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Sekerková G, Kilic S, Cheng YH, Fredrick N, Osmani A, Kim H, Opal P, Martina M. Phenotypical, genotypical and pathological characterization of the moonwalker mouse, a model of ataxia. Neurobiol Dis 2024; 195:106492. [PMID: 38575093 PMCID: PMC11089908 DOI: 10.1016/j.nbd.2024.106492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/13/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024] Open
Abstract
We performed a comprehensive study of the morphological, functional, and genetic features of moonwalker (MWK) mice, a mouse model of spinocerebellar ataxia caused by a gain of function of the TRPC3 channel. These mice show numerous behavioral symptoms including tremor, altered gait, circling behavior, impaired motor coordination, impaired motor learning and decreased limb strength. Cerebellar pathology is characterized by early and almost complete loss of unipolar brush cells as well as slowly progressive, moderate loss of Purkinje cell (PCs). Structural damage also includes loss of synaptic contacts from parallel fibers, swollen ER structures, and degenerating axons. Interestingly, no obvious correlation was observed between PC loss and severity of the symptoms, as the phenotype stabilizes around 2 months of age, while the cerebellar pathology is progressive. This is probably due to the fact that PC function is severely impaired much earlier than the appearance of PC loss. Indeed, PC firing is already impaired in 3 weeks old mice. An interesting feature of the MWK pathology that still remains to be explained consists in a strong lobule selectivity of the PC loss, which is puzzling considering that TRPC is expressed in every PC. Intriguingly, genetic analysis of MWK cerebella shows, among other alterations, changes in the expression of both apoptosis inducing and resistance factors possibly suggesting that damaged PCs initiate specific cellular pathways that protect them from overt cell loss.
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Affiliation(s)
- Gabriella Sekerková
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
| | - Sumeyra Kilic
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Yen-Hsin Cheng
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Natalie Fredrick
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Anne Osmani
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Haram Kim
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Puneet Opal
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Marco Martina
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
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Roles for the Endoplasmic Reticulum in Regulation of Neuronal Calcium Homeostasis. Cells 2019; 8:cells8101232. [PMID: 31658749 PMCID: PMC6829861 DOI: 10.3390/cells8101232] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 02/06/2023] Open
Abstract
By influencing Ca2+ homeostasis in spatially and architecturally distinct neuronal compartments, the endoplasmic reticulum (ER) illustrates the notion that form and function are intimately related. The contribution of ER to neuronal Ca2+ homeostasis is attributed to the organelle being the largest reservoir of intracellular Ca2+ and having a high density of Ca2+ channels and transporters. As such, ER Ca2+ has incontrovertible roles in the regulation of axodendritic growth and morphology, synaptic vesicle release, and neural activity dependent gene expression, synaptic plasticity, and mitochondrial bioenergetics. Not surprisingly, many neurological diseases arise from ER Ca2+ dyshomeostasis, either directly due to alterations in ER resident proteins, or indirectly via processes that are coupled to the regulators of ER Ca2+ dynamics. In this review, we describe the mechanisms involved in the establishment of ER Ca2+ homeostasis in neurons. We elaborate upon how changes in the spatiotemporal dynamics of Ca2+ exchange between the ER and other organelles sculpt neuronal function and provide examples that demonstrate the involvement of ER Ca2+ dyshomeostasis in a range of neurological and neurodegenerative diseases.
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Kim TY, Niimi K, Takahashi E. Protein expression pattern in cerebellum of Cav2.1 mutant, tottering-6j mice. Exp Anim 2016; 65:207-14. [PMID: 26887908 PMCID: PMC4976234 DOI: 10.1538/expanim.15-0120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Neuronal voltage-gated Cav2.1 channel controls a broad array of functions, including neurotransmitter release, neuronal excitability, activity-dependent gene expression, and neuronal survival. The Cav2.1 channel is molecular complexes consisting of several subunits: α1, α2/δ, β, and γ. The pore-forming subunit, α1, is encoded by the Cacna1a gene. Tottering-6j mice, generated by the Neuroscience Mutagenesis Facility at The Jackson Laboratory, are a recessive mutant strain in which the mutation has been chemically induced by ethylnitrosourea. In tottering-6j mice, mutation in the Cacna1a gene results in a base substitution (C-to-A) in the consensus splice acceptor sequence, which results in deletion of a part of the S4-S5 linker, S5, and a part of S5-S6 linker domain I in the α1 subunit of Cav2.1 channel. The mice display motor dysfunctions and absence-like seizures. However, protein expression in the cerebellum of tottering-6j mice has not been investigated. Real-time quantitative reverse transcription polymerase chain reaction and histological analyses of the cerebellum of tottering-6j mice revealed high expression levels of tyrosine hydroxylase, zebrin II, and ryanodine receptor 3 compared with those of wild-type mice. Conversely, a low level of calretinin expression was found compared with wild-type mice. These results indicate that Cacna1a mutation plays a significant role in protein expression patterns and that the tottering-6j mouse is a useful model for understanding protein expression mechanisms.
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Affiliation(s)
- Tae Yeon Kim
- Research Resources Center, RIKEN Brain Science Institute 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Sawada K, Saito S, Horiuchi-Hirose M, Murase K. Enhanced heat shock protein 25 immunoreactivity in cranial nerve motoneurons and their related fiber tracts in rats prenatally-exposed to X-irradiation. Congenit Anom (Kyoto) 2014; 54:87-93. [PMID: 24750554 DOI: 10.1111/cga.12028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 09/01/2013] [Indexed: 11/26/2022]
Abstract
Alterations in histoarchitecture of the brainstem were examined immunohistochemically in 4-week-old rats with a single whole body X-irradiation at a dose of 0.5, 1.0, or 1.5 Gy on embryonic day (ED) 15 using anti-heat shock protein 25 (HSP25). HSP25 immunostaining was seen in the neuronal perikarya of cranial nerve motoneurons, that is, the motor and mesencephalic nuclei of the trigeminal nerve, facial nucleus, abducens nucleus and accessory facial nucleus in the pons, and the ambiguous nucleus, dorsal nucleus of vagus nerve and hypoglossus nucleus in the medulla oblongata of intact controls. In 0.5 to 1.5 Gy-irradiated rats, HSP25 immunostaining in those neurons was more intense than in controls, while the most intense immunostaining was marked in 1.5 Gy-irradiated rats. HSP25 immunostaining was also apparent in the spinal tract of the trigeminal nerve and facial nerve tracts in 0.5 to 1.5 Gy-irradiated rats, but was faint in controls. Interestingly, HSP25 immunostaining was aberrantly enhanced in dendritic arbors in the magnocellular region of medial vestibular nucleus of 0.5-1.5 Gy-irradiated rats. Those arbors were identified as excitatory secondary vestibulo-ocular neurons by double immunofluorescence for HSP25 and SMI-32. The results suggest an increase of HSP25 expression in cranial nerve motoneurons and their related fiber tracts from prenatal exposure to ionizing irradiation. This may be an adaptive response to chronic hypoxia due to malformed brain arteries caused by prenatal ionizing irradiation.
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Affiliation(s)
- Kazuhiko Sawada
- Department of Physical Therapy, Tsukuba International University, Tsuchiura, Japan
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Ohashi R, Sakata SI, Naito A, Hirashima N, Tanaka M. Dendritic differentiation of cerebellar Purkinje cells is promoted by ryanodine receptors expressed by Purkinje and granule cells. Dev Neurobiol 2013; 74:467-80. [PMID: 24123915 DOI: 10.1002/dneu.22139] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/02/2013] [Accepted: 09/28/2013] [Indexed: 11/12/2022]
Abstract
Cerebellar Purkinje cells have the most elaborate dendritic trees among neurons in the brain. We examined the roles of ryanodine receptor (RyR), an intracellular Ca(2+) release channel, in the dendrite formation of Purkinje cells using cerebellar cell cultures. In the cerebellum, Purkinje cells express RyR1 and RyR2, whereas granule cells express RyR2. When ryanodine (10 µM), a blocker of RyR, was added to the culture medium, the elongation and branching of Purkinje cell dendrites were markedly inhibited. When we transferred small interfering RNA (siRNA) against RyR1 into Purkinje cells using single-cell electroporation, dendritic branching but not elongation of the electroporated Purkinje cells was inhibited. On the other hand, transfection of RyR2 siRNA into granule cells also inhibited dendritic branching of Purkinje cells. Furthermore, ryanodine reduced the levels of brain-derived neurotrophic factor (BDNF) in the culture medium. The ryanodine-induced inhibition of dendritic differentiation was partially rescued when BDNF was exogenously added to the culture medium in addition to ryanodine. Overall, these results suggest that RyRs expressed by both Purkinje and granule cells play important roles in promoting the dendritic differentiation of Purkinje cells and that RyR2 expressed by granule cells is involved in the secretion of BDNF from granule cells.
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Affiliation(s)
- Ryo Ohashi
- Department of Cellular Biophysics, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
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Affiliation(s)
| | - Richard Hawkes
- Department of Cell Biology and Anatomy, Genes and Development Research Group and Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary
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Kakizawa S, Yamazawa T, Chen Y, Ito A, Murayama T, Oyamada H, Kurebayashi N, Sato O, Watanabe M, Mori N, Oguchi K, Sakurai T, Takeshima H, Saito N, Iino M. Nitric oxide-induced calcium release via ryanodine receptors regulates neuronal function. EMBO J 2011; 31:417-28. [PMID: 22036948 DOI: 10.1038/emboj.2011.386] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 09/28/2011] [Indexed: 12/13/2022] Open
Abstract
Mobilization of intracellular Ca(2+) stores regulates a multitude of cellular functions, but the role of intracellular Ca(2+) release via the ryanodine receptor (RyR) in the brain remains incompletely understood. We found that nitric oxide (NO) directly activates RyRs, which induce Ca(2+) release from intracellular stores of central neurons, and thereby promote prolonged Ca(2+) signalling in the brain. Reversible S-nitrosylation of type 1 RyR (RyR1) triggers this Ca(2+) release. NO-induced Ca(2+) release (NICR) is evoked by type 1 NO synthase-dependent NO production during neural firing, and is essential for cerebellar synaptic plasticity. NO production has also been implicated in pathological conditions including ischaemic brain injury, and our results suggest that NICR is involved in NO-induced neuronal cell death. These findings suggest that NICR via RyR1 plays a regulatory role in the physiological and pathophysiological functions of the brain.
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Affiliation(s)
- Sho Kakizawa
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
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Plomp JJ, van den Maagdenberg AMJM, Kaja S. The ataxic Cacna1a-mutant mouse rolling nagoya: an overview of neuromorphological and electrophysiological findings. THE CEREBELLUM 2009; 8:222-30. [PMID: 19484318 PMCID: PMC2734259 DOI: 10.1007/s12311-009-0117-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Accepted: 10/02/2008] [Indexed: 11/24/2022]
Abstract
Homozygous rolling Nagoya natural mutant mice display a severe ataxic gait and frequently roll over to their side or back. The causative mutation resides in the Cacna1a gene, encoding the pore-forming α1 subunit of Cav2.1 type voltage-gated Ca2+ channels. These channels are crucially involved in neuronal Ca2+ signaling and in neurotransmitter release at many central synapses and, in the periphery, at the neuromuscular junction. We here review the behavioral, histological, biochemical, and neurophysiological studies on this mouse mutant and discuss its usefulness as a model of human neurological diseases associated with Cav2.1 dysfunction.
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Affiliation(s)
- Jaap J Plomp
- Department of Neurology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.
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Barbado M, Fablet K, Ronjat M, De Waard M. Gene regulation by voltage-dependent calcium channels. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1096-104. [PMID: 19250948 DOI: 10.1016/j.bbamcr.2009.02.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 02/13/2009] [Accepted: 02/16/2009] [Indexed: 12/11/2022]
Abstract
Ca2+ is the most widely used second messenger in cell biology and fulfills a plethora of essential cell functions. One of the most exciting findings of the last decades was the involvement of Ca2+ in the regulation of long-term cell adaptation through its ability to control gene expression. This finding provided a link between cell excitation and gene expression. In this review, we chose to focus on the role of voltage-dependent calcium channels in mediating gene expression in response to membrane depolarization. We illustrate the different pathways by which these channels are involved in excitation-transcription coupling, including the most recent Ca2+ ion-independent strategies that highlight the transcription factor role of calcium channels.
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Affiliation(s)
- Maud Barbado
- Grenoble Institute of Neuroscience, Inserm U 836-Team 3 Calcium Channels, Functions and Pathologies, Bâtiment Edmond Safra, Université Joseph Fourier, Site santé de la Tronche, BP 170, 38042 Grenoble cedex 9, France
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