1
|
Pilotto F, Diab R, Al Qassab Z, Saxena S. Generation and enrichment of cerebellar GABAergic interneurons from human induced pluripotent stem cells and intracellular calcium measurements. STAR Protoc 2024; 5:102936. [PMID: 38735042 PMCID: PMC11101973 DOI: 10.1016/j.xpro.2024.102936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/09/2024] [Accepted: 02/20/2024] [Indexed: 05/14/2024] Open
Abstract
GABAergic interneurons are inhibitory neurons of the CNS, playing a fundamental role in neural circuitry and activity. Here, we provide a robust protocol for the successful enrichment of human cerebellar GABAergic interneurons from human induced pluripotent stem cells (iPSCs) and measuring intracellular calcium transients. We describe in detail steps for culturing iPSCs; generating embryoid bodies; and differentiating and enriching for cerebellar GABAergic neurons (cGNs), with precise steps for their molecular characterization. We then detail the procedure for adeno-associated virus-mediated transduction of cGNs with genetically encoded calcium indicators, followed by intracellular calcium imaging and analyses. For complete details on the use and execution of this protocol, please refer to Pilotto et al.1.
Collapse
Affiliation(s)
- Federica Pilotto
- Institut Neuromyogenè, Inserm Lyon, Lyon, France; CNRS Université Claude Bernard Lyon I, Lyon, France
| | - Rim Diab
- Department of Neurology, Inselspital University Hospital, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Zahraa Al Qassab
- Department of Neurology, Inselspital University Hospital, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Smita Saxena
- Department of Neurology, Inselspital University Hospital, Bern, Switzerland; Department for BioMedical Research, University of Bern, Bern, Switzerland; Department of Physical Medicine & Rehabilitation, University of Missouri, Columbia, MO, USA; NextGen Precision Health, University of Missouri, Columbia, MO, USA.
| |
Collapse
|
2
|
Douthwaite C, Tietje C, Ye X, Liebscher S. Probing cerebellar circuit dysfunction in rodent models of spinocerebellar ataxia by means of in vivo two-photon calcium imaging. STAR Protoc 2024; 5:102911. [PMID: 38412102 PMCID: PMC10907221 DOI: 10.1016/j.xpro.2024.102911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/28/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
Purkinje neuron degeneration characterizes spinocerebellar ataxia type 1, yet the comprehension of the impact on the broader cerebellar circuit remains incomplete. We here detail simultaneous in vivo two-photon calcium imaging of diverse neuronal populations in the cerebellar cortex of Sca1 mice while they are navigating a virtual environment. We outline surgical procedures and protocols to chronically record from identical neurons, and we detail data post-processing and analysis to delineate disease-related alterations in neuronal activity and sensorimotor-driven response properties. For complete details on the use and execution of this protocol, please refer to Pilotto et al.1.
Collapse
Affiliation(s)
- Christopher Douthwaite
- Institute of Clinical Neuroimmunology, Klinikum der Universitaet Muenchen, Ludwig-Maximilians University Munich, Martinsried, Germany; Graduate School of Systemic Neurosciences, Munich, Germany
| | - Christoph Tietje
- Institute of Clinical Neuroimmunology, Klinikum der Universitaet Muenchen, Ludwig-Maximilians University Munich, Martinsried, Germany
| | - XiaoQian Ye
- Institute of Clinical Neuroimmunology, Klinikum der Universitaet Muenchen, Ludwig-Maximilians University Munich, Martinsried, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universitaet Muenchen, Ludwig-Maximilians University Munich, Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; University of Cologne & Department of Neurology, University hospital Cologne, Cologne, Germany.
| |
Collapse
|
3
|
Pilotto F, Del Bondio A, Puccio H. Hereditary Ataxias: From Bench to Clinic, Where Do We Stand? Cells 2024; 13:319. [PMID: 38391932 PMCID: PMC10886822 DOI: 10.3390/cells13040319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/24/2024] Open
Abstract
Cerebellar ataxias are a wide heterogeneous group of movement disorders. Within this broad umbrella of diseases, there are both genetics and sporadic forms. The clinical presentation of these conditions can exhibit a diverse range of symptoms across different age groups, spanning from pure cerebellar manifestations to sensory ataxia and multisystemic diseases. Over the last few decades, advancements in our understanding of genetics and molecular pathophysiology related to both dominant and recessive ataxias have propelled the field forward, paving the way for innovative therapeutic strategies aimed at preventing and arresting the progression of these diseases. Nevertheless, the rarity of certain forms of ataxia continues to pose challenges, leading to limited insights into the etiology of the disease and the identification of target pathways. Additionally, the lack of suitable models hampers efforts to comprehensively understand the molecular foundations of disease's pathophysiology and test novel therapeutic interventions. In the following review, we describe the epidemiology, symptomatology, and pathological progression of hereditary ataxia, including both the prevalent and less common forms of these diseases. Furthermore, we illustrate the diverse molecular pathways and therapeutic approaches currently undergoing investigation in both pre-clinical studies and clinical trials. Finally, we address the existing and anticipated challenges within this field, encompassing both basic research and clinical endeavors.
Collapse
Affiliation(s)
- Federica Pilotto
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Andrea Del Bondio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Hélène Puccio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| |
Collapse
|
4
|
Leung TCS, Fields E, Rana N, Shen RYL, Bernstein AE, Cook AA, Phillips DE, Watt AJ. Mitochondrial damage and impaired mitophagy contribute to disease progression in SCA6. Acta Neuropathol 2024; 147:26. [PMID: 38286873 PMCID: PMC10824820 DOI: 10.1007/s00401-023-02680-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/18/2023] [Accepted: 12/27/2023] [Indexed: 01/31/2024]
Abstract
Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that manifests in midlife and progressively worsens with age. SCA6 is rare, and many patients are not diagnosed until long after disease onset. Whether disease-causing cellular alterations differ at different disease stages is currently unknown, but it is important to answer this question in order to identify appropriate therapeutic targets across disease duration. We used transcriptomics to identify changes in gene expression at disease onset in a well-established mouse model of SCA6 that recapitulates key disease features. We observed both up- and down-regulated genes with the major down-regulated gene ontology terms suggesting mitochondrial dysfunction. We explored mitochondrial function and structure and observed that changes in mitochondrial structure preceded changes in function, and that mitochondrial function was not significantly altered at disease onset but was impaired later during disease progression. We also detected elevated oxidative stress in cells at the same disease stage. In addition, we observed impairment in mitophagy that exacerbates mitochondrial dysfunction at late disease stages. In post-mortem SCA6 patient cerebellar tissue, we observed metabolic changes that are consistent with mitochondrial impairments, supporting our results from animal models being translatable to human disease. Our study reveals that mitochondrial dysfunction and impaired mitochondrial degradation likely contribute to disease progression in SCA6 and suggests that these could be promising targets for therapeutic interventions in particular for patients diagnosed after disease onset.
Collapse
Affiliation(s)
| | - Eviatar Fields
- Department of Biology, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Namrata Rana
- Department of Biology, McGill University, Montreal, QC, Canada
| | | | | | - Anna A Cook
- Department of Biology, McGill University, Montreal, QC, Canada
| | | | - Alanna J Watt
- Department of Biology, McGill University, Montreal, QC, Canada.
| |
Collapse
|
5
|
Schilling K. Revisiting the development of cerebellar inhibitory interneurons in the light of single-cell genetic analyses. Histochem Cell Biol 2024; 161:5-27. [PMID: 37940705 PMCID: PMC10794478 DOI: 10.1007/s00418-023-02251-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2023] [Indexed: 11/10/2023]
Abstract
The present review aims to provide a short update of our understanding of the inhibitory interneurons of the cerebellum. While these cells constitute but a minority of all cerebellar neurons, their functional significance is increasingly being recognized. For one, inhibitory interneurons of the cerebellar cortex are now known to constitute a clearly more diverse group than their traditional grouping as stellate, basket, and Golgi cells suggests, and this diversity is now substantiated by single-cell genetic data. The past decade or so has also provided important information about interneurons in cerebellar nuclei. Significantly, developmental studies have revealed that the specification and formation of cerebellar inhibitory interneurons fundamentally differ from, say, the cortical interneurons, and define a mode of diversification critically dependent on spatiotemporally patterned external signals. Last, but not least, in the past years, dysfunction of cerebellar inhibitory interneurons could also be linked with clinically defined deficits. I hope that this review, however fragmentary, may stimulate interest and help focus research towards understanding the cerebellum.
Collapse
Affiliation(s)
- Karl Schilling
- Anatomisches Institut - Anatomie und Zellbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 10, 53115, Bonn, Germany.
| |
Collapse
|
6
|
Dejanovic B, Sheng M, Hanson JE. Targeting synapse function and loss for treatment of neurodegenerative diseases. Nat Rev Drug Discov 2024; 23:23-42. [PMID: 38012296 DOI: 10.1038/s41573-023-00823-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2023] [Indexed: 11/29/2023]
Abstract
Synapse dysfunction and loss are hallmarks of neurodegenerative diseases that correlate with cognitive decline. However, the mechanisms and therapeutic strategies to prevent or reverse synaptic damage remain elusive. In this Review, we discuss recent advances in understanding the molecular and cellular pathways that impair synapses in neurodegenerative diseases, including the effects of protein aggregation and neuroinflammation. We also highlight emerging therapeutic approaches that aim to restore synaptic function and integrity, such as enhancing synaptic plasticity, preventing synaptotoxicity, modulating neuronal network activity and targeting immune signalling. We discuss the preclinical and clinical evidence for each strategy, as well as the challenges and opportunities for developing effective synapse-targeting therapeutics for neurodegenerative diseases.
Collapse
Affiliation(s)
| | - Morgan Sheng
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jesse E Hanson
- Department of Neuroscience, Genentech, South San Francisco, CA, USA.
| |
Collapse
|
7
|
Opal P. Spinocerebellar ataxia type 1: It's not just about Purkinje cells. Neuron 2023; 111:2461-2462. [PMID: 37591199 DOI: 10.1016/j.neuron.2023.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 07/17/2023] [Accepted: 07/20/2023] [Indexed: 08/19/2023]
Abstract
In this issue of Neuron, Pilotto et al.1 use state-of-the-art in vivo imaging in mice to show that excitatory/inhibitory imbalance drives SCA1 pathophysiology, with hyperexcitable molecular layer interneurons overinhibiting Purkinje cells, leading to hallmark neurodegeneration.
Collapse
Affiliation(s)
- Puneet Opal
- Davee Department of Neurology and Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| |
Collapse
|