1
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Vierra NC. Compartmentalized signaling in the soma: Coordination of electrical and protein kinase A signaling at neuronal ER-plasma membrane junctions. Bioessays 2024:e2400126. [PMID: 39268818 DOI: 10.1002/bies.202400126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 08/22/2024] [Accepted: 08/26/2024] [Indexed: 09/15/2024]
Abstract
Neuronal information processing depends on converting membrane depolarizations into compartmentalized biochemical signals that can modify neuronal activity and structure. However, our understanding of how neurons translate electrical signals into specific biochemical responses remains limited, especially in the soma where gene expression and ion channel function are crucial for neuronal activity. Here, I emphasize the importance of physically compartmentalizing action potential-triggered biochemical reactions within the soma. Emerging evidence suggests that somatic endoplasmic reticulum-plasma membrane (ER-PM) junctions are specialized organelles that coordinate electrical and biochemical signaling. The juxtaposition of ion channels and signaling proteins at a prominent subset of these sites enables compartmentalized calcium and cAMP-dependent protein kinase (PKA) signaling. I explore the hypothesis that these PKA-containing ER-PM junctions serve as critical sites for translating membrane depolarizations into PKA signals and identify key gaps in knowledge of the assembly, regulation, and neurobiological functions of this somatic signaling system.
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Affiliation(s)
- Nicholas C Vierra
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA
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2
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LeBlang CJ, Pazyra-Murphy MF, Silagi ES, Dasgupta S, Tsolias M, Miller T, Petrova V, Zhen S, Jovanovic V, Castellano D, Gerrish K, Ormanoglu P, Tristan C, Singeç I, Woolf CJ, Tasdemir-Yilmaz O, Segal RA. Satellite glial contact enhances differentiation and maturation of human iPSC-derived sensory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.24.604966. [PMID: 39211268 PMCID: PMC11361066 DOI: 10.1101/2024.07.24.604966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Sensory neurons generated from induced pluripotent stem cells (iSNs) are used to model human peripheral neuropathies, however current differentiation protocols produce sensory neurons with an embryonic phenotype. Peripheral glial cells contact sensory neurons early in development and contribute to formation of the canonical pseudounipolar morphology, but these signals are not encompassed in current iSN differentiation protocols. Here, we show that terminal differentiation of iSNs in co-culture with rodent Dorsal Root Ganglion satellite glia (rSG) advances their differentiation and maturation. Co-cultured iSNs develop a pseudounipolar morphology through contact with rSGs. This transition depends on semaphorin-plexin guidance cues and on glial gap junction signaling. In addition to morphological changes, iSNs terminally differentiated in co-culture exhibit enhanced spontaneous action potential firing, more mature gene expression, and increased susceptibility to paclitaxel induced axonal degeneration. Thus, iSNs differentiated in coculture with rSGs provide a better model for investigating human peripheral neuropathies.
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3
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Sahu M, Ganguly M, Sharma P. Role of silver nanoparticles and silver nanoclusters for the detection and removal of Hg(ii). RSC Adv 2024; 14:22374-22392. [PMID: 39010928 PMCID: PMC11247438 DOI: 10.1039/d4ra04182h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 07/08/2024] [Indexed: 07/17/2024] Open
Abstract
Silver metal, being a 3d transition metal in group 11 in the periodic table, is widely used in material science for its distinguished plasmonic properties. Nanoparticles (NPs) and nanoclusters (NCs) are widely used in sensing applications having a surface plasmon band and emissive properties, respectively. Mercury is one of the detrimental toxins and threats to various ecosystems. The distinction between nanoparticles and nanoclusters, the utility and toxicity of heavy metal mercury, fluorometric and colorimetric approaches to the recognition of mercury ions with NPs and NCs, the mechanism of detection, spot detection, and natural water sample analyses were illustrated in detail in this review article. Moreover, the sensing platform and analyte (Hg2+) fate were described for substantiating the mechanism. It was observed that NCs are mostly utilized for fluorometric approaches, while NPs are mostly employed for colorimetric approaches. Fluorometric detection is mainly quenching-based. However, sensing with enhancement was found in a few reports. Adulteration of other metals with silver particles often modifies the sensing platform.
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Affiliation(s)
- Mamta Sahu
- Department of Chemistry, Manipal University Jaipur Dehmi Kalan Jaipur 303007 Rajasthan India
| | - Mainak Ganguly
- Department of Chemistry, Manipal University Jaipur Dehmi Kalan Jaipur 303007 Rajasthan India
| | - Priyanka Sharma
- Department of Chemistry, Manipal University Jaipur Dehmi Kalan Jaipur 303007 Rajasthan India
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4
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Martínez-Camarena Á, Bellia F, Paz Clares M, Vecchio G, Nicolas J, García-España E. Polymeric Nanozyme with SOD Activity Capable of Inhibiting Self- and Metal-Induced α-Synuclein Aggregation. Chemistry 2024; 30:e202401331. [PMID: 38687026 DOI: 10.1002/chem.202401331] [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: 04/03/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/02/2024]
Abstract
Despite decades of research, Parkinson's disease is still an idiopathic pathology for which no cure has yet been found. This is partly explained by the multifactorial character of most neurodegenerative syndromes, whose generation involves multiple pathogenic factors. In Parkinson's disease, two of the most important ones are the aggregation of α-synuclein and oxidative stress. In this work, we address both issues by synthesizing a multifunctional nanozyme based on grafting a pyridinophane ligand that can strongly coordinate CuII, onto biodegradable PEGylated polyester nanoparticles. The resulting nanozyme exhibits remarkable superoxide dismutase activity together with the ability to inhibit the self-induced aggregation of α-synuclein into amyloid-type fibrils. Furthermore, the combination of the chelator and the polymer produces a cooperative effect whereby the resulting nanozyme can also halve CuII-induced α-synuclein aggregation.
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Affiliation(s)
- Álvaro Martínez-Camarena
- ICMol, Departament de Química Inorgànica, Universitat de València, C/Catedrático José Beltrán 2, Paterna, 46980, Spain
- Institut Galien Paris-Saclay, CNRS, Université Paris-Saclay, Orsay, 91400, France
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, Catania, 95125, Italy
- MatMoPol Research Group, Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, Madrid, 28040, Spain
| | - Francesco Bellia
- Istituto di Cristallografia, CNR, P. Gaifami 18, Catania, 95126, Italy
| | - M Paz Clares
- ICMol, Departament de Química Inorgànica, Universitat de València, C/Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Graziella Vecchio
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, Catania, 95125, Italy
| | - Julien Nicolas
- Institut Galien Paris-Saclay, CNRS, Université Paris-Saclay, Orsay, 91400, France
| | - Enrique García-España
- ICMol, Departament de Química Inorgànica, Universitat de València, C/Catedrático José Beltrán 2, Paterna, 46980, Spain
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5
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Raja R, Dumontier E, Phen A, Cloutier JF. Insertion of a neomycin selection cassette in the Amigo1 locus alters gene expression in the olfactory epithelium leading to region-specific defects in olfactory receptor neuron development. Genesis 2024; 62:e23594. [PMID: 38590146 DOI: 10.1002/dvg.23594] [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: 12/04/2023] [Revised: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 04/10/2024]
Abstract
During development of the nervous system, neurons connect to one another in a precisely organized manner. Sensory systems provide a good example of this organization, whereby the composition of the outside world is represented in the brain by neuronal maps. Establishing correct patterns of neural circuitry is crucial, as inaccurate map formation can lead to severe disruptions in sensory processing. In rodents, olfactory stimuli modulate a wide variety of behaviors essential for survival. The formation of the olfactory glomerular map is dependent on molecular cues that guide olfactory receptor neuron axons to broad regions of the olfactory bulb and on cell adhesion molecules that promote axonal sorting into specific synaptic units in this structure. Here, we demonstrate that the cell adhesion molecule Amigo1 is expressed in a subpopulation of olfactory receptor neurons, and we investigate its role in the precise targeting of olfactory receptor neuron axons to the olfactory bulb using a genetic loss-of-function approach in mice. While ablation of Amigo1 did not lead to alterations in olfactory sensory neuron axonal targeting, our experiments revealed that the presence of a neomycin resistance selection cassette in the Amigo1 locus can lead to off-target effects that are not due to loss of Amigo1 expression, including unexpected altered gene expression in olfactory receptor neurons and reduced glomerular size in the ventral region of the olfactory bulb. Our results demonstrate that insertion of a neomycin selection cassette into the mouse genome can have specific deleterious effects on the development of the olfactory system and highlight the importance of removing antibiotic resistance cassettes from genetic loss-of-function mouse models when studying olfactory system development.
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Affiliation(s)
- Reesha Raja
- The Neuro (Montreal Neurological Institute-Hospital), Montréal, Québec, Canada
- Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
| | - Emilie Dumontier
- The Neuro (Montreal Neurological Institute-Hospital), Montréal, Québec, Canada
| | - Alina Phen
- The Neuro (Montreal Neurological Institute-Hospital), Montréal, Québec, Canada
| | - Jean-François Cloutier
- The Neuro (Montreal Neurological Institute-Hospital), Montréal, Québec, Canada
- Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
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6
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Stewart RG, Camacena M, Copits BA, Sack JT. Distinct cellular expression and subcellular localization of Kv2 voltage-gated K + channel subtypes in dorsal root ganglion neurons conserved between mice and humans. J Comp Neurol 2024; 532:e25575. [PMID: 38335058 PMCID: PMC10861167 DOI: 10.1002/cne.25575] [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: 03/02/2023] [Revised: 08/07/2023] [Accepted: 10/03/2023] [Indexed: 02/12/2024]
Abstract
The distinct organization of Kv2 voltage-gated potassium channels on and near the cell body of brain neurons enables their regulation of action potentials and specialized membrane contact sites. Somatosensory neurons have a pseudounipolar morphology and transmit action potentials from peripheral nerve endings through axons that bifurcate to the spinal cord and the cell body within ganglia including the dorsal root ganglia (DRG). Kv2 channels regulate action potentials in somatosensory neurons, yet little is known about where Kv2 channels are located. Here, we define the cellular and subcellular localization of the Kv2 paralogs, Kv2.1 and Kv2.2, in DRG somatosensory neurons with a panel of antibodies, cell markers, and genetically modified mice. We find that relative to spinal cord neurons, DRG neurons have similar levels of detectable Kv2.1 and higher levels of Kv2.2. In older mice, detectable Kv2.2 remains similar, while detectable Kv2.1 decreases. Both Kv2 subtypes adopt clustered subcellular patterns that are distinct from central neurons. Most DRG neurons co-express Kv2.1 and Kv2.2, although neuron subpopulations show preferential expression of Kv2.1 or Kv2.2. We find that Kv2 protein expression and subcellular localization are similar between mouse and human DRG neurons. We conclude that the organization of both Kv2 channels is consistent with physiological roles in the somata and stem axons of DRG neurons. The general prevalence of Kv2.2 in DRG as compared to central neurons and the enrichment of Kv2.2 relative to detectable Kv2.1 in older mice, proprioceptors, and axons suggest more widespread roles for Kv2.2 in DRG neurons.
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Affiliation(s)
- Robert G Stewart
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, California, USA
| | - Miriam Camacena
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, California, USA
| | - Bryan A Copits
- Washington University Pain Center, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, California, USA
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, California, USA
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7
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Ferns M, van der List D, Vierra NC, Lacey T, Murray K, Kirmiz M, Stewart RG, Sack JT, Trimmer JS. Electrically silent KvS subunits associate with native Kv2 channels in brain and impact diverse properties of channel function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.577135. [PMID: 38328147 PMCID: PMC10849721 DOI: 10.1101/2024.01.25.577135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Voltage-gated K+ channels of the Kv2 family are highly expressed in brain and play dual roles in regulating neuronal excitability and in organizing endoplasmic reticulum - plasma membrane (ER-PM) junctions. Studies in heterologous cells suggest that the two pore-forming alpha subunits Kv2.1 and Kv2.2 assemble with "electrically silent" KvS subunits to form heterotetrameric channels with distinct biophysical properties. Here, using mass spectrometry-based proteomics, we identified five KvS subunits as components of native Kv2.1 channels immunopurified from mouse brain, the most abundant being Kv5.1. We found that Kv5.1 co-immunoprecipitates with Kv2.1 and to a lesser extent with Kv2.2 from brain lysates, and that Kv5.1 protein levels are decreased by 70% in Kv2.1 knockout mice and 95% in Kv2.1/2.2 double knockout mice. Multiplex immunofluorescent labelling of rodent brain sections revealed that in neocortex Kv5.1 immunolabeling is apparent in a large percentage of Kv2.1 and Kv2.2-positive layer 2/3 neurons, and in a smaller percentage of layer 5 and 6 neurons. At the subcellular level, Kv5.1 is co-clustered with Kv2.1 and Kv2.2 at ER-PM junctions in cortical neurons, although clustering of Kv5.1-containing channels is reduced relative to homomeric Kv2 channels. We also found that in heterologous cells coexpression with Kv5.1 reduces the clustering and alters the pharmacological properties of Kv2.1 channels. Together, these findings demonstrate that the Kv5.1 electrically silent subunit is a component of a substantial fraction of native brain Kv2 channels, and that its incorporation into heteromeric channels can impact diverse aspects of Kv2 channel function.
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Affiliation(s)
- Michael Ferns
- Dept. of Anesthesiology and Pain Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Deborah van der List
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Nicholas C. Vierra
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Taylor Lacey
- Dept. of Anesthesiology and Pain Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Karl Murray
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Dept. of Psychiatry and Behavioral Sciences, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Michael Kirmiz
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Robert G. Stewart
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Jon T. Sack
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - James S. Trimmer
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
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8
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Stewart RG, Camacena M, Copits BA, Sack JT. Distinct cellular expression and subcellular localization of Kv2 voltage-gated K + channel subtypes in dorsal root ganglion neurons conserved between mice and humans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.530679. [PMID: 38187582 PMCID: PMC10769185 DOI: 10.1101/2023.03.01.530679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The distinct organization of Kv2 voltage-gated potassium channels on and near the cell body of brain neurons enables their regulation of action potentials and specialized membrane contact sites. Somatosensory neurons have a pseudounipolar morphology and transmit action potentials from peripheral nerve endings through axons that bifurcate to the spinal cord and the cell body within ganglia including the dorsal root ganglia (DRG). Kv2 channels regulate action potentials in somatosensory neurons, yet little is known about where Kv2 channels are located. Here we define the cellular and subcellular localization of the Kv2 paralogs, Kv2.1 and Kv2.2, in DRG somatosensory neurons with a panel of antibodies, cell markers, and genetically modified mice. We find that relative to spinal cord neurons, DRG neurons have similar levels of detectable Kv2.1, and higher levels of Kv2.2. In older mice, detectable Kv2.2 remains similar while detectable Kv2.1 decreases. Both Kv2 subtypes adopt clustered subcellular patterns that are distinct from central neurons. Most DRG neurons co-express Kv2.1 and Kv2.2, although neuron subpopulations show preferential expression of Kv2.1 or Kv2.2. We find that Kv2 protein expression and subcellular localization is similar between mouse and human DRG neurons. We conclude that the organization of both Kv2 channels is consistent with physiological roles in the somata and stem axons of DRG neurons. The general prevalence of Kv2.2 in DRG as compared to central neurons and the enrichment of Kv2.2 relative to detectable Kv2.1, in older mice, proprioceptors, and axons suggest more widespread roles for Kv2.2 in DRG neurons.
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Affiliation(s)
- Robert G Stewart
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
| | - Miriam Camacena
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
| | - Bryan A Copits
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
- Department of Anesthesiology and Pain Medicine, University of California Davis, Davis, CA 95616, USA
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9
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Madhwani KR, Sayied S, Ogata CH, Hogan CA, Lentini JM, Mallik M, Dumouchel JL, Storkebaum E, Fu D, O’Connor-Giles KM. tRNA modification enzyme-dependent redox homeostasis regulates synapse formation and memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.566895. [PMID: 38014328 PMCID: PMC10680711 DOI: 10.1101/2023.11.14.566895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Post-transcriptional modification of RNA regulates gene expression at multiple levels. ALKBH8 is a tRNA modifying enzyme that methylates wobble uridines in specific tRNAs to modulate translation. Through methylation of tRNA-selenocysteine, ALKBH8 promotes selenoprotein synthesis and regulates redox homeostasis. Pathogenic variants in ALKBH8 have been linked to intellectual disability disorders in the human population, but the role of ALKBH8 in the nervous system is unknown. Through in vivo studies in Drosophila, we show that ALKBH8 controls oxidative stress in the brain to restrain synaptic growth and support learning and memory. ALKBH8 null animals lack wobble uridine methylation and exhibit a global reduction in protein synthesis, including a specific decrease in selenoprotein levels. Loss of ALKBH8 or independent disruption of selenoprotein synthesis results in ectopic synapse formation. Genetic expression of antioxidant enzymes fully suppresses synaptic overgrowth in ALKBH8 null animals, confirming oxidative stress as the underlying cause of dysregulation. ALKBH8 animals also exhibit associative learning and memory impairments that are reversed by pharmacological antioxidant treatment. Together, these findings demonstrate the critical role of tRNA modification in redox homeostasis in the nervous system and reveal antioxidants as a potential therapy for ALKBH8-associated intellectual disability.
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Affiliation(s)
| | - Shanzeh Sayied
- Department of Neuroscience, Brown University, Providence, RI, USA
| | | | - Caley A. Hogan
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Jenna M. Lentini
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, NY, USA
| | - Moushami Mallik
- Molecular Neurobiology Laboratory, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, NL
| | | | - Erik Storkebaum
- Molecular Neurobiology Laboratory, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, NL
| | - Dragony Fu
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, NY, USA
| | - Kate M. O’Connor-Giles
- Department of Neuroscience, Brown University, Providence, RI, USA
- Carney Institute for Brain Sciences, Brown University, Providence, RI, USA
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10
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Whitebirch AC, Santoro B, Barnett A, Lisgaras CP, Scharfman HE, Siegelbaum SA. Reduced Cholecystokinin-Expressing Interneuron Input Contributes to Disinhibition of the Hippocampal CA2 Region in a Mouse Model of Temporal Lobe Epilepsy. J Neurosci 2023; 43:6930-6949. [PMID: 37643861 PMCID: PMC10573827 DOI: 10.1523/jneurosci.2091-22.2023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 08/04/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023] Open
Abstract
A significant proportion of temporal lobe epilepsy (TLE) patients experience drug-resistant seizures associated with mesial temporal sclerosis, in which there is extensive cell loss in the hippocampal CA1 and CA3 subfields, with a relative sparing of dentate gyrus granule cells and CA2 pyramidal neurons (PNs). A role for CA2 in seizure generation was suggested based on findings of a reduction in CA2 synaptic inhibition (Williamson and Spencer, 1994) and the presence of interictal-like spike activity in CA2 in resected hippocampal tissue from TLE patients (Wittner et al., 2009). We recently found that in the pilocarpine-induced status epilepticus (PILO-SE) mouse model of TLE there was an increase in CA2 intrinsic excitability associated with a loss of CA2 synaptic inhibition. Furthermore, chemogenetic silencing of CA2 significantly reduced seizure frequency, consistent with a role of CA2 in promoting seizure generation and/or propagation (Whitebirch et al., 2022). In the present study, we explored the cellular basis of this inhibitory deficit using immunohistochemical and electrophysiological approaches in PILO-SE male and female mice. We report a widespread decrease in the density of pro-cholecystokinin-immunopositive (CCK+) interneurons and a functional impairment of CCK+ interneuron-mediated inhibition of CA2 PNs. We also found a disruption in the perisomatic perineuronal net in the CA2 stratum pyramidale. Such pathologic alterations may contribute to an enhanced excitation of CA2 PNs and CA2-dependent seizure activity in the PILO-SE mouse model.SIGNIFICANCE STATEMENT Impaired synaptic inhibition in hippocampal circuits has been identified as a key feature that contributes to the emergence and propagation of seizure activity in human patients and animal models of temporal lobe epilepsy (TLE). Among the hippocampal subfields, the CA2 region is particularly resilient to seizure-associated neurodegeneration and has been suggested to play a key role in seizure activity in TLE. Here we report that perisomatic inhibition of CA2 pyramidal neurons mediated by cholecystokinin-expressing interneurons is selectively reduced in acute hippocampal slices from epileptic mice. Parvalbumin-expressing interneurons, in contrast, appear relatively conserved in epileptic mice. These findings advance our understanding of the cellular mechanisms underlying inhibitory disruption in hippocampal circuits in a mouse model of spontaneous recurring seizures.
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Affiliation(s)
- Alexander C Whitebirch
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
| | - Bina Santoro
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
| | - Anastasia Barnett
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
| | - Christos Panagiotis Lisgaras
- Department of Child & Adolescent Psychiatry, New York University Langone Health, New York, New York 10016
- Department of Neuroscience & Physiology, New York University Langone Health, New York, New York 10016
- Department of Psychiatry, New York University Langone Health, New York, New York 10016
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962
| | - Helen E Scharfman
- Department of Child & Adolescent Psychiatry, New York University Langone Health, New York, New York 10016
- Department of Neuroscience & Physiology, New York University Langone Health, New York, New York 10016
- Department of Psychiatry, New York University Langone Health, New York, New York 10016
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962
| | - Steven A Siegelbaum
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
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11
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Daily KP, Badr A, Eltobgy M, Estfanous S, Whitham O, Tan MH, Carafice C, Krause K, McNamara A, Hamilton K, Houle S, Gupta S, Gupta GA, Madhu S, Fitzgerald J, Saadey AA, Laster B, Yan P, Webb A, Zhang X, Pietrzak M, Kokiko-Cochran ON, Ghoneim HE, Amer AO. DNA hypomethylation promotes the expression of CASPASE-4 which exacerbates neuroinflammation and amyloid-β deposition in Alzheimer's disease The Ohio State University College of Medicine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.30.555526. [PMID: 37693600 PMCID: PMC10491177 DOI: 10.1101/2023.08.30.555526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Alzheimer's Disease (AD) is the 6th leading cause of death in the US. It is established that neuroinflammation contributes to the synaptic loss, neuronal death, and symptomatic decline of AD patients. Accumulating evidence suggests a critical role for microglia, innate immune phagocytes of the brain. For instance, microglia release proinflammatory products such as IL-1β which is highly implicated in AD pathobiology. The mechanisms underlying the transition of microglia to proinflammatory promoters of AD remain largely unknown. To address this gap, we performed Reduced Representation Bisulfite Sequencing (RRBS) to profile global DNA methylation changes in human AD brains compared to no disease controls. We identified differential DNA methylation of CASPASE-4 (CASP4), which when expressed, can be involved in generation of IL-1β and is predominantly expressed in immune cells. DNA upstream of the CASP4 transcription start site was hypomethylated in human AD brains, which was correlated with increased expression of CASP4. Furthermore, microglia from a mouse model of AD (5xFAD) express increased levels of CASP4 compared to wild-type (WT) mice. To study the role of CASP4 in AD, we developed a novel mouse model of AD lacking the mouse ortholog of CASP4, CASP11, which is encoded by mouse Caspase-4 (5xFAD/Casp4-/-). The expression of CASP11 was associated with increased accumulation of pathologic protein aggregate amyloid-β (Aβ) and increased microglial production of IL-1β in 5xFAD mice. Utilizing RNA sequencing, we determined that CASP11 promotes unique transcriptomic phenotypes in 5xFAD mouse brains, including alterations of neuroinflammatory and chemokine signaling pathways. Notably, in vitro, CASP11 promoted generation of IL-1β from macrophages in response to cytosolic Aβ through cleavage of downstream effector Gasdermin D (G SDMD). We describe a role for CASP11 and GSDMD in the generation of IL-1β in response to Aβ and the progression of pathologic inflammation in AD. Overall, our results demonstrate that overexpression of CASP4 due to differential methylation in AD microglia contributes to the progression of AD pathobiology, thus identifying CASP4 as a potential target for immunotherapies for the treatment of AD.
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Affiliation(s)
- Kylene P. Daily
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Asmaa Badr
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Mostafa Eltobgy
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Shady Estfanous
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Owen Whitham
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Michelle H. Tan
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Cierra Carafice
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Kathrin Krause
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | - Andrew McNamara
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Kaitlin Hamilton
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Samuel Houle
- Department of Neuroscience, The Ohio State University, Columbus, Ohio 43210
| | - Spandan Gupta
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Gauruv A. Gupta
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Shruthi Madhu
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Julie Fitzgerald
- Department of Neuroscience, The Ohio State University, Columbus, Ohio 43210
| | - Abbey A. Saadey
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Brooke Laster
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Pearlly Yan
- Genomics Shared Resource, Comprehensive Cancer Center, USA; Department of Internal Medicine, The Ohio State University, USA; The Ohio State University, Columbus, OH 43210, USA
| | - Amy Webb
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - Xiaoli Zhang
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - Maciej Pietrzak
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | | | - Hazem E. Ghoneim
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Amal O. Amer
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
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12
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Vierra NC, Ribeiro-Silva L, Kirmiz M, van der List D, Bhandari P, Mack OA, Carroll J, Le Monnier E, Aicher SA, Shigemoto R, Trimmer JS. Neuronal ER-plasma membrane junctions couple excitation to Ca 2+-activated PKA signaling. Nat Commun 2023; 14:5231. [PMID: 37633939 PMCID: PMC10460453 DOI: 10.1038/s41467-023-40930-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 08/16/2023] [Indexed: 08/28/2023] Open
Abstract
Junctions between the endoplasmic reticulum (ER) and the plasma membrane (PM) are specialized membrane contacts ubiquitous in eukaryotic cells. Concentration of intracellular signaling machinery near ER-PM junctions allows these domains to serve critical roles in lipid and Ca2+ signaling and homeostasis. Subcellular compartmentalization of protein kinase A (PKA) signaling also regulates essential cellular functions, however, no specific association between PKA and ER-PM junctional domains is known. Here, we show that in brain neurons type I PKA is directed to Kv2.1 channel-dependent ER-PM junctional domains via SPHKAP, a type I PKA-specific anchoring protein. SPHKAP association with type I PKA regulatory subunit RI and ER-resident VAP proteins results in the concentration of type I PKA between stacked ER cisternae associated with ER-PM junctions. This ER-associated PKA signalosome enables reciprocal regulation between PKA and Ca2+ signaling machinery to support Ca2+ influx and excitation-transcription coupling. These data reveal that neuronal ER-PM junctions support a receptor-independent form of PKA signaling driven by membrane depolarization and intracellular Ca2+, allowing conversion of information encoded in electrical signals into biochemical changes universally recognized throughout the cell.
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Affiliation(s)
- Nicholas C Vierra
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA, USA.
| | - Luisa Ribeiro-Silva
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA, USA
| | - Michael Kirmiz
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA, USA
| | - Deborah van der List
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA, USA
| | - Pradeep Bhandari
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Olivia A Mack
- Chemical Physiology and Biochemistry Department, Oregon Health & Science University, Portland, OR, USA
| | - James Carroll
- Chemical Physiology and Biochemistry Department, Oregon Health & Science University, Portland, OR, USA
| | - Elodie Le Monnier
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Sue A Aicher
- Chemical Physiology and Biochemistry Department, Oregon Health & Science University, Portland, OR, USA
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - James S Trimmer
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA, USA.
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13
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Dixon RE, Trimmer JS. Endoplasmic Reticulum-Plasma Membrane Junctions as Sites of Depolarization-Induced Ca 2+ Signaling in Excitable Cells. Annu Rev Physiol 2023; 85:217-243. [PMID: 36202100 PMCID: PMC9918718 DOI: 10.1146/annurev-physiol-032122-104610] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane contact sites between endoplasmic reticulum (ER) and plasma membrane (PM), or ER-PM junctions, are found in all eukaryotic cells. In excitable cells they play unique roles in organizing diverse forms of Ca2+ signaling as triggered by membrane depolarization. ER-PM junctions underlie crucial physiological processes such as excitation-contraction coupling, smooth muscle contraction and relaxation, and various forms of activity-dependent signaling and plasticity in neurons. In many cases the structure and molecular composition of ER-PM junctions in excitable cells comprise important regulatory feedback loops linking depolarization-induced Ca2+ signaling at these sites to the regulation of membrane potential. Here, we describe recent findings on physiological roles and molecular composition of native ER-PM junctions in excitable cells. We focus on recent studies that provide new insights into canonical forms of depolarization-induced Ca2+ signaling occurring at junctional triads and dyads of striated muscle, as well as the diversity of ER-PM junctions in these cells and in smooth muscle and neurons.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
| | - James S Trimmer
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
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14
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Osteocalcin ameliorates cognitive dysfunctions in a mouse model of Alzheimer's Disease by reducing amyloid β burden and upregulating glycolysis in neuroglia. Cell Death Dis 2023; 9:46. [PMID: 36746932 PMCID: PMC9902399 DOI: 10.1038/s41420-023-01343-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by the accumulation of amyloid β peptides (Aβ) and impaired glucose metabolism in the brain. Osteocalcin (OCN), an osteoblast-derived protein, has been shown to modulate brain functions but whether it has any effect on AD is undetermined. In this study, daily intraperitoneal injection of OCN for 4 weeks ameliorated the anxiety-like behaviors and cognitive dysfunctions in the APP/PS1 transgenic AD mice model, as shown in the increased entries into the central area in open field test, the increased time and entries into open arms in elevated plus maze test, the increased time spent in the light chamber in light-dark transition test, as well as the reduced escape latency and the increased preference for target quadrant in Morris water maze test. Aβ burden in the hippocampus and cortex of AD mice was ameliorated by OCN. Besides, OCN improved the neural network function of the brain, mainly in the enhanced power of high gamma band in the medial prefrontal cortex of AD mice. The proliferation of astrocytes in the hippocampus in AD mice was also inhibited by OCN as demonstrated by immunofluorescence. Furthermore, OCN enhanced glycolysis in astrocytes and microglia, as evidenced by elevated glucose consumption, lactate production, and increased extracellular acidification rate. Such an effect was abolished when the receptor of OCN - Gpr158 was knockdown in astrocytes. Our study revealed OCN as a novel therapeutic factor for AD potentially through reducing Aβ burden and upregulation of glycolysis in neuroglia.
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15
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Jabarin R, Netser S, Wagner S. Beyond the three-chamber test: toward a multimodal and objective assessment of social behavior in rodents. Mol Autism 2022; 13:41. [PMID: 36284353 PMCID: PMC9598038 DOI: 10.1186/s13229-022-00521-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 10/06/2022] [Indexed: 12/31/2022] Open
Abstract
MAIN: In recent years, substantial advances in social neuroscience have been realized, including the generation of numerous rodent models of autism spectrum disorder. Still, it can be argued that those methods currently being used to analyze animal social behavior create a bottleneck that significantly slows down progress in this field. Indeed, the bulk of research still relies on a small number of simple behavioral paradigms, the results of which are assessed without considering behavioral dynamics. Moreover, only few variables are examined in each paradigm, thus overlooking a significant portion of the complexity that characterizes social interaction between two conspecifics, subsequently hindering our understanding of the neural mechanisms governing different aspects of social behavior. We further demonstrate these constraints by discussing the most commonly used paradigm for assessing rodent social behavior, the three-chamber test. We also point to the fact that although emotions greatly influence human social behavior, we lack reliable means for assessing the emotional state of animals during social tasks. As such, we also discuss current evidence supporting the existence of pro-social emotions and emotional cognition in animal models. We further suggest that adequate social behavior analysis requires a novel multimodal approach that employs automated and simultaneous measurements of multiple behavioral and physiological variables at high temporal resolution in socially interacting animals. We accordingly describe several computerized systems and computational tools for acquiring and analyzing such measurements. Finally, we address several behavioral and physiological variables that can be used to assess socio-emotional states in animal models and thus elucidate intricacies of social behavior so as to attain deeper insight into the brain mechanisms that mediate such behaviors. CONCLUSIONS: In summary, we suggest that combining automated multimodal measurements with machine-learning algorithms will help define socio-emotional states and determine their dynamics during various types of social tasks, thus enabling a more thorough understanding of the complexity of social behavior.
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Affiliation(s)
- Renad Jabarin
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel.
| | - Shai Netser
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Shlomo Wagner
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
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16
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Ostendorp A, Ostendorp S, Zhou Y, Chaudron Z, Wolffram L, Rombi K, von Pein L, Falke S, Jeffries CM, Svergun DI, Betzel C, Morris RJ, Kragler F, Kehr J. Intrinsically disordered plant protein PARCL colocalizes with RNA in phase-separated condensates whose formation can be regulated by mutating the PLD. J Biol Chem 2022; 298:102631. [PMID: 36273579 PMCID: PMC9679465 DOI: 10.1016/j.jbc.2022.102631] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 10/16/2022] [Accepted: 10/17/2022] [Indexed: 11/21/2022] Open
Abstract
In higher plants, long-distance RNA transport via the phloem is crucial for communication between distant plant tissues to align development with stress responses and reproduction. Several recent studies suggest that specific RNAs are among the potential long-distance information transmitters. However, it is yet not well understood how these RNAs enter the phloem stream, how they are transported, and how they are released at their destination. It was proposed that phloem RNA-binding proteins facilitate RNA translocation. In the present study, we characterized two orthologs of the phloem-associated RNA chaperone-like (PARCL) protein from Arabidopsis thaliana and Brassica napus at functional and structural levels. Microscale thermophoresis showed that these phloem-abundant proteins can bind a broad spectrum of RNAs and show RNA chaperone activity in FRET-based in vitro assays. Our SAXS experiments revealed a high degree of disorder, typical for RNA-binding proteins. In agroinfiltrated tobacco plants, eYFP-PARCL proteins mainly accumulated in nuclei and nucleoli and formed cytosolic and nuclear condensates. We found that formation of these condensates was impaired by tyrosine-to-glutamate mutations in the predicted prion-like domain (PLD), while C-terminal serine-to-glutamate mutations did not affect condensation but reduced RNA binding and chaperone activity. Furthermore, our in vitro experiments confirmed phase separation of PARCL and colocalization of RNA with the condensates, while mutation as well as phosphorylation of the PLD reduced phase separation. Together, our results suggest that RNA binding and condensate formation of PARCL can be regulated independently by modification of the C-terminus and/or the PLD.
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Affiliation(s)
- Anna Ostendorp
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany,For correspondence: Anna Ostendorp
| | - Steffen Ostendorp
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany
| | - Yuan Zhou
- Max Planck Institute of Molecular Plant Physiology, Department II, Potsdam, Germany
| | - Zoé Chaudron
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany
| | - Lukas Wolffram
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany
| | - Khadija Rombi
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany
| | - Linn von Pein
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany
| | - Sven Falke
- Laboratory for Structural Biology of Infection and Inflammation, c/o DESY, Hamburg, Germany,Universität Hamburg, Department of Chemistry, Institute of Biochemistry and Molecular Biology, Hamburg, Germany
| | - Cy M. Jeffries
- European Molecular Biology Laboratory (EMBL) Hamburg Site, c/o DESY, Hamburg, Germany
| | - Dmitri I. Svergun
- European Molecular Biology Laboratory (EMBL) Hamburg Site, c/o DESY, Hamburg, Germany
| | - Christian Betzel
- Laboratory for Structural Biology of Infection and Inflammation, c/o DESY, Hamburg, Germany,Universität Hamburg, Department of Chemistry, Institute of Biochemistry and Molecular Biology, Hamburg, Germany
| | - Richard J. Morris
- Computational and Systems Biology, John Innes Centre, Norwich, United Kingdom
| | - Friedrich Kragler
- Max Planck Institute of Molecular Plant Physiology, Department II, Potsdam, Germany
| | - Julia Kehr
- Universität Hamburg, Department of Biology, Institute of Plant Science and Microbiology, Hamburg, Germany
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17
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Quintero-Villegas A, Valdés-Ferrer SI. Central nervous system effects of 5-HT 7 receptors: a potential target for neurodegenerative diseases. Mol Med 2022; 28:70. [PMID: 35725396 PMCID: PMC9208181 DOI: 10.1186/s10020-022-00497-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/09/2022] [Indexed: 12/21/2022] Open
Abstract
5-HT7 receptors (5-HT7R) are the most recently identified among the family of serotonin receptors. Their role in health and disease, particularly as mediators of, and druggable targets for, neurodegenerative diseases, is incompletely understood. Unlike other serotonin receptors, for which abundant preclinical and clinical data evaluating their effect on neurodegenerative conditions exist, the available information on the role of the 5-HT7R receptor is limited. In this review, we describe the signaling pathways and cellular mechanisms implicated in the activation of the 5-HT7R; also, we analyze different mechanisms of neurodegeneration and the potential therapeutic implications of pharmacological interventions for 5-HT7R signaling.
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Affiliation(s)
- Alejandro Quintero-Villegas
- Department of Neurology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.,Department of Infectious Diseases, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Sergio Iván Valdés-Ferrer
- Department of Neurology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. .,Department of Infectious Diseases, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. .,Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA.
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18
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Martínez-Camarena Á, Merino M, Sánchez-Sánchez AV, Blasco S, Llinares JM, Mullor JL, García-España E. An antioxidant boehmite amino-nanozyme able to disaggregate Huntington's inclusion bodies. Chem Commun (Camb) 2022; 58:5021-5024. [PMID: 35373809 DOI: 10.1039/d2cc01257j] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A novel amino-nanozyme, based on boehmite nanoparticles (BNPs) functionalised with a tetra-azapyridinophane (L1), has been designed to undermine some of the key issues underlying Huntington disease. L1 forms Cu2+ complexes with a striking SOD activity, while when grafted to the BNPs displays mitoROS scavenging properties and ability to disaggregate mutant huntingtin deposits in cells.
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Affiliation(s)
- Álvaro Martínez-Camarena
- ICMol, Departamento de Química Inorgánica, University of Valencia, C/Catedrático José Beltrán 2, 46980, Paterna, Spain.
| | - Marian Merino
- Bionos Biotech SL, Biopolo La Fe, IIS La Fe, Av. Fernando Abril Martorell, Torre 106 A 7 planta, 46026 València, Spain
| | - Ana Virginia Sánchez-Sánchez
- Bionos Biotech SL, Biopolo La Fe, IIS La Fe, Av. Fernando Abril Martorell, Torre 106 A 7 planta, 46026 València, Spain
| | - Salvador Blasco
- ICMol, Departamento de Química Inorgánica, University of Valencia, C/Catedrático José Beltrán 2, 46980, Paterna, Spain.
| | - José M Llinares
- Departamento de Química Orgánica, University of Valencia, C/Dr Moliner s/n, 46100, Burjassot, Spain
| | - José L Mullor
- Bionos Biotech SL, Biopolo La Fe, IIS La Fe, Av. Fernando Abril Martorell, Torre 106 A 7 planta, 46026 València, Spain
| | - Enrique García-España
- ICMol, Departamento de Química Inorgánica, University of Valencia, C/Catedrático José Beltrán 2, 46980, Paterna, Spain.
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19
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Watts AG, Kanoski SE, Sanchez-Watts G, Langhans W. The physiological control of eating: signals, neurons, and networks. Physiol Rev 2022; 102:689-813. [PMID: 34486393 PMCID: PMC8759974 DOI: 10.1152/physrev.00028.2020] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
During the past 30 yr, investigating the physiology of eating behaviors has generated a truly vast literature. This is fueled in part by a dramatic increase in obesity and its comorbidities that has coincided with an ever increasing sophistication of genetically based manipulations. These techniques have produced results with a remarkable degree of cell specificity, particularly at the cell signaling level, and have played a lead role in advancing the field. However, putting these findings into a brain-wide context that connects physiological signals and neurons to behavior and somatic physiology requires a thorough consideration of neuronal connections: a field that has also seen an extraordinary technological revolution. Our goal is to present a comprehensive and balanced assessment of how physiological signals associated with energy homeostasis interact at many brain levels to control eating behaviors. A major theme is that these signals engage sets of interacting neural networks throughout the brain that are defined by specific neural connections. We begin by discussing some fundamental concepts, including ones that still engender vigorous debate, that provide the necessary frameworks for understanding how the brain controls meal initiation and termination. These include key word definitions, ATP availability as the pivotal regulated variable in energy homeostasis, neuropeptide signaling, homeostatic and hedonic eating, and meal structure. Within this context, we discuss network models of how key regions in the endbrain (or telencephalon), hypothalamus, hindbrain, medulla, vagus nerve, and spinal cord work together with the gastrointestinal tract to enable the complex motor events that permit animals to eat in diverse situations.
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Affiliation(s)
- Alan G Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Scott E Kanoski
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Graciela Sanchez-Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule-Zürich, Schwerzenbach, Switzerland
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20
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Sepela RJ, Stewart RG, Valencia LA, Thapa P, Wang Z, Cohen BE, Sack JT. The AMIGO1 adhesion protein activates Kv2.1 voltage sensors. Biophys J 2022; 121:1395-1416. [PMID: 35314141 PMCID: PMC9072587 DOI: 10.1016/j.bpj.2022.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 11/11/2021] [Accepted: 03/16/2022] [Indexed: 11/30/2022] Open
Abstract
Kv2 voltage-gated potassium channels are modulated by amphoterin-induced gene and open reading frame (AMIGO) neuronal adhesion proteins. Here, we identify steps in the conductance activation pathway of Kv2.1 channels that are modulated by AMIGO1 using voltage-clamp recordings and spectroscopy of heterologously expressed Kv2.1 and AMIGO1 in mammalian cell lines. AMIGO1 speeds early voltage-sensor movements and shifts the gating charge-voltage relationship to more negative voltages. The gating charge-voltage relationship indicates that AMIGO1 exerts a larger energetic effect on voltage-sensor movement than is apparent from the midpoint of the conductance-voltage relationship. When voltage sensors are detained at rest by voltage-sensor toxins, AMIGO1 has a greater impact on the conductance-voltage relationship. Fluorescence measurements from voltage-sensor toxins bound to Kv2.1 indicate that with AMIGO1, the voltage sensors enter their earliest resting conformation, yet this conformation is less stable upon voltage stimulation. We conclude that AMIGO1 modulates the Kv2.1 conductance activation pathway by destabilizing the earliest resting state of the voltage sensors.
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Affiliation(s)
- Rebecka J Sepela
- Department of Physiology and Membrane Biology, University of California, Davis, California
| | - Robert G Stewart
- Department of Physiology and Membrane Biology, University of California, Davis, California
| | - Luis A Valencia
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Parashar Thapa
- Department of Physiology and Membrane Biology, University of California, Davis, California
| | - Zeming Wang
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Bruce E Cohen
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California; Division of Molecular Biophysics & Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California, Davis, California; Department of Anesthesiology and Pain Medicine, University of California, Davis, California.
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21
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Transcriptome and chromatin alterations in social fear indicate association of MEG3 with successful extinction of fear. Mol Psychiatry 2022; 27:4064-4076. [PMID: 35338311 PMCID: PMC9718683 DOI: 10.1038/s41380-022-01481-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 01/31/2022] [Accepted: 02/08/2022] [Indexed: 02/07/2023]
Abstract
Social anxiety disorder is characterized by a persistent fear and avoidance of social situations, but available treatment options are rather unspecific. Using an established mouse social fear conditioning (SFC) paradigm, we profiled gene expression and chromatin alterations after the acquisition and extinction of social fear within the septum, a brain region important for social fear and social behaviors. Here, we particularly focused on the successful versus unsuccessful outcome of social fear extinction training, which corresponds to treatment responsive versus resistant patients in the clinics. Validation of coding and non-coding RNAs revealed specific isoforms of the long non-coding RNA (lncRNA) Meg3 regulated, depending on the success of social fear extinction. Moreover, PI3K/AKT was differentially activated with extinction success in SFC-mice. In vivo knockdown of specific Meg3 isoforms increased baseline activity of PI3K/AKT signaling, and mildly delayed social fear extinction. Using ATAC-Seq and CUT&RUN, we found alterations in the chromatin structure of specific genes, which might be direct targets of lncRNA Meg3.
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Blokland GAM, Grove J, Chen CY, Cotsapas C, Tobet S, Handa R, St Clair D, Lencz T, Mowry BJ, Periyasamy S, Cairns MJ, Tooney PA, Wu JQ, Kelly B, Kirov G, Sullivan PF, Corvin A, Riley BP, Esko T, Milani L, Jönsson EG, Palotie A, Ehrenreich H, Begemann M, Steixner-Kumar A, Sham PC, Iwata N, Weinberger DR, Gejman PV, Sanders AR, Buxbaum JD, Rujescu D, Giegling I, Konte B, Hartmann AM, Bramon E, Murray RM, Pato MT, Lee J, Melle I, Molden E, Ophoff RA, McQuillin A, Bass NJ, Adolfsson R, Malhotra AK, Martin NG, Fullerton JM, Mitchell PB, Schofield PR, Forstner AJ, Degenhardt F, Schaupp S, Comes AL, Kogevinas M, Guzman-Parra J, Reif A, Streit F, Sirignano L, Cichon S, Grigoroiu-Serbanescu M, Hauser J, Lissowska J, Mayoral F, Müller-Myhsok B, Świątkowska B, Schulze TG, Nöthen MM, Rietschel M, Kelsoe J, Leboyer M, Jamain S, Etain B, Bellivier F, Vincent JB, Alda M, O'Donovan C, Cervantes P, Biernacka JM, Frye M, McElroy SL, Scott LJ, Stahl EA, Landén M, Hamshere ML, Smeland OB, Djurovic S, Vaaler AE, Andreassen OA, Baune BT, Air T, Preisig M, Uher R, Levinson DF, Weissman MM, Potash JB, Shi J, Knowles JA, Perlis RH, Lucae S, Boomsma DI, Penninx BWJH, Hottenga JJ, de Geus EJC, Willemsen G, Milaneschi Y, Tiemeier H, Grabe HJ, Teumer A, Van der Auwera S, Völker U, Hamilton SP, Magnusson PKE, Viktorin A, Mehta D, Mullins N, Adams MJ, Breen G, McIntosh AM, Lewis CM, Hougaard DM, Nordentoft M, Mors O, Mortensen PB, Werge T, Als TD, Børglum AD, Petryshen TL, Smoller JW, Goldstein JM. Sex-Dependent Shared and Nonshared Genetic Architecture Across Mood and Psychotic Disorders. Biol Psychiatry 2022; 91:102-117. [PMID: 34099189 PMCID: PMC8458480 DOI: 10.1016/j.biopsych.2021.02.972] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND Sex differences in incidence and/or presentation of schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BIP) are pervasive. Previous evidence for shared genetic risk and sex differences in brain abnormalities across disorders suggest possible shared sex-dependent genetic risk. METHODS We conducted the largest to date genome-wide genotype-by-sex (G×S) interaction of risk for these disorders using 85,735 cases (33,403 SCZ, 19,924 BIP, and 32,408 MDD) and 109,946 controls from the PGC (Psychiatric Genomics Consortium) and iPSYCH. RESULTS Across disorders, genome-wide significant single nucleotide polymorphism-by-sex interaction was detected for a locus encompassing NKAIN2 (rs117780815, p = 3.2 × 10-8), which interacts with sodium/potassium-transporting ATPase (adenosine triphosphatase) enzymes, implicating neuronal excitability. Three additional loci showed evidence (p < 1 × 10-6) for cross-disorder G×S interaction (rs7302529, p = 1.6 × 10-7; rs73033497, p = 8.8 × 10-7; rs7914279, p = 6.4 × 10-7), implicating various functions. Gene-based analyses identified G×S interaction across disorders (p = 8.97 × 10-7) with transcriptional inhibitor SLTM. Most significant in SCZ was a MOCOS gene locus (rs11665282, p = 1.5 × 10-7), implicating vascular endothelial cells. Secondary analysis of the PGC-SCZ dataset detected an interaction (rs13265509, p = 1.1 × 10-7) in a locus containing IDO2, a kynurenine pathway enzyme with immunoregulatory functions implicated in SCZ, BIP, and MDD. Pathway enrichment analysis detected significant G×S interaction of genes regulating vascular endothelial growth factor receptor signaling in MDD (false discovery rate-corrected p < .05). CONCLUSIONS In the largest genome-wide G×S analysis of mood and psychotic disorders to date, there was substantial genetic overlap between the sexes. However, significant sex-dependent effects were enriched for genes related to neuronal development and immune and vascular functions across and within SCZ, BIP, and MDD at the variant, gene, and pathway levels.
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Affiliation(s)
- Gabriëlla A M Blokland
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.
| | - Jakob Grove
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark; Center for Genome Analysis and Personalized Medicine, Aarhus, Denmark; Bioinformatics Research Centre (BiRC), Aarhus, Denmark
| | - Chia-Yen Chen
- Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts; Biogen Inc., Cambridge, Massachusetts
| | - Chris Cotsapas
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Departments of Neurology and Genetics, Yale School of Medicine, New Haven, Connecticut
| | - Stuart Tobet
- Innovation Center on Sex Differences in Medicine (ICON), Massachusetts General Hospital, Boston, Massachusetts; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Robert Handa
- Innovation Center on Sex Differences in Medicine (ICON), Massachusetts General Hospital, Boston, Massachusetts; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - David St Clair
- University of Aberdeen, Institute of Medical Sciences, Aberdeen, United Kingdom
| | - Todd Lencz
- The Feinstein Institute for Medical Research, Manhasset, New York; The Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York; The Zucker Hillside Hospital, Glen Oaks, New York
| | - Bryan J Mowry
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia; Queensland Centre for Mental Health Research, University of Queensland, Brisbane, Queensland, Australia
| | - Sathish Periyasamy
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia; Queensland Centre for Mental Health Research, The Park - Centre for Mental Health, Wacol, Queensland, Australia
| | - Murray J Cairns
- Schizophrenia Research Institute, Sydney, New South Wales, Australia; School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; Priority Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - Paul A Tooney
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; Priority Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle, New South Wales, Australia; Schizophrenia Research Institute, Sydney, New South Wales, Australia
| | - Jing Qin Wu
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; Schizophrenia Research Institute, Sydney, New South Wales, Australia
| | - Brian Kelly
- Priority Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - George Kirov
- MRC Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Patrick F Sullivan
- Departments of Genetics and Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Aiden Corvin
- Neuropsychiatric Genetics Research Group, Department of Psychiatry, Trinity College Dublin, Dublin, Ireland
| | - Brien P Riley
- Virginia Institute for Psychiatric and Behavioral Genetics, Departments of Psychiatry and Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Tõnu Esko
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Lili Milani
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Erik G Jönsson
- Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institutet, Stockholm, Sweden; Norwegian Centre for Mental Disorders Research (NORMENT), KG Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Aarno Palotie
- Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Hannelore Ehrenreich
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Martin Begemann
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Agnes Steixner-Kumar
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Pak C Sham
- Department of Psychiatry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China; State Key Laboratory for Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China; Centre for Genomic Sciences, The University of Hong Kong, Hong Kong, SAR China
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Daniel R Weinberger
- Lieber Institute for Brain Development, Baltimore, Maryland; Departments of Psychiatry, Neurology, Neuroscience and Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Pablo V Gejman
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois; Department of Psychiatry and Behavioral Sciences, North Shore University Health System, Evanston, Illinois
| | - Alan R Sanders
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois; Department of Psychiatry and Behavioral Sciences, North Shore University Health System, Evanston, Illinois
| | - Joseph D Buxbaum
- Departments of Human Genetics and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Dan Rujescu
- Department of Psychiatry, University of Halle, Halle, Germany; Department of Psychiatry, University of Munich, Munich, Germany
| | - Ina Giegling
- Department of Psychiatry, University of Halle, Halle, Germany; Department of Psychiatry, University of Munich, Munich, Germany
| | - Bettina Konte
- Department of Psychiatry, University of Halle, Halle, Germany
| | | | - Elvira Bramon
- Mental Health Neuroscience Research Department, Division of Psychiatry, Faculty of Brain Sciences, University College London, London, United Kingdom
| | - Robin M Murray
- Institute of Psychiatry, King's College London, London, United Kingdom
| | - Michele T Pato
- Institute for Genomic Health, SUNY Downstate Medical Center College of Medicine, Brooklyn, New York; Department of Psychiatry and Zilkha Neurogenetics Institute, Keck School of Medicine at University of Southern California, Los Angeles, California
| | - Jimmy Lee
- Research Division and Department of General Psychiatry, Institute of Mental Health, Singapore, Singapore; Duke-National University of Singapore Graduate Medical School, Singapore
| | - Ingrid Melle
- Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Espen Molden
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway; Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Roel A Ophoff
- University Medical Center Utrecht, Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, Utrecht, the Netherlands; Department of Human Genetics, University of California, Los Angeles, California; David Geffen School of Medicine, and Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California
| | - Andrew McQuillin
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London, United Kingdom
| | - Nicholas J Bass
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London, United Kingdom
| | - Rolf Adolfsson
- Department of Clinical Sciences, Psychiatry, Umeå University Medical Faculty, Umeå, Sweden
| | - Anil K Malhotra
- The Feinstein Institute for Medical Research, Manhasset, New York; The Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York; The Zucker Hillside Hospital, Glen Oaks, New York
| | - Nicholas G Martin
- School of Psychology, University of Queensland, Brisbane, Queensland, Australia; Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Janice M Fullerton
- Neuroscience Research Australia, Sydney, New South Wales, Australia; School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Philip B Mitchell
- School of Psychiatry, University of New South Wales, Sydney, New South Wales, Australia
| | - Peter R Schofield
- Neuroscience Research Australia, Sydney, New South Wales, Australia; School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Andreas J Forstner
- Centre for Human Genetics, University of Marburg, Marburg, Germany; Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn, Germany
| | - Franziska Degenhardt
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn, Germany; Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Duisburg, Germany
| | - Sabrina Schaupp
- Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, LMU Munich, Munich, Germany
| | - Ashley L Comes
- Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, LMU Munich, Munich, Germany; International Max Planck Research School for Translational Psychiatry (IMPRS-TP), Munich, Germany
| | | | - José Guzman-Parra
- Mental Health Department, University Regional Hospital, Biomedical Research Institute of Málaga (IBIMA), Málaga, Spain
| | - Andreas Reif
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Fabian Streit
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lea Sirignano
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sven Cichon
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn, Germany; Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Medical Genetics and Pathology, University Hospital Basel, Basel, Switzerland
| | - Maria Grigoroiu-Serbanescu
- Biometric Psychiatric Genetics Research Unit, Alexandru Obregia Clinical Psychiatric Hospital, Bucharest, Romania
| | - Joanna Hauser
- Department of Psychiatry, Laboratory of Psychiatric Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Jolanta Lissowska
- Cancer Epidemiology and Prevention, M. Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Fermin Mayoral
- Mental Health Department, University Regional Hospital, Biomedical Research Institute of Málaga (IBIMA), Málaga, Spain
| | - Bertram Müller-Myhsok
- University of Liverpool, Liverpool, United Kingdom; Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Beata Świątkowska
- Department of Environmental Epidemiology, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Thomas G Schulze
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, New York; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland; Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, LMU Munich, Munich, Germany; Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Markus M Nöthen
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn, Germany
| | - Marcella Rietschel
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - John Kelsoe
- Department of Psychiatry, University of California San Diego, La Jolla, California
| | - Marion Leboyer
- Faculté de Médecine, Université Paris Est, Créteil, France; Department of Psychiatry and Addiction Medicine, Assistance Publique - Hôpitaux de Paris, Paris, France; Institut national de la santé et de la recherche médicale (INSERM), Paris, France
| | - Stéphane Jamain
- Faculté de Médecine, Université Paris Est, Créteil, France; INSERM U955, Psychiatrie Translationnelle, Créteil, France
| | - Bruno Etain
- Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom; Department of Psychiatry and Addiction Medicine, Assistance Publique - Hôpitaux de Paris, Paris, France; UMR-S1144 Team 1 Biomarkers of relapse and therapeutic response in addiction and mood disorders, INSERM, Paris, France; Psychiatry, Université Paris Diderot, Paris, France
| | - Frank Bellivier
- Department of Psychiatry and Addiction Medicine, Assistance Publique - Hôpitaux de Paris, Paris, France; UMR-S1144 Team 1 Biomarkers of relapse and therapeutic response in addiction and mood disorders, INSERM, Paris, France; Psychiatry, Université Paris Diderot, Paris, France; Paris Bipolar and TRD Expert Centres, FondaMental Foundation, Paris, France
| | - John B Vincent
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada; National Institute of Mental Health, Klecany, Czech Republic
| | - Claire O'Donovan
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Pablo Cervantes
- Department of Psychiatry, Mood Disorders Program, McGill University Health Center, Montréal, Québec, Canada
| | - Joanna M Biernacka
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota
| | - Mark Frye
- Department of Psychiatry & Psychology, Mayo Clinic, Rochester, Minnesota
| | | | - Laura J Scott
- Center for Statistical Genetics and Department of Biostatistics, University of Michigan, Ann Arbor, Michigan
| | - Eli A Stahl
- Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Mikael Landén
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Institute of Neuroscience and Physiology, the Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden
| | - Marian L Hamshere
- MRC Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Olav B Smeland
- Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Srdjan Djurovic
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway; NORMENT Centre, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Arne E Vaaler
- Department of Mental Health, Norwegian University of Science and Technology - NTNU, Trondheim, Norway; Department of Psychiatry, St Olavs' University Hospital, Trondheim, Norway
| | - Ole A Andreassen
- Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Bernhard T Baune
- Department of Psychiatry, Melbourne Medical School, University of Melbourne, Melbourne, Victoria, Australia; Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia; Department of Psychiatry, University of Münster, Münster, Germany
| | - Tracy Air
- Discipline of Psychiatry, The University of Adelaide, Adelaide, South Austrlalia, Australia
| | - Martin Preisig
- Department of Psychiatry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Rudolf Uher
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Douglas F Levinson
- Psychiatry & Behavioral Sciences, Stanford University, Stanford, California
| | - Myrna M Weissman
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York; Division of Translational Epidemiology, New York State Psychiatric Institute, New York, New York
| | - James B Potash
- Department of Psychiatry, University of Iowa, Iowa City, Iowa
| | - Jianxin Shi
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland
| | - James A Knowles
- Psychiatry & The Behavioral Sciences, University of Southern California, Los Angeles, California
| | - Roy H Perlis
- Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Susanne Lucae
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany; Max Planck Institute of Psychiatry, Munich, Germany
| | - Dorret I Boomsma
- Department of Biological Psychology/Netherlands Twin Register, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Amsterdam Public Health Research Institute, Amsterdam UMC, Amsterdam, the Netherlands
| | - Brenda W J H Penninx
- Department of Psychiatry, Vrije Universiteit Medical Center and GGZ inGeest, Amsterdam, the Netherlands
| | - Jouke-Jan Hottenga
- Department of Biological Psychology/Netherlands Twin Register, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Amsterdam Public Health Research Institute, Amsterdam UMC, Amsterdam, the Netherlands
| | - Eco J C de Geus
- Department of Biological Psychology/Netherlands Twin Register, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Amsterdam Public Health Research Institute, Amsterdam UMC, Amsterdam, the Netherlands
| | - Gonneke Willemsen
- Department of Biological Psychology/Netherlands Twin Register, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Amsterdam Public Health Research Institute, Amsterdam UMC, Amsterdam, the Netherlands
| | - Yuri Milaneschi
- Department of Psychiatry, Vrije Universiteit Medical Center and GGZ inGeest, Amsterdam, the Netherlands
| | - Henning Tiemeier
- Child and Adolescent Psychiatry, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Hans J Grabe
- Department of Psychiatry and Psychotherapy, University Medicine Greifswald, Greifswald, Germany
| | - Alexander Teumer
- Institute of Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Sandra Van der Auwera
- Department of Psychiatry and Psychotherapy, University Medicine Greifswald, Greifswald, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | | | - Patrik K E Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Alexander Viktorin
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Divya Mehta
- School of Psychology and Counseling, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Niamh Mullins
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York; Social, Genetic and Developmental Psychiatry Centre, King's College London, London, United Kingdom
| | - Mark J Adams
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom
| | - Gerome Breen
- NIHR Maudsley Biomedical Research Centre, King's College London, London, United Kingdom
| | - Andrew M McIntosh
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom; Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Cathryn M Lewis
- Department of Medical & Molecular Genetics, King's College London, London, United Kingdom
| | - David M Hougaard
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark; Center for Neonatal Screening, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Merete Nordentoft
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark; Copenhagen Mental Health Center, Mental Health Services Capital Region of Denmark Copenhagen, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ole Mors
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark; Psychosis Research Unit, Aarhus University Hospital, Risskov, Denmark
| | - Preben B Mortensen
- Centre for Integrative Sequencing (iSEQ), Aarhus University, Aarhus, Denmark; National Centre for Register-Based Research (NCCR), Aarhus University, Aarhus, Denmark; Centre for Integrated Register-based Research (CIRRAU), Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark
| | - Thomas Werge
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Institute of Biological Psychiatry, Mental Health Center Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
| | - Thomas D Als
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark; Center for Genome Analysis and Personalized Medicine, Aarhus, Denmark
| | - Anders D Børglum
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Copenhagen, Denmark; Center for Genome Analysis and Personalized Medicine, Aarhus, Denmark
| | - Tracey L Petryshen
- Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Concert Pharmaceuticals, Inc., Lexington, Massachusetts
| | - Jordan W Smoller
- Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Jill M Goldstein
- Innovation Center on Sex Differences in Medicine (ICON), Massachusetts General Hospital, Boston, Massachusetts; Department of Psychiatry and Vincent Department of Obstetrics, Gynecology & Reproductive Biology, Massachusetts General Hospital, Boston, Massachusetts; MGH-MIT-HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts; Departments of Psychiatry and Medicine, Harvard Medical School, Boston, Massachusetts.
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Regulation of neuronal excitation-transcription coupling by Kv2.1-induced clustering of somatic L-type Ca 2+ channels at ER-PM junctions. Proc Natl Acad Sci U S A 2021; 118:2110094118. [PMID: 34750263 PMCID: PMC8609631 DOI: 10.1073/pnas.2110094118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2021] [Indexed: 11/18/2022] Open
Abstract
In hippocampal neurons, gene expression is triggered by electrical activity and Ca2+ entry via L-type Cav1.2 channels in a process called excitation–transcription coupling. We identified a domain on the voltage-gated K+ channel Kv2.1 that promotes the clustering of L-type Cav1.2 channels at endoplasmic reticulum–plasma membrane junctions in the soma of neurons. Importantly, we discovered by disrupting this domain that the Kv2.1-mediated clustering of Cav1.2 at this somatic microdomain is critical for depolarization-induced excitation–transcription coupling. In mammalian brain neurons, membrane depolarization leads to voltage-gated Ca2+ channel-mediated Ca2+ influx that triggers diverse cellular responses, including gene expression, in a process termed excitation–transcription coupling. Neuronal L-type Ca2+ channels, which have prominent populations on the soma and distal dendrites of hippocampal neurons, play a privileged role in excitation–transcription coupling. The voltage-gated K+ channel Kv2.1 organizes signaling complexes containing the L-type Ca2+ channel Cav1.2 at somatic endoplasmic reticulum–plasma membrane junctions. This leads to enhanced clustering of Cav1.2 channels, increasing their activity. However, the downstream consequences of the Kv2.1-mediated regulation of Cav1.2 localization and function on excitation–transcription coupling are not known. Here, we have identified a region between residues 478 to 486 of Kv2.1’s C terminus that mediates the Kv2.1-dependent clustering of Cav1.2. By disrupting this Ca2+ channel association domain with either mutations or with a cell-penetrating interfering peptide, we blocked the Kv2.1-mediated clustering of Cav1.2 at endoplasmic reticulum–plasma membrane junctions and the subsequent enhancement of its channel activity and somatic Ca2+ signals without affecting the clustering of Kv2.1. These interventions abolished the depolarization-induced and L-type Ca2+ channel-dependent phosphorylation of the transcription factor CREB and the subsequent expression of c-Fos in hippocampal neurons. Our findings support a model whereby the Kv2.1-Ca2+ channel association domain-mediated clustering of Cav1.2 channels imparts a mechanism to control somatic Ca2+ signals that couple neuronal excitation to gene expression.
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Wang S, Alpsoy A, Sood S, Ordonez-Rubiano SC, Dhiman A, Sun Y, Jiao G, Krusemark CJ, Dykhuizen EC. A Potent, Selective CBX2 Chromodomain Ligand and Its Cellular Activity During Prostate Cancer Neuroendocrine Differentiation. Chembiochem 2021; 22:2335-2344. [PMID: 33950564 PMCID: PMC8358665 DOI: 10.1002/cbic.202100118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/04/2021] [Indexed: 12/16/2022]
Abstract
Polycomb group (PcG) proteins are epigenetic regulators that facilitate both embryonic development and cancer progression. PcG proteins form Polycomb repressive complexes 1 and 2 (PRC1 and PRC2). PRC2 trimethylates histone H3 lysine 27 (H3K27me3), a histone mark recognized by the N-terminal chromodomain (ChD) of the CBX subunit of canonical PRC1. There are five PcG CBX paralogs in humans. CBX2 in particular is upregulated in a variety of cancers, particularly in advanced prostate cancers. Using CBX2 inhibitors to understand and target CBX2 in prostate cancer is highly desirable; however, high structural similarity among the CBX ChDs has been challenging for developing selective CBX ChD inhibitors. Here, we utilize selections of focused DNA encoded libraries (DELs) for the discovery of a selective CBX2 chromodomain probe, SW2_152F. SW2_152F binds to CBX2 ChD with a Kd of 80 nM and displays 24-1000-fold selectivity for CBX2 ChD over other CBX paralogs in vitro. SW2_152F is cell permeable, selectively inhibits CBX2 chromatin binding in cells, and blocks neuroendocrine differentiation of prostate cancer cell lines in response to androgen deprivation.
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Affiliation(s)
- Sijie Wang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Aktan Alpsoy
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
- Purdue Life Science Interdisciplinary Graduate Program, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Surbhi Sood
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
- Purdue Life Science Interdisciplinary Graduate Program, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Sandra Carolina Ordonez-Rubiano
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Alisha Dhiman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Yixing Sun
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Guanming Jiao
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Casey J. Krusemark
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
- Purdue Center for Cancer Research, 201 S. University St. West Lafayette, IN, 47907 USA
| | - Emily C. Dykhuizen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 201 S. University St. West Lafayette, IN, 47907 USA
- Purdue Center for Cancer Research, 201 S. University St. West Lafayette, IN, 47907 USA
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Maverick EE, Leek AN, Tamkun MM. Kv2 channel-AMIGO β-subunit assembly modulates both channel function and cell adhesion molecule surface trafficking. J Cell Sci 2021; 134:jcs256339. [PMID: 34137443 PMCID: PMC8255027 DOI: 10.1242/jcs.256339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 05/17/2021] [Indexed: 11/20/2022] Open
Abstract
The Kv2 channels encode delayed rectifier currents that regulate membrane potential in many tissues. They also have a non-conducting function to form stable junctions between the endoplasmic reticulum and plasma membranes, creating membrane contact sites that mediate functions distinct from membrane excitability. Therefore, proteins that interact with Kv2.1 and Kv2.2 channels can alter conducting and/or non-conducting channel properties. One member of the AMIGO family of proteins is an auxiliary β-subunit for Kv2 channels and modulates Kv2.1 electrical activity. However, the AMIGO family has two additional members of ∼50% similarity that have not yet been characterized as Kv2 β-subunits. In this work, we show that the surface trafficking and localization of all three AMIGOs are controlled by their assembly with both Kv2 channels. Additionally, assembly of each AMIGO with either Kv2.1 or Kv2.2 hyperpolarizes the channel activation midpoint by -10 mV. However, only AMIGO2 significantly slows inactivation and deactivation, leading to a prolonged open state of Kv2 channels. The co-regulatory effects of Kv2s and AMIGOs likely fine-tune both the electrical and non-electrical properties of the cells in which they are expressed.
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Affiliation(s)
- Emily E. Maverick
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
- Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Ashley N. Leek
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
- Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Michael M. Tamkun
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
- Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO 80523, USA
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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26
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Le Cann K, Foerster A, Rösseler C, Erickson A, Hautvast P, Giesselmann S, Pensold D, Kurth I, Rothermel M, Mattis VB, Zimmer-Bensch G, von Hörsten S, Denecke B, Clarner T, Meents J, Lampert A. The difficulty to model Huntington's disease in vitro using striatal medium spiny neurons differentiated from human induced pluripotent stem cells. Sci Rep 2021; 11:6934. [PMID: 33767215 PMCID: PMC7994641 DOI: 10.1038/s41598-021-85656-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/03/2021] [Indexed: 12/21/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expanded polyglutamine repeat in the huntingtin gene. The neuropathology of HD is characterized by the decline of a specific neuronal population within the brain, the striatal medium spiny neurons (MSNs). The origins of this extreme vulnerability remain unknown. Human induced pluripotent stem cell (hiPS cell)-derived MSNs represent a powerful tool to study this genetic disease. However, the differentiation protocols published so far show a high heterogeneity of neuronal populations in vitro. Here, we compared two previously published protocols to obtain hiPS cell-derived striatal neurons from both healthy donors and HD patients. Patch-clamp experiments, immunostaining and RT-qPCR were performed to characterize the neurons in culture. While the neurons were mature enough to fire action potentials, a majority failed to express markers typical for MSNs. Voltage-clamp experiments on voltage-gated sodium (Nav) channels revealed a large variability between the two differentiation protocols. Action potential analysis did not reveal changes induced by the HD mutation. This study attempts to demonstrate the current challenges in reproducing data of previously published differentiation protocols and in generating hiPS cell-derived striatal MSNs to model a genetic neurodegenerative disorder in vitro.
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Affiliation(s)
- Kim Le Cann
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Alec Foerster
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Corinna Rösseler
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Andelain Erickson
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Petra Hautvast
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
| | | | - Daniel Pensold
- Institute of Biology II, Division of Functional Epigenetics in the Animal Model, RWTH Aachen University, 52074, Aachen, Germany
| | - Ingo Kurth
- Intitute of Human Genetic, RWTH Aachen University, 52074, Aachen, Germany
| | - Markus Rothermel
- Institute Für Biology II, Department Chemosensation, AG Neuromodulation, 52074, Aachen, Germany
| | - Virginia B Mattis
- Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
- Fujifilm Cellular Dynamics, Madison, WI, 53711, USA
| | - Geraldine Zimmer-Bensch
- Institute of Biology II, Division of Functional Epigenetics in the Animal Model, RWTH Aachen University, 52074, Aachen, Germany
| | - Stephan von Hörsten
- Intitute of Virology, Clinical and Molecular Virology, Animal Center of Preclinical Experiments (PETZ), 91054, Erlangen, Germany
| | | | - Tim Clarner
- Intitute for Neuroanatomy, MIT 1, 52074, Aachen, Germany
| | - Jannis Meents
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.
- Multi Channel Systems MCS GmbH, Aspenhaustrasse 21, 72770, Reutlingen, Germany.
| | - Angelika Lampert
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.
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27
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Deardorff AS, Romer SH, Fyffe RE. Location, location, location: the organization and roles of potassium channels in mammalian motoneurons. J Physiol 2021; 599:1391-1420. [DOI: 10.1113/jp278675] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 01/08/2021] [Indexed: 11/08/2022] Open
Affiliation(s)
- Adam S. Deardorff
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine Dayton OH 45435 USA
- Department of Neurology and Internal Medicine, Wright State University Boonshoft School of Medicine Dayton OH 45435 USA
| | - Shannon H. Romer
- Odyssey Systems Environmental Health Effects Laboratory, Navy Medical Research Unit‐Dayton Wright‐Patterson Air Force Base OH 45433 USA
| | - Robert E.W. Fyffe
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine Dayton OH 45435 USA
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28
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Marino BLB, de Souza LR, Sousa KPA, Ferreira JV, Padilha EC, da Silva CHTP, Taft CA, Hage-Melim LIS. Parkinson's Disease: A Review from Pathophysiology to Treatment. Mini Rev Med Chem 2021; 20:754-767. [PMID: 31686637 DOI: 10.2174/1389557519666191104110908] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/02/2019] [Accepted: 09/02/2019] [Indexed: 12/15/2022]
Abstract
Parkinson's Disease (PD) is the second most common neurodegenerative disease in the elderly population, with a higher prevalence in men, independent of race and social class; it affects approximately 1.5 to 2.0% of the elderly population over 60 years and 4% for those over 80 years of age. PD is caused by the necrosis of dopaminergic neurons in the substantia nigra, which is the brain region responsible for the synthesis of the neurotransmitter dopamine (DA), resulting in its decrease in the synaptic cleft. The monoamine oxidase B (MAO-B) degrades dopamine, promoting the glutamate accumulation and oxidative stress with the release of free radicals, causing excitotoxicity. The PD symptoms are progressive physical limitations such as rigidity, bradykinesia, tremor, postural instability and disability in functional performance. Considering that there are no laboratory tests, biomarkers or imaging studies to confirm the disease, the diagnosis of PD is made by analyzing the motor features. There is no cure for PD, and the pharmacological treatment consists of a dopaminergic supplement with levodopa, COMT inhibitors, anticholinergics agents, dopaminergic agonists, and inhibitors of MAO-B, which basically aims to control the symptoms, enabling better functional mobility and increasing life expectancy of the treated PD patients. Due to the importance and increasing prevalence of PD in the world, this study reviews information on the pathophysiology, symptomatology as well as the most current and relevant treatments of PD patients.
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Affiliation(s)
- Bianca L B Marino
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Amapa, Brazil
| | - Lucilene R de Souza
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Amapa, Brazil
| | - Kessia P A Sousa
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Amapa, Brazil
| | - Jaderson V Ferreira
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Amapa, Brazil
| | - Elias C Padilha
- Faculdade de Ciencias Farmaceuticas, Universidade Estadual Paulista (UNESP), Campus Araraquara, Departamento de Principios Ativos Naturais e Toxicologia, Araraquara, Sao Paulo, Brazil
| | - Carlos H T P da Silva
- Laboratório Computacional de Química Farmacêutica, Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.,Department of Chemistry, School of Philosophy, Sciences and Letters of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Carlton A Taft
- Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
| | - Lorane I S Hage-Melim
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Amapa, Brazil
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29
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Hawkins NA, Misra SN, Jurado M, Kang SK, Vierra NC, Nguyen K, Wren L, George AL, Trimmer JS, Kearney JA. Epilepsy and neurobehavioral abnormalities in mice with a dominant-negative KCNB1 pathogenic variant. Neurobiol Dis 2020; 147:105141. [PMID: 33132203 PMCID: PMC7725922 DOI: 10.1016/j.nbd.2020.105141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/04/2020] [Accepted: 10/12/2020] [Indexed: 11/23/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEE) are a group of severe epilepsies that usually present with intractable seizures, developmental delay, and often have elevated risk for premature mortality. Numerous genes have been identified as a monogenic cause of DEE, including KCNB1. The voltage-gated potassium channel Kv2.1, encoded by KCNB1, is primarily responsible for delayed rectifier potassium currents that are important regulators of excitability in electrically excitable cells, including neurons. In addition to its canonical role as a voltage-gated potassium conductance, Kv2.1 also serves a highly conserved structural function organizing endoplasmic reticulum-plasma membrane junctions clustered in the soma and proximal dendrites of neurons. The de novo pathogenic variant KCNB1-p.G379R was identified in an infant with epileptic spasms, and atonic, focal and tonic-clonic seizures that were refractory to treatment with standard antiepileptic drugs. Previous work demonstrated deficits in potassium conductance, but did not assess non-conducting functions. To determine if the G379R variant affected Kv2.1 clustering at endoplasmic reticulum-plasma membrane junctions, Kv2.1-G379R was expressed in HEK293T cells. Kv2.1-G379R expression did not induce formation of endoplasmic reticulum-plasma membrane junctions, and co-expression of Kv2.1-G379R with Kv2.1-wild-type lowered induction of these structures relative to Kv2.1-WT alone, consistent with a dominant negative effect. To model this variant in vivo, we introduced Kcnb1G379R into mice using CRISPR/Cas9 genome editing. We characterized neuronal expression, neurological and neurobehavioral phenotypes of Kcnb1G379R/+ (Kcnb1R/+) and Kcnb1G379R/G379R (Kcnb1R/R) mice. Immunohistochemistry studies on brains from Kcnb1+/+, Kcnb1R/+ and Kcnb1R/R mice revealed genotype-dependent differences in the expression levels of Kv2.1 protein, as well as associated Kv2.2 and AMIGO-1 proteins. Kcnb1R/+ and Kcnb1R/R mice displayed profound hyperactivity, repetitive behaviors, impulsivity and reduced anxiety. Spontaneous seizures were observed in Kcnb1R/R mice, as well as seizures induced by exposure to novel environments and/ or handling. Both Kcnb1R/+ and Kcnb1R/R mutants were more susceptible to proconvulsant-induced seizures. In addition, both Kcnb1R/+ and Kcnb1R/R mice exhibited abnormal interictal EEG activity, including isolated spike and slow waves. Overall, the Kcnb1G379R mice recapitulate many features observed in individuals with DEE due to pathogenic variants in KCNB1. This new mouse model of KCNB1-associated DEE will be valuable for improving the understanding of the underlying pathophysiology and will provide a valuable tool for the development of therapies to treat this pharmacoresistant DEE.
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Affiliation(s)
- Nicole A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America
| | - Sunita N Misra
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America; Ann & Robert H. Lurie Children's Hospital of Chicago Chicago, IL 60611, United States of America
| | - Manuel Jurado
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America
| | - Seok Kyu Kang
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America
| | - Nicholas C Vierra
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA 95616, United States of America; Department of preceding Physiology and Membrane Biology, University of California, Davis, CA 95616, United States of America
| | - Kimberly Nguyen
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA 95616, United States of America
| | - Lisa Wren
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America
| | - James S Trimmer
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA 95616, United States of America; Department of preceding Physiology and Membrane Biology, University of California, Davis, CA 95616, United States of America
| | - Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States of America.
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30
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Shahid A, Saher M. Repeated exposure of pyriproxyfen to pregnant female mice causes developmental abnormalities in prenatal pups. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:26998-27009. [PMID: 32382916 DOI: 10.1007/s11356-020-08656-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
The continuous exposure to conventional pesticides leads to severe health and environmental issues especially at prenatal stage during developmental period. Herein, we aimed to investigate the anomalies due to repeated exposure of pyriproxyfen in pregnant female mice and their neonates. Twenty-four pregnant female mice were repeatedly administered with pyriproxyfen at 30, 100, 300, and 1000 mg/kg by oral gauge from gestation day (GD) 7 to gestation day 17 and six females were given distilled water in the control group. All the live pups were euthanized at postnatal day (PND) 7 and their organs (heart, liver, kidney, and brain) were dissected out, weighed, and assessed for further histopathological examinations. The results exhibited a significant (P < 0.001) decrease in the body weight gain of all treated pregnant mice in comparison to the controls and a significant increase in the gestational length was observed in group IV (P < 0.01) and group V (P < 0.001). In addition, no live pups were born in groups IV and V and one pregnant female mouse was also found dead in both treatments. The body weights of the pups were significantly decreased in group II (P < 0.05) and group III (P < 0.001) and the relative organ (liver, heart, and kidney) weight of the pups was increased significantly (P < 0.001, P < 0.01, P < 0.05) due to prenatal exposure in group II as compared to group I. The relative brain weights of the pups were decreased significantly (P < 0.001) in groups II and III as compared to group I. The liver, kidney, heart, and brain sections exhibited various histological alterations in groups II and III by hematoxylin and eosin staining. Furthermore, immunohistochemical staining of the coronal sections of pup's brain showed significant (P < 0.001) reduction in cortical radial thickness and total neural count in group II and III as compared to group I. Therefore, the prenatal exposure to pyriproxyfen provoked the damage to various organs in mice offspring and an increase in fetal death at higher doses.
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Affiliation(s)
- Amna Shahid
- Department of Zoology, Government College University, Katchery Road, Lahore, 54000, Pakistan.
| | - Marryam Saher
- Department of Zoology, Government College University, Katchery Road, Lahore, 54000, Pakistan
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31
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Chow LWC, Leung YM. The versatile Kv channels in the nervous system: actions beyond action potentials. Cell Mol Life Sci 2020; 77:2473-2482. [PMID: 31894358 PMCID: PMC11104815 DOI: 10.1007/s00018-019-03415-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 11/16/2019] [Accepted: 12/09/2019] [Indexed: 12/22/2022]
Abstract
Voltage-gated K+ (Kv) channel opening repolarizes excitable cells by allowing K+ efflux. Over the last two decades, multiple Kv functions in the nervous system have been found to be unrelated to or beyond the immediate control of excitability, such as shaping action potential contours or regulation of inter-spike frequency. These functions include neuronal exocytosis and neurite formation, neuronal cell death, regulation of astrocyte Ca2+, glial cell and glioma proliferation. Some of these functions have been shown to be independent of K+ conduction, that is, they suggest the non-canonical functions of Kv channels. In this review, we focus on neuronal or glial plasmalemmal Kv channel functions which are unrelated to shaping action potentials or immediate control of excitability. Similar functions in other cell types will be discussed to some extent in appropriate contexts.
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Affiliation(s)
- Louis W C Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China
- UNIMED Medical Institute, Hong Kong, China
- Organisation for Oncology and Translational Research, Hong Kong, China
| | - Yuk- Man Leung
- Department of Physiology, China Medical University, Taichung, 40402, Taiwan.
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32
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Detection and imaging of gadolinium accumulation in human bone tissue by micro- and submicro-XRF. Sci Rep 2020; 10:6301. [PMID: 32286449 PMCID: PMC7156386 DOI: 10.1038/s41598-020-63325-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/21/2020] [Indexed: 12/30/2022] Open
Abstract
Gadolinium-based contrast agents (GBCAs) are frequently used in patients undergoing magnetic resonance imaging. In GBCAs gadolinium (Gd) is present in a bound chelated form. Gadolinium is a rare-earth element, which is normally not present in human body. Though the blood elimination half-life of contrast agents is about 90 minutes, recent studies demonstrated that some tissues retain gadolinium, which might further pose a health threat due to toxic effects of free gadolinium. It is known that the bone tissue can serve as a gadolinium depot, but so far only bulk measurements were performed. Here we present a summary of experiments in which for the first time we mapped gadolinium in bone biopsy from a male patient with idiopathic osteoporosis (without indication of renal impairment), who received MRI 8 months prior to biopsy. In our studies performed by means of synchrotron radiation induced micro- and submicro-X-ray fluorescence spectroscopy (SR-XRF), gadolinium was detected in human cortical bone tissue. The distribution of gadolinium displays a specific accumulation pattern. Correlation of elemental maps obtained at ANKA synchrotron with qBEI images (quantitative backscattered electron imaging) allowed assignment of Gd structures to the histological bone structures. Follow-up beamtimes at ESRF and Diamond Light Source using submicro-SR-XRF allowed resolving thin Gd structures in cortical bone, as well as correlating them with calcium and zinc.
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33
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Vierra NC, Kirmiz M, van der List D, Santana LF, Trimmer JS. Kv2.1 mediates spatial and functional coupling of L-type calcium channels and ryanodine receptors in mammalian neurons. eLife 2019; 8:49953. [PMID: 31663850 PMCID: PMC6839919 DOI: 10.7554/elife.49953] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/29/2019] [Indexed: 12/16/2022] Open
Abstract
The voltage-gated K+ channel Kv2.1 serves a major structural role in the soma and proximal dendrites of mammalian brain neurons, tethering the plasma membrane (PM) to endoplasmic reticulum (ER). Although Kv2.1 clustering at neuronal ER-PM junctions (EPJs) is tightly regulated and highly conserved, its function remains unclear. By identifying and evaluating proteins in close spatial proximity to Kv2.1-containing EPJs, we discovered that a significant role of Kv2.1 at EPJs is to promote the clustering and functional coupling of PM L-type Ca2+ channels (LTCCs) to ryanodine receptor (RyR) ER Ca2+ release channels. Kv2.1 clustering also unexpectedly enhanced LTCC opening at polarized membrane potentials. This enabled Kv2.1-LTCC-RyR triads to generate localized Ca2+ release events (i.e., Ca2+ sparks) independently of action potentials. Together, these findings uncover a novel mode of LTCC regulation and establish a unique mechanism whereby Kv2.1-associated EPJs provide a molecular platform for localized somatodendritic Ca2+ signals in mammalian brain neurons.
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Affiliation(s)
- Nicholas C Vierra
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, United States.,Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, United States
| | - Michael Kirmiz
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, United States
| | - Deborah van der List
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, United States.,Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, United States
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, United States
| | - James S Trimmer
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, United States.,Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, United States
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Kirmiz M, Gillies TE, Dickson EJ, Trimmer JS. Neuronal ER-plasma membrane junctions organized by Kv2-VAP pairing recruit Nir proteins and affect phosphoinositide homeostasis. J Biol Chem 2019; 294:17735-17757. [PMID: 31594866 DOI: 10.1074/jbc.ra119.007635] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 10/02/2019] [Indexed: 12/21/2022] Open
Abstract
The association of plasma membrane (PM)-localized voltage-gated potassium (Kv2) channels with endoplasmic reticulum (ER)-localized vesicle-associated membrane protein-associated proteins VAPA and VAPB defines ER-PM junctions in mammalian brain neurons. Here, we used proteomics to identify proteins associated with Kv2/VAP-containing ER-PM junctions. We found that the VAP-interacting membrane-associated phosphatidylinositol (PtdIns) transfer proteins PYK2 N-terminal domain-interacting receptor 2 (Nir2) and Nir3 specifically associate with Kv2.1 complexes. When coexpressed with Kv2.1 and VAPA in HEK293T cells, Nir2 colocalized with cell-surface-conducting and -nonconducting Kv2.1 isoforms. This was enhanced by muscarinic-mediated PtdIns(4,5)P2 hydrolysis, leading to dynamic recruitment of Nir2 to Kv2.1 clusters. In cultured rat hippocampal neurons, exogenously expressed Nir2 did not strongly colocalize with Kv2.1, unless exogenous VAPA was also expressed, supporting the notion that VAPA mediates the spatial association of Kv2.1 and Nir2. Immunolabeling signals of endogenous Kv2.1, Nir2, and VAP puncta were spatially correlated in cultured neurons. Fluorescence-recovery-after-photobleaching experiments revealed that Kv2.1, VAPA, and Nir2 have comparable turnover rates at ER-PM junctions, suggesting that they form complexes at these sites. Exogenous Kv2.1 expression in HEK293T cells resulted in significant differences in the kinetics of PtdIns(4,5)P2 recovery following repetitive muscarinic stimulation, with no apparent impact on resting PtdIns(4,5)P2 or PtdIns(4)P levels. Finally, the brains of Kv2.1-knockout mice had altered composition of PtdIns lipids, suggesting a crucial role for native Kv2.1-containing ER-PM junctions in regulating PtdIns lipid metabolism in brain neurons. These results suggest that ER-PM junctions formed by Kv2 channel-VAP pairing regulate PtdIns lipid homeostasis via VAP-associated PtdIns transfer proteins.
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Affiliation(s)
- Michael Kirmiz
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California 95616
| | - Taryn E Gillies
- Department of Bioengineering, Stanford University, Stanford, California 94305
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, California 95616
| | - James S Trimmer
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California 95616 .,Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, California 95616
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35
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Johnson B, Leek AN, Tamkun MM. Kv2 channels create endoplasmic reticulum / plasma membrane junctions: a brief history of Kv2 channel subcellular localization. Channels (Austin) 2019; 13:88-101. [PMID: 30712450 PMCID: PMC6380216 DOI: 10.1080/19336950.2019.1568824] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The potassium channels Kv2.1 and Kv2.2 are widely expressed throughout the mammalian brain. Kv2.1 provides the majority of delayed rectifying current in rat hippocampus while both channels are differentially expressed in cortex. Particularly unusual is their neuronal surface localization pattern: while half the channel population is freely-diffusive on the plasma membrane as expected from the generalized Singer & Nicolson fluid mosaic model, the other half localizes into micron-sized clusters on the soma, dendrites, and axon initial segment. These clusters contain hundreds of channels, which for Kv2.1, are largely non-conducting. Competing theories of the mechanism underlying Kv2.1 clustering have included static tethering to being corralled by an actin fence. Now, recent work has demonstrated channel clustering is due to formation of endoplasmic reticulum/plasma membrane (ER/PM) junctions through interaction with ER-resident VAMP-associated proteins (VAPs). Interaction between surface Kv2 channels and ER VAPs groups channels together in clusters. ER/PM junctions play important roles in inter-organelle communication: they regulate ion flux, are involved in lipid transfer, and are sites of endo- and exocytosis. Kv2-induced ER/PM junctions are regulated through phosphorylation of the channel C-terminus which in turn regulates VAP binding, providing a rapid means to create or dismantle these microdomains. In addition, insults such as hypoxia or ischemia disrupt this interaction resulting in ER/PM junction disassembly. Kv2 channels are the only known plasma membrane protein to form regulated, injury sensitive junctions in this manner. Furthermore, it is likely that concentrated VAPs at these microdomains sequester additional interactors whose functions are not yet fully understood.
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Affiliation(s)
- Ben Johnson
- a Molecular, Cellular and Integrative Neurosciences Graduate Program , Colorado State University , Fort Collins , CO , USA.,b Department of Biomedical Sciences , Colorado State University , Fort Collins , CO , USA
| | - Ashley N Leek
- a Molecular, Cellular and Integrative Neurosciences Graduate Program , Colorado State University , Fort Collins , CO , USA.,b Department of Biomedical Sciences , Colorado State University , Fort Collins , CO , USA
| | - Michael M Tamkun
- a Molecular, Cellular and Integrative Neurosciences Graduate Program , Colorado State University , Fort Collins , CO , USA.,b Department of Biomedical Sciences , Colorado State University , Fort Collins , CO , USA.,c Department of Biochemistry and Molecular Biology , Colorado State University , Fort Collins , CO , USA
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36
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Dong JX, Lee Y, Kirmiz M, Palacio S, Dumitras C, Moreno CM, Sando R, Santana LF, Südhof TC, Gong B, Murray KD, Trimmer JS. A toolbox of nanobodies developed and validated for use as intrabodies and nanoscale immunolabels in mammalian brain neurons. eLife 2019; 8:48750. [PMID: 31566565 PMCID: PMC6785268 DOI: 10.7554/elife.48750] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/18/2019] [Indexed: 12/30/2022] Open
Abstract
Nanobodies (nAbs) are small, minimal antibodies that have distinct attributes that make them uniquely suited for certain biomedical research, diagnostic and therapeutic applications. Prominent uses include as intracellular antibodies or intrabodies to bind and deliver cargo to specific proteins and/or subcellular sites within cells, and as nanoscale immunolabels for enhanced tissue penetration and improved spatial imaging resolution. Here, we report the generation and validation of nAbs against a set of proteins prominently expressed at specific subcellular sites in mammalian brain neurons. We describe a novel hierarchical validation pipeline to systematically evaluate nAbs isolated by phage display for effective and specific use as intrabodies and immunolabels in mammalian cells including brain neurons. These nAbs form part of a robust toolbox for targeting proteins with distinct and highly spatially-restricted subcellular localization in mammalian brain neurons, allowing for visualization and/or modulation of structure and function at those sites.
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Affiliation(s)
- Jie-Xian Dong
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Yongam Lee
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Michael Kirmiz
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Stephanie Palacio
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Camelia Dumitras
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Claudia M Moreno
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, United States.,Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Richard Sando
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford School of Medicine, Stanford, United States
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, United States
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford School of Medicine, Stanford, United States
| | - Belvin Gong
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Karl D Murray
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - James S Trimmer
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States.,Department of Physiology and Membrane Biology, University of California, Davis, Davis, United States
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37
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Sams C, Ayyala RS, Swenson DW. Falling through the worm hole: an exploration of the imaging workup of the vermiform appendix in the pediatric population. BJR Open 2019; 1:20190016. [PMID: 33178945 PMCID: PMC7592479 DOI: 10.1259/bjro.20190016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 08/17/2019] [Accepted: 08/21/2019] [Indexed: 12/26/2022] Open
Abstract
Despite the thousands of articles discussing appendicitis in the literature, the dilemma of how to best diagnosis and manage pediatric appendicitis remains unsettled. Over the past decade, evidence has been mounting about the use of antibiotics as the sole therapy in uncomplicated appendicitis in the adult population. This debate has even recently bled over into the lay press. While this change in practice pattern is still in its infancy for the pediatric population, radiologists should be aware of this change in therapy and how it can impact the imaging work-up and relevant findings. This article concisely summarizes the imaging findings and various imaging pathways to arrive at the diagnose of appendicitis with an emphasis of how to best be of use to our surgical colleagues in this evolving paradigm. It also highlights venues for further research, namely increasing accuracy of differentiating complicated from uncomplicated appendicitis.
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Affiliation(s)
- Cassandra Sams
- Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy St, Providence
| | - Rama S Ayyala
- Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy St, Providence
| | - David W. Swenson
- Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy St, Providence
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38
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Singh V, Mishra VN, Chaurasia RN, Joshi D, Pandey V. Modes of Calcium Regulation in Ischemic Neuron. Indian J Clin Biochem 2019; 34:246-253. [PMID: 31391713 PMCID: PMC6660593 DOI: 10.1007/s12291-019-00838-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022]
Abstract
Calcium (Ca2+) dysregulation is a major catalytic event. Ca2+ dysregulation leads to neuronal cell death and brain damage result in cerebral ischemia. Neurons are unable in maintaining calcium homeostasis. Ca2+ homeostasis imbalance results in increased calcium influx and impaired calcium extrusion across the plasma membrane. Ca2+ dysregulation is mediated by different cellular and biochemical mechanism, which leads to neuronal loss resulting stroke/cerebral ischemia. A better understanding of the Ca2+ dysregulation might help in the development of new treatments in order to reduce ischemic brain injury. An optimal concentration of Ca2+ does not lead to neurotoxicity in the ischemic neuron. Intracellular Ca2+ act as a trigger for acute neurotoxicity and this cause induction of long-lasting processes leading to necrotic and/or apoptotic post-ischemic delayed neuronal death or of compensatory, neuroprotective mechanisms has increased considerably. Moreover, routes of ischemic Ca2+ influx to neurons, involvement of intracellular Ca2+ stores and Ca2+ buffers, spatial and temporal relations between ischemia-induced increases in intracellular Ca2+ concentration and neurotoxicity will further increase our understanding about underlying mechanism and they can act as a target for the development of drugs. Here, in our article we are trying to provide a brief overview of various Ca2+ influx pathways involve in ischemic neuron and how ischemic neuron attempts to counterbalance this calcium overload.
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Affiliation(s)
- Vineeta Singh
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Vijaya Nath Mishra
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Rameshwar Nath Chaurasia
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Deepika Joshi
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Vibha Pandey
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
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39
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Romer SH, Deardorff AS, Fyffe REW. A molecular rheostat: Kv2.1 currents maintain or suppress repetitive firing in motoneurons. J Physiol 2019; 597:3769-3786. [DOI: 10.1113/jp277833] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/29/2019] [Indexed: 12/26/2022] Open
Affiliation(s)
- Shannon H. Romer
- Neuroscience, Cell Biology & PhysiologyBoonshoft School of MedicineWright State University Fairborn OH 45435 USA
- Oak Ridge Institute for Science and EducationEnvironmental Health Effects LaboratoryNavy Medical Research Unit‐DaytonWright‐Patterson Air Force Base OH 45433 USA
| | - Adam S. Deardorff
- Neuroscience, Cell Biology & PhysiologyBoonshoft School of MedicineWright State University Fairborn OH 45435 USA
- Neurology, Boonshoft School of MedicineWright State University Dayton OH 45409 USA
| | - Robert E. W. Fyffe
- Neuroscience, Cell Biology & PhysiologyBoonshoft School of MedicineWright State University Fairborn OH 45435 USA
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40
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Nabel AL, Callan AR, Gleiss SA, Kladisios N, Leibold C, Felmy F. Distinct Distribution Patterns of Potassium Channel Sub-Units in Somato-Dendritic Compartments of Neurons of the Medial Superior Olive. Front Cell Neurosci 2019; 13:38. [PMID: 30837841 PMCID: PMC6390502 DOI: 10.3389/fncel.2019.00038] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 01/23/2019] [Indexed: 12/17/2022] Open
Abstract
Coincidence detector neurons of the medial superior olive (MSO) are sensitive to interaural time differences in the range of a few tens of microseconds. The biophysical basis for this remarkable acuity is a short integration time constant of the membrane, which is achieved by large low voltage-activated potassium and hyperpolarization-activated inward cation conductances. Additional temporal precision is thought to be achieved through a sub-cellular distribution of low voltage-activated potassium channel expression biased to the soma. To evaluate the contribution of potassium channels, we investigated the presence and sub-cellular distribution profile of seven potassium channel sub-units in adult MSO neurons of gerbils. We find that low- and high voltage-activated potassium channels are present with distinct sub-cellular distributions. Overall, low voltage-activated potassium channels appear to be biased to the soma while high voltage-activated potassium channels are more evenly distributed and show a clear expression at distal dendrites. Additionally, low voltage-activated potassium channel sub-units co-localize with glycinergic inputs while HCN1 channels co-localize more with high voltage-activated potassium channels. Functionally, high voltage-activated potassium currents are already active at low voltages near the resting potential. We describe a possible role of high voltage-activated potassium channels in modulating EPSPs in a computational model and contributing to setting the integration time window of coincidental inputs. Our data shows that MSO neurons express a large set of different potassium channels with distinct functional relevance.
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Affiliation(s)
- Alisha L Nabel
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Alexander R Callan
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sarah A Gleiss
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nikolaos Kladisios
- Institute of Zoology, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Christian Leibold
- Computational Neuroscience, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Felix Felmy
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Institute of Zoology, University of Veterinary Medicine Hannover, Hanover, Germany
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41
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Kirmiz M, Palacio S, Thapa P, King AN, Sack JT, Trimmer JS. Remodeling neuronal ER-PM junctions is a conserved nonconducting function of Kv2 plasma membrane ion channels. Mol Biol Cell 2018; 29:2410-2432. [PMID: 30091655 PMCID: PMC6233057 DOI: 10.1091/mbc.e18-05-0337] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The endoplasmic reticulum (ER) and plasma membrane (PM) form junctions crucial to ion and lipid signaling and homeostasis. The Kv2.1 ion channel is localized at ER–PM junctions in brain neurons and is unique among PM proteins in its ability to remodel these specialized membrane contact sites. Here, we show that this function is conserved between Kv2.1 and Kv2.2, which differ in their biophysical properties, modulation, and cellular expression. Kv2.2 ER–PM junctions are present at sites deficient in the actin cytoskeleton, and disruption of the actin cytoskeleton affects their spatial organization. Kv2.2-containing ER–PM junctions overlap with those formed by canonical ER–PM tethers. The ability of Kv2 channels to remodel ER–PM junctions is unchanged by point mutations that eliminate their ion conduction but eliminated by point mutations within the Kv2-specific proximal restriction and clustering (PRC) domain that do not impact their ion channel function. The highly conserved PRC domain is sufficient to transfer the ER–PM junction–remodeling function to another PM protein. Last, brain neurons in Kv2 double-knockout mice have altered ER–PM junctions. Together, these findings demonstrate a conserved in vivo function for Kv2 family members in remodeling neuronal ER–PM junctions that is distinct from their canonical role as ion-conducting channels shaping neuronal excitability.
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Affiliation(s)
- Michael Kirmiz
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616
| | - Stephanie Palacio
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616
| | - Parashar Thapa
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616
| | - Anna N King
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616.,Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA 95616
| | - James S Trimmer
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616.,Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616
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Identification of VAPA and VAPB as Kv2 Channel-Interacting Proteins Defining Endoplasmic Reticulum-Plasma Membrane Junctions in Mammalian Brain Neurons. J Neurosci 2018; 38:7562-7584. [PMID: 30012696 DOI: 10.1523/jneurosci.0893-18.2018] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/01/2018] [Accepted: 07/07/2018] [Indexed: 11/21/2022] Open
Abstract
Membrane contacts between endoplasmic reticulum (ER) and plasma membrane (PM), or ER-PM junctions, are ubiquitous in eukaryotic cells and are platforms for lipid and calcium signaling and homeostasis. Recent studies have revealed proteins crucial to the formation and function of ER-PM junctions in non-neuronal cells, but little is known of the ER-PM junctions prominent in aspiny regions of mammalian brain neurons. The Kv2.1 voltage-gated potassium channel is abundantly clustered at ER-PM junctions in brain neurons and is the first PM protein that functions to organize ER-PM junctions. However, the molecular mechanism whereby Kv2.1 localizes to and remodels these junctions is unknown. We used affinity immunopurification and mass spectrometry-based proteomics on brain samples from male and female WT and Kv2.1 KO mice and identified the resident ER vesicle-associated membrane protein-associated proteins isoforms A and B (VAPA and VAPB) as prominent Kv2.1-associated proteins. Coexpression with Kv2.1 or its paralog Kv2.2 was sufficient to recruit VAPs to ER-PM junctions. Multiplex immunolabeling revealed colocalization of Kv2.1 and Kv2.2 with endogenous VAPs at ER-PM junctions in brain neurons from male and female mice in situ and in cultured rat hippocampal neurons, and KO of VAPA in mammalian cells reduces Kv2.1 clustering. The association of VAPA with Kv2.1 relies on a "two phenylalanines in an acidic tract" (FFAT) binding domain on VAPA and a noncanonical phosphorylation-dependent FFAT motif comprising the Kv2-specific clustering or PRC motif. These results suggest that Kv2.1 localizes to and organizes neuronal ER-PM junctions through an interaction with VAPs.SIGNIFICANCE STATEMENT Our study identified the endoplasmic reticulum (ER) proteins vesicle-associated membrane protein-associated proteins isoforms A and B (VAPA and VAPB) as proteins copurifying with the plasma membrane (PM) Kv2.1 ion channel. We found that expression of Kv2.1 recruits VAPs to ER-PM junctions, specialized membrane contact sites crucial to distinct aspects of cell function. We found endogenous VAPs at Kv2.1-mediated ER-PM junctions in brain neurons and other mammalian cells and that knocking out VAPA expression disrupts Kv2.1 clustering. We identified domains of VAPs and Kv2.1 necessary and sufficient for their association at ER-PM junctions. Our study suggests that Kv2.1 expression in the PM can affect ER-PM junctions via its phosphorylation-dependent association to ER-localized VAPA and VAPB.
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43
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Kv2 potassium channels form endoplasmic reticulum/plasma membrane junctions via interaction with VAPA and VAPB. Proc Natl Acad Sci U S A 2018; 115:E7331-E7340. [PMID: 29941597 DOI: 10.1073/pnas.1805757115] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Kv2.1 exhibits two distinct forms of localization patterns on the neuronal plasma membrane: One population is freely diffusive and regulates electrical activity via voltage-dependent K+ conductance while a second one localizes to micrometer-sized clusters that contain densely packed, but nonconducting, channels. We have previously established that these clusters represent endoplasmic reticulum/plasma membrane (ER/PM) junctions that function as membrane trafficking hubs and that Kv2.1 plays a structural role in forming these membrane contact sites in both primary neuronal cultures and transfected HEK cells. Clustering and the formation of ER/PM contacts are regulated by phosphorylation within the channel C terminus, offering cells fast, dynamic control over the physical relationship between the cortical ER and PM. The present study addresses the mechanisms by which Kv2.1 and the related Kv2.2 channel interact with the ER membrane. Using proximity-based biotinylation techniques in transfected HEK cells we identified ER VAMP-associated proteins (VAPs) as potential Kv2.1 interactors. Confirmation that Kv2.1 and -2.2 bind VAPA and VAPB employed colocalization/redistribution, siRNA knockdown, and Förster resonance energy transfer (FRET)-based assays. CD4 chimeras containing sequence from the Kv2.1 C terminus were used to identify a noncanonical VAP-binding motif. VAPs were first identified as proteins required for neurotransmitter release in Aplysia and are now known to be abundant scaffolding proteins involved in membrane contact site formation throughout the ER. The VAP interactome includes AKAPs, kinases, membrane trafficking machinery, and proteins regulating nonvesicular lipid transport from the ER to the PM. Therefore, the Kv2-induced VAP concentration at ER/PM contact sites is predicted to have wide-ranging effects on neuronal cell biology.
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