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Talsma AD, Niemi JP, Zigmond RE. Neither injury induced macrophages within the nerve, nor the environment created by Wallerian degeneration is necessary for enhanced in vivo axon regeneration after peripheral nerve injury. J Neuroinflammation 2024; 21:134. [PMID: 38802868 PMCID: PMC11131297 DOI: 10.1186/s12974-024-03132-5] [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: 04/23/2024] [Accepted: 05/13/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND Since the 1990s, evidence has accumulated that macrophages promote peripheral nerve regeneration and are required for enhancing regeneration in the conditioning lesion (CL) response. After a sciatic nerve injury, macrophages accumulate in the injury site, the nerve distal to that site, and the axotomized dorsal root ganglia (DRGs). In the peripheral nervous system, as in other tissues, the macrophage response is derived from both resident macrophages and recruited monocyte-derived macrophages (MDMs). Unresolved questions are: at which sites do macrophages enhance nerve regeneration, and is a particular population needed. METHODS Ccr2 knock-out (KO) and Ccr2gfp/gfp knock-in/KO mice were used to prevent MDM recruitment. Using these strains in a sciatic CL paradigm, we examined the necessity of MDMs and residents for CL-enhanced regeneration in vivo and characterized injury-induced nerve inflammation. CL paradigm variants, including the addition of pharmacological macrophage depletion methods, tested the role of various macrophage populations in initiating or sustaining the CL response. In vivo regeneration, measured from bilateral proximal test lesions (TLs) after 2 d, and macrophages were quantified by immunofluorescent staining. RESULTS Peripheral CL-enhanced regeneration was equivalent between crush and transection CLs and was sustained for 28 days in both Ccr2 KO and WT mice despite MDM depletion. Similarly, the central CL response measured in dorsal roots was unchanged in Ccr2 KO mice. Macrophages at both the TL and CL, but not between them, stained for the pro-regenerative marker, arginase 1. TL macrophages were primarily CCR2-dependent MDMs and nearly absent in Ccr2 KO and Ccr2gfp/gfp KO mice. However, there were only slightly fewer Arg1+ macrophages in CCR2 null CLs than controls due to resident macrophage compensation. Zymosan injection into an intact WT sciatic nerve recruited Arg1+ macrophages but did not enhance regeneration. Finally, clodronate injection into Ccr2gfp KO CLs dramatically reduced CL macrophages. Combined with the Ccr2gfp KO background, depleting MDMs and TL macrophages, and a transection CL, physically removing the distal nerve environment, nearly all macrophages in the nerve were removed, yet CL-enhanced regeneration was not impaired. CONCLUSIONS Macrophages in the sciatic nerve are neither necessary nor sufficient to produce a CL response.
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Affiliation(s)
- Aaron D Talsma
- Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106-4975, USA
| | - Jon P Niemi
- Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106-4975, USA
| | - Richard E Zigmond
- Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106-4975, USA.
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2
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DeVault L, Mateusiak C, Palucki J, Brent M, Milbrandt J, DiAntonio A. The response of Dual-leucine zipper kinase (DLK) to nocodazole: Evidence for a homeostatic cytoskeletal repair mechanism. PLoS One 2024; 19:e0300539. [PMID: 38574058 PMCID: PMC10994325 DOI: 10.1371/journal.pone.0300539] [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: 11/13/2023] [Accepted: 02/28/2024] [Indexed: 04/06/2024] Open
Abstract
Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that low dose nocodazole treatment activates DLK signaling. Activation of DLK signaling results in a DLK-dependent transcriptional signature, which we identify through RNA-seq. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes. We identify alterations to the cytoskeleton including actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.
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Affiliation(s)
- Laura DeVault
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Chase Mateusiak
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Computer Science & Engineering, Washington University, St. Louis, MO, United States of America
| | - John Palucki
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael Brent
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Computer Science & Engineering, Washington University, St. Louis, MO, United States of America
| | - Jeffrey Milbrandt
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, United States of America
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3
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Estera LA, Walsh SP, Headen JA, Williamson RE, Kalinski AL. Neuroinflammation: Breaking barriers and bridging gaps. Neurosci Res 2023; 197:9-17. [PMID: 34748905 DOI: 10.1016/j.neures.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 11/01/2021] [Indexed: 01/04/2023]
Abstract
Neurons are the cells of the nervous system and are responsible for every thought, movement and perception. Immune cells are the cells of the immune system, constantly protecting from foreign pathogens. Understanding the interaction between the two systems is especially important in disease states such as autoimmune or neurodegenerative disease. Unfortunately, this interaction is typically detrimental to the host. However, recent efforts have focused on how neurons and immune cells interact, either directly or indirectly, following traumatic injury to the nervous system. The outcome of this interaction can be beneficial - leading to successful neural repair, or detrimental - leading to functional deficits, depending on where the injury occurs. This review will discuss our understanding of neuron-immune cell interactions after traumatic injury to both the peripheral and central nervous system.
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Affiliation(s)
- Lora A Estera
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | - Sam P Walsh
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | - Jordan A Headen
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | | | - Ashley L Kalinski
- Department of Biology, Ball State University, Muncie, IN 47306, USA.
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4
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Alex Thomas M, Cui X, Artinian LR, Cao Q, Jing J, Silva FC, Wang S, Zigman JM, Sun Y, Shi H, Xue B. Crosstalk between Gut Sensory Ghrelin Signaling and Adipose Tissue Sympathetic Outflow Regulates Metabolic Homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.25.568689. [PMID: 38076894 PMCID: PMC10705268 DOI: 10.1101/2023.11.25.568689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
The stomach-derived orexigenic hormone ghrelin is a key regulator of energy homeostasis and metabolism in humans. The ghrelin receptor, growth hormone secretagogue receptor 1a (GHSR), is widely expressed in the brain and gastrointestinal vagal sensory neurons, and neuronal GHSR knockout results in a profoundly beneficial metabolic profile and protects against diet-induced obesity (DIO) and insulin resistance. Here we show that in addition to the well characterized vagal GHSR, GHSR is robustly expressed in gastrointestinal sensory neurons emanating from spinal dorsal root ganglia. Remarkably, sensory neuron GHSR deletion attenuates DIO through increased energy expenditure and sympathetic outflow to adipose tissue independent of food intake. In addition, neuronal viral tract tracing reveals prominent crosstalk between gut non-vagal sensory afferents and adipose sympathetic outflow. Hence, these findings demonstrate a novel gut sensory ghrelin signaling pathway critical for maintaining energy homeostasis.
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Affiliation(s)
- M. Alex Thomas
- Department of Biology, Georgia State University, Atlanta, GA
| | - Xin Cui
- Department of Biology, Georgia State University, Atlanta, GA
| | | | - Qiang Cao
- Department of Biology, Georgia State University, Atlanta, GA
| | - Jia Jing
- Department of Biology, Georgia State University, Atlanta, GA
| | - Felipe C. Silva
- Department of Biology, Georgia State University, Atlanta, GA
| | - Shirong Wang
- Department of Biology, Georgia State University, Atlanta, GA
| | - Jeffrey M. Zigman
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Yuxiang Sun
- Department of Nutrition, Texas A & M University, College Station, TX
| | - Hang Shi
- Department of Biology, Georgia State University, Atlanta, GA
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA
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5
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DeVault L, Mateusiak C, Palucki J, Brent M, Milbrandt J, DiAntonio A. The response of Dual-Leucine Zipper Kinase (DLK) to nocodazole: evidence for a homeostatic cytoskeletal repair mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561227. [PMID: 37873434 PMCID: PMC10592635 DOI: 10.1101/2023.10.06.561227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that a) low dose nocodazole treatment activates DLK signaling and b) DLK signaling mitigates the microtubule damage caused by the cytoskeletal perturbation. We also perform RNA-seq to discover a DLK-dependent transcriptional signature. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes and promoting actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.
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6
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Jeon Y, Shin YK, Kim H, Choi YY, Kang M, Kwon Y, Cho Y, Chi SW, Shin JE. βPix Guanine Nucleotide Exchange Factor Regulates Regeneration of Injured Peripheral Axons. Int J Mol Sci 2023; 24:14357. [PMID: 37762659 PMCID: PMC10532151 DOI: 10.3390/ijms241814357] [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: 07/29/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Axon regeneration is essential for successful recovery after peripheral nerve injury. Although growth cone reformation and axonal extension are crucial steps in axonal regeneration, the regulatory mechanisms underlying these dynamic processes are poorly understood. Here, we identify βPix (Arhgef7), the guanine nucleotide exchange factor for Rac1 GTPase, as a regulator of axonal regeneration. After sciatic nerve injury in mice, the expression levels of βPix increase significantly in nerve segments containing regenerating axons. In regrowing axons, βPix is localized in the peripheral domain of the growth cone. Using βPix neuronal isoform knockout (NIKO) mice in which the neuronal isoforms of βPix are specifically removed, we demonstrate that βPix promotes neurite outgrowth in cultured dorsal root ganglion neurons and in vivo axon regeneration after sciatic nerve crush injury. Activation of cJun and STAT3 in the cell bodies is not affected in βPix NIKO mice, supporting the local action of βPix in regenerating axons. Finally, inhibiting Src, a kinase previously identified as an activator of the βPix neuronal isoform, causes axon outgrowth defects in vitro, like those found in the βPix NIKO neurons. Altogether, these data indicate that βPix plays an important role in axonal regrowth during peripheral nerve regeneration.
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Affiliation(s)
- Yewon Jeon
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea;
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
| | - Yoon Kyung Shin
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
| | - Hwigyeong Kim
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan 49201, Republic of Korea
| | - Yun Young Choi
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
| | - Minjae Kang
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan 49201, Republic of Korea
| | - Younghee Kwon
- Department School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Yongcheol Cho
- Department of Brain Sciences, DGIST, Daegu 42899, Republic of Korea;
| | - Sung Wook Chi
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea;
| | - Jung Eun Shin
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan 49201, Republic of Korea
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7
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Halawani D, Wang Y, Ramakrishnan A, Estill M, He X, Shen L, Friedel RH, Zou H. Circadian clock regulator Bmal1 gates axon regeneration via Tet3 epigenetics in mouse sensory neurons. Nat Commun 2023; 14:5165. [PMID: 37620297 PMCID: PMC10449865 DOI: 10.1038/s41467-023-40816-7] [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: 10/25/2022] [Accepted: 08/11/2023] [Indexed: 08/26/2023] Open
Abstract
Axon regeneration of dorsal root ganglia (DRG) neurons after peripheral axotomy involves reconfiguration of gene regulatory circuits to establish regenerative gene programs. However, the underlying mechanisms remain unclear. Here, through an unbiased survey, we show that the binding motif of Bmal1, a central transcription factor of the circadian clock, is enriched in differentially hydroxymethylated regions (DhMRs) of mouse DRG after peripheral lesion. By applying conditional deletion of Bmal1 in neurons, in vitro and in vivo neurite outgrowth assays, as well as transcriptomic profiling, we demonstrate that Bmal1 inhibits axon regeneration, in part through a functional link with the epigenetic factor Tet3. Mechanistically, we reveal that Bmal1 acts as a gatekeeper of neuroepigenetic responses to axonal injury by limiting Tet3 expression and restricting 5hmC modifications. Bmal1-regulated genes not only concern axon growth, but also stress responses and energy homeostasis. Furthermore, we uncover an epigenetic rhythm of diurnal oscillation of Tet3 and 5hmC levels in DRG neurons, corresponding to time-of-day effect on axon growth potential. Collectively, our studies demonstrate that targeting Bmal1 enhances axon regeneration.
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Affiliation(s)
- Dalia Halawani
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yiqun Wang
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Shaanxi, China
| | - Aarthi Ramakrishnan
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Molly Estill
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Xijing He
- Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Shaanxi, China
- Department of Orthopedics, Xi'an International Medical Center Hospital, Xi'an, China
| | - Li Shen
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Roland H Friedel
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hongyan Zou
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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8
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Aparicio GI, León A, Gutiérrez Fuster R, Ravenscraft B, Monje PV, Scorticati C. Endogenous Glycoprotein GPM6a Is Involved in Neurite Outgrowth in Rat Dorsal Root Ganglion Neurons. Biomolecules 2023; 13:biom13040594. [PMID: 37189342 DOI: 10.3390/biom13040594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/09/2023] [Accepted: 03/17/2023] [Indexed: 03/29/2023] Open
Abstract
The peripheral nervous system (PNS) has a unique ability for self-repair. Dorsal root ganglion (DRG) neurons regulate the expression of different molecules, such as neurotrophins and their receptors, to promote axon regeneration after injury. However, the molecular players driving axonal regrowth need to be better defined. The membrane glycoprotein GPM6a has been described to contribute to neuronal development and structural plasticity in central-nervous-system neurons. Recent evidence indicates that GPM6a interacts with molecules from the PNS, although its role in DRG neurons remains unknown. Here, we characterized the expression of GPM6a in embryonic and adult DRGs by combining analysis of public RNA-seq datasets with immunochemical approaches utilizing cultures of rat DRG explants and dissociated neuronal cells. M6a was detected on the cell surfaces of DRG neurons throughout development. Moreover, GPM6a was required for DRG neurite elongation in vitro. In summary, we provide evidence on GPM6a being present in DRG neurons for the first time. Data from our functional experiments support the idea that GPM6a could contribute to axon regeneration in the PNS.
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9
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Wang X, Yang C, Wang X, Miao J, Chen W, Zhou Y, Xu Y, An Y, Cheng A, Ye W, Chen M, Song D, Yuan X, Wang J, Qian P, Ruohao Wu A, Zhang ZY, Liu K. Driving axon regeneration by orchestrating neuronal and non-neuronal innate immune responses via the IFNγ-cGAS-STING axis. Neuron 2023; 111:236-255.e7. [PMID: 36370710 PMCID: PMC9851977 DOI: 10.1016/j.neuron.2022.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 09/20/2022] [Accepted: 10/18/2022] [Indexed: 11/13/2022]
Abstract
The coordination mechanism of neural innate immune responses for axon regeneration is not well understood. Here, we showed that neuronal deletion of protein tyrosine phosphatase non-receptor type 2 sustains the IFNγ-STAT1 activity in retinal ganglion cells (RGCs) to promote axon regeneration after injury, independent of mTOR or STAT3. DNA-damage-induced cGAMP synthase (cGAS)-stimulator of interferon genes (STINGs) activation is the functional downstream signaling. Directly activating neuronal STING by cGAMP promotes axon regeneration. In contrast to the central axons, IFNγ is locally translated in the injured peripheral axons and upregulates cGAS expression in Schwann cells and infiltrating blood cells to produce cGAMP, which promotes spontaneous axon regeneration as an immunotransmitter. Our study demonstrates that injured peripheral nervous system (PNS) axons can direct the environmental innate immune response for self-repair and that the neural antiviral mechanism can be harnessed to promote axon regeneration in the central nervous system (CNS).
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Affiliation(s)
- Xu Wang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China,Biomedical Research Institute, Shenzhen Peking University–The Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China,Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou 510515, China,These authors contributed equally
| | - Chao Yang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China,Biomedical Research Institute, Shenzhen Peking University–The Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China,Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou 510515, China,These authors contributed equally
| | - Xuejie Wang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
| | - Jinmin Miao
- Department of Medicinal Chemistry and Molecular Pharmacology, Department of Chemistry, Center for Cancer Research and Institute for Drug Discovery, Purdue University, West Lafayette, IN, USA
| | - Weitao Chen
- Biomedical Research Institute, Shenzhen Peking University–The Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China
| | - Yiren Zhou
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ying Xu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yongyan An
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Aifang Cheng
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China,Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Wenkang Ye
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China,Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Mengxian Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Dong Song
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xue Yuan
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
| | - Jiguang Wang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Peiyuan Qian
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China,Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Angela Ruohao Wu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China,Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China,Center for Aging Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Zhong-Yin Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Department of Chemistry, Center for Cancer Research and Institute for Drug Discovery, Purdue University, West Lafayette, IN, USA
| | - Kai Liu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China; Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China; Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China; Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou 510515, China.
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10
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Adalbert R, Cahalan S, Hopkins EL, Almuhanna A, Loreto A, Pór E, Körmöczy L, Perkins J, Coleman MP, Piercy RJ. Cultured dissociated primary dorsal root ganglion neurons from adult horses enable study of axonal transport. J Anat 2022; 241:1211-1218. [PMID: 35728923 PMCID: PMC9558156 DOI: 10.1111/joa.13719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 11/29/2022] Open
Abstract
Neurological disorders are prevalent in horses, but their study is challenging due to anatomic constraints and the large body size; very few host‐specific in vitro models have been established to study these types of diseases, particularly from adult donor tissue. Here we report the generation of primary neuronal dorsal root ganglia (DRG) cultures from adult horses: the mixed, dissociated cultures, containing neurons and glial cells, remained viable for at least 90 days. Similar to DRG neurons in vivo, cultured neurons varied in size, and they developed long neurites. The mitochondrial movement was detected in cultured cells and was significantly slower in glial cells compared to DRG‐derived neurons. In addition, mitochondria were more elongated in glial cells than those in neurons. Our culture model will be a useful tool to study the contribution of axonal transport defects to specific neurodegenerative diseases in horses as well as comparative studies aimed at evaluating species‐specific differences in axonal transport and survival.
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Affiliation(s)
- Robert Adalbert
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, UK.,Department of Anatomy, Histology, and Embryology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Stephen Cahalan
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, UK
| | - Eleanor L Hopkins
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Abdulaziz Almuhanna
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, UK
| | - Andrea Loreto
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Andrea Loreto, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Erzsébet Pór
- Department of Anatomy, Histology, and Embryology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Laura Körmöczy
- Department of Anatomy, Histology, and Embryology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Justin Perkins
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, UK
| | - Michael P Coleman
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Richard J Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, UK
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11
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Kalpachidou T, Malsch P, Qi Y, Mair N, Geley S, Quarta S, Kummer KK, Kress M. Genetic and functional evidence for gp130/IL6ST-induced transient receptor potential ankyrin 1 upregulation in uninjured but not injured neurons in a mouse model of neuropathic pain. Pain 2022; 163:579-589. [PMID: 34252913 PMCID: PMC8832546 DOI: 10.1097/j.pain.0000000000002402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/27/2021] [Accepted: 06/30/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Peripheral nerve injuries result in pronounced alterations in dorsal root ganglia, which can lead to the development of neuropathic pain. Although the polymodal mechanosensitive transient receptor potential ankyrin 1 (TRPA1) ion channel is emerging as a relevant target for potential analgesic therapies, preclinical studies do not provide unequivocal mechanistic insight into its relevance for neuropathic pain pathogenesis. By using a transgenic mouse model with a conditional depletion of the interleukin-6 (IL-6) signal transducer gp130 in Nav1.8 expressing neurons (SNS-gp130-/-), we provide a mechanistic regulatory link between IL-6/gp130 and TRPA1 in the spared nerve injury (SNI) model. Spared nerve injury mice developed profound mechanical hypersensitivity as indicated by decreased withdrawal thresholds in the von Frey behavioral test in vivo, as well as a significant increase in mechanosensitivity of unmyelinated nociceptive primary afferents in ex vivo skin-nerve recordings. In contrast to wild type and control gp130fl/fl animals, SNS-gp130-/- mice did not develop mechanical hypersensitivity after SNI and exhibited low levels of Trpa1 mRNA in sensory neurons, which were partially restored by adenoviral gp130 re-expression in vitro. Importantly, uninjured but not injured neurons developed increased responsiveness to the TRPA1 agonist cinnamaldehyde, and neurons derived from SNS-gp130-/- mice after SNI were significantly less responsive to cinnamaldehyde. Our study shows for the first time that TRPA1 upregulation is attributed specifically to uninjured neurons in the SNI model, and this depended on the IL-6 signal transducer gp130. We provide a solution to the enigma of TRPA1 regulation after nerve injury and stress its significance as an important target for neuropathic pain disorders.
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Affiliation(s)
- Theodora Kalpachidou
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
| | - Philipp Malsch
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
| | - Yanmei Qi
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
| | - Norbert Mair
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
| | - Stephan Geley
- Institute of Pathophysiology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Serena Quarta
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
| | - Kai K. Kummer
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
| | - Michaela Kress
- Institute of Physiology, DPMP, Medical University of Innsbruck, Innsbruck, Austria
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12
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Adipose tissue-derived neurotrophic factor 3 regulates sympathetic innervation and thermogenesis in adipose tissue. Nat Commun 2021; 12:5362. [PMID: 34508100 PMCID: PMC8433218 DOI: 10.1038/s41467-021-25766-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/31/2021] [Indexed: 02/04/2023] Open
Abstract
Activation of brown fat thermogenesis increases energy expenditure and alleviates obesity. Sympathetic nervous system (SNS) is important in brown/beige adipocyte thermogenesis. Here we discover a fat-derived "adipokine" neurotrophic factor neurotrophin 3 (NT-3) and its receptor Tropomyosin receptor kinase C (TRKC) as key regulators of SNS growth and innervation in adipose tissue. NT-3 is highly expressed in brown/beige adipocytes, and potently stimulates sympathetic neuron neurite growth. NT-3/TRKC regulates a plethora of pathways in neuronal axonal growth and elongation. Adipose tissue sympathetic innervation is significantly increased in mice with adipocyte-specific NT-3 overexpression, but profoundly reduced in mice with TRKC haploinsufficiency (TRKC +/-). Increasing NT-3 via pharmacological or genetic approach promotes beige adipocyte development, enhances cold-induced thermogenesis and protects against diet-induced obesity (DIO); whereas TRKC + /- or SNS TRKC deficient mice are cold intolerant and prone to DIO. Thus, NT-3 is a fat-derived neurotrophic factor that regulates SNS innervation, energy metabolism and obesity.
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13
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Gervasi NM, Dimtchev A, Clark DM, Dingle M, Pisarchik AV, Nesti LJ. C-terminal domain small phosphatase 1 (CTDSP1) regulates growth factor expression and axonal regeneration in peripheral nerve tissue. Sci Rep 2021; 11:14462. [PMID: 34262056 PMCID: PMC8280205 DOI: 10.1038/s41598-021-92822-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 05/04/2021] [Indexed: 11/09/2022] Open
Abstract
Peripheral Nerve Injury (PNI) represents a major clinical and economic burden. Despite the ability of peripheral neurons to regenerate their axons after an injury, patients are often left with motor and/or sensory disability and may develop chronic pain. Successful regeneration and target organ reinnervation require comprehensive transcriptional changes in both injured neurons and support cells located at the site of injury. The expression of most of the genes required for axon growth and guidance and for synapsis formation is repressed by a single master transcriptional regulator, the Repressor Element 1 Silencing Transcription factor (REST). Sustained increase of REST levels after injury inhibits axon regeneration and leads to chronic pain. As targeting of transcription factors is challenging, we tested whether modulation of REST activity could be achieved through knockdown of carboxy-terminal domain small phosphatase 1 (CTDSP1), the enzyme that stabilizes REST by preventing its targeting to the proteasome. To test whether knockdown of CTDSP1 promotes neurotrophic factor expression in both support cells located at the site of injury and in peripheral neurons, we transfected mesenchymal progenitor cells (MPCs), a type of support cells that are present at high concentrations at the site of injury, and dorsal root ganglion (DRG) neurons with REST or CTDSP1 specific siRNA. We quantified neurotrophic factor expression by RT-qPCR and Western blot, and brain-derived neurotrophic factor (BDNF) release in the cell culture medium by ELISA, and we measured neurite outgrowth of DRG neurons in culture. Our results show that CTDSP1 knockdown promotes neurotrophic factor expression in both DRG neurons and the support cells MPCs, and promotes DRG neuron regeneration. Therapeutics targeting CTDSP1 activity may, therefore, represent a novel epigenetic strategy to promote peripheral nerve regeneration after PNI by promoting the regenerative program repressed by injury-induced increased levels of REST in both neurons and support cells.
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Affiliation(s)
- Noreen M Gervasi
- Laboratory of Clinical and Experimental Orthopaedics, Department of Surgery, Uniformed Services University of Health Sciences, 4801 Rockville Pike, Bethesda, MD, 20889, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Alcamena Stem Cell Therapeutics, 1450 South Rolling Road, Suite 4.069, Halethorpe, MD, 21227, USA
| | - Alexander Dimtchev
- Laboratory of Clinical and Experimental Orthopaedics, Department of Surgery, Uniformed Services University of Health Sciences, 4801 Rockville Pike, Bethesda, MD, 20889, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, MD, 20817, USA
| | - Desraj M Clark
- Laboratory of Clinical and Experimental Orthopaedics, Department of Surgery, Uniformed Services University of Health Sciences, 4801 Rockville Pike, Bethesda, MD, 20889, USA
- Department of Orthopaedics and Rehabilitation, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - Marvin Dingle
- Laboratory of Clinical and Experimental Orthopaedics, Department of Surgery, Uniformed Services University of Health Sciences, 4801 Rockville Pike, Bethesda, MD, 20889, USA
- Department of Orthopaedics and Rehabilitation, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - Alexander V Pisarchik
- Alcamena Stem Cell Therapeutics, 1450 South Rolling Road, Suite 4.069, Halethorpe, MD, 21227, USA.
| | - Leon J Nesti
- Laboratory of Clinical and Experimental Orthopaedics, Department of Surgery, Uniformed Services University of Health Sciences, 4801 Rockville Pike, Bethesda, MD, 20889, USA.
- Department of Orthopaedics and Rehabilitation, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA.
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14
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Neuron Replating, a Powerful and Versatile Approach to Study Early Aspects of Neuron Differentiation. eNeuro 2021; 8:ENEURO.0536-20.2021. [PMID: 33958372 PMCID: PMC8143016 DOI: 10.1523/eneuro.0536-20.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/16/2022] Open
Abstract
Neuron differentiation includes formation and outgrowth of neurites that differentiate into axons or dendrites. Directed neurite outgrowth is controlled by growth cones that protrude and retract actin-rich structures to sense environmental cues. These cues control local actin filament dynamics, steer growth cones toward attractants and away from repellents, and navigate neurites through the developing brain. Rodent hippocampal neurons are widely used to study the mechanisms underlying neuron differentiation. Genetic manipulation of isolated neurons including gene inactivation or reporter gene expression can be achieved by classical transfections methods, but these methods are restricted to neurons cultured for several days, after neurite formation or outgrowth. Instead, electroporation allows gene manipulation before seeding. However, reporter gene expression usually takes up to 24 h, and time course of gene inactivation depends on the half live of the targeted mRNA and gene product. Hence, these methods do not allow to study early aspects of neuron differentiation. In the present study, we provide a detailed protocol in which we combined electroporation-based gene manipulation of mouse hippocampal neurons before initial seeding with a replating step after 2 d in vitro (DIV) that resets neurons into an undifferentiated stage. By categorizing neurons according to their differentiation stage, thorough morphometric analyses, live imaging of actin dynamics in growth cones as well as guidance cue-mediated growth cone morphologic changes, we demonstrate that differentiation and function of replated neurons did not differ from non-replated neurons. In summary, we provide a protocol that allows to thoroughly characterize differentiation of mouse primary hippocampal neurons.
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15
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Blazejewski SM, Bennison SA, Liu X, Toyo-Oka K. High-throughput kinase inhibitor screening reveals roles for Aurora and Nuak kinases in neurite initiation and dendritic branching. Sci Rep 2021; 11:8156. [PMID: 33854138 PMCID: PMC8047044 DOI: 10.1038/s41598-021-87521-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/31/2021] [Indexed: 12/25/2022] Open
Abstract
Kinases are essential regulators of a variety of cellular signaling processes, including neurite formation—a foundational step in neurodevelopment. Aberrant axonal sprouting and failed regeneration of injured axons are associated with conditions like traumatic injury, neurodegenerative disease, and seizures. Investigating the mechanisms underlying neurite formation will allow for identification of potential therapeutics. We used a kinase inhibitor library to screen 493 kinase inhibitors and observed that 45% impacted neuritogenesis in Neuro2a (N-2a) cells. Based on the screening, we further investigated the roles of Aurora kinases A, B, and C and Nuak kinases 1 and 2. The roles of Aurora and Nuak kinases have not been thoroughly studied in the nervous system. Inhibition or overexpression of Aurora and Nuak kinases in primary cortical neurons resulted in various neuromorphological defects, with Aurora A regulating neurite initiation, Aurora B and C regulating neurite initiation and elongation, all Aurora kinases regulating arborization, and all Nuak kinases regulating neurite initiation and elongation and arborization. Our high-throughput screening and analysis of Aurora and Nuak kinases revealed their functions and may contribute to the identification of therapeutics.
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Affiliation(s)
- Sara M Blazejewski
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, 19129, USA
| | - Sarah A Bennison
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, 19129, USA
| | - Xiaonan Liu
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, 19129, USA
| | - Kazuhito Toyo-Oka
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, 19129, USA.
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16
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Jeon Y, Shin JE, Kwon M, Cho E, Cavalli V, Cho Y. In Vivo Gene Delivery of STC2 Promotes Axon Regeneration in Sciatic Nerves. Mol Neurobiol 2021; 58:750-760. [PMID: 33011858 DOI: 10.1007/s12035-020-02155-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/29/2020] [Indexed: 12/24/2022]
Abstract
Neurons are vulnerable to injury, and failure to activate self-protective systems after injury leads to neuronal death. However, sensory neurons in dorsal root ganglions (DRGs) mostly survive and regenerate their axons. To understand the mechanisms of the neuronal injury response, we analyzed the injury-responsive transcriptome and found that Stc2 is immediately upregulated after axotomy. Stc2 is required for axon regeneration in vivo and in vitro, indicating that Stc2 is a neuronal factor regulating axonal injury response. The application of the secreted stanniocalcin 2 to injured DRG neurons promotes regeneration. Stc2 thus represents a potential secretory protein with a feedback function regulating regeneration. Finally, the in vivo gene delivery of STC2 increases regenerative growth after injury in peripheral nerves in mice. These results suggest that Stc2 is an injury-responsive gene required for axon regeneration and a potential target for developing therapeutic applications.
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Affiliation(s)
- Yewon Jeon
- Department of Life Sciences, Lab of Axon Regeneration & Degeneration, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Jung Eun Shin
- Department of Molecular Neuroscience, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Minjae Kwon
- Department of Life Sciences, Lab of Axon Regeneration & Degeneration, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Eunhye Cho
- Department of Life Sciences, Lab of Axon Regeneration & Degeneration, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Valeria Cavalli
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Yongcheol Cho
- Department of Life Sciences, Lab of Axon Regeneration & Degeneration, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea.
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17
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Lee B, Cho Y. Experimental Model Systems for Understanding Human Axonal Injury Responses. Int J Mol Sci 2021; 22:E474. [PMID: 33418850 PMCID: PMC7824864 DOI: 10.3390/ijms22020474] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/03/2020] [Accepted: 12/30/2020] [Indexed: 12/26/2022] Open
Abstract
Neurons are structurally unique and have dendrites and axons that are vulnerable to injury. Some neurons in the peripheral nervous system (PNS) can regenerate their axons after injuries. However, most neurons in the central nervous system (CNS) fail to do so, resulting in irreversible neurological disorders. To understand the mechanisms of axon regeneration, various experimental models have been utilized in vivo and in vitro. Here, we collate the key experimental models that revealed the important mechanisms regulating axon regeneration and degeneration in different systems. We also discuss the advantages of experimenting with the rodent model, considering the application of these findings in understanding human diseases and for developing therapeutic methods.
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Affiliation(s)
| | - Yongcheol Cho
- Laboratory of Axon Regeneration & Degeneration, Department of Life Sciences, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Korea;
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18
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Renthal W, Tochitsky I, Yang L, Cheng YC, Li E, Kawaguchi R, Geschwind DH, Woolf CJ. Transcriptional Reprogramming of Distinct Peripheral Sensory Neuron Subtypes after Axonal Injury. Neuron 2020; 108:128-144.e9. [PMID: 32810432 PMCID: PMC7590250 DOI: 10.1016/j.neuron.2020.07.026] [Citation(s) in RCA: 221] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/27/2020] [Accepted: 07/22/2020] [Indexed: 12/27/2022]
Abstract
Primary somatosensory neurons are specialized to transmit specific types of sensory information through differences in cell size, myelination, and the expression of distinct receptors and ion channels, which together define their transcriptional and functional identity. By profiling sensory ganglia at single-cell resolution, we find that all somatosensory neuronal subtypes undergo a similar transcriptional response to peripheral nerve injury that both promotes axonal regeneration and suppresses cell identity. This transcriptional reprogramming, which is not observed in non-neuronal cells, resolves over a similar time course as target reinnervation and is associated with the restoration of original cell identity. Injury-induced transcriptional reprogramming requires ATF3, a transcription factor that is induced rapidly after injury and necessary for axonal regeneration and functional recovery. Our findings suggest that transcription factors induced early after peripheral nerve injury confer the cellular plasticity required for sensory neurons to transform into a regenerative state.
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Affiliation(s)
- William Renthal
- Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 60 Fenwood Rd., Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA.
| | - Ivan Tochitsky
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA
| | - Lite Yang
- Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 60 Fenwood Rd., Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA
| | - Yung-Chih Cheng
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA
| | - Emmy Li
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA
| | - Riki Kawaguchi
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Daniel H Geschwind
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Clifford J Woolf
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA.
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19
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Planning and Analysis of Axon Degeneration Screening Experiments. Methods Mol Biol 2020. [PMID: 32524473 DOI: 10.1007/978-1-0716-0585-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
A network of intersecting molecular pathways interacts to initiate and execute axon destruction. Maximum protection against axon degeneration likely requires more than manipulation of a single target. Here, we describe the process of designing a high-throughput arrayed screening assay for the identification of key factors responsible for axon destruction and/or protection. First, we go over some existing screens in the literature, then discuss the planning, tracking, analysis, and statistics around such a screening experiment. Prioritization of perturbations may allow laboratories to cost-effectively explore the process of screening. We also present the pairing of a combinatorial drug screen with a machine learning algorithm, predicting how to best modulate neurodegenerative and neuroprotective components.
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20
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Collapsin Response Mediator Protein 4 (CRMP4) Facilitates Wallerian Degeneration and Axon Regeneration following Sciatic Nerve Injury. eNeuro 2020; 7:ENEURO.0479-19.2020. [PMID: 32001550 PMCID: PMC7053045 DOI: 10.1523/eneuro.0479-19.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 11/29/2022] Open
Abstract
In contrast to neurons in the CNS, damaged neurons from the peripheral nervous system (PNS) regenerate, but this process can be slow and imperfect. Successful regeneration is orchestrated by cytoskeletal reorganization at the tip of the proximal axon segment and cytoskeletal disassembly of the distal segment. Collapsin response mediator protein 4 (CRMP4) is a cytosolic phospho-protein that regulates the actin and microtubule cytoskeleton. During development, CRMP4 promotes growth cone formation and dendrite development. Paradoxically, in the adult CNS, CRMP4 impedes axon regeneration. Here, we investigated the involvement of CRMP4 in peripheral nerve injury in male and female Crmp4−/− mice following sciatic nerve injury. We find that sensory axon regeneration and Wallerian degeneration are impaired in Crmp4−/− mice following sciatic nerve injury. In vitro analysis of dissociated dorsal root ganglion (DRG) neurons from Crmp4−/− mice revealed that CRMP4 functions in the proximal axon segment to promote the regrowth of severed DRG neurons and in the distal axon segment where it facilitates Wallerian degeneration through calpain-dependent formation of harmful CRMP4 fragments. These findings reveal an interesting dual role for CRMP4 in proximal and distal axon segments of injured sensory neurons that coordinately facilitate PNS axon regeneration.
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21
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Arbat-Plana A, Puigdomenech M, Navarro X, Udina E. Role of Noradrenergic Inputs From Locus Coeruleus on Changes Induced on Axotomized Motoneurons by Physical Exercise. Front Cell Neurosci 2019; 13:65. [PMID: 30863285 PMCID: PMC6399159 DOI: 10.3389/fncel.2019.00065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 02/11/2019] [Indexed: 11/13/2022] Open
Abstract
Physical rehabilitation is one of the cornerstones for the treatment of lesions of the nervous system. After peripheral nerve injuries, activity dependent therapies promote trophic support for the paralyzed muscles, enhance axonal growth and also modulate the maladaptive plastic changes induced by the injury at the spinal level. We have previously demonstrated that an intensive protocol of treadmill running (TR) in rats reduces synaptic stripping on axotomized motoneurons, preserves their perineuronal nets (PNN) and attenuates microglia reactivity. However, it is not clear through which mechanisms exercise is exerting these effects. Here we aimed to evaluate if activation of the locus coeruleus (LC), the noradrenergic center in the brain stem, plays a role in these effects. Since LC is strongly activated during stressful situations, as during intensive exercise, we selectively destroyed the LC by administering the neurotoxin DPS-4 before injuring the sciatic nerve of adult rats. Animals without LC had increased microglia reactivity around injured motoneurons. In these animals, an increasing intensity protocol of TR was not able to prevent synaptic stripping on axotomized motoneurons and the reduction in the thickness of their PNN. In contrast, TR was still able to attenuate microglia reactivity in DSP-4 treated animals, thus indicating that the noradrenergic projections are important for some but not all the effects that exercise induces on the spinal cord after peripheral nerve injury. Moreover, animals subjected to treadmill training showed delayed muscle reinnervation, more evident if treated with DSP-4. However, we did not find differences in treated animals regarding the H/M amplitude ratio, which increased during the first stages of regeneration in all injured groups.
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Affiliation(s)
- Ariadna Arbat-Plana
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Maria Puigdomenech
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Xavier Navarro
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Esther Udina
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Universitat Autònoma de Barcelona, Bellaterra, Spain
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22
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Dubový P, Klusáková I, Hradilová-Svíženská I, Brázda V, Kohoutková M, Joukal M. A Conditioning Sciatic Nerve Lesion Triggers a Pro-regenerative State in Primary Sensory Neurons Also of Dorsal Root Ganglia Non-associated With the Damaged Nerve. Front Cell Neurosci 2019; 13:11. [PMID: 30778286 PMCID: PMC6369159 DOI: 10.3389/fncel.2019.00011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/14/2019] [Indexed: 12/19/2022] Open
Abstract
The primary sensory neurons of dorsal root ganglia (DRG) are a very useful model to study the neuronal regenerative program that is a prerequisite for successful axon regeneration after peripheral nerve injury. Seven days after a unilateral sciatic nerve injury by compression or transection, we detected a bilateral increase in growth-associated protein-43 (GAP-43) and superior cervical ganglion-10 (SCG-10) mRNA and protein levels not only in DRG neurons of lumbar spinal cord segments (L4-L5) associated with injured nerve, but also in remote cervical segments (C6-C8). The increase in regeneration-associated proteins in the cervical DRG neurons was associated with the greater length of regenerated axons 1 day after ulnar nerve crush following prior sciatic nerve injury as compared to controls with only ulnar nerve crush. The increased axonal regeneration capacity of cervical DRG neurons after a prior conditioning sciatic nerve lesion was confirmed by neurite outgrowth assay of in vitro cultivated DRG neurons. Intrathecal injection of IL-6 or a JAK2 inhibitor (AG490) revealed a role for the IL-6 signaling pathway in activating the pro-regenerative state in remote DRG neurons. Our results suggest that the pro-regenerative state induced in the DRG neurons non-associated with the injured nerve reflects a systemic reaction of these neurons to unilateral sciatic nerve injury.
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Affiliation(s)
- Petr Dubový
- Department of Anatomy, Laboratory of Cellular and Molecular Neurobiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ilona Klusáková
- Department of Anatomy, Laboratory of Cellular and Molecular Neurobiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ivana Hradilová-Svíženská
- Department of Anatomy, Laboratory of Cellular and Molecular Neurobiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Václav Brázda
- Department of Anatomy, Laboratory of Cellular and Molecular Neurobiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Marcela Kohoutková
- Department of Anatomy, Laboratory of Cellular and Molecular Neurobiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Marek Joukal
- Department of Anatomy, Laboratory of Cellular and Molecular Neurobiology, Faculty of Medicine, Masaryk University, Brno, Czechia
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23
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Mikhailova MM, Bolshakov AP, Chaban EA, Paltsev MA, Panteleyev AA. Primary culture of mouse embryonic spinal cord neurons: cell composition and suitability for axonal regeneration studies. Int J Neurosci 2019; 129:762-769. [PMID: 30621485 DOI: 10.1080/00207454.2019.1567508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Objective: Primary culture is an effective experimental model to study molecular mechanisms that drive axonal regeneration after central nervous system injury. However, the culture of spinal cord (SC) cells remains poorly characterized. Here, we have analyzed the cell composition of a primary SC culture during its maturation. Methods: Primary cell culture was prepared from mouse embryo spinal cords. After 2, 7, and 14 days of cultivation, the cells were fixed and stained with antibodies against β3-tubulin, nestin, crmp1, SMI-32, DCC or GFAP. We counted percentage of cells positive for the mentioned markers and measured the length of cell processes. Results: We found that β3-tubulin and nestin were both expressed at day 2 of culture in vitro. Surprisingly (given the use of differentiation-supporting culture medium), the number of nestin+ cells has significantly increased during the first week of cultivation. The GFAP+ cells appeared only at the seventh day in vitro, and their fraction increased during the following cultivation. At 14 day in vitro, SC culture contained cells that expressed the markers typical of commissural and motor neurons. At this age, the neurons had the ability to repair injured neurites after mechanical damage. Conclusion: Primary culture of SC cells is a dynamically developing cell population that contains all main types of SC cells and is capable of self-repair. Therefore, the culture of mouse embryonic SC cells represents an adequate experimental model for studying cellular and molecular processes taking place in SC neurons after axonal damage in the absence of external inhibitors.
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Affiliation(s)
- Mariya M Mikhailova
- a National Research Center Kurchatov Institute , Moscow , Russian Federation
| | - Alexey P Bolshakov
- b Institute of Higher Nervous Activity and Neurophysiology Russian Academy of Sciences , Moscow , Russian Federation
| | - Ekaterina A Chaban
- c Emanuel Institute of Biochemical Physics Russian Academy of Sciences , Moscow , Russian Federation
| | - Mikhail A Paltsev
- c Emanuel Institute of Biochemical Physics Russian Academy of Sciences , Moscow , Russian Federation
| | - Andrey A Panteleyev
- a National Research Center Kurchatov Institute , Moscow , Russian Federation
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Han S, Kim DH, Sung J, Yang H, Park JW, Youn I. Electrical stimulation accelerates neurite regeneration in axotomized dorsal root ganglion neurons by increasing MMP-2 expression. Biochem Biophys Res Commun 2019; 508:348-353. [PMID: 30503336 DOI: 10.1016/j.bbrc.2018.11.159] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 11/25/2018] [Indexed: 01/08/2023]
Abstract
Electrical stimulation (ES) can be useful for promoting the regeneration of injured axons, but the mechanism underlying its positive effects is largely unknown. The current study aimed to investigate whether ES could enhance the regeneration of injured neurites in dorsal root ganglion explants and regulate the MMP-2 expression level, which is correlated with regeneration. Significantly increased neurite regeneration and MMP-2 expression was observed in the ES group compared with the sham group. However, an MMP inhibitor significantly decreased this ES-induced neurite regeneration. Our data suggest that the positive effect of ES on neurite regeneration could likely be mediated by an increase in MMP-2 expression, thereby promoting the regeneration of injured neurites.
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Affiliation(s)
- Sungmin Han
- Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02791, Republic of Korea
| | - Dong Hwee Kim
- Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02791, Republic of Korea; Department of Biomedical Science, Korea University College of Medicine, 73, Inchon-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Joohwan Sung
- Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02791, Republic of Korea; Department of Biomedical Science, Korea University College of Medicine, 73, Inchon-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Hwasun Yang
- Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02791, Republic of Korea
| | - Jong Woong Park
- Department of Biomedical Science, Korea University College of Medicine, 73, Inchon-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Inchan Youn
- Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02791, Republic of Korea; KHU-KIST Department of Converging Science and Technology, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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25
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Zigmond RE, Echevarria FD. Macrophage biology in the peripheral nervous system after injury. Prog Neurobiol 2018; 173:102-121. [PMID: 30579784 DOI: 10.1016/j.pneurobio.2018.12.001] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/19/2018] [Accepted: 12/17/2018] [Indexed: 12/23/2022]
Abstract
Neuroinflammation has positive and negative effects. This review focuses on the roles of macrophage in the PNS. Transection of PNS axons leads to degeneration and clearance of the distal nerve and to changes in the region of the axotomized cell bodies. In both locations, resident and infiltrating macrophages are found. Macrophages enter these areas in response to expression of the chemokine CCL2 acting on the macrophage receptor CCR2. In the distal nerve, macrophages and other phagocytes are involved in clearance of axonal debris, which removes molecules that inhibit nerve regeneration. In the cell body region, macrophage trigger the conditioning lesion response, a process in which neurons increase their regeneration after a prior lesion. In mice in which the genes for CCL2 or CCR2 are deleted, neither macrophage infiltration nor the conditioning lesion response occurs in dorsal root ganglia (DRG). Macrophages exist in different phenotypes depending on their environment. These phenotypes have different effects on axonal clearance and neurite outgrowth. The mechanism by which macrophages affect neuronal cell bodies is still under study. Overexpression of CCL2 in DRG in uninjured animals leads to macrophage accumulation in the ganglia and to an increase in the growth potential of DRG neurons. This increased growth requires activation of neuronal STAT3. In contrast, in acute demyelinating neuropathies, macrophages are involved in stripping myelin from peripheral axons. The molecular mechanisms that trigger macrophage action after trauma and in autoimmune disease are receiving increased attention and should lead to avenues to promote regeneration and protect axonal integrity.
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Affiliation(s)
- Richard E Zigmond
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, 44106-4975, USA.
| | - Franklin D Echevarria
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, 44106-4975, USA
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26
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Kaval Oğuz E, Öztürk G. An In Vitro Model for Conditioning Lesion Effect. Cell Mol Neurobiol 2018; 39:61-71. [PMID: 30415355 DOI: 10.1007/s10571-018-0633-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 11/03/2018] [Indexed: 11/24/2022]
Abstract
Axons of a peripheral nerve grow faster after an axotomy if it attains a prior injury a few days earlier. This is called conditioning lesion effect (CLE) and very much valued since it may provide new insights into neuron biology and axonal regeneration. There are established in vivo experimental paradigms to study CLE, however, there is a need to have an in vitro conditioning technique where CLE occurs in a maximally controlled environment. Mouse primary sensory neurons were isolated from lumbar 4-5 dorsal root ganglia and incubated at 37 °C on a silicon-coated watch glass that prevents cell attachment. After this conditioning period they were transferred to laminin coated culture dishes. Similar cultures were set up with freshly isolated neurons from control animals and from the animals that received a sciatic nerve cut 3 days earlier. All preparations were placed on a live cell imaging microscopy providing physiological conditions and photographed for 48 h. Axonal regeneration and neuronal survival was assessed. During the conditioning incubation period neurons remained in suspended aggregates and did not grow axons. The regeneration rate of the in vitro conditioned neurons was much higher than the in vivo conditioned and control preparations during the first day of normal incubation. However, higher regeneration rates were compromised by progressive substantial neuronal death in both types of conditioned cultures but not in the control preparations. By using neutralizing antibodies, we demonstrated that activity of endogenous leukemia inhibitory factor is essential for induction of CLE in this model.
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Affiliation(s)
| | - Gürkan Öztürk
- Physiology Department, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey. .,Regenerative and Restorative Medicine Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey.
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27
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Regulation of Neuroregeneration by Long Noncoding RNAs. Mol Cell 2018; 72:553-567.e5. [PMID: 30401432 DOI: 10.1016/j.molcel.2018.09.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/27/2018] [Accepted: 09/14/2018] [Indexed: 12/24/2022]
Abstract
In mammals, neurons in the peripheral nervous system (PNS) have regenerative capacity following injury, but it is generally absent in the CNS. This difference is attributed, at least in part, to the intrinsic ability of PNS neurons to activate a unique regenerative transcriptional program following injury. Here, we profiled gene expression following sciatic nerve crush in mice and identified long noncoding RNAs (lncRNAs) that act in the regenerating neurons and which are typically not expressed in other contexts. We show that two of these lncRNAs regulate the extent of neuronal outgrowth. We then focus on one of these, Silc1, and show that it regulates neuroregeneration in cultured cells and in vivo, through cis-acting activation of the transcription factor Sox11.
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28
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HSP90 is a chaperone for DLK and is required for axon injury signaling. Proc Natl Acad Sci U S A 2018; 115:E9899-E9908. [PMID: 30275300 DOI: 10.1073/pnas.1805351115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Peripheral nerve injury induces a robust proregenerative program that drives axon regeneration. While many regeneration-associated genes are known, the mechanisms by which injury activates them are less well-understood. To identify such mechanisms, we performed a loss-of-function pharmacological screen in cultured adult mouse sensory neurons for proteins required to activate this program. Well-characterized inhibitors were present as injury signaling was induced but were removed before axon outgrowth to identify molecules that block induction of the program. Of 480 compounds, 35 prevented injury-induced neurite regrowth. The top hits were inhibitors to heat shock protein 90 (HSP90), a chaperone with no known role in axon injury. HSP90 inhibition blocks injury-induced activation of the proregenerative transcription factor cJun and several regeneration-associated genes. These phenotypes mimic loss of the proregenerative kinase, dual leucine zipper kinase (DLK), a critical neuronal stress sensor that drives axon degeneration, axon regeneration, and cell death. HSP90 is an atypical chaperone that promotes the stability of signaling molecules. HSP90 and DLK show two hallmarks of HSP90-client relationships: (i) HSP90 binds DLK, and (ii) HSP90 inhibition leads to rapid degradation of existing DLK protein. Moreover, HSP90 is required for DLK stability in vivo, where HSP90 inhibitor reduces DLK protein in the sciatic nerve. This phenomenon is evolutionarily conserved in Drosophila Genetic knockdown of Drosophila HSP90, Hsp83, decreases levels of Drosophila DLK, Wallenda, and blocks Wallenda-dependent synaptic terminal overgrowth and injury signaling. Our findings support the hypothesis that HSP90 chaperones DLK and is required for DLK functions, including proregenerative axon injury signaling.
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29
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Asghari Adib E, Smithson LJ, Collins CA. An axonal stress response pathway: degenerative and regenerative signaling by DLK. Curr Opin Neurobiol 2018; 53:110-119. [PMID: 30053694 DOI: 10.1016/j.conb.2018.07.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/02/2018] [Indexed: 02/08/2023]
Abstract
Signaling through the dual leucine zipper-bearing kinase (DLK) is required for injured neurons to initiate new axonal growth; however, activation of this kinase also leads to neuronal degeneration and death in multiple models of injury and neurodegenerative diseases. This has spurred current consideration of DLK as a candidate therapeutic target, and raises a vital question: in what context is DLK a friend or foe to neurons? Here, we review our current understanding of DLK's function and mechanisms in regulating both regenerative and degenerative responses to axonal damage and stress in the nervous system.
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Affiliation(s)
- Elham Asghari Adib
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA
| | - Laura J Smithson
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA
| | - Catherine A Collins
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA.
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30
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Frey E, Karney-Grobe S, Krolak T, Milbrandt J, DiAntonio A. TRPV1 Agonist, Capsaicin, Induces Axon Outgrowth after Injury via Ca 2+/PKA Signaling. eNeuro 2018; 5:ENEURO.0095-18.2018. [PMID: 29854941 PMCID: PMC5975717 DOI: 10.1523/eneuro.0095-18.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 05/15/2018] [Accepted: 05/15/2018] [Indexed: 12/22/2022] Open
Abstract
Preconditioning nerve injuries activate a pro-regenerative program that enhances axon regeneration for most classes of sensory neurons. However, nociceptive sensory neurons and central nervous system neurons regenerate poorly. In hopes of identifying novel mechanisms that promote regeneration, we screened for drugs that mimicked the preconditioning response and identified a nociceptive ligand that activates a preconditioning-like response to promote axon outgrowth. We show that activating the ion channel TRPV1 with capsaicin induces axon outgrowth of cultured dorsal root ganglion (DRG) sensory neurons, and that this effect is blocked in TRPV1 knockout neurons. Regeneration occurs only in NF200-negative nociceptive neurons, consistent with a cell-autonomous mechanism. Moreover, we identify a signaling pathway in which TRPV1 activation leads to calcium influx and protein kinase A (PKA) activation to induce a preconditioning-like response. Finally, capsaicin administration to the mouse sciatic nerve activates a similar preconditioning-like response and induces enhanced axonal outgrowth, indicating that this pathway can be induced in vivo. These findings highlight the use of local ligands to induce regeneration and suggest that it may be possible to target selective neuronal populations for repair, including cell types that often fail to regenerate.
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Affiliation(s)
- Erin Frey
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Scott Karney-Grobe
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Trevor Krolak
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jeff Milbrandt
- Department of Genetics, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Aaron DiAntonio
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
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31
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Senger JLB, Verge VMK, Chan KM, Webber CA. The nerve conditioning lesion: A strategy to enhance nerve regeneration. Ann Neurol 2018. [DOI: 10.1002/ana.25209] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | - Valerie M. K. Verge
- Department of Anatomy and Cell Biology, and Cameco MS Neuroscience Research Center; University of Saskatchewan; Saskatoon Saskatchewan
| | - K. Ming Chan
- Department of Physical Rehabilitation; University of Alberta; Edmonton Alberta Canada
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32
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Interactions of Notch1 and TLR4 signaling pathways in DRG neurons of in vivo and in vitro models of diabetic neuropathy. Sci Rep 2017; 7:14923. [PMID: 29097792 PMCID: PMC5668305 DOI: 10.1038/s41598-017-15053-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/17/2017] [Indexed: 12/18/2022] Open
Abstract
Understanding the interactions between Notch1 and toll-like receptor 4 (TLR4) signaling pathways in the development of diabetic peripheral neuropathy may lead to interpretation of the mechanisms and novel approaches for preventing diabetic neuropathic pain. In the present study, the interactions between Notch1 and TLR4 signaling pathways were investigated by using dorsal root ganglion (DRG) from diabetic neuropathic pain rats and cultured DRG neurons under high glucose challenge. The results showed that high glucose induced not only Notch1 mRNA, HES1 mRNA, and TLR4 mRNA expression, but also Notch1 intracellular domain (NICD1) and TLR4 protein expression in DRG neurons. The proportion of NICD1-immunoreactive (IR) and TLR4-IR neurons in DRG cultures was also increased after high glucose challenge. The above alterations could be partially reversed by inhibition of either Notch1 or TLR4 signaling pathway. Inhibition of either Notch1 or TLR4 signaling pathway could improve mechanical allodynia and thermal hyperalgesia thresholds. Inhibition of Notch1 or TLR4 signaling also decreased tumor necrosis factor-α (TNF-α) levels in DRG from diabetic neuropathic rats. These data imply that the interaction between Notch1 and TLR4 signaling pathways is one of the important mechanisms in the development or progression of diabetic neuropathy.
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33
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Fadda A, Bärtschi M, Hemphill A, Widmer HR, Zurbriggen A, Perona P, Vidondo B, Oevermann A. Primary Postnatal Dorsal Root Ganglion Culture from Conventionally Slaughtered Calves. PLoS One 2016; 11:e0168228. [PMID: 27936156 PMCID: PMC5148591 DOI: 10.1371/journal.pone.0168228] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
Neurological disorders in ruminants have an important impact on veterinary health, but very few host-specific in vitro models have been established to study diseases affecting the nervous system. Here we describe a primary neuronal dorsal root ganglia (DRG) culture derived from calves after being conventionally slaughtered for food consumption. The study focuses on the in vitro characterization of bovine DRG cell populations by immunofluorescence analysis. The effects of various growth factors on neuron viability, neurite outgrowth and arborisation were evaluated by morphological analysis. Bovine DRG neurons are able to survive for more than 4 weeks in culture. GF supplementation is not required for neuronal survival and neurite outgrowth. However, exogenously added growth factors promote neurite outgrowth. DRG cultures from regularly slaughtered calves represent a promising and sustainable host specific model for the investigation of pain and neurological diseases in bovines.
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Affiliation(s)
- A. Fadda
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, Theodor Kocher Institute, University of Bern, Switzerland
| | - M. Bärtschi
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - A. Hemphill
- Institute for Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - H. R. Widmer
- Neurocenter and Regenerative Neuroscience Cluster, University Hospital and University of Bern, Bern, Switzerland
| | - A. Zurbriggen
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - P. Perona
- School of Engineering, The University of Edinburgh, Edinburgh, United Kingdom
| | - B. Vidondo
- Veterinary Public Health Institute (VPHI), Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - A. Oevermann
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- * E-mail:
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34
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Loh YHE, Koemeter-Cox A, Finelli MJ, Shen L, Friedel RH, Zou H. Comprehensive mapping of 5-hydroxymethylcytosine epigenetic dynamics in axon regeneration. Epigenetics 2016; 12:77-92. [PMID: 27918235 DOI: 10.1080/15592294.2016.1264560] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In contrast to central nervous system neurons, dorsal root ganglia (DRG) neurons can switch to a regenerative state after peripheral axotomy. In a screen for chromatin regulators of the regenerative responses in this conditioning lesion paradigm, we identified Tet methylcytosine dioxygenase 3 (Tet3) as upregulated in DRG neurons, along with increased 5-hydroxymethylcytosine (5hmC). We generated genome-wide 5hmC maps in adult DRG, which revealed that peripheral and central axotomy (leading to no regenerative effect) triggered differential 5hmC changes that are associated with distinct signaling pathways. 5hmC was altered in a large set of regeneration-associated genes (RAGs), including well-known RAGs, such as Atf3, Bdnf, and Smad1, that regulate axon growth potential of DRG neurons, thus supporting its role for RAG regulation. Our analyses also predicted HIF-1, STAT, and IRF as potential transcription factors that may collaborate with Tet3 for 5hmC modifications. Intriguingly, central axotomy resulted in widespread 5hmC modifications that had little overlap with those of peripheral axotomy, thus potentially constituting a roadblock for regeneration. Our study revealed 5hmC dynamics as a previously unrecognized epigenetic mechanism underlying the divergent responses after axonal injury.
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Affiliation(s)
- Yong-Hwee Eddie Loh
- a Fishberg Department of Neuroscience , Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Andrew Koemeter-Cox
- a Fishberg Department of Neuroscience , Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Mattéa J Finelli
- a Fishberg Department of Neuroscience , Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Li Shen
- a Fishberg Department of Neuroscience , Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Roland H Friedel
- a Fishberg Department of Neuroscience , Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York , NY , USA.,b Department of Neurosurgery , Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Hongyan Zou
- a Fishberg Department of Neuroscience , Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York , NY , USA.,b Department of Neurosurgery , Icahn School of Medicine at Mount Sinai , New York , NY , USA
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35
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Hao Y, Frey E, Yoon C, Wong H, Nestorovski D, Holzman LB, Giger RJ, DiAntonio A, Collins C. An evolutionarily conserved mechanism for cAMP elicited axonal regeneration involves direct activation of the dual leucine zipper kinase DLK. eLife 2016; 5. [PMID: 27268300 PMCID: PMC4896747 DOI: 10.7554/elife.14048] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/12/2016] [Indexed: 11/13/2022] Open
Abstract
A broadly known method to stimulate the growth potential of axons is to elevate intracellular levels of cAMP, however the cellular pathway(s) that mediate this are not known. Here we identify the Dual Leucine-zipper Kinase (DLK, Wnd in Drosophila) as a critical target and effector of cAMP in injured axons. DLK/Wnd is thought to function as an injury ‘sensor’, as it becomes activated after axonal damage. Our findings in both Drosophila and mammalian neurons indicate that the cAMP effector kinase PKA is a conserved and direct upstream activator of Wnd/DLK. PKA is required for the induction of Wnd signaling in injured axons, and DLK is essential for the regenerative effects of cAMP in mammalian DRG neurons. These findings link two important mediators of responses to axonal injury, DLK/Wnd and cAMP/PKA, into a unified and evolutionarily conserved molecular pathway for stimulating the regenerative potential of injured axons. DOI:http://dx.doi.org/10.7554/eLife.14048.001 Adult mammals typically cannot repair damage to the nerve fibers in their brain or spinal cord. This is because these nerve cells cannot generally grow new nerve fibers. However this inability to regenerate nerve fibers is not set in stone. Instead, it can be unlocked by a second injury in nerves elsewhere in the body, the so-called “peripheral nervous system”. This process relies on an enzyme called DLK, which becomes activated in damaged nerve fibers. But how does DLK ‘sense’ damage to nerve fibers? Injuring the peripheral nervous system causes the levels of a molecule called cAMP to increase in the damaged nerve cells, and the elevated cAMP levels stimulate the nerve fibers to regenerate. However, it was not known if cAMP activates DLK, or if the two act independently of each other. By looking at the regeneration of damaged nerve fibers in fruit fly larvae, Hao et al. now show that the cAMP and DLK signaling pathways are clearly linked. Further experiments with nerve cells from mice and human cells revealed more detail about this link. Together the results showed that another enzyme called PKA activates DLK directly when cAMP levels are high. These findings reveal a unified pathway that is the key to unlocking the regenerative potential of injured nerve fibers, which has been conserved for hundreds of millions of years of evolution. Further work could now ask if the DLK enzyme is involved in the other known roles of cAMP signaling in nerve cells; or if cAMP and PKA activate DLK in other forms of nerve damage, including injuries where nerve fibers normally fail to regenerate. DOI:http://dx.doi.org/10.7554/eLife.14048.002
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Affiliation(s)
- Yan Hao
- Department of Molecular Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
| | - Erin Frey
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States
| | - Choya Yoon
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, United States
| | - Hetty Wong
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Douglas Nestorovski
- Department of Molecular Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
| | - Lawrence B Holzman
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Roman J Giger
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, United States.,Department of Neurology, University of Michigan School of Medicine, Ann Arbor, United States
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States
| | - Catherine Collins
- Department of Molecular Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
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36
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Brace EJ, DiAntonio A. Models of axon regeneration in Drosophila. Exp Neurol 2016; 287:310-317. [PMID: 26996133 DOI: 10.1016/j.expneurol.2016.03.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 12/14/2022]
Abstract
Maintaining neuronal connectivity in the face of injury and disease is a major challenge for the nervous system. The great length of axons makes them particularly vulnerable to insult with dire consequences for neuronal function. In the peripheral nervous system there is a program of axonal regeneration that can reestablish connectivity. In the mammalian central nervous system, however, injured axons have little or no capacity to regenerate. The molecular mechanisms that promote axon regeneration have begun to be identified and many of the implicated pathways are evolutionarily conserved. Here we discuss Drosophila models of axonal regrowth, describe insights derived from these studies, and highlight future directions in the use of the fly for dissecting the mechanisms of axonal regeneration.
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Affiliation(s)
- E J Brace
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA, 63110.
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37
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Valakh V, Frey E, Babetto E, Walker LJ, DiAntonio A. Cytoskeletal disruption activates the DLK/JNK pathway, which promotes axonal regeneration and mimics a preconditioning injury. Neurobiol Dis 2015; 77:13-25. [PMID: 25726747 DOI: 10.1016/j.nbd.2015.02.014] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 01/12/2015] [Accepted: 02/15/2015] [Indexed: 10/23/2022] Open
Abstract
Nerve injury can lead to axonal regeneration, axonal degeneration, and/or neuronal cell death. Remarkably, the MAP3K dual leucine zipper kinase, DLK, promotes each of these responses, suggesting that DLK is a sensor of axon injury. In Drosophila, mutations in proteins that stabilize the actin and microtubule cytoskeletons activate the DLK pathway, suggesting that DLK may be activated by cytoskeletal disruption. Here we test this model in mammalian sensory neurons. We find that pharmacological agents designed to disrupt either the actin or microtubule cytoskeleton activate the DLK pathway, and that activation is independent of calcium influx or induction of the axon degeneration program. Moreover, activation of the DLK pathway by targeting the cytoskeleton induces a pro-regenerative state, enhancing axon regeneration in response to a subsequent injury in a process akin to preconditioning. This highlights the potential utility of activating the DLK pathway as a method to improve axon regeneration. Moreover, DLK is required for these responses to cytoskeletal perturbations, suggesting that DLK functions as a key neuronal sensor of cytoskeletal damage.
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Affiliation(s)
- Vera Valakh
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Erin Frey
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Elisabetta Babetto
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Lauren J Walker
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Aaron DiAntonio
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO 63110, USA.
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