1
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Nguyen LH, Xu Y, Mahadeo T, Zhang L, Lin TV, Born HA, Anderson AE, Bordey A. Expression of 4E-BP1 in juvenile mice alleviates mTOR-induced neuronal dysfunction and epilepsy. Brain 2021; 145:1310-1325. [PMID: 34849602 DOI: 10.1093/brain/awab390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/01/2021] [Accepted: 09/22/2021] [Indexed: 11/13/2022] Open
Abstract
Hyperactivation of the mechanistic target of rapamycin (mTOR) pathway during fetal neurodevelopment alters neuron structure and function, leading to focal malformation of cortical development (FMCD) and intractable epilepsy. Recent evidence suggests a role for dysregulated cap-dependent translation downstream of mTOR in the formation of FMCD and seizures. However, it is unknown whether modifying translation once the developmental pathologies are established can reverse neuronal abnormalities and seizures. Addressing these issues is crucial with regards to therapeutics since these neurodevelopmental disorders are predominantly diagnosed during childhood, when patients present with symptoms. Here, we report increased phosphorylation of the mTOR effector and translational repressor, 4E-BP1, in patient FMCD tissue and in a mouse model of FMCD. Using temporally regulated conditional gene expression systems, we found that expression of a constitutively active form of 4E-BP1 that resists phosphorylation by mTOR in juvenile mice reduced neuronal cytomegaly and corrected several neuronal electrophysiological alterations, including depolarized resting membrane potential, irregular firing pattern, and aberrant expression of HCN4 channels. Further, 4E-BP1 expression in juvenile FMCD mice after epilepsy onset resulted in improved cortical spectral activity and decreased spontaneous seizure frequency in adults. Overall, our study uncovered a remarkable plasticity of the juvenile brain that facilitates novel therapeutic opportunities to treat FMCD-related epilepsy during childhood with potentially long-lasting effects in adults.
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Affiliation(s)
- Lena H Nguyen
- Department of Neurosurgery, Yale University School of Medicine; New Haven, CT 06510, USA.,Department of Cellular and Molecular Physiology, Yale University School of Medicine; New Haven, CT 06510, USA
| | - Youfen Xu
- Department of Neurosurgery, Yale University School of Medicine; New Haven, CT 06510, USA
| | - Travorn Mahadeo
- Department of Neurosurgery, Yale University School of Medicine; New Haven, CT 06510, USA
| | - Longbo Zhang
- Department of Neurosurgery, Yale University School of Medicine; New Haven, CT 06510, USA
| | - Tiffany V Lin
- Department of Neurosurgery, Yale University School of Medicine; New Haven, CT 06510, USA
| | - Heather A Born
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital; Houston, TX 77030, USA.,Department of Pediatrics, Baylor College of Medicine; Houston, TX 77030, USA
| | - Anne E Anderson
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital; Houston, TX 77030, USA.,Department of Pediatrics, Baylor College of Medicine; Houston, TX 77030, USA
| | - Angélique Bordey
- Department of Neurosurgery, Yale University School of Medicine; New Haven, CT 06510, USA.,Department of Cellular and Molecular Physiology, Yale University School of Medicine; New Haven, CT 06510, USA
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2
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Puig B, Yang D, Brenna S, Altmeppen HC, Magnus T. Show Me Your Friends and I Tell You Who You Are: The Many Facets of Prion Protein in Stroke. Cells 2020; 9:E1609. [PMID: 32630841 PMCID: PMC7407975 DOI: 10.3390/cells9071609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 12/12/2022] Open
Abstract
Ischemic stroke belongs to the leading causes of mortality and disability worldwide. Although treatments for the acute phase of stroke are available, not all patients are eligible. There is a need to search for therapeutic options to promote neurological recovery after stroke. The cellular prion protein (PrPC) has been consistently linked to a neuroprotective role after ischemic damage: it is upregulated in the penumbra area following stroke in humans, and animal models of stroke have shown that lack of PrPC aggravates the ischemic damage and lessens the functional outcome. Mechanistically, these effects can be linked to numerous functions attributed to PrPC: (1) as a signaling partner of the PI3K/Akt and MAPK pathways, (2) as a regulator of glutamate receptors, and (3) promoting stem cell homing mechanisms, leading to angio- and neurogenesis. PrPC can be cleaved at different sites and the proteolytic fragments can account for the manifold functions. Moreover, PrPC is present on extracellular vesicles (EVs), released membrane particles originating from all types of cells that have drawn attention as potential therapeutic tools in stroke and many other diseases. Thus, identification of the many mechanisms underlying PrPC-induced neuroprotection will not only provide further understanding of the physiological functions of PrPC but also new ideas for possible treatment options after ischemic stroke.
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Affiliation(s)
- Berta Puig
- Neurology Department, Experimental Research in Stroke and Inflammation (ERSI), University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (D.Y.); (S.B.); (T.M.)
| | - Denise Yang
- Neurology Department, Experimental Research in Stroke and Inflammation (ERSI), University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (D.Y.); (S.B.); (T.M.)
| | - Santra Brenna
- Neurology Department, Experimental Research in Stroke and Inflammation (ERSI), University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (D.Y.); (S.B.); (T.M.)
| | | | - Tim Magnus
- Neurology Department, Experimental Research in Stroke and Inflammation (ERSI), University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (D.Y.); (S.B.); (T.M.)
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3
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Del Pino I, Tocco C, Magrinelli E, Marcantoni A, Ferraguto C, Tomagra G, Bertacchi M, Alfano C, Leinekugel X, Frick A, Studer M. COUP-TFI/Nr2f1 Orchestrates Intrinsic Neuronal Activity during Development of the Somatosensory Cortex. Cereb Cortex 2020; 30:5667-5685. [DOI: 10.1093/cercor/bhaa137] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/17/2020] [Accepted: 04/29/2020] [Indexed: 01/19/2023] Open
Abstract
Abstract
The formation of functional cortical maps in the cerebral cortex results from a timely regulated interaction between intrinsic genetic mechanisms and electrical activity. To understand how transcriptional regulation influences network activity and neuronal excitability within the neocortex, we used mice deficient for Nr2f1 (also known as COUP-TFI), a key determinant of primary somatosensory (S1) area specification during development. We found that the cortical loss of Nr2f1 impacts on spontaneous network activity and synchronization of S1 cortex at perinatal stages. In addition, we observed alterations in the intrinsic excitability and morphological features of layer V pyramidal neurons. Accordingly, we identified distinct voltage-gated ion channels regulated by Nr2f1 that might directly influence intrinsic bioelectrical properties during critical time windows of S1 cortex specification. Altogether, our data suggest a tight link between Nr2f1 and neuronal excitability in the developmental sequence that ultimately sculpts the emergence of cortical network activity within the immature neocortex.
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Affiliation(s)
- Isabel Del Pino
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
- Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
| | - Chiara Tocco
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
| | - Elia Magrinelli
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
- Département des Neurosciences Fondamentales, Université de Lausanne, CH-1005 Lausanne, Switzerland
| | - Andrea Marcantoni
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, 10125 Torino, Italy
| | | | - Giulia Tomagra
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, 10125 Torino, Italy
| | | | | | - Xavier Leinekugel
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Andreas Frick
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Michèle Studer
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
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4
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Bedbrook CN, Yang KK, Robinson JE, Mackey ED, Gradinaru V, Arnold FH. Machine learning-guided channelrhodopsin engineering enables minimally invasive optogenetics. Nat Methods 2019; 16:1176-1184. [PMID: 31611694 PMCID: PMC6858556 DOI: 10.1038/s41592-019-0583-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 08/22/2019] [Indexed: 12/13/2022]
Abstract
We engineered light-gated channelrhodopsins (ChRs) whose current strength and light sensitivity enable minimally-invasive neuronal circuit interrogation. Current ChR tools applied to the mammalian brain require intracranial surgery for transgene delivery and implantation of invasive fiber-optic cables to produce light-dependent activation of a small volume of tissue. To facilitate expansive optogenetics without the need for invasive implants, our engineering approach leverages the significant literature of ChR variants to train statistical models for the design of new, high-performance ChRs. With Gaussian Process models trained on a limited experimental set of 102 functionally characterized ChRs, we designed high-photocurrent ChRs with unprecedented light sensitivity; three of these, ChRger1–3, enable optogenetic activation of the nervous system via minimally-invasive systemic transgene delivery, not possible previously due to low per-cell transgene copy produced by systemic delivery. ChRger2 enables light-induced neuronal excitation without invasive intracranial surgery for virus delivery or fiber optic implantation, i.e. enables minimally-invasive optogenetics.
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Affiliation(s)
- Claire N Bedbrook
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Kevin K Yang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - J Elliott Robinson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Elisha D Mackey
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
| | - Frances H Arnold
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA. .,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
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5
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Junctophilin Proteins Tether a Cav1-RyR2-KCa3.1 Tripartite Complex to Regulate Neuronal Excitability. Cell Rep 2019; 28:2427-2442.e6. [DOI: 10.1016/j.celrep.2019.07.075] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/20/2019] [Accepted: 07/19/2019] [Indexed: 12/12/2022] Open
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6
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Acutely elevated O-GlcNAcylation suppresses hippocampal activity by modulating both intrinsic and synaptic excitability factors. Sci Rep 2019; 9:7287. [PMID: 31086206 PMCID: PMC6514166 DOI: 10.1038/s41598-019-43017-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/05/2019] [Indexed: 12/13/2022] Open
Abstract
Post-translational modification (PTM) plays a critical role in increasing proteome complexity and diversifying protein functions. O-GlcNAc modification is a reversible, dynamic and highly abundant PTM catalyzed by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), regardless of substrates. The two enzymes are particularly enriched in the brain, and recent proteomic studies identified that a large number of neuron-specific proteins undergo O-GlcNAc modification. In addition, pathological conditions with aberrant O-GlcNAcylation such as diabetes and obesity are associated with the higher risk of cognitive decline and memory impairment. However, despite its prevalence in the brain, functional significance of O-GlcNAcylation in regulating neuronal properties remains unclear at the molecular level. Here, we report that an acute increase in O-GlcNAcylation induced by pharmacological inhibition of OGA significantly reduces the intrinsic excitability of hippocampal CA1 neurons through the cooperative modulation of multiple voltage-gated ion channels. Moreover, elevated O-GlcNAcylation also suppresses excitatory synaptic transmission at Schaffer collateral-CA1 synapses through the removal of GluA2-containing AMPA receptors from postsynaptic densities. Collectively, our findings demonstrate that a change in O-GlcNAcylation levels dynamically regulates hippocampal activity at both intrinsic and synaptic levels, providing a mechanistic link between dysregulated O-GlcNAcylation and hippocampal dysfunction.
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7
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Luo P, He G, Liu D. HCN channels: New targets for the design of an antidepressant with rapid effects. J Affect Disord 2019; 245:764-770. [PMID: 30448761 DOI: 10.1016/j.jad.2018.11.081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 10/22/2018] [Accepted: 11/11/2018] [Indexed: 12/18/2022]
Abstract
BACKGROUND Major depressive disorder (MDD) is a prevalent neuropsychiatric disease that carries a staggering global burden. Although numerous antidepressants are available on the market, unfortunately, many patients die by committing suicide as a result of the therapeutic lag between treatment initiation and the improvement of depressive symptoms. This therapeutic lag highlights the need for new antidepressants that provide rapid relief of depressive symptoms. METHOD In this review, we discuss the seminal researches on hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in animal models of depression and highlight the substantial evidence supporting the development of rapid-acting antidepressants targeting HCN channels. RESULTS HCN channels are associated with the risk of depression and targeting HCN channels or its auxiliary subunit tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b) function may exert a rapid antidepressant-like effect. CONCLUSIONS Compounds acting on HCN subunits or the TRIP8b-HCN interaction site may be excellent candidates for development into effective drugs with rapid antidepressant action.
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Affiliation(s)
- Pan Luo
- Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - GuoFang He
- Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Dong Liu
- Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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8
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Guarina L, Calorio C, Gavello D, Moreva E, Traina P, Battiato A, Ditalia Tchernij S, Forneris J, Gai M, Picollo F, Olivero P, Genovese M, Carbone E, Marcantoni A, Carabelli V. Nanodiamonds-induced effects on neuronal firing of mouse hippocampal microcircuits. Sci Rep 2018; 8:2221. [PMID: 29396456 PMCID: PMC5797106 DOI: 10.1038/s41598-018-20528-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/11/2018] [Indexed: 01/31/2023] Open
Abstract
Fluorescent nanodiamonds (FND) are carbon-based nanomaterials that can efficiently incorporate optically active photoluminescent centers such as the nitrogen-vacancy complex, thus making them promising candidates as optical biolabels and drug-delivery agents. FNDs exhibit bright fluorescence without photobleaching combined with high uptake rate and low cytotoxicity. Focusing on FNDs interference with neuronal function, here we examined their effect on cultured hippocampal neurons, monitoring the whole network development as well as the electrophysiological properties of single neurons. We observed that FNDs drastically decreased the frequency of inhibitory (from 1.81 Hz to 0.86 Hz) and excitatory (from 1.61 to 0.68 Hz) miniature postsynaptic currents, and consistently reduced action potential (AP) firing frequency (by 36%), as measured by microelectrode arrays. On the contrary, bursts synchronization was preserved, as well as the amplitude of spontaneous inhibitory and excitatory events. Current-clamp recordings revealed that the ratio of neurons responding with AP trains of high-frequency (fast-spiking) versus neurons responding with trains of low-frequency (slow-spiking) was unaltered, suggesting that FNDs exerted a comparable action on neuronal subpopulations. At the single cell level, rapid onset of the somatic AP (“kink”) was drastically reduced in FND-treated neurons, suggesting a reduced contribution of axonal and dendritic components while preserving neuronal excitability.
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Affiliation(s)
- L Guarina
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - C Calorio
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - D Gavello
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - E Moreva
- Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135, Torino, Italy
| | - P Traina
- Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135, Torino, Italy
| | - A Battiato
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - S Ditalia Tchernij
- Department of Physics and "NIS" inter-departmental centre, University of Torino, Via P. Giuria 1, 10125, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - J Forneris
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - M Gai
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Torino, Italy
| | - F Picollo
- Department of Physics and "NIS" inter-departmental centre, University of Torino, Via P. Giuria 1, 10125, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - P Olivero
- Department of Physics and "NIS" inter-departmental centre, University of Torino, Via P. Giuria 1, 10125, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - M Genovese
- Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - E Carbone
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - A Marcantoni
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - V Carabelli
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy.
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9
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Activity-Dependent Facilitation of Ca V1.3 Calcium Channels Promotes KCa3.1 Activation in Hippocampal Neurons. J Neurosci 2017; 37:11255-11270. [PMID: 29038242 DOI: 10.1523/jneurosci.0967-17.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 10/02/2017] [Accepted: 10/07/2017] [Indexed: 11/21/2022] Open
Abstract
CaV1 L-type calcium channels are key to regulating neuronal excitability, with the range of functional roles enhanced by interactions with calmodulin, accessory proteins, or CaMKII that modulate channel activity. In hippocampal pyramidal cells, a prominent elevation of CaV1 activity is apparent in late channel openings that can last for seconds following a depolarizing stimulus train. The current study tested the hypothesis that a reported interaction among CaV1.3 channels, the scaffolding protein densin, and CaMKII could generate a facilitation of channel activity that outlasts a depolarizing stimulus. We found that CaV1.3 but not CaV1.2 channels exhibit a long-duration calcium-dependent facilitation (L-CDF) that lasts up to 8 s following a brief 50 Hz stimulus train, but only when coexpressed with densin and CaMKII. To test the physiological role for CaV1.3 L-CDF, we coexpressed the intermediate-conductance KCa3.1 potassium channel, revealing a strong functional coupling to CaV1.3 channel activity that was accentuated by densin and CaMKII. Moreover, the CaV1.3-densin-CaMKII interaction gave rise to an outward tail current of up to 8 s duration following a depolarizing stimulus in both tsA-201 cells and male rat CA1 pyramidal cells. A slow afterhyperpolarization in pyramidal cells was reduced by a selective block of CaV1 channels by isradipine, a CaMKII blocker, and siRNA knockdown of densin, and spike frequency increased upon selective block of CaV1 channel conductance. The results are important in revealing a CaV1.3-densin-CaMKII interaction that extends the contribution of CaV1.3 calcium influx to a time frame well beyond a brief input train.SIGNIFICANCE STATEMENT CaV1 L-type calcium channels play a key role in regulating the output of central neurons by providing calcium influx during repetitive inputs. This study identifies a long-duration calcium-dependent facilitation (L-CDF) of CaV1.3 channels that depends on the scaffolding protein densin and CaMKII and that outlasts a depolarizing stimulus by seconds. We further show a tight functional coupling between CaV1.3 calcium influx and the intermediate-conductance KCa3.1 potassium channel that promotes an outward tail current of up to 8 s following a depolarizing stimulus. Tests in CA1 hippocampal pyramidal cells reveal that a slow AHP is reduced by blocking different components of the CaV1.3-densin-CaMKII interaction, identifying an important role for CaV1.3 L-CDF in regulating neuronal excitability.
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10
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De Mario A, Peggion C, Massimino ML, Viviani F, Castellani A, Giacomello M, Lim D, Bertoli A, Sorgato MC. The prion protein regulates glutamate-mediated Ca 2+ entry and mitochondrial Ca 2+ accumulation in neurons. J Cell Sci 2017; 130:2736-2746. [PMID: 28701513 DOI: 10.1242/jcs.196972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 07/05/2017] [Indexed: 01/01/2023] Open
Abstract
The cellular prion protein (PrPC) whose conformational misfolding leads to the production of deadly prions, has a still-unclarified cellular function despite decades of intensive research. Following our recent finding that PrPC limits Ca2+ entry via store-operated Ca2+ channels in neurons, we investigated whether the protein could also control the activity of ionotropic glutamate receptors (iGluRs). To this end, we compared local Ca2+ movements in primary cerebellar granule neurons and cortical neurons transduced with genetically encoded Ca2+ probes and expressing, or not expressing, PrPC Our investigation demonstrated that PrPC downregulates Ca2+ entry through each specific agonist-stimulated iGluR and after stimulation by glutamate. We found that, although PrP-knockout (KO) mitochondria were displaced from the plasma membrane, glutamate addition resulted in a higher mitochondrial Ca2+ uptake in PrP-KO neurons than in their PrPC-expressing counterpart. This was because the increased Ca2+ entry through iGluRs in PrP-KO neurons led to a parallel increase in Ca2+-induced Ca2+ release via ryanodine receptor channels. These data thus suggest that PrPC takes part in the cell apparatus controlling Ca2+ homeostasis, and that PrPC is involved in protecting neurons from toxic Ca2+ overloads.
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Affiliation(s)
- Agnese De Mario
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Caterina Peggion
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Maria Lina Massimino
- CNR Neuroscience Institute, Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Francesca Viviani
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Angela Castellani
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Marta Giacomello
- Department of Biology, University of Padova, 35131 Padova, Italy
| | - Dmitry Lim
- Department of Pharmaceutical Science, University of Piemonte Orientale, 28100 Novara, Italy
| | - Alessandro Bertoli
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Maria Catia Sorgato
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy .,CNR Neuroscience Institute, Department of Biomedical Science, University of Padova, 35131 Padova, Italy
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11
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Peggion C, Bertoli A, Sorgato MC. Almost a century of prion protein(s): From pathology to physiology, and back to pathology. Biochem Biophys Res Commun 2016; 483:1148-1155. [PMID: 27581199 DOI: 10.1016/j.bbrc.2016.07.118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 07/27/2016] [Indexed: 12/30/2022]
Abstract
Prions are one of the few pathogens whose name is renowned at all population levels, after the dramatic years pervaded by the fear of eating prion-infected food. If now this, somehow irrational, scare of bovine meat inexorably transmitting devastating brain disorders is largely subdued, several prion-related issues are still unsolved, precluding the design of therapeutic approaches that could slow, if not halt, prion diseases. One unsolved issue is, for example, the role of the prion protein (PrPC), whole conformational misfolding originates the prion but whose physiologic reason d'etre in neurons, and in cells at large, remains enigmatic. Preceded by a historical outline, the present review will discuss the functional pleiotropicity ascribed to PrPC, and whether this aspect could fall, at least in part, into a more concise framework. It will also be devoted to radically different perspectives for PrPC, which have been recently brought to the attention of the scientific world with unexpected force. Finally, it will discuss the possible reasons allowing an evolutionary conserved and benign protein, as PrPC is, to turn into a high affinity receptor for pathologic misfolded oligomers, and to transmit their toxic message into neurons.
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Affiliation(s)
- Caterina Peggion
- Department of Biomedical Sciences, University of Padova, Via Bassi 58/B, 35131 Padova, Italy.
| | - Alessandro Bertoli
- Department of Biomedical Sciences, University of Padova, Via Bassi 58/B, 35131 Padova, Italy
| | - M Catia Sorgato
- Department of Biomedical Sciences, University of Padova, Via Bassi 58/B, 35131 Padova, Italy; C.N.R. Institute of Neuroscience, University of Padova, Via Bassi 58/B, 35131 Padova, Italy.
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