1
|
Le NT. The significance of ERK5 catalytic-independent functions in disease pathways. Front Cell Dev Biol 2023; 11:1235217. [PMID: 37601096 PMCID: PMC10436230 DOI: 10.3389/fcell.2023.1235217] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/26/2023] [Indexed: 08/22/2023] Open
Abstract
Extracellular signal-regulated kinase 5 (ERK5), also known as BMK1 or MAPK7, represents a recent addition to the classical mitogen-activated protein kinase (MAPK) family. This family includes well-known members such as ERK1/2, c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK), as well as atypical MAPKs such as ERK3, ERK4, ERK7 (ERK8), and Nemo-like kinase (NLK). Comprehensive reviews available elsewhere provide detailed insights into ERK5, which interested readers can refer to for in-depth knowledge (Nithianandarajah-Jones et al., 2012; Monti et al., Cancers (Basel), 2022, 14). The primary aim of this review is to emphasize the essential characteristics of ERK5 and shed light on the intricate nature of its activation, with particular attention to the catalytic-independent functions in disease pathways.
Collapse
Affiliation(s)
- Nhat-Tu Le
- Center for Cardiovascular Regeneration, Department of Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, United States
| |
Collapse
|
2
|
Sánchez-Fdez A, Matilla-Almazán S, Del Carmen S, Abad M, Arconada-Luque E, Jiménez-Suárez J, Chinchilla-Tábora LM, Ruíz-Hidalgo MJ, Sánchez-Prieto R, Pandiella A, Esparís-Ogando A. Etiopathogenic role of ERK5 signaling in sarcoma: prognostic and therapeutic implications. Exp Mol Med 2023; 55:1247-1257. [PMID: 37332046 PMCID: PMC10317974 DOI: 10.1038/s12276-023-01008-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 02/28/2023] [Accepted: 03/07/2023] [Indexed: 06/20/2023] Open
Abstract
Sarcomas constitute a heterogeneous group of rare and difficult-to-treat tumors that can affect people of all ages, representing one of the most common forms of cancer in childhood and adolescence. Little is known about the molecular entities involved in sarcomagenesis. Therefore, the identification of processes that lead to the development of the disease may uncover novel therapeutic opportunities. Here, we show that the MEK5/ERK5 signaling pathway plays a critical role in the pathogenesis of sarcomas. By developing a mouse model engineered to express a constitutively active form of MEK5, we demonstrate that the exclusive activation of the MEK5/ERK5 pathway can promote sarcomagenesis. Histopathological analyses identified these tumors as undifferentiated pleomorphic sarcomas. Bioinformatic studies revealed that sarcomas are the tumors in which ERK5 is most frequently amplified and overexpressed. Moreover, analysis of the impact of ERK5 protein expression on overall survival in patients diagnosed with different sarcoma types in our local hospital showed a 5-fold decrease in median survival in patients with elevated ERK5 expression compared with those with low expression. Pharmacological and genetic studies revealed that targeting the MEK5/ERK5 pathway drastically affects the proliferation of human sarcoma cells and tumor growth. Interestingly, sarcoma cells with knockout of ERK5 or MEK5 were unable to form tumors when engrafted into mice. Taken together, our results reveal a role of the MEK5/ERK5 pathway in sarcomagenesis and open a new scenario to be considered in the treatment of patients with sarcoma in which the ERK5 pathway is pathophysiologically involved.
Collapse
Affiliation(s)
- Adrián Sánchez-Fdez
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC)-CSIC, Salamanca, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), CSIC-Universidad de Salamanca, Salamanca, Spain
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Sofía Matilla-Almazán
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC)-CSIC, Salamanca, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), CSIC-Universidad de Salamanca, Salamanca, Spain
| | - Sofía Del Carmen
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
- Departmento de Patología, Hospital Universitario de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Mar Abad
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
- Departmento de Patología, Hospital Universitario de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Elena Arconada-Luque
- Universidad de Castilla-La Mancha, Laboratorio de Oncología Molecular, Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas, Unidad Asociada de Biomedicina UCLM, Unidad asociada al CSIC, Albacete, Spain
| | - Jaime Jiménez-Suárez
- Universidad de Castilla-La Mancha, Laboratorio de Oncología Molecular, Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas, Unidad Asociada de Biomedicina UCLM, Unidad asociada al CSIC, Albacete, Spain
| | - Luis Miguel Chinchilla-Tábora
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
- Departmento de Patología, Hospital Universitario de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Mª José Ruíz-Hidalgo
- Universidad de Castilla-La Mancha, Laboratorio de Oncología Molecular, Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas, Unidad Asociada de Biomedicina UCLM, Unidad asociada al CSIC, Albacete, Spain
- Universidad de Castilla-La Mancha, Departamento de Química Inorgánica, Orgánica y Bioquímica, Área de Bioquímica y Biología Molecular. Facultad de Medicina, Albacete, Spain
| | - Ricardo Sánchez-Prieto
- Universidad de Castilla-La Mancha, Laboratorio de Oncología Molecular, Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas, Unidad Asociada de Biomedicina UCLM, Unidad asociada al CSIC, Albacete, Spain
- Universidad de Castilla-La Mancha, Departamento de Ciencias Médicas, Facultad de Medicina, Albacete, Spain
- Departamento de Biología del Cáncer, Instituto de Investigaciones Biomédicas 'Alberto Sols' (CSIC-UAM), Unidad Asociada de Biomedicina UCLM, Unidad Asociada al CSIC, Madrid, Spain
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas (IIBM-CSIC)-Universidad de Castilla-La Mancha (UCLM), Albacete, Spain
| | - Atanasio Pandiella
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC)-CSIC, Salamanca, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), CSIC-Universidad de Salamanca, Salamanca, Spain
| | - Azucena Esparís-Ogando
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC)-CSIC, Salamanca, Spain.
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), CSIC-Universidad de Salamanca, Salamanca, Spain.
| |
Collapse
|
3
|
Clinical Significance and Regulation of ERK5 Expression and Function in Cancer. Cancers (Basel) 2022; 14:cancers14020348. [PMID: 35053510 PMCID: PMC8773716 DOI: 10.3390/cancers14020348] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/08/2022] [Accepted: 01/08/2022] [Indexed: 02/06/2023] Open
Abstract
Extracellular signal-regulated kinase 5 (ERK5) is a unique kinase among MAPKs family members, given its large structure characterized by the presence of a unique C-terminal domain. Despite increasing data demonstrating the relevance of the ERK5 pathway in the growth, survival, and differentiation of normal cells, ERK5 has recently attracted the attention of several research groups given its relevance in inflammatory disorders and cancer. Accumulating evidence reported its role in tumor initiation and progression. In this review, we explore the gene expression profile of ERK5 among cancers correlated with its clinical impact, as well as the prognostic value of ERK5 and pERK5 expression levels in tumors. We also summarize the importance of ERK5 in the maintenance of a cancer stem-like phenotype and explore the major known contributions of ERK5 in the tumor-associated microenvironment. Moreover, although several questions are still open concerning ERK5 molecular regulation, different ERK5 isoforms derived from the alternative splicing process are also described, highlighting the potential clinical relevance of targeting ERK5 pathways.
Collapse
|
4
|
Li Z, Hu J, Guo J, Fan L, Wang S, Dou N, Zuo J, Yu S. SSeCKS/Gravin/AKAP12 Inhibits PKCζ-Mediated Reduction of ERK5 Transactivation to Prevent Endotoxin-Induced Vascular dysfunction. Cardiovasc Toxicol 2020; 19:372-381. [PMID: 30805771 DOI: 10.1007/s12012-018-09502-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
SSeCKS/Gravin/AKAP12 is a protein kinase C (PKC) substrate that inhibits the activity of PKC through binding with it. SSeCKS is expressed in vascular endothelial cells (ECs). The atypical PKC isoform ζ (PKCζ) is a pathologic mediator of endothelial dysfunction. However, the functional significance of SSeCKS/PKCζ dimerization in the vascular endothelium remains poorly understood. Given this background, we investigated the effects of SSeCKS on endothelial dysfunction and elucidated the possible mechanism involved. Vascular endothelial dysfunction and inflammatory changes were induced by treatment with bacterial endotoxin lipopolysaccharide (LPS, a vascular endothelial toxicity inducer). LPS can increase the level of SSeCKS. However, we also found that depletion of SSeCKS aggravated the LPS-induced vascular endothelial dysfunction, upregulated pro-inflammatory proteins and phosphorylation level of PKCζ, increased ROS formation, decreased extracellular-signal-regulated kinase 5 (ERK5) transcriptional activity, and reduced eNOS expression. Further examination revealed that depletion of SSeCKS increased PKCζ/ERK5 dimerization. These findings provide preliminary evidence that the expression of SSeCKS induced by LPS, as a negative feedback mechanism, has the potential to improve endothelium-dependent relaxation in vascular disease conditions by inhibiting PKCζ-mediated reduction of ERK5 transactivation.
Collapse
Affiliation(s)
- Zilin Li
- Department of Cardiovascular Surgery, Xijing Hospital, Air Force Military Medical University (Fourth Military Medical University), Xi'an, 710032, China
| | - Jing Hu
- Department of Pharmacy, General Hospital of Lanzhou Command, PLA, Lanzhou, 730050, China
| | - Jian Guo
- Department of Cardiovascular Surgery, Xijing Hospital, Air Force Military Medical University (Fourth Military Medical University), Xi'an, 710032, China
| | - Li Fan
- Outpatient Department, PLA, Unit 32058, Chengdu, 610100, China
| | - Shaowei Wang
- Department of Cardiovascular Surgery, Xijing Hospital, Air Force Military Medical University (Fourth Military Medical University), Xi'an, 710032, China
| | - Ning Dou
- Department of Cardiovascular Surgery, Xijing Hospital, Air Force Military Medical University (Fourth Military Medical University), Xi'an, 710032, China
| | - Jian Zuo
- Department of Cardiovascular Surgery, Xijing Hospital, Air Force Military Medical University (Fourth Military Medical University), Xi'an, 710032, China.
| | - Shiqiang Yu
- Department of Cardiovascular Surgery, Xijing Hospital, Air Force Military Medical University (Fourth Military Medical University), Xi'an, 710032, China.
| |
Collapse
|
5
|
Ghahari L, Safari M, Rahimi Jaberi K, Jafari B, Safari K, Madadian M. Mesenchymal Stem Cells with Granulocyte Colony-Stimulating Factor Reduce Stress Oxidative Factors in Parkinson's Disease. IRANIAN BIOMEDICAL JOURNAL 2019. [PMID: 31677610 PMCID: PMC6984711 DOI: 10.29252/ibj.24.2.89] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background: Recent studies have shown that BMSCs have a putative ability to promote neurogenesis and produce behavioral and functional improvement. Our previous study demonstrated that co-treatment of G-CSF and BMSCs have beneficial effects on Parkinson's models. The main purpose of this research was to investigate the effects of these two factors on oxidative stress factors in the brain of Parkinson's rat. Methods: Adult male Wistar rats (weighing 200–250 g) were used and randomly divided into five groups of seven each. To create the Parkinson's model, 6-OHDA was injected into the left SNpc. The BMSCs (2 × 106) and G-CSF (75 µg/kg) were used for treatment after creating the PD model. After four weeks, the brains of rats were removed and processed for immunohistochemical studies, such as TH-positive neurons as well as analysis of oxidative stress factors. Results: The results showed that the injected BMSCs could cross the BBB. The injected cells are also able to settle in different areas of the brain. Analyses of the brain oxidative stress factors showed that G-CSF and BMSCs reduced the expression of MDA and induced the activity of SOD, GSH-Px, and FRAP. Conclusion: Co-administration of G-CSF and BMSCs reduced the expression of pro-inflammatory cytokines and induced the activity of antioxidant enzymes; however, neurogenesis increased in the brain.
Collapse
Affiliation(s)
- Laya Ghahari
- Department of Anatomy, AJA University of Medical Sciences, Tehran, Iran
| | - Manouchehr Safari
- Nervous System Stem Cells Research Center, Semnan university of Medical Sciences, Semnan, Iran
| | - Khojaste Rahimi Jaberi
- Nervous System Stem Cells Research Center, Semnan university of Medical Sciences, Semnan, Iran
| | | | - Katayoun Safari
- Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Mahmoodreza Madadian
- School of Pharmacology, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran
| |
Collapse
|
6
|
Kang C, Kim JS, Kim CY, Kim EY, Chung HM. The Pharmacological Inhibition of ERK5 Enhances Apoptosis in Acute Myeloid Leukemia Cells. Int J Stem Cells 2018; 11:227-234. [PMID: 30343550 PMCID: PMC6285287 DOI: 10.15283/ijsc18053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 12/26/2022] Open
Abstract
Acute myeloid leukemia (AML) is a fatal hematological malignancy which is resistant to a variety of chemotherapy drugs. Extracellular signal-regulated kinase 5 (ERK5) plays a novel role in chemoresistance in some cancer cells and this pathway is a central mediator of cell survival and apoptotic regulation. The aim of this study was to investigate the effect of ERK5 inhibitor, XMD8-92, on proliferation and apoptosis in AML cell lines. Findings showed that XMD8-92 inhibited the activation of ERK5 by G-CSF and decreased the expression of c-Myc and Cyclin D1. The treatment of XMD8-92 reduced the phosphorylation of ERK5 leading to a distinct inhibition of cell proliferation and increased apoptosis in Kasumi-1 and HL-60 cells. Taken together, our study suggests that the inhibition of ERK5 by XMD8-92 can trigger apoptosis and inhibit proliferation in AMLs. Therefore, the inhibition of ERK5 may be an effective adjuvant in AML chemotherapy.
Collapse
Affiliation(s)
- Changhee Kang
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Korea
| | - Jong Soo Kim
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Korea
| | - C-Yoon Kim
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Korea
| | - Eun-Young Kim
- Stem Cell Research Center, Jeju National University, Jeju, Korea.,Mirae Cell Bio Co. LTD, Seoul, Korea
| | - Hyung-Min Chung
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Korea
| |
Collapse
|
7
|
Chen C, Wu S, Lin X, Wu D, Fischbach S, Xiao X. ERK5 plays an essential role in gestational beta-cell proliferation. Cell Prolif 2017; 51:e12410. [PMID: 29159830 DOI: 10.1111/cpr.12410] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 10/24/2017] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVES Restoring a functional beta-cell mass is a fundamental goal in treating diabetes. A complex signalling pathway network coordinates the regulation of beta-cell proliferation, although a role for ERK5 in this network has not been reported. This question was addressed in this study. MATERIALS AND METHODS We studied the activation of extracellular-signal-regulated kinase 5 (ERK5) in pregnant mice, a well-known mouse model of increased beta-cell proliferation. A specific inhibitor of ERK5 activation, BIX02189, was intraperitoneally injected into the pregnant mice to suppress ERK5 signalling. Beta-cell proliferation was determined by quantification of Ki-67+ beta cells. Beta-cell apoptosis was determined by TUNEL assay. The extent of beta-cell proliferation was determined by beta-cell mass. The alteration of ERK5 activation and CyclinD1 levels in purified mouse islets was examined by Western blotting. RESULTS Extracellular-signal-regulated kinase 5 phosphorylation, which represents ERK5 activation, was significantly upregulated in islets from pregnant mice. Suppression of ERK5 activation by BIX02189 in pregnant mice significantly reduced beta-cell proliferation, without affecting beta-cell apoptosis, resulting in increases in random blood glucose levels and impairment of glucose response of the mice. ERK5 seemed to activate CyclinD1 to promote gestational beta-cell proliferation. CONCLUSIONS Extracellular-signal-regulated kinase 5 plays an essential role in the gestational augmentation of beta-cell proliferation. ERK5 may be a promising target for increasing beta-cell mass in diabetes patients.
Collapse
Affiliation(s)
- Congde Chen
- Department of Pediatric Surgery, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Suichun Wu
- Reproductive Medicine Centre, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaokun Lin
- Department of Pediatric Surgery, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Dazhou Wu
- Department of Pediatric Surgery, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Shane Fischbach
- Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Xiangwei Xiao
- Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, USA
| |
Collapse
|
8
|
Extracellular Signal-Regulated Kinase 5 is Required for Low-Concentration H 2O 2-Induced Angiogenesis of Human Umbilical Vein Endothelial Cells. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6895730. [PMID: 28540300 PMCID: PMC5429924 DOI: 10.1155/2017/6895730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/22/2017] [Accepted: 03/09/2017] [Indexed: 01/28/2023]
Abstract
Background. The aim of this study was to assess the effects of low concentrations of H2O2 on angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro and explore the underlying mechanisms. Methods. HUVECs were cultured and stimulated with different concentrations of H2O2. Flow cytometric analysis was used to select an optimal concentration of H2O2 for the following experiments. Cell proliferation, migration, and tubule formation were evaluated by Cell Counting Kit-8 (CCK-8) assays, scratch wound assays, and Matrigel tubule formation assays, respectively. For gain and loss of function studies, constitutively active MEK5 (CA-MEK5) and ERK5 shRNA lentiviruses were used to activate or knock down extracellular signal-regulated kinase 5 (ERK5). Results. We found that low concentrations of H2O2 promoted HUVECs proliferation, migration, and tubule formation. ERK5 in HUVECs was significantly activated by H2O2. Enhanced ERK5 activity significantly amplified the proangiogenic effects of H2O2; in contrast, ERK5 knock-down abrogated the effects of H2O2. Conclusions. Our results confirmed that low concentrations of H2O2 promoted HUVECs angiogenesis in vitro, and ERK5 is an essential mediator of this process. Therefore, ERK5 may be a potential therapeutic target for promoting angiogenesis and improving graft survival.
Collapse
|
9
|
Bortell N, Basova L, Semenova S, Fox HS, Ravasi T, Marcondes MCG. Astrocyte-specific overexpressed gene signatures in response to methamphetamine exposure in vitro. J Neuroinflammation 2017; 14:49. [PMID: 28279172 PMCID: PMC5345234 DOI: 10.1186/s12974-017-0825-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/27/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Astrocyte activation is one of the earliest findings in the brain of methamphetamine (Meth) abusers. Our goal in this study was to identify the characteristics of the astrocytic acute response to the drug, which may be critical in pathogenic outcomes secondary to the use. METHODS We developed an integrated analysis of gene expression data to study the acute gene changes caused by the direct exposure to Meth treatment of astrocytes in vitro, and to better understand how astrocytes respond, what are the early molecular markers associated with this response. We examined the literature in search of similar changes in gene signatures that are found in central nervous system disorders. RESULTS We identified overexpressed gene networks represented by genes of an inflammatory and immune nature and that are implicated in neuroactive ligand-receptor interactions. The overexpressed networks are linked to molecules that were highly upregulated in astrocytes by all doses of methamphetamine tested and that could play a role in the central nervous system. The strongest overexpressed signatures were the upregulation of MAP2K5, GPR65, and CXCL5, and the gene networks individually associated with these molecules. Pathway analysis revealed that these networks are involved both in neuroprotection and in neuropathology. We have validated several targets associated to these genes. CONCLUSIONS Gene signatures for the astrocytic response to Meth were identified among the upregulated gene pool, using an in vitro system. The identified markers may participate in dysfunctions of the central nervous system but could also provide acute protection to the drug exposure. Further in vivo studies are necessary to establish the role of these gene networks in drug abuse pathogenesis.
Collapse
Affiliation(s)
- Nikki Bortell
- Cellular and Molecular Neurosciences Department, The Scripps Research Institute, La Jolla, CA, 92037, USA.,Anschutz Medical Campus, University of Colorado, Denver, CO, USA
| | - Liana Basova
- Cellular and Molecular Neurosciences Department, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Svetlana Semenova
- Department of Psychiatry, University of California San Diego, San Diego, CA, 92093, USA
| | - Howard S Fox
- Department of Experimental Pharmacology, University of Nebraska Medical School, Omaha, NE, 68198, USA
| | - Timothy Ravasi
- KAUST Environmental Epigenetic Program (KEEP), Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia.,Department of Medicine, Division of Genetic, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093, USA
| | - Maria Cecilia G Marcondes
- Cellular and Molecular Neurosciences Department, The Scripps Research Institute, La Jolla, CA, 92037, USA. .,Present address: San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100 - San Diego, San Diego, CA, 92121, USA.
| |
Collapse
|
10
|
Gomez N, Erazo T, Lizcano JM. ERK5 and Cell Proliferation: Nuclear Localization Is What Matters. Front Cell Dev Biol 2016; 4:105. [PMID: 27713878 PMCID: PMC5031611 DOI: 10.3389/fcell.2016.00105] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 09/06/2016] [Indexed: 12/31/2022] Open
Abstract
ERK5, the last MAP kinase family member discovered, is activated by the upstream kinase MEK5 in response to growth factors and stress stimulation. MEK5-ERK5 pathway has been associated to different cellular processes, playing a crucial role in cell proliferation in normal and cancer cells by mechanisms that are both dependent and independent of its kinase activity. Thus, nuclear ERK5 activates transcription factors by either direct phosphorylation or acting as co-activator thanks to a unique transcriptional activation TAD domain located at its C-terminal tail. Consequently, ERK5 has been proposed as an interesting target to tackle different cancers, and either inhibitors of ERK5 activity or silencing the protein have shown antiproliferative activity in cancer cells and to block tumor growth in animal models. Here, we review the different mechanisms involved in ERK5 nuclear translocation and their consequences. Inactive ERK5 resides in the cytosol, forming a complex with Hsp90-Cdc37 superchaperone. In a canonical mechanism, MEK5-dependent activation results in ERK5 C-terminal autophosphorylation, Hsp90 dissociation, and nuclear translocation. This mechanism integrates signals such as growth factors and stresses that activate the MEK5-ERK5 pathway. Importantly, two other mechanisms, MEK5-independent, have been recently described. These mechanisms allow nuclear shuttling of kinase-inactive forms of ERK5. Although lacking kinase activity, these forms activate transcription by interacting with transcription factors through the TAD domain. Both mechanisms also require Hsp90 dissociation previous to nuclear translocation. One mechanism involves phosphorylation of the C-terminal tail of ERK5 by kinases that are activated during mitosis, such as Cyclin-dependent kinase-1. The second mechanism involves overexpression of chaperone Cdc37, an oncogene that is overexpressed in cancers such as prostate adenocarcinoma, where it collaborates with ERK5 to promote cell proliferation. Although some ERK5 kinase inhibitors have shown antiproliferative activity it is likely that those tumors expressing kinase-inactive nuclear ERK5 will not respond to these inhibitors.
Collapse
Affiliation(s)
| | | | - Jose M. Lizcano
- Protein Kinases and Signal Transduction Laboratory, Institut de Neurociencies and Departament de Bioquimica i Biologia Molecular, Facultat de Medicina, Universitat Autonoma de BarcelonaBarcelona, Spain
| |
Collapse
|
11
|
Tortorella SM, Hung A, Karagiannis TC. The implication of cancer progenitor cells and the role of epigenetics in the development of novel therapeutic strategies for chronic myeloid leukemia. Antioxid Redox Signal 2015; 22:1425-62. [PMID: 25366930 DOI: 10.1089/ars.2014.6096] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE Chronic myeloid leukemia (CML) involves the malignant transformation of hematopoietic stem cells, defined largely by the Philadelphia chromosome and expression of the breakpoint cluster region-Abelson (BCR-ABL) oncoprotein. Pharmacological tyrosine kinase inhibitors (TKIs), including imatinib mesylate, have overcome limitations in conventional treatment for the improved clinical management of CML. RECENT ADVANCES Accumulated evidence has led to the identification of a subpopulation of quiescent leukemia progenitor cells with stem-like self renewal properties that may initiate leukemogenesis, which are also shown to be present in residual disease due to their insensitivity to tyrosine kinase inhibition. CRITICAL ISSUES The characterization of quiescent leukemia progenitor cells as a unique cell population in CML pathogenesis has become critical with the complete elucidation of mechanisms involved in their survival independent of BCR-ABL that is important in the development of novel anticancer strategies. Understanding of these functional pathways in CML progenitor cells will allow for their selective therapeutic targeting. In addition, disease pathogenesis and drug responsiveness is also thought to be modulated by epigenetic regulatory mechanisms such as DNA methylation, histone acetylation, and microRNA expression, with a capacity to control CML-associated gene transcription. FUTURE DIRECTIONS A number of compounds in combination with TKIs are under preclinical and clinical investigation to assess their synergistic potential in targeting leukemic progenitor cells and/or the epigenome in CML. Despite the collective promise, further research is required in order to refine understanding, and, ultimately, advance antileukemic therapeutic strategies.
Collapse
Affiliation(s)
- Stephanie M Tortorella
- 1 Epigenomic Medicine, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct , Melbourne, Australia
| | | | | |
Collapse
|
12
|
Doi Y, Takeuchi H, Mizoguchi H, Fukumoto K, Horiuchi H, Jin S, Kawanokuchi J, Parajuli B, Sonobe Y, Mizuno T, Suzumura A. Granulocyte-colony stimulating factor attenuates oligomeric amyloid β neurotoxicity by activation of neprilysin. PLoS One 2014; 9:e103458. [PMID: 25062013 PMCID: PMC4111597 DOI: 10.1371/journal.pone.0103458] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 06/29/2014] [Indexed: 01/07/2023] Open
Abstract
Soluble oligomeric amyloid β (oAβ) causes synaptic dysfunction and neuronal cell death, which are involved in the pathogenesis of Alzheimer's disease (AD). The hematopoietic growth factor granulocyte-colony stimulating factor (G-CSF) is expressed in the central nervous system (CNS) and drives neurogenesis. Here we show that G-CSF attenuated oAβ neurotoxicity through the enhancement of the enzymatic activity of Aβ-degrading enzyme neprilysin (NEP) in neurons, while the NEP inhibitor thiorphan abolished the neuroprotection. Inhibition of MEK5/ERK5, a major downstream effector of G-CSF signaling, also ablated neuroprotective effect of G-CSF. Furthermore, intracerebroventricular administration of G-CSF enhanced NEP enzymatic activity and clearance of Aβ in APP/PS1 transgenic mice. Thus, we propose that G-CSF may be a possible therapeutic strategy against AD.
Collapse
Affiliation(s)
- Yukiko Doi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Hideyuki Takeuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Hiroyuki Mizoguchi
- Futuristic Environmental Simulation Center, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Kazuya Fukumoto
- Futuristic Environmental Simulation Center, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Hiroshi Horiuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Shijie Jin
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Jun Kawanokuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Bijay Parajuli
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Yoshifumi Sonobe
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Tetsuya Mizuno
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- * E-mail:
| | - Akio Suzumura
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| |
Collapse
|
13
|
Rask-Andersen M, Jacobsson JA, Moschonis G, Ek AE, Chrousos GP, Marcus C, Manios Y, Fredriksson R, Schiöth HB. The MAP2K5-linked SNP rs2241423 is associated with BMI and obesity in two cohorts of Swedish and Greek children. BMC MEDICAL GENETICS 2012; 13:36. [PMID: 22594783 PMCID: PMC3459804 DOI: 10.1186/1471-2350-13-36] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 05/04/2012] [Indexed: 11/10/2022]
Abstract
Background Recent genome-wide association studies have identified a single nucleotide polymorphism within the last intron of MAP2K5 associated with a higher body mass index (BMI) in adults. MAP2K5 is a component of the MAPK-family intracellular signaling pathways, responding to extracellular growth factors such as brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF). In this study, we examined the association of this variant in two cohorts of children from Sweden and Greece. Methods We examine the association of rs2241423 to BMI in a cohort of 474 Swedish children admitted for treatment of childhood obesity and 519 children matched for gender, ethnicity and socioeconomic background from the Stockholm area, as well as a cross-sectional cohort of 2308 Greek school children (Healthy Growth Study). Children were genotyped using a predesigned TaqMan polymorphism assay. Logistic regression was used to test for an association of rs2241423 to obesity in the cohort of Swedish children. Linear regression was used to test for an association of rs2241423 to BMI z-score and phenotypic measurements of body adiposity in the cohort of Greek children. Models were adjusted for age and gender. In the cohort of Greek children the model was also adjusted for stage of pubertal development. Results The minor allele of rs2241423, allele A, was associated with a protective effect against obesity in the cohort of Swedish children (p = 0.029, OR = 0.79 (95% CI: 0.64–0.98)), and with a lower BMI z-score in the cohort of Greek children (p = 0.028, β = −0.092). No association to phenotypic measurements of body fat distribution could be observed in our study. Conclusions rs2241423 was associated with BMI and obesity in two independent European cohorts suggesting a role for MAP2K5 in early weight regulation.
Collapse
Affiliation(s)
- Mathias Rask-Andersen
- Department of Neuroscience, Functional Pharmacology, Uppsala University, BMC, Uppsala SE 75124, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Frank T, Klinker F, Falkenburger BH, Laage R, Lühder F, Göricke B, Schneider A, Neurath H, Desel H, Liebetanz D, Bähr M, Weishaupt JH. Pegylated granulocyte colony-stimulating factor conveys long-term neuroprotection and improves functional outcome in a model of Parkinson's disease. ACTA ACUST UNITED AC 2012; 135:1914-25. [PMID: 22427327 DOI: 10.1093/brain/aws054] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent proof-of-principle data showed that the haematopoietic growth factor granulocyte colony-stimulating factor (filgrastim) mediates neuroprotection in rodent models of Parkinson's disease. In preparation for future clinical trials, we performed a preclinical characterization of a pegylated derivative of granulocyte colony-stimulating factor (pegfilgrastim) in the mouse 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson's disease. We determined serum and cerebrospinal fluid drug levels after subcutaneous injection. A single injection of pegfilgrastim was shown to achieve stable levels of granulocyte colony-stimulating factor in both serum and cerebrospinal fluid with substantially higher levels compared to repetitive filgrastim injections. Leucocyte blood counts were only transiently increased after repeated injections. We demonstrated substantial dose-dependent long-term neuroprotection by pegfilgrastim in both young and aged mice, using bodyweight-adjusted doses that are applicable in clinical settings. Importantly, we found evidence for the functionally relevant preservation of nigrostriatal projections by pegfilgrastim in our model of Parkinson's disease, which resulted in improved motor performance. The more stable levels of pegylated neuroprotective proteins in serum and cerebrospinal fluid may represent a general advantage in the treatment of chronic neurodegenerative diseases and the resulting longer injection intervals are likely to improve patient compliance. In summary, we found that pegylation of a neuroprotective growth factor improved its pharmacokinetic profile over its non-modified counterpart in an in vivo model of Parkinson's disease. As the clinical safety profile of pegfilgrastim is already established, these data suggest that evaluation of pegfilgrastim in further Parkinson's disease models and ultimately clinical feasibility studies are warranted.
Collapse
Affiliation(s)
- Tobias Frank
- Department of Neurology, University Medical Centre, Georg-August-University, 37075 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Drew BA, Burow ME, Beckman BS. MEK5/ERK5 pathway: the first fifteen years. Biochim Biophys Acta Rev Cancer 2011; 1825:37-48. [PMID: 22020294 DOI: 10.1016/j.bbcan.2011.10.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 10/07/2011] [Indexed: 12/22/2022]
Abstract
While conventional MAP kinase pathways are one of the most highly studied signal transduction molecules, less is known about the MEK5 signaling pathway. This pathway has been shown to play a role in normal cell growth cycles, survival and differentiation. The MEK5 pathway is also believed to mediate the effects of a number of oncogenes. MEK5 is the upstream activator of ERK5 in many epithelial cells. Activation of the MEK-MAPK pathway is a frequent event in malignant tumor formation and contributes to chemoresistance and anti-apoptotic signaling. This pathway may be involved in a number of more aggressive, metastatic varieties of cancer due to its role in cell survival, proliferation and EMT transitioning. Further study of this pathway may lead to new prognostic factors and new drug targets to combat more aggressive forms of cancer.
Collapse
Affiliation(s)
- Barbara A Drew
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | | | | |
Collapse
|
16
|
Katsarou K, Tsitoura P, Georgopoulou U. MEK5/ERK5/mef2: a novel signaling pathway affected by hepatitis C virus non-enveloped capsid-like particles. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1854-62. [PMID: 21767578 DOI: 10.1016/j.bbamcr.2011.06.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/24/2011] [Accepted: 06/27/2011] [Indexed: 11/17/2022]
Abstract
Hepatitis C virus (HCV) is an RNA positive strand virus, member of the Flaviviridae family. The viral particle is composed of a capsid containing the genome, surrounded by E1 and E2 proteins, however different forms of viral particles have been observed including non-enveloped particles. Previous reports have proposed that hepatitis C non-enveloped capsid-like particles (HCVne) enter cells of hepatic origin via clathrin-mediated endocytosis, during which different signaling events occur. In this report we show that HCVne particles are capable of inducing the recently discovered ERK5 pathway, in a dose dependent way. The ERK5 pathway can be activated by growth factors and other extracellular signals. This specific activation occurs through a well characterized upstream kinase, MEK5, and is capable of inducing gene regulation of mef2. In contrast, when HCV core structural and NS5A non-structural proteins were expressed endogenously no activation of this pathway was detected. These cell signaling events could be of critical importance and might give clues for the elucidation of cellular manifestations associated with HCV infection.
Collapse
|
17
|
Roberts OL, Holmes K, Müller J, Cross DAE, Cross MJ. ERK5 is required for VEGF-mediated survival and tubular morphogenesis of primary human microvascular endothelial cells. J Cell Sci 2010; 123:3189-200. [DOI: 10.1242/jcs.072801] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Extracellular signal-regulated kinase 5 (ERK5) is activated in response to environmental stress and growth factors. Gene ablation of Erk5 in mice is embryonically lethal as a result of disruption of cardiovascular development and vascular integrity. We investigated vascular endothelial growth factor (VEGF)-mediated ERK5 activation in primary human dermal microvascular endothelial cells (HDMECs) undergoing proliferation on a gelatin matrix, and tubular morphogenesis within a collagen gel matrix. VEGF induced sustained ERK5 activation on both matrices. However, manipulation of ERK5 activity by siRNA-mediated gene silencing disrupted tubular morphogenesis without impacting proliferation. Overexpression of constitutively active MEK5 and ERK5 stimulated tubular morphogenesis in the absence of VEGF. Analysis of intracellular signalling revealed that ERK5 regulated AKT phosphorylation. On a collagen gel, ERK5 regulated VEGF-mediated phosphorylation of the pro-apoptotic protein BAD and increased expression of the anti-apoptotic protein BCL2, resulting in decreased caspase-3 activity and apoptosis suppression. Our findings suggest that ERK5 is required for AKT phosphorylation and cell survival and is crucial for endothelial cell differentiation in response to VEGF.
Collapse
Affiliation(s)
- Owain Llŷr Roberts
- NWCRF Institute, School of Biological Sciences, College of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Katherine Holmes
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, L69 3GE, UK
| | - Jürgen Müller
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Darren A. E. Cross
- AstraZeneca, Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, UK
| | - Michael J. Cross
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, L69 3GE, UK
| |
Collapse
|
18
|
Activation of ERK5 in angiotensin II-induced hypertrophy of human aortic smooth muscle cells. Mol Cell Biochem 2008; 322:171-8. [PMID: 19011954 DOI: 10.1007/s11010-008-9954-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Accepted: 10/28/2008] [Indexed: 12/17/2022]
Abstract
Extracellular signal-regulated kinase 5 (ERK5), a recently discovered mitogen-activated protein kinase (MAPK), plays a key role in the development and pathogenesis of cardiovascular disease. In order to clarify the pathophysiological significance of ERK5 in vascular remodeling, we investigated ERK5 phosphorylation in hypertrophy of human aortic smooth muscle cells (HASMCs) induced by angiotensin II (Ang II). The AT1 receptor was involved in Ang II-induced ERK5 activity. Hypertrophy was detected by the measurement of protein synthesis with [(3)H]-Leu incorporation in cultured HASMCs. Ang II rapidly induced phosphorylation of ERK5 at Thr218/Tyr220 residues in a time- and dose-dependent manner. Activation of myocyte enhancer factor-2C (MEF2C) by ERK5 was inhibited by PD98059. Transfecting HASMCs with small interfering RNA (siRNA) to silence ERK5 inhibited Ang II-induced cell hypertrophy. Thus, ERK5 phosphorylation contributes to MEF2C activation and subsequent HASMC hypertrophy induced by Ang II, for a novel molecular mechanism in cardiovascular diseases induced by Ang II.
Collapse
|
19
|
Wang L, Xue J, Zadorozny EV, Robinson LJ. G-CSF stimulates Jak2-dependent Gab2 phosphorylation leading to Erk1/2 activation and cell proliferation. Cell Signal 2008; 20:1890-9. [PMID: 18644434 PMCID: PMC2788816 DOI: 10.1016/j.cellsig.2008.06.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Accepted: 06/27/2008] [Indexed: 01/17/2023]
Abstract
Granulocyte colony-stimulating factor (G-CSF), the major cytokine regulator of neutrophilic granulopoiesis, stimulates both the proliferation and differentiation of myeloid precursors. A variety of signaling proteins have been identified as mediators of G-CSF signaling, but understanding of their specific interactions and organization into signaling pathways for particular cellular effects is incomplete. The present study examined the role of the scaffolding protein Grb2-associated binding protein-2 (Gab2) in G-CSF signaling. We found that a chemical inhibitor of Janus kinases inhibited G-CSF-stimulated Gab2 phosphorylation. Transfection with Jak2 antisense and dominant negative constructs also inhibited Gab2 phosphorylation in response to G-CSF. In addition, G-CSF enhanced the association of Jak2 with Gab2. In vitro, activated Jak2 directly phosphorylated specific Gab2 tyrosine residues. Mutagenesis studies revealed that Gab2 tyrosine 643 (Y643) was a major target of Jak2 in vitro, and a key residue for Jak2-dependent phosphorylation in intact cells. Mutation of Gab2 Y643 inhibited G-CSF-stimulated Erk1/2 activation and Shp2 binding to Gab2. Loss of Y643 also inhibited Gab2-mediated G-CSF-stimulated cell proliferation. Together, these results identify a novel signaling pathway involving Jak2-dependent Gab2 phosphorylation leading to Erk1/2 activation and cell proliferation in response to G-CSF.
Collapse
Affiliation(s)
- Lin Wang
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA
| | - Jia Xue
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA
| | - Eva V. Zadorozny
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA
| | - Lisa J. Robinson
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA
| |
Collapse
|
20
|
Rovida E, Spinelli E, Sdelci S, Barbetti V, Morandi A, Giuntoli S, Dello Sbarba P. ERK5/BMK1 is indispensable for optimal colony-stimulating factor 1 (CSF-1)-induced proliferation in macrophages in a Src-dependent fashion. THE JOURNAL OF IMMUNOLOGY 2008; 180:4166-72. [PMID: 18322228 DOI: 10.4049/jimmunol.180.6.4166] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
CSF-1, by binding to its high-affinity receptor CSF-1R, sustains the survival and proliferation of monocyte/macrophages, which are central cells of innate immunity and inflammation. The MAPK ERK5 (also known as big MAPK-1, BMK1, or MAPK7) is a 98-kDa molecule sharing high homology with ERK1/2. ERK5 is activated by oxidative stress or growth factor stimulation. This study was undertaken to characterize ERK5 involvement in macrophage signaling that is elicited by CSF-1. Exposure to the CSF-1 of primary human macrophages or murine macrophage cell lines, as well as murine fibroblasts expressing ectopic CSF-1R, resulted in a rapid and sustained increase of ERK5 phosphorylation on activation-specific residues. In the BAC1.2F5 macrophage cell line, ERK5 was also activated by another mitogen, GM-CSF, while macrophage activators such as LPS or IFN-gamma and a number of nonproliferative cytokines failed. Src family kinases were found to link the activation of CSF-1R to that of ERK5, whereas protein kinase C or the serine phosphatases PP1 and PP2A seem not to be involved in the process. Treatment of macrophages with ERK5-specific small interfering RNA markedly reduced CSF-1-induced DNA synthesis and total c-Jun phosphorylation and expression, while increasing the expression of the cyclin-dependent kinase inhibitor p27. Following CSF-1 treatment, the active form of ERK5 rapidly translocated from cytosol to nucleus. Taken together, the results reported in this study show that ERK5 is indispensable for optimal CSF-1-induced proliferation and indicate a novel target for its control.
Collapse
Affiliation(s)
- Elisabetta Rovida
- Dipartimento di Patologia e Oncologia Sperimentali, Università degli Studi di Firenze, Florence, Italy.
| | | | | | | | | | | | | |
Collapse
|
21
|
Rovida E, Navari N, Caligiuri A, Dello Sbarba P, Marra F. ERK5 differentially regulates PDGF-induced proliferation and migration of hepatic stellate cells. J Hepatol 2008; 48:107-15. [PMID: 17998143 DOI: 10.1016/j.jhep.2007.08.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 08/04/2007] [Accepted: 08/06/2007] [Indexed: 01/15/2023]
Abstract
BACKGROUND/AIMS Hepatic stellate cells (HSC) are liver-specific pericytes implicated in liver tissue repair. Activation of signaling pathways in HSC modulates hepatic fibrogenesis, but no information is available on the possible role of ERK5, a member of the mitogen-activated protein kinase family, in this process. In this study, we investigated the role of ERK5 in the biologic responses triggered by platelet-derived growth factor (PDGF) in HSC. METHODS Human HSC were cultured on plastic and studied in their myofibroblast-like phenotype. RESULTS PDGF-BB rapidly induced ERK5 activation and translocation to the nucleus. EGF and PDGF-DD were also found to activate ERK5. Interfering with Src activation blocked PDGF-BB-dependent ERK5 phosphorylation. To establish the biological significance of ERK5 activation, HSC were transfected with non-targeting siRNA or siRNA targeting ERK5. ERK5 silencing inhibited PDGF-BB-induced cell proliferation, and expression and activation of c-Jun. In contrast, depletion of ERK5 was associated with significantly increased cell migration, both in the presence or absence of PDGF-BB. This effect was associated with a redistribution of focal contacts, and with decreased phosphorylation of FAK, paxillin, and PAK. CONCLUSIONS ERK5 modulates PDGF-dependent biologic activities in human HSC, generating positive signals for cell proliferation downregulating the ability of the cells to migrate.
Collapse
Affiliation(s)
- Elisabetta Rovida
- Dipartimento di Patologia e Oncologia Sperimentali, University of Florence, Italy
| | | | | | | | | |
Collapse
|
22
|
Nagel S, Burek C, Venturini L, Scherr M, Quentmeier H, Meyer C, Rosenwald A, Drexler HG, MacLeod RAF. Comprehensive analysis of homeobox genes in Hodgkin lymphoma cell lines identifies dysregulated expression of HOXB9 mediated via ERK5 signaling and BMI1. Blood 2007; 109:3015-23. [PMID: 17148583 DOI: 10.1182/blood-2006-08-044347] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Many members of the nearly 200-strong homeobox gene family have been implicated in cancer, mostly following ectopic expression. In this study we analyzed homeobox gene expression in Hodgkin lymphoma (HL) cell lines. Both reverse transcription-polymerase chain reaction (RT-PCR) using degenerate primers and microarray profiling identified consistently up-regulated HOXB9 expression. Analysis of HOXB9 regulation in HL cells revealed E2F3A and BMI1 as activator and repressor, respectively. Furthermore, a constitutively active ERK5 pathway was identified in all HL cell lines analyzed as well as primary HL cells. Our data show that ERK5 probably mediates HOXB9 expression by repressing BMI1. In addition, expression analysis of the neighboring microRNA gene mir-196a1 revealed coregulation with HOXB9. Functional analysis of HOXB9 by knockdown and overexpression assays indicated their influence on both proliferation and apoptosis in HL cells. In summary, we identified up-regulation of HOXB9 in HL mediated by constitutively active ERK5 signaling which may represent novel therapeutic targets in HL.
Collapse
Affiliation(s)
- Stefan Nagel
- Human and Animal Cell Cultures, Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ), Braunschweig, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Pearson GW, Earnest S, Cobb MH. Cyclic AMP selectively uncouples mitogen-activated protein kinase cascades from activating signals. Mol Cell Biol 2006; 26:3039-47. [PMID: 16581779 PMCID: PMC1446939 DOI: 10.1128/mcb.26.8.3039-3047.2006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cells integrate signals to select the appropriate response from an array of possible outcomes. Signal integration causes the reorganization of signaling pathways by undescribed events. To analyze the molecular changes in signaling pathways that elicit different responses, we focused on the interaction between cyclic AMP (cAMP) and growth factors. We show that the activation of extracellular signal-regulated kinase 5 (ERK5), but not ERK1/2, by growth factors is disrupted by cAMP through cAMP-dependent protein kinase (PKA). Activation of MEKK2, a mitogen-activated protein (MAP) kinase kinase kinase upstream of ERK5 that is required for growth factor activation of ERK5, is also disrupted by PKA. Transcription of c-Jun is induced by ERK5, and like ERK5, c-Jun induction is also blocked by cAMP. Transcription from the serum response element, like activation of ERK1/2, is not blocked by cAMP. Collectively, these results support a model in which cAMP shapes the growth factor-induced cellular response through PKA-dependent uncoupling of selected MAP kinase cascades from activating signals.
Collapse
Affiliation(s)
- Gray W Pearson
- Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | | | | |
Collapse
|
24
|
Zhu QS, Xia L, Mills GB, Lowell CA, Touw IP, Corey SJ. G-CSF induced reactive oxygen species involves Lyn-PI3-kinase-Akt and contributes to myeloid cell growth. Blood 2006; 107:1847-56. [PMID: 16282349 PMCID: PMC1895701 DOI: 10.1182/blood-2005-04-1612] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Accepted: 09/09/2005] [Indexed: 11/20/2022] Open
Abstract
Granulocyte colony-stimulating factor (G-CSF) drives the production, survival, differentiation, and inflammatory functions of granulocytes. Reactive oxygen species (ROSs) provide a major thrust of the inflammatory response, though excessive ROSs may be deleterious. G-CSF stimulation showed a time- and dose-dependent increase in ROS production, correlating with activation of Lyn and Akt. Inhibition of Lyn, PI3-kinase, and Akt abrogated G-CSF-induced ROS production. This was also blocked by DPI, a specific inhibitor of NADPH oxidase. Following G-CSF stimulation, neutrophils from Lyn-/- mice produced less ROSs than wild-type littermates. G-CSF induced both serine phosphorylation and membrane translocation of p47phox, a subunit of NADPH oxidase. Because patients with a truncated G-CSF receptor have a high risk of developing acute myeloid leukemia (AML), we hypothesized that dysregulation of ROSs contributes to leukemogenesis. Cells expressing the truncated G-CSF receptor produced more ROSs than those with the full-length receptor. G-CSF-induced ROS production was enhanced in bone marrow-derived neutrophils expressing G-CSFRdelta715, a truncated receptor. The antioxidant N-acetyl-L-cysteine diminished G-CSF-induced ROS production and cell proliferation by inhibiting Akt activation. These data suggest that the G-CSF-induced Lyn-PI3K-Akt pathway drives ROS production. One beneficial effect of therapeutic targeting of Lyn-PI3K-kinase-Akt cascade is abrogating ROS production.
Collapse
MESH Headings
- Acetylcysteine/pharmacology
- Animals
- Bone Marrow Cells/cytology
- Bone Marrow Cells/enzymology
- Cell Line
- Cell Proliferation
- Dose-Response Relationship, Drug
- Drug Design
- Enzyme Inhibitors/therapeutic use
- Granulocyte Colony-Stimulating Factor/deficiency
- Granulocyte Colony-Stimulating Factor/metabolism
- Granulocyte Colony-Stimulating Factor/pharmacology
- Humans
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Mice
- Mice, Knockout
- NADPH Oxidases
- Neutrophils/cytology
- Neutrophils/enzymology
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Phosphoproteins/metabolism
- Protein Transport/drug effects
- Proto-Oncogene Proteins c-akt/antagonists & inhibitors
- Proto-Oncogene Proteins c-akt/metabolism
- Reactive Oxygen Species/metabolism
- Receptors, Granulocyte Colony-Stimulating Factor/genetics
- Receptors, Granulocyte Colony-Stimulating Factor/metabolism
- Sequence Deletion/genetics
- Signal Transduction/drug effects
- Signal Transduction/genetics
- src-Family Kinases/antagonists & inhibitors
- src-Family Kinases/deficiency
- src-Family Kinases/metabolism
Collapse
Affiliation(s)
- Quan-Sheng Zhu
- Division of Pediatrics, University of Texas--M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
25
|
Wu Y, Kajdacsy-Balla A, Strawn E, Basir Z, Halverson G, Jailwala P, Wang Y, Wang X, Ghosh S, Guo SW. Transcriptional characterizations of differences between eutopic and ectopic endometrium. Endocrinology 2006; 147:232-46. [PMID: 16195411 DOI: 10.1210/en.2005-0426] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Endometriosis, defined as the presence of endometrial glandular and stromal cells outside the uterine cavity, is a common gynecological disease with poorly understood pathogenesis. Using laser capture microdissection and a cDNA microarray with 9600 genes/expressed sequence tags (ESTs), we have conducted a comprehensive profiling of gene expression differences between the ectopic and eutopic endometrium taken from 12 women with endometriosis adjusted for menstrual phase and the location of the lesions. With dye-swapping and replicated arrays, we found 904 genes/ESTs that are differentially expressed. We validated the gene expression using real-time RT-PCR. We found that the expression patterns of these genes/ESTs correctly classified the 12 patients into ovarian and nonovarian endometriosis. We identified gene clusters that are location-specific. In addition, we identified several biological themes using Expression Analysis Systematic Explorer. Finally, we identified 79 pathways with over 100 genes with known functions, which include oxidative stress, focal adhesion, Wnt signaling, and MAPK signaling. The identification of these genes and their associated pathways provides new insight. Our findings will stimulate future investigations on molecular genetic mechanisms underlying the pathogenesis of endometriosis.
Collapse
Affiliation(s)
- Yan Wu
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-0509, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Zhuang D, Qiu Y, Haque SJ, Dong F. Tyrosine 729 of the G-CSF receptor controls the duration of receptor signaling: involvement of SOCS3 and SOCS1. J Leukoc Biol 2005; 78:1008-15. [PMID: 16033816 DOI: 10.1189/jlb.0105032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mutations in the granulocyte-colony stimulating factor receptor (G-CSF-R) gene resulting in carboxy terminal truncation have been associated with acute myeloid leukemia (AML). The truncated G-CSF-R from AML patients mediate enhanced and prolonged activation of signal transducer and activator of transcription 5 (Stat5). It has been shown that Src homology-2 (SH2)-containing tyrosine phosphatase-1 attenuates the intensity of G-CSF-induced Stat5 activation through interacting with the carboxy terminus of the G-CSF-R. Using a series of tyrosine-to-phenylalanine substitution mutants, we show here that tyrosine (Tyr) 729, located in the carboxy terminus of the G-CSF-R, controls the duration of G-CSF-stimulated activation of Stat5, Akt, and extracellular signal-regulated kinase 1/2. It is interesting that activation of these signaling molecules by G-CSF was prolonged by pretreating cells with actinomycin D or cyclohexamide, suggesting that de novo protein synthesis is required for appropriate termination of G-CSF-R signaling. The transcripts for suppressor of cytokine signaling 3 (SOCS3) and SOCS1 were up-regulated rapidly upon G-CSF stimulation. Expression of SOCS3 or SOCS1, but not SOCS2 and cytokine-inducible SH2 domain-containing protein, completely suppressed G-CSF-induced Stat5 activation but had only a weak effect on Stat5 activation mediated by the receptor mutant lacking Tyr 729. SOCS1 and SOCS3 also inhibited G-CSF-dependent cell proliferation, but the inhibitory effect of the two SOCS proteins on cell proliferation was diminished when Tyr 729 of the G-CSF-R was mutated. These data indicate that Tyr 729 of the G-CSF-R is required for SOCS1- and SOCS3-mediated negative regulation of G-CSF-R signaling and that the duration and intensity of G-CSF-induced Stat5 activation are regulated by two distinct mechanisms.
Collapse
Affiliation(s)
- Dazhong Zhuang
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA
| | | | | | | |
Collapse
|
27
|
Buschbeck M, Hofbauer S, Di Croce L, Keri G, Ullrich A. Abl-kinase-sensitive levels of ERK5 and its intrinsic basal activity contribute to leukaemia cell survival. EMBO Rep 2005; 6:63-9. [PMID: 15608616 PMCID: PMC1299226 DOI: 10.1038/sj.embor.7400316] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 10/29/2004] [Accepted: 11/19/2004] [Indexed: 11/08/2022] Open
Abstract
It is well established that the mitogen-activated protein kinase (MAPK) signal is regulated through phosphorylation-dependent activation by the three-tiered MAPK cascade. However, our studies on the interaction of the MAPK ERK5 with the tyrosine kinase c-Abl and its oncogenic variants v-Abl and Bcr/Abl disclosed an alternative aspect of regulation. Independent of the MAPK cascade, Abl kinases were able to regulate the cellular amount of ERK5, at least in part, by stabilizing the protein. The resulting level of ERK5 and its intrinsic basal activity, but not necessarily its activation, were essential and sufficient to increase transformation by v-Abl and to mediate survival of Bcr/Abl-expressing leukaemia cells. These results suggest that the ability to regulate the cellular abundance of ERK5 contributes to the oncogenic potential of Abl kinases.
Collapse
Affiliation(s)
- Marcus Buschbeck
- Department of Molecular Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18a, 82152 Martinsried, Germany
- Center for Genomic Regulation (CRG), Passeig Maritim 37–49, 08003 Barcelona, Spain
- Tel: +34 93 224 0935; Fax: +34 93 224 0899; E-mail:
| | - Sebastian Hofbauer
- Department of Molecular Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18a, 82152 Martinsried, Germany
| | - Luciano Di Croce
- Center for Genomic Regulation (CRG), Passeig Maritim 37–49, 08003 Barcelona, Spain
- ICREA, Spain
| | - Gyorgy Keri
- Peptide Biochemistry Research Group of the Hungarian Academy of Science, Department of Medical Chemistry, Semmelweis University, Puskin u. 9, Budapest 1088, Hungary
| | - Axel Ullrich
- Department of Molecular Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18a, 82152 Martinsried, Germany
- Tel: +49 89 8578 2512; Fax: +49 89 8578 2454; E-mail:
| |
Collapse
|
28
|
Schneider A, Krüger C, Steigleder T, Weber D, Pitzer C, Laage R, Aronowski J, Maurer MH, Gassler N, Mier W, Hasselblatt M, Kollmar R, Schwab S, Sommer C, Bach A, Kuhn HG, Schäbitz WR. The hematopoietic factor G-CSF is a neuronal ligand that counteracts programmed cell death and drives neurogenesis. J Clin Invest 2005; 115:2083-98. [PMID: 16007267 PMCID: PMC1172228 DOI: 10.1172/jci23559] [Citation(s) in RCA: 535] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Accepted: 05/17/2005] [Indexed: 12/26/2022] Open
Abstract
G-CSF is a potent hematopoietic factor that enhances survival and drives differentiation of myeloid lineage cells, resulting in the generation of neutrophilic granulocytes. Here, we show that G-CSF passes the intact blood-brain barrier and reduces infarct volume in 2 different rat models of acute stroke. G-CSF displays strong anti-apoptotic activity in mature neurons and activates multiple cell survival pathways. Both G-CSF and its receptor are widely expressed by neurons in the CNS, and their expression is induced by ischemia, which suggests an autocrine protective signaling mechanism. Surprisingly, the G-CSF receptor was also expressed by adult neural stem cells, and G-CSF induced neuronal differentiation in vitro. G-CSF markedly improved long-term behavioral outcome after cortical ischemia, while stimulating neural progenitor response in vivo, providing a link to functional recovery. Thus, G-CSF is an endogenous ligand in the CNS that has a dual activity beneficial both in counteracting acute neuronal degeneration and contributing to long-term plasticity after cerebral ischemia. We therefore propose G-CSF as a potential new drug for stroke and neurodegenerative diseases.
Collapse
|
29
|
Carvajal-Vergara X, Tabera S, Montero JC, Esparís-Ogando A, López-Pérez R, Mateo G, Gutiérrez N, Parmo-Cabañas M, Teixidó J, San Miguel JF, Pandiella A. Multifunctional role of Erk5 in multiple myeloma. Blood 2005; 105:4492-9. [PMID: 15692064 DOI: 10.1182/blood-2004-08-2985] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Abstract
Multiple myeloma is characterized by the accumulation of terminally differentiated B cells in the bone marrow, due to increased proliferation and restricted apoptosis of the myelomatous clone. Here we have studied the participation of a novel mitogen-activated protein kinase (MAPK) route, the extracellular signal-regulated kinase 5 (Erk5) pathway, in the regulation of myeloma cell proliferation and apoptosis. Erk5 was expressed in cells isolated from patients and in myeloma cell lines. The myeloma growth factor interleukin 6 (IL-6) activated Erk5, and this activation was independent of Ras and Src. Expression of a dominant-negative form of Erk5 restricted the proliferation of myeloma cells and inhibited IL-6–dependent cell duplication. This dominant-negative form also sensitized myeloma cells to the proapoptotic action of dexamethasone and PS341. The latter compound caused a profound decrease in the amount of endogenous Erk5 and was less effective in inducing apoptosis when the level of Erk5 was increased by transfection of Erk5. These results place the Erk5 route as a new regulatory signaling pathway that affects multiple myeloma proliferation and apoptosis.
Collapse
|
30
|
Barros JC, Marshall CJ. Activation of either ERK1/2 or ERK5 MAP kinase pathways can lead to disruption of the actin cytoskeleton. J Cell Sci 2005; 118:1663-71. [PMID: 15797923 DOI: 10.1242/jcs.02308] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oncogenic transformation often leads to the disruption of the actin cytoskeleton. Activation of the classical Ras-Raf-MEK1/2-ERK1/2 signalling cascade has been implicated in the effects of oncogenes such as Ras and Src on the cytoskeleton. Many of the studies of the effects of oncogenes on the cytoskeleton have made use of chemical inhibitors of MEK1/2 but it is now clear that these inhibitors also inactivate MEK5 in the MEK5-ERK5 MAP kinase pathway raising the possibility that this pathway may also be involved in oncogenic transformation. We therefore investigated whether activation of ERK5 can lead to disruption of the actin cytoskeleton. We show that activation of ERK5 can lead to loss of actin stress fibres, but by a distinct mechanism to ERK1/2. We demonstrate that ERK5 is activated by oncogenic Src as demonstrated by translocation of endogenous ERK5 from the cytoplasm to nucleus and activation of an ERK5-dependent transcriptional reporter and that ERK5 activation is required for Src-mediated transformation. We also show that in Src-transformed cells inhibition of ERK1/2 signalling is not sufficient for reappearance of the actin cytoskeleton and that ERK5 activation contributes to cytoskeletal disruption by Src. Our results suggest that multiple MAP kinase pathways downstream of oncogenes participate in cytoskeletal alterations.
Collapse
Affiliation(s)
- Joana Castro Barros
- Cancer Research UK Centre for Cell and Molecular Biology, Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
| | | |
Collapse
|
31
|
McCaw BJ, Chow SY, Wong ESM, Tan KL, Guo H, Guy GR. Identification and characterization of mErk5-T, a novel Erk5/Bmk1 splice variant. Gene 2005; 345:183-90. [PMID: 15716121 DOI: 10.1016/j.gene.2004.11.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Revised: 10/25/2004] [Accepted: 11/05/2004] [Indexed: 11/29/2022]
Abstract
Extracellular regulated kinase 5 (ERK5) is an unusually large member of the MAP kinase family of signaling molecules that plays an important role in cellular proliferation, differentiation and survival. Recently, three transcriptional variants of murine Erk5 were described (mErk5-a, -b and -c) that result from alternate splicing across introns 1 and/or 2, the net effect of which is translation of a peptide that lacks the kinase domain. It has been demonstrated that expression of mErk5-b and -c impinge on the function of the full length mErk5 protein product via a dominant negative effect. Here, we report the identification of another murine Erk5 splice variant and the orthologous human transcript that arise due to alternate splicing of intron 4. Failure to splice out intron 4 introduces a premature in-frame stop codon that directs translation of a peptide lacking the nuclear localization signal (NLS) and proline-rich region (PR). Experimental characterization demonstrated that like mERK5, mERK5-T becomes phosphorylated by co-expression with a constitutively active mMEK5 (mMEK5DD), and is able to coimmunoprecipitate with both itself and mERK5. Unlike mERK5, however, activated ERK5-T is unable to translocate from the cytoplasm to the nucleus in HeLaS3 cells, causing the retention of active mERK5 in the cytoplasm. Taken together with previous reports of domain content modification of ERK5 via alternate splicing, these observations add to the suggestion that regulation of ERK5 signaling may be mediated, at least in part, at the level of RNA processing.
Collapse
Affiliation(s)
- B J McCaw
- Signal Transduction Laboratory, Institute of Molecular and Cell Biology, Proteos, 61 Biopolis Drive, Singapore 138673, Singapore
| | | | | | | | | | | |
Collapse
|
32
|
Bogoyevitch MA, Court NW. Counting on mitogen-activated protein kinases—ERKs 3, 4, 5, 6, 7 and 8. Cell Signal 2004; 16:1345-54. [PMID: 15381250 DOI: 10.1016/j.cellsig.2004.05.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Accepted: 05/12/2004] [Indexed: 11/19/2022]
Abstract
Signal transduction pathways in eukaryotic cells integrate diverse extracellular signals, and regulate complex biological responses such as growth, differentiation and death. One group of proline-directed Ser/Thr protein kinases, the mitogen-activated protein kinases (MAPKs), plays a central role in these signalling pathways. Much attention has focused in recent years on three subfamilies of MAPKs, the extracellular signal regulated kinases (ERKs), c-Jun N-terminal kinases (JNKs) and the p38 MAPKs. However, the ERK family is broader than the ERK1 and ERK2 proteins that have been the subject of most studies in this area. Here we overview the work on ERKs 3 to 8, emphasising where possible their biological activities as well as distinctive biochemical properties. It is clear from these studies that these additional ERKs show similarities to ERK1 and ERK2, but with some interesting differences that challenge the paradigm of the archetypical ERK1/2 MAPK pathway.
Collapse
Affiliation(s)
- Marie A Bogoyevitch
- Cell Signalling Laboratory, Biochemistry and Molecular Biology, School of Biomedical and Chemical Sciences, University of Western Australia, Crawley, WA 6009, Australia.
| | | |
Collapse
|
33
|
Suzaki Y, Yoshizumi M, Kagami S, Nishiyama A, Ozawa Y, Kyaw M, Izawa Y, Kanematsu Y, Tsuchiya K, Tamaki T. BMK1 is activated in glomeruli of diabetic rats and in mesangial cells by high glucose conditions. Kidney Int 2004; 65:1749-60. [PMID: 15086914 DOI: 10.1111/j.1523-1755.2004.00576.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND High glucose causes renal cell injury through various signal transduction pathways, including mitogen-activated protein (MAP) kinases cascades. Big MAP kinase 1 (BMK1), also known as extracellular signal-regulated kinase 5 (ERK5), is a recently identified MAP kinase family member and was reported to be sensitive to osmotic and oxidative stress. However, the role of BMK1 in diabetic nephropathy has not been elucidated yet. METHODS We investigated whether BMK1 is activated in the glomeruli of Otsuka Long Evans Tokushima Fatty (OLETF) rats, a model of type 2 diabetes mellitus in comparison with the control Long Evans Tokushima Otsuka (LETO) rats. We also examined the effect of high glucose on BMK1 activity in cultured rat mesangial cells. RESULTS BMK1 and ERK1/2 but not p38 were activated in the glomeruli of OLETF rats, which showed diabetic nephropathy at 52 weeks of age. High glucose, in addition to a high concentration of raffinose, caused rapid and significant activation of BMK1 in rat mesangial cells. MAP kinase/ERK kinase (MEK) inhibitors, U0126 and PD98059, both inhibited BMK1 activation by high glucose in a concentration-dependent manner. Protein kinase C (PKC) inhibition by GF109203X and PKC down-regulation with long-time phorbol myristate acetate (PMA) treatment both inhibited BMK1 and Src kinase activation. Src kinase inhibitors, herbimycin A and PP2, also inhibited high glucose-induced BMK1 activation. PKC inhibitors, Src inhibitors and MEK inhibitors, all inhibited cell proliferation by high glucose. Finally, transfection of dominant-negative MEK5, which is an upstream regulator of BMK1, abolished the BMK1-mediated rat mesangial cell proliferation stimulated by high glucose. CONCLUSION In the present study, we demonstrated that high glucose activates BMK1 both in vivo and in vitro. It was suggested that high glucose induces PKC- and c-Src-dependent BMK1 activation. It could not be denied that BMK1 activation is induced through an osmotic stress-sensitive mechanism. BMK1-mediated mesangial cell growth may be involved in the pathogenesis of diabetic nephropathy.
Collapse
Affiliation(s)
- Yuki Suzaki
- Department of Pharmacology and Pediatrics, The University of Tokushima School of Medicine, Tokushima, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Xu BE, Stippec S, Lenertz L, Lee BH, Zhang W, Lee YK, Cobb MH. WNK1 activates ERK5 by an MEKK2/3-dependent mechanism. J Biol Chem 2003; 279:7826-31. [PMID: 14681216 DOI: 10.1074/jbc.m313465200] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
WNK1 belongs to a unique protein kinase family that lacks the catalytic lysine in its normal position. Mutations in human WNK1 and WNK4 have been implicated in causing a familial form of hypertension. Here we report that overexpression of WNK1 led to increased activity of cotransfected ERK5 in HEK293 cells. ERK5 activation was blocked by the MEK5 inhibitor U0126 and expression of a dominant negative MEK5 mutant. Expression of dominant negative mutants of MEKK2 and MEKK3 also blocked activation of ERK5 by WNK1. Moreover, both MEKK2 and MEKK3 coimmunoprecipitated with endogenous WNK1 from cell lysates. WNK1 phosphorylated both MEKK2 and -3 in vitro, and MEKK3 was activated by WNK1 in 293 cells. Finally, ERK5 activation by epidermal growth factor was attenuated by suppression of WNK1 expression using small interfering RNA. Taken together, these results place WNK1 in the ERK5 MAP kinase pathway upstream of MEKK2/3.
Collapse
Affiliation(s)
- Bing-E Xu
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
Cameron SJ, Abe JI, Malik S, Che W, Yang J. Differential role of MEK5alpha and MEK5beta in BMK1/ERK5 activation. J Biol Chem 2003; 279:1506-12. [PMID: 14583600 DOI: 10.1074/jbc.m308755200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Big mitogen-activated protein kinase 1/extracellular-regulated kinase 5 (BMK1/ERK5) is regulated sequentially by a series of upstream MAP kinase kinases (MEKs) in a signaling cascade. MEKs activate their downstream MAPK by phosphorylation of threonine and tyrosine in the T- X-Y motif. MEK5 is the upstream BMK1 kinase and exists as naturally occurring splice variants, MEK5alpha and MEK5beta. The full-length MEK5 (MEK5alpha) is 89 amino acids longer than MEK5beta at the N terminus, but the precise functional difference between the two splice variants is not known. Dual phosphorylation site mutation of MEK5alpha (Ser-311 --> Asp and Thr- 315 --> Asp; MEK5alpha(S311D/T315D)) activated BMK1, but the corresponding dual phosphorylation sites mutant of MEK5beta could not induce BMK1 kinase activation or nuclear translocation. Furthermore, MEK5beta inhibited epidermal growth factor-induced BMK1 activation and MEK5alpha(S311D/T315D)-induced MEF2 transcriptional activity. Both MEK5alpha and MEK5beta individually co-immunoprecipitated with BMK1, but the presence of MEK5beta prevented association of MEK5alpha with BMK1 suggesting a mechanistic basis for the dominant-negative behavior of MEK5beta on BMK1 activation. The ratio of MEK5alpha to MEK5beta expression was higher in cancer cell lines, and overexpression of MEK5beta-inhibited serum-induced DNA synthesis. These data suggest that alternative splicing of MEK5alpha and MEK5beta may play a critical role in BMK1 activation and subsequent cell proliferation.
Collapse
Affiliation(s)
- Scott J Cameron
- Department of Pharmacology/Physiology, Center for Cardiovascular Research, Department of Anesthesiology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | | | | | | | | |
Collapse
|
36
|
Liu L, Cavanaugh JE, Wang Y, Sakagami H, Mao Z, Xia Z. ERK5 activation of MEF2-mediated gene expression plays a critical role in BDNF-promoted survival of developing but not mature cortical neurons. Proc Natl Acad Sci U S A 2003; 100:8532-7. [PMID: 12826611 PMCID: PMC166263 DOI: 10.1073/pnas.1332804100] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase family whose biological function in the CNS has not been defined. In contrast to ERK1 and ERK2, which are activated by neurotrophins (NTs), cAMP, and neuronal activity in cortical neurons, ERK5 is activated only by NTs. Here, we report that ERK5 expression is high in the brain during early embryonic development but declines as the brain matures to almost undetectable levels by postnatal day (P) 49. Interestingly, expression of a dominant-negative ERK5 blocked brain-derived neurotrophic factor protection against trophic withdrawal in primary cortical neurons cultured from embryonic day (E) 17 but not P0. Furthermore, expression of a dominant-negative ERK5 induced apoptosis in E17 but not P0 cortical neurons maintained in the presence of serum. We also present evidence that ERK5 protection of E17 cortical neurons may be mediated through myocyte enhancer factor 2-induced gene expression. These data suggest that ERK5 activation of myocyte enhancer factor 2-induced gene expression may play an important and novel role in the development of the CNS by mediating NT-promoted survival of embryonic neurons.
Collapse
Affiliation(s)
- Lidong Liu
- Departments of Environmental Health and
Pharmacology,
Graduate Program in Neurobiology and Behavior,
and Graduate Program in Molecular and Cell
Biology, University of Washington, Seattle, WA 98195-7234; and
The Liver Research Center, Department of
Medicine, Rhode Island Hospital and Brown University of Medicine, Providence,
RI 02903
| | - Jane E. Cavanaugh
- Departments of Environmental Health and
Pharmacology,
Graduate Program in Neurobiology and Behavior,
and Graduate Program in Molecular and Cell
Biology, University of Washington, Seattle, WA 98195-7234; and
The Liver Research Center, Department of
Medicine, Rhode Island Hospital and Brown University of Medicine, Providence,
RI 02903
| | - Yupeng Wang
- Departments of Environmental Health and
Pharmacology,
Graduate Program in Neurobiology and Behavior,
and Graduate Program in Molecular and Cell
Biology, University of Washington, Seattle, WA 98195-7234; and
The Liver Research Center, Department of
Medicine, Rhode Island Hospital and Brown University of Medicine, Providence,
RI 02903
| | - Hiroyuki Sakagami
- Departments of Environmental Health and
Pharmacology,
Graduate Program in Neurobiology and Behavior,
and Graduate Program in Molecular and Cell
Biology, University of Washington, Seattle, WA 98195-7234; and
The Liver Research Center, Department of
Medicine, Rhode Island Hospital and Brown University of Medicine, Providence,
RI 02903
| | - Zixu Mao
- Departments of Environmental Health and
Pharmacology,
Graduate Program in Neurobiology and Behavior,
and Graduate Program in Molecular and Cell
Biology, University of Washington, Seattle, WA 98195-7234; and
The Liver Research Center, Department of
Medicine, Rhode Island Hospital and Brown University of Medicine, Providence,
RI 02903
| | - Zhengui Xia
- Departments of Environmental Health and
Pharmacology,
Graduate Program in Neurobiology and Behavior,
and Graduate Program in Molecular and Cell
Biology, University of Washington, Seattle, WA 98195-7234; and
The Liver Research Center, Department of
Medicine, Rhode Island Hospital and Brown University of Medicine, Providence,
RI 02903
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
37
|
Santini V, Scappini B, Indik ZK, Gozzini A, Ferrini PR, Schreiber AD. The carboxy-terminal region of the granulocyte colony-stimulating factor receptor transduces a phagocytic signal. Blood 2003; 101:4615-22. [PMID: 12586631 DOI: 10.1182/blood-2002-07-2271] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Granulocyte colony-stimulating factor (G-CSF) induces proliferation, maturation, and functional activities of myeloid progenitors and mature neutrophils through a specific receptor, the G-CSF-R. Different signals are mediated by distinct regions of the cytoplasmic domain of G-CSF-R, but the precise role of each region has not yet been fully clarified. We evaluated the involvement of Syk kinase, essential in mediating phagocytic signals by Fcgamma receptors, in G-CSF-induced phagocytosis, using murine myeloid 32D cells transfected with wild-type (WT) human G-CSF-R (hG-CSF-R) or with a G-CSF-R mutant truncated at cytoplasmic amino acid 715. The G-CSF-R mutant lacks the immunoreceptor tyrosine-based activation motif (ITAM), putative binding site for Syk. Following treatment of WT hG-CSF-R transfectants with IgG-coated particles, there was a significant increase in phagocytosis in G-CSF-stimulated cells, in which Syk tyrosine phosphorylation occurred, paralleled by enhancement of its tyrosine kinase activity. In the mutant transfectants, no significant increase in phagocytosis or Syk tyrosine phosphorylation occurred after stimulation with G-CSF. We also demonstrated that tyrosine phosphorylation of the Src kinases Hck and Lyn occurs following G-CSF stimulation of cells expressing WT G-CSF-R, but that Hck is not phosphorylated in mutant G-CSF-R transfectants. The increase in phagocytosis following G-CSF stimulation cannot be attributed to a rapid de novo increase in expression of Fcgamma receptors. G-CSF induced expression of Fcgamma receptors only after prolonged stimulation. Our data provide evidence that the carboxy-terminal region of G-CSF-R plays a role in the phagocytosis of IgG-coated particles and that Syk and Hck kinase tyrosine phosphorylation is involved.
Collapse
Affiliation(s)
- Valeria Santini
- Department of Hematology, University of Florence, Florence, Italy.
| | | | | | | | | | | |
Collapse
|
38
|
Szyper-Kravitz M, Uziel O, Shapiro H, Radnay J, Katz T, Rowe JM, Lishner M, Lahav M. Granulocyte colony-stimulating factor administration upregulates telomerase activity in CD34+ haematopoietic cells and may prevent telomere attrition after chemotherapy. Br J Haematol 2003; 120:329-36. [PMID: 12542495 DOI: 10.1046/j.1365-2141.2003.04043.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hematopoietic reconstitution could be associated with premature ageing of the transplanted cells and a high frequency of myelodysplastic syndrome and secondary leukaemia. Telomere length decreases with cell divisions and age, and at a crucial length it is associated with chromosomal instability and cell senescence. Telomerase is a reverse transcriptase enzyme that adds nucleotides to chromosomal ends. Most somatic cells lack telomerase activity yet haematopoietic stem cells retain low levels of telomerase. Some studies have found that chemotherapy and stem cell transplantation lead to the accelerated shortening of telomere length. As granulocyte colony-stimulating factor (G-CSF) is routinely used in the mobilization of stem cells for transplantation, we evaluated its effects on telomerase activity and regulation, and on telomere dynamics, in normal donors and selected lymphoma patients. Administration of G-CSF increased telomerase activity in CD34+ haematopoietic cells compared with controls. In marrow-derived CD34+ cells, telomerase activity increased sevenfold, compared with a 14-fold increase in peripheral-blood-mobilized CD34+ cells. A parallel increase in the expression of human telomerase enzyme reverse transcriptase RNA and protein kinase C alpha occurred. In addition, G-CSF administration to five lymphoma patients after consecutive courses of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy, resulted in telomere length preservation or elongation, as opposed to marked attrition in patients who did not receive growth factors. We conclude that the in vivo administration of G-CSF prevents or attenuates telomere attrition associated with chemotherapy administration. This attenuation may contribute to the preservation of telomere integrity inG-CSF-primed transplanted stem cells.
Collapse
|
39
|
Abstract
ERK5 activity is increased by agents known to activate receptor tyrosine kinases, G-protein coupled receptors, and stress response pathways. We now find a role for cAMP in the regulation of ERK5. ERK5 is activated by forskolin, isoproterenol, and epinephrine in NIH3T3 cells and C2C12 myoblasts. ERK1/2 are also activated by cAMP in NIH3T3 cells, but not in C2C12 myoblasts, demonstrating differential regulation of ERK5 and ERK1/2 by cAMP. We examined the effect of cell context on activation of ERK5 and discovered ERK5 activity is inhibited, rather than activated, by cAMP in confluent, serum-deprived NIH3T3 cells and C2C12 myoblasts. Our results suggest that regulation of MAP kinase pathways by cAMP is not only dictated by cell type, but also by cell context.
Collapse
Affiliation(s)
- Gray W Pearson
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75390-9041, USA
| | | |
Collapse
|
40
|
Weldon CB, Scandurro AB, Rolfe KW, Clayton JL, Elliott S, Butler NN, Melnik LI, Alam J, McLachlan JA, Jaffe BM, Beckman BS, Burow ME. Identification of mitogen-activated protein kinase kinase as a chemoresistant pathway in MCF-7 cells by using gene expression microarray. Surgery 2002; 132:293-301. [PMID: 12219026 DOI: 10.1067/msy.2002.125389] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Components of the mitogen-activated protein kinase (MAPK) cascade have been implicated in apoptotic regulation. This study used gene expression profiling analysis to identify and implicate mitogen-activated protein kinase kinase (MEK5)-BMK1 (big mitogen-activated kinase-1)/extracellular signal related protein kinase (ERK5) pathway as a novel target involved in chemoresistance. METHODS Differential gene expression between apoptotically sensitive (APO+) and apoptotically resistant (APO-) MCF-7 cell variants was determined by using microarray and confirmed by reverse transcriptase- polymerase chain reaction (RT-PCR). An apoptotic/viability reporter gene assay was used to deter-mine the effects of the transfection of a dominant-negative mutant of BMK1 (BMK1/DN) in conjunction with apoptotic-inducing agents (etoposide, tumor necrosis factor-alpha [TNF], or TNF-related apoptosis-inducing ligand [TRAIL]), with or without phorbol ester (PMA). RESULTS Of the 1186 genes detected through microarray analysis, MEK5 was increased 22-fold in APO- cells. Overexpression of MEK5 was confirmed by using RT-PCR analysis. Expression of BMK1/DN alone resulted in a dose-dependent increase in cell death versus control (P <.05). In addition, BMK1/DN enhanced the sensitivity of MCF-7 cells to treatment-induced cell death (P <.05). The ability of PMA to partially suppress TRAIL- and TNF-induced cell death was inhibited by BMK1/DN. However, only TRAIL-induced activity suppression reached statistical significance (P <.05). CONCLUSIONS The overexpression of MEK5 in APO- MCF-7 breast carcinoma cells shows that this MAPK signaling protein represents a potent survival molecule. Molecular inhibition of MEK5 signaling may represent a mechanism for sensitizing cancer cells to chemotherapeutic regimens.
Collapse
Affiliation(s)
- Christopher B Weldon
- Department of Surgery, Tulane University School of Medicine and Tulane University School of Public Health & Tropical Medicine, New Orleans 70112, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Garcia L, Garcia F, Llorens F, Unzeta M, Itarte E, Gómez N. PP1/PP2A phosphatases inhibitors okadaic acid and calyculin A block ERK5 activation by growth factors and oxidative stress. FEBS Lett 2002; 523:90-4. [PMID: 12123810 DOI: 10.1016/s0014-5793(02)02950-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Okadaic acid is an inhibitor of the protein Ser/Thr phosphatases PP1 and PP2A, which blocks the activation of extracellular signal-regulated protein kinase 5 (ERK5), a member of the MAP kinase family activated by growth factors and several types of stressors. The blocking of ERK5 activation by okadaic acid was observed in HeLa cells exposed to epidermal growth factor and H(2)O(2) as well as in PC12 cells stimulated by nerve growth factor and H(2)O(2). Calyculin A, another PP1 and PP2A inhibitor, behaved similarly although these compounds are not structurally related. This suggests that either PP1 or PP2A or both are necessary for ERK5 activation. Protein kinase C (PKC) acts as a negative regulator of the ERK5 activation pathway, however our data suggest that the effects of PKC and the phosphatase are unrelated.
Collapse
Affiliation(s)
- Lourdes Garcia
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | | | | | | | | | | |
Collapse
|
42
|
Guizzetti M, Costa LG. Effect of ethanol on protein kinase Czeta and p70S6 kinase activation by carbachol: a possible mechanism for ethanol-induced inhibition of glial cell proliferation. J Neurochem 2002; 82:38-46. [PMID: 12091463 DOI: 10.1046/j.1471-4159.2002.00942.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The signal transduction pathways that mediate the mitogenic response of muscarinic acetylcholine receptors in astroglial cells have not been fully elucidated. In this study we investigated the activation of p70S6 kinase (p70S6K) by carbachol in 1321 N1 astroctyoma cells. Carbachol induced a dose- and time-dependent activation of p70S6K, as evidenced by increased phosphorylation at Thr-389, Thr-421 and Ser-424, by increased p70S6K activity, and by a shift in its molecular weight. Activation of p70S6K was mediated by M3 muscarinic acetylcholine receptors (mAChRs) and was inhibited by two phosphatidylinositol-3-kinase (PI3-K) inhibitors, by a pseudosubstrate to protein kinase C (PKC) zeta, and by the p70S6K inhibitor rapamycin. Carbachol-induced DNA synthesis was strongly inhibited by rapamycin, suggesting that p70S6K activation plays an important role in carbachol-induced cell proliferation. Ethanol (25-100 mm) has been shown to inhibit carbachol-induced proliferation of astroglial cells. In the same range of concentrations, ethanol also inhibits carbachol-induced activation of PKCzeta and of p70S6K. On the other hand, inhibition of PI3-kinase was only observed at higher ethanol concentrations. These results indicate that activation of the PKCzeta--> p70S6K pathway by M3 mAChRs may play a role in the increased DNA synthesis and may represent a target for ethanol-induced inhibition of astroglial cell proliferation.
Collapse
Affiliation(s)
- Marina Guizzetti
- Department of Environmental Health, University of Washington, 4229 Roosevelt Way NE #100, Seattle, WA 98105, USA.
| | | |
Collapse
|
43
|
Duarte RF, Frank DA. The synergy between stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF): molecular basis and clinical relevance. Leuk Lymphoma 2002; 43:1179-87. [PMID: 12152985 DOI: 10.1080/10428190290026231] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stem cell factor (SCF), an essential growth factor in normal hematopoiesis, exerts potent effects when combined with cytokines. In particular, its synergy with granulocyte colony-stimulating factor (G-CSF) results in important biologic responses. These include enhancement of ex vivo long-term expansion of human primitive hematopoietic cells and increased mobilization of peripheral blood progenitor cells (PBPC) for transplantation. Despite the clinical importance of the interaction between SCF and G-CSF, the absence of a model system in which it could be studied at the cellular level had impaired the ability to understand the basis of their co-operation. To overcome this impediment, a system was recently generated which recapitulates the biologic synergy between SCF and G-CSF. MO7e-G cells have allowed the identification of key events in the synergistic actions of these cytokines on proliferation and gene expression. Among the biochemical and molecular events mediated by these cytokines are the down-regulation of p27kip1 and the independent phosphorylation of STAT3 on tyrosine and serine residues. Recent work has provided increasing evidence for the clinical importance of the combination of SCF and G-CSF. The elucidation of the intracellular events triggered by their receptors is now shedding light on key mediators of their synergistic effects. The identification of these pathways is of considerable importance for understanding fundamental aspects of hematopoiesis, and as potential targets for therapeutic intervention.
Collapse
Affiliation(s)
- Rafael F Duarte
- The Anthony Nolan Research Institute, The Royal Free Campus and UCL Medical School, London, United Kingdom
| | | |
Collapse
|
44
|
Dong F, Qiu Y, Yi T, Touw IP, Larner AC. The carboxyl terminus of the granulocyte colony-stimulating factor receptor, truncated in patients with severe congenital neutropenia/acute myeloid leukemia, is required for SH2-containing phosphatase-1 suppression of Stat activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:6447-52. [PMID: 11714811 DOI: 10.4049/jimmunol.167.11.6447] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The G-CSF receptor transduces signals that regulate the proliferation, differentiation, and survival of myeloid cells. A subgroup of patients with severe congenital neutropenia (SCN) has been shown to harbor mutations in the G-CSF receptor gene that resulted in the truncation of the receptor's carboxyl-terminal region. SCN patients with mutations in the G-CSF receptor gene are predisposed to acute myeloid leukemia. The truncated receptors from SCN/acute myeloid leukemia patients mediate augmented and sustained activation of Stat transcription factors and are accordingly hyperactive in inducing cell proliferation and survival but are defective in inducing differentiation. Little is known about the molecular mechanisms underlying the negative role of the receptor's carboxyl terminus in the regulation of Stat activation and cell proliferation/survival. In this study, we provide evidence that SH2-containing phosphatase-1 (SHP-1) plays a negative regulatory role in G-CSF-induced Stat activation. We also demonstrate that the carboxyl terminus of the G-CSF receptor is required for SHP-1 down-regulation of Stat activation induced by G-CSF. Our results indicate further that this regulation is highly specific because SHP-1 has no effect on the activation of Akt and extracellular signal-related kinase1/2 by G-CSF. The data together strongly suggest that SHP-1 may represent an important mechanism by which the carboxyl terminus of the G-CSF receptor down-regulates G-CSF-induced Stat activation and thereby inhibits cell proliferation and survival in response to G-CSF.
Collapse
Affiliation(s)
- F Dong
- Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
| | | | | | | | | |
Collapse
|