1
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Guner S, Akhayeva T, Nichols CD, Gurdal H. The Ca2+/CaM, Src kinase and/or PI3K-dependent EGFR transactivation via 5-HT2A and 5-HT1B receptor subtypes mediates 5-HT-induced vasoconstriction. Biochem Pharmacol 2022; 206:115317. [DOI: 10.1016/j.bcp.2022.115317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/06/2022] [Accepted: 10/17/2022] [Indexed: 11/02/2022]
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2
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Thomas P. Membrane Progesterone Receptors (mPRs, PAQRs): Review of Structural and Signaling Characteristics. Cells 2022; 11:cells11111785. [PMID: 35681480 PMCID: PMC9179843 DOI: 10.3390/cells11111785] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/17/2022] [Accepted: 05/21/2022] [Indexed: 02/05/2023] Open
Abstract
The role of membrane progesterone receptors (mPRs), which belong to the progestin and adipoQ receptor (PAQR) family, in mediating rapid, nongenomic (non-classical) progestogen actions has been extensively studied since their identification 20 years ago. Although the mPRs have been implicated in progestogen regulation of numerous reproductive and non-reproductive functions in vertebrates, several critical aspects of their structure and signaling functions have been unresolved until recently and remain the subject of considerable debate. This paper briefly reviews recent developments in our understanding of the structure and functional characteristics of mPRs. The proposed membrane topology of mPRα, the structure of its ligand-binding site, and the binding affinities of steroids were predicted from homology modeling based on the structures of other PAQRs, adiponectin receptors, and confirmed by mutational analysis and ligand-binding assays. Extensive data demonstrating that mPR-dependent progestogen regulation of intracellular signaling through mPRs is mediated by activation of G proteins are reviewed. Close association of mPRα with progesterone membrane receptor component 1 (PGRMC1), its role as an adaptor protein to mediate cell-surface expression of mPRα and mPRα-dependent progestogen signaling has been demonstrated in several vertebrate models. In addition, evidence is presented that mPRs can regulate the activity of other hormone receptors.
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Affiliation(s)
- Peter Thomas
- Marine Science Institute, The University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX 78373, USA
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3
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Liu J, Rebecca VW, Kossenkov AV, Connelly T, Liu Q, Gutierrez A, Xiao M, Li L, Zhang G, Samarkina A, Zayasbazan D, Zhang J, Cheng C, Wei Z, Alicea GM, Fukunaga-Kalabis M, Krepler C, Aza-Blanc P, Yang CC, Delvadia B, Tong C, Huang Y, Delvadia M, Morias AS, Sproesser K, Brafford P, Wang JX, Beqiri M, Somasundaram R, Vultur A, Hristova DM, Wu LW, Lu Y, Mills GB, Xu W, Karakousis GC, Xu X, Schuchter LM, Mitchell TC, Amaravadi RK, Kwong LN, Frederick DT, Boland GM, Salvino JM, Speicher DW, Flaherty KT, Ronai ZA, Herlyn M. Neural Crest-Like Stem Cell Transcriptome Analysis Identifies LPAR1 in Melanoma Progression and Therapy Resistance. Cancer Res 2021; 81:5230-5241. [PMID: 34462276 PMCID: PMC8530965 DOI: 10.1158/0008-5472.can-20-1496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/15/2020] [Accepted: 08/26/2021] [Indexed: 02/07/2023]
Abstract
Metastatic melanoma is challenging to clinically address. Although standard-of-care targeted therapy has high response rates in patients with BRAF-mutant melanoma, therapy relapse occurs in most cases. Intrinsically resistant melanoma cells drive therapy resistance and display molecular and biologic properties akin to neural crest-like stem cells (NCLSC) including high invasiveness, plasticity, and self-renewal capacity. The shared transcriptional programs and vulnerabilities between NCLSCs and cancer cells remains poorly understood. Here, we identify a developmental LPAR1-axis critical for NCLSC viability and melanoma cell survival. LPAR1 activity increased during progression and following acquisition of therapeutic resistance. Notably, genetic inhibition of LPAR1 potentiated BRAFi ± MEKi efficacy and ablated melanoma migration and invasion. Our data define LPAR1 as a new therapeutic target in melanoma and highlights the promise of dissecting stem cell-like pathways hijacked by tumor cells. SIGNIFICANCE: This study identifies an LPAR1-axis critical for melanoma invasion and intrinsic/acquired therapy resistance.
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Affiliation(s)
- Jianglan Liu
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Vito W Rebecca
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania.,Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Andrew V Kossenkov
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Thomas Connelly
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Qin Liu
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Alexis Gutierrez
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Min Xiao
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Ling Li
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Gao Zhang
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Anastasia Samarkina
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Delaine Zayasbazan
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Jie Zhang
- Department of Computer Science, New Jersey Institute of Technology, Newark, New Jersey
| | - Chaoran Cheng
- Department of Computer Science, New Jersey Institute of Technology, Newark, New Jersey
| | - Zhi Wei
- Department of Computer Science, New Jersey Institute of Technology, Newark, New Jersey
| | - Gretchen M Alicea
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Mizuho Fukunaga-Kalabis
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Clemens Krepler
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Pedro Aza-Blanc
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Chih-Cheng Yang
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Bela Delvadia
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Cynthia Tong
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Ye Huang
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Maya Delvadia
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Alice S Morias
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Katrin Sproesser
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Patricia Brafford
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Joshua X Wang
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Marilda Beqiri
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Rajasekharan Somasundaram
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Adina Vultur
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Denitsa M Hristova
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Lawrence W Wu
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Yiling Lu
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Gordon B Mills
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Wei Xu
- Abramson Cancer Center, Department of Medicine, Hospital of the University of Pennsylvania, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Giorgos C Karakousis
- Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Xiaowei Xu
- Department of Pathology and Laboratory Medicine, Hospital of University of Pennsylvania, Philadelphia, Pennsylvania
| | - Lynn M Schuchter
- Abramson Cancer Center, Department of Medicine, Hospital of the University of Pennsylvania, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tara C Mitchell
- Abramson Cancer Center, Department of Medicine, Hospital of the University of Pennsylvania, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ravi K Amaravadi
- Abramson Cancer Center, Department of Medicine, Hospital of the University of Pennsylvania, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Lawrence N Kwong
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dennie T Frederick
- Division of Surgical Oncology, Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Genevieve M Boland
- Division of Surgical Oncology, Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Joseph M Salvino
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - David W Speicher
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania
| | - Keith T Flaherty
- Department of Medicine, Harvard Medical School, Boston, Massachusetts.,Division of Medical Oncology, Massachusetts General Hospital Cancer Center, Boston, Massachusetts
| | - Ze'ev A Ronai
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Meenhard Herlyn
- Molecular and Cellular Oncogenesis Program and Melanoma Research Center, The Wistar Institute, Philadelphia, Pennsylvania.
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4
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Wang Q, Tao C, Hannan A, Yoon S, Min X, Peregrin J, Qu X, Li H, Yu H, Zhao J, Zhang X. Lacrimal gland budding requires PI3K-dependent suppression of EGF signaling. SCIENCE ADVANCES 2021; 7:7/27/eabf1068. [PMID: 34193412 PMCID: PMC8245041 DOI: 10.1126/sciadv.abf1068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 05/17/2021] [Indexed: 06/13/2023]
Abstract
The patterning of epithelial buds is determined by the underlying signaling network. Here, we study the cross-talk between phosphoinositide 3-kinase (PI3K) and Ras signaling during lacrimal gland budding morphogenesis. Our results show that PI3K is activated by both the p85-mediated insulin-like growth factor (IGF) and Ras-mediated fibroblast growth factor (FGF) signaling. On the other hand, PI3K also promotes extracellular signal-regulated kinase (ERK) signaling via a direct interaction with Ras. Both PI3K and ERK are upstream regulators of mammalian target of rapamycin (mTOR), and, together, they prevent expansion of epidermal growth factor (EGF) receptor expression from the lacrimal gland stalk to the bud region. We further show that this suppression of EGF signaling is necessary for induction of lacrimal gland buds. These results reveal that the interplay between PI3K, mitogen-activated protein kinase, and mTOR mediates the cross-talk among FGF, IGF, and EGF signaling in support of lacrimal gland development.
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Affiliation(s)
- Qian Wang
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - Chenqi Tao
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - Abdul Hannan
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - Sungtae Yoon
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - Xuanyu Min
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - John Peregrin
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - Xiuxia Qu
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Hongge Li
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
| | - Honglian Yu
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA
- Department of Biochemistry, School of Basic Medicine, Jining Medical University, Jining, Shandong, China
| | - Jean Zhao
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Xin Zhang
- Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, NY, USA.
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5
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G-protein subunit gamma-4 expression has potential for detection, prediction and therapeutic targeting in liver metastasis of gastric cancer. Br J Cancer 2021; 125:220-228. [PMID: 33854208 DOI: 10.1038/s41416-021-01366-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 02/25/2021] [Accepted: 03/11/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The liver is the most common site for haematogenous metastasis of gastric cancer, and liver metastasis is fatal. METHODS We conducted a transcriptomic analysis between metastatic foci in the liver, primary tumour and adjacent tissues from gastric cancer patients with metastasis limited to the liver. We determined mRNA expression levels in tumour tissues of 300 patients with gastric cancer via quantitative RT-PCR. The oncogenic phenotypes of GNG4 were determined with knockdown, knockout and forced expression experiments. We established and compared subcutaneous and liver metastatic mouse xenograft models of gastric cancer to reveal the roles of GNG4 in tumorigenesis in the liver. RESULTS GNG4 was upregulated substantially in primary gastric cancer tissues as well as liver metastatic lesions. High levels of GNG4 in primary cancer tissues were associated with short overall survival and the likelihood of liver recurrence. Functional assays revealed that GNG4 promoted cancer cell proliferation, the cell cycle and adhesiveness. Tumour formation by GNG4-knockout cells was moderately reduced in the subcutaneous mouse model and strikingly attenuated in the liver metastasis mouse model. CONCLUSIONS GNG4 expression may provide better disease monitoring for liver metastasis, and GNG4 may be a novel candidate therapeutic target for liver metastasis.
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6
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Parra-Mercado GK, Fuentes-Gonzalez AM, Hernandez-Aranda J, Diaz-Coranguez M, Dautzenberg FM, Catt KJ, Hauger RL, Olivares-Reyes JA. CRF 1 Receptor Signaling via the ERK1/2-MAP and Akt Kinase Cascades: Roles of Src, EGF Receptor, and PI3-Kinase Mechanisms. Front Endocrinol (Lausanne) 2019; 10:869. [PMID: 31920979 PMCID: PMC6921279 DOI: 10.3389/fendo.2019.00869] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 11/27/2019] [Indexed: 12/28/2022] Open
Abstract
In the present study, we determined the cellular regulators of ERK1/2 and Akt signaling pathways in response to human CRF1 receptor (CRF1R) activation in transfected COS-7 cells. We found that Pertussis Toxin (PTX) treatment or sequestering Gβγ reduced CRF1R-mediated activation of ERK1/2, suggesting the involvement of a Gi-linked cascade. Neither Gs/PKA nor Gq/PKC were associated with ERK1/2 activation. Besides, CRF induced EGF receptor (EGFR) phosphorylation at Tyr1068, and selective inhibition of EGFR kinase activity by AG1478 strongly inhibited the CRF1R-mediated phosphorylation of ERK1/2, indicating the participation of EGFR transactivation. Furthermore, CRF-induced ERK1/2 phosphorylation was not altered by pretreatment with batimastat, GM6001, or an HB-EGF antibody indicating that metalloproteinase processing of HB-EGF ligands is not required for the CRF-mediated EGFR transactivation. We also observed that CRF induced Src and PYK2 phosphorylation in a Gβγ-dependent manner. Additionally, using the specific Src kinase inhibitor PP2 and the dominant-negative-SrcYF-KM, it was revealed that CRF-stimulated ERK1/2 phosphorylation depends on Src activation. PP2 also blocked the effect of CRF on Src and EGFR (Tyr845) phosphorylation, further demonstrating the centrality of Src. We identified the formation of a protein complex consisting of CRF1R, Src, and EGFR facilitates EGFR transactivation and CRF1R-mediated signaling. CRF stimulated Akt phosphorylation, which was dependent on Gi/βγ subunits, and Src activation, however, was only slightly dependent on EGFR transactivation. Moreover, PI3K inhibitors were able to inhibit not only the CRF-induced phosphorylation of Akt, as expected, but also ERK1/2 activation by CRF suggesting a PI3K dependency in the CRF1R ERK signaling. Finally, CRF-stimulated ERK1/2 activation was similar in the wild-type CRF1R and the phosphorylation-deficient CRF1R-Δ386 mutant, which has impaired agonist-dependent β-arrestin-2 recruitment; however, this situation may have resulted from the low β-arrestin expression in the COS-7 cells. When β-arrestin-2 was overexpressed in COS-7 cells, CRF-stimulated ERK1/2 phosphorylation was markedly upregulated. These findings indicate that on the base of a constitutive CRF1R/EGFR interaction, the Gi/βγ subunits upstream activation of Src, PYK2, PI3K, and transactivation of the EGFR are required for CRF1R signaling via the ERK1/2-MAP kinase pathway. In contrast, Akt activation via CRF1R is mediated by the Src/PI3K pathway with little contribution of EGFR transactivation.
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Affiliation(s)
- G. Karina Parra-Mercado
- Laboratory of Signal Transduction, Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City, Mexico
| | - Alma M. Fuentes-Gonzalez
- Laboratory of Signal Transduction, Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City, Mexico
| | - Judith Hernandez-Aranda
- Laboratory of Signal Transduction, Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City, Mexico
| | - Monica Diaz-Coranguez
- Laboratory of Signal Transduction, Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City, Mexico
| | | | - Kevin J. Catt
- Section on Hormonal Regulation, Program on Developmental Endocrinology and Genetics, National Institute of Child Health and Human Development, Bethesda, MD, United States
| | - Richard L. Hauger
- Center of Excellence for Stress and Mental Health, VA Healthcare System, San Diego, CA, United States
- Department of Psychiatry, University of California, San Diego, San Diego, CA, United States
| | - J. Alberto Olivares-Reyes
- Laboratory of Signal Transduction, Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City, Mexico
- *Correspondence: J. Alberto Olivares-Reyes
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7
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Shin SY, Nguyen LK. Dissecting Cell-Fate Determination Through Integrated Mathematical Modeling of the ERK/MAPK Signaling Pathway. Methods Mol Biol 2017; 1487:409-432. [PMID: 27924583 DOI: 10.1007/978-1-4939-6424-6_29] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The past three decades have witnessed an enormous progress in the elucidation of the ERK/MAPK signaling pathway and its involvement in various cellular processes. Because of its importance and complex wiring, the ERK pathway has been an intensive subject for mathematical modeling, which facilitates the unraveling of key dynamic properties and behaviors of the pathway. Recently, however, it became evident that the pathway does not act in isolation but closely interacts with many other pathways to coordinate various cellular outcomes under different pathophysiological contexts. This has led to an increasing number of integrated, large-scale models that link the ERK pathway to other functionally important pathways. In this chapter, we first discuss the essential steps in model development and notable models of the ERK pathway. We then use three examples of integrated, multipathway models to investigate how crosstalk of ERK signaling with other pathways regulates cell-fate decision-making in various physiological and disease contexts. Specifically, we focus on ERK interactions with the phosphoinositide-3 kinase (PI3K), c-Jun N-terminal kinase (JNK), and β-adrenergic receptor (β-AR) signaling pathways. We conclude that integrated modeling in combination with wet-lab experimentation have been and will be instrumental in gaining an in-depth understanding of ERK signaling in multiple biological contexts.
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Affiliation(s)
- Sung-Young Shin
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, VIC, 3800, Australia.,Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Lan K Nguyen
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, VIC, 3800, Australia. .,Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
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8
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Saitoh F, Wakatsuki S, Tokunaga S, Fujieda H, Araki T. Glutamate signals through mGluR2 to control Schwann cell differentiation and proliferation. Sci Rep 2016; 6:29856. [PMID: 27432639 PMCID: PMC4949416 DOI: 10.1038/srep29856] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 06/27/2016] [Indexed: 12/31/2022] Open
Abstract
Rapid saltatory nerve conduction is facilitated by myelin structure, which is produced by Schwann cells (SC) in the peripheral nervous system (PNS). Proper development and degeneration/regeneration after injury requires regulated phenotypic changes of SC. We have previously shown that glutamate can induce SC proliferation in culture. Here we show that glutamate signals through metabotropic glutamate receptor 2 (mGluR2) to induce Erk phosphorylation in SC. mGluR2-elicited Erk phosphorylation requires ErbB2/3 receptor tyrosine kinase phosphorylation to limit the signaling cascade that promotes phosphorylation of Erk, but not Akt. We found that Gβγ and Src are involved in subcellular signaling downstream of mGluR2. We also found that glutamate can transform myelinating SC to proliferating SC, while inhibition of mGluR2 signaling can inhibit demyelination of injured nerves in vivo. These data suggest pathophysiological significance of mGluR2 signaling in PNS and its possible therapeutic importance to combat demyelinating disorders including Charcot-Marie-Tooth disease.
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Affiliation(s)
- Fuminori Saitoh
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan.,Department of Anatomy, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Shuji Wakatsuki
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan
| | - Shinji Tokunaga
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan
| | - Hiroki Fujieda
- Department of Anatomy, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Toshiyuki Araki
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan
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9
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Lai X, Ye L, Liao Y, Jin L, Ma Q, Lu B, Sun Y, Shi Y, Zhou N. Agonist-induced activation of histamine H3 receptor signals to extracellular signal-regulated kinases 1 and 2 through PKC-, PLD-, and EGFR-dependent mechanisms. J Neurochem 2016; 137:200-15. [DOI: 10.1111/jnc.13559] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Xiangru Lai
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Lingyan Ye
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Yuan Liao
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Lili Jin
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Qiang Ma
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Bing Lu
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Yi Sun
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Ying Shi
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Naiming Zhou
- Institute of Biochemistry; College of Life Science; Zijingang Campus; Zhejiang University; Hangzhou Zhejiang 310058 China
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10
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Bar-Lev TH, Harris D, Tomić M, Stojilkovic S, Blumenfeld Z, Brown P, Seger R, Naor Z. Role of PI4K and PI3K-AKT in ERK1/2 activation by GnRH in the pituitary gonadotropes. Mol Cell Endocrinol 2015; 415:12-23. [PMID: 26238084 PMCID: PMC4582010 DOI: 10.1016/j.mce.2015.07.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/29/2015] [Accepted: 07/29/2015] [Indexed: 12/20/2022]
Abstract
The role of PI4K and PI3K-AKT in ERK1/2 activation by GnRH was examined. A relatively long preincubation (60 min) with wortmannin (10 nM and 10 μM), and LY294002 (10 μM and 100 μM) (doses known to inhibit PI3K and PI4K, respectively), were required to inhibit GnRH-and PMA-stimulated ERK1/2 activity in αT3-1 and LβT2 gonadotrope cells. A similar preincubation protocol was required to demonstrate inhibition of IGF-1-stimulated AKT activation lending support for the need of prolonged incubation (60 min) with wortmannin in contrast to other cellular systems. To rule out that the inhibitors acted upon PI(4,5)P2 levels, we followed the [Ca(2+)]i response to GnRH and found that wortmannin has no significant effect on GnRH-induced [Ca(2+)]i responses. Surprisingly, GnRH and PMA reduced, while IGF-1 increased AKT phosphorylation. We suggest that PI3K inhibits GnRH-stimulated αGSU activity, has no effect upon GnRH-stimulated LHβ activity and enhanced the GnRH-stimulated FSHβ transcription. Hence, PI4K and PI3K-AKT play a role in GnRH to ERK1/2 signaling, while PI3K may regulate also GnRH-induced gonadotropin gene expression.
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Affiliation(s)
- Tali H Bar-Lev
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv 69978, Israel
| | - Dagan Harris
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv 69978, Israel
| | - Melanija Tomić
- National Institute of Child Health and Human Development, National Institute of Health, Bethesda, MD 20892-4510, USA
| | - Stanko Stojilkovic
- National Institute of Child Health and Human Development, National Institute of Health, Bethesda, MD 20892-4510, USA
| | - Zeev Blumenfeld
- Reproductive Endocrinology, OB/GYN, Rambam Health Care Campus, Technion-Faculty of Medicine, Haifa 31096, Israel
| | - Pamela Brown
- Medical Research Council (MRC) Centre of Reproductive Health, University of Edinburgh, The Queen's Medical Research Institute, Edinburgh, Scotland EH16 4TJ, United Kingdom
| | - Rony Seger
- Department of Biological Regulation, the Weizmann Institute of Science, Rehovot 76100, Israel
| | - Zvi Naor
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv 69978, Israel.
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11
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Grabauskas G, Wu X, Lu Y, Heldsinger A, Song I, Zhou SY, Owyang C. KATP channels in the nodose ganglia mediate the orexigenic actions of ghrelin. J Physiol 2015; 593:3973-89. [PMID: 26174421 PMCID: PMC4575581 DOI: 10.1113/jp270788] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/26/2015] [Indexed: 12/21/2022] Open
Abstract
Ghrelin, a hunger signalling peptide derived from the peripheral tissues, overcomes the satiety signals evoked by anorexigenic molecules, such as cholecystokinin (CCK) and leptin, to stimulate feeding. Using in vivo and in vitro electrophysiological techniques, we show that ghrelin hyperpolarizes neurons and inhibits currents evoked by leptin and CCK-8. Administering a KATP channel antagonist or silencing Kir6.2, a major subunit of the KATP channel, abolished ghrelin inhibition. The inhibitory actions of ghrelin were also abolished by treating the vagal ganglia neurons with pertussis toxin, as well as phosphatidylinositol 3-kinase (PI3K) or extracellular signal-regulated kinase 1 and 2 (Erk1/2) small interfering RNA. Feeding experiments showed that silencing Kir6.2 in the vagal ganglia abolished the orexigenic actions of ghrelin. These data indicate that ghrelin modulates vagal ganglia neuron excitability by activating KATP conductance via the growth hormone secretagogue receptor subtype 1a-Gαi -PI3K-Erk1/2-KATP pathway. This provides a mechanism to explain the actions of ghrelin with respect to overcoming anorexigenic signals that act via the vagal afferent pathways. Ghrelin is the only known hunger signal derived from the peripheral tissues. Ghrelin overcomes the satiety signals evoked by anorexigenic molecules, such as cholecystokinin (CCK) and leptin, to stimulate feeding. The mechanisms by which ghrelin reduces the sensory signals evoked by anorexigenic hormones, which act via the vagus nerve to stimulate feeding, are unknown. Patch clamp recordings of isolated rat vagal neurons show that ghrelin hyperpolarizes neurons by activating K(+) conductance. Administering a KATP channel antagonist or silencing Kir6.2, a major subunit of the KATP channel, abolished ghrelin inhibition in vitro and in vivo. Patch clamp studies show that ghrelin inhibits currents evoked by leptin and CCK-8, which operate through independent ionic channels. The inhibitory actions of ghrelin were abolished by treating the vagal ganglia neurons with pertussis toxin, as well as phosphatidylinositol 3-kinase (PI3K) or extracellular signal-regulated kinase 1 and 2 (Erk1/2) small interfering RNA. In vivo gene silencing of PI3K and Erk1/2 in the nodose ganglia prevented ghrelin inhibition of leptin- or CCK-8-evoked vagal firing. Feeding experiments showed that silencing Kir6.2 in the vagal ganglia abolished the orexigenic actions of ghrelin. These data indicate that ghrelin modulates vagal ganglia neuron excitability by activating KATP conductance via the growth hormone secretagogue receptor subtype 1a-Gαi -PI3K-Erk1/2-KATP pathway. The resulting hyperpolarization renders the neurons less responsive to signals evoked by anorexigenic hormones. This provides a mechanism to explain the actions of ghrelin with respect to overcoming anorexigenic signals that act via the vagal afferent pathways.
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Affiliation(s)
- Gintautas Grabauskas
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
| | - Xiaoyin Wu
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
| | - Yuanxu Lu
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
| | - Andrea Heldsinger
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
| | - Il Song
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
| | - Shi-Yi Zhou
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
| | - Chung Owyang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health SystemAnn Arbor, MI, USA
- Corresponding author C. Owyang: 3912 Taubman Center, SPC 5362, 1500 East Medical Center Drive, University of Michigan Health System, Ann Arbor, MI 48109, USA.
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12
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Habash T, Saleh A, Roy Chowdhury SK, Smith DR, Fernyhough P. The proinflammatory cytokine, interleukin-17A, augments mitochondrial function and neurite outgrowth of cultured adult sensory neurons derived from normal and diabetic rats. Exp Neurol 2015; 273:177-89. [PMID: 26321687 DOI: 10.1016/j.expneurol.2015.08.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 07/31/2015] [Accepted: 08/24/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Diabetic neuropathy comprises dying back of nerve endings that reflects impairment in axonal plasticity and regenerative nerve growth. Metabolic changes in diabetes can lead to a dysregulation of hormonal mediators, such as cytokines, that may constrain distal nerve fiber growth. Interleukin-17 (IL-17A), a proinflammatory and neurotropic cytokine produced by T-cells, was significantly reduced in sciatic nerve of streptozotocin (STZ)-diabetic rats. Thus we studied the effect of IL-17A on the phenotype of sensory neurons derived from age matched control or type 1 diabetic rats. The aims were to determine the ability of IL-17A to enhance neurite outgrowth in cultured sensory neurons, investigate the signaling pathways activated by IL-17A, study the role of mitochondria and mechanistically link to neurite outgrowth. RESULTS IL-17A (10 ng/ml; p<0.05) significantly and dose-dependently increased total neurite outgrowth in cultures of adult dorsal root ganglia (DRG) sensory neurons derived from both control and streptozotocin (STZ)-diabetic rats. This enhancement was mediated by IL-17A-dependent activation of extracellular-regulated protein kinase (ERK) and phosphoinositide-3 kinase (PI-3K) signal transduction pathways. Pharmacological blockade of one of these activated pathways triggered complete inhibition of neurite outgrowth. IL-17A augmented mitochondrial bioenergetic function of sensory neurons derived from control or diabetic rats and this was also mediated via ERK or PI-3K. IL-17A-dependent elevation of bioenergetic function was associated with augmented expression of proteins of the mitochondrial electron transport system complexes. CONCLUSIONS IL-17A enhanced axonal plasticity through activation of ERK and PI-3K pathways and was associated with augmented mitochondrial bioenergetic function in sensory neurons.
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Affiliation(s)
- Tarek Habash
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada; Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB R3E 0T6, Canada
| | - Ali Saleh
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Subir K Roy Chowdhury
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Darrell R Smith
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Paul Fernyhough
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada; Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB R3E 0T6, Canada.
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13
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Lecat S, Belemnaba L, Galzi JL, Bucher B. Neuropeptide Y receptor mediates activation of ERK1/2 via transactivation of the IGF receptor. Cell Signal 2015; 27:1297-304. [PMID: 25817573 DOI: 10.1016/j.cellsig.2015.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/19/2015] [Accepted: 03/08/2015] [Indexed: 12/24/2022]
Abstract
Neuropeptide Y binds to G-protein coupled receptors whose action results in inhibition of adenylyl cyclase activity. Using HEK293 cells stably expressing the native neuropeptide Y Y1 receptors, we found that the NPY agonist elicits a transient phosphorylation of the extracellular signal-regulated kinases (ERK1/2). We first show that ERK1/2 activation following Y1 receptor stimulation is dependent on heterotrimeric Gi/o since it is completely inhibited by pre-treatment with pertussis toxin. In addition, ERK1/2 activation is internalization-independent since mutant Y1 receptors unable to recruit β-arrestins, can still activate ERK signaling to the same extent as wild-type receptors. We next show that this activation of the MAPK pathway is inhibited by the MEK inhibitor U0126, is not dependent on calcium signaling at the Y1 receptor (no effect upon inhibition of phospholipase C, protein kinase C or protein kinase D) but instead dependent on Gβ/γ and associated signaling pathways that activate PI3-kinase. Although inhibition of the epidermal-growth factor receptor tyrosine kinase did not influence NPY-induced ERK1/2 activation, we show that the inhibition of insulin growth factor receptor IGFR by AG1024 completely blocks activation of ERK1/2 by the Y1 receptor. This Gβ/γ-PI3K-AG1024-sensitive pathway does not involve activation of IGFR through the release of a soluble ligand by metalloproteinases since it is not affected by the metalloproteinase inhibitor marimastat. Finally, we found that a similar pathway, sensitive to wortmannin-AG1024 but insensitive to marimastat, is implicated in activation of ERK signaling in HEK293 cells by endogenously expressed GPCRs coupled to Gq-protein (muscarinic M3 receptors) or coupled to Gs-protein (endothelin ETB receptors). Our analysis is the first to show that β-arrestin recruitment to the NPY Y1 receptor is not necessary for MAPK activation by this receptor but that transactivation of the IGFR receptor is required.
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Affiliation(s)
- Sandra Lecat
- GPCRs, Pain and Inflammation Team, UMR7242, CNRS-University of Strasbourg, LabEx Medalis 300 Bvd Sébastien Brant, CS 10413, 67412 Illkirch, France.
| | - Lazare Belemnaba
- UMR 7213, CNRS-University of Strasbourg, Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, 74 route du Rhin, CS 60024, 67401 Illkirch, France
| | - Jean-Luc Galzi
- GPCRs, Pain and Inflammation Team, UMR7242, CNRS-University of Strasbourg, LabEx Medalis 300 Bvd Sébastien Brant, CS 10413, 67412 Illkirch, France
| | - Bernard Bucher
- UMR 7213, CNRS-University of Strasbourg, Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, 74 route du Rhin, CS 60024, 67401 Illkirch, France
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14
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Cholinergic transactivation of the EGFR in HaCaT keratinocytes stimulates a flotillin-1 dependent MAPK-mediated transcriptional response. Int J Mol Sci 2015; 16:6447-63. [PMID: 25803106 PMCID: PMC4394542 DOI: 10.3390/ijms16036447] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/06/2015] [Accepted: 03/17/2015] [Indexed: 12/13/2022] Open
Abstract
Acetylcholine and its receptors regulate numerous cellular processes in keratinocytes and other non-neuronal cells. Muscarinic acetylcholine receptors are capable of transactivating the epidermal growth factor receptor (EGFR) and, downstream thereof, the mitogen-activated protein kinase (MAPK) cascade, which in turn regulates transcription of genes involved in cell proliferation and migration. We here show that cholinergic stimulation of human HaCaT keratinocytes results in increased transcription of matrix metalloproteinase MMP-3 as well as several ligands of the epidermal growth factor family. Since both metalloproteinases and the said ligands are involved in the transactivation of the EGFR, this transcriptional upregulation may provide a positive feed-forward loop for EGFR/MAPK activation. We here also show that the cholinergic EGFR and MAPK activation and the upregulation of MMP-3 and EGF-like ligands are dependent on the expression of flotillin-1 which we have previously shown to be a regulator of MAPK signaling.
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15
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Ren J, Song D, Bai Q, Verkhratsky A, Peng L. Fluoxetine induces alkalinization of astroglial cytosol through stimulation of sodium-hydrogen exchanger 1: dissection of intracellular signaling pathways. Front Cell Neurosci 2015; 9:61. [PMID: 25784857 PMCID: PMC4347488 DOI: 10.3389/fncel.2015.00061] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 02/10/2015] [Indexed: 01/08/2023] Open
Abstract
Clinical evidence suggest astrocytic abnormality in major depression (MD) while treatment with anti-psychotic drugs affects astroglial functions. Astroglial cells are involved in pH homeostasis of the brain by transporting protons (through sodium-proton transporter 1, NHE1, glutamate transporters EAAT1/2 and proton-lactate co-transporter MCT1) and bicarbonate (through the sodium-bicarbonate co-transporter NBC or the chloride-bicarbonate exchanger AE). Here we show that chronic treatment with fluoxetine increases astroglial pHi by stimulating NHE1-mediated proton extrusion. At a clinically relevant concentration of 1 μM, fluoxetine significantly increased astroglial pHi from 7.05 to 7.34 after 3 weeks and from 7.18 to 7.58 after 4 weeks of drug treatment. Stimulation of NHE1 is a result of transporter phosphorylation mediated by several intracellular signaling cascades that include MAPK/ERK1/2, PI3K/AKT and ribosomal S6 kinase (RSK). Fluoxetine stimulated phosphorylation of ERK1/2, AKT and RSK in a concentration dependent manner. Positive crosstalk exists between two signal pathways, MAPK/ERK1/2 and PI3K/AKT activated by fluoxetine since ERK1/2 phosphrylation could be abolished by inhibitors of PI3K, LY294002 and AKT, triciribine, and AKT phosphorylation by inhibitor of MAPK, U0126. As a result, RSK phosphorylation was not only inhibited by U0126 but also by inhibitor of LY294002. The NHE1 phoshorylation resulted in stimulation of NHE1 activity as revealed by the NH4Cl-prepulse technique; the increase of NHE1 activity was dependent on fluoxetine concentration, and could be inhibited by both U0126 and LY294002. Our findings suggest that regulation of astrocytic pHi and brain pH may be one of the mechanisms underlying fluoxetine action.
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Affiliation(s)
- Jienan Ren
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
| | - Dan Song
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
| | - Qiufang Bai
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
| | - Alexei Verkhratsky
- Faculty of Life Science, The University of Manchester Manchester, UK ; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science Bilbao, Spain ; University of Nizhny Novgorod Nizhny Novgorod, Russia
| | - Liang Peng
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
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16
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Guan XH, Fu QC, Shi D, Bu HL, Song ZP, Xiong BR, Shu B, Xiang HB, Xu B, Manyande A, Cao F, Tian YK. Activation of spinal chemokine receptor CXCR3 mediates bone cancer pain through an Akt-ERK crosstalk pathway in rats. Exp Neurol 2015; 263:39-49. [DOI: 10.1016/j.expneurol.2014.09.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/30/2014] [Accepted: 09/12/2014] [Indexed: 12/29/2022]
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17
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Kendall RT, Lee MH, Pleasant DL, Robinson K, Kuppuswamy D, McDermott PJ, Luttrell LM. Arrestin-dependent angiotensin AT1 receptor signaling regulates Akt and mTor-mediated protein synthesis. J Biol Chem 2014; 289:26155-26166. [PMID: 25081544 DOI: 10.1074/jbc.m114.595728] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Control of protein synthesis is critical to both cell growth and proliferation. The mammalian target of rapamycin (mTOR) integrates upstream growth, proliferation, and survival signals, including those transmitted via ERK1/2 and Akt, to regulate the rate of protein translation. The angiotensin AT1 receptor has been shown to activate both ERK1/2 and Akt in arrestin-based signalsomes. Here, we examine the role of arrestin-dependent regulation of ERK1/2 and Akt in the stimulation of mTOR-dependent protein translation by the AT1 receptor using HEK293 and primary vascular smooth muscle cell models. Nascent protein synthesis stimulated by both the canonical AT1 receptor agonist angiotensin II (AngII), and the arrestin pathway-selective agonist [Sar(1)-Ile(4)-Ile(8)]AngII (SII), is blocked by shRNA silencing of βarrestin1/2 or pharmacological inhibition of Akt, ERK1/2, or mTORC1. In HEK293 cells, SII activates a discrete arrestin-bound pool of Akt and promotes Akt-dependent phosphorylation of mTOR and its downstream effector p70/p85 ribosomal S6 kinase (p70/85S6K). In parallel, SII-activated ERK1/2 helps promote mTOR and p70/85S6K phosphorylation, and is required for phosphorylation of the known ERK1/2 substrate p90 ribosomal S6 kinase (p90RSK). Thus, arrestins coordinate AT1 receptor regulation of ERK1/2 and Akt activity and stimulate protein translation via both Akt-mTOR-p70/85S6K and ERK1/2-p90RSK pathways. These results suggest that in vivo, arrestin pathway-selective AT1 receptor agonists may promote cell growth or hypertrophy through arrestin-mediated mechanisms despite their antagonism of G protein signaling.
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Affiliation(s)
- Ryan T Kendall
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Mi-Hye Lee
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Dorea L Pleasant
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Katherine Robinson
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Dhandapani Kuppuswamy
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29401
| | - Paul J McDermott
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29401
| | - Louis M Luttrell
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29401.
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18
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Song D, Du T. Ammonium activates ouabain-activated signalling pathway in astrocytes: therapeutic potential of ouabain antagonist. Curr Neuropharmacol 2014; 12:334-41. [PMID: 25342941 PMCID: PMC4207073 DOI: 10.2174/1570159x12666140828222115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/18/2014] [Accepted: 06/25/2014] [Indexed: 01/16/2023] Open
Abstract
The causal role of ammonium in hepatic encephalopathy was identified in 1930s. Astroglial cells are primary cellular elements of hepatic encephalopathy which conceptually, can be considered a toxic astrogliopathology. Previously we have reported that acute exposure to ammonium activated ouabain/Na,K-ATPase signalling pathway, which includes Src, EGF receptor, Raf, Ras, MEK and ERK1/2. Chronic incubation of astrocytes with ammonium increased production of endogenous ouabain-like compound. Ouabain antagonist canrenone abolished effects of ammonium on astrocytic swelling, ROS production, and upregulation of gene expression and function of TRPC1 and Cav1.2. However, ammonium induces multiple pathological modifications in astrocytes, and some of them may be not related to this signalling pathway. In this review, we focus on the effect of ammonium on ouabain/Na,K-ATPase signalling pathway and its involvement in ammonium-induced ROS production, cell swelling and aberration of Ca(2+) signals in astrocytes. We also briefly discuss Na,K-ATPase, EGF receptor, endogenous ouabain and ouabain antagonist.
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Affiliation(s)
- Dan Song
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
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19
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Hertz L, Peng L, Song D. Ammonia, like K(+), stimulates the Na(+), K(+), 2 Cl(-) cotransporter NKCC1 and the Na(+),K(+)-ATPase and interacts with endogenous ouabain in astrocytes. Neurochem Res 2014; 40:241-57. [PMID: 24929663 DOI: 10.1007/s11064-014-1352-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/31/2014] [Accepted: 06/03/2014] [Indexed: 12/12/2022]
Abstract
Brain edema during hepatic encephalopathy or acute liver failure as well as following brain ischemia has a multifactorial etiology, but it is a dangerous and occasionally life-threatening complication because the brain is enclosed in the rigid skull. During ischemia the extracellular K(+) concentration increases to very high levels, which when energy becomes available during reperfusion stimulate NKCC1, a cotransporter driven by the transmembrane ion gradients established by the Na(+),K(+)-ATPase and accumulating Na(+), K(+) and 2 Cl(-) together with water. This induces pronounced astrocytic swelling under pathologic conditions, but NKCC1 is probably also activated, although to a lesser extent, during normal brain function. Redistribution of ions and water between extra- and intracellular phases does not create brain edema, which in addition requires uptake across the blood-brain barrier. During hepatic encephalopathy and acute liver failure a crucial factor is the close resemblance between K(+) and NH4(+) in their effects not only on NKCC1 and Na(+),K(+)-ATPase but also on Na(+),K(+)-ATPase-induced signaling by endogenous ouabains. These in turn activate production of ROS and nitrosactive agents which slowly sensitize NKCC1, explaining why cell swelling and brain edema generally are delayed under hyperammonemic conditions, although very high ammonia concentrations can cause immediate NKCC1 activation.
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Affiliation(s)
- Leif Hertz
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, No. 92 Beier Road, Heping District, Shenyang, People's Republic of China
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Ahmed SM, Angers S. Emerging non-canonical functions for heterotrimeric G proteins in cellular signaling. J Recept Signal Transduct Res 2013; 33:177-83. [PMID: 23721574 DOI: 10.3109/10799893.2013.795972] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Classically heterotrimeric G proteins have been described as the principal signal transducing machinery for G-protein-coupled receptors. Receptor activation catalyzes nucleotide exchange on the Gα protein, enabling Gα-GTP and Gβγ-subunits to engage intracellular effectors to generate various cellular effects such as second messenger production or regulation of ion channel conductivity. Recent genetic and proteomic screens have identified novel heterotrimeric G-protein-interacting proteins and expanded their functional roles. This review highlights some examples of recently identified interacting proteins and summarizes how they functionally connect heterotrimeric G proteins to previously underappreciated cellular roles.
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Affiliation(s)
- Syed M Ahmed
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
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21
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Dai H, Song D, Xu J, Li B, Hertz L, Peng L. Ammonia-induced Na,K-ATPase/ouabain-mediated EGF receptor transactivation, MAPK/ERK and PI3K/AKT signaling and ROS formation cause astrocyte swelling. Neurochem Int 2013; 63:610-25. [PMID: 24044899 DOI: 10.1016/j.neuint.2013.09.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 12/13/2022]
Abstract
Ammonia toxicity is clinically important and biologically poorly understood. We reported previously that 3mM ammonia chloride (ammonia), a relevant concentration for hepatic encephalopathy studies, increases production of endogenous ouabain and activity of Na,K-ATPase in astrocytes. In addition, ammonia-induced upregulation of gene expression of α2 isoform of Na,K-ATPase in astrocytes could be inhibited by AG1478, an inhibitor of the EGF receptor (EGFR), and by PP1, an inhibitor of Src, but not by GM6001, an inhibitor of metalloproteinase and shedding of growth factor, suggesting the involvement of endogenous ouabain-induced EGF receptor transactivation. In the present cell culture study, we investigated ammonia effects on phosphorylation of EGF receptor and its intracellular signal pathway towards MAPK/ERK1/2 and PI3K/AKT; interaction between EGF receptor, α1, and α2 isoforms of Na,K-ATPase, Src, ERK1/2, AKT and caveolin-1; and relevance of these signal pathways for ammonia-induced cell swelling, leading to brain edema, an often fatal complication of ammonia toxicity. We found that (i) ammonia increases EGF receptor phosphorylation at EGFR(845) and EGFR(1068); (ii) ammonia-induced ERK1/2 and AKT phosphorylation depends on the activity of EGF receptor and Src, but not on metalloproteinase; (iii) AKT phosphorylation occurs upstream of ERK1/2 phosphorylation; (iv) ammonia stimulates association between the α1 Na,K-ATPase isoform, Src, EGF receptor, ERK1/2, AKT and caveolin-1; (v) ammonia-induced ROS production might occur later than EGFR transactivation; (vi) both ammonia induced ERK phosphorylation and ROS production can be abolished by canrenone, an inhibitor of ouabain, and (vii) ammonia-induced cell swelling depends on signaling via the Na,K-ATPase/ouabain/Src/EGF receptor/PI3K-AKT/ERK1/2, but in response to 3mM ammonia it does not appear until after 12h. Based on literature data it is suggested that the delayed appearance of the ammonia-induced swelling at this concentration reflects required ouabain-induced oxidative damage of the ion and water cotransporter NKCC1. This information may provide new therapeutic targets for treatment of hyperammonic brain disorders.
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Affiliation(s)
- Hongliang Dai
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Dan Song
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Junnan Xu
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Baoman Li
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Leif Hertz
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Liang Peng
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China.
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Stimulation of α1-adrenoceptor or angiotensin type 1 receptor enhances DNA synthesis in human-induced pluripotent stem cells via Gq-coupled receptor-dependent signaling pathways. Eur J Pharmacol 2013; 714:202-9. [DOI: 10.1016/j.ejphar.2013.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 05/31/2013] [Accepted: 06/08/2013] [Indexed: 11/22/2022]
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The role of SIRT1/AKT/ERK pathway in ultraviolet B induced damage on human retinal pigment epithelial cells. Toxicol In Vitro 2013; 27:1728-36. [PMID: 23673314 DOI: 10.1016/j.tiv.2013.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 05/01/2013] [Accepted: 05/03/2013] [Indexed: 11/23/2022]
Abstract
Ultraviolet (UV)-induced damage plays a major role in ocular diseases, such as cataracts and retinal degeneration. UVB may also cause retinal phototoxicity and photic retinopathy. In this study, we explored the effects of UVB on the cell cycle and the role of silent mating type information regulation 2 homolog 1 (SIRT1) in the UVB-induced damage. UVB dose-dependently suppressed the growth of retinal pigment epithelial (RPE) cells by activating the phosphatidylinositol 3-kinase (PI3K) pathway and triggering cell cycle arrest at the S phase. SIRT1, an NAD-dependent histone deacetylase, is involved in multiple biological processes, such as the stress response and the regulation of the cell cycle. However, its role in the effects of UVB on RPE cells is unclear. We showed that UVB down-regulates SIRT1 expression in a dose-dependent manner. Resveratrol, an SIRT1 activator, prevented the UVB-induced damage by inhibiting AKT and ERK phosphorylation. A specific PI3K inhibitor attenuated the UVB-induced ERK1/2 and p53 phosphorylation. Finally, UVB activated the PI3K/AKT/ERK pathway by reducing the expression of SIRT1 in ARPE-19 cells. Our study, therefore, illustrated the molecular mechanisms of UVB-induced phototoxicity and damage of RPE cells. SIRT1 and resveratrol may be significant regulators, protecting against UVB-induced injury.
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Khan SM, Sleno R, Gora S, Zylbergold P, Laverdure JP, Labbé JC, Miller GJ, Hébert TE. The expanding roles of Gβγ subunits in G protein-coupled receptor signaling and drug action. Pharmacol Rev 2013; 65:545-77. [PMID: 23406670 DOI: 10.1124/pr.111.005603] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Gβγ subunits from heterotrimeric G proteins perform a vast array of functions in cells with respect to signaling, often independently as well as in concert with Gα subunits. However, the eponymous term "Gβγ" does not do justice to the fact that 5 Gβ and 12 Gγ isoforms have evolved in mammals to serve much broader roles beyond their canonical roles in cellular signaling. We explore the phylogenetic diversity of Gβγ subunits with a view toward understanding these expanded roles in different cellular organelles. We suggest that the particular content of distinct Gβγ subunits regulates cellular activity, and that the granularity of individual Gβ and Gγ action is only beginning to be understood. Given the therapeutic potential of targeting Gβγ action, this larger view serves as a prelude to more specific development of drugs aimed at individual isoforms.
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Affiliation(s)
- Shahriar M Khan
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Room 1303, Montréal, Québec H3G 1Y6, Canada
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Bayliss A, Evans PD. Characterisation of AmphiAmR4, an amphioxus (Branchiostoma floridae) α₂-adrenergic-like G-protein-coupled receptor. INVERTEBRATE NEUROSCIENCE 2012. [PMID: 23183848 DOI: 10.1007/s10158-012-0145-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Little is known about the evolutionary relationship between vertebrate adrenergic receptors and invertebrate octopamine and tyramine receptors. The complexity of the adrenergic signalling system is believed to be an innovation of the vertebrate lineage but the presence of noradrenaline has been reported in some invertebrate species. The cephalochordate, amphioxus (Branchiostoma floridae), is an ideal model organism for studying the evolution of vertebrate GPCRs, given its unique position at the base of the chordate lineage. Here, we describe the pharmacological characterisation and second messenger coupling abilities of AmphiAmR4, which clusters with α₂-adrenergic receptors in a phylogenetic tree but also shares a high sequence similarity to invertebrate octopamine/tyramine receptors in both BLAST and Hidden Markov Model analyses. Thus, it was of particular interest to determine if AmphiAmR4 displayed similar functional properties to the vertebrate α₂-adrenergic receptors or to invertebrate octopamine or tyramine receptors. When stably expressed in Chinese hamster ovary (CHO) cells, noradrenaline couples the receptor to both the activation of adenylyl cyclase and to the activation of the MAPKinase pathway. Pharmacological studies with a wide range of agonists and antagonists suggest that AmphiAmR4 functions as an α₂-adrenergic-like receptor when expressed in CHO cells.
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Affiliation(s)
- Asha Bayliss
- The Inositide Laboratory, The Babraham Institute, The Babraham Research Campus, Cambridge CB22 3AT, UK
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Zhou Q, Li G, Deng XY, He XB, Chen LJ, Wu C, Shi Y, Wu KP, Mei LJ, Lu JX, Zhou NM. Activated human hydroxy-carboxylic acid receptor-3 signals to MAP kinase cascades via the PLC-dependent PKC and MMP-mediated EGFR pathways. Br J Pharmacol 2012; 166:1756-73. [PMID: 22289163 DOI: 10.1111/j.1476-5381.2012.01875.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE 3-Hydroxy-octanoate, recently identified as a ligand for, the orphan GPCR, HCA(3), is of particular interest given its ability to treat lipid disorders and atherosclerosis. Here we demonstrate the pathway of HCA(3)-mediated activation of ERK1/2. EXPERIMENTAL APPROACH Using CHO-K1 cells stably expressing HCA(3) receptors and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA(3) receptors, HCA(3)-mediated activation of ERK1/2 was measured by Western blot. KEY RESULTS HCA(3)-mediated activation of ERK1/2 was rapid, peaking at 5 min, and was Pertussis toxin sensitive. Our data, obtained by time course analyses in combination with different kinase inhibitors, demonstrated that on agonist stimulation, HCA(3) receptors evoked ERK1/2 activation via two distinct pathways, the PLC/PKC pathway at early time points (≤ 2 min) and the MMP/ epidermal growth factor receptor (EGFR) transactivation pathway with a maximum response at 5 min. Furthermore, our present results also indicated that the βγ-subunits of the G(i) protein play a critical role in HCA(3)-activated ERK1/2 phosphorylation, whereas β-arrestins and Src were not required for ERK1/2 activation. CONCLUSIONS AND IMPLICATIONS We have described the molecular mechanisms underlying the coupling of human HCA(3) receptors to the ERK1/2 MAP kinase pathway in CHO-K1 and A431 cells, which implicate the G(i) protein-initiated, PLC/PKC -and platelet-derived growth factor receptor/EGFR transactivation-dependent pathways. These observations may provide new insights into the pharmacological effects and the physiological functions modulated by the HCA(3)-mediated activation of ERK1/2.
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Affiliation(s)
- Q Zhou
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Science, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Roberts RE. The extracellular signal-regulated kinase (ERK) pathway: a potential therapeutic target in hypertension. J Exp Pharmacol 2012; 4:77-83. [PMID: 27186119 PMCID: PMC4863547 DOI: 10.2147/jep.s28907] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Hypertension is a risk factor for myocardial infarction, stroke, renal failure, heart failure, and peripheral vascular disease. One feature of hypertension is a hyperresponsiveness to contractile agents, and inhibition of vasoconstriction forms the basis of some of the treatments for hypertension. Hypertension is also associated with an increase in the growth and proliferation of vascular smooth muscle cells, which can lead to a thickening of the smooth muscle layer of the blood vessels and a reduction in lumen diameter. Targeting both the enhanced contractile responses, and the increased vascular smooth muscle cell growth could potentially be important pharmacological treatment of hypertension. Extracellular signal-regulated kinase (ERK) is a member of the mitogen-activated protein kinase family that is involved in both vasoconstriction and vascular smooth muscle cell growth and this, therefore, makes it attractive therapeutic target for treatment of hypertension. ERK activity is raised in vascular smooth muscle cells from animal models of hypertension, and inhibition of ERK activation reduces both vascular smooth muscle cell growth and vasoconstriction. This review discusses the potential for targeting ERK activity in the treatment of hypertension.
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Affiliation(s)
- Richard E Roberts
- School of Biomedical Sciences, University of Nottingham, Nottingham, United Kingdom
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Dalton GD, Howlett AC. Cannabinoid CB1 receptors transactivate multiple receptor tyrosine kinases and regulate serine/threonine kinases to activate ERK in neuronal cells. Br J Pharmacol 2012; 165:2497-511. [PMID: 21518335 DOI: 10.1111/j.1476-5381.2011.01455.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Signalling networks that regulate the progression of cannabinoid CB(1) receptor-mediated extracellular signal-regulated kinase (ERK) activation in neurons are poorly understood. We investigated the cellular mechanisms involved in CB(1) receptor-stimulated ERK phosphorylation in a neuronal cell model. EXPERIMENTAL APPROACH Murine N18TG2 neuronal cells were used to analyse the effect of specific protein kinase and phosphatase inhibitors on CB(1) receptor-stimulated ERK phosphorylation. The LI-COR In Cell Western assay and immunoblotting were used to measure ERK phosphorylation. KEY RESULTS The time-course of CB(1) receptor-stimulated ERK activation occurs in three phases that are regulated by distinct cellular mechanisms in N18TG2 cells. Phase I (0-5 min) maximal ERK phosphorylation is mediated by CB(1) receptor-stimulated ligand-independent transactivation of multiple receptor tyrosine kinases (RTKs). Phase I requires G(i/o) βγ subunit-stimulated phosphatidylinositol 3-kinase activation and Src kinase activation and is modulated by inhibition of cAMP-activated protein kinase A (PKA) levels. Src kinase activation is regulated by the protein tyrosine phosphatases 1B and Shp1. The Phase II (5-10 min) rapid decline in ERK phosphorylation involves PKA inhibition and serine/threonine phosphatase PP1/PP2A activation. The Phase III (>10 min) plateau in ERK phosphorylation is mediated by CB(1) receptor-stimulated, ligand-independent, transactivation of multiple RTKs. CONCLUSIONS AND IMPLICATIONS The complex expression of CB(1) receptor-stimulated ERK activation provides cellular selectivity, modulation of sensitivity to agonists, and coincidence detection with RTK signalling. RTK and PKA pathways may provide routes to novel CB(1) -based therapeutic interventions in the treatment of addictive disorders or neurodegenerative diseases. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
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Affiliation(s)
- George D Dalton
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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Nascimento AR, Pimenta MT, Lucas TFG, Royer C, Porto CS, Lazari MFM. Intracellular signaling pathways involved in the relaxin-induced proliferation of rat Sertoli cells. Eur J Pharmacol 2012; 691:283-91. [PMID: 22819701 DOI: 10.1016/j.ejphar.2012.07.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 06/28/2012] [Accepted: 07/03/2012] [Indexed: 01/01/2023]
Abstract
Regulation of Sertoli cell number is a key event to determine normal spermatogenesis. We have previously shown that relaxin and its G-protein coupled receptor RXFP1 are expressed in rat Sertoli cells, and that relaxin stimulates Sertoli cell proliferation. This study examined the mechanisms underlying the mitogenic effect of relaxin in a primary culture of Sertoli cells removed from testes of immature rats. Stimulation with exogenous relaxin increased Sertoli cell number and the expression of the proliferating cell nuclear antigen (PCNA), but did not affect the mRNA level of the differentiation markers cadherins 1 and 2. Relaxin-induced Sertoli cell proliferation was blocked by inhibition of MEK/ERK1/2 or PI3K/AKT pathways, but not by inhibition of PKC or EGFR activity. Relaxin induced a rapid and transient activation of ERK1/2 phosphorylation, which was MEK and SRC-dependent, and involved upstream activation of G(i). AKT activation could be detected 5 min after relaxin stimulation, and was still detected after 24h of stimulation with relaxin. Relaxin-induced AKT phosphorylation was G(i)- but not PKA-dependent, and it was blocked by both PI3K and MEK inhibitors. In conclusion, the mitogenic effect of relaxin in Sertoli cell involves coupling to G(i) and activation of both MEK/ERK1/2 and PI3K/AKT pathways.
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Affiliation(s)
- Aline Rosa Nascimento
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
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Crosstalk between Raf/MEK/ERK and PI3K/AKT in suppression of Bax conformational change by Grp75 under glucose deprivation conditions. J Mol Biol 2011; 414:654-66. [PMID: 21964438 DOI: 10.1016/j.jmb.2011.09.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 07/15/2011] [Accepted: 09/07/2011] [Indexed: 11/22/2022]
Abstract
During glucose deprivation (GD)-induced cellular stress, the molecular chaperone glucose-regulated protein 75 (Grp75)/Mortalin/PBP74/mtHSP70 (hereafter termed "Grp75") plays an important role in the suppression of apoptosis by inhibiting the Bax conformational change that delays the release of cytochrome c. The molecular pathways by which it carries out these functions are still unclear. We hypothesize that the anti-apoptotic effect by the overexpression of Grp75 was through the signal of AKT activated by classic phosphoinositide 3-kinase (PI3K) and also involved PI3K-independent pathways. Using the PC12 cell GD model, we demonstrated a novel mechanism of Grp75 activating AKT, which may be PI3K independent and associated with Raf/MEK (mitogen-activated protein kinase/ERK kinase)/ERK signaling. The PI3K inhibitor LY294002 did not influence the activation of AKT by the Grp75 overexpression under GD; however, the MEK inhibitor U0126 dramatically inhibited AKT phosphorylation in the same assay. In addition to the PI3K/AKT signal pathway, Grp75 overexpression also inhibited the Bax conformational change through the Raf/MEK/ERK signal pathway. In conclusion, Grp75 overexpression in activating AKT can be PI3K independent and associated with Raf/MEK/ERK signaling under GD. At the same time, PI3K may also crosstalk with Raf-1, in which the prosurvival signal of PI3K maintains the expression of Raf-1. The activated AKT and extracellular signal-regulated protein kinases 1 and 2 by Grp75 inhibited the Bax conformational change and subsequent apoptosis.
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Li G, Deng X, Wu C, Zhou Q, Chen L, Shi Y, Huang H, Zhou N. Distinct kinetic and spatial patterns of protein kinase C (PKC)- and epidermal growth factor receptor (EGFR)-dependent activation of extracellular signal-regulated kinases 1 and 2 by human nicotinic acid receptor GPR109A. J Biol Chem 2011; 286:31199-212. [PMID: 21768093 DOI: 10.1074/jbc.m111.241372] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nicotinic acid (niacin) has been widely used as a lipid-lowering drug for several decades, and recently, orphan G protein-coupled receptor GPR109A has been identified as a receptor for niacin. Mechanistic investigations have shown that, upon niacin activation, GPR109A couples to a G(i) protein and inhibits adenylate cyclase activity, leading to inhibition of liberation of free fatty acid. However, the underlying molecular mechanisms for GPR109A signaling remain largely unknown. Using CHO-K1 cells stably expressing GPR109A and A431 cells, which are a human epidermoid cell line with high levels of endogenous expression of functional GPR109A receptors, we found that activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) by niacin was rapid, peaking at 5 min, and was significantly blocked by pertussis toxin. Furthermore, time course experiments with different kinase inhibitors demonstrated that GPR109A induced ERK1/2 activation via the matrix metalloproteinase/epidermal growth factor receptor transactivation pathway at both early and later time points (2-5 min); this pathway was distinct from the PKC pathway-mediated ERK1/2 phosphorylation that occurs at early time points (≤2 min) in response to niacin. Overexpression of Gβγ subunit scavengers βARK1-CT and the Gα subunit of transducin led to a significant reduction of ERK1/2 phosphorylation, suggesting a critical role for βγ subunits in GPR109A-activated ERK1/2 phosphorylation. Using arrestin-2/3-specific siRNA and an internalization-deficient GPR109A mutant, we found that arrestin-2 and arrestin-3 were not involved in GPR109A-mediated ERK1/2 activation. In conclusion, our findings demonstrate that upon binding to niacin GPR109A receptors initially activate G(i), leading to dissociation of the Gβγ subunit from activated G(i), and subsequently induce ERK1/2 activation via two distinct pathways, one PKC-dependent pathway occurring at a peak time of ≤2 min and the other matrix metalloproteinase-dependent growth factor receptor transactivation occurring at both early and later time points (2-5 min).
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Affiliation(s)
- Guo Li
- Institute of Biochemistry, College of Life Science, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
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Nordquist L, Palm F, Andresen BT. Renal and vascular benefits of C-peptide: Molecular mechanisms of C-peptide action. Biologics 2011; 2:441-52. [PMID: 19707375 PMCID: PMC2721399 DOI: 10.2147/btt.s3221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
C-peptide has long been thought to be an inert byproduct of insulin production, but it has become apparent, and accepted, that C-peptide has important biological properties. C-peptide displays beneficial effects in many tissues affected by diabetic complications, such as increased peripheral blood flow and protection from renal damage. However, the mechanisms mediating these effects remain unclear. C-peptide interacts with cellular membranes at unidentified sites distinctive of the insulin family of receptors, and signals to multiple targets known to play a role in diabetes and diabetic complications, such as Na+/K+-ATPase and NOS. In general, the physiological and molecular effects of C-peptide resemble insulin, but C-peptide also possesses traits separate from those of insulin. These basic studies have been confirmed in human studies, suggesting that C-peptide may lend itself to clinical applications. However, the molecular and physiological properties of C-peptide are not completely elucidated, and large clinical studies have not begun. In order to further these goals, we critically summarize the current state of knowledge regarding C-peptide’s renal and vascular effects and the molecular signaling of C-peptide.
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Affiliation(s)
- Lina Nordquist
- Department of Medical Cell Biology, Division of Integrative Physiology, Uppsala University, Uppsala, Sweden
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Choi S, Yeum CH, Kim YD, Park CG, Kim MY, Park JS, Jeong HS, Kim BJ, So I, Kim KW. Receptor tyrosine and MAP kinase are involved in effects of H(2)O(2) on interstitial cells of Cajal in murine intestine. J Cell Mol Med 2011; 14:257-66. [PMID: 20414970 PMCID: PMC3837618 DOI: 10.1111/j.1582-4934.2008.00403.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Hydrogen peroxide (H(2)O(2)) is involved in intestinal motility through changes of smooth muscle activity. However, there is no report as to the modulatory effects of H(2)O(2) on interstitial cells of Cajal (ICC). We investigated the H(2)O(2) effects and signal transductions to determine whether the intestinal motility can be modulated through ICC. We performed whole-cell patch clamp in cultured ICC from murine intestine and molecular analyses. H(2)O(2) hyperpolarized the membrane and inhibited pacemaker currents. These effects were inhibited by glibenclamide, an inhibitor of ATP-sensitive K+ (K(ATP)) channels. The free-radical scavenger catalase inhibited the H(2)O(2)-induced effects. MAFP and AACOCF3 (a cytosolic phospholipase A2 inhibitors) or SC-560 and NS-398 (a selective COX-1 and 2 inhibitor) or AH6809 (an EP2 receptor antagonist) inhibited the H(2)O(2)-induced effects. PD98059 (a mitogen activated/ERK-activating protein kinase inhibitor) inhibited the H(2)O(2)-induced effects, though SB-203580 (a p38 MAPK inhibitor) or a JNK inhibitor did not affect. H(2)O(2)-induced effects could not be inhibited by LY-294002 (an inhibitor of PI3-kinases), calphostin C (a protein kinase C inhibitor) or SQ-22536 (an adenylate cyclase inhibitor). Adenoviral infection analysis revealed H2O2 stimulated tyrosine kinase activity and AG 1478 (an antagonist of epidermal growth factor receptor tyrosine kinase) inhibited the H(2)O(2)-induced effects. These results suggest H(2)O(2) can modulate ICC pacemaker activity and this occur by the activation of K(ATP) channels through PGE(2) production via receptor tyrosine kinase-dependent MAP kinase activation.
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Affiliation(s)
- Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
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Queiroz-Leite GD, Peruzzetto MC, Neri EA, Rebouças NA. Transcriptional regulation of the Na⁺/H⁺ exchanger NHE3 by chronic exposure to angiotensin II in renal epithelial cells. Biochem Biophys Res Commun 2011; 409:470-6. [PMID: 21600882 DOI: 10.1016/j.bbrc.2011.05.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 05/04/2011] [Indexed: 11/27/2022]
Abstract
Angiotensin II (Ang II) exerts an acute bimodal effect on proximal tubule NHE3: while low doses stimulate the exchanger, high doses inhibit it. In the present study, we have investigated the chronic effects of Ang II on NHE3 expression and transcriptional regulation. Treatment of a tubular epithelial cell line, OKP, with Ang II 10(-11)M significantly increased NHE protein expression and mRNA levels, without evidence of bimodal effect. No change in mRNA half-life was detected, but transient transfection studies showed a significant increase in NHE3 promoter activity. Binding sites for Sp1/Egr-1 and AP2 transcription factors of the NHE3 proximal promoter were mutated and we observed that the Sp1/Egr-1 binding site integrity is necessary for Ang II stimulatory effects. Inhibition of cytochrome P450, PI3K, PKA and MAPK pathways prevented the Ang II stimulatory effect on the NHE3 promoter activity. Taking all the results together, our data reveal that chronic Ang II treatment exerts a stimulatory effect on NHE3 expression and promoter activity. The Ang II up-regulation of the NHE3 promoter activity appears to involve the Sp1/Egr-1 binding site and the interplay of several intracellular signaling pathways.
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Affiliation(s)
- Gabriella D Queiroz-Leite
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Kim KH, Yang CS, Shin AR, Jeon SR, Park JK, Kim HJ, Jo EK. Mycobacterial Heparin-binding Hemagglutinin Antigen Activates Inflammatory Responses through PI3-K/Akt, NF-κB, and MAPK Pathways. Immune Netw 2011; 11:123-33. [PMID: 21637390 PMCID: PMC3100523 DOI: 10.4110/in.2011.11.2.123] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 04/04/2011] [Accepted: 04/14/2011] [Indexed: 01/08/2023] Open
Abstract
Background Mycobacterium tuberculosis (Mtb) heparin binding hemagglutinin (HBHA) is an Ag known to evoke effective host immune responses during tuberculosis infection. However, the molecular basis of the host immune response to HBHA has not been fully characterized. In this study, we examined the molecular mechanisms by which HBHA can induce the expression of proinflammatory cytokines in macrophages. Methods HBHA-induced mRNA and protein levels of proinflammatory cytokines were determined in bone marrow-derived macrophages (BMDMs) using RT-PCR and ELISA analysis. The roles of intracellular signaling pathways for NF-κB, PI3-K/Akt, and MAPKs were investigated in macrophage proinflammatory responses after stimulation with HBHA. Results HBHA robustly activated the expression of mRNA and protein of both TNF-α and IL-6, and induced phosphorylation of NF-κB, Akt, and MAPKs in BMDMs. Both TNF-α and IL-6 production by HBHA was regulated by the NF-κB, PI3-K, and MAPK pathways. Furthermore, PI3-K activity was required for the HBHA-induced activation of ERK1/2 and p38 MAPK, but not JNK, pathways. Conclusion These data suggest that mycobacterial HBHA significantly induces proinflammatory responses through crosstalk between the PI3-K and MAPK pathways in macrophages.
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Affiliation(s)
- Ki-Hye Kim
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon 301-747, Korea
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Xu C, Hong MH, Zhang LS, Hou YY, Wang YH, Wang FF, Chen YJ, Xu XJ, Chen J, Xie X, Ma L, Chi ZQ, Liu JG. Serine 363 of the {delta}-opioid receptor is crucial for adopting distinct pathways to activate ERK1/2 in response to stimulation with different ligands. J Cell Sci 2010; 123:4259-70. [PMID: 21098639 DOI: 10.1242/jcs.073742] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Distinct opioid receptor agonists have been proved to induce differential patterns of ERK activation, but the underlying mechanisms remain unclear. Here, we report that Ser363 in the δ-opioid receptor (δOR) determines the different abilities of the δOR agonists DPDPE and TIPP to activate ERK by G-protein- or β-arrestin-dependent pathways. Although both DPDPE and TIPP activated ERK1/2, they showed different temporal, spatial and desensitization patterns of ERK activation. We show that that DPDPE employed G protein as the primary mediator to activate the ERK cascade in an Src-dependent manner, whereas TIPP mainly adopted a β-arrestin1/2-mediated pathway. Moreover, we found that DPDPE gained the capacity to adopt the β-arrestin1/2-mediated pathway upon Ser363 mutation, accompanied by the same pattern of ERK activation as that induced by TIPP. Additionally, we found that TIPP- but not DPDPE-activated ERK could phosphorylate G-protein-coupled receptor kinase-2 and β-arrestin1. However, such functional differences of ERK disappeared with the mutation of Ser363. Therefore, the present study reveals a crucial role for Ser363 in agonist-specific regulation of ERK activation patterns and functions.
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Affiliation(s)
- Chi Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
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Shin Y, Shin Y, Kim S, Park YS, Cho NJ. ERK1/2 activation by theC. elegansmuscarinic acetylcholine receptor GAR-3 in cultured mammalian cells involves multiple signaling pathways. Anim Cells Syst (Seoul) 2010. [DOI: 10.1080/19768354.2010.504341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Holmström TE, Mattsson CL, Wang Y, Iakovleva I, Petrovic N, Nedergaard J. Non-transactivational, dual pathways for LPA-induced Erk1/2 activation in primary cultures of brown pre-adipocytes. Exp Cell Res 2010; 316:2664-75. [PMID: 20576526 DOI: 10.1016/j.yexcr.2010.05.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 05/21/2010] [Accepted: 05/24/2010] [Indexed: 12/17/2022]
Abstract
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.
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Affiliation(s)
- Therese E Holmström
- Department of Physiology, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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c-Met overexpression contributes to the acquired apoptotic resistance of nonadherent ovarian cancer cells through a cross talk mediated by phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2. Neoplasia 2010; 12:128-38. [PMID: 20126471 DOI: 10.1593/neo.91438] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/28/2009] [Accepted: 11/30/2009] [Indexed: 11/18/2022]
Abstract
Ovarian cancer is the most lethal gynecologic cancer mainly because of widespread peritoneal dissemination and malignant ascites. Key to this is the capacity of tumor cells to escape suspension-induced apoptosis (anoikis), which also underlies their resistance to chemotherapy. Here, we used a nonadherent cell culture model to investigate the molecular mechanisms of apoptotic resistance of ovarian cancer cells that may mimic the chemoresistance found in solid tumors. We found that ovarian cancer cells acquired a remarkable resistance to anoikis and apoptosis induced by exposure to clinically relevant doses of two front-line chemotherapeutic drugs cisplatin and paclitaxel when grown in three-dimensional than monolayer cultures. Inhibition of the hepatocyte growth factor (HGF) receptor c-Met, which is frequently overexpressed in ovarian cancer, by a specific inhibitor or small interfering RNA blocked the acquired anoikis resistance and restored chemosensitivity in three-dimensional not in two-dimensional cultures. These effects were found to be dependent on both phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) 1/2 signaling pathways. Inhibitors of PI3K/Akt abrogated ERK1/2 activation and its associated anoikis resistance in response to HGF, suggesting a signaling relay between these two pathways. Furthermore, we identified a central role of Ras as a mechanism of this cross talk. Interestingly, Ras did not lie upstream of PI3K/Akt, whereas PI3K/Akt signaling to ERK1/2 involved Ras. These findings shed new light on the apoptotic resistance mechanism of nonadherent ovarian cancer ascites cells and may have important clinical implications.
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Bandyopadhaya A, Bhowmick S, Chaudhuri K. Activation of proinflammatory response in human intestinal epithelial cells following Vibrio cholerae infection through PI3K/Akt pathway. Can J Microbiol 2010; 55:1310-8. [PMID: 19940940 DOI: 10.1139/w09-093] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vibrio cholerae activates proinflammatory response in cultured intestinal epithelial cells. In this study, we demonstrate that V. cholerae O395 infection of intestinal epithelial cells results in the activation of Akt. Inhibition of Akt significantly decreases IL-1alpha, IL-6, and TNF-alpha production in V. cholerae infected Int407 cells. Analysis of the mechanisms of Akt influences on cytokine response demonstrates that Akt promotes NF-kappaB activation. We have extended these findings to show that Akt activation may be regulated by bacterial genes associated with virulence, adherence, or motility. Insertion mutants in the virulence genes coding for CtxA, ToxT, and OmpU of V. cholerae modulate the activation of PI3K/Akt signaling pathway, whereas an aflagellate non-motile mutant (O395FLAN) and a adherent and less motile mutant (O395Y3N/O395Y4N) of V. cholerae both show very significant down-regulation of Akt activity in Int407 cells. Together, these observations indicate that Akt promotes proinflammatory cytokine production by V. cholerae infected human intestinal epithelial cells through its influences on NF-kappaB.
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Affiliation(s)
- Arunava Bandyopadhaya
- Molecular & Human Genetics Division, Indian Institute of Chemical Biology, Kolkata-700 032, India
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May V, Lutz E, MacKenzie C, Schutz KC, Dozark K, Braas KM. Pituitary adenylate cyclase-activating polypeptide (PACAP)/PAC1HOP1 receptor activation coordinates multiple neurotrophic signaling pathways: Akt activation through phosphatidylinositol 3-kinase gamma and vesicle endocytosis for neuronal survival. J Biol Chem 2010; 285:9749-9761. [PMID: 20093365 PMCID: PMC2843224 DOI: 10.1074/jbc.m109.043117] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
MAPK and Akt pathways are predominant mediators of trophic signaling for many neuronal systems. Among the vasoactive intestinal peptide/secretin/glucagon family of related peptides, pituitary adenylate cyclase-activating polypeptide (PACAP) binding to specific PAC(1) receptor isoforms can engage multiple signaling pathways and promote neuroprotection through mechanisms that are not well understood. Using a primary sympathetic neuronal system, the current studies demonstrate that PACAP activation of PAC(1)HOP1 receptors engages both MAPK and Akt neurotrophic pathways in an integrated program to facilitate neuronal survival after growth factor withdrawal. PACAP not only stimulated prosurvival ERK1/2 and ERK5 activation but also abrogated SAPK/JNK and p38 MAPK signaling in parallel. In contrast to the potent and rapid effects of PACAP in ERK1/2 phosphorylation, PACAP stimulated Akt phosphorylation in a late phase of PAC(1)HOP1 receptor signaling. From inhibitor and immunoprecipitation analyses, the PACAP/PAC(1)HOP1 receptor-mediated Akt responses did not represent transactivation mechanisms but appeared to depend on G alpha(q)/phosphatidylinositol 3-kinase gamma activity and vesicular internalization pathways. Phosphatidylinositol 3-kinase gamma-selective inhibitors blocked PACAP-stimulated Akt phosphorylation in primary neuronal cultures and in PAC(1)HOP1-overexpressing cell lines; RNA interference-mediated knockdown of the receptor effectors attenuated PACAP-mediated Akt activation. Similarly, perturbation of endocytic pathways also blocked Akt phosphorylation. Between ERK and Akt pathways, PACAP-stimulated Akt signaling was the primary cascade that attenuated cultured neuron apoptosis after growth factor withdrawal. The partitioning of PACAP-mediated Akt signaling in endosomes may be a key mechanism contributing to the high spatial and temporal specificity in signal transduction necessary for survival pathways.
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Affiliation(s)
- Victor May
- Departments of Anatomy and Neurobiology and of Pharmacology, The University of Vermont College of Medicine, Burlington, Vermont 05405.
| | - Eve Lutz
- University of Strathclyde, Strathclyde Institute of Pharmacy and Biomedical Sciences, Royal College, 204 George Street, Glasgow G1 1XW, Scotland, United Kingdom
| | - Christopher MacKenzie
- University of Strathclyde, Strathclyde Institute of Pharmacy and Biomedical Sciences, Royal College, 204 George Street, Glasgow G1 1XW, Scotland, United Kingdom
| | - Kristin C Schutz
- Departments of Anatomy and Neurobiology and of Pharmacology, The University of Vermont College of Medicine, Burlington, Vermont 05405
| | - Kate Dozark
- Departments of Anatomy and Neurobiology and of Pharmacology, The University of Vermont College of Medicine, Burlington, Vermont 05405
| | - Karen M Braas
- Departments of Anatomy and Neurobiology and of Pharmacology, The University of Vermont College of Medicine, Burlington, Vermont 05405
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Pazos Y, Alvarez CJP, Camiña JP, Al-Massadi O, Seoane LM, Casanueva FF. Role of obestatin on growth hormone secretion: An in vitro approach. Biochem Biophys Res Commun 2009; 390:1377-81. [PMID: 19895783 DOI: 10.1016/j.bbrc.2009.10.163] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 10/30/2009] [Indexed: 02/01/2023]
Abstract
Obestatin, the ghrelin-associated peptide, showed to activate MAPK signaling with no effect on Akt nor cell proliferating activity in rat tumor somatotroph cells (growth cells, GC). A sequential analysis of the obestatin transmembrane signaling pathway indicated a route involving the consecutive activation of G(i), PI3k, novel PKCepsilon, and Src for ERK1/2 activation. Furthermore, obestatin treatment triggers growth hormone (GH) release in the first 30min, being more acute at 15min. At 1h, obestatin treated cells showed the same levels in GH secretion than controls. Added to this functionality, obestatin was secreted by GC cells. Based on the capacity to stimulate GH release from somatotroph cells, obestatin may act directly in the pituitary through an autocrine/paracrine mechanism.
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Affiliation(s)
- Yolanda Pazos
- Area de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Santiago de Compostela, Spain.
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Lents NH, Irintcheva V, Goel R, Wheeler LW, Baldassare JJ. The rapid activation of N-Ras by alpha-thrombin in fibroblasts is mediated by the specific G-protein Galphai2-Gbeta1-Ggamma5 and occurs in lipid rafts. Cell Signal 2009; 21:1007-14. [PMID: 19250965 DOI: 10.1016/j.cellsig.2009.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 02/18/2009] [Accepted: 02/18/2009] [Indexed: 11/20/2022]
Abstract
alpha-thrombin is a potent mitogen for fibroblasts and initiates a rapid signal transduction pathway leading to the activation of Ras and the stimulation of cell cycle progression. While the signaling events downstream of Ras have been studied in significant detail and appear well conserved across many species and cell types, the precise molecular events beginning with thrombin receptor activation and leading to the activation of Ras are not as well understood. In this study, we examined the immediate events in the rapid response to alpha-thrombin, in a single cell type, and found that an unexpected degree of specificity exists in the pathway linking alpha-thrombin to Ras activation. Specifically, although IIC9 cells express all three Ras isoforms, only N-Ras is rapidly activated by alpha-thrombin. Further, although several Galpha subunits associate with PAR1 and are released following stimulation, only Galpha(i2) couples to the rapid activation of Ras. Similarly, although IIC9 cells express many Gbeta and Ggamma subunits, only a subset associates with Galpha(i2), and of those, only a single Gbetagamma dimer, Gbeta(1)gamma(5), participates in the rapid activation of N-Ras. We then hypothesized that co-localization into membrane microdomains called lipid rafts, or caveolae, is at least partially responsible for this degree of specificity. Accordingly, we found that all components localize to lipid rafts and that disruption of caveolae abolishes the rapid activation of N-Ras by alpha-thrombin. We thus report the molecular elucidation of an extremely specific and rapid signal transduction pathway linking alpha-thrombin stimulation to the activation of Ras.
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Affiliation(s)
- Nathan H Lents
- Department of Sciences at John Jay College of Criminal Justice, City University of New York, New York, NY 10019, USA.
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PI3K-dependent cross-talk interactions converge with Ras as quantifiable inputs integrated by Erk. Mol Syst Biol 2009; 5:246. [PMID: 19225459 PMCID: PMC2657535 DOI: 10.1038/msb.2009.4] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 01/05/2009] [Indexed: 01/08/2023] Open
Abstract
Although it is appreciated that canonical signal-transduction pathways represent dominant modes of regulation embedded in larger interaction networks, relatively little has been done to quantify pathway cross-talk in such networks. Through quantitative measurements that systematically canvas an array of stimulation and molecular perturbation conditions, together with computational modeling and analysis, we have elucidated cross-talk mechanisms in the platelet-derived growth factor (PDGF) receptor signaling network, in which phosphoinositide 3-kinase (PI3K) and Ras/extracellular signal-regulated kinase (Erk) pathways are prominently activated. We show that, while PI3K signaling is insulated from cross-talk, PI3K enhances Erk activation at points both upstream and downstream of Ras. The magnitudes of these effects depend strongly on the stimulation conditions, subject to saturation effects in the respective pathways and negative feedback loops. Motivated by those dynamics, a kinetic model of the network was formulated and used to precisely quantify the relative contributions of PI3K-dependent and -independent modes of Ras/Erk activation.
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Luke TM, Hexum TD. UTP and ATP increase extracellular signal-regulated kinase 1/2 phosphorylation in bovine chromaffin cells through epidermal growth factor receptor transactivation. Purinergic Signal 2008; 4:323-30. [PMID: 18777108 PMCID: PMC2583213 DOI: 10.1007/s11302-008-9098-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Accepted: 03/14/2008] [Indexed: 01/07/2023] Open
Abstract
Adenosine triphosphate (ATP) is coreleased with catecholamines from adrenal medullary chromaffin cells in response to sympathetic nervous system stimulation and may regulate these cells in an autocrine or paracrine manner. Increases in extracellular signal-regulated kinase (ERK) 1/2 phosphorylation were observed in response to ATP stimulation of bovine chromaffin cells. The signaling pathway involved in ATP-mediated ERK1/2 phosphorylation was investigated via Western blot analysis. ATP and uridine 5′-triphosphate (UTP) increased ERK1/2 phosphorylation potently, peaking between 5 and 15 min. The mitogen-activated protein kinase (MAPK/ERK)-activating kinase (MEK) inhibitor PD98059 blocked this response. UTP, which is selective for G-protein-coupled P2Y receptors, was the most potent agonist among several nucleotides tested. Adenosine 5′-O-(3-thio) triphosphate (ATPγS) and ATP were also potent agonists, characteristic of the P2Y2 or P2Y4 receptor subtypes, whereas agonists selective for P2X receptors or other P2Y receptor subtypes were weakly effective. The receptor involved was further characterized by the nonspecific P2 antagonists suramin and reactive blue 2, which each partially inhibited ATP-mediated ERK1/2 phosphorylation. Inhibitors of protein kinase C (PKC), protein kinase A (PKA), Ca2+/calmodulin-dependent protein kinase II (CaMKII), and phosphoinositide-3 kinase (PI3K) had no effect on ATP-mediated ERK1/2 phosphorylation. The Src inhibitor PP2, epidermal growth factor receptor (EGFR) inhibitor AG1478, and metalloproteinase inhibitor GM6001 decreased ATP-mediated ERK1/2 phosphorylation. These results suggest nucleotide-mediated ERK1/2 phosphorylation is mediated by a P2Y2 or P2Y4 receptor, which stimulates metalloproteinase-dependent transactivation of the EGFR.
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Affiliation(s)
- Toni M. Luke
- University of Nebraska Medical Center, 985800 Nebraska Medical Center, Omaha, NE 68198–5800 USA
| | - Terry D. Hexum
- University of Nebraska Medical Center, 985800 Nebraska Medical Center, Omaha, NE 68198–5800 USA
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Inhibition of the PI3K-Akt/PKB survival pathway enhanced an ethanol extract of Rhus verniciflua Stokes-induced apoptosis via a mitochondrial pathway in AGS gastric cancer cell lines. Cancer Lett 2008; 265:197-205. [DOI: 10.1016/j.canlet.2008.02.039] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 02/04/2008] [Accepted: 02/06/2008] [Indexed: 11/23/2022]
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van den Hurk MJJ, Cruijsen PMJM, Schoeber JPH, Scheenen WJJM, Roubos EW, Jenks BG. Intracellular signal transduction by the extracellular calcium-sensing receptor of Xenopus melanotrope cells. Gen Comp Endocrinol 2008; 157:156-64. [PMID: 18508053 DOI: 10.1016/j.ygcen.2008.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 03/28/2008] [Accepted: 04/14/2008] [Indexed: 11/17/2022]
Abstract
The extracellular calcium-sensing receptor (CaR) is expressed in various types of endocrine pituitary cell, but the intracellular mechanism this G protein-coupled receptor uses in these cells is not known. In the present study we investigated possible intracellular signal transduction pathway(s) utilized by the CaR of the endocrine melanotrope cells in the intermediate pituitary lobe of the South African-clawed toad Xenopus laevis. For this purpose, the effects of various pharmacological agents on CaR-evoked secretion of radiolabeled secretory peptides from cultured melanotrope cells were assessed. CaR-evoked secretion, induced by the potent CaR agonist L-phenylalanine (L-Phe), could not be inhibited by cholera toxin, nor by NPC-15437 and PMA, indicating that neither G(s)/PKA nor G(q)/PKC pathways are involved. However, pertussis toxin (G(i/o) protein inhibitor), genistein (inhibitor of PTKs), wortmannin/LY-294002 (PI3-K inhibitor) and U-0126 (inhibitor of extracellular signal-regulated kinase, ERK) all substantially inhibited CaR-evoked secretion, indicating that the Xenopus melanotrope cell possesses a PI3-K/MAPK system that plays some role in CaR-signaling. Since no direct effect of L-Phe on ERK phosphorylation could be shown it is concluded that CaR must act primarily through another, still unknown, signaling pathway in Xenopus melanotropes. Our results indicate that the PI3-K/MAPK system has a facilitating effect on CaR-induced secretion, possibly by sensitizing the CaR.
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Affiliation(s)
- Maarten J J van den Hurk
- Department of Cellular Animal Physiology, Donders Centre for Neuroscience, EURON European Graduate School for Neuroscience, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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Alcántara-Hernández R, Casas-González P, García-Sáinz JA. Roles of c-Src in alpha1B-adrenoceptor phosphorylation and desensitization. ACTA ACUST UNITED AC 2008; 28:29-39. [PMID: 18257749 DOI: 10.1111/j.1474-8673.2007.00414.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1 The role of the protein tyrosine kinase, c-Src, on the function and phosphorylation of alpha1B-adrenoceptors (alpha1B-AR) and their association with G-protein-coupled receptor kinase (GRK) isozymes was studied. 2 Inhibitors of this kinase (PP2 and Src Inhibitor II) decreased ( approximately 50-75%) noradrenaline- (NA) and phorbol myristate acetate-mediated receptor phosphorylation. Expression of a dominant-negative mutant of c-Src similarly reduced receptor phosphorylation induced by the natural agonists, active phorbol esters and endothelin-1 (ET-1). 3 c-Src, GRK2, GRK3 and GRK5 coimmunoprecipitate with alpha1B-ARs in the basal state. In cells treated with NA or phorbol myristate acetate the amount of coimmunoprecipitated GRK2 and GRK3 increased ( approximately 2- to 3-fold), while treatment with ET-1 only augmented the amount of coimmunoprecipitated GRK2 ( approximately 2-fold). The Src inhibitor, PP2, markedly attenuated all these increases. 4 Cell pretreatment with PP2 amplified the increase in intracellular-free calcium observed with NA, in the basal state and after the stimulation (desensitization) induced by ET-1. 5 The data suggest a role of c-Src in alpha1B-AR desensitization/phosphorylation and in the interaction of these ARs with GRKs.
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Affiliation(s)
- R Alcántara-Hernández
- Departamento de Biología Celular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ap. Postal 70-248, México DF 04510
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Pazos Y, Alvarez CJP, Camiña JP, Casanueva FF. Stimulation of extracellular signal-regulated kinases and proliferation in the human gastric cancer cells KATO-III by obestatin. Growth Factors 2007; 25:373-81. [PMID: 18365868 DOI: 10.1080/08977190801889313] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Obestatin, the ghrelin-associated peptide, activates cell proliferation in the gastric cancer cell line KATO-III. The results showed that this peptide induced cell proliferation by mitogen-activated kinase kinase/extracellular signal-regulated kinases1/2 (ERK1/2) phosphorylation. A sequential analysis of the obestatin transmembrane signalling pathway indicated that the ERK1/2 activity is partially blocked after preincubation of the cells with pertussis toxin, as well as by wortmannin (an inhibitor of phosphoinositide 3-kinase (PI3K)), staurosporine (an inhibitor of protein kinase C (PKC)) and 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2, which inhibits the non receptor tyrosine kinase Src). Upon administration of obestatin, the intracellular levels of phospho-PKCepsilon- and theta-isoenzymes rise with similar time-courses, from which PKCepsilon appears to be the responsible for ERK1/2 response. Based on the experimental data, a signalling pathway involving the consecutive activation of G(i), PI3K, novel PKCepsilon and Src for ERK1/2 activation is proposed. These results point to a functionally active peptide that regulates proliferation of the gastric cancer cells KATO-III.
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Affiliation(s)
- Yolanda Pazos
- Molecular Endocrinology, Research Area, Complejo Hospitalario Universitario de Santiago, (CHUS), Santiago de Compostela, Spain.
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Kam AYF, Liu AMF, Wong YH. Formyl peptide-receptor like-1 requires lipid raft and extracellular signal-regulated protein kinase to activate inhibitor-κB kinase in human U87 astrocytoma cells. J Neurochem 2007; 103:1553-66. [PMID: 17727628 DOI: 10.1111/j.1471-4159.2007.04876.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Formyl peptide-receptor like-1 (FPRL-1) may possess critical roles in Alzheimer's diseases, chemotaxis and release of neurotoxins, possibly through its regulation of nuclear factor-kappaB (NFkappaB). Here we illustrate that activation of FPRL-1 in human U87 astrocytoma or Chinese hamster ovary cells stably expressing the receptor resulted in the phosphorylations of inhibitor-kappaB kinase (IKK), an onset kinase for NFkappaB signaling cascade. FPRL-1 selective hexapeptide Trp-Lys-Tyr-Met-Val-Met (WKYMVM) promoted IKK phosphorylations in time- and dose-dependent manners while pre-treatment of pertussis toxin abrogated the Galpha(i/o)-dependent stimulations. The FPRL-1-mediated IKK phosphorylation required extracellular signal-regulated protein kinase (ERK), phosphatidylinositol 3-kinase and cellular Src (c-Src), but not c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. Despite its ability to mobilize Ca(2+), WKYMVM did not require Ca(2+) for the modulation of IKK phosphorylation. Activation of FPRL-1 also induced NFkappaB-driven luciferase expression. Interestingly, cholesterol depletion from plasma membrane by methyl-beta-cyclodextrin abolished the FPRL-1-stimulated IKK phosphorylation, denoting the important role of lipid raft integrity in the FPRL-1 to IKK signaling. Furthermore, we demonstrated that in U87 cells, several signaling intermediates in the FPRL-1-IKK pathway including Galpha(i2), c-Src and ERK were constitutively localized at the raft microdomains. WKYMVM administration not only resulted in higher amount of ERK recruitment to the raft region, but also specifically stimulated raft-associated c-Src and ERK phosphorylations. Taken together, these results demonstrate that FPRL-1 is capable of activating NFkappaB signaling through IKK phosphorylation and this may serve as a useful therapeutical target for FPRL-1-related diseases.
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Affiliation(s)
- Angel Y F Kam
- Department of Biochemistry, the Molecular Neuroscience Center, and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, China
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