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Lukomska A, Rheaume BA, Frost MP, Theune WC, Xing J, Damania A, Trakhtenberg EF. Augmenting fibronectin levels in injured adult CNS promotes axon regeneration in vivo. Exp Neurol 2024; 379:114877. [PMID: 38944331 PMCID: PMC11283980 DOI: 10.1016/j.expneurol.2024.114877] [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: 02/23/2024] [Revised: 06/06/2024] [Accepted: 06/25/2024] [Indexed: 07/01/2024]
Abstract
In an attempt to repair injured central nervous system (CNS) nerves/tracts, immune cells are recruited into the injury site, but endogenous response in adult mammals is insufficient for promoting regeneration of severed axons. Here, we found that a portion of retinal ganglion cell (RGC) CNS projection neurons that survive after optic nerve crush (ONC) injury are enriched for and upregulate fibronectin (Fn)-interacting integrins Itga5 and ItgaV, and that Fn promotes long-term survival and long-distance axon regeneration of a portion of axotomized adult RGCs in culture. We then show that, Fn is developmentally downregulated in the axonal tracts of optic nerve and spinal cord, but injury-activated macrophages/microglia upregulate Fn while axon regeneration-promoting zymosan augments their recruitment (and thereby increases Fn levels) in the injured optic nerve. Finally, we found that Fn's RGD motif, established to interact with Itga5 and ItgaV, promotes long-term survival and long-distance axon regeneration of adult RGCs after ONC in vivo, with some axons reaching the optic chiasm when co-treated with Rpl7a gene therapy. Thus, experimentally augmenting Fn levels in the injured CNS is a promising approach for therapeutic neuroprotection and axon regeneration of at least a portion of neurons.
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Affiliation(s)
- Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Bruce A Rheaume
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Matthew P Frost
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - William C Theune
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ashiti Damania
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA..
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2
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Yao H, Zhang M, Wang D. The next decade of SET: from an oncoprotein to beyond. J Mol Cell Biol 2024; 16:mjad082. [PMID: 38157418 PMCID: PMC11267991 DOI: 10.1093/jmcb/mjad082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/22/2023] [Accepted: 12/24/2023] [Indexed: 01/03/2024] Open
Abstract
This year marks the fourth decade of research into the protein SET, which was discovered in 1992. SET was initially identified as an oncoprotein but later shown to be a multifaceted protein involved in regulating numerous biological processes under both physiological and pathophysiological conditions. SET dysfunction is closely associated with diseases, such as cancer and Alzheimer's disease. With the increasing understanding of how SET works and how it is regulated in cells, targeting aberrant SET has emerged as a potential strategy for disease intervention. In this review, we present a comprehensive overview of the advancements in SET studies, encompassing its biological functions, regulatory networks, clinical implications, and pharmacological inhibitors. Furthermore, we provide insights into the future prospects of SET research, with a particular emphasis on its promising potential in the realm of immune modulation.
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Affiliation(s)
- Han Yao
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
| | - Meng Zhang
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
| | - Donglai Wang
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
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3
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Lukomska A, Frost MP, Theune WC, Xing J, Gupta M, Trakhtenberg EF. Nfe2l3 promotes neuroprotection and long-distance axon regeneration after injury in vivo. Exp Neurol 2024; 375:114741. [PMID: 38395216 PMCID: PMC10981571 DOI: 10.1016/j.expneurol.2024.114741] [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: 11/11/2023] [Revised: 01/22/2024] [Accepted: 02/20/2024] [Indexed: 02/25/2024]
Abstract
Nuclear factor erythroid 2 like (Nfe2l) gene family members 1-3 mediate cellular response to oxidative stress, including in the central nervous system (CNS). However, neuronal functions of Nfe2l3 are unknown. Here, we comparatively evaluated expression of Nfe2l1, Nfe2l2, and Nfe2l3 in singe cell RNA-seq (scRNA-seq)-profiled cortical and retinal ganglion cell (RGC) CNS projection neurons, investigated whether Nfe2l3 regulates neuroprotection and axon regeneration after CNS injury in vivo, and characterized a gene network associated with Nfe2l3 in neurons. We showed that, Nfe2l3 expression transiently peaks in developing immature cortical and RGC projection neurons, but is nearly abolished in adult neurons and is not upregulated after injury. Furthermore, within the retina, Nfe2l3 is enriched in RGCs, primarily neonatally, and not upregulated in injured RGCs, whereas Nfe2l1 and Nfe2l2 are expressed robustly in other retinal cell types as well and are upregulated in injured RGCs. We also found that, expressing Nfe2l3 in injured RGCs through localized intralocular viral vector delivery promotes neuroprotection and long-distance axon regeneration after optic nerve injury in vivo. Moreover, Nfe2l3 provided a similar extent of neuroprotection and axon regeneration as viral vector-targeting of Pten and Klf9, which are prominent regulators of neuroprotection and long-distance axon regeneration. Finally, we bioinformatically characterized a gene network associated with Nfe2l3 in neurons, which predicted the association of Nfe2l3 with established mechanisms of neuroprotection and axon regeneration. Thus, Nfe2l3 is a novel neuroprotection and axon regeneration-promoting factor with a therapeutic potential for treating CNS injury and disease.
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Affiliation(s)
- Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Matthew P Frost
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - William C Theune
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Mahit Gupta
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA.
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4
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Lukomska A, Theune WC, Frost MP, Xing J, Kearney A, Trakhtenberg EF. Upregulation of developmentally-downregulated miR-1247-5p promotes neuroprotection and axon regeneration in vivo. Neurosci Lett 2024; 823:137662. [PMID: 38286398 PMCID: PMC10923146 DOI: 10.1016/j.neulet.2024.137662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 01/31/2024]
Abstract
Numerous micro-RNAs (miRNAs) affect neurodevelopment and neuroprotection, but potential roles of many miRNAs in regulating these processes are still unknown. Here, we used the retinal ganglion cell (RGC) central nervous system (CNS) projection neuron and optic nerve crush (ONC) injury model, to optimize a mature miRNA arm-specific quantification method for characterizing the developmental regulation of miR-1247-5p in RGCs, investigated whether injury affects its expression, and tested whether upregulating miR-1247-5p-mimic in RGCs promotes neuroprotection and axon regeneration. We found that, miR-1247-5p is developmentally-downregulated in RGCs, and is further downregulated after ONC. Importantly, RGC-specific upregulation of miR-1247-5p promoted neuroprotection and axon regeneration after injury in vivo. To gain insight into the underlying mechanisms, we analyzed by bulk-mRNA-seq embryonic and adult RGCs, along with adult RGCs transduced by miR-1247-5p-expressing viral vector, and identified developmentally-regulated cilial and mitochondrial biological processes, which were reinstated to their embryonic levels in adult RGCs by upregulation of miR-1247-5p. Since axon growth is also a developmentally-regulated process, in which mitochondrial dynamics play important roles, it is possible that miR-1247-5p promoted neuroprotection and axon regeneration through regulating mitochondrial functions.
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Affiliation(s)
- Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - William C Theune
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Matthew P Frost
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Anja Kearney
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA.
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5
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Wang L, Wang XD, Yang B, Wang XM, Peng YQ, Tan HJ, Xiao HM. Novel SETBP1 mutation in a chinese family with intellectual disability. BMC Med Genomics 2023; 16:233. [PMID: 37798664 PMCID: PMC10552191 DOI: 10.1186/s12920-023-01649-x] [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: 03/01/2023] [Accepted: 08/28/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Intellectual disability (ID) is characterized by an IQ < 70, which implies below-average intellectual function and a lack of skills necessary for daily living. ID may occur due to multiple causes, such as metabolic, infectious, and chromosomal causes. ID affects approximately 1-3% of the population; however, the cause can be identified in only 25% of clinical patients. METHODS To find the cause of genetic ID in a family, we performed whole-exome sequencing and Sanger sequencing to confirm the presence of a SETBP1 variant and real-time quantitative polymerase chain reaction to detect SETBP1 expression in the proband and normal controls. RESULTS A novel variant, c.942_943insGT (p. Asp316TrpfsTer28), was found in SETBP1. Furthermore, we observed that SETBP1 expression in patients was only 20% that of normal controls (P < 0.05). CONCLUSION A heterozygous variant in SETBP1 associated with ID was found. This report provides further evidence for its genetic basis and support for clinical genetic diagnosis.
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Affiliation(s)
- Le Wang
- School of Basic Medical Science, Hunan University of Medicine, Huaihua, Hunan, China
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Xu-Dong Wang
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Bo Yang
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Xue-Meng Wang
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Yu-Qian Peng
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Hang-Jing Tan
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Hong-Mei Xiao
- Center for System Biology, Data Sciences, and Reproductive Health, School of Basic Medical Science, Central South University, Changsha, Hunan, China.
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6
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Xing J, Theune WC, Lukomska A, Frost MP, Damania A, Trakhtenberg EF. Experimental upregulation of developmentally downregulated ribosomal protein large subunits 7 and 7A promotes axon regeneration after injury in vivo. Exp Neurol 2023; 368:114510. [PMID: 37633482 PMCID: PMC10529763 DOI: 10.1016/j.expneurol.2023.114510] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/08/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
Ribosomal proteins are involved in neurodevelopment and central nervous system (CNS) disease and injury. However, the roles of specific ribosomal protein subunits in developmental axon growth, and their potential as therapeutic targets for treating CNS injuries, are still poorly understood. Here, we show that ribosomal protein large (Rpl) and small (Rps) subunit genes are substantially (56-fold) enriched amongst the genes, which are downregulated during maturation of retinal ganglion cell (RGC) CNS projection neurons. We also show that Rpl and Rps subunits are highly co-regulated in RGCs, and partially re-upregulated after optic nerve crush (ONC). Because developmental downregulation of ribosomal proteins coincides with developmental decline in neuronal intrinsic axon growth capacity, we hypothesized that Rpl/Rps incomplete re-upregulation after injury may be a part of the cellular response which attempts to reactivate intrinsic axon growth mechanisms. We found that experimentally upregulating Rpl7 and Rpl7A promoted axon regeneration after ONC in vivo. Finally, we characterized gene networks associated with Rpl/Rps, and showed that Rpl7 and Rpl7A belong to the cluster of genes, which are shared between translational and neurodevelopmental biological processes (based on gene-ontology) that are co-downregulated in maturing RGCs during the decline in intrinsic axon growth capacity.
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Affiliation(s)
- Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT 06030, USA
| | - William C Theune
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT 06030, USA
| | - Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT 06030, USA
| | - Matthew P Frost
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT 06030, USA
| | - Ashiti Damania
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT 06030, USA.
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7
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Soucy JR, Aguzzi EA, Cho J, Gilhooley MJ, Keuthan C, Luo Z, Monavarfeshani A, Saleem MA, Wang XW, Wohlschlegel J, Baranov P, Di Polo A, Fortune B, Gokoffski KK, Goldberg JL, Guido W, Kolodkin AL, Mason CA, Ou Y, Reh TA, Ross AG, Samuels BC, Welsbie D, Zack DJ, Johnson TV. Retinal ganglion cell repopulation for vision restoration in optic neuropathy: a roadmap from the RReSTORe Consortium. Mol Neurodegener 2023; 18:64. [PMID: 37735444 PMCID: PMC10514988 DOI: 10.1186/s13024-023-00655-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/07/2023] [Indexed: 09/23/2023] Open
Abstract
Retinal ganglion cell (RGC) death in glaucoma and other optic neuropathies results in irreversible vision loss due to the mammalian central nervous system's limited regenerative capacity. RGC repopulation is a promising therapeutic approach to reverse vision loss from optic neuropathies if the newly introduced neurons can reestablish functional retinal and thalamic circuits. In theory, RGCs might be repopulated through the transplantation of stem cell-derived neurons or via the induction of endogenous transdifferentiation. The RGC Repopulation, Stem Cell Transplantation, and Optic Nerve Regeneration (RReSTORe) Consortium was established to address the challenges associated with the therapeutic repair of the visual pathway in optic neuropathy. In 2022, the RReSTORe Consortium initiated ongoing international collaborative discussions to advance the RGC repopulation field and has identified five critical areas of focus: (1) RGC development and differentiation, (2) Transplantation methods and models, (3) RGC survival, maturation, and host interactions, (4) Inner retinal wiring, and (5) Eye-to-brain connectivity. Here, we discuss the most pertinent questions and challenges that exist on the path to clinical translation and suggest experimental directions to propel this work going forward. Using these five subtopic discussion groups (SDGs) as a framework, we suggest multidisciplinary approaches to restore the diseased visual pathway by leveraging groundbreaking insights from developmental neuroscience, stem cell biology, molecular biology, optical imaging, animal models of optic neuropathy, immunology & immunotolerance, neuropathology & neuroprotection, materials science & biomedical engineering, and regenerative neuroscience. While significant hurdles remain, the RReSTORe Consortium's efforts provide a comprehensive roadmap for advancing the RGC repopulation field and hold potential for transformative progress in restoring vision in patients suffering from optic neuropathies.
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Affiliation(s)
- Jonathan R Soucy
- Department of Ophthalmology, Schepens Eye Research Institute of Mass. Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Erika A Aguzzi
- The Institute of Ophthalmology, University College London, London, England, UK
| | - Julie Cho
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Michael James Gilhooley
- The Institute of Ophthalmology, University College London, London, England, UK
- Moorfields Eye Hospital, London, England, UK
| | - Casey Keuthan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ziming Luo
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Aboozar Monavarfeshani
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Meher A Saleem
- Bascom Palmer Eye Institute, University of Miami Health System, Miami, FL, USA
| | - Xue-Wei Wang
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Petr Baranov
- Department of Ophthalmology, Schepens Eye Research Institute of Mass. Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, QC, Canada
- University of Montreal Hospital Research Centre, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, OR, USA
| | - Kimberly K Gokoffski
- Department of Ophthalmology, Roski Eye Institute, University of Southern California, Los Angeles, CA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Alex L Kolodkin
- The Solomon H Snyder, Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Carol A Mason
- Departments of Pathology and Cell Biology, Neuroscience, and Ophthalmology, College of Physicians and Surgeons, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Yvonne Ou
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Ahmara G Ross
- Departments of Ophthalmology and Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, Callahan Eye Hospital, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Derek Welsbie
- Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California, San Diego, CA, USA
| | - Donald J Zack
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, 21287 MD, USA
- Departments of Neuroscience, Molecular Biology & Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomas V Johnson
- Departments of Neuroscience, Molecular Biology & Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Cellular & Molecular Medicine Program, Johns Hopkins University School of Medicine, Baltimore, 21287 MD, USA.
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8
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Lukomska A, Theune WC, Xing J, Frost MP, Damania A, Gupta M, Trakhtenberg EF. Experimental gene expression of developmentally downregulated Crmp1, Crmp4, and Crmp5 promotes axon regeneration and retinal ganglion cell survival after optic nerve injury. Brain Res 2023; 1809:148368. [PMID: 37059258 PMCID: PMC10227878 DOI: 10.1016/j.brainres.2023.148368] [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: 02/25/2023] [Revised: 03/29/2023] [Accepted: 04/10/2023] [Indexed: 04/16/2023]
Abstract
Collapsin response mediator proteins (Crmps) play roles in neuronal development and axon growth. However, neuronal-specific roles of Crmp1, Crmp4, and Crmp5 in regeneration of injured central nervous system (CNS) axons in vivo are unclear. Here, we analyzed developmental and subtype-specific expression of Crmp genes in retinal ganglion cells (RGCs), tested whether overexpressing Crmp1, Crmp4, or Crmp5 in RGCs through localized intralocular AAV2 delivery promotes axon regeneration after optic nerve injury in vivo, and characterized developmental co-regulation of gene-concept networks associated with Crmps. We found that all Crmp genes are developmentally downregulated in RGCs during maturation. However, while Crmp1, Crmp2, and Crmp4 were expressed to a varying degree in most RGC subtypes, Crmp3 and Crmp5 were expressed only in a small subset of RGC subtypes. We then found that after optic nerve injury, Crmp1, Crmp4, and Crmp5 promote RGC axon regeneration to varying extents, with Crmp4 promoting the most axon regeneration and also localizing to axons. We also found that Crmp1 and Crmp4, but not Crmp5, promote RGC survival. Finally, we found that Crmp1, Crmp2, Crmp4, and Crmp5's ability to promote axon regeneration is associated with neurodevelopmental mechanisms, which control RGC's intrinsic axon growth capacity.
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Affiliation(s)
- Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - William C Theune
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Matthew P Frost
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ashiti Damania
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Mahit Gupta
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA.
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9
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Lukomska A, Kim J, Rheaume BA, Xing J, Hoyt A, Lecky E, Steidl T, Trakhtenberg EF. Developmentally upregulated transcriptional elongation factor a like 3 suppresses axon regeneration after optic nerve injury. Neurosci Lett 2021; 765:136260. [PMID: 34560191 PMCID: PMC8572158 DOI: 10.1016/j.neulet.2021.136260] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 09/04/2021] [Accepted: 09/19/2021] [Indexed: 11/24/2022]
Abstract
Projection neurons of the mammalian central nervous system (CNS) do not spontaneously regenerate axons which have been damaged by an injury or disease, often leaving patients with permanent disabilities that affect motor, cognitive, or sensory functions. Although several molecular targets which promote some extent of axon regeneration in animal models have been identified, the resulting recovery is very limited, and the molecular mechanisms underlying the axonal regenerative failure in the CNS are still poorly understood. One of the most studied targets for axon regeneration in the CNS is the mTOR pathway. A number of developmentally regulated genes also have been found to play a role in CNS axon regeneration. Here, we found that Transcriptional Elongation Factor A Like 3 (Tceal3), belonging to the Bex/Tceal transcriptional regulator family, which also modulates the mTOR pathway, is developmentally upregulated in retinal ganglion cell (RGCs) projection CNS neurons, and suppresses their capacity to regenerate axons after injury.
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Affiliation(s)
- Agnieszka Lukomska
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Juhwan Kim
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Bruce A Rheaume
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Jian Xing
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Alexela Hoyt
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Emmalyn Lecky
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Tyler Steidl
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT 06030, USA.
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10
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Protein Phosphatase 2A (PP2A) mutations in brain function, development, and neurologic disease. Biochem Soc Trans 2021; 49:1567-1588. [PMID: 34241636 DOI: 10.1042/bst20201313] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 12/15/2022]
Abstract
By removing Ser/Thr-specific phosphorylations in a multitude of protein substrates in diverse tissues, Protein Phosphatase type 2A (PP2A) enzymes play essential regulatory roles in cellular signalling and physiology, including in brain function and development. Here, we review current knowledge on PP2A gene mutations causally involved in neurodevelopmental disorders and intellectual disability, focusing on PPP2CA, PPP2R1A and PPP2R5D. We provide insights into the impact of these mutations on PP2A structure, substrate specificity and potential function in neurobiology and brain development.
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11
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Venugopalan P, Cameron EG, Zhang X, Nahmou M, Muller KJ, Goldberg JL. Physiologic maturation is both extrinsically and intrinsically regulated in progenitor-derived neurons. Sci Rep 2020; 10:2337. [PMID: 32047174 PMCID: PMC7012889 DOI: 10.1038/s41598-020-58120-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/03/2020] [Indexed: 12/15/2022] Open
Abstract
During development, newly-differentiated neurons undergo several morphological and physiological changes to become functional, mature neurons. Physiologic maturation of neuronal cells derived from isolated stem or progenitor cells may provide insight into maturation in vivo but is not well studied. As a step towards understanding how neuronal maturation is regulated, we studied the developmental switch of response to the neurotransmitter GABA, from excitatory depolarization to inhibitory hyperpolarization. We compared acutely isolated retinal ganglion cells (RGCs) at various developmental stages and RGCs differentiated in vitro from embryonic retinal progenitors for the effects of aging and, independently, of retinal environment age on their GABAA receptor (GABAAR) responses, elicited by muscimol. We found that neurons generated in vitro from progenitors exhibited depolarizing, immature GABA responses, like those of early postnatal RGCs. As progenitor-derived neurons aged from 1 to 3 weeks, their GABA responses matured. Interestingly, signals secreted by the early postnatal retina suppressed acquisition of mature GABA responses. This suppression was not associated with changes in expression of GABAAR or of the chloride co-transporter KCC2, but rather with inhibition of KCC2 dimerization in differentiating neurons. Taken together, these data indicate GABA response maturation depends on release of inhibition by developmentally regulated diffusible signals from the retina.
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Affiliation(s)
- Praseeda Venugopalan
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
| | - Evan G Cameron
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA
| | - Xiong Zhang
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
| | - Michael Nahmou
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA
| | - Kenneth J Muller
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
- Department of Physiology & Biophysics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - Jeffrey L Goldberg
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA.
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA.
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12
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Distribution of SET/I2PP2A protein in gastrointestinal tissues. PLoS One 2019; 14:e0222845. [PMID: 31557212 PMCID: PMC6762106 DOI: 10.1371/journal.pone.0222845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 09/09/2019] [Indexed: 11/21/2022] Open
Abstract
SET (also called I2PP2A and TIF-1) is a multi-functional protein that regulates a variety of cell signaling including nucleosome assembly, histone binding, and tumorigenesis. Elevated SET protein levels are observed in various human tumors, and are correlated with poor prognosis and drug-resistance. We recently reported that SET protein levels in cancer cells were positively correlated with poor prognosis of gastric cancer patients. Using immunohistochemistry, SET protein was observed not only in cancer cells, but also in some interstitial cells. However, the tissue distribution of SET has not been investigated. Here we performed co-immunofluorescent staining to characterize SET protein distribution in gastrointestinal tissues. We found that even though the positive rate is much lower than epithelial cells, SET protein is also expressed in non-epithelial cells, such as monocytes/macrophages, neural cells, myofibroblasts, and smooth muscle cells. Our results indicate an extensive role of SET in a variety of cell types.
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13
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Rheaume BA, Jereen A, Bolisetty M, Sajid MS, Yang Y, Renna K, Sun L, Robson P, Trakhtenberg EF. Single cell transcriptome profiling of retinal ganglion cells identifies cellular subtypes. Nat Commun 2018; 9:2759. [PMID: 30018341 PMCID: PMC6050223 DOI: 10.1038/s41467-018-05134-3] [Citation(s) in RCA: 237] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 06/12/2018] [Indexed: 12/13/2022] Open
Abstract
Retinal ganglion cells (RGCs) convey the major output of information collected from the eye to the brain. Thirty subtypes of RGCs have been identified to date. Here, we analyze 6225 RGCs (average of 5000 genes per cell) from right and left eyes by single-cell RNA-seq and classify them into 40 subtypes using clustering algorithms. We identify additional subtypes and markers, as well as transcription factors predicted to cooperate in specifying RGC subtypes. Zic1, a marker of the right eye-enriched subtype, is validated by immunostaining in situ. Runx1 and Fst, the markers of other subtypes, are validated in purified RGCs by fluorescent in situ hybridization (FISH) and immunostaining. We show the extent of gene expression variability needed for subtype segregation, and we show a hierarchy in diversification from a cell-type population to subtypes. Finally, we present a website for comparing the gene expression of RGC subtypes.
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Affiliation(s)
- Bruce A Rheaume
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT, 06030, USA
| | - Amyeo Jereen
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT, 06030, USA
| | - Mohan Bolisetty
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
| | - Muhammad S Sajid
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT, 06030, USA
| | - Yue Yang
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT, 06030, USA
| | - Kathleen Renna
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT, 06030, USA
| | - Lili Sun
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
| | - Paul Robson
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
- Institute for Systems Genomics and Department of Genetics & Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, 06032, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave, Farmington, CT, 06030, USA.
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14
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Kim J, Sajid MS, Trakhtenberg EF. The extent of extra-axonal tissue damage determines the levels of CSPG upregulation and the success of experimental axon regeneration in the CNS. Sci Rep 2018; 8:9839. [PMID: 29959434 PMCID: PMC6026156 DOI: 10.1038/s41598-018-28209-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/19/2018] [Indexed: 02/07/2023] Open
Abstract
The failure of mature central nervous system (CNS) projection neurons to regenerate axons over long distances drastically limits the recovery of functions lost after various CNS injuries and diseases. Although a number of manipulations that stimulate some degree of axon regeneration that overcomes the inhibitory environment after CNS injury have been discovered, the extent of regeneration remains very limited, emphasizing the need for improved therapies. Regenerating axons need nerve tissue environment capable of supporting their growth, and severe extra-axonal tissue damage and remodeling after injury may disrupt such environment. Here, we used traumatic injury to the mouse optic nerve as a model system to investigate how the extent of extra-axonal tissue damage affects experimental axon regeneration. Axon regeneration was stimulated by the shRNA-mediated knockdown (KD) of Pten gene expression in the retinal ganglion cells, and the extent of extra-axonal tissue damage was varied by changing the duration of optic nerve crush. Although no axons were spared using either 1 or 5 seconds crush, we found that Pten KD-stimulated axon regeneration was significantly reduced in 5 seconds compared with 1 second crush. The more severe extra-axonal tissue damage did not cause tissue atrophy, but led to significantly higher upregulation of axon growth-inhibiting chondroitin sulfate proteoglycan (CSPG) in the glial scar and also enlarged glial scar size, compared with less severely damaged tissue. Thus, the success of axon-regenerating approaches that target neuronal intrinsic mechanisms of axon growth is dependent on the preservation of appropriate extra-axonal tissue environment, which may need to be co-concurrently repaired by tissue remodeling methods.
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Affiliation(s)
- Juhwan Kim
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT, 06030, USA
| | - Muhammad S Sajid
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT, 06030, USA
- University of Hartford, 200 Bloomfield Ave., West Hartford, CT, 06117, USA
| | - Ephraim F Trakhtenberg
- Department of Neuroscience, University of Connecticut School of Medicine, 263 Farmington Ave., Farmington, CT, 06030, USA.
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15
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Stevens SJ, van der Schoot V, Leduc MS, Rinne T, Lalani SR, Weiss MM, van Hagen JM, Lachmeijer AM, Stockler-Ipsiroglu SG, Lehman A, Brunner HG. De novo mutations in the SET
nuclear proto-oncogene, encoding a component of the inhibitor of histone acetyltransferases (INHAT) complex in patients with nonsyndromic intellectual disability. Hum Mutat 2018; 39:1014-1023. [DOI: 10.1002/humu.23541] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/12/2018] [Accepted: 04/20/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Servi J.C. Stevens
- Department of Clinical Genetics; Maastricht University Medical Centre; Maastricht the Netherlands
| | - Vyne van der Schoot
- Department of Clinical Genetics; Maastricht University Medical Centre; Maastricht the Netherlands
| | - Magalie S. Leduc
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston Texas
- Baylor Genetics; Houston Texas USA
| | - Tuula Rinne
- Department of Genetics; Radboud University Medical Centre; Nijmegen the Netherlands
| | - Seema R. Lalani
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston Texas
| | - Marjan M. Weiss
- Department of Clinical Genetics; VU University Medical Centre; Amsterdam the Netherlands
| | - Johanna M. van Hagen
- Department of Clinical Genetics; VU University Medical Centre; Amsterdam the Netherlands
| | | | | | - Anna Lehman
- Department of Medical Genetics; British Columbia Children's Hospital; Vancouver Canada
| | - Han G Brunner
- Department of Clinical Genetics; Maastricht University Medical Centre; Maastricht the Netherlands
- Department of Genetics; Radboud University Medical Centre; Nijmegen the Netherlands
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16
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Wu M, Yu G, Yan T, Ke D, Wang Q, Liu R, Wang JZ, Zhang B, Chen D, Wang X. Phosphorylation of SET mediates apoptosis via P53 hyperactivation and NM23-H1 nuclear import. Neurobiol Aging 2018; 69:38-47. [PMID: 29852409 DOI: 10.1016/j.neurobiolaging.2018.04.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 04/12/2018] [Accepted: 04/27/2018] [Indexed: 01/22/2023]
Abstract
Apoptosis plays an important role in neuron loss in Alzheimer's disease (AD). SET, an endogenous inhibitor of protein phosphatase-2A, is phosphorylated in AD brains and positively correlates with cell apoptosis. However, the mechanism underlying phosphorylated SET association with apoptosis remains unknown. Here, we show that mimetic phosphorylation of SET (S9E) induced apoptosis of primary cultured neurons. To investigate its mechanism, we overexpressed SET (S9E) in HEK293/tau cells and observed apoptosis accompanied with a marked increase of cleaved caspase-3 and cytoplasmic SET (S9E) retention with enhanced protein phosphatase-2A inhibition, which subsequently caused p53 hyperphosphorylation and activation. In addition, it caused the release of nucleoside diphosphate kinase A isoform a, a positive regulator of p53 with a DNase activity from SET/nucleoside diphosphate kinase A isoform a complex, and migration into the nucleus, resulting in DNA damage. Besides, it reduced nuclear tau accumulation leading to DNA protection deficiency. These findings suggest that SET phosphorylation is involved in the neuronal apoptotic pathway in AD and provide a new insight into the mechanism of this pathology.
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Affiliation(s)
- Mengjuan Wu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guang Yu
- Experimental Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tonghai Yan
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dan Ke
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qun Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rong Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dan Chen
- School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Xiaochuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.
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17
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Xiao H, Sun Z, Wan J, Hou S, Xiong Y. Overexpression of protocadherin 7 inhibits neuronal survival by downregulating BIRC5 in vitro. Exp Cell Res 2018; 366:71-80. [PMID: 29548751 DOI: 10.1016/j.yexcr.2018.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/12/2018] [Accepted: 03/13/2018] [Indexed: 12/29/2022]
Abstract
Protocadherins (Pcdhs) are widely-expressed transmembrane proteins in the nervous system. Recent studies suggest that Pcdhs play multiple critical roles during neuronal development. However, the cellular mechanisms of Pcdh7 in neurons are still largely unknown. In the current study, we demonstrated that the expression of Pcdh7 during mouse brain development was regulated spatiotemporally. We observed that the elevated expression of Pcdh7 led to activation of the intrinsic apoptotic pathway in primary cortical neurons. Whole transcriptome sequencing revealed that 12 genes were involved in the apoptotic pathway including baculoviral inhibitor of apoptosis (IAP) repeat containing 5 (BIRC5). The neuronal apoptosis caused by Pcdh7 overexpression could be significantly inhibited by either a missense mutation in the conserved motif CM2 domain of Pcdh7 or BIRC5 overexpression. These results suggest the existence of Pcdh7-BIRC5 signaling cascade in the cortical neurons and represent a potential therapeutic area for further investigation.
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Affiliation(s)
- Huajuan Xiao
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Ziling Sun
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Jun Wan
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China; Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Shengtao Hou
- Brain Research Center and Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Yi Xiong
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.
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18
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Wang J, Li Y, King R, Struebing FL, Geisert EE. Optic nerve regeneration in the mouse is a complex trait modulated by genetic background. Mol Vis 2018; 24:174-186. [PMID: 29463955 PMCID: PMC5815339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/13/2018] [Indexed: 10/24/2022] Open
Abstract
Purpose The present study is designed to identify the influences of genetic background on optic nerve regeneration using the two parental strains (C57BL/6J and DBA/2J) and seven BXD recombinant inbred mouse strains. Methods To study regeneration in the optic nerve, Pten was knocked down in the retinal ganglion cells using adenoassociated virus (AAV) delivery of shRNA, and a mild inflammatory response was induced with an intravitreal injection of zymosan with CPT-cAMP. The axons of the retinal ganglion cells were damaged by optic nerve crush (ONC). Following a 12-day survival period, regenerating axons were labeled by cholera toxin B, and 2 days later, the regenerating axons within the optic nerve were examined. The number of axons at 0.5 mm and 1 mm from the crush site were counted. In addition, we measured the distance that five axons had grown down the nerve and the longest distance a single axon reached. Results The analysis revealed a considerable amount of differential axonal regeneration across the seven BXD strains and the parental strains. There was a statistically significant difference (p=0.014 Mann-Whitney U test) in the regenerative capacity in the number of axons reaching 0.5 mm from a low of 236.1±24.4 axons in the BXD102 mice to a high of 759.8±79.2 axons in the BXD29 mice. There were also statistically significant differences (p=0.014 Mann-Whitney U test) in the distance axons traveled. Looking at a minimum of five axons, the shortest distance was 787.2±46.5 µm in the BXD102 mice, and the maximum distance was 2025.5±223.3 µm in the BXD29 mice. Conclusions Differences in genetic background can have a profound effect on axonal regeneration causing a threefold increase in the number of regenerating axons at 0.5 mm from the crush site and a 2.5-fold increase in the distance traveled by at least five axons in the damaged optic nerve.
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Affiliation(s)
- Jiaxing Wang
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China,Department of Ophthalmology, Emory University, Atlanta, GA
| | - Ying Li
- Department of Ophthalmology, Emory University, Atlanta, GA
| | - Rebecca King
- Department of Ophthalmology, Emory University, Atlanta, GA
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19
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Pinto G, Radulovic M, Godovac-Zimmermann J. Spatial perspectives in the redox code-Mass spectrometric proteomics studies of moonlighting proteins. MASS SPECTROMETRY REVIEWS 2018; 37:81-100. [PMID: 27186965 DOI: 10.1002/mas.21508] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/03/2016] [Indexed: 06/05/2023]
Abstract
The Redox Code involves specific, reversible oxidative changes in proteins that modulate protein tertiary structure, interactions, trafficking, and activity, and hence couple the proteome to the metabolic/oxidative state of cells. It is currently a major focus of study in cell biology. Recent studies of dynamic cellular spatial reorganization with MS-based subcellular-spatial-razor proteomics reveal that protein constituents of many subcellular structures, including mitochondria, the endoplasmic reticulum, the plasma membrane, and the extracellular matrix, undergo changes in their subcellular abundance/distribution in response to oxidative stress. These proteins are components of a diverse variety of functional processes spatially distributed across cells. Many of the same proteins are involved in response to suppression of DNA replication indicate that oxidative stress is strongly intertwined with DNA replication/proliferation. Both are replete with networks of moonlighting proteins that show coordinated changes in subcellular location and that include primary protein actuators of the redox code involved in the processing of NAD+ /NADH, NADP+ /NADPH, Cys/CySS, and GSH/GSSG redox couples. Small groups of key proteins such as {KPNA2, KPNB1, PCNA, PTMA, SET} constitute "spatial switches" that modulate many nuclear processes. Much of the functional response involves subcellular protein trafficking, including nuclear import/export processes, vesicle-mediated trafficking, the endoplasmic reticulum/Golgi pathway, chaperone-assisted processes, and other transport systems. This is not visible to measurements of total protein abundance by transcriptomics or proteomics. Comprehensive pictures of cellular function will require collection of data on the subcellular transport and local functions of many moonlighting proteins, especially of those with critical roles in spatial coordination across cells. The proteome-wide analysis of coordinated changes in abundance and trafficking of proteins offered by MS-based proteomics has a unique, crucial role to play in deciphering the complex adaptive systems that underlie cellular function. © 2016 Wiley Periodicals, Inc. Mass Spec Rev.
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Affiliation(s)
- Gabriella Pinto
- Division of Medicine, Center for Nephrology, Royal Free Campus, University College London, Rowland Hill Street, London, NW3 2PF, United Kingdom
| | - Marko Radulovic
- Insitute of Oncology and Radiology, Pasterova 14, Belgrade, 11000, Serbia
| | - Jasminka Godovac-Zimmermann
- Division of Medicine, Center for Nephrology, Royal Free Campus, University College London, Rowland Hill Street, London, NW3 2PF, United Kingdom
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20
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Dorard E, Chasseigneaux S, Gorisse-Hussonnois L, Broussard C, Pillot T, Allinquant B. Soluble Amyloid Precursor Protein Alpha Interacts with alpha3-Na, K-ATPAse to Induce Axonal Outgrowth but Not Neuroprotection: Evidence for Distinct Mechanisms Underlying these Properties. Mol Neurobiol 2017; 55:5594-5610. [PMID: 28983842 DOI: 10.1007/s12035-017-0783-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/20/2017] [Indexed: 01/09/2023]
Abstract
Amyloid precursor protein (APP) is cleaved not only to generate the amyloid peptide (Aß), involved in neurodegenerative processes, but can also be metabolized by alpha secretase to produce and release soluble N-terminal APP (sAPPα), which has many properties including the induction of axonal elongation and neuroprotection. The mechanisms underlying the properties of sAPPα are not known. Here, we used proteomic analysis of mouse cortico-hippocampal membranes to identify the neuronal specific alpha3 (α3)-subunit of the plasma membrane enzyme Na, K-ATPase (NKA) as a new binding partner of sAPPα. We showed that sAPPα recruits very rapidly clusters of α3-NKA at neuronal surface, and its binding triggers a cascade of events promoting sAPPα-induced axonal outgrowth. The binding of sAPPα with α3-NKA was not observed for sAPPα-induced Aß1-42 oligomers neuroprotection, neither the downstream events particularly the interaction of sAPPα with APP before endocytosis, ERK signaling, and the translocation of SET from the nucleus to the plasma membrane. These data suggest that the mechanisms of the axonal growth promoting and neuroprotective properties of sAPPα appear to be specific and independent. The signals at the cell surface specific to trigger these mechanisms require further study.
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Affiliation(s)
- Emilie Dorard
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France.,SynAging, 54500, Vandoeuvre-les, Nancy, France
| | - Stéphanie Chasseigneaux
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France.,INSERM U1144, Université Paris Descartes and Université Paris Diderot UMR-S 1144, 75006, Paris, France
| | - Lucie Gorisse-Hussonnois
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France
| | - Cédric Broussard
- Plate-forme Protéomique, Université Paris Descartes 3P5, Institut Cochin, 75014, Paris, France
| | | | - Bernadette Allinquant
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France.
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KLF9 and JNK3 Interact to Suppress Axon Regeneration in the Adult CNS. J Neurosci 2017; 37:9632-9644. [PMID: 28871032 DOI: 10.1523/jneurosci.0643-16.2017] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/22/2017] [Accepted: 08/23/2017] [Indexed: 01/22/2023] Open
Abstract
Neurons in the adult mammalian CNS decrease in intrinsic axon growth capacity during development in concert with changes in Krüppel-like transcription factors (KLFs). KLFs regulate axon growth in CNS neurons including retinal ganglion cells (RGCs). Here, we found that knock-down of KLF9, an axon growth suppressor that is normally upregulated 250-fold in RGC development, promotes long-distance optic nerve regeneration in adult rats of both sexes. We identified a novel binding partner, MAPK10/JNK3 kinase, and found that JNK3 (c-Jun N-terminal kinase 3) is critical for KLF9's axon-growth-suppressive activity. Interfering with a JNK3-binding domain or mutating two newly discovered serine phosphorylation acceptor sites, Ser106 and Ser110, effectively abolished KLF9's neurite growth suppression in vitro and promoted axon regeneration in vivo These findings demonstrate a novel, physiologic role for the interaction of KLF9 and JNK3 in regenerative failure in the optic nerve and suggest new therapeutic strategies to promote axon regeneration in the adult CNS.SIGNIFICANCE STATEMENT Injured CNS nerves fail to regenerate spontaneously. Promoting intrinsic axon growth capacity has been a major challenge in the field. Here, we demonstrate that knocking down Krüppel-like transcription factor 9 (KLF9) via shRNA promotes long-distance axon regeneration after optic nerve injury and uncover a novel and important KLF9-JNK3 interaction that contributes to axon growth suppression in vitro and regenerative failure in vivo These studies suggest potential therapeutic approaches to promote axon regeneration in injury and other degenerative diseases in the adult CNS.
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22
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Pharmacological intervention of early neuropathy in neurodegenerative diseases. Pharmacol Res 2017; 119:169-177. [PMID: 28167240 DOI: 10.1016/j.phrs.2017.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/31/2017] [Accepted: 02/02/2017] [Indexed: 12/11/2022]
Abstract
Extensive studies have reported the significant roles of numerous cellular features and processes in properly maintaining neuronal morphology and function throughout the lifespan of an animal. Any alterations in their homeostasis appear to be strongly associated with neuronal aging and the pathogenesis of various neurodegenerative diseases, even before the occurrence of prominent neuronal death. However, until recently, the primary focus of studies regarding many neurodegenerative diseases has been on the massive cell death occurring at the late stages of disease progression. Thus, our understanding on early neuropathy in these diseases remains relatively limited. The complicated nature of various neuropathic features manifested early in neurodegenerative diseases suggests the involvement of a system-wide transcriptional regulation and epigenetic control. Epigenetic alterations and consequent changes in the neuronal transcriptome are now begun to be extensively studied in various neurodegenerative diseases. Upon the catastrophic incident of neuronal death in disease progression, it is utterly difficult to reverse the deleterious defects by pharmacological treatments, and therefore, therapeutics targeting the system-wide transcriptional dysregulation associated with specific early neuropathy is considered a better option. Here, we review our current understanding on the system-wide transcriptional dysregulation that is likely associated with early neuropathy shown in various neurodegenerative diseases and discuss the possible future developments of pharmaceutical therapeutics.
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Reaching the brain: Advances in optic nerve regeneration. Exp Neurol 2017; 287:365-373. [DOI: 10.1016/j.expneurol.2015.12.015] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 12/22/2015] [Indexed: 11/20/2022]
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Zhou X, Updegraff BL, Guo Y, Peyton M, Girard L, Larsen JE, Xie XJ, Zhou Y, Hwang TH, Xie Y, Rodriguez-Canales J, Villalobos P, Behrens C, Wistuba II, Minna JD, O'Donnell KA. PROTOCADHERIN 7 Acts through SET and PP2A to Potentiate MAPK Signaling by EGFR and KRAS during Lung Tumorigenesis. Cancer Res 2016; 77:187-197. [PMID: 27821484 DOI: 10.1158/0008-5472.can-16-1267-t] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 10/11/2016] [Accepted: 10/23/2016] [Indexed: 12/14/2022]
Abstract
Non-small cell lung cancer (NSCLC) is the leading cause of cancer-associated deaths worldwide. Given the efficacy of membrane proteins as therapeutic targets in human malignancies, we examined cell-surface receptors that may act as drivers of lung tumorigenesis. Here, we report that the PROTOCADHERIN PCDH7 is overexpressed frequently in NSCLC tumors where this event is associated with poor clinical outcome. PCDH7 overexpression synergized with EGFR and KRAS to induce MAPK signaling and tumorigenesis. Conversely, PCDH7 depletion suppressed ERK activation, sensitized cells to MEK inhibitors, and reduced tumor growth. PCDH7 potentiated ERK signaling by facilitating interaction of protein phosphatase PP2A with its potent inhibitor, the SET oncoprotein. By establishing an oncogenic role for PCDH7 in lung tumorigenesis, our results provide a rationale to develop novel PCDH7 targeting therapies that act at the cell surface of NSCLC cells to compromise their growth. Cancer Res; 77(1); 187-97. ©2016 AACR.
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Affiliation(s)
- Xiaorong Zhou
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas.,Department of Immunology, Nantong University School of Medicine, Nantong, China
| | - Barrett L Updegraff
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Yabin Guo
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Michael Peyton
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, Texas
| | - Luc Girard
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, Texas.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, Texas
| | - Jill E Larsen
- Department of Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland
| | - Xian-Jin Xie
- Department of Clinical Science, UT Southwestern Medical Center, Dallas, Texas.,Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas
| | - Yunyun Zhou
- Department of Clinical Science, UT Southwestern Medical Center, Dallas, Texas
| | - Tae Hyun Hwang
- Department of Clinical Science, UT Southwestern Medical Center, Dallas, Texas
| | - Yang Xie
- Department of Clinical Science, UT Southwestern Medical Center, Dallas, Texas
| | - Jaime Rodriguez-Canales
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Pamela Villalobos
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Carmen Behrens
- Department of Thoracic Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ignacio I Wistuba
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - John D Minna
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, Texas.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, Texas.,Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Kathryn A O'Donnell
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas. .,Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas
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25
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The zebrafish homologs of SET/I2PP2A oncoprotein: expression patterns and insights into their physiological roles during development. Biochem J 2016; 473:4609-4627. [PMID: 27754889 DOI: 10.1042/bcj20160523] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/13/2016] [Accepted: 10/17/2016] [Indexed: 01/12/2023]
Abstract
The oncoprotein SET/I2PP2A (protein phosphatase 2A inhibitor 2) participates in various cellular mechanisms such as transcription, cell cycle regulation and cell migration. SET is also an inhibitor of the serine/threonine phosphatase PP2A, which is involved in the regulation of cell homeostasis. In zebrafish, there are two paralogous set genes that encode Seta (269 amino acids) and Setb (275 amino acids) proteins which share 94% identity. We show here that seta and setb are similarly expressed in the eye, the otic vesicle, the brain and the lateral line system, as indicated by in situ hybridization labeling. Whole-mount immunofluorescence analysis revealed the expression of Seta/b proteins in the eye retina, the olfactory pit and the lateral line neuromasts. Loss-of-function studies using antisense morpholino oligonucleotides targeting both seta and setb genes (MOab) resulted in increased apoptosis, reduced cell proliferation and morphological defects. The morphant phenotypes were partially rescued when MOab was co-injected with human SET mRNA. Knockdown of setb with a transcription-blocking morpholino oligonucleotide (MOb) resulted in phenotypic defects comparable with those induced by setb gRNA (guide RNA)/Cas9 [CRISPR (clustered regularly interspaced short palindromic repeats)-associated 9] injections. In vivo labeling of hair cells showed a significantly decreased number of neuromasts in MOab-, MOb- and gRNA/Cas9-injected embryos. Microarray analysis of MOab morphant transcriptome revealed differential expression in gene networks controlling transcription in the sensory organs, including the eye retina, the ear and the lateral line. Collectively, our results suggest that seta and setb are required during embryogenesis and play roles in the zebrafish sensory system development.
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26
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Cell types differ in global coordination of splicing and proportion of highly expressed genes. Sci Rep 2016; 6:32249. [PMID: 27577089 PMCID: PMC5006053 DOI: 10.1038/srep32249] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/01/2016] [Indexed: 01/01/2023] Open
Abstract
Balance in the transcriptome is regulated by coordinated synthesis and degradation of RNA molecules. Here we investigated whether mammalian cell types intrinsically differ in global coordination of gene splicing and expression levels. We analyzed RNA-seq transcriptome profiles of 8 different purified mouse cell types. We found that different cell types vary in proportion of highly expressed genes and the number of alternatively spliced transcripts expressed per gene, and that the cell types that express more variants of alternatively spliced transcripts per gene are those that have higher proportion of highly expressed genes. Cell types segregated into two clusters based on high or low proportion of highly expressed genes. Biological functions involved in negative regulation of gene expression were enriched in the group of cell types with low proportion of highly expressed genes, and biological functions involved in regulation of transcription and RNA splicing were enriched in the group of cell types with high proportion of highly expressed genes. Our findings show that cell types differ in proportion of highly expressed genes and the number of alternatively spliced transcripts expressed per gene, which represent distinct properties of the transcriptome and may reflect intrinsic differences in global coordination of synthesis, splicing, and degradation of RNA molecules.
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27
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Radulovic M, Baqader NO, Stoeber K, Godovac-Zimmermann J. Spatial Cross-Talk between Oxidative Stress and DNA Replication in Human Fibroblasts. J Proteome Res 2016; 15:1907-38. [PMID: 27142241 DOI: 10.1021/acs.jproteome.6b00101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MS-based proteomics has been applied to a differential network analysis of the nuclear-cytoplasmic subcellular distribution of proteins between cell-cycle arrest: (a) at the origin activation checkpoint for DNA replication, or (b) in response to oxidative stress. Significant changes were identified for 401 proteins. Cellular response combines changes in trafficking and in total abundance to vary the local compartmental abundances that are the basis of cellular response. Appreciable changes for both perturbations were observed for 245 proteins, but cross-talk between oxidative stress and DNA replication is dominated by 49 proteins that show strong changes for both. Many nuclear processes are influenced by a spatial switch involving the proteins {KPNA2, KPNB1, PCNA, PTMA, SET} and heme/iron proteins HMOX1 and FTH1. Dynamic spatial distribution data are presented for proteins involved in caveolae, extracellular matrix remodelling, TGFβ signaling, IGF pathways, emerin complexes, mitochondrial protein import complexes, spliceosomes, proteasomes, and so on. The data indicate that for spatially heterogeneous cells cross-compartmental communication is integral to their system biology, that coordinated spatial redistribution for crucial protein networks underlies many functional changes, and that information on dynamic spatial redistribution of proteins is essential to obtain comprehensive pictures of cellular function. We describe how spatial data of the type presented here can provide priorities for further investigation of crucial features of high-level spatial coordination across cells. We suggest that the present data are related to increasing indications that much of subcellular protein transport is constitutive and that perturbation of these constitutive transport processes may be related to cancer and other diseases. A quantitative, spatially resolved nucleus-cytoplasm interaction network is provided for further investigations.
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Affiliation(s)
- Marko Radulovic
- Division of Medicine, University College London, Center for Nephrology , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom.,Insitute of Oncology and Radiology , Pasterova 14, 11000 Belgrade, Serbia
| | - Noor O Baqader
- Division of Medicine, University College London, Center for Nephrology , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
| | - Kai Stoeber
- Research Department of Pathology and UCL Cancer Institute, Rockefeller Building, University College London , University Street, London WC1E 6JJ, United Kingdom
| | - Jasminka Godovac-Zimmermann
- Division of Medicine, University College London, Center for Nephrology , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
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28
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Trakhtenberg EF, Pita-Thomas W, Fernandez SG, Patel KH, Venugopalan P, Shechter JM, Morkin MI, Galvao J, Liu X, Dombrowski SM, Goldberg JL. Serotonin receptor 2C regulates neurite growth and is necessary for normal retinal processing of visual information. Dev Neurobiol 2016; 77:419-437. [PMID: 26999672 DOI: 10.1002/dneu.22391] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 01/25/2016] [Accepted: 03/12/2016] [Indexed: 12/21/2022]
Abstract
Serotonin (5HT) is present in a subpopulation of amacrine cells, which form synapses with retinal ganglion cells (RGCs), but little is known about the physiological role of retinal serotonergic circuitry. We found that the 5HT receptor 2C (5HTR2C) is upregulated in RGCs after birth. Amacrine cells generate 5HT and about half of RGCs respond to 5HTR2C agonism with calcium elevation. We found that there are on average 83 5HT+ amacrine cells randomly distributed across the adult mouse retina, all negative for choline acetyltransferase and 90% positive for tyrosine hydroxylase. We also investigated whether 5HTR2C and 5HTR5A affect RGC neurite growth. We found that both suppress neurite growth, and that RGCs from the 5HTR2C knockout (KO) mice grow longer neurites. Furthermore, 5HTR2C is subject to post-transcriptional editing, and we found that only the edited isoform's suppressive effect on neurite growth could be reversed by a 5HTR2C inverse agonist. Next, we investigated the physiological role of 5HTR2C in the retina, and found that 5HTR2C KO mice showed increased amplitude on pattern electroretinogram. Finally, RGC transcriptional profiling and pathways analysis suggested partial developmental compensation for 5HTR2C absence. Taken together, our findings demonstrate that 5HTR2C regulates neurite growth and RGC activity and is necessary for normal amplitude of RGC response to physiologic stimuli, and raise the hypothesis that these functions are modulated by a subset of 5HT+/ChAT-/TH+ amacrine cells as part of retinal serotonergic circuitry. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 419-437, 2017.
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Affiliation(s)
- Ephraim F Trakhtenberg
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts.,Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida
| | - Wolfgang Pita-Thomas
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Department of Anatomy and Neurobiology, Washington University, St. Louis, Missouri
| | - Stephanie G Fernandez
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Karan H Patel
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Praseeda Venugopalan
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts.,Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Jesse M Shechter
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Melina I Morkin
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Joana Galvao
- Shiley Eye Center, University of California, San Diego, California
| | - Xiongfei Liu
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Susan M Dombrowski
- Genomatix Software, Ann Arbor, Michigan.,Department of Obstetrics & Gynecology, Wayne State University School of Medicine, Detroit, Michigan
| | - Jeffrey L Goldberg
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida.,Shiley Eye Center, University of California, San Diego, California.,Byers Eye Institute, Stanford University, Palo Alto, California
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29
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van Niekerk EA, Tuszynski MH, Lu P, Dulin JN. Molecular and Cellular Mechanisms of Axonal Regeneration After Spinal Cord Injury. Mol Cell Proteomics 2015; 15:394-408. [PMID: 26695766 DOI: 10.1074/mcp.r115.053751] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 12/28/2022] Open
Abstract
Following axotomy, a complex temporal and spatial coordination of molecular events enables regeneration of the peripheral nerve. In contrast, multiple intrinsic and extrinsic factors contribute to the general failure of axonal regeneration in the central nervous system. In this review, we examine the current understanding of differences in protein expression and post-translational modifications, activation of signaling networks, and environmental cues that may underlie the divergent regenerative capacity of central and peripheral axons. We also highlight key experimental strategies to enhance axonal regeneration via modulation of intraneuronal signaling networks and the extracellular milieu. Finally, we explore potential applications of proteomics to fill gaps in the current understanding of molecular mechanisms underlying regeneration, and to provide insight into the development of more effective approaches to promote axonal regeneration following injury to the nervous system.
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Affiliation(s)
- Erna A van Niekerk
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093;
| | - Mark H Tuszynski
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093; §Veterans Administration Medical Center, San Diego, CA 92161
| | - Paul Lu
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093; §Veterans Administration Medical Center, San Diego, CA 92161
| | - Jennifer N Dulin
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093
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30
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Ma TC, Willis DE. What makes a RAG regeneration associated? Front Mol Neurosci 2015; 8:43. [PMID: 26300725 PMCID: PMC4528284 DOI: 10.3389/fnmol.2015.00043] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/24/2015] [Indexed: 12/31/2022] Open
Abstract
Regenerative failure remains a significant barrier for functional recovery after central nervous system (CNS) injury. As such, understanding the physiological processes that regulate axon regeneration is a central focus of regenerative medicine. Studying the gene transcription responses to axon injury of regeneration competent neurons, such as those of the peripheral nervous system (PNS), has provided insight into the genes associated with regeneration. Though several individual “regeneration-associated genes” (RAGs) have been identified from these studies, the response to injury likely regulates the expression of functionally coordinated and complementary gene groups. For instance, successful regeneration would require the induction of genes that drive the intrinsic growth capacity of neurons, while simultaneously downregulating the genes that convey environmental inhibitory cues. Thus, this view emphasizes the transcriptional regulation of gene “programs” that contribute to the overall goal of axonal regeneration. Here, we review the known RAGs, focusing on how their transcriptional regulation can reveal the underlying gene programs that drive a regenerative phenotype. Finally, we will discuss paradigms under which we can determine whether these genes are injury-associated, or indeed necessary for regeneration.
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Affiliation(s)
- Thong C Ma
- Department of Neurology, Columbia University New York, NY, USA
| | - Dianna E Willis
- Brain Mind Research Institute, Weill Cornell Medical College New York, NY, USA ; Burke-Cornell Medical Research Institute White Plains, NY, USA
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31
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Trakhtenberg EF, Morkin MI, Patel KH, Fernandez SG, Sang A, Shaw P, Liu X, Wang Y, Mlacker GM, Gao H, Velmeshev D, Dombrowski SM, Vitek MP, Goldberg JL. The N-terminal Set-β Protein Isoform Induces Neuronal Death. J Biol Chem 2015; 290:13417-26. [PMID: 25833944 DOI: 10.1074/jbc.m114.633883] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 11/06/2022] Open
Abstract
Set-β protein plays different roles in neurons, but the diversity of Set-β neuronal isoforms and their functions have not been characterized. The expression and subcellular localization of Set-β are altered in Alzheimer disease, cleavage of Set-β leads to neuronal death after stroke, and the full-length Set-β regulates retinal ganglion cell (RGC) and hippocampal neuron axon growth and regeneration in a subcellular localization-dependent manner. Here we used various biochemical approaches to investigate Set-β isoforms and their role in the CNS, using the same type of neurons, RGCs, across studies. We found multiple alternatively spliced isoforms expressed from the Set locus in purified RGCs. Set transcripts containing the Set-β-specific exon were the most highly expressed isoforms. We also identified a novel, alternatively spliced Set-β transcript lacking the nuclear localization signal and demonstrated that the full-length (∼39-kDa) Set-β is localized predominantly in the nucleus, whereas a shorter (∼25-kDa) Set-β isoform is localized predominantly in the cytoplasm. Finally, we show that an N-terminal Set-β cleavage product can induce neuronal death.
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Affiliation(s)
- Ephraim F Trakhtenberg
- From the Neuroscience Program and Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Melina I Morkin
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Karan H Patel
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | | | - Alan Sang
- the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Peter Shaw
- the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Xiongfei Liu
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Yan Wang
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Gregory M Mlacker
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Han Gao
- From the Neuroscience Program and
| | - Dmitry Velmeshev
- Molecular and Cellular Pharmacology Program,University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Susan M Dombrowski
- Genomatix Software, Ann Arbor, Michigan 48108, the Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan 48201
| | - Michael P Vitek
- Oncotide Pharmaceuticals Inc., Durham, North Carolina 27709, and the Department of Neurology, Duke University Medical Center, Durham, North Carolina 27708
| | - Jeffrey L Goldberg
- From the Neuroscience Program and Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093,
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32
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Pita-Thomas W, Steketee MB, Moysidis SN, Thakor K, Hampton B, Goldberg JL. Promoting filopodial elongation in neurons by membrane-bound magnetic nanoparticles. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 11:559-67. [PMID: 25596077 DOI: 10.1016/j.nano.2014.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 10/30/2014] [Accepted: 11/24/2014] [Indexed: 12/15/2022]
Abstract
Filopodia are 5-10 μm long processes that elongate by actin polymerization, and promote axon growth and guidance by exerting mechanical tension and by molecular signaling. Although axons elongate in response to mechanical tension, the structural and functional effects of tension specifically applied to growth cone filopodia are unknown. Here we developed a strategy to apply tension specifically to retinal ganglion cell (RGC) growth cone filopodia through surface-functionalized, membrane-targeted superparamagnetic iron oxide nanoparticles (SPIONs). When magnetic fields were applied to surface-bound SPIONs, RGC filopodia elongated directionally, contained polymerized actin filaments, and generated retrograde forces, behaving as bona fide filopodia. Data presented here support the premise that mechanical tension induces filopodia growth but counter the hypothesis that filopodial tension directly promotes growth cone advance. Future applications of these approaches may be used to induce sustained forces on multiple filopodia or other subcellular microstructures to study axon growth or cell migration. From the clinical editor: Mechanical tension to the tip of filopodia is known to promote axonal growth. In this article, the authors used superparamagnetic iron oxide nanoparticles (SPIONs) targeted specifically to membrane molecules, then applied external magnetic field to elicit filopodial elongation, which provided a tool to study the role of mechanical forces in filopodia dynamics and function.
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Affiliation(s)
- Wolfgang Pita-Thomas
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Anatomy and Neurobiology, Washington University, St. Louis, MO, USA
| | - Michael B Steketee
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Ophthalmology and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stavros N Moysidis
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kinjal Thakor
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Blake Hampton
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jeffrey L Goldberg
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Ophthalmology, Shiley Eye Center, UC San Diego, San Diego, CA, USA.
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