivation (OGD) neural cells. The effects of MCP on apoptotic cell death and infarction volume, the bioactivities of scavenging O2(-), NO and ONOO(-), inhibiting lipid peroxidation and modulating JNK3 signaling pathway were investigated. Major results are summarized as below: (1) MCP dose-dependently attenuated apoptotic cell death in neural cells under OGD condition in vitro and reduced infarction volume in ischemic brains in vivo; (2) MCP had directing scavenging effects on NO, O2(-) and ONOO(-) and inhibited lipid peroxidation; (3) MCP inhibited the activations of JNK3/c-Jun/Fas-L and JNK3/cytochrome C/caspases-3 signaling cascades in ischemic brains in vivo. Taken together, we conclude that MCP could be a promising neuroprotective ingredient of M. charantia and its mechanisms could be at least in part attributed to its antioxidant activities and inhibiting JNK3 signaling cascades during cerebral ischemia/reperfusion injury. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibition of Cartilage Acidic Protein 1 Reduces Ultraviolet B Irradiation Induced-Apoptosis through P38 Mitogen-Activated Protein Kinase and Jun Amino-Terminal Kinase Pathways

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Yinghong Ji

2016-11-01

Full Text Available Background/Aims: Ultraviolet B (UVB irradiation can easily induce apoptosis in human lens epithelial cells (HLECs and further lead to various eye diseases including cataract. Here for the first time, we investigated the role of cartilage acidic protein 1 (CRTAC1 gene in UVB irradiation induced-apoptosis in HLECs. Methods: Three groups of HLECs were employed including model group, empty vector group, and CRTAC1 interference group. Results: After UVB irradiation, the percentage of primary apoptotic cells was obviously fewer in CRTAC1 interference group. Meanwhile, inhibition of CRTAC1 also reduced both reactive oxygen species (ROS production and intracellular Ca2+ concentration, but the level of mitochondrial membrane potential (Δψm was increased in HLECs. Further studies indicated that superoxide dismutase (SOD activity and total antioxidative (T-AOC level were significantly increased in CRTAC1-inhibited cells, while the levels of malondialdehyde (MDA and lactate dehydrogenase (LDH were significantly decreased. ELISA analysis of CRTAC1-inhibited cells showed that the concentrations of tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 were significantly decreased, but the concentration of interleukin-10 (IL-10 was significantly increased. Western blot analyses of eight apoptosis-associated proteins including Bax, Bcl-2, p38, phospho-p38 (p-p38, Jun amino-terminal kinases (JNK1/2, phospho-JNK1/2 (p-JNK1/2, calcium-sensing receptor (CasR, and Ca2+/calmodulin-dependent protein kinase II (CaMKII indicated that the inhibition of CRTAC1 alleviated oxidative stress and inflammation response, inactivated calcium-signaling pathway, p38 and JNK1/2 signal pathways, and eventually reduced UVB irradiation induced-apoptosis in HLECs. Conclusion: These results provided new insights into the mechanism of cataract development, and demonstrated that CRTAC1 could be a potentially novel target for cataract treatment.

Inhibition of Cartilage Acidic Protein 1 Reduces Ultraviolet B Irradiation Induced-Apoptosis through P38 Mitogen-Activated Protein Kinase and Jun Amino-Terminal Kinase Pathways.

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Ji, Yinghong; Rong, Xianfang; Li, Dan; Cai, Lei; Rao, Jun; Lu, Yi

2016-01-01

Ultraviolet B (UVB) irradiation can easily induce apoptosis in human lens epithelial cells (HLECs) and further lead to various eye diseases including cataract. Here for the first time, we investigated the role of cartilage acidic protein 1 (CRTAC1) gene in UVB irradiation induced-apoptosis in HLECs. Three groups of HLECs were employed including model group, empty vector group, and CRTAC1 interference group. After UVB irradiation, the percentage of primary apoptotic cells was obviously fewer in CRTAC1 interference group. Meanwhile, inhibition of CRTAC1 also reduced both reactive oxygen species (ROS) production and intracellular Ca2+ concentration, but the level of mitochondrial membrane potential (Δψm) was increased in HLECs. Further studies indicated that superoxide dismutase (SOD) activity and total antioxidative (T-AOC) level were significantly increased in CRTAC1-inhibited cells, while the levels of malondialdehyde (MDA) and lactate dehydrogenase (LDH) were significantly decreased. ELISA analysis of CRTAC1-inhibited cells showed that the concentrations of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly decreased, but the concentration of interleukin-10 (IL-10) was significantly increased. Western blot analyses of eight apoptosis-associated proteins including Bax, Bcl-2, p38, phospho-p38 (p-p38), Jun amino-terminal kinases (JNK1/2), phospho-JNK1/2 (p-JNK1/2), calcium-sensing receptor (CasR), and Ca2+/calmodulin-dependent protein kinase II (CaMKII) indicated that the inhibition of CRTAC1 alleviated oxidative stress and inflammation response, inactivated calcium-signaling pathway, p38 and JNK1/2 signal pathways, and eventually reduced UVB irradiation induced-apoptosis in HLECs. These results provided new insights into the mechanism of cataract development, and demonstrated that CRTAC1 could be a potentially novel target for cataract treatment. © 2016 The Author(s) Published by S. Karger AG, Basel.

Cytosolic calcium mediates RIP1/RIP3 complex-dependent necroptosis through JNK activation and mitochondrial ROS production in human colon cancer cells.

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Sun, Wen; Wu, Xiaxia; Gao, Hongwei; Yu, Jie; Zhao, Wenwen; Lu, Jin-Jian; Wang, Jinhua; Du, Guanhua; Chen, Xiuping

2017-07-01

Necroptosis is a form of programmed necrosis mediated by signaling complexes with receptor-interacting protein 1 (RIP1) and RIP3 kinases as the main mediators. However, the underlying execution pathways of this phenomenon have yet to be elucidated in detail. In this study, a RIP1/RIP3 complex was formed in 2-methoxy-6-acetyl-7-methyljuglone (MAM)-treated HCT116 and HT29 colon cancer cells. With this formation, mitochondrial reactive oxygen species (ROS) levels increased, mitochondrial depolarization occurred, and ATP concentrations decreased. This process was identified as necroptosis. This finding was confirmed by experiments showing that MAM-induced cell death was attenuated by the pharmacological or genetic blockage of necroptosis signaling, including RIP1 inhibitor necrostatin-1s (Nec-1s) and siRNA-mediated gene silencing of RIP1 and RIP3, but was unaffected by caspase inhibitor z-vad-fmk or necrosis inhibitor 2-(1H-Indol-3-yl)-3-pentylamino-maleimide (IM54). Transmission electron microscopy (TEM) analysis further revealed the ultrastructural features of MAM-induced necroptosis. MAM-induced RIP1/RIP3 complex triggered necroptosis through cytosolic calcium (Ca 2+ ) accumulation and sustained c-Jun N-terminal kinase (JNK) activation. Both calcium chelator BAPTA-AM and JNK inhibitor SP600125 could attenuate necroptotic features, including mitochondrial ROS elevation, mitochondrial depolarization, and ATP depletion. 2-thenoyltrifluoroacetone (TTFA), which is a mitochondrial complex II inhibitor, was found to effectively reverse both MAM induced mitochondrial ROS generation and cell death, indicating the complex II was the ROS-producing site. The essential role of mitochondrial ROS was confirmed by the protective effect of overexpression of manganese superoxide dismutase (MnSOD). MAM-induced necroptosis was independent of TNFα, p53, MLKL, and lysosomal membrane permeabilization. In summary, our study demonstrated that RIP1/RIP3 complex-triggered cytosolic calcium

The impact of JNK inhibitor D-JNKI-1 in a murine model of chronic colitis induced by dextran sulfate sodium

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Kersting S

2013-05-01

Full Text Available Sabine Kersting,1* Volker Behrendt,1* Jonas Kersting,1 Kirstin Reinecke,3 Christoph Hilgert,1 Ingo Stricker,2 Thomas Herdegen,3 Monika S Janot,1 Waldemar Uhl,1 Ansgar M Chromik1 1Department of General and Visceral Surgery, St Josef Hospital, Ruhr University of Bochum, Bochum, Germany; 2Department of Pathology, Ruhr University of Bochum, Bochum, Germany; 3Institute of Experimental and Clinical Pharmacology, University Hospital of Schleswig-Holstein, Kiel, Germany *The two authors Sabine Kersting and Volker Behrendt contributed equally to this work Purpose: The c-Jun N-terminal kinases (JNK are involved in the activation of T cells and the synthesis of proinflammatory cytokines. Several studies have established the relevance of the JNK pathway in inflammatory bowel diseases. The present study analyzed the therapeutic effect of D-JNKI-1, a specific JNK-inhibiting peptide, in a low-dose dextran sulfate sodium (DSS model of chronic colitis. Methods: DSS colitis was induced in female C57/BL6 mice by cyclic administration using different concentrations of DSS (1.0% and 1.5%. Mice in the intervention groups received subcutaneous administration of 1 µg/kg D-JNKI-1 on days 2, 12, and 22. They were monitored daily to assess the severity of colitis, body weight, stool consistency, and the occurrence of occult blood or gross rectal bleeding using evaluation of the disease activity index. The animals were sacrificed after 30 days, and the inflamed intestine was histologically evaluated using a crypt damage score. Immunohistochemical quantification of CD4+ and CD8+ cells was also carried out. Results: Administration of 1 µg/kg D-JNKI-1 resulted in a significant decrease in the disease activity index (P = 0.013 for 1.0% DSS; P = 0.007 for 1.5% DSS. As a mild form of colitis was induced, histological examination did not show any distinct damage to the mucosa and crypts. However, expression of CD4+ and CD8+ cells was reduced in mice treated with D-JNKI-1 (not

Redox-sensitive up-regulation of eNOS by purple grape juice in endothelial cells: role of PI3-kinase/Akt, p38 MAPK, JNK, FoxO1 and FoxO3a.

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Mahmoud Alhosin

Full Text Available The vascular protective effect of grape-derived polyphenols has been attributable, in part, to their direct action on blood vessels by stimulating the endothelial formation of nitric oxide (NO. The aim of the present study was to determine whether Concord grape juice (CGJ, which contains high levels of polyphenols, stimulates the expression of endothelial NO synthase (eNOS in porcine coronary artery endothelial cells and, if so, to determine the signaling pathway involved. CGJ dose- and time-dependently increased eNOS mRNA and protein levels and this effect is associated with an increased formation of NO in endothelial cells. The stimulatory effect of CGJ on eNOS mRNA is not associated with an increased eNOS mRNA stability and inhibited by antioxidants such as MnTMPyP, PEG-catalase, and catalase, and by wortmannin (an inhibitor of PI3-kinase, SB 203580 (an inhibitor of p38 MAPK, and SP 600125 (an inhibitor of JNK. Moreover, CGJ induced the formation of reactive oxygen species (ROS in endothelial cells and this effect is inhibited by MnTMPyP, PEG-catalase, and catalase. The CGJ-induced the phosphorylation of p38 MAPK and JNK kinases is abolished by MnTMPyP. CGJ induced phosphorylation of transcription factors FoxO1 and FoxO3a, which regulate negatively eNOS expression, and this effect is prevented by MnTMPyP, PEG-catalase, wortmannin, SB203580 and SP600125. Moreover, chromatin immunoprecipitation assay indicated that the FoxO3a protein is associated with the eNOS promoter in control cells and that CGJ induced its dissociation. Thus, the present study indicates that CGJ up-regulates the expression of eNOS mRNA and protein leading to an increased formation of NO in endothelial cells. The stimulatory effect of CGJ is a redox-sensitive event involving PI3-kinase/Akt, p38 MAPK and JNK pathways, and the inactivation of the FoxO transcription factors, FoxO1 and FoxO3a, thereby preventing their repression of the eNOS gene.

Kaempferol Attenuates Cardiac Hypertrophy via Regulation of ASK1/MAPK Signaling Pathway and Oxidative Stress.

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Feng, Hong; Cao, Jianlei; Zhang, Guangyu; Wang, Yanggan

2017-07-01

Kaempferol has been demonstrated to provide benefits for the treatment of atherosclerosis, coronary heart disease, hyperlipidemia, and diabetes through its antioxidant and anti-inflammatory properties. However, its role in cardiac hypertrophy remains to be elucidated. The aim of our study was to investigate the effects of kaempferol on cardiac hypertrophy and the underlying mechanism. Mice subjected to aorta banding were treated with or without kaempferol (100 mg/kg/d, p. o.) for 6 weeks. Echocardiography was performed to evaluate cardiac function. Mice hearts were collected for pathological observation and molecular mechanism investigation. H9c2 cardiomyocytes were stimulated with or without phenylephrine for in vitro study. Kaempferol significantly attenuated cardiac hypertrophy induced by aorta banding as evidenced by decreased cardiomyocyte areas and interstitial fibrosis, accompanied with improved cardiac functions and decreased apoptosis. The ASK1/MAPK signaling pathways (JNK1/2 and p38) were markedly activated in the aorta banding mouse heart but inhibited by kaempferol treatment. In in vitro experiments, kaempferol also inhibited the activity of ASK1/JNK1/2/p38 signaling pathway and the enlargement of H9c2 cardiomyocytes. Furthermore, our study revealed that kaempferol could protect the mouse heart and H9c2 cells from pathological oxidative stress. Our investigation indicated that treatment with kaempferol protects against cardiac hypertrophy, and its cardioprotection may be partially explained by the inhibition of the ASK1/MAPK signaling pathway and the regulation of oxidative stress. Georg Thieme Verlag KG Stuttgart · New York.

c-Jun controls the efficiency of MAP kinase signaling by transcriptional repression of MAP kinase phosphatases

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Sprowles, Amy; Robinson, Dan; Wu Yimi; Kung, H.-J.; Wisdom, Ron

2005-01-01

The mammalian JNK signaling pathway regulates the transcriptional response of cells to environmental stress, including UV irradiation. This signaling pathway is composed of a classical MAP kinase cascade; activation results in phosphorylation of the transcription factor substrates c-Jun and ATF2, and leads to changes in gene expression. The defining components of this pathway are conserved in the fission yeast S. pombe, where the genetic studies have shown that the ability of the JNK homolog Spc1 to be activated in response to UV irradiation is dependent on the presence of the transcription factor substrate Atf1. We have used genetic analysis to define the role of c-Jun in activation of the mammalian JNK signaling pathway. Our results show that optimal activation of JNK requires the presence of its transcription factor substrate c-Jun. Mutational analysis shows that the ability of c-Jun to support efficient activation of JNK requires the ability of Jun to bind DNA, suggesting a transcriptional mechanism. Consistent with this, we show that c-Jun represses the expression of several MAP kinase phosphatases. In the absence of c-Jun, the increased expression of MAP kinase phosphatases leads to impaired activation of the ERK, JNK, and p38 MAP kinases after pathway activation. The results show that one function of c-Jun is to regulate the efficiency of signaling by the ERK, p38, and JNK MAP kinases, a function that is likely to affect cellular responses to many different stimuli

The role of the stress-activated protein kinase (SAPK/JNK) signaling pathway in radiation-induced apoptosis

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Verheij, M.; Ruiter, G.A.; Zerp, S.F.; Bartelink, H.; Blitterswijk, W.J. van; Fuks, Z.; Haimovitz-Friedman, A.

1998-01-01

Ionizing radiation, like a variety of other cellular stress factors, initiates apoptosis, or programmed cell death, in many cell systems. This mode of radiation-induced cell kill should be distinguished from clonogenic cell death due to unrepaired DNA damage. Ionizing radiation not only exerts its effect on the nuclear DNA, but also at the plasma membrane level where it may activate multiple signal transduction pathways. One of these pathways is the stress-activated protein kinase (SAPK) cascade which transduces death signals from the cell membrane to the nucleus. This review discusses recent evidence on the critical role of this signaling system in radiation- and stress-induced apoptosis. An improved understanding of the mechanisms involved in radiation-induced apoptosis may ultimately provide novel strategies of intervention in specific signal transduction pathways to favorably alter the therapeutic ratio in the treatment of human malignancies. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Diosgenin Induces Apoptosis in HepG2 Cells through Generation of Reactive Oxygen Species and Mitochondrial Pathway

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Dae Sung Kim

2012-01-01

Full Text Available Diosgenin, a naturally occurring steroid saponin found abundantly in legumes and yams, is a precursor of various synthetic steroidal drugs. Diosgenin is studied for the mechanism of its action in apoptotic pathway in human hepatocellular carcinoma cells. Based on DAPI staining, diosgenin-treated cells manifested nuclear shrinkage, condensation, and fragmentation. Treatment of HepG2 cells with 40 μM diosgenin resulted in activation of the caspase-3, -8, -9 and cleavage of poly-ADP-ribose polymerase (PARP and the release of cytochrome c. In the upstream, diosgenin increased the expression of Bax, decreased the expression of Bid and Bcl-2, and augmented the Bax/Bcl-2 ratio. Diosgenin-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of JNK, p38 MAPK and apoptosis signal-regulating kinase (ASK-1, as well as generation of the ROS. NAC administration, a scavenger of ROS, reversed diosgene-induced cell death. These results suggest that diosgenin-induced apoptosis in HepG2 cells through Bcl-2 protein family-mediated mitochndria/caspase-3-dependent pathway. Also, diosgenin strongly generated ROS and this oxidative stress might induce apoptosis through activation of ASK1, which are critical upstream signals for JNK/p38 MAPK activation in HepG2 cancer cells.

Histone methyltransferase SETDB1 maintains survival of mouse spermatogonial stem/progenitor cells via PTEN/AKT/FOXO1 pathway.

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Liu, Tiantian; Chen, Xiaoxu; Li, Tianjiao; Li, Xueliang; Lyu, Yinghua; Fan, Xiaoteng; Zhang, Pengfei; Zeng, Wenxian

2017-10-01

Spermatogonial stem cells (SSCs) possess the capacity of self-renewal and differentiation, which are the basis of spermatogenesis. In maintenance of SSC homeostasis, intrinsic/extrinsic factors and various signaling pathways tightly control the fate of SSCs. Methyltransferase SETDB1 (Set domain, bifurcated 1) catalyzes histone H3 lysine 9 (H3K9) trimethylation and represses gene expression. SETDB1 is required for maintaining the survival of spermatogonial stem cells in mice. However, the underlying molecular mechanism remains unclear. In the present study, we found that Setdb1 regulates PTEN/AKT/FOXO1 pathway to inhibit SSC apoptosis. Co-immunoprecipitation and reporter gene assay revealed that SETDB1 interacted and coordinated with AKT to regulate FOXO1 activity and expression of the downstream target genes Bim and Puma. Among the SETDB1-bound genes, the H3K9me3 levels on the promoter regions of Bim and Pten decreased in Setdb1-KD group; in contrast, H3K9me3 status on promoters of Bax and Puma remained unchanged. Therefore, SETDB1 was responsible for regulating the transcription activity of genes in the apoptotic pathway at least in part through modulating H3K9me3. This study replenishes the research on the epigenetic regulation of SSC survival, and provides a new insight for the future study of epigenetic regulation of spermatogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Signal transduction of p53-independent apoptotic pathway induced by hexavalent chromium in U937 cells

International Nuclear Information System (INIS)

Hayashi, Yoko; Kondo, Takashi; Zhao Qingli; Ogawa Ryohei; Cui Zhengguo; Feril, Loreto B.; Teranishi, Hidetoyo; Kasuya, Minoru

2004-01-01

It has been reported that the hexavalent chromium compound (Cr(VI)) can induce both p53-dependent and p53-independent apoptosis. While a considerable amount of information is available on the p53-dependent pathway, only little is known about the p53-independent pathway. To elucidate the p53-independent mechanism, the roles of the Ca 2+ -calpain- and mitochondria-caspase-dependent pathways in apoptosis induced by Cr(VI) were investigated. When human lymphoma U937 cells, p53 mutated cells, were treated with 20 μM Cr(VI) for 24 h, nuclear morphological changes and DNA fragmentation were observed. Production of hydroxyl radicals revealed by electron paramagnetic resonance (EPR)-spin trapping, and increase of intracellular calcium ion concentration monitored by digital imaging were also observed in Cr(VI)-treated cells. An intracellular Ca 2+ chelator, BAPTA-AM, and calpain inhibitors suppressed the Cr(VI)-induced DNA fragmentation. The number of cells showing low mitochondrial membrane potential (MMP), high level of superoxide anion radicals (O 2 - ), and high activity of caspase-3, which are indicators of mitochondria-caspase-dependent pathway, increased significantly in Cr(VI)-treated cells. An antioxidant, N-acetyl-L-cysteine (NAC), decreased DNA fragmentation and inhibited the changes in MMP, O 2 - formation, and activation of caspase-3 induced by Cr(VI). No increase of the expressions of Fas and phosphorylated JNK was observed after Cr(VI) treatment. Cell cycle analysis revealed that the fraction of G2/M phase tended to increase after 24 h of treatment, suggesting that Cr(VI)-induced apoptosis is related to the G2 block. These results indicate that Ca 2+ -calpain- and mitochondria-caspase-dependent pathways play significant roles in the Cr(VI)-induced apoptosis via the G2 block, which are independent of JNK and Fas activation. The inhibition of apoptosis and all its signal transductions by NAC suggests that intracellular reactive oxygen species (ROS) are

Angiotensin II increases CTGF expression via MAPKs/TGF-{beta}1/TRAF6 pathway in atrial fibroblasts

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Gu, Jun [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Liu, Xu, E-mail: xkliuxu@yahoo.cn [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Wang, Quan-xing, E-mail: shmywqx@126.com [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Tan, Hong-wei [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Guo, Meng [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Jiang, Wei-feng; Zhou, Li [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China)

2012-10-01

The activation of transforming growth factor-{beta}1(TGF-{beta}1)/Smad signaling pathway and increased expression of connective tissue growth factor (CTGF) induced by angiotensin II (AngII) have been proposed as a mechanism for atrial fibrosis. However, whether TGF{beta}1/non-Smad signaling pathways involved in AngII-induced fibrogenetic factor expression remained unknown. Recently tumor necrosis factor receptor associated factor 6 (TRAF6)/TGF{beta}-associated kinase 1 (TAK1) has been shown to be crucial for the activation of TGF-{beta}1/non-Smad signaling pathways. In the present study, we explored the role of TGF-{beta}1/TRAF6 pathway in AngII-induced CTGF expression in cultured adult atrial fibroblasts. AngII (1 {mu}M) provoked the activation of P38 mitogen activated protein kinase (P38 MAPK), extracellular signal-regulated kinase 1/2(ERK1/2) and c-Jun NH(2)-terminal kinase (JNK). AngII (1 {mu}M) also promoted TGF{beta}1, TRAF6, CTGF expression and TAK1 phosphorylation, which were suppressed by angiotensin type I receptor antagonist (Losartan) as well as p38 MAPK inhibitor (SB202190), ERK1/2 inhibitor (PD98059) and JNK inhibitor (SP600125). Meanwhile, both TGF{beta}1 antibody and TRAF6 siRNA decreased the stimulatory effect of AngII on TRAF6, CTGF expression and TAK1 phosphorylation, which also attenuated AngII-induced atrial fibroblasts proliferation. In summary, the MAPKs/TGF{beta}1/TRAF6 pathway is an important signaling pathway in AngII-induced CTGF expression, and inhibition of TRAF6 may therefore represent a new target for reversing Ang II-induced atrial fibrosis. -- Highlights: Black-Right-Pointing-Pointer MAPKs/TGF{beta}1/TRAF6 participates in AngII-induced CTGF expression in atrial fibroblasts. Black-Right-Pointing-Pointer TGF{beta}1/TRAF6 participates in AngII-induced atrial fibroblasts proliferation. Black-Right-Pointing-Pointer TRAF6 may represent a new target for reversing Ang II-induced atrial fibrosis.

In vivo and in vitro assessment of pathways involved in contrast media-induced renal cells apoptosis

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Quintavalle, C; Brenca, M; De Micco, F; Fiore, D; Romano, S; Romano, M F; Apone, F; Bianco, A; Zabatta, M A; Troncone, G; Briguori, C; Condorelli, G

2011-01-01

Contrast-induced nephropathy accounts for >10% of all causes of hospital-acquired renal failure, causes a prolonged in-hospital stay and represents a powerful predictor of poor early and late outcome. Mechanisms of contrast-induced nephropathy are not completely understood. In vitro data suggests that contrast media (CM) induces a direct toxic effect on renal tubular cells through the activation of the intrinsic apoptotic pathway. It is unclear whether this effect has a role in the clinical setting. In this work, we evaluated the effects of CM both in vivo and in vitro. By analyzing urine samples obtained from patients who experienced contrast-induced acute kidney injury (CI-AKI), we verified, by western blot and immunohistochemistry, that CM induces tubular renal cells apoptosis. Furthermore, in cultured cells, CM caused a dose–response increase in reactive oxygen species (ROS) production, which triggered Jun N-terminal kinases (JNK1/2) and p38 stress kinases marked activation and thus apoptosis. Inhibition of JNK1/2 and p38 by different approaches (i.e. pharmacological antagonists and transfection of kinase-death mutants of the upstream p38 and JNK kinases) prevented CM-induced apoptosis. Interestingly, N-acetylcysteine inhibited ROS production, and thus stress kinases and apoptosis activation. Therefore, we conclude that CM-induced tubular renal cells apoptosis represents a key mechanism of CI-AKI. PMID:21562587

DISCO interacting protein 2 determines direction of axon projection under the regulation of c-Jun N-terminal kinase in the Drosophila mushroom body

International Nuclear Information System (INIS)

Nitta, Yohei; Sugie, Atsushi

2017-01-01

Precisely controlled axon guidance for complex neuronal wiring is essential for appropriate neuronal function. c-Jun N-terminal kinase (JNK) was found to play a role in axon guidance recently as well as in cell proliferation, protection and apoptosis. In spite of many genetic and molecular studies on these biological processes regulated by JNK, how JNK regulates axon guidance accurately has not been fully explained thus far. To address this question, we use the Drosophila mushroom body (MB) as a model since the α/β axons project in two distinct directions. Here we show that DISCO interacting protein 2 (DIP2) is required for the accurate direction of axonal guidance. DIP2 expression is under the regulation of Basket (Bsk), the Drosophila homologue of JNK. We additionally found that the Bsk/DIP2 pathway is independent from the AP-1 transcriptional factor complex pathway, which is directly activated by Bsk. In conclusion, our findings revealed DIP2 as a novel effector downstream of Bsk modulating the direction of axon projection. - Highlights: • DIP2 is required for accurate direction of axon guidance in Drosophila mushroom body. • DIP2 is a downstream of JNK in the axon guidance of Drosophila mushroom body neuron. • JNK/DIP2 pathway is independent from JNK/AP-1 transcriptional factor complex pathway.

SC1 Promotes MiR124-3p Expression to Maintain the Self-Renewal of Mouse Embryonic Stem Cells by Inhibiting the MEK/ERK Pathway.

Science.gov (United States)

Wei, Qing; Liu, Hongliang; Ai, Zhiying; Wu, Yongyan; Liu, Yingxiang; Shi, Zhaopeng; Ren, Xuexue; Guo, Zekun

2017-01-01

Self-renewal is one of the most important features of embryonic stem (ES) cells. SC1 is a small molecule modulator that effectively maintains the self-renewal of mouse ES cells in the absence of leukemia inhibitory factor (LIF), serum and feeder cells. However, the mechanism by which SC1 maintains the undifferentiated state of mouse ES cells remains unclear. In this study, microarray and small RNA deep-sequencing experiments were performed on mouse ES cells treated with or without SC1 to identify the key genes and microRNAs that contributed to self-renewal. SC1 regulates the expressions of pluripotency and differentiation factors, and antagonizes the retinoic acid (RA)-induced differentiation in the presence or absence of LIF. SC1 inhibits the MEK/ERK pathway through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and pathway reporting experiments. Small RNA deep-sequencing revealed that SC1 significantly modulates the expression of multiple microRNAs with crucial functions in ES cells. The expression of miR124-3p is upregulated in SC1-treated ES cells, which significantly inhibits the MEK/ERK pathway by targeting Grb2, Sos2 and Egr1. SC1 enhances the self-renewal capacity of mouse ES cells by modulating the expression of key regulatory genes and pluripotency-associated microRNAs. SC1 significantly upregulates miR124-3p expression to further inhibit the MEK/ ERK pathway by targeting Grb2, Sos2 and Egr1. © 2017 The Author(s). Published by S. Karger AG, Basel.

Effect of LIPUS on inflammatory factors, cell apoptosis and integrin signaling pathway in osteoarthritis animal models

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Li-Cai Zhang

2017-05-01

Full Text Available Objective: To study the effect of low-intensity pulsed ultrasound (LIPUS on inflammatory factors, cell apoptosis and integrin signaling pathway in osteoarthritis animal models. Methods: Male New Zealand white rabbits were selected as the experimental animals and randomly divided into sham group, osteoarthritis model group (OA group and LIPUS intervention group (LIPUS group, animal models with osteoarthritis in hind limb knee joint were established and then given LIPUS intervention. 6 weeks after the intervention, the articular cartilage was separated to detect the expression of inflammatory factors, cell apoptosis molecules and integrin signaling pathway molecules. Results: OPN, NO, IL-1β, TNF-α, Fas, FasL, LC3-II, Beclin-1, Integrinβ1, FAK, ERK1/2, JNK, p38MAPK, MMP-1 and MMP-3 protein expression in articular cartilage of OA group were significantly higher than those of Sham group while Col-I and Col-II protein expression were significantly lower than those of Sham group; OPN, NO, IL-1β, TNF-α, Fas, FasL, LC3-II, Beclin-1, Integrinβ1, FAK, ERK1/2, JNK, p38MAPK, MMP-1 and MMP-3 protein expression in articular cartilage of LIPUS group were significantly lower than those of OA group while Col-I and Col-II protein expression were significantly higher than those of OA group. Conclusion: LIPUS has inhibiting effect on the inflammation, apoptosis and integrin signaling pathway in articular cartilage of osteoarthritis animal models, and it can promote the repair of articular cartilage.

Ubiquitylation and the Fanconi Anemia Pathway

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Garner, Elizabeth; Smogorzewska, Agata

2012-01-01

The Fanconi anemia (FA) pathway maintains genome stability through co-ordination of DNA repair of interstrand crosslinks (ICLs). Disruption of the FA pathway yields hypersensitivity to interstrand crosslinking agents, bone marrow failure and cancer predisposition. Early steps in DNA damage dependent activation of the pathway are governed by monoubiquitylation of FANCD2 and FANCI by the intrinsic FA E3 ubiquitin ligase, FANCL. Downstream FA pathway components and associated factors such as FAN1 and SLX4 exhibit ubiquitin-binding motifs that are important for their DNA repair function, underscoring the importance of ubiquitylation in FA pathway mediated repair. Importantly, ubiquitylation provides the foundations for cross-talk between repair pathways, which in concert with the FA pathway, resolve interstrand crosslink damage and maintain genomic stability. PMID:21605559

The Spalt transcription factors regulate cell proliferation, survival and epithelial integrity downstream of the Decapentaplegic signalling pathway

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María F. Organista

2012-10-01

The expression of the spalt genes is regulated by the Decapentaplegic signalling pathway in the Drosophila wing. These genes participate in the patterning of the longitudinal wing veins by regulating the expression of vein-specific genes, and in the establishment of cellular affinities in the central region of the wing blade epithelium. The Spalt proteins act as transcription factors, most likely regulating gene expression by repression, but the identity of their target genes in the wing is still unknown. As a preliminary step to unravel the genetic hierarchy controlled by the Spalt proteins, we have analysed their requirements during wing development, and addressed to what extent they mediate all the functions of the Decapentaplegic pathway in this developmental system. We identify additional functions for Spalt in cell division, survival, and maintenance of epithelial integrity. Thus, Spalt activity is required to promote cell proliferation, acting in the G2/M transition of the cell cycle. The contribution of Spalt to cell division is limited to the central region of the wing blade, as they do not mediate the extra growth triggered by Decapentaplegic signalling in the peripheral regions of the wing disc. In addition, Spalt function is required to maintain cell viability in cells exposed to high levels of Decapentaplegic signalling. This aspect of Spalt function is related to the repression of JNK signalling in the spalt domain of expression. Finally, we further characterise the requirements of Spalt to maintain epithelial integrity by regulating cellular affinities between cells located in the central wing region. Our results indicate that Spalt function mediates most of the requirements identified for Decapentaplegic signalling, contributing to establish the cellular qualities that differentiate central versus peripheral territories in the wing blade.

Carabrol suppresses LPS-induced nitric oxide synthase expression by inactivation of p38 and JNK via inhibition of I-κBα degradation in RAW 264.7 cells

International Nuclear Information System (INIS)

Lee, Hwa Jin; Lim, Hyo Jin; Lee, Da Yeon; Jung, Hyeyoun; Kim, Mi-Ran; Moon, Dong-Cheul; Kim, Keun Il; Lee, Myeong-Sok; Ryu, Jae-Ha

2010-01-01

Carabrol, isolated from Carpesium macrocephalum, showed anti-inflammatory potential in LPS-induced RAW 264.7 murine macrophages. In present study, carabrol demonstrated the inhibitory activity on pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α. In addition, mRNA and protein levels of iNOS and COX-2 were reduced by carabrol. Molecular analysis revealed that these suppressive effects were correlated with the inactivation of p38 and JNK via inhibition of NF-κB activation. Immunoblotting showed that carabrol suppressed LPS-induced degradation of I-κBα and decreased nuclear translocation of p65. Taken together, these results suggest that carabrol can be a modulator of pro-inflammatory signal transduction pathway in RAW 264.7 cells.

LW-214, a newly synthesized flavonoid, induces intrinsic apoptosis pathway by down-regulating Trx-1 in MCF-7 human breast cells.

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Pan, Di; Li, Wei; Miao, Hanchi; Yao, Jing; Li, Zhiyu; Wei, Libin; Zhao, Li; Guo, Qinglong

2014-02-15

In this study, the anticancer effect of LW-214, a newly synthesized flavonoid, against MCF-7 human breast cancer cells and the underlying mechanisms were investigated. LW-214 triggered the mitochondrial apoptotic pathway by increasing Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (ΔΨm) and caspase-9 activation, degradation of poly (ADP-ribose) polymerase (PARP), cytochrome c (Cyt c) release and apoptosis-inducing factor (AIF) transposition. Further research revealed that both the reactive oxygen species (ROS) generation and the apoptosis signal regulating kinase 1 (ASK1) activation by LW-214 were induced by down-regulating the thioredoxin-1 (Trx-1) expression. The ROS elevation and ASK1 activation induced a sustained phosphorylation of c-Jun N-terminal kinase (JNK), while SP600125, as known as JNK inhibitor, almost reversed LW-214-induced apoptosis in MCF-7 cells. Overexpression of Trx-1 in MCF-7 cells attenuated LW-214-mediated apoptosis as well as the JNK activation and reversed the expression of mitochondrial apoptosis-related protein. Accordingly, the in vivo study showed that LW-214 exhibited a potential antitumor effect in BALB/c species mice inoculated MCF-7 tumor with low systemic toxicity, and the mechanism was the same as in vitro study. Taken together, these findings indicated that LW-214 may down-regulated Trx-1 function, causing intracellular ROS generation and releasing the ASK1, and lead to JNK activation, which consequently induced the mitochondrial apoptosis in vitro and in vivo. Copyright © 2013 Elsevier Inc. All rights reserved.

The sonic hedgehog signaling pathway maintains the cancer stem cell self-renewal of anaplastic thyroid cancer by inducing snail expression.

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Heiden, Katherine B; Williamson, Ashley J; Doscas, Michelle E; Ye, Jin; Wang, Yimin; Liu, Dingxie; Xing, Mingzhao; Prinz, Richard A; Xu, Xiulong

2014-11-01

Cancer stem cells (CSCs) have been recently identified in thyroid neoplasm. Anaplastic thyroid cancer (ATC) contains a higher percentage of CSCs than well-differentiated thyroid cancer. The signaling pathways and the transcription factors that regulate thyroid CSC self-renewal remain poorly understood. The objective of this study is to use two ATC cell lines (KAT-18 and SW1736) as a model to study the role of the sonic hedgehog (Shh) pathway in maintaining thyroid CSC self-renewal and to understand its underlying molecular mechanisms. The expression and activity of aldehyde dehydrogenase (ALDH), a marker for thyroid CSCs, was analyzed by Western blot and ALDEFLUOR assay, respectively. The effect of three Shh pathway inhibitors (cyclopamine, HhAntag, GANT61), Shh, Gli1, Snail knockdown, and Gli1 overexpression on thyroid CSC self-renewal was analyzed by ALDEFLUOR assay and thyrosphere formation. The sensitivity of transfected KAT-18 cells to radiation was evaluated by a colony survival assay. Western blot analysis revealed that ALDH protein levels in five thyroid cancer cell lines (WRO82, a follicular thyroid cancer cell line; BCPAP and TPC1, two papillary thyroid cancer cell lines; KAT-18 and SW1736, two ATC cell lines) correlated with the percentage of the ALDH(High) cells as well as Gli1 and Snail expression. The Shh pathway inhibitors, Shh and Gli1 knockdown, in KAT-18 cells decreased thyroid CSC self-renewal and increased radiation sensitivity. In contrast, Gli1 overexpression led to increased thyrosphere formation, an increased percentage of ALDH(High) cells, and increased radiation resistance in KAT-18 cells. Inhibition of the Shh pathway by three specific inhibitors led to decreased Snail expression and a decreased number of ALDH(High) cells in KAT-18 and SW1736. Snail gene knockdown decreased the number of ALDH(High) cells in KAT-18 and SW1736 cells. The Shh pathway promotes the CSC self-renewal in ATC cell lines by Gli1-induced Snail expression.

Docosahexaenoic Acid Inhibits Tumor Promoter-Induced Urokinase-Type Plasminogen Activator Receptor by Suppressing PKCδ- and MAPKs-Mediated Pathways in ECV304 Human Endothelial Cells.

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Sen Lian

Full Text Available The overexpression of urokinase-type plasminogen activator receptor (uPAR is associated with inflammation and virtually all human cancers. Despite the fact that docosahexaenoic acid (DHA has been reported to possess anti-inflammatory and anti-tumor properties, the negative regulation of uPAR by DHA is still undefined. Here, we investigated the effect of DHA on 12-O-tetradecanoylphorbol-13-acetate (TPA-induced uPAR expression and the underlying molecular mechanisms in ECV304 human endothelial cells. DHA concentration-dependently inhibited TPA-induced uPAR. Specific inhibitors and mutagenesis studies showed that PKCδ, JNK1/2, Erk1/2, NF-κB, and AP-1 were critical for TPA-induced uPAR expression. Application of DHA suppressed TPA-induced translocation of PKCδ, activation of the JNK1/2 and Erk1/2 signaling pathways, and subsequent AP-1 and NF-κB transactivation. In conclusion, these observations suggest a novel role for DHA in reducing uPAR expression and cell invasion by inhibition of PKCδ, JNK1/2, and Erk1/2, and the reduction of AP-1 and NF-κB activation in ECV304 human endothelial cells.

NF-κB and JNK mediated apoptosis and G0/G1 arrest of HeLa cells induced by rubiarbonol G, an arborinane-type triterpenoid from Rubia yunnanensis.

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Zeng, Guang-Zhi; Wang, Zhe; Zhao, Li-Mei; Fan, Jun-Ting; Tan, Ning-Hua

2018-06-28

Rubia yunnanensis is a medicinal plant mainly grown in Yunnan province in Southwest China, and its root named "Xiaohongshen" has been used as a herb in Yunnan for the treatment of cancers. Three major types of chemical components, Rubiaceae-type cyclopeptides, quinones, and triterpenoids, were identified from R. yunnanensis, in which some of compounds including rubiarbonol G (RG), a unique arboriane-type triterpenoid, showed cytotoxicity on cancer cells. But the cytotoxic mechanism of RG has not been reported. To investigate the cytotoxic mechanism of RG on cancer cells. RG was evaluated its cytotoxicity on 7 cancer cell lines by the SRB assay, and detected the effect on apoptosis and cell cycle arrest by Annexin V-FITC/PI apoptosis assay and DNA contents analysis. The expression and activity of apoptosis and cell cycle related proteins were also investigated by western blot and caspase activity assay. Furthermore, the effect of RG on NF-κB signaling was also tested by luciferase assay, western blot, and immunofluorescence staining. RG showed potent cytotoxicity on 7 human cancer cell lines, whose activity was attributed to apoptosis induction and G 0 /G 1 arrest in HeLa cells. Results from the mechanism study showed that RG promoted the activation of ERK1/2 and JNK pathway in MAPK family, which in turn increased the expression of p53, thereby triggering the G 0 /G 1 arrest through p53/p21/cyclin D1 signaling. Moreover, RG-mediated JNK activation down-regulated the expression of the anti-apoptotic protein Bcl-2, which caused the release of cytochrome c to the cytosol and activated the cleavage of caspase cascade and poly(ADP-ribose) polymerase, thereby inducing apoptosis in HeLa cells. In addition, RG was also found to inhibit the activation of NF-κB signaling by down-regulating the expression and attenuating the translocation to nucleus of NF-κB p65, by which the down-stream p53, cyclin D1, Bcl-2, and caspases were regulated, thereby triggering apoptosis and G

Loss of MURC/Cavin-4 induces JNK and MMP-9 activity enhancement in vascular smooth muscle cells and exacerbates abdominal aortic aneurysm.

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Miyagawa, Kotaro; Ogata, Takehiro; Ueyama, Tomomi; Kasahara, Takeru; Nakanishi, Naohiko; Naito, Daisuke; Taniguchi, Takuya; Hamaoka, Tetsuro; Maruyama, Naoki; Nishi, Masahiro; Kimura, Taizo; Yamada, Hiroyuki; Aoki, Hiroki; Matoba, Satoaki

2017-06-03

Abdominal aortic aneurysm (AAA) is relatively common in elderly patients with atherosclerosis. MURC (muscle-restricted coiled-coil protein)/Cavin-4 modulating the caveolae function of muscle cells is expressed in cardiomyocytes, skeletal muscle cells and smooth muscle cells. Here, we show a novel functional role of MURC/Cavin-4 in vascular smooth muscle cells (VSMCs) and AAA development. Both wild-type (WT) and MURC/Cavin-4 knockout (MURC -/- ) mice subjected to periaortic application of CaCl 2 developed AAAs. Six weeks after CaCl 2 treatment, internal and external aortic diameters were significantly increased in MURC -/- AAAs compared with WT AAAs, which were accompanied by advanced fibrosis in the tunica media of MURC -/- AAAs. The activity of JNK and matrix metalloproteinase (MMP) -2 and -9 were increased in MURC -/- AAAs compared with WT AAAs at 5 days after CaCl 2 treatment. At 6 weeks after CaCl 2 treatment, MURC -/- AAAs exhibited attenuated JNK activity compared with WT AAAs. There was no difference in the activity of MMP-2 or -9 between saline and CaCl 2 treatments. In MURC/Cavin-4-knockdown VSMCs, TNFα-induced activity of JNK and MMP-9 was enhanced compared with control VSMCs. Furthermore, WT, MURC -/- , apolipoprotein E -/- (ApoE -/- ), and MURC/Cavin-4 and ApoE double-knockout (MURC -/- ApoE -/- ) mice were subjected to angiotensin II (Ang II) infusion. In both ApoE -/- and MURC -/- ApoE -/- mice infused for 4 weeks with Ang II, AAAs were promoted. The internal aortic diameter was significantly increased in Ang II-infused MURC -/- ApoE -/- mice compared with Ang II-infused ApoE -/- mice. In MURC/Cavin-4-knockdown VSMCs, Ang II-induced activity of JNK and MMP-9 was enhanced compared with control VSMCs. Our results suggest that MURC/Cavin-4 in VSMCs modulates AAA progression at the early stage via the activation of JNK and MMP-9. MURC/Cavin-4 is a potential therapeutic target against AAA progression. Copyright © 2017 Elsevier Inc. All rights reserved.

Treatment with a JNK inhibitor increases, whereas treatment with a p38 inhibitor decreases, H2O2-induced calf pulmonary arterial endothelial cell death.

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Park, Woo Hyun

2017-08-01

Oxidative stress induces apoptosis in endothelial cells (ECs). Reactive oxygen species (ROS) promote cell death by regulating the activity of various mitogen-activated protein kinases (MAPKs) in ECs. The present study investigated the effects of MAPK inhibitors on cell survival and glutathione (GSH) levels upon H 2 O 2 treatment in calf pulmonary artery ECs (CPAECs). H 2 O 2 treatment inhibited the growth and induced the death of CPAECs, as well as causing GSH depletion and the loss of mitochondrial membrane potential (MMP). While treatment with the MEK or JNK inhibitor impaired the growth of H 2 O 2 -treated CPAECs, treatment with the p38 inhibitor attenuated this inhibition of growth. Additionally, JNK inhibitor treatment increased the proportion of sub-G 1 phase cells in H 2 O 2 -treated CPAECs and further decreased the MMP. However, treatment with a p38 inhibitor reversed the effects of H 2 O 2 treatment on cell growth and the MMP. Similarly, JNK inhibitor treatment further increased, whereas p38 inhibitor treatment decreased, the proportion of GSH-depleted cells in H 2 O 2 -treated CPAECs. Each of the MAPK inhibitors affected cell survival, and ROS or GSH levels differently in H 2 O 2 -untreated, control CPAECs. The data suggest that the exposure of CPAECs to H 2 O 2 caused the cell growth inhibition and cell death through GSH depletion. Furthermore, JNK inhibitor treatment further enhanced, whereas p38 inhibitors attenuated, these effects. Thus, the results of the present study suggest a specific protective role for the p38 inhibitor, and not the JNK inhibitor, against H 2 O 2 -induced cell growth inhibition and cell death.

CoQ10 Augments Rosuvastatin Neuroprotective Effect in a Model of Global Ischemia via Inhibition of NF-κB/JNK3/Bax and Activation of Akt/FOXO3A/Bim Cues

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Sarah A. Abd El-Aal

2017-10-01

Full Text Available Statins were reported to lower the Coenzyme Q10 (CoQ10 content upon their inhibition of HMG-CoA reductase enzyme and both are known to possess neuroprotective potentials; therefore, the aim is to assess the possible use of CoQ10 as an adds-on therapy to rosuvastatin to improve its effect using global I/R model. Rats were allocated into sham, I/R, rosuvastatin (10 mg/kg, CoQ10 (10 mg/kg and their combination. Drugs were administered orally for 7 days before I/R. Pretreatment with rosuvastatin and/or CoQ10 inhibited the hippocampal content of malondialdehyde, nitric oxide, and boosted glutathione and superoxide dismutase. They also opposed the upregulation of gp91phox, and p47phox subunits of NADPH oxidase. Meanwhile, both agents reduced content/expression of TNF-α, iNOS, NF-κBp65, ICAM-1, and MPO. Besides, all regimens abated cytochrome c, caspase-3 and Bax, but increased Bcl-2 in favor of cell survival. On the molecular level, they increased p-Akt and its downstream target p-FOXO3A, with the inhibition of the nuclear content of FOXO3A to downregulate the expression of Bim, a pro-apoptotic gene. Additionally, both treatments downregulate the JNK3/c-Jun signaling pathway. The effect of the combination regimen overrides that of either treatment alone. These effects were reflected on the alleviation of the hippocampal damage in CA1 region inflicted by I/R. Together, these findings accentuate the neuroprotective potentials of both treatments against global I/R by virtue of their rigorous multi-pronged actions, including suppression of hippocampal oxidative stress, inflammation, and apoptosis with the involvement of the Akt/FOXO3A/Bim and JNK3/c-Jun/Bax signaling pathways. The study also nominates CoQ10 as an adds-on therapy with statins.

A novel differentiation pathway from CD4⁺ T cells to CD4⁻ T cells for maintaining immune system homeostasis.

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Zhao, X; Sun, G; Sun, X; Tian, D; Liu, K; Liu, T; Cong, M; Xu, H; Li, X; Shi, W; Tian, Y; Yao, J; Guo, H; Zhang, D

2016-04-14

CD4(+) T lymphocytes are key players in the adaptive immune system and can differentiate into a variety of effector and regulatory T cells. Here, we provide evidence that a novel differentiation pathway of CD4(+) T cells shifts the balance from a destructive T-cell response to one that favors regulation in an immune-mediated liver injury model. Peripheral CD4(-)CD8(-)NK1.1(-) double-negative T cells (DNT) was increased following Concanavalin A administration in mice. Adoptive transfer of DNT led to significant protection from hepatocyte necrosis by direct inhibition on the activation of lymphocytes, a process that occurred primarily through the perforin-granzyme B route. These DNT converted from CD4(+) rather than CD8(+) T cells, a process primarily regulated by OX40. DNT migrated to the liver through the CXCR3-CXCL9/CXCL10 interaction. In conclusion, we elucidated a novel differentiation pathway from activated CD4(+) T cells to regulatory DNT cells for maintaining homeostasis of the immune system in vivo, and provided key evidence that utilizing this novel differentiation pathway has potential application in the prevention and treatment of autoimmune diseases.

Neuroprotective effects of Arctium lappa L. roots against glutamate-induced oxidative stress by inhibiting phosphorylation of p38, JNK and ERK 1/2 MAPKs in PC12 cells.

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Tian, Xing; Sui, Shuang; Huang, Jin; Bai, Jun-Peng; Ren, Tian-Shu; Zhao, Qing-Chun

2014-07-01

Many studies have shown that glutamate-induced oxidative stress can lead to neuronal cell death involved in the development of neurodegenerative diseases. In this work, protective effects of ethyl acetate extract (EAE) of Arctium lappa L. roots against glutamate-induced oxidative stress in PC12 cells were evaluated. Also, the effects of EAE on antioxidant system, mitochondrial pathway, and signal transduction pathway were explored. Pretreatment with EAE significantly increased cell viability, activities of GSH-Px and SOD, mitochondrial membrane potential and reduced LDH leakage, ROS formation, and nuclear condensation in a dose-dependent manner. Furthermore, western blot results revealed that EAE increased the Bcl-2/Bax ratio, and inhibited the up-regulation of caspase-3, release of cytochrome c, phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK 1/2). Therefore, our results indicate that EAE may be a promising neuroprotective agent for the prevention and treatment of neurodegenerative diseases implicated with oxidative stress. Copyright © 2014 Elsevier B.V. All rights reserved.

p8 inhibits the growth of human pancreatic cancer cells and its expression is induced through pathways involved in growth inhibition and repressed by factors promoting cell growth

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Vasseur Sophie

2003-11-01

Full Text Available Abstract Background p8 is a stress-induced protein with multiple functions and biochemically related to the architectural factor HMG-I/Y. We analyzed the expression and function of p8 in pancreatic cancer-derived cells. Methods Expression of p8 was silenced in the human pancreatic cancer cell lines Panc-1 and BxPc-3 by infection with a retrovirus expressing p8 RNA in the antisense orientation. Cell growth was measured in control and p8-silenced cells. Influence on p8 expression of the induction of intracellular pathways promoting cellular growth or growth arrest was monitored. Results p8-silenced cells grew more rapidly than control cells transfected with the empty retrovirus. Activation of the Ras→Raf→MEK→ERK and JNK intracellular pathways down-regulated p8 expression. In addition, the MEK1/2 inhibitor U0126 and the JNK inhibitor SP600125 up-regulates expression of p8. Conversely, p38 or TGFβ-1 induced p8 expression whereas the specific p38 inhibitor SB203580 down-regulated p8 expression. Finally, TGFβ-1 induction was in part mediated through p38. Conclusions p8 inhibits the growth of human pancreatic cancer cells. p8 expression is induced through pathways involved in growth inhibition and repressed by factors that promote cell growth. These results suggest that p8 belongs to a pathway regulating the growth of pancreatic cancer cells.

Interleukin-1β-induced iNOS expression in human lung carcinoma A549 cells: involvement of STAT and MAPK pathways

International Nuclear Information System (INIS)

Ravichandran, Kameswaran; Tyagi, Alpna; Deep, Gagan; Agarwal, Chapla; Agarwal, Rajesh

2011-01-01

For understanding of signaling molecules important in lung cancer growth and progression, IL-1β effect was analyzed on iNOS expression and key signaling molecules in human lung carcinoma A549 cells and established the role of specific signaling molecules by using specific chemical inhibitors. IL-1β exposure (10 ng/ml) induced strong iNOS expression in serum starved A549 cells. Detailed molecular analyses showed that IL-1β increased expression of phosphorylated STAT1 (Tyr701 and Ser727) and STAT3 (Tyr705 and Ser727) both in total cell lysates and nuclear lysates. Further, IL-1β exposure strongly activated MAPKs (ERK1/2, JNK1/2 and p38) and Akt as well as increased nuclear levels of NF-κB and HIF-1α in A549 cells. Use of specific chemical inhibitors for JAK1 kinase (piceatannol), JAK2 kinase (AG-490), MEK1/2 (PD98059) and JNK1/2 (SP600125) revealed that IL-1β-induced iNOS expression involved signaling pathways in addition to JAKSTAT and ERK1/2-JNK1/2 activation. Overall, these results suggested that instead of specific pharmacological inhibitors, use of chemopreventive agents with broad spectrum efficacy to inhibit IL-1β-induced signaling cascades and iNOS expression would be a better strategy towards lung cancer prevention and/or treatment. (author)

Anti-atherosclerotic activities of flavonoids from the flowers of Helichrysum arenarium L. MOENCH through the pathway of anti-inflammation.

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Mao, Zhonghua; Gan, Chunli; Zhu, Jiuxin; Ma, Nan; Wu, Lijun; Wang, Libo; Wang, Xiaobo

2017-06-15

We have successfully established AS model using thoracic aortas vascular ring which evaluated by the morphological changes of blood vessels, the proliferation of VSMC, and the expression of inflammation factors VEGF, CRP, JNK2 and p38. This AS model has the advantages of low cost, convenient and short period of established time. Moreover, we investigated the anti-AS activities of 7 flavonoids Narirutin (1), Naringin (2), Eriodictyol (3), Luteolin (4), Galuteolin (5), Astragalin (6), Kaempferol (7) from flowers of Helichrysum arenarium L. MOENCH by examining the vascular morphology, the inhibition on the expression of inflammation factors CRP, VEGF, JNK2, p38. In addition, we investigated the anti-AS activities of these 7 flavonoids by examining NO secretion of RAW264.7 cells in response to LPS. All above inflammation factors have been proved to be involved in the formation of AS. After comprehensive analysis of all results to discuss the structure-activity relationship, we summarized the conclusions at follow: compounds 1-7 could inhibit the expression of VEGF, CRP, JNK2, p38 and NO at different level, and we evaluated that flavonol aglycone have more significant anti-inflammation than it's glycoside, and the anti-AS activity of flavonols were stronger than flavanones and flavones, which means that 3-group might be the effective group. Eventually, we supposed the main anti-inflammatory mechanism of these compounds was to reduce the expression of CRP, inhibit the kinases activity of JNK2 and p38, and then the MAPK pathway was suppressed, which resulted in the decrease of NO synthesis, VEGF expression and endothelial adhesion factor expression. And eventually, the scar tissue and vascular stenosis formations were prevented. This conclusion suggested flavonoids have the potential of preventing AS formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Andrographolide inhibits nuclear factor-κB activation through JNK-Akt-p65 signaling cascade in tumor necrosis factor-α-stimulated vascular smooth muscle cells.

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Chen, Yu-Ying; Hsu, Ming-Jen; Hsieh, Cheng-Ying; Lee, Lin-Wen; Chen, Zhih-Cherng; Sheu, Joen-Rong

2014-01-01

Critical vascular inflammation leads to vascular dysfunction and cardiovascular diseases, including abdominal aortic aneurysms, hypertension, and atherosclerosis. Andrographolide is the most active and critical constituent isolated from the leaves of Andrographis paniculata, a herbal medicine widely used for treating anti-inflammation in Asia. In this study, we investigated the mechanisms of the inhibitory effects of andrographolide in vascular smooth muscle cells (VSMCs) exposed to a proinflammatory stimulus, tumor necrosis factor-α (TNF-α). Treating TNF-α-stimulated VSMCs with andrographolide suppressed the expression of inducible nitric oxide synthase in a concentration-dependent manner. A reduction in TNF-α-induced c-Jun N-terminal kinase (JNK), Akt, and p65 phosphorylation was observed in andrographolide-treated VSMCs. However, andrographolide affected neither IκBα degradation nor p38 mitogen-activated protein kinase or extracellular signal-regulated kinase 1/2 phosphorylation under these conditions. Both treatment with LY294002, a phosphatidylinositol 3-kinase/Akt inhibitor, and treatment with SP600125, a JNK inhibitor, markedly reversed the andrographolide-mediated inhibition of p65 phosphorylation. In addition, LY294002 and SP600125 both diminished Akt phosphorylation, whereas LY294002 had no effects on JNK phosphorylation. These results collectively suggest that therapeutic interventions using andrographolide can benefit the treatment of vascular inflammatory diseases, and andrographolide-mediated inhibition of NF-κB activity in TNF-α-stimulated VSMCs occurs through the JNK-Akt-p65 signaling cascade, an IκBα-independent mechanism.

Andrographolide Inhibits Nuclear Factor-κB Activation through JNK-Akt-p65 Signaling Cascade in Tumor Necrosis Factor-α-Stimulated Vascular Smooth Muscle Cells

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Yu-Ying Chen

2014-01-01

Full Text Available Critical vascular inflammation leads to vascular dysfunction and cardiovascular diseases, including abdominal aortic aneurysms, hypertension, and atherosclerosis. Andrographolide is the most active and critical constituent isolated from the leaves of Andrographis paniculata, a herbal medicine widely used for treating anti-inflammation in Asia. In this study, we investigated the mechanisms of the inhibitory effects of andrographolide in vascular smooth muscle cells (VSMCs exposed to a proinflammatory stimulus, tumor necrosis factor-α (TNF-α. Treating TNF-α-stimulated VSMCs with andrographolide suppressed the expression of inducible nitric oxide synthase in a concentration-dependent manner. A reduction in TNF-α-induced c-Jun N-terminal kinase (JNK, Akt, and p65 phosphorylation was observed in andrographolide-treated VSMCs. However, andrographolide affected neither IκBα degradation nor p38 mitogen-activated protein kinase or extracellular signal-regulated kinase 1/2 phosphorylation under these conditions. Both treatment with LY294002, a phosphatidylinositol 3-kinase/Akt inhibitor, and treatment with SP600125, a JNK inhibitor, markedly reversed the andrographolide-mediated inhibition of p65 phosphorylation. In addition, LY294002 and SP600125 both diminished Akt phosphorylation, whereas LY294002 had no effects on JNK phosphorylation. These results collectively suggest that therapeutic interventions using andrographolide can benefit the treatment of vascular inflammatory diseases, and andrographolide-mediated inhibition of NF-κB activity in TNF-α-stimulated VSMCs occurs through the JNK-Akt-p65 signaling cascade, an IκBα-independent mechanism.

JNK Phosphorylates SIRT6 to Stimulate DNA Double-Strand Break Repair in Response to Oxidative Stress by Recruiting PARP1 to DNA Breaks

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Michael Van Meter

2016-09-01

Full Text Available The accumulation of damage caused by oxidative stress has been linked to aging and to the etiology of numerous age-related diseases. The longevity gene, sirtuin 6 (SIRT6, promotes genome stability by facilitating DNA repair, especially under oxidative stress conditions. Here we uncover the mechanism by which SIRT6 is activated by oxidative stress to promote DNA double-strand break (DSB repair. We show that the stress-activated protein kinase, c-Jun N-terminal kinase (JNK, phosphorylates SIRT6 on serine 10 in response to oxidative stress. This post-translational modification facilitates the mobilization of SIRT6 to DNA damage sites and is required for efficient recruitment of poly (ADP-ribose polymerase 1 (PARP1 to DNA break sites and for efficient repair of DSBs. Our results demonstrate a post-translational mechanism regulating SIRT6, and they provide the link between oxidative stress signaling and DNA repair pathways that may be critical for hormetic response and longevity assurance.

Activation of Extracellular Signal-Regulated Kinase but Not of p38 Mitogen-Activated Protein Kinase Pathways in Lymphocytes Requires Allosteric Activation of SOS

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Jun, Jesse E.; Yang, Ming; Chen, Hang; Chakraborty, Arup K.

2013-01-01

Thymocytes convert graded T cell receptor (TCR) signals into positive selection or deletion, and activation of extracellular signal-related kinase (ERK), p38, and Jun N-terminal protein kinase (JNK) mitogen-activated protein kinases (MAPKs) has been postulated to play a discriminatory role. Two families of Ras guanine nucleotide exchange factors (RasGEFs), SOS and RasGRP, activate Ras and the downstream RAF-MEK-ERK pathway. The pathways leading to lymphocyte p38 and JNK activation are less well defined. We previously described how RasGRP alone induces analog Ras-ERK activation while SOS and RasGRP cooperate to establish bimodal ERK activation. Here we employed computational modeling and biochemical experiments with model cell lines and thymocytes to show that TCR-induced ERK activation grows exponentially in thymocytes and that a W729E allosteric pocket mutant, SOS1, can only reconstitute analog ERK signaling. In agreement with RasGRP allosterically priming SOS, exponential ERK activation is severely decreased by pharmacological or genetic perturbation of the phospholipase Cγ (PLCγ)-diacylglycerol-RasGRP1 pathway. In contrast, p38 activation is not sharply thresholded and requires high-level TCR signal input. Rac and p38 activation depends on SOS1 expression but not allosteric activation. Based on computational predictions and experiments exploring whether SOS functions as a RacGEF or adaptor in Rac-p38 activation, we established that the presence of SOS1, but not its enzymatic activity, is critical for p38 activation. PMID:23589333

Up-regulation of P-glycoprotein expression by catalase via JNK activation in HepG2 cells.

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Li, Lin; Xu, Jianfeng; Min, Taishan; Huang, Weida

2006-01-01

Overexpression of the MDR1 gene is one of the reasons for multidrug resistance (MDR). Some studies suggested that antioxidants could down-regulate MDR1 expression as a possible cancer treatment. In this report, we try to determine the effects of antioxidants (catalase or N-acetylcysteine [NAC]) on the regulation of intrinsic MDR1 overexpression in HepG2 cells. Adding catalase or N-acetylcysteine to the HepG2 culture led to a significant increase of MDR1 mRNA and P-glycoprotein drug transporter activity. After catalase or NAC treatment, a reduced intracellular reactive oxygen species (ROS) was observed. The JNK inhibitor SP600125 abolished the positive effects of catalase on drug transporter activity in a dose-dependent manner. Furthermore, the up-regulation of P-glycoprotein functions by catalase was only observed in HepG2 cells but not in other cell lines tested (MCF-7, A549, A431). These data suggested that catalase can up-regulate P-glycoprotein expression in HepG2 cells via reducing intracellular ROS, and JNK may mediate this process.

INTERPLAY OF SORBITOL PATHWAY OF GLUCOSE METABOLISM, 12/15-LIPOXYGENASE, AND MITOGEN-ACTIVATED PROTEIN KINASES IN THE PATHOGENESIS OF DIABETIC PERIPHERAL NEUROPATHY

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Stavniichuk, Roman; Shevalye, Hanna; Hirooka, Hiroko; Nadler, Jerry L.; Obrosova, Irina G.

2012-01-01

The interactions among multiple pathogenetic mechanisms of diabetic peripheral neuropathy largely remain unexplored. Increased activity of aldose reductase, the first enzyme of the sorbitol pathway, leads to accumulation of cytosolic Ca++, essentially required for 12/15-lipoxygenase activation. The latter, in turn, causes oxidative-nitrosative stress, an important trigger of MAPK phosphorylation. This study therefore evaluated the interplay of aldose reductase, 12/15-lipoxygenase, and MAPKs in diabetic peripheral neuropathy. In experiment 1, male control and streptozotocin-diabetic mice were maintained with or without the aldose reductase inhibitor fidarestat, 16 mg kg−1 d−1, for 12 weeks. In experiment 2, male control and streptozotocin-diabetic wild-type (C57Bl6/J) and 12/15-lipoxygenase-deficient mice were used. Fidarestat treatment did not affect diabetes-induced increase in glucose concentrations, but normalized sorbitol and fructose concentrations (enzymatic spectrofluorometric assays) as well as 12(S) hydroxyeicosatetraenoic concentration (ELISA), a measure of 12/15-lipoxygenase activity, in the sciatic nerve and spinal cord. 12/15-lipoxygenase expression in these two tissues (Western blot analysis) as well as dorsal root ganglia (immunohistochemistry) was similarly elevated in untreated and fidarestat-treated diabetic mice. 12/15-lipoxygenase gene deficiency prevented diabetesassociated p38 MAPK and ERK, but not SAPK/JNK, activation in the sciatic nerve (Western blot analysis) and all three MAPK activation in the dorsal root ganglia (immunohistochemistry). In contrast, spinal cord p38 MAPK, ERK, and SAPK/JNK were similarly activated in diabetic wild-type and 12/15-lipoxygenase−/− mice. These findings identify the nature and tissue specificity of interactions among three major mechanisms of diabetic peripheral neuropathy, and suggest that combination treatments, rather than monotherapies, can sometimes be an optimal choice for its management. PMID

ERK5 pathway regulates the phosphorylation of tumour suppressor hDlg during mitosis

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Inesta-Vaquera, Francisco A. [Departamento de Inmunologia y Oncologia, Centro Nacional de Biotecnologia-CSIC, Campus de Cantoblanco-UAM, 28049 Madrid (Spain); Campbell, David G.; Arthur, J. Simon C. [MRC Protein Phosphorylation Unit, Sir James Black Building, School of Life Sciences, University of Dundee, Dundee DD1 5EH (United Kingdom); Cuenda, Ana, E-mail: acuenda@cnb.csic.es [Departamento de Inmunologia y Oncologia, Centro Nacional de Biotecnologia-CSIC, Campus de Cantoblanco-UAM, 28049 Madrid (Spain)

2010-08-13

Research highlights: {yields} hDlg is phosphorylated during mitosis in multiple residues. {yields} Prospho-hDlg is excluded from the midbody during mitosis. {yields} hDlg is not phosphorylated by p38{gamma} or JNK1/2 during mitosis. {yields} ERK5 pathway mediates hDlg phosphorylation in mitosis. -- Abstract: Human disc-large (hDlg) is a scaffold protein critical for the maintenance of cell polarity and adhesion. hDlg is thought to be a tumour suppressor that regulates the cell cycle and proliferation. However, the mechanism and pathways involved in hDlg regulation during these processes is still unclear. Here we report that hDlg is phosphorylated during mitosis, and we establish the identity of at least three residues phosphorylated in hDlg; some are previously unreported. Phosphorylation affects hDlg localisation excluding it from the contact point between the two daughter cells. Our results reveal a previously unreported pathway for hDlg phosphorylation in mitosis and show that ERK5 pathway mediates hDlg cell cycle dependent phosphorylation. This is likely to have important implications in the correct timely mitotic entry and mitosis progression.

ERK5 pathway regulates the phosphorylation of tumour suppressor hDlg during mitosis

International Nuclear Information System (INIS)

Inesta-Vaquera, Francisco A.; Campbell, David G.; Arthur, J. Simon C.; Cuenda, Ana

2010-01-01

Research highlights: → hDlg is phosphorylated during mitosis in multiple residues. → Prospho-hDlg is excluded from the midbody during mitosis. → hDlg is not phosphorylated by p38γ or JNK1/2 during mitosis. → ERK5 pathway mediates hDlg phosphorylation in mitosis. -- Abstract: Human disc-large (hDlg) is a scaffold protein critical for the maintenance of cell polarity and adhesion. hDlg is thought to be a tumour suppressor that regulates the cell cycle and proliferation. However, the mechanism and pathways involved in hDlg regulation during these processes is still unclear. Here we report that hDlg is phosphorylated during mitosis, and we establish the identity of at least three residues phosphorylated in hDlg; some are previously unreported. Phosphorylation affects hDlg localisation excluding it from the contact point between the two daughter cells. Our results reveal a previously unreported pathway for hDlg phosphorylation in mitosis and show that ERK5 pathway mediates hDlg cell cycle dependent phosphorylation. This is likely to have important implications in the correct timely mitotic entry and mitosis progression.

Free fatty acid palmitate activates unfolded protein response pathway and promotes apoptosis in meniscus cells.

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Haywood, J; Yammani, R R

2016-05-01

Obesity is the major risk factor for the development of osteoarthritis (OA); however, the mechanisms involved are not clearly understood. Obesity is associated with increased production of adipokine and elevated levels of circulating free fatty acids (FFA). A recent study has shown that saturated fatty acid palmitate induced pro-inflammatory and pro-apoptotic pathways in chondrocytes. Meniscus has been shown to be more susceptible than articular cartilage to catabolic stimuli. Thus, the aim of this study was to determine the effect of FFA (specifically, palmitate) on meniscus cells. Cultured primary porcine meniscus cells were stimulated with 500 μM FFA (palmitate and oleate) for 24 h to induce endoplasmic reticulum (ER) stress. After treatment, cell lysates were prepared and immunoblotted for C/EBP homologous protein (CHOP). To determine the activation of unfolded protein response (UPR) signaling, cell lysates were probed for cJun n-terminal kinase (JNK), cleaved caspase -3 and Xbp-1s, an alternative mRNA splicing product generated due to Ire1α activation. Treatment of isolated primary meniscus cells with palmitate but not oleate induced expression of CHOP and Xbp-1s. Palmitate treatment of meniscus cells also activated JNK and increased expression of caspase-3, thus promoting apoptosis in meniscus cells. Palmitate induces ER stress and promotes apoptotic pathways in meniscus cells. This is the first study to establish ER stress as a key metabolic mechanistic link between obesity and OA, in addition to (or operating with) biomechanical factors. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Snake venom toxin from vipera lebetina turanica induces apoptosis of colon cancer cells via upregulation of ROS- and JNK-mediated death receptor expression

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Park, Mi Hee; Jo, MiRan; Won, Dohee; Song, Ho Sueb; Han, Sang Bae; Song, Min Jong; Hong, Jin Tae

2012-01-01

Abundant research suggested that the cancer cells avoid destruction by the immune system through down-regulation or mutation of death receptors. Therefore, it is very important that finding the agents that increase the death receptors of cancer cells. In this study, we demonstrated that the snake venom toxin from Vipera lebetina turanica induce the apoptosis of colon cancer cells through reactive oxygen species (ROS) and c-Jun N-terminal kinases (JNK) dependent death receptor (DR4 and DR5) expression. We used cell viability assays, DAPI/TUNEL assays, as well as western blot for detection of apoptosis related proteins and DRs to demonstrate that snake venom toxin-induced apoptosis is DR4 and DR5 dependent. We carried out transient siRNA knockdowns of DR4 and DR5 in colon cancer cells. We showed that snake venom toxin inhibited growth of colon cancer cells through induction of apoptosis. We also showed that the expression of DR4 and DR5 was increased by treatment of snake venom toxin. Moreover, knockdown of DR4 or DR5 reversed the effect of snake venom toxin. Snake venom toxin also induced JNK phosphorylation and ROS generation, however, pretreatment of JNK inhibitor and ROS scavenger reversed the inhibitory effect of snake venom toxin on cancer cell proliferation, and reduced the snake venom toxin-induced upregulation of DR4 and DR5 expression. Our results indicated that snake venom toxin could inhibit human colon cancer cell growth, and these effects may be related to ROS and JNK mediated activation of death receptor (DR4 and DR5) signals

HMGB1 induces an inflammatory response in endothelial cells via the RAGE-dependent endoplasmic reticulum stress pathway

International Nuclear Information System (INIS)

Luo, Ying; Li, Shu-Jun; Yang, Jian; Qiu, Yuan-Zhen; Chen, Fang-Ping

2013-01-01

Highlights: •Mechanisms of inflammatory response induced by HMGB1 are incompletely understood. •We found that endoplasmic reticulum stress mediate the inflammatory response induced by HMGB1. •RAGE-mediated ERS pathways are involved in those processes. •We reported a new mechanism for HMGB1 induced inflammatory response. -- Abstract: The high mobility group 1B protein (HMGB1) mediates chronic inflammatory responses in endothelial cells, which play a critical role in atherosclerosis. However, the underlying mechanism is unknown. The goal of our study was to identify the effects of HMGB1 on the RAGE-induced inflammatory response in endothelial cells and test the possible involvement of the endoplasmic reticulum stress pathway. Our results showed that incubation of endothelial cells with HMGB1 (0.01–1 μg/ml) for 24 h induced a dose-dependent activation of endoplasmic reticulum stress transducers, as assessed by PERK and IRE1 protein expression. Moreover, HMGB1 also promoted nuclear translocation of ATF6. HMGB1-mediated ICAM-1 and P-selectin production was dramatically suppressed by PERK siRNA or IRE1 siRNA. However, non-targeting siRNA had no such effects. HMGB1-induced increases in ICAM-1 and P-selectin expression were also inhibited by a specific eIF2α inhibitor (salubrinal) and a specific JNK inhibitor (SP600125). Importantly, a blocking antibody specifically targeted against RAGE (anti-RAGE antibody) decreased ICAM-1, P-selectin and endoplasmic reticulum stress molecule (PERK, eIF2α, IRE1 and JNK) protein expression levels. Collectively, these novel findings suggest that HMGB1 promotes an inflammatory response by inducing the expression of ICAM-1 and P-selectin via RAGE-mediated stimulation of the endoplasmic reticulum stress pathway

Andrographolide Inhibits Inflammatory Cytokines Secretion in LPS-Stimulated RAW264.7 Cells through Suppression of NF-κB/MAPK Signaling Pathway.

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Li, Yu; He, Shengnan; Tang, Jishun; Ding, Nana; Chu, Xiaoyan; Cheng, Lianping; Ding, Xuedong; Liang, Ting; Feng, Shibin; Rahman, Sajid Ur; Wang, Xichun; Wu, Jinjie

2017-01-01

Andrographolide, the main active component extracted from Andrographis paniculata (Burm.f.) Wall. ex Nees, exerts anti-inflammatory effects; however, the principal molecular mechanisms remain unclear. The objective of this study was to investigate the molecular mechanisms of Andrographolide in modifying lipopolysaccharide- (LPS-) induced signaling pathway in RAW264.7 cells. An in vitro model of inflammation was induced by LPS in mouse RAW264.7 cells in the presence of Andrographolide. The concentration and expression levels of proinflammatory cytokines were determined by an enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. The nuclear level of NF- κ B was measured by an electrophoretic mobility shift assay (EMSA). The expression levels of NF- κ B, p38, ERK, and JNK were determined by western blot. Andrographolide dose-dependently inhibited the release and mRNA expression of TNF- α , IL-6, and IL-1 β in LPS-stimulated RAW264.7 cells. The nuclear level of p65 protein was decreased in Andrographolide treatment group. Western blot analysis showed that Andrographolide suppressed LPS-induced NF- κ B activation and the phosphorylation of IkBa, ERK1/2, JNK, and p38. These results suggest that Andrographolide exerts an anti-inflammatory effect by inhibiting the activation of NF- κ B/MAPK signaling pathway and the induction of proinflammatory cytokines.

A dual character of flavonoids in influenza A virus replication and spread through modulating cell-autonomous immunity by MAPK signaling pathways

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Dong, Wenjuan; Wei, Xiuli; Zhang, Fayun; Hao, Junfeng; Huang, Feng; Zhang, Chunling; Liang, Wei

2014-01-01

Flavonoids are well known as a large class of polyphenolic compounds, which have a variety of physiological activities, including anti-influenza virus activity. The influenza A/WSN/33 infected A549 cells have been used to screen anti-influenza virus drugs from natural flavonoid compounds library. Unexpectedly, some flavonoid compounds significantly inhibited virus replication, while the others dramatically promoted virus replication. In this study, we attempted to understand these differences between flavonoid compounds in their antivirus mechanisms. Hesperidin and kaempferol were chosen as representatives of both sides, each of which exhibited the opposite effects on influenza virus replication. Our investigation revealed that the opposite effects produced by hesperidin and kaempferol on influenza virus were due to inducing the opposite cell-autonomous immune responses by selectively modulating MAP kinase pathways: hesperidin up-regulated P38 and JNK expression and activation, thus resulting in the enhanced cell-autonomous immunity; while kaempferol dramatically down-regulated p38 and JNK expression and activation, thereby suppressing cell-autonomous immunity. In addition, hesperidin restricted RNPs export from nucleus by down-regulating ERK activation, but kaempferol promoted RNPs export by up-regulating ERK activation. Our findings demonstrate that a new generation of anti-influenza virus drugs could be developed based on selective modulation of MAP kinase pathways to stimulate cell-autonomous immunity. PMID:25429875

Andrographolide Inhibits Inflammatory Cytokines Secretion in LPS-Stimulated RAW264.7 Cells through Suppression of NF-κB/MAPK Signaling Pathway

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Yu Li

2017-01-01

Full Text Available Andrographolide, the main active component extracted from Andrographis paniculata (Burm.f. Wall. ex Nees, exerts anti-inflammatory effects; however, the principal molecular mechanisms remain unclear. The objective of this study was to investigate the molecular mechanisms of Andrographolide in modifying lipopolysaccharide- (LPS- induced signaling pathway in RAW264.7 cells. An in vitro model of inflammation was induced by LPS in mouse RAW264.7 cells in the presence of Andrographolide. The concentration and expression levels of proinflammatory cytokines were determined by an enzyme-linked immunosorbent assay (ELISA and quantitative real-time polymerase chain reaction (qRT-PCR, respectively. The nuclear level of NF-κB was measured by an electrophoretic mobility shift assay (EMSA. The expression levels of NF-κB, p38, ERK, and JNK were determined by western blot. Andrographolide dose-dependently inhibited the release and mRNA expression of TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells. The nuclear level of p65 protein was decreased in Andrographolide treatment group. Western blot analysis showed that Andrographolide suppressed LPS-induced NF-κB activation and the phosphorylation of IkBa, ERK1/2, JNK, and p38. These results suggest that Andrographolide exerts an anti-inflammatory effect by inhibiting the activation of NF-κB/MAPK signaling pathway and the induction of proinflammatory cytokines.

Acrolein increases 5-lipoxygenase expression in murine macrophages through activation of ERK pathway.

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Kim, Chae E; Lee, Seung J; Seo, Kyo W; Park, Hye M; Yun, Jung W; Bae, Jin U; Bae, Sun S; Kim, Chi D

2010-05-15

Episodic exposure to acrolein-rich pollutants has been linked to acute myocardial infarction, and 5-lipoxygenase (5-LO) is involved in the production of matrix metalloproteinase-9 (MMP-9), which destabilizes atherosclerotic plaques. Thus, the present study determined the effect of acrolein on 5-LO/leukotriene B(4) (LTB(4)) production in murine macrophages. Stimulation of J774A.1 cells with acrolein led to increased LTB(4) production in association with increased 5-LO expression. Acrolein-evoked 5-LO expression was blocked by pharmacological inhibition of the ERK pathway, but not by inhibitors for JNK and p38 MAPK pathways. In line with these results, acrolein exclusively increased the phosphorylation of ERK among these MAPK, suggesting a role for the ERK pathway in acrolein-induced 5-LO expression with subsequent production of LTB(4). Among the receptor tyrosine kinases including epidermal growth factor receptor (EGFR) and platelet derived growth factor receptor (PDGFR), acrolein-evoked ERK phosphorylation was attenuated by AG1478, an EGFR inhibitor, but not by AG1295, a PDGFR inhibitor. In addition, acrolein-evoked 5-LO expression was also inhibited by inhibition of EGFR pathway, but not by inhibition of PDGFR pathway. These observations suggest that acrolein has a profound effect on the 5-LO pathway via an EGFR-mediated activation of ERK pathway, leading to acute ischemic syndromes through the generation of LTB(4), subsequent MMP-9 production and plaque rupture.

Acrolein increases 5-lipoxygenase expression in murine macrophages through activation of ERK pathway

International Nuclear Information System (INIS)

Kim, Chae E.; Lee, Seung J.; Seo, Kyo W.; Park, Hye M.; Yun, Jung W.; Bae, Jin U.; Bae, Sun S.; Kim, Chi D.

2010-01-01

Episodic exposure to acrolein-rich pollutants has been linked to acute myocardial infarction, and 5-lipoxygenase (5-LO) is involved in the production of matrix metalloproteinase-9 (MMP-9), which destabilizes atherosclerotic plaques. Thus, the present study determined the effect of acrolein on 5-LO/leukotriene B 4 (LTB 4 ) production in murine macrophages. Stimulation of J774A.1 cells with acrolein led to increased LTB 4 production in association with increased 5-LO expression. Acrolein-evoked 5-LO expression was blocked by pharmacological inhibition of the ERK pathway, but not by inhibitors for JNK and p38 MAPK pathways. In line with these results, acrolein exclusively increased the phosphorylation of ERK among these MAPK, suggesting a role for the ERK pathway in acrolein-induced 5-LO expression with subsequent production of LTB 4 . Among the receptor tyrosine kinases including epidermal growth factor receptor (EGFR) and platelet derived growth factor receptor (PDGFR), acrolein-evoked ERK phosphorylation was attenuated by AG1478, an EGFR inhibitor, but not by AG1295, a PDGFR inhibitor. In addition, acrolein-evoked 5-LO expression was also inhibited by inhibition of EGFR pathway, but not by inhibition of PDGFR pathway. These observations suggest that acrolein has a profound effect on the 5-LO pathway via an EGFR-mediated activation of ERK pathway, leading to acute ischemic syndromes through the generation of LTB 4 , subsequent MMP-9 production and plaque rupture.

Maintaining protein composition in cilia.

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Stephen, Louise A; Elmaghloob, Yasmin; Ismail, Shehab

2017-12-20

The primary cilium is a sensory organelle that is vital in regulating several signalling pathways. Unlike most organelles cilia are open to the rest of the cell, not enclosed by membranes. The distinct protein composition is crucial to the function of cilia and many signalling proteins and receptors are specifically concentrated within distinct compartments. To maintain this composition, a mechanism is required to deliver proteins to the cilium whilst another must counter the entropic tendency of proteins to distribute throughout the cell. The combination of the two mechanisms should result in the concentration of ciliary proteins to the cilium. In this review we will look at different cellular mechanisms that play a role in maintaining the distinct composition of cilia, including regulation of ciliary access and trafficking of ciliary proteins to, from and within the cilium.

Ethanol Extracts of Fruiting Bodies of Antrodia cinnamomea Suppress CL1-5 Human Lung Adenocarcinoma Cells Migration by Inhibiting Matrix Metalloproteinase-2/9 through ERK, JNK, p38, and PI3K/Akt Signaling Pathways

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Ying-Yi Chen

2012-01-01

Full Text Available Cancer metastasis is a primary cause of cancer death. Antrodia cinnamomea (A. cinnamomea, a medicinal mushroom in Taiwan, has shown antioxidant and anticancer activities. In this study, we first observed that ethanol extract of fruiting bodies of A. cinnamomea (EEAC exerted a concentration-dependent inhibitory effect on migration and motility of the highly metastatic CL1-5 cells in the absence of cytotoxicity. The results of a gelatin zymography assay showed that A. cinnamomea suppressed the activities of matrix metalloproteinase-(MMP- 2 and MMP-9 in a concentration-dependent manner. Western blot results demonstrated that treatment with A. cinnamomea decreased the expression of MMP-9 and MMP-2; while the expression of the endogenous inhibitors of these proteins, that is, tissue inhibitors of MMP (TIMP-1 and TIMP-2 increased. Further investigation revealed that A. cinnamomea suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. A. cinnamomea also suppressed the expressions of PI3K and phosphorylation of Akt. Furthermore, treatment of CL1-5 cells with inhibitors specific for PI3K (LY 294002, ERK1/2 (PD98059, JNK (SP600125, and p38 MAPK (SB203580 decreased the expression of MMP-2 and MMP-9. This is the first paper confirming the antimigration activity of this potentially beneficial mushroom against human lung adenocarcinoma CL1-5 cancer cells.

Hepatitis B virus X protein promotes interleukin-7 receptor expression via NF-κB and Notch1 pathway to facilitate proliferation and migration of hepatitis B virus-related hepatoma cells

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Fanyun Kong

2016-11-01

Full Text Available Abstract Background Interleukin-7 receptor (IL-7R is involved in the abnormal function of solid tumors, but the role and regulatory mechanisms of IL-7R in HBV-related hepatocellular carcinoma (HCC are still unclear. Methods Gene and protein expression levels of IL-7R were examined in hepatoma cells transfected with hepatitis B virus (HBV plasmids and in hepatoma cells transfected with the multifunctional nonstructural protein X (HBX. The expression of HBX and IL-7R was measured by immunohistochemical analysis in HBV-related HCC tissues. The role of NF-κB and Notch1 pathways in HBX-mediated expression of IL-7R in hepatoma cells was examined. Activation of IL-7R downstream of intracellular signaling proteins AKT, JNK, STAT5, and the associated molecules CyclinD1 and matrix metalloproteinase-9 (MMP-9, was assessed in HBX-positive cells with or without treatment with IL-7R short hairpin RNA (shRNA. Additionally, the role of IL-7R in HBX-mediated proliferation and migration of hepatoma cells was investigated. Results The expression of IL-7R was increased in hepatoma cells transfected with HBV plasmids; HBX was responsible for the HBV-mediated upregulation of IL-7R. Compared to adjacent tissues, the expression of HBX and IL-7R was increased in HBV-related HCC tissues. Additionally, the relative expression levels of HBX were associated with IL-7R in HBV-related HCC tissues. The activation of NF-κB pathways and expression of Notch1 were increased in hepatoma cells transfected with HBX, and inhibition of NF-κB and Notch1 pathways significantly decreased HBX-mediated expression of IL-7R. The activation of AKT and JNK and the expression of CyclinD1 and MMP-9 were increased in HBX-positive cells. When cells were treated with IL-7R shRNA, the activation of AKT and JNK, as well as the expression of CyclinD1 and MMP-9, were significantly inhibited. Additionally, IL-7R was responsible for HBX-induced proliferation and migration ability of hepatoma cells

Wnts enhance neurotrophin-induced neuronal differentiation in adult bone-marrow-derived mesenchymal stem cells via canonical and noncanonical signaling pathways.

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Hung-Li Tsai

Full Text Available Wnts were previously shown to regulate the neurogenesis of neural stem or progenitor cells. Here, we explored the underlying molecular mechanisms through which Wnt signaling regulates neurotrophins (NTs in the NT-induced neuronal differentiation of human mesenchymal stem cells (hMSCs. NTs can increase the expression of Wnt1 and Wnt7a in hMSCs. However, only Wnt7a enables the expression of synapsin-1, a synaptic marker in mature neurons, to be induced and triggers the formation of cholinergic and dopaminergic neurons. Human recombinant (hrWnt7a and general neuron makers were positively correlated in a dose- and time-dependent manner. In addition, the expression of synaptic markers and neurites was induced by Wnt7a and lithium, a glycogen synthase kinase-3β inhibitor, in the NT-induced hMSCs via the canonical/β-catenin pathway, but was inhibited by Wnt inhibitors and frizzled-5 (Frz5 blocking antibodies. In addition, hrWnt7a triggered the formation of cholinergic and dopaminergic neurons via the non-canonical/c-jun N-terminal kinase (JNK pathway, and the formation of these neurons was inhibited by a JNK inhibitor and Frz9 blocking antibodies. In conclusion, hrWnt7a enhances the synthesis of synapse and facilitates neuronal differentiation in hMSCS through various Frz receptors. These mechanisms may be employed widely in the transdifferentiation of other adult stem cells.

Macrolactin F inhibits RANKL-mediated osteoclastogenesis by suppressing Akt, MAPK and NFATc1 pathways and promotes osteoblastogenesis through a BMP-2/smad/Akt/Runx2 signaling pathway.

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Li, Liang; Sapkota, Mahesh; Gao, Ming; Choi, Hyukjae; Soh, Yunjo

2017-11-15

The balance between bone formation and bone resorption is maintained by osteoblasts and osteoclasts. In the current study, macrolactin F (MF) was investigated for novel biological activity on the receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis in primary bone marrow-derived macrophages (BMMs). We found that RANKL-induced osteoclast formation and differentiation from BMMs was significantly inhibited by MF in a dose-dependent manner without cytotoxicity. RANKL-induced F-actin ring formation and bone resorption activity in BMMs which was attenuated by MF. In addition, MF suppressed the expression of osteoclast-related genes, including c-myc, RANK, tartrate-resistant acid phosphatase (TRAP), nuclear factor of activated T cells c1 (NFATc1), cathepsin K and matrix metalloproteinase 9 (MMP9). Furthermore, the protein expression NFATc1, c-Fos, MMP9, cathepsin K and phosphorylation of Jun N-terminal kinase (JNK), p38 and Akt were also down-regulated by MF treatment. Interestingly, MF promoted pre-osteoblast cell differentiation on Alizarin Red-mineralization activity, alkaline phosphatase (ALP) activity, and the expression of osteoblastogenic markers including Runx2, Osterix, Smad4, ALP, type I collagen alpha 1 (Col1α), osteopontin (OPN), and osteocalcin (OCN) via activation of the BMP-2/smad/Akt/Runx2 pathway on MC3T3-E1. Taken together, these results indicate that MF may be useful as a therapeutic agent to enhance bone health and treat osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Signal Transduction Pathways (MAPKs, NF-κB, and C/EBP) Regulating COX-2 Expression in Nasal Fibroblasts from Asthma Patients with Aspirin Intolerance

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Garcia-Garcia, Francesc Josep; Mullol, Joaquim; Perez-Gonzalez, Maria; Pujols, Laura; Alobid, Isam

2012-01-01

Background Recent studies have revealed that cyclooxygenase-2 (COX-2) expression is down-regulated in aspirin-induced asthma (AIA). Various signal pathways (MAPKs, NF-κB and C/EBP) are involved in COX-2 regulation. Objective To investigate the regulation of COX-2 expression through MAP-kinase pathway activation and nuclear factor translocation in aspirin-induced asthma (AIA). Methods Fibroblasts were isolated from specimens of nasal mucosa (NM, N = 5) and nasal polyps (NP, N = 5). After IL-1β (1 ng/ml) incubation, COX-2 and phosphorylated forms of ERK, JNK and p38 MAPK were measured by Western blot. MAPK’s role in IL-1β-induced COX-2 expression was assessed by treating cells with ERK (PD98059), JNK (SP600125) and p38 MAPK (SB203580) inhibitors (0.1–10 µM) prior to IL-1β exposure. NF-κB and C/EBP nuclear translocation was measured by Western blot and TransAM® after IL-1β (10 ng/ml) exposure. Results No differences were observed in the MAPK phosphorylation time-course between NM and NP-AIA fibroblasts. The p38 MAPK inhibitor at 10 µM significantly reduced IL-1β-induced COX-2 expression in NM fibroblasts (85%). In NP-AIA fibroblasts the COX-2 inhibition (65%) at 1 and 10 µM was not statistically significant compared to non-treated cells. ERK and JNK inhibitors had no significant effect in either the NM or NP-AIA cultures. The effect of IL-1β on NF-κB and C/EBP subunits’ nuclear translocation was similar between NM and NP-AIA fibroblasts. Conclusions These results suggest that p38 MAPK is the only MAPK involved in IL-1β-induced COX-2 expression. NM and NP-AIA fibroblasts have similar MAPK phosphorylation dynamics and nuclear factor translocation (NF-κB and C/EBP). COX-2 downregulation observed in AIA patients appears not to be caused by differences in MAPK dynamics or transcription factor translocation. PMID:23240010

Proteomic Assessment of Biochemical Pathways That Are Critical to Nickel-Induced Toxicity Responses in Human Epithelial Cells

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Ge, Yue; Bruno, Maribel; Haykal-Coates, Najwa; Wallace, Kathleen; Andrews, Debora; Swank, Adam; Winnik, Witold; Ross, Jeffrey A.

2016-01-01

Understanding the mechanisms underlying toxicity initiated by nickel, a ubiquitous environmental contaminant and known human carcinogen is necessary for proper assessment of its risks to human and environment. Among a variety of toxic mechanisms, disruption of protein responses and protein response-based biochemical pathways represents a key mechanism through which nickel induces cytotoxicity and carcinogenesis. To identify protein responses and biochemical pathways that are critical to nickel-induced toxicity responses, we measured cytotoxicity and changes in expression and phosphorylation status of 14 critical biochemical pathway regulators in human BEAS-2B cells exposed to four concentrations of nickel using an integrated proteomic approach. A subset of the pathway regulators, including interleukin-6, and JNK, were found to be linearly correlated with cell viability, and may function as molecular determinants of cytotoxic responses of BEAS-2B cells to nickel exposures. In addition, 128 differentially expressed proteins were identified by two dimensional electrophoresis (2-DE) and mass spectrometry. Principal component analysis, hierarchical cluster analyses, and ingenuity signaling pathway analysis (IPA) identified putative nickel toxicity pathways. Some of the proteins and pathways identified have not previously been linked to nickel toxicity. Based on the consistent results obtained from both ELISA and 2-DE proteomic analysis, we propose a core signaling pathway regulating cytotoxic responses of human BEAS-2B cells to nickel exposures, which integrates a small set of proteins involved in glycolysis and gluconeogenesis pathways, apoptosis, protein degradation, and stress responses including inflammation and oxidative stress. PMID:27626938

Recapitulation of Extracellular LAMININ Environment Maintains Stemness of Satellite Cells In Vitro.

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Ishii, Kana; Sakurai, Hidetoshi; Suzuki, Nobuharu; Mabuchi, Yo; Sekiya, Ichiro; Sekiguchi, Kiyotoshi; Akazawa, Chihiro

2018-02-13

Satellite cells function as precursor cells in mature skeletal muscle homeostasis and regeneration. In healthy tissue, these cells are maintained in a state of quiescence by a microenvironment formed by myofibers and basement membrane in which LAMININs (LMs) form a major component. In the present study, we evaluated the satellite cell microenvironment in vivo and found that these cells are encapsulated by LMα2-5. We sought to recapitulate this satellite cell niche in vitro by culturing satellite cells in the presence of recombinant LM-E8 fragments. We show that treatment with LM-E8 promotes proliferation of satellite cells in an undifferentiated state, through reduced phosphorylation of JNK and p38. On transplantation into injured muscle tissue, satellite cells cultured with LM-E8 promoted the regeneration of skeletal muscle. These findings represent an efficient method of culturing satellite cells for use in transplantation through the recapitulation of the satellite cell niche using recombinant LM-E8 fragments. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Involvement of caspase-12-dependent apoptotic pathway in ionic radiocontrast urografin-induced renal tubular cell injury

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Wu, Cheng Tien [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Weng, Te I. [Department of Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Chen, Li Ping [Department of Dentistry, Chang Gang Memorial Hospital, Chang Gang University, Taoyuan, Taiwan (China); Chiang, Chih Kang [Department of Integrated Diagnostics and Therapeutics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Liu, Shing Hwa, E-mail: shinghwaliu@ntu.edu.tw [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Urology, National Taiwan University Hospital, Taipei, Taiwan (China)

2013-01-01

Contrast medium (CM) induces a direct toxic effect on renal tubular cells. This toxic effect subjects in the disorder of CM-induced nephropathy. Our previous work has demonstrated that CM shows to activate the endoplasmic reticulum (ER)-related adaptive unfolding protein response (UPR) activators. Glucose-regulated protein 78 (GRP78)/eukaryotic initiation factor 2α (eIF2α)-related pathways play a protective role during the urografin (an ionic CM)-induced renal tubular injury. However, the involvement of ER stress-related apoptotic signals in the urografin-induced renal tubular cell injury remains unclear. Here, we examined by the in vivo and in vitro experiments to explore whether ER stress-regulated pro-apoptotic activators participate in urografin-induced renal injury. Urografin induced renal tubular dilation, tubular cells detachment, and necrosis in the kidneys of rats. The tubular apoptosis, ER stress-related pro-apoptotic transcriptional factors, and kidney injury marker-1 (kim-1) were also conspicuously up-regulated in urografin-treated rats. Furthermore, treatment of normal rat kidney (NRK)-52E tubular cells with urografin augmented the expressions of activating transcription factor-6 (ATF-6), C/EBP homologous protein (CHOP), Bax, caspase-12, JNK, and inositol-requiring enzyme (IRE) 1 signals. Urografin-induced renal tubular cell apoptosis was not reversed by the inhibitors of ATF-6, JNK signals or CHOP siRNA transfection, but it could be partially reversed by the inhibitor of caspase-12. Taken together, the present results and our previous findings suggest that exposure of CM/urografin activates the ER stress-regulated survival- and apoptosis-related signaling pathways in renal tubular cells. Caspase-12-dependent apoptotic pathway may be partially involved in the urografin-induced nephropathy. -- Highlights: ► Ionic contrast medium-urografin induces renal tubular cell apoptosis. ► Urografin induces the ER stress-regulated survival and apoptosis

Increasing Maternal Body Mass Index Is Associated with Systemic Inflammation in the Mother and the Activation of Distinct Placental Inflammatory Pathways1

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Aye, Irving L.M.H.; Lager, Susanne; Ramirez, Vanessa I.; Gaccioli, Francesca; Dudley, Donald J.; Jansson, Thomas; Powell, Theresa L.

2014-01-01

ABSTRACT Obese pregnant women have increased levels of proinflammatory cytokines in maternal circulation and placental tissues. However, the pathways contributing to placental inflammation in obesity are largely unknown. We tested the hypothesis that maternal body mass index (BMI) was associated with elevated proinflammatory cytokines in maternal and fetal circulations and increased activation of placental inflammatory pathways. A total of 60 women of varying pre-/early pregnancy BMI, undergoing delivery by Cesarean section at term, were studied. Maternal and fetal (cord) plasma were collected for analysis of insulin, leptin, IL-1beta, IL-6, IL-8, monocyte chemoattractant protein (MCP) 1, and TNFalpha by multiplex ELISA. Activation of the inflammatory pathways in the placenta was investigated by measuring the phosphorylated and total protein expression of p38-mitogen-activated protein kinase (MAPK), c-Jun-N-terminal kinase (JNK)-MAPK, signal transducer-activated transcription factor (STAT) 3, caspase-1, IL-1beta, IkappaB-alpha protein, and p65 DNA-binding activity. To determine the link between activated placental inflammatory pathways and elevated maternal cytokines, cultured primary human trophoblast (PHT) cells were treated with physiological concentrations of insulin, MCP-1, and TNFalpha, and inflammatory signaling analyzed by Western blot. Maternal BMI was positively correlated with maternal insulin, leptin, MCP-1, and TNFalpha, whereas only fetal leptin was increased with BMI. Placental phosphorylation of p38-MAPK and STAT3, and the expression of IL-1beta protein, were increased with maternal BMI; phosphorylation of p38-MAPK was also correlated with birth weight. In contrast, placental NFkappaB, JNK and caspase-1 signaling, and fetal cytokine levels were unaffected by maternal BMI. In PHT cells, p38-MAPK was activated by MCP-1 and TNFalpha, whereas STAT3 phosphorylation was increased following TNFalpha treatment. Maternal BMI is associated with elevated

LTB4 stimulates growth of human pancreatic cancer cells via MAPK and PI-3 kinase pathways

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Tong, W.-G.; Ding, X.-Z.; Talamonti, Mark S.; Bell, Richard H.; Adrian, Thomas E.

2005-01-01

We have previously shown the importance of LTB4 in human pancreatic cancer. LTB4 receptor antagonists block growth and induce apoptosis in pancreatic cancer cells both in vitro and in vivo. Therefore, we investigated the effect of LTB4 on proliferation of human pancreatic cancer cells and the mechanisms involved. LTB4 stimulated DNA synthesis and proliferation of both PANC-1 and AsPC-1 human pancreatic cancer cells, as measured by thymidine incorporation and cell number. LTB4 stimulated rapid and transient activation of MEK and ERK1/2 kinases. The MEK inhibitors, PD98059 and U0126, blocked LTB4-stimulated ERK1/2 activation and cell proliferation. LTB4 also stimulated phosphorylation of p38 MAPK; however, the p38 MAPK inhibitor, SB203580, failed to block LTB4-stimulated growth. The activity of JNK/SAPK was not affected by LTB4 treatment. Phosphorylation of Akt was also induced by LTB4 and this effect was blocked by the PI-3 kinase inhibitor wortmannin, which also partially blocked LTB4-stimulated cell proliferation. In conclusion, LTB4 stimulates proliferation of human pancreatic cancer cells through MEK/ERK and PI-3 kinase/Akt pathways, while p38 MPAK and JNK/SAPK are not involved

Upregulation of endothelial heme oxygenase-1 expression through the activation of the JNK pathway by sublethal concentrations of acrolein

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Wu, C.C.; Hsieh, C.W.; Lai, P.H.; Lin, J.B.; Liu, Y.C.; Wung, B.S.

2006-01-01

Acrolein is a highly electrophilic α,β-unsaturated aldehyde that is present in cigarette smoke. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by various such electrophilic compounds. In this study, the regulatory effects of acrolein upon the expression of HO-1 were investigated in endothelial cells (ECs). We demonstrate that acrolein induces the elevation of HO-1 protein levels, and subsequent enzyme activity, at non-cytotoxic concentrations. An additional α,β-unsaturated aldehyde, cinnamaldehyde, was also found to increase HO-1 expression and have less cytotoxicity than acrolein. Moreover, acrolein-mediated HO-1 induction is abrogated in the presence of actinomycin D and cycloheximide. Nrf2 is a transcription factor involved in the induction of HO-1 through an antioxidant response element (ARE) in the promoter region of the HO-1 gene. We show that acrolein induces Nrf2 translocation and ARE-luciferase reporter activity. Acrolein was also found to induce the production of both superoxide and H 2 O 2 at levels greater than 100 μM. However, with the exception of NAC, no antioxidant generated any effect upon acrolein-dependent HO-1 expression in ECs. Our present findings suggest that reactive oxygen species (ROS) may not be a major modulator for HO-1 induction. Using buthionine sulfoximine to deplete the intracellular GSH levels further enhanced the effects of acrolein. We also found that cellular GSH level was rapidly reduced after both 10 and 100 μM acrolein treatment. However, after 6 h of exposure to ECs, only 10 μM acrolein treatment increases GSH level. In addition, only the JNK inhibitor SP600125 and tyrosine kinase inhibitor genistein had any significant inhibitory impact upon the upregulation of HO-1 by acrolein. Pretreatment with a range of other PI3 kinase inhibitors, including wortmannin and LY294002, showed no effects. Hence, we show in our current experiments that a sublethal concentration of acrolein is in fact a novel HO-1 inducer

Upregulation of endothelial heme oxygenase-1 expression through the activation of the JNK pathway by sublethal concentrations of acrolein.

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Wu, C C; Hsieh, C W; Lai, P H; Lin, J B; Liu, Y C; Wung, B S

2006-08-01

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde that is present in cigarette smoke. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by various such electrophilic compounds. In this study, the regulatory effects of acrolein upon the expression of HO-1 were investigated in endothelial cells (ECs). We demonstrate that acrolein induces the elevation of HO-1 protein levels, and subsequent enzyme activity, at non-cytotoxic concentrations. An additional alpha,beta-unsaturated aldehyde, cinnamaldehyde, was also found to increase HO-1 expression and have less cytotoxicity than acrolein. Moreover, acrolein-mediated HO-1 induction is abrogated in the presence of actinomycin D and cycloheximide. Nrf2 is a transcription factor involved in the induction of HO-1 through an antioxidant response element (ARE) in the promoter region of the HO-1 gene. We show that acrolein induces Nrf2 translocation and ARE-luciferase reporter activity. Acrolein was also found to induce the production of both superoxide and H2O2 at levels greater than 100 microM. However, with the exception of NAC, no antioxidant generated any effect upon acrolein-dependent HO-1 expression in ECs. Our present findings suggest that reactive oxygen species (ROS) may not be a major modulator for HO-1 induction. Using buthionine sulfoximine to deplete the intracellular GSH levels further enhanced the effects of acrolein. We also found that cellular GSH level was rapidly reduced after both 10 and 100 microM acrolein treatment. However, after 6 h of exposure to ECs, only 10 microM acrolein treatment increases GSH level. In addition, only the JNK inhibitor SP600125 and tyrosine kinase inhibitor genistein had any significant inhibitory impact upon the upregulation of HO-1 by acrolein. Pretreatment with a range of other PI3 kinase inhibitors, including wortmannin and LY294002, showed no effects. Hence, we show in our current experiments that a sublethal concentration of acrolein is in fact a

Metformin prevents endoplasmic reticulum stress-induced apoptosis through AMPK-PI3K-c-Jun NH2 pathway

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Jung, T.W.; Lee, M.W.; Lee, Y.-J.; Kim, S.M.

2012-01-01

Type 2 diabetes mellitus is thought to be partially associated with endoplasmic reticulum (ER) stress toxicity on pancreatic beta cells and the result of decreased insulin synthesis and secretion. In this study, we showed that a well-known insulin sensitizer, metformin, directly protects against dysfunction and death of ER stress-induced NIT-1 cells (a mouse pancreatic beta cell line) via AMP-activated protein kinase (AMPK) and phosphatidylinositol-3 (PI3) kinase activation. We also showed that exposure of NIT-1 cells to metformin (5mM) increases cellular resistance against ER stress-induced NIT-1 cell dysfunction and death. AMPK and PI3 kinase inhibitors abolished the effect of metformin on cell function and death. Metformin-mediated protective effects on ER stress-induced apoptosis were not a result of an unfolded protein response or the induced inhibitors of apoptotic proteins. In addition, we showed that exposure of ER stressed-induced NIT-1 cells to metformin decreases the phosphorylation of c-Jun NH(2) terminal kinase (JNK). These data suggest that metformin is an important determinant of ER stress-induced apoptosis in NIT-1 cells and may have implications for ER stress-mediated pancreatic beta cell destruction via regulation of the AMPK-PI3 kinase-JNK pathway.

Celecoxib Ameliorates Non-Alcoholic Steatohepatitis in Type 2 Diabetic Rats via Suppression of the Non-Canonical Wnt Signaling Pathway Expression

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Tian, Feng; Zhang, Ya Jie; Li, Yu; Xie, Ying

2014-01-01

Our aim was to test whether pharmacological inhibition of cycloxygenase-2 (COX-2) reverses non-alcoholic steatohepatitis (NASH) in type 2 diabetes mellitus (T2DM) rats via suppression of the non-canonical Wnt signaling pathway expression. Twenty-four male Sprague-Dawley rats were randomly distributed to two groups and were fed with a high fat and sucrose (HF-HS) diet or a normal chow diet, respectively. After four weeks, rats fed with a HF-HS diet were made diabetic with low-dose streptozotocin. At the 9th week the diabetic rats fed with a HF-HS diet or the non-diabetic rats fed with a normal chow diet were further divided into two subgroups treated with vehicle or celecoxib (a selective COX-2 inhibitor, 10 mg/Kg/day, gavage) for the last 4 weeks, respectively. At the end of the 12th week, rats were anesthetized. NASH was assessed by histology. Related cytokine expression was measured at both the protein and gene levels through immunohistochemistry (IHC), Western blot and real-time PCR. T2DM rats fed with a HF-HS diet developed steatohepatitis and insulin resistance associated with elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin levels and the non-alcoholic fatty liver disease (NAFLD) activity score (NAS). The expression of Wnt5a, JNK1, NF-κB p65, and COX-2 were all significantly increased in the T2DM-NASH group compared with the control and control-cele group. Hepatic injury was improved by celecoxib in T2DM-NASH-Cele group indicated by reduced serum ALT and AST levels and hepatic inflammation was reduced by celecoxib showed by histology and the NAFLD activity score (NAS). Serum related metabolic parameters, HOMA-IR and insulin sensitivity index were all improved by celecoxib. The expression of Wnt5a, JNK1, NF-κB p65, and COX-2 expression were all suppressed by celecoxib in T2DM-NASH-Cele group. The results of the present study indicated that celecoxib ameliorated NASH in T2DM rats via suppression of the non-canonical Wnt

Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis

International Nuclear Information System (INIS)

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

2016-01-01

Highlights: • Taurine zinc SDs could prevent the bile-induced reduction in L02 cell viability. • Taurine zinc SDs can prevent cholestatic liver injury. • Taurine zinc SDs can inhibit BDL-induced hepatocyte apoptosis. • Taurine zinc SDs shows the cholesterol-lowering effects on cholestasis. • Taurine zinc SDs may suppress inflammation via dampening JNK phosphorylation. - Abstract: Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160 mg/kg) for 17 days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce

Gene Expression Profile Reveals Abnormalities of Multiple Signaling Pathways in Mesenchymal Stem Cell Derived from Patients with Systemic Lupus Erythematosus

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Yu Tang

2012-01-01

Full Text Available We aimed to compare bone-marrow-derived mesenchymal stem cells (BMMSCs between systemic lupus erythematosus (SLE and normal controls by means of cDNA microarray, immunohistochemistry, immunofluorescence, and immunoblotting. Our results showed there were a total of 1, 905 genes which were differentially expressed by BMMSCs derived from SLE patients, of which, 652 genes were upregulated and 1, 253 were downregulated. Gene ontology (GO analysis showed that the majority of these genes were related to cell cycle and protein binding. Pathway analysis exhibited that differentially regulated signal pathways involved actin cytoskeleton, focal adhesion, tight junction, and TGF-β pathway. The high protein level of BMP-5 and low expression of Id-1 indicated that there might be dysregulation in BMP/TGF-β signaling pathway. The expression of Id-1 in SLE BMMSCs was reversely correlated with serum TNF-α levels. The protein level of cyclin E decreased in the cell cycling regulation pathway. Moreover, the MAPK signaling pathway was activated in BMMSCs from SLE patients via phosphorylation of ERK1/2 and SAPK/JNK. The actin distribution pattern of BMMSCs from SLE patients was also found disordered. Our results suggested that there were distinguished differences of BMMSCs between SLE patients and normal controls.

Chronic intermittent hypoxia induces liver fibrosis in mice with diet-induced obesity via TLR4/MyD88/MAPK/NF-kB signaling pathways.

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Kang, Hyeon Hui; Kim, In Kyoung; Lee, Hye In; Joo, Hyonsoo; Lim, Jeong Uk; Lee, Jongmin; Lee, Sang Haak; Moon, Hwa Sik

2017-08-19

Obstructive sleep apnea (OSA) is associated with nonalcoholic fatty liver disease (NAFLD), and causes chronic intermittent hypoxia (CIH) during sleep. Inflammation is associated with the development of metabolic complications induced by CIH. Research suggests that innate immune mechanisms are involved in the pro-inflammatory pathways of liver fibrosis. The purpose of this study was to investigate whether innate immune responses induce liver fibrosis, and to evaluate mechanisms underlying hepatic inflammation related to CIH in a murine diet-induced obesity (DIO) model. Inflammatory and oxidative stress markers, TLR4, MyD88, Toll/interleukin-1-receptor-domain-containing adaptor-inducing interferon-β (TRIF), I-κB, NF-κB, p38 MAPK, c-JNK, and ERK activation, were measured in the serum and liver. As a result, α1(I)-collagen mRNA was significantly higher in DIO mice exposed to CIH than in the control groups. CIH mice exhibited liver fibrosis and significantly higher protein expression of TLR4, MyD88, phosphorylated (phospho-) I-κB, and phospho-ERK1/2 activation in the liver, and higher expression of NF-κB than that in the controls. TRIF, p38 MAPK, and JNK activation did not differ significantly between groups. We conclude that CIH in DIO mice leads to liver fibrosis via TLR4/MyD88/MAPK/NF-kB signaling pathways. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Kaempferol Attenuates Myocardial Ischemic Injury via Inhibition of MAPK Signaling Pathway in Experimental Model of Myocardial Ischemia-Reperfusion Injury

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Suchal, Kapil; Malik, Salma; Gamad, Nanda; Malhotra, Rajiv Kumar; Goyal, Sameer N.; Chaudhary, Uma; Bhatia, Jagriti; Ojha, Shreesh; Arya, Dharamvir Singh

2016-01-01

Kaempferol (KMP), a dietary flavonoid, has antioxidant, anti-inflammatory, and antiapoptotic effects. Hence, we investigated the effect of KMP in ischemia-reperfusion (IR) model of myocardial injury in rats. We studied male albino Wistar rats that were divided into sham, IR-control, KMP-20 + IR, and KMP 20 per se groups. KMP (20 mg/kg; i.p.) was administered daily to rats for the period of 15 days, and, on the 15th day, ischemia was produced by one-stage ligation of left anterior descending coronary artery for 45 min followed by reperfusion for 60 min. After completion of surgery, rats were sacrificed; heart was removed and processed for biochemical, morphological, and molecular studies. KMP pretreatment significantly ameliorated IR injury by maintaining cardiac function, normalizing oxidative stress, and preserving morphological alterations. Furthermore, there was a decrease in the level of inflammatory markers (TNF-α, IL-6, and NFκB), inhibition of active JNK and p38 proteins, and activation of ERK1/ERK2, a prosurvival kinase. Additionally, it also attenuated apoptosis by reducing the expression of proapoptotic proteins (Bax and Caspase-3), TUNEL positive cells, and increased level of antiapoptotic proteins (Bcl-2). In conclusion, KMP protected against IR injury by attenuating inflammation and apoptosis through the modulation of MAPK pathway. PMID:27087891

Kaempferol Attenuates Myocardial Ischemic Injury via Inhibition of MAPK Signaling Pathway in Experimental Model of Myocardial Ischemia-Reperfusion Injury

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Kapil Suchal

2016-01-01

Full Text Available Kaempferol (KMP, a dietary flavonoid, has antioxidant, anti-inflammatory, and antiapoptotic effects. Hence, we investigated the effect of KMP in ischemia-reperfusion (IR model of myocardial injury in rats. We studied male albino Wistar rats that were divided into sham, IR-control, KMP-20 + IR, and KMP 20 per se groups. KMP (20 mg/kg; i.p. was administered daily to rats for the period of 15 days, and, on the 15th day, ischemia was produced by one-stage ligation of left anterior descending coronary artery for 45 min followed by reperfusion for 60 min. After completion of surgery, rats were sacrificed; heart was removed and processed for biochemical, morphological, and molecular studies. KMP pretreatment significantly ameliorated IR injury by maintaining cardiac function, normalizing oxidative stress, and preserving morphological alterations. Furthermore, there was a decrease in the level of inflammatory markers (TNF-α, IL-6, and NFκB, inhibition of active JNK and p38 proteins, and activation of ERK1/ERK2, a prosurvival kinase. Additionally, it also attenuated apoptosis by reducing the expression of proapoptotic proteins (Bax and Caspase-3, TUNEL positive cells, and increased level of antiapoptotic proteins (Bcl-2. In conclusion, KMP protected against IR injury by attenuating inflammation and apoptosis through the modulation of MAPK pathway.

Increasing maternal body mass index is associated with systemic inflammation in the mother and the activation of distinct placental inflammatory pathways.

Science.gov (United States)

Aye, Irving L M H; Lager, Susanne; Ramirez, Vanessa I; Gaccioli, Francesca; Dudley, Donald J; Jansson, Thomas; Powell, Theresa L

2014-06-01

Obese pregnant women have increased levels of proinflammatory cytokines in maternal circulation and placental tissues. However, the pathways contributing to placental inflammation in obesity are largely unknown. We tested the hypothesis that maternal body mass index (BMI) was associated with elevated proinflammatory cytokines in maternal and fetal circulations and increased activation of placental inflammatory pathways. A total of 60 women of varying pre-/early pregnancy BMI, undergoing delivery by Cesarean section at term, were studied. Maternal and fetal (cord) plasma were collected for analysis of insulin, leptin, IL-1beta, IL-6, IL-8, monocyte chemoattractant protein (MCP) 1, and TNFalpha by multiplex ELISA. Activation of the inflammatory pathways in the placenta was investigated by measuring the phosphorylated and total protein expression of p38-mitogen-activated protein kinase (MAPK), c-Jun-N-terminal kinase (JNK)-MAPK, signal transducer-activated transcription factor (STAT) 3, caspase-1, IL-1beta, IkappaB-alpha protein, and p65 DNA-binding activity. To determine the link between activated placental inflammatory pathways and elevated maternal cytokines, cultured primary human trophoblast (PHT) cells were treated with physiological concentrations of insulin, MCP-1, and TNFalpha, and inflammatory signaling analyzed by Western blot. Maternal BMI was positively correlated with maternal insulin, leptin, MCP-1, and TNFalpha, whereas only fetal leptin was increased with BMI. Placental phosphorylation of p38-MAPK and STAT3, and the expression of IL-1beta protein, were increased with maternal BMI; phosphorylation of p38-MAPK was also correlated with birth weight. In contrast, placental NFkappaB, JNK and caspase-1 signaling, and fetal cytokine levels were unaffected by maternal BMI. In PHT cells, p38-MAPK was activated by MCP-1 and TNFalpha, whereas STAT3 phosphorylation was increased following TNFalpha treatment. Maternal BMI is associated with elevated maternal

Dietary Lycium barbarum Polysaccharide Induces Nrf2/ARE Pathway and Ameliorates Insulin Resistance Induced by High-Fat via Activation of PI3K/AKT Signaling

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Yi Yang

2014-01-01

Full Text Available Lycium barbarum polysaccharide (LBP, an antioxidant from wolfberry, displays the antioxidative and anti-inflammatory effects on experimental models of insulin resistance in vivo. However, the effective mechanism of LBP on high-fat diet-induced insulin resistance is still unknown. The objective of the study was to investigate the mechanism involved in LBP-mediated phosphatidylinositol 3-kinase (PI3K/AKT/Nrf2 axis against high-fat-induced insulin resistance. HepG2 cells were incubated with LBP for 12 hrs in the presence of palmitate. C57BL/6J mice were fed a high-fat diet supplemented with LBP for 24 weeks. We analyzed the expression of nuclear factor-E2-related factor 2 (Nrf2, Jun N-terminal kinases (JNK, and glycogen synthase kinase 3β (GSK3β involved in insulin signaling pathway in vivo and in vitro. First, LBP significantly induced phosphorylation of Nrf2 through PI3K/AKT signaling. Second, LBP obviously increased detoxification and antioxidant enzymes expression and reduced reactive oxygen species (ROS levels via PI3K/AKT/Nrf2 axis. Third, LBP also regulated phosphorylation levels of GSK3β and JNK through PI3K/AKT signaling. Finally, LBP significantly reversed glycolytic and gluconeogenic genes expression via the activation of Nrf2-mediated cytoprotective effects. In summary, LBP is novel antioxidant against insulin resistance induced by high-fat diet via activation of PI3K/AKT/Nrf2 pathway.

Modulation of hepatic inflammation and energy-sensing pathways in the rat liver by high-fructose diet and chronic stress.

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Veličković, Nataša; Teofilović, Ana; Ilić, Dragana; Djordjevic, Ana; Vojnović Milutinović, Danijela; Petrović, Snježana; Preitner, Frederic; Tappy, Luc; Matić, Gordana

2018-05-29

High-fructose consumption and chronic stress are both associated with metabolic inflammation and insulin resistance. Recently, disturbed activity of energy sensor AMP-activated protein kinase (AMPK) was recognized as mediator between nutrient-induced stress and inflammation. Thus, we analyzed the effects of high-fructose diet, alone or in combination with chronic stress, on glucose homeostasis, inflammation and expression of energy sensing proteins in the rat liver. In male Wistar rats exposed to 9-week 20% fructose diet and/or 4-week chronic unpredictable stress we measured plasma and hepatic corticosterone level, indicators of glucose homeostasis and lipid metabolism, hepatic inflammation (pro- and anti-inflammatory cytokine levels, Toll-like receptor 4, NLRP3, activation of NFκB, JNK and ERK pathways) and levels of energy-sensing proteins AMPK, SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). High-fructose diet led to glucose intolerance, activation of NFκB and JNK pathways and increased intrahepatic IL-1β, TNFα and inhibitory phosphorylation of insulin receptor substrate 1 on Ser 307 . It also decreased phospho-AMPK/AMPK ratio and increased SIRT1 expression. Stress alone increased plasma and hepatic corticosterone but did not influence glucose tolerance, nor hepatic inflammatory or energy-sensing proteins. After the combined treatment, hepatic corticosterone was increased, glucose tolerance remained preserved, while hepatic inflammation was partially prevented despite decreased AMPK activity. High-fructose diet resulted in glucose intolerance, hepatic inflammation, decreased AMPK activity and reduced insulin sensitivity. Chronic stress alone did not exert such effects, but when applied together with high-fructose diet it could partially prevent fructose-induced inflammation, presumably due to increased hepatic glucocorticoids.

The natural compound Guttiferone F sensitizes prostate cancer to starvation induced apoptosis via calcium and JNK elevation.

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Li, Xin; Lao, Yuanzhi; Zhang, Hong; Wang, Xiaoyu; Tan, Hongsheng; Lin, Zhixiu; Xu, Hongxi

2015-04-11

In a cytotoxicity screen in serum-free medium, Guttiferone F showed strong growth inhibitory effect against prostate cancer cells. Prostate cancer cells LNCaP and PC3 were treated with Guttiferone F in serum depleted medium. Sub-G1 phase distributions were estimated with flow cytometry. Mitochondrial disruption was observed under confocal microscope using Mitotracker Red staining. Gene and protein expression changes were detected by real-time PCR and Western blotting. Ca(2+) elevation was examined by Fluo-4 staining under fluorescence microscope. PC3 xenografts in mice were examined by immunohistochemical analysis. Guttiferone F had strong growth inhibitory effect against prostate cancer cell lines under serum starvation. It induced a significant increase in sub-G1 fraction and DNA fragmentation. In serum-free medium, Guttiferone F triggered mitochondria dependent apoptosis by regulating Bcl-2 family proteins. In addition, Guttiferone F attenuated the androgen receptor expression and phosphorylation of ERK1/2, while activating the phosphorylation of JNK and Ca(2+) flux. Combination of caloric restriction with Guttiferone F in vivo could increase the antitumor effect without causing toxicity. Guttiferone F induced prostate cancer cell apoptosis under serum starvation via Ca(2+) elevation and JNK activation. Combined with caloric restriction, Guttiferone F exerted significant growth inhibition of PC3 cells xenograft in vivo. Guttiferone F is therefore a potential anti-cancer compound.

Prevotella intermedia stimulates tissue-type plasminogen activator and plasminogen activator inhibitor-2 expression via multiple signaling pathways in human periodontal ligament cells.

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Guan, Su-Min; He, Jian-Jun; Zhang, Ming; Shu, Lei

2011-06-01

Prevotella intermedia is an important periodontal pathogen that induces various inflammatory and immune responses. In this study, we investigated the effects of P. intermedia on the plasminogen system in human periodontal ligament (hPDL) cells and explored the signaling pathways involved. Using semi-quantitative reverse transcription (RT)-PCR and quantitative real-time RT-qPCR, we demonstrated that P. intermedia challenge increased tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor (PAI)-2 expression in a concentration- and time-dependent manner, but exerted no influence on urokinase-type plasminogen activator and PAI-1mRNA expression in hPDL cells. Prevotella intermedia stimulation also enhanced tPA protein secretion as confirmed by enzyme-linked immunosorbent assay. Western blot results revealed that P. intermedia treatment increased phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinase (p38). ERK, JNK and protein kinase C inhibitors significantly attenuated the P. intermedia-induced tPA and PAI-2 expression. Furthermore, p38 and phosphatidylinositol 3-kinase inhibitors markedly decreased PAI-2 expression, whereas they showed no or little inhibition on tPA expression. In contrast, inhibition of protein kinase A greatly enhanced the upregulatory effect of P. intermedia on tPA and PAI-2 expression. Our results suggest that P. intermedia may contribute to periodontal tissue destruction by upregulating tPA and PAI-2 expression in hPDL cells via multiple signaling pathways. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Diabetes and overexpression of proNGF cause retinal neurodegeneration via activation of RhoA pathway.

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Mohammed M H Al-Gayyar

Full Text Available Our previous studies showed positive correlation between accumulation of proNGF, activation of RhoA and neuronal death in diabetic models. Here, we examined the neuroprotective effects of selective inhibition of RhoA kinase in the diabetic rat retina and in a model that stably overexpressed the cleavage-resistance proNGF plasmid in the retina. Male Sprague-Dawley rats were rendered diabetic using streptozotocin or stably express cleavage-resistant proNGF plasmid. The neuroprotective effects of the intravitreal injection of RhoA kinase inhibitor Y27632 were examined in vivo. Effects of proNGF were examined in freshly isolated primary retinal ganglion cell (RGC cultures and RGC-5 cell line. Retinal neurodegeneration was assessed by counting TUNEL-positive and Brn-3a positive retinal ganglion cells. Expression of proNGF, p75(NTR, cleaved-PARP, caspase-3 and p38MAPK/JNK were examined by Western-blot. Activation of RhoA was assessed by pull-down assay and G-LISA. Diabetes and overexpression of proNGF resulted in retinal neurodegeneration as indicated by 9- and 6-fold increase in TUNEL-positive cells, respectively. In vitro, proNGF induced 5-fold cell death in RGC-5 cell line, and it induced >10-fold cell death in primary RGC cultures. These effects were associated with significant upregulation of p75(NTR and activation of RhoA. While proNGF induced TNF-α expression in vivo, it selectively activated RhoA in primary RGC cultures and RGC-5 cell line. Inhibiting RhoA kinase with Y27632 significantly reduced diabetes- and proNGF-induced activation of proapoptotic p38MAPK/JNK, expression of cleaved-PARP and caspase-3 and prevented retinal neurodegeneration in vivo and in vitro. Taken together, these results provide compelling evidence for a causal role of proNGF in diabetes-induced retinal neurodegeneration through enhancing p75(NTR expression and direct activation of RhoA and p38MAPK/JNK apoptotic pathways.

Tanreqing Injection Attenuates Lipopolysaccharide-Induced Airway Inflammation through MAPK/NF-κB Signaling Pathways in Rats Model

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Liu, Wei; Jiang, Hong-li; Cai, Lin-li; Yan, Min; Dong, Shou-jin; Mao, Bing

2016-01-01

Background. Tanreqing injection (TRQ) is a commonly used herbal patent medicine for treating inflammatory airway diseases in view of its outstanding anti-inflammatory properties. In this study, we explored the signaling pathways involved in contributions of TRQ to LPS-induced airway inflammation in rats. Methods/Design. Adult male Sprague Dawley (SD) rats randomly divided into different groups received intratracheal instillation of LPS and/or intraperitoneal injection of TRQ. Bronchoalveolar Lavage Fluid (BALF) and lung samples were collected at 24 h, 48 h, and 96 h after TRQ administration. Protein and mRNA levels of tumor necrosis factor- (TNF-) α, Interleukin- (IL-) 1β, IL-6, and IL-8 in BALF and lung homogenate were observed by ELISA and real-time PCR, respectively. Lung sections were stained for p38 MAPK and NF-κB detection by immunohistochemistry. Phospho-p38 MAPK, phosphor-extracellular signal-regulated kinases ERK1/2, phospho-SAPK/JNK, phospho-NF-κB p65, phospho-IKKα/β, and phospho-IκB-α were measured by western blot analysis. Results. The results showed that TRQ significantly counteracted LPS-stimulated release of TNF-α, IL-1β, IL-6, and IL-8, attenuated cells influx in BALF, mitigated mucus hypersecretion, suppressed phosphorylation of NF-κB p65, IκB-α, ΙKKα/β, ERK1/2, JNK, and p38 MAPK, and inhibited p38 MAPK and NF-κB p65 expression in rat lungs. Conclusions. Results of the current research indicate that TRQ possesses potent exhibitory effects in LPS-induced airway inflammation by, at least partially, suppressing the MAPKs and NF-κB signaling pathways, in a general dose-dependent manner. PMID:27366191

Inhibition of c-Jun N-terminal Kinase Signaling Pathway Alleviates Lipopolysaccharide-induced Acute Respiratory Distress Syndrome in Rats

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Jian-Bo Lai

2016-01-01

Conclusions: Inhibiting JNK alleviated LPS-induced acute lung inflammation and had no effects on pulmonary edema and fibrosis. JNK inhibitor might be a potential therapeutic medication in ARDS, in the context of reducing lung inflammatory.

Mitochondrial quality control pathways as determinants of metabolic health

NARCIS (Netherlands)

Held, Ntsiki M.; Houtkooper, Riekelt H.

2015-01-01

Mitochondrial function is key for maintaining cellular health, while mitochondrial failure is associated with various pathologies, including inherited metabolic disorders and age-related diseases. In order to maintain mitochondrial quality, several pathways of mitochondrial quality control have

Fisetin Ameliorated Photodamage by Suppressing the Mitogen-Activated Protein Kinase/Matrix Metalloproteinase Pathway and Nuclear Factor-κB Pathways.

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Chiang, Hsiu-Mei; Chan, Shih-Yun; Chu, Yin; Wen, Kuo-Ching

2015-05-13

Ultraviolet (UV) irradiation is one of the most important extrinsic factors contributing to skin photodamage. After UV irradiation, a series of signal transductions in the skin will be activated, leading to inflammatory response and photoaged skin. In this study, fisetin, a flavonol that exists in fruits and vegetables, was investigated for its photoprotective effects. The results revealed that 5-25 μM fisetin inhibits cyclooxygenase-2 (COX-2) and matrix metalloproteinase (MMP)-1, MMP-3, MMP-9 expression induced by ultraviolet B (UVB) irradiation in human skin fibroblasts. In addition, fisetin suppressed UVB-induced collagen degradation. With regard to its effect on upper-stream signal transduction, we found that fisetin reduced the expression of ultraviolet (UV)-induced ERK, JNK, and p38 phosphorylation in the mitogen-activated protein kinase (MAP kinase) pathway. Furthermore, fisetin reduced inhibitor κB (IκB) degradation and increased the amount of p65, which is a major subunit of nuclear factor-κB (NF-κB), in cytoplasm. It also suppressed NF-κB translocated to the nucleus and inhibited cAMP response element-binding protein (CREB) Ser-133 phosphorylation level in the phosphoinositide 3-kinase/protein kinase B/CREB (PI3K/AKT/CREB) pathway. Finally, fisetin inhibited UV-induced intracellular reactive oxygen species (ROS), prostaglandin E2 (PGE2), and nitric oxide (NO) generation. The mentioned effects and mechanisms suggest that fisetin can be used in the development of photoprotective agents.

Cisplatin induces expression of drug resistance-related genes through c-jun N-terminal kinase pathway in human lung cancer cells.

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Xu, Li; Fu, Yingya; Li, Youlun; Han, Xiaoli

2017-08-01

Change of multidrug resistance-related genes (e.g., lung resistance protein, LRP) and overexpression of anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are responsible for cisplatin resistance. In our study, we investigated the mechanism by which cisplatin induces LRP, Bcl-2, Bcl-xL, XIAP, and Survivin expression in human lung adenocarcinoma A549 cells and human H446 small cell lung cancer cells at mRNA and protein levels. In our study, cell proliferation was assessed with CCK-8 assays, and cell apoptosis was assessed with flow cytometric analysis and Annexin-V/PI staining. qPCR was used to complete RNA experiments. Protein expression was assessed with Western blotting. Cisplatin increased Bcl-2, LRP, and Survivin expression, but decreased Bcl-xL and XIAP expression in a dose-dependent manner. Preincubation with JNK-specific inhibitor, SP600125, significantly inhibited these genes' expression at mRNA and protein levels, enhanced chemosensitivity of lung cancer cells to cisplatin, and promoted cisplatin-induced apoptosis. Our data suggest that the JNK signaling pathway plays an important role in cisplatin resistance. Lung resistance protein (LRP) and anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are involved in the process. The results reminded us of a novel therapy target for lung cancer treatment.

Resveratrol alleviates diabetes-induced testicular dysfunction by inhibiting oxidative stress and c-Jun N-terminal kinase signaling in rats

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Faid, Iman; Al-Hussaini, Heba; Kilarkaje, Narayana, E-mail: knarayana@hsc.edu.kw

2015-12-15

Diabetes adversely affects reproductive functions in humans and animals. The present study investigated the effects of Resveratrol on diabetes-induced alterations in oxidative stress, c-Jun N-terminal kinase (JNK) signaling and apoptosis in the testis. Adult male Wistar rats (13–15 weeks; n = 6/group) were segregated into 1) normal control, 2) Resveratrol-treated (5 mg/kg; ip; given during last 3 weeks), 3) Streptozotocin-induced diabetic and, 4) Resveratrol-treated diabetic groups, and euthanized on day 42 after the confirmation of diabetes. Resveratrol did not normalize blood glucose levels in diabetic rats. Resveratrol supplementation recovered diabetes-induced decreases in reproductive organ weights, sperm count and motility, intra-testicular levels of superoxide dismutase, catalase, and glutathione peroxidase and an increase in 4-hydroxynonenal activities (P < 0.05). Resveratrol also recovered diabetes-induced increases in JNK signaling pathway proteins, namely, ASK1 (apoptosis signal-regulating kinase 1), JNKs (46 and 54 kDa isoforms) and p-JNK to normal control levels (P < 0.05). Interestingly, the expression of a down-stream target of ASK1, MKK4 (mitogen-activated protein kinase kinase 4) and its phosphorylated form (p-MKK4) did not change in experimental groups. Resveratrol inhibited diabetes-induced increases in AP-1 (activator protein-1) components, c-Jun and ATF2 (activating transcription factor 2), but not their phosphorylated forms, to normal control levels (P < 0.05). Further, Resveratrol inhibited diabetes-induced increase in cleaved-caspase-3 to normal control levels. In conclusion, Resveratrol alleviates diabetes-induced apoptosis in testis by modulating oxidative stress, JNK signaling pathway and caspase-3 activities, but not by inhibiting hyperglycemia, in rats. These results suggest that Resveratrol supplementation may be a useful strategy to treat diabetes-induced testicular dysfunction. - Highlights: • Resveratrol up-regulates glutathione

Resveratrol alleviates diabetes-induced testicular dysfunction by inhibiting oxidative stress and c-Jun N-terminal kinase signaling in rats

International Nuclear Information System (INIS)

Faid, Iman; Al-Hussaini, Heba; Kilarkaje, Narayana

2015-01-01

Diabetes adversely affects reproductive functions in humans and animals. The present study investigated the effects of Resveratrol on diabetes-induced alterations in oxidative stress, c-Jun N-terminal kinase (JNK) signaling and apoptosis in the testis. Adult male Wistar rats (13–15 weeks; n = 6/group) were segregated into 1) normal control, 2) Resveratrol-treated (5 mg/kg; ip; given during last 3 weeks), 3) Streptozotocin-induced diabetic and, 4) Resveratrol-treated diabetic groups, and euthanized on day 42 after the confirmation of diabetes. Resveratrol did not normalize blood glucose levels in diabetic rats. Resveratrol supplementation recovered diabetes-induced decreases in reproductive organ weights, sperm count and motility, intra-testicular levels of superoxide dismutase, catalase, and glutathione peroxidase and an increase in 4-hydroxynonenal activities (P < 0.05). Resveratrol also recovered diabetes-induced increases in JNK signaling pathway proteins, namely, ASK1 (apoptosis signal-regulating kinase 1), JNKs (46 and 54 kDa isoforms) and p-JNK to normal control levels (P < 0.05). Interestingly, the expression of a down-stream target of ASK1, MKK4 (mitogen-activated protein kinase kinase 4) and its phosphorylated form (p-MKK4) did not change in experimental groups. Resveratrol inhibited diabetes-induced increases in AP-1 (activator protein-1) components, c-Jun and ATF2 (activating transcription factor 2), but not their phosphorylated forms, to normal control levels (P < 0.05). Further, Resveratrol inhibited diabetes-induced increase in cleaved-caspase-3 to normal control levels. In conclusion, Resveratrol alleviates diabetes-induced apoptosis in testis by modulating oxidative stress, JNK signaling pathway and caspase-3 activities, but not by inhibiting hyperglycemia, in rats. These results suggest that Resveratrol supplementation may be a useful strategy to treat diabetes-induced testicular dysfunction. - Highlights: • Resveratrol up-regulates glutathione

Piper betle leaf extracts induced human hepatocellular carcinoma Hep3B cell death via MAPKs regulating the p73 pathway in vitro and in vivo.

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Wu, Pei-Fang; Tseng, Hsien-Chun; Chyau, Charng-Cherng; Chen, Jing-Hsien; Chou, Fen-Pi

2014-12-01

Extracts of Piper betle leaf (PBLs) are rich in bioactive compounds with potential chemopreventive ability. In this study, Hep3B cells which are p53 null were used to investigate the anti-tumor effect of PBLs in the cell and in the xenograft model. The results revealed that PBLs (0.1 to 1 mg mL(-1)) induced a dose- and time-dependent increase of cell toxicity. The underlying mechanisms as evidenced by flow cytometry and western blot analysis showed that PBLs triggered ATM, cAbl, and p73 expressions and activated JNK and p38 pathways that subsequently led to cell cycle arrest and mitochondria-dependent apoptosis. PBLs also inhibited tumor growth in Hep3B-bearing mice via inducing the MAPK-p73 pathway. Our results demonstrated the in vitro and in vivo anti-tumor potential of PBLs, supporting their application as a novel chemopreventive agent for the treatment of human hepatocellular carcinoma (HCC) in the future via targeting the p73 pathway.

Calcium has a permissive role in interleukin-1beta-induced c-jun N-terminal kinase activation in insulin-secreting cells

DEFF Research Database (Denmark)

Størling, Joachim; Zaitsev, Sergei V; Kapelioukh, Iouri L

2005-01-01

The c-jun N-terminal kinase (JNK) signaling pathway mediates IL-1beta-induced apoptosis in insulin-secreting cells, a mechanism relevant to the destruction of pancreatic beta-cells in type 1 and 2 diabetes. However, the mechanisms that contribute to IL-1beta activation of JNK in beta-cells are la...

Inhibition of Vascular c-Jun N-Terminal Kinase 2 Improves Obesity-Induced Endothelial Dysfunction After Roux-en-Y Gastric Bypass.

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Doytcheva, Petia; Bächler, Thomas; Tarasco, Erika; Marzolla, Vincenzo; Engeli, Michael; Pellegrini, Giovanni; Stivala, Simona; Rohrer, Lucia; Tona, Francesco; Camici, Giovanni G; Vanhoutte, Paul M; Matter, Christian M; Lutz, Thomas A; Lüscher, Thomas F; Osto, Elena

2017-11-14

Roux-en-Y gastric bypass (RYGB) reduces obesity-associated comorbidities and cardiovascular mortality. RYGB improves endothelial dysfunction, reducing c-Jun N-terminal kinase (JNK) vascular phosphorylation. JNK activation links obesity with insulin resistance and endothelial dysfunction. Herein, we examined whether JNK1 or JNK2 mediates obesity-induced endothelial dysfunction and if pharmacological JNK inhibition can mimic RYGB vascular benefits. After 7 weeks of a high-fat high-cholesterol diet, obese rats underwent RYGB or sham surgery; sham-operated ad libitum-fed rats received, for 8 days, either the control peptide D-TAT or the JNK peptide inhibitor D-JNKi-1 (20 mg/kg per day subcutaneous). JNK peptide inhibitor D-JNKi-1 treatment improved endothelial vasorelaxation in response to insulin and glucagon-like peptide-1, as observed after RYGB. Obesity increased aortic phosphorylation of JNK2, but not of JNK1. RYGB and JNK peptide inhibitor D-JNKi-1 treatment blunted aortic JNK2 phosphorylation via activation of glucagon-like peptide-1-mediated signaling. The inhibitory phosphorylation of insulin receptor substrate-1 was reduced, whereas the protein kinase B/endothelial NO synthase pathway was increased and oxidative stress was decreased, resulting in improved vascular NO bioavailability. Decreased aortic JNK2 phosphorylation after RYGB rapidly improves obesity-induced endothelial dysfunction. Pharmacological JNK inhibition mimics the endothelial protective effects of RYGB. These findings highlight the therapeutic potential of novel strategies targeting vascular JNK2 against the severe cardiovascular disease associated with obesity. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Apigenin potentiates the antitumor activity of 5-FU on solid Ehrlich carcinoma: Crosstalk between apoptotic and JNK-mediated autophagic cell death platforms

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Gaballah, Hanaa H., E-mail: hanaahibishy@hotmail.com [Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Tanta University, Tanta, 3111 (Egypt); Gaber, Rasha A. [Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Tanta University, Tanta, 3111 (Egypt); Mohamed, Darin A. [Histopathology Department, Faculty of Medicine, Tanta University, Tanta, 3111 (Egypt)

2017-02-01

Background: Although 5- Fluorouracil (5-FU) has exhibited effectiveness against cancer, novel therapeutic strategies are needed to enhance its antitumor efficiency and modulate its cytotoxity. Apigenin, a flavonoid present in fruits and vegetables, is a potent dietary phytochemical effective in cancer chemoprevention. Aim: This study was undertaken to investigate the potential synergistic antitumor activity of apigenin and 5-FU on Solid Ehrlich carcinoma (SEC). Methods: Eighty Swiss albino male mice were divided into four equal groups: vehicle treated control SEC, SEC + 5-FU, SEC + apigenin, SEC + 5-FU + apigenin. Beclin-1 and caspases 3, 9 and JNK activities were estimated by ELISA; mRNA expression levels of the antiapoptotic gene Mcl-1 were estimated using quantitative real-time RT-PCR, while tissue malondialdehyde (MDA), glutathione peroxidase and total antioxidant capacity were evaluated spectrophotometrically. A part of the tumor was examined for histopathological and Ki-67 immunohistochemistry analysis. Results: 5-FU and/or apigenin caused significant increase in tissue levels of Beclin-1, caspases 3, 9 and JNK activities, MDA with significant decrease in tumor volume, Mcl-1expression, tissue glutathione peroxidase and total antioxidant capacity and alleviated the histopathological changes with significant decrease of Ki-67 proliferation index compared to vehicle treated SEC control group. In conclusion: The combination of 5-FU and apigenin had a greater effect than each of 5-FU or apigenin alone against solid Ehrlich carcinoma in mice. - Highlights: • Apigenin potentiated 5-FU cytotoxicity in EAC solid tumor models in vivo. • It acted via autophagy stimulation, downregulating MCL-1 and Ki-67 expression. • It caused JNK activation and ROS accumulation; resulted in tumor growth inhibition. • Apigenin can be used as a co-adjuvant agent in cancer therapy.

Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

Science.gov (United States)

Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

2015-08-01

Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

The polyphenol fisetin protects bone by repressing NF-κB and MKP-1-dependent signaling pathways in osteoclasts.

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Laurent Léotoing

Full Text Available Osteoporosis is a bone pathology leading to increase fractures risk and challenging quality of life. Since current treatments could exhibit deleterious side effects, the use of food compounds derived from plants represents a promising innovative alternative due to their potential therapeutic and preventive activities against human diseases. In this study, we investigated the ability of the polyphenol fisetin to counter osteoporosis and analyzed the cellular and molecular mechanisms involved. In vivo, fisetin consumption significantly prevented bone loss in estrogen deficiency and inflammation mice osteoporosis models. Indeed, bone mineral density, micro-architecture parameters and bone markers were positively modulated by fisetin. Consistent with in vivo results, we showed that fisetin represses RANKL-induced osteoclast differentiation and activity as demonstrated by an inhibition of multinucleated cells formation, TRAP activity and differentiation genes expression. The signaling pathways NF-κB, p38 MAPK, JNK and the key transcription factors c-Fos and NFATc1 expressions induced by RANKL, were negatively regulated by fisetin. We further showed that fisetin inhibits the constitutive proteasomal degradation of MKP-1, the phosphatase that deactivates p38 and JNK. Consistently, using shRNA stable cell lines, we demonstrated that impairment of MKP-1 decreases fisetin potency. Taken together, these results strongly support that fisetin should be further considered as a bone protective agent.

The Polyphenol Fisetin Protects Bone by Repressing NF-κB and MKP-1-Dependent Signaling Pathways in Osteoclasts

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Léotoing, Laurent; Wauquier, Fabien; Guicheux, Jérôme; Miot-Noirault, Elisabeth; Wittrant, Yohann; Coxam, Véronique

2013-01-01

Osteoporosis is a bone pathology leading to increase fractures risk and challenging quality of life. Since current treatments could exhibit deleterious side effects, the use of food compounds derived from plants represents a promising innovative alternative due to their potential therapeutic and preventive activities against human diseases. In this study, we investigated the ability of the polyphenol fisetin to counter osteoporosis and analyzed the cellular and molecular mechanisms involved. In vivo, fisetin consumption significantly prevented bone loss in estrogen deficiency and inflammation mice osteoporosis models. Indeed, bone mineral density, micro-architecture parameters and bone markers were positively modulated by fisetin. Consistent with in vivo results, we showed that fisetin represses RANKL-induced osteoclast differentiation and activity as demonstrated by an inhibition of multinucleated cells formation, TRAP activity and differentiation genes expression. The signaling pathways NF-κB, p38 MAPK, JNK and the key transcription factors c-Fos and NFATc1 expressions induced by RANKL, were negatively regulated by fisetin. We further showed that fisetin inhibits the constitutive proteasomal degradation of MKP-1, the phosphatase that deactivates p38 and JNK. Consistently, using shRNA stable cell lines, we demonstrated that impairment of MKP-1 decreases fisetin potency. Taken together, these results strongly support that fisetin should be further considered as a bone protective agent. PMID:23861901

Phosphorylation- and nucleotide-binding-induced changes to the stability and hydrogen exchange patterns of JNK1ß1 provide insight into its mechanisms of activation

CSIR Research Space (South Africa)

Owen, GR

2014-10-01

Full Text Available –deuterium exchange (HX) mass spectrometry were used to investigate the changes to the stability and conformation/conformational dynamics of JNK1ß1 induced by phosphorylative activation. Equivalent studies were also employed to determine the effects of nucleotide...

PHOTOBIOMODULATION-MEDIATED PATHWAY DIAGNOSTICS

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TIMON CHENG-YI LIU

2013-01-01

Full Text Available Cellular pathways are ordinarily diagnosed with pathway inhibitors, related gene regulation, or fluorescent protein markers. They are also suggested to be diagnosed with pathway activation modulation of photobiomodulation (PBM in this paper. A PBM on a biosystem function depends on whether the biosystem is in its function-specific homeostasis (FSH. An FSH, a negative feedback response for the function to be performed perfectly, is maintained by its FSH-essential subfunctions and its FSH-non-essential subfunctions (FNSs. A function in its FSH or far from its FSH is called a normal or dysfunctional function. A direct PBM may self-adaptatively modulate a dysfunctional function until it is normal so that it can be used to discover the optimum pathways for an FSH to be established. An indirect PBM may self-adaptatively modulate a dysfunctional FNS of a normal function until the FNS is normal, and the normal function is then upgraded so that it can be used to discover the redundant pathways for a normal function to be upgraded.

Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

International Nuclear Information System (INIS)

Pan, Mu-Yun; Shen, Yuh-Chiang; Lu, Chien-Hsing; Yang, Shu-Yi; Ho, Tsing-Fen; Peng, Yu-Ta; Chang, Chia-Che

2012-01-01

endoplasmic reticulum (ER) stress inducer. ► Prodigiosin-induced cytotoxicity involves ER stress-mediated cell death. ► Prodigiosin transcriptionally induces CHOP to suppress BCL2 for evoking cell death. ► Prodigiosin engages the IRE1–JNK and PERK–eIF2α pathways to up-regulate CHOP.

Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

Energy Technology Data Exchange (ETDEWEB)

Pan, Mu-Yun [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Yuh-Chiang [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); National Research Institute of Chinese Medicine, Taipei, Taiwan (China); Lu, Chien-Hsing [Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Yang, Shu-Yi [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Ho, Tsing-Fen [Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Peng, Yu-Ta [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China)

2012-12-15

as an endoplasmic reticulum (ER) stress inducer. ► Prodigiosin-induced cytotoxicity involves ER stress-mediated cell death. ► Prodigiosin transcriptionally induces CHOP to suppress BCL2 for evoking cell death. ► Prodigiosin engages the IRE1–JNK and PERK–eIF2α pathways to up-regulate CHOP.

Theobromine inhibits differentiation of 3T3-L1 cells during the early stage of adipogenesis via AMPK and MAPK signaling pathways.

Science.gov (United States)

Jang, Yeon Jeong; Koo, Hyun Jung; Sohn, Eun-Hwa; Kang, Se Chan; Rhee, Dong-Kwon; Pyo, Suhkneung

2015-07-01

Obesity is characterized by hypertrophy and/or by the differentiation or adipogenesis of pre-existing adipocytes. In this study, we investigated the inhibitory effects of theobromine, a type of alkaloid in cocoa, on adipocyte differentiation of 3T3-L1 preadipocytes and its mechanisms of action. Theobromine inhibited the accumulation of lipid droplets, the expression of PPARγ and C/EBPα, and the mRNA expression of aP2 and leptin. The inhibition of adipogenic differentiation by theobromine occurred primarily in the early stages of differentiation. In addition, theobromine arrested the cell cycle at the G0/G1 phase and regulated the expressions of CDK2, p27, and p21. Theobromine treatment increased AMPK phosphorylation and knockdown of AMPKα1/α2 prevented the ability of theobromine to inhibit PPARγ expression in the differentiating 3T3-L1 cells. Theobromine reduced the phosphorylation of ERK and JNK. Moreover, the secretion and the mRNA level of TNF-α and IL-6 were inhibited by theobromine treatment. These data suggest that theobromine inhibits adipocyte differentiation during the early stages of adipogenesis by regulating the expression of PPARγ and C/EBPα through the AMPK and ERK/JNK signaling pathways in 3T3-L1 preadipocytes.

Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis.

Science.gov (United States)

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

2016-07-29

Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160mg/kg) for 17days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce phosphorylation of JNK and ERK2, which suppresses inflammation, apoptosis and cholangiocyte proliferation during cholestasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Magnolol Affects Cellular Proliferation, Polyamine Biosynthesis and Catabolism-Linked Protein Expression and Associated Cellular Signaling Pathways in Human Prostate Cancer Cells in vitro

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Brendan T. McKeown

2015-01-01

Full Text Available Background: Prostate cancer is the most commonly diagnosed form of cancer in men in Canada and the United States. Both genetic and environmental factors contribute to the development and progression of many cancers, including prostate cancer. Context and purpose of this study: This study investigated the effects of magnolol, a compound found in the roots and bark of the magnolia tree Magnolia officinalis, on cellular proliferation and proliferation-linked activities of PC3 human prostate cancer cells in vitro. Results: PC3 cells exposed to magnolol at a concentration of 80 μM for 6 hours exhibited decreased protein expression of ornithine decarboxylase, a key regulator in polyamine biosynthesis, as well as affecting the expression of other proteins involved in polyamine biosynthesis and catabolism. Furthermore, protein expression of the R2 subunit of ribonucleotide reductase, a key regulatory protein associated with DNA synthesis, was significantly decreased. Finally, the MAPK (mitogen-activated protein kinase, PI3K (phosphatidylinositol 3-kinase, NFκB (nuclear factor of kappa-light-chain-enhancer of activated B cells and AP-1 (activator protein 1 cellular signaling pathways were assayed to determine which, if any, of these pathways magnolol exposure would alter. Protein expressions of p-JNK-1 and c-jun were significantly increased while p-p38, JNK-1/2, PI3Kp85, p-PI3Kp85, p-Akt, NFκBp65, p-IκBα and IκBα protein expressions were significantly decreased. Conclusions: These alterations further support the anti-proliferative effects of magnolol on PC3 human prostate cancer cells in vitro and suggest that magnolol may have potential as a novel anti-prostate cancer agent.

Somatotropinomas, but not nonfunctioning pituitary adenomas, maintain a functional apoptotic RET/Pit1/ARF/p53 pathway that is blocked by excess GDNF.

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Diaz-Rodriguez, Esther; Garcia-Rendueles, Angela R; Ibáñez-Costa, Alejandro; Gutierrez-Pascual, Ester; Garcia-Lavandeira, Montserrat; Leal, Alfonso; Japon, Miguel A; Soto, Alfonso; Venegas, Eva; Tinahones, Francisco J; Garcia-Arnes, Juan A; Benito, Pedro; Angeles Galvez, Maria; Jimenez-Reina, Luis; Bernabeu, Ignacio; Dieguez, Carlos; Luque, Raul M; Castaño, Justo P; Alvarez, Clara V

2014-11-01

Acromegaly is caused by somatotroph cell adenomas (somatotropinomas [ACROs]), which secrete GH. Human and rodent somatotroph cells express the RET receptor. In rodents, when normal somatotrophs are deprived of the RET ligand, GDNF (Glial Cell Derived Neurotrophic Factor), RET is processed intracellularly to induce overexpression of Pit1 [Transcription factor (gene : POUF1) essential for transcription of Pituitary hormones GH, PRL and TSHb], which in turn leads to p19Arf/p53-dependent apoptosis. Our purpose was to ascertain whether human ACROs maintain the RET/Pit1/p14ARF/p53/apoptosis pathway, relative to nonfunctioning pituitary adenomas (NFPAs). Apoptosis in the absence and presence of GDNF was studied in primary cultures of 8 ACROs and 3 NFPAs. Parallel protein extracts were analyzed for expression of RET, Pit1, p19Arf, p53, and phospho-Akt. When GDNF deprived, ACRO cells, but not NFPAs, presented marked level of apoptosis that was prevented in the presence of GDNF. Apoptosis was accompanied by RET processing, Pit1 accumulation, and p14ARF and p53 induction. GDNF prevented all these effects via activation of phospho-AKT. Overexpression of human Pit1 (hPit1) directly induced p19Arf/p53 and apoptosis in a pituitary cell line. Using in silico studies, 2 CCAAT/enhancer binding protein alpha (cEBPα) consensus-binding sites were found to be 100% conserved in mouse, rat, and hPit1 promoters. Deletion of 1 cEBPα site prevented the RET-induced increase in hPit1 promoter expression. TaqMan qRT-PCR (real time RT-PCR) for RET, Pit1, Arf, TP53, GDNF, steroidogenic factor 1, and GH was performed in RNA from whole ACRO and NFPA tumors. ACRO but not NFPA adenomas express RET and Pit1. GDNF expression in the tumors was positively correlated with RET and negatively correlated with p53. In conclusion, ACROs maintain an active RET/Pit1/p14Arf/p53/apoptosis pathway that is inhibited by GDNF. Disruption of GDNF's survival function might constitute a new therapeutic route in

Polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via Wnt/β-catenin pathway

International Nuclear Information System (INIS)

Patel, Rachana; Ingle, Arvind; Maru, Girish B.

2008-01-01

Tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. However, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, are limited. Hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of PBP extract employing 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in Sprague-Dawley rats as experimental model. The present study suggests that PBPs, like other tea polyphenols, also inhibit DMH-induced colorectal tumorigenesis by decreasing tumor volume and multiplicity. This study also shows that although the pretreatment with PBP extract could induce detoxifying enzymes in hepatic and colorectal tissue, it did not show any additional chemopreventive effects when compared to treatments with PBP extract after initiation with DMH. Mechanistically, PBP extract may inhibit colorectal carcinogenesis by decreasing DMH-induced cell proliferation via Wnt/β-catenin pathway. Treatments with PBP extract showed decreased levels of COX-2, c-MYC and cyclin D1 proteins which aid cell proliferation probably by regulating β-catenin by maintaining expression of APC and decreasing inactivation of GSK3β. DMH-induced activation of MAP kinases such as ERK and JNK was also found to be inhibited by treatments with PBP extract. In conclusion, the protective effects of PBP extract could be attributed to inhibition of DMH-induced cellular proliferation probably through β-catenin regulation

Community College Pathways: A Descriptive Report of Summative Assessments and Student Learning

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Strother, Scott; Sowers, Nicole

2014-01-01

Carnegie's Community College Pathways (CCP) offers two pathways, Statway® and Quantway®, that reduce the amount of time required to complete developmental mathematics and earn college-level mathematics credit. The Pathways aim to improve student success in mathematics while maintaining rigorous content, pedagogy, and learning outcomes. It is…

Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

International Nuclear Information System (INIS)

Yano, Hiroyuki; Hamanaka, Ryoji; Nakamura, Miki; Sumiyoshi, Hideaki; Matsuo, Noritaka; Yoshioka, Hidekatsu

2012-01-01

Highlights: ► We examine how radiation affects the expression level and signal pathway of collagen. ► TGF-β1 mRNA is elevated earlier than those of collagen genes after irradiation. ► Smad pathway mediates the expression of collagen in radiation induced fibrosis. ► MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both α1and α2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-β1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-β receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of α2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

Energy Technology Data Exchange (ETDEWEB)

Yano, Hiroyuki [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Division of Radioisotope Research, Department of Research Support, Research Promotion Project, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Hamanaka, Ryoji; Nakamura, Miki [Cell Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Sumiyoshi, Hideaki; Matsuo, Noritaka [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Yoshioka, Hidekatsu, E-mail: hidey@oita-u.ac.jp [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)

2012-02-17

Highlights: Black-Right-Pointing-Pointer We examine how radiation affects the expression level and signal pathway of collagen. Black-Right-Pointing-Pointer TGF-{beta}1 mRNA is elevated earlier than those of collagen genes after irradiation. Black-Right-Pointing-Pointer Smad pathway mediates the expression of collagen in radiation induced fibrosis. Black-Right-Pointing-Pointer MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both {alpha}1and {alpha}2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-{beta}1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-{beta} receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of {alpha}2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

Protective Effects of Maillard Reaction Products of Whey Protein Concentrate against Oxidative Stress through an Nrf2-Dependent Pathway in HepG2 Cells.

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Pyo, Min Cheol; Yang, Sung-Yong; Chun, Su-Hyun; Oh, Nam Su; Lee, Kwang-Won

2016-09-01

Whey protein concentrate (WPC), which contains α-lactalbumin and β-lactoglobulin, is utilized widely in the food industry. The Maillard reaction is a complex reaction that produces Maillard reaction products (MRPs), which are associated with the formation of antioxidant compounds. In this study, the hepatoprotection activity of MRPs of WPC against oxidative stress through the nuclear factor-E2-related factor 2 (Nrf2)-dependent antioxidant pathway in HepG2 cells was examined. Glucose-whey protein concentrate conjugate (Glc-WPC) was obtained from Maillard reaction between WPC and glucose. The fluorescence intensity of Glc-WPC increased after 7 d compared to native WPC, and resulted in loss of 48% of the free amino groups of WPC. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of Glc-WPC showed the presence of a high-molecular-weight portion. Treatment of HepG2 cells with Glc-WPC increased cell viability in the presence of oxidative stress, inhibited the generation of intracellular reactive oxygen species by tert-butyl hydroperoxide (t-BHP), and increased the glutathione level. Nrf2 translocation and Nrf2, reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H)-quinone oxidoreductase 1 (NOQ1), heme oxygenase-1 (HO-1), glutamate-L-cysteine ligase (GCL)M and GCLC mRNA levels were increased by Glc-WPC. Also, Glc-WPC increased the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK). The results of this study demonstrate that Glc-WPC activates the Nrf2-dependent pathway through the phosphorylation of ERK1/2 and JNK in HepG2 cells, and induces production of antioxidant enzymes and phase II enzymes.

EGCG Maintains Th1/Th2 Balance and Mitigates Ulcerative Colitis Induced by Dextran Sulfate Sodium through TLR4/MyD88/NF-κB Signaling Pathway in Rats

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Xue Bing

2017-01-01

Full Text Available Objective. To observe the protective effect of epigallocatechin gallate (EGCG on dextran sulfate sodium- (DSS- induced ulcerative colitis in rats and to explore the roles of TLR4/MyD88/NF-κB signaling pathway. Methods. Rat models of ulcerative colitis were established by giving DSS. EGCG (50 mg/kg/d was given to assess disease activity index. HE staining was applied to observe histological changes. ELISA and qPCR detected the expression of inflammatory factors. Flow cytometry was used to measure the percentage of CD4+IFN-γ+ and CD4+IL-4+ in the spleen and colon. TLR4 antagonist E5564 was given in each group. Flow cytometry was utilized to detect CD4+IFN-γ+ and CD4+IL-4+ cells. Immunohistochemistry, qPCR, and western blot assay were applied to measure the expression of TLR4, MyD88, and NF-κB. Results. EGCG improved the intestinal mucosal injury in rats, inhibited production of inflammatory factors, maintained the balance of Th1/Th2, and reduced the expression of TLR4, MyD88, and NF-κB. After TLR4 antagonism, the protective effect of EGCG on intestinal mucosal injury was weakened in rats with ulcerative colitis, and the expressions of inflammatory factors were upregulated. Conclusion. EGCG can inhibit the intestinal inflammatory response by reducing the severity of ulcerative colitis and maintaining the Th1/Th2 balance through the TLR4/MyD88/NF-κB signaling pathway.

Andrographolide protects mouse astrocytes against hypoxia injury by promoting autophagy and S100B expression

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Juan Du

2018-04-01

Full Text Available Andrographolide (ANDRO has been studied for its immunomodulation, anti-inflammatory, and neuroprotection effects. Because brain hypoxia is the most common factor of secondary brain injury after traumatic brain injury, we studied the role and possible mechanism of ANDRO in this process using hypoxia-injured astrocytes. Mouse cortical astrocytes C8-D1A (astrocyte type I clone from C57/BL6 strains were subjected to 3 and 21% of O2 for various times (0–12 h to establish an astrocyte hypoxia injury model in vitro. After hypoxia and ANDRO administration, the changes in cell viability and apoptosis were assessed using CCK-8 and flow cytometry. Expression changes in apoptosis-related proteins, autophagy-related proteins, main factors of JNK pathway, ATG5, and S100B were determined by western blot. Hypoxia remarkably damaged C8-D1A cells evidenced by reduction of cell viability and induction of apoptosis. Hypoxia also induced autophagy and overproduction of S100B. ANDRO reduced cell apoptosis and promoted cell autophagy and S100B expression. After ANDRO administration, autophagy-related proteins, S-100B, JNK pathway proteins, and ATG5 were all upregulated, while autophagy-related proteins and s100b were downregulated when the jnk pathway was inhibited or ATG5 was knocked down. ANDRO conferred a survival advantage to hypoxia-injured astrocytes by reducing cell apoptosis and promoting autophagy and s100b expression. Furthermore, the promotion of autophagy and s100b expression by ANDRO was via activation of jnk pathway and regulation of ATG5.

Hydrogen sulfide protects against chemical hypoxia-induced injury by inhibiting ROS-activated ERK1/2 and p38MAPK signaling pathways in PC12 cells.

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Aiping Lan

Full Text Available Hydrogen sulfide (H(2S has been proposed as a novel neuromodulator and neuroprotective agent. Cobalt chloride (CoCl(2 is a well-known hypoxia mimetic agent. We have demonstrated that H(2S protects against CoCl(2-induced injuries in PC12 cells. However, whether the members of mitogen-activated protein kinases (MAPK, in particular, extracellular signal-regulated kinase1/2(ERK1/2 and p38MAPK are involved in the neuroprotection of H(2S against chemical hypoxia-induced injuries of PC12 cells is not understood. We observed that CoCl(2 induced expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α, decreased cystathionine-β synthase (CBS, a synthase of H(2S expression, and increased generation of reactive oxygen species (ROS, leading to injuries of the cells, evidenced by decrease in cell viability, dissipation of mitochondrial membrane potential (MMP , caspase-3 activation and apoptosis, which were attenuated by pretreatment with NaHS (a donor of H(2S or N-acetyl-L cystein (NAC, a ROS scavenger. CoCl(2 rapidly activated ERK1/2, p38MAPK and C-Jun N-terminal kinase (JNK. Inhibition of ERK1/2 or p38MAPK or JNK with kinase inhibitors (U0126 or SB203580 or SP600125, respectively or genetic silencing of ERK1/2 or p38MAPK by RNAi (Si-ERK1/2 or Si-p38MAPK significantly prevented CoCl(2-induced injuries. Pretreatment with NaHS or NAC inhibited not only CoCl(2-induced ROS production, but also phosphorylation of ERK1/2 and p38MAPK. Thus, we demonstrated that a concurrent activation of ERK1/2, p38MAPK and JNK participates in CoCl(2-induced injuries and that H(2S protects PC12 cells against chemical hypoxia-induced injuries by inhibition of ROS-activated ERK1/2 and p38MAPK pathways. Our results suggest that inhibitors of ERK1/2, p38MAPK and JNK or antioxidants may be useful for preventing and treating hypoxia-induced neuronal injury.

The dependence receptor Ret induces apoptosis in somatotrophs through a Pit-1/p53 pathway, preventing tumor growth.

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Cañibano, Carmen; Rodriguez, Noela L; Saez, Carmen; Tovar, Sulay; Garcia-Lavandeira, Montse; Borrello, Maria Grazia; Vidal, Anxo; Costantini, Frank; Japon, Miguel; Dieguez, Carlos; Alvarez, Clara V

2007-04-18

Somatotrophs are the only pituitary cells that express Ret, GFRalpha1 and GDNF. This study investigated the effects of Ret in a somatotroph cell line, in primary pituitary cultures and in Ret KO mice. Ret regulates somatotroph numbers by inducing Pit-1 overexpression, leading to increased p53 expression and apoptosis, both of which can be prevented with Ret or Pit-1 siRNA. The Pit-1 overexpression is mediated by sustained activation of PKCdelta, JNK, c/EBPalpha and CREB induced by a complex of Ret, caspase 3 and PKCdelta. In the presence of GDNF, Akt is activated, and the Pit-1 overexpression and resulting apoptosis are blocked. The adenopituitary of Ret KO mice is larger than normal, showing Pit-1 and somatotroph hyperplasia. In normal animals, activation of the Ret/Pit-1/p53 pathway by retroviral introduction of Ret blocked tumor growth in vivo. Thus, somatotrophs have an intrinsic mechanism for controlling Pit-1/GH production through an apoptotic/survival pathway. Ret might be of value for treatment of pituitary adenomas.

A novel berbamine derivative inhibits cell viability and induces apoptosis in cancer stem-like cells of human glioblastoma, via up-regulation of miRNA-4284 and JNK/AP-1 signaling.

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Fan Yang

Full Text Available Glioblastoma (GBM is the most common primary brain tumor, accounting for approximately 40% of all central nervous system malignancies. Despite standard treatment consisting of surgical resection, radiotherapy and/or chemotherapy, the prognosis for GBM is poor; with a median survival of 14.6 months. The cancer stem cell or cancer-initiating cell model has provided a new paradigm for understanding development and recurrence of GBM following treatment. Berbamine (BBM is a natural compound derived from the Berberis amurensis plant, and along with its derivatives, has been shown to exhibit antitumor activity in several cancers. Here, we reported that a novel synthetic Berbamine derivative, BBMD3, inhibits cell viability and induces apoptosis of cancer stem-like cells (CSCs in a time- and dose-dependent manner when the CSCs from four GBM patients (PBT003, PBT008, PBT022, and PBT030 were cultured. These CSCs grew in neurospheres and expressed CD133 and nestin as markers. Treatment with BBMD3 destroyed the neurosphere morphology, and led to the induction of apoptosis in the CSCs. Induction of apoptosis in these CSCs is dependent upon activation of caspase-3 and cleavage of poly (ADP-ribose polymerase (PARP. MicroRNA-4284 (miR-4284 was shown to be over-expressed about 4-fold in the CSCs following BBMD3 treatment. Furthermore, transfection of synthetic anti-sense oligonucleotide against human miR-4284 partially blocked the anticancer effects of BBMD3 on the GBM derived CSCs. BBMD3 also increased phosphorylation of the c-Jun N-terminal kinase (JNK/stress-activated protein kinase (SAPK, resulting in an increase expression of phosphorylated c-Jun and total c-Fos; the major components of transcriptional factor AP-1. The JNK-c-Jun/AP-1 signaling pathway plays an important role in the induction of apoptosis in response to UV irradiation and some drug treatments. Targeting glioblastoma stem-like cells with BBMD3 is therefore novel, and may have promise as an

Immunomodulatory Activity of Ganoderma atrum Polysaccharide on Purified T Lymphocytes through Ca2+/CaN and Mitogen-Activated Protein Kinase Pathway Based on RNA Sequencing.

Science.gov (United States)

Xiang, Quan-Dan; Yu, Qiang; Wang, Hui; Zhao, Ming-Ming; Liu, Shi-Yu; Nie, Shao-Ping; Xie, Ming-Yong

2017-07-05

Our previous study has demonstrated that Ganoderma atrum polysaccharide (PSG-1) has immunomodulatory activity on spleen lymphocytes. However, how PSG-1 exerts its effect on purified lymphocytes is still obscure. Thus, this study aimed to investigate the immunomodulatory activity of PSG-1 on purified T lymphocytes and further elucidate the underlying mechanism based on RNA sequencing (RNA-seq). Our results showed that PSG-1 promoted T lymphocytes proliferation and increased the production of IL-2, IFN-γ, and IL-12. Meanwhile, RNA-seq analysis found 394 differentially expressed genes. KEGG pathway analysis identified 20 significant canonical pathways and seven biological functions. Furthermore, PSG-1 elevated intracellular Ca 2+ concentration and calcineurin (CaN) activity and raised the p-ERK, p-JNK, and p-p38 expression levels. T lymphocytes proliferation and the production of IL-2, IFN-γ, and IL-12 were decreased by the inhibitors of calcium channel and mitogen-activated protein kinases (MAPKs). These results indicated that PSG-1 possesses immunomodulatory activity on purified T lymphocytes, in which Ca 2+ /CaN and MAPK pathways play essential roles.

Resveratrol suppresses TPA-induced matrix metalloproteinase-9 expression through the inhibition of MAPK pathways in oral cancer cells.

Science.gov (United States)

Lin, Feng-Yan; Hsieh, Yi-Hsien; Yang, Shun-Fa; Chen, Chang-Tai; Tang, Chih-Hsin; Chou, Ming-Yung; Chuang, Yi-Ting; Lin, Chiao-Wen; Chen, Mu-Kuan

2015-10-01

Naturally occurring agents, such as resveratrol, have been determined to benefit health. Numerous studies have demonstrated that resveratrol has antioxidative, cardioprotective, and neuroprotective properties. However, the effect of resveratrol exerts on the metastasis of oral cancer cells remains unclear. In this study, we investigated the effect the anti-invasive activity of resveratrol on a human oral cancer cell line (SCC-9) in vitro and the underlying mechanisms. Cell viability was examined by MTT assay, whereas cell motility was measured by migration and wound-healing assays. Zymography, reverse-transcriptase polymerase chain reaction (PCR), and promoter assays confirmed the inhibitory effects of resveratrol on matrix metalloproteinase-9 (MMP-9) expression in oral cancer cells. We established that various concentrations (0-100 μM) of resveratrol inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced migration capacities of SCC-9 cells and caused no cytotoxic effects. Zymography and Western blot analyses suggested that resveratrol inhibited TPA-induced MMP-9 gelatinolytic activity and protein expression. In addition, the results indicated that resveratrol inhibited the phosphorylation of c-Jun N-terminal kinase (JNK)1/2 and extracellular-signal-regulated kinase (ERK)1/2 involved in downregulating protein expression and the transcription of MMP-9. In summary, resveratrol inhibited MMP-9 expression and oral cancer cell metastasis by downregulating JNK1/2 and ERK1/2 signals pathways and, thus, exerts beneficial effects in chemoprevention. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Plasticity of the MAPK signaling network in response to mechanical stress.

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Andrea M Pereira

Full Text Available Cells display versatile responses to mechanical inputs and recent studies have identified the mitogen-activated protein kinase (MAPK cascades mediating the biological effects observed upon mechanical stimulation. Although, MAPK pathways can act insulated from each other, several mechanisms facilitate the crosstalk between the components of these cascades. Yet, the combinatorial complexity of potential molecular interactions between these elements have prevented the understanding of their concerted functions. To analyze the plasticity of the MAPK signaling network in response to mechanical stress we performed a non-saturating epistatic screen in resting and stretched conditions employing as readout a JNK responsive dJun-FRET biosensor. By knocking down MAPKs, and JNK pathway regulators, singly or in pairs in Drosophila S2R+ cells, we have uncovered unexpected regulatory links between JNK cascade kinases, Rho GTPases, MAPKs and the JNK phosphatase Puc. These relationships have been integrated in a system network model at equilibrium accounting for all experimentally validated interactions. This model allows predicting the global reaction of the network to its modulation in response to mechanical stress. It also highlights its context-dependent sensitivity.

Glycyrrhizic Acid Promotes M1 Macrophage Polarization in Murine Bone Marrow-Derived Macrophages Associated with the Activation of JNK and NF-κB.

Science.gov (United States)

Mao, Yulong; Wang, Baikui; Xu, Xin; Du, Wei; Li, Weifen; Wang, Youming

2015-01-01

The roots and rhizomes of Glycyrrhiza species (licorice) have been widely used as natural sweeteners and herbal medicines. The aim of this study is to investigate the effect of glycyrrhizic acid (GA) from licorice on macrophage polarization. Both phenotypic and functional activities of murine bone marrow-derived macrophages (BMDMs) treated by GA were assessed. Our results showed that GA obviously increased the cell surface expression of CD80, CD86, and MHCII molecules. Meanwhile, GA upregulated the expression of CCR7 and the production of TNF-α, IL-12, IL-6, and NO (the markers of classically activated (M1) macrophages), whereas it downregulated the expression of MR, Ym1, and Arg1 (the markers of alternatively activated (M2) macrophage). The functional tests showed that GA dramatically enhanced the uptake of FITC-dextran and E. coli K88 by BMDMs and decreased the intracellular survival of E. coli K88 and S. typhimurium. Moreover, we demonstrated that JNK and NF-κB activation are required for GA-induced NO and M1-related cytokines production, while ERK1/2 pathway exhibits a regulatory effect via induction of IL-10. Together, these findings indicated that GA promoted polarization of M1 macrophages and enhanced its phagocytosis and bactericidal capacity. The results expanded our knowledge about the role of GA in macrophage polarization.

iTRAQ proteomics analysis reveals that PI3K is highly associated with bupivacaine-induced neurotoxicity pathways.

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Zhao, Wei; Liu, Zhongjie; Yu, Xujiao; Lai, Luying; Li, Haobo; Liu, Zipeng; Li, Le; Jiang, Shan; Xia, Zhengyuan; Xu, Shi-yuan

2016-02-01

Bupivacaine, a commonly used local anesthetic, has potential neurotoxicity through diverse signaling pathways. However, the key mechanism of bupivacaine-induced neurotoxicity remains unclear. Cultured human SH-SY5Y neuroblastoma cells were treated (bupivacaine) or untreated (control) with bupivacaine for 24 h. Compared to the control group, bupivacaine significantly increased cyto-inhibition, cellular reactive oxygen species, DNA damage, mitochondrial injury, apoptosis (increased TUNEL-positive cells, cleaved caspase 3, and Bcl-2/Bax), and activated autophagy (enhanced LC3II/LC3I ratio). To explore changes in protein expression and intercommunication among the pathways involved in bupivacaine-induced neurotoxicity, an 8-plex iTRAQ proteomic technique and bioinformatics analysis were performed. Compared to the control group, 241 differentially expressed proteins were identified, of which, 145 were up-regulated and 96 were down-regulated. Bioinformatics analysis of the cross-talk between the significant proteins with altered expression in bupivacaine-induced neurotoxicity indicated that phosphatidyl-3-kinase (PI3K) was the most frequently targeted protein in each of the interactions. We further confirmed these results by determining the downstream targets of the identified signaling pathways (PI3K, Akt, FoxO1, Erk, and JNK). In conclusion, our study demonstrated that PI3K may play a central role in contacting and regulating the signaling pathways that contribute to bupivacaine-induced neurotoxicity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ligation of major histocompatibility complex class I antigens (MHC-I) prevents apoptosis induced by Fas or SAPK/JNK activation in T-lymphoma cells

DEFF Research Database (Denmark)

Lamberth, K; Claesson, M H

2001-01-01

Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti-apoptotic......Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti......-apoptotic Bcl-2 protein and stabilized the mitochondrial membrane potential (Deltapsim). MHC-I ligation also prevented downregulation of Bcl-2 and destabilization of Deltapsim induced by anti-Fas Ab treatment or anisomycin exposure. Studies on three different Jurkat cell mutants deficient for src p56(lck), ZAP......-70 kinase, or TCR/CD3 gamma-chain showed that the cells undergo apoptosis after Fas ligation. Anisomycin exposure induced apoptosis in the src p56(lck)-deficient cell line but not in the two other mutant cell lines. Simultaneous cross-linking of MHC-I and Fas ligation inhibited apoptosis in the ZAP...

Effect of QSKL on MAPK and RhoA Pathways in a Rat Model of Heart Failure

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Kai Xia

2017-01-01

Full Text Available Qishenkeli (QSKL is one of the Chinese medicine formulae for treating heart failure and has been shown to have an antifibrotic effect. However, the mechanism of its therapeutic effects remains unclear. In this study, we aimed to explore whether QSKL could exert an antifibrotic effect by attenuating ras homolog family member A (RhoA and mitogen activated protein kinase (MAPK pathways. Rats were randomly divided into sham group, model group, QSKL group, and positive control group. Heart failure was induced by ligation of the left ventricle anterior descending artery. Cardiac functions were measured by echocardiography and collagen deposition was assessed by Masson staining. Expressions of the key molecules involved in the RhoA and MAPK pathways were also measured. Twenty-one days after surgery, cardiac functions were severely impaired and collagen deposition was remarkable, while QSKL treatment could improve heart functions and alleviate collagen deposition. Further results demonstrated that the effects may be mediated by suppressing expressions of extracellular signal-regulated kinase (ERK and c-Jun N-terminal kinase (JNK. Moreover, expressions of RhoA, Rho-associated protein kinase 1/2 (ROCK1/2, and phosphorylated myosin light chain (p-MLC were also downregulated by QSKL compared with the model group. The cardioprotective mechanism of QSKL on heart failure is probably mediated by regulating both the MAPK and RhoA signaling pathways.

Inhibition of NF-κB Pathway and Modulation of MAPK Signaling Pathways in Glioblastoma and Implications for Lovastatin and Tumor Necrosis Factor-Related Apoptosis Inducing Ligand (TRAIL Combination Therapy.

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Pi Chu Liu

Full Text Available Glioblastoma is a common malignant brain tumor and it is refractory to therapy because it usually contains a mixture of cell types. The tumor necrosis factor-related apoptosis inducing ligand (TRAIL has been shown to induce apoptosis in a range of tumor cell types. Previously, we found that two human glioblastoma cell lines are resistant to TRAIL, while lovastatin sensitizes these glioblastoma cells to TRAIL-induced cell death. In this study, we investigated the mechanisms underlying the TRAIL-induced apoptosis in human glioblastoma cell lines by lovastatin. Furthermore, we have confirmed the anti-tumor effect of combination therapy with lovastatin and TRAIL in the subcutaneous brain tumor model. We showed that lovastatin significantly up-regulated the expression of death receptor 5 (DR5 in glioblastoma cell lines as well as in tumor-bearing mice with peri-tumoral administration of lovastatin. Further study in glioblastoma cell lines suggested that lovastatin treatment could inhibit NF-κB and Erk/MAPK pathways but activates JNK pathway. These results suggest that lovastatin sensitizes TRAIL-induced apoptosis by up-regulation of DR5 level via NF-κB inactivation, but also directly induces apoptosis by dysregulation of MAPK pathway. Our in vivo study showed that local peri-tumoral co-injection of lovastatin and TRAIL substantially reduced tumor growth compared with single injection of lovastatin or TRAIL in subcutaneous nude mice model. This study suggests that combined treatment of lovastatin and TRAIL is a promising therapeutic strategy to TRAIL-resistant glioblastoma.

Central melanin-concentrating hormone influences liver and adipose metabolism via specific hypothalamic nuclei and efferent autonomic/JNK1 pathways.

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Imbernon, Monica; Beiroa, Daniel; Vázquez, María J; Morgan, Donald A; Veyrat-Durebex, Christelle; Porteiro, Begoña; Díaz-Arteaga, Adenis; Senra, Ana; Busquets, Silvia; Velásquez, Douglas A; Al-Massadi, Omar; Varela, Luis; Gándara, Marina; López-Soriano, Francisco-Javier; Gallego, Rosalía; Seoane, Luisa M; Argiles, Josep M; López, Miguel; Davis, Roger J; Sabio, Guadalupe; Rohner-Jeanrenaud, Françoise; Rahmouni, Kamal; Dieguez, Carlos; Nogueiras, Ruben

2013-03-01

Specific neuronal circuits modulate autonomic outflow to liver and white adipose tissue. Melanin-concentrating hormone (MCH)-deficient mice are hypophagic, lean, and do not develop hepatosteatosis when fed a high-fat diet. Herein, we sought to investigate the role of MCH, an orexigenic neuropeptide specifically expressed in the lateral hypothalamic area, on hepatic and adipocyte metabolism. Chronic central administration of MCH and adenoviral vectors increasing MCH signaling were performed in rats and mice. Vagal denervation was performed to assess its effect on liver metabolism. The peripheral effects on lipid metabolism were assessed by real-time polymerase chain reaction and Western blot. We showed that the activation of MCH receptors promotes nonalcoholic fatty liver disease through the parasympathetic nervous system, whereas it increases fat deposition in white adipose tissue via the suppression of sympathetic traffic. These metabolic actions are independent of parallel changes in food intake and energy expenditure. In the liver, MCH triggers lipid accumulation and lipid uptake, with c-Jun N-terminal kinase being an essential player, whereas in adipocytes MCH induces metabolic pathways that promote lipid storage and decreases lipid mobilization. Genetic activation of MCH receptors or infusion of MCH specifically in the lateral hypothalamic area modulated hepatic lipid metabolism, whereas the specific activation of this receptor in the arcuate nucleus affected adipocyte metabolism. Our findings show that central MCH directly controls hepatic and adipocyte metabolism through different pathways. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Pathways towards the proliferation of avoidance in anxiety and implications for treatment

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Arnaudova, I.; Kindt, M.; Fanselow, M.; Beckers, T.

Avoidance is a key symptom of anxiety disorders. Maladaptive avoidance impairs general functioning acutely and maintains chronic anxiety. A better understanding of the mechanisms that elicit and maintain excessive avoidance might provide opportunities to improve treatment. Here, we discuss pathways

Preserving breastfeeding for the rehospitalized infant: a clinical pathway.

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Spatz, Diane L; Goldschmidt, Karen A

2006-01-01

The benefits of feeding newborns with human milk are well established. Unfortunately some hospital practices do not support successful breastfeeding; practices such as early hospital discharge after birth, lack of appropriate follow-up primary care providers, and lack of access to breastfeeding support services can contribute to breastfeeding failure, as well as morbidity and mortality in the infant. Infants experiencing breastfeeding difficulties are sometimes admitted to the hospital with diagnoses such as hyperbilirubinemia/jaundice, dehydration/hypernatremia, rule out sepsis, and weight loss/failure to thrive. This article describes a clinical pathway developed with the express purpose of maintaining and enhancing lactation in mother-infant dyads experiencing breastfeeding difficulties. The goal of the pathway is to maintain lactation and breastfeeding while returning the infant to a state of health. A key focus of the pathway is milk transfer, a concept that is missing from much of the research on lactation difficulties. The pathway considers breastfeeding from both a maternal and an infant perspective, with a goal of preserving breastfeeding. It uses technology to support the breastfeeding process and could be useful for all practitioners working with mother-infant dyads experiencing breastfeeding difficulties.

Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

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Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

2016-06-01

Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells.

Curcumin induces down-regulation of EZH2 expression through the MAPK pathway in MDA-MB-435 human breast cancer cells.

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Hua, Wen-Feng; Fu, Yong-Shui; Liao, Yi-Ji; Xia, Wen-Jie; Chen, Yang-Chao; Zeng, Yi-Xin; Kung, Hsiang-Fu; Xie, Dan

2010-07-10

Curcumin, a natural compound isolated from turmeric, may inhibit cell proliferation in various tumor cells through a mechanism that is not fully understood. The enhancer of zeste homolog 2 (EZH2) gene is overexpressed in human breast cancers with poor prognosis. In this study, we observed a dose- and time-dependent down-regulation of expression of EZH2 by curcumin that correlates with decreased proliferation in the MDA-MB-435 breast cancer cell line. The curcumin treatment resulted in an accumulation of cells in the G(1) phase of the cell cycle. Further investigation revealed that curcumin-induced down-regulation of EZH2 through stimulation of three major members of the mitogen-activated protein kinase (MAPK) pathway: c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38 kinase. These data suggest that an underlying mechanism of the MAPK pathway mediates the down-regulation of EZH2, thus contributing to the anti-proliferative effects of curcumin against breast cancer. Copyright 2010 Elsevier B.V. All rights reserved.

Apoptotic cells can induce non-autonomous apoptosis through the TNF pathway

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Pérez-Garijo, Ainhoa; Fuchs, Yaron; Steller, Hermann

2013-01-01

Apoptotic cells can produce signals to instruct cells in their local environment, including ones that stimulate engulfment and proliferation. We identified a novel mode of communication by which apoptotic cells induce additional apoptosis in the same tissue. Strong induction of apoptosis in one compartment of the Drosophila wing disc causes apoptosis of cells in the other compartment, indicating that dying cells can release long-range death factors. We identified Eiger, the Drosophila tumor necrosis factor (TNF) homolog, as the signal responsible for apoptosis-induced apoptosis (AiA). Eiger is produced in apoptotic cells and, through activation of the c-Jun N-terminal kinase (JNK) pathway, is able to propagate the initial apoptotic stimulus. We also show that during coordinated cell death of hair follicle cells in mice, TNF-α is expressed in apoptotic cells and is required for normal cell death. AiA provides a mechanism to explain cohort behavior of dying cells that is seen both in normal development and under pathological conditions. DOI: http://dx.doi.org/10.7554/eLife.01004.001 PMID:24066226

Enterococcus faecalis from healthy infants modulates inflammation through MAPK signaling pathways.

Directory of Open Access Journals (Sweden)

Shugui Wang

Full Text Available Colonizing commensal bacteria after birth are required for the proper development of the gastrointestinal tract. It is believed that bacterial colonization pattern in neonatal gut affects gut barrier function and immune system maturation. Studies on the development of faecal microbiota in infants showed that the neonatal gut was first colonized with enterococci followed by other microbiota such as Bifidobacterium. Other studies showed that babies who developed allergy were less often colonized with Enterococcus during the first month of life as compared to healthy infants. Many studies have been conducted to elucidate how bifidobacteria or lactobacilli, some of which are considered probiotic, regulate infant gut immunity. However, fewer studies have been focused on enterococi. In our study, we demonstrate that E. faecalis, isolated from healthy newborns, suppress inflammatory responses activated in vivo and in vitro. We found E. faecalis attenuates proinflammatory cytokine secretions, especially IL-8, through JNK and p38 signaling pathways. This finding shed light on how the first colonizer, E.faecalis, regulates inflammatory responses in the host.

Activation of JNK and c-Jun is involved in glucose oxidase-mediated cell death of human lymphoma cells.

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Son, Young-Ok; Jang, Yong-Suk; Shi, Xianglin; Lee, Jeong-Chae

2009-12-31

Mitogen-activated protein kinases (MAPK) affect the activation of activator protein-1 (AP-1), which plays an important role in regulating a range of cellular processes. However, the roles of these signaling factors on hydrogen peroxide (H(2)O(2))-induced cell death are unclear. This study examined the effects of H(2)O(2) on the activation of MAPK and AP-1 by exposing the cells to H(2)O(2) generated by either glucose oxidase or a bolus addition. Exposing BJAB or Jurkat cells to H(2)O(2) affected the activities of MAPK differently according to the method of H(2)O(2) exposure. H(2)O(2) increased the AP-1-DNA binding activity in these cells, where continuously generated H(2)O(2) led to an increase in mainly the c-Fos, FosB and c-Jun proteins. The c-Jun-NH(2)-terminal kinase (JNK)-mediated activation of c-Jun was shown to be related to the H(2)O(2)-induced cell death. However, the suppression of H(2)O(2)-induced oxidative stress by either JNK inhibitor or c-Jun specific antisense transfection was temporary in the cells exposed to glucose oxidase but not to a bolus H(2)O(2). This was associated with the disruption of death signaling according to the severe and prolonged depletion of reduced glutathione. Overall, these results suggest that H(2)O(2) may decide differently the mode of cell death by affecting the intracellular redox state of thiol-containing antioxidants, and this depends more closely on the duration exposed to H(2)O(2) than the concentration of this agent.

Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

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Saher, G; Hildt, E

1999-09-24

Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

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Renoz, François; Noël, Christine; Errachid, Abdelmounaim; Foray, Vincent; Hance, Thierry

2015-01-01

In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

Conservation of Planar Polarity Pathway Function Across the Animal Kingdom.

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Hale, Rosalind; Strutt, David

2015-01-01

Planar polarity is a well-studied phenomenon resulting in the directional coordination of cells in the plane of a tissue. In invertebrates and vertebrates, planar polarity is established and maintained by the largely independent core and Fat/Dachsous/Four-jointed (Ft-Ds-Fj) pathways. Loss of function of these pathways can result in a wide range of developmental or cellular defects, including failure of gastrulation and problems with placement and function of cilia. This review discusses the conservation of these pathways across the animal kingdom. The lack of vital core pathway components in basal metazoans suggests that the core planar polarity pathway evolved shortly after, but not necessarily alongside, the emergence of multicellularity.

c-Jun/AP-1 pathway-mediated cyclin D1 expression participates in low dose arsenite-induced transformation in mouse epidermal JB6 Cl41 cells

International Nuclear Information System (INIS)

Zhang Dongyun; Li Jingxia; Gao Jimin; Huang Chuanshu

2009-01-01

Arsenic is a well-documented human carcinogen associated with skin carcinogenesis. Our previous work reveals that arsenite exposure is able to induce cell transformation in mouse epidermal cell JB6 Cl41 through the activation of ERK, rather than JNK pathway. Our current studies further evaluate downstream pathway in low dose arsenite-induced cell transformation in JB6 Cl41 cells. Our results showed that treatment of cells with low dose arsenite induced activation of c-Jun/AP-1 pathway, and ectopic expression of dominant negative mutant of c-Jun (TAM67) blocked arsenite-induced transformation. Furthermore, our data indicated that cyclin D1 was an important downstream molecule involved in c-Jun/AP-1-mediated cell transformation upon low dose arsenite exposure, because inhibition of cyclin D1 expression by its specific siRNA in the JB6 Cl41 cells resulted in impairment of anchorage-independent growth of cells induced by low dose arsenite. Collectively, our results demonstrate that c-Jun/AP-1-mediated cyclin D1 expression is at least one of the key events implicated in cell transformation upon low dose arsenite exposure

Inhibition of ERK1/2 or AKT Activity Equally Enhances Radiation Sensitization in B16F10 Cells

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Kalal, Bhuvanesh Sukhlal; Fathima, Faraz; Pai, Vinitha Ramanath; Sanjeev, Ganesh; Krishna, Chilakapati Murali; Upadhya, Dinesh

2018-01-01

Background The aim of the study was to evaluate the radiation sensitizing ability of ERK1/2, PI3K-AKT and JNK inhibitors in highly radiation resistant and metastatic B16F10 cells which carry wild-type Ras and Braf. Methods Mouse melanoma cell line B16F10 was exposed to 1.0, 2.0 and 3.0 Gy of electron beam radiation. Phosphorylated ERK1/2, AKT and JNK levels were estimated by ELISA. Cells were exposed to 2.0 and 3.0 Gy of radiation with or without prior pharmacological inhibition of ERK1/2, AKT as well as JNK pathways. Cell death induced by radiation as well as upon inhibition of these pathways was measured by TUNEL assay using flow cytometry. Results Exposure of B16F10 cells to 1.0, 2.0 and 3.0 Gy of electron beam irradiation triggered an increase in all the three phosphorylated proteins compared to sham-treated and control groups. B16F10 cells pre-treated with either ERK1/2 or AKT inhibitors equally enhanced radiation-induced cell death at 2.0 as well as 3.0 Gy (P < 0.001), while inhibition of JNK pathway increased radiation-induced cell death to a lesser extent. Interestingly combined inhibition of ERK1/2 or AKT pathways did not show additional cell death compared to individual ERK1/2 or AKT inhibition. This indicates that ERK1/2 or AKT mediates radiation resistance through common downstream molecules in B16F10 cells. Conclusions Even without activating mutations in Ras or Braf genes, ERK1/2 and AKT play a critical role in B16F10 cell survival upon radiation exposure and possibly act through common downstream effector/s. PMID:29581812

Fluoride-induced IL-8 release in human epithelial lung cells: Relationship to EGF-receptor-, SRC- and MAP-kinase activation

International Nuclear Information System (INIS)

Refsnes, Magne; Skuland, Tonje; Schwarze, Per E.; Ovrevik, Johan; Lag, Marit

2008-01-01

Exposure of human epithelial lung cells to fluorides is known to induce a marked increase in the release of interleukin (IL)-8, a chemokine involved in neutrophil recruitment. In the present study, the involvement of mitogen-activating protein kinases (MAPKs), the role of upstream activation of Src family kinases (SFKs), epidermal growth factor receptor (EGFR) activation and the interrelationships between these pathways in fluoride-induced IL-8 were examined in a human epithelial lung cell line (A549). Sodium fluoride strongly activated MAPK, in particular JNK1/2 and p38. The ERK1/2-inhibitor PD98059, the p38-inhibitor SB202190 and the JNK1/2-inhibitor SP600125 partially inhibited the fluoride-induced IL-8 response. Combinations of these inhibitors reduced the responses nearly to basal levels. Treatment with siRNA against JNK2 also reduced the IL-8 response to fluoride. Furthermore, fluoride activated SFKs, which was abolished by the SFK-inhibitor PP2. PP2 substantially inhibited the increased levels of IL-8, and partially reduced the fluoride-induced activation of ERK1/2, p38 and JNK1/2. Fluoride exposure also led to a phosphorylation of the EGFR, that was partially inhibited by PP2. AG1478, an EGFR-inhibitor, partially reduced the fluoride-induced IL-8 response and the phosphorylation of JNK1/2 and ERK1/2, but less the phosphorylation of p38. The effects of AG1478 were less than that of PP2. In conclusion, our findings suggest that the fluoride-induced IL-8 release involves the combined activation of ERK1/2, JNK1/2 and p38, and that the phosphorylation of these kinases, and in particular JNK1/2 and ERK1/2, partly, is mediated via a SFK-dependent EGFR-linked pathway. SFK-dependent, but EGFR-independent mechanisms seem important, and especially for phosphorylation of p38

Modelling and performance analysis of clinical pathways using the stochastic process algebra PEPA.

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Yang, Xian; Han, Rui; Guo, Yike; Bradley, Jeremy; Cox, Benita; Dickinson, Robert; Kitney, Richard

2012-01-01

Hospitals nowadays have to serve numerous patients with limited medical staff and equipment while maintaining healthcare quality. Clinical pathway informatics is regarded as an efficient way to solve a series of hospital challenges. To date, conventional research lacks a mathematical model to describe clinical pathways. Existing vague descriptions cannot fully capture the complexities accurately in clinical pathways and hinders the effective management and further optimization of clinical pathways. Given this motivation, this paper presents a clinical pathway management platform, the Imperial Clinical Pathway Analyzer (ICPA). By extending the stochastic model performance evaluation process algebra (PEPA), ICPA introduces a clinical-pathway-specific model: clinical pathway PEPA (CPP). ICPA can simulate stochastic behaviours of a clinical pathway by extracting information from public clinical databases and other related documents using CPP. Thus, the performance of this clinical pathway, including its throughput, resource utilisation and passage time can be quantitatively analysed. A typical clinical pathway on stroke extracted from a UK hospital is used to illustrate the effectiveness of ICPA. Three application scenarios are tested using ICPA: 1) redundant resources are identified and removed, thus the number of patients being served is maintained with less cost; 2) the patient passage time is estimated, providing the likelihood that patients can leave hospital within a specific period; 3) the maximum number of input patients are found, helping hospitals to decide whether they can serve more patients with the existing resource allocation. ICPA is an effective platform for clinical pathway management: 1) ICPA can describe a variety of components (state, activity, resource and constraints) in a clinical pathway, thus facilitating the proper understanding of complexities involved in it; 2) ICPA supports the performance analysis of clinical pathway, thereby assisting

c-Jun N-terminal kinase 3 expression in the retina of ocular hypertension mice: a possible target to reduce ganglion cell apoptosis

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Yue He

2015-01-01

Full Text Available Glaucoma, a type of optic neuropathy, is characterized by the loss of retinal ganglion cells. It remains controversial whether c-Jun N-terminal kinase (JNK participates in the apoptosis of retinal ganglion cells in glaucoma. This study sought to explore a possible mechanism of action of JNK signaling pathway in glaucoma-induced retinal optic nerve damage. We established a mouse model of chronic ocular hypertension by reducing the aqueous humor followed by photocoagulation using the laser ignition method. Results showed significant pathological changes in the ocular tissues after the injury. Apoptosis of retinal ganglion cells increased with increased intraocular pressure, as did JNK3 mRNA expression in the retina. These data indicated that the increased expression of JNK3 mRNA was strongly associated with the increase in intraocular pressure in the retina, and correlated positively with the apoptosis of retinal ganglion cells.

ML-7 amplifies the quinocetone-induced cell death through akt and MAPK-mediated apoptosis on HepG2 cell line.

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Zhou, Yan; Zhang, Shen; Deng, Sijun; Dai, Chongshan; Tang, Shusheng; Yang, Xiayun; Li, Daowen; Zhao, Kena; Xiao, Xilong

2016-01-01

The study aims at evaluating the combination of the quinocetone and the ML-7 in preclinical hepatocellular carcinoma models. To this end, the effect of quinocetone and ML-7 on apoptosis induction and signaling pathways was analyzed on HepG2 cell lines. Here, we report that ML-7, in a nontoxic concentration, sensitized the HepG2 cells to quinocetone-induced cytotoxicity. Also, ML-7 profoundly enhances quinocetone-induced apoptosis in HepG2 cell line. Mechanistic investigations revealed that ML-7 and quinocetone act in concert to trigger the cleavage of caspase-8 as well as Bax/Bcl-2 ratio up-regulation and subsequent cleavage of Bid, capsases-9 and -3. Importantly, ML-7 weakened the quinocetone-induced Akt pathway activation, but strengthened the phosphorylation of p-38, ERK and JNK. Further treatment of Akt activator and p-38 inhibitor almost completely abolished the ML-7/quinocetone-induced apoptosis. In contrast, the ERK and JNK inhibitor aggravated the ML-7/quinocetone-induced apoptosis, indicating that the synergism critically depended on p-38 phosphorylation and HepG2 cells provoke Akt, ERK and JNK signaling pathways to against apoptosis. In conclusion, the rational combination of quinocetone and ML-7 presents a promising approach to trigger apoptosis in hepatocellular carcinoma, which warrants further investigation.

Early transcriptional response to aminoglycoside antibiotic suggests alternate pathways leading to apoptosis of sensory hair cells in the mouse inner ear

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Neil eSegil

2015-05-01

Full Text Available Aminoglycoside antibiotics are the drug of choice for treating many bacterial infections, but their administration results in hearing loss in nearly one fourth of the patients who receive them. Several biochemical pathways have been implicated in aminoglycoside antibiotic ototoxicity; however, little is known about how hair cells respond to aminoglycoside antibiotics at the transcriptome level. Here we have investigated the genome-wide response to the aminoglycoside antibiotic gentamicin. Using organotypic cultures of the perinatal organ of Corti, we performed RNA sequencing using cDNA libraries obtained from FACS-purified hair cells. Within 3 hours of gentamicin treatment, the messenger RNA level of more than three thousand genes in hair cells changed significantly. Bioinformatic analysis of these changes highlighted several known signal transduction pathways, including the JNK pathway and the NF-κB pathway, in addition to genes involved in the stress response, apoptosis, cell cycle control, and DNA damage repair. In contrast, only 698 genes, mainly involved in cell cycle and metabolite biosynthetic processes, were significantly affected in the non-hair cell population. The gene expression profiles of hair cells in response to gentamicin share a considerable similarity with those previously observed in gentamicin-induced nephrotoxicity. Our findings suggest that previously observed early responses to gentamicin in hair cells in specific signaling pathways are reflected in changes in gene expression. Additionally, the observed changes in gene expression of cell cycle regulatory genes indicate a disruption of the postmitotic state, which may suggest an alternative pathway regulating gentamicin-induced hair cell death. This work provides a more comprehensive view of aminoglycoside antibiotic ototoxicity, and thus contribute to identifying potential pathways or therapeutic targets to alleviate this important side effect of aminoglycoside

c-Jun NH2-terminal kinase activity in subcutaneous adipose tissue but not nuclear factor-kappaB activity in peripheral blood mononuclear cells is an independent determinant of insulin resistance in healthy individuals

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Sourris, Karly C; Lyons, Jasmine G; de Courten, Maximilian

2009-01-01

Chronic low-grade activation of the immune system (CLAIS) predicts type 2 diabetes via a decrease in insulin sensitivity. Our study investigated potential relationships between nuclear factor-kappaB (NF-kappaB) and c-Jun NH(2)-terminal kinase (JNK) pathways-two pathways proposed as the link between...

Plasmodium berghei NK65 in Combination with IFN-γ Induces Endothelial Glucocorticoid Resistance via Sustained Activation of p38 and JNK

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Zielińska, Karolina A.; de Cauwer, Lode; Knoops, Sofie; Van der Molen, Kristof; Sneyers, Alexander; Thommis, Jonathan; De Souza, J. Brian; Opdenakker, Ghislain; De Bosscher, Karolien; Van den Steen, Philippe E.

2017-01-01

Malaria-associated acute respiratory distress syndrome (MA-ARDS) is an often lethal complication of malaria. Currently, no adequate therapy for this syndrome exists. Although glucocorticoids (GCs) have been used to improve clinical outcome of ARDS, their therapeutic benefits remain unclear. We previously developed a mouse model of MA-ARDS, in which dexamethasone treatment revealed GC resistance. In the present study, we investigated GC sensitivity of mouse microvascular lung endothelial cells stimulated with interferon-γ (IFN-γ) and Plasmodium berghei NK65 (PbNK65). Upon challenge with IFN-γ alone, dexamethasone inhibited the expression of CCL5 (RANTES) by 90% and both CCL2 (MCP-1) and CXCL10 (IP-10) by 50%. Accordingly, whole transcriptome analysis revealed that dexamethasone differentially affected several gene clusters and in particular inhibited a large cluster of IFN-γ-induced genes, including chemokines. In contrast, combined stimulation with IFN-γ and PbNK65 extract impaired inhibitory actions of GCs on chemokine release, without affecting the capacity of the GC receptor to accumulate in the nucleus. Subsequently, we investigated the effects of GCs on two signaling pathways activated by IFN-γ. Dexamethasone left phosphorylation and protein levels of signal transducer and activator of transcription 1 (STAT1) unhampered. In contrast, dexamethasone inhibited the IFN-γ-induced activation of two mitogen-activated protein kinases (MAPK), JNK, and p38. However, PbNK65 extract abolished the inhibitory effects of GCs on MAPK signaling, inducing GC resistance. These data provide novel insights into the mechanisms of GC actions in endothelial cells and show how malaria may impair the beneficial effects of GCs. PMID:29033931

Plasmodium berghei NK65 in Combination with IFN-γ Induces Endothelial Glucocorticoid Resistance via Sustained Activation of p38 and JNK

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Karolina A. Zielińska

2017-09-01

Full Text Available Malaria-associated acute respiratory distress syndrome (MA-ARDS is an often lethal complication of malaria. Currently, no adequate therapy for this syndrome exists. Although glucocorticoids (GCs have been used to improve clinical outcome of ARDS, their therapeutic benefits remain unclear. We previously developed a mouse model of MA-ARDS, in which dexamethasone treatment revealed GC resistance. In the present study, we investigated GC sensitivity of mouse microvascular lung endothelial cells stimulated with interferon-γ (IFN-γ and Plasmodium berghei NK65 (PbNK65. Upon challenge with IFN-γ alone, dexamethasone inhibited the expression of CCL5 (RANTES by 90% and both CCL2 (MCP-1 and CXCL10 (IP-10 by 50%. Accordingly, whole transcriptome analysis revealed that dexamethasone differentially affected several gene clusters and in particular inhibited a large cluster of IFN-γ-induced genes, including chemokines. In contrast, combined stimulation with IFN-γ and PbNK65 extract impaired inhibitory actions of GCs on chemokine release, without affecting the capacity of the GC receptor to accumulate in the nucleus. Subsequently, we investigated the effects of GCs on two signaling pathways activated by IFN-γ. Dexamethasone left phosphorylation and protein levels of signal transducer and activator of transcription 1 (STAT1 unhampered. In contrast, dexamethasone inhibited the IFN-γ-induced activation of two mitogen-activated protein kinases (MAPK, JNK, and p38. However, PbNK65 extract abolished the inhibitory effects of GCs on MAPK signaling, inducing GC resistance. These data provide novel insights into the mechanisms of GC actions in endothelial cells and show how malaria may impair the beneficial effects of GCs.

Cyclophilin B protects SH-SY5Y human neuroblastoma cells against MPP(+)-induced neurotoxicity via JNK pathway.

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Oh, Yoojung; Jeong, Kwon; Kim, Kiyoon; Lee, Young-Seok; Jeong, Suyun; Kim, Sung Soo; Yoon, Kyung-Sik; Ha, Joohun; Kang, Insug; Choe, Wonchae

2016-09-23

Parkinson's disease (PD) is the second most common neurodegenerative disorder of aging. PD involves a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. 1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyidine (MPTP) and its toxic metabolite 1-methyl-4-phenylpyridinium ion (MPP+) inhibit the complex I of the mitochondrial electron transport chain, and have been widely used to construct PD models. Cyclophilin B (CypB) is an endoplasmic reticulum protein that binds to cyclosporine A as a cyclophilin family member. CypB has peptidyl-prolyl cis-trans isomerase (PPIase) activity. We investigated the protective effects of overexpressed CypB on MPP+-induced neurocytotoxicity in SH-SY5Y human neuroblastoma cells. Overexpressed CypB decreased MPP(+)-induced oxidative stress through the modulation of antioxidant enzymes including manganese superoxide dismutase and catalase, and prevented neurocytotoxicity via mitogen-activated protein kinase, especially the c-Jun N-terminal kinase pathway. In addition, CypB inhibited the activation of MPP(+)-induced the pro-apoptotic molecules poly (ADP-ribose) polymerase, Bax, and Bcl-2, and attenuated MPP(+)-induced mitochondrial dysfunction. The data suggest that overexpressed CypB protects neuronal cells from MPP+-induced dopaminergic neuronal cell death. Copyright © 2016 Elsevier Inc. All rights reserved.

Maintainability allocation

International Nuclear Information System (INIS)

Guyot, Christian.

1980-06-01

The author gives the general lines of a method for the allocation and for the evaluation of maintainability of complex systems which is to be developed during the conference. The maintainability objective is supposed to be formulated under the form of a mean time to repair (M.T.T.R.) [fr

Supplementing diet with Manitoba lingonberry juice reduces kidney ischemia-reperfusion injury.

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Isaak, Cara K; Wang, Pengqi; Prashar, Suvira; O, Karmin; Brown, Daniel Cw; Debnath, Samir C; Siow, Yaw L

2017-07-01

Lingonberry (Vaccinium vitis-idaea L.) contains high levels of anthocyanins which are bioavailable in the kidney and may be protective against ischemia-reperfusion (IR)-induced acute kidney injury. This study investigated the effect of lingonberry juice on the IR-induced stress-activated signalling pathway and inflammatory response in the kidney. Sprague-Dawley rats subjected to kidney IR had significantly impaired kidney function, with increased activation of the JNK signalling pathway and increased inflammatory response, measured using a multiplex panel containing an extensive array of inflammatory biomarkers. In rats fed 1 mL lingonberry juice daily for 3 weeks prior to IR, kidney function was protected and attenuation of inflammatory response and JNK signalling was reflected in the reduction of the measured biomarkers. In vitro results in cultured HK-2 cells confirmed that lingonberry anthocyanins reduced JNK signalling and inflammatory gene expression after IR. This study shows, for the first time, that daily supplementation with lingonberry juice may protect against loss of kidney function induced by IR injury by modulating JNK signalling and inhibiting the subsequent inflammatory response. © 2017 Her Majesty the Queen in Right of Canada. Journal of the Science of Food and Agriculture © 2017 Society of Chemical Industry. © 2017 Her Majesty the Queen in Right of Canada. Journal of the Science of Food and Agriculture © 2017 Society of Chemical Industry.

Schisantherin A suppresses osteoclast formation and wear particle-induced osteolysis via modulating RANKL signaling pathways

Energy Technology Data Exchange (ETDEWEB)

He, Yi; Zhang, Qing; Shen, Yi; Chen, Xia; Zhou, Feng; Peng, Dan, E-mail: xyeypd@163.com

2014-07-04

Highlights: • Schisantherin A suppresses osteoclasts formation and function in vitro. • Schisantherin A impairs RANKL signaling pathway. • Schisantherin A suppresses osteolysis in vivo. • Schisantherin A may be used for treating osteoclast related diseases. - Abstract: Receptor activator of NF-κB ligand (RANKL) plays critical role in osteoclastogenesis. Targeting RANKL signaling pathways has been a promising strategy for treating osteoclast related bone diseases such as osteoporosis and aseptic prosthetic loosening. Schisantherin A (SA), a dibenzocyclooctadiene lignan isolated from the fruit of Schisandra sphenanthera, has been used as an antitussive, tonic, and sedative agent, but its effect on osteoclasts has been hitherto unknown. In the present study, SA was found to inhibit RANKL-induced osteoclast formation and bone resorption. The osteoclastic specific marker genes induced by RANKL including c-Src, SA inhibited OSCAR, cathepsin K and TRAP in a dose dependent manner. Further signal transduction studies revealed that SA down-regulate RANKL-induced nuclear factor-kappaB (NF-κB) signaling activation by suppressing the phosphorylation and degradation of IκBα, and subsequently preventing the NF-κB transcriptional activity. Moreover, SA also decreased the RANKL-induced MAPKs signaling pathway, including JNK and ERK1/2 posphorylation while had no obvious effects on p38 activation. Finally, SA suppressed the NF-κB and MAPKs subsequent gene expression of NFATc1 and c-Fos. In vivo studies, SA inhibited osteoclast function and exhibited bone protection effect in wear-particle-induced bone erosion model. Taken together, SA could attenuate osteoclast formation and wear particle-induced osteolysis by mediating RANKL signaling pathways. These data indicated that SA is a promising therapeutic natural compound for the treatment of osteoclast-related prosthesis loosening.

Stress responses during ageing: molecular pathways regulating protein homeostasis.

Science.gov (United States)

Kyriakakis, Emmanouil; Princz, Andrea; Tavernarakis, Nektarios

2015-01-01

The ageing process is characterized by deterioration of physiological function accompanied by frailty and ageing-associated diseases. The most broadly and well-studied pathways influencing ageing are the insulin/insulin-like growth factor 1 signaling pathway and the dietary restriction pathway. Recent studies in diverse organisms have also delineated emerging pathways, which collectively or independently contribute to ageing. Among them the proteostatic-stress-response networks, inextricably affect normal ageing by maintaining or restoring protein homeostasis to preserve proper cellular and organismal function. In this chapter, we survey the involvement of heat stress and endoplasmic reticulum stress responses in the regulation of longevity, placing emphasis on the cross talk between different response mechanisms and their systemic effects. We further discuss novel insights relevant to the molecular pathways mediating these stress responses that may facilitate the development of innovative interventions targeting age-related pathologies such as diabetes, cancer, cardiovascular and neurodegenerative diseases.

Activation of human natural killer cells by the soluble form of cellular prion protein

International Nuclear Information System (INIS)

Seong, Yeon-Jae; Sung, Pil Soo; Jang, Young-Soon; Choi, Young Joon; Park, Bum-Chan; Park, Su-Hyung; Park, Young Woo; Shin, Eui-Cheol

2015-01-01

Cellular prion protein (PrP C ) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrP C in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrP C protein on human natural killer (NK) cells. Recombinant soluble PrP C protein was generated by fusion of human PrP C with the Fc portion of human IgG 1 (PrP C -Fc). PrP C -Fc binds to the surface of human NK cells, particularly to CD56 dim NK cells. PrP C -Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrP C -Fc facilitated the IL-15-induced proliferation of NK cells. PrP C -Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrP C -Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrP C -Fc protein activates human NK cells via the ERK and JNK signaling pathways. - Highlights: • Recombinant soluble PrP C (PrP C -Fc) was generated by fusion of human PrP C with IgG1 Fc portion. • PrP C -Fc protein induces the production of cytokines and degranulation from human NK cells. • PrP C -Fc protein enhances the IL-15-induced proliferation of human NK cells. • PrP C -Fc protein activates human NK cells via the ERK and JNK signaling pathways

Nicotine promotes cell proliferation and induces resistance to cisplatin by α7 nicotinic acetylcholine receptor‑mediated activation in Raw264.7 and El4 cells.

Science.gov (United States)

Wang, Yan Yan; Liu, Yao; Ni, Xiao Yan; Bai, Zhen Huan; Chen, Qiong Yun; Zhang, Ye; Gao, Feng Guang

2014-03-01

Although nicotine is a risk factor for carcinogenesis and atherosclerosis, epidemiological data indicate that nicotine has therapeutic benefits in treating Alzheimer's disease. Our previous studies also showed that nicotine-treated dendritic cells have potential antitumor effects. Hence, the precise effects of nicotine on the biological characterizations of cells are controversial. The aim of the present study was to assess the roles of α7 nicotinic acetylcholine receptors (nAChRs), Erk1/2-p38-JNK and PI3K-Akt pathway in nicotine-mediated proliferation and anti-apoptosis effects. The results firstly showed that nicotine treatment clearly augmented cell viability and upregulated PCNA expression in both Raw264.7 and El4 cells. Meanwhile, nicotine afforded protection against cisplatin-induced toxicity through inhibiting caspase-3 activation and upregulating anti-apoptotic protein expression. Further exploration demonstrated that nicotine efficiently abolished cisplatin-promoted mitochondria translocation of Bax and the release of cytochrome c. The pretreatment of α-bungarotoxin and tubocurarine chloride significantly attenuated nicotine-augmented cell viability, abolished caspase-3 activation and α7 nAChR upregulation. Both Erk-JNK-p38 and PI3K-Akt signaling pathways could be activated by nicotine treatment in Raw264.7 and El4 cells. Notably, when Erk-JNK and PI3K-Akt activities were inhibited, nicotine-augmented cell proliferation and anti-apoptotic effects were abolished accordingly. The results presented here indicate that nicotine could achieve α7 nAChR-mediated proliferation and anti-apoptotic effects by activating Erk-JNK and PI3K-Akt pathways respectively, providing potential therapeutic molecules to deal with smoking-associated human diseases.

Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

Directory of Open Access Journals (Sweden)

François Renoz

Full Text Available In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

Identification of a c-Jun N-terminal kinase-2-dependent signal amplification cascade that regulates c-Myc levels in ras transformation

DEFF Research Database (Denmark)

Mathiasen, D.P.; Egebjerg, C.; Andersen, S.H.

2012-01-01

are essential for ras transformation. Previous studies show that ERK-mediated serine 62 phosphorylation protects c-Myc from proteasomal degradation. ERK is, however, not alone sufficient to stabilize c-Myc but requires the cooperation of cancerous inhibitor of protein phosphatase 2A (CIP2A), an oncogene...... that counteracts protein phosphatase 2A-mediated dephosphorylation of c-Myc. Here we show that JNK2 regulates Cip2a transcription via ATF2. ATF2 and c-Myc cooperate to activate the transcription of ATF3. Remarkably, not only ectopic JNK2, but also ectopic ATF2, CIP2A, c-Myc and ATF3 are sufficient to rescue...... the defective ras transformation of JNK2-deficient cells. Thus, these data identify the key signal converging point of JNK2 and ERK pathways and underline the central role of CIP2A in ras transformation.Oncogene advance online publication, 27 June 2011; doi:10.1038/onc.2011.230....

miR-126-5p by direct targeting of JNK-interacting protein-2 (JIP-2) plays a key role in Theileria-infected macrophage virulence

KAUST Repository

Haidar, Malak

2018-03-23

Theileria annulata is an apicomplexan parasite that infects and transforms bovine macrophages that disseminate throughout the animal causing a leukaemia-like disease called tropical theileriosis. Using deep RNAseq of T. annulata-infected B cells and macrophages we identify a set of microRNAs induced by infection, whose expression diminishes upon loss of the hyper-disseminating phenotype of virulent transformed macrophages. We describe how infection-induced upregulation of miR-126-5p ablates JIP-2 expression to release cytosolic JNK to translocate to the nucleus and trans-activate AP-1-driven transcription of mmp9 to promote tumour dissemination. In non-disseminating attenuated macrophages miR-126-5p levels drop, JIP-2 levels increase, JNK1 is retained in the cytosol leading to decreased c-Jun phosphorylation and dampened AP-1-driven mmp9 transcription. We show that variation in miR-126-5p levels depends on the tyrosine phosphorylation status of AGO2 that is regulated by Grb2-recruitment of PTP1B. In attenuated macrophages Grb2 levels drop resulting in less PTP1B recruitment, greater AGO2 phosphorylation, less miR-126-5p associated with AGO2 and a consequent rise in JIP-2 levels. Changes in miR-126-5p levels therefore, underpin both the virulent hyper-dissemination and the attenuated dissemination of T. annulata-infected macrophages.

Odontella aurita-enriched diet prevents high fat diet-induced liver insulin resistance.

Science.gov (United States)

Amine, Hamza; Benomar, Yacir; Haimeur, Adil; Messaouri, Hafida; Meskini, Nadia; Taouis, Mohammed

2016-01-01

The beneficial effect of polyunsaturated omega-3 fatty acid (w-3 FA) consumption regarding cardiovascular diseases, insulin resistance and inflammation has been widely reported. Fish oil is considered as the main source of commercialized w-3 FAs, and other alternative sources have been reported such as linseed or microalgae. However, despite numerous reports, the underlying mechanisms of action of w-3 FAs on insulin resistance are still not clearly established, especially those from microalgae. Here, we report that Odontella aurita, a microalga rich in w-3 FAs eicosapentaenoic acid, prevents high fat diet-induced insulin resistance and inflammation in the liver of Wistar rats. Indeed, a high fat diet (HFD) increased plasma insulin levels associated with the impairment of insulin receptor signaling and the up-regulation of toll-like receptor 4 (TLR4) expressions. Importantly, Odontella aurita-enriched HFD (HFOA) reduces body weight and plasma insulin levels and maintains normal insulin receptor expression and responsiveness. Furthermore, HFOA decreased TLR4 expression, JNK/p38 phosphorylation and pro-inflammatory factors. In conclusion, we demonstrate for the first time, to our knowledge, that diet supplementation with whole Ondontella aurita overcomes HFD-induced insulin resistance through the inhibition of TLR4/JNK/p38 MAP kinase signaling pathways. © 2016 Society for Endocrinology.

Identification of Chemical Inhibitors of β-Catenin-Driven Liver Tumorigenesis in Zebrafish.

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Kimberley J Evason

2015-07-01

Full Text Available Hepatocellular carcinoma (HCC is one of the most lethal human cancers. The search for targeted treatments has been hampered by the lack of relevant animal models for the genetically diverse subsets of HCC, including the 20-40% of HCCs that are defined by activating mutations in the gene encoding β-catenin. To address this chemotherapeutic challenge, we created and characterized transgenic zebrafish expressing hepatocyte-specific activated β-catenin. By 2 months post fertilization (mpf, 33% of transgenic zebrafish developed HCC in their livers, and 78% and 80% of transgenic zebrafish showed HCC at 6 and 12 mpf, respectively. As expected for a malignant process, transgenic zebrafish showed significantly decreased mean adult survival compared to non-transgenic control siblings. Using this novel transgenic model, we screened for druggable pathways that mediate β-catenin-induced liver growth and identified two c-Jun N-terminal kinase (JNK inhibitors and two antidepressants (one tricyclic antidepressant, amitriptyline, and one selective serotonin reuptake inhibitor that suppressed this phenotype. We further found that activated β-catenin was associated with JNK pathway hyperactivation in zebrafish and in human HCC. In zebrafish larvae, JNK inhibition decreased liver size specifically in the presence of activated β-catenin. The β-catenin-specific growth-inhibitory effect of targeting JNK was conserved in human liver cancer cells. Our other class of hits, antidepressants, has been used in patient treatment for decades, raising the exciting possibility that these drugs could potentially be repurposed for cancer treatment. In support of this proposal, we found that amitriptyline decreased tumor burden in a mouse HCC model. Our studies implicate JNK inhibitors and antidepressants as potential therapeutics for β-catenin-induced liver tumors.

Can we safely target the WNT pathway?

Science.gov (United States)

Kahn, Michael

2015-01-01

WNT–β-catenin signalling is involved in a multitude of developmental processes and the maintenance of adult tissue homeostasis by regulating cell proliferation, differentiation, migration, genetic stability and apoptosis, as well as by maintaining adult stem cells in a pluripotent state. Not surprisingly, aberrant regulation of this pathway is therefore associated with a variety of diseases, including cancer, fibrosis and neurodegeneration. Despite this knowledge, therapeutic agents specifically targeting the WNT pathway have only recently entered clinical trials and none has yet been approved. This Review examines the problems and potential solutions to this vexing situation and attempts to bring them into perspective. PMID:24981364

Polysaccharide of Dendrobium huoshanense activates macrophages via toll-like receptor 4-mediated signaling pathways.

Science.gov (United States)

Xie, Song-Zi; Hao, Ran; Zha, Xue-Qiang; Pan, Li-Hua; Liu, Jian; Luo, Jian-Ping

2016-08-01

The present work aimed at investigating the pattern recognition receptor (PRR) and immunostimulatory mechanism of a purified Dendrobium huoshanense polysaccharide (DHP). We found that DHP could bind to the surface of macrophages and stimulate macrophages to secrete NO, TNF-α and IL-1β. To unravel the mechanism for the binding of DHP to macrophages, flow cytometry, confocal laser-scanning microscopy, affinity electrophoresis, SDS-PAGE and western blotting were employed to verify the type of PRR responsible for the recognition of DHP by RAW264.7 macrophages and peritoneal macrophages of C3H/HeN and C3H/HeJ macrophages. Results showed that toll-like receptor 4 (TLR4) was an essential receptor for macrophages to directly bind DHP. Further, the phosphorylation of ERK, JNK, Akt and p38 were observed to be time-dependently promoted by DHP, as well as the nuclear translocation of NF-κB p65. These results suggest that DHP activates macrophages via its direct binding to TLR4 to trigger TLR4 signaling pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

c-Jun amino-terminal kinase-1 mediates glucose-responsive upregulation of the RNA editing enzyme ADAR2 in pancreatic beta-cells.

Directory of Open Access Journals (Sweden)

Liu Yang

Full Text Available A-to-I RNA editing catalyzed by the two main members of the adenosine deaminase acting on RNA (ADAR family, ADAR1 and ADAR2, represents a RNA-based recoding mechanism implicated in a variety of cellular processes. Previously we have demonstrated that the expression of ADAR2 in pancreatic islet β-cells is responsive to the metabolic cues and ADAR2 deficiency affects regulated cellular exocytosis. To investigate the molecular mechanism by which ADAR2 is metabolically regulated, we found that in cultured β-cells and primary islets, the stress-activated protein kinase JNK1 mediates the upregulation of ADAR2 in response to changes of the nutritional state. In parallel with glucose induction of ADAR2 expression, JNK phosphorylation was concurrently increased in insulin-secreting INS-1 β-cells. Pharmacological inhibition of JNKs or siRNA knockdown of the expression of JNK1 prominently suppressed glucose-augmented ADAR2 expression, resulting in decreased efficiency of ADAR2 auto-editing. Consistently, the mRNA expression of Adar2 was selectively reduced in the islets from JNK1 null mice in comparison with that of wild-type littermates or JNK2 null mice, and ablation of JNK1 diminished high-fat diet-induced Adar2 expression in the islets from JNK1 null mice. Furthermore, promoter analysis of the mouse Adar2 gene identified a glucose-responsive region and revealed the transcription factor c-Jun as a driver of Adar2 transcription. Taken together, these results demonstrate that JNK1 serves as a crucial component in mediating glucose-responsive upregulation of ADAR2 expression in pancreatic β-cells. Thus, the JNK1 pathway may be functionally linked to the nutrient-sensing actions of ADAR2-mediated RNA editing in professional secretory cells.

Microenvironment Dependent Photobiomodulation on Function-Specific Signal Transduction Pathways

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Timon Cheng-Yi Liu

2014-01-01

Full Text Available Cellular photobiomodulation on a cellular function has been shown to be homeostatic. Its function-specific pathway mechanism would be further discussed in this paper. The signal transduction pathways maintaining a normal function in its function-specific homeostasis (FSH, resisting the activation of many other irrelative signal transduction pathways, are so sparse that it can be supposed that there may be normal function-specific signal transduction pathways (NSPs. A low level laser irradiation or monochromatic light may promote the activation of partially activated NSP and/or its redundant NSP so that it may induce the second-order phase transition of a function from its dysfunctional one far from its FSH to its normal one in a function-specific microenvironment and may also induce the first-order functional phase transition of the normal function from low level to high level.

Pratol, an O-Methylated Flavone, Induces Melanogenesis in B16F10 Melanoma Cells via p-p38 and p-JNK Upregulation

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You Chul Chung

2017-10-01

Full Text Available Tyrosinase is the rate-limiting enzyme critical for melanin synthesis. It controls pigmentation in the skin. Activation of tyrosinase is currently the most common approach in the development of tanning and haircare products. Pratol is a 7-hydroxy-4-methoxyflavone found in Trifolium pratense. In this study, we investigated the effects of pratol on melanogenesis. We also studied the mechanism of action of pratol in B16F10 mouse melanoma cells. The cells were treated with various concentrations (6.25, 12.5, 25, and 50 μM of pratol to observe its effects. The results showed that pratol significantly increased melanin content and tyrosinase activity in the cells without being cytotoxic. In addition, pratol strongly increased the expression of tyrosinase and tyrosinase-related protein-1 and 2 by enhancing the expression of microphthalmia-associated transcription factor. Furthermore, pratol stimulated melanogenesis via the phosphorylation of p38, c-Jun N-terminal kinases (JNK, and extracellular signal–regulated kinase (ERK. The findings from an assay searching for the inhibitor revealed that SB203580 (a specific p38 inhibitor or SP600125 (a p-JNK inhibitor attenuated pratol-induced cellular tyrosinase activity whereas PD98059 (an ERK inhibitor did not. Additionally, pratol interfered with the phosphorylation of p-AKT. We also found that pratol-induced melanogenesis was reversed by H89, which is a specific protein kinase A inhibitor. The results suggest that, owing to its multi-functional properties, pratol may be a potential tanning agent or a therapeutic agent for hair depigmentation in the cosmetic industry.

Ergonomics Contribution in Maintainability

Science.gov (United States)

Teymourian, Kiumars; Seneviratne, Dammika; Galar, Diego

2017-09-01

The objective of this paper is to describe an ergonomics contribution in maintainability. The economical designs, inputs and training helps to increase the maintainability indicators for industrial devices. This analysis can be helpful, among other cases, to compare systems, to achieve a better design regarding maintainability requirements, to improve this maintainability under specific industrial environment and to foresee maintainability problems due to eventual changes in a device operation conditions. With this purpose, this work first introduces the notion of ergonomics and human factors, maintainability and the implementation of assessment of human postures, including some important postures to perform maintenance activities. A simulation approach is used to identify the critical posture of the maintenance personnel and implements the defined postures with minimal loads on the personnel who use the equipment in a practical scenario. The simulation inputs are given to the designers to improve the workplace/equipment in order to high level of maintainability. Finally, the work concludes summarizing the more significant aspects and suggesting future research.

Betalactam antibiotics affect human dendritic cells maturation through MAPK/NF-kB systems. Role in allergic reactions to drugs

International Nuclear Information System (INIS)

Lopez, Soledad; Gomez, Enrique; Torres, Maria J.; Pozo, David; Fernandez, Tahia D.; Ariza, Adriana; Sanz, Maria L.; Blanca, Miguel; Mayorga, Cristobalina

2015-01-01

The mechanisms leading to drug allergy in predisposed patients, especially those related to T-cell-mediated drug hypersensitivity, are not well understood. A key event in allergic reactions to drugs is the maturation process undergone by dendritic cells (DCs). Although amoxicillin (AX) has been reported to interact and maturate DCs from patients with AX-induced delayed-type hypersensitivity, the cell signaling pathways related to AX-mediated DC maturation have not been elucidated. We sought to determine the role of the MAPK and NF-κΒ pathways on AX-induced DC maturation and functional status. For that purpose, in monocyte-derived-DCs from AX-delayed allergic patients and tolerant subjects, we analyzed the activation pattern of p38MAPK, JNK, and ERK signaling and the NF-κB, maturation markers as well as endocytosis and allostimulatory capacities driven by AX-stimulated-DCs. Our data reveal that AX induces an increase in the phosphorylation levels of the three MAPKsand activated NF-κB in DCs from allergic patients. Moreover, the inhibition of these pathways prevents the up-regulation of surface molecules induced by AX. Additionally, we observed that the allostimulatory capacity and the endocytosis down-regulation in AX-stimulated-DCs from allergic patients depend on JNK and NF-κB activities. Taken together, our data shed light for the first time on the main signaling pathways involved in DC maturation from AX-delayed allergic patient. - Highlights: • The cell signaling pathways related to drug-mediated DC maturation were tested. • Amoxicillin induces activation of MAPK and NF-κB in DCs from allergic patients. • The inhibition of these pathways prevents the up-regulation of DC surface molecules. • Their allostimulatory and endocytosis capacities depend on JNK and NF-κB activities. • The low involvement of p38-MAPK could be the cause of an incomplete DC maturation.

Betalactam antibiotics affect human dendritic cells maturation through MAPK/NF-kB systems. Role in allergic reactions to drugs

Energy Technology Data Exchange (ETDEWEB)

Lopez, Soledad [CABIMER-Andalusian Center for Molecular Biology and Regenerative Medicine, Seville (Spain); Department of Medical Biochemistry, Molecular Biology and Immunology, The University of Seville Medical School, Seville (Spain); Gomez, Enrique [Research Laboratory, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Torres, Maria J. [Allergy Service, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Pozo, David [CABIMER-Andalusian Center for Molecular Biology and Regenerative Medicine, Seville (Spain); Department of Medical Biochemistry, Molecular Biology and Immunology, The University of Seville Medical School, Seville (Spain); Fernandez, Tahia D.; Ariza, Adriana [Research Laboratory, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Sanz, Maria L. [Department of Allergology and Clinical Immunology, University Clinic of Navarra, Pamplona (Spain); Blanca, Miguel [Allergy Service, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Mayorga, Cristobalina, E-mail: lina.mayorga@ibima.eu [Research Laboratory, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Allergy Service, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain)

2015-11-01

The mechanisms leading to drug allergy in predisposed patients, especially those related to T-cell-mediated drug hypersensitivity, are not well understood. A key event in allergic reactions to drugs is the maturation process undergone by dendritic cells (DCs). Although amoxicillin (AX) has been reported to interact and maturate DCs from patients with AX-induced delayed-type hypersensitivity, the cell signaling pathways related to AX-mediated DC maturation have not been elucidated. We sought to determine the role of the MAPK and NF-κΒ pathways on AX-induced DC maturation and functional status. For that purpose, in monocyte-derived-DCs from AX-delayed allergic patients and tolerant subjects, we analyzed the activation pattern of p38MAPK, JNK, and ERK signaling and the NF-κB, maturation markers as well as endocytosis and allostimulatory capacities driven by AX-stimulated-DCs. Our data reveal that AX induces an increase in the phosphorylation levels of the three MAPKsand activated NF-κB in DCs from allergic patients. Moreover, the inhibition of these pathways prevents the up-regulation of surface molecules induced by AX. Additionally, we observed that the allostimulatory capacity and the endocytosis down-regulation in AX-stimulated-DCs from allergic patients depend on JNK and NF-κB activities. Taken together, our data shed light for the first time on the main signaling pathways involved in DC maturation from AX-delayed allergic patient. - Highlights: • The cell signaling pathways related to drug-mediated DC maturation were tested. • Amoxicillin induces activation of MAPK and NF-κB in DCs from allergic patients. • The inhibition of these pathways prevents the up-regulation of DC surface molecules. • Their allostimulatory and endocytosis capacities depend on JNK and NF-κB activities. • The low involvement of p38-MAPK could be the cause of an incomplete DC maturation.

Barium inhibits arsenic-mediated apoptotic cell death in human squamous cell carcinoma cells.

Science.gov (United States)

Yajima, Ichiro; Uemura, Noriyuki; Nizam, Saika; Khalequzzaman, Md; Thang, Nguyen D; Kumasaka, Mayuko Y; Akhand, Anwarul A; Shekhar, Hossain U; Nakajima, Tamie; Kato, Masashi

2012-06-01

Our fieldwork showed more than 1 μM (145.1 μg/L) barium in about 3 μM (210.7 μg/L) arsenic-polluted drinking well water (n = 72) in cancer-prone areas in Bangladesh, while the mean concentrations of nine other elements in the water were less than 3 μg/L. The types of cancer include squamous cell carcinomas (SCC). We hypothesized that barium modulates arsenic-mediated biological effects, and we examined the effect of barium (1 μM) on arsenic (3 μM)-mediated apoptotic cell death of human HSC-5 and A431 SCC cells in vitro. Arsenic promoted SCC apoptosis with increased reactive oxygen species (ROS) production and JNK1/2 and caspase-3 activation (apoptotic pathway). In contrast, arsenic also inhibited SCC apoptosis with increased NF-κB activity and X-linked inhibitor of apoptosis protein (XIAP) expression level and decreased JNK activity (antiapoptotic pathway). These results suggest that arsenic bidirectionally promotes apoptotic and antiapoptotic pathways in SCC cells. Interestingly, barium in the presence of arsenic increased NF-κB activity and XIAP expression and decreased JNK activity without affecting ROS production, resulting in the inhibition of the arsenic-mediated apoptotic pathway. Since the anticancer effect of arsenic is mainly dependent on cancer apoptosis, barium-mediated inhibition of arsenic-induced apoptosis may promote progression of SCC in patients in Bangladesh who keep drinking barium and arsenic-polluted water after the development of cancer. Thus, we newly showed that barium in the presence of arsenic might inhibit arsenic-mediated cancer apoptosis with the modulation of the balance between arsenic-mediated promotive and suppressive apoptotic pathways.