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Zhang H, Xiang L, Yuan H, Yu H. PTPRO inhibition ameliorates spinal cord injury through shifting microglial M1/M2 polarization via the NF-κB/STAT6 signaling pathway. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167141. [PMID: 38565385 DOI: 10.1016/j.bbadis.2024.167141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Abstract
Spinal cord injury (SCI) induces severe neuroinflammation, and subsequently neurological dysfunction. Activated microglia are critical for modulation of neuroinflammation. Protein tyrosine phosphatase receptor type O (PTPRO), a member of protein tyrosine phosphatases (PTPs), exerts a pro-inflammatory role in multiple human diseases; however, its role in SCI remains unclarified. Here, a T7 spinal cord compression injury model was established in Sprague-Dawley (SD) rats, and PTPRO expression was upregulated in injured spinal cord and microglia after SCI. Microglia M1 and M2 polarization in vitro were induced using LPS/IFN-γ and IL-4, respectively. PTPRO expression was elevated in M1-polarized microglia, and PTPRO downregulation mediated by PTPRO shRNA (shPTPRO) decreased CD86+ cell proportion, iNOS, TNF-α, IL-1β, and IL-6 levels, and p65 phosphorylation. PTPRO was downregulated in M2 microglia, and PTPRO upregulation by PTPRO overexpression plasmid (OE-PTPRO) reduced CD206+ cell percentage, Arg-1, IL-10, and TGF-β1 levels and STAT6 phosphorylation. Mechanistically, the transcription factor SOX4 elevated PTPRO expression and its promoter activity. SOX4 overexpression enhanced M1 polarization and p65 phosphorylation, while its knockdown promoted M2 polarization and STAT6 phosphorylation. PTPRO might mediate the function of SOX4 in BV2 microglia polarization. Furthermore, lentivirus-mediated downregulation of PTPRO following SCI improved locomotor functional recovery, demonstrated by elevated BBB scores, incline angle, consistent hindlimb coordination, and reduced lesion area and neuronal apoptosis. PTPRO downregulation promoted microglia M2 polarization, NF-κB inactivation and STAT6 activation after injury. In conclusion, PTPRO inhibition improves spinal cord injury through facilitating M2 microglia polarization via the NF-κB/STAT6 signaling pathway, which is probably controlled by SOX4.
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Affiliation(s)
- Haocong Zhang
- Department of Orthopaedics, The General Hospital of Northern Theater Command, No. 83 Wenhua Road, Shenhe District, Shenyang, Liaoning, 110016, China
| | - Liangbi Xiang
- Department of Orthopaedics, The General Hospital of Northern Theater Command, No. 83 Wenhua Road, Shenhe District, Shenyang, Liaoning, 110016, China
| | - Hong Yuan
- Department of Orthopaedics, The General Hospital of Northern Theater Command, No. 83 Wenhua Road, Shenhe District, Shenyang, Liaoning, 110016, China
| | - Hailong Yu
- Department of Orthopaedics, The General Hospital of Northern Theater Command, No. 83 Wenhua Road, Shenhe District, Shenyang, Liaoning, 110016, China.
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Wang S, Xie Z, Jun T, Ma X, Zhang M, Rao F, Xu H, Lu J, Ding X, Li Z. Identification of potential crucial genes and therapeutic targets for epilepsy. Eur J Med Res 2024; 29:43. [PMID: 38212777 PMCID: PMC10782668 DOI: 10.1186/s40001-024-01643-8] [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: 03/14/2023] [Accepted: 01/04/2024] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND Epilepsy, a central neurological disorder, has a complex genetic architecture. There is some evidence suggesting that genetic factors play a role in both the occurrence of epilepsy and its treatment. However, the genetic determinants of epilepsy are largely unknown. This study aimed to identify potential therapeutic targets for epilepsy. METHODS Differentially expressed genes (DEGs) were extracted from the expression profiles of GSE44031 and GSE1834. Gene co-expression analysis was used to confirm the regulatory relationship between newly discovered epilepsy candidate genes and known epilepsy genes. Expression quantitative trait loci analysis was conducted to determine if epilepsy risk single-nucleotide polymorphisms regulate DEGs' expression in human brain tissue. Finally, protein-protein interaction analysis and drug-gene interaction analysis were performed to assess the role of DEGs in epilepsy treatment. RESULTS The study found that the protein tyrosine phosphatase receptor-type O gene (PTPRO) and the growth arrest and DNA damage inducible alpha gene (GADD45A) were significantly upregulated in epileptic rats compared to controls in both datasets. Gene co-expression analysis revealed that PTPRO was co-expressed with RBP4, NDN, PAK3, FOXG1, IDS, and IDS, and GADD45A was co-expressed with LRRK2 in human brain tissue. Expression quantitative trait loci analysis suggested that epilepsy risk single-nucleotide polymorphisms could be responsible for the altered PTPRO and GADD45A expression in human brain tissue. Moreover, the protein encoded by GADD45A had a direct interaction with approved antiepileptic drug targets, and GADD45A interacts with genistein and cisplatin. CONCLUSIONS The results of this study highlight PTPRO and GADD45A as potential genes for the diagnosis and treatment of epilepsy.
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Affiliation(s)
- Shitao Wang
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China.
| | - Zhenrong Xie
- The Medical Biobank, First Affiliated Hospital of Kunming Medical University, Kunming, 650032, Yunnan, China
| | - Tian Jun
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
| | - Xuelu Ma
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
| | - Mengen Zhang
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
| | - Feng Rao
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
| | - Hui Xu
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
| | - Jinghong Lu
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
| | - Xiangqian Ding
- Department of Neurosurgery, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Zongyou Li
- Department of Neurology, Affiliated Fuyang People's Hospital of Anhui Medical University, Fuyang, 236000, Anhui, China
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Veshchitskii A, Merkulyeva N. Calcium-binding protein parvalbumin in the spinal cord and dorsal root ganglia. Neurochem Int 2023; 171:105634. [PMID: 37967669 DOI: 10.1016/j.neuint.2023.105634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 09/20/2023] [Accepted: 10/26/2023] [Indexed: 11/17/2023]
Abstract
Parvalbumin is one of the calcium-binding proteins. In the spinal cord, it is mainly expressed in inhibitory neurons; in the dorsal root ganglia, it is expressed in proprioceptive neurons. In contrast to in the brain, weak systematization of parvalbumin-expressing neurons occurs in the spinal cord. The aim of this paper is to provide a systematic review of parvalbumin-expressing neuronal populations throughout the spinal cord and the dorsal root ganglia of mammals, regarding their mapping, co-expression with some functional markers. The data reviewed are mostly concerning rodentia species because they are predominantly presented in literature.
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Affiliation(s)
- Aleksandr Veshchitskii
- Neuromorphology Lab, Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Natalia Merkulyeva
- Neuromorphology Lab, Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia.
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Identification of Protein Tyrosine Phosphatase Receptor Type O (PTPRO) as a Synaptic Adhesion Molecule that Promotes Synapse Formation. J Neurosci 2017; 37:9828-9843. [PMID: 28871037 DOI: 10.1523/jneurosci.0729-17.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/26/2017] [Accepted: 08/22/2017] [Indexed: 01/07/2023] Open
Abstract
The proper formation of synapses-specialized unitary structures formed between two neurons-is critical to mediating information flow in the brain. Synaptic cell adhesion molecules (CAMs) are thought to participate in the initiation of the synapse formation process. However, in vivo functional analysis demonstrates that most well known synaptic CAMs regulate synaptic maturation and plasticity rather than synapse formation, suggesting that either CAMs work synergistically in the process of forming synapses or more CAMs remain to be found. By screening for unknown CAMs using a co-culture system, we revealed that protein tyrosine phosphatase receptor type O (PTPRO) is a potent CAM that induces the formation of artificial synapse clusters in co-cultures of human embryonic kidney 293 cells and hippocampal neurons cultured from newborn mice regardless of gender. PTPRO was enriched in the mouse brain and localized to postsynaptic sites at excitatory synapses. The overexpression of PTPRO in cultured hippocampal neurons increased the number of synapses and the frequency of miniature EPSCs (mEPSCs). The knock-down (KD) of PTPRO expression in cultured neurons by short hairpin RNA (shRNA) reduced the number of synapses and the frequencies of the mEPSCs. The effects of shRNA KD were rescued by expressing either full-length PTPRO or a truncated PTPRO lacking the cytoplasmic domain. Consistent with these results, the N-terminal extracellular domain of PTPRO was required for its synaptogenic activity in the co-culture assay. Our data show that PTPRO is a synaptic CAM that serves as a potent initiator of the formation of excitatory synapses.SIGNIFICANCE STATEMENT The formation of synapses is critical for the brain to execute its function and synaptic cell adhesion molecules (CAMs) play essential roles in initiating the formation of synapses. By screening for unknown CAMs using a co-culture system, we revealed that protein tyrosine phosphatase receptor type O (PTPRO) is a potent CAM that induces the formation of artificial synapse clusters. Using loss-of-function and gain-of-function approaches, we show that PTPRO promotes the formation of excitatory synapses. The N-terminal extracellular domain of PTPRO was required for its synaptogenic activity in cultured hippocampal neurons and the co-culture assay. Together, our data show that PTPRO is a synaptic CAM that serves as a potent initiator of synapse formation.
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5
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Three-dimensional electron microscopy reveals the evolution of glomerular barrier injury. Sci Rep 2016; 6:35068. [PMID: 27725732 PMCID: PMC5057164 DOI: 10.1038/srep35068] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/20/2016] [Indexed: 12/26/2022] Open
Abstract
Glomeruli are highly sophisticated filters and glomerular disease is the leading cause of kidney failure. Morphological change in glomerular podocytes and the underlying basement membrane are frequently observed in disease, irrespective of the underlying molecular etiology. Standard electron microscopy techniques have enabled the identification and classification of glomerular diseases based on two-dimensional information, however complex three-dimensional ultrastructural relationships between cells and their extracellular matrix cannot be easily resolved with this approach. We employed serial block face-scanning electron microscopy to investigate Alport syndrome, the commonest monogenic glomerular disease, and compared findings to other genetic mouse models of glomerular disease (Myo1e−/−, Ptpro−/−). These analyses revealed the evolution of basement membrane and cellular defects through the progression of glomerular injury. Specifically we identified sub-podocyte expansions of the basement membrane with both cellular and matrix gene defects and found a corresponding reduction in podocyte foot process number. Furthermore, we discovered novel podocyte protrusions invading into the glomerular basement membrane in disease and these occurred frequently in expanded regions of basement membrane. These findings provide new insights into mechanisms of glomerular barrier dysfunction and suggest that common cell-matrix-adhesion pathways are involved in the progression of disease regardless of the primary insult.
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6
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McClelland KS, Bell K, Larney C, Harley VR, Sinclair AH, Oshlack A, Koopman P, Bowles J. Purification and Transcriptomic Analysis of Mouse Fetal Leydig Cells Reveals Candidate Genes for Specification of Gonadal Steroidogenic Cells1. Biol Reprod 2015; 92:145. [DOI: 10.1095/biolreprod.115.128918] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/02/2015] [Indexed: 01/12/2023] Open
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7
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Hartin SN, Hudson ML, Yingling C, Ackley BD. A Synthetic Lethal Screen Identifies a Role for Lin-44/Wnt in C. elegans Embryogenesis. PLoS One 2015; 10:e0121397. [PMID: 25938228 PMCID: PMC4418752 DOI: 10.1371/journal.pone.0121397] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/31/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The C. elegans proteins PTP-3/LAR-RPTP and SDN-1/Syndecan are conserved cell adhesion molecules. Loss-of-function (LOF) mutations in either ptp-3 or sdn-1 result in low penetrance embryonic developmental defects. Work from other systems has shown that syndecans can function as ligands for LAR receptors in vivo. We used double mutant analysis to test whether ptp-3 and sdn-1 function in a linear genetic pathway during C. elegans embryogenesis. RESULTS We found animals with LOF in both sdn-1 and ptp-3 exhibited a highly penetrant synthetic lethality (SynLet), with only a small percentage of animals surviving to adulthood. Analysis of the survivors demonstrated that these animals had a synergistic increase in the penetrance of embryonic developmental defects. Together, these data strongly suggested PTP-3 and SDN-1 function in parallel during embryogenesis. We subsequently used RNAi to knockdown ~3,600 genes predicted to encode secreted and/or transmembrane molecules to identify genes that interacted with ptp-3 or sdn-1. We found that the Wnt ligand, lin-44, was SynLet with sdn-1, but not ptp-3. We used 4-dimensional time-lapse analysis to characterize the interaction between lin-44 and sdn-1. We found evidence that loss of lin-44 caused defects in the polarization and migration of endodermal precursors during gastrulation, a previously undescribed role for lin-44 that is strongly enhanced by the loss of sdn-1. CONCLUSIONS PTP-3 and SDN-1 function in compensatory pathways during C. elegans embryonic and larval development, as simultaneous loss of both genes has dire consequences for organismal survival. The Wnt ligand lin-44 contributes to the early stages of gastrulation in parallel to sdn-1, but in a genetic pathway with ptp-3. Overall, the SynLet phenotype provides a robust platform to identify ptp-3 and sdn-1 interacting genes, as well as other genes that function in development, yet might be missed in traditional forward genetic screens.
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Affiliation(s)
- Samantha N. Hartin
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States of America
| | - Martin L. Hudson
- Department of Biology and Physics, Kennesaw State University, Kennesaw, GA, United States of America
| | - Curtis Yingling
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States of America
| | - Brian D. Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States of America
- * E-mail:
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8
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Xu B, Park D, Ohtake Y, Li H, Hayat U, Liu J, Selzer ME, Longo FM, Li S. Role of CSPG receptor LAR phosphatase in restricting axon regeneration after CNS injury. Neurobiol Dis 2015; 73:36-48. [PMID: 25220840 PMCID: PMC4427014 DOI: 10.1016/j.nbd.2014.08.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 08/05/2014] [Accepted: 08/29/2014] [Indexed: 12/11/2022] Open
Abstract
Extracellular matrix molecule chondroitin sulfate proteoglycans (CSPGs) are highly upregulated in scar tissues and form a potent chemical barrier for CNS axon regeneration. Recent studies support that the receptor protein tyrosine phosphatase σ (PTPσ) and its subfamily member leukocyte common antigen related phosphatase (LAR) act as transmembrane receptors to mediate CSPG inhibition. PTPσ deficiency increased regrowth of ascending axons into scar tissues and descending corticospinal tract (CST) axons into the caudal spinal cord after spinal cord injury (SCI). Pharmacological LAR inhibition enhanced serotonergic axon growth in SCI mice. However, transgenic LAR deletion on axon growth in vivo and the role of LAR in regulating regrowth of other fiber tracts have not been studied. Here, we studied the role of LAR in restricting regrowth of injured descending CNS axons in deficient mice. LAR deletion increased regrowth of serotonergic axons into scar tissues and caudal spinal cord after dorsal over-hemitransection. LAR deletion also stimulated regrowth of CST fibers into the caudal spinal cord. LAR protein was upregulated days to weeks after injury and co-localized to serotonergic and CST axons. Moreover, LAR deletion improved functional recovery by increasing BMS locomotor scores and stride length and reducing grid walk errors. This is the first transgenic study that demonstrates the crucial role of LAR in restricting regrowth of injured CNS axons.
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Affiliation(s)
- Bin Xu
- Department of Neurosurgery, Affiliated Shanxi Dayi Hospital, Shanxi Academy of Medical Sciences, China; Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Dongsun Park
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Yosuke Ohtake
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Hui Li
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Umar Hayat
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Junjun Liu
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Neurology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Frank M Longo
- Department of Neurology and Neurological Science, Stanford University, Stanford, CA 94305, USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
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9
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Jeon M, Zinn K. R3 receptor tyrosine phosphatases: conserved regulators of receptor tyrosine kinase signaling and tubular organ development. Semin Cell Dev Biol 2014; 37:119-26. [PMID: 25242281 DOI: 10.1016/j.semcdb.2014.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/04/2014] [Indexed: 12/25/2022]
Abstract
R3 receptor tyrosine phosphatases (RPTPs) are characterized by extracellular domains composed solely of long chains of fibronectin type III repeats, and by the presence of a single phosphatase domain. There are five proteins in mammals with this structure, two in Drosophila and one in Caenorhabditis elegans. R3 RPTPs are selective regulators of receptor tyrosine kinase (RTK) signaling, and a number of different RTKs have been shown to be direct targets for their phosphatase activities. Genetic studies in both invertebrate model systems and in mammals have shown that R3 RPTPs are essential for tubular organ development. They also have important functions during nervous system development. R3 RPTPs are likely to be tumor suppressors in a number of types of cancer.
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Affiliation(s)
- Mili Jeon
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States; Department of Molecular and Cellular Physiology and Structural Biology, Howard Hughes Medical Institute, Stanford School of Medicine, Palo Alto, CA 94305, United States
| | - Kai Zinn
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States.
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10
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Stoker AW. RPTPs in axons, synapses and neurology. Semin Cell Dev Biol 2014; 37:90-7. [PMID: 25234542 DOI: 10.1016/j.semcdb.2014.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 01/06/2023]
Abstract
Receptor-like protein tyrosine phosphatases represent a large protein family related to cell adhesion molecules, with diverse roles throughout neural development in vertebrates and invertebrates. This review focuses on their roles in axon growth, guidance and repair, as well as more recent findings demonstrating their key roles in pre-synaptic and post-synaptic maturation and function. These enzymes have been linked to memory and neuropsychiatric defects in loss-of-function rodent models, highlighting their potential as future drug targets.
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Affiliation(s)
- Andrew W Stoker
- Institute of Child Health, University College London, United Kingdom.
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11
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Tchetchelnitski V, van den Eijnden M, Schmidt F, Stoker AW. Developmental co-expression and functional redundancy of tyrosine phosphatases with neurotrophin receptors in developing sensory neurons. Int J Dev Neurosci 2014; 34:48-59. [PMID: 24491805 DOI: 10.1016/j.ijdevneu.2014.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 01/22/2014] [Accepted: 01/22/2014] [Indexed: 12/11/2022] Open
Abstract
Receptor-type protein tyrosine phosphatases (RPTPs) have been implicated as direct or indirect regulators of neurotrophin receptors (TRKs). It remains less clear if and how such RPTPs might regulate TRK proteins in vivo during development. Here we present a comparative expression profile of RPTP genes and Trk genes during early stages of murine, dorsal root ganglion maturation. We find little if any specific, temporal mRNA co-regulation between individual RPTP and Ntrk genes between E12.5 and E14.5. Moreover, a double fluorescent in-situ hybridization and immunofluorescence study of seven Rptp genes with Ntrks revealed widespread co-expression of RPTPs in individual neurons, but no tight correlation with Trk expression profiles. No Rptp is expressed in 100% of Ntrk1-expressing neurons, whereas at least 6 RPTPs are expressed in 100% of Ntrk2- and Ntrk3-expressing neurons. An exception is Ptpro, which showed very selective expression. Short hairpin RNA suppression of Ptprf, Ptprs or Ptpro in primary, E13.5 DRG neurons did not alter TRK signalling. We therefore propose that TRK signalling may not be simply dependent on rate-limiting regulation by individual RPTP subtypes during sensory neuron development. Instead, TRK signalling has the potential to be buffered by concurrent inputs from several RPTPs in individual neurons.
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MESH Headings
- Adaptor Proteins, Signal Transducing/deficiency
- Adaptor Proteins, Signal Transducing/genetics
- Animals
- Cells, Cultured
- Embryo, Mammalian
- Ganglia, Spinal/cytology
- Ganglia, Spinal/embryology
- Gene Expression Regulation, Developmental/physiology
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- HEK293 Cells
- Humans
- Mice
- Protein Tyrosine Phosphatases/genetics
- Protein Tyrosine Phosphatases/metabolism
- RNA, Messenger/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/metabolism
- Regulatory-Associated Protein of mTOR
- Sensory Receptor Cells/metabolism
- Signal Transduction/genetics
- Transfection
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Affiliation(s)
- Viktoria Tchetchelnitski
- Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, United Kingdom
| | | | - Fanny Schmidt
- MERCK SERONO SA.-Geneva, 9 Chemin des Mines, CH-1202 Geneve, Switzerland
| | - Andrew W Stoker
- Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, United Kingdom.
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12
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Sakuraba J, Shintani T, Tani S, Noda M. Substrate specificity of R3 receptor-like protein-tyrosine phosphatase subfamily toward receptor protein-tyrosine kinases. J Biol Chem 2013; 288:23421-31. [PMID: 23814054 DOI: 10.1074/jbc.m113.458489] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Receptor-like protein-tyrosine phosphatases (RPTPs) are involved in various aspects of cellular functions, such as proliferation, differentiation, survival, migration, and metabolism. A small number of RPTPs have been reported to regulate activities of some cellular proteins including receptor protein-tyrosine kinases (RPTKs). However, our understanding about the roles of individual RPTPs in the regulation of RPTKs is still limited. The R3 RPTP subfamily reportedly plays pivotal roles in the development of several tissues including the vascular and nervous systems. Here, we examined enzyme-substrate relationships between the four R3 RPTP subfamily members and 21 RPTK members selected from 14 RPTK subfamilies by using a mammalian two-hybrid system with substrate-trapping RPTP mutants. Among the 84 RPTP-RPTK combinations conceivable, we detected 30 positive interactions: 25 of the enzyme-substrate relationships were novel. We randomly chose several RPTKs assumed to be substrates for R3 RPTPs, and validated the results of this screen by in vitro dephosphorylation assays, and by cell-based assays involving overexpression and knock-down experiments. Because their functional relationships were verified without exception, it is probable that the RPTKs identified as potential substrates are actually physiological substrates for the R3 RPTPs. Interestingly, some RPTKs were recognized as substrates by all R3 members, but others were recognized by only one or a few members. The enzyme-substrate relationships identified in the present study will shed light on physiological roles of the R3 RPTP subfamily.
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Affiliation(s)
- Juichi Sakuraba
- Division of Molecular Neurobiology, National Institute for Basic Biology, Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8787, Japan
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13
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Protein tyrosine phosphatase receptor type O inhibits trigeminal axon growth and branching by repressing TrkB and Ret signaling. J Neurosci 2013; 33:5399-410. [PMID: 23516305 DOI: 10.1523/jneurosci.4707-12.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Axonal branches of the trigeminal ganglion (TG) display characteristic growth and arborization patterns during development. Subsets of TG neurons express different receptors for growth factors, but these are unlikely to explain the unique patterns of axonal arborizations. Intrinsic modulators may restrict or enhance cellular responses to specific ligands and thereby contribute to the development of axon growth patterns. Protein tyrosine phosphatase receptor type O (PTPRO), which is required for Eph receptor-dependent retinotectal development in chick and for development of subsets of trunk sensory neurons in mouse, may be such an intrinsic modulator of TG neuron development. PTPRO is expressed mainly in TrkB-expressing (TrkB(+)) and Ret(+) mechanoreceptors within the TG during embryogenesis. In PTPRO mutant mice, subsets of TG neurons grow longer and more elaborate axonal branches. Cultured PTPRO(-/-) TG neurons display enhanced axonal outgrowth and branching in response to BDNF and GDNF compared with control neurons, indicating that PTPRO negatively controls the activity of BDNF/TrkB and GDNF/Ret signaling. Mouse PTPRO fails to regulate Eph signaling in retinocollicular development and in hindlimb motor axon guidance, suggesting that chick and mouse PTPRO have different substrate specificities. PTPRO has evolved to fine tune growth factor signaling in a cell-type-specific manner and to thereby increase the diversity of signaling output of a limited number of receptor tyrosine kinases to control the branch morphology of developing sensory neurons. The regulation of Eph receptor-mediated developmental processes by protein tyrosine phosphatases has diverged between chick and mouse.
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14
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Hendriks WJAJ, Pulido R. Protein tyrosine phosphatase variants in human hereditary disorders and disease susceptibilities. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1673-96. [PMID: 23707412 DOI: 10.1016/j.bbadis.2013.05.022] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/14/2013] [Accepted: 05/16/2013] [Indexed: 12/18/2022]
Abstract
Reversible tyrosine phosphorylation of proteins is a key regulatory mechanism to steer normal development and physiological functioning of multicellular organisms. Phosphotyrosine dephosphorylation is exerted by members of the super-family of protein tyrosine phosphatase (PTP) enzymes and many play such essential roles that a wide variety of hereditary disorders and disease susceptibilities in man are caused by PTP alleles. More than two decades of PTP research has resulted in a collection of PTP genetic variants with corresponding consequences at the molecular, cellular and physiological level. Here we present a comprehensive overview of these PTP gene variants that have been linked to disease states in man. Although the findings have direct bearing for disease diagnostics and for research on disease etiology, more work is necessary to translate this into therapies that alleviate the burden of these hereditary disorders and disease susceptibilities in man.
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Affiliation(s)
- Wiljan J A J Hendriks
- Department of Cell Biology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Liao WH, Cheng CH, Hung KS, Chiu WT, Chen GD, Hwang PP, Hwang SPL, Kuan YS, Huang CJ. Protein tyrosine phosphatase receptor type O (Ptpro) regulates cerebellar formation during zebrafish development through modulating Fgf signaling. Cell Mol Life Sci 2013; 70:2367-81. [PMID: 23361036 PMCID: PMC3676743 DOI: 10.1007/s00018-013-1259-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 12/13/2012] [Accepted: 01/03/2013] [Indexed: 02/04/2023]
Abstract
Protein activities controlled by receptor protein tyrosine phosphatases (RPTPs) play comparably important roles in transducing cell surface signals into the cytoplasm by protein tyrosine kinases. Previous studies showed that several RPTPs are involved in neuronal generation, migration, and axon guidance in Drosophila, and the vertebrate hippocampus, retina, and developing limbs. However, whether the protein tyrosine phosphatase type O (ptpro), one kind of RPTP, participates in regulating vertebrate brain development is largely unknown. We isolated the zebrafish ptpro gene and found that its transcripts are primarily expressed in the embryonic and adult central nervous system. Depletion of zebrafish embryonic Ptpro by antisense morpholino oligonucleotide knockdown resulted in prominent defects in the forebrain and cerebellum, and the injected larvae died on the 4th day post-fertilization (dpf). We further investigated the function of ptpro in cerebellar development and found that the expression of ephrin-A5b (efnA5b), a Fgf signaling induced cerebellum patterning factor, was decreased while the expression of dusp6, a negative-feedback gene of Fgf signaling in the midbrain-hindbrain boundary region, was notably induced in ptpro morphants. Further analyses demonstrated that cerebellar defects of ptpro morphants were partially rescued by inhibiting Fgf signaling. Moreover, Ptpro physically interacted with the Fgf receptor 1a (Fgfr1a) and dephosphorylated Fgfr1a in a dose-dependant manner. Therefore, our findings demonstrate that Ptpro activity is required for patterning the zebrafish embryonic brain. Specifically, Ptpro regulates cerebellar formation during zebrafish development through modulating Fgf signaling.
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Affiliation(s)
- Wei-Hao Liao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 104, Taiwan
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Expression profiling during mammary epithelial cell three-dimensional morphogenesis identifies PTPRO as a novel regulator of morphogenesis and ErbB2-mediated transformation. Mol Cell Biol 2012; 32:3913-24. [PMID: 22851698 DOI: 10.1128/mcb.00068-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Identification of genes that are upregulated during mammary epithelial cell morphogenesis may reveal novel regulators of tumorigenesis. We have demonstrated that gene expression programs in mammary epithelial cells grown in monolayer cultures differ significantly from those in three-dimensional (3D) cultures. We identify a protein tyrosine phosphate, PTPRO, that was upregulated in mature MCF-10A mammary epithelial 3D structures but had low to undetectable levels in monolayer cultures. Downregulation of PTPRO by RNA interference inhibited proliferation arrest during morphogenesis. Low levels of PTPRO expression correlated with reduced survival for breast cancer patients, suggesting a tumor suppressor function. Furthermore, we showed that the receptor tyrosine kinase ErbB2/HER2 is a direct substrate of PTPRO and that loss of PTPRO increased ErbB2-induced cell proliferation and transformation, together with tyrosine phosphorylation of ErbB2. Moreover, in patients with ErbB2-positive breast tumors, low PTPRO expression correlated with poor clinical prognosis compared to ErbB2-positive patients with high levels of PTPRO. Thus, PTPRO is a novel regulator of ErbB2 signaling, a potential tumor suppressor, and a novel prognostic marker for patients with ErbB2-positive breast cancers. We have identified the protein tyrosine phosphatase PTPRO as a regulator of three-dimensional epithelial morphogenesis of mammary epithelial cells and as a regulator of ErbB2-mediated transformation. In addition, we demonstrated that ErbB2 is a direct substrate of PTPRO and that decreased expression of PTPRO predicts poor prognosis for ErbB2-positive breast cancer patients. Thus, our results identify PTPRO as a novel regulator of mammary epithelial transformation, a potential tumor suppressor, and a predictive biomarker for breast cancer.
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Mohebiany AN, Nikolaienko RM, Bouyain S, Harroch S. Receptor-type tyrosine phosphatase ligands: looking for the needle in the haystack. FEBS J 2012; 280:388-400. [PMID: 22682003 DOI: 10.1111/j.1742-4658.2012.08653.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reversible protein phosphorylation plays a pivotal role in intercellular communication. Together with protein tyrosine kinases, protein tyrosine phosphatases (PTPs) are involved in the regulation of key cellular processes by controlling the phosphorylation levels of diverse effectors. Among PTPs, receptor-like protein tyrosine phosphatases (RPTPs) are involved in important developmental processes, particularly in the formation of the nervous system. Until recently, few ligands had been identified for RPTPs, making it difficult to grasp the effects these receptors have on cellular processes, as well as the mechanisms through which their functions are mediated. However, several potential RPTP ligands have now been identified to provide us with unparalleled insights into RPTP function. In this review, we focus on the nature and biological outcomes of these extracellular interactions between RPTPs and their associated ligands.
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Affiliation(s)
- Alma N Mohebiany
- Department of Neuroscience, Institut Pasteur de Paris, Paris, France
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LeBlanc M, Kulle B, Sundet K, Agartz I, Melle I, Djurovic S, Frigessi A, Andreassen OA. Genome-wide study identifies PTPRO and WDR72 and FOXQ1-SUMO1P1 interaction associated with neurocognitive function. J Psychiatr Res 2012; 46:271-8. [PMID: 22126837 DOI: 10.1016/j.jpsychires.2011.11.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 10/01/2011] [Accepted: 11/02/2011] [Indexed: 01/05/2023]
Abstract
BACKGROUND Several aspects of neurocognitive function have high heritability, but the molecular genetic mechanisms underlying neurocognition are not known. We performed a genome-wide association study (GWAS) to identify genes associated with neurocognition. METHODS 700 Subjects (schizophrenia spectrum disorder, n=190, bipolar disorder n=157 and healthy individuals n=353) were tested with an extensive neuropsychological test battery, and genotyped using the Affymetrix Genome-Wide Human SNP Array 6.0. After quality control, linear regression analysis of each of the 24 cognitive tests on the SNP dosage was performed, including age, gender, education and disease group as covariates. Additionally, 9 SNPs trending toward genome-wide significance were considered for epistatic interactions. RESULTS Four SNPs and 2 independent association signals achieving genome-wide significance were identified. Three intronic SNPs in PTPRO were associated with learning and memory (CVLT-II LDFR) (rs17222089, p=1.55×10(-8); rs11056571, p=1.68×10(-8); and rs2300290, p=1.09×10(-8)). rs719714 downstream of WDR72 was associated with executive functioning (CW-3: Inhibition, D-KEFS) (p=4.32×10(-8)). A highly significant epistatic interaction was found between rs9378605 upstream of FOXQ1 and rs11699311 downstream of SUMO1P1 for the Grooved Pegboard test (p=7.6×10(-14)). CONCLUSIONS We identified four novel loci associated with neurocognitive function and one novel epistatic interaction. The findings should be replicated in independent samples, but indicate a role of PTPRO in learning and memory, WDR72 with executive functioning, and an interaction between FOXQ1 and SUMO1P1 for psychomotor speed.
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Affiliation(s)
- Marissa LeBlanc
- Epi-Gen, Institute of Clinical Medicine, Akershus University Hospital, University of Oslo, Oslo, Norway.
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Interaction of an intracellular pentraxin with a BTB-Kelch protein is associated with ubiquitylation, aggregation and neuronal apoptosis. Mol Cell Neurosci 2011; 47:254-64. [PMID: 21549840 DOI: 10.1016/j.mcn.2011.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 04/06/2011] [Accepted: 04/18/2011] [Indexed: 11/21/2022] Open
Abstract
Neuronal pentraxin with chromo domain (NPCD) comprises a group of neuronally expressed pentraxins with both membrane and cytosolic isoforms; the functions of cytosolic NPCD isoforms are not clear. Here, we demonstrate that a cytosolic NPCD isoform selectively interacts with the BTB-Kelch protein Mayven/Kelch-like 2 (KLHL2), an actin-binding protein implicated in process outgrowth in oligodendrocytes. The KLHL2-NPCD interaction was identified by a yeast two-hybrid screen and confirmed through colocalization and co-immunoprecipitation studies. Truncation analysis indicates that the Kelch domains of KLHL2 interact with the pentraxin domain of NPCD. NPCD forms protein inclusion bodies (aggresomes) when overexpressed in tissue culture cells, KLHL2 localizes to these aggresomes, and overexpression of KLHL2 increases NPCD aggresome formation. Since other members of the BTB-Kelch family can act as Cullin-RING type E3 ubiquitin ligases, we tested the potential role of KLHL2 as a ubiquitin ligase for NPCD. We found that KLHL2 interacts selectively with Cullin 3, a key component of BTB-Kelch ubiquitin ligase complexes. Further, overexpression of KLHL2 promotes NPCD ubiquitylation. Together, these results suggest a novel E3 ubiquitin ligase function of KLHL2, with NPCD as a substrate. As the formation of aggresomes is often associated with protein aggregation in neurodegenerative diseases, we tested the effects of NPCD overexpression and KLHL2 coexpression on neuronal viability. Overexpression of NPCD in hippocampal neurons led to cell death and apoptosis; this effect was exacerbated by KLHL2 co-expression. Our findings implicate KLHL2 in ubiquitin ligase activity, and suggest potential roles of NPCD and KLHL2 in neurodegeneration.
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Matozaki T, Murata Y, Mori M, Kotani T, Okazawa H, Ohnishi H. Expression, localization, and biological function of the R3 subtype of receptor-type protein tyrosine phosphatases in mammals. Cell Signal 2010; 22:1811-7. [PMID: 20633639 DOI: 10.1016/j.cellsig.2010.07.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Accepted: 07/06/2010] [Indexed: 11/26/2022]
Abstract
The R3 subtype of receptor-type protein tyrosine phosphatases (RPTPs) includes VE-PTP, DEP-1, PTPRO, and SAP-1. All of these enzymes share a similar structure, with a single catalytic domain and putative tyrosine phosphorylation sites in the cytoplasmic region and fibronectin type III-like domains in the extracellular region. The expression of each R3 RPTP is largely restricted to a single or limited number of cell types, with VE-PTP and DEP-1 being expressed in endothelial or hematopoietic cells, PTPRO in neurons and in podocytes of the renal glomerulus, and SAP-1 in gastrointestinal epithelial cells. In addition, these RPTPs are localized specifically at the apical surface of polarized cells. The structure, expression, and localization of the R3 RPTPs suggest that they perform tissue-specific functions and that they might act through a common mechanism that includes activation of Src family kinases. In this review, we describe recent insights into R3-subtype RPTPs, particularly those of mammals.
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Affiliation(s)
- Takashi Matozaki
- Laboratory of Biosignal Sciences, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-Machi, Maebashi, Gunma 371-8512, Japan.
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