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Sample records for erk signalling pathway

  1. Homocysteine enhances MMP-9 production in murine macrophages via ERK and Akt signaling pathways

    International Nuclear Information System (INIS)

    Lee, Seung Jin; Lee, Yi Sle; Seo, Kyo Won; Bae, Jin Ung; Kim, Gyu Hee; Park, So Youn; Kim, Chi Dae

    2012-01-01

    Homocysteine (Hcy) at elevated levels is an independent risk factor of cardiovascular diseases, including atherosclerosis. In the present study, we investigated the effect of Hcy on the production of matrix metalloproteinases (MMP) in murine macrophages. Among the MMP known to regulate the activities of collagenase and gelatinase, Hcy exclusively increased the gelatinolytic activity of MMP-9 in J774A.1 cells as well as in mouse peritoneal macrophages. Furthermore, this activity was found to be correlated with Western blot findings in J774A.1 cells, which showed that MMP-9 expression was concentration- and time-dependently increased by Hcy. Inhibition of the ERK and Akt pathways led to a significant decrease in Hcy-induced MMP-9 expression, and combined treatment with inhibitors of the ERK and Akt pathways showed an additive effects. Activity assays for ERK and Akt showed that Hcy increased the phosphorylation of both, but these phosphorylation were not affected by inhibitors of the Akt and ERK pathways. In line with these findings, the molecular inhibition of ERK and Akt using siRNA did not affect the Hcy-induced phosphorylation of Akt and ERK, respectively. Taken together, these findings suggest that Hcy enhances MMP-9 production in murine macrophages by separately activating the ERK and Akt signaling pathways. -- Highlights: ► Homocysteine (Hcy) induced MMP-9 production in murine macrophages. ► Hcy induced MMP-9 production through ERK and Akt signaling pathways. ► ERK and Akt signaling pathways were activated by Hcy in murine macrophages. ► ERK and Akt pathways were additively act on Hcy-induced MMP-9 production. ► Hcy enhances MMP-9 production in macrophages via activation of ERK and Akt signaling pathways in an independent manner.

  2. Homocysteine enhances MMP-9 production in murine macrophages via ERK and Akt signaling pathways

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    Lee, Seung Jin; Lee, Yi Sle; Seo, Kyo Won; Bae, Jin Ung; Kim, Gyu Hee; Park, So Youn; Kim, Chi Dae, E-mail: chidkim@pusan.ac.kr

    2012-04-01

    Homocysteine (Hcy) at elevated levels is an independent risk factor of cardiovascular diseases, including atherosclerosis. In the present study, we investigated the effect of Hcy on the production of matrix metalloproteinases (MMP) in murine macrophages. Among the MMP known to regulate the activities of collagenase and gelatinase, Hcy exclusively increased the gelatinolytic activity of MMP-9 in J774A.1 cells as well as in mouse peritoneal macrophages. Furthermore, this activity was found to be correlated with Western blot findings in J774A.1 cells, which showed that MMP-9 expression was concentration- and time-dependently increased by Hcy. Inhibition of the ERK and Akt pathways led to a significant decrease in Hcy-induced MMP-9 expression, and combined treatment with inhibitors of the ERK and Akt pathways showed an additive effects. Activity assays for ERK and Akt showed that Hcy increased the phosphorylation of both, but these phosphorylation were not affected by inhibitors of the Akt and ERK pathways. In line with these findings, the molecular inhibition of ERK and Akt using siRNA did not affect the Hcy-induced phosphorylation of Akt and ERK, respectively. Taken together, these findings suggest that Hcy enhances MMP-9 production in murine macrophages by separately activating the ERK and Akt signaling pathways. -- Highlights: ► Homocysteine (Hcy) induced MMP-9 production in murine macrophages. ► Hcy induced MMP-9 production through ERK and Akt signaling pathways. ► ERK and Akt signaling pathways were activated by Hcy in murine macrophages. ► ERK and Akt pathways were additively act on Hcy-induced MMP-9 production. ► Hcy enhances MMP-9 production in macrophages via activation of ERK and Akt signaling pathways in an independent manner.

  3. [Effects of electromagnetic radiation on RAF/MEK/ERK signaling pathway in rats hippocampus].

    Science.gov (United States)

    Zuo, Hong-yan; Wang, De-wen; Peng, Rui-yun; Wang, Shui-ming; Gao, Ya-bing; Xu, Xin-ping; Ma, Jun-Jie

    2009-05-01

    To study the development of changes for signaling molecules related to Raf/MEK/ERK pathway in hippocampus of rats after electromagnetic radiation, and investigate the mechanisms of radiation injury. Rats were exposed to X-HPM, S-HPM and EMP radiation source respectively, and animal model of electromagnetic radiation was established. Western blot was used to detect the expression of Raf-1, phosphorylated Raf-1 and phospholylated ERK. The expression of Raf-1 down-regulated during 6 h-14 d after radiation, most significantly at 7 d, and recovered at 28 d. There was no significant difference between the radiation groups. The expression of phosphorylated Raf-1 and phosphorylated ERK both up-regulated at 6 h and 7 d after radiation, more significantly at 6 h, and the two microwave groups were more serious for phosphorylated ERK. During 6 h-14 d after S-HPM radiation, the expression of phosphorylated Raf-1 increased continuously, but phosphorylated ERK changed wavily, 6 h and 7 d were expression peak. Raf/MEK/ERK signaling pathway participates in the hippocampus injury induced by electromagnetic radiation. The excessive activation of ERK pathway may result in the apoptosis and death of neurons, which is the important mechanism of recognition disfunction caused by electromagnetic radiation.

  4. Dynamics and control of the ERK signaling pathway: Sensitivity, bistability, and oscillations.

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    Arkun, Yaman; Yasemi, Mohammadreza

    2018-01-01

    Cell signaling is the process by which extracellular information is transmitted into the cell to perform useful biological functions. The ERK (extracellular-signal-regulated kinase) signaling controls several cellular processes such as cell growth, proliferation, differentiation and apoptosis. The ERK signaling pathway considered in this work starts with an extracellular stimulus and ends with activated (double phosphorylated) ERK which gets translocated into the nucleus. We model and analyze this complex pathway by decomposing it into three functional subsystems. The first subsystem spans the initial part of the pathway from the extracellular growth factor to the formation of the SOS complex, ShC-Grb2-SOS. The second subsystem includes the activation of Ras which is mediated by the SOS complex. This is followed by the MAPK subsystem (or the Raf-MEK-ERK pathway) which produces the double phosphorylated ERK upon being activated by Ras. Although separate models exist in the literature at the subsystems level, a comprehensive model for the complete system including the important regulatory feedback loops is missing. Our dynamic model combines the existing subsystem models and studies their steady-state and dynamic interactions under feedback. We establish conditions under which bistability and oscillations exist for this important pathway. In particular, we show how the negative and positive feedback loops affect the dynamic characteristics that determine the cellular outcome.

  5. Eight paths of ERK1/2 signalling pathway regulating hepatocyte ...

    Indian Academy of Sciences (India)

    2011-12-05

    Dec 5, 2011 ... This study aims at exploring which paths of ERK1/2 signalling pathway participate in the regulation of rat .... total RNA was used to synthesize the first strand of cDNA. ..... stem cells contribute to regeneration of injured liver.

  6. The ERK5 and ERK1/2 signaling pathways play opposing regulatory roles during chondrogenesis of adult human bone marrow-derived multipotent progenitor cells.

    Science.gov (United States)

    Bobick, Brent E; Matsche, Alexander I; Chen, Faye H; Tuan, Rocky S

    2010-07-01

    Adult human bone marrow-derived multipotent progenitor cells (MPCs) are able to differentiate into a variety of specialized cell types, including chondrocytes, and are considered a promising candidate cell source for use in cartilage tissue engineering. In this study, we examined the regulation of MPC chondrogenesis by mitogen-activated protein kinases in an attempt to better understand how to generate hyaline cartilage in the laboratory that more closely resembles native tissue. Specifically, we employed the high-density pellet culture model system to assess the roles of ERK5 and ERK1/2 pathway signaling in MPC chondrogenesis. Western blotting revealed that high levels of ERK5 phosphorylation correlate with low levels of MPC chondrogenesis and that as TGF-beta 3-enhanced MPC chondrogenesis proceeds, phospho-ERK5 levels steadily decline. Conversely, levels of phospho-ERK1/2 paralleled the progression of MPC chondrogenesis. siRNA-mediated knockdown of ERK5 pathway components MEK5 and ERK5 resulted in increased MPC pellet mRNA transcript levels of the cartilage-characteristic marker genes SOX9, COL2A1, AGC, L-SOX5, and SOX6, as well as enhanced accumulation of SOX9 protein, collagen type II protein, and Alcian blue-stainable proteoglycan. In contrast, knockdown of ERK1/2 pathway members MEK1 and ERK1 decreased expression of all chondrogenic markers tested. Finally, overexpression of MEK5 and ERK5 also depressed MPC chondrogenesis, as indicated by diminished activity of a co-transfected collagen II promoter-luciferase reporter construct. In conclusion, our results suggest a novel role for the ERK5 pathway as an important negative regulator of adult human MPC chondrogenesis and illustrate that the ERK5 and ERK1/2 kinase cascades play opposing roles regulating MPC cartilage formation. (c) 2010 Wiley-Liss, Inc.

  7. Sotos syndrome is associated with deregulation of the MAPK/ERK-signaling pathway.

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    Remco Visser

    Full Text Available Sotos syndrome (SoS is characterized by tall stature, characteristic craniofacial features and mental retardation. It is caused by haploinsufficiency of the NSD1 gene. In this study, our objective was to identify downstream effectors of NSD1 and to map these effectors in signaling pathways associated with growth. Genome-wide expression studies were performed on dermal fibroblasts from SoS patients with a confirmed NSD1 abnormality. To substantiate those results, phosphorylation, siRNA and transfection experiments were performed. A significant association was demonstrated with the Mitogen-Activated Protein Kinase (MAPK pathway. Members of the fibroblast growth factor family such as FGF4 and FGF13 contributed strongly to the differential expression in this pathway. In addition, a diminished activity state of the MAPK/ERK pathway was demonstrated in SoS. The Ras Interacting Protein 1 (RASIP1 was identified to exhibit upregulated expression in SoS. It was shown that RASIP1 dose-dependently potentiated bFGF induced expression of the MAPK responsive SBE reporter providing further support for a link between NSD1 and the MAPK/ERK signaling pathway. Additionally, we demonstrated NSD1 expression in the terminally differentiated hypertrophic chondrocytes of normal human epiphyseal growth plates. In short stature syndromes such as hypochondroplasia and Noonan syndrome, the activation level of the FGF-MAPK/ERK-pathway in epiphyseal growth plates is a determining factor for statural growth. In analogy, we propose that deregulation of the MAPK/ERK pathway in SoS results in altered hypertrophic differentiation of NSD1 expressing chondrocytes and may be a determining factor in statural overgrowth and accelerated skeletal maturation in SoS.

  8. The expression of ER, PR in endometrial cancer and analysis of their correlation with ERK signaling pathway.

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    Luo, Lan; Xu, Lina; Tang, Liang

    2017-12-12

    Endometrial carcinoma (EC) is a common malignant tumor in gynecology. Its incidence and development are closely associated with the levels of estrogenic and progesterone hormone. Extracellular signal-regulated kinase (ERK) signaling pathway abnormity is associated with a variety of tumors. This study detected estrogen receptor (ER), progesterone receptor (PR), ERK1, and ERK2 expression in EC and analyzed their correlations. A total of 40 EC patients in our hospital were selected as test group, while another 40 healthy volunteers were enrolled as control group. ER, PR, ERK1, and ERK2 expression in EC tissue, para-carcinoma tissue, and normal endometrial tissue were detected by immunohistochemistry and Western blot. The positive rate of ER, PR, ERK1, and ERK2 in the test group was 50%, 40%, 60%, and 65%, respectively, which were significantly higher than those in the control (PPR, ERK1, and ERK2 protein expressions in EC cell were significantly higher than those in the control (PPR (PPR, which were correlated with higher levels of ERK1 and ERK2, suggesting they might be involved in the pathogenesis of EC.

  9. Kaempferol induces chondrogenesis in ATDC5 cells through activation of ERK/BMP-2 signaling pathway.

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    Nepal, Manoj; Li, Liang; Cho, Hyoung Kwon; Park, Jong Kun; Soh, Yunjo

    2013-12-01

    Endochondral bone formation occurs when mesenchymal cells condense to differentiate into chondrocytes, the primary cell types of cartilage. The aim of the present study was to identify novel factors regulating chondrogenesis. We investigated whether kaempferol induces chondrogenic differentiation in clonal mouse chondrogenic ATDC5 cells. Kaempferol treatment stimulated the accumulation of cartilage nodules in a dose-dependent manner. Kaempferol-treated ATDC5 cells stained more intensely with alcian blue staining than control cells, suggesting greater synthesis of matrix proteoglycans in the kaempferol-treated cells. Similarly, kaempferol induced greater activation of alkaline phosphatase activity than control cells, and it enhanced the expression of chondrogenic marker genes, such as collagen type I, collagen type X, OCN, Runx2, and Sox9. Kaempferol induced an acute activation of extracellular signal-regulated kinase (ERK) but not c-jun N-terminal kinase or p38 MAP kinase. PD98059, an inhibitor of MAPK/ERK, decreased in stained cells treated with kaempferol. Furthermore, kaempferol greatly expressed the protein and mRNA levels of BMP-2, suggesting chondrogenesis was stimulated via a BMP-2 pathway. Taken together, our results suggest that kaempferol has chondromodulating effects via an ERK/BMP-2 signaling pathway and could potentially be used as a therapeutic agent for bone growth disorders. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Benzoquinone activates the ERK/MAPK signaling pathway via ROS production in HL-60 cells

    International Nuclear Information System (INIS)

    Ruiz-Ramos, Ruben; Cebrian, Mariano E.; Garrido, Efrain

    2005-01-01

    Benzene (BZ) is a class I carcinogen and its oxidation to reactive intermediates is a prerequisite of hematoxicity and myelotoxicity. The generated metabolites include hydroquinone, which is further oxidized to the highly reactive 1,4-benzoquinone (BQ) in bone marrow. Therefore, we explored the mechanisms underlying BQ-induced HL-60 cell proliferation by studying the role of BQ-induced reactive oxygen species (ROS) in the activation of the ERK-MAPK signaling pathway. BQ treatment (0.01-30 μM) showed that doses below 10 μM did not significantly reduce viability. ROS production after 3 μM BQ treatment increased threefold; however, catalase addition reduced ROS generation to basal levels. FACS analysis showed that BQ induced a fivefold increase in the proportion of cells in S-phase. We also observed a high proportion of Bromodeoxyuridine (BrdU) stained cells, indicating a higher DNA synthesis rate. BQ also produced rapid and prolonged phosphorylation of ERK1/2 proteins. Simultaneous treatment with catalase or PD98059, a potent MEK protein inhibitor, reduced cell recruitment into the S-phase and also abolished the ERK1/2 protein phosphorylation induced by BQ, suggesting that MEK/ERK is an important pathway involved in BQ-induced ROS mediated proliferation. The prolonged activation of ERK1/2 contributes to explain the increased S-phase cell recruitment and to understand the leukemogenic processes associated with exposure to benzene metabolites. Thus, the possible mechanism by which BQ induce HL-60 cells to enter the cell cycle and proliferate is linked to ROS production and its growth promoting effects by specific activation of regulating genes known to be activated by redox mechanisms

  11. Magnolin inhibits cell migration and invasion by targeting the ERKs/RSK2 signaling pathway

    International Nuclear Information System (INIS)

    Lee, Cheol-Jung; Lee, Mee-Hyun; Yoo, Sun-Mi; Choi, Kyung-Il; Song, Ji-Hong; Jang, Jeong-Hoon; Oh, Sei-Ryang; Ryu, Hyung-Won; Lee, Hye-Suk; Surh, Young-Joon; Cho, Yong-Yeon

    2015-01-01

    Magnolin is a natural compound abundantly found in Magnolia flos, which has been traditionally used in oriental medicine to treat headaches, nasal congestion and anti-inflammatory reactions. Our recent results have demonstrated that magnolin targets the active pockets of ERK1 and ERK2, which are important signaling molecules in cancer cell metastasis. The aim of this study is to evaluate the effects of magnolin on cell migration and to further explore the molecular mechanisms involved. Magnolin-mediated signaling inhibition was confirmed by Western blotting using RSK2 +/+ and RSK2 −/− MEFs, A549 and NCI-H1975 lung cancer cells, and by NF-κB and Cox-2 promoter luciferase reporter assays. Inhibition of cell migration by magnolin was examined by wound healing and/or Boyden Chamber assays using JB6 Cl41 and A549 human lung cancer cells. The molecular mechanisms involved in cell migration and epithelial-to-mesenchymal transition were determined by zymography, Western blotting, real-time PCR and immunocytofluorescence. Magnolin inhibited NF-κB transactivation activity by suppressing the ERKs/RSK2 signaling pathway. Moreover, magnolin abrogated the increase in EGF-induced COX-2 protein levels and wound healing. In human lung cancer cells such as A549 and NCI-H1975, which harbor constitutive active Ras and EGFR mutants, respectively, magnolin suppressed wound healing and cell invasion as seen by a Boyden chamber assay. In addition, it was observed that magnolin inhibited MMP-2 and −9 gene expression and activity. The knockdown or knockout of RSK2 in A549 lung cancer cells or MEFs revealed that magnolin targeting ERKs/RSK2 signaling suppressed epithelial-to-mesenchymal transition by modulating EMT marker proteins such as N-cadherin, E-cadherin, Snail, Vimentin and MMPs. These results demonstrate that magnolin inhibits cell migration and invasion by targeting the ERKs/RSK2 signaling pathway. The online version of this article (doi:10.1186/s12885-015-1580-7) contains

  12. Sulfuretin Attenuates MPP+-Induced Neurotoxicity through Akt/GSK3β and ERK Signaling Pathways

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    Ramesh Pariyar

    2017-12-01

    Full Text Available Parkinson’s disease (PD is the second most common neurodegenerative disease. It is caused by the death of dopaminergic neurons in the substantia nigra pars compacta. Oxidative stress and mitochondrial dysfunction contribute to the loss of dopaminergic neurons in PD. Sulfuretin is a potent antioxidant that is reported to be beneficial in the treatment of neurodegenerative diseases. In this study, we examined the protective effect of sulfuretin against 1-methyl-4-phenyl pyridinium (MPP+-induced cell model of PD in SH-SY5Y cells and the underlying molecular mechanisms. Sulfuretin significantly decreased MPP+-induced apoptotic cell death, accompanied by a reduction in caspase 3 activity and polyADP-ribose polymerase (PARP cleavage. Furthermore, it attenuated MPP+-induced production of intracellular reactive oxygen species (ROS and disruption of mitochondrial membrane potential (MMP. Consistently, sulfuretin decreased p53 expression and the Bax/Bcl-2 ratio. Moreover, sulfuretin significantly increased the phosphorylation of Akt, GSK3β, and ERK. Pharmacological inhibitors of PI3K/Akt and ERK abolished the cytoprotective effects of sulfuretin against MPP+. An inhibitor of GSK3β mimicked sulfuretin-induced protection against MPP+. Taken together, these results suggest that sulfuretin significantly attenuates MPP+-induced neurotoxicity through Akt/GSK3β and ERK signaling pathways in SH-SY5Y cells. Our findings suggest that sulfuretin might be one of the potential candidates for the treatment of PD.

  13. Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway

    International Nuclear Information System (INIS)

    Huai, Lei; Wang, Cuicui; Zhang, Cuiping; Li, Qihui; Chen, Yirui; Jia, Yujiao; Li, Yan; Xing, Haiyan; Tian, Zheng; Rao, Qing; Wang, Min; Wang, Jianxiang

    2012-01-01

    Highlights: ► Metformin induces differentiation in NB4 and primary APL cells. ► Metformin induces activation of the MEK/ERK signaling pathway in APL cells. ► Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. ► Metformin induces the relocalization and degradation of the PML-RARα fusion protein. ► The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RARα and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.

  14. Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Huai, Lei; Wang, Cuicui; Zhang, Cuiping; Li, Qihui; Chen, Yirui; Jia, Yujiao; Li, Yan; Xing, Haiyan; Tian, Zheng; Rao, Qing; Wang, Min [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer Metformin induces differentiation in NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces activation of the MEK/ERK signaling pathway in APL cells. Black-Right-Pointing-Pointer Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces the relocalization and degradation of the PML-RAR{alpha} fusion protein. Black-Right-Pointing-Pointer The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RAR{alpha} and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.

  15. Lanthanum chloride impairs spatial memory through ERK/MSK1 signaling pathway of hippocampus in rats.

    Science.gov (United States)

    Liu, Huiying; Yang, Jinghua; Liu, Qiufang; Jin, Cuihong; Wu, Shengwen; Lu, Xiaobo; Zheng, Linlin; Xi, Qi; Cai, Yuan

    2014-12-01

    Rare earth elements (REEs) are used in many fields for their diverse physical and chemical properties. Surveys have shown that REEs can impair learning and memory in children and cause neurobehavioral defects in animals. However, the mechanism underlying these impairments has not yet been completely elucidated. Lanthanum (La) is often selected to study the effects of REEs. The aim of this study was to investigate the spatial memory impairments induced by lanthanum chloride (LaCl3) and the probable underlying mechanism. Wistar rats were exposed to LaCl3 in drinking water at 0 % (control, 0 mM), 0.25 % (18 mM), 0.50 % (36 mM), and 1.00 % (72 mM) from birth to 2 months after weaning. LaCl3 considerably impaired the spatial learning and memory of rats in the Morris water maze test, damaged the synaptic ultrastructure and downregulated the expression of p-MEK1/2, p-ERK1/2, p-MSK1, p-CREB, c-FOS and BDNF in the hippocampus. These results indicate that LaCl3 exposure impairs the spatial learning and memory of rats, which may be attributed to disruption of the synaptic ultrastructure and inhibition of the ERK/MSK1 signaling pathway in the hippocampus.

  16. Myostatin regulates miR-431 expression via the Ras-Mek-Erk signaling pathway.

    Science.gov (United States)

    Wu, Rimao; Li, Hu; Li, Tingting; Zhang, Yong; Zhu, Dahai

    2015-05-29

    MicroRNAs (miRNAs) play critical regulatory roles in controlling myogenic development both in vitro and in vivo; however, the molecular mechanisms underlying transcriptional regulation of miRNA genes in skeletal muscle cells are largely unknown. Here, using a microarray hybridization approach, we identified myostatin-regulated miRNA genes in skeletal muscle tissues by systematically searching miRNAs that are differentially expressed between wild-type and myostatin-null mice during development. We found that 116 miRNA genes were differentially expressed in muscles between these mice across different developmental stages. We further characterized myostatin-regulated miR-431 was upregulated in skeletal muscle tissues of myostatin-null mice. In functional studies, we found that overexpression of miR-431 in C2C12 myoblast cells attenuated myostatin-induced suppression of myogenic differentiation. Mechanistic studies further demonstrated that myostatin acted through the Ras-Mek-Erk signaling pathway to transcriptionally regulate miR-431 expression C2C12 cells. Our findings provide new insight into the mechanisms underlying transcriptional regulation of miRNA genes by myostatin during skeletal muscle development. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Ethanol negatively regulates hepatic differentiation of hESC by inhibition of the MAPK/ERK signaling pathway in vitro.

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    Wei Gao

    Full Text Available Alcohol insult triggers complex events in the liver, promoting fibrogenic/inflammatory signals and in more advanced cases, aberrant matrix deposition. It is well accepted that the regenerative capacity of the adult liver is impaired during alcohol injury. The liver progenitor/stem cells have been shown to play an important role in liver regeneration -in response to various chronic injuries; however, the effects of alcohol on stem cell differentiation in the liver are not well understood.We employed hepatic progenitor cells derived from hESCs to study the impact of ethanol on hepatocyte differentiation by exposure of these progenitor cells to ethanol during hepatocyte differentiation.We found that ethanol negatively regulated hepatic differentiation of hESC-derived hepatic progenitor cells in a dose-dependent manner. There was also a moderate cell cycle arrest at G1/S checkpoint in the ethanol treated cells, which is associated with a reduced level of cyclin D1 in these cells. Ethanol treatment specifically inhibited the activation of the ERK but not JNK nor the p38 MAP signaling pathway. At the same time, the WNT signaling pathway was also reduced in the cells exposed to ethanol. Upon evaluating the effects of the inhibitors of these two signaling pathways, we determined that the Erk inhibitor replicated the effects of ethanol on the hepatocyte differentiation and attenuated the WNT/β-catenin signaling, however, inhibitors of WNT only partially replicated the effects of ethanol on the hepatocyte differentiation.Our results demonstrated that ethanol negatively regulated hepatic differentiation of hESC-derived hepatic progenitors through inhibiting the MAPK/ERK signaling pathway, and subsequently attenuating the WNT signaling pathway. Thus, our finding provides a novel insight into the mechanism by which alcohol regulates cell fate selection of hESC-derived hepatic progenitor cells, and the identified pathways may provide therapeutic targets

  18. Odontogenic differentiation of human dental pulp cells by calcium silicate materials stimulating via FGFR/ERK signaling pathway

    International Nuclear Information System (INIS)

    Liu, Chao-Hsin; Hung, Chi-Jr; Huang, Tsui-Hsien; Lin, Chi-Chang; Kao, Chia-Tze; Shie, Ming-You

    2014-01-01

    Bone healing needs a complex interaction of growth factors that establishes an environment for efficient bone formation. We examine how calcium silicate (CS) and tricalcium phosphate (β-TCP) cements influence the behavior of human dental pulp cells (hDPCs) through fibroblast growth factor receptor (FGFR) and active MAPK pathways, in particular ERK. The hDPCs are cultured with β-TCP and CS, after which the cells' viability and odontogenic differentiation markers are determined by using PrestoBlue® assay and western blot, respectively. The effect of small interfering RNA (siRNA) transfection targeting FGFR was also evaluated. The results showed that CS promoted cell proliferation and enhances FGFR expression. It was also found that CS increases ERK and p38 activity in hDPCs, and furthermore, raises the expression and secretion of DSP, and DMP-1. Additionally, statistically significant differences (p < 0.05) have been found in the calcium deposition in si-FGFR transfection and ERK inhibitor between CS and β-TCP; these variations indicated that ERK/MAPK signaling is involved in the silicon-induced odontogenic differentiation of hDPCs. The current study shows that CS substrates play a key role in odontoblastic differentiation of hDPCs through FGFR and modulate ERK/MAPK activation. - Highlights: • CS influences the behavior of hDPCs through fibroblast growth factor receptor. • CS increases ERK and p38 activity in hDPCs. • ERK/MAPK signaling is involved in the Si-induced odontogenic differentiation of hDPCs. • Ca staining shows that FGFR regulates hDPC differentiation on CS, but not on β-TCP

  19. Developmental fluoride exposure influenced rat's splenic development and cell cycle via disruption of the ERK signal pathway.

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    Ma, Yanqin; Zhang, Kankan; Ren, Fengjun; Wang, Jundong

    2017-11-01

    Excessive fluoride exposure has been reported to cause damage to spleen. Neonatal period is characterized by rapid proliferation and differentiation of lymphocyte in the spleen. Children may be more sensitive to the toxicity of fluoride compared to the adults. The aim of this study was to investigate the effects of postnatal exposure (from neonatal period to early adulthood) to fluoride on the development of spleen on a regular basis and the underlying signal pathway. Results showed a marked decrease in spleen weight index and altered morphology in the spleen of fluoride-treated group on PND-84, which reflected fluoride inhibition of the development of spleen. Fluoride exposure induced cell cycle arrest of splenocytes and decreased the mRNA expression of IL-2, which indicated compromised baseline lymphocyte proliferation in the spleen. Time course research from 3-wk-of-age until 12-wk-of-age showed an adverse and cumulative impact of fluoride on the development of spleen. In view of the key role of MAPK/ERK pathway in lymphocyte development, Raf-1/MEK-1/ERK-2/c-fos mRNA expression and ERK/p-ERK protein expression were detected. Results showed despite a transitory increase in mRNA expression from PND-42 to PND-63 in fluoride-treated group, the expression of these genes on PND-84 decreased significantly compared with PND-42 or PND-63. NaF significantly inhibited the phosphorylation of ERK protein on PND-84. Taken together, these results emphasized the vital role of ERK pathway in the interfered development of spleen induced by a high dose of fluoride exposure in rats. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Aspirin Reduces Cardiac Interstitial Fibrosis by Inhibiting Erk1/2-Serpine2 and P-Akt Signalling Pathways.

    Science.gov (United States)

    Li, Xuelian; Wang, GuoYuan; QiLi, MuGe; Liang, HaiHai; Li, TianShi; E, XiaoQiang; Feng, Ying; Zhang, Ying; Liu, Xiao; Qian, Ming; Xu, BoZhi; Shen, ZhiHang; Gitau, Samuel Chege; Zhao, DanDan; Shan, HongLi

    2018-01-01

    Cardiac interstitial fibrosis is an abnormality of various cardiovascular diseases, including myocardial infarction, hypertrophy, and atrial fibrillation, and it can ultimately lead to heart failure. However, there is a lack of practical therapeutic approaches to treat fibrosis and reverse the damage to the heart. The purpose of this study was to investigate the effect of long-term aspirin administration on pressure overload-induced cardiac fibrosis in mice and reveal the underlying mechanisms of aspirin treatment. C57BL/6 mice were subjected to transverse aortic constriction (TAC), and treated with 10 mg·kg-1·day-1 of aspirin for 4 weeks. Masson staining and a collagen content assay were used to detect the effects of aspirin on cardiac fibrosis in vivo and in vitro. Western blot and qRT-PCR were applied to examine the impact of aspirin on extracellular signal-regulated kinases (Erks), p-Akt/β-catenin, SerpinE2, collagen I, and collagen III levels in the mice heart. Aspirin significantly suppressed the expression of α-smooth muscle actin (α-SMA; 1.19±0.19-fold) and collagen I (0.95±0.09-fold) in TAC mice. Aspirin, at doses of 100 and 1000 µM, also significantly suppressed angiotensin II-induced α-SMA and collagen I in cultured CFs. The enhanced phosphorylation of Erk1/2 caused by TAC (p-Erk1, 1.49±0.19-fold; p-Erk2, 1.96±0.68-fold) was suppressed by aspirin (p-Erk1, 1.04±0.15-fold; p-Erk2, 0.87±0.06-fold). SerpinE2 levels were suppressed via the Erk1/2 signalling pathway following treatment with aspirin (1.36±0.12-fold for TAC; 1.06±0.07-fold for aspirin+TAC). The p-Akt and β-catenin levels were also significantly inhibited in vivo and in vitro. Our study reveals a novel mechanism by which aspirin alleviates pressure overload-induced cardiac interstitial fibrosis in TAC mice by suppressing the p-Erk1/2 and p-Akt/β-catenin signalling pathways. © 2018 The Author(s). Published by S. Karger AG, Basel.

  1. Gold nanoparticles stimulate differentiation and mineralization of primary osteoblasts through the ERK/MAPK signaling pathway

    International Nuclear Information System (INIS)

    Zhang, Dawei; Liu, Dandan; Zhang, Jinchao; Fong, Chichun; Yang, Mengsu

    2014-01-01

    Gold nanoparticles (AuNPs) have shown great promise for a variety of applications, including chemistry, biology, and medicine. Recently, AuNPs have found promising applications in cartilage and bone repair. However, to realize the above promised applications, more work needs to be carried out to clarify the interactions between biological systems and AuNPs. In the present study, primary osteoblasts were used to evaluate the biocompatibility of 20-nm and 40-nm AuNPs, including morphology, proliferation, differentiation, gene and protein expression, and the underlying mechanisms. The results demonstrated that AuNPs were taken up by osteoblasts and aggregated in perinuclear compartment and vescular structures, but no morphological changes were observed. AuNPs could significantly promote the proliferation of osteoblasts, enhance the ALP activities, and increase the number of bone nodules and calcium content in vitro. In addition, the expression of BMP-2, Runx-2, OCN and Col-1 was remarkably up-regulated in the presence of AuNPs. It is noteworthy that 20-nm AuNPs are more potent than 40-nm AuNPs in regulating osteoblast activities. Besides, AuNPs increased the level of ERK phosphorylation/total ERK, suggesting the activation of ERK/MAPK pathway is involved in above activities. In conclusion, AuNPs exhibited great biocompatibility with osteoblasts, and have tremendous potential to be used as drug and/or gene delivery carrier for bone and tissue engineering in the future. - Highlights: • AuNPs aggregated in perinuclear compartment and vescular structures of osteoblasts. • AuNPs up-regulated the expression of Runx-2, BMP-2, OCN and Col I of osteoblasts. • AuNPs enhanced osteoblast differentiation by activating the ERK/MAPK pathway. • The size of nanoparticles may be important to exhibit their biological effects. • AuNPs have tremendous potential in bone and tissue engineering in future

  2. Ferulic acid suppresses activation of hepatic stellate cells through ERK1/2 and Smad signaling pathways in vitro.

    Science.gov (United States)

    Xu, Tianjiao; Pan, Zhi; Dong, Miaoxian; Yu, Chunlei; Niu, Yingcai

    2015-01-01

    Hepatic stellate cells (HSCs) are the primary source of matrix components in hepatic fibrosis. Ferulic acid (FA) has antifibrotic potential in renal and cardiac disease. However, whether FA comprises inhibitive effects of HSCs activation remains to be clarified. This study aims at evaluating the hypothesis that FA inhibits extracellular matrix (ECM)-related gene expression by the interruption of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) or/and Smad signaling pathways in HSC-T6. Our results indicated that FA significantly inhibited both viability and activation of HSC-T6 cells in vitro. In addition, we demonstrated, for the first time, that FA dramatically inhibited the expression of α1(I) collagen (Col-I) and fibronectin at levels of transcription and translation. Moreover, FA treatment inhibited Smad transcriptional activity, as evaluated by transient transfection with a plasmid construction containing SMAD response element and the luciferase reporter gene. Furthermore, FA inhibition of HSCs activation involved in both focal adhesion kinase (FAK)-dependent ERK1/2 and Smad signaling pathways with independent manner. Blocking transforming growth factor-β by a neutralizing antibody caused a marked reduction in both ERK1/2 and Smad signaling. These results support FA as an effective therapeutic agent for the prevention and treatment of hepatic fibrosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. The aryl hydrocarbon receptor suppresses osteoblast proliferation and differentiation through the activation of the ERK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Haitao; Du, Yuxuan; Zhang, Xulong; Sun, Ying; Li, Shentao; Dou, Yunpeng [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Li, Zhanguo [Department of Rheumatology and Immunology, Clinical Immunology Center, Peking University People' s Hospital, No. 11 Xizhimen South Street, Beijing 100044 (China); Yuan, Huihui, E-mail: huihui_yuan@163.com [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Zhao, Wenming, E-mail: zhao-wenming@163.com [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China)

    2014-11-01

    Ahr activation is known to be associated with synovitis and exacerbated rheumatoid arthritis (RA), but its contributions to bone loss have not been completely elucidated. Osteoblast proliferation and differentiation are abnormal at the erosion site in RA. Here, we reported that the expression of Ahr was increased in the hind paws' bone upon collagen-induced arthritis (CIA) in mice, and the levels of Ahr were negatively correlated with bone mineral density (BMD). In addition, immunofluorescent staining showed that the high expression of Ahr was mainly localized in osteoblasts from the CIA mice compared to normal controls. Moreover, the luciferase intensity of Ahr in the nucleus increased by 12.5% in CIA osteoblasts compared to that in normal controls. In addition, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) activation of the Ahr inhibited pre-osteoblast MC3T3-E1 cellular proliferation and differentiation in a dose-dependent manner. Interestingly, the levels of alkaline phosphatase (ALP) mRNA expression in the osteoblasts of CIA mice were reduced compared to normal controls. In contrast, decreased ALP expression by activated Ahr was completely reversed after pretreatment with an Ahr inhibitor (CH-223191) in MC3T3-E1 cell lines and primary osteoblasts on day 5. Our data further showed that activation of Ahr promoted the phosphorylation of ERK after 5 days. Moreover, Ahr-dependent activation of the ERK signaling pathway decreased the levels of proliferation cells and inhibited ALP activity in MC3T3-E1 cells. These results demonstrated that the high expression of Ahr may suppress osteoblast proliferation and differentiation through activation of the ERK signaling pathway, further enabling bone erosion in CIA mice. - Highlights: • The upregulation of Ahr was localized in osteoblasts of CIA mice. • The overexpression of Ahr suppressed osteoblast development. • The Ahr activated ERK signaling pathway to exacerbate bone erosion.

  4. Aurora-A overexpression enhances cell-aggregation of Ha-ras transformants through the MEK/ERK signaling pathway

    International Nuclear Information System (INIS)

    Tseng, Ya-Shih; Lee, Jenq-Chang; Huang, Chi-Ying F; Liu, Hsiao-Sheng

    2009-01-01

    Overexpression of Aurora-A and mutant Ras (Ras V12 ) together has been detected in human bladder cancer tissue. However, it is not clear whether this phenomenon is a general event or not. Although crosstalk between Aurora-A and Ras signaling pathways has been reported, the role of these two genes acting together in tumorigenesis remains unclear. Real-time PCR and sequence analysis were utilized to identify Ha- and Ki-ras mutation (Gly -> Val). Immunohistochemistry staining was used to measure the level of Aurora-A expression in bladder and colon cancer specimens. To reveal the effect of overexpression of the above two genes on cellular responses, mouse NIH3T3 fibroblast derived cell lines over-expressing either Ras V12 and wild-type Aurora-A (designated WT) or Ras V12 and kinase-inactivated Aurora-A (KD) were established. MTT and focus formation assays were conducted to measure proliferation rate and focus formation capability of the cells. Small interfering RNA, pharmacological inhibitors and dominant negative genes were used to dissect the signaling pathways involved. Overexpression of wild-type Aurora-A and mutation of Ras V12 were detected in human bladder and colon cancer tissues. Wild-type Aurora-A induces focus formation and aggregation of the Ras V12 transformants. Aurora-A activates Ral A and the phosphorylation of AKT as well as enhances the phosphorylation of MEK, ERK of WT cells. Finally, the Ras/MEK/ERK signaling pathway is responsible for Aurora-A induced aggregation of the Ras V12 transformants. Wild-type-Aurora-A enhances focus formation and aggregation of the Ras V12 transformants and the latter occurs through modulating the Ras/MEK/ERK signaling pathway

  5. Inhibition of CD147 expression promotes chemosensitivity in HNSCC cells by deactivating MAPK/ERK signaling pathway.

    Science.gov (United States)

    Ma, Chao; Wang, Jianqi; Fan, Longkun; Guo, Yanjun

    2017-02-01

    Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers in the world. CD147, a transmembrane glycoprotein, has been reported to be correlated with cancer progression, metastasis, and chemoresistance in various cancers. In this study, we aimed to investigate the mechanism of CD147 in regulating drug resistance in HNSCC cells. qRT-PCR were used to evaluated the expression of CD147 in 57 HNSCC tumorous tissues and 2 cell lines. Increased expression of CD147 was found in most HNSCC samples, and the expression level of CD147 was correlated with multidrug resistance. CD147 RNA silencing decreased the chemoresistance of HNSCC cells by deactivating MAPK/ERK signaling pathway. Further investigation revealed that either rescue expression of CD147 or treatment of MAPK/ERK activator phorbol 12-myristate 13-acetate (PMA) in CD147 knockdown CRC cell line attenuated the decreased chemoresistance in CD147 knockdown cells. Taken together, our results suggest that CD147 promotes chemoresistance by activating MAPK/ERK signaling pathway in HNSCC. Copyright © 2017. Published by Elsevier Inc.

  6. Curcumin Inhibits Apoptosis of Chondrocytes through Activation ERK1/2 Signaling Pathways Induced Autophagy

    Directory of Open Access Journals (Sweden)

    Xiaodong Li

    2017-04-01

    Full Text Available Osteoarthritis (OA is an inflammatory disease of load-bearing synovial joints that is currently treated with drugs that exhibit numerous side effects and are only temporarily effective in treating pain, the main symptom of the disease. Consequently, there is an acute need for novel, safe, and more effective chemotherapeutic agents for the treatment of osteoarthritis and related arthritic diseases. Curcumin, the principal curcuminoid and the most active component in turmeric, is a biologically active phytochemical. Evidence from several recent in vitro studies suggests that curcumin may exert a chondroprotective effect through actions such as anti-inflammatory, anti-oxidative stress, and anti-catabolic activity that are critical for mitigating OA disease pathogenesis and symptoms. In the present study, we investigated the protective mechanisms of curcumin on interleukin 1β (IL-1β-stimulated primary chondrocytes in vitro. The treatment of interleukin (IL-1β significantly reduces the cell viability of chondrocytes in dose and time dependent manners. Co-treatment of curcumin with IL-1β significantly decreased the growth inhibition. We observed that curcumin inhibited IL-1β-induced apoptosis and caspase-3 activation in chondrocytes. Curcumin can increase the expression of phosphorylated extracellular signal-regulated kinases 1/2 (ERK1/2, autophagy marker light chain 3 (LC3-II, and Beclin-1 in chondrocytes. The expression of autophagy markers could be decreased when the chondrocytes were incubated with ERK1/2 inhibitor U0126. Our results suggest that curcumin suppresses apoptosis and inflammatory signaling through its actions on the ERK1/2-induced autophagy in chondrocytes. We propose that curcumin should be explored further for the prophylactic treatment of osteoarthritis in humans and companion animals.

  7. PBX3 promotes migration and invasion of colorectal cancer cells via activation of MAPK/ERK signaling pathway.

    Science.gov (United States)

    Han, Hai-Bo; Gu, Jin; Ji, Deng-Bo; Li, Zhao-Wei; Zhang, Yuan; Zhao, Wei; Wang, Li-Min; Zhang, Zhi-Qian

    2014-12-28

    To investigate the role of pre-B-cell leukemia homeobox (PBX)3 in migration and invasion of colorectal cancer (CRC) cells. We detected PBX3 expression in five cell lines and surgical specimens from 111 patients with CRC using real-time reverse transcription-polymerase chain reaction. We forced expression of PBX3 in low metastatic HT-29 and SW480 cells and knocked down expression of PBX3 in highly metastatic LOVO and HCT-8 cells. Wound healing and Boyden chamber assays were used to detect cell migration and invasion after altered expression of PBX3. Western blot was performed to detect the change of signaling molecule ERK1/2 following PBX3 overexpression. High level of PBX3 expression was correlated with the invasive potential of CRC cells, and significantly associated with lymph node invasion (P = 0.02), distant metastasis (P = 0.04), advanced TNM stage (P = 0.03) and poor overall survival of patients (P migration and invasion, while inhibited PBX3 expression in highly metastatic cells suppressed migration and invasion. Furthermore, upregulation of phosphorylated extracellular signal-regulated kinase (ERK)1/2 was found to be one of the targeted molecules responsible for PBX3-induced CRC cell migration and invasion. PBX3 induces invasion and metastasis of CRC cells partially through activation of the MAPK/ERK signaling pathway.

  8. Verteporfin inhibits papillary thyroid cancer cells proliferation and cell cycle through ERK1/2 signaling pathway

    Science.gov (United States)

    Liao, Tian; Wei, Wen-Jun; Wen, Duo; Hu, Jia-Qian; Wang, Yu; Ma, Ben; Cao, Yi-Min; Xiang, Jun; Guan, Qing; Chen, Jia-Ying; Sun, Guo-Hua; Zhu, Yong-Xue; Li, Duan-Shu; Ji, Qing-Hai

    2018-01-01

    Verteporfin, a FDA approved second-generation photosensitizer, has been demonstrated to have anticancer activity in various tumors, but not including papillary thyroid cancer (PTC). In current pre-clinical pilot study, we investigate the effect of verteporfin on proliferation, apoptosis, cell cycle and tumor growth of PTC. Our results indicate verteporfin attenuates cell proliferation, arrests cell cycle in G2/S phase and induces apoptosis of PTC cells. Moreover, treatment of verteporfin dramatically suppresses tumor growth from PTC cells in xenograft mouse model. We further illustrate that exposure to MEK inhibitor U0126 inactivates phosphorylation of ERK1/2 and MEK in verteporfin-treated PTC cells. These data suggest verteporfin exhibits inhibitory effect on PTC cells proliferation and cell cycle partially via ERK1/2 signalling pathway, which strongly encourages the further application of verteporfin in the treatment against PTC. PMID:29721041

  9. Lipo-PGE1 suppresses collagen production in human dermal fibroblasts via the ERK/Ets-1 signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yoolhee Yang

    Full Text Available Dysregulation of collagen production contributes to various pathological processes, including tissue fibrosis as well as impaired wound healing. Lipo-prostaglandin E1 (Lipo-PGE1, a lipid microsphere-incorporated prostaglandin E1, is used as a vasodilator for the treatment of peripheral vascular diseases. Lipo-PGE1 was recently shown to enhance human dermal fibroblast (HDF migration and in vivo wound healing. No published study has characterized the role of Lipo-PGE1 in collagen regulation in HDFs. Here, we investigated the cellular signaling mechanism by which Lipo-PGE1 regulates collagen in HDFs. Collagen production was evaluated by the Sircol collagen assay, Western blot analysis of type I collagen and real time PCR. Unexpectedly, Lipo-PGE1 decreased mRNA expression of collagen 1A1, 1A2, and 3A1. Lipo-PGE1 markedly inhibited type I collagen and total soluble collagen production. In addition, Lipo-PGE1 inhibited transforming growth factor-β-induced collagen expression via Smad2 phosphorylation. To further investigate whether extracellular signal-regulated kinase (ERK/Ets-1 signaling, a crucial pathway in collagen regulation, is involved in Lipo-PGE1-inhibited collagen production, cells were pretreated with an ERK-specific inhibitor, PD98059, prior to the addition of Lipo-PGE1. Lipo-PGE1-inhibited collagen mRNA expression and total soluble collagen production were recovered by pretreatment with PD98059. Moreover, Lipo-PGE1 directly induced the phosphorylation of ERK. Furthermore, silencing of Ets-1 recovered Lipo-PGE1-inhibited collagen production and PD98059 blocked Lipo-PGE1-enhanced Ets-1 expression. The present study reveals an important role for Lipo-PGE1 as a negative regulator of collagen gene expression and production via ERK/Ets-1 signaling. These results suggest that Lipo-PGE1 could potentially be a therapeutic target in diseases with deregulated collagen turnover.

  10. Crocin Improves the Endothelial Function Regulated by Kca3.1 Through ERK and Akt Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Huike Yang

    2018-03-01

    . Conclusion: In the present study, these data strongly support the hypothesis that crocin could improve endothelial function through stimulation of the eNOS/NO pathway and other endothelial markers. This functional improvement is regulated by KCa3.1 via the MEK/ERK and PI3K/Akt signaling pathway.

  11. Terbinafine stimulates the pro-inflammatory responses in human monocytic THP-1 cells through an ERK signaling pathway.

    Science.gov (United States)

    Mizuno, Katsuhiko; Fukami, Tatsuki; Toyoda, Yasuyuki; Nakajima, Miki; Yokoi, Tsuyoshi

    2010-10-23

    Oral antifungal terbinafine has been reported to cause liver injury with inflammatory responses in a small percentage of patients. However the underlying mechanism remains unknown. To examine the inflammatory reactions, we investigated whether terbinafine and other antifungal drugs increase the release of pro-inflammatory cytokines using human monocytic cells. Dose- and time-dependent changes in the mRNA expression levels and the release of interleukin (IL)-8 and tumor necrosis factor (TNF)α from human monocytic THP-1 and HL-60 cells with antifungal drugs were measured. Effects of terbinafine on the phosphorylation of extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK)1/2 were investigated. The release of IL-8 and TNFα from THP-1 and HL-60 cells was significantly increased by treatment with terbinafine but not by fluconazole, suggesting that terbinafine can stimulate monocytes and increase the pro-inflammatory cytokine release. Terbinafine also significantly increased the phosphorylation of ERK1/2 and p38 MAP kinase in THP-1 cells. Pretreatment with a MAP kinase/ERK kinase (MEK)1/2 inhibitor U0126 significantly suppressed the increase of IL-8 and TNFα levels by terbinafine treatment in THP-1 cells, but p38 MAPK inhibitor SB203580 did not. These results suggested that an ERK1/2 pathway plays an important role in the release of IL-8 and TNFα in THP-1 cells treated with terbinafine. The release of inflammatory mediators by terbinafine might be one of the mechanisms underlying immune-mediated liver injury. This in vitro method may be useful to predict adverse inflammatory reactions that lead to drug-induced liver injury. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Hepatitis C virus E2 protein promotes human hepatoma cell proliferation through the MAPK/ERK signaling pathway via cellular receptors

    International Nuclear Information System (INIS)

    Zhao Lanjuan; Wang Lu; Ren Hao; Cao Jie; Li Li; Ke Jinshan; Qi Zhongtian

    2005-01-01

    Dysregulation of mitogen-activated protein kinase (MAPK) signaling pathways by various viruses has been shown to be responsible for viral pathogenicity. The molecular mechanism by which hepatitis C virus (HCV) infection caused human liver diseases has been investigated on the basis of abnormal intracellular signal events. Current data are very limited involved in transmembrane signal transduction triggered by HCV E2 protein. Here we explored regulation of the MAPK/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway by E2 expressed in Chinese hamster oval cells. In human hepatoma Huh-7 cells, E2 specifically activated the MAPK/ERK pathway including downstream transcription factor ATF-2 and greatly promoted cell proliferation. CD81 and low density lipoprotein receptor (LDLR) on the cell surface mediated binding of E2 to Huh-7 cells. The MAPK/ERK activation and cell proliferation driven by E2 were suppressed by blockage of CD81 as well as LDLR. Furthermore, pretreatment with an upstream kinase MEK1/2 inhibitor U0126 also impaired the MAPK/ERK activation and cell proliferation induced by E2. Our results suggest that the MAPK/ERK signaling pathway triggered by HCV E2 via its receptors maintains survival and growth of target cells

  13. [Effect of ERK1/2 Signaling Pathway Inhibitor PD98059 on the Expression of Ras, BRaf, MEK, ERK1/2 in Marrow Nucleated Red Blood Cells of CMS Patients].

    Science.gov (United States)

    Han, Yuan-Fang; Ji, Lin-Hua; Feng, Ting-Ting; Liu, Fang; Cui, Sen; Su, Juan

    2017-10-01

    To investigate the effect of ERK1 / 2 signaling pathway inhibitor PD98059 on Ras, Raf, MEK, ERK1, ERK2 expression in order to explore a new way for basic research and clinical treatment of the chronic mountain sickness(CMS). Sixteen CMS patients were selected, the bone marrow was collected for isolation of monomuclear cells (MNC), the cells were sorted by using CD71 and CD235a antibody magnetic beads, then positive cells were diveded into 5 groups: blank control, DMSO and PD98059 5, 10 and 20 µmol/L, and were cultured in hypoxid condition for 72 hours. The Ras-GTP levels in supernatant was detected by ELISA, the RT-PCR was used to determine the expression of BRaf, MEK, ERK1, ERK2 mRNA in nucleated red blood cells, and the Western blot method was used to detect expression of BRaf, MEK, ERK1, ERK2 protein. PD98059 had no effect on the level of Ras-GTP in each groups. Compared with the blank control group, the expression levels of BRaf, MEK mRNA in DMSO group were not statistically significant (P values were 0.826, 0.298). Compared with the PD98059 20 mol/L group, the expression level of ERK1/2 mRNA was statistically significant (P=0.001, 0.002). Compared with the blank control group, expression levels of p-BRaf, p-MEK protein in DMSO group were not statistically significant (P=0.370, 0.351). Compared with the PD98059 20 mol/L group, the difference of p-ERK1/2 protein level in other 4 groups were statistically significant (P values were <0.001, 0.007). PD98059 can up-regulate the expressions of ERK1/2 miRNA and p-ERK1/2 protein in bone marrow nucleated red blood cells, the Ras / Raf / MEK / ERK 1/2 pathway is the main signal transduction pathway in regulating bone marrow nucleated red blood cells, suggesting that Ras/Raf /MEK /ERK 1/2 pathway may be involved in the pathogenesis of chronic mountain sickness process.

  14. The Fas-associated death domain protein/caspase-8/c-FLIP signaling pathway is involved in TNF-induced activation of ERK

    International Nuclear Information System (INIS)

    Lueschen, Silke; Falk, Markus; Scherer, Gudrun; Ussat, Sandra; Paulsen, Maren; Adam-Klages, Sabine

    2005-01-01

    The cytokine TNF activates multiple signaling pathways leading to cellular responses ranging from proliferation and survival to apoptosis. While most of these pathways have been elucidated in detail over the past few years, the molecular mechanism leading to the activation of the MAP kinases ERK remains ill defined and is controversially discussed. Therefore, we have analyzed TNF-induced ERK activation in various human and murine cell lines and show that it occurs in a cell-type-specific manner. In addition, we provide evidence for the involvement of the signaling components Fas-associated death domain protein (FADD), caspase-8, and c-FLIP in the pathway activating ERK in response to TNF. This conclusion is based on the following observations: (I) Overexpression of FADD, caspase-8, or a c-FLIP protein containing the death effector domains only leads to enhanced and prolonged ERK activation after TNF treatment. (II) TNF-induced ERK activation is strongly diminished in the absence of FADD. Interestingly, the enzymatic function of caspase-8 is not required for TNF-induced ERK activation. Additional evidence suggests a role for this pathway in the proliferative response of murine fibroblasts to TNF

  15. CTGF enhances resistance to 5-FU-mediating cell apoptosis through FAK/MEK/ERK signal pathway in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Yang K

    2016-11-01

    Full Text Available Kai Yang, Kai Gao, Gui Hu, Yanguang Wen, Changwei Lin, Xiaorong Li Department of General Surgery, The Third Affiliated Hospital of Central South University, Central South University, Changsha, Hunan, People’s Republic of China Abstract: Colorectal cancer (CRC is one of the most commonly diagnosed cancers among both males and females; the chemotherapy drug 5-fluorouracil (5-FU is one of a doctors’ first lines of defense against CRC. However, therapeutic failures are common because of the emergence of drug resistance. Connective tissue growth factor (CTGF is a secreted protein that binds to integrins, and regulates the invasiveness and metastasis of certain carcinoma cells. Here, we found that CTGF was upregulated in drug-resistant phenotype of human CRC cells. Overexpression of CTGF enhanced the resistance to 5-FU-induced cell apoptosis. Moreover, downregulating the expression of CTGF promoted the curative effect of chemotherapy and blocked the cell cycle in the G1 phase. We also found that CTGF facilitated resistance to 5-FU-induced apoptosis by increasing the expression of B-cell lymphoma-extra large (Bcl-xL and survivin. Then we pharmacologically blocked MEK/ERK signal pathway and assessed 5-FU response by MTT assays. Our current results indicate that the expression of phosphorylated forms of MEK/ERK increased in high CTGF expression cells and MEK inhibited increases in 5-FU-mediated apoptosis of resistant CRC cells. Therefore, our data suggest that MEK/ERK signaling contributes to 5-FU resistance through upstream of CTGF, and supports CRC cell growth. Comprehending the molecular mechanism underlying 5-FU resistance may ultimately aid the fight against CRC. Keywords: connective tissue growth factor, 5-fluorouracil, mitogen-activated protein kinase/extracellular regulated protein kinases, phosphatidyl inositol 3-kinase/serine/threonine kinase Akt, colorectal cancer

  16. Ghrelin inhibits the apoptosis of MC3T3-E1 cells through ERK and AKT signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Qiu-Hua; Liu, Yuan; Wu, Shan-Shan; Cui, Rong-Rong; Yuan, Ling-Qing, E-mail: allenylq@hotmail.com; Liao, Er-Yuan, E-mail: eyliao@21cn.com

    2013-11-01

    Ghrelin is a 28-amino-acid peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR) and strongly stimulates the release of growth hormone from the hypothalamus–pituitary axis. Previous studies have identified the important physiological effects of ghrelin on bone metabolism, such as regulating proliferation and differentiation of osteoblasts, independent of GH/IGF-1 axis. However, research on effects and mechanisms of ghrelin on osteoblast apoptosis is still rare. In this study, we identified expression of GHSR in MC3T3-E1 cells and determined the effects of ghrelin on the apoptosis of osteoblastic MC3T3-E1 cells and the mechanism involved. Our data demonstrated that ghrelin inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as determined by terminal deoxynucleotidyl transferase-mediated deoxyribonucleotide triphosphate nick end-labeling (TUNEL) and ELISA assays. Moreover, ghrelin upregulated Bcl-2 expression and downregulated Bax expression in a dose-dependent manner. Our study also showed decreased activated caspase-3 activity under the treatment of ghrelin. Further study suggested that ghrelin stimulated the phosphorylation of ERK and AKT. Pretreatment of cells with the ERK inhibitor PD98059, PI3K inhibitor LY294002, and GHSR-siRNA blocked the ghrelin-induced activation of ERK and AKT, respectively; however, ghrelin did not stimulate the phosphorylation of p38 or JNK. PD90859, LY294002 and GHSR-siRNA attenuated the anti-apoptosis effect of ghrelin in MC3T3-E1 cells. In conclusion, ghrelin inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, which may be mediated by activating the GHSR/ERK and GHSR/PI3K/AKT signaling pathways. - Highlights: • We explored the effects of ghrelin on serum deprivation-induced MC3T3-E1 cells apoptosis. • Both ELISA and TUNEL were used to detect the apoptosis. • The receptor of ghrelin, GHSR, was expressed in MC3T3-E1

  17. Ghrelin inhibits the apoptosis of MC3T3-E1 cells through ERK and AKT signaling pathway

    International Nuclear Information System (INIS)

    Liang, Qiu-Hua; Liu, Yuan; Wu, Shan-Shan; Cui, Rong-Rong; Yuan, Ling-Qing; Liao, Er-Yuan

    2013-01-01

    Ghrelin is a 28-amino-acid peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR) and strongly stimulates the release of growth hormone from the hypothalamus–pituitary axis. Previous studies have identified the important physiological effects of ghrelin on bone metabolism, such as regulating proliferation and differentiation of osteoblasts, independent of GH/IGF-1 axis. However, research on effects and mechanisms of ghrelin on osteoblast apoptosis is still rare. In this study, we identified expression of GHSR in MC3T3-E1 cells and determined the effects of ghrelin on the apoptosis of osteoblastic MC3T3-E1 cells and the mechanism involved. Our data demonstrated that ghrelin inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as determined by terminal deoxynucleotidyl transferase-mediated deoxyribonucleotide triphosphate nick end-labeling (TUNEL) and ELISA assays. Moreover, ghrelin upregulated Bcl-2 expression and downregulated Bax expression in a dose-dependent manner. Our study also showed decreased activated caspase-3 activity under the treatment of ghrelin. Further study suggested that ghrelin stimulated the phosphorylation of ERK and AKT. Pretreatment of cells with the ERK inhibitor PD98059, PI3K inhibitor LY294002, and GHSR-siRNA blocked the ghrelin-induced activation of ERK and AKT, respectively; however, ghrelin did not stimulate the phosphorylation of p38 or JNK. PD90859, LY294002 and GHSR-siRNA attenuated the anti-apoptosis effect of ghrelin in MC3T3-E1 cells. In conclusion, ghrelin inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, which may be mediated by activating the GHSR/ERK and GHSR/PI3K/AKT signaling pathways. - Highlights: • We explored the effects of ghrelin on serum deprivation-induced MC3T3-E1 cells apoptosis. • Both ELISA and TUNEL were used to detect the apoptosis. • The receptor of ghrelin, GHSR, was expressed in MC3T3-E1

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

    Directory of Open Access Journals (Sweden)

    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.

  19. MFAP5 promotes tumor progression and bone metastasis by regulating ERK/MMP signaling pathways in breast cancer.

    Science.gov (United States)

    Wu, Zhiqiang; Wang, Ting; Fang, Meng; Huang, Wending; Sun, Zhengwang; Xiao, Jianru; Yan, Wangjun

    2018-04-06

    Breast cancer accounts for about 30% of all cancers in women, while approximately 70% breast cancer patients developed bone metastases throughout the course of their disease, highlighting the importance of exploring new therapeutic targets. Microfibrillar-associated protein 5 (MFAP5) is a component of extracellular elastic microfibril which has been confirmed to function in tissue development and cancer progression. But the role of MFAP5 in breast cancer remains unclear. The present study demonstrated that MFAP5 was up-regulated in breast cancers compared with that in normal breast tissues, and further increased in breast cancer bone metastasis. Functionally, MFAP5 overexpression accelerated breast cancer cell proliferation and migration, while an opposite effect was observed when MFAP5 was knocked down. In addition, up-regulation of MFAP5 increased the expression of MMP2 and MMP9 and activated the ERK signaling pathway. Conversely, inhibition of MFAP5 suppressed the expression of MMP2, MMP9, p-FAK, p-Erk1/2 and p-cJun. These findings may provide a better understanding about the mechanism of breast cancer and suggest that MFAP5 may be a potential prognostic biomarker and therapeutic target for breast cancer, especially for bone metastasis of breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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

  1. MVP interacts with YPEL4 and inhibits YPEL4-mediated activities of the ERK signal pathway.

    Science.gov (United States)

    Liang, Pei; Wan, Yongqi; Yan, Yan; Wang, Yuequn; Luo, Na; Deng, Yun; Fan, Xiongwei; Zhou, Junmei; Li, Yongqing; Wang, Zequn; Yuan, Wuzhou; Tang, Ming; Mo, Xiaoyang; Wu, Xiushan

    2010-06-01

    Human YPEL4 is a member of YPEL family. It contains a Yippee domain, which is a putative zinc-finger-like, metal-binding domain. The human YPEL4 gene maps to chromosome 11q12.1, is ubiquitously expressed in adult tissues, and encodes a nuclear protein of 127 amino acids, the function of which remains unknown. To gain insights into the cellular function of this protein, we searched for YPEL4-interacting proteins using a yeast two-hybrid screen. The major vault protein (MVP), a lung resistance associated protein, was identified as a binding partner of YPEL4. The interaction between YPEL4 and MVP in mammalian cells was further demonstrated by a series of biochemical assays including the mammalian two-hybrid assay, GST pull-down assay, co-immunoprecipitation assay, and immunocytochemistry. Using a reporter system, we found that MVP can inhibit YPEL4's ability to activate Elk-1 in the MAPK signaling pathway. This study provides new clues for understanding the molecular mechanism of YPEL4 in cell division and signal transduction pathways and should be helpful for understanding molecular functions of the YPEL family.

  2. Loss of p53 induces cell proliferation via Ras-independent activation of the Raf/Mek/Erk signaling pathway

    Science.gov (United States)

    Drosten, Matthias; Sum, Eleanor Y. M.; Lechuga, Carmen G.; Simón-Carrasco, Lucía; Jacob, Harrys K. C.; García-Medina, Raquel; Huang, Sidong; Beijersbergen, Roderick L.; Bernards, Rene; Barbacid, Mariano

    2014-01-01

    The Ras family of small GTPases constitutes a central node in the transmission of mitogenic stimuli to the cell cycle machinery. The ultimate receptor of these mitogenic signals is the retinoblastoma (Rb) family of pocket proteins, whose inactivation is a required step to license cell proliferation. However, little is known regarding the molecular events that connect Ras signaling with the cell cycle. Here, we provide genetic evidence to illustrate that the p53/p21 Cdk-interacting protein 1 (Cip1)/Rb axis is an essential component of the Ras signaling pathway. Indeed, knockdown of p53, p21Cip1, or Rb restores proliferative properties in cells arrested by ablation of the three Ras loci, H-, N- and K-Ras. Ras signaling selectively inactivates p53-mediated induction of p21Cip1 expression by inhibiting acetylation of specific lysine residues in the p53 DNA binding domain. Proliferation of cells lacking both Ras proteins and p53 can be prevented by reexpression of the human p53 ortholog, provided that it retains an active DNA binding domain and an intact lysine residue at position 164. These results unveil a previously unidentified role for p53 in preventing cell proliferation under unfavorable mitogenic conditions. Moreover, we provide evidence that cells lacking Ras and p53 proteins owe their proliferative properties to the unexpected retroactivation of the Raf/Mek/Erk cascade by a Ras-independent mechanism. PMID:25288756

  3. Pituitary adenylate cyclase activating peptide (PACAP participates in adipogenesis by activating ERK signaling pathway.

    Directory of Open Access Journals (Sweden)

    Tatjana Arsenijevic

    Full Text Available Pituitary adenylate cyclase activating peptide (PACAP belongs to the secretin/glucagon/vasoactive intestinal peptide (VIP family. Its action can be mediated by three different receptor subtypes: PAC1, which has exclusive affinity for PACAP, and VPAC1 and VPAC2 which have equal affinity for PACAP and VIP. We showed that all three receptors are expressed in 3T3-L1 cells throughout their differentiation into adipocytes. We established the activity of these receptors by cAMP accumulation upon induction by PACAP. Together with insulin and dexamethasone, PACAP induced adipogenesis in 3T3-L1 cell line. PACAP increased cAMP production within 15 min upon stimulation and targeted the expression and phosphorylation of MAPK (ERK1/2, strengthened by the ERK1/2 phosphorylation being partially or completely abolished by different combinations of PACAP receptors antagonists. We therefore speculate that ERK1/2 activation is crucial for the activation of CCAAT/enhancer- binding protein β (C/EBPβ.

  4. Effect of mitomycin combined with Nd-YAG laser on cell proliferation and invasion as well as MEK/ERK signaling pathway in obstructive lacrimal duct model

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    Yu Yan

    2017-11-01

    Full Text Available Objective: To study the effect of mitomycin (MMC combined with Nd-YAG laser on cell proliferation and invasion as well as MEK/ERK signaling pathway in obstructive lacrimal duct model. Methods: New Zealand rabbits were selected as experimental animals and divided into model group, laser group and MMC + laser group; obstructive lacrimal duct model was established, then laser group were given Nd-YAG laser intervention, and MMC + laser group were given Nd-YAG laser combined with mitomycin intervention. 2 months after intervention, the expression of proliferation molecules, invasion molecules and MEK-ERK signaling molecules in lacrimal duct tissue were measured. Results: TGF-β, CTGF, PCNA, Ki-67, Col-I, Col-III, MEK, ERK1/2, MMP2 and MMP9 protein levels in lacrimal duct tissue of laser group were significantly higher than those of model group while TSG-6, Cthrc1 and TIMP1 protein levels were significantly lower than those of model group; TGF-β, CTGF, PCNA, Ki- 67, Col-I, Col-III, MEK, ERK1/2, MMP2 and MMP9 protein levels in lacrimal duct tissue of MMC + laser group were significantly lower than those of laser group while TSG-6, Cthrc1 and TIMP1 protein levels were significantly higher than those of laser group. Conclusion: Mitomycin can inhibit cell proliferation and invasion as well as MEK/ERK signaling pathway activation in obstructive lacrimal duct model after Nd-YAG laser treatment.

  5. Low-level shear stress promotes migration of liver cancer stem cells via the FAK-ERK1/2 signalling pathway.

    Science.gov (United States)

    Sun, Jinghui; Luo, Qing; Liu, Lingling; Song, Guanbin

    2018-07-28

    Cancer stem cells (CSCs) are a small subpopulation of tumour cells that have been proposed to be responsible for cancer initiation, chemotherapy resistance and cancer recurrence. Shear stress activated cellular signalling is involved in cellular migration, proliferation and differentiation. However, little is known about the effects of shear stress on the migration of liver cancer stem cells (LCSCs). Here, we studied the effects of shear stress that are generated from a parallel plated flow chamber system, on LCSC migration and the activation of focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2), using transwell assay and western blot, respectively. We found that 2 dyne/cm 2 shear stress loading for 6 h promotes LCSC migration and activation of the FAK and ERK1/2 signalling pathways, whereas treatment with the FAK phosphorylation inhibitor PF573228 or the ERK1/2 phosphorylation inhibitor PD98059 suppressed the shear stress-promoted migration, indicating the involvement of FAK and ERK1/2 activation in shear stress-induced LCSC migration. Additionally, atomic force microscopy (AFM) analysis showed that shear stress lowers LCSC stiffness via the FAK and ERK1/2 pathways, suggesting that the mechanism by which shear stress promotes LCSC migration might partially be responsible for the decrease in cell stiffness. Further experiments focused on the role of the actin cytoskeleton, demonstrating that the F-actin filaments in LCSCs are less well-defined after shear stress treatment, providing an explanation for the reduction in cell stiffness and the promotion of cell migration. Overall, our study demonstrates that shear stress promotes LCSC migration through the activation of the FAK-ERK1/2 signalling pathways, which further results in a reduction of organized actin and softer cell bodies. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Activation of the ERK1/2 Signaling Pathway during the Osteogenic Differentiation of Mesenchymal Stem Cells Cultured on Substrates Modified with Various Chemical Groups

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    Bing Bai

    2013-01-01

    Full Text Available The current study examined the influence of culture substrates modified with the functional groups –OH, –COOH, –NH2, and –CH3 using SAMs technology, in conjunction with TAAB control, on the osteogenic differentiation of rabbit BMSCs. The CCK-8 assay revealed that BMSCs exhibited substrate-dependent cell viability. The cells plated on –NH2- and –OH-modified substrates were well spread and homogeneous, but those on the –COOH- and –CH3-modified substrates showed more rounded phenotype. The mRNA expression of BMSCs revealed that –NH2-modified substrate promoted the mRNA expression and osteogenic differentiation of the BMSCs. The contribution of ERK1/2 signaling pathway to the osteogenic differentiation of BMSCs cultured on the –NH2-modified substrate was investigated in vitro. The –NH2-modified substrate promoted the expression of integrins; the activation of FAK and ERK1/2. Inhibition of ERK1/2 activation by PD98059, a specific inhibitor of the ERK signaling pathway, blocked ERK1/2 activation in a dose-dependent manner, as revealed for expression of Cbfα-1 and ALP. Blockade of ERK1/2 phosphorylation in BMSCs by PD98059 suppressed osteogenic differentiation on chemical surfaces. These findings indicate a potential role for ERK in the osteogenic differentiation of BMSCs on surfaces modified by specific chemical functional groups, indicating that the microenvironment affects the differentiation of BMSCs. This observation has important implications for bone tissue engineering.

  7. Inhibition of the Ras-ERK pathway in mitotic COS7 cells is due to the inability of EGFR/Raf to transduce EGF signaling to downstream proteins.

    Science.gov (United States)

    Shi, Huaiping; Zhang, Tianying; Yi, Yongqing; Ma, Yue

    2016-06-01

    Although previous studies have shown that Ras-ERK signaling in mitosis is closed due to the inhibition of signal transduction, the events involved in the molecular mechanisms are still unclear. In the present study, we investigated the Ras-ERK signaling pathway in mitotic COS7 cells. The results demonstrated that treatment with epidermal growth factor (EGF) failed to increase the endocytosis of EGF-EGFR (EGF receptor) complexes in mitotic COS7 cells, although a large amount of endosomes were found in asynchronous COS7 cells. Clathrin expression levels in mitotic COS7 cells were inhibited whereas caveolin expression levels in mitotic COS7 cells were almost unaffected. Y1068 and Y1086 residues of EGFR in the mitotic COS7 cells were activated. However, Grb2 and Shc in the mitotic COS7 cells did not bind to activated EGFR. Ras activity was inhibited in the mitotic COS7 cells whereas its downstream protein, Raf, was obviously phosphorylated by EGF in mitosis. Treatment with phorbol 12-myristate 13-acetate (PMA) also increased the phosphorylation levels of Raf in the mitotic COS7 cells. Nevertheless, Raf phosphorylation in mitosis was significantly inhibited by AG1478. Lastly, activation of EGF-mediated MEK and ERK in the mitotic COS7 cells was obviously inhibited. In summary, our results suggest that the Ras-ERK pathway is inhibited in mitotic COS7 cells which may be the dual result of the difficulty in the transduction of EGF signaling by EGFR or Raf to downstream proteins.

  8. Kruppel-like factor 2 inhibit the angiogenesis of cultured human liver sinusoidal endothelial cells through the ERK1/2 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiao-Qing, E-mail: zeng.xiaoqing@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Li, Na, E-mail: Linala.2009@163.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Pan, Du-Yi, E-mail: lasikesmi@hotmail.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Miao, Qing, E-mail: sadsadvenus@163.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Ma, Gui-Fen, E-mail: ma.guifen@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Liu, Yi-Mei, E-mail: liuyimei1988@163.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Tseng, Yu-Jen, E-mail: dianatseng14@gmail.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Li, Feng, E-mail: li.feng2@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Xu, Li-Li, E-mail: xu.lili3@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Chen, Shi-Yao, E-mail: chen.shiyao@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Institute of Endoscopic Research of Zhongshan Hospital, Fudan University, Shanghai (China)

    2015-09-04

    Kruppel-like factor 2 (KLF2) is a crucial anti-angiogenic factor. However, its precise role in hepatic angiogenesis induced by liver sinusoidal endothelial cells (LSECs) remain unclear. This study was aimed to evaluate the effect of KLF2 on angiogenesis of LSECs and to explore the corresponding mechanism. Cultured human LSECs were infected with different lentiviruses to overexpress or suppress KLF2 expression. The CCK-8 assay, transwell migration assay and tube formation test, were used to investigate the roles of KLF2 in the proliferation, migration and vessel tube formation of LSECs, respectively. The expression and phosphorylation of ERK1/2 were detected by western blot. We discovered that the up-regulation of KLF2 expression dramatically inhibited proliferation, migration and tube formation in treated LSECs. Correspondingly, down-regulation of KLF2 expression significantly promoted proliferation, migration and tube formation in treated LSECs. Additionally, KLF2 inhibited the phosphorylation of ERK1/2 pathway, followed by the function of KLF2 in the angiogenesis of LSECs disrupted. In conclusion, KLF2 suppressed the angiogenesis of LSECs through inhibition of cell proliferation, migration, and vessel tube formation. These functions of KLF2 may be mediated through the ERK1/2 signaling pathway. - Highlights: • Overexpression of KLF2 inhibits the proliferation and migration of LSECs. • Overexpression of KLF2 inhibits the angiogenesis of LSECs. • ERK1/2 signaling pathway involved in the anti-angiogenic process of KLF2 on LSECs.

  9. Icariin stimulates angiogenesis by activating the MEK/ERK- and PI3K/Akt/eNOS-dependent signal pathways in human endothelial cells

    International Nuclear Information System (INIS)

    Chung, Byung-Hee; Kim, Jong-Dai; Kim, Chun-Ki; Kim, Jung Huan; Won, Moo-Ho; Lee, Han-Soo; Dong, Mi-Sook; Ha, Kwon-Soo; Kwon, Young-Geun; Kim, Young-Myeong

    2008-01-01

    We investigated the molecular effect and signal pathway of icariin, a major flavonoid of Epimedium koreanum Nakai, on angiogenesis. Icariin stimulated in vitro endothelial cell proliferation, migration, and tubulogenesis, which are typical phenomena of angiogenesis, as well as increased in vivo angiogenesis. Icariin activated the angiogenic signal modulators, ERK, phosphatidylinositol 3-kinase (PI3K), Akt, and endothelial nitric oxide synthase (eNOS), and increased NO production, without affecting VEGF expression, indicating that icariin may directly stimulate angiogenesis. Icariin-induced ERK activation and angiogenic events were significantly inhibited by the MEK inhibitor PD98059, without affecting Akt and eNOS phosphorylation. The PI3K inhibitor Wortmannin suppressed icariin-mediated angiogenesis and Akt and eNOS activation without affecting ERK phosphorylation. Moreover, the NOS inhibitor NMA partially reduced the angiogenic activity of icariin. These results suggest that icariin stimulated angiogenesis by activating the MEK/ERK- and PI3K/Akt/eNOS-dependent signal pathways and may be a useful drug for angiogenic therapy

  10. Functional significance of the signal transduction pathways Akt and Erk in ovarian follicles: in vitro and in vivo studies in cattle and sheep

    Directory of Open Access Journals (Sweden)

    Ryan Kate E

    2008-10-01

    Full Text Available Abstract Background The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell function in vitro, and on follicle development in vivo. Methods Bovine granulosa and theca cells were cultured for six days and stimulated with FSH and/or IGF, or LH in combination with PD98059 (Erk inhibitor and/or LY294002 (Akt inhibitor and their effect on cell number and hormone secretion (estradiol, activin-A, inhibin-A, follistatin, progesterone and androstenedione determined. In addition, ovarian follicles were treated in vivo with PD98059 and/or LY294002 in ewes on Day 3 of the cycle and follicles were recovered 48 hours later. Results We have shown that gonadotropin- and IGF-stimulated hormone production by granulosa and theca cells is reduced by treatment with PD98059 and LY294002 in vitro. Furthermore, treatment with PD98059 and LY294002 reduced follicle growth and oestradiol production in vivo. Conclusion These results demonstrate an important functional role for the Akt and Erk signalling pathways in follicle function, growth and development.

  11. Lithium attenuates cannabinoid-induced dependence in the animal model: involvement of phosphorylated ERK1/2 and GSK-3β signaling pathways.

    Directory of Open Access Journals (Sweden)

    Hamid Reza Rahimi

    2014-09-01

    Full Text Available Cannabis is one of the most banned drugs in the world. Cannabinoid-induced dependence or withdrawal signs are indicated by the result of complex molecular mechanisms including upstream protein kinases (PKs, such as an extracellular signal regulated kinase1/2 (ERK1/2 and downstream glycogen synthase kinase-3β (GSK-3β, which lead to neuronal plasticity. In this study, we examined the protective effect of lithium (Li as a potent ERK1/2 and GSK-3β modulator to prevent the development of dependence on cannabinoids. For this purpose, rats were treated twice daily with increasing doses of WIN 55,212-2 (WIN, 2-8 mg/kg, intraperitoneally (i.p., for five consecutive days. AM251 (AM, 2 mg/kg, a cannabinoid antagonist, was injected i.p to induce manifestations of abstinence in rat dependency on WIN, and the subsequent withdrawal signs were recorded. To evaluate the preventive effect of Li, the rats were pre-treated with Li (10 mg/kg, i.p. twice daily, 30 minutes before every injection of WIN. SL327, as an ERK1/2 inhibitor, was also injected (SL, 50 mg/kg, i.p. 30 minutes before the last doses of WIN in separate groups. The p-ERK1/2, total ERK1/2, p-GSK-3β and total GSK-3β expressions were determined with Western blot method after 60 minutes, prior to the Li, WIN or AM injections. Li and SL pre-treatment attenuated the global withdrawal signs in regarding their modulation effect on the up-regulation of p-ERK1/2 cascade enhanced by AM injection. Furthermore, the p-GSK-3β expression was up-regulated with SL and Li pre-treatment against AM injection, without alteration on the total contents of ERK1/2 and GSK-3β level. Therefore, p-ERK1/2 and p-GSK-3β pathways are involved in the cannabinoid-induced dependence. However, no crosstalk was indicated between these two pathways. In conclusion, Li neuroprotectionwith regard to cannabinoid abstinence may occur through the regulation of the p-ERK1/2 cascade inconsequent of p-GSK-3β signaling pathways in rats.

  12. BIG1, a brefeldin A-inhibited guanine nucleotide-exchange protein regulates neurite development via PI3K-AKT and ERK signaling pathways.

    Science.gov (United States)

    Zhou, C; Li, C; Li, D; Wang, Y; Shao, W; You, Y; Peng, J; Zhang, X; Lu, L; Shen, X

    2013-12-19

    The elongation of neuron is highly dependent on membrane trafficking. Brefeldin A (BFA)-inhibited guanine nucleotide-exchange protein 1 (BIG1) functions in the membrane trafficking between the Golgi apparatus and the plasma membrane. BFA, an uncompetitive inhibitor of BIG1 can inhibit neurite outgrowth and polarity development. In this study, we aimed to define the possible role of BIG1 in neurite development and to further investigate the potential mechanism. By immunostaining, we found that BIG1 was extensively colocalized with synaptophysin, a marker for synaptic vesicles in soma and partly in neurites. The amount of both protein and mRNA of BIG1 were up-regulated during rat brain development. BIG1 depletion significantly decreased the neurite length and inhibited the phosphorylation of phosphatidylinositide 3-kinase (PI3K) and protein kinase B (AKT). Inhibition of BIG1 guanine nucleotide-exchange factor (GEF) activity by BFA or overexpression of the dominant-negative BIG1 reduced PI3K and AKT phosphorylation, indicating regulatory effects of BIG1 on PI3K-AKT signaling pathway is dependent on its GEF activity. BIG1 siRNA or BFA treatment also significantly reduced extracellular signal-regulated kinase (ERK) phosphorylation. Overexpression of wild-type BIG1 significantly increased ERK phosphorylation, but the dominant-negative BIG1 had no effect on ERK phosphorylation, indicating the involvement of BIG1 in ERK signaling regulation may not be dependent on its GEF activity. Our result identified a novel function of BIG1 in neurite development. The newly recognized function integrates the function of BIG1 in membrane trafficking with the activation of PI3K-AKT and ERK signaling pathways which are critical in neurite development. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Chlorpyrifos promotes colorectal adenocarcinoma H508 cell growth through the activation of EGFR/ERK1/2 signaling pathway but not cholinergic pathway.

    Science.gov (United States)

    Suriyo, Tawit; Tachachartvanich, Phum; Visitnonthachai, Daranee; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2015-12-02

    Aside from the effects on neuronal cholinergic system, epidemiological studies suggest an association between chlorpyrifos (CPF) exposure and cancer risk. This in vitro study examined the effects of CPF and its toxic metabolite, chlorpyrifos oxon (CPF-O), on the growth of human colorectal adenocarcinoma H508, colorectal adenocarcinoma HT-29, normal colon epithelial CCD841, liver hepatocellular carcinoma HepG2, and normal liver hepatocyte THLE-3 cells. The results showed that CPF (5-100 μM) concentration-dependently increased viability of H508 and CCD841 cells in serum-free conditions. This increasing trend was not found in HT-29, HepG2 and THLE-3 cells. In contrast, CPF-O (50-100 μM) reduced the viability of all cell lines. Cell cycle analysis showed the induction of cells in the S phase, and EdU incorporation assay revealed the induction of DNA synthesis in CPF-treated H508 cells indicating that CPF promotes cell cycle progression. Despite the observation of acetylcholinesterase activity inhibition and reactive oxygen species (ROS) generation, atropine (a non-selective muscarinic acetylcholine receptor antagonist) and N-acetylcysteine (a potent antioxidant) failed to inhibit the growth-promoting effect of CPF. CPF increased the phosphorylation of epidermal growth factor receptor (EGFR) and its downstream effector, extracellular signal regulated kinase (ERK1/2), in H508 cells. AG-1478 (a specific EGFR tyrosine kinase inhibitor) and U0126 (a specific MEK inhibitor) completely mitigated the growth promoting effect of CPF. Altogether, these results suggest that EGFR/ERK1/2 signaling pathway but not cholinergic pathway involves in CPF-induced colorectal adenocarcinoma H508 cell growth. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Gomisin N Inhibits Melanogenesis through Regulating the PI3K/Akt and MAPK/ERK Signaling Pathways in Melanocytes

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    Jae Kyoung Chae

    2017-02-01

    Full Text Available Gomisin N, one of the lignan compounds found in Schisandra chinensis has been shown to possess anti-oxidative, anti-tumorigenic, and anti-inflammatory activities in various studies. Here we report, for the first time, the anti-melenogenic efficacy of Gomisin N in mammalian cells as well as in zebrafish embryos. Gomisin N significantly reduced the melanin content without cellular toxicity. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, Gomisin N downregulated the expression levels of key proteins that function in melanogenesis. Gomisin N downregulated melanocortin 1 receptor (MC1R, adenylyl cyclase 2, microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP-1, and tyrosinase-related protein-2 (TRP-2. In addition, Gomisin N-treated Melan-A cells exhibited increased p-Akt and p-ERK levels, which implies that the activation of the PI3K/Akt and MAPK/ERK pathways may function to inhibit melanogenesis. We also validated that Gomisin N reduced melanin production by repressing the expression of MITF, tyrosinase, TRP-1, and TRP-2 in mouse and human cells as well as in developing zebrafish embryos. Collectively, we conclude that Gomisin N inhibits melanin synthesis by repressing the expression of MITF and melanogenic enzymes, probably through modulating the PI3K/Akt and MAPK/ERK pathways.

  15. Apurinic/apyrimidinic endonuclease1/redox factor-1 (Ape1/Ref-1) is essential for IL-21-induced signal transduction through ERK1/2 pathway

    International Nuclear Information System (INIS)

    Juliana, Farha M.; Nara, Hidetoshi; Onoda, Tadashi; Rahman, Mizanur; Araki, Akemi; Jin, Lianjin; Fujii, Hodaka; Tanaka, Nobuyuki; Hoshino, Tomoaki; Asao, Hironobu

    2012-01-01

    Highlights: ► IL-21 induces nuclear accumulation of Ape1/Ref-1 protein. ► Ape1/Ref-1 is indispensable in IL-21-induced cell proliferation and survival signal. ► Ape1/Ref-1 is required for IL-21-induced ERK1/2 activation. -- Abstract: IL-21 is a pleiotropic cytokine that regulates T-cell and B-cell differentiation, NK-cell activation, and dendritic cell functions. IL-21 activates the JAK-STAT, ERK, and PI3K pathways. We report here that Ape1/Ref-1 has an essential role in IL-21-induced cell growth signal transduction. Overexpression of Ape1/Ref-1 enhances IL-21-induced cell proliferation, but it is suppressed by overexpressing an N-terminal deletion mutant of Ape1/Ref-1 that lacks the redox domain. Furthermore, knockdown of the Ape1/Ref-1 mRNA dramatically compromises IL-21-induced ERK1/2 activation and cell proliferation with increasing cell death. These impaired activities are recovered by the re-expression of Ape1/Ref-1 in the knockdown cells. Our findings are the first demonstration that Ape1/Ref-1 is an indispensable molecule for the IL-21-mediated signal transduction through ERK1/2 activation.

  16. [6]-Gingerol Prevents Disassembly of Cell Junctions and Activities of MMPs in Invasive Human Pancreas Cancer Cells through ERK/NF-κB/Snail Signal Transduction Pathway

    Directory of Open Access Journals (Sweden)

    Sung Ok Kim

    2013-01-01

    Full Text Available To study the effects of [6]-gingerol, a ginger phytochemical, on tight junction (TJ molecules, we investigated TJ tightening and signal transduction pathways in human pancreatic duct cell-derived cancer cell line PANC-1. The following methods were utilized: MTT assay to determine cytotoxicity; zymography to examine matrix metalloproteinase (MMP activities; transepithelial electrical resistance (TER and paracellular flux for TJ measurement; RT-PCR and immunoblotting for proteins related to TJ and invasion; and EMSA for NF-κB activity in PANC-1 cells. Results revealed that TER significantly increased and claudin 4 and MMP-9 decreased compared to those of the control. TJ protein levels, including zonula occludens (ZO- 1, occludin, and E-cadherin, increased in [6]-gingerol-treated cells, which correlated with a decrease in paracellular flux and MMP activity. Furthermore, NF-κB/Snail nuclear translocation was suppressed via downregulation of the extracellular signal-regulated kinase (ERK pathway in response to [6]-gingerol treatment. Moreover, treatment with U0126, an ERK inhibitor, completely blocked NF-κB activity. In conclusion, these findings demonstrate that [6]-gingerol regulates TJ-related proteins and suppresses invasion and metastasis through NF-κB/Snail inhibition via inhibition of the ERK pathway. Therefore, [6]-gingerol may suppress the invasive activity of PANC-1 cells.

  17. Shengui Sansheng San extraction is an angiogenic switch via regulations of AKT/mTOR, ERK1/2 and Notch1 signal pathways after ischemic stroke.

    Science.gov (United States)

    Liu, Bowen; Luo, Cheng; Zheng, Zhaoguang; Xia, Zhenyan; Zhang, Qian; Ke, Chienchih; Liu, Renshyan; Zhao, Yonghua

    2018-05-15

    As a traditional Chinese herbal formula, Shengui Sansheng San (SSS) has been employed for stroke treatment more than 300 years. We hypothesize that SSS extraction is an angiogenic switch in penumbra post-stroke, and corresponding mechanisms are investigated. In present study, rats were subjected to permanent middle cerebral artery occlusion model (MCAo) and were treated with low, middle and high doses of SSS extraction. We assessed neurological function and survival rate, and measured infarct volume by 2,3,5-triphenyltetrazolium chloride staining on day 7 after ischemia. von Willebrand factor (vWF), stromal cell-derived factor-1 alpha (SDF-1α) /chemokine (C-X-C motif) receptor 4 (CXCR4) axis, vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) as well as protein kinase B (AKT)/mammalian target of rapamycin (mTOR) /hypoxia-inducible factor-1 alpha (HIF-1α), extracellular signal-regulated kinase 1/2 (ERK1/2) and Notch1 signaling pathways were respectively investigated by immunofluorescence assay or western blotting in vivo and oxygen-glucose-deprived (OGD) brain microvascular endothelial cells (BMECs); simultaneously, wound healing of BMECs and tube formation assay were administrated. Compared to MCAo group, SSS extraction could significantly improve neurological functional scores, survival rate and cerebral infarct volume, enhance vWF + vascular density and perimeter, SDF-1α/CXCR4 axis, VEGF expression, as well as activate AKT/mTOR/HIF-1α and ERK1/2 and inhibit Notch1 pathways in penumbra. In vitro, containing SSS extraction serum increased BMEC migration, capillary formation and VEGF expression via up-regulations of AKT/mTOR and ERK1/2 pathways in OGD BMECs, but ERK inhibitor (U0126) reversed the result of VEGF expression in high dose of SSS group. Additionally, VEGFR2 and Notch1 expressions were suppressed by containing SSS extraction serum. All results were in dose dependent manner. Our study firstly demonstrates that SSS extraction is an

  18. Curcumin Improves Amyloid β-Peptide (1-42 Induced Spatial Memory Deficits through BDNF-ERK Signaling Pathway.

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    Lu Zhang

    Full Text Available Curcumin, the most active component of turmeric, has various beneficial properties, such as antioxidant, anti-inflammatory, and antitumor effects. Previous studies have suggested that curcumin reduces the levels of amyloid and oxidized proteins and prevents memory deficits and thus is beneficial to patients with Alzheimer's disease (AD. However, the molecular mechanisms underlying curcumin's effect on cognitive functions are not well-understood. In the present study, we examined the working memory and spatial reference memory in rats that received a ventricular injection of amyloid-β1-42 (Aβ1-42, representing a rodent model of Alzheimer's disease (AD. The rats treated with Aβ1-42 exhibited obvious cognitive deficits in behavioral tasks. Chronic (seven consecutive days, once per day but not acute (once a day curcumin treatments (50, 100, and 200 mg/kg improved the cognitive functions in a dose-dependent manner. In addition, the beneficial effect of curcumin is accompanied by increased BDNF levels and elevated levels of phosphorylated ERK in the hippocampus. Furthermore, the cognition enhancement effect of curcumin could be mimicked by the overexpression of BDNF in the hippocampus and blocked by either bilateral hippocampal injections with lentiviruses that express BDNF shRNA or a microinjection of ERK inhibitor. These findings suggest that chronic curcumin ameliorates AD-related cognitive deficits and that upregulated BDNF-ERK signaling in the hippocampus may underlie the cognitive improvement produced by curcumin.

  19. 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.

  20. ERK1/2 signalling pathway is involved in CD147-mediated gastric cancer cell line SGC7901 proliferation and invasion.

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    Chen, Liping; Pan, Yuqin; Gu, Ling; Nie, Zhenlin; He, Bangshun; Song, Guoqi; Li, Rui; Xu, Yeqiong; Gao, Tianyi; Wang, Shukui

    2013-08-01

    This study aimed to investigate the role of CD147 in the progression of gastric cancer and the signalling pathway involved in CD147-mediated gastric cancer cell line SGC7901 proliferation and invasion. Short hairpin RNA (shRNA) expression vectors targeting CD147 were constructed to silence CD147, and the expression of CD147 was monitored by quantitative realtime reverse transcriptase polymerase chain reaction and Western blot and further confirmed by immunohistochemistry in vivo. Cell proliferation was determined by Cell Counting Kit-8 assay, the activities of matrix metalloproteinase (MMP)-2 and MMP-9 were determined by gelatin zymography, and the invasion of SGC7901 was determined by invasion assay. The phosphorylation and non-phosphorylation of the mitogen-activated protein kinases, extracellular signal-regulated kinase1/2 (ERK1/2), P38 and c-Jun NH2-terminal kinase were examined by Western blot. Additionally, the ERK1/2 inhibitor U0126 were used to confirm the signalling pathway involved in CD147-mediated SGC7901 progression. The BALB/c nude mice were used to study tumour progression in vivo. The results revealed that CD147 silencing inhibited the proliferation and invasion of SGC7901 cells, and down-regulated the activities of MMP-2 and MMP-9 and the phosphorylation of the ERK1/2 in SGC7901 cells. ERK1/2 inhibitor U0126 decreased the proliferation, and invasion of SGC7901 cells, and down-regulated the MMP-2 and MMP-9 activities. In a nude mouse model of subcutaneous xenografts, the tumour volume was significantly smaller in the SGC7901/shRNA group compared to the SGC7901 and SGC7901/snc-RNA group. Immunohistochemistry analysis showed that CD147 and p-ERK1/2 protein expressions were down-regulated in the SGC7901/shRNA2 group compared to the SGC7901 and SGC7901/snc-RNA group. These results suggest that ERK1/2 pathway involves in CD147-mediated gastric cancer growth and invasion. These findings further highlight the importance of CD147 in cancer progression

  1. HER2 induces cell proliferation and invasion of non-small-cell lung cancer by upregulating COX-2 expression via MEK/ERK signaling pathway

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    Chi F

    2016-05-01

    Full Text Available Feng Chi, Rong Wu, Xueying Jin, Min Jiang, Xike Zhu Department of Medical Oncology, Shengjing Hospital of China Medical University, Shenyang, People’s Republic of China Abstract: HER2 positivity has been well studied in various cancers, but its importance in non-small-cell lung cancer (NSCLC is still being explored. In this study, quantitative reverse transcription polymerase chain reaction (qRT-PCR was performed to detect HER2 and COX-2 expression in NSCLC tissues. Then, pcDNA3.1-HER2 was used to overexpress HER2, while HER2 siRNA and COX-2 siRNA were used to silence HER2 and COX-2 expression. MTT assay and invasion assay were used to detect the effects of HER2 on cell proliferation and invasion. Our study revealed that HER2 and COX-2 expression were upregulated in NSCLC tissues and HER2 exhibited a significant positive correlation with the levels of COX-2 expression. Overexpression of HER2 evidently elevated COX-2 expression, while silencing of HER2 evidently decreased COX-2 expression. Furthermore, overexpressed HER2 induced the ERK phosphorylation, and this was abolished by the treatment with U0126, a pharmacological inhibitor of MEK, an upstream kinase of ERK. HER2-induced expression and promoter activity of COX-2 were also suppressed by U0126, suggesting that the MEK/ERK signaling pathway regulates COX-2 expression. In addition, HER2 induced activation of AKT signaling pathway, which was reversed by pretreatment with U0126 and COX-2 siRNA. MTT and invasion assays revealed that HER2 induced cell proliferation and invasion that were reversed by pretreatment with U0126 and COX-2 siRNA. In this study, our results demonstrated for the first time that HER2 elevated COX-2 expression through the activation of MEK/ERK pathway, which subsequently induced cell proliferation and invasion via AKT pathway in NSCLC tissues. Keywords: HER2, MEK/ERK, COX-2, AKT signaling pathway, non-small-cell lung cancer

  2. TGF-β-stimulated aberrant expression of class III β-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    International Nuclear Information System (INIS)

    Chung, Eun Jee; Chun, Ji Na; Jung, Sun-Ah; Cho, Jin Won; Lee, Joon H.

    2011-01-01

    Highlights: ► TGF-β induces aberrant expression of βIII in RPE cells via the ERK pathway. ► TGF-β increases O-GlcNAc modification of βIII in RPE cells. ► Mature RPE cells have the capacity to express a neuron-associated gene by TGF-β. -- Abstract: The class III β-tubulin isotype (β III ) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III β-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-β (TGF-β) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-β on the aberrant expression of class III β-tubulin and the intracellular signaling pathway mediating these changes. TGF-β-induced aberrant expression and O-linked-β-N-acetylglucosamine (O-GlcNac) modification of class III β-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-β also stimulated phosphorylation of ERK. TGF-β-induced aberrant expression of class III β-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-β stimulated aberrant expression of class III β-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-β stimulation and provide useful information towards understanding the pathogenesis of proliferative vitreoretinal diseases.

  3. TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

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    Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

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

    Science.gov (United States)

    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.

  5. Secreted Clusterin protein inhibits osteoblast differentiation of bone marrow mesenchymal stem cells by suppressing ERK1/2 signaling pathway.

    Science.gov (United States)

    Abdallah, Basem M; Alzahrani, Abdullah M; Kassem, Moustapha

    2018-05-01

    Secreted Clusterin (sCLU, also known as Apolipoprotein J) is an anti-apoptotic glycoprotein involved in the regulation of cell proliferation, lipid transport, extracellular tissue remodeling and apoptosis. sCLU is expressed and secreted by mouse bone marrow-derived skeletal (stromal or mesenchymal) stem cells (mBMSCs), but its functional role in MSC biology is not known. In this study, we demonstrated that Clusterin mRNA expression and protein secretion in conditioned medium increased during adipocyte differentiation and decreased during osteoblast differentiation of mBMSCs. Treatment of mBMSC cultures with recombinant sCLU protein increased cell proliferation and exerted an inhibitory effect on the osteoblast differentiation while stimulated adipocyte differentiation in a dose-dependent manner. siRNA-mediated silencing of Clu expression in mBMSCs reduced adipocyte differentiation and stimulated osteoblast differentiation of mBMSCs. Furthermore, the inhibitory effect of sCLU on the osteoblast differentiation of mBMSCs was mediated by the suppression of extracellular signal-regulated kinase (ERK1/2) phosphorylation. In conclusion, we identified sCLU as a regulator of mBMSCs lineage commitment to osteoblasts versus adipocytes through a mechanism mediated by ERK1/2 signaling. Inhibiting sCLU is a possible therapeutic approach for enhancing osteoblast differentiation and consequently bone formation. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Fisetin inhibits laryngeal carcinoma through regulation of AKT/NF-κB/mTOR and ERK1/2 signaling pathways.

    Science.gov (United States)

    Zhang, Xi-Jun; Jia, Shen-Shan

    2016-10-01

    Targeting cancer cells is crucial for improving the efficiency of laryngeal cancer treatment. However, the signaling pathway and therapeutic strategy, related to the tumor, still need further research. Dietary flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) found in many fruits and vegetables has been shown in preclinical studies to inhibit cancer growth through regulating cell cycle, apoptosis, angiogenesis, invasion and metastasis without causing any toxicity to normal cells. PI3K/AKT and ERK1/2 have been known as essential signaling pathways to modulate cell proliferation, apoptosis as well as autophagy via mTOR, Caspase-3 and NF-κB signals. In our study, flow cytometry and western blot assays suggested that apoptosis was induced by fisetin administration, promoting Caspase-3 expressions by regulating PI3K/AKT/NF-κB. Additionally, fisetin suppressed TU212 cells proliferation, which was linked with ERK1/2 inactivation. Further, the activation of PI3K/AKT-regulated mTOR was inhibited by fisetin, leading to transcription suppression and proliferation inhibition of TU212 cells. In vivo studies also showed that the tumor volume and weight of nude mice were reduced for fisetin use with KI-67 decrease and LC3II increase in tumor tissue samples. Together, our data indicated that fisetin had a potential role in controlling human laryngeal cancer through inhibiting tumor cell proliferation, inducing apoptosis and autophagy regulated by ERK1/2 and AKT/NF-κB/mTOR signaling pathways, which might provide a therapeutic strategy for laryngeal cancer inhibition in future. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. Methylcobalamin promotes proliferation and migration and inhibits apoptosis of C2C12 cells via the Erk1/2 signaling pathway

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    Okamoto, Michio [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tanaka, Hiroyuki, E-mail: tanahiro-osk@umin.ac.jp [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Okada, Kiyoshi [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kuroda, Yusuke [Department of Orthopaedic Surgery, Kansai Rosai Hospital, 3-1-69 Inabaso, Amagasaki, Hyogo 660-8511 (Japan); Nishimoto, Shunsuke; Murase, Tsuyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-01-17

    Highlights: •Methylcobalamin activated the Erk1/2 signaling pathway in C2C12 cells. •Methylcobalamin promoted the proliferation and migration in C2C12 cells. •C2C12 cell apoptosis during differentiation was inhibited by methylcobalamin. -- Abstract: Methylcobalamin (MeCbl) is a vitamin B12 analog that has some positive effects on peripheral nervous disorders. Although some previous studies revealed the effects of MeCbl on neurons, its effect on the muscle, which is the final target of motoneuron axons, remains to be elucidated. This study aimed to determine the effect of MeCbl on the muscle. We found that MeCbl promoted the proliferation and migration of C2C12 myoblasts in vitro and that these effects are mediated by the Erk1/2 signaling pathway without affecting the activity of the Akt signaling pathway. We also demonstrated that MeCbl inhibits C2C12 cell apoptosis during differentiation. Our results suggest that MeCbl has beneficial effects on the muscle in vitro. MeCbl administration may provide a novel therapeutic approach for muscle injury or degenerating muscle after denervation.

  8. Cardiac ankyrin repeat protein attenuates cardiac hypertrophy by inhibition of ERK1/2 and TGF-β signaling pathways.

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    Yao Song

    Full Text Available AIMS: It has been reported that cardiac ankyrin repeat protein is associated with heart development and diseases. This study is aimed to investigate the role of CARP in heart hypertrophy in vivo. METHODS AND RESULTS: We generated a cardiac-specific CARP-overexpressing transgenic mouse. Although such animals did not display any overt physiological abnormality, they developed less cardiac hypertrophy in response to pressure overload than did wildtype mice, as indicated by heart weight/body weight ratios, echocardiographic and histological analyses, and expression of hypertrophic markers. These mice also exhibited less cardiac hypertrophy after infusion of isoproterenol. To gain a molecular insight into how CARP attenuated heart hypertrophy, we examined expression of the mitogen-activated protein kinase cascade and found that the concentrations of phosphorylated ERK1/2 and MEK were markedly reduced in the hearts of transgenic mice subjected to pressure overload. In addition, the expressions of TGF-β and phosphorylated Smad3 were significantly downregulated in the hearts of CARP Tg mice in response to pressure overload. Furthermore, addition of human TGF-β1 could reverse the inhibitory effect of CARP on the hypertrophic response induced by phenylephrine in cardiomyocytes. It was also evidenced that the inhibitory effect of CARP on cardiac hypertrophy was not attributed to apoptosis. CONCLUSION: CARP attenuates cardiac hypertrophy, in which the ERK and TGF-β pathways may be involved. Our findings highlight the significance of CARP as an anti-hypertrophic factor in therapy of cardiac hypertrophy.

  9. Biphasic activation of PI3K/Akt and MAPK/Erk1/2 signaling pathways in bovine herpesvirus type 1 infection of MDBK cells

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    Zhu Liqian

    2011-04-01

    Full Text Available Abstract Many viruses have been known to control key cellular signaling pathways to facilitate the virus infection. The possible involvement of signaling pathways in bovine herpesvirus type 1 (BoHV-1 infection is unknown. This study indicated that infection of MDBK cells with BoHV-1 induced an early-stage transient and a late-stage sustained activation of both phosphatidylinositol 3-kinase (PI3K/Akt and mitogen activated protein kinases/extracellular signal-regulated kinase 1/2 (MAPK/Erk1/2 signaling pathways. Analysis with the stimulation of UV-irradiated virus indicated that the virus binding and/or entry process was enough to trigger the early phase activations, while the late phase activations were viral protein expression dependent. Biphasic activation of both pathways was suppressed by the selective inhibitor, Ly294002 for PI3K and U0126 for MAPK kinase (MEK1/2, respectively. Furthermore, treatment of MDBK cells with Ly294002 caused a 1.5-log reduction in virus titer, while U0126 had little effect on the virus production. In addition, the inhibition effect of Ly294002 mainly occurred at the post-entry stage of the virus replication cycle. This revealed for the first time that BoHV-1 actively induced both PI3K/Akt and MAPK/Erk1/2 signaling pathways, and the activation of PI3K was important for fully efficient replication, especially for the post-entry stage.

  10. Upregulation of CD147 promotes cell invasion, epithelial-to-mesenchymal transition and activates MAPK/ERK signaling pathway in colorectal cancer.

    Science.gov (United States)

    Xu, Tao; Zhou, Mingliang; Peng, Lipan; Kong, Shuai; Miao, Ruizheng; Shi, Yulong; Sheng, Hongguang; Li, Leping

    2014-01-01

    Colorectal cancer (CRC) is one of the most common cancers in the world. CD147, a transmembrane protein, has been reported to be correlated with various cancers. In this study, we aimed to investigate the mechanism of CD147 in regulating drug resistance, cell invasion and epithelial-to-mesenchymal transition (EMT) in CRC cells. qRT-PCR and western blotting were used to evaluated the expression of CD147 in 40 CRC cases and 4 cell lines. Increased expression of CD147 at both mRNA and protein levels was found in CRC samples, and the level of CD147 was correlated with lymph node metastasis. CD147 overexpression increased the 5-Fluorouracil (5-FU) resistance, enhanced the invasion and EMT of CRC cells by regulating EMT markers and MMPs. Adverse results were obtained in CD147 knockdown CRC cell line. Further investigation revealed that CD147 activated MAPK/ERK pathway, ERK inhibitor U0126 suppressed the CD147-induced cell invasion, migration and MMP-2, MMP-9 expression. Taken together, our study indicates that CD147 promotes the 5-FU resistance, and MAPK/ERK signaling pathway is involved in CD147-promoted invasion and EMT of CRC cells.

  11. Oncogenic Ras-Induced Morphologic Change Is through MEK/ERK Signaling Pathway to Downregulate Stat3 at a Posttranslational Level in NIH3T3 Cells

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    Hsuan-Heng Yeh

    2008-01-01

    Full Text Available Ras is a key regulator of the MAP kinase-signaling cascade and may cause morphologic change of Ras-transformed cells. Signal transducer and activator of transcription 3 (Stat3 can be activated by cytokine stimulation. In this study, we unravel that Ha-rasV12 overexpression can downregulate the expression of Stat3 protein at a posttranslational level in NIH3T3 cells. Furthermore, we demonstrate that Stat3 expression downregulated by Ha-rasV12 overexpression is through proteosome degradation and not through a mTOR/p70S6K-related signaling pathway. The suppression of Stat3 accompanied by the morphologic change induced by Ha-rasV12 was through mitogen extracellular kinase (MEK/extracellular-regulated kinase (ERK signaling pathway. Microtubule disruption is involved in Ha-rasV12-induced morphologic change, which could be reversed by overexpression of Stat3. Taken together, we are the first to demonstrate that Stat3 protein plays a critical role in Ha-rasV12-induced morphologic change. Oncogenic Ras-triggered morphologic change is through the activation of MEK/ERK to posttranslationally downregulate Stat3 expression. Our finding may shed light on developing novel therapeutic strategies against Ras-related tumorigenesis.

  12. RhNRG-1β Protects the Myocardium against Irradiation-Induced Damage via the ErbB2-ERK-SIRT1 Signaling Pathway.

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    Anxin Gu

    Full Text Available Radiation-induced heart disease (RIHD, which is a serious side effect of the radiotherapy applied for various tumors due to the inevitable irradiation of the heart, cannot be treated effectively using current clinical therapies. Here, we demonstrated that rhNRG-1β, an epidermal growth factor (EGF-like protein, protects myocardium tissue against irradiation-induced damage and preserves cardiac function. rhNRG-1β effectively ameliorated irradiation-induced myocardial nuclear damage in both cultured adult rat-derived cardiomyocytes and rat myocardium tissue via NRG/ErbB2 signaling. By activating ErbB2, rhNRG-1β maintained mitochondrial integrity, ATP production, respiratory chain function and the Krebs cycle status in irradiated cardiomyocytes. Moreover, the protection of irradiated cardiomyocytes and myocardium tissue by rhNRG-1β was at least partly mediated by the activation of the ErbB2-ERK-SIRT1 signaling pathway. Long-term observations further showed that rhNRG-1β administered in the peri-irradiation period exerts continuous protective effects on cardiac pump function, the myocardial energy metabolism, cardiomyocyte volume and interstitial fibrosis in the rats receiving radiation via NRG/ErbB2 signaling. Our findings indicate that rhNRG-1β can protect the myocardium against irradiation-induced damage and preserve cardiac function via the ErbB2-ERK-SIRT1 signaling pathway.

  13. M-CSF signals through the MAPK/ERK pathway via Sp1 to induce VEGF production and induces angiogenesis in vivo.

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    Jennifer M Curry

    Full Text Available BACKGROUND: M-CSF recruits mononuclear phagocytes which regulate processes such as angiogenesis and metastases in tumors. VEGF is a potent activator of angiogenesis as it promotes endothelial cell proliferation and new blood vessel formation. Previously, we reported that in vitro M-CSF induces the expression of biologically-active VEGF from human monocytes. METHODOLOGY AND RESULTS: In this study, we demonstrate the molecular mechanism of M-CSF-induced VEGF production. Using a construct containing the VEGF promoter linked to a luciferase reporter, we found that a mutation reducing HIF binding to the VEGF promoter had no significant effect on luciferase production induced by M-CSF stimulation. Further analysis revealed that M-CSF induced VEGF through the MAPK/ERK signaling pathway via the transcription factor, Sp1. Thus, inhibition of either ERK or Sp1 suppressed M-CSF-induced VEGF at the mRNA and protein level. M-CSF also induced the nuclear localization of Sp1, which was blocked by ERK inhibition. Finally, mutating the Sp1 binding sites within the VEGF promoter or inhibiting ERK decreased VEGF promoter activity in M-CSF-treated human monocytes. To evaluate the biological significance of M-CSF induced VEGF production, we used an in vivo angiogenesis model to illustrate the ability of M-CSF to recruit mononuclear phagocytes, increase VEGF levels, and enhance angiogenesis. Importantly, the addition of a neutralizing VEGF antibody abolished M-CSF-induced blood vessel formation. CONCLUSION: These data delineate an ERK- and Sp1-dependent mechanism of M-CSF induced VEGF production and demonstrate for the first time the ability of M-CSF to induce angiogenesis via VEGF in vivo.

  14. TGF-β1 downregulates StAR expression and decreases progesterone production through Smad3 and ERK1/2 signaling pathways in human granulosa cells.

    Science.gov (United States)

    Fang, Lanlan; Chang, Hsun-Ming; Cheng, Jung-Chien; Leung, Peter C K; Sun, Ying-Pu

    2014-11-01

    Regulation of progesterone production in granulosa cells is important for normal reproductive functions. Steroidogenic acute regulatory protein (StAR) is recognized as the key regulatory protein involved in the rate-limiting step of steroidogenesis. TGF-β1 protein is detected in human follicular fluid, and TGF-β1 and its receptors are expressed in human granulosa cells. However, the functional role of TGF-β1 in the regulation of StAR expression and progesterone production in human granulosa cells remains unknown. Our objective was to investigate the effects of TGF-β1 on StAR expression and progesterone production in human granulosa cells. SVOG cells are human granulosa cells that were obtained from women undergoing in vitro fertilization and immortalized with SV40 large T antigen. SVOG cells were used to investigate the effects of TGF-β1 on StAR expression and progesterone production at an academic research center. Levels of mRNA and protein were examined by RT-qPCR and western blotting, respectively. The accumulation levels of progesterone were measured by enzyme-linked immunosorbent assay (ELISA). TGF-β1 treatment downregulated StAR expression and decreased progesterone production. The suppressive effects of TGF-β1 on StAR expression and progesterone production were abolished by the inhibition of TGF-β type I receptor. In addition, treatment with TGF-β1 activated the Smad2/3 and ERK1/2 signaling pathways. The inhibition of the Smad3 and ERK1/2 signaling pathways attenuated the TGF-β1-induced downregulation of StAR expression and progesterone production. TGF-β1 downregulated StAR expression and decreased progesterone production by activating the Smad3 and ERK1/2 signaling pathways in human granulosa cells.

  15. Involvement of ERK1/2 signaling pathway in atrazine action on FSH-stimulated LHR and CYP19A1 expression in rat granulosa cells

    International Nuclear Information System (INIS)

    Fa, Svetlana; Pogrmic-Majkic, Kristina; Samardzija, Dragana; Glisic, Branka; Kaisarevic, Sonja; Kovacevic, Radmila; Andric, Nebojsa

    2013-01-01

    Worldwide used herbicide atrazine is linked to reproductive dysfunction in females. In this study, we investigated the effects and the mechanism of atrazine action in the ovary using a primary culture of immature granulosa cells. In granulosa cells, follicle-stimulating hormone (FSH) activates both cyclic adenosine monophosphate (cAMP) and extracellular-regulated kinase 1/2 (ERK1/2) cascades, with cAMP pathway being more important for luteinizing hormone receptor (LHR) and aromatase (CYP19A1) mRNA expression. We report that 48 h after atrazine exposure the FSH-stimulated LHR and CYP19A1 mRNA expression and estradiol synthesis were decreased, with LHR mRNA being more sensitive to atrazine than CYP19A1 mRNA. Inadequate acquisition of LHR in the FSH-stimulated and atrazine-exposed granulosa cells renders human chorionic gonadotropin (hCG) ineffective to stimulate amphiregulin (Areg), epiregulin (Ereg), and progesterone receptor (Pgr) mRNA expression, suggesting anti-ovulatory effect of atrazine. To dissect the signaling cascade involved in atrazine action in granulosa cells, we used U0126, a pharmacological inhibitor of ERK1/2. U0126 prevents atrazine-induced decrease in LHR and CYP19A1 mRNA levels and estradiol production in the FSH-stimulated granulosa cells. ERK1/2 inactivation restores the ability of hCG to induce expression of the ovulatory genes in atrazine-exposed granulosa cells. Cell-based ELISA assay revealed that atrazine does not change the FSH-stimulated ERK1/2 phosphorylation in granulosa cells. The results from this study reveal that atrazine does not affect but requires ERK1/2 phosphorylation to cause decrease in the FSH-induced LHR and CYP19A1 mRNA levels and estradiol production in immature granulosa cells, thus compromising ovulation and female fertility. - Highlights: • Atrazine inhibits estradiol production in FSH-stimulated granulosa cells. • Atrazine inhibits LHR and Cyp19a1 mRNA expression in FSH-stimulated granulosa cells. • Atrazine

  16. Involvement of ERK1/2 signaling pathway in atrazine action on FSH-stimulated LHR and CYP19A1 expression in rat granulosa cells

    Energy Technology Data Exchange (ETDEWEB)

    Fa, Svetlana; Pogrmic-Majkic, Kristina; Samardzija, Dragana; Glisic, Branka; Kaisarevic, Sonja; Kovacevic, Radmila; Andric, Nebojsa, E-mail: nebojsa.andric@dbe.uns.ac.rs

    2013-07-01

    Worldwide used herbicide atrazine is linked to reproductive dysfunction in females. In this study, we investigated the effects and the mechanism of atrazine action in the ovary using a primary culture of immature granulosa cells. In granulosa cells, follicle-stimulating hormone (FSH) activates both cyclic adenosine monophosphate (cAMP) and extracellular-regulated kinase 1/2 (ERK1/2) cascades, with cAMP pathway being more important for luteinizing hormone receptor (LHR) and aromatase (CYP19A1) mRNA expression. We report that 48 h after atrazine exposure the FSH-stimulated LHR and CYP19A1 mRNA expression and estradiol synthesis were decreased, with LHR mRNA being more sensitive to atrazine than CYP19A1 mRNA. Inadequate acquisition of LHR in the FSH-stimulated and atrazine-exposed granulosa cells renders human chorionic gonadotropin (hCG) ineffective to stimulate amphiregulin (Areg), epiregulin (Ereg), and progesterone receptor (Pgr) mRNA expression, suggesting anti-ovulatory effect of atrazine. To dissect the signaling cascade involved in atrazine action in granulosa cells, we used U0126, a pharmacological inhibitor of ERK1/2. U0126 prevents atrazine-induced decrease in LHR and CYP19A1 mRNA levels and estradiol production in the FSH-stimulated granulosa cells. ERK1/2 inactivation restores the ability of hCG to induce expression of the ovulatory genes in atrazine-exposed granulosa cells. Cell-based ELISA assay revealed that atrazine does not change the FSH-stimulated ERK1/2 phosphorylation in granulosa cells. The results from this study reveal that atrazine does not affect but requires ERK1/2 phosphorylation to cause decrease in the FSH-induced LHR and CYP19A1 mRNA levels and estradiol production in immature granulosa cells, thus compromising ovulation and female fertility. - Highlights: • Atrazine inhibits estradiol production in FSH-stimulated granulosa cells. • Atrazine inhibits LHR and Cyp19a1 mRNA expression in FSH-stimulated granulosa cells. • Atrazine

  17. 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.

  18. Both ERK/MAPK and TGF-Beta/Smad Signaling Pathways Play a Role in the Kidney Fibrosis of Diabetic Mice Accelerated by Blood Glucose Fluctuation

    Directory of Open Access Journals (Sweden)

    Xiaoyun Cheng

    2013-01-01

    Full Text Available Background. The notion that diabetic nephropathy is the leading cause of renal fibrosis prompted us to investigate the effects of blood glucose fluctuation (BGF under high glucose condition on kidney in the mice. Methods. The diabetic and BGF animal models were established in this study. Immunohistochemistry, Western blot, and RT-PCR analysis were applied to detect the expression of type I collagen, matrix metalloproteinase-1 (MMP1, metalloproteinase inhibitor 1 (TIMP1, transforming growth factor beta 1 (TGF-β1, phosphorylated-ERK, p38, smad2/3, and Akt. Results. BGF treatment increased type I collagen synthesis by two times compared with the control. The expression of MMP1 was reduced markedly while TIMP1 synthesis was enhanced after BGF treatment. ERK phosphorylation exhibits a significant increase in the mice treated with BGF. Furthermore, BGF can markedly upregulate TGF-β1 expression. The p-smad2 showed 2-fold increases compared with the only diabetic mice. However, p-AKT levels were unchanged after BGF treatment. Conclusions. These data demonstrate that BGF can accelerate the trend of kidney fibrosis in diabetic mice by increasing collagen production and inhibiting collagen degradation. Both ERK/MAPK and TGF-β/smad signaling pathways seem to play a role in the development of kidney fibrosis accelerated by blood glucose fluctuation.

  19. Pioglitazone improves the ability of learning and memory via activating ERK1/2 signaling pathway in the hippocampus of T2DM rats.

    Science.gov (United States)

    Gao, F; Zang, L; Wu, D Y; Li, Y J; Zhang, Q; Wang, H B; Tian, G L; Mu, Y M

    2017-06-09

    To explore the correlation between effect of PIO (pioglitazone, PIO) on learning as well as memory and ERK1/2 (extracellular signal regulated kinase 1/2, ERK1/2) pathway in T2DM (type 2 diabetes mellitus, T2DM) rats, further to elucidate the potential mechanism of PIO in improvement of learning and memory. 12-week-old male SD rats (number of 10 per group) were randomly divided into control group (CON), T2DM group (DM) and T2DM +PIO group (DM+PG). Rats in DM and DM+PG groups were given high fat diet for 20 weeks, then treated with Streptozotocin (27mg/kg) by intraperitoneal injection at 21week. After 72h, the FBG (fasting blood glucose, FBG) was greater than 7.0mmol/L can considered T2DM rats. DM+PG group was treated with PIO (10 mg·kg -1 ·d -1 ) by gavage daily. After Hyperinsulinemic-Euglycemic Clamp Study and Morris water maze test at 30-week, all of animals were sacrificed. The expressions of RKIP (Raf-1 kinase inhibitor protein, RKIP) and ERK1/2 in hippocampus were detected using Western Blot and real-time PCR. The FBG level: DM group (7.68±0.54mmol/L) was higher than CON group (5.35±0.63mmol/L) and DM+PG group (6.07±0.84mmol/L), the differences were considered statistically significant (P 0.05); The relative content of p-ERK1/2 protein in CON group and DM+PG group rats dorsal were higher than those in group DM, the difference was considered statistically significant (P0.05). Activation of ERK1/2 signal transduction pathway via reducing RKIP in the hippocampus may be one of the mechanisms of PIO to improve the learning and memory of the T2DM rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Amentoflavone protects dopaminergic neurons in MPTP-induced Parkinson's disease model mice through PI3K/Akt and ERK signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qin; Qin, Liyue; Huang, Fei, E-mail: Fei_H@hotmail.com; Wang, Xiaoshuang; Yang, Liu; Shi, Hailian; Wu, Hui; Zhang, Beibei; Chen, Ziyu; Wu, Xiaojun, E-mail: xiaojunwu320@126.com

    2017-03-15

    Parkinson's disease (PD) is characterized by the progressive degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc). Mitochondrial dysfunction and cell apoptosis are suggested to be actively involved in the pathogenesis of PD. In the present study, the neuroprotective effect of amentoflavone (AF), a naturally occurring biflavonoid from Selaginella tamariscina, was examined in PD models both in vitro and in vivo. On SH-SY5Y cells, AF treatment dose-dependently reduced 1-methyl-4-phenylpyridinium (MPP{sup +})-induced nuclear condensation and loss of cell viability without obvious cytotoxicity. It inhibited the activation of caspase-3 and p21 but increased the Bcl-2/Bax ratio. Further study disclosed that AF enhanced the phosphorylation of PI3K, Akt and ERK1/2 down-regulated by MPP{sup +} in SH-SY5Y cells, the effect of which could be blocked by LY294002, the inhibitor of PI3K. Consistently, AF alleviated the behavioral deterioration in pole and traction tests and rescued the loss of dopaminergic neurons in SNpc and fibers in striatum in methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced mice. It also could enhance the activation of PI3K and Akt as well as Bcl-2/Bax ratio in SN. Moreover, AF alleviated gliosis as well as the gene expression levels of IL-1β and iNOS in SN. Collectively, these results suggested that AF protected dopaminergic neurons against MPTP/MPP{sup +}-induced neurotoxicity, which might be mediated through activation of PI3K/Akt and ERK signaling pathways in dopaminergic neurons and attenuation of neuroinflammation. - Highlights: • AF protected dopaminergic neurons against MPTP/MPP{sup +}-induced neurotoxicity. • AF modulated PI3K/Akt and ERK signaling pathways. • AF could alleviate neuroinflammation in SN.

  1. Amentoflavone protects dopaminergic neurons in MPTP-induced Parkinson's disease model mice through PI3K/Akt and ERK signaling pathways

    International Nuclear Information System (INIS)

    Cao, Qin; Qin, Liyue; Huang, Fei; Wang, Xiaoshuang; Yang, Liu; Shi, Hailian; Wu, Hui; Zhang, Beibei; Chen, Ziyu; Wu, Xiaojun

    2017-01-01

    Parkinson's disease (PD) is characterized by the progressive degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc). Mitochondrial dysfunction and cell apoptosis are suggested to be actively involved in the pathogenesis of PD. In the present study, the neuroprotective effect of amentoflavone (AF), a naturally occurring biflavonoid from Selaginella tamariscina, was examined in PD models both in vitro and in vivo. On SH-SY5Y cells, AF treatment dose-dependently reduced 1-methyl-4-phenylpyridinium (MPP + )-induced nuclear condensation and loss of cell viability without obvious cytotoxicity. It inhibited the activation of caspase-3 and p21 but increased the Bcl-2/Bax ratio. Further study disclosed that AF enhanced the phosphorylation of PI3K, Akt and ERK1/2 down-regulated by MPP + in SH-SY5Y cells, the effect of which could be blocked by LY294002, the inhibitor of PI3K. Consistently, AF alleviated the behavioral deterioration in pole and traction tests and rescued the loss of dopaminergic neurons in SNpc and fibers in striatum in methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced mice. It also could enhance the activation of PI3K and Akt as well as Bcl-2/Bax ratio in SN. Moreover, AF alleviated gliosis as well as the gene expression levels of IL-1β and iNOS in SN. Collectively, these results suggested that AF protected dopaminergic neurons against MPTP/MPP + -induced neurotoxicity, which might be mediated through activation of PI3K/Akt and ERK signaling pathways in dopaminergic neurons and attenuation of neuroinflammation. - Highlights: • AF protected dopaminergic neurons against MPTP/MPP + -induced neurotoxicity. • AF modulated PI3K/Akt and ERK signaling pathways. • AF could alleviate neuroinflammation in SN.

  2. Ell3 stimulates proliferation, drug resistance, and cancer stem cell properties of breast cancer cells via a MEK/ERK-dependent signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hee-Jin [Department of Biomedical Science, College of Life Science, CHA University, Seoul (Korea, Republic of); Kim, Gwangil [Department of Pathology, CHA Bundang Medical Center, CHA University, Seoul (Korea, Republic of); Park, Kyung-Soon, E-mail: kspark@cha.ac.kr [Department of Biomedical Science, College of Life Science, CHA University, Seoul (Korea, Republic of)

    2013-08-09

    Highlights: •Ell3 enhances proliferation and drug resistance of breast cancer cell lines. •Ell3 is related to the cancer stem cell characteristics of breast cancer cell lines. •Ell3 enhances oncogenicity of breast cancer through the ERK1/2 signaling pathway. -- Abstract: Ell3 is a RNA polymerase II transcription elongation factor that is enriched in testis. The C-terminal domain of Ell3 shows strong similarities to that of Ell (eleven−nineteen lysine-rich leukemia gene), which acts as a negative regulator of p53 and regulates cell proliferation and survival. Recent studies in our laboratory showed that Ell3 induces the differentiation of mouse embryonic stem cells by protecting differentiating cells from apoptosis via the promotion of p53 degradation. In this study, we evaluated the function of Ell3 in breast cancer cell lines. MCF-7 cell lines overexpressing Ell3 were used to examine cell proliferation and cancer stem cell properties. Ectopic expression of Ell3 in breast cancer cell lines induces proliferation and 5-FU resistance. In addition, Ell3 expression increases the cancer stem cell population, which is characterized by CD44 (+) or ALDH1 (+) cells. Mammosphere-forming potential and migration ability were also increased upon Ell3 expression in breast cancer cell lines. Through biochemical and molecular biological analyses, we showed that Ell3 regulates proliferation, cancer stem cell properties and drug resistance in breast cancer cell lines partly through the MEK−extracellular signal-regulated kinase signaling pathway. Murine xenograft experiments showed that Ell3 expression promotes tumorigenesis in vivo. These results suggest that Ell3 may play a critical role in promoting oncogenesis in breast cancer by regulating cell proliferation and cancer stem cell properties via the ERK1/2 signaling pathway.

  3. Ell3 stimulates proliferation, drug resistance, and cancer stem cell properties of breast cancer cells via a MEK/ERK-dependent signaling pathway

    International Nuclear Information System (INIS)

    Ahn, Hee-Jin; Kim, Gwangil; Park, Kyung-Soon

    2013-01-01

    Highlights: •Ell3 enhances proliferation and drug resistance of breast cancer cell lines. •Ell3 is related to the cancer stem cell characteristics of breast cancer cell lines. •Ell3 enhances oncogenicity of breast cancer through the ERK1/2 signaling pathway. -- Abstract: Ell3 is a RNA polymerase II transcription elongation factor that is enriched in testis. The C-terminal domain of Ell3 shows strong similarities to that of Ell (eleven−nineteen lysine-rich leukemia gene), which acts as a negative regulator of p53 and regulates cell proliferation and survival. Recent studies in our laboratory showed that Ell3 induces the differentiation of mouse embryonic stem cells by protecting differentiating cells from apoptosis via the promotion of p53 degradation. In this study, we evaluated the function of Ell3 in breast cancer cell lines. MCF-7 cell lines overexpressing Ell3 were used to examine cell proliferation and cancer stem cell properties. Ectopic expression of Ell3 in breast cancer cell lines induces proliferation and 5-FU resistance. In addition, Ell3 expression increases the cancer stem cell population, which is characterized by CD44 (+) or ALDH1 (+) cells. Mammosphere-forming potential and migration ability were also increased upon Ell3 expression in breast cancer cell lines. Through biochemical and molecular biological analyses, we showed that Ell3 regulates proliferation, cancer stem cell properties and drug resistance in breast cancer cell lines partly through the MEK−extracellular signal-regulated kinase signaling pathway. Murine xenograft experiments showed that Ell3 expression promotes tumorigenesis in vivo. These results suggest that Ell3 may play a critical role in promoting oncogenesis in breast cancer by regulating cell proliferation and cancer stem cell properties via the ERK1/2 signaling pathway

  4. Protein kinase D1 stimulates proliferation and enhances tumorigenesis of MCF-7 human breast cancer cells through a MEK/ERK-dependent signaling pathway

    International Nuclear Information System (INIS)

    Karam, Manale; Legay, Christine; Auclair, Christian; Ricort, Jean-Marc

    2012-01-01

    Protein kinase D1, PKD1, is a novel serine/threonine kinase whose altered expression and dysregulation in many tumors as well as its activation by several mitogens suggest that this protein could regulate proliferation and tumorigenesis. Nevertheless, the precise signaling pathways used are still unclear and the potential direct role of PKD1 in tumor development and progression has not been yet investigated. In order to clarify the role of PKD1 in cell proliferation and tumorigenesis, we studied the effects of PKD1 overexpression in a human adenocarcinoma breast cancer cell line, MCF-7 cells. We demonstrated that overexpression of PKD1 specifically promotes MCF-7 cell proliferation through accelerating G0/G1 to S phase transition of the cell cycle. Moreover, inhibition of endogenous PKD1 significantly reduced cell proliferation. Taken together, these results clearly strengthen the regulatory role of PKD1 in cell growth. We also demonstrated that overexpression of PKD1 specifically diminished serum- and anchorage-dependence for proliferation and survival in vitro and allowed MCF-7 cells to form tumors in vivo. Thus, all these data highlight the central role of PKD1 in biological processes which are hallmarks of malignant transformation. Analysis of two major signaling pathways implicated in MCF-7 cell proliferation showed that PKD1 overexpression significantly increased ERK1/2 phosphorylation state without affecting Akt phosphorylation. Moreover, PKD1 overexpression-stimulated cell proliferation and anchorage-independent growth were totally impaired by inhibition of the MEK/ERK kinase cascade. However, neither of these effects was affected by blocking the PI 3-kinase/Akt signaling pathway. Thus, the MEK/ERK signaling appears to be a determining pathway mediating the biological effects of PKD1 in MCF-7 cells. Taken together, all these data demonstrate that PKD1 overexpression increases the aggressiveness of MCF-7 breast cancer cells through enhancing their oncogenic

  5. Dihydroartemisinin alleviates bile duct ligation-induced liver fibrosis and hepatic stellate cell activation by interfering with the PDGF-βR/ERK signaling pathway.

    Science.gov (United States)

    Chen, Qin; Chen, Lianyun; Kong, Desong; Shao, Jiangjuan; Wu, Li; Zheng, Shizhong

    2016-05-01

    Liver fibrosis represents a frequent event following chronic insult to trigger wound healing responses in the liver. Activation of hepatic stellate cells (HSCs), which is a pivotal event during liver fibrogenesis, is accompanied by enhanced expressions of a series of marker proteins and pro-fibrogenic signaling molecules. Artemisinin, a powerful antimalarial medicine, is extracted from the Chinese herb Artemisia annua L., and can inhibit the proliferation of cancer cells. Dihydroartemisinin (DHA), the major active metabolite of artemisinin, is able to attenuate lung injury and fibrosis. However, the effect of DHA on liver fibrosis remains unclear. The aim of this study was to investigate the effect of DHA on bile duct ligation-induced injury and fibrosis in rats. DHA improved the liver histological architecture and attenuated collagen deposition in the fibrotic rat liver. Experiments in vitro showed that DHA inhibited the proliferation of HSCs and arrested the cell cycle at the S checkpoint by altering several cell-cycle regulatory proteins. Moreover, DHA reduced the protein expressions of a-SMA, α1 (I) collagen and fibronectin, being associated with interference of the platelet-derived growth factor β receptor (PDGF-βR)-mediated ERK pathway. These data collectively revealed that DHA relieved liver fibrosis possibly by targeting HSCs via the PDGF-βR/ERK pathway. DHA may be a therapeutic antifibrotic agent for the treatment of hepatic fibrosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. GLP-1 Treatment Improves Diabetic Retinopathy by Alleviating Autophagy through GLP-1R-ERK1/2-HDAC6 Signaling Pathway.

    Science.gov (United States)

    Cai, Xiangsheng; Li, Jingjing; Wang, Mingzhu; She, Miaoqin; Tang, Yongming; Li, Jinlong; Li, Hongwei; Hui, Hongxiang

    2017-01-01

    Objective: Apoptosis and autophagy of retinal cells, which may be induced by oxidative stress, are tightly associated with the pathogenesis of diabetic retinopathy (DR). The autophagy induced by oxidative stress is considered as excessively stimulated autophagy, which accelerates the progression of DR. This study aims to investigate the protective effect of GLP-1 treatment on alleviating apoptosis and autophagy of retinal cells in type 2 diabetic rats and reveals its possible mechanism. Methods: Type 2 diabetic rats were induced by fed with high sugar, high fat diet and followed with streptozotocin injection. GLP-1 was applied to treat the diabetic rats for one week after the onset of diabetes. The expressions of oxidative stress-related enzymes, retinal GLP-1R, mitochondria-dependent apoptosis- related genes, autophagy markers, and autophagy-associated pathway genes were studied by Western blotting or immunohistochemistry analysis. Results: GLP-1treatment reduced the levels of NOX3 and SOD2 in DR. The expression of BCL2 was increased, while the levels of caspase3 and LC3B were reduced through GLP-1 treatment in DR . GLP-1 treatment restored the GLP-1R expression and decreased the levels of phosphorylated AKT and phosphorylated ERK1/2, which was accompanied with the reduction of the HDAC6 levels in DR. Conclusions: GLP-1 treatment can alleviate autophagy which may be induced by oxidative stress; this protective effect is likely through GLP-1R-ERK1/2-HDAC6 signaling pathway.

  7. [Intervention effects of Zuoguiwan containing serum on osteoblast through ERK1/2 and Wnt/β-catenin signaling pathway in models with kidney-Yang-deficiency, kidney-Yin-deficiency osteoporosis syndromes].

    Science.gov (United States)

    Zhang, Jian-Hua; Xin, Jing; Fan, Lian-Xia; Yin, Hua

    2017-10-01

    To clarify the effects of Zuoguiwan containing serum on osteoblast proliferation and alkaline phosphatase(ALP) expression and its effects on the expression of β-catenin, ERK1, ERK2 mRNA and protein of osteoblast through ERK1/2, Wnt/β-catenin signaling pathway in models with osteoporosis(OP) kidney-Yang-deficiency, osteoporosis(OP) kidney-Yin-deficiency syndrome. Rat osteoporosis models were established by ovariectomy surgery, and 10 weeks after surgery, hydrocortisone was injected and thyroxine was administered by intragastric administration to establish OP kidney-Yang-deficiency rat model, and OP kidney-Yin-deficiency rat model. Osteoblasts were obtained from 24 h newborn rat skull and were identified by alkaline phosphatase and alizarin red staining. Zuoguiwan containing serum of OP, OP kidney-Yang-deficiency, and OP kidney-Yin-deficiency, as well as the blank serum were used to intervene the osteoblast, and the cells proliferation was detected by MTS. ELISA assay was used to detect ALP expression. RT-PCR assay was used to detect the mRNA expression of ERK1, ERK2, β-catenin and protein expression levels were detected by Western blot. The results showed that Zuoguiwan containing serum in OP kidney-Yin-deficiency model had stronger effect than OP kidney-Yang-deficiency in promoting osteoblast proliferation, ALP expression, osteoblast ERK1/2, Wnt/β-catenin signaling pathway related factors β-catenin, ERK1, ERK2 mRNA and protein expression levels. This was consistent with the TCM theory of "Zuoguiwan nourishes kidney Yin", providing a scientific basis for the clinical and dialectical treatment of osteoporosis. Zuoguiwan could regulate the proliferation and differentiation of bone cells by ERK1/2 and Wnt/β-catenin signaling pathway, which may be one of the mechanisms of Zuoguiwan for the prevention of osteoporosis. Copyright© by the Chinese Pharmaceutical Association.

  8. Perlecan Domain V induces VEGf secretion in brain endothelial cells through integrin α5β1 and ERK-dependent signaling pathways.

    Directory of Open Access Journals (Sweden)

    Douglas N Clarke

    Full Text Available Perlecan Domain V (DV promotes brain angiogenesis by inducing VEGF release from brain endothelial cells (BECs following stroke. In this study, we define the specific mechanism of DV interaction with the α(5β(1 integrin, identify the downstream signal transduction pathway, and further investigate the functional significance of resultant VEGF release. Interestingly, we found that the LG3 portion of DV, which has been suggested to possess most of DV's angio-modulatory activity outside of the brain, binds poorly to α(5β(1 and induces less BEC proliferation compared to full length DV. Additionally, we implicate DV's DGR sequence as an important element for the interaction of DV with α(5β(1. Furthermore, we investigated the importance of AKT and ERK signaling in DV-induced VEGF expression and secretion. We show that DV increases the phosphorylation of ERK, which leads to subsequent activation and stabilization of eIF4E and HIF-1α. Inhibition of ERK activity by U0126 suppressed DV-induced expression and secretion of VEGR in BECs. While DV was capable of phosphorylating AKT we show that AKT phosphorylation does not play a role in DV's induction of VEGF expression or secretion using two separate inhibitors, LY294002 and Akt IV. Lastly, we demonstrate that VEGF activity is critical for DV increases in BEC proliferation, as well as angiogenesis in a BEC-neuronal co-culture system. Collectively, our findings expand our understanding of DV's mechanism of action on BECs, and further support its potential as a novel stroke therapy.

  9. Perlecan Domain V Induces VEGf Secretion in Brain Endothelial Cells through Integrin α5β1 and ERK-Dependent Signaling Pathways

    Science.gov (United States)

    Clarke, Douglas N.; Al Ahmad, Abraham; Lee, Boyeon; Parham, Christi; Auckland, Lisa; Fertala, Andrezj; Kahle, Michael; Shaw, Courtney S.; Roberts, Jill; Bix, Gregory J.

    2012-01-01

    Perlecan Domain V (DV) promotes brain angiogenesis by inducing VEGF release from brain endothelial cells (BECs) following stroke. In this study, we define the specific mechanism of DV interaction with the α5β1 integrin, identify the downstream signal transduction pathway, and further investigate the functional significance of resultant VEGF release. Interestingly, we found that the LG3 portion of DV, which has been suggested to possess most of DV’s angio-modulatory activity outside of the brain, binds poorly to α5β1 and induces less BEC proliferation compared to full length DV. Additionally, we implicate DV’s DGR sequence as an important element for the interaction of DV with α5β1. Furthermore, we investigated the importance of AKT and ERK signaling in DV-induced VEGF expression and secretion. We show that DV increases the phosphorylation of ERK, which leads to subsequent activation and stabilization of eIF4E and HIF-1α. Inhibition of ERK activity by U0126 suppressed DV-induced expression and secretion of VEGR in BECs. While DV was capable of phosphorylating AKT we show that AKT phosphorylation does not play a role in DV’s induction of VEGF expression or secretion using two separate inhibitors, LY294002 and Akt IV. Lastly, we demonstrate that VEGF activity is critical for DV increases in BEC proliferation, as well as angiogenesis in a BEC-neuronal co-culture system. Collectively, our findings expand our understanding of DV’s mechanism of action on BECs, and further support its potential as a novel stroke therapy. PMID:23028886

  10. BMP6 down-regulates GDNF expression through SMAD1/5 and ERK1/2 signaling pathways in human granulosa-lutein cells.

    Science.gov (United States)

    Zhang, Xin-Yue; Chang, Hsun-Ming; Taylor, Elizabeth L; Leung, Peter C K; Liu, Rui-Zhi

    2018-05-09

    Bone morphogenetic protein 6 (BMP6) is a critical regulator of follicular development that is expressed in mammalian oocytes and granulosa cells. Glial cell line-derived neurotrophic factor (GDNF) is an intraovarian neurotrophic factor that plays an essential role in regulating mammalian oocyte maturation. The aim of this study was to investigate the effect of BMP6 on the regulation of GDNF expression and the potential underlying mechanisms. We used an established immortalized human granulosa cell line (SVOG cells) and primary human granulosa-lutein cells as in vitro cell models. Our results showed that BMP6 significantly down-regulated the expression of GDNF in both SVOG and primary human granulosa-lutein cells. Using dual inhibition approaches (kinase receptor inhibitor and small interfering RNA knockdown), our results showed that both ALK2 and ALK3 are involved in BMP6-induced down-regulation of GDNF. In addition, BMP6 induced the phosphorylation of SMAD1/5/8 and ERK1/2 but not AKT or p38. Among three downstream mediators, both SMAD1 and SMAD5 are involved in BMP6-induced down-regulation of GDNF. Moreover, concomitant knockdown of endogenous SMAD4 and inhibition of ERK1/2 activity completely reversed BMP6-induced down-regulation of GDNF, indicating that both SMAD and ERK1/2 signaling pathways are required for the regulatory effect of BMP6 on GDNF expression. Our findings suggest an additional role for an intrafollicular growth factor in regulating follicular function through their paracrine interactions in human granulosa cells.

  11. Echinocystic acid inhibits RANKL-induced osteoclastogenesis by regulating NF-κB and ERK signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jian-hui, E-mail: jianhui_yangxa@163.com [Rehabilitation Center, First Affiliated Hospital of Health Science Center, Xi’an Jiaotong University, Xi’an, 710061, Shaanxi Province (China); Li, Bing [Department of Dermatology, the 451st Hospital of People’s Liberation Army, Xi’an 710054, Shaanxi Province (China); Wu, Qiong; Lv, Jian-guo; Nie, Hui-Yong [Rehabilitation Center, First Affiliated Hospital of Health Science Center, Xi’an Jiaotong University, Xi’an, 710061, Shaanxi Province (China)

    2016-09-02

    Receptor activator of nuclear factor-κB ligand (RANKL) is a key factor in the differentiation and activation of osteoclasts. Echinocystic acid (EA), a pentacyclic triterpene isolated from the fruits of Gleditsia sinensis Lam, was reported to prevent reduction of bone mass and strength and improve the cancellous bone structure and biochemical properties in ovariectomy rats. However, the molecular mechanism of EA on the osteoclast formation has not been reported. The purpose of this study was to investigate the effects and mechanism of EA on RANKL-induced osteoclastogenesis. Our results showed that EA inhibited the formation of osteoclast, as well as the expression of osteoclastogenesis-related marker proteins in bone marrow macrophages (BMMs). At molecular levels, EA inhibited RANKL-induced NF-κB activation and ERK phosphorylation in BMMs. In conclusion, the present study demonstrated that EA can suppress osteoclastogenesis in vitro. Moreover, we clarified that these inhibitory effects of EA occur through suppression of NF-κB and ERK activation. Therefore, EA may be a potential agent in the treatment of osteoclast-related diseases such as osteoporosis. - Highlights: • EA inhibited the formation of osteoclast in BMMs. • EA inhibits the expression of osteoclastogenesis-related marker proteins in BMMs. • EA inhibits RANKL-induced NF-κB activation in BMMs. • EA inhibits RANKL-induced ERK phosphorylation in BMMs.

  12. CREBBP knockdown enhances RAS/RAF/MEK/ERK signaling in Ras pathway mutated acute lymphoblastic leukemia but does not modulate chemotherapeutic response.

    Science.gov (United States)

    Dixon, Zach A; Nicholson, Lindsay; Zeppetzauer, Martin; Matheson, Elizabeth; Sinclair, Paul; Harrison, Christine J; Irving, Julie A E

    2017-04-01

    Relapsed acute lymphoblastic leukemia is the most common cause of cancer-related mortality in young people and new therapeutic strategies are needed to improve outcome. Recent studies have shown that heterozygous inactivating mutations in the histone acetyl transferase, CREBBP , are particularly frequent in relapsed childhood acute lymphoblastic leukemia and associated with a hyperdiploid karyotype and KRAS mutations. To study the functional impact of CREBBP haploinsufficiency in acute lymphoblastic leukemia, RNA interference was used to knock down expression of CREBBP in acute lymphoblastic leukemia cell lines and various primagraft acute lymphoblastic leukemia cells. We demonstrate that attenuation of CREBBP results in reduced acetylation of histone 3 lysine 18, but has no significant impact on cAMP-dependent target gene expression. Impaired induction of glucocorticoid receptor targets was only seen in 1 of 4 CREBBP knockdown models, and there was no significant difference in glucocorticoid-induced apoptosis, sensitivity to other acute lymphoblastic leukemia chemotherapeutics or histone deacetylase inhibitors. Importantly, we show that CREBBP directly acetylates KRAS and that CREBBP knockdown enhances signaling of the RAS/RAF/MEK/ERK pathway in Ras pathway mutated acute lymphoblastic leukemia cells, which are still sensitive to MEK inhibitors. Thus, CREBBP mutations might assist in enhancing oncogenic RAS signaling in acute lymphoblastic leukemia but do not alter response to MEK inhibitors. Copyright© Ferrata Storti Foundation.

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

    Science.gov (United States)

    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).

  14. Signaling pathways of interleukin-1 actions in the brain: anatomical distribution of phospho-ERK1/2 in the brain of rat treated systemically with interleukin-1beta.

    Science.gov (United States)

    Nadjar, A; Combe, C; Busquet, P; Dantzer, R; Parnet, P

    2005-01-01

    Interleukin-1beta is released at the periphery during infection and acts on the nervous system to induce fever, neuroendocrine activation, and behavioral changes. These effects are mediated by brain type I IL-1 receptors. In vitro studies have shown the ability of interleukin-1beta to activate mitogen-activated protein kinase signaling pathways including p38, c-Jun N-terminal kinase and extracellular signal-regulated protein kinase 1 and 2 (ERK1/2). In contrast to other mitogen-activated protein kinases, little is known about ERK1/2 activation in the rat brain in response to interleukin-1beta. The aim of the present study was therefore to investigate spatial and temporal activation of ERK1/2 in the rat brain after peripheral administration of interleukin-1beta using immunohistochemistry to detect the phosphorylated form of the kinase. In non-stimulated conditions, phosphorylated ERK1/2 immunoreactivity was observed in neurons throughout the brain. Administration of interleukin-1beta (60 microg/kg, i.p.) induced the phosphorylation of ERK1/2 in areas at the interface between brain and blood or cerebrospinal fluid: meninges, circumventricular organs, endothelial like cells of the blood vessels, and in brain nuclei involved in behavioral depression, fever and neuroendocrine activation: paraventricular nucleus of the hypothalamus, supraoptic nucleus, central amygdala and arcuate nucleus. Double labeling of phosphorylated ERK1/2 and cell markers revealed the expression of phosphorylated ERK1/2 in neurons, astrocytes and microglia. Since phosphorylated ERK1/2 was found in structures in which type I IL-1 receptor has already been identified as well as in structures lacking this receptor, activation of ERK1/2 is likely to occur in response to both direct and indirect action of interleukin-1beta on its target cells.

  15. The progesterone-induced enhancement of object recognition memory consolidation involves activation of the extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin (mTOR) pathways in the dorsal hippocampus

    Science.gov (United States)

    Orr, Patrick T.; Rubin, Amanda J.; Fan, Lu; Kent, Brianne A.; Frick, Karyn M.

    2012-01-01

    Although much recent work has elucidated the biochemical mechanisms underlying the modulation of memory by 17β-estradiol, little is known about the signaling events through which progesterone (P) regulates memory. We recently demonstrated that immediate post-training infusion of P into the dorsal hippocampus enhances object recognition memory consolidation in young ovariectomized female mice (Orr et al., 2009). The goal of the present study was to identify the biochemical alterations that might underlie this mnemonic enhancement. We hypothesized that the P-induced enhancement of object recognition would be dependent on activation of the ERK and mTOR pathways. In young ovariectomized mice, we found that bilateral dorsal hippocampal infusion of P significantly increased levels of phospho-p42 ERK and the mTOR substrate S6K in the dorsal hippocampus 5 minutes after infusion. Phospho-p42 ERK levels were downregulated 15 minutes after infusion and returned to baseline 30 minutes after infusion, suggesting a biphasic effect of P on ERK activation. Dorsal hippocampal ERK and mTOR activation were necessary for P to facilitate memory consolidation, as suggested by the fact that inhibitors of both pathways infused into the dorsal hippocampus immediately after training blocked the P-induced enhancement of object recognition. Collectively, these data provide the first demonstration that the ability of P to enhance memory consolidation depends on the rapid activation of cell signaling and protein synthesis pathways in the dorsal hippocampus. PMID:22265866

  16. Fluid shear stress suppresses TNF-α-induced apoptosis in MC3T3-E1 cells: Involvement of ERK5-AKT-FoxO3a-Bim/FasL signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Bin, Geng; Bo, Zhang; Jing, Wang; Jin, Jiang; Xiaoyi, Tan; Cong, Chen; Liping, An; Jinglin, Ma; Cuifang, Wang; Yonggang, Chen [The Second Hospital of Lanzhou University, #82 Cuiyingmen, Lanzhou, 730000 Gansu (China); Orthopaedics Key Laboratory of Gansu Province, Lanzhou, 730000 Gansu (China); Yayi, Xia, E-mail: xiayayildey@163.com [The Second Hospital of Lanzhou University, #82 Cuiyingmen, Lanzhou, 730000 Gansu (China); Orthopaedics Key Laboratory of Gansu Province, Lanzhou, 730000 Gansu (China)

    2016-05-01

    TNF-α is known to induce osteoblasts apoptosis, whereas mechanical stimulation has been shown to enhance osteoblast survival. In the present study, we found that mechanical stimulation in the form of fluid shear stress (FSS) suppresses TNF-α induced apoptosis in MC3T3-E1 cells. Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family that has been implicated in cell survival. We also demonstrated that FSS imposed by flow chamber in vitro leads to a markedly activation of ERK5, which was shown to be protective against TNF-α-induced apoptosis, whereas the transfection of siRNA against ERK5 (ERK5-siRNA) reversed the FSS-medicated anti-apoptotic effects. An initial FSS-mediated activation of ERK5 that phosphorylates AKT to increase its activity, and a following forkhead box O 3a (FoxO3a) was phosphorylated by activated AKT. Phosphorylated FoxO3a is sequestered in the cytoplasm, and prevents it from translocating to nucleus where it can increase the expression of FasL and Bim. The inhibition of AKT-FoxO3a signalings by a PI3K (PI3-kinase)/AKT inhibitor (LY294002) or the transfection of ERK5-siRNA led to the nuclear translocation of non-phosphorylated FoxO3a, and increased the protein expression of FasL and Bim. In addition, the activation of caspase-3 by TNF-α was significantly inhibited by aforementioned FSS-medicated mechanisms. In brief, the activation of ERK5-AKT-FoxO3a signaling pathways by FSS resulted in a decreased expression of FasL and Bim and an inhibition of caspase-3 activation, which exerts a protective effect that prevents osteoblasts from apoptosis. - Highlights: • Fluid shear stress inhibits osteoblast apoptosis induced by TNF-α. • Inhibition of ERK5 activity by transfection of ERK5 siRNA blocks FSS-mediated anti-apoptotic effect in osteoblast. • Activated ERK5-AKT-FoxO3a-Bim/FasL signaling pathways by FSS is required to protect osteoblast from apoptosis.

  17. Vanillin Protects Dopaminergic Neurons against Inflammation-Mediated Cell Death by Inhibiting ERK1/2, P38 and the NF-κB Signaling Pathway.

    Science.gov (United States)

    Yan, Xuan; Liu, Dian-Feng; Zhang, Xiang-Yang; Liu, Dong; Xu, Shi-Yao; Chen, Guang-Xin; Huang, Bing-Xu; Ren, Wen-Zhi; Wang, Wei; Fu, Shou-Peng; Liu, Ju-Xiong

    2017-02-12

    Neuroinflammation plays a very important role in the pathogenesis of Parkinson's disease (PD). After activation, microglia produce pro-inflammatory mediators that damage surrounding neurons. Consequently, the inhibition of microglial activation might represent a new therapeutic approach of PD. Vanillin has been shown to protect dopaminergic neurons, but the mechanism is still unclear. Herein, we further study the underlying mechanisms in lipopolysaccharide (LPS)-induced PD models. In vivo, we firstly established rat models of PD by unilateral injection of LPS into substantia nigra (SN), and then examined the role of vanillin in motor dysfunction, microglial activation and degeneration of dopaminergic neurons. In vitro, murine microglial BV-2 cells were treated with vanillin prior to the incubation of LPS, and then the inflammatory responses and the related signaling pathways were analyzed. The in vivo results showed that vanillin markedly improved the motor dysfunction, suppressed degeneration of dopaminergic neurons and inhibited microglial over-activation induced by LPS intranigral injection. The in vitro studies demonstrated that vanillin reduces LPS-induced expression of inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), IL-1β, and IL-6 through regulating ERK1/2, p38 and NF-κB signaling. Collectively, these data indicated that vanillin has a role in protecting dopaminergic neurons via inhibiting inflammatory activation.

  18. Vanillin Protects Dopaminergic Neurons against Inflammation-Mediated Cell Death by Inhibiting ERK1/2, P38 and the NF-κB Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xuan Yan

    2017-02-01

    Full Text Available Neuroinflammation plays a very important role in the pathogenesis of Parkinson’s disease (PD. After activation, microglia produce pro-inflammatory mediators that damage surrounding neurons. Consequently, the inhibition of microglial activation might represent a new therapeutic approach of PD. Vanillin has been shown to protect dopaminergic neurons, but the mechanism is still unclear. Herein, we further study the underlying mechanisms in lipopolysaccharide (LPS-induced PD models. In vivo, we firstly established rat models of PD by unilateral injection of LPS into substantia nigra (SN, and then examined the role of vanillin in motor dysfunction, microglial activation and degeneration of dopaminergic neurons. In vitro, murine microglial BV-2 cells were treated with vanillin prior to the incubation of LPS, and then the inflammatory responses and the related signaling pathways were analyzed. The in vivo results showed that vanillin markedly improved the motor dysfunction, suppressed degeneration of dopaminergic neurons and inhibited microglial over-activation induced by LPS intranigral injection. The in vitro studies demonstrated that vanillin reduces LPS-induced expression of inducible nitric oxide (iNOS, cyclooxygenase-2 (COX-2, IL-1β, and IL-6 through regulating ERK1/2, p38 and NF-κB signaling. Collectively, these data indicated that vanillin has a role in protecting dopaminergic neurons via inhibiting inflammatory activation.

  19. Sphingosine-1-phosphate promotes extravillous trophoblast cell invasion by activating MEK/ERK/MMP-2 signaling pathways via S1P/S1PR1 axis activation.

    Science.gov (United States)

    Yang, Weiwei; Li, Qinghua; Pan, Zhifang

    2014-01-01

    Successful placentation depends on the proper invasion of extravillous trophoblast (EVT) cells into maternal tissues. Previous reports demonstrated that S1P receptors are expressed in the EVT cells and S1P could regulate migration and function of trophoblast cells via S1P receptors. However, little is known about roles of S1P in the invasion of EVT cells. Our study was performed to investigate S1P effect on the invasion of EVT cells. We used the extravillous trophoblast cell line HTR8/SVneo cells to evaluate the effect. In vitro invasion assay was employed to determine the invasion of HTR8/SVneo cells induced by S1P. MMP-2 enzyme activity and relative level in the supernatants of HTR8/SVneo was assessed by gelatin zymography and western blot. Based on the above, siRNA and specific inhibitors were used for the intervention and study of potential signal pathways, and Real-time qPCR and western blot were used to test the mRNA and protein level of potential signal targets. We found that S1P could promote HTR8/SVneo cell invasion and upregulates activity and level of MMP-2. The promotion requires activation of MEK-ERK and is dependent on the axis of S1P/S1PR1. Our investigation of S1P may provide new insights into the molecular mechanisms of EVT invasion.

  20. Mechanisms Involving Ang II and MAPK/ERK1/2 Signaling Pathways Underlie Cardiac and Renal Alterations during Chronic Undernutrition

    Science.gov (United States)

    Pereira-Acácio, Amaury; Luzardo, Ricardo; Sampaio, Luzia S.; Luna-Leite, Marcia A.; Lara, Lucienne S.; Einicker-Lamas, Marcelo; Panizzutti, Rogério; Madeira, Caroline; Vieira-Filho, Leucio D.; Castro-Chaves, Carmen; Ribeiro, Valdilene S.; Paixão, Ana D. O.; Medei, Emiliano; Vieyra, Adalberto

    2014-01-01

    Background Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction. Methodology/Principal Findings Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+)ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R) was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan. Conclusion/Significance The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood. PMID:24983243

  1. On the nanotoxicity of PAMAM dendrimers: Superfect® stimulates the EGFR-ERK1/2 signal transduction pathway via an oxidative stress-dependent mechanism in HEK 293 cells.

    Science.gov (United States)

    Akhtar, Saghir; Chandrasekhar, Bindu; Attur, Sreeja; Yousif, Mariam H M; Benter, Ibrahim F

    2013-05-01

    Polyamidoamine (PAMAM) dendrimers are cationic branch-like macromolecules that may serve as drug delivery systems for gene-based therapies such as RNA interference. For their safe use in the clinic, they should ideally only enhance drug delivery to target tissues and exhibit no adverse effects. However, little is known about their toxicological profiles in terms of their interactions with cellular signal transduction pathways such as the epidermal growth factor receptor (EGFR). The EGFR is an important signaling cascade that regulates cell growth, differentiation, migration, survival and apoptosis. Here, we investigated the impact of naked, unmodified Superfect (SF), a commercially available generation 6 PAMAM dendrimer, on the epidermal growth factor receptor (EGFR) tyrosine kinase-extracellular-regulated kinase 1/2 (ERK1/2) signaling pathway in human embryonic kidney (HEK 293) cells. At concentrations routinely used for transfection, SF exhibited time and dose-dependent stimulation of EGFR and ERK1/2 phosphorylation whereas AG1478, a selective EGFR tyrosine kinase antagonist, inhibited EGFR-ERK1/2 signaling. SF-induced phosphorylation of EGFR for 1h was partly reversible upon removal of the dendrimer and examination of cells 24 later. Co-treatment of SF with epidermal growth factor (EGF) ligand resulted in greater EGFR stimulation than either agent alone implying that the stimulatory effects of SF and the ligand are synergistic. Dendrimer-induced stimulation of EGFR-ERK1/2 signaling could be attenuated by the antioxidants apocynin, catalase and tempol implying that an oxidative stress dependent mechanism was involved. These results show for the first time that PAMAM dendrimers, aside from their ability to improve drug delivery, can modulate the important EGFR-ERK1/2 cellular signal transduction pathway - a novel finding that may have a bearing on their safe application as drug delivery systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Kaempferol Inhibits Angiogenesis by Suppressing HIF-1α and VEGFR2 Activation via ERK/p38 MAPK and PI3K/Akt/mTOR Signaling Pathways in Endothelial Cells.

    Science.gov (United States)

    Kim, Gi Dae

    2017-12-01

    Kaempferol has been shown to inhibit vascular formation in endothelial cells. However, the underlying mechanisms are not fully understood. In the present study, we evaluated whether kaempferol exerts antiangiogenic effects by targeting extracellular signal-regulated kinase (ERK)/p38 mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathways in endothelial cells. Endothelial cells were treated with various concentrations of kaempferol for 24 h. Cell viability was determined by the 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay; vascular formation was analyzed by tube formation, wound healing, and mouse aortic ring assays. Activation of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor receptor 2 (VEGFR2), ERK/p38 MAPK, and PI3K/Akt/mTOR was analyzed by Western blotting. Kaempferol significantly inhibited cell migration and tube formation in endothelial cells, and suppressed microvessel sprouting in the mouse aortic ring assay. Moreover, kaempferol suppressed the activation of HIF-1α, VEGFR2, and other markers of ERK/p38 MAPK and PI3K/Akt/mTOR signaling pathways in endothelial cells. These results suggest that kaempferol inhibits angiogenesis by suppressing HIF-1α and VEGFR2 activation via ERK/p38 MAPK and PI3K/Akt/mTOR signaling in endothelial cells.

  3. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    International Nuclear Information System (INIS)

    Zhang, Bingyu; Luo, Qing; Mao, Xinjian; Xu, Baiyao; Yang, Li; Ju, Yang; Song, Guanbin

    2014-01-01

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  4. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingyu [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Luo, Qing, E-mail: qing.luo@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Mao, Xinjian [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Xu, Baiyao [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Yang, Li [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Ju, Yang [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2014-03-10

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  5. Mechanical stimuli activation of calpain is required for myoblast differentiation and occurs via an ERK/MAP kinase signaling pathway

    DEFF Research Database (Denmark)

    Grossi, Alberto; Karlsson, Anders H; Lawson, Moira Ann

    2006-01-01

    a magnetic bead stimulation assay and C2C12 mouse myoblasts cell population, we have shown that mechanical signals transmitted through the C2C12 cells interaction with laminin cause an increase in cellular differentiation. This signaling results in an increase in the number of myotubes formed in the cultures...

  6. Synergetic topography and chemistry cues guiding osteogenic differentiation in bone marrow stromal cells through ERK1/2 and p38 MAPK signaling pathway.

    Science.gov (United States)

    Zhang, Xinran; Li, Haotian; Lin, Chucheng; Ning, Congqin; Lin, Kaili

    2018-01-30

    Both the topographic surface and chemical composition modification can enhance rapid osteogenic differentiation and bone formation. Till now, the synergetic effects of topography and chemistry cues guiding biological responses have been rarely reported. Herein, the ordered micro-patterned topography and classically essential trace element of strontium (Sr) ion doping were selected to imitate topography and chemistry cues, respectively. The ordered micro-patterned topography on Sr ion-doped bioceramics was successfully duplicated using the nylon sieve as the template. Biological response results revealed that the micro-patterned topography design or Sr doping could promote cell attachment, ALP activity, and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Most importantly, the samples both with micro-patterned topography and Sr doping showed the highest promotion effects, and could synergistically activate the ERK1/2 and p38 MAPK signaling pathways. The results suggested that the grafts with both specific topography and chemistry cues have synergetic effects on osteogenic activity of BMSCs and provide an effective approach to design functional bone grafts and cell culture substrates.

  7. Differential roles of MAPK-Erk1/2 and MAPK-p38 in insulin or insulin-like growth factor-I (IGF-I) signaling pathways for progesterone production in human ovarian cells.

    Science.gov (United States)

    Seto-Young, D; Avtanski, D; Varadinova, M; Park, A; Suwandhi, P; Leiser, A; Parikh, G; Poretsky, L

    2011-06-01

    Insulin and insulin like-growth factor-I (IGF-I) participate in the regulation of ovarian steroidogenesis. In insulin resistant states ovaries remain sensitive to insulin because insulin can activate alternative signaling pathways, such as phosphatidylinositol-3-kinase (PI-3 kinase) and mitogen-activated protein-kinase (MAPK) pathways, as well as insulin receptors and type 1 IGF receptors. We investigated the roles of MAPK-Erk1/2 and MAPK-p38 in insulin and IGF-I signaling pathways for progesterone production in human ovarian cells. Human ovarian cells were cultured in tissue culture medium in the presence of varying concentrations of insulin or IGF-I, with or without PD98059, a specific MAPK-Erk1/2 inhibitor, with or without SB203580, a specific MAPK-p38 inhibitor or with or without a specific PI-3-kinase inhibitor LY294002. Progesterone concentrations were measured using radioimmunoassay. PD98059 alone stimulated progesterone production in a dose-dependent manner by up to 65% (pprogesterone production by 13-18% (pprogesterone production by 17-20% (pprogesterone production by 20-30% (pprogesterone production by 40-60% (pprogesterone synthesis while SB203580 abolished insulin-induced progesterone production. Either PD98059 or SB203580 abolished IGF-I-induced progesterone production. Both MAPK-Erk1/2 and MAPK-p38 participate in IGF-I-induced signaling pathways for progesterone production, while insulin-induced progesterone production requires MAPK-p38, but not MAPK-Erk1/2. These studies provide further evidence for divergence of insulin and IGF-I signaling pathways for human ovarian cell steroidogenesis. © Georg Thieme Verlag KG Stuttgart · New York.

  8. A Novel Anti-Inflammatory Role for Ginkgolide B in Asthma via Inhibition of the ERK/MAPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiao Chu

    2011-09-01

    Full Text Available Ginkgolide B is an anti-inflammatory extract of Ginkgo biloba and has been used therapeutically. It is a known inhibitor of platelet activating factor (PAF, which is important in the pathogenesis of asthma. Here, a non-infectious mouse model of asthma is used to evaluate the anti-inflammatory capacity of ginkgolide B (GKB and characterize the interaction of GKB with the mitogen activated protein kinase (MAPK pathway. BALB/c mice that were sensitized and challenged to ovalbumin (OVA were treated with GKB (40 mg/kg one hour before they were challenged with OVA. Our study demonstrated that GKB may effectively inhibit the increase of T-helper 2 cytokines, such as interleukin (IL-5 and IL-13 in bronchoalveolar lavage fluid (BALF. Furthermore, the eosinophil count in BALF significantly decreased after treatment of GKB when compared with the OVA-challenged group. Histological studies demonstrated that GKB substantially inhibited OVA-induced eosinophilia in lung tissue and mucus hyper-secretion by goblet cells in the airway. These results suggest that ginkgolide B may be useful for the treatment of asthma and its efficacy is related to suppression of extracellular regulating kinase/MAPK pathway.

  9. Serum from Chronic Hepatitis B Patients Promotes Growth and Proliferation via the IGF-II/IGF-IR/MEK/ERK Signaling Pathway in Hepatocellular Carcinoma Cells.

    Science.gov (United States)

    Ji, Yuanyuan; Wang, Zhidong; Chen, Haiyan; Zhang, Lei; Zhuo, Fei; Yang, Qingqing

    2018-05-09

    Chronic hepatitis B virus (HBV) infection (CHB) plays a central role in the etiology of hepatocellular carcinoma (HCC). Emerging evidence implicates insulin-like growth factor (IGF)-II as a major risk factor for the growth and development of HCC. However, the relationship between HBV infection and IGF-II functions remains to be elucidated. Levels of circulating IGF-II and IGF-I receptor (IGF-IR) in healthy donors (HDs) and CHB patients were tested by ELISA. Human HCC cell lines (HepG-2, SMMC-7721, MHCC97-H) were incubated with serum from HDs and CHB patients at various concentrations for 24, 48, and 72 h. MTT and plate colony formation assays, BrdU ELISA, ELISA, small-interfering RNA (siRNA) transfection, quantitative real-time PCR, and western blot were applied to assess the functional and molecular mechanisms in HCC cell lines. Serum levels of IGF-II and IGF-IR were significantly higher in CHB patients than in HDs. Additionally, serum from CHB patients directly induced cell growth, proliferation, IGF-II secretion, and HDGF-related protein-2 (HRP-2) and nuclear protein 1 (NUPR1) mRNA and protein expression in HCC cells. Moreover, serum from CHB patients increased IGF-II-induced cell growth, proliferation, and HRP-2 and NUPR1 mRNA and protein expression in HCC cells. Blockade of IGF-IR clearly inhibited the above effects. Most importantly, interference with IGF-II function markedly repressed the cell proliferation and HRP-2 and NUPR1 mRNA and protein expression induced by serum from CHB patients. Furthermore, serum from CHB patients induced ERK phosphorylation via IGF-IR, with the MEK inhibitor PD98059 significantly decreasing CHB patient serum-induced IGF-II secretion, cell proliferation, and HRP-2 and NUPR1 mRNA and protein expression. Serum from CHB patients increases cell growth and proliferation and enhances HRP-2 and NUPR1 expression in HCC cells via the IGF-II/IGF-IR/MEK/ERK signaling pathway. These findings help to explain the molecular mechanisms

  10. Sweet Dream Liquid Chinese Medicine Ameliorates Learning and Memory Deficit in a Rat Model of Paradoxical Sleep Deprivation through the ERK/CREB Signaling Pathway.

    Science.gov (United States)

    Su, Xinyun; Wang, Chunhua; Wang, Xiuhua; Han, Fang; Lv, Changjun; Zhang, Xiuli

    2016-05-01

    Sweet dream oral liquid (SDOL), a traditional Chinese herbal compound contains 17 traditional Chinese medicines. It has various pharmacological effects, such as improving brain dysfunction and increasing sleeping quality. This study investigated the neuroprotective effect and the underlying mechanisms of SDOL-impaired hippocampus learning and memory-induced paradoxical sleep deprivation (PSD) in rats. Sixty Male Wistar rats were randomly divided into six groups. Before PSD, SDOL treatment group rats were intragastrically administered SDOL for 25 days at dose of 2.1, 4.2, and 8.4 mL/kg body weight per day. Normal control group, large platform control group, and PSD groups were treated with normal saline instead of SDOL. After 25 days treatment, PSD and SDOL groups were deprived of paradoxical sleep for 72 h. Then two behavioral studies were conducted to test the spatial learning and memory ability using the open field test and Morris water maze test. Expression of the c-fos, c-jun, cyclic AMP response element binding protein (CREB), extracellular signal-regulated protein kinase (ERK), mitogen-activated protein kinases (MAPK)/ERK kinase (MEK), and p-CREB, p-ERK, and p-MEK in the hippocampus were also assayed by western blot. In this study, PSD decreased the levels of p-CREB, p-ERK, p-MEK, c-fos, and c-jun. However, SDOL treatment increased expressions of these proteins. Our results showed that SDOL improved 72-h PSD-induced cognitive impairment. These affects may be mediated by increasing the contents of c-fos, c-jun, and p-CREB/ERK signaling.

  11. Endothelial ERK signaling controls lymphatic fate specification

    Science.gov (United States)

    Deng, Yong; Atri, Deepak; Eichmann, Anne; Simons, Michael

    2013-01-01

    Lymphatic vessels are thought to arise from PROX1-positive endothelial cells (ECs) in the cardinal vein in response to induction of SOX18 expression; however, the molecular event responsible for increased SOX18 expression has not been established. We generated mice with endothelial-specific, inducible expression of an RAF1 gene with a gain-of-function mutation (RAF1S259A) that is associated with Noonan syndrome. Expression of mutant RAF1S259A in ECs activated ERK and induced SOX18 and PROX1 expression, leading to increased commitment of venous ECs to the lymphatic fate. Excessive production of lymphatic ECs resulted in lymphangiectasia that was highly reminiscent of abnormal lymphatics seen in Noonan syndrome and similar “RASopathies.” Inhibition of ERK signaling during development abrogated the lymphatic differentiation program and rescued the lymphatic phenotypes induced by expression of RAF1S259A. These data suggest that ERK activation plays a key role in lymphatic EC fate specification and that excessive ERK activation is the basis of lymphatic abnormalities seen in Noonan syndrome and related diseases. PMID:23391722

  12. Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

    Science.gov (United States)

    Su, Tzu-Rong; Lin, Jen-Jie; Tsai, Chi-Chu; Huang, Tsu-Kei; Yang, Zih-Yan; Wu, Ming-O; Zheng, Yu-Qing; Su, Ching-Chyuan; Wu, Yu-Jen

    2013-01-01

    Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP1), and dopachrome tautomerase (Dct). In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK). Using inhibitors against PI3K/Akt (LY294002) or MEK/ERK-specific (PD98059), the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763) restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions. PMID:24129178

  13. Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

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    Yu-Jen Wu

    2013-10-01

    Full Text Available Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP1, and dopachrome tautomerase (Dct. In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK/extracellular signal-regulated kinase (ERK. Using inhibitors against PI3K/Akt (LY294002 or MEK/ERK-specific (PD98059, the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763 restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions.

  14. Anti-Inflammatory Effects of Tanshinone IIA on Atherosclerostic Vessels of Ovariectomized ApoE-/- Mice are Mediated by Estrogen Receptor Activation and Through the ERK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2015-03-01

    expression of p-ERK1/2. Tanshinone IIA had no effect of level of serum 17ß-estradiol levels. All of the effects of Tanshinone IIA were similar to estrogen and were inhibited by the estrogen receptor antagonist ICI182780. Conclusion: Tanshinone IIA may play an anti-inflammatory and anti-oxidative stress role in OVX atherosclerotic apoE-/- mice by activating the estrogen receptor through the ERK signaling pathway. Therefore, Tanshinone IIA, as a phytoestrogen, could be used for estrogen replacement therapy for cardiovascular disease of postmenopausal women.

  15. BMP suppresses PTEN expression via RAS/ERK signaling.

    Science.gov (United States)

    Beck, Stayce E; Carethers, John M

    2007-08-01

    Bone morphogenetic protein (BMP), a member of the transforming growth factor beta family, classically utilizes the SMAD signaling pathway for its growth suppressive effects,and loss of this signaling cascade may accelerate cell growth. In the colon cancer predisposition syndrome Juvenile Polyposis, as well as in the late progression stages of nonsyndromic colorectal cancers, SMAD4 function is typically abrogated. Here, we utilized the SMAD4-null SW480 colon cancer cell line to examine BMPs effect on a potential target gene, PTEN, and how its expression might be regulated. Initial treatment of the SMAD4-null cells with BMP resulted in mild growth suppression, but with prolonged exposure to BMP, the cells become growth stimulatory, which coincided with observed decreases in transcription and translation of PTEN, and with corresponding increases in phospho-AKT protein levels. BMP-induced PTEN suppression was mediated via the RAS/ERK pathway, as pharmacologic inhibition of RAS/ERK, or interference with protein function in the cytosol by DN-RAS prevented BMP-induced growth promotion and changes in PTEN levels, as did treatment with noggin, a BMP ligand inhibitor. Thus, BMP downregulates PTEN via RAS/ERK in a SMAD4-null environment that contributes to cell growth, and constitutes a SMAD4-independent but BMP-responsive signaling pathway.

  16. Simulated physiological stretch increases expression of extracellular matrix proteins in human bladder smooth muscle cells via integrin α4/αv-FAK-ERK1/2 signaling pathway.

    Science.gov (United States)

    Chen, Shulian; Peng, Chuandu; Wei, Xin; Luo, Deyi; Lin, Yifei; Yang, Tongxin; Jin, Xi; Gong, Lina; Li, Hong; Wang, Kunjie

    2017-08-01

    To investigate the effect of simulated physiological stretch on the expression of extracellular matrix (ECM) proteins and the role of integrin α4/αv, focal adhesion kinase (FAK), extracellular regulated protein kinases 1/2 (ERK1/2) in the stretch-induced ECM protein expression of human bladder smooth muscle cells (HBSMCs). HBSMCs were seeded onto silicone membrane and subjected to simulated physiological stretch at the range of 5, 10, and 15% elongation. Expression of primary ECM proteins in HBSMCs was analyzed by real-time polymerase chain reaction and Western blot. Specificity of the FAK and ERK1/2 was determined by Western blot with FAK inhibitor and ERK1/2 inhibitor (PD98059). Specificity of integrin α4 and integrin αv was determined with small interfering ribonucleic acid (siRNA) transfection. The expression of collagen I (Col1), collagen III (Col3), and fibronectin (Fn) was increased significantly under the simulated physiological stretch of 10 and 15%. Integrin α4 and αv, FAK, ERK1/2 were activated by 10% simulated physiological stretch compared with the static condition. Pretreatment of ERK1/2 inhibitor, FAK inhibitor, integrin α4 siRNA, or integrin αv siRNA reduced the stretch-induced expression of ECM proteins. And FAK inhibitor decreased the stretch-induced ERK1/2 activity and ECM protein expression. Integrin α4 siRNA or integrin αv siRNA inhibited the stretch-induced activity of FAK. Simulated physiological stretch increases the expression of ECM proteins in HBSMCs, and integrin α4/αv-FAK-ERK1/2 signaling pathway partly modulates the mechano-transducing process.

  17. TGF-β1 stimulates migration of type II endometrial cancer cells by down-regulating PTEN via activation of SMAD and ERK1/2 signaling pathways.

    Science.gov (United States)

    Xiong, Siyuan; Cheng, Jung-Chien; Klausen, Christian; Zhao, Jianfang; Leung, Peter C K

    2016-09-20

    PTEN acts as a tumor suppressor primarily by antagonizing the PI3K/AKT signaling pathway. PTEN is frequently mutated in human cancers; however, in type II endometrial cancers its mutation rate is very low. Overexpression of TGF-β1 and its receptors has been reported to correlate with metastasis of human cancers and reduced survival rates. Although TGF-β1 has been shown to regulate PTEN expression through various mechanisms, it is not yet known if the same is true in type II endometrial cancer. In the present study, we show that treatment with TGF-β1 stimulates the migration of two type II endometrial cancer cell lines, KLE and HEC-50. In addition, TGF-β1 treatment down-regulates both mRNA and protein levels of PTEN. Overexpression of PTEN or inhibition of PI3K abolishes TGF-β1-stimulated cell migration. TGF-β1 induces SMAD2/3 phosphorylation and knockdown of common SMAD4 inhibits the suppressive effects of TGF-β1 on PTEN mRNA and protein. Interestingly, TGF-β1 induces ERK1/2 phosphorylation and pre-treatment with a MEK inhibitor attenuates the suppression of PTEN protein, but not mRNA, by TGF-β1. This study provides important insights into the molecular mechanisms mediating TGF-β1-induced down-regulation of PTEN and demonstrates an important role of PTEN in the regulation of type II endometrial cancer cell migration.

  18. Oleoylethanolamide exerts anti-inflammatory effects on LPS-induced THP-1 cells by enhancing PPARα signaling and inhibiting the NF-κB and ERK1/2/AP-1/STAT3 pathways.

    Science.gov (United States)

    Yang, Lichao; Guo, Han; Li, Ying; Meng, Xianglan; Yan, Lu; Dan Zhang; Wu, Sangang; Zhou, Hao; Peng, Lu; Xie, Qiang; Jin, Xin

    2016-10-10

    The present study aimed to examine the anti-inflammatory actions of oleoylethanolamide (OEA) in lipopolysaccharide (LPS)-induced THP-1 cells. The cells were stimulated with LPS (1 μg/ml) in the presence or absence of OEA (10, 20 and 40 μM). The pro-inflammatory cytokines were evaluated by qRT-PCR and ELISA. The THP-1 cells were transiently transfected with PPARα small-interfering RNA, and TLR4 activity was determined with a blocking test using anti-TLR4 antibody. Additionally, a special inhibitor was used to analyse the intracellular signaling pathway. OEA exerted a potent anti-inflammatory effect by reducing the production of pro-inflammatory cytokines and TLR4 expression, and by enhancing PPARα expression. The modulatory effects of OEA on LPS-induced inflammation depended on PPARα and TLR4. Importantly, OEA inhibited LPS-induced NF-κB activation, IκBα degradation, expression of AP-1, and the phosphorylation of ERK1/2 and STAT3. In summary, our results demonstrated that OEA exerts anti-inflammatory effects by enhancing PPARα signaling, inhibiting the TLR4-mediated NF-κB signaling pathway, and interfering with the ERK1/2-dependent signaling cascade (TLR4/ERK1/2/AP-1/STAT3), which suggests that OEA may be a therapeutic agent for inflammatory diseases.

  19. Metformin inhibits heme oxygenase-1 expression in cancer cells through inactivation of Raf-ERK-Nrf2 signaling and AMPK-independent pathways

    International Nuclear Information System (INIS)

    Do, Minh Truong; Kim, Hyung Gyun; Khanal, Tilak; Choi, Jae Ho; Kim, Dong Hee; Jeong, Tae Cheon; Jeong, Hye Gwang

    2013-01-01

    Resistance to therapy is the major obstacle to more effective cancer treatment. Heme oxygenase-1 (HO-1) is often highly up-regulated in tumor tissues, and its expression is further increased in response to therapies. It has been suggested that inhibition of HO-1 expression is a potential therapeutic approach to sensitize tumors to chemotherapy and radiotherapy. In this study, we tested the hypothesis that the anti-tumor effects of metformin are mediated by suppression of HO-1 expression in cancer cells. Our results indicate that metformin strongly suppresses HO-1 mRNA and protein expression in human hepatic carcinoma HepG2, cervical cancer HeLa, and non-small-cell lung cancer A549 cells. Metformin also markedly reduced Nrf2 mRNA and protein levels in whole cell lysates and suppressed tert-butylhydroquinone (tBHQ)-induced Nrf2 protein stability and antioxidant response element (ARE)-luciferase activity in HepG2 cells. We also found that metformin regulation of Nrf2 expression is mediated by a Keap1-independent mechanism and that metformin significantly attenuated Raf-ERK signaling to suppress Nrf2 expression in cancer cells. Inhibition of Raf-ERK signaling by PD98059 decreased Nrf2 mRNA expression in HepG2 cells, confirming that the inhibition of Nrf2 expression is mediated by an attenuation of Raf-ERK signaling in cancer cells. The inactivation of AMPK by siRNA, DN-AMPK or the pharmacological AMPK inhibitor compound C, revealed that metformin reduced HO-1 expression in an AMPK-independent manner. These results highlight the Raf-ERK-Nrf2 axis as a new molecular target in anticancer therapy in response to metformin treatment. - Highlights: • Metformin inhibits HO-1 expression in cancer cells. • Metformin attenuates Raf-ERK-Nrf2 signaling. • Suppression of HO-1 by metformin is independent of AMPK. • HO-1 inhibition contributes to anti-proliferative effects of metformin

  20. Knowledge-based identification of the ERK2/STAT3 signal pathway as a therapeutic target for type 2 diabetes and drug discovery.

    Science.gov (United States)

    Kinoshita, Takayoshi; Doi, Kentaro; Sugiyama, Hajime; Kinoshita, Shuhei; Wada, Mutsuyo; Naruto, Shuji; Tomonaga, Atsushi

    2011-09-01

    Many existing agents for diabetes therapy are unable to restore or maintain normal glucose homeostasis or prevent the eventual emergence of hyperglycemia-related complication. Therefore, agents based on novel mechanisms are sought to complement and extend the current therapeutic approaches. Based on the initial paper research, we focused on active STAT3 as an attractive pharmacological target for type 2 diabetes. The subsequent text mining with a unique query to identify suppressors but not activators of STAT3 revealed the ERK2/STAT3 pathway as a novel diabetes target. The description of ERK2 inhibitors as diabetes target had not been found in our text mining research at present. The mechanism-based peptide inhibitor for ERK2 was identified using the knowledge of the KIM sequence, which has an important role in the recognition of cognate kinases, phosphatases, scaffold proteins, and substrates. The peptide inhibitor was confirmed to exert effects in vitro and in vivo. The peptide inhibitor conferred a significant decrease in HOMA-IR levels on Day 28 compared with that in the vehicle group. Besides lowering the fasting blood glucose level, the peptide inhibitor also attenuated the blood glucose increment in the fed state, as compared with the vehicle group. © 2011 John Wiley & Sons A/S.

  1. Low-dose strontium stimulates osteogenesis but high-dose doses cause apoptosis in human adipose-derived stem cells via regulation of the ERK1/2 signaling pathway.

    Science.gov (United States)

    Aimaiti, Abudousaimi; Maimaitiyiming, Asihaerjiang; Boyong, Xu; Aji, Kaisaier; Li, Cao; Cui, Lei

    2017-12-19

    Strontium is a widely used anti-osteoporotic agent due to its dual effects on inhibiting bone resorption and stimulating bone formation. Thus, we studied the dose response of strontium on osteo-inductive efficiency in human adipose-derived stem cells (hASCs). Qualitative alkaline phosphatase (ALP) staining, quantitative ALP activity, Alizarin Red staining, real-time polymerase chain reaction and Western blot were used to investigate the in vitro effects of a range of strontium concentrations on hASC osteogenesis and associated signaling pathways. In vitro work revealed that strontium (25-500 μM) promoted osteogenic differentiation of hASCs according to ALP activity, extracellular calcium deposition, and expression of osteogenic genes such as runt-related transcription factor 2, ALP, collagen-1, and osteocalcin. However, osteogenic differentiation of hASCs was significantly inhibited with higher doses of strontium (1000-3000 μM). These latter doses of strontium promoted apoptosis, and phosphorylation of ERK1/2 signaling was increased and accompanied by the downregulation of Bcl-2 and increased phosphorylation of BAX. The inhibition of ERK1/2 decreased apoptosis in hASCs. Lower concentrations of strontium facilitate osteogenic differentiation of hASCs up to a point; higher doses cause apoptosis of hASCs, with activation of the ERK1/2 signaling pathway contributing to this process.

  2. A standardized bark extract of Pinus pinaster Aiton (Pycnogenol®) attenuated chronic obstructive pulmonary disease via Erk-sp1 signaling pathway.

    Science.gov (United States)

    Shin, Na-Rae; Ryu, Hyung-Won; Ko, Je-Won; Park, Ji-Won; Kwon, Ok-Kyoung; Oh, Sei-Ryang; Kim, Jong-Choon; Shin, In-Sik; Ahn, Kyung-Seop

    2016-12-24

    A standardized bark extract of Pinus pinaster Aiton (Pycnogenol ® ; PYC) used as an herbal medicine to treat various diseases in Europe and North America. This study evaluates the ability of PYC to inhibit chronic obstructive pulmonary disease (COPD) in the cigarette smoke extract (CSE)-stimulated human airway epithelial cell line NCI-H292 and in a cigarette smoke (CS) and lipopolysaccharide (LPS)-induced mouse model. To induce COPD, the mice intranasally received LPS on day 4 and were exposed to CS for 1h per day (total eight cigarettes per day) from days 1-7. The mice were administered PYC at a dose of 15mg/kg and 30mg/kg 1h before CS exposure. In the CSE-stimulated NCI-H292 cells, PYC significantly inhibited Erk phosphorylation, sp1 expression, MUC5AC, and pro-inflammatory cytokines in a concentration-dependent manner, as evidenced by a reduction in their mRNA levels. Co-treatment with PYC and Erk inhibitors markedly reduced the levels inflammatory mediators compared to only PYC-treatment. In the COPD mice model, PYC decreased the inflammatory cell count and the levels of pro-inflammatory cytokines in the broncho-alveolar lavage fluid compared with COPD mice. PYC attenuated the recruitment of inflammatory cells in the airways and decreased the expression levels of Erk phosphorylation and sp1. PYC also inhibited the expression of myeloperoxidase and matrix metalloproteinases-9 in lung tissue. Our results indicate that PYC inhibited the reduction in the inflammatory response in CSE-stimulated NCI-H292 cells and the COPD mouse model via the Erk-sp1 pathway. Therefore, we suggest that PYC has the potential to treat COPD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Molecular Mechanism: ERK Signaling, Drug Addiction, and Behavioral Effects.

    Science.gov (United States)

    Sun, Wei-Lun; Quizon, Pamela M; Zhu, Jun

    2016-01-01

    Addiction to psychostimulants has been considered as a chronic psychiatric disorder characterized by craving and compulsive drug seeking and use. Over the past two decades, accumulating evidence has demonstrated that repeated drug exposure causes long-lasting neurochemical and cellular changes that result in enduring neuroadaptation in brain circuitry and underlie compulsive drug consumption and relapse. Through intercellular signaling cascades, drugs of abuse induce remodeling in the rewarding circuitry that contributes to the neuroplasticity of learning and memory associated with addiction. Here, we review the role of the extracellular signal-regulated kinase (ERK), a member of the mitogen-activated protein kinase, and its related intracellular signaling pathways in drug-induced neuroadaptive changes that are associated with drug-mediated psychomotor activity, rewarding properties and relapse of drug seeking behaviors. We also discuss the neurobiological and behavioral effects of pharmacological and genetic interferences with ERK-associated molecular cascades in response to abused substances. Understanding the dynamic modulation of ERK signaling in response to drugs may provide novel molecular targets for therapeutic strategies to drug addiction. Copyright © 2016. Published by Elsevier Inc.

  4. IL-1β Upregulates StAR and Progesterone Production Through the ERK1/2- and p38-Mediated CREB Signaling Pathways in Human Granulosa-Lutein Cells.

    Science.gov (United States)

    Dang, Xuan; Zhu, Qinling; He, Yaqiong; Wang, Yuan; Lu, Yao; Li, Xiaoxue; Qi, Jia; Wu, Hasiximuke; Sun, Yun

    2017-10-01

    The proinflammatory cytokine interleukin-1β (IL-1β) may be involved in several ovulation-associated events, such as protease synthesis, prostaglandin production, and steroidogenesis in granulosa cells. However, the exact effect of IL-1β on progesterone synthesis in granulosa cells and the underlying mechanism remain unclear. By using cultured granulosa-lutein cells collected from women undergoing in vitro fertilization or intracytoplasmic sperm injection, we found that IL-1β upregulated steroidogenic acute regulatory protein (StAR) expression and progesterone synthesis in granulosa-lutein cells, which was comparable with luteinizing hormone effect and could be abolished by an IL-1 receptor antagonist. Moreover, IL-1β activated the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB), and knockdown of CREB attenuated the induction of StAR expression and progesterone synthesis by IL-1β in granulosa-lutein cells. Furthermore, IL-1β activated the extracellular signal-regulated kinase (ERK)1/2 and p38 pathways and inhibition of the ERK1/2 and p38 pathways attenuated the IL-1β-induced phosphorylation of CREB, StAR expression, and progesterone synthesis in granulosa-lutein cells. In conclusion, IL-1β could upregulate StAR expression and stimulate progesterone biosynthesis through increase in CREB phosphorylation via activating the ERK1/2 and p38 pathways in human granulosa-lutein cells. Copyright © 2017 Endocrine Society.

  5. MTBP inhibits the Erk1/2-Elk-1 signaling in hepatocellular carcinoma

    Science.gov (United States)

    Ranjan, Atul; Iyer, Swathi V.; Ward, Christopher; Link, Tim; Diaz, Francisco J.; Dhar, Animesh; Tawfik, Ossama W.; Weinman, Steven A.; Azuma, Yoshiaki; Izumi, Tadahide; Iwakuma, Tomoo

    2018-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the prognosis of HCC patients, especially those with metastasis, remains extremely poor. This is partly due to unclear molecular mechanisms underlying HCC metastasis. Our previous study indicates that MDM2 Binding Protein (MTBP) suppresses migration and metastasis of HCC cells. However, signaling pathways regulated by MTBP remain unknown. To identify metastasis-associated signaling pathways governed by MTBP, we have performed unbiased luciferase reporter-based signal array analyses and found that MTBP suppresses the activity of the ETS-domain transcription factor Elk-1, a downstream target of Erk1/2 MAP kinases. MTBP also inhibits phosphorylation of Elk-1 and decreases mRNA expression of Elk-1 target genes. Reduced Elk-1 activity is caused by inhibited nuclear translocation of phosphorylated Erk1/2 (p-Erk) by MTBP and subsequent inhibition of Elk-1 phosphorylation. We also reveal that MTBP inhibits the interaction of p-Erk with importin-7/RanBP7 (IPO7), an importin family member which shuttles p-Erk into the nucleus, by binding to IPO7. Moreover, high levels of MTBP in human HCC tissues are correlated with cytoplasmic localization of p-Erk1/2. Our study suggests that MTBP suppresses metastasis, at least partially, by down-modulating the Erk1/2-Elk-1 signaling pathway, thus identifying a novel regulatory mechanism of HCC metastasis by regulating the subcellular localization of p-Erk. PMID:29765550

  6. Ghrelin promotes human non-small cell lung cancer A549 cell proliferation through PI3K/Akt/mTOR/P70S6K and ERK signaling pathways.

    Science.gov (United States)

    Zhu, Jianhua; Yao, Jianfeng; Huang, Rongfu; Wang, Yueqin; Jia, Min; Huang, Yan

    2018-04-06

    Ghrelin is a gastric acyl-peptide that plays an important role in cell proliferation. In the present study, we explored the role of ghrelin in A549 cell proliferation and the possible molecular mechanisms. We found that ghrelin promotes A549 cell proliferation, knockdown of the growth hormone secretagogue receptor (GHSR) attenuated A549 cell proliferation caused by ghrelin. Ghrelin induced the rapid phosphorylation of phosphatidylinositol 3-kinase (PI3K), Akt, ERK, mammalian target of rapamycin (mTOR) and P70S6K. PI3K inhibitor (LY 294002), ERK inhibitor (PD98059) and mTOR inhibitor (Rapamycin) inhibited ghrelin-induced A549 cell proliferation. Moreover, GHSR siRNA inhibited phosphorylation of PI3K, Akt, ERK, mTOR and P70S6K induced by ghrelin. Akt and mTOR/P70S6K phosphorylation was inhibited by LY 294002 but not by PD98059. These results indicate that ghrelin promotes A549 cell proliferation via GHSR-dependent PI3K/Akt/mTOR/P70S6K and ERK signaling pathways. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. SIRT1 induces resistance to apoptosis in human granulosa cells by activating the ERK pathway and inhibiting NF-κB signaling with anti-inflammatory functions.

    Science.gov (United States)

    Han, Ying; Luo, Haining; Wang, Hui; Cai, Jun; Zhang, Yunshan

    2017-10-01

    SIRT1, a member of the sirtuin family, has recently emerged as a vital molecule in controlling ovarian function. The aims of the present study were to investigate SIRT1 expression and analyze SIRT1-mediated apoptosis in human granulosa cells (GCs). Human ovarian tissues were subjected to immunohistochemistry for localization of SIRT1 expression. SIRT1 knockdown in a human ovarian GC tumor line (COV434) was achieved by small interfering RNA, and the relationship between apoptosis and SIRT1 was assessed by quantitative reverse transcription polymerase chain reaction and western blotting. We further detected SIRT1 expression in human luteinized GCs. Associations among SIRT1 knockdown, SIRT1 stimulation (resveratrol) and expression of ERK1/2 and apoptotic regulatory proteins were analyzed in cell lines and luteinized GCs. Resveratrol downregulated the levels of nuclear factor (NF)-κB/p65, but this inhibitory effect was attenuated by suppressing SIRT1 activity. The NF-κB/p65 inhibitor pyrrolidine dithiocarbamate achieved similar anti-apoptosis effects. These results suggest that SIRT1 might play an anti-apoptotic role in apoptosis processes in GCs, possibly by sensing and regulating the ERK1/2 pathway, which has important clinical implications. Thus, our study provides a mechanistic link, whereby activation of SIRT1 function might help to sustain human reproduction by maintaining GCs as well as oocytes, offering a novel approach for developing a new class of therapeutic anti-inflammatory agents.

  8. Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's Sarcoma-associated herpesvirus by herpes simplex virus type 1

    Directory of Open Access Journals (Sweden)

    Lv Zhigang

    2011-10-01

    Full Text Available Abstract Background Kaposi's sarcoma-associated herpesvirus (KSHV is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS, primary effusion lymphoma (PEL and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1 was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. Results By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1/signal transducer and activator of transcription 3 (STAT3 or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K/protein kinase B (PKB, also called AKT pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN and glycogen synthase kinase-3β (GSK-3β. PTEN/PI3K/AKT/GSK-3β pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK mitogen-activated protein kinase (MAPK pathway also partially contributed to HSV-1-induced KSHV replication. Conclusions HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.

  9. Caffeine Inhibits the Activation of Hepatic Stellate Cells Induced by Acetaldehyde via Adenosine A2A Receptor Mediated by the cAMP/PKA/SRC/ERK1/2/P38 MAPK Signal Pathway

    Science.gov (United States)

    Yang, Wanzhi; Wang, Qi; Zhao, Han; Yang, Feng; Lv, Xiongwen; Li, Jun

    2014-01-01

    Hepatic stellate cell (HSC) activation is an essential event during alcoholic liver fibrosis. Evidence suggests that adenosine aggravates liver fibrosis via the adenosine A2A receptor (A2AR). Caffeine, which is being widely consumed during daily life, inhibits the action of adenosine. In this study, we attempted to validate the hypothesis that caffeine influences acetaldehyde-induced HSC activation by acting on A2AR. Acetaldehyde at 50, 100, 200, and 400 μM significantly increased HSC-T6 cells proliferation, and cell proliferation reached a maximum at 48 h after exposure to 200 μM acetaldehyde. Caffeine and the A2AR antagonist ZM241385 decreased the cell viability and inhibited the expression of procollagen type I and type III in acetaldehyde-induced HSC-T6 cells. In addition, the inhibitory effect of caffeine on the expression of procollagen type I was regulated by A2AR-mediated signal pathway involving cAMP, PKA, SRC, and ERK1/2. Interestingly, caffeine’s inhibitory effect on the expression of procollagen type III may depend upon the A2AR-mediated P38 MAPK-dependent pathway. Conclusions: Caffeine significantly inhibited acetaldehyde-induced HSC-T6 cells activation by distinct A2AR mediated signal pathway via inhibition of cAMP-PKA-SRC-ERK1/2 for procollagen type I and via P38 MAPK for procollagen type III. PMID:24682220

  10. Combined MEK and ERK inhibition overcomes therapy-mediated pathway reactivation in RAS mutant tumors.

    Directory of Open Access Journals (Sweden)

    Mark Merchant

    Full Text Available Mitogen-activated protein kinase (MAPK pathway dysregulation is implicated in >30% of all cancers, rationalizing the development of RAF, MEK and ERK inhibitors. While BRAF and MEK inhibitors improve BRAF mutant melanoma patient outcomes, these inhibitors had limited success in other MAPK dysregulated tumors, with insufficient pathway suppression and likely pathway reactivation. In this study we show that inhibition of either MEK or ERK alone only transiently inhibits the MAPK pathway due to feedback reactivation. Simultaneous targeting of both MEK and ERK nodes results in deeper and more durable suppression of MAPK signaling that is not achievable with any dose of single agent, in tumors where feedback reactivation occurs. Strikingly, combined MEK and ERK inhibition is synergistic in RAS mutant models but only additive in BRAF mutant models where the RAF complex is dissociated from RAS and thus feedback productivity is disabled. We discovered that pathway reactivation in RAS mutant models occurs at the level of CRAF with combination treatment resulting in a markedly more active pool of CRAF. However, distinct from single node targeting, combining MEK and ERK inhibitor treatment effectively blocks the downstream signaling as assessed by transcriptional signatures and phospho-p90RSK. Importantly, these data reveal that MAPK pathway inhibitors whose activity is attenuated due to feedback reactivation can be rescued with sufficient inhibition by using a combination of MEK and ERK inhibitors. The MEK and ERK combination significantly suppresses MAPK pathway output and tumor growth in vivo to a greater extent than the maximum tolerated doses of single agents, and results in improved anti-tumor activity in multiple xenografts as well as in two Kras mutant genetically engineered mouse (GEM models. Collectively, these data demonstrate that combined MEK and ERK inhibition is functionally unique, yielding greater than additive anti-tumor effects and

  11. Enhancement of osteogenic differentiation of rat adipose tissue-derived mesenchymal stem cells by zinc sulphate under electromagnetic field via the PKA, ERK1/2 and Wnt/β-catenin signaling pathways.

    Directory of Open Access Journals (Sweden)

    Ezzatollah Fathi

    Full Text Available Zinc ion as an essential trace element and electromagnetic fields (EMFs has been reported to be involved in the regulation of bone metabolism. The aim of this study was to elucidate the effects of zinc sulphate (ZnSO4 on the osteogenic differentiation of adipose tissue-derived mesenchymal stem cells (ADSCs in the presence of EMF as a strategy in osteoporosis therapy. Alkaline phophatase (ALP activity measurement, calcium assay and expression of several osteoblastic marker genes were examined to assess the effect of ZnSO4 on the osteogenic differentiation of ADSCs under EMF. The expression of cAMP and PKA was evaluated by ELISA. The expression of β-catenin, Wnt1, Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5 and reduced dickkopf1 (DKK1 genes were used to detect the Wnt/β-catenin pathway. It was found that ZnSO4, in the presence of EMF, resulted in an increase in the expression of osteogenic genes, ALP activity and calcium levels. EMF, in the presence of ZnSO4, increased the cAMP level and protein kinase A (PKA activity. Treatment of ADSCs with (MAPK/ERK kinase 1/2 inhibitor, or PKA inhibitor, significantly inhibited the promotion of osteogenic markers, indicating that the induction of osteogenesis was dependent on the ERK and PKA signaling pathways. Real-time PCR analysis showed that ZnSO4, in the presence of EMF, increased the mRNA expressions of β-catenin, Wnt1, Wnt3a, LRP5 and DKK1. In this study, it was shown that 0.432 μg/ml ZnSO4, in the presence of 50 Hz, 20 mT EMF, induced the osteogenic differentiation of ADSCs via PKA, ERK1/2 and Wnt/β-catenin signaling pathways.

  12. Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

    International Nuclear Information System (INIS)

    Ham, Young-Mi; Mahoney, Sarah Jane

    2013-01-01

    The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors

  13. Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Young-Mi, E-mail: youngmi_ham@hms.harvard.edu [College of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States); Mahoney, Sarah Jane [Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States)

    2013-06-10

    The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors.

  14. Chronic Fluoxetine Treatment Upregulates the Activity of the ERK1/2-NF-κB Signaling Pathway in the Hippocampus and Prefrontal Cortex of Rats Exposed to Forced-Swimming Stress.

    Science.gov (United States)

    Cui, Jingqiu; Yang, Kun; Yu, Xue; Wang, Jing-Lan; Li, Jie; Zhang, Yong; Li, Hengfen

    2016-01-01

    The aim of this study was to explore whether or not the antidepressant actions of fluoxetine (FLX) are correlated with extracellular signal-regulated kinase 1 and 2 (ERK1/2) and nuclear factor κ-light chain enhancer of activated B cells (NF-κB) in the hippocampus (HC) and prefrontal cortex (PFC) of rats. A total of 108 male Sprague-Dawley rats were randomly divided into 6 groups of 18 rats each. Group 1 was the control group, while group 2 comprised the depressed model in which rats were subjected to 28 days of forced-swimming stress (FST); groups 3-6 were also subjected to 28 days of FST and treated with FLX once a day for 1 day (group 3; F1d), 1 week (group 4; F1w), 2 weeks (group 5; F2w), or 4 weeks (group 6; F4w). The control group was not subjected to FST or treated with FLX. Behavior tests that included the Morris water maze (MWM) and saccharin preference were performed, and ERK1/2 and NF-κB proteins were assayed using Western blot. The rats in the control group and in groups 5 and 6 (F2w and F4w, respectively) had a significantly shorter average escape latency, needed more attempts in order to successfully cross the platform, and had a greater saccharin preference than those in the depressed group (p < 0.05). In the depressed group, the phosphorylated ERK1/2 (p-ERK1/2) and phosphorylated NF-κB (p-NF-κB) expression in the HC and PFC were lower than in the control group (p < 0.05). Treatment with FLX reversed the changes in the expression of p-ERK1/2 and p-NF-κB in rats in the F2w and F4w groups. In this study, FLX treatment for 2 weeks or longer reversed the impaired spatial learning, memory, and anhedonia observed in the depressed model rats and upregulated the activities of the ERK1/2-NF-κB signaling pathway. © 2016 S. Karger AG, Basel.

  15. MicroRNA-134 regulates lung cancer cell H69 growth and apoptosis by targeting WWOX gene and suppressing the ERK1/2 signaling pathway

    International Nuclear Information System (INIS)

    Chen, Tianjun; Gao, Fei; Feng, Sifang; Yang, Tian; Chen, Mingwei

    2015-01-01

    MicroRNAs have been shown to act as crucial modulators during carcinogenesis. Recent studies have implied that miR-134 expression associated with epithelial-to-mesenchymal transition phenotype and invasive potential of NSCLC cells. Our study investigated the pathogenic implications of miR-134 in small cell lung cancer (SCLC). Overexpression or inhibition MiR-134 expression by miR-134 mimics or miR-134 inhibitors (anti-miR-134) in SCLC cell lines was detected using qRT-PCR. Lactate dehydrogenase (LDH) assay, MTT assays and flow cytometry were performed in order to clarify the growth and apoptosis of SCLC cells which had been transfected with miR-134 mimics or anti-miR-134. WWOX expression in H69 cells was detected by qRT-PCR and western blot, respectively. The results showed that overexpression miR-134 was significantly promoting SCLC cells growth and inhibit its apoptosis. In addition, reduced miR-134 expression was significantly correlated with cell growth inhibition and apoptosis promotion. Furthermore, transfection of miR-134 mimics into the SCLC cells markedly down-regulated the level of WWOX, whereas, anti-miR-134 up-regulated WWOX expression. We also found that overexpression WWOX attenuate miR-134 induced H69 cells growth, and promote cell apoptosis. Moreover, miR-134 promoted cell proliferation and inhibit apoptosis via the activation of ERK1/2 pathway. These findings suggest that miR-134 may be an ideal diagnostic and prognostic marker, and may be attributed to the molecular therapy of SCLC. - Highlights: • MiR-134 play roles in small cell lung cancer cell growth and apoptosis. • MiR-134 negative regulated the level of WWOX in H69 cells. • WWOX overexpression attenuate miR-134 induced H69 cells growth. • MiR-134 promotes cell growth via the activation of ERK1/2 pathway

  16. ERK-dependent and -independent pathways trigger human neural progenitor cell migration

    International Nuclear Information System (INIS)

    Moors, Michaela; Cline, Jason E.; Abel, Josef; Fritsche, Ellen

    2007-01-01

    Besides differentiation and apoptosis, cell migration is a basic process in brain development in which neural cells migrate several centimeters within the developing brain before reaching their proper positions and forming the right connections. For identifying signaling events that control neural migration and are therefore potential targets of chemicals to disturb normal brain development, we developed a human neurosphere-based migration assay based on normal human neural progenitor (NHNP) cells, in which the distance is measured that cells wander over time. Applying this assay, we investigated the role of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the regulation of NHNP cell migration. Exposure to model substances like ethanol or phorbol 12-myristate 13-acetate (PMA) revealed a correlation between ERK1/2 activation and cell migration. The participation of phospho-(P-) ERK1/2 was confirmed by exposure of the cells to the MEK inhibitor PD98059, which directly prohibits ERK1/2 phosphorylation and inhibited cell migration. We identified protein kinase C (PKC) and epidermal growth factor receptor (EGFR) as upstream signaling kinases governing ERK1/2 activation, thereby controlling NHNP cell migration. Additionally, treatments with src kinase inhibitors led to a diminished cell migration without affecting ERK1/2 phosphorylation. Based on these results, we postulate that migration of NHNP cells is controlled via ERK1/2-dependent and -independent pathways

  17. Prostaglandin E2 blocks menadione-induced apoptosis through the Ras/Raf/Erk signaling pathway in promonocytic leukemia cell lines.

    Science.gov (United States)

    Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

    2012-04-01

    Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E(2) (PGE(2)) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE(2) as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE(2) markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP(2) receptor antagonist AH6809 abrogated the inhibitory effect of PGE(2), suggesting the role of the EP(2)/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE(2). The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE(2) on menadione-treated cells. Furthermore, PGE(2) activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE(2) via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics.

  18. Layer specific and general requirements for ERK/MAPK signaling in the developing neocortex

    Science.gov (United States)

    Xing, Lei; Larsen, Rylan S; Bjorklund, George Reed; Li, Xiaoyan; Wu, Yaohong; Philpot, Benjamin D; Snider, William D; Newbern, Jason M

    2016-01-01

    Aberrant signaling through the Raf/MEK/ERK (ERK/MAPK) pathway causes pathology in a family of neurodevelopmental disorders known as 'RASopathies' and is implicated in autism pathogenesis. Here, we have determined the functions of ERK/MAPK signaling in developing neocortical excitatory neurons. Our data reveal a critical requirement for ERK/MAPK signaling in the morphological development and survival of large Ctip2+ neurons in layer 5. Loss of Map2k1/2 (Mek1/2) led to deficits in corticospinal tract formation and subsequent corticospinal neuron apoptosis. ERK/MAPK hyperactivation also led to reduced corticospinal axon elongation, but was associated with enhanced arborization. ERK/MAPK signaling was dispensable for axonal outgrowth of layer 2/3 callosal neurons. However, Map2k1/2 deletion led to reduced expression of Arc and enhanced intrinsic excitability in both layers 2/3 and 5, in addition to imbalanced synaptic excitation and inhibition. These data demonstrate selective requirements for ERK/MAPK signaling in layer 5 circuit development and general effects on cortical pyramidal neuron excitability. DOI: http://dx.doi.org/10.7554/eLife.11123.001 PMID:26848828

  19. Antimetastatic Therapies of the Polysulfide Diallyl Trisulfide against Triple-Negative Breast Cancer (TNBC via Suppressing MMP2/9 by Blocking NF-κB and ERK/MAPK Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Yuping Liu

    Full Text Available Migration and invasion are two crucial steps of tumor metastasis. Blockage of these steps may be an effective strategy to reduce the risk. The objective of the present study was to investigate the effects of diallyl trisulfide (DATS, a natural organosulfuric compound with most sulfur atoms found in garlic, on migration and invasion in triple negative breast cancer (TNBC cells. Molecular mechanisms underlying the anticancer effects of DATS were further investigated.MDA-MB-231 cells and HS 578t breast cancer cells were treated with different concentrations of DATS. DATS obviously suppressed the migration and invasion of two cell lines and changed the morphological. Moreover, DATS inhibited the mRNA/protein/ enzymes activities of MMP2/9 via attenuating the NF-κB pathway. DATS also inhibited ERK/MAPK rather than p38 and JNK.DATS inhibits MMP2/9 activity and the metastasis of TNBC cells, and emerges as a potential anti-cancer agent. The inhibitory effects are associated with down-regulation of the transcriptional activities of NF-κB and ERK/MAPK signaling pathways.

  20. Rac1 signaling regulates cigarette smoke-induced inflammation in the lung via the Erk1/2 MAPK and STAT3 pathways.

    Science.gov (United States)

    Jiang, Jun-Xia; Zhang, Shui-Juan; Shen, Hui-Juan; Guan, Yan; Liu, Qi; Zhao, Wei; Jia, Yong-Liang; Shen, Jian; Yan, Xiao-Feng; Xie, Qiang-Min

    2017-07-01

    Cigarette smoke (CS) is a major risk factor for the development of chronic obstructive pulmonary disease (COPD). Our previous studies have indicated that Rac1 is involved in lipopolysaccharide-induced pulmonary injury and CS-mediated epithelial-mesenchymal transition. However, the contribution of Rac1 activity to CS-induced lung inflammation remains not fully clear. In this study, we investigated the regulation of Rac1 in CS-induced pulmonary inflammation. Mice or 16HBE cells were exposed to CS or cigarette smoke extract (CSE) to induce acute inflammation. The lungs of mice exposed to CS showed an increase in the release of interleukin-6 (IL-6) and keratinocyte-derived chemokine (KC), as well as an accumulation of inflammatory cells, indicating high Rac1 activity. The exposure of 16HBE cells to CSE resulted in elevated Rac1 levels, as well as increased release of IL-6 and interleukin-8 (IL-8). Selective inhibition of Rac1 ameliorated the release of IL-6 and KC as well as inflammation in the lungs of CS-exposed mice. Histological assessment showed that treatment with a Rac1 inhibitor, NSC23766, led to a decrease in CD68 and CD11b positive cells and the infiltration of neutrophils and macrophages into the alveolar spaces. Selective inhibition or knockdown of Rac1 decreased IL-6 and IL-8 release in 16HBE cells induced by CSE, which correlated with CSE-induced Rac1-regulated Erk1/2 mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription-3 (STAT3) signaling. Our data suggest an important role for Rac1 in the pathological alterations associated with CS-mediated inflammation. Rac1 may be a promising therapeutic target for the treatment of CS-induced pulmonary inflammation. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Symmetry breaking in spreading RAT2 fibroblasts requires the MAPK/ERK pathway scaffold RACK1 that integrates FAK, p190A-RhoGAP and ERK2 signaling

    Czech Academy of Sciences Publication Activity Database

    Klímová, Zuzana; Bráborec, Vojtěch; Maninová, Miloslava; Čáslavský, Josef; Weber, M. J.; Vomastek, Tomáš

    2016-01-01

    Roč. 1863, č. 9 (2016), s. 2189-2200 ISSN 0167-4889 R&D Projects: GA ČR GA13-06405S Institutional support: RVO:61388971 Keywords : RACK1 * ERK * FAK Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.521, year: 2016

  2. Roles of 1,25(OH2D3 and Vitamin D Receptor in the Pathogenesis of Rheumatoid Arthritis and Systemic Lupus Erythematosus by Regulating the Activation of CD4+ T Cells and the PKCδ/ERK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiao-Jie He

    2016-12-01

    Full Text Available Background/Aims: The study aims to elucidate the roles of 1,25(OH2D3 and vitamin D receptor (VDR in the pathogenesis of rheumatoid arthritis (RA and systemic lupus erythematosus (SLE by regulating the activation of CD4+ T cells and the PKCδ/ERK signaling pathway. Methods: From January 2013 to December 2015, a total of 130 SLE patients, 137 RA patients and 130 healthy controls were selected in this study. Serum levels of 1,25(OH2D3 and VDR mRNA expression were detected by ELISA and real-time fluorescence quantitative PCR (RT-qPCR. Density gradient centrifugation was performed to separate peripheral blood mononuclear cells (PBMCs. CD4+ T cells were separated using magnetic activated cell sorting (MACS. CD4+T cells in logarithmic growth phase were collected and assigned into 9 groups: the normal control group, the normal negative control (NC group, the VDR siRNA group, the RA control group, the RA NC group, the VDR over-expressed RA group, the SLE control group, the SLE NC group, and the VDR over-expressed SLE group. The mRNA and protein expressions of VDR, PKCδ, ERK1/2, CD11a, CD70 and CD40L were detected by RT-qPCR and Western blotting. Bisulfite genomic sequencing was conducted to monitor the methylation status of CD11a, CD70 and CD40L. Results: Compared with healthy controls, serum 1,25(OH2D3 level and VDR mRNA expression in peripheral blood were decreased in SLE patients and RA patients. With the increase of concentrations of 1,25(OH2D3 treatment, the VDR mRNA expression and DNA methylation levels of CD11a, CD70 and CD40L were declined, while the expressions of PKCδ, ERK1/2, CD11a, CD70 and CD40L were elevated in SLE, RA and normal CD4+T cells. Compared with the SLE contro, RA control, SLE NC and RA NC groups, the expressions of PKCδ, ERK1/2, CD11a, CD70 and CD40L decreased but DNA methylation levels of CD11a, CD70 and CD40L increased in the VDR over-expressed SLE group and VDR over-expressed RA group. However, compared with the normal

  3. Discovery and validation of the tumor-suppressive function of long noncoding RNA PANDA in human diffuse large B-cell lymphoma through the inactivation of MAPK/ERK signaling pathway.

    Science.gov (United States)

    Wang, Yingjun; Zhang, Mingzhi; Xu, Huanan; Wang, Yifei; Li, Zhaoming; Chang, Yu; Wang, Xinhuan; Fu, Xiaorui; Zhou, Zhiyuan; Yang, Siyuan; Wang, Bei; Shang, Yufeng

    2017-09-22

    Diffuse large B-cell lymphoma (DLBCL) is one of the leading causes of cancer-related mortality, and responds badly to existing treatment. Thus, it is of urgent need to identify novel prognostic markers and therapeutic targets of DLBCL. Recent studies have shown that long non-coding RNAs (lncRNAs) play an important role in the development of cancer. By using the next generation HiSeq sequencing assay, we determined lncRNAs exhibiting differential expression between DLBCL patients and healthy controls. Then, RT-qPCR was performed for identification in clinical samples and cell materials, and lncRNA PANDA was verified to be down-regulated in DLBCL patients and have considerable diagnostic potential. In addition, decreased serum PANDA level was correlated to poorer clinical outcome and lower overall survival in DLBCL patients. Subsequently, we determined the experimental role of lncRNA PANDA in DLBCL progression. Luciferase reporter assay and chromatin immunoprecipitation assay suggested that lncRNA PANDA was induced by p53 and p53 interacts with the promoter region of PANDA. Cell functional assay further indicated that PANDA functioned as a tumor suppressor gene through the suppression of cell growth by a G0/G1 cell cycle arrest in DLBCL. More importantly, Cignal Signal Transduction Reporter Array and western blot assay showed that lncRNA PANDA inactivated the MAPK/ERK signaling pathway. In conclusion, our integrated approach demonstrates that PANDA in DLBCL confers a tumor suppressive function through inhibiting cell proliferation and silencing MAPK/ERK signaling pathway. Thus, PANDA may be a promising therapeutic target for patients with DLBCL.

  4. Constitutive activation of the ERK pathway in melanoma and skin melanocytes in Grey horses.

    Science.gov (United States)

    Jiang, Lin; Campagne, Cécile; Sundström, Elisabeth; Sousa, Pedro; Imran, Saima; Seltenhammer, Monika; Pielberg, Gerli; Olsson, Mats J; Egidy, Giorgia; Andersson, Leif; Golovko, Anna

    2014-11-21

    Constitutive activation of the ERK pathway, occurring in the vast majority of melanocytic neoplasms, has a pivotal role in melanoma development. Different mechanisms underlie this activation in different tumour settings. The Grey phenotype in horses, caused by a 4.6 kb duplication in intron 6 of Syntaxin 17 (STX17), is associated with a very high incidence of cutaneous melanoma, but the molecular mechanism behind the melanomagenesis remains unknown. Here, we investigated the involvement of the ERK pathway in melanoma development in Grey horses. Grey horse melanoma tumours, cell lines and normal skin melanocytes were analyzed with help of indirect immunofluorescence and immunoblotting for the expression of phospho-ERK1/2 in comparison to that in non-grey horse and human counterparts. The mutational status of BRAF, RAS, GNAQ, GNA11 and KIT genes in Grey horse melanomas was determined by direct sequencing. The effect of RAS, RAF and PI3K/AKT pathways on the activation of the ERK signaling in Grey horse melanoma cells was investigated with help of specific inhibitors and immunoblotting. Individual roles of RAF and RAS kinases on the ERK activation were examined using si-RNA based approach and immunoblotting. We found that the ERK pathway is constitutively activated in Grey horse melanoma tumours and cell lines in the absence of somatic activating mutations in BRAF, RAS, GNAQ, GNA11 and KIT genes or alterations in the expression of the main components of the pathway. The pathway is mitogenic and is mediated by BRAF, CRAF and KRAS kinases. Importantly, we found high activation of the ERK pathway also in epidermal melanocytes, suggesting a general predisposition to melanomagenesis in these horses. These findings demonstrate that the presence of the intronic 4.6 kb duplication in STX17 is strongly associated with constitutive activation of the ERK pathway in melanocytic cells in Grey horses in the absence of somatic mutations commonly linked to the activation of this

  5. Non-Smad signaling pathways.

    Science.gov (United States)

    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.

  6. Brain-Derived Neurotrophic Factor Increases Synaptic Protein Levels via the MAPK/Erk Signaling Pathway and Nrf2/Trx Axis Following the Transplantation of Neural Stem Cells in a Rat Model of Traumatic Brain Injury.

    Science.gov (United States)

    Chen, Tao; Wu, Yu; Wang, Yuzi; Zhu, Jigao; Chu, Haiying; Kong, Li; Yin, Liangwei; Ma, Haiying

    2017-11-01

    Brain-derived neurotrophic factor (BDNF) plays an important role in promoting the growth, differentiation, survival and synaptic stability of neurons. Presently, the transplantation of neural stem cells (NSCs) is known to induce neural repair to some extent after injury or disease. In this study, to investigate whether NSCs genetically modified to encode the BDNF gene (BDNF/NSCs) would further enhance synaptogenesis, BDNF/NSCs or naive NSCs were directly engrafted into lesions in a rat model of traumatic brain injury (TBI). Immunohistochemistry, western blotting and RT-PCR were performed to detect synaptic proteins, BDNF-TrkB and its downstream signaling pathways, at 1, 2, 3 or 4 weeks after transplantation. Our results showed that BDNF significantly increased the expression levels of the TrkB receptor gene and the phosphorylation of the TrkB protein in the lesions. The expression levels of Ras, phosphorylated Erk1/2 and postsynaptic density protein-95 were elevated in the BDNF/NSCs-transplanted groups compared with those in the NSCs-transplanted groups throughout the experimental period. Moreover, the nuclear factor (erythroid-derived 2)-like 2/Thioredoxin (Nrf2/Trx) axis, which is a specific therapeutic target for the treatment of injury or cell death, was upregulated by BDNF overexpression. Therefore, we determined that the increased synaptic proteins level implicated in synaptogenesis might be associated with the activation of the MAPK/Erk1/2 signaling pathway and the upregulation of the antioxidant agent Trx modified by BDNF-TrkB following the BDNF/NSCs transplantation after TBI.

  7. Human umbilical cord mesenchymal stem cells alleviate interstitial fibrosis and cardiac dysfunction in a dilated cardiomyopathy rat model by inhibiting TNF-α and TGF-β1/ERK1/2 signaling pathways

    Science.gov (United States)

    Zhang, Changyi; Zhou, Guichi; Chen, Yezeng; Liu, Sizheng; Chen, Fen; Xie, Lichun; Wang, Wei; Zhang, Yonggang; Wang, Tianyou; Lai, Xiulan; Ma, Lian

    2018-01-01

    Dilated cardiomyopathy (DCM) is a disease of the heart characterized by pathological remodeling, including patchy interstitial fibrosis and degeneration of cardiomyocytes. In the present study, the beneficial role of human umbilical cord-derived mesenchymal stem cells (HuMSCs) derived from Wharton's jelly was evaluated in the myosin-induced rat model of DCM. Male Lewis rats (aged 8-weeks) were injected with porcine myosin to induce DCM. Cultured HuMSCs (1×106 cells/rat) were intravenously injected 28 days after myosin injection and the effects on myocardial fibrosis and the underlying signaling pathways were investigated and compared with vehicle-injected and negative control rats. Myosin injections in rats (vehicle group and experimental group) for 28 days led to severe fibrosis and significant deterioration of cardiac function indicative of DCM. HuMSC treatment reduced fibrosis as determined by Masson's staining of collagen deposits, as well as quantification of molecular markers of myocardial fibrosis such as collagen I/III, profibrotic factors transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and connective tissue growth factor (CTGF). HuMSC treatment restored cardiac function as observed using echocardiography. In addition, western blot analysis indicated that HuMSC injections in DCM rats inhibited the expression of TNF-α, extracellular-signal regulated kinase 1/2 (ERK1/2) and TGF-β1, which is a master switch for inducing myocardial fibrosis. These findings suggested that HuMSC injections attenuated myocardial fibrosis and dysfunction in a rat model of DCM, likely by inhibiting TNF-α and the TGF-β1/ERK1/2 fibrosis pathways. Therefore, HuMSC treatment may represent a potential therapeutic method for treatment of DCM. PMID:29115435

  8. Region- or state-related differences in expression and activation of extracellular signal-regulated kinases (ERKs in naïve and pain-experiencing rats

    Directory of Open Access Journals (Sweden)

    Cui Xiu-Yu

    2007-07-01

    Full Text Available Abstract Background Extracellular signal-regulated kinase (ERK, one member of the mitogen-activated protein kinase (MAPK family, has been suggested to regulate a diverse array of cellular functions, including cell growth, differentiation, survival, as well as neuronal plasticity. Recent evidence indicates a role for ERKs in nociceptive processing in both dorsal root ganglion and spinal cord. However, little literature has been reported to examine the differential distribution and activation of ERK isoforms, ERK1 and ERK2, at different levels of pain-related pathways under both normal and pain states. In the present study, quantitative blot immunolabeling technique was used to determine the spatial and temporal expression of ERK1 and ERK2, as well as their activated forms, in the spinal cord, primary somatosensory cortex (SI area of cortex, and hippocampus under normal, transient pain and persistent pain states. Results In naïve rats, we detected regional differences in total expression of ERK1 and ERK2 across different areas. In the spinal cord, ERK1 was expressed more abundantly than ERK2, while in the SI area of cortex and hippocampus, there was a larger amount of ERK2 than ERK1. Moreover, phosphorylated ERK2 (pERK2, not phosphorylated ERK1 (pERK1, was normally expressed with a high level in the SI area and hippocampus, but both pERK1 and pERK2 were barely detectable in normal spinal cord. Intraplantar saline or bee venom injection, mimicking transient or persistent pain respectively, can equally initiate an intense and long-lasting activation of ERKs in all three areas examined. However, isoform-dependent differences existed among these areas, that is, pERK2 exhibited stronger response than pERK1 in the spinal cord, whereas ERK1 was more remarkably activated than ERK2 in the S1 area and hippocampus. Conclusion Taken these results together, we conclude that: (1 under normal state, while ERK immunoreactivity is broadly distributed in the rat

  9. Blockade of the ERK pathway markedly sensitizes tumor cells to HDAC inhibitor-induced cell death

    International Nuclear Information System (INIS)

    Ozaki, Kei-ichi; Minoda, Ai; Kishikawa, Futaba; Kohno, Michiaki

    2006-01-01

    Constitutive activation of the extracellular signal-regulated kinase (ERK) pathway is associated with the neoplastic phenotype of a large number of human tumor cells. Although specific blockade of the ERK pathway by treating such tumor cells with potent mitogen-activated protein kinase/ERK kinase (MEK) inhibitors completely suppresses their proliferation, it by itself shows only a modest effect on the induction of apoptotic cell death. However, these MEK inhibitors markedly enhance the efficacy of histone deacetylase (HDAC) inhibitors to induce apoptotic cell death: such an enhanced cell death is observed only in tumor cells in which the ERK pathway is constitutively activated. Co-administration of MEK inhibitor markedly sensitizes tumor cells to HDAC inhibitor-induced generation of reactive oxygen species, which appears to mediate the enhanced cell death induced by the combination of these agents. These results suggest that the combination of MEK inhibitors and HDAC inhibitors provides an efficient chemotherapeutic strategy for the treatment of tumor cells in which the ERK pathway is constitutively activated

  10. Piper sarmentosum Roxb. produces antidepressant-like effects in rodents, associated with activation of the CREB-BDNF-ERK signaling pathway and reversal of HPA axis hyperactivity.

    Science.gov (United States)

    Li, Qing; Qu, Fa-Lin; Gao, Yue; Jiang, Yi-Ping; Rahman, Khalid; Lee, Kuo-Hsiung; Han, Ting; Qin, Lu-Ping

    2017-03-06

    There are many plants of genus Piper which have been reported to induce antidepressant-like effects, Piper sarmentosum (PS) is one of them. PS is a Chinese herbal medicine and a traditional edible vegetable. In the present study, the antidepressant-like effects of PS extracts and the ethyl acetate fraction of PS extracts (PSY) were assessed using the open field test (OFT), forced swimming test (FST), and tail suspension test (TST) in mice. Furthermore, we applied a 4 consecutive weeks of chronic unpredictable mild stress (CUMS) as a model of depression in rats, followed by a sucrose preference test. Then we examined the possible mechanisms of this action. The activity of the hypothalamic-pituitary-adrenal (HPA) axis was evaluated by detecting the serum corticosterone (CORT) concentrations, and the protein expression levels of brain-derived neurotrophic factor (BDNF), the phosphorylated form CREB and ERK1/2 were detected by qRT-PCR or Western blot. The results showed that PS extracts (100, 200mg/kg) and PSY (12.5, 25, 50mg/kg) treatment produced antidepressant-like effects in mice similar to fluoxetine (20mg/kg), indicated by the reduced immobility time in the FST and TST, while both had no influence on the locomotor activity in the OFT. PSY treatment significantly increased sucrose preference and reduced serum CORT levels in CUMS rats. Moreover, PSY up-regulated BDNF protein levels, and increased CREB and ERK phosphorylation levels in the hippocampus on CUMS rats. These findings suggest that the antidepressant-like effects of PS extracts and PSY are mediated, at least in part, by modulating HPA axis, BDNF, CREB and ERK phosphorylation and expression in the hippocampus. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  11. Analgesic effect of paeoniflorin in rats with neonatal maternal separation-induced visceral hyperalgesia is mediated through adenosine A(1) receptor by inhibiting the extracellular signal-regulated protein kinase (ERK) pathway.

    Science.gov (United States)

    Zhang, Xiao-Jun; Chen, Hong-Li; Li, Zhi; Zhang, Hong-Qi; Xu, Hong-Xi; Sung, Joseph J Y; Bian, Zhao-Xiang

    2009-11-01

    Paeoniflorin (PF), a chief active ingredient in the root of Paeonia lactiflora Pall (family Ranunculaceae), is effective in relieving colorectal distention (CRD)-induced visceral pain in rats with visceral hyperalgesia induced by neonatal maternal separation (NMS). This study aimed at exploring the underlying mechanisms of PF's analgesic effect on CRD-evoked nociceptive signaling in the central nervous system (CNS) and investigating whether the adenosine A(1) receptor is involved in PF's anti-nociception. CRD-induced visceral pain as well as phosphorylated-extracellular signal-regulated protein kinase (p-ERK) and phospho-cAMP response element-binding protein (p-CREB) expression in the CNS structures of NMS rats were suppressed by NMDA receptor antagonist dizocilpine (MK-801) and ERK phosphorylation inhibitor U0126. PF could similarly inhibit CRD-evoked p-ERK and c-Fos expression in laminae I-II of the lumbosacral dorsal horn and anterior cingulate cortex (ACC). PF could also reverse the CRD-evoked increased glutamate concentration by CRD as shown by dynamic microdialysis monitoring in ACC, whereas, DPCPX, an antagonist of adenosine A(1) receptor, significantly blocked the analgesic effect of PF and PF's inhibition on CRD-induced p-ERK and p-CREB expression. These results suggest that PF's analgesic effect is possibly mediated by adenosine A(1) receptor by inhibiting CRD-evoked glutamate release and the NMDA receptor dependent ERK signaling.

  12. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

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    Wei-Ru Huang

    Full Text Available Avian reovirus (ARV protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128 of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication.

  13. Activation of MAPK/ERK signaling by Burkholderia pseudomallei cycle inhibiting factor (Cif.

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    Mei Ying Ng

    Full Text Available Cycle inhibiting factors (Cifs are virulence proteins secreted by the type III secretion system of some Gram-negative pathogenic bacteria including Burkholderia pseudomallei. Cif is known to function to deamidate Nedd8, leading to inhibition of Cullin E3 ubiquitin ligases (CRL and consequently induction of cell cycle arrest. Here we show that Cif can function as a potent activator of MAPK/ERK signaling without significant activation of other signaling pathways downstream of receptor tyrosine kinases. Importantly, we found that the ability of Cif to activate ERK is dependent on its deamidase activity, but independent of Cullin E3 ligase inhibition. This suggests that apart from Nedd8, other cellular targets of Cif-dependent deamidation exist. We provide evidence that the mechanism involved in Cif-mediated ERK activation is dependent on recruitment of the Grb2-SOS1 complex to the plasma membrane. Further investigation revealed that Cif appears to modify the phosphorylation status of SOS1 in a region containing the CDC25-H and proline-rich domains. It is known that prolonged Cullin E3 ligase inhibition leads to cellular apoptosis. Therefore, we hypothesize that ERK activation is an important mechanism to counter the pro-apoptotic effects of Cif. Indeed, we show that Cif dependent ERK activation promotes phosphorylation of the proapoptotic protein Bim, thereby potentially conferring a pro-survival signal. In summary, we identified a novel deamidation-dependent mechanism of action of the B. pseudomallei virulence factor Cif/CHBP to activate MAPK/ERK signaling. Our study demonstrates that bacterial proteins such as Cif can serve as useful molecular tools to uncover novel aspects of mammalian signaling pathways.

  14. Quercetin Inhibits Pulmonary Arterial Endothelial Cell Transdifferentiation Possibly by Akt and Erk1/2 Pathways

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    Shian Huang

    2017-01-01

    Full Text Available This study aimed to investigate the effects and mechanisms of quercetin on pulmonary arterial endothelial cell (PAEC transdifferentiation into smooth muscle-like cells. TGF-β1-induced PAEC transdifferentiation models were applied to evaluate the pharmacological actions of quercetin. PAEC proliferation was detected with CCK8 method and BurdU immunocytochemistry. Meanwhile, the identification and transdifferentiation of PAECs were determined by FVIII immunofluorescence staining and α-SMA protein expression. The related mechanism was elucidated based on the levels of Akt and Erk1/2 signal pathways. As a result, quercetin effectively inhibited the TGF-β1-induced proliferation and transdifferentiation of the PAECs and activation of Akt/Erk1/2 cascade in the cells. In conclusion, quercetin is demonstrated to be effective for pulmonary arterial hypertension (PAH probably by inhibiting endothelial transdifferentiation possibly via modulating Akt and Erk1/2 expressions.

  15. 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.

  16. Kaempferol Reduces Matrix Metalloproteinase-2 Expression by Down-Regulating ERK1/2 and the Activator Protein-1 Signaling Pathways in Oral Cancer Cells

    Science.gov (United States)

    Lin, Chiao-Wen; Chen, Pei-Ni; Chen, Mu-Kuan; Yang, Wei-En; Tang, Chih-Hsin; Yang, Shun-Fa; Hsieh, Yih-Shou

    2013-01-01

    Background Kaempferol has been proposed as a potential drug for cancer chemoprevention and treatment because it is a natural polyphenol contained in plant-based foods. Recent studies have demonstrated that kaempferol protects against cardiovascular disease and cancer. Based on this finding, we investigated the mechanisms by which kaempferol produces the anti-metastatic effect in human tongue squamous cell carcinoma SCC4 cells. Methodology/Principal Findings In this study, we provided molecular evidence associated with the anti-metastatic effect of kaempferol by demonstrating a substantial suppression of SCC4 cell migration and invasion. This effect was associated with reduced expressions of MMP-2 and TIMP-2 mRNA and protein levels. Analysis of the transcriptional regulation indicated that kaempferol inhibited MMP-2 transcription by suppressing c-Jun activity. Kaempferol also produced an inhibitory effect on the phosphorylation of ERK1/2. Conclusions These findings provide new insights into the molecular mechanisms involved in the anti-metastatic effect of kaempferol, and are valuable in the prevention of oral cancer metastasis. PMID:24278338

  17. Chimaphilin inhibits human osteosarcoma cell invasion and metastasis through suppressing the TGF-β1-induced epithelial-to-mesenchymal transition markers via PI-3K/Akt, ERK1/2, and Smad signaling pathways.

    Science.gov (United States)

    Dong, Feng; Liu, Tingting; Jin, Hao; Wang, Wenbo

    2018-01-01

    Epithelial-to-mesenchymal transition is a cellular process associated with cancer invasion and metastasis. However, the antimetastatic effects of chimaphilin remain elusive. In this study, we attempted to investigate the potential use of chimaphilin as an inhibitor of TGF-β1-induced epithelial-to-mesenchymal transition in U2OS cells. We found that TGF-β1 induced epithelial-to-mesenchymal transition to promote U2OS cell invasion and metastasis. Western blotting demonstrated that chimaphilin inhibited U2OS cell invasion and migration, increased the expression of the epithelial phenotype marker E-cadherin, repressed the expression of the mesenchymal phenotype marker vimentin, as well as decreased the level of epithelial-to-mesenchymal-inducing transcription factors Snail1 and Slug during the initiation of TGF-β1-induced epithelial-to-mesenchymal transition. In this study, we revealed that chimaphilin up-regulated the E-cadherin expression level and inhibited the production of vimentin, Snail1, and Slug in TGF-β1-induced U2OS cells by blocking PI-3K/Akt and ERK 1/2 signaling pathway. Additionally, the TGF-β1-mediated phosphorylated levels of Smad2/3 were inhibited by chimaphilin pretreatment. Above all, we conclude that chimaphilin represents an effective inhibitor of the metastatic potential of U2OS cells through suppression of TGF-β1-induced epithelial-to-mesenchymal transition.

  18. Convergence of BMI1 and CHD7 on ERK Signaling in Medulloblastoma

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    Sara Badodi

    2017-12-01

    Full Text Available Summary: We describe molecular convergence between BMI1 and CHD7 in the initiation of medulloblastoma. Identified in a functional genomic screen in mouse models, a BMI1High;CHD7Low expression signature within medulloblastoma characterizes patients with poor overall survival. We show that BMI1-mediated repression of the ERK1/2 pathway leads to increased proliferation and tumor burden in primary human MB cells and in a xenograft model, respectively. We provide evidence that repression of the ERK inhibitor DUSP4 by BMI1 is dependent on a more accessible chromatin configuration in G4 MB cells with low CHD7 expression. These findings extend current knowledge of the role of BMI1 and CHD7 in medulloblastoma pathogenesis, and they raise the possibility that pharmacological targeting of BMI1 or ERK may be particularly indicated in a subgroup of MB with low expression levels of CHD7. : Badodi et al. find convergence of the chromatin modifiers BMI1 and CHD7 in medulloblastoma pathogenesis, and they show that this pathway regulates tumor proliferation and growth via ERK signaling. Keywords: BMI1, CHD7, DUSP4, ERK, medulloblastoma, PcG genes, mouse models, epigenetics, chromatin

  19. DA-9801 promotes neurite outgrowth via ERK1/2-CREB pathway in PC12 cells.

    Science.gov (United States)

    Won, Jong Hoon; Ahn, Kyong Hoon; Back, Moon Jung; Ha, Hae Chan; Jang, Ji Min; Kim, Ha Hyung; Choi, Sang-Zin; Son, Miwon; Kim, Dae Kyong

    2015-01-01

    In the present study, we examined the mechanisms underlying the effect of DA-9801 on neurite outgrowth. We found that DA-9801 elicits its effects via the mitogen-activated protein kinase (MEK) extracellular signal-regulated kinase (ERK)1/2-cAMP response element-binding protein (CREB) pathway. DA-9801, an extract from a mixture of Dioscorea japonica and Dioscorea nipponica, was reported to promote neurite outgrowth in PC12 cells. The effects of DA-9801 on cell viability and expression of neuronal markers were evaluated in PC12 cells. To investigate DA-9801 action, specific inhibitors targeting the ERK signaling cascade were used. No cytotoxicity was observed in PC12 cells at DA-9801 concentrations of less than 30 µg/mL. In the presence of nerve growth factor (NGF, 2 ng/mL), DA-9801 promoted neurite outgrowth and increased the relative mRNA levels of neurofilament-L (NF-L), a marker of neuronal differentiation. The Raf-1 inhibitor GW5074 and MEK inhibitor PD98059 significantly attenuated DA-9801-induced neurite outgrowth. Additionally, the MEK1 and MEK2 inhibitor SL327 significantly attenuated the increase in the percentage of neurite-bearing PC12 cells induced by DA-9801 treatment. Conversely, the selective p38 mitogen-activated protein kinase inhibitor SB203580 did not attenuate the DA-9801 treatment-induced increase in the percentage of neurite-bearing PC12 cells. DA-9801 enhanced the phosphorylation of ERK1/2 and CREB in PC12 cells incubated with and without NGF. Pretreatment with PD98059 blocked the DA-9801-induced phosphorylation of ERK1/2 and CREB. In conclusion, DA-9801 induces neurite outgrowth by affecting the ERK1/2-CREB signaling pathway. Insights into the mechanism underlying this effect of DA-9801 may suggest novel potential strategies for the treatment of peripheral neuropathy.

  20. Differential phosphorylation of Smad1 integrates BMP and neurotrophin pathways through Erk/Dusp in axon development.

    Science.gov (United States)

    Finelli, Mattéa J; Murphy, Kevin J; Chen, Lei; Zou, Hongyan

    2013-05-30

    Sensory axon development requires concerted actions of growth factors for the precise control of axonal outgrowth and target innervation. How developing sensory neurons integrate different cues is poorly understood. We demonstrate here that Smad1 activation is required for neurotrophin-mediated sensory axon growth in vitro and in vivo. Through differential phosphorylation, Smad1 exerts transcriptional selectivity to regulate the expression and activity of Erk1 and Erk2-two key neurotrophin effectors. Specifically, bone morphogenetic proteins (BMPs) signal through carboxy-terminal phosphorylation of Smad1 (pSmad1C) to induce Erk1/2 transcription for enhanced neurotrophin responsiveness. Meanwhile, neurotrophin signaling results in linker phosphorylation of Smad1 (pSmad1L), which in turn upregulates an Erk-specific dual-specificity phosphatase, Dusp6, leading to reduced pErk1/2 and constituting a negative-feedback loop for the prevention of axon overgrowth. Together, the BMP and neurotrophin pathways form a tightly regulated signaling network with a balanced ratio of Erk1/2 and pErk1/2 to direct the precise connections between sensory neurons and peripheral targets. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Trihydrophobin 1 Phosphorylation by c-Src Regulates MAPK/ERK Signaling and Cell Migration

    Science.gov (United States)

    Wu, Weibin; Sun, Zhichao; Wu, Jingwen; Peng, Xiaomin; Gan, Huacheng; Zhang, Chunyi; Ji, Lingling; Xie, Jianhui; Zhu, Haiyan; Ren, Shifang

    2012-01-01

    c-Src activates Ras-MAPK/ERK signaling pathway and regulates cell migration, while trihydrophobin 1 (TH1) inhibits MAPK/ERK activation and cell migration through interaction with A-Raf and PAK1 and inhibiting their kinase activities. Here we show that c-Src interacts with TH1 by GST-pull down assay, coimmunoprecipitation and confocal microscopy assay. The interaction leads to phosphorylation of TH1 at Tyr-6 in vivo and in vitro. Phosphorylation of TH1 decreases its association with A-Raf and PAK1. Further study reveals that Tyr-6 phosphorylation of TH1 reduces its inhibition on MAPK/ERK signaling, enhances c-Src mediated cell migration. Moreover, induced tyrosine phosphorylation of TH1 has been found by EGF and estrogen treatments. Taken together, our findings demonstrate a novel mechanism for the comprehensive regulation of Ras/Raf/MEK/ERK signaling and cell migration involving tyrosine phosphorylation of TH1 by c-Src. PMID:22238675

  2. The MEK1/2-ERK Pathway Inhibits Type I IFN Production in Plasmacytoid Dendritic Cells

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    Vaclav Janovec

    2018-02-01

    Full Text Available Recent studies have reported that the crosslinking of regulatory receptors (RRs, such as blood dendritic cell antigen 2 (BDCA-2 (CD303 or ILT7 (CD85g, of plasmacytoid dendritic cells (pDCs efficiently suppresses the production of type I interferons (IFN-I, α/β/ω and other cytokines in response to toll-like receptor 7 and 9 (TLR7/9 ligands. The exact mechanism of how this B cell receptor (BCR-like signaling blocks TLR7/9-mediated IFN-I production is unknown. Here, we stimulated BCR-like signaling by ligation of RRs with BDCA-2 and ILT7 mAbs, hepatitis C virus particles, or BST2 expressing cells. We compared BCR-like signaling in proliferating pDC cell line GEN2.2 and in primary pDCs from healthy donors, and addressed the question of whether pharmacological targeting of BCR-like signaling can antagonize RR-induced pDC inhibition. To this end, we tested the TLR9-mediated production of IFN-I and proinflammatory cytokines in pDCs exposed to a panel of inhibitors of signaling molecules involved in BCR-like, MAPK, NF-ĸB, and calcium signaling pathways. We found that MEK1/2 inhibitors, PD0325901 and U0126 potentiated TLR9-mediated production of IFN-I in GEN2.2 cells. More importantly, MEK1/2 inhibitors significantly increased the TLR9-mediated IFN-I production blocked in both GEN2.2 cells and primary pDCs upon stimulation of BCR-like or phorbol 12-myristate 13-acetate-induced protein kinase C (PKC signaling. Triggering of BCR-like and PKC signaling in pDCs resulted in an upregulation of the expression and phoshorylation of c-FOS, a downstream gene product of the MEK1/2-ERK pathway. We found that the total level of c-FOS was higher in proliferating GEN2.2 cells than in the resting primary pDCs. The PD0325901-facilitated restoration of the TLR9-mediated IFN-I production correlated with the abrogation of MEK1/2-ERK-c-FOS signaling. These results indicate that the MEK1/2-ERK pathway inhibits TLR9-mediated type I IFN production in pDCs and that

  3. Stimulation of Alpha7 Nicotinic Acetylcholine Receptor Attenuates Nicotine-Induced Upregulation of MMP, MCP-1, and RANTES through Modulating ERK1/2/AP-1 Signaling Pathway in RAW264.7 and MOVAS Cells

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    Liping Liu

    2017-01-01

    Full Text Available Vagus nerve stimulation through alpha7 nicotine acetylcholine receptors (α7-nAChR signaling had been demonstrated attenuation of inflammation. This study aimed to determine whether PNU-282987, a selective α7-nAChR agonist, affected activities of matrix metalloproteinase (MMP and inflammatory cytokines in nicotine-treatment RAW264.7 and MOVAS cells and to assess the underlying molecular mechanisms. RAW264.7 and MOVAS cells were treated with nicotine at different concentrations (0, 1, 10, and 100 ng/ml for 0–120 min. Nicotine markedly stimulated the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2 and c-Jun in RAW264.7 cells. Pretreatment with U0126 significantly suppressed phosphorylation of ERK1/2 and further attenuated nicotine-induced activation of c-Jun and upregulation of MMP-2, MMP-9, monocyte chemotactic protein- (MCP- 1, and regulated upon activation normal T cell expressed and secreted (RANTES. Similarly, nicotine treatment also increased phosphorylation of c-Jun and expressions of MMP-2, MMP-9, MCP-1, and RANTES in MOVAS cells. When cells were pretreated with PNU-282987, nicotine-induced activations of ERK1/2 and c-Jun in RAW264.7 cells and c-Jun in MOVAS cells were effectively inhibited. Furthermore, nicotine-induced secretions of MMP-2, MMP-9, MCP-1, and RANTES were remarkably downregulated. Treatment with α7-nAChR agonist inhibits nicotine-induced upregulation of MMP and inflammatory cytokines through modulating ERK1/2/AP-1 signaling in RAW264.7 cells and AP-1 in MOVAS cells, providing a new therapeutic for abdominal aortic aneurysm.

  4. Sodium Ferulate Prevents Daunorubicin - Induced Apoptosis in H9c2 Cells via Inhibition of the ERKs Pathway

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    Zhi-Juan Wu

    2015-07-01

    Full Text Available Background: Daunorubicin (DNR-induced cardiotoxicity, which is closely associated with cardiomyocyte apoptosis, limits the drug's clinical application. The activation of the extracellular regulated protein kinases (ERKs pathway is responsible for the pro-apoptosis effect of DNR Sodium ferulate (SF has recently been found to attenuate both DNR-induced cardiotoxicity and mitochondrial apoptosis in juvenile rats. Nonetheless, the precise mechanism underlying SF-induced cardio-protection remains unclear. Methods: The DNR-injured H9c2 cell model was prepared by incubating the cells in 1 µM DNR for 24 h. Amounts of 15.6, 31.3 or 62.5 µM SF were simultaneously added to the cells. The effect of SF on the cytotoxic and apoptotic parameters of the cells was studied by monitoring apoptosis regulation via the ERKs pathway. Results: SF attenuated DNR-induced cell death (particularly apoptotic death, cTnI and β-tubulin degradation, and cellular morphological changes. SF reduced mitochondrial membrane potential depolarization, cytochrome c leakage, and caspase-9 and caspase-3 activation. SF also decreased ERK1/2, phospho-ERK1/2, p53 and Bax expression and increased Bcl-2 expression. These effects were similar to the results observed when using the pharmacological ERKs phosphorylation inhibitor, AZD6244. Conclusion: We determined that SF protects H9c2 cells from DNR-induced apoptosis through a mechanism that involves the interruption of the ERKs signaling pathway.

  5. PDGFR alpha signaling in the primary cilium regulates NHE1-dependent fibroblast migration via coordinated differential activity of MEK1/2-ERK1/2-p90(RSK) and AKT signaling pathways

    DEFF Research Database (Denmark)

    Clement, Ditte L.; Mally, Sabine; Stock, Christian

    2013-01-01

    In fibroblasts, platelet-derived growth factor receptor alpha (PDGFR alpha) is upregulated during growth arrest and compartmentalized to the primary cilium. PDGF-AA mediated activation of the dimerized ciliary receptor produces a phosphorylation cascade through the PI3K-AKT and MEK1/2-ERK1/2 path...

  6. Triiodothyronine promotes the proliferation of epicardial progenitor cells through the MAPK/ERK pathway

    International Nuclear Information System (INIS)

    Deng, Song-Bai; Jing, Xiao-Dong; Wei, Xiao-ming; Du, Jian-Lin; Liu, Ya-Jie; Qin, Qin; She, Qiang

    2017-01-01

    Thyroid hormone has important functions in the development and physiological function of the heart. The aim of this study was to determine whether 3,5,3′-Triiodothyronine (T3) can promote the proliferation of epicardial progenitor cells (EPCs) and to investigate the potential underlying mechanism. Our results showed that T3 significantly promoted the proliferation of EPCs in a concentration- and time-dependent manner. The thyroid hormone nuclear receptor inhibitor bisphenol A (100 μmol/L) did not affect T3's ability to induce proliferation. Further studies showed that the mRNA expression levels of mitogen-activated protein kinase 1 (MAPK1), MAPK3, and Ki67 in EPCs in the T3 group (10 nmol/L) increased 2.9-, 3-, and 4.1-fold, respectively, compared with those in the control group (P < 0.05). In addition, the mRNA expression of the cell cycle protein cyclin D1 in the T3 group increased approximately 2-fold compared with the control group (P < 0.05), and there were more EPCs in the S phase of the cell cycle (20.6% vs. 12.0%, P < 0.05). The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway inhibitor U0126 (10 μmol/L) significantly inhibited the ability of T3 to promote the proliferation of EPCs and to alter cell cycle progression. This study suggested that T3 significantly promotes the proliferation of EPCs, and this effect may be achieved through activation of the MAPK/ERK signaling pathway. - Highlights: • Epicardial progenitor cells were successfully cultured from E12.5 mice. • Thyroid hormone T3 significantly promoted the proliferation of EPCs. • This biological effect may be mediated via activation of the MAPK/ERK pathway.

  7. Mechano-growth factor induces migration of rat mesenchymal stem cells by altering its mechanical properties and activating ERK pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jiamin; Wu, Kewen; Lin, Feng; Luo, Qing; Yang, Li; Shi, Yisong [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China); Sung, Kuo-Li Paul [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China); Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093-0412 (United States)

    2013-11-08

    Highlights: •MGF induced the migration of rat MSC in a concentration-dependent manner. •MGF enhanced the mechanical properties of rMSC in inducing its migration. •MGF activated the ERK 1/2 signaling pathway of rMSC in inducing its migration. •rMSC mechanics may synergy with ERK 1/2 pathway in MGF-induced rMSC migration. -- Abstract: Mechano-growth factor (MGF) generated by cells in response to mechanical stimulation has been identified as a mechano effector molecule, playing a key role in regulating mesenchymal stem cell (MSC) function, including proliferation and migration. However, the mechanism(s) underlying how MGF-induced MSC migration occurs is still unclear. In the present study, MGF motivated migration of rat MSCs (rMSCs) in a concentration-dependent manner and optimal concentration of MGF at 50 ng/mL (defined as MGF treatment in this paper) was demonstrated. Notably, enhancement of mechanical properties that is pertinent to cell migration, such as cell traction force and cell stiffness were found to respond to MGF treatment. Furthermore, MGF increased phosphorylation of extracellular signal-regulated kinase (ERK), ERK inhibitor (i.e., PD98059) suppressed ERK phosphorylation, and abolished MGF-induced rMSC migration were found, demonstrating that ERK is involved molecule for MGF-induced rMSC migration. These in vitro evidences of MGF-induced rMSC migration and its direct link to altering rMSC mechanics and activating the ERK pathway, uncover the underlying biomechanical and biological mechanisms of MGF-induced rMSC migration, which may help find MGF-based application of MSC in clinical therapeutics.

  8. Coordinating ERK signaling via the molecular scaffold Kinase Suppressor of Ras [version 1; referees: 2 approved

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    Danielle Frodyma

    2017-08-01

    Full Text Available Many cancers, including those of the colon, lung, and pancreas, depend upon the signaling pathways induced by mutated and constitutively active Ras. The molecular scaffolds Kinase Suppressor of Ras 1 and 2 (KSR1 and KSR2 play potent roles in promoting Ras-mediated signaling through the Raf/MEK/ERK kinase cascade. Here we summarize the canonical role of KSR in cells, including its central role as a scaffold protein for the Raf/MEK/ERK kinase cascade, its regulation of various cellular pathways mediated through different binding partners, and the phenotypic consequences of KSR1 or KSR2 genetic inactivation. Mammalian KSR proteins have a demonstrated role in cellular and organismal energy balance with implications for cancer and obesity. Targeting KSR1 in cancer using small molecule inhibitors has potential for therapy with reduced toxicity to the patient. RNAi and small molecule screens using KSR1 as a reference standard have the potential to expose and target vulnerabilities in cancer. Interestingly, although KSR1 and KSR2 are similar in structure, KSR2 has a distinct physiological role in regulating energy balance. Although KSR proteins have been studied for two decades, additional analysis is required to elucidate both the regulation of these molecular scaffolds and their potent effect on the spatial and temporal control of ERK activation in health and disease.

  9. SNT-2 interacts with ERK2 and negatively regulates ERK2 signaling in response to EGF stimulation

    International Nuclear Information System (INIS)

    Huang Lin; Gotoh, Noriko; Zhang Shengliang; Shibuya, Masabumi; Yamamoto, Tadashi; Tsuchida, Nobuo

    2004-01-01

    The control of cellular responses with fibroblast growth factors and neurotrophins is mediated through membrane-linked docking proteins, SNT (suc1-binding neurotrophic target)-1/FRS2α and SNT-2/FRS2β. ERK1/2 are members of the mitogen-activated protein kinase family that regulate diverse cellular activities in response to various stimuli. Here, we demonstrate that SNT-2 does not become tyrosine phosphorylated significantly in response to EGF but forms a complex with ERK2 via the region of 186-252 amino acid residues, and the complex formation is enhanced upon EGF stimulation. SNT-2 downregulates ERK2 phosphorylation, suppresses and delays ERK2 nuclear accumulation which occurs following EGF stimulation. In contrast, the mutant SNT-2 which carries deletion of 186-252 amino acids and lacks ERK2 binding does not have these effects. These observations suggest that SNT-2 negatively regulates ERK2 signaling activated via EGF stimulation through direct binding to ERK2

  10. PEA3/ETV4-related transcription factors coupled with active ERK signalling are associated with poor prognosis in gastric adenocarcinoma

    LENUS (Irish Health Repository)

    Keld, R

    2011-06-28

    Background: Transcription factors often play important roles in tumourigenesis. Members of the PEA3 subfamily of ETS-domain transcription factors fulfil such a role and have been associated with tumour metastasis in several different cancers. Moreover, the activity of the PEA3 subfamily transcription factors is potentiated by Ras-ERK pathway signalling, which is itself often deregulated in tumour cells.\\r\

  11. Oscillatory Dynamics of the Extracellular Signal-regulated Kinase Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Shankaran, Harish; Wiley, H. S.

    2010-12-01

    The extracellular signal-regulated kinase (ERK) pathway is a central signaling pathway in development and disease and is regulated by multiple negative and positive feedback loops. Recent studies have shown negative feedback from ERK to upstream regulators can give rise to biochemical oscillations with a periodicity of between 15-30 minutes. Feedback due to the stimulated transcription of negative regulators of the ERK pathway can also give rise to transcriptional oscillations with a periodicity of 1-2h. The biological significance of these oscillations is not clear, but recent evidence suggests that transcriptional oscillations participate in developmental processes, such as somite formation. Biochemical oscillations are more enigmatic, but could provide a mechanism for encoding different types of inputs into a common signaling pathway.

  12. miR-322 stabilizes MEK1 expression to inhibit RAF/MEK/ERK pathway activation in cartilage.

    Science.gov (United States)

    Bluhm, Björn; Ehlen, Harald W A; Holzer, Tatjana; Georgieva, Veronika S; Heilig, Juliane; Pitzler, Lena; Etich, Julia; Bortecen, Toman; Frie, Christian; Probst, Kristina; Niehoff, Anja; Belluoccio, Daniele; Van den Bergen, Jocelyn; Brachvogel, Bent

    2017-10-01

    Cartilage originates from mesenchymal cell condensations that differentiate into chondrocytes of transient growth plate cartilage or permanent cartilage of the articular joint surface and trachea. MicroRNAs fine-tune the activation of entire signaling networks and thereby modulate complex cellular responses, but so far only limited data are available on miRNAs that regulate cartilage development. Here, we characterize a miRNA that promotes the biosynthesis of a key component in the RAF/MEK/ERK pathway in cartilage. Specifically, by transcriptome profiling we identified miR-322 to be upregulated during chondrocyte differentiation. Among the various miR-322 target genes in the RAF/MEK/ERK pathway, only Mek1 was identified as a regulated target in chondrocytes. Surprisingly, an increased concentration of miR-322 stabilizes Mek1 mRNA to raise protein levels and dampen ERK1/2 phosphorylation, while cartilage-specific inactivation of miR322 in mice linked the loss of miR-322 to decreased MEK1 levels and to increased RAF/MEK/ERK pathway activation. Such mice died perinatally due to tracheal growth restriction and respiratory failure. Hence, a single miRNA can stimulate the production of an inhibitory component of a central signaling pathway to impair cartilage development. © 2017. Published by The Company of Biologists Ltd.

  13. Viral exploitation of the MEK/ERK pathway - A tale of vaccinia virus and other viruses.

    Science.gov (United States)

    Bonjardim, Cláudio A

    2017-07-01

    The VACV replication cycle is remarkable in the sense that it is performed entirely in the cytoplasmic compartment of vertebrate cells, due to its capability to encode enzymes required either for regulating the macromolecular precursor pool or the biosynthetic processes. Although remarkable, this gene repertoire is not sufficient to confer the status of a free-living microorganism to the virus, and, consequently, the virus relies heavily on the host to successfully generate its progeny. During the complex virus-host interaction, viruses must deal not only with the host pathways to accomplish their temporal demands but also with pathways that counteract viral infection, including the inflammatory, innate and acquired immune responses. This review focuses on VACV and other DNA or RNA viruses that stimulate the MEK (MAPK - Mitogen Activated Protein Kinase)/ERK- Extracellular signal-Regulated Kinase) pathway as part of their replication cycle. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. P2X7 receptor activates extracellular signal-regulated kinases ERK1 and ERK2 independently of Ca2+ influx

    DEFF Research Database (Denmark)

    Amstrup, Jan; Novak, Ivana

    2003-01-01

    P2X7 nucleotide receptors modulate a spectrum of cellular events in various cells including epithelia, such as exocrine pancreas. Although the pharmacology and channel properties of the P2X7 receptors have been studied intensively, signal transduction pathways are relatively unknown. In this study...... we applied a heterologous expression system of rat P2X7 receptors in HEK-293 cells. We followed the receptor expression and function using the enhanced green fluorescent protein (EGFP) tag, activation of intracellular proteins and increases in cellular Ca2+. EGFP-P2X7 receptors localized...... to the plasma membrane, clusters within the membrane and intracellularly. Stimulation of P2X7 receptors in HEK-293 cells led to an activation of extracellular signal-regulated kinases ERK1 and ERK2 and this activation was seen after just 1 min of stimulation with ATP. Using C- and N-terminal P2X7-receptor...

  15. Disruption of MEK/ERK/c-Myc signaling radiosensitizes prostate cancer cells in vitro and in vivo.

    Science.gov (United States)

    Ciccarelli, Carmela; Di Rocco, Agnese; Gravina, Giovanni Luca; Mauro, Annunziata; Festuccia, Claudio; Del Fattore, Andrea; Berardinelli, Paolo; De Felice, Francesca; Musio, Daniela; Bouché, Marina; Tombolini, Vincenzo; Zani, Bianca Maria; Marampon, Francesco

    2018-06-29

    Prostate cancer (PCa) cell radioresistance causes the failure of radiation therapy (RT) in localized or locally advanced disease. The aberrant accumulation of c-Myc oncoprotein, known to promote PCa onset and progression, may be due to the control of gene transcription and/or MEK/ERK-regulated protein stabilization. Here, we investigated the role of MEK/ERK signaling in PCa. LnCAP, 22Rv1, DU145, and PC3 PCa cell lines were used in in vitro and in vivo experiments. U0126, trametinib MEK/ERK inhibitors, and c-Myc shRNAs were used. Radiation was delivered using an x-6 MV photon linear accelerator. U0126 in vivo activity alone or in combination with irradiation was determined in murine xenografts. Inhibition of MEK/ERK signaling down-regulated c-Myc protein in PCa cell lines to varying extents by affecting expression of RNA and protein, which in turn determined radiosensitization in in vitro and in vivo xenograft models of PCa cells. The crucial role played by c-Myc in the MEK/ERK pathways was demonstrated in 22Rv1 cells by the silencing of c-Myc by means of short hairpin mRNA, which yielded effects resembling the targeting of MEK/ERK signaling. The clinically approved compound trametinib used in vitro yielded the same effects as U0126 on growth and C-Myc expression. Notably, U0126 and trametinib induced a drastic down-regulation of BMX, which is known to prevent apoptosis in cancer cells. The results of our study suggest that signal transduction-based therapy can, by disrupting the MEK/ERK/c-Myc axis, reduce human PCa radioresistance caused by increased c-Myc expression in vivo and in vitro and restores apoptosis signals.

  16. ERK mutations confer resistance to mitogen-activated protein kinase pathway inhibitors.

    Science.gov (United States)

    Goetz, Eva M; Ghandi, Mahmoud; Treacy, Daniel J; Wagle, Nikhil; Garraway, Levi A

    2014-12-01

    The use of targeted therapeutics directed against BRAF(V600)-mutant metastatic melanoma improves progression-free survival in many patients; however, acquired drug resistance remains a major medical challenge. By far, the most common clinical resistance mechanism involves reactivation of the MAPK (RAF/MEK/ERK) pathway by a variety of mechanisms. Thus, targeting ERK itself has emerged as an attractive therapeutic concept, and several ERK inhibitors have entered clinical trials. We sought to preemptively determine mutations in ERK1/2 that confer resistance to either ERK inhibitors or combined RAF/MEK inhibition in BRAF(V600)-mutant melanoma. Using a random mutagenesis screen, we identified multiple point mutations in ERK1 (MAPK3) and ERK2 (MAPK1) that could confer resistance to ERK or RAF/MEK inhibitors. ERK inhibitor-resistant alleles were sensitive to RAF/MEK inhibitors and vice versa, suggesting that the future development of alternating RAF/MEK and ERK inhibitor regimens might help circumvent resistance to these agents. ©2014 American Association for Cancer Research.

  17. 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

  18. Hypoxia Downregulates MAPK/ERK but Not STAT3 Signaling in ROS-Dependent and HIF-1-Independent Manners in Mouse Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Jan Kučera

    2017-01-01

    Full Text Available Hypoxia is involved in the regulation of stem cell fate, and hypoxia-inducible factor 1 (HIF-1 is the master regulator of hypoxic response. Here, we focus on the effect of hypoxia on intracellular signaling pathways responsible for mouse embryonic stem (ES cell maintenance. We employed wild-type and HIF-1α-deficient ES cells to investigate hypoxic response in the ERK, Akt, and STAT3 pathways. Cultivation in 1% O2 for 24 h resulted in the strong dephosphorylation of ERK and its upstream kinases and to a lesser extent of Akt in an HIF-1-independent manner, while STAT3 phosphorylation remained unaffected. Downregulation of ERK could not be mimicked either by pharmacologically induced hypoxia or by the overexpression. Dual-specificity phosphatases (DUSP 1, 5, and 6 are hypoxia-sensitive MAPK-specific phosphatases involved in ERK downregulation, and protein phosphatase 2A (PP2A regulates both ERK and Akt. However, combining multiple approaches, we revealed the limited significance of DUSPs and PP2A in the hypoxia-mediated attenuation of ERK signaling. Interestingly, we observed a decreased reactive oxygen species (ROS level in hypoxia and a similar phosphorylation pattern for ERK when the cells were supplemented with glutathione. Therefore, we suggest a potential role for the ROS-dependent attenuation of ERK signaling in hypoxia, without the involvement of HIF-1.

  19. High Glucose Concentration Stimulates NHE-1 Activity in Distal Nephron Cells: the Role of the Mek/Erk1/2/p90RSK and p38MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Juliana Martins da Costa-Pessoa

    2014-02-01

    Full Text Available Aims: In models of diabetes, distal nephron cells contribute to glucose uptake and oxidation. How these cells contribute to the use of glucose for the regulation of H+ extrusion remains unknown. We used Madin-Darby Canine Kidney (MDCK cells to investigate the effect of acute or chronic high glucose concentration on the abundance and activity of the Na+/H+ exchanger (NHE-1. Methods: Using RT-PCR, we also evaluated the mRNA expression for sodium glucose co-transporters SGLT1 and SGLT2. Protein abundance was analyzed using immunoblotting, and intracellular pH (pHi recovery was evaluated using microscopy in conjunction with the fluorescent probe BCECF/AM. The Na+-dependent pHi recovery rate was monitored with HOE-694 (50 µM and/or S3226 (10 µM, specific NHE-1 and NHE-3 inhibitors. Results: MDCK cells did not express the mRNA for SGLT1 or SGLT2 but did express the GLUT2, NHE-1 and NHE-3 proteins. Under control conditions, we observed a greater contribution of NHE-1 to pHi recovery relative to the other H+ transporters. Acute high glucose treatment increased the HOE-694-sensitive pHi recovery rate and p-Erk1/2 and p90RSK abundance. These parameters were reduced by PD-98059, a Mek inhibitor (1 µM. Chronic high glucose treatment also increased the HOE-694-sensitive pHi recovery rate and p-p38MAPK abundance. Both parameters were reduced by SB-203580, a p38MAPK inhibitor (10 µM. Conclusion: These results suggested that extracellular high glucose stimulated NHE-1 acutely and chronically through Mek/Erk1/2/p90RSK and p38MAPK pathways, respectively.

  20. Vascular endothelial growth factor signaling regulates the segregation of artery and vein via ERK activity during vascular development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Se-Hee [McAllister Heart Institute, Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Schmitt, Christopher E.; Woolls, Melissa J. [McAllister Heart Institute, Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Dept. of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511 (United States); Holland, Melinda B. [McAllister Heart Institute, Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Kim, Jun-Dae [Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Dept. of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511 (United States); Jin, Suk-Won, E-mail: suk-won.jin@yale.edu [Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Dept. of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511 (United States)

    2013-01-25

    Highlights: ► VEGF-A signaling regulates the segregation of axial vessels. ► VEGF-A signaling is mediated by PKC and ERK in this process. ► Ectopic activation of ERK is sufficient to rescue defects in vessel segregation. -- Abstract: Segregation of two axial vessels, the dorsal aorta and caudal vein, is one of the earliest patterning events occur during development of vasculature. Despite the importance of this process and recent advances in our understanding on vascular patterning during development, molecular mechanisms that coordinate the segregation of axial vessels remain largely elusive. In this report, we find that vascular endothelial growth factor-A (Vegf-A) signaling regulates the segregation of dorsal aorta and axial vein during development. Inhibition of Vegf-A pathway components including ligand Vegf-A and its cognate receptor Kdrl, caused failure in segregation of axial vessels in zebrafish embryos. Similarly, chemical inhibition of Mitogen-activated protein kinase kinase (Map2k1)/Extracellular-signal-regulated kinases (Erk) and phosphatidylinositol 3-kinases (PI3 K), which are downstream effectors of Vegf-A signaling pathway, led to the fusion of two axial vessels. Moreover, we find that restoring Erk activity by over-expression of constitutively active MEK in embryos with a reduced level of Vegf-A signaling can rescue the defects in axial vessel segregation. Taken together, our data show that segregation of axial vessels requires the function of Vegf-A signaling, and Erk may function as the major downstream effector in this process.

  1. Vascular endothelial growth factor signaling regulates the segregation of artery and vein via ERK activity during vascular development

    International Nuclear Information System (INIS)

    Kim, Se-Hee; Schmitt, Christopher E.; Woolls, Melissa J.; Holland, Melinda B.; Kim, Jun-Dae; Jin, Suk-Won

    2013-01-01

    Highlights: ► VEGF-A signaling regulates the segregation of axial vessels. ► VEGF-A signaling is mediated by PKC and ERK in this process. ► Ectopic activation of ERK is sufficient to rescue defects in vessel segregation. -- Abstract: Segregation of two axial vessels, the dorsal aorta and caudal vein, is one of the earliest patterning events occur during development of vasculature. Despite the importance of this process and recent advances in our understanding on vascular patterning during development, molecular mechanisms that coordinate the segregation of axial vessels remain largely elusive. In this report, we find that vascular endothelial growth factor-A (Vegf-A) signaling regulates the segregation of dorsal aorta and axial vein during development. Inhibition of Vegf-A pathway components including ligand Vegf-A and its cognate receptor Kdrl, caused failure in segregation of axial vessels in zebrafish embryos. Similarly, chemical inhibition of Mitogen-activated protein kinase kinase (Map2k1)/Extracellular-signal-regulated kinases (Erk) and phosphatidylinositol 3-kinases (PI3 K), which are downstream effectors of Vegf-A signaling pathway, led to the fusion of two axial vessels. Moreover, we find that restoring Erk activity by over-expression of constitutively active MEK in embryos with a reduced level of Vegf-A signaling can rescue the defects in axial vessel segregation. Taken together, our data show that segregation of axial vessels requires the function of Vegf-A signaling, and Erk may function as the major downstream effector in this process

  2. Attenuation of everolimus-induced cytotoxicity by a protective autophagic pathway involving ERK activation in renal cell carcinoma cells

    Science.gov (United States)

    Zeng, Yizhou; Tian, Xiaofang; Wang, Quan; He, Weiyang; Fan, Jing; Gou, Xin

    2018-01-01

    Aim The mammalian target of rapamycin (mTOR) pathway is a critical target for cancer treatment and the mTOR inhibitor everolimus (RAD001) has been approved for treatment of renal cell carcinoma (RCC). However, the limited efficacy of RAD001 has led to the development of drug resistance. Autophagy is closely related to cell survival and death, which may be activated under RAD001 stimulation. The aim of the present study was to identify the underlying mechanisms of RAD001 resistance in RCC cells through cytoprotective autophagy involving activation of the extracellular signal-regulated kinase (ERK) pathway. Methods and results: RAD001 strongly induced autophagy of RCC cells in a dose- and time-dependent manner, as confirmed by Western blot analysis. Importantly, suppression of autophagy by the pharmacological inhibitor chloroquine effectively enhanced RAD001-induced apoptotic cytotoxicity, as demonstrated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Western blot analysis, indicating a cytoprotective role for RAD001-induced autophagy. In addition, as was shown by the MTT assay, flow cytometry, and Western blot analysis, RAD001 robustly activated ERK, but not c-Jun N-terminal kinase and p38. Activation of ERK was inhibited by the pharmacological inhibitor selumetinib (AZD6244), which effectively promoted RAD001-induced cell death. Moreover, employing AZD6244 markedly attenuated RAD001-induced autophagy and enhanced RAD001-induced apoptosis, which play a central role in RAD001-induced cell death. Furthermore, RAD001-induced autophagy is regulated by ERK-mediated phosphorylation of Beclin-1 and B-cell lymphoma 2, as confirmed by Western blot analysis. Conclusion These results suggest that RAD001-induced autophagy involves activation of the ERK, which may impair cytotoxicity of RAD001 in RCC cells. Thus, inhibition of the activation of ERK pathway-mediated autophagy may be useful to overcome chemoresistance to RAD001. PMID:29719377

  3. Omentin inhibits TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via ERK/NF-{kappa}B pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Xia, E-mail: zhongxia1977@126.com [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China); Li, Xiaonan; Liu, Fuli; Tan, Hui [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China); Shang, Deya, E-mail: wenhuashenghuo1@163.com [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Black-Right-Pointing-Pointer Omentin reduces expression of ICAM-1 and VCAM-1 induced by TNF-{alpha} in HUVECs. Black-Right-Pointing-Pointer Omentin inhibits TNF-{alpha}-induced ERK and NF-{kappa}B activation in HUVECs. Black-Right-Pointing-Pointer Omentin supreeses TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 via ERK/NF-{kappa}B pathway. -- Abstract: In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-{alpha} (TNF-{alpha}) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-{alpha}-activated signal pathway of nuclear factor-{kappa}B (NF-{kappa}B) by preventing NF-{kappa}B inhibitory protein (I{kappa}B{alpha}) degradation and NF-{kappa}B/DNA binding activity. Omentin pretreatment significantly inhibited TNF-{alpha}-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-{alpha}-induced NF-{kappa}B activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-{alpha}. These results suggest that omentin may inhibit TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-{kappa}B pathway.

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

    Directory of Open Access Journals (Sweden)

    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

  5. ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death.

    Science.gov (United States)

    Darling, Nicola J; Balmanno, Kathryn; Cook, Simon J

    2017-01-01

    Disruption of protein folding in the endoplasmic reticulum (ER) causes ER stress. Activation of the unfolded protein response (UPR) acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2) signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.

  6. ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death.

    Directory of Open Access Journals (Sweden)

    Nicola J Darling

    Full Text Available Disruption of protein folding in the endoplasmic reticulum (ER causes ER stress. Activation of the unfolded protein response (UPR acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2 signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.

  7. Insulin signaling pathways in lepidopteran steroidogenesis

    Directory of Open Access Journals (Sweden)

    Wendy eSmith

    2014-02-01

    Full Text Available Molting and metamorphosis are stimulated by the secretion of ecdysteroid hormones from the prothoracic glands. Insulin-like hormones have been found to enhance prothoracic gland activity, providing a mechanism to link molting to nutritional state. In silk moths (Bombyx mori, the prothoracic glands are directly stimulated by insulin and the insulin-like hormone bombyxin. Further, in Bombyx , the neuropeptide prothoracicotropic hormone (PTTH appears to act at least in part through the insulin-signaling pathway. In the prothoracic glands of Manduca sexta, while insulin stimulates the phosphorylation of the insulin receptor and Akt, neither insulin nor bombyxin II stimulate ecdysone secretion. Involvement of the insulin-signaling pathway in Manduca prothoracic glands was explored using two inhibitors of phosphatidylinositol-3-kinase (PI3K, LY294002 and wortmannin. PI3K inhibitors block the phosphorylation of Akt and 4EBP but have no effect on ecdysone secretion, or on the phosphorylation of the MAPkinase, ERK. Inhibitors that block phosphorylation of ERK, including the MEK inhibitor U0126, and high doses of the RSK inhibitor SL0101, effectively inhibit ecdysone secretion. The results highlight differences between the two lepidopteran insects most commonly used to directly study ecdysteroid secretion. In Bombyx, the PTTH and insulin-signaling pathways intersect; both insulin and PTTH enhance the phosphorylation of Akt and stimulate ecdysteroid secretion, and inhibition of PI3K reduces ecdysteroid secretion. By contrast, in Manduca, the action of PTTH is distinct from insulin. The results highlight species differences in the roles of translational regulators such as 4EBP, and members of the MAPkinase pathway such as ERK and RSK, in the effects of nutritionally-sensitive hormones such as insulin on ecdysone secretion and molting.

  8. Defined spatiotemporal features of RAS-ERK signals dictate cell fate in MCF-7 mammary epithelial cells.

    Science.gov (United States)

    Herrero, Ana; Casar, Berta; Colón-Bolea, Paula; Agudo-Ibáñez, Lorena; Crespo, Piero

    2016-06-15

    Signals conveyed through the RAS-ERK pathway are essential for the determination of cell fate. It is well established that signal variability is achieved in the different microenvironments in which signals unfold. It is also known that signal duration is critical for decisions concerning cell commitment. However, it is unclear how RAS-ERK signals integrate time and space in order to elicit a given biological response. To investigate this, we used MCF-7 cells, in which EGF-induced transient ERK activation triggers proliferation, whereas sustained ERK activation in response to heregulin leads to adipocytic differentiation. We found that both proliferative and differentiating signals emanate exclusively from plasma membrane-disordered microdomains. Of interest, the EGF signal can be transformed into a differentiating stimulus by HRAS overexpression, which prolongs ERK activation, but only if HRAS localizes at disordered membrane. On the other hand, HRAS signals emanating from the Golgi complex induce apoptosis and can prevent heregulin-induced differentiation. Our results indicate that within the same cellular context, RAS can exert different, even antagonistic, effects, depending on its sublocalization. Thus cell destiny is defined by the ability of a stimulus to activate RAS at the appropriate sublocalization for an adequate period while avoiding switching on opposing RAS signals. © 2016 Herrero et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  9. Calpain-mediated proteolysis of polycystin-1 C-terminus induces JAK2 and ERK signal alterations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunho [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Department of Medicine, University of Maryland, Baltimore, MD (United States); Kang, Ah-Young [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Department of Medicine, Program of Immunology, Graduate School, Seoul National University, Seoul (Korea, Republic of); Ko, Ah-ra [Clinical Research Center, Samsung Biomedical Research Institute, Seoul (Korea, Republic of); Park, Hayne Cho [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); So, Insuk [Department of Physiology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jong Hoon [Department of Biological Science, Sookmyung Women’s University, Seoul (Korea, Republic of); Cheong, Hae Il [Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Pediatrics, Seoul National University Children’s Hospital, Seoul (Korea, Republic of); Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Hwang, Young-Hwan [Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Internal Medicine, Eulji General Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of); and others

    2014-01-01

    Autosomal dominant polycystic kidney disease (ADPKD), a hereditary renal disease caused by mutations in PKD1 (85%) or PKD2 (15%), is characterized by the development of gradually enlarging multiple renal cysts and progressive renal failure. Polycystin-1 (PC1), PKD1 gene product, is an integral membrane glycoprotein which regulates a number of different biological processes including cell proliferation, apoptosis, cell polarity, and tubulogenesis. PC1 is a target of various proteolytic cleavages and proteosomal degradations, but its role in intracellular signaling pathways remains poorly understood. Herein, we demonstrated that PC1 is a novel substrate for μ- and m-calpains, which are calcium-dependent cysteine proteases. Overexpression of PC1 altered both Janus-activated kinase 2 (JAK2) and extracellular signal-regulated kinase (ERK) signals, which were independently regulated by calpain-mediated PC1 degradation. They suggest that the PC1 function on JAK2 and ERK signaling pathways might be regulated by calpains in response to the changes in intracellular calcium concentration. - Highlights: • Polycystin-1 is a target of ubiquitin-independent degradation by calpains. • The PEST domain is required for calpain-mediated degradation of polycystin-1. • Polycystin-1 may independently regulate JAK2 and ERK signaling pathways.

  10. BMP Suppresses PTEN Expression via RAS/ERK Signaling

    OpenAIRE

    Beck, Stayce E.; Carethers, John M.

    2007-01-01

    Bone morphogenetic protein (BMP), a member of the transforming growth factor β family, classically utilizes the SMAD signaling pathway for its growth suppressive effects, and loss of this signaling cascade may accelerate cell growth. In the colon cancer predisposition syndrome Juvenile Polyposis, as well as in the late progression stages of nonsyndromic colorectal cancers, SMAD4 function is typically abrogated. Here, we utilized the SMAD4-null SW480 colon cancer cell line to examine BMPs effe...

  11. Triiodothyronine promotes the proliferation of epicardial progenitor cells through the MAPK/ERK pathway.

    Science.gov (United States)

    Deng, Song-Bai; Jing, Xiao-Dong; Wei, Xiao-Ming; Du, Jian-Lin; Liu, Ya-Jie; Qin, Qin; She, Qiang

    2017-04-29

    Thyroid hormone has important functions in the development and physiological function of the heart. The aim of this study was to determine whether 3,5,3'-Triiodothyronine (T3) can promote the proliferation of epicardial progenitor cells (EPCs) and to investigate the potential underlying mechanism. Our results showed that T3 significantly promoted the proliferation of EPCs in a concentration- and time-dependent manner. The thyroid hormone nuclear receptor inhibitor bisphenol A (100 μmol/L) did not affect T3's ability to induce proliferation. Further studies showed that the mRNA expression levels of mitogen-activated protein kinase 1 (MAPK1), MAPK3, and Ki67 in EPCs in the T3 group (10 nmol/L) increased 2.9-, 3-, and 4.1-fold, respectively, compared with those in the control group (P < 0.05). In addition, the mRNA expression of the cell cycle protein cyclin D1 in the T3 group increased approximately 2-fold compared with the control group (P < 0.05), and there were more EPCs in the S phase of the cell cycle (20.6% vs. 12.0%, P < 0.05). The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway inhibitor U0126 (10 μmol/L) significantly inhibited the ability of T3 to promote the proliferation of EPCs and to alter cell cycle progression. This study suggested that T3 significantly promotes the proliferation of EPCs, and this effect may be achieved through activation of the MAPK/ERK signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. MAT2B promotes adipogenesis by modulating SAMe levels and activating AKT/ERK pathway during porcine intramuscular preadipocyte differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Cunzhen; Chen, Xiaochang; Wu, Wenjing; Wang, Wusu; Pang, Weijun; Yang, Gongshe, E-mail: gsyang999@hotmail.com

    2016-05-15

    Intramuscular fat (IMF) has been demonstrated as one of the crucial factors of livestock meat quality. The MAT2B protein with MAT2α catalyzes the formation of methyl donor S- adenosylmethionine (SAMe) to mediate cell metabolism including proliferation and apoptosis. However, the regulatory effect of MAT2B on IMF deposition is still unclear. In this study, the effect of MAT2B on adipogenesis and its potential mechanism during porcine intramuscular preadipocyte differentiation was studied. The results showed that overexpression of MAT2B promoted adipogenesis and significantly up-regulated the mRNA and protein levels of adipogenic marker genes including FASN, PPARγ and aP2, consistently, knockdown of MAT2B inhibited lipid accumulation and down-regulated the mRNA and protein levels of the above genes. Furthermore, flow cytometry and EdU-labeling assay indicated that MAT2B regulate adipogenesis was partly due to influence intracellular SAMe levels and further affect cell clonal expansion. Also, increased expression of MAT2B activated the phosphorylations of AKT and ERK1/2, whereas knockdown of MAT2B blocked AKT signaling and repressed the phosphorylation of ERK1/2. Moreover, the inhibitory effect of LY294002 (a specific PI3K inhibitor) on the activities of AKT and ERK1/2 was partially recovered by overexpression of MAT2B in porcine intramuscular adipocytes. Finally, Co-IP experiments showed that MAT2B can directly interact with AKT. Taken together, our findings suggested that MAT2B acted as a positive regulator through modifying SAMe levels as well as activating AKT/ERK signaling pathway to promote porcine intramuscular adipocyte differentiation. - Highlights: • MAT2B up-regulates the expression of adipogenic marker genes and promotes porcine intramuscular preadipocyte differentiation. • MAT2B influences intracellular SAMe levels and further affects cell clonal expansion. • MAT2B interacts with AKT and activates AKT/ERK signaling pathway.

  13. S1P/S1PR3 signaling mediated proliferation of pericytes via Ras/pERK pathway and CAY10444 had beneficial effects on spinal cord injury.

    Science.gov (United States)

    Tang, Hai-Bin; Jiang, Xiao-Jian; Wang, Chen; Liu, Shi-Chang

    2018-04-15

    Pericytes have long been regarded merely to maintain structural and functional integrity of blood-brain barrier (BBB). Nevertheless, it has also been identified as a component of scar-forming stromal cells after spinal cord injury (SCI). In process of enlargement of spinal cavity after SCI, the number of pericytes increased and outnumbered astrocytes. However, the mechanism of proliferation of pericytes remains unclear. Sphingosine-1-phosphate (S1P) has been reported to play important roles in the formation of glia scar, but previous studies had paid more attention to the astrocytes. The present study aimed to observe the effects of S1P and S1P receptors (S1PRs) on proliferation of pericytes and investigate the underlying mechanism. By double immunostaining, we found that the number of PDGFRβ-positive pericytes was gradually increased and sealed the cavity, which surrounded by reactive astrocytes. Moreover, the subtype of S1PR3 was found to be induced by SCI and mainly expressed on pericytes. Further, by use of CAY10444, an inhibitor of S1PR3, we showed that S1P/S1PR3 mediated the proliferation of pericytes through Ras/pERK pathway. Moreover, CAY10444 was found to have the effects of enhancing neuronal survival, alleviating glial scar formation, and improving locomotion recovery after SCI. The results suggested that S1P/S1PR3 might be a promising target for clinical therapy for SCI. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Acrolein increases 5-lipoxygenase expression in murine macrophages through activation of ERK pathway.

    Science.gov (United States)

    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.

  15. 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.

  16. ERK2 dependent signaling contributes to wound healing after a partial-thickness burn

    International Nuclear Information System (INIS)

    Satoh, Yasushi; Saitoh, Daizoh; Takeuchi, Atsuya; Ojima, Kenichiro; Kouzu, Keita; Kawakami, Saki; Ito, Masataka; Ishihara, Masayuki; Sato, Shunichi; Takishima, Kunio

    2009-01-01

    Burn healing is a complex physiological process involving multiple cell activities, such as cell proliferation, migration and differentiation. Although extracellular signal-regulated kinases (ERK) have a pivotal role in regulating a variety of cellular responses, little is known about the individual functions of ERK isoform for healing in vivo. This study investigated the role of ERK2 in burn healing. To assess this, Erk2 +/- mice generated by gene targeting were used. The resultant mice exhibited significant delay in re-epithelization of partial-thickness burns in the skin in comparison to wild-type. An in vitro proliferation assay revealed that keratinocytes from Erk2 +/- mice grew significantly slower than those prepared from wild-type. These results highlight the importance of ERK2 in the process of burn healing.

  17. Erk signaling suppresses embryonic stem cell self-renewal to specify endoderm

    DEFF Research Database (Denmark)

    Hamilton, William B; Brickman, Joshua M

    2014-01-01

    Fgf signaling via Erk activation has been associated with both neural induction and the generation of a primed state for the differentiation of embryonic stem cells (ESCs) to all somatic lineages. To dissect the role of Erk in both ESC self-renewal and lineage specification, we explored...

  18. Genetic Validation of Cell Proliferation via Ras-Independent Activation of the Raf/Mek/Erk Pathway.

    Science.gov (United States)

    Lechuga, Carmen G; Simón-Carrasco, Lucía; Jacob, Harrys K C; Drosten, Matthias

    2017-01-01

    Signaling transmitted by the Ras family of small GTPases (H-, N-, and K-Ras) is essential for proliferation of mouse embryonic fibroblasts (MEFs). However, constitutive activation of the downstream Raf/Mek/Erk pathway can bypass the requirement for Ras proteins and allow cells to proliferate in the absence of the three Ras isoforms. Here we describe a protocol for a colony formation assay that permits evaluating the role of candidate proteins that are positive or negative regulators of cell proliferation mediated via Ras-independent Raf/Mek/Erk pathway activation. K-Ras lox (H-Ras -/- , N-Ras -/- , K-Ras lox/lox , RERT ert/ert ) MEFs are infected with retro- or lentiviral vectors expressing wild-type or constitutively activated candidate cDNAs, shRNAs, or sgRNAs in combination with Cas9 to ascertain the possibility of candidate proteins to function either as an activator or inhibitor of Ras-independent Raf/Mek/Erk activation. These cells are then seeded in the absence or presence of 4-Hydroxytamoxifen (4-OHT), which activates the resident CreERT2 alleles resulting in elimination of the conditional K-Ras alleles and ultimately generating Rasless cells. Colony formation in the presence of 4-OHT indicates cell proliferation via Ras-independent Raf/Mek/Erk activation.

  19. A genome-wide RNAi screen reveals MAP kinase phosphatases as key ERK pathway regulators during embryonic stem cell differentiation.

    Directory of Open Access Journals (Sweden)

    Shen-Hsi Yang

    Full Text Available Embryonic stem cells and induced pluripotent stem cells represent potentially important therapeutic agents in regenerative medicine. Complex interlinked transcriptional and signaling networks control the fate of these cells towards maintenance of pluripotency or differentiation. In this study we have focused on how mouse embryonic stem cells begin to differentiate and lose pluripotency and, in particular, the role that the ERK MAP kinase and GSK3 signaling pathways play in this process. Through a genome-wide siRNA screen we have identified more than 400 genes involved in loss of pluripotency and promoting the onset of differentiation. These genes were functionally associated with the ERK and/or GSK3 pathways, providing an important resource for studying the roles of these pathways in controlling escape from the pluripotent ground state. More detailed analysis identified MAP kinase phosphatases as a focal point of regulation and demonstrated an important role for these enzymes in controlling ERK activation kinetics and subsequently determining early embryonic stem cell fate decisions.

  20. MAPK/ERK and Wnt/β-Catenin pathways are synergistically involved in proliferation of Sca-1 positive hepatic progenitor cells

    International Nuclear Information System (INIS)

    Jin, Caixia; Samuelson, Lisa; Cui, Cai-Bin; Sun, Yangzhong; Gerber, David A.

    2011-01-01

    Highlights: → Activation of MAPK/ERK pathway with epidermal growth factor (EGF) significantly increased Sca-1 + HPC proliferation and colony formation. → Activation of either IL-6/STAT3 or Wnt/β-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. → Wnt/β-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation and maintain long-term HPCs in vitro. -- Abstract: Hepatic progenitor cells (HPCs) persist in adulthood and have the potential to play a major role in regenerating diseased liver. However, the signaling pathways that both directly and indirectly regulate HPCs' self-renewal and differentiation remain elusive. Previously, we identified a bipotent, stem cell antigen-1 (Sca-1) positive HPC population from naive adult liver tissue. In the present study, we aimed to investigate the involvement of various signaling pathways in Sca-1 + HPC proliferation. Epidermal growth factor (EGF) supplementation shows a significant increase in Sca-1 + HPC proliferation and colony formation while stimulating phosphorylation of ERK1/2 and activating the induction of Cyclin D1. There were no demonstrable effects of EGF on Akt. The MEK inhibitor, PD0325901, inhibits proliferation and ERK1/2 phosphorylation while also suppressing the expression of Cyclin D1. In addition, activation of either IL-6/STAT3 or Wnt/β-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. The Wnt/β-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation ratio and maintain long-term HPC in vitro. The data indicates that the MAPK/ERK pathway is both essential and critical for HPC proliferation, and the Wnt signaling pathway is not sufficient, while it works synergistically with the MAPK/ERK signaling pathway to promote HPC proliferation.

  1. MAPK/ERK and Wnt/{beta}-Catenin pathways are synergistically involved in proliferation of Sca-1 positive hepatic progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Caixia [Department of Surgery, University of North Carolina at Chapel Hill (United States); Department of Medical Genetics and Cell Biology, Ningxia Medical University, Yinchuan 750004 (China); Samuelson, Lisa; Cui, Cai-Bin; Sun, Yangzhong [Department of Surgery, University of North Carolina at Chapel Hill (United States); Gerber, David A., E-mail: david_gerber@med.unc.edu [Department of Surgery, University of North Carolina at Chapel Hill (United States); Lineberger Cancer Center, University of North Carolina at Chapel Hill (United States)

    2011-06-17

    Highlights: {yields} Activation of MAPK/ERK pathway with epidermal growth factor (EGF) significantly increased Sca-1{sup +} HPC proliferation and colony formation. {yields} Activation of either IL-6/STAT3 or Wnt/{beta}-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. {yields} Wnt/{beta}-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation and maintain long-term HPCs in vitro. -- Abstract: Hepatic progenitor cells (HPCs) persist in adulthood and have the potential to play a major role in regenerating diseased liver. However, the signaling pathways that both directly and indirectly regulate HPCs' self-renewal and differentiation remain elusive. Previously, we identified a bipotent, stem cell antigen-1 (Sca-1) positive HPC population from naive adult liver tissue. In the present study, we aimed to investigate the involvement of various signaling pathways in Sca-1{sup +} HPC proliferation. Epidermal growth factor (EGF) supplementation shows a significant increase in Sca-1{sup +} HPC proliferation and colony formation while stimulating phosphorylation of ERK1/2 and activating the induction of Cyclin D1. There were no demonstrable effects of EGF on Akt. The MEK inhibitor, PD0325901, inhibits proliferation and ERK1/2 phosphorylation while also suppressing the expression of Cyclin D1. In addition, activation of either IL-6/STAT3 or Wnt/{beta}-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. The Wnt/{beta}-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation ratio and maintain long-term HPC in vitro. The data indicates that the MAPK/ERK pathway is both essential and critical for HPC proliferation, and the Wnt signaling pathway is not sufficient, while it works synergistically with the MAPK/ERK signaling pathway to promote HPC proliferation.

  2. P2Y2 Receptor and EGFR Cooperate to Promote Prostate Cancer Cell Invasion via ERK1/2 Pathway.

    Science.gov (United States)

    Li, Wei-Hua; Qiu, Ying; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

    2015-01-01

    As one member of G protein-coupled P2Y receptors, P2Y2 receptor can be equally activated by extracellular ATP and UTP. Our previous studies have proved that activation of P2Y2 receptor by extracellular ATP could promote prostate cancer cell invasion and metastasis in vitro and in vivo via regulating the expressions of some epithelial-mesenchymal transition/invasion-related genes (including IL-8, E-cadherin, Snail and Claudin-1), and the most significant change in expression of IL-8 was observed after P2Y2 receptor activation. However, the signaling pathway downstream of P2Y2 receptor and the role of IL-8 in P2Y2-mediated prostate cancer cell invasion remain unclear. Here, we found that extracellular ATP/UTP induced activation of EGFR and ERK1/2. After knockdown of P2Y2 receptor, the ATP -stimulated phosphorylation of EGFR and ERK1/2 was significantly suppressed. Further experiments showed that inactivation of EGFR and ERK1/2 attenuated ATP-induced invasion and migration, and suppressed ATP-mediated IL-8 production. In addition, knockdown of IL-8 inhibited ATP-mediated invasion and migration of prostate cancer cells. These findings suggest that P2Y2 receptor and EGFR cooperate to upregulate IL-8 production via ERK1/2 pathway, thereby promoting prostate cancer cell invasion and migration. Thus blocking of the P2Y2-EGFR-ERK1/2 pathway may provide effective therapeutic interventions for prostate cancer.

  3. ERK pathway activation bidirectionally affects visual recognition memory and synaptic plasticity in the perirhinal cortex

    Directory of Open Access Journals (Sweden)

    Davide eSilingardi

    2011-12-01

    Full Text Available ERK 1,2 pathway mediates experience-dependent gene transcription in neurons and several studies have identified its pivotal role in experience-dependent synaptic plasticity and in forms of long term memory involving hippocampus, amygdala or striatum. The perirhinal cortex (PRHC plays an essential role in familiarity-based object recognition memory. It is still unknown whether ERK activation in PRHC is necessary for recognition memory consolidation. Most important, it is unknown whether by modulating the gain of the ERK pathway it is possible to bidirectionally affect visual recognition memory and PRHC synaptic plasticity.We have first pharmacologically blocked ERK activation in the PRHC of adult mice and found that this was sufficient to impair long term recognition memory in a familiarity-based task, the Object Recognition Task (ORT. We have then tested performance in the ORT in Ras-GRF1 knock-out (KO mice, which exhibit a reduced activation of ERK by neuronal activity, and in ERK1 KO mice, which have an increased activation of ERK2 and exhibit enhanced striatal plasticity and striatal mediated memory. We found that Ras-GRF1 KO mice have normal short-term memory but display a long term memory deficit; memory reconsolidation is also impaired. On the contrary, ERK1 KO mice exhibit a better performance than WT mice at 72 hour retention interval, suggesting a longer lasting recognition memory. In parallel with behavioural data, LTD was strongly reduced and LTP was significantly smaller in PRHC slices from Ras-GRF1 KO than in WT mice while enhanced LTP and LTD were found in PRHC slices from ERK1 KO mice.

  4. BMP-2 Overexpression Augments Vascular Smooth Muscle Cell Motility by Upregulating Myosin Va via Erk Signaling

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2014-01-01

    Full Text Available Background. The disruption of physiologic vascular smooth muscle cell (VSMC migration initiates atherosclerosis development. The biochemical mechanisms leading to dysfunctional VSMC motility remain unknown. Recently, cytokine BMP-2 has been implicated in various vascular physiologic and pathologic processes. However, whether BMP-2 has any effect upon VSMC motility, or by what manner, has never been investigated. Methods. VSMCs were adenovirally transfected to genetically overexpress BMP-2. VSMC motility was detected by modified Boyden chamber assay, confocal time-lapse video assay, and a colony wounding assay. Gene chip array and RT-PCR were employed to identify genes potentially regulated by BMP-2. Western blot and real-time PCR detected the expression of myosin Va and the phosphorylation of extracellular signal-regulated kinases 1/2 (Erk1/2. Immunofluorescence analysis revealed myosin Va expression locale. Intracellular Ca2+ oscillations were recorded. Results. VSMC migration was augmented in VSMCs overexpressing BMP-2 in a dose-dependent manner. siRNA-mediated knockdown of myosin Va inhibited VSMC motility. Both myosin Va mRNA and protein expression significantly increased after BMP-2 administration and were inhibited by Erk1/2 inhibitor U0126. BMP-2 induced Ca2+ oscillations, generated largely by a “cytosolic oscillator”. Conclusion. BMP-2 significantly increased VSMCs migration and myosin Va expression, via the Erk signaling pathway and intracellular Ca2+ oscillations. We provide additional insight into the pathophysiology of atherosclerosis, and inhibition of BMP-2-induced myosin Va expression may represent a potential therapeutic strategy.

  5. Immunomodulatory effect of tea saponin in immune T-cells and T-lymphoma cells via regulation of Th1, Th2 immune response and MAPK/ERK2 signaling pathway.

    Science.gov (United States)

    Bhardwaj, Jyoti; Chaudhary, Narendra; Seo, Hyo-Jin; Kim, Min-Yong; Shin, Tai-Sun; Kim, Jong-Deog

    2014-06-01

    The anti-cancer activity of saponins and phenolic compounds present in green tea was previously reported. However, the immunomodulatory and adjuvanticity activity of tea saponin has never been studied. In this study, we investigated the immunomodulatory effect of tea saponin in T-lymphocytes and EL4 cells via regulation of cytokine response and mitogen-activated protein kinases (MAPK) signaling pathway. Quantitative analysis of mRNA expression level of cytokines were performed by reverse transcription polymerase chain reaction following stimulation with tea saponin, ovalbumin (OVA) alone or tea saponin in combination with OVA. Tea saponin inhibited the proliferation of EL4 cells measured in a dose-dependent manner. No cytotoxicity effect of tea saponin was detected in T-lymphocytes; rather, tea saponin enhanced the proliferation of T-lymphocytes. Tea saponin with OVA increased the expression of interleukin (IL)-1, IL-2, IL-12, interferon-γ and tumor necrosis factor (TNF)-α and decreased the expression level of IL-10 and IL-8 in T-lymphocytes. Furthermore, tea saponin, in the presence of OVA, downregulated the MAPK signaling pathway via inhibition of IL-4, IL-8 and nuclear factor kappaB (NF-κB) in EL4 cells. Th1 cytokines enhancer and Th2 cytokines and NF-κB inhibitor, tea saponin can markedly inhibit the proliferation and invasiveness of T-lymphoma (EL4) cells, possibly due to TNF-α- and NF-κB-mediated regulation of MAPK signaling pathway.

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Oxygen-glucose deprivation preconditioning protects neurons against oxygen-glucose deprivation/reperfusion induced injury via bone morphogenetic protein-7 mediated ERK, p38 and Smad signalling pathways.

    Science.gov (United States)

    Guan, Junhong; Du, Shaonan; Lv, Tao; Qu, Shengtao; Fu, Qiang; Yuan, Ye

    2016-01-01

    Bone morphogenetic protein (BMP)-7 mediated neuroprotective effect of cerebral ischemic preconditioning (IPC) has been studied in an ischemic animal model, but the underlying cellular mechanisms have not been clearly clarified. In this study, primary cortical neurons and the SH-SY5Y cell line were used to investigate the role of BMP-7 and its downstream signals in the neuroprotective effects of oxygen-glucose deprivation preconditioning (OGDPC). Immunocytochemistry was used to detect the expression of neurofilament in neurons. MTT and lactate dehydrogenase activity assays were used to measure the cytotoxicity. Western blot was used to detect the protein expression of BMP-7 and downstream signals. BMP inhibitor, mitogen-activated protein kinase inhibitors, Smad inhibitor and siRNA of Smad 1 were used to investigate the role of corresponding signalling pathways in the OGDPC. Results showed that OGDPC-induced overexpression of BMP-7 in primary cortical neurons and SH-SY5Y cells. Both of endogenous and exogenous BMP-7 could replicate the neuroprotective effects seen in OGDPC pretreatment. In addition, extracellular regulated protein kinases, p38 and Smad signalling pathway were found to be involved in the neuroprotective effects mediated by OGDPC via BMP-7. This study primarily reveals the cellular mechanisms of the neuroprotection mediated by OGDPC, and provides evidence for better understanding of this intrinsic factor against ischemia. © 2015 Wiley Publishing Asia Pty Ltd.

  9. p16(INK4A) inhibits the pro-metastatic potentials of osteosarcoma cells through targeting the ERK pathway and TGF-β1.

    Science.gov (United States)

    Silva, Gabriela; Aboussekhra, Abdelilah

    2016-05-01

    Extracellular signal-regulated kinase (ERK) is a downstream component of the evolutionarily conserved mitogen-activated protein kinase-signaling pathway, which controls the expression of a plethora of genes implicated in various physiological processes. This pathway is often hyper-activated by mutations or abnormal extracellular signaling in different types of human cancer, including the most common primary malignant bone tumor osteosarcomas. p16(INK4A) is an important tumor suppressor gene frequently lost in osteosarcomas, and is associated with the progression of these malignancies. We have shown, here, that the ERK1/2 protein kinase is also activated by p16(INK4A) down-regulation in osteosarcoma cells and normal human as well as mouse cells. This inhibitory effect is associated with the suppression of the upstream kinase MEK1/2, and is mediated via the repression of miR-21-5p and the consequent up-regulation of the MEK/ERK antagonist SPRY2 in osteosarcoma cells. Furthermore, we have shown that p16(INK4) inhibits the migration/invasion abilities of these cells through miR-21-5p-dependent inhibition of ERK1/2. In addition, we present clear evidence that p16(INK4) represses the paracrine pro-migratory effect of osteosarcoma cells on stromal fibroblasts through the inhibition of the TGF-β1 expression/secretion. This effect is also ERK1/2-dependent, indicating that in addition to their cell-autonomous actions, p16(INK4) and ERK1/2 have also non-cell-autonomous cancer-related functions. Together, these results indicate that the tumor suppressor p16(INK4) protein represses the carcinogenic process of osteosarcoma cells not only as a cell cycle regulator, but also as a negative regulator of pro-carcinogenic/-metastatic pathways. This indicates that targeting the ERK pathway is of utmost therapeutic value. © 2015 Wiley Periodicals, Inc.

  10. Requirement of ERα and basal activities of EGFR and Src kinase in Cd-induced activation of MAPK/ERK pathway in human breast cancer MCF-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiulong, E-mail: songxiulong@hotmail.com; Wei, Zhengxi; Shaikh, Zahir A., E-mail: zshaikh@uri.edu

    2015-08-15

    Cadmium (Cd) is a common environmental toxicant and an established carcinogen. Epidemiological studies implicate Cd with human breast cancer. Low micromolar concentrations of Cd promote proliferation of human breast cancer cells in vitro. The growth promotion of breast cancer cells is associated with the activation of MAPK/ERK pathway. This study explores the mechanism of Cd-induced activation of MAPK/ERK pathway. Specifically, the role of cell surface receptors ERα, EGFR, and Src kinase was evaluated in human breast cancer MCF-7 cells treated with 1–3 μM Cd. The activation of ERK was studied using a serum response element (SRE) luciferase reporter assay. Receptor phosphorylation was detected by Western blot analyses. Cd treatment increased both the SRE reporter activity and ERK1/2 phosphorylation in a concentration-dependent manner. Cd treatment had no effect on reactive oxygen species (ROS) generation. Also, blocking the entry of Cd into the cells with manganese did not diminish Cd-induced activation of MAPK/ERK. These results suggest that the effect of Cd was likely not caused by intracellular ROS generation, but through interaction with the membrane receptors. While Cd did not appear to activate either EGFR or Src kinase, their inhibition completely blocked the Cd-induced activation of ERK as well as cell proliferation. Similarly, silencing ERα with siRNA or use of ERα antagonist blocked the effects of Cd. Based on these results, it is concluded that not only ERα, but also basal activities of EGFR and Src kinase are essential for Cd-induced signal transduction and activation of MAPK/ERK pathway for breast cancer cell proliferation. - Highlights: • Low micromolar concentrations of Cd rapidly activate ERK1/2 in MCF-7 cells. • Signal transduction and resulting cell proliferation require EGFR, ERα, and Src. • These findings implicate Cd in promotion of breast cancer.

  11. The TORC1/P70S6K and TORC1/4EBP1 signaling pathways have a stronger contribution on skeletal muscle growth than MAPK/ERK in an early vertebrate: Differential involvement of the IGF system and atrogenes.

    Science.gov (United States)

    Fuentes, Eduardo N; Einarsdottir, Ingibjörg Eir; Paredes, Rodolfo; Hidalgo, Christian; Valdes, Juan Antonio; Björnsson, Björn Thrandur; Molina, Alfredo

    2015-01-01

    Knowledge about the underlying mechanisms, particularly the signaling pathways that account for muscle growth in vivo in early vertebrates is still scarce. Fish (Paralichthys adspersus) were fasted for 3weeks to induce a catabolic period of strong muscle atrophy. Subsequently, fish were refed for 2weeks to induce compensatory muscle hypertrophy. During refeeding, the fish were treated daily with either rapamycin (TORC blocker), PD98059 (MEK blocker), or PBS (V; vehicle), or were untreated (C; control). Rapamycin and PD98059 differentially impaired muscle cellularity in vivo, growth performance, and the expression of growth-related genes, and the inhibition of TORC1 had a greater impact on fish muscle growth than the inhibition of MAPK. Blocking TORC1 inhibited the phosphorylation of P70S6K and 4EBP1, two downstream components activated by TORC1, thus affecting protein contents in muscle. Concomitantly, the gene expression in muscle of igf-1, 2 and igfbp-4, 5 was down-regulated while the expression of atrogin-1, murf-1, and igfbp-2, 3 was up-regulated. Muscle hypertrophy was abolished and muscle atrophy was promoted, which finally affected body weight. TORC2 complex was not affected by rapamycin. On the other hand, the PD98059 treatment triggered ERK inactivation, a downstream component activated by MEK. mRNA contents of igf-1 in muscle were down-regulated, and muscle hypertrophy was partially impaired. The present study provides the first direct data on the in vivo contribution of TORC1/P70S6K, TORC1/4EBP1, and MAPK/ERK signaling pathways in the skeletal muscle of an earlier vertebrate, and highlights the transcendental role of TORC1 in growth from the cellular to organism level. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Protective function of pyridoxamine on retinal photoreceptor cells via activation of the p‑Erk1/2/Nrf2/Trx/ASK1 signalling pathway in diabetic mice.

    Science.gov (United States)

    Ren, Xiang; Sun, Hong; Zhang, Chenghong; Li, Chen; Wang, Jinlei; Shen, Jie; Yu, Dong; Kong, Li

    2016-07-01

    The present study aimed to investigate the mechanisms that mediate the protective effects of pyridoxamine (PM) on light‑damaged retinal photoreceptor cells in diabetic mice. A high‑fat diet and streptozotocin were used to induce a mouse model of type II diabetes. During the experiment, mice were divided the mice into three types of group, as follows: Control groups (negative control and light‑damaged groups); experimental groups (diabetic and diabetic light‑damaged groups); and treatment groups (25, 50 and 100 mg/kg PM‑treated groups). Using hematoxylin‑eosin staining, the number of nuclear layer cells were counted. Western blotting and immunohistochemistry were performed to measure the levels of thioredoxin (Trx), phospho‑extracellular signal‑regulated kinase 1/2 (p‑Erk1/2), nuclear factor erythroid 2‑related factor 2 (Nrf2) and apoptosis signal‑regulating kinase 1 (ASK1). The photoreceptor cell count in the outer nuclear layer of the light‑damaged, diabetic control and diabetic light‑damaged groups were significantly reduced compared with the negative control group (PTrx, p‑Erk1/2 and Nrf2 expression levels (PTrx, p‑Erk1/2 and Nrf2 expression levels were significantly increased (PTrx, p‑Erk1/2 and Nrf2 expression, and the downregulation of ASK1 expression.

  13. Light-Mediated Kinetic Control Reveals the Temporal Effect of the Raf/MEK/ERK Pathway in PC12 Cell Neurite Outgrowth

    Science.gov (United States)

    Zhang, Kai; Duan, Liting; Ong, Qunxiang; Lin, Ziliang; Varman, Pooja Mahendra; Sung, Kijung; Cui, Bianxiao

    2014-01-01

    It has been proposed that differential activation kinetics allows cells to use a common set of signaling pathways to specify distinct cellular outcomes. For example, nerve growth factor (NGF) and epidermal growth factor (EGF) induce different activation kinetics of the Raf/MEK/ERK signaling pathway and result in differentiation and proliferation, respectively. However, a direct and quantitative linkage between the temporal profile of Raf/MEK/ERK activation and the cellular outputs has not been established due to a lack of means to precisely perturb its signaling kinetics. Here, we construct a light-gated protein-protein interaction system to regulate the activation pattern of the Raf/MEK/ERK signaling pathway. Light-induced activation of the Raf/MEK/ERK cascade leads to significant neurite outgrowth in rat PC12 pheochromocytoma cell lines in the absence of growth factors. Compared with NGF stimulation, light stimulation induces longer but fewer neurites. Intermittent on/off illumination reveals that cells achieve maximum neurite outgrowth if the off-time duration per cycle is shorter than 45 min. Overall, light-mediated kinetic control enables precise dissection of the temporal dimension within the intracellular signal transduction network. PMID:24667437

  14. ERK1/2 activation in human taste bud cells regulates fatty acid signaling and gustatory perception of fat in mice and humans.

    Science.gov (United States)

    Subramaniam, Selvakumar; Ozdener, Mehmet Hakan; Abdoul-Azize, Souleymane; Saito, Katsuyoshi; Malik, Bilal; Maquart, Guillaume; Hashimoto, Toshihiro; Marambaud, Philippe; Aribi, Mourad; Tordoff, Michael G; Besnard, Philippe; Khan, Naim Akhtar

    2016-10-01

    Obesity is a major public health problem. An in-depth knowledge of the molecular mechanisms of oro-sensory detection of dietary lipids may help fight it. Humans and rodents can detect fatty acids via lipido-receptors, such as CD36 and GPR120. We studied the implication of the MAPK pathways, in particular, ERK1/2, in the gustatory detection of fatty acids. Linoleic acid, a dietary fatty acid, induced via CD36 the phosphorylation of MEK1/2-ERK1/2-ETS-like transcription factor-1 cascade, which requires Fyn-Src kinase and lipid rafts in human taste bud cells (TBCs). ERK1/2 cascade was activated by Ca 2+ signaling via opening of the calcium-homeostasis modulator-1 (CALHM1) channel. Furthermore, fatty acid-evoked Ca 2+ signaling and ERK1/2 phosphorylation were decreased in both human TBCs after small interfering RNA knockdown of CALHM1 channel and in TBCs from Calhm1 -/- mice. Targeted knockdown of ERK1/2 by small interfering RNA or PD0325901 (MEK1/2 inhibitor) in the tongue and genetic ablation of Erk1 or Calhm1 genes impaired preference for dietary fat in mice. Lingual inhibition of ERK1/2 in healthy volunteers also decreased orogustatory sensitivity for linoleic acid. Our data demonstrate that ERK1/2-MAPK cascade is regulated by the opening of CALHM1 Ca 2+ channel in TBCs to modulate orogustatory detection of dietary lipids in mice and humans.-Subramaniam, S., Ozdener, M. H., Abdoul-Azize, S., Saito, K., Malik, B., Maquart, G., Hashimoto, T., Marambaud, P., Aribi, M., Tordoff, M. G., Besnard, P., Khan, N. A. ERK1/2 activation in human taste bud cells regulates fatty acid signaling and gustatory perception of fat in mice and humans. © FASEB.

  15. Enhanced expressions of microvascular smooth muscle receptors after focal cerebral ischemia occur via the MAPK MEK/ERK pathway

    Directory of Open Access Journals (Sweden)

    Edvinsson Lars

    2008-09-01

    Full Text Available Abstract Background MEK1/2 is a serine/threonine protein that phosphorylates extracellular signal-regulated kinase (ERK1/2. Cerebral ischemia results in enhanced expression of cerebrovascular contractile receptors in the middle cerebral artery (MCA leading to the ischemic region. Here we explored the role of the MEK/ERK pathway in receptor expression following ischemic brain injury using the specific MEK1 inhibitor U0126. Methods and result Rats were subjected to a 2-h middle cerebral artery occlusion (MCAO followed by reperfusion for 48-h and the ischemic area was calculated. The expression of phosphorylated ERK1/2 and Elk-1, and of endothelin ETA and ETB, angiotensin AT1, and 5-hydroxytryptamine 5-HT1B receptors were analyzed with immunohistochemistry using confocal microscopy in cerebral arteries, microvessels and in brain tissue. The expression of endothelin ETB receptor was analyzed by quantitative Western blot. We demonstrate that there is an increase in the number of contractile smooth muscle receptors in the MCA and in micro- vessels within the ischemic region. The enhanced expression occurs in the smooth muscle cells as verified by co-localization studies. This receptor upregulation is furthermore associated with enhanced expression of pERK1/2 and of transcription factor pElk-1 in the vascular smooth muscle cells. Blockade of transcription with the MEK1 inhibitor U0126, given at the onset of reperfusion or as late as 6 hours after the insult, reduced transcription (pERK1/2 and pElk-1, the enhanced vascular receptor expression, and attenuated the cerebral infarct and improved neurology score. Conclusion Our results show that MCAO results in upregulation of cerebrovascular ETB, AT1 and 5-HT1B receptors. Blockade of this event with a MEK1 inhibitor as late as 6 h after the insult reduced the enhanced vascular receptor expression and the associated cerebral infarction.

  16. Critical nodes in signalling pathways

    DEFF Research Database (Denmark)

    Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

    2006-01-01

    Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique role...... using insulin signalling as a model system....

  17. Secretin Modulates the Postnatal Development of Mouse Cerebellar Cortex Via PKA- and ERK-dependent Pathways

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2017-11-01

    Full Text Available Postnatal development of the cerebellum is critical for its intact function such as motor coordination and has been implicated in the pathogenesis of psychiatric disorders. We previously reported that deprivation of secretin (SCT from cerebellar Purkinje neurons impaired motor coordination and motor learning function, while leaving the potential role of SCT in cerebellar development to be determined. SCT and its receptor (SCTR were constitutively expressed in the postnatal cerebellum in a temporal and cell-specific manner. Using a SCT knockout mouse model, we provided direct evidence showing altered developmental patterns of Purkinje cells (PCs and granular cells (GCs. SCT deprivation reduced the PC density, impaired the PC dendritic formation, induced accelerated GC migration and potentiated cerebellar apoptosis. Furthermore, our results indicated the involvement of protein kinase A (PKA and extracellular signal regulated kinase (ERK signaling pathways in SCT-mediated protective effects against neuronal apoptosis. Results of this study illustrated a novel function of SCT in the postnatal development of cerebellum, emphasizing the necessary role of SCT in cerebellar-related functions.

  18. Glucose dependence of glycogen synthase activity regulation by GSK3 and MEK/ERK inhibitors and angiotensin-(1-7) action on these pathways in cultured human myotubes.

    Science.gov (United States)

    Montori-Grau, Marta; Tarrats, Núria; Osorio-Conles, Oscar; Orozco, Anna; Serrano-Marco, Lucía; Vázquez-Carrera, Manuel; Gómez-Foix, Anna M

    2013-05-01

    Glycogen synthase (GS) is activated by glucose/glycogen depletion in skeletal muscle cells, but the contributing signaling pathways, including the chief GS regulator GSK3, have not been fully defined. The MEK/ERK pathway is known to regulate GSK3 and respond to glucose. The aim of this study was to elucidate the GSK3 and MEK/ERK pathway contribution to GS activation by glucose deprivation in cultured human myotubes. Moreover, we tested the glucose-dependence of GSK3 and MEK/ERK effects on GS and angiotensin (1-7) actions on these pathways. We show that glucose deprivation activated GS, but did not change phospho-GS (Ser640/1), GSK3β activity or activity-activating phosphorylation of ERK1/2. We then treated glucose-replete and -depleted cells with SB415286, U0126, LY294 and rapamycin to inhibit GSK3, MEK1/2, PI3K and mTOR, respectively. SB415286 activated GS and decreased the relative phospho-GS (Ser640/1) level, more in glucose-depleted than -replete cells. U0126 activated GS and reduced the phospho-GS (Ser640/1) content significantly in glucose-depleted cells, while GSK3β activity tended to increase. LY294 inactivated GS in glucose-depleted cells only, without affecting relative phospho-GS (Ser640/1) level. Rapamycin had no effect on GS activation. Angiotensin-(1-7) raised phospho-ERK1/2 but not phospho-GSK3β (Ser9) content, while it inactivated GS and increased GS phosphorylation on Ser640/1, in glucose-replete cells. In glucose-depleted cells, angiotensin-(1-7) effects on ERK1/2 and GS were reverted, while relative phospho-GSK3β (Ser9) content decreased. In conclusion, activation of GS by glucose deprivation is not due to GS Ser640/1 dephosphorylation, GSK3β or ERK1/2 regulation in cultured myotubes. However, glucose depletion enhances GS activation/Ser640/1 dephosphorylation due to both GSK3 and MEK/ERK inhibition. Angiotensin-(1-7) inactivates GS in glucose-replete cells in association with ERK1/2 activation, not with GSK3 regulation, and glucose

  19. Role of ERK/MAPK in endothelin receptor signaling in human aortic smooth muscle cells

    DEFF Research Database (Denmark)

    Chen, Qing-wen; Edvinsson, Lars; Xu, Cang-Bao

    2009-01-01

    muscle cells (VSMCs) through activation of endothelin type A (ETA) and type B (ETB) receptors. The extracellular signal-regulated kinase 1 and 2 (ERK1/2) mitogen-activated protein kinases (MAPK) are involved in ET-1-induced VSMC contraction and proliferation. This study was designed to investigate...... agonist, Sarafotoxin 6c (S6c) caused a time-dependent ERK1/2 activation with a maximal effect by less than 20% of the ET-1-induced activation of ERK1/2. Increase in bosentan concentration up to 10 microM further inhibited ET-1-induced activation of ERK1/2 and had a stronger inhibitory effect than BQ123...

  20. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid.

    Directory of Open Access Journals (Sweden)

    Jae Sung You

    Full Text Available Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis.

  1. Fluvastatin inhibits AGE-induced cell proliferation and migration via an ERK5-dependent Nrf2 pathway in vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Ae-Rang Hwang

    Full Text Available Advanced glycation endproduct (AGE-induced vascular smooth muscle cell (VSMC proliferation and reactive oxygen species (ROS production are emerging as important mechanisms of diabetic vasculopathy, but little is known about the molecular mechanism responsible for the antioxidative effects of statins on AGEs. It has been reported that statins exert pleiotropic effects on the cardiovascular system due to decreases in AGE-induced cell proliferation, migration, and vascular inflammation. Thus, in the present study, the authors investigated the molecular mechanism by which statins decrease AGE-induced cell proliferation and VSMC migration. In cultured VSMCs, statins upregulated Nrf2-related antioxidant gene, NQO1 and HO-1, via an ERK5-dependent Nrf2 pathway. Inhibition of ERK5 by siRNA or BIX02189 (a specific ERK5 inhibitor reduced the statin-induced upregulations of Nrf2, NQO1, and HO-1. Furthermore, fluvastatin was found to significantly increase ARE promoter activity through ERK5 signaling, and to inhibit AGE-induced VSMC proliferation and migration as determined by MTT assay, cell counting, FACS analysis, a wound scratch assay, and a migration chamber assay. In addition, AGE-induced proliferation was diminished in the presence of Ad-CA-MEK5α encoding a constitutively active mutant form of MEK5α (an upstream kinase of ERK5, whereas depletion of Nrf2 restored statin-mediated reduction of AGE-induced cell proliferation. Moreover, fluvastatin suppressed the protein expressions of cyclin D1 and Cdk4, but induced p27, and blocked VSMC proliferation by regulating cell cycle. These results suggest statin-induced activation of an ERK5-dependent Nrf2 pathway reduces VSMC proliferation and migration induced by AGEs, and that the ERK5-Nrf2 signal module be viewed as a potential therapeutic target of vasculopathy in patients with diabetes and complications of the disease.

  2. 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

    Directory of Open Access Journals (Sweden)

    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.

  3. Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

    International Nuclear Information System (INIS)

    He, Shu-Fang; Jin, Shi-Yun; Wu, Hao; Wang, Bin; Wu, Yun-Xiang; Zhang, Shu-Jie; Irwin, Michael G.; Wong, Tak-Ming; Zhang, Ye

    2015-01-01

    Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

  4. Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

    Energy Technology Data Exchange (ETDEWEB)

    He, Shu-Fang; Jin, Shi-Yun; Wu, Hao; Wang, Bin; Wu, Yun-Xiang [Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China); Zhang, Shu-Jie [Department of Ultrasound, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China); Irwin, Michael G.; Wong, Tak-Ming [Department of Anesthesiology, University of Hong Kong (Hong Kong); Zhang, Ye, E-mail: zhangye_hassan@aliyun.com [Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China)

    2015-11-01

    Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

  5. Reduced juvenile long-term depression in tuberous sclerosis complex is mitigated in adults by compensatory recruitment of mGluR5 and Erk signaling.

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    Wyatt B Potter

    Full Text Available Tuberous sclerosis complex (TSC is a multisystem genetic disease that manifests with mental retardation, tumor formation, autism, and epilepsy. Heightened signaling through the mammalian target of rapamycin (mTOR pathway is involved in TSC pathology, however it remains unclear how other signaling pathways are perturbed and contribute to disease symptoms. Reduced long-term depression (LTD was recently reported in TSC mutant mice. We find that although reduced LTD is a feature of the juvenile mutant hippocampus, heightened expression of metabotropic glutamate receptor 5 and constitutively activated Erk signaling in the adult hippocampus drives wild-type levels of LTD. Increased mGluR5 and Erk results in a novel mTOR-independent LTD in CA1 hippocampus of adult mice, and contributes to the development of epileptiform bursting activity in the TSC2(+/- CA3 region of the hippocampus. Inhibition of mGluR5 or Erk signaling restores appropriate mTOR-dependence to LTD, and significantly reduces epileptiform bursting in TSC2(+/- hippocampal slices. We also report that adult TSC2(+/- mice exhibit a subtle perseverative behavioral phenotype that is eliminated by mGluR5 antagonism. These findings highlight the potential of modulating the mGluR5-Erk pathway in a developmental stage-specific manner to treat TSC.

  6. Astragalus Polysaccharide Suppresses Skeletal Muscle Myostatin Expression in Diabetes: Involvement of ROS-ERK and NF-κB Pathways

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    Min Liu

    2013-01-01

    Full Text Available Objective. The antidiabetes drug astragalus polysaccharide (APS is capable of increasing insulin sensitivity in skeletal muscle and improving whole-body glucose homeostasis. Recent studies suggest that skeletal muscle secreted growth factor myostatin plays an important role in regulating insulin signaling and insulin resistance. We hypothesized that regulation of skeletal muscle myostatin expression may be involved in the improvement of insulin sensitivity by APS. Methods. APS was administered to 13-week-old diabetic KKAy and nondiabetic C57BL/6J mice for 8 weeks. Complementary studies examined APS effects on the saturated acid palmitate-induced insulin resistance and myostatin expression in C2C12 cells. Results. APS treatment ameliorated hyperglycemia, hyperlipidemia, and insulin resistance and decreased the elevation of myostatin expression and malondialdehyde production in skeletal muscle of noninsulin-dependent diabetic KKAy mice. In C2C12 cells in vitro, saturated acid palmitate-induced impaired glucose uptake, overproduction of ROS, activation of extracellular regulated protein kinases (ERK, and NF-κB were partially restored by APS treatment. The protective effects of APS were mimicked by ERK and NF-κB inhibitors, respectively. Conclusion. Our study demonstrates elevated myostatin expression in skeletal muscle of type 2 diabetic KKAy mice and in cultured C2C12 cells exposed to palmitate. APS is capable of improving insulin sensitivity and decreasing myostatin expression in skeletal muscle through downregulating ROS-ERK-NF-κB pathway.

  7. Functional Redundancy of ERK1 and ERK2 MAP Kinases during Development

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    Christophe Frémin

    2015-08-01

    Full Text Available ERK1 and ERK2 are the effector kinases of the ERK1/2 MAP-kinase signaling pathway, which plays a central role in transducing signals controlling cell proliferation, differentiation, and survival. Deregulated activity of the ERK1/2 pathway is linked to a group of developmental syndromes and contributes to the pathogenesis of various human diseases. One fundamental question that remains unaddressed is whether ERK1 and ERK2 have evolved unique physiological functions or whether they are used redundantly to reach a threshold of global ERK activity. Here, we show that the extent of development of the mouse placenta and embryo bearing different combinations of Erk1 and Erk2 alleles is strictly correlated with total ERK1/2 activity. We further demonstrate that transgenic expression of ERK1 fully rescues the embryonic and placental developmental defects associated with the loss of ERK2. We conclude that ERK1 and ERK2 exert redundant functions in mouse development.

  8. ERK/CANP rapid signaling mediates 17β-estradiol-induced proliferation of human breast cancer cell line MCF-7 cells.

    Science.gov (United States)

    Wang, Guo-Sheng; Huang, Yan-Gang; Li, Huan; Bi, Shi-Jie; Zhao, Jin-Long

    2014-01-01

    17β-estradiol (E2) exerts its functions through both genomic and non-genomic signaling pathways. Because E2 is important in breast cancer development, we investigated whether its actions in promoting breast cancer cell proliferation occur through the non-genomic signaling pathway via extracellular signal-regulated kinase 1/2 (ERK1/2)/calcium-activated neutral protease (CANP). MCF-7 breast cancer cells were treated with ERKl/2 inhibitor (PD98059) or CANP inhibitor (calpeptin) before exposure to 1×10(-8) M E2. MTT colorimetry and flow cytometry were used to analyze effects on cell proliferation and cell cycle progression, respectively. Expression of phosphorylated-ERK (p-ERK), total ERK, and Capn4 proteins were assessed by Western blotting. Cell proliferation increased in cells treated with E2 for 24 h (P<0.05), and the proportion of cells in G0/G1 was decreased, accompanied by accelerated G1/S. Calpeptin pre-treatment significantly inhibited the E2-induced proliferation of MCF-7 cells (P<0.05), while also ameliorating the effects of E2 on cell cycle progression. Further, expression of p-ERK was rapidly up-regulated (after 10 min) by E2 (P<0.05), an effect that persisted 16 h after E2 exposure but which was significantly inhibited by PD98059 (P<0.05). Finally, expression of Capn4 protein was rapidly up-regulated in E2-exposed cells (P<0.05), but this change was significantly inhibited by PD98059 or calpeptin (P<0.05) pre-treatment. Thus, the rapid, non-genomic ERK/CANP signaling pathway mediates E2-induced proliferation of human breast cancer cells.

  9. Pten Regulates Retinal Amacrine Cell Number by Modulating Akt, Tgfβ, and Erk Signaling.

    Science.gov (United States)

    Tachibana, Nobuhiko; Cantrup, Robert; Dixit, Rajiv; Touahri, Yacine; Kaushik, Gaurav; Zinyk, Dawn; Daftarian, Narsis; Biernaskie, Jeff; McFarlane, Sarah; Schuurmans, Carol

    2016-09-07

    All tissues are genetically programmed to acquire an optimal size that is defined by total cell number and individual cellular dimensions. The retina contains stereotyped proportions of one glial and six neuronal cell types that are generated in overlapping waves. How multipotent retinal progenitors know when to switch from making one cell type to the next so that appropriate numbers of each cell type are generated is poorly understood. Pten is a phosphatase that controls progenitor cell proliferation and differentiation in several lineages. Here, using a conditional loss-of-function strategy, we found that Pten regulates retinal cell division and is required to produce the full complement of rod photoreceptors and amacrine cells in mouse. We focused on amacrine cell number control, identifying three downstream Pten effector pathways. First, phosphoinositide 3-kinase/Akt signaling is hyperactivated in Pten conditional knock-out (cKO) retinas, and misexpression of constitutively active Akt (Akt-CA) in retinal explants phenocopies the reduction in amacrine cell production observed in Pten cKOs. Second, Akt-CA activates Tgfβ signaling in retinal explants, which is a negative feedback pathway for amacrine cell production. Accordingly, Tgfβ signaling is elevated in Pten cKO retinas, and epistatic analyses placed Pten downstream of TgfβRII in amacrine cell number control. Finally, Pten regulates Raf/Mek/Erk signaling levels to promote the differentiation of all amacrine cell subtypes, which are each reduced in number in Pten cKOs. Pten is thus a positive regulator of amacrine cell production, acting via multiple downstream pathways, highlighting its diverse actions as a mediator of cell number control. Despite the importance of size for optimal organ function, how individual cell types are generated in correct proportions is poorly understood. There are several ways to control cell number, including readouts of organ function (e.g., secreted hormones reach functional

  10. Andrographolide Induces Apoptosis of C6 Glioma Cells via the ERK-p53-Caspase 7-PARP Pathway

    Directory of Open Access Journals (Sweden)

    Shih-Hung Yang

    2014-01-01

    Full Text Available Background. Glioma is the most malignant tumor of the central nervous system. Efforts on the development of new chemotherapy are mandatory. Andrographolide (AND, a diterpenoid lactone isolated from the Andrographis paniculata, has been shown to have antitumor activities in several types of cancer cells. Whether AND can exert its antitumor activity in glioblastoma cells remains unknown. This study examined the anticancer effects of AND, both in vitro and in vivo. Methods. Cell apoptosis was assayed by flow cytometry and nuclear staining. The signaling pathway for AND was determined by western blotting. The effects of AND on tumor growth was evaluated in a mouse model. Results and Conclusion. In vitro, with application of specific inhibitors and siRNA, AND-induced apoptosis was proven through ROS-ERK-P53-caspase 7-PARP signaling pathway. In vivo, AND significantly retarded tumor growth and caused regression of well-formed tumors in vivo. Furthermore, AND did not induce apoptosis or activate ERK and p53 in primary cultured astrocyte cells, and it may serve as a potential therapeutic candidate for the treatment of glioma.

  11. Instillation of Sericin Enhances Corneal Wound Healing through the ERK Pathway in Rat Debrided Corneal Epithelium

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    Noriaki Nagai

    2018-04-01

    Full Text Available Sericin is a major constituent of silk produced by silkworms. We previously found that the instillation of sericin enhanced the proliferation of corneal epithelial cells, and acted to promote corneal wound healing in both normal and diabetic model rats. However, the mechanisms by which sericin promotes the proliferation of corneal cells have not been established. In this study, we investigated the effects of sericin on Akt and ERK activation in a human corneal epithelial cell line (HCE-T cells and rat debrided corneal epithelium. Although Akt phosphorylation was not detected following the treatment of HCE-T cells with sericin, ERK1/2 phosphorylation was enhanced. The growth of HCE-T cells treated with sericin was significantly increased, with the cell growth of sericin-treated HCE-T cells being 1.7-fold higher in comparison with vehicle-treated HCE-T cells. On the other hand, both of an ERK inhibitor U0126 (non-specific specific inhibitor and SCH772984 (specific inhibitor attenuated the enhanced cell growth by sericin, and the growth level in the case of co-treatment with sericin and ERK1/2 inhibitor was similar to that of cells treated with ERK1/2 inhibitor alone. In an in vivo study using rat debrided corneal epithelium, the corneal wound healing rate was enhanced by the instillation of sericin, and this enhancement was also attenuated by the instillation of U0126. In addition, the corneal wound healing rate in rats co-instilled with sericin and U0126 was similar to that following the instillation of U0126 alone. In conclusion, we found that the instillation of sericin enhanced cell proliferation via the activation of the MAPK/ERK pathway, resulting in the promotion of corneal wound healing in rat eyes. These findings provide significant information for designing further studies to develop potent corneal wound-healing drugs.

  12. Retroactive signaling in short signaling pathways.

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    Jacques-Alexandre Sepulchre

    Full Text Available In biochemical signaling pathways without explicit feedback connections, the core signal transduction is usually described as a one-way communication, going from upstream to downstream in a feedforward chain or network of covalent modification cycles. In this paper we explore the possibility of a new type of signaling called retroactive signaling, offered by the recently demonstrated property of retroactivity in signaling cascades. The possibility of retroactive signaling is analysed in the simplest case of the stationary states of a bicyclic cascade of signaling cycles. In this case, we work out the conditions for which variables of the upstream cycle are affected by a change of the total amount of protein in the downstream cycle, or by a variation of the phosphatase deactivating the same protein. Particularly, we predict the characteristic ranges of the downstream protein, or of the downstream phosphatase, for which a retroactive effect can be observed on the upstream cycle variables. Next, we extend the possibility of retroactive signaling in short but nonlinear signaling pathways involving a few covalent modification cycles.

  13. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wakao, Kazufumi [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Watanabe, Tadashi [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Takadama, Tadatoshi; Ui, Sadaharu [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Shigemi, Zenpei; Kagawa, Hiroki [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Higashi, Chizuka; Ohga, Rie; Taira, Takahiro [Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898 (Japan); Fujimuro, Masahiro, E-mail: fuji2@mb.kyoto-phu.ac.jp [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan)

    2014-02-07

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  14. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    International Nuclear Information System (INIS)

    Wakao, Kazufumi; Watanabe, Tadashi; Takadama, Tadatoshi; Ui, Sadaharu; Shigemi, Zenpei; Kagawa, Hiroki; Higashi, Chizuka; Ohga, Rie; Taira, Takahiro; Fujimuro, Masahiro

    2014-01-01

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  15. Aberrant Signaling Pathways in Glioma

    International Nuclear Information System (INIS)

    Nakada, Mitsutoshi; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka; Teng, Lei; Pyko, Ilya V.; Hamada, Jun-Ichiro

    2011-01-01

    Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies

  16. Beta1 integrin inhibits apoptosis induced by cyclic stretch in annulus fibrosus cells via ERK1/2 MAPK pathway.

    Science.gov (United States)

    Zhang, Kai; Ding, Wei; Sun, Wei; Sun, Xiao-jiang; Xie, You-zhuan; Zhao, Chang-qing; Zhao, Jie

    2016-01-01

    Low back pain is associated with intervertebral disc degeneration (IVDD) due to cellular loss through apoptosis. Mechanical factors play an important role in maintaining the survival of the annulus fibrosus (AF) cells and the deposition of extracellular matrix. However, the mechanisms that excessive mechanical forces lead to AF cell apoptosis are not clear. The present study was to look for how AF cells sense mechanical changes. In vivo experiments, the involvement of mechanoreceptors in apoptosis was examined by RT-PCR and/or immunoblotting in the lumbar spine of rats subjected to unbalanced dynamic and static forces. In vitro experiments, we investigated apoptotic signaling pathways in untransfected and transfected AF cells with the lentivirus vector for rat β1 integrin overexpression after cyclic stretch. Apoptosis in AF cells was assessed using flow cytometry, Hoechst 33258 nuclear staining. Western blotting was used to analyze expression of β1 integrin and caspase-3 and ERK1/2 MAPK signaling molecules. In the rat IVDD model, unbalanced dynamic and static forces induced apoptosis of disc cells, which corresponded to decreased expression of β1 integrin. Cyclic stretch-induced apoptosis in rat AF cells correlated with the activation of caspase-3 and with decreased levels of β1 integrin and the phosphorylation levels of ERK1/2 activation level. However, the overexpression of β1 integrin in AF cells ameliorated cyclic stretch-induced apoptosis and decreased caspase-3 activation. Furthermore, ERK1/2-specific inhibitor promotes apoptosis in vector β1-infected AF cells. These results suggest that the disruption of β1 integrin signaling may underlie disc cell apoptosis induced by mechanical stress. Further work is necessary to fully elucidate the pathophysiological mechanisms that underlie IVDD caused by unbalanced dynamic and static forces.

  17. [Progesterone Promotes Human Bone Marrow Mesenchymal Stem Cells to Synthesize Fibronectin via ERK Pathway].

    Science.gov (United States)

    Wu, Zhen-Yong; Chen, Jing-Li; Huang, Shu; Zhang, Hui; Wang, Fang; Wang, Yan; Bi, Xiao-Yun; Guo, Zi-Kuan

    2015-12-01

    To investigate whether the progesterone can promote fibronection (FN) synthesis by human bone marrow mesenchymal stem cells (MSCs) and to explore the potential underlying mechanism. The human bone marrow MSCs were cultured in a serum-free medium with progesterone for 72 hours, the MTT test was performed to observe the proliferation status and adhension ability of the treated cells. Western blot was used to detect the content of FN in MSDs with GAPDH as the internal reference, the phosphorylation of ERK1/2, as well as the FN content in MSC treated by PD98059, a specific inhibitor of ERK1/2. The progesterone at a range of certain doses not effect on the proliferation of human bone marrow MSCs. Progesterone (25 µg/L) treatment enhanced the FN expression and adherent ability of marrow MSCs. Progesterone could induce prompt phosphorylation of ERK 1/2 and its promoting effects on FN synthesis was reversed by PD98059. The progesterone can promote FN synthesis by human bone marrow MSCs via ERK 1/2 pathway, and it might be used to culture MSCs in serum-free medium.

  18. TCDD promoted EMT of hFPECs via AhR, which involved the activation of EGFR/ERK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhan [School of Public Health, Xinxiang Medical University, 453003 (China); The Fifth Affiliated Hospital, Zhengzhou University, 450052 (China); Bu, Yongjun [School of Public Health, Xinxiang Medical University, 453003 (China); Liu, Xiaozhuan [Medical College, Henan University of Science & Technology, 471023 (China); Wang, Xugang; Zhang, Guofu; Wang, Erhui; Ding, Shibin; Liu, Yongfeng; Shi, Ruling [School of Public Health, Xinxiang Medical University, 453003 (China); Li, Qiaoyun; Fu, Jianhong [The Fifth Affiliated Hospital, Zhengzhou University, 450052 (China); Yu, Zengli, E-mail: zly@zzu.edu.cn [School of Public Health, Xinxiang Medical University, 453003 (China); School of Public Health, Zhengzhou University, 450001 (China)

    2016-05-01

    One critical step of second palatal fusion is the newly formed medial epithelia seam (MES) disintegration, which involves apoptosis, epithelial to mesenchymal transition (EMT), and cell migration. Although the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) produces cleft palate at high rates, little is known about the effects of TCDD exposure on the fate of palatal epithelial cells. By using primary epithelial cells isolated from human fetal palatal shelves (hFPECs), we show that TCDD increased cell proliferation and EMT, as demonstrated by increased the epithelial markers (E-cadherin and cytokeratin14) and enhanced the mesenchymal markers (vimentin and fibronectin), but had no effect on cell migration and apoptosis. TCDD exposure led to a dose-dependent increase in Slug protein expression. Coimmunoprecipitation revealed that TCDD promoted AhR to form a protein complex with Slug. ChIP assay confirmed that TCDD exposure recruited AhR to the xenobiotic responsive element of Slug promoter. Knockdown of AhR by siRNA remarkably weakened TCDD-induced binding of AhR to the XRE promoter of slug, thereby suppressed TCDD-induced vimentin. Further experiment showed that TCDD stimulated EGFR phosphorylation did not influence the TGFβ3/Smad signaling; whereas TCDD increased phosphorylation of ERK1/2 and p38 with no effect on activation of JNK. By using varieties of inhibitors, we confirmed that TCDD promoted proliferation and EMT of hFPECs via activation of EGFR/ERK pathway. These data make a novel contribution to the molecular mechanism of cleft palate by TCDD. - Highlights: • TCDD exposure promoted cell proliferation and EMT of hFPECs; • AhR signaling was activated and required for TCDD-induced EMT; • TCDD-mediated EMT of hFPECs involved the activation of EGFR/ERK signaling; • TCDD exposure had no effect on TGFβ3/Smad pathway.

  19. TCDD promoted EMT of hFPECs via AhR, which involved the activation of EGFR/ERK signaling

    International Nuclear Information System (INIS)

    Gao, Zhan; Bu, Yongjun; Liu, Xiaozhuan; Wang, Xugang; Zhang, Guofu; Wang, Erhui; Ding, Shibin; Liu, Yongfeng; Shi, Ruling; Li, Qiaoyun; Fu, Jianhong; Yu, Zengli

    2016-01-01

    One critical step of second palatal fusion is the newly formed medial epithelia seam (MES) disintegration, which involves apoptosis, epithelial to mesenchymal transition (EMT), and cell migration. Although the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) produces cleft palate at high rates, little is known about the effects of TCDD exposure on the fate of palatal epithelial cells. By using primary epithelial cells isolated from human fetal palatal shelves (hFPECs), we show that TCDD increased cell proliferation and EMT, as demonstrated by increased the epithelial markers (E-cadherin and cytokeratin14) and enhanced the mesenchymal markers (vimentin and fibronectin), but had no effect on cell migration and apoptosis. TCDD exposure led to a dose-dependent increase in Slug protein expression. Coimmunoprecipitation revealed that TCDD promoted AhR to form a protein complex with Slug. ChIP assay confirmed that TCDD exposure recruited AhR to the xenobiotic responsive element of Slug promoter. Knockdown of AhR by siRNA remarkably weakened TCDD-induced binding of AhR to the XRE promoter of slug, thereby suppressed TCDD-induced vimentin. Further experiment showed that TCDD stimulated EGFR phosphorylation did not influence the TGFβ3/Smad signaling; whereas TCDD increased phosphorylation of ERK1/2 and p38 with no effect on activation of JNK. By using varieties of inhibitors, we confirmed that TCDD promoted proliferation and EMT of hFPECs via activation of EGFR/ERK pathway. These data make a novel contribution to the molecular mechanism of cleft palate by TCDD. - Highlights: • TCDD exposure promoted cell proliferation and EMT of hFPECs; • AhR signaling was activated and required for TCDD-induced EMT; • TCDD-mediated EMT of hFPECs involved the activation of EGFR/ERK signaling; • TCDD exposure had no effect on TGFβ3/Smad pathway.

  20. Auricular Electroacupuncture Reduced Inflammation-Related Epilepsy Accompanied by Altered TRPA1, pPKCα, pPKCε, and pERk1/2 Signaling Pathways in Kainic Acid-Treated Rats

    Directory of Open Access Journals (Sweden)

    Yi-Wen Lin

    2014-01-01

    Full Text Available Background. Inflammation is often considered to play a crucial role in epilepsy by affecting iron status and metabolism. In this study, we investigated the curative effect of auricular acupuncture and somatic acupuncture on kainic acid- (KA- induced epilepsy in rats. Methods. We established an epileptic seizure model in rats by KA (12 mg, ip. The 2 Hz electroacupuncture (EA was applied at auricular and applied at Zusanli and Shangjuxu (ST36-ST37 acupoints for 20 min for 3 days/week for 6 weeks beginning on the day following the KA injection. Results. The electrophysiological results indicated that neuron overexcitation occurred in the KA-treated rats. This phenomenon could be reversed among either the auricular EA or ST36-ST37 EA treatment, but not in the sham-control rats. The Western blot results revealed that TRPA1, but not TRPV4, was upregulated by injecting KA and could be attenuated by administering auricular or ST36-ST37 EA, but not in the sham group. In addition, potentiation of TRPA1 was accompanied by increased PKCα and reduced PKCε. Furthermore, pERK1/2, which is indicated in inflammation, was also increased by KA. Furthermore, the aforementioned mechanisms could be reversed by administering auricular EA and could be partially reversed by ST36-ST37 EA. Conclusions. These results indicate a novel mechanism for treating inflammation-associated epilepsy and can be translated into clinical therapy.

  1. Role of ERK/MAPK in endothelin receptor signaling in human aortic smooth muscle cells

    DEFF Research Database (Denmark)

    Chen, Qing-wen; Edvinsson, Lars; Xu, Cang-Bao

    2009-01-01

    muscle cells (VSMCs) through activation of endothelin type A (ETA) and type B (ETB) receptors. The extracellular signal-regulated kinase 1 and 2 (ERK1/2) mitogen-activated protein kinases (MAPK) are involved in ET-1-induced VSMC contraction and proliferation. This study was designed to investigat...

  2. Exosome uptake depends on ERK1/2-heat shock protein 27 signaling and lipid Raft-mediated endocytosis negatively regulated by caveolin-1.

    Science.gov (United States)

    Svensson, Katrin J; Christianson, Helena C; Wittrup, Anders; Bourseau-Guilmain, Erika; Lindqvist, Eva; Svensson, Lena M; Mörgelin, Matthias; Belting, Mattias

    2013-06-14

    The role of exosomes in cancer can be inferred from the observation that they transfer tumor cell derived genetic material and signaling proteins, resulting in e.g. increased tumor angiogenesis and metastasis. However, the membrane transport mechanisms and the signaling events involved in the uptake of these virus-like particles remain ill-defined. We now report that internalization of exosomes derived from glioblastoma (GBM) cells involves nonclassical, lipid raft-dependent endocytosis. Importantly, we show that the lipid raft-associated protein caveolin-1 (CAV1), in analogy with its previously described role in virus uptake, negatively regulates the uptake of exosomes. We find that exosomes induce the phosphorylation of several downstream targets known to associate with lipid rafts as signaling and sorting platforms, such as extracellular signal-regulated kinase-1/2 (ERK1/2) and heat shock protein 27 (HSP27). Interestingly, exosome uptake appears dependent on unperturbed ERK1/2-HSP27 signaling, and ERK1/2 phosphorylation is under negative influence by CAV1 during internalization of exosomes. These findings significantly advance our general understanding of exosome-mediated uptake and offer potential strategies for how this pathway may be targeted through modulation of CAV1 expression and ERK1/2 signaling.

  3. ROS mediates interferon gamma induced phosphorylation of Src, through the Raf/ERK pathway, in MCF-7 human breast cancer cell line.

    Science.gov (United States)

    Zibara, Kazem; Zeidan, Asad; Bjeije, Hassan; Kassem, Nouhad; Badran, Bassam; El-Zein, Nabil

    2017-03-01

    Interferon gamma (IFN-ɣ) is a pleiotropic cytokine which plays dual contrasting roles in cancer. Although IFN-ɣ has been clinically used to treat various malignancies, it was recently shown to have protumorigenic activities. Reactive oxygen species (ROS) are overproduced in cancer cells, mainly due to NADPH oxidase activity, which results into several changes in signaling pathways. In this study, we examined IFN-ɣ effect on the phosphorylation levels of key signaling proteins, through ROS production, in the human breast cancer cell line MCF-7. After treatment by IFN-ɣ, results showed a significant increase in the phosphorylation of STAT1, Src, raf, AKT, ERK1/2 and p38 signaling molecules, in a time specific manner. Src and Raf were found to be involved in early stages of IFN-ɣ signaling since their phosphorylation increased very rapidly. Selective inhibition of Src-family kinases resulted in an immediate significant decrease in the phosphorylation status of Raf and ERK1/2, but not p38 and AKT. On the other hand, IFN-ɣ resulted in ROS generation, through H 2 O 2 production, whereas pre-treatment with the ROS inhibitor NAC caused ROS inhibition and a significant decrease in the phosphorylation levels of AKT, ERK1/2, p38 and STAT1. Moreover, pretreatment with a selective NOX1 inhibitor resulted in a significant decrease of AKT phosphorylation. Finally, no direct relationship was found between ROS production and calcium mobilization. In summary, IFN-ɣ signaling in MCF-7 cell line is ROS-dependent and follows the Src/Raf/ERK pathway whereas its signaling through the AKT pathway is highly dependent on NOX1.

  4. The human transient receptor potential vanilloid 3 channel is sensitized via the ERK pathway

    Czech Academy of Sciences Publication Activity Database

    Vyklická, Lenka; Boukalová, Štěpána; Mačíková, Lucie; Chvojka, Štěpán; Vlachová, Viktorie

    2017-01-01

    Roč. 292, č. 51 (2017), s. 21083-21091 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA15-15839S Institutional support: RVO:67985823 Keywords : epidermal growth factor receptor (EGFR) * extracellular-signal-regulated kinase (ERK) * keratinocyte * phosphorylation * transient receptor potential channels * TRP channels Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 4.125, year: 2016

  5. Adaptation to TKI Treatment Reactivates ERK Signaling in Tyrosine Kinase-Driven Leukemias and Other Malignancies.

    Science.gov (United States)

    Bruner, J Kyle; Ma, Hayley S; Li, Li; Qin, Alice Can Ran; Rudek, Michelle A; Jones, Richard J; Levis, Mark J; Pratz, Keith W; Pratilas, Christine A; Small, Donald

    2017-10-15

    FMS-like tyrosine kinase-3 (FLT3) tyrosine kinase inhibitors (TKI) have been tested extensively to limited benefit in acute myeloid leukemia (AML). We hypothesized that FLT3/internal tandem duplication (ITD) leukemia cells exhibit mechanisms of intrinsic signaling adaptation to TKI treatment that are associated with an incomplete response. Here, we identified reactivation of ERK signaling within hours following treatment of FLT3/ITD AML cells with selective inhibitors of FLT3. When these cells were treated with inhibitors of both FLT3 and MEK in combination, ERK reactivation was abrogated and anti-leukemia effects were more pronounced compared with either drug alone. ERK reactivation was also observed following inhibition of other tyrosine kinase-driven cancer cells, including EGFR-mutant lung cancer, HER2-amplified breast cancer, and BCR-ABL leukemia. These studies reveal an adaptive feedback mechanism in tyrosine kinase-driven cancers associated with reactivation of ERK signaling in response to targeted inhibition. Cancer Res; 77(20); 5554-63. ©2017 AACR . ©2017 American Association for Cancer Research.

  6. Upregulation of MAPK/Erk and PI3K/Akt pathways in ulcerative colitis-associated colon cancer.

    Science.gov (United States)

    Setia, Shruti; Nehru, Bimla; Sanyal, Sankar Nath

    2014-10-01

    An extracellular signal like a cytokine or chemokine, secreted in the inflammatory microenvironment can activate the mitogen activated protein kinase (MAPK) pathway by binding to a cytokine receptor tyrosine kinase, which further activates tyrosine kinases such as Janus Kinase-3 (Jak-3). This signal is transferred from Jak-3 to the DNA in the nucleus of the cell by a chain of kinases, ultimately activating extracellular receptor kinase (Erk/MAPK). The latter phosphorylates c-myc, an oncogene, which alters the levels and activities of many transcription factors leading to cell survival, proliferation and invasion. The oncogenic PI3K pathway plays a similar role by activating c-myc, leading to cell survival and proliferation. The present study explores the role of ulcerative colitis in colon cancer by investigating the activities of tyrosine kinase activated MAPK pathway and various components of the PI3K pathway including PI3K, PTEN, PDK1, GSK3β, Akt, mTOR, Wnt and β-catenin. This was done by western blot and fluorescent immunohistochemical analysis of the above-mentioned proteins. Also, the morphological and histological investigation of the colonic samples from various animal groups revealed significant alterations as compared to the control in both inflammatory as well as carcinogenic conditions. These effects were reduced to a large extent by the co-administration of celecoxib, a second-generation non-steroidal anti-inflammatory drug (NSAID). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Chemokine CXCL13 mediates orofacial neuropathic pain via CXCR5/ERK pathway in the trigeminal ganglion of mice.

    Science.gov (United States)

    Zhang, Qian; Cao, De-Li; Zhang, Zhi-Jun; Jiang, Bao-Chun; Gao, Yong-Jing

    2016-07-11

    Trigeminal nerve damage-induced neuropathic pain is a severely debilitating chronic orofacial pain syndrome. Spinal chemokine CXCL13 and its receptor CXCR5 were recently demonstrated to play a pivotal role in the pathogenesis of spinal nerve ligation-induced neuropathic pain. Whether and how CXCL13/CXCR5 in the trigeminal ganglion (TG) mediates orofacial pain are unknown. The partial infraorbital nerve ligation (pIONL) was used to induce trigeminal neuropathic pain in mice. The expression of ATF3, CXCL13, CXCR5, and phosphorylated extracellular signal-regulated kinase (pERK) in the TG was detected by immunofluorescence staining and western blot. The effect of shRNA targeting on CXCL13 or CXCR5 on pain hypersensitivity was checked by behavioral testing. pIONL induced persistent mechanical allodynia and increased the expression of ATF3, CXCL13, and CXCR5 in the TG. Inhibition of CXCL13 or CXCR5 by shRNA lentivirus attenuated pIONL-induced mechanical allodynia. Additionally, pIONL-induced neuropathic pain and the activation of ERK in the TG were reduced in Cxcr5 (-/-) mice. Furthermore, MEK inhibitor (PD98059) attenuated mechanical allodynia and reduced TNF-α and IL-1β upregulation induced by pIONL. TNF-α inhibitor (Etanercept) and IL-1β inhibitor (Diacerein) attenuated pIONL-induced orofacial pain. Finally, intra-TG injection of CXCL13 induced mechanical allodynia, increased the activation of ERK and the production of TNF-α and IL-1β in the TG of WT mice, but not in Cxcr5 (-/-) mice. Pretreatment with PD98059, Etanercept, or Diacerein partially blocked CXCL13-induced mechanical allodynia, and PD98059 also reduced CXCL13-induced TNF-α and IL-1β upregulation. CXCL13 and CXCR5 contribute to orofacial pain via ERK-mediated proinflammatory cytokines production. Targeting CXCL13/CXCR5/ERK/TNF-α and IL-1β pathway in the trigeminal ganglion may offer effective treatment for orofacial neuropathic pain.

  8. Nonmyocyte ERK1/2 signaling contributes to load-induced cardiomyopathy in Marfan mice.

    Science.gov (United States)

    Rouf, Rosanne; MacFarlane, Elena Gallo; Takimoto, Eiki; Chaudhary, Rahul; Nagpal, Varun; Rainer, Peter P; Bindman, Julia G; Gerber, Elizabeth E; Bedja, Djahida; Schiefer, Christopher; Miller, Karen L; Zhu, Guangshuo; Myers, Loretha; Amat-Alarcon, Nuria; Lee, Dong I; Koitabashi, Norimichi; Judge, Daniel P; Kass, David A; Dietz, Harry C

    2017-08-03

    Among children with the most severe presentation of Marfan syndrome (MFS), an inherited disorder of connective tissue caused by a deficiency of extracellular fibrillin-1, heart failure is the leading cause of death. Here, we show that, while MFS mice (Fbn1C1039G/+ mice) typically have normal cardiac function, pressure overload (PO) induces an acute and severe dilated cardiomyopathy in association with fibrosis and myocyte enlargement. Failing MFS hearts show high expression of TGF-β ligands, with increased TGF-β signaling in both nonmyocytes and myocytes; pathologic ERK activation is restricted to the nonmyocyte compartment. Informatively, TGF-β, angiotensin II type 1 receptor (AT1R), or ERK antagonism (with neutralizing antibody, losartan, or MEK inhibitor, respectively) prevents load-induced cardiac decompensation in MFS mice, despite persistent PO. In situ analyses revealed an unanticipated axis of activation in nonmyocytes, with AT1R-dependent ERK activation driving TGF-β ligand expression that culminates in both autocrine and paracrine overdrive of TGF-β signaling. The full compensation seen in wild-type mice exposed to mild PO correlates with enhanced deposition of extracellular fibrillin-1. Taken together, these data suggest that fibrillin-1 contributes to cardiac reserve in the face of hemodynamic stress, critically implicate nonmyocytes in disease pathogenesis, and validate ERK as a therapeutic target in MFS-related cardiac decompensation.

  9. ERK5 pathway regulates the phosphorylation of tumour suppressor hDlg during mitosis

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 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.

  11. Role of ERK signaling pathway in up-regulation of γ-AChR during development of resistance to non-depolarizing muscular relaxants in skeletal muscles of burned rats%ERK信号通路在烧伤大鼠骨骼肌对非去极化肌松药抵抗形成时γ-AChR上调中的作用

    Institute of Scientific and Technical Information of China (English)

    靳天; 王宏; 吴进; 李士通

    2016-01-01

    Objective To evaluate the role of ERK signaling pathway in up-regulation of fetal gamma-acetylcholine receptor (μ-AChR) during the development of resistance to non-depolarizing muscular relaxants in skeletal muscles of burned rats.Methods Thirty adult male SPF Sprague-Dawley rats,weighing 230-250 g,aged 9-10 weeks,were randomly divided into 3 groups (n=10 each) using a random number table:control group (C group),burn group (B group) and ERK1/2 inhibitor U0126 group (U group).The surface area of bilateral hindlimbs was shaved,and the tibialis anterior muscle of the right hiudlimb was exposed to 95 ℃ copper for 12 s in anesthetized rats.At 1.5 h after burn,15 mg/kg U0126 was injected intraperitoneally in group U,and the equal volume of dimethyl sulfoxide was given in C and B groups.The tibialis anterior muscle was obtained on 7th day after establishment of the model for determination of the expression of μ-AChR and adult epsilon-AChR (ε-AChR) mRNA in skeletal muscle cells using real-time polymerase chain reaction.The concentration-effect curve of rocuronium was drawn using muscular tension experiment,and the half inhibitory concentration (IC50) and 95% confidence interval were calculated.Resuits Compared with group C,the expression of μ-AChR mRNA in skeletal muscle cells was significantly up-regulated,and the IC50 was significantly increased in group B (P<0.05).Compared with group B,the expression of γ-AChR mRNA in skeletal muscle cells was significantly down-regulated,and the IC50 was significantly decreased in group U (P<0.05).There was no significant difference in the expression of ε-AChR in skeletal muscle cells between the three groups (P>0.05).Conclusion Up-regulation of μ,-AChR is dependent on activation of ERK signaling pathway during the development of resistance to non-depolarizing muscular relaxants in skeletal muscles of burned rats.%目的 评价细胞外信号调节激酶(ERK)信号通路在烧伤大鼠骨骼肌对非去极化肌松药

  12. CCN2 is required for the TGF-β induced activation of Smad1-Erk1/2 signaling network.

    Directory of Open Access Journals (Sweden)

    Sashidhar S Nakerakanti

    Full Text Available Connective tissue growth factor (CCN2 is a multifunctional matricellular protein, which is frequently overexpressed during organ fibrosis. CCN2 is a mediator of the pro-fibrotic effects of TGF-β in cultured cells, but the specific function of CCN2 in the fibrotic process has not been elucidated. In this study we characterized the CCN2-dependent signaling pathways that are required for the TGF-β induced fibrogenic response. By depleting endogenous CCN2 we show that CCN2 is indispensable for the TGF-β-induced phosphorylation of Smad1 and Erk1/2, but it is unnecessary for the activation of Smad3. TGF-β stimulation triggered formation of the CCN2/β(3 integrin protein complexes and activation of Src signaling. Furthermore, we demonstrated that signaling through the α(vβ(3 integrin receptor and Src was required for the TGF-β induced Smad1 phosphorylation. Recombinant CCN2 activated Src and Erk1/2 signaling, and induced phosphorylation of Fli1, but was unable to stimulate Smad1 or Smad3 phosphorylation. Additional experiments were performed to investigate the role of CCN2 in collagen production. Consistent with the previous studies, blockade of CCN2 abrogated TGF-β-induced collagen mRNA and protein levels. Recombinant CCN2 potently stimulated collagen mRNA levels and upregulated activity of the COL1A2 promoter, however CCN2 was a weak inducer of collagen protein levels. CCN2 stimulation of collagen was dose-dependent with the lower doses (<50 ng/ml having a stimulatory effect and higher doses having an inhibitory effect on collagen gene expression. In conclusion, our study defines a novel CCN2/α(vβ(3 integrin/Src/Smad1 axis that contributes to the pro-fibrotic TGF-β signaling and suggests that blockade of this pathway may be beneficial for the treatment of fibrosis.

  13. Receptor-interacting Protein 140 Overexpression Promotes Neuro-2a Neuronal Differentiation by ERK1/2 Signaling

    Directory of Open Access Journals (Sweden)

    Xiao Feng

    2015-01-01

    Full Text Available Background: Abnormal neuronal differentiation plays an important role in central nervous system (CNS development abnormalities such as Down syndrome (DS, a disorder that results directly from overexpression of genes in trisomic cells. Receptor-interacting protein 140 (RIP140 is significantly upregulated in DS brains, suggesting its involvement in DS CNS development abnormalities. However, the role of RIP140 in neuronal differentiation is still not clear. The current study aimed to investigate the effect of RIP140 overexpression on the differentiation of neuro-2a (N2a neuroblastoma cells, in vitro. Methods: Stably RIP140-overexpressing N2a (N2a-RIP140 cells were used as a neurodevelopmental model, and were constructed by lipofection and overexpression validated by real-time polymerase chain reaction and Western blot. Retinoic acid (RA was used to stimulate N2a differentiation. Combining the expression of Tuj1 at the mRNA and protein levels, the percentage of cells baring neurites, and the number of neurites per cell body was semi-quantified to determine the effect of RIP140 on differentiation of N2a cells. Furthermore, western blot and the ERK1/2 inhibitor U0126 were used to identify the specific signaling pathway by which RIP140 induces differentiation of N2a cells. Statistical significance of the differences between groups was determined by one-way analysis of variance followed by the Dunnett test. Results: Compared to untransfected N2a cells RIPl40 expression in N2a-RIP140 cells was remarkably upregulated at both the mRNA and protein levels. N2a-RIP140 cells had a significantly increased percentage of cells baring neurites, and numbers of neurites per cell, as compared to N2a cells, in the absence and presence of RA (P < 0.05. In addition, Tuj1, a neuronal biomarker, was strongly upregulated in N2a-RIP140 cells (P < 0.05 and phosphorylated ERK1/2 (p-ERK1/2 levels in N2a-RIP140 cells were dramatically increased, while differentiation was

  14. Mono-(2-ethylhexyl)-phthalate (MEHP) affects ERK-dependent GDNF signalling in mouse stem-progenitor spermatogonia

    International Nuclear Information System (INIS)

    Lucas, Benjamin E.G.; Fields, Christopher; Joshi, Neeraj; Hofmann, Marie-Claude

    2012-01-01

    Highlights: ► MEHP affects SSC proliferation in a dose- and time-dependent manner. ► MEHP does not increase apoptosis, necrosis or the production of ROS in SSCs. ► MEHP reduces the activity of the GDNF/ERK1/2/FOS signalling pathway in SSCs. ► MEHP does not affect the GDNF/SRC/MYCN signalling pathway in SSCs. -- Abstract: Many commercial and household products such as lubricants, cosmetics, plastics, and paint contain phthalates, in particular bis-(2-ethyhexyl)-phthalate (DEHP). As a consequence, phthalates have been found in a number of locations and foods (streambeds, household dust, bottled water and dairy products). Epidemiological and animal studies analysing phthalate exposure in males provide evidence of degradation in sperm quality, associated to an increase in the incidence of genital birth defects and testicular cancers. In the testis, spermatogenesis is maintained throughout life by a small number of spermatogonial stem cells (SSCs) that self-renew or differentiate to produce adequate numbers of spermatozoa. Disruption or alteration of SSC self-renewal induce decreased sperm count and sperm quality, or may potentially lead to testicular cancer. GDNF, or glial cell-line-derived neurotrophic factor, is a growth factor that is essential for the self-renewal of SSCs and continuous spermatogenesis. In the present study, the SSC-derived cell line C18-4 was used as a model for preliminary assessment of the effects of mono-(2-ethylhexyl)-phthalate (MEHP, main metabolite of DEHP) on spermatogonial stem cells. Our data demonstrate that MEHP disrupts one of the known GDNF signalling pathways in these cells. MEHP induced a decrease of C18-4 cell viability in a time- and dose-dependent manner, as well as a disruption of ERK1/2 activation but not of SRC signalling. As a result, we observed a decrease of expression of the transcription factor FOS, which is downstream of the GDNF/ERK1/2 axis in these cells. Taken together, our data suggest that MEHP exposure

  15. Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: Effect on myotube fusion

    International Nuclear Information System (INIS)

    Roffe, Suzy; Hagai, Yosey; Pines, Mark; Halevy, Orna

    2010-01-01

    Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels. This reduction was reversed by inhibitors of the phosphoinositide 3'-kinase/Akt (PI3K/Akt) and MAPK/ERK pathways, suggesting their specific role in mediating halofuginone's inhibitory effect on Smad3 phosphorylation. Halofuginone enhanced Akt, MAPK/ERK and p38 MAPK phosphorylation and inhibited Smad3 phosphorylation in myotubes, all of which are crucial for myotube fusion. In addition, halofuginone increased the association Akt and MAPK/ERK with Smad3. As a consequence, halofuginone promoted myotube fusion, as reflected by an increased percentage of C2 and mdx myotubes containing high numbers of nuclei, and this was reversed by specific inhibitors of the PI3K and MAPK/ERK pathways. Together, the data suggest a role, either direct or via inhibition of Smad3 phosphorylation, for Akt or MAPK/ERK in halofuginone-enhanced myotube fusion, a feature which is crucial to improving muscle function in muscular dystrophies.

  16. Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: Effect on myotube fusion

    Energy Technology Data Exchange (ETDEWEB)

    Roffe, Suzy [Department of Animal Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel); Hagai, Yosey [Department of Animal Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel); Institute of Animal Sciences, Volcani Center, Bet Dagan 50250 (Israel); Pines, Mark [Institute of Animal Sciences, Volcani Center, Bet Dagan 50250 (Israel); Halevy, Orna, E-mail: halevyo@agri.huji.ac.il [Department of Animal Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel)

    2010-04-01

    Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels. This reduction was reversed by inhibitors of the phosphoinositide 3'-kinase/Akt (PI3K/Akt) and MAPK/ERK pathways, suggesting their specific role in mediating halofuginone's inhibitory effect on Smad3 phosphorylation. Halofuginone enhanced Akt, MAPK/ERK and p38 MAPK phosphorylation and inhibited Smad3 phosphorylation in myotubes, all of which are crucial for myotube fusion. In addition, halofuginone increased the association Akt and MAPK/ERK with Smad3. As a consequence, halofuginone promoted myotube fusion, as reflected by an increased percentage of C2 and mdx myotubes containing high numbers of nuclei, and this was reversed by specific inhibitors of the PI3K and MAPK/ERK pathways. Together, the data suggest a role, either direct or via inhibition of Smad3 phosphorylation, for Akt or MAPK/ERK in halofuginone-enhanced myotube fusion, a feature which is crucial to improving muscle function in muscular dystrophies.

  17. Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

    Science.gov (United States)

    Ma, Dandan; Kou, Xiaoxing; Jin, Jing; Xu, Taotao; Wu, Mengjie; Deng, Liquan; Fu, Lusi; Liu, Yi; Wu, Gang; Lu, Haiping

    2016-01-01

    Reduced mechanical stimuli in many pathological cases, such as hemimastication and limited masticatory movements, can significantly affect the metabolic activity of mandibular condylar chondrocytes and the growth of mandibles. However, the molecular mechanisms for these phenomena remain unclear. In this study, we hypothesized that integrin-focal adhesion kinase (FAK)-ERK (extracellular signal–regulated kinase)/PI3K (phosphatidylinositol-3-kinase) signaling pathway mediated the cellular response of condylar chondrocytes to mechanical loading. Primary condylar chondrocytes were exposed to hydrostatic compressive forces (HCFs) of different magnitudes (0, 50, 100, 150, 200, and 250 kPa) for 2 h. We measured the viability, morphology, and apoptosis of the chondrocytes with different treatments as well as the gene, protein expression, and phosphorylation of mechanosensitivity-related molecules, such as integrin α2, integrin α5, integrin β1, FAK, ERK, and PI3K. HCFs could significantly increase the viability and surface area of condylar chondrocytes and decrease their apoptosis in a dose-dependent manner. HCF of 250 kPa resulted in a 1.51 ± 0.02-fold increase of cell viability and reduced the ratio of apoptotic cells from 18.10% ± 0.56% to 7.30% ± 1.43%. HCFs could significantly enhance the mRNA and protein expression of integrin α2, integrin α5, and integrin β1 in a dose-dependent manner, but not ERK1, ERK2, or PI3K. Instead, HCF could significantly increase phosphorylation levels of FAK, ERK1/2, and PI3K in a dose-dependent manner. Cilengitide, the potent integrin inhibitor, could dose-dependently block such effects of HCFs. HCFs enhances the viability and decreases the apoptosis of condylar chondrocytes through the integrin-FAK-ERK/PI3K pathway. PMID:27827993

  18. Conjugated linoleic acid induces human adipocyte delipidation: autocrine/paracrine regulation of MEK/ERK signaling by adipocytokines

    DEFF Research Database (Denmark)

    Brown, J Mark; Boysen, Maria Sandberg; Chung, Soonkyu

    2004-01-01

    of MEK/ERK could be attenuated by pretreatment with U0126 and pertussis toxin. In parallel, pretreatment with U0126 blocked the ability of trans-10, cis-12 CLA to alter gene expression and attenuate glucose and fatty acid uptake of the cultures. Intriguingly, the induction by CLA of MEK/ERK signaling...

  19. Src-independent ERK signaling through the rat α3 isoform of Na/K-ATPase.

    Science.gov (United States)

    Madan, Namrata; Xu, Yunhui; Duan, Qiming; Banerjee, Moumita; Larre, Isabel; Pierre, Sandrine V; Xie, Zijian

    2017-03-01

    The Na/K-ATPase α1 polypeptide supports both ion-pumping and signaling functions. The Na/K-ATPase α3 polypeptide differs from α1 in both its primary structure and its tissue distribution. The expression of α3 seems particularly important in neurons, and recent clinical evidence supports a unique role of this isoform in normal brain function. The nature of this specific role of α3 has remained elusive, because the ubiquitous presence of α1 has hindered efforts to characterize α3-specific functions in mammalian cell systems. Using Na/K-ATPase α1 knockdown pig kidney cells (PY-17), we generated the first stable mammalian cell line expressing a ouabain-resistant form of rat Na/K-ATPase α3 in the absence of endogenous pig α1 detectable by Western blotting. In these cells, Na/K-ATPase α3 formed a functional ion-pumping enzyme and rescued the expression of Na/K-ATPase β1 and caveolin-1 to levels comparable with those observed in PY-17 cells rescued with a rat Na/K-ATPase α1 (AAC-19). The α3-containing enzymes had lower Na + affinity and lower ouabain-sensitive transport activity than their α1-containing counterparts under basal conditions, but showed a greater capacity to be activated when intracellular Na + was increased. In contrast to Na/K-ATPase α1, α3 could not regulate Src. Upon exposure to ouabain, Src activation did not occur, yet ERK was activated through Src-independent pathways involving PI3K and PKC. Hence, α3 expression confers signaling and pumping properties that are clearly distinct from that of cells expressing Na/K-ATPase α1. Copyright © 2017 the American Physiological Society.

  20. Signaling transduction pathways involved in basophil adhesion and histamine release

    DEFF Research Database (Denmark)

    Sha, Quan; Poulsen, Lars K.; Gerwien, Jens

    2006-01-01

    Little is known about basophil with respect to the different signaling transduction pathways involved in spontaneous, cytokine or anti-IgE induced adhesion and how this compares to IgE-dependent and IgE-independent mediator secretion. The purpose of the present study was to investigate the roles...... of beta1 and beta2 integrins in basophil adhesion as well as hosphatidylinositol 3-kinase (PI3K), src-kinases and extracellular signal regulated kinase (ERK) 1/2 in basophil adhesion and histamine release (HR)....

  1. Urotensin II increases foam cell formation by repressing ABCA1 expression through the ERK/NF-κB pathway in THP-1 macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan [Department of Anesthesiology, The Second Affiliated Hospital of University of South China, Hengyang 421001, Hunan (China); Wu, Jian-Feng [Department of Cardiovascular Medicine, The Second Affiliated Hospital of University of South China, Hengyang 421001, Hunan (China); Tang, Yan-Yan; Zhang, Min; Li, Yuan [Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang 421001, Hunan (China); Chen, Kong; Zeng, Meng-Ya [Department of Cardiovascular Medicine, The Second Affiliated Hospital of University of South China, Hengyang 421001, Hunan (China); Yao, Feng; Xie, Wei [Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang 421001, Hunan (China); Zheng, Xi-Long [Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute of Alberta, University of Calgary, Health Sciences Center, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1 (Canada); Zeng, Gao-Feng, E-mail: qichingnudou@tom.com [Department of Cardiovascular Medicine, The Second Affiliated Hospital of University of South China, Hengyang 421001, Hunan (China); Tang, Chao-Ke, E-mail: tangchaoke@qq.com [Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang 421001, Hunan (China)

    2014-10-03

    Highlights: • U II reduces cholesterol efflux in THP-1 macrophages. • U II decreases the expression of ABCA1. • Inhibition of the ERK/NF-κB pathway reduces U II effects on ABCA1 expression and cholesterol efflux. - Abstract: Objective: Foam cell formation in the arterial wall plays a key role in the development of atherosclerosis. Recent studies showed that Urotensin II (U II) is involved in the pathogenesis of atherosclerosis. Here we examined the effects of human U II on ATP-binding cassette transporter A1 (ABCA1) expression and the underlying mechanism in THP-1 macrophages. Methods and results: Cultured THP-1 macrophages were treated with U II, followed by measuring the intracellular lipid contents, cholesterol efflux and ABCA1 levels. The results showed that U II dramatically decreased ABCA1 levels and impaired cholesterol efflux. However, the effects of U II on ABCA1 protein expression and cellular cholesterol efflux were partially reversed by inhibition of extracellular signal regulated kinase 1/2 (ERK1/2) and nuclear factor kappa B (NF-κB) activity, suggesting the potential roles of ERK1/2 and NF-κB in ABCA1 expression, respectively. Conclusion: Our current data indicate that U II may have promoting effects on the progression of atherosclerosis, likely through suppressing ABCA1 expression via activation of the ERK/NF-κB pathway and reducing cholesterol efflux to promote macrophage foam cell formation.

  2. PTK6 promotes cancer migration and invasion in pancreatic cancer cells dependent on ERK signaling.

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    Hiroaki Ono

    Full Text Available Protein Tyrosine Kinase 6 (PTK6 is a non-receptor type tyrosine kinase that may be involved in some cancers. However, the biological role and expression status of PTK6 in pancreatic cancer is unknown. Therefore in this study, we evaluated the functional role of PTK6 on pancreatic cancer invasion. Five pancreatic cancer cell lines expressed PTK6 at varying levels. PTK6 expression was also observed in human pancreatic adenocarcinomas. PTK6 suppression by siRNA significantly reduced both cellular migration and invasion (0.59/0.49 fold for BxPC3, 0.61/0.62 for Panc1, 0.42/0.39 for MIAPaCa2, respectively, p<0.05 for each. In contrast, forced overexpression of PTK6 by transfection of a PTK6 expression vector in Panc1 and MIAPaCa2 cells increased cellular migration and invasion (1.57/1.67 fold for Panc1, 1.44/1.57 for MIAPaCa2, respectively, p<0.05. Silencing PTK6 reduced ERK1/2 activation, but not AKT or STAT3 activation, while PTK6 overexpression increased ERK1/2 activation. U0126, a specific inhibitor of ERK1/2, completely abolished the effect of PTK6 overexpression on cellular migration and invasion. These results suggest that PTK6 regulates cellular migration and invasion in pancreatic cancer via ERK signaling. PTK6 may be a novel therapeutic target for pancreatic cancer.

  3. Robustness of MEK-ERK Dynamics and Origins of Cell-to-Cell Variability in MAPK Signaling

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    Sarah Filippi

    2016-06-01

    Full Text Available Cellular signaling processes can exhibit pronounced cell-to-cell variability in genetically identical cells. This affects how individual cells respond differentially to the same environmental stimulus. However, the origins of cell-to-cell variability in cellular signaling systems remain poorly understood. Here, we measure the dynamics of phosphorylated MEK and ERK across cell populations and quantify the levels of population heterogeneity over time using high-throughput image cytometry. We use a statistical modeling framework to show that extrinsic noise, particularly that from upstream MEK, is the dominant factor causing cell-to-cell variability in ERK phosphorylation, rather than stochasticity in the phosphorylation/dephosphorylation of ERK. We furthermore show that without extrinsic noise in the core module, variable (including noisy signals would be faithfully reproduced downstream, but the within-module extrinsic variability distorts these signals and leads to a drastic reduction in the mutual information between incoming signal and ERK activity.

  4. EXPRESSION AND SIGNIFICANCE OF ERK PROTEIN IN HUMAN BREAST CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    张秀梅; 李柏林; 宋敏; 宋继谒

    2004-01-01

    Objective: To investigate the expression of ERK and p-ERK protein in human breast cancer and their corresponding tissue, to assess the significance of ERK signal pathway in tumorigenesis and progression of breast carcinoma. Methods: 40 breast cancer cases were used in S-P immunohistochemistry technique and Western Blot study. Results: The expression of ERK1, ERK2, and p- ERK protein levels increased remarkably in breast cancer tissues in comparison to normal tissues (P<0.01). The expression was upregulated by 1.32-, 1.53-and 4.27-fold, respectively. The overexpressions of ERK1, ERK2, and p- ERK proteins were obviously correlated with clinical stage of breast cancer. Protein levels of ERK and p-ERK were higher in stage III patients than in stage I and stage II patients (P<0.05). These proteins were strongly related with axillary lymph node metastasis of breast cancer, but not correlated with histopathological type and status of ER and PR of breast cancer. Expression of ERK1, and ERK2, protein showed a positive linear correlation. Conclusion: ERK signal transduction pathway is a key factor during human breast tumorigenesis and breast cancer progression.

  5. Effects of exosomes derived from MDA-MB-231 on proliferation of endothelial cells and the role of MAPK/ERK and PI3K/Akt pathways

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    Shuang LONG

    2012-11-01

    Full Text Available Objective  To investigate the effects of exosomes derived from breast cancer cell line MDA-MB-231 on proliferation of human umbilical cord vein endothelial cells (HUVECs, and evaluate the role of MAPK/ERK and PI3K/Akt signal transduction pathway during the process. Methods  Exosomes were derived and purified from MDA-MB-231 by cryogenic ultracentrifugation and density gradient centrifugation. MTT assay was carried out for measurement of cell proliferation in HUVECs with exosome of 50, 100, 200 and 400μg/ml. The states of cell cycle of HUVECs co-cultured with 200μg/ml exosomes were detected by flow cytometry. The effects of 200μg/ml exosomes on the expression of ERK, Akt and phosphorylated ERK, Akt in HUVECs were detected with Western blotting. Results  Exosomes derived from MDA-MB-231 significantly promoted HUVECs proliferation in a classical time-and dose-dependent manner. Flow cytometry revealed that, co-cultured with 200μg/ml exosomes for 24h, S-phase cells in HUVECs increased, while G1/S phase cells in HUVECs decreased. Western blotting showed that, cocultured with 200μg/ml exosomes for 24h, 48h and 72h, the expressions of phosphorylated ERK and Akt were up-regulated in a time-dependent manner. Conclusion  Exosomes derived from breast cancer cell line MDA-MB-231 may promote HUVECs proliferation, the changes in cell cycle and the continuous activation of the MAPK/ERK and PI3K/Akt signal transduction pathways may be the underlying mechanism.

  6. Adenosine A2A receptor-dependent proliferation of pulmonary endothelial cells is mediated through calcium mobilization, PI3-kinase and ERK1/2 pathways

    International Nuclear Information System (INIS)

    Ahmad, Aftab; Schaack, Jerome B.; White, Carl W.; Ahmad, Shama

    2013-01-01

    Highlights: •A 2A receptor-induced pulmonary endothelial growth is mediated by PI3K and ERK1/2. •Cytosolic calcium mobilization is also critical for pulmonary endothelial growth. •Effectors of A 2A receptor, like tyrosine kinases and cAMP increase PI3K/Akt signaling. •Activation of A 2A receptor can contribute to vascular remodeling. -- Abstract: Hypoxia and HIF-2α-dependent A 2A receptor expression and activation increase proliferation of human lung microvascular endothelial cells (HLMVECs). This study was undertaken to investigate the signaling mechanisms that mediate the proliferative effects of A 2A receptor. A 2A receptor-mediated proliferation of HLMVECs was inhibited by intracellular calcium chelation, and by specific inhibitors of ERK1/2 and PI3-kinase (PI3K). The adenosine A 2A receptor agonist CGS21680 caused intracellular calcium mobilization in controls and, to a greater extent, in A 2A receptor-overexpressing HLMVECs. Adenoviral-mediated A 2A receptor overexpression as well as receptor activation by CGS21680 caused increased PI3K activity and Akt phosphorylation. Cells overexpressing A 2A receptor also manifested enhanced ERK1/2 phosphorylation upon CGS21680 treatment. A 2A receptor activation also caused enhanced cAMP production. Likewise, treatment with 8Br-cAMP increased PI3K activity. Hence A 2A receptor-mediated cAMP production and PI3K and Akt phosphorylation are potential mediators of the A 2A -mediated proliferative response of HLMVECs. Cytosolic calcium mobilization and ERK1/2 phosphorylation are other critical effectors of HLMVEC proliferation and growth. These studies underscore the importance of adenosine A 2A receptor in activation of survival and proliferative pathways in pulmonary endothelial cells that are mediated through PI3K/Akt and ERK1/2 pathways

  7. Comparison of growth factor signalling pathway utilisation in cultured normal melanocytes and melanoma cell lines

    International Nuclear Information System (INIS)

    Kim, Ji Eun; Stones, Clare; Joseph, Wayne R; Leung, Euphemia; Finlay, Graeme J; Shelling, Andrew N; Phillips, Wayne A; Shepherd, Peter R; Baguley, Bruce C

    2012-01-01

    The phosphatidylinositol-3-kinase (PI3K-PKB), mitogen activated protein kinase (MEK-ERK) and the mammalian target of rapamycin (mTOR- p70S6K), are thought to regulate many aspects of tumour cell proliferation and survival. We have examined the utilisation of these three signalling pathways in a number of cell lines derived from patients with metastatic malignant melanoma of known PIK3CA, PTEN, NRAS and BRAF mutational status. Western blotting was used to compare the phosphorylation status of components of the PI3K-PKB, MEK-ERK and mTOR-p70S6K signalling pathways, as indices of pathway utilisation. Normal melanocytes could not be distinguished from melanoma cells on the basis of pathway utilisation when grown in the presence of serum, but could be distinguished upon serum starvation, where signalling protein phosphorylation was generally abrogated. Surprisingly, the differential utilisation of individual pathways was not consistently associated with the presence of an oncogenic or tumour suppressor mutation of genes in these pathways. Utilisation of the PI3K-PKB, MEK-ERK and mTOR-p70S6K signalling pathways in melanoma, as determined by phosphorylation of signalling components, varies widely across a series of cell lines, and does not directly reflect mutation of genes coding these components. The main difference between cultured normal melanocytes and melanoma cells is not the pathway utilisation itself, but rather in the serum dependence of pathway utilisation

  8. Transcriptional Regulation of Δ6-Desaturase by Peroxisome Proliferative-Activated Receptor δ Agonist in Human Pancreatic Cancer Cells: Role of MEK/ERK1/2 Pathway

    Directory of Open Access Journals (Sweden)

    Maryam Darabi

    2013-01-01

    Full Text Available The Δ6-desaturase (Δ6D, also known as fatty acid desaturase 2, is a regulatory enzyme in de novo fatty acid synthesis, which has been linked to obesity and diabetes. The aim of the present study was to investigate the effect of peroxisome proliferative-activated receptor δ (PPARδ agonist and MEK/ERK1/2-dependent pathway on the expression of Δ6D in human pancreatic carcinoma cell line PANC-1. PANC-1 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and PPARδ agonist GW0742. Changes in mRNA and protein expression of Δ6D were then determined using real-time RT-PCR and Western blot, respectively. The expression of Δ6D (P40%, P25%, P<0.05 pretreatment. PPARδ and MEK/ERK1/2 signaling pathways affect differentially the expression of Δ6D in pancreatic cancer cells. Furthermore, there may be an inhibitory crosstalk between these two regulatory pathways on the mRNA expression of Δ6D and subsequently on Δ6D protein expression.

  9. MEK/ERK and p38 MAPK regulate chondrogenesis of rat bone marrow mesenchymal stem cells through delicate interaction with TGF-beta1/Smads pathway.

    Science.gov (United States)

    Li, J; Zhao, Z; Liu, J; Huang, N; Long, D; Wang, J; Li, X; Liu, Y

    2010-08-01

    This study was carried out to reveal functions and mechanisms of MEK/ERK and p38 pathways in chondrogenesis of rat bone marrow mesenchymal stem cells (BMSCs), and to investigate further any interactions between the mitogen-activated protein kinase (MAPK) and transforming growth factor-beta1 (TGF-beta1)/Smads pathway in the process. Chondrogenic differentiation of rat BMSCs was initiated in micromass culture, in the presence of TGF-beta1, for 2 weeks. ERK1/2 and p38 kinase activities were investigated by Western Blot analysis. Specific MAPK inhibitors PD98059 and SB20350 were employed to investigate regulatory effects of MEK/ERK and p38 signals on gene expression of chondrocyte-specific markers, and TGF-beta1 downstream pathways of Smad2/3. ERK1/2 was phosphorylated in a rapid but transient manner, whereas p38 was activated in a slow and sustained way. The two MAPK subtypes played opposing roles in mediating transcription of cartilage-specific genes for Col2alpha and aggrecan. TGF-beta1-stimulated gene expression of chondrogenic regulators, Sox9, Runx2 and Ihh, was also affected by activity of PD98059 and SB203580, to different degrees. However, influences of MAPK inhibitors on gene expression were relatively minor when not treated with TGF-beta1. In addition, gene transcription of Smad2/3 was significantly upregulated by TGF-beta1, but was regulated more subtly by treatment with MAPK inhibitors. MAPK subtypes seemed to regulate chondrogenesis with a delicate balance, interacting with the TGF-beta1/Smads signalling pathway.

  10. OCD-like behavior is caused by dysfunction of thalamo-amygdala circuits and upregulated TrkB/ERK-MAPK signaling as a result of SPRED2 deficiency.

    Science.gov (United States)

    Ullrich, M; Weber, M; Post, A M; Popp, S; Grein, J; Zechner, M; Guerrero González, H; Kreis, A; Schmitt, A G; Üçeyler, N; Lesch, K-P; Schuh, K

    2018-02-01

    Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disease affecting about 2% of the general population. It is characterized by persistent intrusive thoughts and repetitive ritualized behaviors. While gene variations, malfunction of cortico-striato-thalamo-cortical (CSTC) circuits, and dysregulated synaptic transmission have been implicated in the pathogenesis of OCD, the underlying mechanisms remain largely unknown. Here we show that OCD-like behavior in mice is caused by deficiency of SPRED2, a protein expressed in various brain regions and a potent inhibitor of Ras/ERK-MAPK signaling. Excessive self-grooming, reflecting OCD-like behavior in rodents, resulted in facial skin lesions in SPRED2 knockout (KO) mice. This was alleviated by treatment with the selective serotonin reuptake inhibitor fluoxetine. In addition to the previously suggested involvement of cortico-striatal circuits, electrophysiological measurements revealed altered transmission at thalamo-amygdala synapses and morphological differences in lateral amygdala neurons of SPRED2 KO mice. Changes in synaptic function were accompanied by dysregulated expression of various pre- and postsynaptic proteins in the amygdala. This was a result of altered gene transcription and triggered upstream by upregulated tropomyosin receptor kinase B (TrkB)/ERK-MAPK signaling in the amygdala of SPRED2 KO mice. Pathway overactivation was mediated by increased activity of TrkB, Ras, and ERK as a specific result of SPRED2 deficiency and not elicited by elevated brain-derived neurotrophic factor levels. Using the MEK inhibitor selumetinib, we suppressed TrkB/ERK-MAPK pathway activity in vivo and reduced OCD-like grooming in SPRED2 KO mice. Altogether, this study identifies SPRED2 as a promising new regulator, TrkB/ERK-MAPK signaling as a novel mediating mechanism, and thalamo-amygdala synapses as critical circuitry involved in the pathogenesis of OCD.

  11. CNS germinomas are characterized by global demethylation, chromosomal instability and mutational activation of the Kit-, Ras/Raf/Erk- and Akt-pathways

    Science.gov (United States)

    Schulte, Simone Laura; Waha, Andreas; Steiger, Barbara; Denkhaus, Dorota; Dörner, Evelyn; Calaminus, Gabriele; Leuschner, Ivo; Pietsch, Torsten

    2016-01-01

    CNS germinomas represent a unique germ cell tumor entity characterized by undifferentiated tumor cells and a high response rate to current treatment protocols. Limited information is available on their underlying genomic, epigenetic and biological alterations. We performed a genome-wide analysis of genomic copy number alterations in 49 CNS germinomas by molecular inversion profiling. In addition, CpG dinucleotide methylation was studied by immunohistochemistry for methylated cytosine residues. Mutational analysis was performed by resequencing of candidate genes including KIT and RAS family members. Ras/Erk and Akt pathway activation was analyzed by immunostaining with antibodies against phospho-Erk, phosho-Akt, phospho-mTOR and phospho-S6. All germinomas coexpressed Oct4 and Kit but showed an extensive global DNA demethylation compared to other tumors and normal tissues. Molecular inversion profiling showed predominant genomic instability in all tumors with a high frequency of regional gains and losses including high level gene amplifications. Activating mutations of KIT exons 11, 13, and 17 as well as a case with genomic KIT amplification and activating mutations or amplifications of RAS gene family members including KRAS, NRAS and RRAS2 indicated mutational activation of crucial signaling pathways. Co-activation of Ras/Erk and Akt pathways was present in 83% of germinomas. These data suggest that CNS germinoma cells display a demethylated nuclear DNA similar to primordial germ cells in early development. This finding has a striking coincidence with extensive genomic instability. In addition, mutational activation of Kit-, Ras/Raf/Erk- and Akt- pathways indicate the biological importance of these pathways and their components as potential targets for therapy. PMID:27391150

  12. Receptor for advanced glycation end products inhibits proliferation in osteoblast through suppression of Wnt, PI3K and ERK signaling

    International Nuclear Information System (INIS)

    Li, Guofeng; Xu, Jingren; Li, Zengchun

    2012-01-01

    Highlights: ► RAGE overexpression suppresses cell proliferation in MC3T3-E1 cells. ► RAGE overexpression decreases Wnt/β-catenin signaling. ► RAGE overexpression decreases ERK and PI3K signaling. ► Inhibition of Wnt signaling abolishes PI3K signaling restored by RAGE blockade. ► Inhibition of Wnt signaling abolishes ERK signaling restored by RAGE blockade. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a crucial role in bone metabolism. However, the role of RAGE in the control of osteoblast proliferation is not yet evaluated. In the present study, we demonstrate that RAGE overexpression inhibits osteoblast proliferation in vitro. The negative regulation of RAGE on cell proliferation results from suppression of Wnt, PI3K and ERK signaling, and is restored by RAGE neutralizing antibody. Prevention of Wnt signaling using Sfrp1 or DKK1 rescues RAGE-decreased PI3K and ERK signaling and cell proliferation, indicating that the altered cell growth in RAGE overexpressing cells is in part secondary to alterations in Wnt signaling. Consistently, RAGE overexpression inhibits the expression of Wnt targets cyclin D1 and c-myc, which is partially reversed by RAGE blockade. Overall, these results suggest that RAGE inhibits osteoblast proliferation via suppression of Wnt, PI3K and ERK signaling, which provides novel mechanisms by which RAGE regulates osteoblast growth.

  13. Receptor for advanced glycation end products inhibits proliferation in osteoblast through suppression of Wnt, PI3K and ERK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guofeng [Department of Emergency Surgery, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China); Xu, Jingren [Department of Traditional Chinese Orthopaedics, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China); Li, Zengchun, E-mail: lizc.2007@yahoo.com.cn [Department of Emergency Surgery, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer RAGE overexpression suppresses cell proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer RAGE overexpression decreases Wnt/{beta}-catenin signaling. Black-Right-Pointing-Pointer RAGE overexpression decreases ERK and PI3K signaling. Black-Right-Pointing-Pointer Inhibition of Wnt signaling abolishes PI3K signaling restored by RAGE blockade. Black-Right-Pointing-Pointer Inhibition of Wnt signaling abolishes ERK signaling restored by RAGE blockade. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a crucial role in bone metabolism. However, the role of RAGE in the control of osteoblast proliferation is not yet evaluated. In the present study, we demonstrate that RAGE overexpression inhibits osteoblast proliferation in vitro. The negative regulation of RAGE on cell proliferation results from suppression of Wnt, PI3K and ERK signaling, and is restored by RAGE neutralizing antibody. Prevention of Wnt signaling using Sfrp1 or DKK1 rescues RAGE-decreased PI3K and ERK signaling and cell proliferation, indicating that the altered cell growth in RAGE overexpressing cells is in part secondary to alterations in Wnt signaling. Consistently, RAGE overexpression inhibits the expression of Wnt targets cyclin D1 and c-myc, which is partially reversed by RAGE blockade. Overall, these results suggest that RAGE inhibits osteoblast proliferation via suppression of Wnt, PI3K and ERK signaling, which provides novel mechanisms by which RAGE regulates osteoblast growth.

  14. Transcutaneous electrical nerve stimulation attenuates CFA-induced hyperalgesia and inhibits spinal ERK1/2-COX-2 pathway activation in rats.

    Science.gov (United States)

    Fang, Jun-Fan; Liang, Yi; Du, Jun-Ying; Fang, Jian-Qiao

    2013-06-15

    Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacologic treatment for pain relief. In previous animal studies, TENS effectively alleviated Complete Freund's Adjuvant (CFA)- or carrageenan-induced inflammatory pain. Although TENS is known to produce analgesia via opioid activation in the brain and at the spinal level, few reports have investigated the signal transduction pathways mediated by TENS. Prior studies have verified the importance of the activation of extracellular signal-regulated kinase (ERK) signal transduction pathway in the spinal cord dorsal horn (SCDH) in acute and persistent inflammatory pains. Here, by using CFA rat model, we tested the efficacy of TENS on inhibiting the expressions of p-ERK1/2 and of its downstream cyclooxygenase-2 (COX-2) and the level of prostaglandin E2 (PGE2) at spinal level. Rats were randomly divided into control, model and TENS groups, and injected subcutaneously with 100 μl CFA or saline in the plantar surface of right hind paw. Rats in the TENS group were treated with TENS (constant aquare wave, 2 Hz and 100 Hz alternating frequencies, intensities ranging from 1 to 2 mA, lasting for 30 min each time) at 5 h and 24 h after injection. Paw withdrawal thresholds (PWTs) were measured with dynamic plantar aesthesiometer at 3d before modeling and 5 h, 6 h, and 25 h after CFA injection. The ipsilateral sides of the lumbar spinal cord dosral horns were harvested for detecting the expressions of p-ERK1/2 and COX-2 by western blot analysis and qPCR, and PGE2 by ELISA. CFA-induced periphery inflammation decreased PWTs and increased paw volume of rats. TENS treatment significantly alleviated mechanical hyperalgesia caused by CFA. However, no anti-inflammatory effect of TENS was observed. Expression of p-ERK1/2 protein and COX-2 mRNA was significantly up-regualted at 5 h and 6 h after CFA injection, while COX-2 and PGE2 protein level only increased at 6 h after modeling. Furthermore, the high expression of p-ERK1

  15. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling

    Directory of Open Access Journals (Sweden)

    Kai Wang

    2016-05-01

    Full Text Available Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ loci occludin and zona occludens (ZO-1. Confocal microscopy showed organized expressions in proteins related to TJ assembly, i.e., occludin and ZO-1, in response to PPE. Furthermore, PPE led to the activation of AMPK, ERK1/2, p38, and Akt. Using selective inhibitors, we found that the positive effects of PPE on barrier function were abolished in cells in which AMPK and ERK1/2 signaling were inhibited. Moreover, rats fed a diet supplemented with PPE (0.3% in the diet exhibited increased colonic epithelium ZO-1 expression. Overall, these data suggest that PPE strengthens intestinal barrier function by activating AMPK and ERK signaling and provide novel insights into the potential application of propolis for human gut health.

  16. Periodic mechanical stress activates EGFR-dependent Rac1 mitogenic signals in rat nucleus pulpous cells via ERK1/2

    International Nuclear Information System (INIS)

    Gao, Gongming; Shen, Nan; Jiang, Xuefeng; Sun, Huiqing; Xu, Nanwei; Zhou, Dong; Nong, Luming; Ren, Kewei

    2016-01-01

    The mitogenic effects of periodic mechanical stress on nucleus pulpous cells have been studied extensively but the mechanisms whereby nucleus pulpous cells sense and respond to mechanical stimulation remain a matter of debate. We explored this question by performing cell culture experiments in our self-developed periodic stress field and perfusion culture system. Under periodic mechanical stress, rat nucleus pulpous cell proliferation was significantly increased (p < 0.05 for each) and was associated with increases in the phosphorylation and activation of EGFR, Rac1, and ERK1/2 (p < 0.05 for each). Pretreatment with the ERK1/2 selective inhibitor PD98059 reduced periodic mechanical stress-induced nucleus pulpous cell proliferation (p < 0.05 for each), while the activation levels of EGFR and Rac1 were not inhibited. Proliferation and phosphorylation of ERK1/2 were inhibited after pretreatment with the Rac1 inhibitor NSC23766 in nucleus pulpous cells in response to periodic mechanical stress (p < 0.05 for each), while the phosphorylation site of EGFR was not affected. Inhibition of EGFR activity with AG1478 abrogated nucleus pulpous cell proliferation (p < 0.05 for each) and attenuated Rac1 and ERK1/2 activation in nucleus pulpous cells subjected to periodic mechanical stress (p < 0.05 for each). These findings suggest that periodic mechanical stress promotes nucleus pulpous cell proliferation in part through the EGFR-Rac1-ERK1/2 signaling pathway, which links these three important signaling molecules into a mitogenic cascade. - Highlights: • The mechanism involved in nucleus pulpous cells to respond to mechanical stimuli. • Periodic mechanical stress can stimulate the phosphorylation of EGFR. • EGFR activates Rac1 and leads to rat nucleus pulpous cell proliferation. • EGFR and Rac1 activate ERK1/2 mitogenic signals in nucleus pulpous cells. • EGFR-Rac1-ERK1/2 is constitutes at least one critical signal transduction pathway.

  17. Periodic mechanical stress activates EGFR-dependent Rac1 mitogenic signals in rat nucleus pulpous cells via ERK1/2

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Gongming [Department of Orthopedics, The Affiliated Changzhou No. 2 Hospital of Nanjing Medical University, Changzhou 213003 (China); Shen, Nan [Department of Clinical Pharmacy, The Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin 214400 (China); Jiang, Xuefeng; Sun, Huiqing [Department of Orthopedics, The Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin 214400 (China); Xu, Nanwei; Zhou, Dong [Department of Orthopedics, The Affiliated Changzhou No. 2 Hospital of Nanjing Medical University, Changzhou 213003 (China); Nong, Luming, E-mail: lumingnong@hotmail.com [Department of Orthopedics, The Affiliated Changzhou No. 2 Hospital of Nanjing Medical University, Changzhou 213003 (China); Ren, Kewei, E-mail: keweiren@hotmail.com [Department of Orthopedics, The Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin 214400 (China)

    2016-01-15

    The mitogenic effects of periodic mechanical stress on nucleus pulpous cells have been studied extensively but the mechanisms whereby nucleus pulpous cells sense and respond to mechanical stimulation remain a matter of debate. We explored this question by performing cell culture experiments in our self-developed periodic stress field and perfusion culture system. Under periodic mechanical stress, rat nucleus pulpous cell proliferation was significantly increased (p < 0.05 for each) and was associated with increases in the phosphorylation and activation of EGFR, Rac1, and ERK1/2 (p < 0.05 for each). Pretreatment with the ERK1/2 selective inhibitor PD98059 reduced periodic mechanical stress-induced nucleus pulpous cell proliferation (p < 0.05 for each), while the activation levels of EGFR and Rac1 were not inhibited. Proliferation and phosphorylation of ERK1/2 were inhibited after pretreatment with the Rac1 inhibitor NSC23766 in nucleus pulpous cells in response to periodic mechanical stress (p < 0.05 for each), while the phosphorylation site of EGFR was not affected. Inhibition of EGFR activity with AG1478 abrogated nucleus pulpous cell proliferation (p < 0.05 for each) and attenuated Rac1 and ERK1/2 activation in nucleus pulpous cells subjected to periodic mechanical stress (p < 0.05 for each). These findings suggest that periodic mechanical stress promotes nucleus pulpous cell proliferation in part through the EGFR-Rac1-ERK1/2 signaling pathway, which links these three important signaling molecules into a mitogenic cascade. - Highlights: • The mechanism involved in nucleus pulpous cells to respond to mechanical stimuli. • Periodic mechanical stress can stimulate the phosphorylation of EGFR. • EGFR activates Rac1 and leads to rat nucleus pulpous cell proliferation. • EGFR and Rac1 activate ERK1/2 mitogenic signals in nucleus pulpous cells. • EGFR-Rac1-ERK1/2 is constitutes at least one critical signal transduction pathway.

  18. Atorvastatin inhibits insulin synthesis by inhibiting the Ras/Raf/ERK/CREB pathway in INS-1 cells

    Science.gov (United States)

    Sun, Hongxi; Li, Yu; Sun, Bei; Hou, Ningning; Yang, Juhong; Zheng, Miaoyan; Xu, Jie; Wang, Jingyu; Zhang, Yi; Zeng, Xianwei; Shan, Chunyan; Chang, Bai; Chen, Liming; Chang, Baocheng

    2016-01-01

    Abstract Backround: Type 2 diabetes has become a global epidemic disease. Atorvastatin has become a cornerstone in the prevention and treatment of atherosclerosis. However, increasing evidence showed that statins can dose-dependently increase the risk of diabetes mellitus. The mechanism is not clear. Objective: The Ras complex pathway (Ras/Raf/extracellular signal-regulated kinase [ERK]/cAMP response element-binding protein [CREB]) is the major pathway that regulates the gene transcription. Except for the inhibition of cholesterol synthesis by inhibiting the 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-COA) reductase, statins can also downregulate the phosphorylation of a series of downstream substrates including the key proteins of the Ras complex pathway, therefore may inhibit the insulin syntheses in pancreatic beta cells. In our study, we investigated the inhibitory effect and the underlying mechanism of atorvastatin on insulin synthesis in rat islets. Methods: Islets were isolated from Wistar rats and cultured in Roswell Park Memorial Institute (RPMI)-1640 medium. The insulin content in the medium was measured by radioimmunoassay before and after the treatment of 50 μM atorvastatin. Effect of atorvastatin on the expression of insulin message Ribonucleic acid (mRNA) in pancreatic islet beta cells was also detected using quantitative real-time polymerase chain reaction. Western blotting was used to explore the possible role of the Ras complex pathway (Ras/Raf/ERK/CREB) in atorvastatin-inhibited insulin synthesis. The effects of atorvastatin on the binding of nuclear transcription factor p-CREB with CRE in INS-1 cells were examined via chromatin immunoprecipitation assay. Results: Compared with the control group, the insulin level decreased by 27.1% at 24 hours after atorvastatin treatment. Atorvastatin inhibited insulin synthesis by decreasing insulin mRNA expression of pancreatic islet beta cells. The activities of Ras, Raf-1, and p-CREB in the Ras complex

  19. Inhibition of host extracellular signal-regulated kinase (ERK) activation decreases new world alphavirus multiplication in infected cells

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Kelsey; Amaya, Moushimi [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States); Mueller, Claudius [Center for Applied Proteomics and Personalized Medicine, George Mason University, 10900 University Boulevard, Manassas, VA (United States); Roberts, Brian [Leidos Health Life Sciences, 5202 Presidents Court, Suite 110, Frederick, MD (United States); Kehn-Hall, Kylene; Bailey, Charles [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States); Petricoin, Emanuel [Center for Applied Proteomics and Personalized Medicine, George Mason University, 10900 University Boulevard, Manassas, VA (United States); Narayanan, Aarthi, E-mail: anaraya1@gmu.edu [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States)

    2014-11-15

    New World alphaviruses belonging to the family Togaviridae are classified as emerging infectious agents and Category B select agents. Our study is focused on the role of the host extracellular signal-regulated kinase (ERK) in the infectious process of New World alphaviruses. Infection of human cells by Venezuelan equine encephalitis virus (VEEV) results in the activation of the ERK-signaling cascade. Inhibition of ERK1/2 by the small molecule inhibitor Ag-126 results in inhibition of viral multiplication. Ag-126-mediated inhibition of VEEV was due to potential effects on early and late stages of the infectious process. While expression of viral proteins was down-regulated in Ag-126 treated cells, we did not observe any influence of Ag-126 on the nuclear distribution of capsid. Finally, Ag-126 exerted a broad-spectrum inhibitory effect on New World alphavirus multiplication, thus indicating that the host kinase, ERK, is a broad-spectrum candidate for development of novel therapeutics against New World alphaviruses. - Highlights: • VEEV infection activated multiple components of the ERK signaling cascade. • Inhibition of ERK activation using Ag-126 inhibited VEEV multiplication. • Activation of ERK by Ceramide C6 increased infectious titers of TC-83. • Ag-126 inhibited virulent strains of all New World alphaviruses. • Ag-126 treatment increased percent survival of infected cells.

  20. Inhibition of host extracellular signal-regulated kinase (ERK) activation decreases new world alphavirus multiplication in infected cells

    International Nuclear Information System (INIS)

    Voss, Kelsey; Amaya, Moushimi; Mueller, Claudius; Roberts, Brian; Kehn-Hall, Kylene; Bailey, Charles; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    New World alphaviruses belonging to the family Togaviridae are classified as emerging infectious agents and Category B select agents. Our study is focused on the role of the host extracellular signal-regulated kinase (ERK) in the infectious process of New World alphaviruses. Infection of human cells by Venezuelan equine encephalitis virus (VEEV) results in the activation of the ERK-signaling cascade. Inhibition of ERK1/2 by the small molecule inhibitor Ag-126 results in inhibition of viral multiplication. Ag-126-mediated inhibition of VEEV was due to potential effects on early and late stages of the infectious process. While expression of viral proteins was down-regulated in Ag-126 treated cells, we did not observe any influence of Ag-126 on the nuclear distribution of capsid. Finally, Ag-126 exerted a broad-spectrum inhibitory effect on New World alphavirus multiplication, thus indicating that the host kinase, ERK, is a broad-spectrum candidate for development of novel therapeutics against New World alphaviruses. - Highlights: • VEEV infection activated multiple components of the ERK signaling cascade. • Inhibition of ERK activation using Ag-126 inhibited VEEV multiplication. • Activation of ERK by Ceramide C6 increased infectious titers of TC-83. • Ag-126 inhibited virulent strains of all New World alphaviruses. • Ag-126 treatment increased percent survival of infected cells

  1. MEK-ERK pathway modulation ameliorates disease phenotypes in a mouse model of Noonan syndrome associated with the Raf1L613V mutation

    Science.gov (United States)

    Wu, Xue; Simpson, Jeremy; Hong, Jenny H.; Kim, Kyoung-Han; Thavarajah, Nirusha K.; Backx, Peter H.; Neel, Benjamin G.; Araki, Toshiyuki

    2011-01-01

    Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden death in children and young adults. Abnormalities in several signaling pathways are implicated in the pathogenesis of HCM, but the role of the RAS-RAF-MEK-ERK MAPK pathway has been controversial. Noonan syndrome (NS) is one of several autosomal-dominant conditions known as RASopathies, which are caused by mutations in different components of this pathway. Germline mutations in RAF1 (which encodes the serine-threonine kinase RAF1) account for approximately 3%–5% of cases of NS. Unlike other NS alleles, RAF1 mutations that confer increased kinase activity are highly associated with HCM. To explore the pathogenesis of such mutations, we generated knockin mice expressing the NS-associated Raf1L613V mutation. Like NS patients, mice heterozygous for this mutation (referred to herein as L613V/+ mice) had short stature, craniofacial dysmorphia, and hematologic abnormalities. Valvuloseptal development was normal, but L613V/+ mice exhibited eccentric cardiac hypertrophy and aberrant cardiac fetal gene expression, and decompensated following pressure overload. Agonist-evoked MEK-ERK activation was enhanced in multiple cell types, and postnatal MEK inhibition normalized the growth, facial, and cardiac defects in L613V/+ mice. These data show that different NS genes have intrinsically distinct pathological effects, demonstrate that enhanced MEK-ERK activity is critical for causing HCM and other RAF1-mutant NS phenotypes, and suggest a mutation-specific approach to the treatment of RASopathies. PMID:21339642

  2. Fucoxanthin prevents H2O2-induced neuronal apoptosis via concurrently activating the PI3-K/Akt cascade and inhibiting the ERK pathway.

    Science.gov (United States)

    Yu, Jie; Lin, Jia-Jia; Yu, Rui; He, Shan; Wang, Qin-Wen; Cui, Wei; Zhang, Jin-Rong

    2017-01-01

    Background : As a natural carotenoid abundant in chloroplasts of edible brown algae, fucoxanthin possesses various health benefits, including anti-oxidative activity in particular. Objective : In the present study, we studied whether fucoxanthin protected against hydrogen peroxide (H 2 O 2 )-induced neuronal apoptosis. Design : The neuroprotective effects of fucoxanthin on H 2 O 2 -induced toxicity were studied in both SH-SY5Y cells and primary cerebellar granule neurons. Results : Fucoxanthin significantly protected against H 2 O 2 -induced neuronal apoptosis and intracellular reactive oxygen species. H 2 O 2 treatment led to the reduced activity of phosphoinositide 3-kinase (PI3-K)/Akt cascade and the increased activity of extracellular signal-regulated kinase (ERK) pathway in SH-SY5Y cells. Moreover, fucoxanthin significantly restored the altered activities of PI3-K/Akt and ERK pathways induced by H 2 O 2 . Both specific inhibitors of glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase kinase (MEK) significantly protected against H 2 O 2 -induced neuronal death. Furthermore, the neuroprotective effects of fucoxanthin against H 2 O 2 -induced neuronal death were abolished by specific PI3-K inhibitors. Conclusions : Our data strongly revealed that fucoxanthin protected against H 2 O 2 -induced neurotoxicity via concurrently activating the PI3-K/Akt cascade and inhibiting the ERK pathway, providing support for the use of fucoxanthin to treat neurodegenerative disorders induced by oxidative stress.

  3. PHO-ERK1/2 interaction with mitochondria regulates the permeability transition pore in cardioprotective signaling.

    Science.gov (United States)

    Hernández-Reséndiz, Sauri; Zazueta, Cecilia

    2014-07-11

    The molecular mechanism(s) by which extracellular signal-regulated kinase 1/2 (ERK1/2) and other kinases communicate with downstream targets have not been fully determined. Multiprotein signaling complexes undergoing spatiotemporal redistribution may enhance their interaction with effector proteins promoting cardioprotective response. Particularly, it has been proposed that some active kinases in association with caveolae may converge into mitochondria. Therefore, in this study we investigate if PHO-ERK1/2 interaction with mitochondria may provide a mechanistic link in the regulation of these organelles in cardioprotective signaling. Using a model of dilated cardiomyopathy followed by ischemia-reperfusion injury, we determined ERK1/2 signaling at the level of mitochondria and evaluated its effect on the permeability transition pore. The most important finding of the present study is that, under cardioprotective conditions, a subpopulation of activated ERK1/2 was directed to the mitochondrial membranes through vesicular trafficking, concurring with increased phosphorylation of mitochondrial proteins and inhibition of the mitochondrial permeability transition pore opening. In addition, our results suggest that vesicles enriched with caveolin-3 could form structures that may drive ERK1/2, GSK3β and Akt to mitochondria. Signaling complexes including PHO-ERK, PHO-Akt, PHO-eNOS and caveolin-3 contribute to cardioprotection by directly targeting the mitochondrial proteome and regulating the opening of the permeability transition pore in this model. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Exposure to a specific time-varying electromagnetic field inhibits cell proliferation via cAMP and ERK signaling in cancer cells.

    Science.gov (United States)

    Buckner, Carly A; Buckner, Alison L; Koren, Stan A; Persinger, Michael A; Lafrenie, Robert M

    2018-04-01

    Exposure to specific electromagnetic field (EMF) patterns can affect a variety of biological systems. We have shown that exposure to Thomas-EMF, a low-intensity, frequency-modulated (25-6 Hz) EMF pattern, inhibited growth and altered cell signaling in malignant cells. Exposure to Thomas-EMF for 1 h/day inhibited the growth of malignant cells including B16-BL6 mouse melanoma cells, MDA-MB-231, MDA-MB-468, BT-20, and MCF-7 human breast cancer and HeLa cervical cancer cells but did not affect non-malignant cells. The Thomas-EMF-dependent changes in cell proliferation were mediated by adenosine 3',5'-cyclic monophosphate (cAMP) and extracellular-signal-regulated kinase (ERK) signaling pathways. Exposure of malignant cells to Thomas-EMF transiently changed the level of cellular cAMP and promoted ERK phosphorylation. Pharmacologic inhibitors (SQ22536) and activators (forskolin) of cAMP production both blocked the ability of Thomas-EMF to inhibit cell proliferation, and an inhibitor of the MAP kinase pathway (PD98059) was able to partially block Thomas-EMF-dependent inhibition of cell proliferation. Genetic modulation of protein kinase A (PKA) in B16-BL6 cells also altered the effect of Thomas-EMF on cell proliferation. Cells transfected with the constitutively active form of PKA (PKA-CA), which interfered with ERK phosphorylation, also interfered with the Thomas-EMF effect on cell proliferation. The non-malignant cells did not show any EMF-dependent changes in cAMP levels, ERK phosphorylation, or cell growth. These data indicate that exposure to the specific Thomas-EMF pattern can inhibit the growth of malignant cells in a manner dependent on contributions from the cAMP and MAP kinase pathways. Bioelectromagnetics. 39;217-230, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ping, E-mail: lping@sdu.edu.cn [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China); Kong, Feng; Wang, Jue [Central Laboratory, The Second Hospital of Shandong University, Shandong, Jinan 250033 (China); Lu, Qinghua [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China); Xu, Haijia [Department of Cardiology, Wendeng Central Hospital of Weihai City, Shandong, Weihai 264400 (China); Qi, Tonggang [Central Laboratory, The Second Hospital of Shandong University, Shandong, Jinan 250033 (China); Meng, Juan [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China)

    2015-02-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  6. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    International Nuclear Information System (INIS)

    Liu, Ping; Kong, Feng; Wang, Jue; Lu, Qinghua; Xu, Haijia; Qi, Tonggang; Meng, Juan

    2015-01-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  7. Altered ERK1/2 Signaling in the Brain of Learned Helpless Rats: Relevance in Vulnerability to Developing Stress-Induced Depression

    Directory of Open Access Journals (Sweden)

    Yogesh Dwivedi

    2016-01-01

    Full Text Available Extracellular signal-regulated kinase 1/2- (ERK1/2- mediated cellular signaling plays a major role in synaptic and structural plasticity. Although ERK1/2 signaling has been shown to be involved in stress and depression, whether vulnerability to develop depression is associated with abnormalities in ERK1/2 signaling is not clearly known. The present study examined ERK1/2 signaling in frontal cortex and hippocampus of rats that showed vulnerability (learned helplessness, (LH or resiliency (non-learned helplessness, (non-LH to developing stress-induced depression. In frontal cortex and hippocampus of LH rats, we found that mRNA and protein expressions of ERK1 and ERK2 were significantly reduced, which was associated with their reduced activation and phosphorylation in cytosolic and nuclear fractions, where ERK1 and ERK2 target their substrates. In addition, ERK1/2-mediated catalytic activities and phosphorylation of downstream substrates RSK1 (cytosolic and nuclear and MSK1 (nuclear were also lower in the frontal cortex and hippocampus of LH rats without any change in their mRNA or protein expression. None of these changes were evident in non-LH rats. Our study indicates that ERK1/2 signaling is differentially regulated in LH and non-LH rats and suggests that abnormalities in ERK1/2 signaling may be crucial in the vulnerability to developing depression.

  8. Urotensin II inhibits skeletal muscle glucose transport signaling pathways via the NADPH oxidase pathway.

    Directory of Open Access Journals (Sweden)

    Hong-Xia Wang

    Full Text Available Our previous studies have demonstrated that the urotensin (UII and its receptor are up-regulated in the skeletal muscle of mice with type II diabetes mellitus (T2DM, but the significance of UII in skeletal muscle insulin resistance remains unknown. The purpose of this study was to investigate the effect of UII on NADPH oxidase and glucose transport signaling pathways in the skeletal muscle of mice with T2DM and in C2C12 mouse myotube cells. KK/upj-AY/J mice (KK mice were divided into the following groups: KK group, with saline treatment for 2 weeks; KK+ urantide group, with daily 30 µg/kg body weight injections over the same time period of urantide, a potent urotensin II antagonist peptide; Non-diabetic C57BL/6J mice were used as normal controls. After urantide treatment, mice were subjected to an intraperitoneal glucose tolerance test, in addition to measurements of the levels of ROS, NADPH oxidase and the phosphorylated AKT, PKC and ERK. C2C12 cells were incubated with serum-free DMEM for 24 hours before conducting the experiments, and then administrated with 100 nM UII for 2 hours or 24 hours. Urantide treatment improved glucose tolerance, decreased the translocation of the NADPH subunits p40-phox and p47-phox, and increased levels of the phosphorylated PKC, AKT and ERK. In contrast, UII treatment increased ROS production and p47-phox and p67-phox translocation, and decreased the phosphorylated AKT, ERK1/2 and p38MAPK; Apocynin abrogated this effect. In conclusion, UII increased ROS production by NADPH oxidase, leading to the inhibition of signaling pathways involving glucose transport, such as AKT/PKC/ERK. Our data imply a role for UII at the molecular level in glucose homeostasis, and possibly in skeletal muscle insulin resistance in T2DM.

  9. Gene network analysis shows immune-signaling and ERK1/2 as novel genetic markers for multiple addiction phenotypes: alcohol, smoking and opioid addiction.

    Science.gov (United States)

    Reyes-Gibby, Cielito C; Yuan, Christine; Wang, Jian; Yeung, Sai-Ching J; Shete, Sanjay

    2015-06-05

    Addictions to alcohol and tobacco, known risk factors for cancer, are complex heritable disorders. Addictive behaviors have a bidirectional relationship with pain. We hypothesize that the associations between alcohol, smoking, and opioid addiction observed in cancer patients have a genetic basis. Therefore, using bioinformatics tools, we explored the underlying genetic basis and identified new candidate genes and common biological pathways for smoking, alcohol, and opioid addiction. Literature search showed 56 genes associated with alcohol, smoking and opioid addiction. Using Core Analysis function in Ingenuity Pathway Analysis software, we found that ERK1/2 was strongly interconnected across all three addiction networks. Genes involved in immune signaling pathways were shown across all three networks. Connect function from IPA My Pathway toolbox showed that DRD2 is the gene common to both the list of genetic variations associated with all three addiction phenotypes and the components of the brain neuronal signaling network involved in substance addiction. The top canonical pathways associated with the 56 genes were: 1) calcium signaling, 2) GPCR signaling, 3) cAMP-mediated signaling, 4) GABA receptor signaling, and 5) G-alpha i signaling. Cancer patients are often prescribed opioids for cancer pain thus increasing their risk for opioid abuse and addiction. Our findings provide candidate genes and biological pathways underlying addiction phenotypes, which may be future targets for treatment of addiction. Further study of the variations of the candidate genes could allow physicians to make more informed decisions when treating cancer pain with opioid analgesics.

  10. DMPD: Signal integration between IFNgamma and TLR signalling pathways in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16920490 Signal integration between IFNgamma and TLR signalling pathways in macroph...tml) (.csml) Show Signal integration between IFNgamma and TLR signalling pathways in macrophages. PubmedID 16920490 Title Signal inte...gration between IFNgamma and TLR signalling pathways in

  11. Neuronal Orphan G-Protein Coupled Receptor Proteins Mediate Plasmalogens-Induced Activation of ERK and Akt Signaling.

    Directory of Open Access Journals (Sweden)

    Md Shamim Hossain

    Full Text Available The special glycerophospholipids plasmalogens (Pls are enriched in the brain and reported to prevent neuronal cell death by enhancing phosphorylation of Akt and ERK signaling in neuronal cells. Though the activation of Akt and ERK was found to be necessary for the neuronal cells survival, it was not known how Pls enhanced cellular signaling. To answer this question, we searched for neuronal specific orphan GPCR (G-protein coupled receptor proteins, since these proteins were believed to play a role in cellular signal transduction through the lipid rafts, where both Pls and some GPCRs were found to be enriched. In the present study, pan GPCR inhibitor significantly reduced Pls-induced ERK signaling in neuronal cells, suggesting that Pls could activate GPCRs to induce signaling. We then checked mRNA expression of 19 orphan GPCRs and 10 of them were found to be highly expressed in neuronal cells. The knockdown of these 10 neuronal specific GPCRs by short hairpin (sh-RNA lentiviral particles revealed that the Pls-mediated phosphorylation of ERK was inhibited in GPR1, GPR19, GPR21, GPR27 and GPR61 knockdown cells. We further found that the overexpression of these GPCRs enhanced Pls-mediated phosphorylation of ERK and Akt in cells. Most interestingly, the GPCRs-mediated cellular signaling was reduced significantly when the endogenous Pls were reduced. Our cumulative data, for the first time, suggest a possible mechanism for Pls-induced cellular signaling in the nervous system.

  12. Stretch activates human myometrium via ERK, caldesmon and focal adhesion signaling.

    Directory of Open Access Journals (Sweden)

    Yunping Li

    2009-10-01

    Full Text Available An incomplete understanding of the molecular mechanisms responsible for myometrial activation from the quiescent pregnant state to the active contractile state during labor has hindered the development of effective therapies for preterm labor. Myometrial stretch has been implicated clinically in the initiation of labor and the etiology of preterm labor, but the molecular mechanisms involved in the human have not been determined. We investigated the mechanisms by which gestation-dependent stretch contributes to myometrial activation, by using human uterine samples from gynecologic hysterectomies and Cesarean sections. Here we demonstrate that the Ca requirement for activation of the contractile filaments in human myometrium increases with caldesmon protein content during gestation and that an increase in caldesmon phosphorylation can reverse this inhibitory effect during labor. By using phosphotyrosine screening and mass spectrometry of stretched human myometrial samples, we identify 3 stretch-activated focal adhesion proteins, FAK, p130Cas, and alpha actinin. FAK-Y397, which signals integrin engagement, is constitutively phosphorylated in term human myometrium whereas FAK-Y925, which signals downstream ERK activation, is phosphorylated during stretch. We have recently identified smooth muscle Archvillin (SmAV as an ERK regulator. A newly produced SmAV-specific antibody demonstrates gestation-specific increases in SmAV protein levels and stretch-specific increases in SmAV association with focal adhesion proteins. Thus, whereas increases in caldesmon levels suppress human myometrium contractility during pregnancy, stretch-dependent focal adhesion signaling, facilitated by the ERK activator SmAV, can contribute to myometrial activation. These results suggest that focal adhesion proteins may present new targets for drug discovery programs aimed at regulation of uterine contractility.

  13. GLP-1 signals via ERK in peripheral nerve and prevents nerve dysfunction in diabetic mice

    DEFF Research Database (Denmark)

    Jolivalt, CG; Fineman, M; Deacon, Carolyn F.

    2011-01-01

    not affect blood sugar, insulin levels or paw thermal response latencies in either control or diabetic mice. However, the reductions of motor nerve conduction velocity and paw intraepidermal fibre density seen in diabetic mice were attenuated by exenatide treatment. Conclusions: These data show...... that the peripheral nerve of diabetic rodents exhibits functional GLP-1R and suggest that GLP-1R-mediated ERK-signalling in sciatic nerve of diabetic rodents may protect large motor fibre function and small C fibre structure by a mechanism independent of glycaemic control....

  14. Indirubin-3-Oxime Prevents H2O2-Induced Neuronal Apoptosis via Concurrently Inhibiting GSK3β and the ERK Pathway.

    Science.gov (United States)

    Yu, Jie; Zheng, Jiacheng; Lin, Jiajia; Jin, Linlu; Yu, Rui; Mak, Shinghung; Hu, Shengquan; Sun, Hongya; Wu, Xiang; Zhang, Zaijun; Lee, Mingyuen; Tsim, Wahkeung; Su, Wei; Zhou, Wenhua; Cui, Wei; Han, Yifan; Wang, Qinwen

    2017-05-01

    Oxidative stress-induced neuronal apoptosis plays an important role in many neurodegenerative disorders. In this study, we have shown that indirubin-3-oxime, a derivative of indirubin originally designed for leukemia therapy, could prevent hydrogen peroxide (H 2 O 2 )-induced apoptosis in both SH-SY5Y cells and primary cerebellar granule neurons. H 2 O 2 exposure led to the increased activities of glycogen synthase kinase 3β (GSK3β) and extracellular signal-regulated kinase (ERK) in SH-SY5Y cells. Indirubin-3-oxime treatment significantly reversed the altered activity of both the PI3-K/Akt/GSK3β cascade and the ERK pathway induced by H 2 O 2 . In addition, both GSK3β and mitogen-activated protein kinase inhibitors significantly prevented H 2 O 2 -induced neuronal apoptosis. Moreover, specific inhibitors of the phosphoinositide 3-kinase (PI3-K) abolished the neuroprotective effects of indirubin-3-oxime against H 2 O 2 -induced neuronal apoptosis. These results strongly suggest that indirubin-3-oxime prevents H 2 O 2 -induced apoptosis via concurrent inhibiting GSK3β and the ERK pathway in SH-SY5Y cells, providing support for the use of indirubin-3-oxime to treat neurodegenerative disorders caused or exacerbated by oxidative stress.

  15. Interstitial Fluid Flow Increases Hepatocellular Carcinoma Cell Invasion through CXCR4/CXCL12 and MEK/ERK Signaling

    Science.gov (United States)

    2015-01-01

    Hepatocellular carcinoma (HCC) is the most common form of liver cancer (~80%), and it is one of the few cancer types with rising incidence in the United States. This highly invasive cancer is very difficult to detect until its later stages, resulting in limited treatment options and low survival rates. There is a dearth of knowledge regarding the mechanisms associated with the effects of biomechanical forces such as interstitial fluid flow (IFF) on hepatocellular carcinoma invasion. We hypothesized that interstitial fluid flow enhanced hepatocellular carcinoma cell invasion through chemokine-mediated autologous chemotaxis. Utilizing a 3D in vitro invasion assay, we demonstrated that interstitial fluid flow promoted invasion of hepatocellular carcinoma derived cell lines. Furthermore, we showed that autologous chemotaxis influences this interstitial fluid flow-induced invasion of hepatocellular carcinoma derived cell lines via the C-X-C chemokine receptor type 4 (CXCR4)/C-X-C motif chemokine 12 (CXCL12) signaling axis. We also demonstrated that mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling affects interstitial fluid flow-induced invasion; however, this pathway was separate from CXCR4/CXCL12 signaling. This study demonstrates, for the first time, the potential role of interstitial fluid flow in hepatocellular carcinoma invasion. Uncovering the mechanisms that control hepatocellular carcinoma invasion will aid in enhancing current liver cancer therapies and provide better treatment options for patients. PMID:26560447

  16. Urotensin II contributes to collagen synthesis and up-regulates Egr-1 expression in cultured pulmonary arterial smooth muscle cells through the ERK1/2 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [Biomedical Engineering Institute, School of Control Science and Engineering, Shandong University, Jinan 250061 (China); Cai, Zhifeng; Liu, Mengmeng [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan 250012 (China); Zhao, Cuifen, E-mail: zhaocuifen@sdu.edu.cn [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan 250012 (China); Li, Dong [Research Room of Hypothermia Medicine, Qilu Hospital, Shandong University, Jinan 250012 (China); Lv, Chenguang; Wang, Yuping; Xu, Tengfei [Biomedical Engineering Institute, School of Control Science and Engineering, Shandong University, Jinan 250061 (China)

    2015-11-27

    Aim: The objective of this study was to investigate the effects of urotensin II (UII) treatment on the proliferation and collagen synthesis of cultured rat pulmonary arterial smooth muscle cells (PASMCs) and to explore whether these effects are mediated by mitogen-activated protein kinase (MAPK) signaling pathways and early growth response 1 (Egr-1). Methods: The proliferation of cultured PASMCs stimulated with different doses of UII was detected by BrdU incorporation. The mRNA expression levels of procollagen I (procol I), procollagen III (procol III), extracellular regulated protein kinase 1/2 (ERK1/2), stress-stimulated protein kinase (Sapk), p38 MAPK (p38), and Egr-1 mRNA in cultured PASMCs after treatment with UII, the UII-specific antagonist urantide, and the ERK1/2 inhibitor PD98059 were detected by real-time polymerase chain reaction (PCR), and the protein expression levels of procol I, procol III, phosphorylated (p)-ERK1/2, p-Sapk, p-p38, and Egr-1 were detected by Western blotting. Results: Treatment with UII increased the proliferation of cultured PASMCs in a dose-dependent manner (P < 0.05). However, treatment with urantide and PD98059 inhibited the promoting effect of UII on PASMC proliferation (P < 0.05). Real-time PCR analysis showed that UII up-regulated the expression of procol I, procol III, ERK1/2, Sapk, and Egr-1 mRNA (P < 0.05), but not p38 mRNA. However, the up-regulating effect of UII was inhibited by PD98059 and urantide. Western blotting analysis showed that UII increased the synthesis of collagen I, collagen III, p-ERK1/2, p-Sapk, and Egr-1, and these effects also were inhibited by PD98059 and urantide (P < 0.05). Conclusions: Egr-1 participates in the UII-mediated proliferation and collagen synthesis of cultured rat PASMCs via activation of the ERK1/2 signaling pathway.

  17. Panax ginseng total protein promotes proliferation and secretion of collagen in NIH/3T3 cells by activating extracellular signal-related kinase pathway

    Directory of Open Access Journals (Sweden)

    Xuenan Chen

    2017-07-01

    Conclusion: Our studies suggest that GTP promoted proliferation and secretion of collagen in NIH/3T3 cells by activating the ERK signal pathway, which shed light on a potential function of GTP in promoting wound healing.

  18. Release of overexpressed CypB activates ERK signaling through CD147 binding for hepatoma cell resistance to oxidative stress.

    Science.gov (United States)

    Kim, Kiyoon; Kim, Hunsung; Jeong, Kwon; Jung, Min Hyung; Hahn, Bum-Soo; Yoon, Kyung-Sik; Jin, Byung Kwan; Jahng, Geon-Ho; Kang, Insug; Ha, Joohun; Choe, Wonchae

    2012-08-01

    Cyclophilin, a cytosolic receptor for the immunosuppressive drug cyclosporin A, plays a role in diverse pathophysiologies along with its receptor, CD147. Although the interaction between cyclophilin A and CD147 is well established in inflammatory disease, that of cyclophilin B (CypB) with CD147 has not been fully explored, especially in cancer cell biology, and the exact molecular mechanism underlying such an association is poorly understood. In this study, we first identified high expression levels of CypB in 54 % of hepatocellular carcinoma patient tissues but in only 12.5 % of normal liver tissues. Then, we demonstrated that CypB overexpression protects human hepatoma cells against oxidative stress through its binding to CD147; this protective effect depends on the peptidyl prolyl isomerase activity of CypB. siRNA-mediated knockdown of CypB expression rendered hepatoma cells more vulnerable to ROS-mediated apoptosis. Furthermore, we also determined that a direct interaction between secreted CypB and CD147 regulates the extracellular signal-regulated kinase intracellular signaling pathway and is indispensible for the protective functions of CypB. For the first time, we demonstrated that CypB has an essential function in protecting hepatoma cells against oxidative stress through binding to CD147 and regulating the ERK pathway.

  19. Induction of keratinocyte migration by ECa 233 is mediated through FAK/Akt, ERK, and p38 MAPK signaling.

    Science.gov (United States)

    Singkhorn, Sawana; Tantisira, Mayuree H; Tanasawet, Supita; Hutamekalin, Pilaiwanwadee; Wongtawatchai, Tulaporn; Sukketsiri, Wanida

    2018-03-13

    Centella asiatica is widely considered the most important medicinal plant for treating and relieving skin diseases. Recently developed standardized extract of Centella asiatica ECa 233 has demonstrated positive effects on wound healing of incision and burn wound in rats. However, knowledge associated with wound healing mechanism of ECa 233 was scare. Therefore, this study aimed to investigate the effect and underlying molecular mechanisms of ECa 233 on the migration of a human keratinocyte cell line (HaCaT) using scratch wound healing assay. Formation of filopodia, a key protein in cell migration as well as signaling pathways possibly involved were subsequently assessed. It was found that HaCaT cell migration was significantly enhanced by ECa 233 in a concentration- and time-dependent manner. The filopodia formations were accordingly increased in exposure to ECa 233 at concentrations of 0.1-100 μg/ml. Furthermore, ECa 233 was found to significantly upregulate the expression of Rac1 and RhoA and to induce phosphorylation of FAK and Akt as well as ERK and p38 MAPK. Taken all together, it is suggestive that ECa 233 induces cell migration and subsequently promotes wound healing activity, through the activation of FAK, Akt, and MAPK signaling pathways thereby supporting the role of ECa 233 to be further developed for the clinical treatment of wound. Copyright © 2018 John Wiley & Sons, Ltd.

  20. ERKs and mitochondria-related pathways are essential for glycyrrhizic acid-mediated neuroprotection against glutamate-induced toxicity in differentiated PC12 cells

    International Nuclear Information System (INIS)

    Wang, D.; Guo, T.Q.; Wang, Z.Y.; Lu, J.H.; Liu, D.P.; Meng, Q.F.; Xie, J.; Zhang, X.L.; Liu, Y.; Teng, L.S.

    2014-01-01

    The present study focuses on the neuroprotective effect of glycyrrhizic acid (GA, a major compound separated from Glycyrrhiza Radix, which is a crude Chinese traditional drug) against glutamate-induced cytotoxicity in differentiated PC12 (DPC12) cells. The results showed that GA treatment improved cell viability and ameliorated abnormal glutamate-induced alterations in mitochondria in DPC12 cells. GA reversed glutamate-suppressed B-cell lymphoma 2 levels, inhibited glutamate-enhanced expressions of Bax and cleaved caspase 3, and reduced cytochrome C (Cyto C) release. Exposure to glutamate strongly inhibited phosphorylation of AKT (protein kinase B) and extracellular signal-regulated kinases (ERKs); however, GA pretreatment enhanced activation of ERKs but not AKT. The presence of PD98059 (a mitogen-activated protein/extracellular signal-regulated kinase kinase [MEK] inhibitor) but not LY294002 (a phosphoinositide 3-kinase [PI3K] inhibitor) diminished the potency of GA for improving viability of glutamate-exposed DPC12 cells. These results indicated that ERKs and mitochondria-related pathways are essential for the neuroprotective effect of GA against glutamate-induced toxicity in DPC12 cells. The present study provides experimental evidence supporting GA as a potential therapeutic agent for use in the treatment of neurodegenerative diseases

  1. ERKs and mitochondria-related pathways are essential for glycyrrhizic acid-mediated neuroprotection against glutamate-induced toxicity in differentiated PC12 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D. [School of Life Sciences, Jilin University, Changchun (China); The State Engineering Laboratory of AIDS Vaccine, Jilin University, Changchun (China); Guo, T.Q. [School of Life Sciences, Jilin University, Changchun (China); Wang, Z.Y. [State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun (China); Lu, J.H.; Liu, D.P.; Meng, Q.F.; Xie, J. [School of Life Sciences, Jilin University, Changchun (China); Zhang, X.L. [Faculty of ScienceNational University of Singapore (Singapore); Liu, Y. [School of Life Sciences, Jilin University, Changchun (China); Teng, L.S. [School of Life Sciences, Jilin University, Changchun (China); The State Engineering Laboratory of AIDS Vaccine, Jilin University, Changchun (China)

    2014-07-25

    The present study focuses on the neuroprotective effect of glycyrrhizic acid (GA, a major compound separated from Glycyrrhiza Radix, which is a crude Chinese traditional drug) against glutamate-induced cytotoxicity in differentiated PC12 (DPC12) cells. The results showed that GA treatment improved cell viability and ameliorated abnormal glutamate-induced alterations in mitochondria in DPC12 cells. GA reversed glutamate-suppressed B-cell lymphoma 2 levels, inhibited glutamate-enhanced expressions of Bax and cleaved caspase 3, and reduced cytochrome C (Cyto C) release. Exposure to glutamate strongly inhibited phosphorylation of AKT (protein kinase B) and extracellular signal-regulated kinases (ERKs); however, GA pretreatment enhanced activation of ERKs but not AKT. The presence of PD98059 (a mitogen-activated protein/extracellular signal-regulated kinase kinase [MEK] inhibitor) but not LY294002 (a phosphoinositide 3-kinase [PI3K] inhibitor) diminished the potency of GA for improving viability of glutamate-exposed DPC12 cells. These results indicated that ERKs and mitochondria-related pathways are essential for the neuroprotective effect of GA against glutamate-induced toxicity in DPC12 cells. The present study provides experimental evidence supporting GA as a potential therapeutic agent for use in the treatment of neurodegenerative diseases.

  2. A natural diarylheptanoid promotes neuronal differentiation via activating ERK and PI3K-Akt dependent pathways.

    Science.gov (United States)

    Tang, G; Dong, X; Huang, X; Huang, X-J; Liu, H; Wang, Y; Ye, W-C; Shi, L

    2015-09-10

    Neuronal differentiation is a critical developmental process that determines accurate synaptic connection and circuit wiring. A wide variety of naturally occurring compounds have been shown as promising drug leads for the generation and differentiation of neurons. Here we report that a diarylheptanoid from the plant Alpinia officinarum, 7-(4-hydroxyphenyl)-1-phenyl-4E-hepten-3-one (Cpd 1), exhibited potent activities in neuronal differentiation and neurite outgrowth. Cpd 1 induced differentiation of neuroblastoma Neuro-2a cells into a neuron-like morphology, and accelerated the establishment of axon-dendrite polarization of cultured hippocampal neurons. Moreover, Cpd 1 promoted neurite extension in both Neuro-2a cells and neurons. We showed that the effects of Cpd 1 on neuronal differentiation and neurite growth were specifically dependent on the activation of extracellular signal-regulated kinases (ERKs) and phosphoinositide 3-kinase (PI3K)-Akt signaling pathways. Importantly, intraperitoneal administration of Cpd 1 promoted the differentiation of new-born progenitor cells into mature neurons in the adult hippocampal dentate gyrus. Collectively, this study identifies a naturally occurring diarylheptanoid with beneficial effects on neuronal differentiation and neurite outgrowth in vitro and in vivo. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Heterotrimeric G protein-dependent WNT-5A signaling to ERK1/2 mediates distinct aspects of microglia proinflammatory transformation

    Directory of Open Access Journals (Sweden)

    Halleskog Carina

    2012-05-01

    Full Text Available Abstract Background WNT-5A signaling in the central nervous system is important for morphogenesis, neurogenesis and establishment of functional connectivity; the source of WNT-5A and its importance for cellular communication in the adult brain, however, are mainly unknown. We have previously investigated the inflammatory effects of WNT/β-catenin signaling in microglia in Alzheimer's disease. WNT-5A, however, generally recruits β-catenin-independent signaling. Thus, we aim here to characterize the role of WNT-5A and downstream signaling pathways for the inflammatory transformation of the brain's macrophages, the microglia. Methods Mouse brain sections were used for immunohistochemistry. Primary isolated microglia and astrocytes were employed to characterize the WNT-induced inflammatory transformation and underlying intracellular signaling pathways by immunoblotting, quantitative mRNA analysis, proliferation and invasion assays. Further, measurements of G protein activation by [γ-35 S]GTP binding, examination of calcium fluxes and cyclic AMP production were used to define intracellular signaling pathways. Results Astrocytes in the adult mouse brain express high levels of WNT-5A, which could serve as a novel astroglia-microglia communication pathway. The WNT-5A-induced proinflammatory microglia response is characterized by increased expression of inducible nitric oxide synthase, cyclooxygenase-2, cytokines, chemokines, enhanced invasive capacity and proliferation. Mapping of intracellular transduction pathways reveals that WNT-5A activates heterotrimeric Gi/o proteins to reduce cyclic AMP levels and to activate a Gi/o protein/phospholipase C/calcium-dependent protein kinase/extracellular signal-regulated kinase 1/2 (ERK1/2 axis. We show further that WNT-5A-induced ERK1/2 signaling is responsible for distinct aspects of the proinflammatory transformation, such as matrix metalloprotease 9/13 expression, invasion and proliferation. Conclusions

  4. Signaling pathway networks mined from human pituitary adenoma proteomics data

    Directory of Open Access Journals (Sweden)

    Zhan Xianquan

    2010-04-01

    Full Text Available Abstract Background We obtained a series of pituitary adenoma proteomic expression data, including protein-mapping data (111 proteins, comparative proteomic data (56 differentially expressed proteins, and nitroproteomic data (17 nitroproteins. There is a pressing need to clarify the significant signaling pathway networks that derive from those proteins in order to clarify and to better understand the molecular basis of pituitary adenoma pathogenesis and to discover biomarkers. Here, we describe the significant signaling pathway networks that were mined from human pituitary adenoma proteomic data with the Ingenuity pathway analysis system. Methods The Ingenuity pathway analysis system was used to analyze signal pathway networks and canonical pathways from protein-mapping data, comparative proteomic data, adenoma nitroproteomic data, and control nitroproteomic data. A Fisher's exact test was used to test the statistical significance with a significance level of 0.05. Statistical significant results were rationalized within the pituitary adenoma biological system with literature-based bioinformatics analyses. Results For the protein-mapping data, the top pathway networks were related to cancer, cell death, and lipid metabolism; the top canonical toxicity pathways included acute-phase response, oxidative-stress response, oxidative stress, and cell-cycle G2/M transition regulation. For the comparative proteomic data, top pathway networks were related to cancer, endocrine system development and function, and lipid metabolism; the top canonical toxicity pathways included mitochondrial dysfunction, oxidative phosphorylation, oxidative-stress response, and ERK/MAPK signaling. The nitroproteomic data from a pituitary adenoma were related to cancer, cell death, lipid metabolism, and reproductive system disease, and the top canonical toxicity pathways mainly related to p38 MAPK signaling and cell-cycle G2/M transition regulation. Nitroproteins from a

  5. Cervical spinal erythropoietin induces phrenic motor facilitation via ERK and Akt signaling

    Science.gov (United States)

    Dale, Erica A.; Satriotomo, Irawan; Mitchell, Gordon S.

    2012-01-01

    Erythropoietin (EPO) is typically known for its role in erythropoiesis, but is also a potent neurotrophic/neuroprotective factor for spinal motor neurons. Another trophic factor regulated by Hypoxia-Inducible Factor-1, vascular endothelial growth factor (VEGF), signals via ERK and Akt activation to elicit long-lasting phrenic motor facilitation (pMF). Since EPO also signals via ERK and Akt activation, we tested the hypothesis that EPO elicits similar pMF. Using retrograde labeling and immunohistochemical techniques, we demonstrate in adult, male, Sprague-Dawley rats that EPO and its receptor, EPO-R, are expressed in identified phrenic motor neurons. Intrathecal EPO at C4 elicits long-lasting pMF; integrated phrenic nerve burst amplitude increased >90 min post-injection (63±12% baseline 90 min post-injection; pphrenic motor neurons; EPO also increased pAkt (1.6 fold vs controls; pphrenic motor neurons (p<0.05), indicating a complex interaction between these kinases. We conclude that EPO elicits spinal plasticity in respiratory motor control. Since EPO expression is hypoxia-sensitive, it may play a role in respiratory plasticity in conditions of prolonged or recurrent low oxygen. PMID:22539857

  6. DA-Raf, a dominant-negative antagonist of the Ras-ERK pathway, is a putative tumor suppressor.

    Science.gov (United States)

    Kanno, Emiri; Kawasaki, Osamu; Takahashi, Kazuya; Takano, Kazunori; Endo, Takeshi

    2018-01-01

    Activating mutations of RAS genes, particularly KRAS, are detected with high frequency in human tumors. Mutated Ras proteins constitutively activate the ERK pathway (Raf-MEK-ERK phosphorylation cascade), leading to cellular transformation and tumorigenesis. DA-Raf1 (DA-Raf) is a splicing variant of A-Raf and contains the Ras-binding domain (RBD) but lacks the kinase domain. Accordingly, DA-Raf antagonizes the Ras-ERK pathway in a dominant-negative fashion and suppresses constitutively activated K-Ras-induced cellular transformation. Thus, we have addressed whether DA-Raf serves as a tumor suppressor of Ras-induced tumorigenesis. DA-Raf(R52Q), which is generated from a single nucleotide polymorphism (SNP) in the RBD, and DA-Raf(R52W), a mutant detected in a lung cancer, neither bound to active K-Ras nor interfered with the activation of the ERK pathway. They were incapable of suppressing activated K-Ras-induced cellular transformation and tumorigenesis in mice, in which K-Ras-transformed cells were transplanted. Furthermore, although DA-Raf was highly expressed in lung alveolar epithelial type 2 (AE2) cells, its expression was silenced in AE2-derived lung adenocarcinoma cell lines with oncogenic KRAS mutations. These results suggest that DA-Raf represents a tumor suppressor protein against Ras-induced tumorigenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. GEP100/Arf6 is required for epidermal growth factor-induced ERK/Rac1 signaling and cell migration in human hepatoma HepG2 cells.

    Directory of Open Access Journals (Sweden)

    ZhenZhen Hu

    Full Text Available BACKGROUND: Epidermal growth factor (EGF signaling is implicated in the invasion and metastasis of hepatoma cells. However, the signaling pathways for EGF-induced motility of hepatoma cells remain undefined. METHODOLOGY/PRINCIPAL FINDINGS: We found that EGF dose-dependently stimulated the migration of human hepatoma cells HepG2, with the maximal effect at 10 ng/mL. Additionally, EGF increased Arf6 activity, and ectopic expression of Arf6 T27N, a dominant negative Arf6 mutant, largely abolish EGF-induced cell migration. Blocking GEP100 with GEP100 siRNA or GEP100-△PH, a pleckstrin homology (PH domain deletion mutant of GEP100, blocked EGF-induced Arf6 activity and cell migration. EGF also increased ERK and Rac1 activity. Ectopic expression GEP100 siRNA, GEP100-△PH, or Arf6-T27N suppressed EGF-induced ERK and Rac1 activity. Furthermore, blocking ERK signaling with its inhibitor U0126 remarkably inhibited both EGF-induced Rac1 activation as well as cell migration, and ectopic expression of inactive mutant form of Rac1 (Rac1-T17N also largely abolished EGF-induced cell migration. CONCLUSIONS/SIGNIFICANCE: Taken together, this study highlights the function of the PH domain of GEP100 and its regulated Arf6/ERK/Rac1 signaling cascade in EGF-induced hepatoma cell migration. These findings could provide a rationale for designing new therapy based on inhibition of hepatoma metastasis.

  8. Tenascin-C induces resistance to apoptosis in pancreatic cancer cell through activation of ERK/NF-κB pathway.

    Science.gov (United States)

    Shi, Meiyan; He, Xiaodan; Wei, Wei; Wang, Juan; Zhang, Ti; Shen, Xiaohong

    2015-06-01

    As a glycol-protein located in extracellular matrix (ECM), tenascin-C (TNC) is absent in most normal adult tissues but is highly expressed in the majority of malignant solid tumors. Pancreatic cancer is characterized by an abundant fibrous tissue rich in TNC. Although it was reported that TNC's expression increased in the progression from low-grade precursor lesions to invasive cancer and was associated with tumor differentiation in human pancreatic cancer, studies on the relations between TNC and tumor progression in pancreatic cancer were rare. In this study, we performed an analysis to determine the effects of TNC on modulating cell apoptosis and chemo-resistance and explored its mechanisms involving activation in pancreatic cancer cell. The expressions of TNC, ERK1/2/p-ERK1/2, Bcl-xL and Bcl-2 were detected by immunohistochemistry and western blotting. Then the effects of exogenous and endogenous TNC on the regulation of tumor proliferation, apoptosis and gemcitabine cytotoxicity were investigated. The associations among the TNC knockdown, TNC stimulation and expressions of ERK1/2/NF-κB/p65 and apoptotic regulatory proteins were also analyzed in cell lines. The mechanism of TNC on modulating cancer cell apoptosis and drug resistant through activation of ERK1/2/NF-κB/p65 signals was evaluated. The effect of TNC on regulating cell cycle distribution was also tested. TNC, ERK1/2/p-ERK1/2, and apoptotic regulatory proteins Bcl-xL and Bcl-2 were highly expressed in human pancreatic cancer tissues. In vitro, exogenous TNC promoted pancreatic cancer cell growth also mediates basal as well as starved and drug-induced apoptosis in pancreatic cancer cells. The effects of TNC on anti-apoptosis were induced by the activation state of ERK1/2/NF-κB/p65 signals in pancreatic cell. TNC phosphorylate ERK1/2 to induce NF-κB/p65 nucleus translocation. The latter contributes to promote Bcl-xL, Bcl-2 protein expressions and reduce caspase activity, which inhibit cell apoptotic

  9. DA-Raf-Mediated Suppression of the Ras--ERK Pathway Is Essential for TGF-β1-Induced Epithelial-Mesenchymal Transition in Alveolar Epithelial Type 2 Cells.

    Science.gov (United States)

    Watanabe-Takano, Haruko; Takano, Kazunori; Hatano, Masahiko; Tokuhisa, Takeshi; Endo, Takeshi

    2015-01-01

    Myofibroblasts play critical roles in the development of idiopathic pulmonary fibrosis by depositing components of extracellular matrix. One source of lung myofibroblasts is thought to be alveolar epithelial type 2 cells that undergo epithelial-mesenchymal transition (EMT). Rat RLE-6TN alveolar epithelial type 2 cells treated with transforming growth factor-β1 (TGF-β1) are converted into myofibroblasts through EMT. TGF-β induces both canonical Smad signaling and non-canonical signaling, including the Ras-induced ERK pathway (Raf-MEK-ERK). However, the signaling mechanisms regulating TGF-β1-induced EMT are not fully understood. Here, we show that the Ras-ERK pathway negatively regulates TGF-β1-induced EMT in RLE-6TN cells and that DA-Raf1 (DA-Raf), a splicing isoform of A-Raf and a dominant-negative antagonist of the Ras-ERK pathway, plays an essential role in EMT. Stimulation of the cells with fibroblast growth factor 2 (FGF2), which activated the ERK pathway, prominently suppressed TGF-β1-induced EMT. An inhibitor of MEK, but not an inhibitor of phosphatidylinositol 3-kinase, rescued the TGF-β1-treated cells from the suppression of EMT by FGF2. Overexpression of a constitutively active mutant of a component of the Ras-ERK pathway, i.e., H-Ras, B-Raf, or MEK1, interfered with EMT. Knockdown of DA-Raf expression with siRNAs facilitated the activity of MEK and ERK, which were only weakly and transiently activated by TGF-β1. Although DA-Raf knockdown abrogated TGF-β1-induced EMT, the abrogation of EMT was reversed by the addition of the MEK inhibitor. Furthermore, DA-Raf knockdown impaired the TGF-β1-induced nuclear translocation of Smad2, which mediates the transcription required for EMT. These results imply that intrinsic DA-Raf exerts essential functions for EMT by antagonizing the TGF-β1-induced Ras-ERK pathway in RLE-6TN cells.

  10. Curcumin Reverses the Diazepam-Induced Cognitive Impairment by Modulation of Oxidative Stress and ERK 1/2/NF-κB Pathway in Brain

    Directory of Open Access Journals (Sweden)

    Alexandra C. Sevastre-Berghian

    2017-01-01

    Full Text Available Oxidative stress and inflammation can be involved in cognitive dysfunction associated with neurodegenerative disorders. Diazepam (DZP administration has been chosen to simulate the memory impairment. The aim of this study was to evaluate the effects of curcumin (CUR on spatial cognition, ambulatory activity, and blood and brain oxidative stress levels. The ERK/NF-κB signaling pathway and the histopathological changes in the hippocampus and frontal lobe, in diazepam-treated rats, were also analyzed. The animals were divided into 4 groups: control, carboxymethylcellulose (CMC + CUR, CMC + DZP, and CUR + CMC + DZP. CUR (150 mg/kg b.w. was orally administered for 28 days. DZP (2 mg/kg b.w. was intraperitoneally administered 20 minutes before the behavioral tests (open field test, Y-maze, and elevated plus maze. CUR improved the spontaneous alternation behavior, decreased the oxidative stress levels, both in the blood and in the hippocampus, and downregulated the extracellular signal-regulated kinase (ERK 1/2/nuclear transcription factor- (NF- κB/pNF-κB pathway in the hippocampus and the iNOS expression in the hippocampus and frontal lobe of the DZP-treated rats. Histopathologically, no microscopic changes were found. The immunohistochemical signal of iNOS decreased in the DZP and CUR-treated group. Thus, our findings suggest that curcumin administration may improve the cognitive performance and may also have an antioxidant effect.

  11. Overexpression of activin-A and -B in malignant mesothelioma – Attenuated Smad3 signaling responses and ERK activation promote cell migration and invasive growth

    Energy Technology Data Exchange (ETDEWEB)

    Tamminen, Jenni A.; Yin, Miao [Research Programs Unit, Translational Cancer Biology, University of Helsinki (Finland); Transplantation Laboratory, Haartman Institute, University of Helsinki (Finland); Rönty, Mikko [Helsinki University Central Hospital Laboratory, Helsinki (Finland); Department of Pathology, University of Helsinki (Finland); Sutinen, Eva [Helsinki University Central Hospital Laboratory, Helsinki (Finland); Department of Medicine, Division of Pulmonary Medicine, University of Helsinki (Finland); Pasternack, Arja; Ritvos, Olli [Helsinki University Central Hospital Laboratory, Helsinki (Finland); Department of Bacteriology and Immunology, University of Helsinki (Finland); Myllärniemi, Marjukka [Transplantation Laboratory, Haartman Institute, University of Helsinki (Finland); Helsinki University Central Hospital Laboratory, Helsinki (Finland); Department of Medicine, Division of Pulmonary Medicine, University of Helsinki (Finland); Koli, Katri, E-mail: katri.koli@helsinki.fi [Research Programs Unit, Translational Cancer Biology, University of Helsinki (Finland); Transplantation Laboratory, Haartman Institute, University of Helsinki (Finland)

    2015-03-01

    Activin-A and activin-B, members of the TGF-β superfamily, are regulators of reproductive functions, inflammation and wound healing. These dimeric molecules regulate various cellular activities such as proliferation, migration and suvival. Malignant mesothelioma is an asbestos exposure related tumor affecting mainly pleura and it usually has a dismal prognosis. Here, we demonstrate that both activin-A and -B are abundantly expressed in mesothelioma tumor tissue as well as in cultured primary and established mesothelioma cells. Migratory and invasive mesothelioma cells were also found to have attenuated activation of the Smad2/3 pathway in response to activins. Migration and invasive growth of the cells in three-dimentional matrix was prevented by inhibition of activin activity using a soluble activin receptor 2B (sActR2B-Fc). This was associated with decreased ERK activity. Furthermore, migration and invasive growth was significantly inhibited by blocking ERK phosphorylation. Mesothelioma tumors are locally invasive and our results clearly suggest that acivins have a tumor-promoting function in mesothelioma through increasing expression and switching from canonical Smad3 pathway to non-canonical ERK pathway signaling. Blocking activin activity offers a new therapeutic approach for inhibition of mesothelioma invasive growth. - Highlights: • Activin-A and activin-B are highly expressed in mesothelioma. • Mesothelioma cell migration and invasive growth can be blocked with sActR2B. • Activin induced Smad3 activity is attenuated in invasive mesothelioma cells. • Activins induce ERK activity in mesothelioma cells.

  12. 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

  13. ANGPTL3 is a novel biomarker as it activates ERK/MAPK pathway in oral cancer

    International Nuclear Information System (INIS)

    Koyama, Tomoyoshi; Ogawara, Katsunori; Kasamatsu, Atsushi; Okamoto, Atsushi; Kasama, Hiroki; Minakawa, Yasuyuki; Shimada, Ken; Yokoe, Hidetaka; Shiiba, Masashi; Tanzawa, Hideki; Uzawa, Katsuhiro

    2015-01-01

    Angiopoietin-like 3 (ANGPTL3), which is involved in new blood vessel growth and stimulation of mitogen-activated protein kinase (MAPK), is expressed aberrantly in several types of human cancers. However, little is known about the relevance of ANGPTL3 in the behavior of oral squamous cell carcinoma (OSCC). In this study, we evaluated ANGPTL3 mRNA and protein in OSCC-derived cell lines (n = 8) and primary OSCCs (n = 109) and assessed the effect of ANGPTL3 on the biology and function of OSCCs in vitro and in vivo. Significant (P < 0.05) ANGPTL3 upregulation was detected in the cell lines and most primary OSCCs (60%) compared with the normal counterparts. The ANGPTL3 expression level was correlated closely (P < 0.05) with tumoral size. In patients with T3/T4 tumors, the overall survival rate with an ANGPTL3-positive tumor was significantly (P < 0.05) lower than that of ANGPTL3-negative cases. In vitro, cellular growth in ANGPTL3 knockdown cells significantly (P < 0.05) decreased with inactivated extracellular regulated kinase (ERK) and cell-cycle arrest at the G1 phase resulting from upregulation of the cyclin-dependent kinase inhibitors, including p21 Cip1 and p27 Kip1 . We also observed a marked (P < 0.05) reduction in the growth in ANGPTL3 knockdown-cell xenografts with decreased levels of phosphorylated ERK relative to control-cell xenografts. The current data indicated that ANGPTL3 may play a role in OSCCs via MAPK signaling cascades, making it a potentially useful diagnostic/therapeutic target for use in patients with OSCC

  14. Bax/Mcl-1 balance affects neutrophil survival in intermittent hypoxia and obstructive sleep apnea: effects of p38MAPK and ERK1/2 signaling.

    Science.gov (United States)

    Dyugovskaya, Larissa; Polyakov, Andrey; Cohen-Kaplan, Victoria; Lavie, Peretz; Lavie, Lena

    2012-10-22

    Prolonged neutrophil survival is evident in various cardiovascular and respiratory morbidities, in hypoxic conditions in-vitro and in patients with obstructive sleep apnea (OSA) characterized by nightly intermittent hypoxia (IH). This may lead to persistent inflammation, tissue injury and dysfunction. We therefore investigated by a translational approach the potential contribution of the intrinsic stress-induced mitochondrial pathway in extending neutrophil survival under IH conditions. Thus, neutrophils of healthy individuals treated with IH in-vitro and neutrophils of OSA patients undergoing nightly IH episodes in-vivo were investigated. Specifically, the balance between pro-apoptotic Bax and anti-apoptotic Mcl-1 protein expression, and the potential involvement of p38MAPK and ERK1/2 signaling pathways in the control of Mcl-1 expression were investigated. Purified neutrophils were exposed to IH and compared to normoxia and to sustained hypoxia (SH) using a BioSpherix-OxyCycler C42 system. Bax and Mcl-1 levels, and p38MAPK and ERK1/2 phosphorylation were determined by western blotting. Also, Bax/Mcl-1 expression and Bax translocation to the mitochondria were assessed by confocal microscopy in pre-apoptotic neutrophils, before the appearance of apoptotic morphology. Co-localization of Bax and mitochondria was quantified by LSM 510 CarlZeiss MicroImaging using Manders Overlap Coefficient. A paired two-tailed t test, with Bonferroni correction for multiple comparisons, was used for statistical analysis. Compared to normoxia, IH and SH up-regulated the anti-apoptotic Mcl-1 by about 2-fold, down-regulated the pro-apoptotic Bax by 41% and 27%, respectively, and inhibited Bax co-localization with mitochondria before visible morphological signs of apoptosis were noted. IH induced ERK1/2 and p38MAPKs phosphorylation, whereas SH induced only p38MAPK phosphorylation. Accordingly, both ERK and p38MAPK inhibitors attenuated the IH-induced Mcl-1 increase. In SH, only p38MAPK

  15. Decreased nuclear stiffness via FAK-ERK1/2 signaling is necessary for osteopontin-promoted migration of bone marrow-derived mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lingling, E-mail: liulingling2012@163.com [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Luo, Qing, E-mail: qing.luo@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Sun, Jinghui, E-mail: sunjhemail@163.com [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Wang, Aoli, E-mail: leaf13332@163.com [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Shi, Yisong, E-mail: shiyis@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Ju, Yang, E-mail: ju@mech.nagoya-u.ac.jp [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Morita, Yasuyuki, E-mail: morita@mech.nagoya-u.ac.jp [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2017-06-15

    Migration of bone marrow-derived mesenchymal stem cells (BMSCs) plays an important role in many physiological and pathological settings, including wound healing. During the migration of BMSCs through interstitial tissues, the movement of the nucleus must be coordinated with the cytoskeletal dynamics, which in turn affects the cell migration efficiency. Our previous study indicated that osteopontin (OPN) significantly promotes the migration of rat BMSCs. However, the nuclear behaviors and involved molecular mechanisms in OPN-mediated BMSC migration are largely unclear. In the present study, using an atomic force microscope (AFM), we found that OPN could decrease the nuclear stiffness of BMSCs and reduce the expression of lamin A/C, which is the main determinant of nuclear stiffness. Increased lamin A/C expression attenuates BMSC migration by increasing nuclear stiffness. Decreased lamin A/C expression promotes BMSC migration by decreasing nuclear stiffness. Furthermore, OPN promotes BMSC migration by diminishing lamin A/C expression and decreasing nuclear stiffness via the FAK-ERK1/2 signaling pathway. This study provides strong evidence for the role of nuclear mechanics in BMSC migration as well as new insight into the molecular mechanisms of OPN-promoted BMSC migration. - Highlights: • OPN promotes BMSC migration by decreasing nuclear stiffness. • Lamin A/C knockdown decreases, while its overexpression enhances, the nuclear stiffness of BMSCs. • Lamin A/C overexpression and downregulation affect the migration of BMSCs. • OPN diminishes lamin A/C expression and decreases nuclear stiffness through the activation of the FAK-ERK1/2 signaling pathway. • OPN promotes BMSC migration via the FAK-ERK1/2 signaling pathway.

  16. Decreased nuclear stiffness via FAK-ERK1/2 signaling is necessary for osteopontin-promoted migration of bone marrow-derived mesenchymal stem cells

    International Nuclear Information System (INIS)

    Liu, Lingling; Luo, Qing; Sun, Jinghui; Wang, Aoli; Shi, Yisong; Ju, Yang; Morita, Yasuyuki; Song, Guanbin

    2017-01-01

    Migration of bone marrow-derived mesenchymal stem cells (BMSCs) plays an important role in many physiological and pathological settings, including wound healing. During the migration of BMSCs through interstitial tissues, the movement of the nucleus must be coordinated with the cytoskeletal dynamics, which in turn affects the cell migration efficiency. Our previous study indicated that osteopontin (OPN) significantly promotes the migration of rat BMSCs. However, the nuclear behaviors and involved molecular mechanisms in OPN-mediated BMSC migration are largely unclear. In the present study, using an atomic force microscope (AFM), we found that OPN could decrease the nuclear stiffness of BMSCs and reduce the expression of lamin A/C, which is the main determinant of nuclear stiffness. Increased lamin A/C expression attenuates BMSC migration by increasing nuclear stiffness. Decreased lamin A/C expression promotes BMSC migration by decreasing nuclear stiffness. Furthermore, OPN promotes BMSC migration by diminishing lamin A/C expression and decreasing nuclear stiffness via the FAK-ERK1/2 signaling pathway. This study provides strong evidence for the role of nuclear mechanics in BMSC migration as well as new insight into the molecular mechanisms of OPN-promoted BMSC migration. - Highlights: • OPN promotes BMSC migration by decreasing nuclear stiffness. • Lamin A/C knockdown decreases, while its overexpression enhances, the nuclear stiffness of BMSCs. • Lamin A/C overexpression and downregulation affect the migration of BMSCs. • OPN diminishes lamin A/C expression and decreases nuclear stiffness through the activation of the FAK-ERK1/2 signaling pathway. • OPN promotes BMSC migration via the FAK-ERK1/2 signaling pathway.

  17. Resveratrol prevents high glucose-induced epithelial-mesenchymal transition in renal tubular epithelial cells by inhibiting NADPH oxidase/ROS/ERK pathway.

    Science.gov (United States)

    He, Ting; Guan, Xu; Wang, Song; Xiao, Tangli; Yang, Ke; Xu, Xinli; Wang, Junping; Zhao, Jinghong

    2015-02-15

    Resveratrol (RSV) is reported to have renoprotective activity against diabetic nephropathy, while the mechanisms underlying its function have not been fully elucidated. In this study, we investigate the effect and related mechanism of RSV against high glucose-induced epithelial to mesenchymal transition (EMT) in human tubular epithelial cells (HK-2). A typical EMT is induced by high glucose in HK-2 cells, accompanied by increased levels of reactive oxygen species (ROS). RSV exhibits a strong ability to inhibit high glucose-induced EMT by decreasing intracellular ROS levels via down-regulation of NADPH oxidase subunits NOX1 and NOX4. The activation of extracellular signal-regulated kinase (ERK1/2) is found to be involved in high glucose-induced EMT in HK-2 cells. RSV, like NADPH oxidase inhibitor diphenyleneiodonium, can block ERK1/2 activation induced by high glucose. Our results demonstrate that RSV is a potent agent against high glucose-induced EMT in renal tubular cells via inhibition of NADPH oxidase/ROS/ERK1/2 pathway. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Effects of chronic sleep deprivation on the extracellular signal-regulated kinase pathway in the temporomandibular joint of rats.

    Directory of Open Access Journals (Sweden)

    Chuan Ma

    Full Text Available OBJECTIVES: To examine the possible involvement and regulatory mechanisms of extracellular signal-regulated kinase (ERK pathway in the temporomandibular joint (TMJ of rats subjected to chronic sleep deprivation (CSD. METHODS: Rats were subjected to CSD using the modified multiple platform method (MMPM. The serum levels of corticosterone (CORT and adrenocorticotropic hormone (ACTH were tested and histomorphology and ultrastructure of the TMJ were observed. The ERK and phospho-ERK (p-ERK expression levels were detected by Western blot analysis, and the MMP-1, MMP-3, and MMP-13 expression levels were detected by real-time quantitative polymerase chain reaction (PCR and Western blotting. RESULTS: The elevated serum CORT and ACTH levels confirmed that the rats were under CSD stress. Hematoxylin and eosin (HE staining and scanning electron microscopy (SEM showed pathological alterations in the TMJ following CSD; furthermore, the p-ERK was activated and the mRNA and protein expression levels of MMP-1, MMP-3, and MMP-13 were upregulated after CSD. In the rats administered with the selective ERK inhibitor U0126, decreased tissue destruction was observed. Phospho-ERK activation was visibly blocked and the MMP-1, MMP-3, and MMP-13 mRNA and protein levels were lower than the corresponding levels in the CSD without U0126 group. CONCLUSION: These findings indicate that CSD activates the ERK pathway and upregulates the MMP-1, MMP-3, and MMP-13 mRNA and protein levels in the TMJ of rats. Thus, CSD induces ERK pathway activation and causes pathological alterations in the TMJ. ERK may be associated with TMJ destruction by promoting the expression of MMPs.

  19. The human leukocyte antigen G promotes trophoblast fusion and β-hCG production through the Erk1/2 pathway in human choriocarcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ji-meng [School of Medicine, Nankai University, Tianjin 300071 (China); State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Zhao, Hong-xi [Department of Obstetrics and Gynecology, Tangdu Hospital, Fourth Military Medical University, Xi’an 710038 (China); Wang, Li [Department of Obstetrics and Gynecology, General Hospital of Chinese People’s Liberation Army, Beijing 100853 (China); Gao, Zhi-ying, E-mail: gaozy301@yahoo.com.cn [Department of Obstetrics and Gynecology, General Hospital of Chinese People’s Liberation Army, Beijing 100853 (China); Yao, Yuan-qing, E-mail: yqyao@126.com [Department of Obstetrics and Gynecology, General Hospital of Chinese People’s Liberation Army, Beijing 100853 (China)

    2013-05-10

    Highlights: •HLA-G expression promotes BeWo cells fusion and fusogenic gene expression. •HLA-G is capable of inducing β-hCG production in human choriocarcinoma cell lines. •Up-regulation of β-hCG production by HLA-G is mediated via the Erk1/2 pathway. -- Abstract: The human leukocyte antigen G (HLA-G) is expressed on the fetal–maternal interface and plays a role in protecting fetal-derived trophoblasts from the maternal immune response, allowing trophoblasts to invade the uterus. However, HLA-G also possesses immune suppressing-independent functions. We found that HLA-G expressing BeWo choriocarcinoma cells increased cell–cell fusion compared to control BeWo cells under forskolin treatment. Regardless of forskolin treatment, the expression of fusogenic gene mRNAs, including syncytin-1, the transcription factor glial cell missing 1 (Gcm1), and beta human chorionic gonadotropin (β-hCG) were elevated. HLA-G up-regulates β-hCG production in human choriocarcinoma cells because HLA-G knockdown in JEG-3 cells induces a dramatic decrease in β-hCG compared with control cells. The defect in β-hCG production in HLA-G knocked-down cells could not be completely overcome by stimulating hCG production through increasing intracellular cAMP levels. HLA-G expressing cells have increased phosphorylation levels for extracellular signal-regulated kinase1/2 (Erk1/2) in BeWo cells. The Erk1/2 pathway is inactivated after the inhibition of HLA-G expression in JEG-3 cells. Finally, Erk1/2 inhibition was able to suppress the increased hCG production induced by HLA-G expression. Together, these data suggest novel roles for HLA-G in regulating β-hCG production via the modulation of the Erk1/2 pathway and by inducing trophoblast cell fusion.

  20. Interaction between Wnt/β-catenin and RAS-ERK pathways and an anti-cancer strategy via degradations of β-catenin and RAS by targeting the Wnt/β-catenin pathway.

    Science.gov (United States)

    Jeong, Woo-Jeong; Ro, Eun Ji; Choi, Kang-Yell

    2018-01-01

    Aberrant activation of the Wnt/β-catenin and RAS-extracellular signal-regulated kinase (ERK) pathways play important roles in the tumorigenesis of many different types of cancer, most notably colorectal cancer (CRC). Genes for these two pathways, such as adenomatous polyposis coli ( APC ) and KRAS are frequently mutated in human CRC, and involved in the initiation and progression of the tumorigenesis, respectively. Moreover, recent studies revealed interaction of APC and KRAS mutations in the various stages of colorectal tumorigenesis and even in metastasis accompanying activation of the cancer stem cells (CSCs). A key event in the synergistic cooperation between Wnt/β-catenin and RAS-ERK pathways is a stabilization of both β-catenin and RAS especially mutant KRAS by APC loss, and pathological significance of this was indicated by correlation of increased β-catenin and RAS levels in human CRC where APC mutations occur as high as 90% of CRC patients. Together with the notion of the protein activity reduction by lowering its level, inhibition of both β-catenin and RAS especially by degradation could be a new ideal strategy for development of anti-cancer drugs for CRC. In this review, we will discuss interaction between the Wnt/β-catenin and RAS-ERK pathways in the colorectal tumorigenesis by providing the mechanism of RAS stabilization by aberrant activation of Wnt/β-catenin. We will also discuss our small molecular anti-cancer approach controlling CRC by induction of specific degradations of both β-catenin and RAS via targeting Wnt/β-catenin pathway especially for the KYA1797K, a small molecule specifically binding at the regulator of G-protein signaling (RGS)-domain of Axin.

  1. Decoding resistant hypertension signalling pathways.

    Science.gov (United States)

    Parreira, Ricardo Cambraia; Lacerda, Leandro Heleno Guimarães; Vasconcellos, Rebecca; Lima, Swiany Silveira; Santos, Anderson Kenedy; Fontana, Vanessa; Sandrim, Valéria Cristina; Resende, Rodrigo Ribeiro

    2017-12-01

    Resistant hypertension (RH) is a clinical condition in which the hypertensive patient has become resistant to drug therapy and is often associated with increased cardiovascular morbidity and mortality. Several signalling pathways have been studied and related to the development and progression of RH: modulation of sympathetic activity by leptin and aldosterone, primary aldosteronism, arterial stiffness, endothelial dysfunction and variations in the renin-angiotensin-aldosterone system (RAAS). miRNAs comprise a family of small non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. miRNAs are involved in the development of both cardiovascular damage and hypertension. Little is known of the molecular mechanisms that lead to development and progression of this condition. This review aims to cover the potential roles of miRNAs in the mechanisms associated with the development and consequences of RH, and explore the current state of the art of diagnostic and therapeutic tools based on miRNA approaches. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

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

    Science.gov (United States)

    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.

  3. Lead acetate induces EGFR activation upstream of SFK and PKCα linkage to the Ras/Raf-1/ERK signaling

    International Nuclear Information System (INIS)

    Wang, C.-Y.; Wang, Y.-T.; Tzeng, D.-W.; Yang, J.-L.

    2009-01-01

    Lead acetate (Pb), a probable human carcinogen, can activate protein kinase C (PKC) upstream of extracellular signal-regulated kinase 1 and 2 (ERK1/2). Yet, it remains unclear whether Pb activation of PKC → ERK1/2 involves receptor/non-receptor tyrosine kinases and the Ras signaling transducer. Here we demonstrate a novel mechanism elicited by Pb for transmitting ERK1/2 signaling in CL3 human non-small-cell lung adenocarcinoma cells. Pb induction of higher steady-state levels of Ras-GTP was essential for increasing phospho-Raf-1 S338 and phospho-ERK1/2. Pre-treatment of the cells with a conventional PKC inhibitor Goe6976 or depleting PKCα using specific small interfering RNA blocked Pb induction of Ras-GTP. Pb also activated cellular tyrosine kinases. Specific pharmacological inhibitors, PD153035 for epidermal growth factor receptor (EGFR) and SU6656 for Src family tyrosine kinases (SFK), but not AG1296 for platelet-derived growth factor receptor, could suppress the Pb-induced tyrosine kinases, PKCα, Ras-GTP, phospho-Raf-1 S338 and phospho-ERK1/2. Furthermore, phosphorylation of tyrosines on the EGFR multiple autophosphorylation sites and the conserved SFK autophosphorylation site occurred during exposure of cells to Pb for 1-5 min and 5-30 min, respectively. Intriguingly, Pb activation of EGFR required the intrinsic kinase activity but not dimerization of the receptor. Inhibition of SFK or PKCα activities did not affect EGFR phosphorylation, while knockdown of EGFR blocked SFK phosphorylation and PKCα activation following Pb. Together, these results indicate that immediate activation of EGFR in response to Pb is obligatory for activation of SFK and PKCα and subsequent the Ras-Raf-1-MKK1/2-ERK1/2 signaling cascade

  4. ERK1/2 signaling plays an important role in topoisomerase II poison-induced G2/M checkpoint activation.

    Science.gov (United States)

    Kolb, Ryan H; Greer, Patrick M; Cao, Phu T; Cowan, Kenneth H; Yan, Ying

    2012-01-01

    Topo II poisons, which target topoisomerase II (topo II) to generate enzyme mediated DNA damage, have been commonly used for anti-cancer treatment. While clinical evidence demonstrate a capability of topo II poisons in inducing apoptosis in cancer cells, accumulating evidence also show that topo II poison treatment frequently results in cell cycle arrest in cancer cells, which was associated with subsequent resistance to these treatments. Results in this report indicate that treatment of MCF-7 and T47D breast cancer cells with topo II poisons resulted in an increased phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and an subsequent induction of G2/M cell cycle arrest. Furthermore, inhibition of ERK1/2 activation using specific inhibitors markedly attenuated the topo II poison-induced G2/M arrest and diminished the topo II poison-induced activation of ATR and Chk1 kinases. Moreover, decreased expression of ATR by specific shRNA diminished topo II poison-induced G2/M arrest but had no effect on topo II poison-induced ERK1/2 activation. In contrast, inhibition of ERK1/2 signaling had little, if any, effect on topo II poison-induced ATM activation. In addition, ATM inhibition by either incubation of cells with ATM specific inhibitor or transfection of cells with ATM specific siRNA did not block topo II poison-induced G2/M arrest. Ultimately, inhibition of ERK1/2 signaling greatly enhanced topo II poison-induced apoptosis. These results implicate a critical role for ERK1/2 signaling in the activation of G2/M checkpoint response following topo II poison treatment, which protects cells from topo II poison-induced apoptosis.

  5. Plasmalogens rescue neuronal cell death through an activation of AKT and ERK survival signaling.

    Directory of Open Access Journals (Sweden)

    Md Shamim Hossain

    Full Text Available Neuronal cells are susceptible to many stresses, which will cause the apoptosis and neurodegenerative diseases. The precise molecular mechanism behind the neuronal protection against these apoptotic stimuli is necessary for drug discovery. In the present study, we have found that plasmalogens (Pls, which are glycerophospholipids containing vinyl ether linkage at sn-1 position, can protect the neuronal cell death upon serum deprivation. Interestingly, caspse-9, but not caspase-8 and caspase-12, was cleaved upon the serum starvation in Neuro-2A cells. Pls treatments effectively reduced the activation of caspase-9. Furthermore, cellular signaling experiments showed that Pls enhanced phosphorylation of the phosphoinositide 3-kinase (PI3K-dependent serine/threonine-specific protein kinase AKT and extracellular-signal-regulated kinases ERK1/2. PI3K/AKT inhibitor LY294002 and MAPK/ERK kinase (MEK inhibitor U0126 treatments study clearly indicated that Pls-mediated cell survival was dependent on the activation of these kinases. In addition, Pls also inhibited primary mouse hippocampal neuronal cell death induced by nutrient deprivation, which was associated with the inhibition of caspase-9 and caspase-3 cleavages. It was reported that Pls content decreased in the brain of the Alzheimer's patients, which indicated that the reduction of Pls content could endanger neurons. The present findings, taken together, suggest that Pls have an anti-apoptotic action in the brain. Further studies on precise mechanisms of Pls-mediated protection against cell death may lead us to establish a novel therapeutic approach to cure neurodegenerative disorders.

  6. Effect of electrical stimulation on neural regeneration via the p38-RhoA and ERK1/2-Bcl-2 pathways in spinal cord-injured rats.

    Science.gov (United States)

    Joo, Min Cheol; Jang, Chul Hwan; Park, Jong Tae; Choi, Seung Won; Ro, Seungil; Kim, Min Seob; Lee, Moon Young

    2018-02-01

    Although electrical stimulation is therapeutically applied for neural regeneration in patients, it remains unclear how electrical stimulation exerts its effects at the molecular level on spinal cord injury (SCI). To identify the signaling pathway involved in electrical stimulation improving the function of injured spinal cord, 21 female Sprague-Dawley rats were randomly assigned to three groups: control (no surgical intervention, n = 6), SCI (SCI only, n = 5), and electrical simulation (ES; SCI induction followed by ES treatment, n = 10). A complete spinal cord transection was performed at the 10 th thoracic level. Electrical stimulation of the injured spinal cord region was applied for 4 hours per day for 7 days. On days 2 and 7 post SCI, the Touch-Test Sensory Evaluators and the Basso-Beattie-Bresnahan locomotor scale were used to evaluate rat sensory and motor function. Somatosensory-evoked potentials of the tibial nerve of a hind paw of the rat were measured to evaluate the electrophysiological function of injured spinal cord. Western blot analysis was performed to measure p38-RhoA and ERK1/2-Bcl-2 pathways related protein levels in the injured spinal cord. Rat sensory and motor functions were similar between SCI and ES groups. Compared with the SCI group, in the ES group, the latencies of the somatosensory-evoked potential of the tibial nerve of rats were significantly shortened, the amplitudes were significantly increased, RhoA protein level was significantly decreased, protein gene product 9.5 expression, ERK1/2, p38, and Bcl-2 protein levels in the spinal cord were significantly increased. These data suggest that ES can promote the recovery of electrophysiological function of the injured spinal cord through regulating p38-RhoA and ERK1/2-Bcl-2 pathway-related protein levels in the injured spinal cord.

  7. Effect of electrical stimulation on neural regeneration via the p38-RhoA and ERK1/2-Bcl-2 pathways in spinal cord-injured rats

    Science.gov (United States)

    Joo, Min Cheol; Jang, Chul Hwan; Park, Jong Tae; Choi, Seung Won; Ro, Seungil; Kim, Min Seob; Lee, Moon Young

    2018-01-01

    Although electrical stimulation is therapeutically applied for neural regeneration in patients, it remains unclear how electrical stimulation exerts its effects at the molecular level on spinal cord injury (SCI). To identify the signaling pathway involved in electrical stimulation improving the function of injured spinal cord, 21 female Sprague-Dawley rats were randomly assigned to three groups: control (no surgical intervention, n = 6), SCI (SCI only, n = 5), and electrical simulation (ES; SCI induction followed by ES treatment, n = 10). A complete spinal cord transection was performed at the 10th thoracic level. Electrical stimulation of the injured spinal cord region was applied for 4 hours per day for 7 days. On days 2 and 7 post SCI, the Touch-Test Sensory Evaluators and the Basso-Beattie-Bresnahan locomotor scale were used to evaluate rat sensory and motor function. Somatosensory-evoked potentials of the tibial nerve of a hind paw of the rat were measured to evaluate the electrophysiological function of injured spinal cord. Western blot analysis was performed to measure p38-RhoA and ERK1/2-Bcl-2 pathways related protein levels in the injured spinal cord. Rat sensory and motor functions were similar between SCI and ES groups. Compared with the SCI group, in the ES group, the latencies of the somatosensory-evoked potential of the tibial nerve of rats were significantly shortened, the amplitudes were significantly increased, RhoA protein level was significantly decreased, protein gene product 9.5 expression, ERK1/2, p38, and Bcl-2 protein levels in the spinal cord were significantly increased. These data suggest that ES can promote the recovery of electrophysiological function of the injured spinal cord through regulating p38-RhoA and ERK1/2-Bcl-2 pathway-related protein levels in the injured spinal cord. PMID:29557386

  8. 8-O-Acetyl Shanzhiside Methylester From Lamiophlomis Rotata Reduces Neuropathic Pain by Inhibiting the ERK/TNF-α Pathway in Spinal Astrocytes

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2018-03-01

    Full Text Available Lamiophlomis rotata (L. rotata; Benth. Kudo is an effective traditional herb in the clinical treatment of chronic pain syndromes in China. 8-O-acetyl shanzhiside methylester (8-OaS, a chief component in L. rotata, possesses potent immunosuppressive activities and favorable analgesic effects. This study was proposed to compare the analgesic effects of 8-OaS with those of lidocaine and ketamine in a spinal nerve ligation (SNL model by behavioral tests, and then investigated its effects upon the expression of spinal glial fibrillary acidic protein (GFAP, phosphorylated extracellular regulated protein kinases (pERK and tumor necrosis factor-alpha (TNF-α via immunofluorescence staining and western blot analyses. The data showed consecutive intrathecal injection of 8-OaS for 2 weeks brought about remarkable palliation of neuropathic pain (NP, possessing similar anti-allodynia effects with those of lidocaine and ketamine. Two weeks after surgery, pERK within the spinal dorsal horn was mainly expressed in astrocytes more than neurons and microglia, and 8-OaS inhibited spinal astrocytic activation and TNF-α expression. Finally, co-treatment of 8-OaS and PD98059 (an Extracellular signal-regulated kinase, ERK inhibitor did not lead to remarkable increase in pain relief or TNF-α expression comparing to rats treated with 8-OaS or PD98059 alone. In conclusion, the anti-nociceptive effects of 8-OaS in the condition of NP relied on the inhibition of SNL-induced astrocyte activation, probably via the down-regulation of the ERK/TNF-α pathway.

  9. 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.

  10. Icaritin induces MC3T3-E1 subclone14 cell differentiation through estrogen receptor-mediated ERK1/2 and p38 signaling activation.

    Science.gov (United States)

    Wu, Zhidi; Ou, Ling; Wang, Chaopeng; Yang, Li; Wang, Panpan; Liu, Hengrui; Xiong, Yingquan; Sun, Kehuan; Zhang, Ronghua; Zhu, Xiaofeng

    2017-10-01

    Icaritin (ICT), a hydrolytic product of icariin from the genus Epimedium, has many indicated pharmacological and biological activities. Several studies have shown that ICT has potential osteoprotective effects, including stimulation of osteoblast differentiation and inhibition of osteoclast differentiation. However, the molecular mechanism for this anabolic action of ICT remains largely unknown. Here, we found that ICT could enhance MC3T3-E1 subclone 14 preosteoblastic cell differentiation associated with increased mRNA levels and protein expression of the differentiation markers alkaline phosphatase (ALP), type 1 collagen (COL1), osteocalcin (OC), osteoponin (OPN) and runt-related transcription factor 2 (RUNX2), and improved mineralization, confirmed by bone nodule formation and collagen synthesis. To characterize the underlying mechanisms, we examined the effect of ICT on estrogen receptor (ER) and mitogen-activated protein kinase (MAPK) signaling. ICT treatment induced p38 kinase and extracellular signal-regulated kinase 1/2 (ERK1/2) activation, but it demonstrated at the same time point no effect on activation of c-Jun N-terminal kinase (JNK). ER antagonist ICI182780, p38 antagonist SB203580 and ERK1/2 antagonist PD98059 markedly inhibited the ICT-induced the mRNA expression of ALP, COL1, OC and OPN. ICI182780 attenuated the ICT-induced phosphorylation of p38 and ERK1/2. These observations indicate a potential mechanism of osteogenic effects of ICT involving the ERK1/2 and p38 pathway activation through the ER. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Radiotherapy-induced plasticity of prostate cancer mobilizes stem-like non-adherent, Erk signaling-dependent cells

    Czech Academy of Sciences Publication Activity Database

    Kyjacová, Lenka; Hubáčková, Soňa; Krejčíková, Kateřina; Strauss, R.; Hanzlíková, Hana; Dzijak, Rastislav; Imrichová, Terezie; Šímová, Jana; Reiniš, Milan; Bartek, Jiří; Hodný, Zdeněk

    2015-01-01

    Roč. 22, č. 6 (2015), s. 898-911 ISSN 1350-9047 R&D Projects: GA ČR GA13-17658S; GA MZd NT14461 EU Projects: European Commission 259893 Institutional support: RVO:68378050 Keywords : Radiotherapy-induced plasticity * prostate cancer * Erk signaling Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.218, year: 2015

  12. Effect of Repeated Electroacupuncture Intervention on Hippocampal ERK and p38MAPK Signaling in Neuropathic Pain Rats

    Directory of Open Access Journals (Sweden)

    Jun-ying Wang

    2015-01-01

    Full Text Available Results of our past studies showed that hippocampal muscarinic acetylcholine receptor (mAChR-1 mRNA and differentially expressed proteins participating in MAPK signaling were involved in electroacupuncture (EA induced cumulative analgesia in neuropathic pain rats, but the underlying intracellular mechanism remains unknown. The present study was designed to observe the effect of EA stimulation (EAS on hippocampal extracellular signal-regulated kinases (ERK and p38 MAPK signaling in rats with chronic constrictive injury (CCI of the sciatic nerve, so as to reveal its related intracellular targets in pain relief. After CCI, the thermal pain thresholds of the affected hind were significantly decreased compared with the control group (P<0.05. Following one and two weeks’ EAS of ST 36-GB34, the pain thresholds were significantly upregulated (P<0.05, and the effect of EA2W was remarkably superior to that of EA2D and EA1W (P<0.05. Correspondingly, CCI-induced decreased expression levels of Ras, c-Raf, ERK1 and p-ERK1/2 proteins, and p38 MAPK mRNA and p-p38MAPK protein in the hippocampus tissues were reversed by EA2W (P<0.05. The above mentioned results indicated that EA2W induced cumulative analgesic effect may be closely associated with its function in removing neuropathic pain induced suppression of intracellular ERK and p38MAPK signaling in the hippocampus.

  13. Modularized Smad-regulated TGFβ signaling pathway.

    Science.gov (United States)

    Li, Yongfeng; Wang, Minli; Carra, Claudio; Cucinotta, Francis A

    2012-12-01

    The transforming Growth Factor β (TGFβ) signaling pathway is a prominent regulatory signaling pathway controlling various important cellular processes. TGFβ signaling can be induced by several factors including ionizing radiation. The pathway is regulated in a negative feedback loop through promoting the nuclear import of the regulatory Smads and a subsequent expression of inhibitory Smad7, that forms ubiquitin ligase with Smurf2, targeting active TGFβ receptors for degradation. In this work, we proposed a mathematical model to study the Smad-regulated TGFβ signaling pathway. By modularization, we are able to analyze mathematically each component subsystem and recover the nonlinear dynamics of the entire network system. Meanwhile the excitability, a common feature observed in the biological systems, in the TGFβ signaling pathway is discussed and supported as well by numerical simulation, indicating the robustness of the model. Published by Elsevier Inc.

  14. Neuronal extracellular signal-regulated kinase (ERK activity as marker and mediator of alcohol and opioid dependence

    Directory of Open Access Journals (Sweden)

    Eva R. Zamora-Martinez

    2014-03-01

    Full Text Available Early pioneering work in the field of biochemistry identified phosphorylation as a crucial post-translational modification of proteins with the ability to both indicate and arbitrate complex physiological processes. More recent investigations have functionally linked phosphorylation of extracellular signal-regulated kinase (ERK to a variety of neurophysiological mechanisms ranging from acute neurotransmitter action to long-term gene expression. ERK phosphorylation serves as an intracellular bridging mechanism that facilitates neuronal communication and plasticity. Drugs of abuse, including alcohol and opioids, act as artificial yet powerful rewards that impinge upon natural reinforcement processes critical for survival. The graded progression from initial exposure to addiction (or substance dependence is believed to result from drug- and drug context-induced adaptations in neuronal signaling processes across brain reward and stress circuits following excessive drug use. In this regard, commonly abused drugs as well as drug-associated experiences are capable of modifying the phosphorylation of ERK within central reinforcement systems. In addition, chronic drug and alcohol exposure may drive ERK-regulated epigenetic and structural alterations that underlie a long-term propensity for escalating drug use. Under the influence of such a neurobiological vulnerability, encountering drug-associated cues and contexts can produce subsequent alterations in ERK signaling that drive relapse to drug and alcohol seeking. Current studies are determining precisely which molecular and regional ERK phosphorylation-associated events contribute to the addiction process, as well as which neuroadaptations need to be targeted in order to return dependent individuals to a healthy state.

  15. In brown adipocytes, adrenergically induced β1-/β3-(Gs)-, α2-(Gi)- and α1-(Gq)-signalling to Erk1/2 activation is not mediated via EGF receptor transactivation

    International Nuclear Information System (INIS)

    Wang, Yanling; Fälting, Johanna M.; Mattsson, Charlotte L.; Holmström, Therése E.; Nedergaard, Jan

    2013-01-01

    Brown adipose tissue is unusual in that the neurotransmitter norepinephrine influences cell destiny in ways generally associated with effects of classical growth factors: regulation of cell proliferation, of apoptosis, and progression of differentiation. The norepinephrine effects are mediated through G-protein-coupled receptors; further mediation of such stimulation to e.g. Erk1/2 activation is in cell biology in general accepted to occur through transactivation of the EGF receptor (by external or internal pathways). We have examined here the significance of such transactivation in brown adipocytes. Stimulation of mature brown adipocytes with cirazoline (α 1 -adrenoceptor coupled via G q ), clonidine (α 2 via G i ) or CL316243 (β 3 via G s ) or via β 1 -receptors significantly activated Erk1/2. Pretreatment with the EGF receptor kinase inhibitor AG1478 had, remarkably, no significant effect on Erk1/2 activation induced by any of these adrenergic agonists (although it fully abolished EGF-induced Erk1/2 activation), demonstrating absence of EGF receptor-mediated transactivation. Results with brown preadipocytes (cells in more proliferative states) were not qualitatively different. Joint stimulation of all adrenoceptors with norepinephrine did not result in synergism on Erk1/2 activation. AG1478 action on EGF-stimulated Erk1/2 phosphorylation showed a sharp concentration–response relationship (IC 50 0.3 µM); a minor apparent effect of AG1478 on norepinephrine-stimulated Erk1/2 phosphorylation showed nonspecific kinetics, implying caution in interpretation of partial effects of AG1478 as reported in other systems. Transactivation of the EGF receptor is clearly not a universal prerequisite for coupling of G-protein coupled receptors to Erk1/2 signalling cascades. - Highlights: • In brown adipocytes, norepinephrine regulates proliferation, apoptosis, differentiation. • EGF receptor transactivation is supposed to mediate GPCR-induced Erk1/2 activation. •

  16. The MAPK ERK5, but not ERK1/2, inhibits the progression of monocytic phenotype to the functioning macrophage

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuening [Department of Pathology and Laboratory Medicine, Rutgers, NJ Medical School, 185 South Orange Ave, Newark, NJ 07103 (United States); Pesakhov, Stella [Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, PO Box 653, 84105 Beer-Sheva (Israel); Harrison, Jonathan S [Department of Medicine, Rutgers, Robert Wood Johnson Medical School, New Brunswick, NJ 08903 (United States); Kafka, Michael; Danilenko, Michael [Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, PO Box 653, 84105 Beer-Sheva (Israel); Studzinski, George P, E-mail: studzins@njms.rutgers.edu [Department of Pathology and Laboratory Medicine, Rutgers, NJ Medical School, 185 South Orange Ave, Newark, NJ 07103 (United States)

    2015-01-01

    Intracellular signaling pathways present targets for pharmacological agents with potential for treatment of neoplastic diseases, with some disease remissions already recorded. However, cellular compensatory mechanisms usually negate the initial success. For instance, attempts to interrupt aberrant signaling downstream of the frequently mutated ras by inhibiting ERK1/2 has shown only limited usefulness for cancer therapy. Here, we examined how ERK5, that overlaps the functions of ERK1/2 in cell proliferation and survival, functions in a manner distinct from ERK1/2 in human AML cells induced to differentiate by 1,25D-dihydroxyvitamin D{sub 3} (1,25D). Using inhibitors of ERK1/2 and of MEK5/ERK5 at concentrations specific for each kinase in HL60 and U937 cells, we observed that selective inhibition of the kinase activity of ERK5, but not of ERK1/2, in the presence of 1,25D resulted in macrophage-like cell morphology and enhancement of phagocytic activity. Importantly, this was associated with increased expression of the macrophage colony stimulating factor receptor (M-CSFR), but was not seen when M-CSFR expression was knocked down. Interestingly, inhibition of ERK1/2 led to activation of ERK5 in these cells. Our results support the hypothesis that ERK5 negatively regulates the expression of M-CSFR, and thus has a restraining function on macrophage differentiation. The addition of pharmacological inhibitors of ERK5 may influence trials of differentiation therapy of AML. - Highlights: • ERK5 has at least some functions in AML cells which are distinct from those of ERK1/2. • ERK5 activity negatively controls the expression of M-CSFR. • ERK5 retards the progression of differentiation from monocyte to functional macrophage.

  17. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes.

    Science.gov (United States)

    Liu, Ping; Kong, Feng; Wang, Jue; Lu, Qinghua; Xu, Haijia; Qi, Tonggang; Meng, Juan

    2015-02-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0-G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Resveratrol engages AMPK to attenuate ERK and mTOR signaling in sensory neurons and inhibits incision-induced acute and chronic pain

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    Tillu Dipti V

    2012-01-01

    Full Text Available Abstract Background Despite advances in our understanding of basic mechanisms driving post-surgical pain, treating incision-induced pain remains a major clinical challenge. Moreover, surgery has been implicated as a major cause of chronic pain conditions. Hence, more efficacious treatments are needed to inhibit incision-induced pain and prevent the transition to chronic pain following surgery. We reasoned that activators of AMP-activated protein kinase (AMPK may represent a novel treatment avenue for the local treatment of incision-induced pain because AMPK activators inhibit ERK and mTOR signaling, two important pathways involved in the sensitization of peripheral nociceptors. Results To test this hypothesis we used a potent and efficacious activator of AMPK, resveratrol. Our results demonstrate that resveratrol profoundly inhibits ERK and mTOR signaling in sensory neurons in a time- and concentration-dependent fashion and that these effects are mediated by AMPK activation and independent of sirtuin activity. Interleukin-6 (IL-6 is thought to play an important role in incision-induced pain and resveratrol potently inhibited IL-6-mediated signaling to ERK in sensory neurons and blocked IL-6-mediated allodynia in vivo through a local mechanism of action. Using a model of incision-induced allodynia in mice, we further demonstrate that local injection of resveratrol around the surgical wound strongly attenuates incision-induced allodynia. Intraplantar IL-6 injection and plantar incision induces persistent nociceptive sensitization to PGE2 injection into the affected paw after the resolution of allodynia to the initial stimulus. We further show that resveratrol treatment at the time of IL-6 injection or plantar incision completely blocks the development of persistent nociceptive sensitization consistent with the blockade of a transition to a chronic pain state by resveratrol treatment. Conclusions These results highlight the importance of signaling

  19. 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.

  20. Cryptotanshinone Regulates Androgen Synthesis through the ERK/c-Fos/CYP17 Pathway in Porcine Granulosa Cells

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    Danfeng Ye

    2017-01-01

    Full Text Available The aim of the study is to investigate the molecular mechanism behind androgen reduction in porcine granulosa cells (pGCs with Salvia miltiorrhiza Bunge extract cryptotanshinone. PGCs were isolated from porcine ovaries and identified. Androgen excess model of the pGCs was induced with the MAPK inhibitor PD98059 and then treated with cryptotanshinone. The testosterone level was measured by radioimmunoassay in the culture media. The protein levels of P-ERK1/2, c-Fos, and CYP17 in the cells were measured by western blot. Cryptotanshinone decreased the concentration of testosterone and the protein level of CYP17 and increased the protein levels of P-ERK1/2 and c-Fos in the androgen excess mode. After the c-Fos gene was silenced by infection with c-Fos shRNA lentivirus, we measured the mRNA expression by quantitative RT-PCR and protein level by western blot of P-ERK1/2, c-Fos, and CYP17. This showed that the mRNA expression and protein level of P-ERK1/2 and c-Fos were significantly reduced in the shRNA–c-Fos group compared to the scrambled group, while those of CYP17 were significantly increased. So we concluded that cryptotanshinone can significantly reduce the androgen excess induced by PD98059 in pGCs. The possible molecular mechanism for this activity is regulating the ERK/c-Fos/CYP17 pathway.

  1. Spaced training rescues memory and ERK1/2 signaling in fragile X syndrome model mice.

    Science.gov (United States)

    Seese, Ronald R; Wang, Kathleen; Yao, Yue Qin; Lynch, Gary; Gall, Christine M

    2014-11-25

    Recent studies have shown that short, spaced trains of afferent stimulation produce much greater long-term potentiation (LTP) than that obtained with a single, prolonged stimulation episode. The present studies demonstrate that spaced training regimens, based on these LTP timing rules, facilitate learning in wild-type (WT) mice and can offset learning and synaptic signaling impairments in the fragile X mental retardation 1 (Fmr1) knockout (KO) model of fragile X syndrome. We determined that 5 min of continuous training supports object location memory (OLM) in WT but not Fmr1 KO mice. However, the same amount of training distributed across three short trials, spaced by one hour, produced robust long-term memory in the KOs. At least three training trials were needed to realize the benefit of spacing, and intertrial intervals shorter or longer than 60 min were ineffective. Multiple short training trials also rescued novel object recognition in Fmr1 KOs. The spacing effect was surprisingly potent: just 1 min of OLM training, distributed across three trials, supported robust memory in both genotypes. Spacing also rescued training-induced activation of synaptic ERK1/2 in dorsal hippocampus of Fmr1 KO mice. These results show that a spaced training regimen designed to maximize synaptic potentiation facilitates recognition memory in WT mice and can offset synaptic signaling and memory impairments in a model of congenital intellectual disability.

  2. Propiconazole-enhanced hepatic cell proliferation is associated with dysregulation of the cholesterol biosynthesis pathway leading to activation of Erk1/2 through Ras farnesylation

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Lynea A.; Moore, Tanya; Nesnow, Stephen, E-mail: nesnow.stephen@epa.gov

    2012-04-15

    Propiconazole is a mouse hepatotumorigenic fungicide designed to inhibit CYP51, a key enzyme in the biosynthesis of ergosterol in fungi and is widely used in agriculture to prevent fungal growth. Metabolomic studies in mice revealed that propiconazole increased levels of hepatic cholesterol metabolites and bile acids, and transcriptomic studies revealed that genes within the cholesterol biosynthesis, cholesterol metabolism and bile acid biosyntheses pathways were up-regulated. Hepatic cell proliferation was also increased by propiconazole. AML12 immortalized hepatocytes were used to study propiconazole's effects on cell proliferation focusing on the dysregulation of cholesterol biosynthesis and resulting effects on Ras farnesylation and Erk1/2 activation as a primary pathway. Mevalonate, a key intermediate in the cholesterol biosynthesis pathway, increases cell proliferation in several cancer cell lines and tumors in vivo and serves as the precursor for isoprenoids (e.g. farnesyl pyrophosphate) which are crucial in the farnesylation of the Ras protein by farnesyl transferase. Farnesylation targets Ras to the cell membrane where it is involved in signal transduction, including the mitogen-activated protein kinase (MAPK) pathway. In our studies, mevalonic acid lactone (MVAL), a source of mevalonic acid, increased cell proliferation in AML12 cells which was reduced by farnesyl transferase inhibitors (L-744,832 or manumycin) or simvastatin, an HMG-CoA reductase inhibitor, indicating that this cell system responded to alterations in the cholesterol biosynthesis pathway. Cell proliferation in AML12 cells was increased by propiconazole which was reversed by co-incubation with L-744,832 or simvastatin. Increasing concentrations of exogenous cholesterol muted the proliferative effects of propiconazole and the inhibitory effects of L-733,832, results ascribed to reduced stimulation of the endogenous cholesterol biosynthesis pathway. Western blot analysis of subcellular

  3. 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.

  4. Enhanced expressions of microvascular smooth muscle receptors after focal cerebral ischemia occur via the MAPK MEK/ERK pathway

    DEFF Research Database (Denmark)

    Maddahi, A.; Edvinsson, L.

    2008-01-01

    ), the enhanced vascular receptor expression, and attenuated the cerebral infarct and improved neurology score. CONCLUSION: Our results show that MCAO results in upregulation of cerebrovascular ETB, AT1 and 5-HT1B receptors. Blockade of this event with a MEK1 inhibitor as late as 6 h after the insult reduced...... the role of the MEK/ERK pathway in receptor expression following ischemic brain injury using the specific MEK1 inhibitor U0126. METHODS AND RESULT: Rats were subjected to a 2-h middle cerebral artery occlusion (MCAO) followed by reperfusion for 48-h and the ischemic area was calculated. The expression...... of phosphorylated ERK1/2 and Elk-1, and of endothelin ETA and ETB, angiotensin AT1, and 5-hydroxytryptamine 5-HT1B receptors were analyzed with immunohistochemistry using confocal microscopy in cerebral arteries, microvessels and in brain tissue. The expression of endothelin ETB receptor was analyzed...

  5. Different Expression of Extracellular Signal-Regulated Kinases (ERK) 1/2 and Phospho-Erk Proteins in MBA-MB-231 and MCF-7 Cells after Chemotherapy with Doxorubicin or Docetaxel.

    Science.gov (United States)

    Taherian, Aliakbar; Mazoochi, Tahereh

    2012-01-01

    Curative treatment of breast cancer patients using chemotherapy often fails as a result of intrinsic or acquired resistance of the tumor to the drug. ERK is one of the main components of the Ras/Raf/MEK/ERK cascade, which mediates signal from cell surface receptors to transcription factors to regulate different gene expression. In this study, cytotoxicity and the expression of Erk1/2 and phospho-ERK was compared in MDA-MB-231 (ER-) and MCF-7 (ER+) cell lines after treatment with doxorubicin (DOX) or docetaxel (DOCT). Cell cytotoxicity of DOX or DOCT was calculated using MTT assay. Immonofluorescent technique was used to show MDR-1 protein in MDA-MB-231 and MCF-7 cells after treatment with DOX or DOCT. The expression of ERK1/2 and phpspho-ERK was assayed with immunoblotting. Comparing IC50 values showed that MDA-MB-231 cells are more sensitive than MCF-7 cells to DOX or DOCT. Immonofluorescent results confirmed the expression of MDR-1 in these two cell lines after DOX or DOCT treatment. In MDA-MB-231 cells the expression of ERK1/2 and phospho-ERK was decreased after DOX treatment in a dose-dependent manner. In contrast in MCF-7 cells the expression of ERK1/2 and phospho-ERK was increased after DOX treatment. DOCT treatment demonstrated the same result with less significant differences than DOX. The heterogeneity seen in cell lines actually reflects the heterogeneity of breast cancers. That is why, patients categorized in one group respond differently to a single treatment. These results emphasize the importance of a more accurate classification and a more specific treatment of breast cancer subtypes.

  6. Mitochondrial fission promotes cell migration by Ca2+ /CaMKII/ERK/FAK pathway in hepatocellular carcinoma.

    Science.gov (United States)

    Sun, Xiacheng; Cao, Haiyan; Zhan, Lei; Yin, Chun; Wang, Gang; Liang, Ping; Li, Jibin; Wang, Zhe; Liu, Bingrong; Huang, Qichao; Xing, Jinliang

    2018-07-01

    Mitochondrial dynamics of fission and fusion plays critical roles in a diverse range of important cellular functions, and its deregulation has been increasingly implicated in human diseases. Previous studies have shown that increased mitochondrial fission significantly promoted the proliferation of hepatocellular carcinoma (HCC) cells. However, how they influence the migration of tumour cells remained largely unknown. In the present study, we further investigated the effect of mitochondrial fission on the migration and metastasis of hepatocellular carcinoma cells. Moreover, the underlying molecular mechanisms and therapeutic application were explored. Our data showed that dynamin-1-like protein expression was strongly increased in distant metastasis of hepatocellular carcinoma when compared to primary hepatocellular carcinoma. In contrast, the mitochondrial fusion protein mitofusin 1 showed an opposite trend. Moreover, the expression of dynamin-1-like protein and mitofusin 1 was significantly associated with the disease-free survival of hepatocellular carcinoma patients. In addition, our data further showed that mitochondrial fission significantly promoted the reprogramming of focal-adhesion dynamics and lamellipodia formation in hepatocellular carcinoma cells mainly by activating typical Ca 2+ /CaMKII/ERK/FAK pathway. Importantly, treatment with mitochondrial division inhibitor-1 significantly decreased calcium signalling in hepatocellular carcinoma cells and had a potential treatment effect for hepatocellular carcinoma metastasis in vivo. Taken together, our findings demonstrate that mitochondrial fission plays a critical role in the regulation of hepatocellular carcinoma cell migration, which provides strong evidence for this process as a drug target in hepatocellular carcinoma metastasis treatment. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Investigation of radiation-induced multilayered signalling response of the inflammatory pathway

    International Nuclear Information System (INIS)

    Babini, G.; Ugolini, M.; Morini, J.; Baiocco, G.; Ottolenghi, A.; Mariotti, L.; Tabarelli de Fatis, P.; Liotta, M.

    2015-01-01

    Ionising radiation exposure of cells might induce the perturbation of cell functions and, in particular, the activation or inhibition of several important pathways. This perturbation can cause the deregulation of both intra- and extra-cellular signalling cascades (such as the inflammatory pathway) and alter not only the behaviour of directly exposed cells but also the neighbouring nonirradiated ones, through the so-called bystander effect. The aim of the present work was to investigate the complex nonlinear interactions between the inflammatory pathway and other strictly interlaced signalling pathways, such as Erk1/2 and Akt/PKB, focusing on the radiation-induced perturbation of such pathways in the dose range of 0 -2 Gy. The results show how radiation affects these interconnected pathways and how confounding factors, such as the change of culture medium, can hide radiation-induced perturbations. (authors)

  8. Modularized TGFbeta-Smad Signaling Pathway

    Science.gov (United States)

    Li, Yongfeng; Wang, M.; Carra, C.; Cucinotta, F. A.

    2011-01-01

    The Transforming Growth Factor beta (TGFbeta) signaling pathway is a prominent regulatory signaling pathway controlling various important cellular processes. It can be induced by several factors, including ionizing radiation. It is regulated by Smads in a negative feedback loop through promoting increases in the regulatory Smads in the cell nucleus, and subsequent expression of inhibitory Smad, Smad7 to form a ubiquitin ligase with Smurf targeting active TGF receptors for degradation. In this work, we proposed a mathematical model to study the radiation-induced Smad-regulated TGF signaling pathway. By modularization, we are able to analyze each module (subsystem) and recover the nonlinear dynamics of the entire network system. Meanwhile the excitability, a common feature observed in the biological systems, along the TGF signaling pathway is discussed by mathematical analysis and numerical simulation.

  9. Potential role of insulin signaling on vascular smooth muscle cell migration, proliferation, and inflammation pathways.

    Science.gov (United States)

    Cersosimo, Eugenio; Xu, Xiaojing; Musi, Nicolas

    2012-02-15

    To investigate the role of insulin signaling pathways in migration, proliferation, and inflammation of vascular smooth muscle cells (VSMCs), we examined the expression of active components of the phosphatidyl inositol 3 (PI-3) kinase (p-Akt) and mitogen-activated protein kinase (MAPK) (p-Erk) in primary cultures of VSMCs from human coronary arteries. VSMCs were treated in a dose-response manner with insulin (0, 1, 10, and 100 nM) for 20 min, and Akt and Erk phosphorylation were measured by Western blot analysis. In separate experiments, we evaluated the effect of 200 μM palmitate, in the presence and absence of 8 μM pioglitazone, on insulin-stimulated (100 nM for 20 min) Akt and Erk phosphorylation. The phosphorylation of Akt and Erk in VSMCs exhibited a dose dependency with a three- to fourfold increase, respectively, at the highest dose (100 nM). In the presence of palmitate, insulin-induced Akt phosphorylation was completely abolished, and there was a threefold increase in p-Erk. With addition of pioglitazone, the phosphorylation of Akt by insulin remained unchanged, whereas insulin-stimulated Erk phosphorylation was reduced by pioglitazone. These data in VSMCs indicate that high palmitate decreases insulin-stimulated Akt phosphorylation and stimulates MAPK, whereas preexposure peroxisome proliferator-activated receptor-γ agonist pioglitazone preserves Akt phosphorylation and simultaneously attenuates MAPK signaling. Our results suggest that metabolic and mitogenic insulin signals have different sensitivity, are independently regulated, and may play a role in arterial smooth muscle cells migration, proliferation, and inflammation in conditions of acute hyperinsulinemia.

  10. Signaling pathways regulating murine pancreatic development

    DEFF Research Database (Denmark)

    Serup, Palle

    2012-01-01

    The recent decades have seen a huge expansion in our knowledge about pancreatic development. Numerous lineage-restricted transcription factor genes have been identified and much has been learned about their function. Similarly, numerous signaling pathways important for pancreas development have...... been identified and the specific roles have been investigated by genetic and cell biological methods. The present review presents an overview of the principal signaling pathways involved in regulating murine pancreatic growth, morphogenesis, and cell differentiation....

  11. 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.

  12. Leptin Stimulates Prolactin mRNA Expression in the Goldfish Pituitary through a Combination of the PI3K/Akt/mTOR, MKK3/6/p38MAPK and MEK1/2/ERK1/2 Signalling Pathways.

    Science.gov (United States)

    Yan, Aifen; Chen, Yanfeng; Chen, Shuang; Li, Shuisheng; Zhang, Yong; Jia, Jirong; Yu, Hui; Liu, Lian; Liu, Fang; Hu, Chaoqun; Tang, Dongsheng; Chen, Ting

    2017-12-20

    Leptin actions at the pituitary level have been extensively investigated in mammalian species, but remain insufficiently characterized in lower vertebrates, especially in teleost fish. Prolactin (PRL) is a pituitary hormone of central importance to osmoregulation in fish. Using goldfish as a model, we examined the global and brain-pituitary distribution of a leptin receptor (lepR) and examined the relationship between expression of lepR and major pituitary hormones in different pituitary regions. The effects of recombinant goldfish leptin-AI and leptin-AII on PRL mRNA expression in the pituitary were further analysed, and the mechanisms underlying signal transduction for leptin-induced PRL expression were determined by pharmacological approaches. Our results showed that goldfish lepR is abundantly expressed in the brain-pituitary regions, with highly overlapping PRL transcripts within the pituitary. Recombinant goldfish leptin-AI and leptin-AII proteins could stimulate PRL mRNA expression in dose- and time-dependent manners in the goldfish pituitary, by both intraperitoneal injection and primary cell incubation approaches. Moreover, the PI3K/Akt/mTOR, MKK 3/6 /p 38 MAPK, and MEK 1/2 /ERK 1/2 -but not JAK2/STAT 1, 3 and 5 cascades-were involved in leptin-induced PRL mRNA expression in the goldfish pituitary.

  13. Non-transactivational, dual pathways for LPA-induced Erk1/2 activation in primary cultures of brown pre-adipocytes

    International Nuclear Information System (INIS)

    Holmstroem, Therese E.; Mattsson, Charlotte L.; Wang, Yanling; Iakovleva, Irina; Petrovic, Natasa; Nedergaard, Jan

    2010-01-01

    In many cell types, G-protein-coupled receptor (GPCR)-induced Erk1/2 MAP kinase activation is mediated via receptor tyrosine kinase (RTK) transactivation, in particular via the epidermal growth factor (EGF) receptor. Lysophosphatidic acid (LPA), acting via GPCRs, is a mitogen and MAP kinase activator in many systems, and LPA can regulate adipocyte proliferation. The mechanism by which LPA activates the Erk1/2 MAP kinase is generally accepted to be via EGF receptor transactivation. In primary cultures of brown pre-adipocytes, EGF can induce Erk1/2 activation, which is obligatory and determinant for EGF-induced proliferation of these cells. Therefore, we have here examined whether LPA, via EGF transactivation, can activate Erk1/2 in brown pre-adipocytes. We found that LPA could induce Erk1/2 activation. However, the LPA-induced Erk1/2 activation was independent of transactivation of EGF receptors (or PDGF receptors) in these cells (whereas in transformed HIB-1B brown adipocytes, the LPA-induced Erk1/2 activation indeed proceeded via EGF receptor transactivation). In the brown pre-adipocytes, LPA instead induced Erk1/2 activation via two distinct non-transactivational pathways, one G i -protein dependent, involving PKC and Src activation, the other, a PTX-insensitive pathway, involving PI3K (but not Akt) activation. Earlier studies showing LPA-induced Erk1/2 activation being fully dependent on RTK transactivation have all been performed in cell lines and transfected cells. The present study implies that in non-transformed systems, RTK transactivation may not be involved in the mediation of GPCR-induced Erk1/2 MAP kinase activation.

  14. 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol negatively regulates activation of STAT3 and ERK pathways and exhibits anti-cancer effects in HepG2 cells.

    Science.gov (United States)

    Ai, Hui-Han; Zhou, Zi-Long; Sun, Lu-Guo; Yang, Mei-Ting; Li, Wei; Yu, Chun-Lei; Song, Zhen-Bo; Huang, Yan-Xin; Wu, Yin; Liu, Lei; Yang, Xiao-Guang; Zhao, Yu-Qing; Bao, Yong-Li; Li, Yu-Xin

    2017-11-01

    The pro-inflammatory cytokine interleukin 6 (IL-6), via activating its downstream JAK/STAT3 and Ras/ERK signaling pathways, is involved in cell growth, proliferation and anti-apoptotic activities in various malignancies. To screen inhibitors of IL-6 signaling, we constructed a STAT3 and ERK dual-pathway responsive luciferase reporter vector (Co.RE). Among several candidates, the natural compound 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol (25-OCH 3 -PPD, GS25) was identified to clearly inhibit the luciferase activity of Co.RE. GS25 was confirmed to indeed inhibit activation of both STAT3 and ERK pathways and expression of downstream target genes of IL-6, and to predominantly decrease the viability of HepG2 cells via induction of cell cycle arrest and apoptosis. Interestingly, GS25 showed preferential inhibition of HepG2 cell viability relative to normal liver L02 cells. Further investigation showed that GS25 could not induce apoptosis and block activation of STAT3 and ERK pathways in L02 cells as efficiently as in HepG2 cells, which may result in differential effects of GS25 on malignant and normal liver cells. In addition, GS25 was found to potently suppress the expression of endogenous STAT3 at a higher concentration and dramatically induce p38 phosphorylation in HepG2 cells, which could mediate its anti-cancer effects. Finally, we demonstrated that GS25 also inhibited tumor growth in HepG2 xenograft mice. Taken together, these findings indicate that GS25 elicits its anti-cancer effects on HepG2 cells through multiple mechanisms and has the potential to be used as an inhibitor of IL-6 signaling. Thus, GS25 may be developed as a treatment for hepatocarcinoma with low toxicity on normal liver tissues as well as other inflammation-associated diseases.

  15. 3D Organotypic Culture Model to Study Components of ERK Signaling.

    Science.gov (United States)

    Chioni, Athina-Myrto; Bajwa, Rabia Tayba; Grose, Richard

    2017-01-01

    Organotypic models are 3D in vitro representations of an in vivo environment. Their complexity can range from an epidermal replica to the establishment of a cancer microenvironment. These models have been used for many years, in an attempt to mimic the structure and function of cells and tissues found inside the body. Methods for developing 3D organotypic models differ according to the tissue of interest and the experimental design. For example, cultures may be grown submerged in culture medium and or at an air-liquid interface. Our group is focusing on an air-liquid interface 3D organotypic model. These cultures are grown on a nylon membrane-covered metal grid with the cells embedded in a Collagen-Matrigel gel. This allows cells to grow in an air-liquid interface to enable diffusion and nourishment from the medium below. Subsequently, the organotypic cultures can be used for immunohistochemical staining of various components of ERK signaling, which is a key player in mediating communication between cells and their microenvironment.

  16. Simple, mammalian cell-based assay for identification of inhibitors of the Erk MAP kinase pathway

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Pejchalová, K.; Wilcox, W.R.

    2007-01-01

    Roč. 25, č. 4 (2007), s. 391-395 ISSN 0167-6997 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Erk * inhibitor * FGFR3 Subject RIV: BO - Biophysics Impact factor: 2.806, year: 2007

  17. SPRY4-mediated ERK1/2 signaling inhibition abolishes 17β-estradiol-induced cell growth in endometrial adenocarcinoma cell.

    Science.gov (United States)

    Li, Mingjiang; Zhang, Hui; Zhao, Xingbo; Yan, Lei; Wang, Chong; Li, Chunyan; Li, Changzhong

    2014-08-01

    Basic fibroblast growth factor (FGF2)-mediated Extracellular signal-regulated kinases1/2 (ERK1/2) signaling is a critical modulator in angiogenesis. SPRY4 has been reported to be a feedback negative regulator of FGFs-induced ERK1/2 signaling. The aim of this study was to explore the role of SPRY4 in endometrial adenocarcinoma cell. The effect of SPRY4 expression on FGF2-mediated ERK1/2 signaling was detected by luciferase assay and Western blot analysis. The growth of Ishikawa cells was detected using colony formation assay and cell number counting experiment. We found that plasmid-driven SPRY4 expression efficiently blocked the activity of FGF2-induced ERK1/2 signaling in Ishikawa cells. SPRY4 expression significantly reduced the proliferation and 17β-estradiol-induced proliferation of Ishikawa cells. SPRY4 may function as a tumor suppressor in endometrial adenocarcinoma.

  18. RSK is a principal effector of the RAS-ERK pathway for eliciting a coordinate promotile/invasive gene program and phenotype in epithelial cells

    DEFF Research Database (Denmark)

    Doehn, Ulrik; Hauge, Camilla; Frank, Scott R

    2009-01-01

    The RAS-stimulated RAF-MEK-ERK pathway confers epithelial cells with critical motile and invasive capacities during development, tissue regeneration, and carcinoma progression, often via promoting the epithelial-mesenchymal transition (EMT). Many mechanisms by which ERK exerts this control remain...... elusive. We demonstrate that the ERK-activated kinase RSK is necessary to induce mesenchymal motility and invasive capacities in nontransformed epithelial and carcinoma cells. RSK is sufficient to induce certain motile responses. Expression profiling analysis revealed that a primary role of RSK...... to stimulate motility and invasion. These findings uncover a mechanism whereby the RAS-ERK pathway controls epithelial cell motility by identifying RSK as a key effector, from which emanate multiple highly coordinate transcription-dependent mechanisms for stimulation of motility and invasive properties....

  19. Targeting Apoptosis Signaling Pathways for Anticancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fulda, Simone, E-mail: simone.fulda@kgu.de [Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Frankfurt (Germany)

    2011-08-29

    Treatment approaches for cancer, for example chemotherapy, radiotherapy, or immunotherapy, primarily act by inducing cell death in cancer cells. Consequently, the inability to trigger cell death pathways or alternatively, evasion of cancer cells to the induction of cell death pathways can result in resistance of cancers to current treatment protocols. Therefore, in order to overcome treatment resistance a better understanding of the underlying mechanisms that regulate cell death and survival pathways in cancers and in response to cancer therapy is necessary to develop molecular-targeted therapies. This strategy should lead to more effective and individualized treatment strategies that selectively target deregulated signaling pathways in a tumor type- and patient-specific manner.

  20. Targeting Apoptosis Signaling Pathways for Anticancer Therapy

    International Nuclear Information System (INIS)

    Fulda, Simone

    2011-01-01

    Treatment approaches for cancer, for example chemotherapy, radiotherapy, or immunotherapy, primarily act by inducing cell death in cancer cells. Consequently, the inability to trigger cell death pathways or alternatively, evasion of cancer cells to the induction of cell death pathways can result in resistance of cancers to current treatment protocols. Therefore, in order to overcome treatment resistance a better understanding of the underlying mechanisms that regulate cell death and survival pathways in cancers and in response to cancer therapy is necessary to develop molecular-targeted therapies. This strategy should lead to more effective and individualized treatment strategies that selectively target deregulated signaling pathways in a tumor type- and patient-specific manner.

  1. Hyperglycemia regulates TXNIP/TRX/ROS axis via p38 MAPK and ERK pathways in pancreatic cancer.

    Science.gov (United States)

    Li, Wei; Wu, Zheng; Ma, Qingyong; Liu, Jiangbo; Xu, Qinhong; Han, Liang; Duan, Wanxing; Lv, Yunfu; Wang, Fengfei; Reindl, Katie M; Wu, Erxi

    2014-01-01

    Approximately 85% of pancreatic cancer patients suffer from glucose intolerance or even diabetes because high glucose levels can contribute to oxidative stress which promotes tumor development. As one of the reactive oxygen species (ROS)-regulating factors, thioredoxin-interacting protein (TXNIP), is involved in the maintenance of thioredoxin (TRX)-mediated redox regulation. In this study, we demonstrated that high glucose levels increased the expression of TXNIP in time- and concentration-dependent manners and modulated the activity of TRX and ROS production in pancreatic cancer cells, BxPC-3 and Panc-1. We also found that glucose activated both p38 MAPK and ERK pathways and inhibitors of these pathways impaired the TXNIP/TRX/ROS axis. Knockdown of TXNIP restored TRX activity and decreased ROS production under high glucose conditions. Moreover, we observed that the integrated optical density (IOD) of TXNIP staining as well as the protein and mRNA expression levels of TXNIP were higher in the tumor tissues of pancreatic cancer patients with diabetes. Taken together, these results indicate that hyperglycemia-induced TXNIP expression is involved in diabetes-mediated oxidative stress in pancreatic cancer via p38 MAPK and ERK pathways.

  2. Asiatic acid attenuates methamphetamine-induced neuroinflammation and neurotoxicity through blocking of NF-kB/STAT3/ERK and mitochondria-mediated apoptosis pathway.

    Science.gov (United States)

    Park, Ji-Hyun; Seo, Young Ho; Jang, Jung-Hee; Jeong, Chul-Ho; Lee, Sooyeun; Park, Byoungduck

    2017-12-11

    Methamphetamine (METH) is a commonly abused drug that may result in neurotoxic effects. Recent studies have suggested that involvement of neuroinflammatory processes in brain dysfunction is induced by misuse of this drug. However, the mechanism underlying METH-induced inflammation and neurotoxicity in neurons is still unclear. In this study, we investigated whether asiatic acid (AA) effected METH-mediated neuroinflammation and neurotoxicity in dopaminergic neuronal cells. And we further determined whether the effect involved in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription (STAT)3 and extracellular signal-regulated kinase (ERK) pathway. We used the human dopaminergic neuroblastoma SH-SY5Y cell line, murine microglial BV2 cell line, and primary culture of rat embryo mesencephalic neurons. Pro-inflammatory cytokine production was monitored by ELISA and RT/real-time PCR. The cell cycle distribution and mitochondrial membrane integrity was analyzed by flow cytometry. We used immunoblotting, DNA-binding activity, and immunofluorescence staining to analyze the effect of AA on activation of the NF-κB, STAT3, MAPK-ERK, and apoptosis signaling pathways. METH induced TNF receptor (TNFR) expression and led to morphological changes of cells. Additionally, this drug increased pro-inflammatory cytokine (TNFα and IL-6) expression. AA significantly suppressed METH-induced TNFR expression in concentration dependent. Increased secretion of TNFα and IL-6 was inhibited in METH-stimulated neuronal cells by AA administration. AA showed significant protection against METH-induced translocation of NF-κB/STAT3 and ERK phosphorylation. AA inhibited METH-induced proteolytic fragmentation of caspase-3 and PARP. The pro-apoptotic protein Bax was significantly decreased, while the anti-apoptotic protein Bcl-xL was increased by AA treatment in METH-stimulated cells. A similar protective effect of AA on

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

    Science.gov (United States)

    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.

  4. Involvement of ERK-Nrf-2 signaling in ionizing radiation induced cell death in normal and tumor cells.

    Directory of Open Access Journals (Sweden)

    Raghavendra S Patwardhan

    Full Text Available Prolonged oxidative stress favors tumorigenic environment and inflammation. Oxidative stress may trigger redox adaptation mechanism(s in tumor cells but not normal cells. This may increase levels of intracellular antioxidants and establish a new redox homeostasis. Nrf-2, a master regulator of battery of antioxidant genes is constitutively activated in many tumor cells. Here we show that, murine T cell lymphoma EL-4 cells show constitutive and inducible radioresistance via activation of Nrf-2/ERK pathway. EL-4 cells contained lower levels of ROS than their normal counterpart murine splenic lymphocytes. In response to radiation, the thiol redox circuits, GSH and thioredoxin were modified in EL-4 cells. Pharmacological inhibitors of ERK and Nrf-2 significantly enhanced radiosensitivity and reduced clonogenic potential of EL-4 cells. Unirradiated lymphoma cells showed nuclear accumulation of Nrf-2, upregulation of its dependent genes and protein levels. Interestingly, MEK inhibitor abrogated its nuclear translocation suggesting role of ERK in basal and radiation induced Nrf-2 activation in tumor cells. Double knockdown of ERK and Nrf-2 resulted in higher sensitivity to radiation induced cell death as compared to individual knockdown cells. Importantly, NF-kB which is reported to be constitutively active in many tumors was not present at basal levels in EL-4 cells and its inhibition did not influence radiosensitivity of EL-4 cells. Thus our results reveal that, tumor cells which are subjected to heightened oxidative stress employ master regulator cellular redox homeostasis Nrf-2 for prevention of radiation induced cell death. Our study reveals the molecular basis of tumor radioresistance and highlights role of Nrf-2 and ERK.

  5. Molecular Signaling Pathways Mediating Osteoclastogenesis Induced by Prostate Cancer Cells

    International Nuclear Information System (INIS)

    Rafiei, Shahrzad; Komarova, Svetlana V

    2013-01-01

    Advanced prostate cancer commonly metastasizes to bone leading to osteoblastic and osteolytic lesions. Although an osteolytic component governed by activation of bone resorbing osteoclasts is prominent in prostate cancer metastasis, the molecular mechanisms of prostate cancer-induced osteoclastogenesis are not well-understood. We studied the effect of soluble mediators released from human prostate carcinoma cells on osteoclast formation from mouse bone marrow and RAW 264.7 monocytes. Soluble factors released from human prostate carcinoma cells significantly increased viability of naïve bone marrow monocytes, as well as osteoclastogenesis from precursors primed with receptor activator of nuclear factor κ-B ligand (RANKL). The prostate cancer-induced osteoclastogenesis was not mediated by RANKL as it was not inhibited by osteoprotegerin (OPG). However inhibition of TGFβ receptor I (TβRI), or macrophage-colony stimulating factor (MCSF) resulted in attenuation of prostate cancer-induced osteoclastogenesis. We characterized the signaling pathways induced in osteoclast precursors by soluble mediators released from human prostate carcinoma cells. Prostate cancer factors increased basal calcium levels and calcium fluctuations, induced nuclear localization of nuclear factor of activated t-cells (NFAT)c1, and activated prolonged phosphorylation of ERK1/2 in RANKL-primed osteoclast precursors. Inhibition of calcium signaling, NFATc1 activation, and ERK1/2 phosphorylation significantly reduced the ability of prostate cancer mediators to stimulate osteoclastogenesis. This study reveals the molecular mechanisms underlying the direct osteoclastogenic effect of prostate cancer derived factors, which may be beneficial in developing novel osteoclast-targeting therapeutic approaches

  6. Angiogenic activity of sesamin through the activation of multiple signal pathways

    International Nuclear Information System (INIS)

    Chung, Byung-Hee; Lee, Jung Joon; Kim, Jong-Dai; Jeoung, Dooil; Lee, Hansoo; Choe, Jongseon; Ha, Kwon-Soo; Kwon, Young-Geun; Kim, Young-Myeong

    2010-01-01

    The natural product sesamin has been known to act as a potent antioxidant and prevent endothelial dysfunction. We here found that sesamin increased in vitro angiogenic processes, such as endothelial cell proliferation, migration, and tube formation, as well as neovascularization in an animal model. This compound elicited the activation of multiple angiogenic signal modulators, such as ERK, Akt, endothelial nitric oxide synthase (eNOS), NO production, FAK, and p38 MAPK, but not Src. The MEK inhibitor PD98059 and the PI3K inhibitor Wortmannin specifically inhibited sesamin-induced activation of the ERK and Akt/eNOS pathways. These inhibitors reduced angiogenic events, with high specificity for MEK/ERK-dependent cell proliferation and migration and PI3K/Akt-mediated tube formation. Moreover, inhibition of p38 MAPK effectively inhibited sesamin-induced cell migration. The angiogenic activity of sesamin was not associated with VEGF expression. Furthermore, this compound did not induce vascular permeability and upregulated ICAM-1 and VCAM-1 expression, which are hallmarks of vascular inflammation. These results suggest that sesamin stimulates angiogenesis in vitro and in vivo through the activation of MEK/ERK-, PI3K/Akt/eNOS-, p125 FAK -, and p38 MAPK-dependent pathways, without increasing vascular inflammation, and may be used for treating ischemic diseases and tissue regeneration.

  7. Mucin 4 Gene Silencing Reduces Oxidative Stress and Calcium Oxalate Crystal Formation in Renal Tubular Epithelial Cells Through the Extracellular Signal-Regulated Kinase Signaling Pathway in Nephrolithiasis Rat Model

    Directory of Open Access Journals (Sweden)

    Ling Sun

    2018-05-01

    Full Text Available Background/Aims: Nephrolithiasis plagues a great number of patients all over the world. Increasing evidence shows that the extracellular signal-regulated kinase (ERK signaling pathway and renal tubular epithelial cell (RTEC dysfunction and attrition are central to the pathogenesis of kidney diseases. Mucin 4 (MUC4 is reported as an activator of ERK signaling pathway in epithelial cells. In this study, using rat models of calcium oxalate (CaOx nephrolithiasis, the present study aims to define the roles of MUC4 and ERK signaling pathway as contributors to oxidative stress and CaOx crystal formation in RTEC. Methods: Data sets of nephrolithiasis were searched using GEO database and a heat flow map was drawn. Then MUC4 function was predicted. Wistar rats were prepared for the purpose of model establishment of ethylene glycol and ammonium chloride induced CaOx nephrolithiasis. In order to assess the detailed regulatory mechanism of MUC4 silencing on the ERK signaling pathway and RTEC, we used recombinant plasmid to downregulate MUC4 expression in Wistar rat-based models. Samples from rat urine, serum and kidney tissues were reviewed to identify oxalic acid and calcium contents, BUN, Cr, Ca2+ and P3+ levels, calcium crystal formation in renal tubules and MUC4 positive expression rate. Finally, RT-qPCR, Western blot analysis, and ELISA were employed to access oxidative stress state and CaOx crystal formation in RTEC. Results: Initially, MUC4 was found to have an influence on the process of nephrolithiasis. MUC4 was upregulated in the CaOx nephrolithiasis model rats. We proved that the silencing of MUC4 triggered the inactivation of ERK signaling pathway. Following the silencing of MUC4 or the inhibition of ERK signaling pathway, the oxalic acid and calcium contents in rat urine, BUN, Cr, Ca2+ and P3+ levels in rat serum, p-ERK1/2, MCP-1 and OPN expressions in RTEC and H2O2 and MDA levels in the cultured supernatant were downregulated, but the GSH

  8. Blockade of the ERK pathway enhances the therapeutic efficacy of the histone deacetylase inhibitor MS-275 in human tumor xenograft models

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Toshiaki; Ozaki, Kei-ichi; Fujio, Kohsuke; Kajikawa, Shu-hei [Laboratory of Cell Regulation, Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8521 (Japan); Uesato, Shin-ichi [Department of Biotechnology, Faculty of Engineering, Kansai University, Osaka 564-8680 (Japan); Watanabe, Kazushi [Proubase Technology Inc., Kanagawa 211-0063 (Japan); Tanimura, Susumu [Laboratory of Cell Regulation, Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8521 (Japan); Koji, Takehiko [Department of Histology and Cell Biology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Kohno, Michiaki, E-mail: kohnom@nagasaki-u.ac.jp [Laboratory of Cell Regulation, Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8521 (Japan); Proubase Technology Inc., Kanagawa 211-0063 (Japan); Kyoto University Graduate School of Pharmaceutical Sciences, Kyoto 606-8501 (Japan)

    2013-04-19

    Highlights: •Blockade of the ERK pathway enhances the anticancer efficacy of HDAC inhibitors. •MEK inhibitors sensitize human tumor xenografts to HDAC inhibitor cytotoxicity. •Such the enhanced efficacy is achieved by a transient blockade of the ERK pathway. •This drug combination provides a promising therapeutic strategy for cancer patients. -- Abstract: The ERK pathway is up-regulated in various human cancers and represents a prime target for mechanism-based approaches to cancer treatment. Specific blockade of the ERK pathway alone induces mostly cytostatic rather than pro-apoptotic effects, however, resulting in a limited therapeutic efficacy of the ERK kinase (MEK) inhibitors. We previously showed that MEK inhibitors markedly enhance the ability of histone deacetylase (HDAC) inhibitors to induce apoptosis in tumor cells with constitutive ERK pathway activation in vitro. To evaluate the therapeutic efficacy of such drug combinations, we administered the MEK inhibitor PD184352 or AZD6244 together with the HDAC inhibitor MS-275 in nude mice harboring HT-29 or H1650 xenografts. Co-administration of the MEK inhibitor markedly sensitized the human xenografts to MS-275 cytotoxicity. A dose of MS-275 that alone showed only moderate cytotoxicity thus suppressed the growth of tumor xenografts almost completely as well as induced a marked reduction in tumor cellularity when administered with PD184352 or AZD6244. The combination of the two types of inhibitor also induced marked oxidative stress, which appeared to result in DNA damage and massive cell death, specifically in the tumor xenografts. The enhanced therapeutic efficacy of the drug combination was achieved by a relatively transient blockade of the ERK pathway. Administration of both MEK and HDAC inhibitors represents a promising chemotherapeutic strategy with improved safety for cancer patients.

  9. Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Wada, Eiji, E-mail: gacchu1@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Zammit, Peter S., E-mail: peter.zammit@kcl.ac.uk [Randall Division of Cell and Molecular Biophysics, King' s College London, London SE1 1UL (United Kingdom); Shiozuka, Masataka, E-mail: cmuscle@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Matsuda, Ryoichi, E-mail: cmatsuda@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan)

    2015-05-01

    Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc on differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.

  10. Lipopolysaccharide can modify differentiation and immunomodulatory potential of periodontal ligament stem cells via ERK1,2 signaling.

    Science.gov (United States)

    Kukolj, Tamara; Trivanović, Drenka; Djordjević, Ivana Okić; Mojsilović, Slavko; Krstić, Jelena; Obradović, Hristina; Janković, Srdja; Santibanez, Juan Francisco; Jauković, Aleksandra; Bugarski, Diana

    2018-01-01

    Lipopolysaccharide (LPS) is a pertinent deleterious factor in oral microenvironment for cells which are carriers of regenerative processes. The aim of this study was to investigate the emerging in vitro effects of LPS (Escherichia coli) on human periodontal ligament stem cell (PDLSC) functions and associated signaling pathways. We demonstrated that LPS did not affect immunophenotype, proliferation, viability, and cell cycle of PDLSCs. However, LPS modified lineage commitment of PDLSCs inhibiting osteogenesis by downregulating Runx2, ALP, and Ocn mRNA expression, while stimulating chondrogenesis and adipogenesis by upregulating Sox9 and PPARγ mRNA expression. LPS promoted myofibroblast-like phenotype of PDLSCs, since it significantly enhanced PDLSC contractility, as well as protein and/or gene expression of TGF-β, fibronectin (FN), α-SMA, and NG2. LPS also increased protein and gene expression levels of anti-inflammatory COX-2 and pro-inflammatory IL-6 molecules in PDLSCs. Inhibition of peripheral blood mononuclear cells (MNCs) transendothelial migration in presence of LPS-treated PDLSCs was accompanied by the reduction of CD29 expression within MNCs. However, LPS treatment did not change the inhibitory effect of PDLSCs on mitogen-stimulated proliferation of CD4 + and the ratio of CD4 + CD25 high /CD4 + CD25 low lymphocytes. LPS-treated PDLSCs did not change the frequency of CD34 + and CD45 + cells, but decreased the frequency of CD33 + and CD14 + myeloid cells within MNCs. Moreover, LPS treatment attenuated the stimulatory effect of PDLSCs on CFC activity of MNCs, predominantly the CFU-GM number. The results indicated that LPS-activated ERK1,2 was at least partly involved in the observed effects on PDLSC differentiation capacity, acquisition of myofibroblastic attributes, and changes of their immunomodulatory features. © 2017 Wiley Periodicals, Inc.

  11. Fluoxetine increases the activity of the ERK-CREB signal system and alleviates the depressive-like behavior in rats exposed to chronic forced swim stress.

    Science.gov (United States)

    Qi, Xiaoli; Lin, Wenjuan; Li, Junfa; Li, Huanhuan; Wang, Weiwen; Wang, Donglin; Sun, Meng

    2008-08-01

    Our previous research indicates that the extracellular signal-regulated kinase (ERK)-cyclic AMP-responsive-element-binding protein (CREB) signal system may be involved in the molecular mechanism of depression. The present study further investigated the effect of antidepressant fluoxetine on the ERK-CREB signal system and the depressive-like behaviors in rats. Fluoxetine was administrated to either naive rats or stressed rats for 21 days. The results showed that chronic forced swim stress induced depressive-like behaviors and decreased the levels of P-ERK2, P-CREB, ERK1/2 and CREB in hippocampus and prefrontal cortex. Fluoxetine alleviated the depressive-like behaviors and reversed the disruptions of the P-ERK2 and P-CREB in stressed rats. Fluoxetine also exerted mood-elevating effect and increased the levels of the P-ERK2 and P-CREB in naive rats. These results suggest that the ERK-CREB signal system may be the targets of the antidepressant action of fluoxetine and participate in the neuronal mechanism of depression.

  12. 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.

  13. HGF potentiates extracellular matrix-driven migration of human myoblasts: involvement of matrix metalloproteinases and MAPK/ERK pathway.

    Science.gov (United States)

    González, Mariela Natacha; de Mello, Wallace; Butler-Browne, Gillian S; Silva-Barbosa, Suse Dayse; Mouly, Vincent; Savino, Wilson; Riederer, Ingo

    2017-10-10

    The hepatocyte growth factor (HGF) is required for the activation of muscle progenitor cells called satellite cells (SC), plays a role in the migration of proliferating SC (myoblasts), and is present as a soluble factor during muscle regeneration, along with extracellular matrix (ECM) molecules. In this study, we aimed at determining whether HGF is able to interact with ECM proteins, particularly laminin 111 and fibronectin, and to modulate human myoblast migration. We evaluated the expression of the HGF-receptor c-Met, laminin, and fibronectin receptors by immunoblotting, flow cytometry, or immunofluorescence and used Transwell assays to analyze myoblast migration on laminin 111 and fibronectin in the absence or presence of HGF. Zymography was used to check whether HGF could modulate the production of matrix metalloproteinases by human myoblasts, and the activation of MAPK/ERK pathways was evaluated by immunoblotting. We demonstrated that human myoblasts express c-Met, together with laminin and fibronectin receptors. We observed that human laminin 111 and fibronectin have a chemotactic effect on myoblast migration, and this was synergistically increased when low doses of HGF were added. We detected an increase in MMP-2 activity in myoblasts treated with HGF. Conversely, MMP-2 inhibition decreased the HGF-associated stimulation of cell migration triggered by laminin or fibronectin. HGF treatment also induced in human myoblasts activation of MAPK/ERK pathways, whose specific inhibition decreased the HGF-associated stimulus of cell migration triggered by laminin 111 or fibronectin. We demonstrate that HGF induces ERK phosphorylation and MMP production, thus stimulating human myoblast migration on ECM molecules. Conceptually, these data state that the mechanisms involved in the migration of human myoblasts comprise both soluble and insoluble moieties. This should be taken into account to optimize the design of therapeutic cell transplantation strategies by improving

  14. Identification and characterization of an alternative splice variant of Mpl with a high affinity for TPO and its activation of ERK1/2 signaling.

    Science.gov (United States)

    Wang, Qiong; Sun, Rui; Wu, Leyan; Huang, Junfeng; Wang, Ping; Yuan, Hailong; Qiu, Feifei; Xu, Xiaohong; Wu, Di; Yu, Ying; Liu, Xin; Zhang, Qing

    2013-12-01

    The thrombopoietin receptor is a crucial element in thrombopoietin-initiated signaling pathways, which stimulates the differentiation of normal hematopoietic progenitor cells, the maturation of megakaryocytes, and the generation of platelets. In this study, we identified a novel activating variant of thrombopoietin receptor, termed Mpl-D, in human megakaryoblastic leukemia Dami cells and demonstrated that the binding affinity of the Mpl-D receptor for thrombopoietin is enhanced. Cell cycle analysis revealed that in the presence of thrombopoietin, most Mpl-D expressing NIH3T3 (NIH3T3/Mpl-D) cells were prevalent in G1 phase while the S and G2/M populations were less frequently observed. Unexpectedly, thrombopoietin induced strong and prolonged ERK1/2 signaling in NIH3T3/Mpl-D cells compared with its receptor wild-type expressing NIH3T3 (NIH3T3/Mpl-F) cells. Further analysis of the mRNA levels of cyclin D1/D2 in NIH3T3/Mpl-D cells demonstrated markedly down-regulated expression compared to NIH3T3/Mpl-F cells in the presence of thrombopoietin. Thus, the prolonged activation of ERK1/2 by Mpl-D might lead to G1 cell cycle arrest through a profound reduction of cyclin D1/D2 in order to support cell survival without proliferation. We also provided tertiary structural basis for the Mpl-D and thrombopoietin interaction, which might provide insights into how Mpl-D effectively increases binding to thrombopoietin and significantly contributes to its specific signaling pathway. These results suggest a new paradigm for the regulation of cytokine receptor expression and function through the alternative splicing variant of Mpl in Dami cells, which may play a role in the pathogenesis of megakaryoblastic leukemia. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Oleic Acid Induces Lung Injury in Mice through Activation of the ERK Pathway

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    Cassiano Felippe Gonçalves-de-Albuquerque

    2012-01-01

    Full Text Available Oleic acid (OA can induce acute lung injury in experimental models. In the present work, we used intratracheal OA injection to show augmented oedema formation, cell migration and activation, lipid mediator, and cytokine productions in the bronchoalveolar fluids of Swiss Webster mice. We also demonstrated that OA-induced pulmonary injury is dependent on ERK1/2 activation, since U0126, an inhibitor of ERK1/2 phosphorylation, blocked neutrophil migration, oedema, and lipid body formation as well as IL-6, but not IL-1β production. Using a mice strain carrying a null mutation for the TLR4 receptor, we proved that increased inflammatory parameters after OA challenges were not due to the activation of the TLR4 receptor. With OA being a Na/K-ATPase inhibitor, we suggest the possible involvement of this enzyme as an OA target triggering lung inflammation.

  16. Tumour compartment transcriptomics demonstrates the activation of inflammatory and odontogenic programmes in human adamantinomatous craniopharyngioma and identifies the MAPK/ERK pathway as a novel therapeutic target.

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    Apps, John R; Carreno, Gabriela; Gonzalez-Meljem, Jose Mario; Haston, Scott; Guiho, Romain; Cooper, Julie E; Manshaei, Saba; Jani, Nital; Hölsken, Annett; Pettorini, Benedetta; Beynon, Robert J; Simpson, Deborah M; Fraser, Helen C; Hong, Ying; Hallang, Shirleen; Stone, Thomas J; Virasami, Alex; Donson, Andrew M; Jones, David; Aquilina, Kristian; Spoudeas, Helen; Joshi, Abhijit R; Grundy, Richard; Storer, Lisa C D; Korbonits, Márta; Hilton, David A; Tossell, Kyoko; Thavaraj, Selvam; Ungless, Mark A; Gil, Jesus; Buslei, Rolf; Hankinson, Todd; Hargrave, Darren; Goding, Colin; Andoniadou, Cynthia L; Brogan, Paul; Jacques, Thomas S; Williams, Hywel J; Martinez-Barbera, Juan Pedro

    2018-05-01

    Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. β-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP

  17. Hedgehog signaling pathway in neuroblastoma differentiation.

    Science.gov (United States)

    Souzaki, Ryota; Tajiri, Tatsuro; Souzaki, Masae; Kinoshita, Yoshiaki; Tanaka, Sakura; Kohashi, Kenichi; Oda, Yoshinao; Katano, Mitsuo; Taguchi, Tomoaki

    2010-12-01

    The hedgehog (Hh) signaling pathway is activated in some adult cancers. On the other hand, the Hh signaling pathway plays an important role in the development of the neural crest in embryos. The aim of this study is to show the activation of Hh signaling pathway in neuroblastoma (NB), a pediatric malignancy arising from neural crest cells, and to reveal the meaning of the Hh signaling pathway in NB development. This study analyzed the expression of Sonic hedgehog (Shh), GLI1, and Patched 1 (Ptch1), transactivators of Hh signaling pathway, by immunohistochemistry in 82 NB and 10 ganglioneuroblastoma cases. All 92 cases were evaluated for the status of MYCN amplification. Of the 92 cases, 67 (73%) were positive for Shh, 62 cases (67%) were positive for GLI1, and 73 cases (79%) were positive for Ptch1. Only 2 (10%) of the 20 cases with MYCN amplification were positive for Shh and GLI1, and 4 cases (20%) were positive for Ptch1 (MYCN amplification vs no MYCN amplification, P ≦ .01). The percentage of GLI1-positive cells in the cases with INSS stage 1 without MYCN amplification was significantly higher than that with INSS stage 4. Of 72 cases without MYCN amplification, 60 were GLI1-positive. Twelve cases were GLI1-negative, and the prognosis of the GLI1-positive cases was significantly better than that of the GLI1-negative cases (P = .015). Most of NBs without MYCN amplification were positive for Shh, GLI1, and Ptch1. In the cases without MYCN amplification, the high expression of GLI1 was significantly associated with early clinical stage and a good prognosis of the patients. In contrast to adult cancers, the activation of the Hh signaling pathway in NB may be associated with the differentiation of the NB. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. TRPC6 channel-mediated neurite outgrowth in PC12 cells and hippocampal neurons involves activation of RAS/MEK/ERK, PI3K, and CAMKIV signaling.

    Science.gov (United States)

    Heiser, Jeanine H; Schuwald, Anita M; Sillani, Giacomo; Ye, Lian; Müller, Walter E; Leuner, Kristina

    2013-11-01

    The non-selective cationic transient receptor canonical 6 (TRPC6) channels are involved in synaptic plasticity changes ranging from dendritic growth, spine morphology changes and increase in excitatory synapses. We previously showed that the TRPC6 activator hyperforin, the active antidepressant component of St. John's wort, induces neuritic outgrowth and spine morphology changes in PC12 cells and hippocampal CA1 neurons. However, the signaling cascade that transmits the hyperforin-induced transient rise in intracellular calcium into neuritic outgrowth is not yet fully understood. Several signaling pathways are involved in calcium transient-mediated changes in synaptic plasticity, ranging from calmodulin-mediated Ras-induced signaling cascades comprising the mitogen-activated protein kinase, PI3K signal transduction pathways as well as Ca(2+) /calmodulin-dependent protein kinase II (CAMKII) and CAMKIV. We show that several mechanisms are involved in TRPC6-mediated synaptic plasticity changes in PC12 cells and primary hippocampal neurons. Influx of calcium via TRPC6 channels activates different pathways including Ras/mitogen-activated protein kinase/extracellular signal-regulated kinases, phosphatidylinositide 3-kinase/protein kinase B, and CAMKIV in both cell types, leading to cAMP-response element binding protein phosphorylation. These findings are interesting not only in terms of the downstream targets of TRPC6 channels but also because of their potential to facilitate further understanding of St. John's wort extract-mediated antidepressant activity. Alterations in synaptic plasticity are considered to play an important role in the pathogenesis of depression. Beside several other proteins, TRPC6 channels regulate synaptic plasticity. This study demonstrates that different pathways including Ras/MEK/ERK, PI3K/Akt, and CAMKIV are involved in the improvement of synaptic plasticity by the TRPC6 activator hyperforin, the antidepressant active constituent of St. John

  19. Bax/Mcl-1 balance affects neutrophil survival in intermittent hypoxia and obstructive sleep apnea: effects of p38MAPK and ERK1/2 signaling

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    Dyugovskaya Larissa

    2012-10-01

    Full Text Available Abstract Background Prolonged neutrophil survival is evident in various cardiovascular and respiratory morbidities, in hypoxic conditions in-vitro and in patients with obstructive sleep apnea (OSA characterized by nightly intermittent hypoxia (IH. This may lead to persistent inflammation, tissue injury and dysfunction. We therefore investigated by a translational approach the potential contribution of the intrinsic stress-induced mitochondrial pathway in extending neutrophil survival under IH conditions. Thus, neutrophils of healthy individuals treated with IH in-vitro and neutrophils of OSA patients undergoing nightly IH episodes in-vivo were investigated. Specifically, the balance between pro-apoptotic Bax and anti-apoptotic Mcl-1 protein expression, and the potential involvement of p38MAPK and ERK1/2 signaling pathways in the control of Mcl-1 expression were investigated. Methods Purified neutrophils were exposed to IH and compared to normoxia and to sustained hypoxia (SH using a BioSpherix-OxyCycler C42 system. Bax and Mcl-1 levels, and p38MAPK and ERK1/2 phosphorylation were determined by western blotting. Also, Bax/Mcl-1 expression and Bax translocation to the mitochondria were assessed by confocal microscopy in pre-apoptotic neutrophils, before the appearance of apoptotic morphology. Co-localization of Bax and mitochondria was quantified by LSM 510 CarlZeiss MicroImaging using Manders Overlap Coefficient. A paired two-tailed t test, with Bonferroni correction for multiple comparisons, was used for statistical analysis. Results Compared to normoxia, IH and SH up-regulated the anti-apoptotic Mcl-1 by about 2-fold, down-regulated the pro-apoptotic Bax by 41% and 27%, respectively, and inhibited Bax co-localization with mitochondria before visible morphological signs of apoptosis were noted. IH induced ERK1/2 and p38MAPKs phosphorylation, whereas SH induced only p38MAPK phosphorylation. Accordingly, both ERK and p38MAPK inhibitors attenuated

  20. 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.

  1. Beyond Gap Junction Channel Function: the Expression of Cx43 Contributes to Aldosterone-Induced Mesangial Cell Proliferation via the ERK1/2 and PKC Pathways

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    Aiqing Zhang

    2015-06-01

    Full Text Available Aims: This study aimed to explore the precise mechanism and signaling pathways of mesangial cell (MC proliferation from a new point of view considering Connexin 43 (Cx43. Methods: MC proliferation was measured by the incorporation of 3H-thymidine (3H-TdR. Cx43 was over-expressed in MC cells using lipofectamine 2000, and the expression level was tested with reverse transcription-polymerase chain reaction (RT-PCR and Western blot analyses. The gap junction channel function was explored by Lucifer Yellow scrape loading and dye transfer (SLDT, and the intracellular calcium concentrations ([Ca2+]i were characterized by confocal microscopy on cells loaded with Fura-3/AM. Results: There was an inverse correlation between Cx43 expression and MC proliferation (P0.05. Our data also showed that the mineralcorticoid receptor (MR antagonist spironolactone, ERK1/2 inhibitor PD98059 and PKC inhibitor GF109203X could attenuate the down-regulation of Cx43 expression in Aldo-induced MC proliferation; however, the PI3K inhibitor LY294002 could block MC proliferation without affecting Cx43 expression at either the mRNA or protein level. In addition, Aldo promoted MC proliferation in parallel with increasing [Ca2+]i (PConclusions: Our study provides preliminary evidence that Cx43 is an important regulator of Aldo-promoted MC proliferation. Furthermore, reduced Cx43 expression promoted MC proliferation independent of the gap junction channel function, and this process might be mediated through the ERK1/2- and PKC-dependent pathways.

  2. Oxyfadichalcone C inhibits melanoma A375 cell proliferation and metastasis via suppressing PI3K/Akt and MAPK/ERK pathways.

    Science.gov (United States)

    Peng, Xiaolin; Wang, Zhengming; Liu, Yang; Peng, Xin; Liu, Yao; Zhu, Shan; Zhang, Zhe; Qiu, Yuling; Jin, Meihua; Wang, Ran; Zhang, Qingying; Kong, Dexin

    2018-08-01

    Melanoma remains to be one of the most incurable cancers. Discovery of novel antitumor agent for melanoma therapy is expected. We recently isolated Oxyfadichalcone C from Oxytropis falcate and investigated the anti-proliferative and anti-metastatic activity on human melanoma A375 cells in vitro. Cell viability was determined using MTT assay and soft agar cloning formation assay. The effect of Oxyfadichalcone C on cell cycle distribution and apoptosis were analyzed by flow cytometry. Cell metastasis was determined by wound healing assay, Transwell assay and Gelatin zymography assay. The effect of Oxyfadichalcone C on signal proteins of PI3K/Akt and MAPK/ERK pathways was examined by western blot analysis. Synergism assay was employed to determine whether combination of Oxyfadichalcone C with Vemurafenib would enhance the anti-proliferative effect. Oxyfadichalcone C potently inhibited proliferation, induced G1 phase arrest and weak apoptosis in A375 cells. Anti-migration and anti-invasion activities were also indicated. Such effects were associated with upregulation of p27, reduction of cyclin D1, p-pRb, p-Integrin β1, as well as the proteolytic activity of metalloproteinase (MMP)-2/9. Meanwhile, key molecules of PI3K/Akt and MAPK/ERK pathways were downregulated, which might be involved in the inhibition against proliferation and metastasis of A375 cells by Oxyfadichalcone C. In addition, combination of Oxyfadichalcone C with Vemurafenib at a ratio of IC50 Oxyfadichalcone C : 5 × IC 50 Vemurafenib exhibited synergistic anti-proliferative effect on A375 cells. Our findings suggest that Oxyfadichalcone C has the potential to be developed as a promising drug candidate for the treatment of melanoma. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Morus alba and active compound oxyresveratrol exert anti-inflammatory activity via inhibition of leukocyte migration involving MEK/ERK signaling.

    Science.gov (United States)

    Chen, Yi-Ching; Tien, Yin-Jing; Chen, Chun-Houh; Beltran, Francesca N; Amor, Evangeline C; Wang, Ran-Juh; Wu, Den-Jen; Mettling, Clément; Lin, Yea-Lih; Yang, Wen-Chin

    2013-02-23

    Morus alba has long been used in traditional Chinese medicine to treat inflammatory diseases; however, the scientific basis for such usage and the mechanism of action are not well understood. This study investigated the action of M. alba on leukocyte migration, one key step in inflammation. Gas chromatography-mass spectrometry (GC-MS) and cluster analyses of supercritical CO2 extracts of three Morus species were performed for chemotaxonomy-aided plant authentication. Phytochemistry and CXCR4-mediated chemotaxis assays were used to characterize the chemical and biological properties of M. alba and its active compound, oxyresveratrol. fluorescence-activated cell sorting (FACS) and Western blot analyses were conducted to determine the mode of action of oxyresveratrol. Chemotaxonomy was used to help authenticate M. alba. Chemotaxis-based isolation identified oxyresveratrol as an active component in M. alba. Phytochemical and chemotaxis assays showed that the crude extract, ethyl acetate fraction and oxyresveratrol from M. alba suppressed cell migration of Jurkat T cells in response to SDF-1. Mechanistic study indicated that oxyresveratrol diminished CXCR4-mediated T-cell migration via inhibition of the MEK/ERK signaling cascade. A combination of GC-MS and cluster analysis techniques are applicable for authentication of the Morus species. Anti-inflammatory benefits of M. alba and its active compound, oxyresveratrol, may involve the inhibition of CXCR-4-mediated chemotaxis and MEK/ERK pathway in T and other immune cells.

  4. α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways

    Science.gov (United States)

    Ru, Yusha; Huang, Yue; Liu, Huijuan; Du, Juan; Meng, Zhu; Dou, Zexia; Liu, Xun; Wei, Rui Hua; Zhang, Yan; Zhao, Shaozhen

    2015-01-01

    Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1β, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10−4 μg/μl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH’s protective effects, suggesting that both pathways are necessary for α-MSH’s protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED. PMID:26685899

  5. α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways.

    Science.gov (United States)

    Ru, Yusha; Huang, Yue; Liu, Huijuan; Du, Juan; Meng, Zhu; Dou, Zexia; Liu, Xun; Wei, Rui Hua; Zhang, Yan; Zhao, Shaozhen

    2015-12-21

    Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1β, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10(-4) μg/μl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH's protective effects, suggesting that both pathways are necessary for α-MSH's protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED.

  6. TPL-2-ERK1/2 signaling promotes host resistance against intracellular bacterial infection by negative regulation of type I IFN production.

    Science.gov (United States)

    McNab, Finlay W; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S; Wu, Xuemei; Graham, Christine M; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C; O'Garra, Anne

    2013-08-15

    Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading cause of mortality and morbidity worldwide, causing ≈ 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1, and TNF-α, as well as IFN-γ and CD4(+) Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I IFN have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL-10 is known to inhibit the immune response to M. tuberculosis in murine models through the negative regulation of key proinflammatory cytokines and the subsequent Th1 response. We show in this study, using a combination of transcriptomic analysis, genetics, and pharmacological inhibitors, that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I IFN production. The TPL-2-ERK1/2 signaling pathway regulated production by macrophages of several cytokines important in the immune response to M. tuberculosis as well as regulating induction of a large number of additional genes, many in a type I IFN-dependent manner. In the absence of TPL-2 in vivo, excess type I IFN promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I IFN may promote susceptibility to this important disease.

  7. fundTPL-2 – ERK1/2 Signaling Promotes Host Resistance against Intracellular Bacterial Infection by Negative Regulation of Type I Interferon Production3

    Science.gov (United States)

    McNab, Finlay W.; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S.; Wu, Xuemei; Graham, Christine M.; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C.; O’Garra, Anne

    2013-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of mortality and morbidity worldwide, causing approximately 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1 and TNF-α, as well as IFN-γ and CD4+ Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I interferon have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL-10 is known to inhibit the immune response to Mtb in murine models through the negative regulation of key pro-inflammatory cytokines and the subsequent Th1 response. We show here, using a combination of transcriptomic analysis, genetics and pharmacological inhibitors that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I interferon production. The TPL-2-ERK1/2 signalling pathway regulated production by macrophages of several cytokines important in the immune response to Mtb as well as regulating induction of a large number of additional genes, many in a type I IFN dependent manner. In the absence of TPL-2 in vivo, excess type I interferon promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I interferon may promote susceptibility to this important disease. PMID:23842752

  8. Novel Reporter for Faithful Monitoring of ERK2 Dynamics in Living Cells and Model Organisms

    Science.gov (United States)

    Sipieter, François; Cappe, Benjamin; Gonzalez Pisfil, Mariano; Spriet, Corentin; Bodart, Jean-François; Cailliau-Maggio, Katia; Vandenabeele, Peter; Héliot, Laurent; Riquet, Franck B.

    2015-01-01

    Uncoupling of ERK1/2 phosphorylation from subcellular localization is essential towards the understanding of molecular mechanisms that control ERK1/2-mediated cell-fate decision. ERK1/2 non-catalytic functions and discoveries of new specific anchors responsible of the subcellular compartmentalization of ERK1/2 signaling pathway have been proposed as regulation mechanisms for which dynamic monitoring of ERK1/2 localization is necessary. However, studying the spatiotemporal features of ERK2, for instance, in different cellular processes in living cells and tissues requires a tool that can faithfully report on its subcellular distribution. We developed a novel molecular tool, ERK2-LOC, based on the T2A-mediated coexpression of strictly equimolar levels of eGFP-ERK2 and MEK1, to faithfully visualize ERK2 localization patterns. MEK1 and eGFP-ERK2 were expressed reliably and functionally both in vitro and in single living cells. We then assessed the subcellular distribution and mobility of ERK2-LOC using fluorescence microscopy in non-stimulated conditions and after activation/inhibition of the MAPK/ERK1/2 signaling pathway. Finally, we used our coexpression system in Xenopus laevis embryos during the early stages of development. This is the first report on MEK1/ERK2 T2A-mediated coexpression in living embryos, and we show that there is a strong correlation between the spatiotemporal subcellular distribution of ERK2-LOC and the phosphorylation patterns of ERK1/2. Our approach can be used to study the spatiotemporal localization of ERK2 and its dynamics in a variety of processes in living cells and embryonic tissues. PMID:26517832

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

    Science.gov (United States)

    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.

  10. ERK5 signaling gets XIAPed: a role for ubiquitin in the disassembly of a MAPK cascade

    Science.gov (United States)

    Klein, Aileen M; Cobb, Melanie H

    2014-01-01

    Mitogen-activated protein kinase (MAPK) cascades are tightly controlled through a series of well-characterized phospho-regulatory events. In this issue, Takeda et al (2014) identify the inhibitor of apoptosis protein, XIAP, as a key regulator of ERK5 activation via uncoupling of upstream kinase activity by non-degradative ubiquitination. PMID:25012518

  11. Cell Signaling and Differential Protein Expression in Neuronal Differentiation of Bone Marrow Mesenchymal Stem Cells with Hypermethylated Salvador/Warts/Hippo (SWH Pathway Genes.

    Directory of Open Access Journals (Sweden)

    Hui-Hung Tzeng

    Full Text Available Human mesenchymal stem cells (MSCs modified by targeting DNA hypermethylation of genes in the Salvador/Warts/Hippo pathway were induced to differentiate into neuronal cells in vitro. The differentiated cells secreted a significant level of brain-derived neurotrophy factor (BDNF and the expression of BDNF receptor tyrosine receptor kinase B (TrkB correlated well with the secretion of BDNF. In the differentiating cells, CREB was active after the binding of growth factors to induce phosphorylation of ERK in the MAPK/ERK pathway. Downstream of phosphorylated CREB led to the functional maturation of differentiated cells and secretion of BDNF, which contributed to the sustained expression of pERK and pCREB. In summary, both PI3K/Akt and MAPK/ERK signaling pathways play important roles in the neuronal differentiation of MSCs. The main function of the PI3K/Akt pathway is to maintain cell survival during neural differentiation; whereas the role of the MAPK/ERK pathway is probably to promote the maturation of differentiated MSCs. Further, cellular levels of protein kinase C epsilon type (PKC-ε and kinesin heavy chain (KIF5B increased with time of induction, whereas the level of NME/NM23 nucleoside diphosphate kinase 1 (Nm23-H1 decreased during the time course of differentiation. The correlation between PKC-ε and TrkB suggested that there is cross-talk between PKC-ε and the PI3K/Akt signaling pathway.

  12. The Fog signaling pathway: Insights into signaling in morphogenesis

    Science.gov (United States)

    Manning, Alyssa J.; Rogers, Stephen L.

    2014-01-01

    Epithelia form the building blocks of many tissue and organ types. Epithelial cells often form a contiguous 2-dimensional sheet that is held together by strong adhesions. The mechanical properties conferred by these adhesions allow the cells to undergo dramatic three-dimensional morphogenetic movements while maintaining cell–cell contacts during embryogenesis and post-embryonic development. The Drosophila Folded gastrulation pathway triggers epithelial cell shape changes that drive gastrulation and tissue folding and is one of the most extensively studied examples of epithelial morphogenesis. This pathway has yielded key insights into the signaling mechanisms and cellular machinery involved in epithelial remodeling. In this review, we discuss principles of morphogenesis and signaling that have been discovered through genetic and cell biological examination of this pathway. We also consider various regulatory mechanisms and the system's relevance to mammalian development. We propose future directions that will continue to broaden our knowledge of morphogenesis across taxa. PMID:25127992

  13. Celecoxib induces proliferation and Amphiregulin production in colon subepithelial myofibroblasts, activating erk1-2 signaling in synergy with EGFR.

    Science.gov (United States)

    Benelli, Roberto; Venè, Roberta; Minghelli, Simona; Carlone, Sebastiano; Gatteschi, Beatrice; Ferrari, Nicoletta

    2013-01-01

    The COX-2 inhibitor Celecoxib, tested in phase III trials for the prevention of sporadic colon adenomas, reduced the appearance of new adenomas, but was unable to affect the incidence of colon cancer. Moreover the 5years follow-up showed that patients discontinuing Celecoxib treatment had an increased incidence of adenomas as compared to the placebo arm. In the APC(min/+) mouse model short term treatment with Celecoxib reduced gut adenomas, but a prolonged administration of the drug induced fibroblast activation and intestinal fibrosis with a final tumor burden. The way Celecoxib could directly activate human colon myofibroblasts (MF) has not yet been investigated. We found that MF are activated by non toxic doses of Celecoxib. Celecoxib induces erk1-2 and Akt phosphorylation within 5'. This short term activation is apparently insufficient to cause phenotypic changes, but the contemporary triggering of EGFR causes an impressive synergic effect inducing MF proliferation and the neo-expression and release of Amphiregulin (AREG), a well known EGFR agonist involved in colon cancer progression. As a confirm to these observations, the erk inhibitor U0126 and the EGFR inhibitors Tyrphostin and Cetuximab were able to contrast AREG induction. Our data provide evidence that Celecoxib directly activates MF empowering EGFR signaling. According to these results the association with EGFR (or erk1-2) inhibitors could abolish the off-target activity of Celecoxib, possibly extending the potential of this drug for colon cancer prevention. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. Fasting up-regulates ferroportin 1 expression via a Ghrelin/GHSR/MAPK signaling pathway.

    Science.gov (United States)

    Luo, Qian-Qian; Zhou, Yu-Fu; Chen, Mesona Yung-Jin; Liu, Li; Ma, Juan; Zhang, Meng-Wan; Zhang, Fa-Li; Ke, Ya; Qian, Zhong-Ming

    2018-