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Ransdell JL, Carrasquillo Y, Bosch MK, Mellor RL, Ornitz DM, Nerbonne JM. Loss of Intracellular Fibroblast Growth Factor 14 (iFGF14) Increases the Excitability of Mature Hippocampal and Cortical Pyramidal Neurons. bioRxiv 2024:2024.05.04.592532. [PMID: 38746081 PMCID: PMC11092765 DOI: 10.1101/2024.05.04.592532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Mutations in FGF14 , which encodes intracellular fibroblast growth factor 14 (iFGF14), have been linked to spinocerebellar ataxia type 27 (SCA27), a multisystem disorder associated with progressive deficits in motor coordination and cognitive function. Mice ( Fgf14 -/- ) lacking iFGF14 display similar phenotypes, and we have previously shown that the deficits in motor coordination reflect reduced excitability of cerebellar Purkinje neurons, owing to the loss of iFGF14-mediated regulation of the voltage-dependence of inactivation of the fast transient component of the voltage-gated Na + (Nav) current, I NaT . Here, we present the results of experiments designed to test the hypothesis that loss of iFGF14 also attenuates the intrinsic excitability of mature hippocampal and cortical pyramidal neurons. Current-clamp recordings from adult mouse hippocampal CA1 pyramidal neurons in acute in vitro slices, however, revealed that repetitive firing rates were higher in Fgf14 -/- , than in wild type (WT), cells. In addition, the waveforms of individual action potentials were altered in Fgf14 -/- hippocampal CA1 pyramidal neurons, and the loss of iFGF14 reduced the time delay between the initiation of axonal and somal action potentials. Voltage-clamp recordings revealed that the loss of iFGF14 altered the voltage-dependence of activation, but not inactivation, of I NaT in CA1 pyramidal neurons. Similar effects of the loss of iFGF14 on firing properties were evident in current-clamp recordings from layer 5 visual cortical pyramidal neurons. Additional experiments demonstrated that the loss of iFGF14 does not alter the distribution of anti-Nav1.6 or anti-ankyrin G immunofluorescence labeling intensity along the axon initial segments (AIS) of mature hippocampal CA1 or layer 5 visual cortical pyramidal neurons in situ . Taken together, the results demonstrate that, in contrast with results reported for neonatal (rat) hippocampal pyramidal neurons in dissociated cell culture, the loss of iFGF14 does not disrupt AIS architecture or Nav1.6 localization/distribution along the AIS of mature hippocampal (or cortical) pyramidal neurons in situ .
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Redmann V, Lamb CA, Hwang S, Orchard RC, Kim S, Razi M, Milam A, Park S, Yokoyama CC, Kambal A, Kreamalmeyer D, Bosch MK, Xiao M, Green K, Kim J, Pruett-Miller SM, Ornitz DM, Allen PM, Beatty WL, Schmidt RE, DiAntonio A, Tooze SA, Virgin HW. Clec16a is Critical for Autolysosome Function and Purkinje Cell Survival. Sci Rep 2016; 6:23326. [PMID: 26987296 PMCID: PMC4796910 DOI: 10.1038/srep23326] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/22/2016] [Indexed: 11/29/2022] Open
Abstract
CLEC16A is in a locus genetically linked to autoimmune diseases including multiple sclerosis, but the function of this gene in the nervous system is unknown. Here we show that two mouse strains carrying independent Clec16a mutations developed neurodegenerative disease characterized by motor impairments and loss of Purkinje cells. Neurons from Clec16a-mutant mice exhibited increased expression of the autophagy substrate p62, accumulation of abnormal intra-axonal membranous structures bearing the autophagy protein LC3, and abnormal Golgi morphology. Multiple aspects of endocytosis, lysosome and Golgi function were normal in Clec16a-deficient murine embryonic fibroblasts and HeLa cells. However, these cells displayed abnormal bulk autophagy despite unimpaired autophagosome formation. Cultured Clec16a-deficient cells exhibited a striking accumulation of LC3 and LAMP-1 positive autolysosomes containing undigested cytoplasmic contents. Therefore Clec16a, an autophagy protein that is critical for autolysosome function and clearance, is required for Purkinje cell survival.
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Affiliation(s)
- Veronika Redmann
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christopher A. Lamb
- The Francis Crick Institute, Lincoln’s Inn Fields Laboratory, London, WC2A 3LY, UK
| | - Seungmin Hwang
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Robert C. Orchard
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sungsu Kim
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Minoo Razi
- The Francis Crick Institute, Lincoln’s Inn Fields Laboratory, London, WC2A 3LY, UK
| | - Ashley Milam
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sunmin Park
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christine C. Yokoyama
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Amal Kambal
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Darren Kreamalmeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marie K. Bosch
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Maolei Xiao
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Karen Green
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jungsu Kim
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224, USA
| | - Shondra M. Pruett-Miller
- Genome Engineering and iPSC Center, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David M. Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Paul M. Allen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Wandy L. Beatty
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Robert E. Schmidt
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sharon A. Tooze
- The Francis Crick Institute, Lincoln’s Inn Fields Laboratory, London, WC2A 3LY, UK
| | - Herbert W. Virgin
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
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Bosch MK, Nerbonne JM, Townsend RR, Miyazaki H, Nukina N, Ornitz DM, Marionneau C. Proteomic analysis of native cerebellar iFGF14 complexes. Channels (Austin) 2016; 10:297-312. [PMID: 26889602 DOI: 10.1080/19336950.2016.1153203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Intracellular Fibroblast Growth Factor 14 (iFGF14) and the other intracellular FGFs (iFGF11-13) regulate the properties and densities of voltage-gated neuronal and cardiac Na(+) (Nav) channels. Recent studies have demonstrated that the iFGFs can also regulate native voltage-gated Ca(2+) (Cav) channels. In the present study, a mass spectrometry (MS)-based proteomic approach was used to identify the components of native cerebellar iFGF14 complexes. Using an anti-iFGF14 antibody, native iFGF14 complexes were immunoprecipitated from wild type adult mouse cerebellum. Parallel control experiments were performed on cerebellar proteins isolated from mice (Fgf14(-/-)) harboring a targeted disruption of the Fgf14 locus. MS analyses of immunoprecipitated proteins demonstrated that the vast majority of proteins identified in native cerebellar iFGF14 complexes are Nav channel pore-forming (α) subunits or proteins previously reported to interact with Nav α subunits. In contrast, no Cav channel α or accessory subunits were revealed in cerebellar iFGF14 immunoprecipitates. Additional experiments were completed using an anti-PanNav antibody to immunoprecipitate Nav channel complexes from wild type and Fgf14(-/-) mouse cerebellum. Western blot and MS analyses revealed that the loss of iFGF14 does not measurably affect the protein composition or the relative abundance of Nav channel interacting proteins in native adult mouse cerebellar Nav channel complexes.
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Affiliation(s)
- Marie K Bosch
- a Department of Developmental Biology , Washington University School of Medicine , St. Louis , MO , USA
| | - Jeanne M Nerbonne
- a Department of Developmental Biology , Washington University School of Medicine , St. Louis , MO , USA.,b Internal Medicine, Washington University School of Medicine , St. Louis , MO , USA
| | - R Reid Townsend
- b Internal Medicine, Washington University School of Medicine , St. Louis , MO , USA.,c Cell Biology & Physiology, Washington University School of Medicine , St. Louis , MO , USA
| | - Haruko Miyazaki
- d Laboratory of Structural Pathology, Doshisha University, Kyotanabe-shi, Kyoto , Japan
| | - Nobuyuki Nukina
- d Laboratory of Structural Pathology, Doshisha University, Kyotanabe-shi, Kyoto , Japan
| | - David M Ornitz
- a Department of Developmental Biology , Washington University School of Medicine , St. Louis , MO , USA
| | - Céline Marionneau
- e L'Institut du Thorax, INSERM UMR1087, CNRS UMR6291, Université de Nantes , Nantes , France
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Bosch MK, Nerbonne JM, Ornitz DM. Dual transgene expression in murine cerebellar Purkinje neurons by viral transduction in vivo. PLoS One 2014; 9:e104062. [PMID: 25093726 PMCID: PMC4122438 DOI: 10.1371/journal.pone.0104062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 07/08/2014] [Indexed: 12/19/2022] Open
Abstract
Viral-vector mediated gene transfer to cerebellar Purkinje neurons in vivo is a promising avenue for gene therapy of cerebellar ataxias and for genetic manipulation in functional studies of animal models of cerebellar disease. Here, we report the results of experiments designed to identify efficient methods for viral transduction of adult murine Purkinje neurons in vivo. For these analyses, several lentiviral and an adeno-associated virus (AAV), serotype 1, vector with various promoter combinations were generated and compared for in situ transduction efficiency, assayed by fluorescent reporter protein expression in Purkinje neurons. Additional experiments were also conducted to identify the optimal experimental strategy for co-expression of two proteins in individual Purkinje neurons. Of the viruses tested, AAV1 with a CAG promoter exhibited the highest specificity for Purkinje neurons. To deliver two proteins to the same Purkinje neuron, several methods were tested, including: an internal ribosome entry site (IRES), a 2A sequence, a dual promoter vector, and co-injection of two viruses. Efficient expression of both proteins in the same Purkinje neuron was only achieved by co-injecting two AAV1-CAG viruses. We found that use of an AAV1-CAG virus outperformed similar lentivirus vectors and that co-injection of two AAV1-CAG viruses could be used to efficiently deliver two proteins to the same Purkinje neuron in adult mice. AAV1 with a CAG promoter is highly efficient and selective at transducing adult cerebellar Purkinje neurons and two AAV-CAG viruses can be used to efficiently express two proteins in the same neuron in vivo.
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Affiliation(s)
- Marie K. Bosch
- Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Jeanne M. Nerbonne
- Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Internal Medicine, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - David M. Ornitz
- Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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Xiao M, Bosch MK, Nerbonne JM, Ornitz DM. FGF14 localization and organization of the axon initial segment. Mol Cell Neurosci 2013; 56:393-403. [PMID: 23891806 DOI: 10.1016/j.mcn.2013.07.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 06/26/2013] [Accepted: 07/21/2013] [Indexed: 01/26/2023] Open
Abstract
The axon initial segment (AIS) is highly enriched in the structural proteins ankyrin G and βIV-spectrin, the pore-forming (α) subunits of voltage-gated sodium (Nav) channels, and functional Nav channels, and is critical for the initiation of action potentials. We previously reported that FGF14, a member of the intracellular FGF (iFGF) sub-family, is expressed in cerebellar Purkinje neurons and that the targeted inactivation of Fgf14 in mice (Fgf14(-/-)) results in markedly reduced Purkinje neuron excitability. Here, we demonstrate that FGF14 immunoreactivity is high in the AIS of Purkinje neurons and is distributed in a decreasing, proximal to distal, gradient. This pattern is evident early in the postnatal development of Purkinje neurons and is also observed in many other types of central neurons. In (Scn8a(med)) mice, which are deficient in expression of the Nav1.6 α subunit, FGF14 immunoreactivity is markedly increased and expanded in the Purkinje neuron AIS, in parallel with increased expression of the Nav1.1 (Scn1a) α subunit and expanded expression of βIV-spectrin. Although Nav1.1, FGF14, and βIV-spectrin are affected, ankyrin G immunoreactivity at the AIS of Scn8a(med) and wild type (WT) Purkinje neurons was not significantly different. In Fgf14(-/-) Purkinje neurons, βIV-spectrin and ankyrin G immunoreactivity at the AIS were also similar to WT Purkinje neurons, although both the Nav1.1 and Nav1.6 α subunits are modestly, but significantly (p<0.005), reduced within sub-domains of the AIS, changes that may contribute to the reduced excitability of Fgf14(-/-) Purkinje neurons.
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Affiliation(s)
- Maolei Xiao
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Bosch MK, Evelo RG, Styring S, Rutherford AW, Hoff AJ. ESE relaxation measurements in photosystem II. The influence of the reaction center non-heme iron on the spin-lattice relaxation of Tyr D. FEBS Lett 1991; 292:279-83. [PMID: 1659998 DOI: 10.1016/0014-5793(91)80884-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The spin-lattice relaxation of the tyrosine radical D. in Photosystem II particles was studied at 4.2 K in samples in which flash-induced oscillations of the oxidation state of the Mn-cluster of the oxygen evolving system were abolished by addition of ANT2P, leaving Fe2+/Fe3+ oscillations intact. Samples subjected to 0, 1 or 2 light-flashes all showed the same relaxation kinetics. No period-2 oscillation in the spin-lattice relaxation corresponding to the Fe2+/Fe(3+)-oscillation was observed. Thus the T1-oscillations of D. as a function of flash number in untreated samples are solely caused by the charge-oscillations of the Mn-cluster (1989, Biochim, Biophys. Acta 973, 428-442).
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Affiliation(s)
- M K Bosch
- Department of Biophysics, Huygens Laboratory, Leiden University, The Netherlands
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