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Hahn N, Bens M, Kempfer M, Reißig C, Schmidl L, Geis C. Protecting RNA quality for spatial transcriptomics while improving immunofluorescent staining quality. Front Neurosci 2023; 17:1198154. [PMID: 37274189 PMCID: PMC10234422 DOI: 10.3389/fnins.2023.1198154] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/03/2023] [Indexed: 06/06/2023] Open
Abstract
In comparison to bulk sequencing or single cell sequencing, spatial transcriptomics preserves the spatial information in tissue slices and can even be mapped to immunofluorescent stainings, allowing translation of gene expression information into their spatial context. This enables to unravel complex interactions of neighboring cells or to link cell morphology to transcriptome data. The 10× Genomics Visium platform offers to combine spatial transcriptomics with immunofluorescent staining of cryo-sectioned tissue slices. We applied this technique to fresh frozen mouse brain slices and developed a protocol that still protects RNA quality while improving buffers for immunofluorescent staining. We investigated the impact of various parameters, including fixation time and buffer composition, on RNA quality and antibody binding. Here, we propose an improved version of the manufacturer protocol, which does not alter RNA quality and facilitates the use of multiple additional antibodies that were not compatible with the manufacturer protocol before. Finally, we discuss the influence of various staining parameters, which contribute to the development of application specific staining protocols.
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Affiliation(s)
- Nina Hahn
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Martin Bens
- Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), Jena, Germany
| | - Marin Kempfer
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena, Germany
| | - Christin Reißig
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena, Germany
| | - Lars Schmidl
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena, Germany
| | - Christian Geis
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
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Sell J, Rahmati V, Kempfer M, Irani SR, Ritzau-Jost A, Hallermann S, Geis C. Comparative Effects of Domain-Specific Human Monoclonal Antibodies Against LGI1 on Neuronal Excitability. Neurol Neuroimmunol Neuroinflamm 2023; 10:10/3/e200096. [PMID: 37028941 PMCID: PMC10099296 DOI: 10.1212/nxi.0000000000200096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 01/04/2023] [Indexed: 04/09/2023]
Abstract
BACKGROUND AND OBJECTIVES Autoantibodies to leucine-rich glioma inactivated protein 1 (LGI1) cause an autoimmune limbic encephalitis with frequent focal seizures and anterograde memory dysfunction. LGI1 is a neuronal secreted linker protein with 2 functional domains: the leucine-rich repeat (LRR) and epitempin (EPTP) regions. LGI1 autoantibodies are known to interfere with presynaptic function and neuronal excitability; however, their epitope-specific mechanisms are incompletely understood. METHODS We used patient-derived monoclonal autoantibodies (mAbs), which target either LRR or EPTP domains of LGI1 to investigate long-term antibody-induced alteration of neuronal function. LRR- and EPTP-specific effects were evaluated by patch-clamp recordings in cultured hippocampal neurons and compared with biophysical neuron modeling. Kv1.1 channel clustering at the axon initial segment (AIS) was quantified by immunocytochemistry and structured illumination microscopy techniques. RESULTS Both EPTP and LRR domain-specific mAbs decreased the latency of first somatic action potential firing. However, only the LRR-specific mAbs increased the number of action potential firing together with enhanced initial instantaneous frequency and promoted spike-frequency adaptation, which were less pronounced after the EPTP mAb. This also led to an effective reduction in the slope of ramp-like depolarization in the subthreshold response, suggesting Kv1 channel dysfunction. A biophysical model of a hippocampal neuron corroborated experimental results and suggests that an isolated reduction of the conductance of Kv1-mediated K+ currents largely accounts for the antibody-induced alterations in the initial firing phase and spike-frequency adaptation. Furthermore, Kv1.1 channel density was spatially redistributed from the distal toward the proximal site of AIS under LRR mAb treatment and, to a lesser extant, under EPTP mAb. DISCUSSION These findings indicate an epitope-specific pathophysiology of LGI1 autoantibodies. The pronounced neuronal hyperexcitability and SFA together with dropped slope of ramp-like depolarization after LRR-targeted interference suggest disruption of LGI1-dependent clustering of K+ channel complexes. Moreover, considering the effective triggering of action potentials at the distal AIS, the altered spatial distribution of Kv1.1 channel density may contribute to these effects through impairing neuronal control of action potential initiation and synaptic integration.
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Affiliation(s)
- Josefine Sell
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany
| | - Vahid Rahmati
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany
| | - Marin Kempfer
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany
| | - Sarosh R Irani
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany
| | - Andreas Ritzau-Jost
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany
| | - Stefan Hallermann
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany
| | - Christian Geis
- From the Section Translational Neuroimmunology (J.S., V.R., M.K., C.G.), Department of Neurology, Jena University Hospital, Germany; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Neurology (S.R.I.), Oxford University Hospitals, UK; and Carl-Ludwig-Institute of Physiology (A.R.-J., S.H.), Faculty of Medicine, Leipzig University, Germany.
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