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Li J, Veeraraghavan P, Young SM. Ca V 2.1 α 1 subunit motifs that control presynaptic Ca V 2.1 subtype abundance are distinct from Ca V 2.1 preference. J Physiol 2024; 602:485-506. [PMID: 38155373 PMCID: PMC10872416 DOI: 10.1113/jp284957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 11/30/2023] [Indexed: 12/30/2023] Open
Abstract
Presynaptic voltage-gated Ca2+ channel (CaV ) subtype abundance at mammalian synapses regulates synaptic transmission in health and disease. In the mammalian central nervous system (CNS), most presynaptic terminals are CaV 2.1 dominant with a developmental reduction in CaV 2.2 and CaV 2.3 levels, and CaV 2 subtype levels are altered in various diseases. However, the molecular mechanisms controlling presynaptic CaV 2 subtype levels are largely unsolved. Because the CaV 2 α1 subunit cytoplasmic regions contain varying levels of sequence conservation, these regions are proposed to control presynaptic CaV 2 subtype preference and abundance. To investigate the potential role of these regions, we expressed chimeric CaV 2.1 α1 subunits containing swapped motifs with the CaV 2.2 and CaV 2.3 α1 subunit on a CaV 2.1/CaV 2.2 null background at the calyx of Held presynaptic terminals. We found that expression of CaV 2.1 α1 subunit chimeras containing the CaV 2.3 loop II-III region or cytoplasmic C-terminus (CT) resulted in a large reduction of presynaptic Ca2+ currents compared to the CaV 2.1 α1 subunit. However, the Ca2+ current sensitivity to the CaV 2.1 blocker agatoxin-IVA was the same between the chimeras and the CaV 2.1 α1 subunit. Additionally, we found no reduction in presynaptic Ca2+ currents with CaV 2.1/2.2 cytoplasmic CT chimeras. We conclude that the motifs in the CaV 2.1 loop II-III and CT do not individually regulate CaV 2.1 preference, although these motifs control CaV 2.1 levels and the CaV 2.3 CT contains motifs that negatively regulate presynaptic CaV 2.3 levels. We propose that the motifs controlling presynaptic CaV 2.1 preference are distinct from those regulating CaV 2.1 levels and may act synergistically to impact pathways regulating CaV 2.1 preference and abundance. KEY POINTS: Presynaptic CaV 2 subtype abundance regulates neuronal circuit properties, although the mechanisms regulating presynaptic CaV 2 subtype abundance and preference remain enigmatic. The CaV α1 subunit determines subtype and contains multiple motifs implicated in regulating presynaptic subtype abundance and preference. The CaV 2.1 α1 subunit domain II-III loop and cytoplasmic C-terminus are positive regulators of presynaptic CaV 2.1 abundance but do not regulate preference. The CaV 2.3 α1 subunit cytoplasmic C-terminus negatively regulates presynaptic CaV 2 subtype abundance but not preference, whereas the CaV 2.2 α1 subunit cytoplasmic C-terminus is not a key regulator of presynaptic CaV 2 subtype abundance or preference. The CaV 2 α1 subunit motifs determining the presynaptic CaV 2 preference are distinct from abundance.
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Affiliation(s)
- Jianing Li
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA, USA
- Cell Developmental Biology Graduate Program, University of Iowa, Iowa City, IA 52242, USA
| | | | - Samuel M. Young
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA, USA
- Department of Otolaryngology, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
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Suryavanshi P, Sawant-Pokam P, Clair S, Brennan KC. Increased presynaptic excitability in a migraine with aura mutation. Brain 2024; 147:680-697. [PMID: 37831655 PMCID: PMC10834252 DOI: 10.1093/brain/awad326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/24/2023] [Accepted: 09/04/2023] [Indexed: 10/15/2023] Open
Abstract
Migraine is a common and disabling neurological disorder. The headache and sensory amplifications of migraine are attributed to hyperexcitable sensory circuits, but a detailed understanding remains elusive. A mutation in casein kinase 1 delta (CK1δ) was identified in non-hemiplegic familial migraine with aura and advanced sleep phase syndrome. Mice carrying the CK1δT44A mutation were more susceptible to spreading depolarization (the phenomenon that underlies migraine aura), but mechanisms underlying this migraine-relevant phenotype were not known. We used a combination of whole-cell electrophysiology and multiphoton imaging, in vivo and in brain slices, to compare CK1δT44A mice (adult males) to their wild-type littermates. We found that despite comparable synaptic activity at rest, CK1δT44A neurons were more excitable upon repetitive stimulation than wild-type, with a reduction in presynaptic adaptation at excitatory but not inhibitory synapses. The mechanism of this adaptation deficit was a calcium-dependent enhancement of the size of the readily releasable pool of synaptic vesicles, and a resultant increase in glutamate release, in CK1δT44A compared to wild-type synapses. Consistent with this mechanism, CK1δT44A neurons showed an increase in the cumulative amplitude of excitatory post-synaptic currents, and a higher excitation-to-inhibition ratio during sustained activity compared to wild-type. At a local circuit level, action potential bursts elicited in CK1δT44A neurons triggered an increase in recurrent excitation compared to wild-type, and at a network level, CK1δT44A mice showed a longer duration of 'up state' activity, which is dependent on recurrent excitation. Finally, we demonstrated that the spreading depolarization susceptibility of CK1δT44A mice could be returned to wild-type levels with the same intervention (reduced extracellular calcium) that normalized presynaptic adaptation. Taken together, these findings show a stimulus-dependent presynaptic gain of function at glutamatergic synapses in a genetic model of migraine, that accounts for the increased spreading depolarization susceptibility and may also explain the sensory amplifications that are associated with the disease.
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Affiliation(s)
- Pratyush Suryavanshi
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
- Interdepartmental Neuroscience Program, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, USA
| | - Punam Sawant-Pokam
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Sarah Clair
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - K C Brennan
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
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3
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Gomez K, Santiago U, Nelson TS, Allen HN, Calderon-Rivera A, Hestehave S, Rodríguez Palma EJ, Zhou Y, Duran P, Loya-Lopez S, Zhu E, Kumar U, Shields R, Koseli E, McKiver B, Giuvelis D, Zuo W, Inyang KE, Dorame A, Chefdeville A, Ran D, Perez-Miller S, Lu Y, Liu X, Handoko, Arora PS, Patek M, Moutal A, Khanna M, Hu H, Laumet G, King T, Wang J, Damaj MI, Korczeniewska OA, Camacho CJ, Khanna R. A peptidomimetic modulator of the Ca V2.2 N-type calcium channel for chronic pain. Proc Natl Acad Sci U S A 2023; 120:e2305215120. [PMID: 37972067 PMCID: PMC10666126 DOI: 10.1073/pnas.2305215120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 10/09/2023] [Indexed: 11/19/2023] Open
Abstract
Transmembrane Cav2.2 (N-type) voltage-gated calcium channels are genetically and pharmacologically validated, clinically relevant pain targets. Clinical block of Cav2.2 (e.g., with Prialt/Ziconotide) or indirect modulation [e.g., with gabapentinoids such as Gabapentin (GBP)] mitigates chronic pain but is encumbered by side effects and abuse liability. The cytosolic auxiliary subunit collapsin response mediator protein 2 (CRMP2) targets Cav2.2 to the sensory neuron membrane and regulates their function via an intrinsically disordered motif. A CRMP2-derived peptide (CBD3) uncouples the Cav2.2-CRMP2 interaction to inhibit calcium influx, transmitter release, and pain. We developed and applied a molecular dynamics approach to identify the A1R2 dipeptide in CBD3 as the anchoring Cav2.2 motif and designed pharmacophore models to screen 27 million compounds on the open-access server ZincPharmer. Of 200 curated hits, 77 compounds were assessed using depolarization-evoked calcium influx in rat dorsal root ganglion neurons. Nine small molecules were tested electrophysiologically, while one (CBD3063) was also evaluated biochemically and behaviorally. CBD3063 uncoupled Cav2.2 from CRMP2, reduced membrane Cav2.2 expression and Ca2+ currents, decreased neurotransmission, reduced fiber photometry-based calcium responses in response to mechanical stimulation, and reversed neuropathic and inflammatory pain across sexes in two different species without changes in sensory, sedative, depressive, and cognitive behaviors. CBD3063 is a selective, first-in-class, CRMP2-based peptidomimetic small molecule, which allosterically regulates Cav2.2 to achieve analgesia and pain relief without negative side effect profiles. In summary, CBD3063 could potentially be a more effective alternative to GBP for pain relief.
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Affiliation(s)
- Kimberly Gomez
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Ulises Santiago
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA15261
| | - Tyler S. Nelson
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Heather N. Allen
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Aida Calderon-Rivera
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Sara Hestehave
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Erick J. Rodríguez Palma
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Yuan Zhou
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ85724
| | - Paz Duran
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Santiago Loya-Lopez
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Elaine Zhu
- Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University Grossman School of Medicine, New York, NY10016
- Interdisciplinary Pain Research Program, New York University Langone Health, New York, NY10016
| | - Upasana Kumar
- Department of Diagnostic Sciences, Center for Orofacial Pain and Temporomandibular Disorders, Rutgers School of Dental Medicine, Newark, NJ07101
| | - Rory Shields
- Rutgers School of Graduate Studies, Newark Health Science Campus, Newark, NJ07101
| | - Eda Koseli
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, Richmond, VA23298
| | - Bryan McKiver
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, Richmond, VA23298
| | - Denise Giuvelis
- Department of Biomedical Sciences, College of Osteopathic Medicine, Center for Excellence in the Neurosciences, University of New England, Biddeford, ME04005
| | - Wanhong Zuo
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ07103
| | | | - Angie Dorame
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ85724
| | - Aude Chefdeville
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ85724
| | - Dongzhi Ran
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing400016, China
| | - Samantha Perez-Miller
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Yi Lu
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing400016, China
| | - Xia Liu
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing400016, China
| | - Handoko
- Department of Chemistry, New York University, New York, NY10003
| | | | - Marcel Patek
- Bright Rock Path Limited Liability Company, Tucson, AZ85724
| | - Aubin Moutal
- Department of Pharmacology and Physiology, School of Medicine, St. Louis University, St. Louis, MO63104
| | - May Khanna
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
| | - Huijuan Hu
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ07103
| | - Geoffroy Laumet
- Department of Physiology, Michigan State University, East Lansing, MI48824
| | - Tamara King
- Department of Biomedical Sciences, College of Osteopathic Medicine, Center for Excellence in the Neurosciences, University of New England, Biddeford, ME04005
| | - Jing Wang
- Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University Grossman School of Medicine, New York, NY10016
- Interdisciplinary Pain Research Program, New York University Langone Health, New York, NY10016
- Department of Neuroscience and Physiology and Neuroscience Institute, School of Medicine, New York University, New York, NY10010
| | - M. Imad Damaj
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, Richmond, VA23298
| | - Olga A. Korczeniewska
- Department of Diagnostic Sciences, Center for Orofacial Pain and Temporomandibular Disorders, Rutgers School of Dental Medicine, Newark, NJ07101
- Rutgers School of Graduate Studies, Newark Health Science Campus, Newark, NJ07101
| | - Carlos J. Camacho
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA15261
| | - Rajesh Khanna
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY10010
- New York University Pain Research Center, New York, NY10010
- Department of Neuroscience and Physiology and Neuroscience Institute, School of Medicine, New York University, New York, NY10010
- Chemical, and Biomolecular Engineering Department, Tandon School of Engineering, New York University, New York City, NY11201
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Dahimene S, Page KM, Nieto-Rostro M, Pratt WS, Dolphin AC. The Interplay Between Splicing of Two Exon Combinations Differentially Affects Membrane Targeting and Function of Human Ca V2.2. Function (Oxf) 2023; 5:zqad060. [PMID: 38020068 PMCID: PMC10666670 DOI: 10.1093/function/zqad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/16/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
N-type calcium channels (CaV2.2) are predominantly localized in presynaptic terminals, and are particularly important for pain transmission in the spinal cord. Furthermore, they have multiple isoforms, conferred by alternatively spliced or cassette exons, which are differentially expressed. Here, we have examined alternatively spliced exon47 variants that encode a long or short C-terminus in human CaV2.2. In the Ensembl database, all short exon47-containing transcripts were associated with the absence of exon18a, therefore, we also examined the effect of inclusion or absence of exon18a, combinatorially with the exon47 splice variants. We found that long exon47, only in the additional presence of exon18a, results in CaV2.2 currents that have a 3.6-fold greater maximum conductance than the other three combinations. In contrast, cell-surface expression of CaV2.2 in both tsA-201 cells and hippocampal neurons is increased ∼4-fold by long exon47, relative to short exon47, in either the presence or the absence of exon18a. This surprising discrepancy between trafficking and function indicates that cell-surface expression is enhanced by long exon47, independently of exon18a. However, in the presence of long exon47, exon18a mediates an additional permissive effect on CaV2.2 gating. We also investigated the single-nucleotide polymorphism in exon47 that has been linked to schizophrenia and Parkinson's disease, which we found is only non-synonymous in the short exon47 C-terminal isoform, resulting in two minor alleles. This study highlights the importance of investigating the combinatorial effects of exon inclusion, rather than each in isolation, in order to increase our understanding of calcium channel function.
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Affiliation(s)
- Shehrazade Dahimene
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Karen M Page
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Manuela Nieto-Rostro
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Wendy S Pratt
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
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5
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Li G, Roy B, Huang X, Mu Y, Yuan J, Xia Y, Song Y, Peng Z. High expression of N-type calcium channel indicates a favorable prognosis in gliomas. Medicine (Baltimore) 2022; 101:e29782. [PMID: 35777045 PMCID: PMC9239611 DOI: 10.1097/md.0000000000029782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
For the diagnosis and prognosis of glioma, the development of prognostic biomarkers is critical. The N-type calcium channel, whose predominant subunit is encoded by calcium voltage-gated channel subunit alpha1 B (CACNA1B), is mostly found in the nervous system and is closely associated with neurosensory functions. However, the link between the expression of CACNA1B and glioma remains unknown. We used ONCOMINE to explore the differences in CACNA1B expression among different cancers. We then conducted survival analysis and COX analysis using TCGA_LGG and TCGA_GBM datasets, which were divided into CACNA1Bhigh and CACNA1Blow based on the median. We examined the differences in other favorable prognostic markers or clinical characteristics between CACNA1Bhigh and CACNA1Blow using t tests. Differentially expressed genes were identified, and KEGG pathway enrichment was performed. We compared the expression of methyltransferases and analyzed the differentially methylated regions. Immunohistochemistry results were retrieved from the Human Protein Atlas database for validation purposes. CACNA1B was expressed at lower levels in gliomas, and, for the first time, we found that high expression of CACNA1B in gliomas predicts a good prognosis. Other favorable prognostic markers, such as isocitrate dehydrogenase mutation, 1p/19q codeletion, and O6-methylguanine-DNA methyltransferase promoter methylation, were increased in tandem with high expression of CACNA1B. Differentially expressed genes were enriched in multiple pathways related to cancer progression and aberrant epigenetic alterations were significantly associated with CACNA1B. High expression of N-type calcium channels indicates a favorable prognosis for gliomas. This study provides a better understanding of the link between gliomas and N-type calcium channels and may offer guidance for the future treatment of gliomas.
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Affiliation(s)
- Guibin Li
- Guangzhou KingMed Transformative Medicine Institute, Guangzhou, China
- *Correspondence: Guibin Li, Guangzhou KingMed Transformative Medicine Institute, No. 10 Luoxuan 3rd Road, International Biotech Island, Guangzhou 510320, Guangdong Province, China (e-mail: )
| | | | - Xiaoqiang Huang
- KingMed Center for Clinical Laboratory Co. Ltd., Guangzhou, China
| | - Yafei Mu
- Guangzhou KingMed Transformative Medicine Institute, Guangzhou, China
| | - Jiecheng Yuan
- KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, China
| | - Yang Xia
- Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Yue Song
- Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ziyue Peng
- Second Affiliated Hospital, Harbin Medical University, Harbin, China
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Kadurin I, Dahimene S, Page KM, Ellaway JIJ, Chaggar K, Troeberg L, Nagase H, Dolphin AC. ADAM17 Mediates Proteolytic Maturation of Voltage-Gated Calcium Channel Auxiliary α 2δ Subunits, and Enables Calcium Current Enhancement. Function (Oxf) 2022; 3:zqac013. [PMID: 35462614 PMCID: PMC9016415 DOI: 10.1093/function/zqac013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 01/07/2023] Open
Abstract
The auxiliary α2δ subunits of voltage-gated calcium (CaV) channels are key to augmenting expression and function of CaV1 and CaV2 channels, and are also important drug targets in several therapeutic areas, including neuropathic pain. The α2δ proteins are translated as preproteins encoding both α2 and δ, and post-translationally proteolyzed into α2 and δ subunits, which remain associated as a complex. In this study, we have identified ADAM17 as a key protease involved in proteolytic processing of pro-α2δ-1 and α2δ-3 subunits. We provide three lines of evidence: First, proteolytic cleavage is inhibited by chemical inhibitors of particular metalloproteases, including ADAM17. Second, proteolytic cleavage of both α2δ-1 and α2δ-3 is markedly reduced in cell lines by knockout of ADAM17 but not ADAM10. Third, proteolytic cleavage is reduced by the N-terminal active domain of TIMP-3 (N-TIMP-3), which selectively inhibits ADAM17. We have found previously that proteolytic cleavage into mature α2δ is essential for the enhancement of CaV function, and in agreement, knockout of ADAM17 inhibited the ability of α2δ-1 to enhance both CaV2.2 and CaV1.2 calcium currents. Finally, our data also indicate that the main site of proteolytic cleavage of α2δ-1 is the Golgi apparatus, although cleavage may also occur at the plasma membrane. Thus, our study identifies ADAM17 as a key protease required for proteolytic maturation of α2δ-1 and α2δ-3, and thus a potential drug target in neuropathic pain.
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Affiliation(s)
- Ivan Kadurin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Shehrazade Dahimene
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Karen M Page
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Joseph I J Ellaway
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Kanchan Chaggar
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Linda Troeberg
- Norwich Medical School, University of East Anglia, Norwich NR4 7UQ, UK
| | - Hideaki Nagase
- Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK
| | - Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
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7
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Bunda A, Andrade A. BaseScope™ Approach to Visualize Alternative Splice Variants in Tissue. Methods Mol Biol 2022; 2537:185-196. [PMID: 35895265 DOI: 10.1007/978-1-0716-2521-7_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Defining the cell-specific alternative splicing landscape in complex tissues is an important goal to gain functional insights. Deep-sequencing techniques coupled to genetic strategies for cell identification has provided important cues on cell-specific exon usage in complex tissues like the nervous system. BaseScope™ has emerged as a powerful and highly sensitive alternative to in situ hybridization to determine exon composition in tissue with spatial and morphological context. In this protocol, we will review how BaseScope was utilized to detect the e37a-Cacna1b splice variant of the presynaptic calcium channel CaV2.2 or N-type. This splice variant arises from a pair of mutually exclusive exons (e37a and e37b). E37a-Cacna1b is heavily underrepresented relative to e37b-Cacna1b and both exons share 60% of their sequence. By using BaseScope™, we were able to discover that e37a-Cacna1b is expressed in excitatory pyramidal neurons of hippocampus and cortex, as well as motor neurons of the ventral horn of the spinal cord.
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Affiliation(s)
- Alexandra Bunda
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH, USA
| | - Arturo Andrade
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH, USA.
- Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI, USA.
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8
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Dong Y, Gao Y, Xu S, Wang Y, Yu Z, Li Y, Li B, Yuan T, Yang B, Zhang XC, Jiang D, Huang Z, Zhao Y. Closed-state inactivation and pore-blocker modulation mechanisms of human Ca V2.2. Cell Rep 2021; 37:109931. [PMID: 34731621 DOI: 10.1016/j.celrep.2021.109931] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/13/2021] [Accepted: 10/11/2021] [Indexed: 11/19/2022] Open
Abstract
N-type voltage-gated calcium (CaV) channels mediate Ca2+ influx at presynaptic terminals in response to action potentials and play vital roles in synaptogenesis, release of neurotransmitters, and nociceptive transmission. Here, we elucidate a cryo-electron microscopy (cryo-EM) structure of the human CaV2.2 complex in apo, ziconotide-bound, and two CaV2.2-specific pore blockers-bound states. The second voltage-sensing domain (VSD) is captured in a resting-state conformation, trapped by a phosphatidylinositol 4,5-bisphosphate (PIP2) molecule, which is distinct from the other three VSDs of CaV2.2, as well as activated VSDs observed in previous structures of CaV channels. This structure reveals the molecular basis for the unique inactivation process of CaV2.2 channels, in which the intracellular gate formed by S6 helices is closed and a W-helix from the domain II-III linker stabilizes closed-state inactivation. The structures of this inactivated, drug-bound complex lay a solid foundation for developing new state-dependent blockers for treatment of chronic pain.
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Affiliation(s)
- Yanli Dong
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiwei Gao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuai Xu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yuhang Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuoya Yu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bin Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tian Yuan
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bei Yang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuejun Cai Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daohua Jiang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China; IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China.
| | - Yan Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
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9
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Wang SM, Goguadze N, Kimura Y, Yasui Y, Pan B, Wang TY, Nakamura Y, Lin YT, Hogan QH, Wilson KL, Su TP, Wu HE. Genomic Action of Sigma-1 Receptor Chaperone Relates to Neuropathic Pain. Mol Neurobiol 2021; 58:2523-2541. [PMID: 33459966 PMCID: PMC8128747 DOI: 10.1007/s12035-020-02276-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 12/28/2020] [Indexed: 11/16/2022]
Abstract
Sigma-1 receptors (Sig-1Rs) are endoplasmic reticulum (ER) chaperones implicated in neuropathic pain. Here we examine if the Sig-1R may relate to neuropathic pain at the level of dorsal root ganglia (DRG). We focus on the neuronal excitability of DRG in a "spare nerve injury" (SNI) model of neuropathic pain in rats and find that Sig-1Rs likely contribute to the genesis of DRG neuronal excitability by decreasing the protein level of voltage-gated Cav2.2 as a translational inhibitor of mRNA. Specifically, during SNI, Sig-1Rs translocate from ER to the nuclear envelope via a trafficking protein Sec61β. At the nucleus, the Sig-1R interacts with cFos and binds to the promoter of 4E-BP1, leading to an upregulation of 4E-BP1 that binds and prevents eIF4E from initiating the mRNA translation for Cav2.2. Interestingly, in Sig-1R knockout HEK cells, Cav2.2 is upregulated. In accordance with those findings, we find that intra-DRG injection of Sig-1R agonist (+)pentazocine increases frequency of action potentials via regulation of voltage-gated Ca2+ channels. Conversely, intra-DRG injection of Sig-1R antagonist BD1047 attenuates neuropathic pain. Hence, we discover that the Sig-1R chaperone causes neuropathic pain indirectly as a translational inhibitor.
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MESH Headings
- Animals
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Endoplasmic Reticulum/metabolism
- Eukaryotic Initiation Factor-4E/metabolism
- Ganglia, Spinal/metabolism
- Gene Expression Regulation
- Genome
- HEK293 Cells
- Humans
- Intracellular Signaling Peptides and Proteins/metabolism
- Male
- Nerve Tissue/injuries
- Nerve Tissue/pathology
- Neuralgia/genetics
- Nuclear Envelope/metabolism
- Promoter Regions, Genetic/genetics
- Protein Biosynthesis
- Proto-Oncogene Proteins c-fos/metabolism
- RNA Caps/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats, Sprague-Dawley
- Receptors, sigma/agonists
- Receptors, sigma/genetics
- Receptors, sigma/metabolism
- SEC Translocation Channels/metabolism
- Transcription, Genetic
- Sigma-1 Receptor
- Rats
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Affiliation(s)
- Shao-Ming Wang
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Nino Goguadze
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Yuriko Kimura
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Yuko Yasui
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Bin Pan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Tzu-Yun Wang
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
- Department of Psychiatry, College of Medicine, National Cheng Kung University, Tainan City, 70101, Taiwan
| | - Yoki Nakamura
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
- Department of Pharmacology, Graduate School of Biomedical & Health Science, Hiroshima University, Hiroshima, 734-8553, Japan
| | - Yu-Ting Lin
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Katherine L Wilson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA.
| | - Hsiang-En Wu
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
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10
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Kowalska M, Prendecki M, Piekut T, Kozubski W, Dorszewska J. Migraine: Calcium Channels and Glia. Int J Mol Sci 2021; 22:2688. [PMID: 33799975 PMCID: PMC7962070 DOI: 10.3390/ijms22052688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/26/2021] [Accepted: 03/03/2021] [Indexed: 01/03/2023] Open
Abstract
Migraine is a common neurological disease that affects about 11% of the adult population. The disease is divided into two main clinical subtypes: migraine with aura and migraine without aura. According to the neurovascular theory of migraine, the activation of the trigeminovascular system (TGVS) and the release of numerous neuropeptides, including calcitonin gene-related peptide (CGRP) are involved in headache pathogenesis. TGVS can be activated by cortical spreading depression (CSD), a phenomenon responsible for the aura. The mechanism of CSD, stemming in part from aberrant interactions between neurons and glia have been studied in models of familial hemiplegic migraine (FHM), a rare monogenic form of migraine with aura. The present review focuses on those interactions, especially as seen in FHM type 1, a variant of the disease caused by a mutation in CACNA1A, which encodes the α1A subunit of the P/Q-type voltage-gated calcium channel.
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Affiliation(s)
- Marta Kowalska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355 Poznan, Poland; (M.K.); (M.P.); (T.P.)
| | - Michał Prendecki
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355 Poznan, Poland; (M.K.); (M.P.); (T.P.)
| | - Thomas Piekut
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355 Poznan, Poland; (M.K.); (M.P.); (T.P.)
| | - Wojciech Kozubski
- Chair and Department of Neurology, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355 Poznan, Poland;
| | - Jolanta Dorszewska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355 Poznan, Poland; (M.K.); (M.P.); (T.P.)
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11
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Hasan MM, Ragnarsson L, Cardoso FC, Lewis RJ. Transfection methods for high-throughput cellular assays of voltage-gated calcium and sodium channels involved in pain. PLoS One 2021; 16:e0243645. [PMID: 33667217 PMCID: PMC7935312 DOI: 10.1371/journal.pone.0243645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 05/21/2020] [Accepted: 11/25/2020] [Indexed: 11/24/2022] Open
Abstract
Chemical transfection is broadly used to transiently transfect mammalian cells, although often associated with cellular stress and membrane instability, which imposes challenges for most cellular assays, including high-throughput (HT) assays. In the current study, we compared the effectiveness of calcium phosphate, FuGENE and Lipofectamine 3000 to transiently express two key voltage-gated ion channels critical in pain pathways, CaV2.2 and NaV1.7. The expression and function of these channels were validated using two HT platforms, the Fluorescence Imaging Plate Reader FLIPRTetra and the automated patch clamp QPatch 16X. We found that all transfection methods tested demonstrated similar effectiveness when applied to FLIPRTetra assays. Lipofectamine 3000-mediated transfection produced the largest peak currents for automated patch clamp QPatch assays. However, the FuGENE-mediated transfection was the most effective for QPatch assays as indicated by the superior number of cells displaying GΩ seal formation in whole-cell patch clamp configuration, medium to large peak currents, and higher rates of accomplished assays for both CaV2.2 and NaV1.7 channels. Our findings can facilitate the development of HT automated patch clamp assays for the discovery and characterization of novel analgesics and modulators of pain pathways, as well as assisting studies examining the pharmacology of mutated channels.
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Affiliation(s)
- Md. Mahadhi Hasan
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Lotten Ragnarsson
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Fernanda C. Cardoso
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
- * E-mail: (FCC); (RJL)
| | - Richard J. Lewis
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
- * E-mail: (FCC); (RJL)
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12
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Zhang D, Tu H, Wang C, Cao L, Hu W, Hackfort BT, Muelleman RL, Wadman MC, Li YL. Inhibition of N-type calcium channels in cardiac sympathetic neurons attenuates ventricular arrhythmogenesis in heart failure. Cardiovasc Res 2021; 117:137-148. [PMID: 31995173 PMCID: PMC7797209 DOI: 10.1093/cvr/cvaa018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/13/2019] [Accepted: 01/21/2020] [Indexed: 02/07/2023] Open
Abstract
AIMS Cardiac sympathetic overactivation is an important trigger of ventricular arrhythmias in patients with chronic heart failure (CHF). Our previous study demonstrated that N-type calcium (Cav2.2) currents in cardiac sympathetic post-ganglionic (CSP) neurons were increased in CHF. This study investigated the contribution of Cav2.2 channels in cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. METHODS AND RESULTS Rat CHF was induced by surgical ligation of the left coronary artery. Lentiviral Cav2.2-α shRNA or scrambled shRNA was transfected in vivo into stellate ganglia (SG) in CHF rats. Final experiments were performed at 14 weeks after coronary artery ligation. Real-time polymerase chain reaction and western blot data showed that in vivo transfection of Cav2.2-α shRNA reduced the expression of Cav2.2-α mRNA and protein in the SG in CHF rats. Cav2.2-α shRNA also reduced Cav2.2 currents and cell excitability of CSP neurons and attenuated cardiac sympathetic nerve activities (CSNA) in CHF rats. The power spectral analysis of heart rate variability (HRV) further revealed that transfection of Cav2.2-α shRNA in the SG normalized CHF-caused cardiac sympathetic overactivation in conscious rats. Twenty-four-hour continuous telemetry electrocardiogram recording revealed that this Cav2.2-α shRNA not only decreased incidence and duration of ventricular tachycardia/ventricular fibrillation but also improved CHF-induced heterogeneity of ventricular electrical activity in conscious CHF rats. Cav2.2-α shRNA also decreased susceptibility to ventricular arrhythmias in anaesthetized CHF rats. However, Cav2.2-α shRNA failed to improve CHF-induced cardiac contractile dysfunction. Scrambled shRNA did not affect Cav2.2 currents and cell excitability of CSP neurons, CSNA, HRV, and ventricular arrhythmogenesis in CHF rats. CONCLUSIONS Overactivation of Cav2.2 channels in CSP neurons contributes to cardiac sympathetic hyperactivation and ventricular arrhythmogenesis in CHF. This suggests that discovering purely selective and potent small-molecule Cav2.2 channel blockers could be a potential therapeutic strategy to decrease fatal ventricular arrhythmias in CHF.
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MESH Headings
- Action Potentials
- Animals
- Calcium/metabolism
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Calcium Signaling
- Cells, Cultured
- Disease Models, Animal
- Heart/innervation
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/physiopathology
- Heart Rate
- Male
- RNA Interference
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Rats, Sprague-Dawley
- Stellate Ganglion/metabolism
- Stellate Ganglion/physiopathology
- Sympathetic Fibers, Postganglionic/metabolism
- Sympathetic Fibers, Postganglionic/physiopathology
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/metabolism
- Tachycardia, Ventricular/physiopathology
- Tachycardia, Ventricular/prevention & control
- Ventricular Fibrillation/genetics
- Ventricular Fibrillation/metabolism
- Ventricular Fibrillation/physiopathology
- Ventricular Fibrillation/prevention & control
- Rats
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Chaojun Wang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cardiovascular Disease, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, China
| | - Liang Cao
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cardiac Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Wenfeng Hu
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Bryan T Hackfort
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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13
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Sato-Numata K, Numata T, Ueta Y, Okada Y. Expression and functions of N-type Cav2.2 and T-type Cav3.1 channels in rat vasopressin neurons under normotonic conditions. J Physiol Sci 2020; 70:49. [PMID: 33059597 PMCID: PMC10717235 DOI: 10.1186/s12576-020-00775-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/28/2020] [Indexed: 11/10/2022]
Abstract
Arginine vasopressin (AVP) neurons play essential roles in sensing the change in systemic osmolarity and regulating AVP release from their neuronal terminals to maintain the plasma osmolarity. AVP exocytosis depends on the Ca2+ entry via voltage-gated Ca2+ channels (VGCCs) in AVP neurons. In this study, suppression by siRNA-mediated knockdown and pharmacological sensitivity of VGCC currents evidenced molecular and functional expression of N-type Cav2.2 and T-type Cav3.1 in AVP neurons under normotonic conditions. Also, both the Cav2.2 and Cav3.1 currents were found to be sensitive to flufenamic acid (FFA). TTX-insensitive spontaneous action potentials were suppressed by FFA and T-type VGCC blocker Ni2+. However, Cav2.2-selective ω-conotoxin GVIA failed to suppress the firing activity. Taken together, it is concluded that Cav2.2 and Cav3.1 are molecularly and functionally expressed and both are sensitive to FFA in unstimulated rat AVP neurons. Also, it is suggested that Cav3.1 is primarily involved in their action potential generation.
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Affiliation(s)
- Kaori Sato-Numata
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan
- Department of Physiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Tomohiro Numata
- Department of Physiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku, Kitakyushu-shi, Fukuoka, 807-8555, Japan
| | - Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
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14
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Cocoș R, Raicu F, Băjenaru OL, Olaru I, Dumitrescu L, Popescu BO. CACNA1B gene variants in adult-onset isolated focal dystonia. Neurol Sci 2020; 42:1113-1117. [PMID: 33051750 PMCID: PMC7870633 DOI: 10.1007/s10072-020-04778-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 09/26/2020] [Indexed: 12/25/2022]
Abstract
Background Isolated focal dystonia (IFD) is a heterogeneous group of potentially invalidating movement disorders. The etiopathogenesis is complex, both genetic and environmental factors playing a role, but remains elusive. The CACNA1B gene codes for the N-type neuronal voltage-gated calcium channels CaV2.2, which may play a role in the development of some IFD. Methods We analyzed samples from the GENDYS cohort for mutations in CACNA1B gene, using targeted next-generation sequencing (NGS). Results The GENDYS cohort consists of 120 people with adult-onset IFD (cervical dystonia 47.5%, blepharospasm 47.2%, others 8.3%). Of these, 35% had subsequent topographical extension. Average age at onset was 42 and average disease durations 8 years. Targeted NGS revealed a novel frameshift mutation c.2291AGG > A, in exon 19, and a previously reported variant, c.6834T > G, in exon 47. Conclusion Our findings suggest that disease-causing mutations in CACNA1B gene may be involved in the development of some adult-onset IFD. To our knowledge, this is the first study that identified a disease-causing CACNA1B gene mutation in association with adult-onset IFD.
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Affiliation(s)
- Relu Cocoș
- Department of Medical Genetics, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Str, 020021, Bucharest, Romania
| | - Florina Raicu
- Department of Medical Genetics, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Str, 020021, Bucharest, Romania
- Francisc I. Rainer Anthropological Research Institute, Romanian Academy, 8 Eroii Sanitari Bld, 050474, Bucharest, Romania
| | - Ovidiu Lucian Băjenaru
- Department of Clinical Neurosciences, Colentina Hospital Neurology Division, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Str, 020021, Bucharest, Romania
- Ana Aslan National Institute of Geriatrics and Gerontology, 9 Căldărușani Str, 011241, Bucharest, Romania
| | - Iulia Olaru
- Department of Clinical Neurosciences, Colentina Hospital Neurology Division, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Str, 020021, Bucharest, Romania
- Department of Neurology, Colentina Clinical Hospital, 19-21 Stefan cel Mare Str, 020125, Bucharest, Romania
| | - Laura Dumitrescu
- Department of Clinical Neurosciences, Colentina Hospital Neurology Division, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Str, 020021, Bucharest, Romania
- Department of Neurology, Colentina Clinical Hospital, 19-21 Stefan cel Mare Str, 020125, Bucharest, Romania
| | - Bogdan Ovidiu Popescu
- Department of Clinical Neurosciences, Colentina Hospital Neurology Division, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Str, 020021, Bucharest, Romania.
- Department of Neurology, Colentina Clinical Hospital, 19-21 Stefan cel Mare Str, 020125, Bucharest, Romania.
- Laboratory of Ultrastructural Pathology, Victor Babeș National Institute of Pathology, 99-101 Splaiul Independentei Str, 050096, Bucharest, Romania.
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15
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Coste de Bagneaux P, von Elsner L, Bierhals T, Campiglio M, Johannsen J, Obermair GJ, Hempel M, Flucher BE, Kutsche K. A homozygous missense variant in CACNB4 encoding the auxiliary calcium channel beta4 subunit causes a severe neurodevelopmental disorder and impairs channel and non-channel functions. PLoS Genet 2020; 16:e1008625. [PMID: 32176688 PMCID: PMC7176149 DOI: 10.1371/journal.pgen.1008625] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 07/02/2019] [Revised: 04/22/2020] [Accepted: 01/23/2020] [Indexed: 12/27/2022] Open
Abstract
P/Q-type channels are the principal presynaptic calcium channels in brain functioning in neurotransmitter release. They are composed of the pore-forming CaV2.1 α1 subunit and the auxiliary α2δ-2 and β4 subunits. β4 is encoded by CACNB4, and its multiple splice variants serve isoform-specific functions as channel subunits and transcriptional regulators in the nucleus. In two siblings with intellectual disability, psychomotor retardation, blindness, epilepsy, movement disorder and cerebellar atrophy we identified rare homozygous variants in the genes LTBP1, EMILIN1, CACNB4, MINAR1, DHX38 and MYO15 by whole-exome sequencing. In silico tools, animal model, clinical, and genetic data suggest the p.(Leu126Pro) CACNB4 variant to be likely pathogenic. To investigate the functional consequences of the CACNB4 variant, we introduced the corresponding mutation L125P into rat β4b cDNA. Heterologously expressed wild-type β4b associated with GFP-CaV1.2 and accumulated in presynaptic boutons of cultured hippocampal neurons. In contrast, the β4b-L125P mutant failed to incorporate into calcium channel complexes and to cluster presynaptically. When co-expressed with CaV2.1 in tsA201 cells, β4b and β4b-L125P augmented the calcium current amplitudes, however, β4b-L125P failed to stably complex with α1 subunits. These results indicate that p.Leu125Pro disrupts the stable association of β4b with native calcium channel complexes, whereas membrane incorporation, modulation of current density and activation properties of heterologously expressed channels remained intact. Wildtype β4b was specifically targeted to the nuclei of quiescent excitatory cells. Importantly, the p.Leu125Pro mutation abolished nuclear targeting of β4b in cultured myotubes and hippocampal neurons. While binding of β4b to the known interaction partner PPP2R5D (B56δ) was not affected by the mutation, complex formation between β4b-L125P and the neuronal TRAF2 and NCK interacting kinase (TNIK) seemed to be disturbed. In summary, our data suggest that the homozygous CACNB4 p.(Leu126Pro) variant underlies the severe neurological phenotype in the two siblings, most likely by impairing both channel and non-channel functions of β4b.
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Affiliation(s)
| | - Leonie von Elsner
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marta Campiglio
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Jessika Johannsen
- Childrens Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gerald J. Obermair
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
- Division Physiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bernhard E. Flucher
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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16
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Abstract
BACKGROUND The aim of this study was to determine the effects of different concentrations of muscone on the ketamine requirement for hypnosis and analgesia and possible mechanism in mice. METHODS In the hypnotic response experiment, muscone (0.5, 1.0, 2.0, 4.0, and 8.0 mg/kg) was administered 15 minutes before ketamine by intraperitoneal injection. The hypnotic response was evaluated by loss of righting reflex (LORR). In the analgesia experiment, muscone (0.5, 1.0, 2.0, and 4.0 mg/kg) was administered 15 minutes before 50 mg/kg ketamine injection. Pain threshold was assessed by measuring the tail-flick latency induced by heat radiation. Twenty minutes after ketamine injection, the mRNA expression of N-methyl-D-aspartate receptors (NR) subunits, γ-aminobutyric acid (GABA) receptors subunits, opioid receptors subunits, and some Na and Ca channels were detected by qPCR in the hippocampus of mice. RESULTS The 50% effective dose (ED50) with 95% confidence interval of ketamine-induced LORR was 49.2 (43.4-56.4) mg/kg. About 4.0 or 8.0 mg/kg muscone increased ED50 of ketamine-induced hypnosis, which was 82.7 (70.0-98.4) mg/kg or 72.0 (65.4-85.7) mg/kg, respectively. In the analgesic experiment, ketamine alone caused an obvious analgesic effect, whereas different dose of muscone decreased pain threshold in the presence of ketamine; 4.0 mg/kg muscone up-regulated the mRNA expression of NR1 and inhibited ketamine-induced increase of δ-opioid receptor mRNA level. Muscone also inhibited Cav2.1 mRNA expression in the presence of ketamine. CONCLUSION Muscone reduced the hypnotic and analgesic effect of ketamine in dose-independent manner in mice, which may be related to the changes of NR1 and δ-opioid receptor.
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Affiliation(s)
- Chuiliang Liu
- Department of Anesthesiology, ChanCheng Center Hospital, Foshan, China
| | - Zeqi Huang
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Province Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhipeng Li
- Department of Anesthesiology, ChanCheng Center Hospital, Foshan, China
- Key Laboratory of Orthopaedics and Traumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Junhua Li
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Province Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yujuan Li
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Province Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
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Miao QL, Herlitze S, Mark MD, Noebels JL. Adult loss of Cacna1a in mice recapitulates childhood absence epilepsy by distinct thalamic bursting mechanisms. Brain 2020; 143:161-174. [PMID: 31800012 PMCID: PMC6935748 DOI: 10.1093/brain/awz365] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/09/2019] [Accepted: 09/29/2019] [Indexed: 12/15/2022] Open
Abstract
Inborn errors of CACNA1A-encoded P/Q-type calcium channels impair synaptic transmission, producing early and lifelong neurological deficits, including childhood absence epilepsy, ataxia and dystonia. Whether these impairments owe their pathologies to defective channel function during the critical period for thalamic network stabilization in immature brain remains unclear. Here we show that mice with tamoxifen-induced adult-onset ablation of P/Q channel alpha subunit (iKOp/q) display identical patterns of dysfunction, replicating the inborn loss-of-function phenotypes and, therefore demonstrate that these neurological defects do not rely upon developmental abnormality. Unexpectedly, unlike the inborn model, the adult-onset pattern of excitability changes believed to be pathogenic within the thalamic network is non-canonical. Specifically, adult ablation of P/Q channels does not promote Cacna1g-mediated burst firing or T-type calcium current (IT) in the thalamocortical relay neurons; however, burst firing in thalamocortical relay neurons remains essential as iKOp/q mice generated on a Cacna1g deleted background show substantially diminished seizure generation. Moreover, in thalamic reticular nucleus neurons, burst firing is impaired accompanied by attenuated IT. Interestingly, inborn deletion of thalamic reticular nucleus-enriched, human childhood absence epilepsy-linked gene Cacna1h in iKOp/q mice reduces thalamic reticular nucleus burst firing and promotes rather than reduces seizure, indicating an epileptogenic role for loss-of-function Cacna1h gene variants reported in human childhood absence epilepsy cases. Together, our results demonstrate that P/Q channels remain critical for maintaining normal thalamocortical oscillations and motor control in the adult brain, and suggest that the developmental plasticity of membrane currents regulating pathological rhythmicity is both degenerate and age-dependent.
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Affiliation(s)
- Qing-Long Miao
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston TX, USA
| | - Stefan Herlitze
- Department of Zoology and Neurobiology, Ruhr University of Bochum, Bochum, Germany
| | - Melanie D Mark
- Department of Zoology and Neurobiology, Ruhr University of Bochum, Bochum, Germany
| | - Jeffrey L Noebels
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston TX, USA
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18
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Bunda A, LaCarubba B, Bertolino M, Akiki M, Bath K, Lopez-Soto J, Lipscombe D, Andrade A. Cacna1b alternative splicing impacts excitatory neurotransmission and is linked to behavioral responses to aversive stimuli. Mol Brain 2019; 12:81. [PMID: 31630675 PMCID: PMC6802325 DOI: 10.1186/s13041-019-0500-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/11/2019] [Indexed: 12/26/2022] Open
Abstract
Presynaptic CaV2.2 channels control calcium entry that triggers neurotransmitter release at both central and peripheral synapses. The Cacna1b gene encodes the α1-pore forming subunit of CaV2.2 channels. Distinct subsets of splice variants of CaV2.2 derived from cell-specific alternative splicing of the Cacna1b pre-mRNA are expressed in specific subpopulations of neurons. Four cell-specific sites of alternative splicing in Cacna1b that alter CaV2.2 channel function have been described in detail: three cassette exons (e18a, e24a, and e31a) and a pair of mutually exclusive exons (e37a/e37b). Cacna1b mRNAs containing e37a are highly enriched in a subpopulation of nociceptors where they influence nociception and morphine analgesia. E37a-Cacna1b mRNAs are also expressed in brain, but their cell-specific expression in this part of the nervous system, their functional consequences in central synapses and their role on complex behavior have not been studied. In this report, we show that e37a-Cacna1b mRNAs are expressed in excitatory projection neurons where CaV2.2 channels are known to influence transmitter release at excitatory inputs from entorhinal cortex (EC) to dentate gyrus (DG). By comparing behaviors of WT mice to those that only express e37b-CaV2.2 channels, we found evidence that e37a-CaV2.2 enhances behavioral responses to aversive stimuli. Our results suggest that alternative splicing of Cacna1b e37a influences excitatory transmitter release and couples to complex behaviors.
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Affiliation(s)
- Alexandra Bunda
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, 46 College Road, Durham, NH 03824 USA
| | - Brianna LaCarubba
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, 46 College Road, Durham, NH 03824 USA
| | - Melanie Bertolino
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, 46 College Road, Durham, NH 03824 USA
| | - Marie Akiki
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, 46 College Road, Durham, NH 03824 USA
| | - Kevin Bath
- Department of Cognitive, Linguistic and Psychological Sciences, Brown University, 190 Thayer Street, Providence, RI 02912 USA
| | - Javier Lopez-Soto
- Robert J and Nancy D Carney Institute for Brain Science & Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912 USA
| | - Diane Lipscombe
- Robert J and Nancy D Carney Institute for Brain Science & Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912 USA
| | - Arturo Andrade
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, 46 College Road, Durham, NH 03824 USA
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19
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Mishima K, Nakasatomi M, Takahashi S, Ikeuchi H, Sakairi T, Kaneko Y, Hiromura K, Nojima Y, Maeshima A. Attenuation of renal fibrosis after unilateral ureteral obstruction in mice lacking the N-type calcium channel. PLoS One 2019; 14:e0223496. [PMID: 31596895 PMCID: PMC6785082 DOI: 10.1371/journal.pone.0223496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 09/22/2019] [Indexed: 11/18/2022] Open
Abstract
The N-type Ca2+ channel (Cav2.2) is distributed in sympathetic nerves that innervate the tubules, the vessels, and the juxtaglomerular granular cells of the kidney. However, the role of N-type Ca2+ channels in renal disease remains unknown. To address this issue, Cav2.2 knockout mice were utilized. Immunoreactive Cav2.2 was undetectable in normal kidneys of C57BL/6N mice, but it became positive in the interstitial S100-positive nerve fibers after unilateral ureteral obstruction (UUO). There were no significant differences in mean blood pressure, heart rate, and renal function between wild-type littermates and Cav2.2-knockout mice at baseline, as well as after UUO. Cav2.2 deficiency significantly reduced the EVG-positive fibrotic area, alpha-SMA expression, the production of type I collagen, and the hypoxic area in the obstructed kidneys. The expression of tyrosine hydroxylase, a marker for sympathetic neurons, was significantly increased in the obstructed kidneys of wild-type mice, but not in Cav2.2-knockout mice. These data suggest that increased Cav2.2 is implicated in renal nerve activation leading to the progression of renal fibrosis. Blockade of Cav2.2 might be a novel therapeutic approach for preventing renal fibrosis.
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Affiliation(s)
- Keiichiro Mishima
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masao Nakasatomi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shunsuke Takahashi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hidekazu Ikeuchi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Toru Sakairi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yoriaki Kaneko
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Keiju Hiromura
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yoshihisa Nojima
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Akito Maeshima
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
- * E-mail:
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20
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Bunda A, LaCarubba B, Akiki M, Andrade A. Tissue- and cell-specific expression of a splice variant in the II-III cytoplasmic loop of Cacna1b. FEBS Open Bio 2019; 9:1603-1616. [PMID: 31314171 PMCID: PMC6722902 DOI: 10.1002/2211-5463.12701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/19/2019] [Accepted: 07/15/2019] [Indexed: 11/25/2022] Open
Abstract
Presynaptic CaV2.2 (N‐type) channels are fundamental for transmitter release across the nervous system. The gene encoding CaV2.2 channels, Cacna1b, contains alternatively spliced exons that result in functionally distinct splice variants (e18a, e24a, e31a, and 37a/37b). Alternative splicing of the cassette exon 18a generates two mRNA transcripts (+e18a‐Cacna1b and ∆e18a‐Cacna1b). In this study, using novel mouse genetic models and in situ hybridization (BaseScope™), we confirmed that +e18a‐Cacna1b splice variants are expressed in monoaminergic regions of the midbrain. We expanded these studies and identified +e18a‐Cacna1b mRNA in deep cerebellar cells and spinal cord motor neurons. Furthermore, we determined that +e18a‐Cacna1b is enriched in cholecystokinin‐expressing interneurons. Our results provide key information to understand cell‐specific functions of CaV2.2 channels.
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Affiliation(s)
- Alexandra Bunda
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | - Brianna LaCarubba
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | - Marie Akiki
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | - Arturo Andrade
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
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21
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Luan C, Ye Y, Singh T, Barghouth M, Eliasson L, Artner I, Zhang E, Renström E. The calcium channel subunit gamma-4 is regulated by MafA and necessary for pancreatic beta-cell specification. Commun Biol 2019; 2:106. [PMID: 30911681 PMCID: PMC6420573 DOI: 10.1038/s42003-019-0351-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 02/08/2019] [Indexed: 12/22/2022] Open
Abstract
Voltage-gated Ca2+ (CaV) channels trigger glucose-induced insulin secretion in pancreatic beta-cell and their dysfunction increases diabetes risk. These heteromeric complexes include the main subunit alpha1, and the accessory ones, including subunit gamma that remains unexplored. Here, we demonstrate that CaV gamma subunit 4 (CaVγ4) is downregulated in islets from human donors with diabetes, diabetic Goto-Kakizaki (GK) rats, as well as under conditions of gluco-/lipotoxic stress. Reduction of CaVγ4 expression results in decreased expression of L-type CaV1.2 and CaV1.3, thereby suppressing voltage-gated Ca2+ entry and glucose stimulated insulin exocytosis. The most important finding is that CaVγ4 expression is controlled by the transcription factor responsible for beta-cell specification, MafA, as verified by chromatin immunoprecipitation and experiments in beta-cell specific MafA knockout mice (MafA Δβcell ). Taken together, these findings suggest that CaVγ4 is necessary for maintaining a functional differentiated beta-cell phenotype. Treatment aiming at restoring CaVγ4 may help to restore beta-cell function in diabetes.
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Affiliation(s)
- Cheng Luan
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
| | - Yingying Ye
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
| | - Tania Singh
- Stem Cell Center, Department of Laboratory Medicine, Lund University, 221 85 Lund, Sweden
| | - Mohammad Barghouth
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
| | - Lena Eliasson
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
| | - Isabella Artner
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
- Stem Cell Center, Department of Laboratory Medicine, Lund University, 221 85 Lund, Sweden
| | - Enming Zhang
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
| | - Erik Renström
- Lund University Diabetes Center, Department of Clinical Sciences Malmö, Lund University, 202 13 Malmö, Sweden
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22
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Abstract
Most cells in the body acquire iron via receptor-mediated endocytosis of transferrin, the circulating iron transport protein. When cellular iron levels are sufficient, the uptake of transferrin decreases to limit further iron assimilation and prevent excessive iron accumulation. In iron overload conditions, such as hereditary hemochromatosis and thalassemia major, unregulated iron entry into the plasma overwhelms the carrying capacity of transferrin, resulting in non-transferrin-bound iron (NTBI), a redox-active, potentially toxic form of iron. Plasma NTBI is rapidly cleared from the circulation primarily by the liver and other organs (e.g., pancreas, heart, and pituitary) where it contributes significantly to tissue iron overload and related pathology. While NTBI is usually not detectable in the plasma of healthy individuals, it does appear to be a normal constituent of brain interstitial fluid and therefore likely serves as an important source of iron for most cell types in the CNS. A growing body of literature indicates that NTBI uptake is mediated by non-transferrin-bound iron transporters such as ZIP14, L-type and T-type calcium channels, DMT1, ZIP8, and TRPC6. This review provides an overview of NTBI uptake by various tissues and cells and summarizes the evidence for and against the roles of individual transporters in this process.
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Affiliation(s)
- Mitchell D Knutson
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, USA.
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23
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Brusich DJ, Spring AM, James TD, Yeates CJ, Helms TH, Frank CA. Drosophila CaV2 channels harboring human migraine mutations cause synapse hyperexcitability that can be suppressed by inhibition of a Ca2+ store release pathway. PLoS Genet 2018; 14:e1007577. [PMID: 30080864 PMCID: PMC6095605 DOI: 10.1371/journal.pgen.1007577] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 05/08/2017] [Revised: 08/16/2018] [Accepted: 07/20/2018] [Indexed: 11/28/2022] Open
Abstract
Gain-of-function mutations in the human CaV2.1 gene CACNA1A cause familial hemiplegic migraine type 1 (FHM1). To characterize cellular problems potentially triggered by CaV2.1 gains of function, we engineered mutations encoding FHM1 amino-acid substitutions S218L (SL) and R192Q (RQ) into transgenes of Drosophila melanogaster CaV2/cacophony. We expressed the transgenes pan-neuronally. Phenotypes were mild for RQ-expressing animals. By contrast, single mutant SL- and complex allele RQ,SL-expressing animals showed overt phenotypes, including sharply decreased viability. By electrophysiology, SL- and RQ,SL-expressing neuromuscular junctions (NMJs) exhibited enhanced evoked discharges, supernumerary discharges, and an increase in the amplitudes and frequencies of spontaneous events. Some spontaneous events were gigantic (10-40 mV), multi-quantal events. Gigantic spontaneous events were eliminated by application of TTX-or by lowered or chelated Ca2+-suggesting that gigantic events were elicited by spontaneous nerve firing. A follow-up genetic approach revealed that some neuronal hyperexcitability phenotypes were reversed after knockdown or mutation of Drosophila homologs of phospholipase Cβ (PLCβ), IP3 receptor, or ryanodine receptor (RyR)-all factors known to mediate Ca2+ release from intracellular stores. Pharmacological inhibitors of intracellular Ca2+ store release produced similar effects. Interestingly, however, the decreased viability phenotype was not reversed by genetic impairment of intracellular Ca2+ release factors. On a cellular level, our data suggest inhibition of signaling that triggers intracellular Ca2+ release could counteract hyperexcitability induced by gains of CaV2.1 function.
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Affiliation(s)
- Douglas J. Brusich
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Ashlyn M. Spring
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, United States of America
| | - Thomas D. James
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, United States of America
| | - Catherine J. Yeates
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, United States of America
| | - Timothy H. Helms
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - C. Andrew Frank
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, United States of America
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, United States of America
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24
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Li Y, Liu Y, Fan J, Zhou Q, Song X, Peng Z, Qin Z, Tao T. Validation and bioinformatic analysis of propofol-induced differentially expressed microRNAs in primary cultured neural stem cells. Gene 2018; 664:90-100. [PMID: 29679758 DOI: 10.1016/j.gene.2018.04.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/26/2018] [Accepted: 04/16/2018] [Indexed: 11/27/2022]
Abstract
Propofol, a widely used intravenous anesthetic, was previously considered as a neuroprotective agent. Recently, however, accumulating evidence suggests that it may cause neurotoxicity, especially in the development of neural stem cells (NSCs). The potential mechanisms contributing to propofol-induced neurotoxicity during neurogenesis, such as those involving microRNAs (miRNAs), are still unknown. In this study, a total of 27 differentially expressed miRNAs were identified in our initial screen and 6 miRNAs were validated by qRT-PCR. Three miRNAs were up-regulated (miR-377-5p, miR-194-3p and miR-143-5p), and three were down-regulated (miR-3583-3p, miR-466b-5p and miR-410-5p). Following gene ontology and KEGG pathway enrichment analysis, Gabbr1, Canca1b and Gabbr2, which are enriched in the GABAergic synapse pathway, were selected as genes potentially playing a role in propofol-induced neurotoxicity. Gabbr1 and Cacna1b, which are targeted by miRNAs that are up-regulated following propofol exposure, showed decreased expression at the mRNA and protein levels. Gabbr2, targeted by miRNAs that were down-regulated following treatment with propofol, was up-regulated at both the levels of mRNA and protein expression. The two clusters of miRNAs that show differential expression following propofol exposure may act in a synergistic manner to regulate several genes simultaneously during the development of NSCs. Our results may contribute to clarify the molecular mechanism and provide potential therapeutic targets for propofol induced neurotoxicity.
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Affiliation(s)
- Yan Li
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Youtan Liu
- Department of Anesthesiology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Jun Fan
- Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China; Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangzhou, China
| | - Quan Zhou
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiuling Song
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhiyong Peng
- Department of Anesthesiology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Zaisheng Qin
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
| | - Tao Tao
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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25
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Abstract
Auxiliary α2δ subunits are important proteins for trafficking of voltage-gated calcium channels (CaV) at the active zones of synapses. We have previously shown that the post-translational proteolytic cleavage of α2δ is essential for their modulatory effects on the trafficking of N-type (CaV2.2) calcium channels (Kadurin et al., 2016). We extend these results here by showing that the probability of presynaptic vesicular release is reduced when an uncleaved α2δ is expressed in rat neurons and that this inhibitory effect is reversed when cleavage of α2δ is restored. We also show that asynchronous release is influenced by the maturation of α2δ-1, highlighting the role of CaV channels in this component of vesicular release. We present additional evidence that CaV2.2 co-immunoprecipitates preferentially with cleaved wild-type α2δ. Our data indicate that the proteolytic maturation increases the association of α2δ-1 with CaV channel complex and is essential for its function on synaptic release.
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Affiliation(s)
- Laurent Ferron
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUnited Kingdom
| | - Ivan Kadurin
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUnited Kingdom
| | - Annette C Dolphin
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUnited Kingdom
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26
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Allen SE, Toro CP, Andrade A, López-Soto EJ, Denome S, Lipscombe D. Cell-Specific RNA Binding Protein Rbfox2 Regulates Ca V2.2 mRNA Exon Composition and Ca V2.2 Current Size. eNeuro 2017; 4:ENEURO.0332-16.2017. [PMID: 29067356 PMCID: PMC5633781 DOI: 10.1523/eneuro.0332-16.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 09/14/2017] [Accepted: 09/21/2017] [Indexed: 01/25/2023] Open
Abstract
The majority of multiexon mammalian genes contain alternatively spliced exons that have unique expression patterns in different cell populations and that have important cell functions. The expression profiles of alternative exons are controlled by cell-specific splicing factors that can promote exon inclusion or exon skipping but with few exceptions we do not know which specific splicing factors control the expression of alternatively spliced exons of known biological function. Many ion channel genes undergo extensive alternative splicing including Cacna1b that encodes the voltage-gated CaV2.2 α1 subunit. Alternatively spliced exon 18a in Cacna1b RNA encodes 21 amino acids in the II-III loop of CaV2.2, and its expression differs across the nervous system and over development. Genome-wide, protein-RNA binding analyses coupled to high-throughput RNA sequencing show that RNA binding Fox (Rbfox) proteins associate with CaV2.2 (Cacna1b) pre-mRNAs. Here, we link Rbfox2 to suppression of e18a. We show increased e18a inclusion in CaV2.2 mRNAs: (1) after siRNA knockdown of Rbfox2 in a neuronal cell line and (2) in RNA from sympathetic neurons of adult compared to early postnatal mice. By immunoprecipitation of Rbfox2-RNA complexes followed by qPCR, we demonstrate reduced Rbfox2 binding upstream of e18a in RNA from sympathetic neurons of adult compared to early postnatal mice. CaV2.2 currents in cell lines and in sympathetic neurons expressing only e18a-CaV2.2 are larger compared to currents from those expressing only Δ18a-CaV2.2. We conclude that Rbfox2 represses e18a inclusion during pre-mRNA splicing of CaV2.2, limiting the size of CaV2.2 currents early in development in certain neuronal populations.
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MESH Headings
- Action Potentials/genetics
- Animals
- Animals, Newborn
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Cells, Cultured
- Exons/genetics
- Female
- Gene Expression Regulation, Developmental/genetics
- Humans
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Models, Molecular
- Neurons/physiology
- RNA Splicing Factors/genetics
- RNA Splicing Factors/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Rats
- Superior Cervical Ganglion/cytology
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Affiliation(s)
- Summer E. Allen
- Department of Neuroscience, and the Brown Institute for Brain Science, Brown University, Providence, RI 02912
| | - Cecilia P. Toro
- Department of Biology, Linfield College, McMinnville, OR 97128
| | - Arturo Andrade
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824
| | - Eduardo J. López-Soto
- Department of Neuroscience, and the Brown Institute for Brain Science, Brown University, Providence, RI 02912
| | - Sylvia Denome
- Department of Neuroscience, and the Brown Institute for Brain Science, Brown University, Providence, RI 02912
| | - Diane Lipscombe
- Department of Neuroscience, and the Brown Institute for Brain Science, Brown University, Providence, RI 02912
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Abstract
Migraine is an episodic headache disorder affecting more than 10% of the general population. Migraine arises from a primary brain dysfunction that leads to activation and sensitization of the trigeminovascular system. A major incompletely understood issue in the neurobiology of migraine concerns the molecular and cellular mechanisms that underlie the primary brain dysfunction and lead to activation and sensitization of the trigeminovascular system, thus generating and maintaining migraine pain. Here the author reviews recent discoveries that have advanced our understanding of these mechanisms toward a unifying pathophysiological hypothesis, in which cortical spreading depression (CSD), the phenomenon underlying migraine aura, assumes a key role. In particular, the author discusses the main recent findings in the genetics and neurobiology of familial hemiplegic migraine and the insights they provide into the molecular and cellular mechanisms that may lead to the increased susceptibility of CSD in migraineurs.
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Affiliation(s)
- Daniela Pietrobon
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
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Benleulmi-Chaachoua A, Chen L, Sokolina K, Wong V, Jurisica I, Emerit MB, Darmon M, Espin A, Stagljar I, Tafelmeyer P, Zamponi GW, Delagrange P, Maurice P, Jockers R. Protein interactome mining defines melatonin MT1 receptors as integral component of presynaptic protein complexes of neurons. J Pineal Res 2016; 60:95-108. [PMID: 26514267 DOI: 10.1111/jpi.12294] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 10/26/2015] [Indexed: 01/11/2023]
Abstract
In mammals, the hormone melatonin is mainly produced by the pineal gland with nocturnal peak levels. Its peripheral and central actions rely either on its intrinsic antioxidant properties or on binding to melatonin MT1 and MT2 receptors, belonging to the G protein-coupled receptor (GPCR) super-family. Melatonin has been reported to be involved in many functions of the central nervous system such as circadian rhythm regulation, neurotransmission, synaptic plasticity, memory, sleep, and also in Alzheimer's disease and depression. However, little is known about the subcellular localization of melatonin receptors and the molecular aspects involved in neuronal functions of melatonin. Identification of protein complexes associated with GPCRs has been shown to be a valid approach to improve our understanding of their function. By combining proteomic and genomic approaches we built an interactome of MT1 and MT2 receptors, which comprises 378 individual proteins. Among the proteins interacting with MT1 , but not with MT2 , we identified several presynaptic proteins, suggesting a potential role of MT1 in neurotransmission. Presynaptic localization of MT1 receptors in the hypothalamus, striatum, and cortex was confirmed by subcellular fractionation experiments and immunofluorescence microscopy. MT1 physically interacts with the voltage-gated calcium channel Cav 2.2 and inhibits Cav 2.2-promoted Ca(2+) entry in an agonist-independent manner. In conclusion, we show that MT1 is part of the presynaptic protein network and negatively regulates Cav 2.2 activity, providing a first hint for potential synaptic functions of MT1.
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Affiliation(s)
- Abla Benleulmi-Chaachoua
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Lina Chen
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Kate Sokolina
- Donnelly Centre, Department of Biochemistry, Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Victoria Wong
- Donnelly Centre, Department of Biochemistry, Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Igor Jurisica
- Princess Margaret Cancer Centre, University Health Network and TECHNA Institute for the Advancement of Technology for Health, Toronto, ON, Canada
| | - Michel Boris Emerit
- Sorbonne Paris Cité, Université Paris Descartes, Paris, France
- Centre de Psychiatrie et Neurosciences, INSERM U894, Paris, France
| | - Michèle Darmon
- Sorbonne Paris Cité, Université Paris Descartes, Paris, France
- Centre de Psychiatrie et Neurosciences, INSERM U894, Paris, France
| | - Almudena Espin
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Igor Stagljar
- Donnelly Centre, Department of Biochemistry, Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | | | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | | | - Pascal Maurice
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Ralf Jockers
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- Sorbonne Paris Cité, Université Paris Descartes, Paris, France
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29
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Bahamonde MI, Serra SA, Drechsel O, Rahman R, Marcé-Grau A, Prieto M, Ossowski S, Macaya A, Fernández-Fernández JM. A Single Amino Acid Deletion (ΔF1502) in the S6 Segment of CaV2.1 Domain III Associated with Congenital Ataxia Increases Channel Activity and Promotes Ca2+ Influx. PLoS One 2015; 10:e0146035. [PMID: 26716990 PMCID: PMC4696675 DOI: 10.1371/journal.pone.0146035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/11/2015] [Indexed: 02/07/2023] Open
Abstract
Mutations in the CACNA1A gene, encoding the pore-forming CaV2.1 (P/Q-type) channel α1A subunit, result in heterogeneous human neurological disorders, including familial and sporadic hemiplegic migraine along with episodic and progressive forms of ataxia. Hemiplegic Migraine (HM) mutations induce gain-of-channel function, mainly by shifting channel activation to lower voltages, whereas ataxia mutations mostly produce loss-of-channel function. However, some HM-linked gain-of-function mutations are also associated to congenital ataxia and/or cerebellar atrophy, including the deletion of a highly conserved phenylalanine located at the S6 pore region of α1A domain III (ΔF1502). Functional studies of ΔF1502 CaV2.1 channels, expressed in Xenopus oocytes, using the non-physiological Ba2+ as the charge carrier have only revealed discrete alterations in channel function of unclear pathophysiological relevance. Here, we report a second case of congenital ataxia linked to the ΔF1502 α1A mutation, detected by whole-exome sequencing, and analyze its functional consequences on CaV2.1 human channels heterologously expressed in mammalian tsA-201 HEK cells, using the physiological permeant ion Ca2+. ΔF1502 strongly decreases the voltage threshold for channel activation (by ~ 21 mV), allowing significantly higher Ca2+ current densities in a range of depolarized voltages with physiological relevance in neurons, even though maximal Ca2+ current density through ΔF1502 CaV2.1 channels is 60% lower than through wild-type channels. ΔF1502 accelerates activation kinetics and slows deactivation kinetics of CaV2.1 within a wide range of voltage depolarization. ΔF1502 also slowed CaV2.1 inactivation kinetic and shifted the inactivation curve to hyperpolarized potentials (by ~ 28 mV). ΔF1502 effects on CaV2.1 activation and deactivation properties seem to be of high physiological relevance. Thus, ΔF1502 strongly promotes Ca2+ influx in response to either single or trains of action potential-like waveforms of different durations. Our observations support a causative role of gain-of-function CaV2.1 mutations in congenital ataxia, a neurodevelopmental disorder at the severe-most end of CACNA1A-associated phenotypic spectrum.
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Affiliation(s)
- Maria Isabel Bahamonde
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Selma Angèlica Serra
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Oliver Drechsel
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Rubayte Rahman
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Anna Marcé-Grau
- Pediatric Neurology Research Group, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marta Prieto
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Stephan Ossowski
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Alfons Macaya
- Pediatric Neurology Research Group, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - José M. Fernández-Fernández
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
- * E-mail:
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30
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Kros L, Eelkman Rooda OHJ, Spanke JK, Alva P, van Dongen MN, Karapatis A, Tolner EA, Strydis C, Davey N, Winkelman BHJ, Negrello M, Serdijn WA, Steuber V, van den Maagdenberg AMJM, De Zeeuw CI, Hoebeek FE. Cerebellar output controls generalized spike-and-wave discharge occurrence. Ann Neurol 2015; 77:1027-49. [PMID: 25762286 PMCID: PMC5008217 DOI: 10.1002/ana.24399] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 01/13/2023]
Abstract
Objective Disrupting thalamocortical activity patterns has proven to be a promising approach to stop generalized spike‐and‐wave discharges (GSWDs) characteristic of absence seizures. Here, we investigated to what extent modulation of neuronal firing in cerebellar nuclei (CN), which are anatomically in an advantageous position to disrupt cortical oscillations through their innervation of a wide variety of thalamic nuclei, is effective in controlling absence seizures. Methods Two unrelated mouse models of generalized absence seizures were used: the natural mutant tottering, which is characterized by a missense mutation in Cacna1a, and inbred C3H/HeOuJ. While simultaneously recording single CN neuron activity and electrocorticogram in awake animals, we investigated to what extent pharmacologically increased or decreased CN neuron activity could modulate GSWD occurrence as well as short‐lasting, on‐demand CN stimulation could disrupt epileptic seizures. Results We found that a subset of CN neurons show phase‐locked oscillatory firing during GSWDs and that manipulating this activity modulates GSWD occurrence. Inhibiting CN neuron action potential firing by local application of the γ‐aminobutyric acid type A (GABA‐A) agonist muscimol increased GSWD occurrence up to 37‐fold, whereas increasing the frequency and regularity of CN neuron firing with the use of GABA‐A antagonist gabazine decimated its occurrence. A single short‐lasting (30–300 milliseconds) optogenetic stimulation of CN neuron activity abruptly stopped GSWDs, even when applied unilaterally. Using a closed‐loop system, GSWDs were detected and stopped within 500 milliseconds. Interpretation CN neurons are potent modulators of pathological oscillations in thalamocortical network activity during absence seizures, and their potential therapeutic benefit for controlling other types of generalized epilepsies should be evaluated. Ann Neurol 2015;77:1027–1049
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Affiliation(s)
- Lieke Kros
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
| | | | - Jochen K Spanke
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Parimala Alva
- Science and Technology Research Institute, University of Hertfordshire, Hatfield, United Kingdom
| | - Marijn N van Dongen
- Bioelectronics Section, Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, Delft, the Netherlands
| | - Athanasios Karapatis
- Bioelectronics Section, Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, Delft, the Netherlands
| | - Else A Tolner
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
| | - Christos Strydis
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Neil Davey
- Science and Technology Research Institute, University of Hertfordshire, Hatfield, United Kingdom
| | - Beerend H J Winkelman
- Netherlands Institute for Neuroscience, Royal Dutch Academy for Arts and Sciences, Amsterdam, the Netherlands
| | - Mario Negrello
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Wouter A Serdijn
- Bioelectronics Section, Faculty of Electrical Engineering, Mathematics, and Computer Science, Delft University of Technology, Delft, the Netherlands
| | - Volker Steuber
- Science and Technology Research Institute, University of Hertfordshire, Hatfield, United Kingdom
| | - Arn M J M van den Maagdenberg
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
- Netherlands Institute for Neuroscience, Royal Dutch Academy for Arts and Sciences, Amsterdam, the Netherlands
| | - Freek E Hoebeek
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
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31
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Zhu L, McDavid S, Currie KPM. "Slow" Voltage-Dependent Inactivation of CaV2.2 Calcium Channels Is Modulated by the PKC Activator Phorbol 12-Myristate 13-Acetate (PMA). PLoS One 2015. [PMID: 26222492 PMCID: PMC4519294 DOI: 10.1371/journal.pone.0134117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
CaV2.2 (N-type) voltage-gated calcium channels (Ca2+ channels) play key roles in neurons and neuroendocrine cells including the control of cellular excitability, neurotransmitter / hormone secretion, and gene expression. Calcium entry is precisely controlled by channel gating properties including multiple forms of inactivation. “Fast” voltage-dependent inactivation is relatively well-characterized and occurs over the tens-to- hundreds of milliseconds timeframe. Superimposed on this is the molecularly distinct, but poorly understood process of “slow” voltage-dependent inactivation, which develops / recovers over seconds-to-minutes. Protein kinases can modulate “slow” inactivation of sodium channels, but little is known about if/how second messengers control “slow” inactivation of Ca2+ channels. We investigated this using recombinant CaV2.2 channels expressed in HEK293 cells and native CaV2 channels endogenously expressed in adrenal chromaffin cells. The PKC activator phorbol 12-myristate 13-acetate (PMA) dramatically prolonged recovery from “slow” inactivation, but an inactive control (4α-PMA) had no effect. This effect of PMA was prevented by calphostin C, which targets the C1-domain on PKC, but only partially reduced by inhibitors that target the catalytic domain of PKC. The subtype of the channel β-subunit altered the kinetics of inactivation but not the magnitude of slowing produced by PMA. Intracellular GDP-β-S reduced the effect of PMA suggesting a role for G proteins in modulating “slow” inactivation. We postulate that the kinetics of recovery from “slow” inactivation could provide a molecular memory of recent cellular activity and help control CaV2 channel availability, electrical excitability, and neurotransmission in the seconds-to-minutes timeframe.
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Affiliation(s)
- Lei Zhu
- Department of Anesthesiology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Sarah McDavid
- Department of Anesthesiology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Kevin P. M. Currie
- Department of Anesthesiology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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32
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Carreira RJ, Shyti R, Balluff B, Abdelmoula WM, van Heiningen SH, van Zeijl RJ, Dijkstra J, Ferrari MD, Tolner EA, McDonnell LA, van den Maagdenberg AMJM. Large-scale mass spectrometry imaging investigation of consequences of cortical spreading depression in a transgenic mouse model of migraine. J Am Soc Mass Spectrom 2015; 26:853-61. [PMID: 25877011 PMCID: PMC4422864 DOI: 10.1007/s13361-015-1136-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/10/2015] [Accepted: 03/10/2015] [Indexed: 05/04/2023]
Abstract
Cortical spreading depression (CSD) is the electrophysiological correlate of migraine aura. Transgenic mice carrying the R192Q missense mutation in the Cacna1a gene, which in patients causes familial hemiplegic migraine type 1 (FHM1), exhibit increased propensity to CSD. Herein, mass spectrometry imaging (MSI) was applied for the first time to an animal cohort of transgenic and wild type mice to study the biomolecular changes following CSD in the brain. Ninety-six coronal brain sections from 32 mice were analyzed by MALDI-MSI. All MSI datasets were registered to the Allen Brain Atlas reference atlas of the mouse brain so that the molecular signatures of distinct brain regions could be compared. A number of metabolites and peptides showed substantial changes in the brain associated with CSD. Among those, different mass spectral features showed significant (t-test, P < 0.05) changes in the cortex, 146 and 377 Da, and in the thalamus, 1820 and 1834 Da, of the CSD-affected hemisphere of FHM1 R192Q mice. Our findings reveal CSD- and genotype-specific molecular changes in the brain of FHM1 transgenic mice that may further our understanding about the role of CSD in migraine pathophysiology. The results also demonstrate the utility of aligning MSI datasets to a common reference atlas for large-scale MSI investigations.
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Affiliation(s)
- Ricardo J. Carreira
- />Center for Proteomics and Metabolomics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Reinald Shyti
- />Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Benjamin Balluff
- />Center for Proteomics and Metabolomics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Walid M. Abdelmoula
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Rene J. van Zeijl
- />Center for Proteomics and Metabolomics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Jouke Dijkstra
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michel D. Ferrari
- />Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Else A. Tolner
- />Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Liam A. McDonnell
- />Center for Proteomics and Metabolomics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
- />Fondazione Pisana per la Scienza ONLUS, Pisa, Italy
| | - Arn M. J. M. van den Maagdenberg
- />Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- />Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
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33
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Tian X, Gala U, Zhang Y, Shang W, Nagarkar Jaiswal S, di Ronza A, Jaiswal M, Yamamoto S, Sandoval H, Duraine L, Sardiello M, Sillitoe RV, Venkatachalam K, Fan H, Bellen HJ, Tong C. A voltage-gated calcium channel regulates lysosomal fusion with endosomes and autophagosomes and is required for neuronal homeostasis. PLoS Biol 2015; 13:e1002103. [PMID: 25811491 PMCID: PMC4374850 DOI: 10.1371/journal.pbio.1002103] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [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: 07/13/2014] [Accepted: 02/11/2015] [Indexed: 01/03/2023] Open
Abstract
Autophagy helps deliver sequestered intracellular cargo to lysosomes for proteolytic degradation and thereby maintains cellular homeostasis by preventing accumulation of toxic substances in cells. In a forward mosaic screen in Drosophila designed to identify genes required for neuronal function and maintenance, we identified multiple cacophony (cac) mutant alleles. They exhibit an age-dependent accumulation of autophagic vacuoles (AVs) in photoreceptor terminals and eventually a degeneration of the terminals and surrounding glia. cac encodes an α1 subunit of a Drosophila voltage-gated calcium channel (VGCC) that is required for synaptic vesicle fusion with the plasma membrane and neurotransmitter release. Here, we show that cac mutant photoreceptor terminals accumulate AV-lysosomal fusion intermediates, suggesting that Cac is necessary for the fusion of AVs with lysosomes, a poorly defined process. Loss of another subunit of the VGCC, α2δ or straightjacket (stj), causes phenotypes very similar to those caused by the loss of cac, indicating that the VGCC is required for AV-lysosomal fusion. The role of VGCC in AV-lysosomal fusion is evolutionarily conserved, as the loss of the mouse homologues, Cacna1a and Cacna2d2, also leads to autophagic defects in mice. Moreover, we find that CACNA1A is localized to the lysosomes and that loss of lysosomal Cacna1a in cerebellar cultured neurons leads to a failure of lysosomes to fuse with endosomes and autophagosomes. Finally, we show that the lysosomal CACNA1A but not the plasma-membrane resident CACNA1A is required for lysosomal fusion. In summary, we present a model in which the VGCC plays a role in autophagy by regulating the fusion of AVs with lysosomes through its calcium channel activity and hence functions in maintaining neuronal homeostasis. A voltage-gated calcium channel required for neurotransmitter release also regulates the fusion of neuronal lysosomes with endosomes and autophagosomes, thereby helping to maintain cellular homeostasis. Autophagy is a cellular process used by cells to prevent the accumulation of toxic substances. It delivers misfolded proteins and damaged organelles by fusing autophagosomes—organelles formed by a double membrane that surrounds the “debris” to be eliminated—with lysosomes. How this fusion process is regulated during autophagy, however, remains to be established. Here, we analyze this process in flies and mice, and find that loss of different subunits of a specific type of Voltage Gated Calcium Channel (VGCC) leads to defects in lysosomal fusion with autophagosomes in neurons. It was already known that VGCCs control calcium entry at synaptic terminals to promote the fusion of synaptic vesicles with the plasma membrane, and that mutations in the subunits of VGCCs in humans cause neurological diseases. Our data indicate that defects in autophagy and lysosomal fusion are independent of defects in synaptic vesicle fusion and neurotransmitter release, and we show that a specific VGCC is present on lysosomal membranes where it is required for lysosomal fusion with endosomes and autophagosomes. These observations suggest that the fusion events required in autophagy rely on mechanisms similar to those that trigger the fusion of synaptic vesicles with the presynaptic membrane.
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Affiliation(s)
- Xuejun Tian
- Life Sciences Institute and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, China
| | - Upasana Gala
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Yongping Zhang
- Life Sciences Institute and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, China
| | - Weina Shang
- Life Sciences Institute and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, China
| | - Sonal Nagarkar Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alberto di Ronza
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Manish Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
| | - Shinya Yamamoto
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Hector Sandoval
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Lita Duraine
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
| | - Marco Sardiello
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Roy V. Sillitoe
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
- Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
| | - Kartik Venkatachalam
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Integrative Biology and Pharmacology, University of Texas School of Medicine, Houston, Texas, United States of America
| | - Hengyu Fan
- Life Sciences Institute and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, China
| | - Hugo J. Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail: (CT), (HJB)
| | - Chao Tong
- Life Sciences Institute and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, China
- * E-mail: (CT), (HJB)
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Cens T, Rousset M, Collet C, Charreton M, Garnery L, Le Conte Y, Chahine M, Sandoz JC, Charnet P. Molecular characterization and functional expression of the Apis mellifera voltage-dependent Ca2+ channels. Insect Biochem Mol Biol 2015; 58:12-27. [PMID: 25602183 DOI: 10.1016/j.ibmb.2015.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/09/2015] [Accepted: 01/09/2015] [Indexed: 06/04/2023]
Abstract
Voltage-gated Ca(2+) channels allow the influx of Ca(2+) ions from the extracellular space upon membrane depolarization and thus serve as a transducer between membrane potential and cellular events initiated by Ca(2+) transients. Most insects are predicted to possess three genes encoding Cavα, the main subunit of Ca(2+) channels, and several genes encoding the two auxiliary subunits, Cavβ and Cavα2δ; however very few of these genes have been cloned so far. Here, we cloned three full-length cDNAs encoding the three Cavα subunits (AmelCav1a, AmelCav2a and AmelCav3a), a cDNA encoding a novel variant of the Cavβ subunit (AmelCavβc), and three full-length cDNAs encoding three Cavα2δ subunits (AmelCavα2δ1 to 3) of the honeybee Apis mellifera. We identified several alternative or mutually exclusive exons in the sequence of the AmelCav2 and AmelCav3 genes. Moreover, we detected a stretch of glutamine residues in the C-terminus of the AmelCav1 subunit that is reminiscent of the motif found in the human Cav2.1 subunit of patients with Spinocerebellar Ataxia type 6. All these subunits contain structural domains that have been identified as functionally important in their mammalian homologues. For the first time, we could express three insect Cavα subunits in Xenopus oocytes and we show that AmelCav1a, 2a and 3a form Ca(2+) channels with distinctive properties. Notably, the co-expression of AmelCav1a or AmelCav2a with AmelCavβc and AmCavα2δ1 produces High Voltage-Activated Ca(2+) channels. On the other hand, expression of AmelCav3a alone leads to Low Voltage-Activated Ca(2+) channels.
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Affiliation(s)
- Thierry Cens
- Institut des Biomolécules Max Mousseron (IBMM), CNRS UMR 5247, Place Eugène Bataillon, 34095 Montpellier cedex 5, France; Centre de Recherche de Biochimie Macromoléculaire (CRBM), CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier cedex 5, France; Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier cedex 5, France.
| | - Matthieu Rousset
- Institut des Biomolécules Max Mousseron (IBMM), CNRS UMR 5247, Place Eugène Bataillon, 34095 Montpellier cedex 5, France; Centre de Recherche de Biochimie Macromoléculaire (CRBM), CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier cedex 5, France; Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier cedex 5, France.
| | - Claude Collet
- INRA UR 406 Abeilles et Environnement, 228 Route de l'aérodrome, Domaine Saint Paul, Site Agroparc, CS40509, 84914 Avignon cedex 9, France.
| | - Mercedes Charreton
- INRA UR 406 Abeilles et Environnement, 228 Route de l'aérodrome, Domaine Saint Paul, Site Agroparc, CS40509, 84914 Avignon cedex 9, France.
| | - Lionel Garnery
- Laboratoire Evolution Génome et Spéciation (LEGS), CNRS UPR 9034, Avenue de la Terrasse, Bâtiment 13, 91198 Gif sur Yvette, France.
| | - Yves Le Conte
- INRA UR 406 Abeilles et Environnement, 228 Route de l'aérodrome, Domaine Saint Paul, Site Agroparc, CS40509, 84914 Avignon cedex 9, France.
| | - Mohamed Chahine
- Centre de recherche, Institut universitaire en santé mentale de Québec, 2601 Chemin de la Canardière, Québec Québec G1J 2G3, Canada.
| | - Jean-Christophe Sandoz
- Laboratoire Evolution Génome et Spéciation (LEGS), CNRS UPR 9034, Avenue de la Terrasse, Bâtiment 13, 91198 Gif sur Yvette, France.
| | - Pierre Charnet
- Institut des Biomolécules Max Mousseron (IBMM), CNRS UMR 5247, Place Eugène Bataillon, 34095 Montpellier cedex 5, France; Centre de Recherche de Biochimie Macromoléculaire (CRBM), CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier cedex 5, France; Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier cedex 5, France.
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Rose SJ, Kriener LH, Heinzer AK, Fan X, Raike RS, van den Maagdenberg AMJM, Hess EJ. The first knockin mouse model of episodic ataxia type 2. Exp Neurol 2014; 261:553-62. [PMID: 25109669 DOI: 10.1016/j.expneurol.2014.08.001] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/07/2014] [Accepted: 08/01/2014] [Indexed: 12/28/2022]
Abstract
Episodic ataxia type 2 (EA2) is an autosomal dominant disorder associated with attacks of ataxia that are typically precipitated by stress, ethanol, caffeine or exercise. EA2 is caused by loss-of-function mutations in the CACNA1A gene, which encodes the α1A subunit of the CaV2.1 voltage-gated Ca(2+) channel. To better understand the pathomechanisms of this disorder in vivo, we created the first genetic animal model of EA2 by engineering a mouse line carrying the EA2-causing c.4486T>G (p.F1406C) missense mutation in the orthologous mouse Cacna1a gene. Mice homozygous for the mutated allele exhibit a ~70% reduction in CaV2.1 current density in Purkinje cells, though surprisingly do not exhibit an overt motor phenotype. Mice hemizygous for the knockin allele (EA2/- mice) did exhibit motor dysfunction measurable by rotarod and pole test. Studies using Cre-flox conditional genetics explored the role of cerebellar Purkinje cells or cerebellar granule cells in the poor motor performance of EA2/- mice and demonstrate that manipulation of either cell type alone did not cause poor motor performance. Thus, it is possible that subtle dysfunction arising from multiple cell types is necessary for the expression of certain ataxia syndromes.
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Affiliation(s)
- Samuel J Rose
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Lisa H Kriener
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ann K Heinzer
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Xueliang Fan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Robert S Raike
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Arn M J M van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands; Department of Neurology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
| | - Ellen J Hess
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Wang D, Fisher TE. Expression of CaV 2.2 and splice variants of CaV 2.1 in oxytocin- and vasopressin-releasing supraoptic neurones. J Neuroendocrinol 2014; 26:100-10. [PMID: 24344901 DOI: 10.1111/jne.12127] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/25/2013] [Accepted: 12/12/2013] [Indexed: 11/29/2022]
Abstract
The magnocellular neurosecretory cells (MNCs) release vasopressin (VP) and oxytocin (OT) from their axon terminals into the circulation and from their somata and dendrites to exert paracrine effects on other MNCs. MNCs express several types of voltage-gated Ca(2+) channels, including Ca(V)2.1 and Ca(V)2.2. These two channels types are similar in structure and function in other cells, but although influx of Ca(2+) through Ca(V)2.2 triggers the release of both OT and VP into the circulation, Ca(V)2.1 is involved in stimulating the release of VP but not OT. Release of OT from MNC somata is also triggered by Ca(V)2.2 but not Ca(V)2.1. These observations could be explained by differences in the level of expression of Ca(V)2.1 in VP and OT MNCs or by differences in the way that the two channels interact with the exocytotic apparatus. We used immunohistochemistry to confirm earlier work suggesting that MNCs express variants of Ca(V)2.1 lacking portions of an internal loop that enables the channels to interact with synaptic proteins. We used an antibody that would recognise both the full-length Ca(V)2.1 and the deletion variants to show that OT MNCs express fewer Ca(V)2.1 channels than do VP MNCs in both somata and axon terminals. We used the reverse transcriptase-polymerase chain reaction and immunocytochemistry to test whether MNCs express similar deletion variants of Ca(V)2.2 and were unable to find any evidence to support this. Our data suggest that the different roles that Ca(V)2.1 and Ca(V)2.2 play in MNC secretion may be a result of the different levels of expression of Ca(V)2.1 in VP and OT MNCs, as well as the expression in MNCs of deletion variants of Ca(V)2.1 that do not interact with exocytotic proteins and therefore may be less likely to mediate exocytotic release.
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Affiliation(s)
- D Wang
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Eikermann-Haerter K, Negro A, Ayata C. Spreading depression and the clinical correlates of migraine. Rev Neurosci 2013; 24:353-63. [PMID: 23907418 DOI: 10.1515/revneuro-2013-0005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/27/2013] [Indexed: 12/14/2022]
Abstract
Migraine is the most common neurologic condition. One-third of migraineurs experience transient neurologic symptoms, the so-called aura. There is strong evidence that spreading depression (SD) is the electrophysiologic substrate of migraine aura. SD is an intense pan-depolarization wave that slowly propagates in gray matter by way of contiguity and transiently disrupts neuronal function. When induced subcortically, striatal SD causes hemiparesis, hippocampal SD can trigger seizures and impact cognition, and bilateral thalamic SD can diminish consciousness. Recent data show that transgenic mice expressing familial hemiplegic migraine (FHM) type 1 mutations in voltage-gated Ca2+ channels (Cav2.1) develop mutation-specific aura-like signs after a cortical SD similar to patients with the respective mutation. These signs are associated with facilitated subcortical SD propagation. As in FHM, mice with the R192Q mutation develop pure hemiplegia associated with cortical SDs propagating into caudoputamen. S218L mice display additional signs such as seizures and coma when SD propagates into hippocampus and thalamus. In hyperexcitable FHM brains, SD may propagate between cortex and subcortical structures via permissive gray matter bridges, or originate de novo in subcortical structures, to explain unusual and severe aura signs and symptoms. Reciprocal spread and reverberating waves can explain protracted attacks.
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Hullugundi SK, Ferrari MD, van den Maagdenberg AMJM, Nistri A. The mechanism of functional up-regulation of P2X3 receptors of trigeminal sensory neurons in a genetic mouse model of familial hemiplegic migraine type 1 (FHM-1). PLoS One 2013; 8:e60677. [PMID: 23577145 PMCID: PMC3618040 DOI: 10.1371/journal.pone.0060677] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [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: 12/06/2012] [Accepted: 03/01/2013] [Indexed: 12/05/2022] Open
Abstract
A knock-in (KI) mouse model of FHM-1 expressing the R192Q missense mutation of the Cacna1a gene coding for the α1 subunit of CaV2.1 channels shows, at the level of the trigeminal ganglion, selective functional up-regulation of ATP -gated P2X3 receptors of sensory neurons that convey nociceptive signals to the brainstem. Why P2X3 receptors are constitutively more responsive, however, remains unclear as their membrane expression and TRPV1 nociceptor activity are the same as in wildtype (WT) neurons. Using primary cultures of WT or KI trigeminal ganglia, we investigated whether soluble compounds that may contribute to initiating (or maintaining) migraine attacks, such as TNFα, CGRP, and BDNF, might be responsible for increasing P2X3 receptor responses. Exogenous application of TNFα potentiated P2X3 receptor-mediated currents of WT but not of KI neurons, most of which expressed both the P2X3 receptor and the TNFα receptor TNFR2. However, sustained TNFα neutralization failed to change WT or KI P2X3 receptor currents. This suggests that endogenous TNFα does not regulate P2X3 receptor responses. Nonetheless, on cultures made from both genotypes, exogenous TNFα enhanced TRPV1 receptor-mediated currents expressed by a few neurons, suggesting transient amplification of TRPV1 nociceptor responses. CGRP increased P2X3 receptor currents only in WT cultures, although prolonged CGRP receptor antagonism or BDNF neutralization reduced KI currents to WT levels. Our data suggest that, in KI trigeminal ganglion cultures, constitutive up-regulation of P2X3 receptors probably is already maximal and is apparently contributed by basal CGRP and BDNF levels, thereby rendering these neurons more responsive to extracellular ATP.
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Affiliation(s)
- Swathi K. Hullugundi
- Neuroscience Department, International School for Advanced Studies (SISSA),Trieste, Italy
| | - Michel D. Ferrari
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Arn M. J. M. van den Maagdenberg
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
- Department of Human Genetics, Leiden Genetics University Medical Centre, Leiden, The Netherlands
| | - Andrea Nistri
- Neuroscience Department, International School for Advanced Studies (SISSA),Trieste, Italy
- * E-mail:
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Franceschini A, Vilotti S, Ferrari MD, van den Maagdenberg AMJM, Nistri A, Fabbretti E. TNFα levels and macrophages expression reflect an inflammatory potential of trigeminal ganglia in a mouse model of familial hemiplegic migraine. PLoS One 2013; 8:e52394. [PMID: 23326332 PMCID: PMC3543418 DOI: 10.1371/journal.pone.0052394] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [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: 06/13/2012] [Accepted: 11/13/2012] [Indexed: 01/16/2023] Open
Abstract
Latent changes in trigeminal ganglion structure and function resembling inflammatory conditions may predispose to acute attacks of migraine pain. Here, we investigated whether, in trigeminal sensory ganglia, cytokines such as TNFα might contribute to a local inflammatory phenotype of a transgenic knock-in (KI) mouse model of familial hemiplegic migraine type-1 (FHM-1). To this end, macrophage occurrence and cytokine expression in trigeminal ganglia were compared between wild type (WT) and R192Q mutant CaV2.1 Ca2+ channel (R192Q KI) mice, a genetic model of FHM-1. Cellular and molecular characterization was performed using a combination of confocal immunohistochemistry and cytokine assays. With respect to WT, R192Q KI trigeminal ganglia were enriched in activated macrophages as suggested by their morphology and immunoreactivity to the markers Iba1, CD11b, and ED1. R192Q KI trigeminal ganglia constitutively expressed higher mRNA levels of IL1β, IL6, IL10 and TNFα cytokines and the MCP-1 chemokine. Consistent with the report that TNFα is a major factor to sensitize trigeminal ganglia, we observed that, following an inflammatory reaction evoked by LPS injection, TNFα expression and macrophage occurrence were significantly higher in R192Q KI ganglia with respect to WT ganglia. Our data suggest that, in KI trigeminal ganglia, the complex cellular and molecular environment could support a new tissue phenotype compatible with a neuroinflammatory profile. We propose that, in FHM patients, this condition might contribute to trigeminal pain pathophysiology through release of soluble mediators, including TNFα, that may modulate the crosstalk between sensory neurons and resident glia, underlying the process of neuronal sensitisation.
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Affiliation(s)
- Alessia Franceschini
- Neuroscience Department, International School for Advanced Studies, Trieste, Italy
| | - Sandra Vilotti
- Neuroscience Department, International School for Advanced Studies, Trieste, Italy
| | - Michel D. Ferrari
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Arn M. J. M. van den Maagdenberg
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
- Department of Human Genetics, Leiden Genetics University Medical Centre, Leiden, The Netherlands
| | - Andrea Nistri
- Neuroscience Department, International School for Advanced Studies, Trieste, Italy
| | - Elsa Fabbretti
- Neuroscience Department, International School for Advanced Studies, Trieste, Italy
- Center for Biomedical Sciences and Engineering, University of Nova Gorica, Nova Gorica, Slovenia
- * E-mail:
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Yang T, Puckerin A, Colecraft HM. Distinct RGK GTPases differentially use α1- and auxiliary β-binding-dependent mechanisms to inhibit CaV1.2/CaV2.2 channels. PLoS One 2012; 7:e37079. [PMID: 22590648 PMCID: PMC3349659 DOI: 10.1371/journal.pone.0037079] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [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: 02/14/2012] [Accepted: 04/13/2012] [Indexed: 11/30/2022] Open
Abstract
CaV1/CaV2 channels, comprised of pore-forming α1 and auxiliary (β,α2δ) subunits, control diverse biological responses in excitable cells. Molecules blocking CaV1/CaV2 channel currents (ICa) profoundly regulate physiology and have many therapeutic applications. Rad/Rem/Rem2/Gem GTPases (RGKs) strongly inhibit CaV1/CaV2 channels. Understanding how RGKs block ICa is critical for insights into their physiological function, and may provide design principles for developing novel CaV1/CaV2 channel inhibitors. The RGK binding sites within CaV1/CaV2 channel complexes responsible for ICa inhibition are ambiguous, and it is unclear whether there are mechanistic differences among distinct RGKs. All RGKs bind β subunits, but it is unknown if and how this interaction contributes to ICa inhibition. We investigated the role of RGK/β interaction in Rem inhibition of recombinant CaV1.2 channels, using a mutated β (β2aTM) selectively lacking RGK binding. Rem blocked β2aTM-reconstituted channels (74% inhibition) less potently than channels containing wild-type β2a (96% inhibition), suggesting the prevalence of both β-binding-dependent and independent modes of inhibition. Two mechanistic signatures of Rem inhibition of CaV1.2 channels (decreased channel surface density and open probability), but not a third (reduced maximal gating charge), depended on Rem binding to β. We identified a novel Rem binding site in CaV1.2 α1C N-terminus that mediated β-binding-independent inhibition. The CaV2.2 α1B subunit lacks the Rem binding site in the N-terminus and displays a solely β-binding-dependent form of channel inhibition. Finally, we discovered an unexpected functional dichotomy amongst distinct RGKs— while Rem and Rad use both β-binding-dependent and independent mechanisms, Gem and Rem2 use only a β-binding-dependent method to inhibit CaV1.2 channels. The results provide new mechanistic perspectives, and reveal unexpected variations in determinants, underlying inhibition of CaV1.2/CaV2.2 channels by distinct RGK GTPases.
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Affiliation(s)
- Tingting Yang
- Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York, New York, United States of America
- * E-mail: (HMC); (TY)
| | - Akil Puckerin
- Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York, New York, United States of America
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York, New York, United States of America
- * E-mail: (HMC); (TY)
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Todorov B, Kros L, Shyti R, Plak P, Haasdijk ED, Raike RS, Frants RR, Hess EJ, Hoebeek FE, De Zeeuw CI, van den Maagdenberg AMJM. Purkinje cell-specific ablation of Cav2.1 channels is sufficient to cause cerebellar ataxia in mice. Cerebellum 2012; 11:246-58. [PMID: 21870131 PMCID: PMC3311848 DOI: 10.1007/s12311-011-0302-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/30/2022]
Abstract
The Cacna1a gene encodes the α(1A) subunit of voltage-gated Ca(V)2.1 Ca(2+) channels that are involved in neurotransmission at central synapses. Ca(V)2.1-α(1)-knockout (α1KO) mice, which lack Ca(V)2.1 channels in all neurons, have a very severe phenotype of cerebellar ataxia and dystonia, and usually die around postnatal day 20. This early lethality, combined with the wide expression of Ca(V)2.1 channels throughout the cerebellar cortex and nuclei, prohibited determination of the contribution of particular cerebellar cell types to the development of the severe neurobiological phenotype in Cacna1a mutant mice. Here, we crossed conditional Cacna1a mice with transgenic mice expressing Cre recombinase, driven by the Purkinje cell-specific Pcp2 promoter, to specifically ablate the Ca(V)2.1-α(1A) subunit and thereby Ca(V)2.1 channels in Purkinje cells. Purkinje cell Ca(V)2.1-α(1A)-knockout (PCα1KO) mice aged without difficulties, rescuing the lethal phenotype seen in α1KO mice. PCα1KO mice exhibited cerebellar ataxia starting around P12, much earlier than the first signs of progressive Purkinje cell loss, which appears in these mice between P30 and P45. Secondary cell loss was observed in the granular and molecular layers of the cerebellum and the volume of all individual cerebellar nuclei was reduced. In this mouse model with a cell type-specific ablation of Ca(V)2.1 channels, we show that ablation of Ca(V)2.1 channels restricted to Purkinje cells is sufficient to cause cerebellar ataxia. We demonstrate that spatial ablation of Ca(V)2.1 channels may help in unraveling mechanisms of human disease.
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Affiliation(s)
- Boyan Todorov
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Lieke Kros
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Reinald Shyti
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Petra Plak
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | | | - Robert S. Raike
- Department of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA USA
| | - Rune R. Frants
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Ellen J. Hess
- Department of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA USA
| | - Freek E. Hoebeek
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, Royal Dutch Academy for Sciences (KNAW), Amsterdam, The Netherlands
| | - Arn M. J. M. van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
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Waithe D, Ferron L, Page KM, Chaggar K, Dolphin AC. Beta-subunits promote the expression of Ca(V)2.2 channels by reducing their proteasomal degradation. J Biol Chem 2011; 286:9598-611. [PMID: 21233207 PMCID: PMC3059031 DOI: 10.1074/jbc.m110.195909] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/22/2010] [Indexed: 02/03/2023] Open
Abstract
The β-subunits of voltage-gated calcium channels regulate their functional expression and properties. Two mechanisms have been proposed for this, an effect on gating and an enhancement of expression. With respect to the effect on expression, β-subunits have been suggested to enhance trafficking by masking an unidentified endoplasmic reticulum (ER) retention signal. Here we have investigated whether, and how, β-subunits affect the level of Ca(V)2.2 channels within somata and neurites of cultured sympathetic neurons. We have used YFP-Ca(V)2.2 containing a mutation (W391A), that prevents binding of β-subunits to its I-II linker and found that expression of this channel was much reduced compared with WT CFP-Ca(V)2.2 when both were expressed in the same neuron. This effect was particularly evident in neurites and growth cones. The difference between the levels of YFP-Ca(V)2.2(W391A) and CFP-Ca(V)2.2(WT) was lost in the absence of co-expressed β-subunits. Furthermore, the relative reduction of expression of Ca(V)2.2(W391A) compared with the WT channel was reversed by exposure to two proteasome inhibitors, MG132 and lactacystin, particularly in the somata. In further experiments in tsA-201 cells, we found that proteasome inhibition did not augment the cell surface Ca(V)2.2(W391A) level but resulted in the observation of increased ubiquitination, particularly of mutant channels. In contrast, we found no evidence for selective retention of Ca(V)2.2(W391A) in the ER, in either the soma or growth cones. In conclusion, there is a marked effect of β-subunits on Ca(V)2.2 expression, particularly in neurites, but our results point to protection from proteasomal degradation rather than masking of an ER retention signal.
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Affiliation(s)
- Dominic Waithe
- From the Department of Neuroscience, Physiology and Pharmacology, University College London, Gower St., London WC1E 6BT, United Kingdom
| | - Laurent Ferron
- From the Department of Neuroscience, Physiology and Pharmacology, University College London, Gower St., London WC1E 6BT, United Kingdom
| | - Karen M. Page
- From the Department of Neuroscience, Physiology and Pharmacology, University College London, Gower St., London WC1E 6BT, United Kingdom
| | - Kanchan Chaggar
- From the Department of Neuroscience, Physiology and Pharmacology, University College London, Gower St., London WC1E 6BT, United Kingdom
| | - Annette C. Dolphin
- From the Department of Neuroscience, Physiology and Pharmacology, University College London, Gower St., London WC1E 6BT, United Kingdom
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Evans RM, You H, Hameed S, Altier C, Mezghrani A, Bourinet E, Zamponi GW. Heterodimerization of ORL1 and opioid receptors and its consequences for N-type calcium channel regulation. J Biol Chem 2010; 285:1032-40. [PMID: 19887453 PMCID: PMC2801230 DOI: 10.1074/jbc.m109.040634] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 10/22/2009] [Indexed: 01/15/2023] Open
Abstract
We have investigated the heterodimerization of ORL1 receptors and classical members of the opioid receptor family. All three classes of opioid receptors could be co-immunoprecipitated with ORL1 receptors from both transfected tsA-201 cell lysate and rat dorsal root ganglia lysate, suggesting that these receptors can form heterodimers. Consistent with this hypothesis, in cells expressing either one of the opioid receptors together with ORL1, prolonged ORL1 receptor activation via nociceptin application resulted in internalization of the opioid receptors. Conversely, mu-, delta-, and kappa-opioid receptor activation with the appropriate ligands triggered the internalization of ORL1. The mu-opioid receptor/ORL1 receptor heterodimers were shown to associate with N-type calcium channels, with activation of mu-opioid receptors triggering N-type channel internalization, but only in the presence of ORL1. Furthermore, the formation of opioid receptor/ORL1 receptor heterodimers attenuated the ORL1 receptor-mediated inhibition of N-type channels, in part because of constitutive opioid receptor activity. Collectively, our data support the existence of heterodimers between ORL1 and classical opioid receptors, with profound implications for effectors such as N-type calcium channels.
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Affiliation(s)
- Rhian M. Evans
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary T2N 4N1, Canada and
| | - Haitao You
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary T2N 4N1, Canada and
| | - Shahid Hameed
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary T2N 4N1, Canada and
| | - Christophe Altier
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary T2N 4N1, Canada and
| | | | - Emmanuel Bourinet
- the Institut de Génomique Fonctionnelle, CNRS, 34094 Montpellier, France
| | - Gerald W. Zamponi
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary T2N 4N1, Canada and
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Changing the "channel": aminopyridines potentiate synaptic and neuromuscular transmission by targeting the voltage-activated calcium channel beta subunit. J Biol Chem 2009; 284:e99971. [PMID: 20050319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
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Brittain JM, Piekarz AD, Wang Y, Kondo T, Cummins TR, Khanna R. An atypical role for collapsin response mediator protein 2 (CRMP-2) in neurotransmitter release via interaction with presynaptic voltage-gated calcium channels. J Biol Chem 2009; 284:31375-90. [PMID: 19755421 PMCID: PMC2781534 DOI: 10.1074/jbc.m109.009951] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 08/11/2009] [Indexed: 11/06/2022] Open
Abstract
Collapsin response mediator proteins (CRMPs) specify axon/dendrite fate and axonal growth of neurons through protein-protein interactions. Their functions in presynaptic biology remain unknown. Here, we identify the presynaptic N-type Ca(2+) channel (CaV2.2) as a CRMP-2-interacting protein. CRMP-2 binds directly to CaV2.2 in two regions: the channel domain I-II intracellular loop and the distal C terminus. Both proteins co-localize within presynaptic sites in hippocampal neurons. Overexpression in hippocampal neurons of a CRMP-2 protein fused to enhanced green fluorescent protein caused a significant increase in Ca(2+) channel current density, whereas lentivirus-mediated CRMP-2 knockdown abolished this effect. Interestingly, the increase in Ca(2+) current density was not due to a change in channel gating. Rather, cell surface biotinylation studies showed an increased number of CaV2.2 at the cell surface in CRMP-2-overexpressing neurons. These neurons also exhibited a significant increase in vesicular release in response to a depolarizing stimulus. Depolarization of CRMP-2-enhanced green fluorescent protein-overexpressing neurons elicited a significant increase in release of glutamate compared with control neurons. Toxin block of Ca(2+) entry via CaV2.2 abolished this stimulated release. Thus, the CRMP-2-Ca(2+) channel interaction represents a novel mechanism for modulation of Ca(2+) influx into nerve terminals and, hence, of synaptic strength.
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Affiliation(s)
- Joel M. Brittain
- From the Paul and Carole Stark Neurosciences Research Institute and
| | - Andrew D. Piekarz
- From the Paul and Carole Stark Neurosciences Research Institute and
- Departments of Pharmacology and Toxicologyand
| | - Yuying Wang
- From the Paul and Carole Stark Neurosciences Research Institute and
| | - Takako Kondo
- Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Theodore R. Cummins
- From the Paul and Carole Stark Neurosciences Research Institute and
- Departments of Pharmacology and Toxicologyand
| | - Rajesh Khanna
- From the Paul and Carole Stark Neurosciences Research Institute and
- Departments of Pharmacology and Toxicologyand
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Takahashi E, Niimi K, Itakura C. Age-related spatial and nonspatial short-term memory in Cav2.1alpha1 mutant mice, Rolling Nagoya. Behav Brain Res 2009; 204:241-5. [PMID: 19467269 DOI: 10.1016/j.bbr.2009.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2009] [Revised: 05/13/2009] [Accepted: 05/16/2009] [Indexed: 12/21/2022]
Abstract
Aged heterozygous Rolling Nagoya mice carrying Cav2.1alpha1 mutation show deficits with regard to spatial short-term memory using hippocampus-related object location test, but not with regard to nonspatial memory using perirhinal cortex-related object recognition test. In hippocampus, wild-type Cav2.1alpha1 mRNA exhibited lower expression and mutant-type expression was higher in aged heterozygous mice. In perirhinal cortex, there were no significantly different expressions. Alteration of age-dependent expressions of Cav2.1 channels differs in different regions with related effects on behavioral performances.
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Affiliation(s)
- Eiki Takahashi
- RIKEN Brain Science Institute, Research Resources Center, Hirosawa 2-1, Wako, Saitama 351-0198, Japan.
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Chen YH, He LL, Buchanan DR, Zhang Y, Fitzmaurice A, Yang J. Functional dissection of the intramolecular Src homology 3-guanylate kinase domain coupling in voltage-gated Ca2+ channel beta-subunits. FEBS Lett 2009; 583:1969-75. [PMID: 19427861 DOI: 10.1016/j.febslet.2009.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 03/25/2009] [Accepted: 05/04/2009] [Indexed: 11/19/2022]
Abstract
The beta-subunit of voltage-gated Ca(2+) channels is essential for trafficking the channels to the plasma membrane and regulating their gating. It contains a Src homology 3 (SH3) domain and a guanylate kinase (GK) domain, which interact intramolecularly. We investigated the structural underpinnings of this intramolecular coupling and found that in addition to a previously described SH3 domain beta strand, two structural elements are crucial for maintaining a strong and yet potentially modifiable SH3-GK intramolecular coupling: an intrinsically weak SH3-GK interface and a direct connection of the SH3 and GK domains. Alterations of these elements uncouple the two functions of the beta-subunit, degrading its ability to regulate gating while leaving its chaperone effect intact.
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Affiliation(s)
- Yu-hang Chen
- Department of Biological Sciences, 917 Fairchild Center, MC2462, Columbia University, New York, NY 10027, USA
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Marques JM, Alonso I, Santos C, Silveira I, Olsson IAS. The spatial learning phenotype of heterozygous leaner mice is robust to systematic variation of the housing environment. Comp Med 2009; 59:129-138. [PMID: 19389304 PMCID: PMC2703144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 09/20/2008] [Accepted: 10/05/2008] [Indexed: 05/27/2023]
Abstract
Providing stimulation and allowing the performance of motivated behaviors through environmental enrichment improves learning and memory in rodents and delays cognitive impairment in neurodegenerative disease models. The leaner mutation affects the Ca(v)2.1 voltage-gated calcium channel alpha(1A)-subunit gene, and homozygous mice show severe phenotypic alterations. Although several authors have described heterozygous mice as normal, recent studies in our laboratory indicate motor and cognitive impairment in tg(la)/+ mice. In the present study, we evaluated whether this impairment is robust to systematic variation of the housing environment from barren to standard and furnished (enriched) cages. Wildtype (n = 55) and tg(la)/+ (n = 79) C57Bl/6J mice were assigned randomly to 1 of the 3 housing systems and tested on the Morris water maze at 6, 12, and 20 mo of age. The results confirmed impaired performance in tg(la)/+ mice, particularly in older mice. At 12 and 20 mo, only wildtype (and not tg(la)/+) mice showed evidence of learning (spending increased time in the target quadrant) during the probe trial. Housing also affected performance: at 12 mo, only mice from furnished cages showed evidence of learning, and in aged mice (20 mo), only those housed in more complex environments showed long-term memory (8 mo after previous testing) of the platform position. In conclusion, a heterozygous mutation in a Ca(2+) channel gene causes cognitive deficits in leaner mice that are robust to environmental variation but attenuated by physical and behavioral stimulation.
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Affiliation(s)
- Joana M Marques
- Laboratory Animal Science Porto, Porto, Portugal
- Section for Comparative Physiology and Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Neurobiology of Action, Gulbenkian Science Institute, Oeiras, Portugal
| | - Isabel Alonso
- UnIGENe, IBMC - Instituto de Biologia Molecular e Celular Porto, Porto, Portugal
| | - Cristina Santos
- Serviço de Bioestatistica e Informática Médica, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Isabel Silveira
- UnIGENe, IBMC - Instituto de Biologia Molecular e Celular Porto, Porto, Portugal
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Frank CA, Pielage J, Davis GW. A presynaptic homeostatic signaling system composed of the Eph receptor, ephexin, Cdc42, and CaV2.1 calcium channels. Neuron 2009; 61:556-69. [PMID: 19249276 PMCID: PMC2699049 DOI: 10.1016/j.neuron.2008.12.028] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 11/24/2008] [Accepted: 12/30/2008] [Indexed: 01/05/2023]
Abstract
The molecular mechanisms underlying the homeostatic modulation of presynaptic neurotransmitter release remain largely unknown. In a screen, we isolated mutations in Drosophila ephexin (Rho-type guanine nucleotide exchange factor) that disrupt the homeostatic enhancement of presynaptic release following impairment of postsynaptic glutamate receptor function at the Drosophila neuromuscular junction. We show that Ephexin is sufficient presynaptically for synaptic homeostasis and localizes in puncta throughout the nerve terminal. However, ephexin mutations do not alter other aspects of neuromuscular development, including morphology or active zone number. We then show that, during synaptic homeostasis, Ephexin functions primarily with Cdc42 in a signaling system that converges upon the presynaptic CaV2.1 calcium channel. Finally, we show that Ephexin binds the Drosophila Eph receptor (Eph) and Eph mutants disrupt synaptic homeostasis. Based on these data, we propose that Ephexin/Cdc42 couples synaptic Eph signaling to the modulation of presynaptic CaV2.1 channels during the homeostatic enhancement of presynaptic release.
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Affiliation(s)
- C Andrew Frank
- Department of Biochemistry and Biophysics, 1550 4th Street, Rock Hall 4th Floor North, University of California, San Francisco, San Francisco, CA 94158, USA
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Clark JM, Symington SB. Neurotoxic implications of the agonistic action of CS-syndrome pyrethroids on the N-type Ca(v)2.2 calcium channel. Pest Manag Sci 2008; 64:628-38. [PMID: 18383452 DOI: 10.1002/ps.1573] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Cismethrin (T-syndrome) and deltamethrin (CS-syndrome) pyrethroids have been previously shown to increase membrane depolarization and calcium influx, but only deltamethrin increased Ca(2+)-dependent neurotransmitter release from rat brain synaptosomes. Deltamethrin's action was blocked by omega-conotoxin GVIA, delineating a separate action at N-type Ca(v)2.2 channels that is consistent with the in vivo release of neurotransmitter. It is hypothesized that other CS-syndrome pyrethroids will elicit similar actions at presynaptic nerve terminals. RESULTS Nine additional pyrethroids were similarly examined, and these data were used in a cluster analysis. CS-syndrome pyrethroids that possessed alpha-cyano groups, cypermethrin, deltamethrin and esfenvalerate, all caused Ca(2+) influx and neurotransmitter release and clustered with two other alpha-cyano pyrethroids, cyfluthrin and cyhalothrin, that shared these same actions. T-syndrome pyrethroids, bioallethrin, cismethrin and fenpropathrin, did not share these actions and clustered with two non-alpha-cyano pyrethroids, tefluthin and bifenthrin, which likewise did not elicit these actions. Deltamethrin reduced peak current of heterologously expressed wild-type Ca(v)2.2, increased peak current of T422E Ca(v)2.2 and was 20-fold more potent on T422E Ca(v)2.2 than on wild-type channels, indicating that the permanently phosphorylated form of Ca(v)2.2 is the preferred target. CONCLUSIONS Ca(v)2.2 is directly modified by deltamethrin, but the resulting perturbation is dependent upon its phosphorylation state. The present findings may provide a partial explanation for the different toxic syndromes produced by these structurally distinct pyrethroids.
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Affiliation(s)
- J Marshall Clark
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, MA 01003, USA.
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