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Ryu HH, Kim SY, Lee YS. Connecting the dots between SHP2 and glutamate receptors. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:129-135. [PMID: 32140036 PMCID: PMC7043995 DOI: 10.4196/kjpp.2020.24.2.129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 11/18/2022]
Abstract
SHP2 is an unusual protein phosphatase that functions as an activator for several signaling pathways, including the RAS pathway, while most other phosphatases suppress their downstream signaling cascades. The physiological and pathophysiological roles of SHP2 have been extensively studied in the field of cancer research. Mutations in the PTPN11 gene which encodes SHP2 are also highly associated with developmental disorders, such as Noonan syndrome (NS), and cognitive deficits including learning disabilities are common among NS patients. However, the molecular and cellular mechanism by which SHP2 is involved in cognitive functions is not well understood. Recent studies using SHP2 mutant mice or pharmacological inhibitors have shown that SHP2 plays critical role in learning and memory and synaptic plasticity. Here, we review the recent studies demonstrating that SHP2 is involved in synaptic plasticity, and learning and memory, by the regulation of the expression and/or function of glutamate receptors. We suggest that each cell type may have distinct paths connecting the dots between SHP2 and glutamate receptors, and these paths may also change with aging.
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Affiliation(s)
- Hyun-Hee Ryu
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sun Yong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Yong-Seok Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea
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2
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Garg M, Wahid M, Khan F. Regulation of peripheral and central immunity: Understanding the role of Src homology 2 domain-containing tyrosine phosphatases, SHP-1 & SHP-2. Immunobiology 2019; 225:151847. [PMID: 31561841 DOI: 10.1016/j.imbio.2019.09.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/25/2019] [Accepted: 09/03/2019] [Indexed: 01/20/2023]
Abstract
Protein tyrosine phosphorylation is a potent post-translational regulatory mechanism necessary for maintaining normal physiological functioning of immune cells and it is under the stringent control of antagonizing actions of Protein tyrosine phosphatases and kinases. Two such important Non-Receptor protein tyrosine phosphatases, SHP-1 and SHP-2, have been found to be expressed in immune cells and reported to be key regulators of immune cell development, functions, and differentiation by modulating the duration and amplitude of the downstream cascade transduced via receptors. They also have been conceded as the immune checkpoints & therapeutic targets and hence, it is important to understand their significance intricately. This review compares the roles of these two important cytoplasmic PTPs, SHP1 & SHP-2 in the regulation of peripheral as well as central immunity.
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Affiliation(s)
- Manika Garg
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi-110062, India.
| | - Mohd Wahid
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia.
| | - Farah Khan
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi-110062, India.
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3
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Ryu HH, Kim T, Kim JW, Kang M, Park P, Kim YG, Kim H, Ha J, Choi JE, Lee J, Lim CS, Kim CH, Kim SJ, Silva AJ, Kaang BK, Lee YS. Excitatory neuron-specific SHP2-ERK signaling network regulates synaptic plasticity and memory. Sci Signal 2019; 12:12/571/eaau5755. [PMID: 30837304 DOI: 10.1126/scisignal.aau5755] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mutations in RAS signaling pathway components cause diverse neurodevelopmental disorders, collectively called RASopathies. Previous studies have suggested that dysregulation in RAS-extracellular signal-regulated kinase (ERK) activation is restricted to distinct cell types in different RASopathies. Some cases of Noonan syndrome (NS) are associated with gain-of-function mutations in the phosphatase SHP2 (encoded by PTPN11); however, SHP2 is abundant in multiple cell types, so it is unclear which cell type(s) contribute to NS phenotypes. Here, we found that expressing the NS-associated mutant SHP2D61G in excitatory, but not inhibitory, hippocampal neurons increased ERK signaling and impaired both long-term potentiation (LTP) and spatial memory in mice, although endogenous SHP2 was expressed in both neuronal types. Transcriptomic analyses revealed that the genes encoding SHP2-interacting proteins that are critical for ERK activation, such as GAB1 and GRB2, were enriched in excitatory neurons. Accordingly, expressing a dominant-negative mutant of GAB1, which reduced its interaction with SHP2D61G, selectively in excitatory neurons, reversed SHP2D61G-mediated deficits. Moreover, ectopic expression of GAB1 and GRB2 together with SHP2D61G in inhibitory neurons resulted in ERK activation. These results demonstrate that RAS-ERK signaling networks are notably different between excitatory and inhibitory neurons, accounting for the cell type-specific pathophysiology of NS and perhaps other RASopathies.
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Affiliation(s)
- Hyun-Hee Ryu
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - TaeHyun Kim
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Jung-Woong Kim
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Minkyung Kang
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Pojeong Park
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Yong Gyu Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Hyopil Kim
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Jiyeon Ha
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Ja Eun Choi
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Jisu Lee
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Chae-Seok Lim
- Department of Pharmacology, Wonkwang University School of Medicine, Iksan 54538, Korea
| | - Chul-Hong Kim
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Alcino J Silva
- Department of Neurobiology, Integrative Center for Learning and Memory, Brain Research Institute, University of California Los Angeles, California, CA 90095, USA
| | - Bong-Kiun Kaang
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Yong-Seok Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea. .,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea
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Ding X, Yang W, Liu XD, Yang X, Wang HM, Tai J. Spinal SHP2 Contributes to Exaggerated Incisional Pain in Adult Rats Subjected to Neonatal and Adult Incisions via PI3K. Neuroscience 2018; 385:102-120. [PMID: 29909075 DOI: 10.1016/j.neuroscience.2018.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 05/23/2018] [Accepted: 06/07/2018] [Indexed: 12/24/2022]
Abstract
Neonatal injury-induced exaggeration of pain hypersensitivity after adult trauma is a significant clinical challenge. However, the underlying mechanisms remain poorly understood. Growing evidence shows that spinal Src homology-2 domain-containing protein tyrosine phosphatase-2 (SHP2) contributes to chronic pain in adult rodents. Here we demonstrated that the phosphorylation and expression of SHP2 in synaptosomal fraction of the spinal dorsal horn are elevated in adult rats subjected to neonatal and adult incisions (nIN-IN), and the upregulation of SHP2 is highly correlated with pain hypersensitivity. Intrathecal blockade of SHP2 phosphorylation using a SHP2 protein tyrosine phosphatase inhibitor NSC-87877, or knockdown of SHP2 by intrathecal delivery of small interfering RNA (siRNA), ameliorates mechanical allodynia and heat hyperalgesia in nIN-IN rats. Moreover, the expression of phosphatidylinositol 3-kinase (PI3K) in the spinal dorsal horn is significantly increased in nIN-IN rats. Intrathecal application of PI3K inhibitor, LY294002 or wortmannin, alleviates pain hypersensitivity in nIN-IN rats. Additionally, intrathecal administration of NSC-87877 or SHP2 siRNA attenuates the upregulation of PI3K. Finally, no alternation of SHP2 phosphorylation in the dorsal root ganglion and dorsal root of nIN-IN rats as well as PI3K expression in the dorsal root of nIN-IN rats intrathecally treated with NSC-87877 or SHP2 siRNA is observed. These results suggest that the phosphorylation and expression of SHP2 in the spinal dorsal horn play vital roles in neonatal incision-induced exaggeration of adult incisional pain via PI3K. Thus, SHP2 and PI3K may serve as potential therapeutic targets for exaggerated incisional pain induced by neonatal and adult injuries.
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Affiliation(s)
- Xu Ding
- Nutrition Research Unit, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Wei Yang
- Department of Surgical Oncology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Xiao-Dan Liu
- Department of Pathology, Peking University, Beijing, China
| | - Xi Yang
- Department of Laboratory Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Huan-Min Wang
- Department of Surgical Oncology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Jun Tai
- Beijing Key Laboratory for Pediatric Diseases of Otolaryngology, Head and Neck Surgery; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
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Shim SY, Jeong HJ, Park HJ, Kwon EY, Kim BM, Choi YJ, Choi YH, Cho SJ, Choi JH, Park EA. Functional variation of SHP-2 promoter is associated with preterm birth and delayed myelination and motor development in preterm infants. Sci Rep 2017; 7:6052. [PMID: 28729690 PMCID: PMC5519743 DOI: 10.1038/s41598-017-06401-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/13/2017] [Indexed: 12/18/2022] Open
Abstract
Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP-2) is a cytoplasmic tyrosine phosphatase that is highly expressed in hematopoietic cells and in the CNS and exerts opposite effects on signal transduction by exerting a neuroprotective or proapoptotic effect. Several mutations of SHP-2 have been found in children with myeloproliferative disorders or malignant leukemia, and some of these can affect brain development. In the present study, we aimed to identify and functionally characterize genetic variations in SHP-2 in 72 preterm and 58 full-term infants and to evaluate the effect of the variations on neurodevelopment in preterm infants. Twelve genetic variations were identified. Among them, two variations in the SHP-2 promoter, g.-317C > T and g.-273G > A, were found to significantly increase promoter activity, and the frequency of g.-273G > A was higher in preterm infants than in full-term infants. Two transcription factors, NF-κB and GABPα, were found to be involved in the transcriptional regulation of SHP-2 by the two above-mentioned variations. In particular, we found that g.-273G > A was significantly associated with delayed myelination and poor motor development in preterm infants. Our results suggest that a functional promoter variation in SHP-2 is associated with spontaneous preterm birth itself as well as white matter myelination and neurodevelopment.
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Affiliation(s)
- So-Yeon Shim
- Division of Neonatology, Department of Pediatrics, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Hye Jin Jeong
- Neuroscience Research Institute, Gachon University, Incheon, Korea
| | - Hyo Jin Park
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Eun Young Kwon
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Bo Min Kim
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Yang Ji Choi
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Youn-Hee Choi
- Department of Physiology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Su Jin Cho
- Division of Neonatology, Department of Pediatrics, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Ji Ha Choi
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea.
| | - Eun Ae Park
- Division of Neonatology, Department of Pediatrics, School of Medicine, Ewha Womans University, Seoul, Korea.
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Noonan syndrome-associated SHP2 mutation differentially modulates the expression of postsynaptic receptors according to developmental maturation. Neurosci Lett 2017; 649:41-47. [PMID: 28366775 DOI: 10.1016/j.neulet.2017.03.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/07/2017] [Accepted: 03/20/2017] [Indexed: 11/20/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system, and related signaling involves both AMPA and NMDA subtype receptors. The expression of glutamate receptors is dynamically regulated during development. Recent studies showed that the dysregulation of glutamate receptor expression and function is associated with neurodevelopmental disorders including intellectual disability. Previously, a Noonan syndrome (NS)-associated SHP2 mutation (SHP2D61G) was shown to increase the synaptic delivery of AMPA receptor, subsequently impairing synaptic plasticity and learning in adult mice. However, how the mutant SHP2 affects glutamate receptor expression during development is not known. Here, we found that the SHP2D61G differentially regulates the expression of AMPA and NMDA receptors depending on the stage of neuronal maturation. In cultured neurons (immature stage; DIV 6), overexpression of SHP2D61G significantly increased the average size and the number of NMDA receptor-containing particles, but not those with AMPA receptors. In early matured neurons (DIV 12), SHP2D61G significantly increased only the average size of AMPA receptor particles, and subsequently increased their number in matured neurons (DIV 18). Importantly, all the changes described above for SHP2D61G neurons were reversed by inhibiting MAPK. These data demonstrate that the increased activation of MAPK signaling pathway by SHP2D61G could deregulate the surface expression of synaptic receptors during neuronal development, which likely contributes to cognitive impairments in NS patients.
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7
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Gu W, Prasadam I, Yu M, Zhang F, Ling P, Xiao Y, Yu C. Gamma tocotrienol targets tyrosine phosphatase SHP2 in mammospheres resulting in cell death through RAS/ERK pathway. BMC Cancer 2015; 15:609. [PMID: 26315028 PMCID: PMC4552156 DOI: 10.1186/s12885-015-1614-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 08/21/2015] [Indexed: 12/11/2022] Open
Abstract
Background There is increasing evidence supporting the concept of cancer stem cells (CSCs), which are responsible for the initiation, growth and metastasis of tumors. CSCs are thus considered the target for future cancer therapies. To achieve this goal, identifying potential therapeutic targets for CSCs is essential. Methods We used a natural product of vitamin E, gamma tocotrienol (gamma-T3), to treat mammospheres and spheres from colon and cervical cancers. Western blotting and real-time RT-PCR were employed to identify the gene and protein targets of gamma-T3 in mammospheres. Results We found that mammosphere growth was inhibited in a dose dependent manner, with total inhibition at high doses. Gamma-T3 also inhibited sphere growth in two other human epithelial cancers, colon and cervix. Our results suggested that both Src homology 2 domain-containing phosphatase 1 (SHP1) and 2 (SHP2) were affected by gamma-T3 which was accompanied by a decrease in K- and H-Ras gene expression and phosphorylated ERK protein levels in a dose dependent way. In contrast, expression of self-renewal genes TGF-beta and LIF, as well as ESR signal pathways were not affected by the treatment. These results suggest that gamma-T3 specifically targets SHP2 and the RAS/ERK signaling pathway. Conclusions SHP1 and SHP2 are potential therapeutic targets for breast CSCs and gamma-T3 is a promising natural drug for future breast cancer therapy. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1614-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wenyi Gu
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, The corner of Cooper Rd. St Lucia, Brisbane, QLD 4072, Australia.
| | - Indira Prasadam
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
| | - Meihua Yu
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, The corner of Cooper Rd. St Lucia, Brisbane, QLD 4072, Australia.
| | - Fengxia Zhang
- School of Biomedical Science, the University of Queensland, Brisbane, Australia.
| | - Patrick Ling
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
| | - Yin Xiao
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
| | - Chengzhong Yu
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, The corner of Cooper Rd. St Lucia, Brisbane, QLD 4072, Australia.
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Yoshikawa A, Kamide T, Hashida K, Ta HM, Inahata Y, Takarada-Iemata M, Hattori T, Mori K, Takahashi R, Matsuyama T, Hayashi Y, Kitao Y, Hori O. Deletion of Atf6α impairs astroglial activation and enhances neuronal death following brain ischemia in mice. J Neurochem 2015; 132:342-53. [PMID: 25351847 DOI: 10.1111/jnc.12981] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/22/2014] [Accepted: 10/22/2014] [Indexed: 01/02/2023]
Abstract
To dissect the role of endoplasmic reticulum (ER) stress and unfolded protein response in brain ischemia, we investigated the relevance of activating transcription factor 6α (ATF6α), a master transcriptional factor in the unfolded protein response, after permanent middle cerebral artery occlusion (MCAO) in mice. Enhanced expression of glucose-regulated protein78, a downstream molecular chaperone of ATF6α, was observed in both neurons and glia in the peri-infarct region of wild-type mice after MCAO. Analysis using wild-type and Atf6α(-/-) mice revealed a larger infarct volume and increased cell death in the peri-ischemic region of Atf6α(-/-) mice 5 days after MCAO. These phenotypes in Atf6α(-/-) mice were associated with reduced levels of astroglial activation/glial scar formation, and a spread of tissue damage into the non-infarct area. Further analysis in mice and cultured astrocytes revealed that signal transducer and activator of transcription 3 (STAT3)-glial fibrillary acidic protein signaling were diminished in Atf6α(-/-) astrocytes. A chemical chaperone, 4-phenylbutyrate, restored STAT3-glial fibrillary acidic protein signaling, while ER stressors, such as tunicamycin and thapsigargin, almost completely abolished signaling in cultured astrocytes. Furthermore, ER stress-induced deactivation of STAT3 was mediated, at least in part, by the ER stress-responsive tyrosine phosphatase, TC-PTP/PTPN2. These results suggest that ER stress plays critical roles in determining the level of astroglial activation and neuronal survival after brain ischemia.
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Affiliation(s)
- Akifumi Yoshikawa
- Department of Neurosurgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa City, Ishikawa, Japan
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Jo A, Park H, Lee SH, Ahn SH, Kim HJ, Park EM, Choi YH. SHP-2 binds to caveolin-1 and regulates Src activity via competitive inhibition of CSK in response to H2O2 in astrocytes. PLoS One 2014; 9:e91582. [PMID: 24632723 PMCID: PMC3954793 DOI: 10.1371/journal.pone.0091582] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 02/12/2014] [Indexed: 01/26/2023] Open
Abstract
Reactive oxygen species (ROS) regulate diverse cellular functions by triggering signal transduction events, such as Src and mitogen-activated protein (MAP) kinases. Here, we report the role of caveolin-1 and Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP-2) in H2O2-induced signaling pathway in brain astrocytes. H2O2-mediated oxidative stress induced phosphorylation of caveolin-1 and association between p-caveolin-1 and SHP-2. SHP-2 specifically bound to wild-type caveolin-1 similarly to c-Src tyrosine kinase (CSK), but not to phosphorylation-deficient mutant of caveolin-1 (Y14A), and interfered with complex formation between caveolin-1 and CSK. In the presence of CSK siRNA, binding between caveolin-1 and SHP-2 was enhanced by H2O2 treatment, which led to reduced Src phosphorylation at tyrosine (Tyr) 530 and enhanced Src phosphorylation at Tyr 419. In contrast, siRNA targeting of SHP-2 facilitated H2O2-mediated interaction between caveolin-1 and CSK and enhanced Src phosphorylation at Tyr 530, leading to subsequent decrease in Src downstream signaling, such as focal adhesion kinase (FAK) and extracellular signal-related kinase (ERK). Our results collectively indicate that SHP-2 alters Src kinase activity by interfering with the complex formation between CSK and phosphotyrosine caveolin-1 in the presence of H2O2, thus functions as a positive regulator in Src signaling under oxidative stress in brain astrocytes.
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Affiliation(s)
- Ara Jo
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
| | - Hyunju Park
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
| | - Sung-Hee Lee
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
| | - So-Hee Ahn
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
| | - Hee Ja Kim
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
| | - Eun-Mi Park
- Department of Pharmacology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
| | - Youn-Hee Choi
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul, Korea
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Huang YS, Cheng CY, Chueh SH, Hueng DY, Huang YF, Chu CM, Wu ST, Tai MC, Liang CM, Liao MH, Chen CC, Shen LH, Ma KH. Involvement of SHP2 in focal adhesion, migration and differentiation of neural stem cells. Brain Dev 2012; 34:674-84. [PMID: 22118986 DOI: 10.1016/j.braindev.2011.10.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 10/10/2011] [Accepted: 10/26/2011] [Indexed: 11/25/2022]
Abstract
OBJECTIVES SHP2 (Src-homology-2 domain-containing protein tyrosine phosphatase) plays an important role in cell adhesion, migration and cell signaling. However, its role in focal adhesion, differentiation and migration of neural stem cells is still unclear. METHODS In this study, rat neurospheres were cultured in suspension and differentiated neural stem cells were cultured on collagen-coated surfaces. RESULTS The results showed that p-SHP2 co-localized with focal adhesion kinase (FAK) and paxillin in neurospheres and in differentiated neural precursor cells, astrocytes, neurons, and oligodendrocytes. Suppression of SHP2 activity by PTP4 or siRNA-mediated SHP2 silencing caused reduction in the cell migration and neurite outgrowth, and thinning of glial cell processes. Differentiation-induced activation of FAK, Src, paxillin, ERK1/2, and RhoA was decreased by SHP2 inactivation. CONCLUSIONS These results indicate that SHP2 is recruited in focal adhesions of neural stem cells and regulates focal adhesion formation. SHP2-mediated regulation of neural differentiation and migration may be related to formation of focal adhesions and RhoA and ERK1/2 activation.
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Affiliation(s)
- Yuahn-Sieh Huang
- Department of Anatomy, Faculty of Medicine, Chung Shan Medical University, Taichung, Taiwan, ROC
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Hagihara K, Zhang EE, Ke YH, Liu G, Liu JJ, Rao Y, Feng GS. Shp2 acts downstream of SDF-1alpha/CXCR4 in guiding granule cell migration during cerebellar development. Dev Biol 2009; 334:276-84. [PMID: 19635473 DOI: 10.1016/j.ydbio.2009.07.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 07/07/2009] [Accepted: 07/20/2009] [Indexed: 10/20/2022]
Abstract
Shp2 is a non-receptor protein tyrosine phosphatase containing two Src homology 2 (SH2) domains that is implicated in intracellular signaling events controlling cell proliferation, differentiation and migration. To examine the role of Shp2 in brain development, we created mice with Shp2 selectively deleted in neural stem/progenitor cells. Homozygous mutant mice exhibited early postnatal lethality with defects in neural stem cell self-renewal and neuronal/glial cell fate specification. Here we report a critical role of Shp2 in guiding neuronal cell migration in the cerebellum. In homozygous mutants, we observed reduced and less foliated cerebellum, ectopic presence of external granule cells and mispositioned Purkinje cells, a phenotype very similar to that of mutant mice lacking either SDF-1alpha or CXCR4. Consistently, Shp2-deficient granule cells failed to migrate toward SDF-1alpha in an in vitro cell migration assay, and SDF-1alpha treatment triggered a robust induction of tyrosyl phosphorylation on Shp2. Together, these results suggest that although Shp2 is involved in multiple signaling events during brain development, a prominent role of the phosphatase is to mediate SDF-1alpha/CXCR4 signal in guiding cerebellar granule cell migration.
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Affiliation(s)
- Kazuki Hagihara
- Burnham Institute for Medical Research, La Jolla, CA 92037, USA
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Krajewska M, Banares S, Zhang EE, Huang X, Scadeng M, Jhala US, Feng GS, Krajewski S. Development of diabesity in mice with neuronal deletion of Shp2 tyrosine phosphatase. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 172:1312-24. [PMID: 18403587 DOI: 10.2353/ajpath.2008.070594] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Obesity and diabetes, termed "diabesity," are serious health problems that are increasing in frequency. However, the molecular mechanisms and neuronal regulation of these metabolic disorders are not fully understood. We show here that Shp2, a widely expressed Src homology 2-containing Tyr phosphatase, plays a critical role in the adult brain to control food intake, energy balance, and metabolism. Mice with a neuron-specific, conditional Shp2 deletion were generated by crossing a pan-neuronal Cre-line (CRE3) with Shp2(flox/flox) mice. These congenic mice, CRE3/Shp2-KO, developed obesity and diabetes and the associated pathophysiological complications that resemble those encountered in humans, including hyperglycemia, hyperinsulinemia, hyperleptinemia, insulin and leptin resistance, vasculitis, diabetic nephropathy, urinary bladder infections, prostatitis, gastric paresis, and impaired spermatogenesis. This mouse model may help to elucidate the molecular mechanisms that lead to the development of diabesity in humans and provide a tool to study the in vivo complications of uncontrolled diabetes.
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Affiliation(s)
- Maryla Krajewska
- Burnham Institute for Medical Research, University of California San Diego, La Jolla, CA 92037, USA
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13
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Feng M, Sun R, Zhang C, Sun E, Wei S, Wan J, Sun R. Increased expression of tyrosine phosphatase SHP2 in experimental pneumococcal meningitis: correlation with tumor necrosis factor-alpha and cerebrospinal fluid pleocytosis. J Child Neurol 2008; 23:287-92. [PMID: 18305318 DOI: 10.1177/0883073807309247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Protein tyrosine phosphatase SHP2 plays a crucial role in the development of the central nervous system. To explore the expression and possible role of SHP2 during the course of bacterial meningitis, this article reports a juvenile rat bacterial meningitis model established by direct intracisternal injection of Streptococcus pneumoniae. Expression of SHP2 at both mRNA and protein levels were assessed. White blood cell count and concentration of tumor necrosis factor-alpha (TNF-alpha) in cerebrospinal fluid (CSF) were also measured. In the cortex, bacterial meningitis led to a significant upregulation of mRNA encoding SHP2. SHP2 protein levels and CSF white blood cell count were positively correlated. However, there was no significant correlation between the levels of SHP2 protein and TNF-alpha concentrations in CSF. These findings do not support an essential role of SHP2 in the pathogenesis of experimental pneumoniae meningitis, but it is possible that SHP2 protein expression may be used as a marker of disease activity.
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Affiliation(s)
- Mei Feng
- Key Laboratory of Clinical and Basic Research, Shandong University Qilu Hospital, Jinan, China
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14
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Chong ZZ, Maiese K. The Src homology 2 domain tyrosine phosphatases SHP-1 and SHP-2: diversified control of cell growth, inflammation, and injury. Histol Histopathol 2007; 22:1251-67. [PMID: 17647198 PMCID: PMC2515712 DOI: 10.14670/hh-22.1251] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Interest in the diverse biology of protein tyrosine phosphatases that are encoded by more than 100 genes in the human genome continues to grow at an accelerated pace. In particular, two cytoplasmic protein tyrosine phosphatases composed of two Src homology 2 (SH2) NH2-terminal domains and a C-terminal protein-tyrosine phosphatase domain referred to as SHP-1 and SHP-2 are known to govern a host of cellular functions. SHP-1 and SHP-2 modulate progenitor cell development, cellular growth, tissue inflammation, and cellular chemotaxis, but more recently the role of SHP-1 and SHP-2 to directly control cell survival involving oxidative stress pathways has come to light. SHP-1 and SHP-2 are fundamental for the function of several growth factor and metabolic pathways yielding far reaching implications for disease pathways and disorders such as diabetes, neurodegeneration, and cancer. Although SHP-1 and SHP-2 can employ similar or parallel cellular pathways, these proteins also clearly exert opposing effects upon downstream cellular cascades that affect early and late apoptotic programs. SHP-1 and SHP-2 modulate cellular signals that involve phosphatidylinositol 3-kinase, Akt, Janus kinase 2, signal transducer and activator of transcription proteins, mitogen-activating protein kinases, extracellular signal-related kinases, c-Jun-amino terminal kinases, and nuclear factor-kappaB. Our progressive understanding of the impact of SHP-1 and SHP-2 upon multiple cellular environments and organ systems should continue to facilitate the targeted development of treatments for a variety of disease entities.
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Affiliation(s)
- Z Z Chong
- Division of Cellular and Molecular Cerebral Ischemia, Institute of Environmental Health Sciences, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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15
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Hwang IK, Lee HY, Yoo KY, Kim DH, Kim JH, Kim CH, Lim BO, Kang TC, Bang KH, Seong NS, Lee HJ, Kim JD, Won MH. Transient ischemia-induced expression and changes of tyrosine kinase A in the hippocampal dentate gyrus of the gerbil. Int J Neurosci 2006; 116:975-89. [PMID: 16861162 DOI: 10.1080/00207450600552978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The present study examined ischemia-related changes in tyrosine kinase A (trkA) immunoreactivity and its protein content in the dentate gyrus after 5 min of transient forebrain ischemia in gerbils. One day after ischemic insult, cresyl violet-positive polymorphic cells showed ischemic degeneration. The ischemia-induced changes in trkA immunoreactivity were found in the polymorphic layer (PL) and granule cell layer (GCL) of the dentate gyrus. In the sham-operated group, trkA immunoreactivity in the dentate gyrus was very weak. From 30 min after ischemia, trkA immunoreactivity was increased in the dentate gyrus and peaked in the dentate gyrus at 12 h after ischemia-reperfusion. Thereafter, trkA immunoreactivity was decreased time-dependently after ischemia-reperfusion. Four days after ischemic insult, trkA immunoreactivity was similar to that of the sham-operated group. In addition, it was found that ischemia-related changes in trkA protein content were similar to the immunohistochemical changes. These results suggest that the chronological changes of trkA in the dentate gyrus after transient forebrain ischemia may be associated with ischemic damage in polymorphic cells of the dentate gyrus.
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Affiliation(s)
- In Koo Hwang
- Department of Anatomy, College of Medicine Hallym University, Chunchon, South Korea
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16
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Hwang IK, Lee KY, Yoo KY, Kim DS, Lee NS, Jeong YG, Kang TC, Han BH, Kim JS, Won MH. Tyrosine kinase A but not phosphacan/protein tyrosine phosphatase-ζ/β immunoreactivity and protein level changes in neurons and astrocytes in the gerbil hippocampus proper after transient forebrain ischemia. Brain Res 2005; 1036:35-41. [PMID: 15725399 DOI: 10.1016/j.brainres.2004.12.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Revised: 11/27/2004] [Accepted: 12/04/2004] [Indexed: 11/22/2022]
Abstract
In the present study, ischemia-related changes in tyrosine kinase A (trkA) and phosphacan/protein tyrosine phosphatase-zeta/beta (PTP-zeta/beta) immunoreactivities and protein contents were examined in the hippocampus proper after transient forebrain ischemia for 5 min in a gerbil model. Our investigations showed that ischemia-induced changes occurred in trkA immunoreactivity in the hippocampal CA1 region, but not in the CA2/3 region of the hippocampus proper. In the sham-operated group, trkA immunoreactivity was barely detectable. trkA immunoreactivity increased from 30 min after ischemia and peaked at 12 h. Four days after ischemic insult, trkA immunoreactivity was observed in GFAP-immunoreactive astrocytes in the strata oriens and radiatum. In addition, we found that ischemia-related changes in trkA protein content were similar to immunohistochemical changes. On the other hand, PTP-zeta/beta immunoreactivities in the hippocampus proper were unaltered by forebrain ischemia. These results suggest that chronological changes of trkA after transient forebrain ischemia may be associated with an ischemic damage compensatory mechanism in CA1 pyramidal cells.
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Affiliation(s)
- In Koo Hwang
- Department of Anatomy, College of Medicine, Hallym University, Chunchon 200-702, South Korea
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Gharami K, Das S. Role of protein-tyrosine phosphatases on β-adrenergic receptor mediated morphological differentiation of astrocytes. J Chem Neuroanat 2003; 26:125-32. [PMID: 14599662 DOI: 10.1016/s0891-0618(03)00045-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A role of protein-tyrosine phosphatases in isoproterenol induced differentiation of cultured astrocytes was investigated. Unlike serine/threonine phosphatase inhibitors, the tyrosine phosphatase inhibitor, sodium orthovanadate effectively blocked transformation of the polygonal astrocytes to process bearing stellate cells on exposure to isoproterenol for 2 days. Isoproterenol caused a stimulation of c-AMP dependent protein kinase activity in the cells only at the initial stages (45 min) and at 12 and 24 h, there was a decline in the level of phospho-tyrosinated proteins which could be antagonised by the protein kinase A inhibitor, H89. Genestein, a protein-tyrosine kinase inhibitor, had no effect on the alteration in the morphology of the astroglial cells induced by isoproterenol but by itself, decreased the dephosphorylation of the phospho-tyrosinated proteins, the decline being less than that observed in isoproterenol treated cells. Moreover, unlike H89, genestein had no effect on isoproterenol-induced dephosphorylation of phospho-tyrosinated proteins. Taken together it appears that the dephosphorylation of tyrosine residues during isoproterenol-induced astrocyte differentiation is a downstream event of protein kinase A stimulation and needs to attain a critical level in order for the cells to differentiate.
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Affiliation(s)
- Kusumika Gharami
- Division of Neurobiology, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Jadavpur, 700032 Calcutta, India
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18
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Cebo C, Durier V, Lagant P, Maes E, Florea D, Lefebvre T, Strecker G, Vergoten G, Zanetta JP. Function and molecular modeling of the interaction between human interleukin 6 and its HNK-1 oligosaccharide ligands. J Biol Chem 2002; 277:12246-52. [PMID: 11788581 DOI: 10.1074/jbc.m106816200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Interleukin 6 (IL-6) is endowed with a lectin activity for oligosaccharide ligands possessing the HNK-1 epitope (3-sulfated glucuronic acid) found on some mammalian glycoprotein N-glycans (Cebo, C., Dambrouck, T., Maes, E., Laden, C., Strecker, G., Michalski, J. C., and Zanetta, J. P. (2001) J. Biol. Chem. 276, 5685-5691). Using high affinity oligosaccharide ligands, it is demonstrated that this lectin activity is responsible for the early dephosphorylation of tyrosine residues found on specific proteins induced by interleukin 6 in human resting lymphocytes. The gp130 glycoprotein, the signal-transducing molecule of the IL-6 pathway, is itself a molecule possessing the HNK-1 epitope. This indicates that IL-6 is a bi-functional molecule able to extracellularly associate its alpha-receptor with the gp130 surface complex. Computational modeling indicates that the lower energy conformers of the high affinity ligands of IL-6 have a common structure. Docking experiments of these conformers suggest that the carbohydrate recognition domain of IL-6 is localized in the domain previously identified as site 3 of IL-6 (Somers, W., Stahl, M., and Seehra, J. S. (1997) EMBO J. 16, 989-997), already known to be involved in interactions with gp130.
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Affiliation(s)
- Christelle Cebo
- CNRS Unité Mixte de Recherche 8576, Laboratoire de Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologie de Lille Bâtiment C9, 59655 Villeneuve d'Ascq Cedex, France
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Aoki Y, Huang Z, Thomas SS, Bhide PG, Huang I, Moskowitz MA, Reeves SA. Increased susceptibility to ischemia-induced brain damage in transgenic mice overexpressing a dominant negative form of SHP2. FASEB J 2000; 14:1965-73. [PMID: 11023980 DOI: 10.1096/fj.00-0105com] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Cell culture studies have established SH2 domain-containing protein tyrosine phosphatase-2 (SHP2) as an important factor in growth factor and cytokine-activated signaling pathways. However, the significance of SHP2 in the mammalian central nervous system (CNS) is not known since early embryonic lethality occurs in shp2 null mice. To bypass this embryonic lethality, transgenic animals containing a catalytically inactive mutant of SHP2 (SHP2-CS) under the control of a nestin intron II/thymidine kinase minimal promoter were generated. In the developing CNS of these animals, although high-level transgene expression was detected in the neuroepithelium, there was no obvious abnormality in progenitor cell proliferation or migration. In the adult brain, high-level transgene expression was detected in the subventricular zone, rostral migratory stream, dentate gyrus of hippocampus, and cerebellum. Because SHP2 function is likely important in cell survival pathways, we used a focal cerebral ischemia model to examined whether SHP2 is important during CNS injury. Ischemia-induced damage and neuronal death was found to be significantly greater in nestin-SHP2-CS mice than in wild-type littermates. These findings indicate that SHP2 is a required factor in signaling pathway(s) important for neuronal survival.
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Affiliation(s)
- Y Aoki
- CNS Signaling Laboratory, Molecular Neuro-Oncology, Massachusetts General Hospital, Charlestown, MA 02129, USA
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20
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Althaus HH, Richter-Landsberg C. Glial cells as targets and producers of neurotrophins. INTERNATIONAL REVIEW OF CYTOLOGY 2000; 197:203-77. [PMID: 10761118 DOI: 10.1016/s0074-7696(00)97005-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Glial cells fulfill important tasks within the neural network of the central and peripheral nervous systems. The synthesis and secretion of various polypeptidic factors (cytokines) and a number of receptors, with which glial cells are equipped, allow them to communicate with their environment. Evidence has accumulated during recent years that neurotrophins play an important role not only for neurons but also for glial cells. This brief update of some morphological, immunocytochemical, and biochemical characteristics of glial cell lineages conveys our present knowledge about glial cells as targets and producers of neurotrophins under normal and pathological conditions. The chapter discusses the presence of neurotrophin receptors on glial cells, glial cells as producers of neurotrophins, signaling pathways downstream Trk and p75NTR, and the significance of neurotrophins and their receptors for glial cells during development, in cell death and survival, and in neurological disorders.
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Affiliation(s)
- H H Althaus
- AG Neural Regeneration, Max Planck Institute for Experimental Medicine, Göttingen, Germany
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21
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Held-Feindt J, Krisch B, Forstreuter F, Mentlein R. Somatostatin receptors in gliomas. JOURNAL OF PHYSIOLOGY, PARIS 2000; 94:251-8. [PMID: 11088002 DOI: 10.1016/s0928-4257(00)00213-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gliomas differ from non-malignant glial cells in the overexpression or mutations of genes involved in cell cycle or growth regulation. One example is the overexpression of the somatostatin receptor subtype 2 (sst2), especially of the splice variant sst2A. The reasons for this overexpression are not known. However, the coding sequence and part of the promoter region is not mutated. In accordance to this, the sst2 is functionally active and is internalised upon agonist stimulation. Immunoelectronmicroscopic studies show that the activated sst2 is internalised via caveolin-positive endosomal vesicles and later accumulates in multivesicular bodies and lysosomal compartments. The activated sst2 is found to be co-localised with the inhibitory G-protein Gialpha at the plasma membrane and in early endosomal vesicles. Multiple signal transduction pathways are induced. Stimulation of sst2 lowers cAMP levels elicited by forskolin and activates the protein tyrosine phosphatase SHP-2. In contrast to other sst2-expressing cells a long term antiproliferative effect of somatostatin or sst2-selective agonists are not detected in cultivated glioma cells. However, continuous stimulation of sst2 decreases the expression of genes promoting tumour survival.
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Hasegawa S, Morioka M, Goto S, Korematsu K, Okamura A, Yano S, Kai, Y, Hamada JI, Ushio Y. Expression of neuron specific phosphatase, striatal enriched phosphatase (STEP) in reactive astrocytes after transient forebrain ischemia. Glia 2000. [DOI: 10.1002/(sici)1098-1136(20000215)29:4<316::aid-glia3>3.0.co;2-o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Arregui CO, Balsamo J, Lilien J. Regulation of signaling by protein-tyrosine phosphatases: potential roles in the nervous system. Neurochem Res 2000; 25:95-105. [PMID: 10685609 DOI: 10.1023/a:1007595617447] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
During neuronal development, cells respond to a variety of environmental cues through cell surface receptors that are coupled to a signaling transduction machinery based on protein tyrosine phosphorylation and dephosphorylation. Receptor and non-receptor tyrosine kinases have received a great deal of attention; however, in the last few years, receptor (plasma membrane associated) and non-receptor protein-tyrosine phosphatases (PTPs) have also been shown to play important roles in development of the nervous system. In many cases PTPs have provocative distribution patterns or have been shown to be associated with specific cell adhesion and growth factor receptors. Additionally, altering PTP expression levels or activity impairs neuronal behavior. In this review we outline what is currently known about the role of PTPs in development, differentiation and neuronal physiology.
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Affiliation(s)
- C O Arregui
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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Bell MW, Alvarez K, Ghalayini AJ. Association of the tyrosine phosphatase SHP-2 with transducin-alpha and a 97-kDa tyrosine-phosphorylated protein in photoreceptor rod outer segments. J Neurochem 1999; 73:2331-40. [PMID: 10582591 DOI: 10.1046/j.1471-4159.1999.0732331.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Increasing evidence indicates that tyrosine phosphorylation, controlled by the concerted action of tyrosine kinases and protein tyrosine phosphatases (PTPs), plays important roles in retinal photoreceptor rod outer segments (ROS). We characterized PTP activity in isolated bovine ROS that is significantly inhibited by orthovanadate. Incubating ROS in the presence of exogenous Mg2+, ATP, and orthovanadate dramatically enhanced the tyrosine phosphorylation of several endogenous proteins. SHP-2, a PTP with two SH2 domains, was identified in ROS by immunoblot analysis and was found to associate with ROS membranes. Immunocytochemistry showed localization of SHP-2 in photoreceptor outer segments and possibly in the outer plexiform, inner nuclear, and inner plexiform cell layers of the retina as well. SHP-2 associated with transducin-alpha and a 97-kDa tyrosine-phosphorylated protein in ROS, suggesting the formation of a multimeric signaling complex. Based on its association with transducin-alpha and a 97-kDa protein, SHP-2 may regulate the tyrosine phosphorylation of endogenous proteins, including transducin-alpha, and may play a significant role in a novel signaling pathway in photoreceptors.
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Affiliation(s)
- M W Bell
- Department of Biochemistry, Baylor College of Medicine, Houston, Texas, USA
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