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Bu H, Li Z, Lu Y, Zhuang Z, Zhen Y, Zhang L. Deciphering the multifunctional role of dual leucine zipper kinase (DLK) and its therapeutic potential in disease. Eur J Med Chem 2023; 255:115404. [PMID: 37098296 DOI: 10.1016/j.ejmech.2023.115404] [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: 03/01/2023] [Revised: 04/19/2023] [Accepted: 04/19/2023] [Indexed: 04/27/2023]
Abstract
Dual leucine zipper kinase (DLK, MAP3K12), a serine/threonine protein kinase, plays a key role in neuronal development, as it regulates axon regeneration and degeneration through its downstream kinase. Importantly, DLK is closely related to the pathogenesis of numerous neurodegenerative diseases and the induction of β-cell apoptosis that leads to diabetes. In this review, we summarize the current understanding of DLK function, and then discuss the role of DLK signaling in human diseases. Furthermore, various types of small molecule inhibitors of DLK that have been published so far are described in detail in this paper, providing some strategies for the design of DLK small molecule inhibitors in the future.
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Affiliation(s)
- Haiqing Bu
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Zhijia Li
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Yingying Lu
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Zhiyao Zhuang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Yongqi Zhen
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Lan Zhang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
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2
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Zheng B, Tuszynski MH. Regulation of axonal regeneration after mammalian spinal cord injury. Nat Rev Mol Cell Biol 2023; 24:396-413. [PMID: 36604586 DOI: 10.1038/s41580-022-00562-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2022] [Indexed: 01/06/2023]
Abstract
One hundred years ago, Ramón y Cajal, considered by many as the founder of modern neuroscience, stated that neurons of the adult central nervous system (CNS) are incapable of regenerating. Yet, recent years have seen a tremendous expansion of knowledge in the molecular control of axon regeneration after CNS injury. We now understand that regeneration in the adult CNS is limited by (1) a failure to form cellular or molecular substrates for axon attachment and elongation through the lesion site; (2) environmental factors, including inhibitors of axon growth associated with myelin and the extracellular matrix; (3) astrocyte responses, which can both limit and support axon growth; and (4) intraneuronal mechanisms controlling the establishment of an active cellular growth programme. We discuss these topics together with newly emerging hypotheses, including the surprising finding from transcriptomic analyses of the corticospinal system in mice that neurons revert to an embryonic state after spinal cord injury, which can be sustained to promote regeneration with neural stem cell transplantation. These gains in knowledge are steadily advancing efforts to develop effective treatment strategies for spinal cord injury in humans.
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Affiliation(s)
- Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA. .,VA San Diego Research Service, San Diego, CA, USA.
| | - Mark H Tuszynski
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA. .,VA San Diego Research Service, San Diego, CA, USA.
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Katz JS, Rothstein JD, Cudkowicz ME, Genge A, Oskarsson B, Hains AB, Chen C, Galanter J, Burgess BL, Cho W, Kerchner GA, Yeh FL, Ghosh AS, Cheeti S, Brooks L, Honigberg L, Couch JA, Rothenberg ME, Brunstein F, Sharma KR, van den Berg L, Berry JD, Glass JD. A Phase 1 study of GDC-0134, a dual leucine zipper kinase inhibitor, in ALS. Ann Clin Transl Neurol 2022; 9:50-66. [PMID: 35014217 PMCID: PMC8791798 DOI: 10.1002/acn3.51491] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 12/21/2022] Open
Abstract
Objective Dual leucine zipper kinase (DLK), which regulates the c‐Jun N‐terminal kinase pathway involved in axon degeneration and apoptosis following neuronal injury, is a potential therapeutic target in amyotrophic lateral sclerosis (ALS). This first‐in‐human study investigated safety, tolerability, and pharmacokinetics (PK) of oral GDC‐0134, a small‐molecule DLK inhibitor. Plasma neurofilament light chain (NFL) levels were explored in GDC‐0134‐treated ALS patients and DLK conditional knockout (cKO) mice. Methods The study included placebo‐controlled, single and multiple ascending‐dose (SAD; MAD) stages, and an open‐label safety expansion (OLE) with adaptive dosing for up to 48 weeks. Results Forty‐nine patients were enrolled. GDC‐0134 (up to 1200 mg daily) was well tolerated in the SAD and MAD stages, with no serious adverse events (SAEs). In the OLE, three study drug‐related SAEs occurred: thrombocytopenia, dysesthesia (both Grade 3), and optic ischemic neuropathy (Grade 4); Grade ≤2 sensory neurological AEs led to dose reductions/discontinuations. GDC‐0134 exposure was dose‐proportional (median half‐life = 84 h). Patients showed GDC‐0134 exposure‐dependent plasma NFL elevations; DLK cKO mice also exhibited plasma NFL compared to wild‐type littermates. Interpretation This trial characterized GDC‐0134 safety and PK, but no adequately tolerated dose was identified. NFL elevations in GDC‐0134‐treated patients and DLK cKO mice raised questions about interpretation of biomarkers affected by both disease and on‐target drug effects. The safety profile of GDC‐0134 was considered unacceptable and led to discontinuation of further drug development for ALS. Further work is necessary to understand relationships between neuroprotective and potentially therapeutic effects of DLK knockout/inhibition and NFL changes in patients with ALS.
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Affiliation(s)
- Jonathan S Katz
- Forbes Norris MDA/ALS Research Center, California Pacific Medical Center, San Francisco, California, USA
| | | | - Merit E Cudkowicz
- Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Angela Genge
- Montreal Neurological Institute & Hospital, Montreal, QC, Canada
| | | | - Avis B Hains
- Genentech, Inc., South San Francisco, California, USA
| | - Chen Chen
- Genentech, Inc., South San Francisco, California, USA
| | | | | | - William Cho
- Genentech, Inc., South San Francisco, California, USA
| | | | - Felix L Yeh
- Genentech, Inc., South San Francisco, California, USA
| | | | | | - Logan Brooks
- Genentech, Inc., South San Francisco, California, USA
| | - Lee Honigberg
- Genentech, Inc., South San Francisco, California, USA
| | | | | | | | | | | | - James D Berry
- Neurological Clinical Research Institute, Boston, Massachusetts, USA
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4
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Li Y, Ritchie EM, Steinke CL, Qi C, Chen L, Zheng B, Jin Y. Activation of MAP3K DLK and LZK in Purkinje cells causes rapid and slow degeneration depending on signaling strength. eLife 2021; 10:63509. [PMID: 33475086 PMCID: PMC7870138 DOI: 10.7554/elife.63509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/19/2021] [Indexed: 12/16/2022] Open
Abstract
The conserved MAP3K Dual-Leucine-Zipper Kinase (DLK) and Leucine-Zipper-bearing Kinase (LZK) can activate JNK via MKK4 or MKK7. These two MAP3Ks share similar biochemical activities and undergo auto-activation upon increased expression. Depending on cell-type and nature of insults DLK and LZK can induce pro-regenerative, pro-apoptotic or pro-degenerative responses, although the mechanistic basis of their action is not well understood. Here, we investigated these two MAP3Ks in cerebellar Purkinje cells using loss- and gain-of function mouse models. While loss of each or both kinases does not cause discernible defects in Purkinje cells, activating DLK causes rapid death and activating LZK leads to slow degeneration. Each kinase induces JNK activation and caspase-mediated apoptosis independent of each other. Significantly, deleting CELF2, which regulates alternative splicing of Map2k7, strongly attenuates Purkinje cell degeneration induced by LZK, but not DLK. Thus, controlling the activity levels of DLK and LZK is critical for neuronal survival and health.
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Affiliation(s)
- Yunbo Li
- Neurobiology Section, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
| | - Erin M Ritchie
- Neurobiology Section, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
| | - Christopher L Steinke
- Neurobiology Section, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
| | - Cai Qi
- Neurobiology Section, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
| | - Lizhen Chen
- Neurobiology Section, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San DiegoLa JollaUnited States,VA San Diego Healthcare SystemSan DiegoUnited States
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California San DiegoLa JollaUnited States,Department of Neurosciences, School of Medicine, University of California San DiegoLa JollaUnited States,Kavli Institute of Brain and Mind, University of California San DiegoLa JollaUnited States
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Benn CL, Dawson LA. Clinically Precedented Protein Kinases: Rationale for Their Use in Neurodegenerative Disease. Front Aging Neurosci 2020; 12:242. [PMID: 33117143 PMCID: PMC7494159 DOI: 10.3389/fnagi.2020.00242] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/13/2020] [Indexed: 12/12/2022] Open
Abstract
Kinases are an intensively studied drug target class in current pharmacological research as evidenced by the large number of kinase inhibitors being assessed in clinical trials. Kinase-targeted therapies have potential for treatment of a broad array of indications including central nervous system (CNS) disorders. In addition to the many variables which contribute to identification of a successful therapeutic molecule, drug discovery for CNS-related disorders also requires significant consideration of access to the target organ and specifically crossing the blood-brain barrier (BBB). To date, only a small number of kinase inhibitors have been reported that are specifically designed to be BBB permeable, which nonetheless demonstrates the potential for success. This review considers the potential for kinase inhibitors in the context of unmet medical need for neurodegenerative disease. A subset of kinases that have been the focus of clinical investigations over a 10-year period have been identified and discussed individually. For each kinase target, the data underpinning the validity of each in the context of neurodegenerative disease is critically evaluated. Selected molecules for each kinase are identified with information on modality, binding site and CNS penetrance, if known. Current clinical development in neurodegenerative disease are summarized. Collectively, the review indicates that kinase targets with sufficient rationale warrant careful design approaches with an emphasis on improving brain penetrance and selectivity.
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Goodwani S, Fernandez C, Acton PJ, Buggia-Prevot V, McReynolds ML, Ma J, Hu CH, Hamby ME, Jiang Y, Le K, Soth MJ, Jones P, Ray WJ. Dual Leucine Zipper Kinase Is Constitutively Active in the Adult Mouse Brain and Has Both Stress-Induced and Homeostatic Functions. Int J Mol Sci 2020; 21:ijms21144849. [PMID: 32659913 PMCID: PMC7402291 DOI: 10.3390/ijms21144849] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/04/2020] [Accepted: 07/07/2020] [Indexed: 01/15/2023] Open
Abstract
Dual leucine zipper kinase (DLK, Map3k12) is an axonal protein that governs the balance between degeneration and regeneration through its downstream effectors c-jun N-terminal kinase (JNK) and phosphorylated c-jun (p-c-Jun). In peripheral nerves DLK is generally inactive until induced by injury, after which it transmits signals to the nucleus via retrograde transport. Here we report that in contrast to this mode of regulation, in the uninjured adult mouse cerebellum, DLK constitutively drives nuclear p-c-Jun in cerebellar granule neurons, whereas in the forebrain, DLK is similarly expressed and active, but nuclear p-c-Jun is undetectable. When neurodegeneration results from mutant human tau in the rTg4510 mouse model, p-c-Jun then accumulates in neuronal nuclei in a DLK-dependent manner, and the extent of p-c-Jun correlates with markers of synaptic loss and gliosis. This regional difference in DLK-dependent nuclear p-c-Jun accumulation could relate to differing levels of JNK scaffolding proteins, as the cerebellum preferentially expresses JNK-interacting protein-1 (JIP-1), whereas the forebrain contains more JIP-3 and plenty of SH3 (POSH). To characterize the functional differences between constitutive- versus injury-induced DLK signaling, RNA sequencing was performed after DLK inhibition in the cerebellum and in the non-transgenic and rTg4510 forebrain. In all contexts, DLK inhibition reduced a core set of transcripts that are associated with the JNK pathway. Non-transgenic forebrain showed almost no other transcriptional changes in response to DLK inhibition, whereas the rTg4510 forebrain and the cerebellum exhibited distinct differentially expressed gene signatures. In the cerebellum, but not the rTg4510 forebrain, pathway analysis indicated that DLK regulates insulin growth factor-1 (IGF1) signaling through the transcriptional induction of IGF1 binding protein-5 (IGFBP5), which was confirmed and found to be functionally relevant by measuring signaling through the IGF1 receptor. Together these data illuminate the complex multi-functional nature of DLK signaling in the central nervous system (CNS) and demonstrate its role in homeostasis as well as tau-mediated neurodegeneration.
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Affiliation(s)
- Sunil Goodwani
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Celia Fernandez
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Paul J. Acton
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Virginie Buggia-Prevot
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Morgan L. McReynolds
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Jiacheng Ma
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Cheng Hui Hu
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Mary E. Hamby
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
| | - Yongying Jiang
- Institute for Applied Cancer Science, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (Y.J.); (K.L.); (M.J.S.); (P.J.)
| | - Kang Le
- Institute for Applied Cancer Science, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (Y.J.); (K.L.); (M.J.S.); (P.J.)
| | - Michael J. Soth
- Institute for Applied Cancer Science, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (Y.J.); (K.L.); (M.J.S.); (P.J.)
| | - Philip Jones
- Institute for Applied Cancer Science, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (Y.J.); (K.L.); (M.J.S.); (P.J.)
| | - William J. Ray
- The Neurodegeneration Consortium, Therapeutics Discovery Division, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (S.G.); (C.F.); (P.J.A.); (V.B.-P.); (M.L.M.); (J.M.); (C.H.H.); (M.E.H.)
- Correspondence: ; Tel.: +1-713-794-4558
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Pilato CM, Park JH, Kong L, d'Ydewalle C, Valdivia D, Chen KS, Griswold-Prenner I, Sumner CJ. Motor neuron loss in SMA is not associated with somal stress-activated JNK/c-Jun signaling. Hum Mol Genet 2020; 28:3282-3292. [PMID: 31272106 DOI: 10.1093/hmg/ddz150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/14/2019] [Accepted: 06/21/2019] [Indexed: 01/08/2023] Open
Abstract
A pathological hallmark of spinal muscular atrophy (SMA) is severe motor neuron (MN) loss, which results in muscle weakness and often infantile or childhood mortality. Although it is well established that deficient expression of survival motor neuron (SMN) protein causes SMA, the molecular pathways that execute MN cell death are poorly defined. The c-Jun NH2-terminal kinases (JNKs) are stress-activated kinases with multiple substrates including c-Jun, which can be activated during neuronal injury and neurodegenerative disease leading to neuronal apoptosis. Recently, increased JNK-c-Jun signaling was reported in SMA raising the possibility that JNK inhibitors could be a novel treatment for this disease. We examined JNK-c-Jun activity in SMA mouse and human cultured cells and tissues. Anisomycin treatment of human SMA fibroblasts and sciatic nerve ligation in SMA mice provoked robust phosphorylated-c-Jun (p-c-Jun) expression indicating that SMN-deficiency does not prevent activation of the stress-induced JNK-c-Jun signaling pathway. Despite retained capacity to activate JNK-c-Jun, we observed no basal increase of p-c-Jun levels in SMA compared to control cultured cells, human or mouse spinal cord tissues, or mouse MNs during the period of MN loss in severe SMA model mice. In both controls and SMA, ~50% of α-MN nuclei express p-c-Jun with decreasing expression during the early postnatal period. Together these studies reveal no evidence of stress-activated JNK-c-Jun signaling in MNs of SMA mice or human tissues, but do highlight the important role of JNK-c-Jun activity during normal MN development raising caution about JNK antagonism in this pediatric neuromuscular disease.
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Affiliation(s)
| | | | | | | | | | | | | | - Charlotte J Sumner
- Department of Neurology.,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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8
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Intrathecal Injection of Dual Zipper Kinase shRNA Alleviating the Neuropathic Pain in a Chronic Constrictive Nerve Injury Model. Int J Mol Sci 2018; 19:ijms19082421. [PMID: 30115872 PMCID: PMC6121272 DOI: 10.3390/ijms19082421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 08/08/2018] [Accepted: 08/11/2018] [Indexed: 12/20/2022] Open
Abstract
Dual leucine zipper kinase (DLK) is a member of mitogen-activated protein kinase kinase kinase (MAP3K) family mainly involved in neuronal degeneration. However, the role of DLK signaling in the neuropathic pain has not yet been fully determined. Chronic constrictive injury (CCI) was conducted by four 3-0 chromic gut ligatures loosely ligated around the sciatic nerve. Escalated DLK expression over the dorsal root ganglion was observed from one to four rings of CCI. Remarkable expression of DLK was observed in primary dorsal root ganglion cells culture subjected to electrical stimulation and attenuated by DLK short hairpin RNA (shRNA) treatment. Intrathecal injection of DLK shRNA attenuates the expression of DLK over the dorsal root ganglion and hippocampus neurons and increased the threshold of mechanical allodynia and decreased thermal hyperalgesia. In CatWalk gait analysis, significant decreases of print area, maximum contact maximum intensity, stand phase, single stance, and regular index by CCI were alleviated by the DLK shRNA administration. In conclusion, the expression of DLK was up-regulated in chronic constrictive injury and attenuated by the administration of DLK shRNA, which paralleled the improvement of neurobehavior of neuropathic pain. The modulation of DLK expression is a potential clinic treatment option for neuropathic pain.
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Distinct homeostatic modulations stabilize reduced postsynaptic receptivity in response to presynaptic DLK signaling. Nat Commun 2018; 9:1856. [PMID: 29748610 PMCID: PMC5945772 DOI: 10.1038/s41467-018-04270-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 04/16/2018] [Indexed: 11/08/2022] Open
Abstract
Synapses are constructed with the stability to last a lifetime, yet sufficiently flexible to adapt during injury. Although fundamental pathways that mediate intrinsic responses to neuronal injury have been defined, less is known about how synaptic partners adapt. We have investigated responses in the postsynaptic cell to presynaptic activation of the injury-related Dual Leucine Zipper Kinase pathway at the Drosophila neuromuscular junction. We find that the postsynaptic compartment reduces neurotransmitter receptor levels, thus depressing synaptic strength. Interestingly, this diminished state is stabilized through distinct modulations to two postsynaptic homeostatic signaling systems. First, a retrograde response normally triggered by reduced receptor levels is silenced, preventing a compensatory enhancement in presynaptic neurotransmitter release. However, when global presynaptic release is attenuated, a postsynaptic receptor scaling mechanism persists to adaptively stabilize this diminished neurotransmission state. Thus, the homeostatic set point of synaptic strength is recalibrated to a reduced state as synapses acclimate to injury.
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10
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Zika virus-induced acute myelitis and motor deficits in adult interferon αβ/γ receptor knockout mice. J Neurovirol 2018; 24:273-290. [PMID: 29476408 PMCID: PMC5992253 DOI: 10.1007/s13365-017-0595-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/11/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022]
Abstract
Zika virus (ZIKV) has received widespread attention because of its effect on the developing fetus. It is becoming apparent, however, that severe neurological sequelae, such as Guillian-Barrë syndrome (GBS), myelitis, encephalitis, and seizures can occur after infection of adults. This study demonstrates that a contemporary strain of ZIKV can widely infect astrocytes and neurons in the brain and spinal cord of adult, interferon α/β receptor knockout mice (AG129 strain) and cause progressive hindlimb paralysis, as well as severe seizure-like activity during the acute phase of disease. The severity of hindlimb motor deficits correlated with increased numbers of ZIKV-infected lumbosacral spinal motor neurons and decreased numbers of spinal motor neurons. Electrophysiological compound muscle action potential (CMAP) amplitudes in response to stimulation of the lumbosacral spinal cord were reduced when obvious motor deficits were present. ZIKV immunoreactivity was high, intense, and obvious in tissue sections of the brain and spinal cord. Infection in the brain and spinal cord was also associated with astrogliosis as well as T cell and neutrophil infiltration. CMAP and histological analysis indicated that peripheral nerve and muscle functions were intact. Consequently, motor deficits in these circumstances appear to be primarily due to myelitis and possibly encephalitis as opposed to a peripheral neuropathy or a GBS-like syndrome. Thus, acute ZIKV infection of adult AG129 mice may be a useful model for ZIKV-induced myelitis, encephalitis, and seizure activity.
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11
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Morrey JD, Wang H, Hurst BL, Zukor K, Siddharthan V, Van Wettere AJ, Sinex DG, Tarbet EB. Causation of Acute Flaccid Paralysis by Myelitis and Myositis in Enterovirus-D68 Infected Mice Deficient in Interferon αβ/γ Receptor Deficient Mice. Viruses 2018; 10:E33. [PMID: 29329211 PMCID: PMC5795446 DOI: 10.3390/v10010033] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 01/04/2018] [Accepted: 01/08/2018] [Indexed: 11/16/2022] Open
Abstract
Enterovirus D68 (EV-D68) caused a large outbreak in the summer and fall of 2014 in the United States. It causes serious respiratory disease, but causation of associated paralysis is controversial, because the virus is not routinely identified in cerebrospinal fluid. To establish clinical correlates with human disease, we evaluated EV-D68 infection in non-lethal paralysis mouse models. Ten-day-old mice lacking interferon responses were injected intraperitoneally with the virus. Paralysis developed in hindlimbs. After six weeks of paralysis, the motor neurons were depleted due to viral infection. Hindlimb muscles were also infected and degenerating. Even at the earliest stage of paralysis, muscles were still infected and were degenerating, in addition to presence of virus in the spinal cord. To model natural respiratory infection, five-day-old mice were infected intranasally with EV-D68. Two of the four infected mice developed forelimb paralysis. The affected limbs had muscle disease, but no spinal cord infection was detected. The unique contributions of this study are that EV-D68 causes paralysis in mice, and that causation by muscle disease, with or without spinal cord disease, may help to resolve the controversy that the virus can cause paralysis, even if it cannot be identified in cerebrospinal fluid.
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Affiliation(s)
- John D Morrey
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, 5600 Old Main Hill, Utah State University, Logan, UT 84322, USA.
| | - Hong Wang
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, 5600 Old Main Hill, Utah State University, Logan, UT 84322, USA.
| | - Brett L Hurst
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, 5600 Old Main Hill, Utah State University, Logan, UT 84322, USA.
| | - Katherine Zukor
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, 5600 Old Main Hill, Utah State University, Logan, UT 84322, USA.
| | - Venkatraman Siddharthan
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, 5600 Old Main Hill, Utah State University, Logan, UT 84322, USA.
| | - Arnaud J Van Wettere
- Utah Veterinary Diagnostics Laboratory, Department of Animal, Dairy, and Veterinary Sciences, 950 East 1400 North, Utah State University, Logan, UT 84341, USA.
| | - Donal G Sinex
- Department of Communication Disorders and Deaf Education, 2800 Old Main Hill, Utah State University, Logan, UT 84322, USA.
| | - E Bart Tarbet
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, 5600 Old Main Hill, Utah State University, Logan, UT 84322, USA.
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Chand KK, Lee KM, Lee JD, Qiu H, Willis EF, Lavidis NA, Hilliard MA, Noakes PG. Defects in synaptic transmission at the neuromuscular junction precede motor deficits in a TDP‐43
Q331K
transgenic mouse model of amyotrophic lateral sclerosis. FASEB J 2018; 32:2676-2689. [DOI: 10.1096/fj.201700835r] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Kirat K. Chand
- School of Biomedical Sciences Brisbane Queensland Australia
| | - Kah Meng Lee
- School of Biomedical Sciences Brisbane Queensland Australia
| | - John D. Lee
- School of Biomedical Sciences Brisbane Queensland Australia
| | - Hao Qiu
- School of Biomedical Sciences Brisbane Queensland Australia
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13
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Lee KM, Chand KK, Hammond LA, Lavidis NA, Noakes PG. Functional decline at the aging neuromuscular junction is associated with altered laminin-α4 expression. Aging (Albany NY) 2017; 9:880-899. [PMID: 28301326 PMCID: PMC5391237 DOI: 10.18632/aging.101198] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/03/2017] [Indexed: 12/04/2022]
Abstract
Laminin-α4 is involved in the alignment of active zones to postjunctional folds at the neuromuscular junction (NMJ). Prior study has implicated laminin-α4 in NMJ maintenance, with altered NMJ morphology observed in adult laminin-α4 deficient mice (lama4−/−). The present study further investigated the role of laminin-α4 in NMJ maintenance by functional characterization of transmission properties, morphological investigation of synaptic proteins including synaptic laminin-α4, and neuromotor behavioral testing. Results showed maintained perturbed transmission properties at lama4−/− NMJs from adult (3 months) through to aged (18-22 months). Hind-limb grip force demonstrated similar trends as transmission properties, with maintained weaker grip force across age groups in lama4−/−. Interestingly, both transmission properties and hind-limb grip force in aged wild-types resembled those observed in adult lama4−/−. Most significantly, altered expression of laminin-α4 was noted at the wild-type NMJs prior to the observed decline in transmission properties, suggesting that altered laminin-α4 expression precedes the decline of neurotransmission in aging wild-types. These findings significantly support the role of laminin-α4 in maintenance of the NMJ during aging.
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Affiliation(s)
- Kah Meng Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Kirat K Chand
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.,University of Queensland Centre for Clinical Research, The University of Queensland, Herston, Queensland 4029, Australia
| | - Luke A Hammond
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
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14
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Yin C, Huang GF, Sun XC, Guo Z, Zhang JH. DLK silencing attenuated neuron apoptosis through JIP3/MA2K7/JNK pathway in early brain injury after SAH in rats. Neurobiol Dis 2017; 103:133-143. [PMID: 28396258 DOI: 10.1016/j.nbd.2017.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 03/21/2017] [Accepted: 04/05/2017] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE Dual leucine zipper kinase (DLK/MA3K12) has been reported involved in apoptosis and neuronal degeneration during neural development and traumatic brain injury. This study was designed to investigate the role of DLK with its adaptor protein JNK interacting protein-3 (JIP3), and its downstream MA2K7/JNK signaling pathway in early brain injury (EBI) after subarachnoid hemorrhage (SAH) in a rat model. DESIGN Controlled in vivo laboratory study. SETTING Animal research laboratory. SUBJECTS Two hundred and twenty-three adult male Sprague-Dawley rats weighing 280-320g. INTERVENTIONS SAH was induced by endovascular perforation in rats. The SAH grade, neurological score, and brain water content were measured at 24 and 72h after SAH. Immunofluorescence staining was used to detect the cells that expressed DLK. The terminal deoxynucleotid transferase-deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) was used to detect the neuronal apoptosis. In mechanism research, the expression of DLK, JIP3, phosphorylated-JNK (p-JNK)/JNK, and cleaved caspase-3 (CC-3) were analyzed by western blot at 24h after SAH. The DLK small interfering RNA (siRNA), JIP3 siRNA, MA2K7 siRNA and recombinant DLK protein which injected intracerebroventricularly were given as the interventions. MEASUREMENTS AND MAIN RESULTS The DLK expression was increased in the left cortex neurons and peaked at 24h after SAH. DLK siRNA attenuated brain edema, reduced neuronal apoptosis, and improved the neurobehavioral functions after SAH, but the recombinant DLK protein deteriorated neurobehavioral functions and brain edema. DLK siRNA decreased and recombinant DLK protein increased the expression of MA2K7/p-JNK/CC-3 at 24h after SAH. The JIP3 siRNA reduced the level of JIP3/MA2K7/p-JNK/CC-3, combined DLK siRNA and JIP3 siRNA further decreased the expression of DLK/MA2K7/p-JNK/CC-3, and MA2K7 siRNA lowered the amount of MA2K7/p-JNK/CC-3 at 24h after SAH. CONCLUSIONS As a negative role, DLK was involved in EBI after SAH, possibly mediated by its adaptor protein JIP3 and MA2K7/JNK signaling pathways. To reduce the level of DLK may be a new target as intervention for SAH.
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Affiliation(s)
- Cheng Yin
- Departments of Anesthesiology and Physiology, Loma Linda University School of Medicine, Loma Linda, CA, USA; Department of Neurosurgery, Affiliated Hospital of the University of Electronic Science and Technology of China, Sichuan Provincial People's Hospital, Chengdu, China
| | - Guang-Fu Huang
- Department of Neurosurgery, Affiliated Hospital of the University of Electronic Science and Technology of China, Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiao-Chuan Sun
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zongduo Guo
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - John H Zhang
- Departments of Anesthesiology and Physiology, Loma Linda University School of Medicine, Loma Linda, CA, USA.
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15
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Retrograde apoptotic signaling by the p75 neurotrophin receptor. Neuronal Signal 2017; 1:NS20160007. [PMID: 32714573 PMCID: PMC7373242 DOI: 10.1042/ns20160007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 02/06/2023] Open
Abstract
Neurotrophins are target-derived factors necessary for mammalian nervous system development and maintenance. They are typically produced by neuronal target tissues and interact with their receptors at axonal endings. Therefore, locally generated neurotrophin signals must be conveyed from the axon back to the cell soma. Retrograde survival signaling by neurotrophin binding to Trk receptors has been extensively studied. However, neurotrophins also bind to the p75 receptor, which can induce apoptosis in a variety of contexts. Selective activation of p75 at distal axon ends has been shown to generate a retrograde apoptotic signal, although the mechanisms involved are poorly understood. The present review summarizes the available evidence for retrograde proapoptotic signaling in general and the role of the p75 receptor in particular, with discussion of unanswered questions in the field. In-depth knowledge of the mechanisms of retrograde apoptotic signaling is essential for understanding the etiology of neurodegeneration in many diseases and injuries.
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16
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O'Donovan KJ. Intrinsic Axonal Growth and the Drive for Regeneration. Front Neurosci 2016; 10:486. [PMID: 27833527 PMCID: PMC5081384 DOI: 10.3389/fnins.2016.00486] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 10/10/2016] [Indexed: 02/01/2023] Open
Abstract
Following damage to the adult nervous system in conditions like stroke, spinal cord injury, or traumatic brain injury, many neurons die and most of the remaining spared neurons fail to regenerate. Injured neurons fail to regrow both because of the inhibitory milieu in which they reside as well as a loss of the intrinsic growth capacity of the neurons. If we are to develop effective therapeutic interventions that promote functional recovery for the devastating injuries described above, we must not only better understand the molecular mechanisms of developmental axonal growth in hopes of re-activating these pathways in the adult, but at the same time be aware that re-activation of adult axonal growth may proceed via distinct mechanisms. With this knowledge in hand, promoting adult regeneration of central nervous system neurons can become a more tractable and realistic therapeutic endeavor.
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Affiliation(s)
- Kevin J O'Donovan
- Department of Chemistry and Life Science, United States Military Academy West Point, NY, USA
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17
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Leucine Zipper-bearing Kinase promotes axon growth in mammalian central nervous system neurons. Sci Rep 2016; 6:31482. [PMID: 27511108 PMCID: PMC4980599 DOI: 10.1038/srep31482] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 07/04/2016] [Indexed: 11/11/2022] Open
Abstract
Leucine Zipper-bearing Kinase (LZK/MAP3K13) is a member of the mixed lineage kinase family with high sequence identity to Dual Leucine Zipper Kinase (DLK/MAP3K12). While DLK is established as a key regulator of axonal responses to injury, the role of LZK in mammalian neurons is poorly understood. By gain- and loss-of-function analyses in neuronal cultures, we identify LZK as a novel positive regulator of axon growth. LZK signals specifically through MKK4 and JNKs among MAP2Ks and MAPKs respectively in neuronal cells, with JNK activity positively regulating LZK protein levels. Neuronal maturation or activity deprivation activates the LZK-MKK4-JNK pathway. LZK and DLK share commonalities in signaling, regulation, and effects on axon extension. Furthermore, LZK-dependent regulation of DLK protein expression and the lack of additive effects on axon growth upon co-manipulation suggest complex functional interaction and cross-regulation between these two kinases. Together, our data support the possibility for two structurally related MAP3Ks to work in concert to mediate axonal responses to external insult or injury in mammalian CNS neurons.
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18
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Blondeau A, Lucier JF, Matteau D, Dumont L, Rodrigue S, Jacques PÉ, Blouin R. Dual leucine zipper kinase regulates expression of axon guidance genes in mouse neuronal cells. Neural Dev 2016; 11:13. [PMID: 27468987 PMCID: PMC4965899 DOI: 10.1186/s13064-016-0068-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 07/25/2016] [Indexed: 11/10/2022] Open
Abstract
Background Recent genetic studies in model organisms, such as Drosophila, C. elegans and mice, have highlighted a critical role for dual leucine zipper kinase (DLK) in neural development and axonal responses to injury. However, exactly how DLK fulfills these functions remains to be determined. Using RNA-seq profiling, we evaluated the global changes in gene expression that are caused by shRNA-mediated knockdown of endogenous DLK in differentiated Neuro-2a neuroblastoma cells. Results Our analysis led to the identification of numerous up- and down-regulated genes, among which several were found to be associated with system development and axon guidance according to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, respectively. Because of their importance in axonal growth, pruning and regeneration during development and adult life, we then examined by quantitative RT-PCR the mRNA expression levels of the identified axon guidance genes in DLK-depleted cells. Consistent with the RNA-seq data, our results confirmed that loss of DLK altered expression of the genes encoding neuropilin 1 (Nrp1), plexin A4 (Plxna4), Eph receptor A7 (Epha7), Rho family GTPase 1 (Rnd1) and semaphorin 6B (Sema6b). Interestingly, this regulation of Nrp1 and Plxna4 mRNA expression by DLK in Neuro-2a cells was also reflected at the protein level, implicating DLK in the modulation of the function of these axon guidance molecules. Conclusions Collectively, these results provide the first evidence that axon guidance genes are downstream targets of the DLK signaling pathway, which through their regulation probably modulates neuronal cell development, structure and function. Electronic supplementary material The online version of this article (doi:10.1186/s13064-016-0068-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andréanne Blondeau
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Jean-François Lucier
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Dominick Matteau
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Lauralyne Dumont
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Sébastien Rodrigue
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Pierre-Étienne Jacques
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada.,Département d'informatique, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Canada
| | - Richard Blouin
- Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada.
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19
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Yin C, Huang GF, Sun XC, Guo Z, Zhang JH. Tozasertib attenuates neuronal apoptosis via DLK/JIP3/MA2K7/JNK pathway in early brain injury after SAH in rats. Neuropharmacology 2016; 108:316-23. [PMID: 27084696 DOI: 10.1016/j.neuropharm.2016.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 01/31/2023]
Abstract
BACKGROUND AND PURPOSE Since tozasertib is neuroprotective for injured optic nerve, this study is intended to test whether tozasertib reduces early brain injury after subarachnoid hemorrhage (SAH) in a rat model. METHODS Two hundred sixteen (216) male Sprague-Dawley rats were randomly subjected to endovascular perforation model of SAH and sham group. SAH grade, neurological score, and brain water content were measured at 24 and 72 h after SAH. Dual leucine zipper kinase (DLK) and its downstream factors, JNK-interacting protein 3 (JIP3), MA2K7, p-JNK/JNK (c-Jun N-terminal kinase), and apoptosis related proteins cleaved caspase-3 (CC-3), Bim, Bcl-2, and cleaved caspase-9 (CC-9) were analyzed by western blot at 24 h after SAH. Apoptotic cells were detected by terminal deoxynucleotid transferase-deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL). DLK small interfering RNA (siRNA), JIP3 siRNA and MA2K7 siRNA, the JNK, p38MAPK, and MEK inhibitors SP600125, SB203580, and PD98059 were used for intervention. RESULTS Tozasertib reduced neuronal apoptosis, attenuated brain edema and improved neurobehavioral deficits 24 and 72 h after SAH. At 24 h After SAH, DLK/JIP3/MA2K7/p-JNK/CC-3 expressions were elevated markedly and tozasertib reduced DLK, MA2K7/p-JNK/CC-3 expressions but enhanced JIP3 expression. In the presence of tozasertib, DLK/JIP3/MA2K7 siRNA and SP600125, SB203580 and PD98059 deteriorated the neurobehavioral deficits, brain edema and increased the expression of CC-3. SAH potentiated the expression of Bim, CC-9, and CC-3 but reduced Bcl-2, while tozasertib reduced expression of Bim, CC-9, and CC-3 but enhanced Bcl-2. CONCLUSIONS Tozasertib reduced neuronal apoptosis and improved outcome possibly via DLK/JIP3/MA2K7/JNK pathways after SAH.
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Affiliation(s)
- Cheng Yin
- Departments of Anesthesiology and Physiology, Loma Linda University School of Medicine, Loma Linda, CA, USA; Department of Neurosurgery, Hospital of the University of Electronic Science and Technology of China, Sichuan Provincial People's Hospital, Chengdu, China
| | - Guang-Fu Huang
- Department of Neurosurgery, Hospital of the University of Electronic Science and Technology of China, Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiao-Chuan Sun
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zongduo Guo
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - John H Zhang
- Departments of Anesthesiology and Physiology, Loma Linda University School of Medicine, Loma Linda, CA, USA.
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20
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Rho1-Wnd signaling regulates loss-of-cell polarity-induced cell invasion in Drosophila. Oncogene 2015; 35:846-55. [PMID: 25961917 DOI: 10.1038/onc.2015.137] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 03/21/2015] [Accepted: 03/30/2015] [Indexed: 12/11/2022]
Abstract
Both cell polarity and c-Jun N-terminal kinase (JNK) activity are essential to the maintenance of tissue homeostasis, and disruption of either is commonly seen in cancer progression. Despite the established connection between loss-of-cell polarity and JNK activation, much less is known about the molecular mechanism by which aberrant cell polarity induces JNK-mediated cell migration and tumor invasion. Here we show results from a genetic screen using an in vivo invasion model via knocking down cell polarity gene in Drosophila wing discs, and identify Rho1-Wnd signaling as an important molecular link that mediates loss-of-cell polarity-triggered JNK activation and cell invasion. We show that Wallenda (Wnd), a protein kinase of the mitogen-activated protein kinase kinase kinase family, by forming a complex with the GTPase Rho1, is both necessary and sufficient for Rho1-induced JNK-dependent cell invasion, MMP1 activation and epithelial-mesenchymal transition. Furthermore, Wnd promotes cell proliferation and tissue growth through wingless production when apoptosis is inhibited by p35. Finally, Wnd shows oncogenic cooperation with Ras(V12) to trigger tumor growth in eye discs and causes invasion into the ventral nerve cord. Together, our data not only provides a novel mechanistic insight on how cell polarity loss contributes to cell invasion, but also highlights the value of the Drosophila model system to explore human cancer biology.
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21
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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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22
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Abstract
Motoneuron death after transection of the axons (axotomy) in neonates is believed to share the same mechanistic bases as naturally occurring programmed cell death during development. The c-Jun N-terminal kinase pathway is activated in both forms of motoneuron death, but it remains unknown to what extent these two forms of motoneuron death depend on this pathway and which upstream kinases are involved. We found that numbers of facial motoneurons are doubled in neonatal mice deficient in either ZPK/DLK (zipper protein kinase, also known as dual leucine zipper kinase), a mitogen-activated protein kinase kinase kinase, or in MKK4/MAP2K4, a mitogen-activated protein kinase kinase directly downstream of ZPK/DLK, and that the facial motoneurons in those mutant mice are completely resistant to axotomy-induced death. Conditional deletion of MKK4/MAP2K4 in neurons further suggested that ZPK/DLK and MKK4/MAP2K4-dependent mechanisms underlying axotomy-induced death are motoneuron autonomous. Nevertheless, quantitative analysis of facial motoneurons during embryogenesis revealed that both ZPK/DLK and MKK4/MAP2K4-dependent and -independent mechanisms contribute to developmental elimination of excess motoneurons. In contrast to MKK4/MAP2K4, mice lacking MKK7/MAP2K7, another mitogen-activated protein kinase kinase directly downstream of ZPK/DLK, conditionally in neurons did not have excess facial motoneurons. However, some MKK7/MAP2K7-deficient facial motoneurons were resistant to axotomy-induced death, indicating a synergistic effect of MKK7/MAP2K7 on axotomy-induced death of these facial motoneurons. Together, our study provides compelling evidence for the pivotal roles of the ZPK/DLK and MKK4/MAP2K4-dependent mechanism in axotomy-induced motoneuron death in neonates and also demonstrates that axotomy-induced motoneuron death is not identical to developmental motoneuron death with respect to the involvement of ZPK/DLK, MKK4/MAP2K4 and MKK7/MAP2K7.
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23
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Loss of the spectraplakin short stop activates the DLK injury response pathway in Drosophila. J Neurosci 2013; 33:17863-73. [PMID: 24198375 DOI: 10.1523/jneurosci.2196-13.2013] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The MAPKKK dual leucine zipper-containing kinase (DLK, Wallenda in Drosophila) is an evolutionarily conserved component of the axonal injury response pathway. After nerve injury, DLK promotes degeneration of distal axons and regeneration of proximal axons. This dual role in coordinating degeneration and regeneration suggests that DLK may be a sensor of axon injury, and so understanding how DLK is activated is important. Two mechanisms are known to activate DLK. First, increasing the levels of DLK via overexpression or loss of the PHR ubiquitin ligases that target DLK activate DLK signaling. Second, in Caenorhabditis elegans, a calcium-dependent mechanism, can activate DLK. Here we describe a new mechanism that activates DLK in Drosophila: loss of the spectraplakin short stop (shot). In a genetic screen for mutants with defective neuromuscular junction development, we identify a hypomorphic allele of shot that displays synaptic terminal overgrowth and a precocious regenerative response to nerve injury. We demonstrate that both phenotypes are the result of overactivation of the DLK signaling pathway. We further show that, unlike mutations in the PHR ligase Highwire, loss of function of shot activates DLK without a concomitant increase in the levels of DLK. As a spectraplakin, Shot binds to both actin and microtubules and promotes cytoskeletal stability. The DLK pathway is also activated by downregulation of the TCP1 chaperonin complex, whose normal function is to promote cytoskeletal stability. These findings support the model that DLK is activated by cytoskeletal instability, which is a shared feature of both spectraplakin mutants and injured axons.
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24
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Abstract
The extensive lengths of neuronal processes necessitate efficient mechanisms for communication with the cell body. Neuronal regeneration after nerve injury requires new transcription; thus, long-distance retrograde signalling from axonal lesion sites to the soma and nucleus is required. In recent years, considerable progress has been made in elucidating the mechanistic basis of this system. This has included the discovery of a priming role for early calcium waves; confirmation of central roles for mitogen-activated protein kinase signalling effectors, the importin family of nucleocytoplasmic transport factors and molecular motors such as dynein; and demonstration of the importance of local translation as a key regulatory mechanism. These recent findings provide a coherent mechanistic framework for axon-soma communication in the injured nerve and shed light on the integration of cytoplasmic and nuclear transport in all eukaryotic cells.
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Affiliation(s)
- Ida Rishal
- Department of Biological Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Mike Fainzilber
- Department of Biological Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
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25
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Independent pathways downstream of the Wnd/DLK MAPKKK regulate synaptic structure, axonal transport, and injury signaling. J Neurosci 2013; 33:12764-78. [PMID: 23904612 DOI: 10.1523/jneurosci.5160-12.2013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Mitogen-activated protein (MAP) kinase signaling cascades orchestrate diverse cellular activities with common molecular players. To achieve specific cellular outcomes in response to specific signals, scaffolding proteins play an important role. Here we investigate the role of the scaffolding protein JNK interacting protein-1 (JIP1) in neuronal signaling by a conserved axonal MAP kinase kinase kinase, known as Wallenda (Wnd) in Drosophila and dual leucine kinase (DLK) in vertebrates and Caenorhabditis elegans. Recent studies in multiple model organisms suggest that Wnd/DLK regulates both regenerative and degenerative responses to axonal injury. Here we report a new role for Wnd in regulating synaptic structure during development, which implies that Wnd is also active in uninjured neurons. This synaptic role of Wnd can be functionally separated from the role of Wnd in axonal regeneration and injury signaling by the requirement for the JIP1 scaffold and the p38b MAP kinase. JIP1 mediates the synaptic function of Wnd via p38, which is not required for injury signaling or new axonal growth after injury. Our results indicate that Wnd regulates multiple independent pathways in Drosophila motoneurons and that JIP1 scaffolds a specific downstream cascade required for the organization of presynaptic microtubules during synaptic development.
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26
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Kurup N, Sharifnia P, Jin Y. Spatial and temporal dynamics of neurite regrowth. Curr Opin Neurobiol 2013; 23:1011-7. [PMID: 23856616 DOI: 10.1016/j.conb.2013.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/19/2013] [Accepted: 06/20/2013] [Indexed: 11/26/2022]
Abstract
Injury to mature neurites triggers a series of events that have both growth promoting and inhibitory roles. Recent evidence from a variety of experimental models has revealed new neuronal re-growth modulators. The action of these modulators must be precisely regulated both in time and space, and involves multiple cellular processes including retrograde signaling and local translation in the injured neurite. New genetic techniques, in combination with pharmacological approaches, have served to advance mechanistic dissection of neuronal response to injury. Better understanding of the spatio-temporal cues would greatly aid in the development of effective regenerative therapies.
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Affiliation(s)
- Naina Kurup
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA; Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
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27
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Tedeschi A, Bradke F. The DLK signalling pathway--a double-edged sword in neural development and regeneration. EMBO Rep 2013; 14:605-14. [PMID: 23681442 DOI: 10.1038/embor.2013.64] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/23/2013] [Indexed: 01/08/2023] Open
Abstract
Dual leucine zipper kinase (DLK), a mitogen-activated protein kinase kinase kinase, controls axon growth, apoptosis and neuron degeneration during neural development, as well as neurodegeneration after various insults to the adult nervous system. Interestingly, recent studies have also highlighted a role of DLK in promoting axon regeneration in diverse model systems. Invertebrates and vertebrates, cold- and warm-blooded animals, as well as central and peripheral mammalian nervous systems all differ in their ability to regenerate injured axons. Here, we discuss how DLK-dependent signalling regulates apparently contradictory functions during neural development and regeneration in different species. In addition, we outline strategies to fine-tune DLK function, either alone or together with other approaches, to promote axon regeneration in the adult mammalian central nervous system.
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Affiliation(s)
- Andrea Tedeschi
- Laboratory for Axon Growth & Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
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Functional genomic screening identifies dual leucine zipper kinase as a key mediator of retinal ganglion cell death. Proc Natl Acad Sci U S A 2013; 110:4045-50. [PMID: 23431148 DOI: 10.1073/pnas.1211284110] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Glaucoma, a major cause of blindness worldwide, is a neurodegenerative optic neuropathy in which vision loss is caused by loss of retinal ganglion cells (RGCs). To better define the pathways mediating RGC death and identify targets for the development of neuroprotective drugs, we developed a high-throughput RNA interference screen with primary RGCs and used it to screen the full mouse kinome. The screen identified dual leucine zipper kinase (DLK) as a key neuroprotective target in RGCs. In cultured RGCs, DLK signaling is both necessary and sufficient for cell death. DLK undergoes robust posttranscriptional up-regulation in response to axonal injury in vitro and in vivo. Using a conditional knockout approach, we confirmed that DLK is required for RGC JNK activation and cell death in a rodent model of optic neuropathy. In addition, tozasertib, a small molecule protein kinase inhibitor with activity against DLK, protects RGCs from cell death in rodent glaucoma and traumatic optic neuropathy models. Together, our results establish a previously undescribed drug/drug target combination in glaucoma, identify an early marker of RGC injury, and provide a starting point for the development of more specific neuroprotective DLK inhibitors for the treatment of glaucoma, nonglaucomatous forms of optic neuropathy, and perhaps other CNS neurodegenerations.
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Yan D, Jin Y. Regulation of DLK-1 kinase activity by calcium-mediated dissociation from an inhibitory isoform. Neuron 2013; 76:534-48. [PMID: 23141066 DOI: 10.1016/j.neuron.2012.08.043] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2012] [Indexed: 01/19/2023]
Abstract
MAPKKK dual leucine zipper-bearing kinases (DLKs) are regulators of synaptic development and axon regeneration. The mechanisms underlying their activation are not fully understood. Here, we show that C. elegans DLK-1 is activated by a Ca(2+)-dependent switch from inactive heteromeric to active homomeric protein complexes. We identify a DLK-1 isoform, DLK-1S, that shares identical kinase and leucine zipper domains with the previously described long isoform DLK-1L but acts to inhibit DLK-1 function by binding to DLK-1L. The switch between homo- or heteromeric DLK-1 complexes is influenced by Ca(2+) concentration. A conserved hexapeptide in the DLK-1L C terminus is essential for DLK-1 activity and is required for Ca(2+) regulation. The mammalian DLK-1 homolog MAP3K13 contains an identical C-terminal hexapeptide and can functionally complement dlk-1 mutants, suggesting that the DLK activation mechanism is conserved. The DLK activation mechanism is ideally suited for rapid and spatially controlled signal transduction in response to axonal injury and synaptic activity.
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Affiliation(s)
- Dong Yan
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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Shin JE, Cho Y, Beirowski B, Milbrandt J, Cavalli V, DiAntonio A. Dual leucine zipper kinase is required for retrograde injury signaling and axonal regeneration. Neuron 2012; 74:1015-22. [PMID: 22726832 DOI: 10.1016/j.neuron.2012.04.028] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2012] [Indexed: 11/18/2022]
Abstract
Here we demonstrate that the dual leucine zipper kinase (DLK) promotes robust regeneration of peripheral axons after nerve injury in mice. Peripheral axon regeneration is accelerated by prior injury; however, DLK KO neurons do not respond to a preconditioning lesion with enhanced regeneration in vivo or in vitro. Assays for activation of transcription factors in injury-induced proregenerative pathways reveal that loss of DLK abolishes upregulation of p-STAT3 and p-cJun in the cell body after axonal injury. DLK is not required for the phosphorylation of STAT3 at the site of nerve injury but is necessary for retrograde transport of p-STAT3 to the cell body. These data demonstrate that DLK enhances regeneration by promoting a retrograde injury signal that is required for the activation of the neuronal proregenerative program.
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Affiliation(s)
- Jung Eun Shin
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Yang S, Xiong CJ, Sun HM, Li XS, Zhang GQ, Wu B, Zhou DS. The distribution of HCN2-positive cells in the gastrointestinal tract of mice. J Anat 2012; 221:303-10. [PMID: 22803609 DOI: 10.1111/j.1469-7580.2012.01546.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2012] [Indexed: 01/19/2023] Open
Abstract
HCN2 channels are involved in the spontaneous rhythmic activities of some CNS neurons and act by generating I(f) current. The gastrointestinal (GI) tract is known to be capable of spontaneous rhythmic activity; however, the possible role of HCN2 channels in this organ has not yet been elucidated. This study investigated the distribution of HCN2-positive cells in the mouse GI tract using immunohistochemistry. To identify the nature of these HCN2 cells, anti-ChAT and anti-Kit antibodies were used to co-label neurons and the interstitial cells of Cajal (ICCs), respectively. Additionally, differences in the distribution of HCN2-positive cells within the GI tract were also analyzed. Our results showed that HCN2 channels were mainly located within the myenteric neurons of the enteric nervous system in the GI tract. Double-staining revealed that HCN2-positive neurons were labeled by ChAT, indicating that these HCN2-positive cells are also cholinergic neurons. Although the HCN2-positive cells were not stained by the anti-Kit antibody, their processes were in close proximity to ICCs around the myenteric plexus region. Moreover, several differences in the distribution of HCN2 in the stomach, small intestine and colon were partly consistent with the regional differences in the spontaneous rhythmic activities of these organs. Basing on the role HCN2, we suggested that HCN2 channels facilitate the release of Ach from cholinergic neurons to affect the GI peristalsis by acting on M receptors on the ICCs. However, the HCN2 channels are not directly involved in spontaneous slow-wave initiation by ICCs.
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Affiliation(s)
- Shu Yang
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
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Ghosh AS, Wang B, Pozniak CD, Chen M, Watts RJ, Lewcock JW. DLK induces developmental neuronal degeneration via selective regulation of proapoptotic JNK activity. ACTA ACUST UNITED AC 2012; 194:751-64. [PMID: 21893599 PMCID: PMC3171129 DOI: 10.1083/jcb.201103153] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
DLK is part of a specialized JNK signaling complex in axons that promotes apoptosis via c-Jun but axon degeneration via distinct JNK substrates. The c-Jun N-terminal kinase (JNK) signaling pathway is essential for neuronal degeneration in multiple contexts but also regulates neuronal homeostasis. It remains unclear how neurons are able to dissociate proapoptotic JNK signaling from physiological JNK activity. In this paper, we show that the mixed lineage kinase dual leucine zipper kinase (DLK) selectively regulates the JNK-based stress response pathway to mediate axon degeneration and neuronal apoptosis without influencing other aspects of JNK signaling. This specificity is dependent on interaction of DLK with the scaffolding protein JIP3 to form a specialized JNK signaling complex. Local activation of DLK-based signaling in the axon results in phosphorylation of c-Jun and apoptosis after redistribution of JNK to the cell body. In contrast, regulation of axon degeneration by DLK is c-Jun independent and mediated by distinct JNK substrates. DLK-null mice displayed reduced apoptosis in multiple neuronal populations during development, demonstrating that prodegenerative DLK signaling is required in vivo.
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Affiliation(s)
- Arundhati Sengupta Ghosh
- Neurodegeneration Laboratories, Department of Neuroscience, Genentech, Inc., South San Francisco, CA 94080, USA
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Daviau A, Couture JP, Blouin R. Loss of DLK expression in WI-38 human diploid fibroblasts induces a senescent-like proliferation arrest. Biochem Biophys Res Commun 2011; 413:282-7. [PMID: 21893036 DOI: 10.1016/j.bbrc.2011.08.086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 08/17/2011] [Indexed: 10/17/2022]
Abstract
DLK, a serine/threonine kinase that functions as an upstream activator of the mitogen-activated protein kinase (MAPK) pathways, has been shown to play a role in development, cell differentiation, apoptosis and neuronal response to injury. Interestingly, recent studies have shown that DLK may also be required for cell proliferation, although little is known about its specific functions. To start addressing this issue, we studied how DLK expression is modulated during cell cycle progression and what effect DLK depletion has on cell proliferation in WI-38 fibroblasts. Our results indicate that DLK protein levels are low in serum-starved cells, but that serum addition markedly stimulated it. Moreover, RNA interference experiments demonstrate that DLK is required for ERK activity, expression of the cell cycle regulator cyclin D1 and proliferation of WI-38 cells. DLK-depleted cells also show a senescent phenotype as revealed by senescence-associated galactosidase activity and up-regulation of the senescence pathway proteins p53 and p21. Consistent with a role for p53 in this response, inhibition of p53 expression by RNA interference significantly alleviated senescence induced by DLK knockdown. Together, these findings indicate that DLK participates in cell proliferation and/or survival, at least in part, by modulating the expression of cell cycle regulatory proteins.
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Affiliation(s)
- Alex Daviau
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
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