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Wahl N, Espeso-Gil S, Chietera P, Nagel A, Laighneach A, Morris DW, Rajarajan P, Akbarian S, Dechant G, Apostolova G. SATB2 organizes the 3D genome architecture of cognition in cortical neurons. Mol Cell 2024; 84:621-639.e9. [PMID: 38244545 PMCID: PMC10923151 DOI: 10.1016/j.molcel.2023.12.024] [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: 01/27/2023] [Revised: 10/02/2023] [Accepted: 12/15/2023] [Indexed: 01/22/2024]
Abstract
The DNA-binding protein SATB2 is genetically linked to human intelligence. We studied its influence on the three-dimensional (3D) epigenome by mapping chromatin interactions and accessibility in control versus SATB2-deficient cortical neurons. We find that SATB2 affects the chromatin looping between enhancers and promoters of neuronal-activity-regulated genes, thus influencing their expression. It also alters A/B compartments, topologically associating domains, and frequently interacting regions. Genes linked to SATB2-dependent 3D genome changes are implicated in highly specialized neuronal functions and contribute to cognitive ability and risk for neuropsychiatric and neurodevelopmental disorders. Non-coding DNA regions with a SATB2-dependent structure are enriched for common variants associated with educational attainment, intelligence, and schizophrenia. Our data establish SATB2 as a cell-type-specific 3D genome modulator, which operates both independently and in cooperation with CCCTC-binding factor (CTCF) to set up the chromatin landscape of pyramidal neurons for cognitive processes.
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Affiliation(s)
- Nico Wahl
- Institute for Neuroscience, Medical University of Innsbruck, Innsbruck 6020, Austria.
| | - Sergio Espeso-Gil
- Institute for Neuroscience, Medical University of Innsbruck, Innsbruck 6020, Austria; Department of Psychiatry, Friedman Brain Institute, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Paola Chietera
- Institute for Neuroscience, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Amelie Nagel
- Institute for Neuroscience, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Aodán Laighneach
- Centre for Neuroimaging, Cognition and Genomics (NICOG), School of Biological and Chemical Sciences, University of Galway, Galway, H91 TK33, Ireland
| | - Derek W Morris
- Centre for Neuroimaging, Cognition and Genomics (NICOG), School of Biological and Chemical Sciences, University of Galway, Galway, H91 TK33, Ireland
| | - Prashanth Rajarajan
- Department of Psychiatry, Friedman Brain Institute, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Schahram Akbarian
- Department of Psychiatry, Friedman Brain Institute, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Georg Dechant
- Institute for Neuroscience, Medical University of Innsbruck, Innsbruck 6020, Austria.
| | - Galina Apostolova
- Institute for Neuroscience, Medical University of Innsbruck, Innsbruck 6020, Austria.
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2
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Kovács-Öller T, Szarka G, Hoffmann G, Péntek L, Valentin G, Ross L, Völgyi B. Extrinsic and Intrinsic Factors Determine Expression Levels of Gap Junction-Forming Connexins in the Mammalian Retina. Biomolecules 2023; 13:1119. [PMID: 37509155 PMCID: PMC10377540 DOI: 10.3390/biom13071119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Gap junctions (GJs) are not static bridges; instead, GJs as well as the molecular building block connexin (Cx) proteins undergo major expression changes in the degenerating retinal tissue. Various progressive diseases, including retinitis pigmentosa, glaucoma, age-related retinal degeneration, etc., affect neurons of the retina and thus their neuronal connections endure irreversible changes as well. Although Cx expression changes might be the hallmarks of tissue deterioration, GJs are not static bridges and as such they undergo adaptive changes even in healthy tissue to respond to the ever-changing environment. It is, therefore, imperative to determine these latter adaptive changes in GJ functionality as well as in their morphology and Cx makeup to identify and distinguish them from alterations following tissue deterioration. In this review, we summarize GJ alterations that take place in healthy retinal tissue and occur on three different time scales: throughout the entire lifespan, during daily changes and as a result of quick changes of light adaptation.
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Affiliation(s)
- Tamás Kovács-Öller
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Gergely Szarka
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Gyula Hoffmann
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Loretta Péntek
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Gréta Valentin
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Liliana Ross
- Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Béla Völgyi
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
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3
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Genet N, Genet G, Chavkin NW, Paila U, Fang JS, Vasavada HH, Goldberg JS, Acharya BR, Bhatt NS, Baker K, McDonnell SP, Huba M, Sankaranarayanan D, Ma GZM, Eichmann A, Thomas JL, Ffrench-Constant C, Hirschi KK. Connexin 43-mediated neurovascular interactions regulate neurogenesis in the adult brain subventricular zone. Cell Rep 2023; 42:112371. [PMID: 37043357 PMCID: PMC10564973 DOI: 10.1016/j.celrep.2023.112371] [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: 04/12/2022] [Revised: 02/20/2023] [Accepted: 03/22/2023] [Indexed: 04/13/2023] Open
Abstract
The subventricular zone (SVZ) is the largest neural stem cell (NSC) niche in the adult brain; herein, the blood-brain barrier is leaky, allowing direct interactions between NSCs and endothelial cells (ECs). Mechanisms by which direct NSC-EC interactions in the adult SVZ control NSC behavior are unclear. We found that Cx43 is highly expressed by SVZ NSCs and ECs, and its deletion in either leads to increased NSC proliferation and neuroblast generation, suggesting that Cx43-mediated NSC-EC interactions maintain NSC quiescence. This is further supported by single-cell RNA sequencing and in vitro studies showing that ECs control NSC proliferation by regulating expression of genes associated with NSC quiescence and/or activation in a Cx43-dependent manner. Cx43 mediates these effects in a channel-independent manner involving its cytoplasmic tail and ERK activation. Such insights inform adult NSC regulation and maintenance aimed at stem cell therapies for neurodegenerative disorders.
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Affiliation(s)
- Nafiisha Genet
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Gael Genet
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Nicholas W Chavkin
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Umadevi Paila
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Jennifer S Fang
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Hema H Vasavada
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Joshua S Goldberg
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Bipul R Acharya
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Neha S Bhatt
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Kasey Baker
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA; Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neurology, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Stephanie P McDonnell
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Mahalia Huba
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Danya Sankaranarayanan
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Gerry Z M Ma
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK; Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
| | - Anne Eichmann
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Jean-Leon Thomas
- Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neurology, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Charles Ffrench-Constant
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK; Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
| | - Karen K Hirschi
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA.
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Understanding the Role of ATP Release through Connexins Hemichannels during Neurulation. Int J Mol Sci 2023; 24:ijms24032159. [PMID: 36768481 PMCID: PMC9916920 DOI: 10.3390/ijms24032159] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/30/2022] [Accepted: 01/04/2023] [Indexed: 01/25/2023] Open
Abstract
Neurulation is a crucial process in the formation of the central nervous system (CNS), which begins with the folding and fusion of the neural plate, leading to the generation of the neural tube and subsequent development of the brain and spinal cord. Environmental and genetic factors that interfere with the neurulation process promote neural tube defects (NTDs). Connexins (Cxs) are transmembrane proteins that form gap junctions (GJs) and hemichannels (HCs) in vertebrates, allowing cell-cell (GJ) or paracrine (HCs) communication through the release of ATP, glutamate, and NAD+; regulating processes such as cell migration and synaptic transmission. Changes in the state of phosphorylation and/or the intracellular redox potential activate the opening of HCs in different cell types. Cxs such as Cx43 and Cx32 have been associated with proliferation and migration at different stages of CNS development. Here, using molecular and cellular biology techniques (permeability), we demonstrate the expression and functionality of HCs-Cxs, including Cx46 and Cx32, which are associated with the release of ATP during the neurulation process in Xenopus laevis. Furthermore, applications of FGF2 and/or changes in intracellular redox potentials (DTT), well known HCs-Cxs modulators, transiently regulated the ATP release in our model. Importantly, the blockade of HCs-Cxs by carbenoxolone (CBX) and enoxolone (ENX) reduced ATP release with a concomitant formation of NTDs. We propose two possible and highly conserved binding sites (N and E) in Cx46 that may mediate the pharmacological effect of CBX and ENX on the formation of NTDs. In summary, our results highlight the importance of ATP release mediated by HCs-Cxs during neurulation.
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5
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Singhal P, Senecal JMM, Nagy JI. Expression of the gap junction protein connexin36 in small intensely fluorescent (SIF) cells in cardiac parasympathetic ganglia of rodents. Neurosci Lett 2023; 793:136989. [PMID: 36471528 DOI: 10.1016/j.neulet.2022.136989] [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: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/28/2022]
Abstract
In mammals, several endocrine cell types are electrically coupled by connexin36 (Cx36)-containing gap junctions, which mediate intercellular communication and allow regulated and synchronized cellular activity through exchange of ions and small metabolites via formation of intercellular channels that link plasma membranes of apposing cells. One cell type thought to be endocrine-like in nature are small intensely fluorescent (SIF) cells that store catecholamines in their dense-core vesicles and reside in autonomic ganglia. Here, using immunofluorescence approaches, we examined whether SIF cells located specifically in cardiac parasympathetic ganglia of adult and neonatal mice and adult rats follow patterns of Cx36 expression seen in other endocrine cells. In these ganglia, SIF cells were identified by their distinct small soma size, autofluorescence at 475 nm, and immunolabelling for their markers tyrosine hydroxylase and vesicular monoamine transporter-1. SIF cells were often found in pairs or clusters among principal cholinergic neurons. Immunofluorescence labelling of Cx36 occurred exclusively as fine puncta that appeared at contacts between SIF cell processes and somata or at somato-somatic appositions of SIF cells. These puncta were absent in cardiac parasympathetic ganglia of Cx36 null mice. Transgenic mice expressing enhanced green fluorescent protein reporter for Cx36 expression displayed labelling for the reporter in SIF cells. The results suggest that Cx36-containing gap junctions electrically couple SIF cells, which is consistent with previous suggestions that these may be classified as endocrine-type cells that secrete catecholamines into the bloodstream in a regulated manner.
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Affiliation(s)
- P Singhal
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - J M M Senecal
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - J I Nagy
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada.
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Hendi A, Niu LG, Snow AW, Ikegami R, Wang ZW, Mizumoto K. Channel-independent function of UNC-9/Innexin in spatial arrangement of GABAergic synapses in C. elegans. eLife 2022; 11:80555. [PMID: 36378164 PMCID: PMC9665852 DOI: 10.7554/elife.80555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022] Open
Abstract
Precise synaptic connection of neurons with their targets is essential for the proper functioning of the nervous system. A plethora of signaling pathways act in concert to mediate the precise spatial arrangement of synaptic connections. Here we show a novel role for a gap junction protein in controlling tiled synaptic arrangement in the GABAergic motor neurons in Caenorhabditis elegans, in which their axons and synapses overlap minimally with their neighboring neurons within the same class. We found that while EGL-20/Wnt controls axonal tiling, their presynaptic tiling is mediated by a gap junction protein UNC-9/Innexin, that is localized at the presynaptic tiling border between neighboring dorsal D-type GABAergic motor neurons. Strikingly, the gap junction channel activity of UNC-9 is dispensable for its function in controlling tiled presynaptic patterning. While gap junctions are crucial for the proper functioning of the nervous system as channels, our finding uncovered the novel channel-independent role of UNC-9 in synapse patterning.
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Affiliation(s)
- Ardalan Hendi
- Department of Zoology, University of British Columbia
- Life Sciences Institute, University of British Columbia
| | - Long-Gang Niu
- Department of Neuroscience, University of Connecticut Health Center
| | - Andrew William Snow
- Graduate Program in Cell and Developmental Biology, University of British Columbia
| | | | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center
| | - Kota Mizumoto
- Department of Zoology, University of British Columbia
- Life Sciences Institute, University of British Columbia
- Graduate Program in Cell and Developmental Biology, University of British Columbia
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia
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Cibelli A, Scemes E, Spray DC. Activity and Stability of Panx1 Channels in Astrocytes and Neuroblastoma Cells Are Enhanced by Cholesterol Depletion. Cells 2022; 11:3219. [PMID: 36291086 PMCID: PMC9600160 DOI: 10.3390/cells11203219] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/01/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2022] Open
Abstract
Pannexin1 (Panx1) is expressed in both neurons and glia where it forms ATP-permeable channels that are activated under pathological conditions such as epilepsy, migraine, inflammation, and ischemia. Membrane lipid composition affects proper distribution and function of receptors and ion channels, and defects in cholesterol metabolism are associated with neurological diseases. In order to understand the impact of membrane cholesterol on the distribution and function of Panx1 in neural cells, we used fluorescence recovery after photobleaching (FRAP) to evaluate its mobility and electrophysiology and dye uptake to assess channel function. We observed that cholesterol extraction (using methyl-β-cyclodextrin) and inhibition of its synthesis (lovastatin) decreased the lateral diffusion of Panx1 in the plasma membrane. Panx1 channel activity (dye uptake, ATP release and ionic current) was enhanced in cholesterol-depleted Panx1 transfected cells and in wild-type astrocytes compared to non-depleted or Panx1 null cells. Manipulation of cholesterol levels may, therefore, offer a novel strategy by which Panx1 channel activation might modulate various pathological conditions.
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Affiliation(s)
- Antonio Cibelli
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, NY Medical College, Valhalla, NY10595, USA
| | - David C. Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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8
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Expression of Pannexin 1 in the Human Kidney during Embryonal, Early Fetal and Postnatal Development and Its Prognostic Significance in Diabetic Nephropathy. Biomedicines 2022; 10:biomedicines10050944. [PMID: 35625681 PMCID: PMC9139113 DOI: 10.3390/biomedicines10050944] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/31/2022] [Accepted: 04/19/2022] [Indexed: 02/01/2023] Open
Abstract
Pannexins are transmembrane glycoproteins that constitute channels involved in purinergic signaling through ATP release from cells in various physiological and pathological processes. In this study, the distribution of Panx1 expression in different cell populations of healthy postnatal human kidneys and during human embryonic and early fetal development was investigated by double immunohistochemistry. In addition, the glomerular and tubular expression of Panx1 was examined in patients with type 2 diabetes mellitus (DM2) and the control group, and renal Panx1 expression was correlated with serum creatinine. In the 6th week of embryonic development (DW), Panx1 expression was found in mesonephric glomeruli and mesonephric tubules. At the transition from 6th to 7th DW, Panx1 immunoreactivity was found in the mesonephric tubules and mesonephric duct, as well as in the metanephric ureteric bud and ampullae. In the 7th DW, strong Panx1 immunoreactivity was observed in the developing ureteric bud in the metanephros, whereas no Panx1 immunoreactivity was found in the metanephric cup. In the 8th DW, Panx1 expression was also found in the ureteric bud of the metanephros, the renal vesicle and comma-shaped nephron, and the epithelial cells of Bowman’s capsule. Expression of Panx1 was found at an early stage in both the paramesonephric duct and the mesonephric duct and diminished toward the 8th DW. During the 6th–10th DW, colocalization of Panx1 with alpha smooth actin (aSMA) was found in developing blood vessels. In the postnatal kidney, strong Panx1 immunoreactivity was present in medullary and cortical collecting duct cells, renin-producing cells, and proximal tubules. Very weak Panx1 immunoreactivity was found in certain distal tubule cells and the thin descending limbs of the loop of Henle. Panx1 immunoreactivity was also found in nephrin-immunoreactive podocytes. Panx1 was not colocalized with aSMA immunoreactivity in the vessels of the postnatal human kidney, but it was present in the endothelium. A significant positive correlation was found between Panx1 expression in glomeruli and serum creatinine only in diabetic patients and was not found in the nondiabetic group. The spatiotemporal expression of Panx1 during the early stages of human kidney development supports its possible role in cellular differentiation, migration, and positioning in the developing human kidney. In addition, our data suggest that glomerular Panx1 expression is a potential indicator of worsening renal function in patients with type 2 diabetes.
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Köse B, Özkan M, Sur-Erdem İ, Çavdar S. Does astrocyte gap junction protein expression level differ during development in the absence epileptic rats? Synapse 2022; 76:e22225. [PMID: 35137459 DOI: 10.1002/syn.22225] [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: 11/17/2021] [Revised: 01/05/2022] [Accepted: 01/27/2022] [Indexed: 11/09/2022]
Abstract
Intercellular communication via gap junctions (GJ) has a wide variety of complex and essential functions in the CNS. In the present developmental study, we aimed to quantify the number of astrocytic GJ protein connexin 30 (Cx30) of genetic absence epilepsy rats from Strasbourg (GAERS) at postnatal P10, P30, and P60 days in the epileptic focal areas involved in the cortico-thalamic circuit. We compared the results with Wistar rats using immunohistochemistry and Western Blotting. The number of Cx30 immunopositive astrocytes in per unit area were quantified for the somatosensory cortex (SSCx), ventrobasal (VB), and lateral geniculate (LGN) of the two strains and Cx30 Western Blot was applied to the tissue samples from the same regions. Both immunohistochemical and Western Blot results revealed the presence of Cx30 in all regions studied at P10 in both Wistar and GAERS animals. The SSCx, VB, and LGN of Wistar animals showed progressive increase in the number of Cx30 immunopositive labelled astrocytes from P10 to P30 and reached a peak at P30; then a significant decline was observed from P30 to P60 for the SSCx and VB. However, in GAERS Cx30 immunopositive labelled astrocytes showed a progressive increase from P10 to P60 for all brain regions studied. The immunohistochemical data highly corresponded with Western Blotting results. We conclude that the developmental disproportional expression of Cx30 in the epileptic focal areas in GAERS may be related to the onset of absence seizures or may be related to the neurogenesis of absence epilepsy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Büşra Köse
- Department of Anatomy, Koç University School of Medicine, Istanbul, Turkey
| | - Mazhar Özkan
- Department of Anatomy, Tekirdağ Namık Kemal University School of Medicine, Istanbul, Turkey
| | - İlknur Sur-Erdem
- Department of Molecular Biology, Koç University School of Medicine, Istanbul, Turkey
| | - Safiye Çavdar
- Department of Anatomy, Koç University School of Medicine, Istanbul, Turkey
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Karpinski BA, Maynard TM, Bryan CA, Yitsege G, Horvath A, Lee NH, Moody SA, LaMantia AS. Selective disruption of trigeminal sensory neurogenesis and differentiation in a mouse model of 22q11.2 deletion syndrome. Dis Model Mech 2022; 15:dmm047357. [PMID: 33722956 PMCID: PMC8126478 DOI: 10.1242/dmm.047357] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/09/2021] [Indexed: 12/13/2022] Open
Abstract
22q11.2 Deletion Syndrome (22q11DS) is a neurodevelopmental disorder associated with cranial nerve anomalies and disordered oropharyngeal function, including pediatric dysphagia. Using the LgDel 22q11DS mouse model, we investigated whether sensory neuron differentiation in the trigeminal ganglion (CNgV), which is essential for normal orofacial function, is disrupted. We did not detect changes in cranial placode cell translocation or neural crest migration at early stages of LgDel CNgV development. However, as the ganglion coalesces, proportions of placode-derived LgDel CNgV cells increase relative to neural crest cells. In addition, local aggregation of placode-derived cells increases and aggregation of neural crest-derived cells decreases in LgDel CNgV. This change in cell-cell relationships was accompanied by altered proliferation of placode-derived cells at embryonic day (E)9.5, and premature neurogenesis from neural crest-derived precursors, reflected by an increased frequency of asymmetric neurogenic divisions for neural crest-derived precursors by E10.5. These early differences in LgDel CNgV genesis prefigure changes in sensory neuron differentiation and gene expression by postnatal day 8, when early signs of cranial nerve dysfunction associated with pediatric dysphagia are observed in LgDel mice. Apparently, 22q11 deletion destabilizes CNgV sensory neuron genesis and differentiation by increasing variability in cell-cell interaction, proliferation and sensory neuron differentiation. This early developmental divergence and its consequences may contribute to oropharyngeal dysfunction, including suckling, feeding and swallowing disruptions at birth, and additional orofacial sensory/motor deficits throughout life.
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Affiliation(s)
- Beverly A. Karpinski
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20037, USA
| | - Thomas M. Maynard
- The Fralin Biomedical Research Institute, Virginia Tech Carilion School of Medicine, Roanoke, VA 24014, USA
| | - Corey A. Bryan
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20037, USA
| | - Gelila Yitsege
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20037, USA
| | - Anelia Horvath
- Department of Pharmacology and Physiology, The George Washington School of Medicine and Health Sciences, Washington DC, 20037, USA
| | - Norman H. Lee
- Department of Pharmacology and Physiology, The George Washington School of Medicine and Health Sciences, Washington DC, 20037, USA
| | - Sally A. Moody
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20037, USA
| | - Anthony-Samuel LaMantia
- The Fralin Biomedical Research Institute, Virginia Tech Carilion School of Medicine, Roanoke, VA 24014, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
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11
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Talukdar S, Emdad L, Das SK, Fisher PB. GAP junctions: multifaceted regulators of neuronal differentiation. Tissue Barriers 2021; 10:1982349. [PMID: 34651545 DOI: 10.1080/21688370.2021.1982349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Gap junctions are intercellular membrane channels consisting of connexin proteins, which contribute to direct cytoplasmic exchange of small molecules, substrates and metabolites between adjacent cells. These channels play important roles in neuronal differentiation, maintenance, survival and function. Gap junctions regulate differentiation of neurons from embryonic, neural and induced pluripotent stem cells. In addition, they control transdifferentiation of neurons from mesenchymal stem cells. The expression and levels of several connexins correlate with cell cycle changes and different stages of neurogenesis. Connexins such as Cx36, Cx45, and Cx26, play a crucial role in neuronal function. Several connexin knockout mice display lethal or severely impaired phenotypes. Aberrations in connexin expression is frequently associated with various neurodegenerative disorders. Gap junctions also act as promising therapeutic targets for neuronal regenerative medicine, because of their role in neural stem cell integration, injury and remyelination.
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Affiliation(s)
- Sarmistha Talukdar
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States.,Vcu Institute of Molecular Medicine, Richmond, VA, United States
| | - Luni Emdad
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States.,Vcu Institute of Molecular Medicine, Richmond, VA, United States.,Vcu Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States
| | - Swadesh K Das
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States.,Vcu Institute of Molecular Medicine, Richmond, VA, United States.,Vcu Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States
| | - Paul B Fisher
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States.,Vcu Institute of Molecular Medicine, Richmond, VA, United States.,Vcu Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States
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12
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D'Amico D, Valdebenito S, Eugenin EA. The role of Pannexin-1 channels and extracellular ATP in the pathogenesis of the human immunodeficiency virus. Purinergic Signal 2021; 17:563-576. [PMID: 34542793 DOI: 10.1007/s11302-021-09817-3] [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: 06/03/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022] Open
Abstract
Only recently, the role of large ionic channels such as Pannexin-1 channels and Connexin hemichannels has been implicated in several physiological and pathological conditions, including HIV infection and associated comorbidities. These channels are in a closed stage in healthy conditions, but in pathological conditions including HIV, Pannexin-1 channels and Connexin hemichannels become open. Our data demonstrate that acute and chronic HIV infection induces channel opening (Pannexin and Connexin channels), ATP release into the extracellular space, and subsequent activation of purinergic receptors in immune and non-immune cells. We demonstrated that Pannexin and Connexin channels contribute to HIV infection and replication, the long-term survival of viral reservoirs, and comorbidities such as NeuroHIV. Here, we discuss the available data to support the participation of these channels in the HIV life cycle and the potential therapeutic approach to prevent HIV-associated comorbidities.
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Affiliation(s)
- Daniela D'Amico
- Department of Neuroscience , Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX, 77555, USA
| | - Silvana Valdebenito
- Department of Neuroscience , Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX, 77555, USA
| | - Eliseo A Eugenin
- Department of Neuroscience , Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX, 77555, USA.
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13
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Development, Diversity, and Death of MGE-Derived Cortical Interneurons. Int J Mol Sci 2021; 22:ijms22179297. [PMID: 34502208 PMCID: PMC8430628 DOI: 10.3390/ijms22179297] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 12/17/2022] Open
Abstract
In the mammalian brain, cortical interneurons (INs) are a highly diverse group of cells. A key neurophysiological question concerns how each class of INs contributes to cortical circuit function and whether specific roles can be attributed to a selective cell type. To address this question, researchers are integrating knowledge derived from transcriptomic, histological, electrophysiological, developmental, and functional experiments to extensively characterise the different classes of INs. Our hope is that such knowledge permits the selective targeting of cell types for therapeutic endeavours. This review will focus on two of the main types of INs, namely the parvalbumin (PV+) or somatostatin (SOM+)-containing cells, and summarise the research to date on these classes.
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14
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Ngezahayo A, Ruhe FA. Connexins in the development and physiology of stem cells. Tissue Barriers 2021; 9:1949242. [PMID: 34227910 DOI: 10.1080/21688370.2021.1949242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Connexins (Cxs) form gap junction (GJ) channels linking vertebrate cells. During embryogenesis, Cxs are expressed as early as the 4-8 cell stage. As cells differentiate into pluripotent stem cells (PSCs) and during gastrulation, the Cx expression pattern is adapted. Knockdown of Cx43 and Cx45 does not interfere with embryogenic development until the blastula stage, questioning the role of Cxs in PSC physiology and development. Studies in cultivated and induced PSCs (iPSCs) showed that Cx43 is essential for the maintenance of self-renewal and the expression of pluripotency markers. It was found that the role of Cxs in PSCs is more related to regulation of transcription or cell-cell adherence than to formation of GJ channels. Furthermore, a crucial role of Cxs for the self-renewal and differentiation was shown in cultivated adult mesenchymal stem cells. This review aims to highlight aspects that link Cxs to the function and physiology of stem cell development.
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Affiliation(s)
- Anaclet Ngezahayo
- Dept. Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hannover, Germany.,Center for Systems Neuroscience (ZSN), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Frederike A Ruhe
- Dept. Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hannover, Germany
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15
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Çavdar S, Köse B, Sur-Erdem İ, Özkan M. Comparing astrocytic gap junction of genetic absence epileptic rats with control rats: an experimental study. Brain Struct Funct 2021; 226:2113-2123. [PMID: 34097147 DOI: 10.1007/s00429-021-02310-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
The synchronization of astrocytes via gap junctions (GJ) is a crucial mechanism in epileptic conditions, contributing to the synchronization of the neuronal networks. Little is known about the endogenous response of GJ in genetic absence epileptic animal models. We evaluated and quantified astrocyte GJ protein connexin (Cx) 30 and 43 in the somatosensory cortex (SSCx), ventrobasal (VB), centromedian (CM), lateral geniculate (LGN) and thalamic reticular (TRN) nuclei of thalamus of genetic absence epilepsy rats from Strasbourg (GAERS), Wistar albino glaxo rats from Rijswijk (WAG/Rij) and control Wistar animals using immunohistochemistry and Western Blot. The Cx30 and Cx43 immunopositive astrocytes per unit area were quantified for each region of the three animal strains. Furthermore, Cx30 and Cx43 Western Blot was applied to the tissue samples from the same regions of the three strain. The number of Cx30 immunopositive astrocytes showed significant increase in both GAERS and WAG/Rij compared to control Wistar in all brain regions studied except LGN of WAG/Rij animals. Furthermore, Cx43 in both GAERS and WAG/Rij showed significant increase in SSCx, VB and TRN. The protein expression was increased in both Cx30 and Cx43 in the two epileptic strains compared to control Wistar animals. The significant increase in the astrocytic GJ proteins Cx30 and Cx43 and the differences in the co-expression of Cx30 and Cx43 in the genetically absence epileptic strains compared to control Wistar animals may suggest that astrocytic Cx's may be involved in the mechanism of absence epilepsy. Increased number of astrocytic Cx's in GAERS and WAG/Rij may represent a compensatory response of the thalamocortical circuitry to the absence seizures or may be related to the production and/or development of absence seizures.
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Affiliation(s)
- Safiye Çavdar
- Department of Anatomy, Koç University School of Medicine, 34450 Sarıyer, Istanbul, Turkey.
| | - Büşra Köse
- Department of Anatomy, Koç University School of Medicine, 34450 Sarıyer, Istanbul, Turkey
| | - İlknur Sur-Erdem
- Department of Molecular Biology, Koç University School of Medicine, Istanbul, Turkey
| | - Mazhar Özkan
- Department of Anatomy, Tekirdağ Namık Kemal University School of Medicine, Istanbul, Turkey
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16
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Qian D, Zheng Q, Wu D, Ye B, Qian Y, Zhou T, Qiu J, Meng X. Integrated Analysis of ceRNA Network Reveals Prognostic and Metastasis Associated Biomarkers in Breast Cancer. Front Oncol 2021; 11:670138. [PMID: 34055638 PMCID: PMC8158160 DOI: 10.3389/fonc.2021.670138] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 04/07/2021] [Indexed: 01/17/2023] Open
Abstract
Background Breast cancer is a malignancy and lethal tumor in women. Metastasis of breast cancer is one of the causes of poor prognosis. Increasing evidences have suggested that the competing endogenous RNAs (ceRNAs) were associated with the metastasis of breast cancer. Nonetheless, potential roles of ceRNAs in regulating the metastasis of breast cancer remain unclear. Methods The RNA expression (3 levels) and follow-up data of breast cancer and noncancerous tissue samples were downloaded from the Cancer Genome Atlas (TCGA). Differentially expressed and metastasis associated RNAs were identified for functional analysis and constructing the metastasis associated ceRNA network by comprehensively bioinformatic analysis. The Kaplan-Meier (K-M) survival curve was utilized to screen the prognostic RNAs in metastasis associated ceRNA network. Moreover, we further identified the metastasis associated biomarkers with operating characteristic (ROC) curve. Ultimately, the data of Cancer Cell Line Encyclopedia (CCLE, https://portals.broadinstitute.org/ccle) website were selected to obtained the reliable metastasis associated biomarkers. Results 1005 mRNAs, 22 miRNAs and 164 lncRNAs were screened as differentially expressed and metastasis associated RNAs. The results of GO function and KEGG pathway enrichment analysis showed that these RNAs are mainly associated with the metabolic processes and stress responses. Next, a metastasis associated ceRNA (including 104 mRNAs, 19 miRNAs, and 16 lncRNAs) network was established, and 12 RNAs were found to be related to the overall survival (OS) of patients. In addition, 3 RNAs (hsa-miR-105-5p, BCAR1, and PANX2) were identified to serve as reliable metastasis associated biomarkers. Eventually, the results of mechanism analysis suggested that BCAR1 might promote the metastasis of breast cancer by facilitating Rap 1 signaling pathway. Conclusion In the present research, we identified 3 RNAs (hsa-miR-105-5p, BCAR1 and PANX2) might associated with prognosis and metastasis of breast cancer, which might be provide a new perspective for metastasis of breast cancer and contributed to the treatment of breast cancer.
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Affiliation(s)
- Da Qian
- College of Medicine, Soochow University, Soochow, China.,Department of Breast Surgery, Zhejiang Provincial People's Hospital, Hangzhou, China.,Department of Burn and Plastic Surgery-Hand Surgery, First People's Hospital of Changshu City, Changshu Hospital Affiliated to Soochow University, Soochow, China
| | - Qinghui Zheng
- Department of Breast Surgery, Zhejiang Provincial People's Hospital, Hangzhou, China
| | - Danping Wu
- Department of Breast Surgery, First People's Hospital of Changshu City, Changshu Hospital Affiliated to Soochow University, Soochow, China
| | - Buyun Ye
- Second Clinical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yangyang Qian
- Department of Breast Surgery, Zhejiang Provincial People's Hospital, Hangzhou, China
| | - Tao Zhou
- Faculty of Basic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Jie Qiu
- Second Clinical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xuli Meng
- Department of Breast Surgery, Zhejiang Provincial People's Hospital, Hangzhou, China
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17
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Cho HJ, Velichkovska M, Schurhoff N, András IE, Toborek M. Extracellular vesicles regulate gap junction-mediated intercellular communication and HIV-1 infection of human neural progenitor cells. Neurobiol Dis 2021; 155:105388. [PMID: 33962010 DOI: 10.1016/j.nbd.2021.105388] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/13/2021] [Accepted: 05/03/2021] [Indexed: 12/11/2022] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) has been shown to cross the blood-brain barrier and cause HIV-associated neurocognitive disorders (HAND) through a process that may involve direct or indirect interactions with the central nervous system (CNS) cells and alterations of amyloid β (Aβ) homeostasis. The present study focused on the mechanisms of HIV-1 infecting human neural progenitor cells (hNPCs) and affecting NPC intercellular communications with human brain endothelial cells (HBMEC). Despite the lack of the CD4 receptor, hNPCs were effectively infected by HIV-1 via a mechanism involving the chemokine receptors, CXCR4 and CCR5. HIV-1 infection increased expression of connexin-43 (Cx43), phosphorylated Cx43 (pCx43), and pannexin 2 (Panx2) protein levels in hNPCs, suggesting alterations in gap-junction (GJ) and pannexin channel communication. Indeed, a functional GJ assay indicated an increase in communication between HIV-infected hNPCs and non-infected HBMEC. We next analyzed the impact of HBMEC-derived extracellular vesicles (EVs) and EVs carrying Aβ (EV-Aβ) on the expression of Cx43, pCx43, and Panx2 in HIV-1 infected and non-infected hNPCs. Exposure to EV-Aβ resulted in significant reduction of Cx43 and pCx43 protein expression in non-infected hNPCs when compared to EV controls. Interestingly, EV-Aβ treatment significantly increased levels of Cx43, pCx43, and Panx2 in HIV-1-infected hNPCs when compared to non-infected controls. These results were confirmed in a GJ functional assay and an ATP release assay, which is an indicator of connexin hemichannel and/or pannexin channel functions. Overall, the current study demonstrates the importance of hNPCs in HIV-1 infection and indicates that intercellular communications between infected hNPCs and HBMEC can be effectively modulated by EVs carrying Aβ as their cargo.
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Affiliation(s)
- Hyung Joon Cho
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - Martina Velichkovska
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Nicolette Schurhoff
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Ibolya E András
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
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18
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Choi BJ, Chen YCD, Desplan C. Building a circuit through correlated spontaneous neuronal activity in the developing vertebrate and invertebrate visual systems. Genes Dev 2021; 35:677-691. [PMID: 33888564 PMCID: PMC8091978 DOI: 10.1101/gad.348241.121] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
During the development of the vertebrate nervous systems, genetic programs assemble an immature circuit that is subsequently refined by neuronal activity evoked by external stimuli. However, prior to sensory experience, the intrinsic property of the developing nervous system also triggers correlated network-level neuronal activity, with retinal waves in the developing vertebrate retina being the best documented example. Spontaneous activity has also been found in the visual system of Drosophila Here, we compare the spontaneous activity of the developing visual system between mammalian and Drosophila and suggest that Drosophila is an emerging model for mechanistic and functional studies of correlated spontaneous activity.
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Affiliation(s)
- Ben Jiwon Choi
- Department of Biology, New York University, New York, New York 10003, USA
| | | | - Claude Desplan
- Department of Biology, New York University, New York, New York 10003, USA
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19
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Zoidl GR, Spray DC. The Roles of Calmodulin and CaMKII in Cx36 Plasticity. Int J Mol Sci 2021; 22:4473. [PMID: 33922931 PMCID: PMC8123330 DOI: 10.3390/ijms22094473] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 01/07/2023] Open
Abstract
Anatomical and electrophysiological evidence that gap junctions and electrical coupling occur between neurons was initially confined to invertebrates and nonmammals and was thought to be a primitive form of synaptic transmission. More recent studies revealed that electrical communication is common in the mammalian central nervous system (CNS), often coexisting with chemical synaptic transmission. The subsequent progress indicated that electrical synapses formed by the gap junction protein connexin-36 (Cx36) and its paralogs in nonmammals constitute vital elements in mammalian and fish synaptic circuitry. They govern the collective activity of ensembles of coupled neurons, and Cx36 gap junctions endow them with enormous adaptive plasticity, like that seen at chemical synapses. Moreover, they orchestrate the synchronized neuronal network activity and rhythmic oscillations that underlie the fundamental integrative processes, such as memory and learning. Here, we review the available mechanistic evidence and models that argue for the essential roles of calcium, calmodulin, and the Ca2+/calmodulin-dependent protein kinase II in integrating calcium signals to modulate the strength of electrical synapses through interactions with the gap junction protein Cx36.
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Affiliation(s)
- Georg R. Zoidl
- Department of Biology & Center for Vision Research (CVR), York University, Toronto, ON M3J 1P3, Canada
| | - David C. Spray
- Dominick P. Purpura Department of Neuroscience & Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY 10461, USA;
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20
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Noort RJ, Christopher GA, Esseltine JL. Pannexin 1 Influences Lineage Specification of Human iPSCs. Front Cell Dev Biol 2021; 9:659397. [PMID: 33937260 PMCID: PMC8086557 DOI: 10.3389/fcell.2021.659397] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Every single cell in the body communicates with nearby cells to locally organize activities with their neighbors and dysfunctional cell-cell communication can be detrimental during cell lineage commitment, tissue patterning and organ development. Pannexin channels (PANX1, PANX2, and PANX3) facilitate purinergic paracrine signaling through the passage of messenger molecules out of cells. PANX1 is widely expressed throughout the body and has recently been identified in human oocytes as well as 2 and 4-cell stage human embryos. Given its abundance across multiple adult tissues and its expression at the earliest stages of human development, we sought to understand whether PANX1 impacts human induced pluripotent stem cells (iPSCs) or plays a role in cell fate decisions. Western blot, immunofluorescence and flow cytometry reveal that PANX1 is expressed in iPSCs as well as all three germ lineages derived from these cells: ectoderm, endoderm, and mesoderm. PANX1 demonstrates differential glycosylation patterns and subcellular localization across the germ lineages. Using CRISPR-Cas9 gene ablation, we find that loss of PANX1 has no obvious impact on iPSC morphology, survival, or pluripotency gene expression. However, PANX1 gene knockout iPSCs exhibit apparent lineage specification bias under 3-dimensional spontaneous differentiation into the three germ lineages. Indeed, loss of PANX1 increases representation of endodermal and mesodermal populations in PANX1 knockout cells. Importantly, PANX1 knockout iPSCs are fully capable of differentiating toward each specific lineage when exposed to the appropriate external signaling pressures, suggesting that although PANX1 influences germ lineage specification, it is not essential to this process.
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Affiliation(s)
- Rebecca J Noort
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Grace A Christopher
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jessica L Esseltine
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
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21
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Panda AK, K R, Gebrekrstos A, Bose S, Markandeya YS, Mehta B, Basu B. Tunable Substrate Functionalities Direct Stem Cell Fate toward Electrophysiologically Distinguishable Neuron-like and Glial-like Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:164-185. [PMID: 33356098 DOI: 10.1021/acsami.0c17257] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Engineering cellular microenvironment on a functional platform using various biophysical cues to modulate stem cell fate has been the central theme in regenerative engineering. Among the various biophysical cues to direct stem cell differentiation, the critical role of physiologically relevant electric field (EF) stimulation was established in the recent past. The present study is the first to report the strategy to switch EF-mediated differentiation of human mesenchymal stem cells (hMSCs) between neuronal and glial pathways, using tailored functional properties of the biomaterial substrate. We have examined the combinatorial effect of substrate functionalities (conductivity, electroactivity, and topography) on the EF-mediated stem cell differentiation on polyvinylidene-difluoride (PVDF) nanocomposites in vitro, without any biochemical inducers. The functionalities of PVDF have been tailored using conducting nanofiller (multiwall-carbon nanotube, MWNT) and piezoceramic (BaTiO3, BT) by an optimized processing approach (melt mixing-compression molding-rolling). The DC conductivity of PVDF nanocomposites was tuned from ∼10-11 to ∼10-4 S/cm and the dielectric constant from ∼10 to ∼300. The phenotypical changes and genotypical expression of hMSCs revealed the signatures of early differentiation toward neuronal pathway on rolled-PVDF/MWNT and late differentiation toward glial lineage on rolled-PVDF/BT/MWNT. Moreover, we were able to distinguish the physiological properties of differentiated neuron-like and glial-like cells using membrane depolarization and mechanical stimulation. The excitability of the EF-stimulated hMSCs was also determined using whole-cell patch-clamp recordings. Mechanistically, the roles of intracellular reactive oxygen species (ROS), Ca2+ oscillations, and synaptic and gap junction proteins in directing the cellular fate have been established. Therefore, the present work critically unveils complex yet synergistic interaction of substrate functional properties to direct EF-mediated differentiation toward neuron-like and glial-like cells, with distinguishable electrophysiological responses.
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Affiliation(s)
- Asish Kumar Panda
- Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Ravikumar K
- Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Amanuel Gebrekrstos
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Suryasarathi Bose
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Yogananda S Markandeya
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Bhupesh Mehta
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Bikramjit Basu
- Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India
- Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
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22
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Mesnil M, Defamie N, Naus C, Sarrouilhe D. Brain Disorders and Chemical Pollutants: A Gap Junction Link? Biomolecules 2020; 11:biom11010051. [PMID: 33396565 PMCID: PMC7824109 DOI: 10.3390/biom11010051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.
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Affiliation(s)
- Marc Mesnil
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Norah Defamie
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Christian Naus
- Faculty of Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, 6 rue de La Milétrie, bât D1, TSA 51115, 86073 Poitiers, France
- Correspondence: ; Tel.: +33-5-49-45-43-58
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23
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Expression of Connexins 37, 43 and 45 in Developing Human Spinal Cord and Ganglia. Int J Mol Sci 2020; 21:ijms21249356. [PMID: 33302507 PMCID: PMC7770599 DOI: 10.3390/ijms21249356] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/30/2020] [Accepted: 12/06/2020] [Indexed: 12/24/2022] Open
Abstract
Direct intercellular communication via gap junctions has an important role in the development of the nervous system, ranging from cell migration and neuronal differentiation to the formation of neuronal activity patterns. This study characterized and compared the specific spatio-temporal expression patterns of connexins (Cxs) 37, 43 and 45 during early human developmental stages (since the 5th until the 10th developmental week) in the spinal cord (SC) and dorsal root ganglia (DRG) using double immunofluorescence and transmission electron microscopy. We found the expression of all three investigated Cxs during early human development in all the areas of interest, in the SC, DRG, developing paravertebral ganglia of the sympathetic trunk, notochord and all three meningeal layers, with predominant expression of Cx37. Comparing the expression of different Cxs between distinct developmental periods, we did not find significant differences. Specific spatio-temporal pattern of Cxs expression might reflect their relevance in the development of all areas of interest via cellular interconnectivity and synchronization during the late embryonic and early fetal period of human development.
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Dilger N, Neehus AL, Grieger K, Hoffmann A, Menssen M, Ngezahayo A. Gap Junction Dependent Cell Communication Is Modulated During Transdifferentiation of Mesenchymal Stem/Stromal Cells Towards Neuron-Like Cells. Front Cell Dev Biol 2020; 8:869. [PMID: 32984345 PMCID: PMC7487424 DOI: 10.3389/fcell.2020.00869] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/11/2020] [Indexed: 12/22/2022] Open
Abstract
In vitro transdifferentiation of patient-derived mesenchymal stem/stromal cells (MSCs) into neurons is of special interest for treatment of neurodegenerative diseases. Although there are encouraging studies, little is known about physiological modulations during this transdifferentiation process. Here, we focus on the analysis of gap junction dependent cell-cell communication and the expression pattern of gap junction-building connexins during small molecule-induced neuronal transdifferentiation of human bone marrow-derived MSCs. During this process, the MSC markers CD73, CD90, CD105, and CD166 were downregulated while the neuronal marker Tuj1 was upregulated. Moreover, the differentiation protocol used in the present study changed the cellular morphology and physiology. The MSCs evolved from a fibroblastoid morphology towards a neuronal shape with round cell bodies and neurite-like processes. Moreover, depolarization evoked action potentials in the transdifferentiated cells. MSCs expressed mRNAs encoding Cx43 and Cx45 as well as trace levels of Cx26, Cx37- and Cx40 and allowed transfer of microinjected Lucifer yellow. The differentiation protocol increased levels of Cx26 (mRNA and protein) and decreased Cx43 (mRNA and protein) while reducing the dye transfer. Cx36 mRNA was nearly undetectable in all cells regardless of treatment. Treatment of the cells with the gap junction coupling inhibitor carbenoxolone (CBX) only modestly altered connexin mRNA levels and had little effect on neuronal differentiation. Our study indicates that the small molecule-based differentiation protocol generates immature neuron-like cells from MSCs. This might be potentially interesting for elucidating physiological modifications and mechanisms in MSCs during the initial steps of differentiation towards a neuronal lineage.
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Affiliation(s)
- Nadine Dilger
- Department of Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hanover, Germany
| | - Anna-Lena Neehus
- Department of Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hanover, Germany.,Institute of Experimental Hematology, REBIRTH Research Center for Translational and Regenerative Medicine, Hannover Medical School (MHH), Hanover, Germany
| | - Klaudia Grieger
- Department of Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hanover, Germany
| | - Andrea Hoffmann
- Graded Implants and Regenerative Strategies, Department of Orthopedic Surgery, Hannover Medical School, Hanover, Germany.,Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Hanover, Germany
| | - Max Menssen
- Department of Biostatistics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hanover, Germany
| | - Anaclet Ngezahayo
- Department of Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hanover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine Hannover, Hanover, Germany
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25
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Sánchez OF, Rodríguez AV, Velasco-España JM, Murillo LC, Sutachan JJ, Albarracin SL. Role of Connexins 30, 36, and 43 in Brain Tumors, Neurodegenerative Diseases, and Neuroprotection. Cells 2020; 9:E846. [PMID: 32244528 PMCID: PMC7226843 DOI: 10.3390/cells9040846] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/15/2020] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Gap junction (GJ) channels and their connexins (Cxs) are complex proteins that have essential functions in cell communication processes in the central nervous system (CNS). Neurons, astrocytes, oligodendrocytes, and microglial cells express an extraordinary repertory of Cxs that are important for cell to cell communication and diffusion of metabolites, ions, neurotransmitters, and gliotransmitters. GJs and Cxs not only contribute to the normal function of the CNS but also the pathological progress of several diseases, such as cancer and neurodegenerative diseases. Besides, they have important roles in mediating neuroprotection by internal or external molecules. However, regulation of Cx expression by epigenetic mechanisms has not been fully elucidated. In this review, we provide an overview of the known mechanisms that regulate the expression of the most abundant Cxs in the central nervous system, Cx30, Cx36, and Cx43, and their role in brain cancer, CNS disorders, and neuroprotection. Initially, we focus on describing the Cx gene structure and how this is regulated by epigenetic mechanisms. Then, the posttranslational modifications that mediate the activity and stability of Cxs are reviewed. Finally, the role of GJs and Cxs in glioblastoma, Alzheimer's, Parkinson's, and Huntington's diseases, and neuroprotection are analyzed with the aim of shedding light in the possibility of using Cx regulators as potential therapeutic molecules.
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Affiliation(s)
- Oscar F. Sánchez
- Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, 110911 Bogota, Colombia; (A.V.R.); (J.M.V.-E.); (L.C.M.); (J.-J.S.)
| | | | | | | | | | - Sonia-Luz Albarracin
- Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, 110911 Bogota, Colombia; (A.V.R.); (J.M.V.-E.); (L.C.M.); (J.-J.S.)
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26
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Kocovic DM, Limaye PV, Colburn LCH, Singh MB, Milosevic MM, Tadic J, Petronijevic M, Vrzic-Petronijevic S, Andjus PR, Antic SD. Cadmium versus Lanthanum Effects on Spontaneous Electrical Activity and Expression of Connexin Isoforms Cx26, Cx36, and Cx45 in the Human Fetal Cortex. Cereb Cortex 2020; 30:1244-1259. [PMID: 31408166 PMCID: PMC7132928 DOI: 10.1093/cercor/bhz163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/25/2019] [Accepted: 06/25/2019] [Indexed: 12/29/2022] Open
Abstract
Electrical activity is important for brain development. In brain slices, human subplate neurons exhibit spontaneous electrical activity that is highly sensitive to lanthanum. Based on the results of pharmacological experiments in human fetal tissue, we hypothesized that hemichannel-forming connexin (Cx) isoforms 26, 36, and 45 would be expressed on neurons in the subplate (SP) zone. RNA sequencing of dissected human cortical mantles at ages of 17-23 gestational weeks revealed that Cx45 has the highest expression, followed by Cx36 and Cx26. The levels of Cx and pannexin expression between male and female fetal cortices were not significantly different. Immunohistochemical analysis detected Cx45- and Cx26-expressing neurons in the upper segment of the SP zone. Cx45 was present on the cell bodies of human SP neurons, while Cx26 was found on both cell bodies and dendrites. Cx45, Cx36, and Cx26 were strongly expressed in the cortical plate, where newborn migrating neurons line up to form cortical layers. New information about the expression of 3 "neuronal" Cx isoforms in each cortical layer/zone (e.g., SP, cortical plate) and pharmacological data with cadmium and lanthanum may improve our understanding of the cellular mechanisms underlying neuronal development in human fetuses and potential vulnerabilities.
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Affiliation(s)
- Dusica M Kocovic
- Faculty of Biology, University of Belgrade, Belgrade 11000, Serbia
| | - Pallavi V Limaye
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT 06030, USA
| | - Lauren C H Colburn
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT 06030, USA
| | - Mandakini B Singh
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT 06030, USA
| | - Milena M Milosevic
- Faculty of Biology, University of Belgrade, Belgrade 11000, Serbia
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT 06030, USA
| | - Jasmina Tadic
- Faculty of Medicine, University of Belgrade, Belgrade 11000, Serbia
| | | | | | - Pavle R Andjus
- Faculty of Biology, University of Belgrade, Belgrade 11000, Serbia
| | - Srdjan D Antic
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT 06030, USA
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27
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Distasi C, Dionisi M, Ruffinatti FA, Gilardino A, Bardini R, Antoniotti S, Catalano F, Bassino E, Munaron L, Martra G, Lovisolo D. The interaction of SiO 2 nanoparticles with the neuronal cell membrane: activation of ionic channels and calcium influx. Nanomedicine (Lond) 2019; 14:575-594. [PMID: 30810075 DOI: 10.2217/nnm-2018-0256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AIM To clarify the mechanisms of interaction between SiO2 nanoparticles (NPs) and the plasma membrane of GT1-7 neuroendocrine cells, with focus on the activation of calcium-permeable channels, responsible for the long lasting calcium influx and modulation of the electrical activity in these cells. MATERIALS & METHODS Nontoxic doses of SiO2 NPs were administered to the cells. Calcium imaging and patch clamp techniques were combined with a pharmacological approach. RESULTS TRPV4, Cx and Panx-like channels are the major components of the NP-induced inward currents. Preincubation with the antioxidant N-acetyl-L-cysteine strongly reduced the [Ca2+]i increase. CONCLUSION These findings suggest that SiO2 NPs directly activate a complex set of calcium-permeable channels, possibly by catalyzing free radical production.
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Affiliation(s)
- Carla Distasi
- Department of Pharmaceutical Sciences, University of Piemonte Orientale 'A. Avogadro', Via Bovio 6, 28100 Novara, Italy
| | - Marianna Dionisi
- Department of Pharmaceutical Sciences, University of Piemonte Orientale 'A. Avogadro', Via Bovio 6, 28100 Novara, Italy
| | | | - Alessandra Gilardino
- Department of Life Sciences & Systems Biology, University of Torino, via Accademia Albertina 23, 10123 Torino, Italy
| | - Roberta Bardini
- Department of Life Sciences & Systems Biology, University of Torino, via Accademia Albertina 23, 10123 Torino, Italy.,Department of Control & Computer Engineering, Polytechnic University of Turin, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Susanna Antoniotti
- Department of Life Sciences & Systems Biology, University of Torino, via Accademia Albertina 23, 10123 Torino, Italy
| | - Federico Catalano
- Department of Chemistry, Torino, University of Torino, Via P. Giuria 9, 10125, Italy.,Italian Institute of Technology, Central Research Laboratories, Via Morego 30, 16163 Genova, Italy
| | - Eleonora Bassino
- Department of Life Sciences & Systems Biology, University of Torino, via Accademia Albertina 23, 10123 Torino, Italy
| | - Luca Munaron
- Department of Life Sciences & Systems Biology, University of Torino, via Accademia Albertina 23, 10123 Torino, Italy
| | - Gianmario Martra
- Department of Control & Computer Engineering, Polytechnic University of Turin, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.,NIS Interdepartmental Center, University of Torino, Italy
| | - Davide Lovisolo
- Department of Life Sciences & Systems Biology, University of Torino, via Accademia Albertina 23, 10123 Torino, Italy
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28
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Iwai-Takekoshi L, Balasubramanian R, Sitko A, Khan R, Weinreb S, Robinson K, Mason C. Activation of Wnt signaling reduces ipsilaterally projecting retinal ganglion cells in pigmented retina. Development 2018; 145:dev.163212. [PMID: 30254141 DOI: 10.1242/dev.163212] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 09/15/2018] [Indexed: 11/20/2022]
Abstract
In mammalian albinism, disrupted melanogenesis in the retinal pigment epithelium (RPE) is associated with fewer retinal ganglion cells (RGCs) projecting ipsilaterally to the brain, resulting in numerous abnormalities in the retina and visual pathway, especially binocular vision. To further understand the molecular link between disrupted RPE and a reduced ipsilateral RGC projection in albinism, we compared gene expression in the embryonic albino and pigmented mouse RPE. We found that the Wnt pathway, which directs peripheral retinal differentiation and, generally, cell proliferation, is dysregulated in the albino RPE. Wnt2b expression is expanded in the albino RPE compared with the pigmented RPE, and the expanded region adjoins the site of ipsilateral RGC neurogenesis and settling. Pharmacological activation of Wnt signaling in pigmented mice by lithium (Li+) treatment in vivo reduces the number of Zic2-positive RGCs, which are normally fated to project ipsilaterally, to numbers observed in the albino retina. These results implicate Wnt signaling from the RPE to neural retina as a potential factor in the regulation of ipsilateral RGC production, and thus the albino phenotype.
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Affiliation(s)
- Lena Iwai-Takekoshi
- Department of Pathology and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA
| | - Revathi Balasubramanian
- Department of Ophthalmology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA
| | - Austen Sitko
- Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Rehnuma Khan
- Department of Pathology and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA
| | - Samuel Weinreb
- Department of Pathology and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA
| | - Kiera Robinson
- Department of Pathology and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA
| | - Carol Mason
- Department of Pathology and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA .,Department of Ophthalmology, Columbia University, College of Physicians and Surgeons, New York, NY 10027, USA.,Department of Neuroscience, Columbia University, New York, NY 10027, USA.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
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29
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Sanchez-Pupo RE, Johnston D, Penuela S. N-Glycosylation Regulates Pannexin 2 Localization but Is Not Required for Interacting with Pannexin 1. Int J Mol Sci 2018; 19:ijms19071837. [PMID: 29932112 PMCID: PMC6073767 DOI: 10.3390/ijms19071837] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/16/2018] [Accepted: 06/20/2018] [Indexed: 02/07/2023] Open
Abstract
Pannexins (Panx1, 2, 3) are channel-forming glycoproteins expressed in mammalian tissues. We previously reported that N-glycosylation acts as a regulator of the localization and intermixing of Panx1 and Panx3, but its effects on Panx2 are currently unknown. Panx1 and Panx2 intermixing can regulate channel properties, and both pannexins have been implicated in neuronal cell death after ischemia. Our objectives were to validate the predicted N-glycosylation site of Panx2 and to study the effects of Panx2 glycosylation on localization and its capacity to interact with Panx1. We used site-directed mutagenesis, enzymatic de-glycosylation, cell-surface biotinylation, co-immunoprecipitation, and confocal microscopy. Our results showed that N86 is the only N-glycosylation site of Panx2. Panx2 and the N86Q mutant are predominantly localized to the endoplasmic reticulum (ER) and cis-Golgi matrix with limited cell surface localization was seen only in the presence of Panx1. The Panx2 N86Q mutant is glycosylation-deficient and tends to aggregate in the ER reducing its cell surface trafficking but it can still interact with Panx1. Our study indicates that N-glycosylation may be important for folding and trafficking of Panx2. We found that the un-glycosylated forms of Panx1 and 2 can readily interact, regulating their localization and potentially their channel function in cells where they are co-expressed.
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Affiliation(s)
- Rafael E Sanchez-Pupo
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6A5C1, Canada.
| | - Danielle Johnston
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6A5C1, Canada.
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6A5C1, Canada.
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30
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Xu J, He J, Huang H, Peng R, Xi J. MicroRNA-423-3p promotes glioma growth by targeting PANX2. Oncol Lett 2018; 16:179-188. [PMID: 29928399 PMCID: PMC6006452 DOI: 10.3892/ol.2018.8636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/15/2018] [Indexed: 01/08/2023] Open
Abstract
Previously, a number of microRNAs (miRs) have been identified to participate in the development and progression of glioma via the regulation of their target genes. However, the molecular mechanisms underlying the effect of miR-423-3p in glioma growth remain unclear. In the present study, the reverse transcription-quantitative polymerase chain reaction and western blotting were used to assess the mRNA and protein expression levels of miR-423-3p, respectively. An MTT assay and flow cytometry were performed to determine cell proliferation and apoptosis, respectively. A luciferase reporter gene assay was performed to determine the target association between pannexin 2 (PANX2) and miR-423-3p. It was revealed that miR-423-3p was significantly upregulated in glioma tissues compared with normal brain tissues, and the increased expression of miR-423-3p was significantly associated with an advanced grade as well as a poorer prognosis of patients with glioma. Inhibition of miR-423-3p using an miR-423-3p inhibitor resulted in the decreased proliferation of glioma U251 and U87MG Uppsala cells, and the induction of apoptosis. PANX2 was identified as a novel target gene of miR-423-3p, and the expression of PANX2 was revealed to be increased in U251 and U87MG Uppsala cells when miR-423-3p was inhibited. Knockdown of PANX2 attenuated the effects of miR-423-3p inhibition on glioma cell proliferation and apoptosis. Furthermore, PANX2 was significantly downregulated in glioma tissues compared with normal brain tissues, and its levels were markedly lower in World Health Organization (WHO) stage III–IV gliomas compared with WHO stage I–II gliomas. Additionally, the expression levels of PANX2 were identified to be inversely correlated with miR-423-3p expression levels in glioma tissues. Consequently, targeting miR-423-3p may inhibit glioma growth via the upregulation of PANX2.
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Affiliation(s)
- Jing Xu
- Department of Otolaryngology, Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Jian He
- Department of Otolaryngology, Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - He Huang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Renjun Peng
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Jian Xi
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
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31
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Labra VC, Santibáñez CA, Gajardo-Gómez R, Díaz EF, Gómez GI, Orellana JA. The Neuroglial Dialog Between Cannabinoids and Hemichannels. Front Mol Neurosci 2018; 11:79. [PMID: 29662436 PMCID: PMC5890195 DOI: 10.3389/fnmol.2018.00079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/28/2018] [Indexed: 12/11/2022] Open
Abstract
The formation of gap junctions was initially thought to be the central role of connexins, however, recent evidence had brought to light the high relevance of unopposed hemichannels as an independent mechanism for the selective release of biomolecules during physiological and pathological conditions. In the healthy brain, the physiological opening of astrocyte hemichannels modulates basal excitatory synaptic transmission. At the other end, the release of potentially neurotoxic compounds through astroglial hemichannels and pannexons has been insinuated as one of the functional alterations that negatively affect the progression of multiple brain diseases. Recent insights in this matter have suggested encannabinoids (eCBs) as molecules that could regulate the opening of these channels during diverse conditions. In this review, we discuss and hypothesize the possible interplay between the eCB system and the hemichannel/pannexon-mediated signaling in the inflamed brain and during event of synaptic plasticity. Most findings indicate that eCBs seem to counteract the activation of major neuroinflammatory pathways that lead to glia-mediated production of TNF-α and IL-1β, both well-known triggers of astroglial hemichannel opening. In contrast to the latter, in the normal brain, eCBs apparently elicit the Ca2+-activation of astrocyte hemichannels, which could have significant consequences on eCB-dependent synaptic plasticity.
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Affiliation(s)
- Valeria C Labra
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Cristian A Santibáñez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Rosario Gajardo-Gómez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Esteban F Díaz
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Gonzalo I Gómez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
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Hainz N, Beckmann A, Schubert M, Haase A, Martin U, Tschernig T, Meier C. Human stem cells express pannexins. BMC Res Notes 2018; 11:54. [PMID: 29357945 PMCID: PMC5778636 DOI: 10.1186/s13104-018-3125-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/03/2018] [Indexed: 11/23/2022] Open
Abstract
Objective Pannexins are channel proteins important for the release of calcium and adenosine triphosphate, which are among other functions involved in early development. Here, the expression of pannexins was investigated in induced pluripotent stem cells derived from human cord blood endothelial cells (hCBiPS2), in hematopoietic stem cell-derived induced pluripotent stem cells (HSC_F1285_T-iPS2) and in human embryonic stem cells (HES-3). The expression of pannexin (Panx) 1–3 mRNAs was analyzed in all three undifferentiated stem cell lines. Stem cells then underwent undirected differentiation into embryoid bodies and were analyzed regarding expression of germ layer-specific genes. Results Panx1, Panx2, and Panx3 mRNAs were expressed in all undifferentiated stem cell lines investigated. In comparison, Panx1 showed the highest expression among all pannexins. The undirected differentiation resulted in a mixed germ layer genotype in all three stem cell lines. Whereas the expression of Panx1 was not affected by differentiation, the expression of Panx2 was slightly increased in differentiated hCBiPS2 cells, HSC_F1285_T-iPS2 as well as HES3 cells as compared to their undifferentiated counterparts. A slight increase of Panx3 expression was observed in differentiated hCBiPS2 cells only. In conclusion, pluripotent stem cells express all three pannexin genes. Electronic supplementary material The online version of this article (10.1186/s13104-018-3125-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nadine Hainz
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, Saar, 66421, Homburg, Germany
| | - Anja Beckmann
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, Saar, 66421, Homburg, Germany
| | - Madline Schubert
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany
| | - Alexandra Haase
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany
| | - Ulrich Martin
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany
| | - Thomas Tschernig
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, Saar, 66421, Homburg, Germany.
| | - Carola Meier
- Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, Saar, 66421, Homburg, Germany
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33
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Zhang J, Griemsmann S, Wu Z, Dobrowolski R, Willecke K, Theis M, Steinhäuser C, Bedner P. Connexin43, but not connexin30, contributes to adult neurogenesis in the dentate gyrus. Brain Res Bull 2018; 136:91-100. [DOI: 10.1016/j.brainresbull.2017.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 06/21/2017] [Accepted: 07/03/2017] [Indexed: 10/19/2022]
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34
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Horton SM, Luna Lopez C, Blevins E, Howarth H, Weisberg J, Shestopalov VI, Makarenkova HP, Shah SB. Pannexin 1 Modulates Axonal Growth in Mouse Peripheral Nerves. Front Cell Neurosci 2017; 11:365. [PMID: 29213230 PMCID: PMC5702652 DOI: 10.3389/fncel.2017.00365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/06/2017] [Indexed: 01/29/2023] Open
Abstract
The pannexin family of channels consists of three members—pannexin-1 (Panx1), pannexin-2 (Panx2), and pannexin-3 (Panx3) that enable the exchange of metabolites and signaling molecules between intracellular and extracellular compartments. Pannexin-mediated release of intracellular ATP into the extracellular space has been tied to a number of cellular activities, primarily through the activity of type P2 purinergic receptors. Previous work indicates that the opening of Panx1 channels and activation of purinergic receptors by extracellular ATP may cause inflammation and apoptosis. In the CNS (central nervous system) and PNS (peripheral nervous system), coupled pannexin, and P2 functions have been linked to peripheral sensitization (pain) pathways. Purinergic pathways are also essential for other critical processes in the PNS, including myelination and neurite outgrowth. However, whether such pathways are pannexin-dependent remains to be determined. In this study, we use a Panx1 knockout mouse model and pharmacological inhibitors of the Panx1 and the ATP-mediated signaling pathway to fill gaps in our understanding of Panx1 localization in peripheral nerves, roles for Panx1 in axonal outgrowth and myelination, and neurite extension. Our data show that Panx1 is localized to axonal, myelin, and vascular compartments of the peripheral nerves. Knockout of Panx1 gene significantly increased axonal caliber in vivo and axonal growth rate in cultured dorsal root ganglia (DRG) neurons. Furthermore, genetic knockout of Panx1 or inhibition of components of purinergic signaling, by treatment with probenecid and apyrase, resulted in denser axonal outgrowth from cultured DRG explants compared to untreated wild-types. Our findings suggest that Panx1 regulates axonal growth in the peripheral nervous system.
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Affiliation(s)
- Steven M Horton
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | - Carlos Luna Lopez
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | - Elisabeth Blevins
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, United States
| | - Holly Howarth
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
| | - Jake Weisberg
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | | | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Sameer B Shah
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, United States.,Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
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35
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Role of Connexin and Pannexin containing channels in HIV infection and NeuroAIDS. Neurosci Lett 2017; 695:86-90. [PMID: 28886986 DOI: 10.1016/j.neulet.2017.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 07/27/2017] [Accepted: 09/01/2017] [Indexed: 01/31/2023]
Abstract
Neuron-Glia crosstalk is essential for efficient synaptic communication, cell growth and differentiation, neuronal activity, neurotransmitter recycling, and brain immune response. The master regulators of this neuron-glia communication are connexin containing Gap Junctions (GJs) and Hemichannels (HCs) as well as pannexin HCs. However, the role of these channels under pathological conditions, especially in infectious diseases is still in exploratory stages. Human Immunodeficiency Virus-1 (HIV) is one such infectious agent that takes advantage of the host intercellular communication systems, GJs and HCs, to exacerbate viral pathogenesis in the brain in spite of the antiretroviral therapy effectively controlling viral replication in the periphery. Although most infectious agents lead to total "shutdown" of gap junctional communication in parenchymal cells, HIV infection maintains and "hijacks" GJs and HCs to enable few infected cells to spread toxic intracellular agents to neighboring uninfected cells aggravating viral neuropathology even in the absence of viral replication. In this mini-review, we present a comprehensive overview of the role of GJs and HCs in augmenting HIV neuropathogenesis.
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36
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Swayne LA, Boyce AKJ. Regulation of Pannexin 1 Surface Expression by Extracellular ATP: Potential Implications for Nervous System Function in Health and Disease. Front Cell Neurosci 2017; 11:230. [PMID: 28848396 PMCID: PMC5550711 DOI: 10.3389/fncel.2017.00230] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/24/2017] [Indexed: 02/02/2023] Open
Abstract
Pannexin 1 (Panx1) channels are widely recognized for their role in ATP release, and as follows, their function is closely tied to that of ATP-activated P2X7 purinergic receptors (P2X7Rs). Our recent work has shown that extracellular ATP induces clustering of Panx1 with P2X7Rs and their subsequent internalization through a non-canonical cholesterol-dependent mechanism. In other words, we have demonstrated that extracellular ATP levels can regulate the cell surface expression of Panx1. Here we discuss two situations in which we hypothesize that ATP modulation of Panx1 surface expression could be relevant for central nervous system function. The first scenario involves the development of new neurons in the ventricular zone. We propose that ATP-induced Panx1 endocytosis could play an important role in regulating the balance of cell proliferation, survival, and differentiation within this neurogenic niche in the healthy brain. The second scenario relates to the spinal cord, in which we posit that an impairment of ATP-induced Panx1 endocytosis could contribute to pathological neuroplasticity. Together, the discussion of these hypotheses serves to highlight important outstanding questions regarding the interplay between extracellular ATP, Panx1, and P2X7Rs in the nervous system in health and disease.
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Affiliation(s)
- Leigh A Swayne
- Division of Medical Sciences and Island Medical Program, University of Victoria, VictoriaBC, Canada.,Department of Cellular and Physiological Sciences, University of British Columbia, VancouverBC, Canada
| | - Andrew K J Boyce
- Division of Medical Sciences and Island Medical Program, University of Victoria, VictoriaBC, Canada
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Lapato AS, Tiwari-Woodruff SK. Connexins and pannexins: At the junction of neuro-glial homeostasis & disease. J Neurosci Res 2017; 96:31-44. [PMID: 28580666 DOI: 10.1002/jnr.24088] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/08/2017] [Accepted: 05/01/2017] [Indexed: 12/15/2022]
Abstract
In the central nervous system (CNS), connexin (Cx)s and pannexin (Panx)s are an integral component of homeostatic neuronal excitability and synaptic plasticity. Neuronal Cx gap junctions form electrical synapses across biochemically similar GABAergic networks, allowing rapid and extensive inhibition in response to principle neuron excitation. Glial Cx gap junctions link astrocytes and oligodendrocytes in the pan-glial network that is responsible for removing excitotoxic ions and metabolites. In addition, glial gap junctions help constrain excessive excitatory activity in neurons and facilitate astrocyte Ca2+ slow wave propagation. Panxs do not form gap junctions in vivo, but Panx hemichannels participate in autocrine and paracrine gliotransmission, alongside Cx hemichannels. ATP and other gliotransmitters released by Cx and Panx hemichannels maintain physiologic glutamatergic tone by strengthening synapses and mitigating aberrant high frequency bursting. Under pathological depolarizing and inflammatory conditions, gap junctions and hemichannels become dysregulated, resulting in excessive neuronal firing and seizure. In this review, we present known contributions of Cxs and Panxs to physiologic neuronal excitation and explore how the disruption of gap junctions and hemichannels lead to abnormal glutamatergic transmission, purinergic signaling, and seizures.
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Affiliation(s)
- Andrew S Lapato
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA, 92521.,Center for Glial-Neuronal Interactions, University of California Riverside, Riverside, CA, 92521
| | - Seema K Tiwari-Woodruff
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA, 92521.,Center for Glial-Neuronal Interactions, University of California Riverside, Riverside, CA, 92521.,Neuroscience Graduate Program, University of California Riverside, Riverside, CA, 92521
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38
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Wilkaniec A, Gąssowska M, Czapski GA, Cieślik M, Sulkowski G, Adamczyk A. P2X7 receptor-pannexin 1 interaction mediates extracellular alpha-synuclein-induced ATP release in neuroblastoma SH-SY5Y cells. Purinergic Signal 2017; 13:347-361. [PMID: 28516276 PMCID: PMC5563296 DOI: 10.1007/s11302-017-9567-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/30/2017] [Indexed: 12/14/2022] Open
Abstract
Abnormalities of alpha-synuclein (ASN), the main component of protein deposits (Lewy bodies), were observed in Parkinson’s disease (PD), dementia with Lewy bodies, Alzheimer’s disease, and other neurodegenerative disorders. These alterations include increase in the levels of soluble ASN oligomers in the extracellular space. Numerous works have identified several mechanisms of their toxicity, including stimulation of the microglial P2X7 receptor leading to oxidative stress. While the significant role of purinergic signaling—particularly, P2 family receptors—in neurodegenerative disorders is well known, the interaction of extracellular soluble ASN with neuronal purinergic receptors is yet to be studied. Therefore, in this study, we have investigated the effect of ASN on P2 purinergic receptors and ATP-dependent signaling. We used neuroblastoma SH-SY5Y cell line and rat synaptoneurosomes treated with exogenous soluble ASN. The experiments were performed using spectrofluorometric, radiochemical, and immunochemical methods. We found the following: (i) ASN-induced intracellular free calcium mobilization in neuronal cells and nerve endings depends on the activation of purinergic P2X7 receptors; (ii) activation of P2X7 receptors leads to pannexin 1 recruitment to form an active complex responsible for ATP release; and (iii) ASN greatly decreases the activity of extracellular ecto-ATPase responsible for ATP degradation. Thus, it is concluded that purinergic receptors might be putative pharmacological targets in the molecular mechanism of extracellular ASN toxicity. Interference with P2X7 signaling seems to be a promising strategy for the prevention or therapy of PD and other neurodegenerative disorders.
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Affiliation(s)
- Anna Wilkaniec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland.
| | - Magdalena Gąssowska
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Grzegorz A Czapski
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Magdalena Cieślik
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Grzegorz Sulkowski
- Department of Neurochemistry, Laboratory of Pathoneurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Agata Adamczyk
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
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Tilley SK, Joseph RM, Kuban KCK, Dammann OU, O’Shea TM, Fry RC. Genomic biomarkers of prenatal intrauterine inflammation in umbilical cord tissue predict later life neurological outcomes. PLoS One 2017; 12:e0176953. [PMID: 28493900 PMCID: PMC5426658 DOI: 10.1371/journal.pone.0176953] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/19/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Preterm birth is a major risk factor for neurodevelopmental delays and disorders. This study aimed to identify genomic biomarkers of intrauterine inflammation in umbilical cord tissue in preterm neonates that predict cognitive impairment at 10 years of age. STUDY DESIGN Genome-wide messenger RNA (mRNA) levels from umbilical cord tissue were obtained from 43 neonates born before 28 weeks of gestation. Genes that were differentially expressed across four indicators of intrauterine inflammation were identified and their functions examined. Exact logistic regression was used to test whether expression levels in umbilical cord tissue predicted neurocognitive function at 10 years of age. RESULTS Placental indicators of inflammation were associated with changes in the mRNA expression of 445 genes in umbilical cord tissue. Transcripts with decreased expression showed significant enrichment for biological signaling processes related to neuronal development and growth. The altered expression of six genes was found to predict neurocognitive impairment when children were 10 years old These genes include two that encode for proteins involved in neuronal development. CONCLUSION Prenatal intrauterine inflammation is associated with altered gene expression in umbilical cord tissue. A set of six of the differentially expressed genes predict cognitive impairment later in life, suggesting that the fetal environment is associated with significant adverse effects on neurodevelopment that persist into later childhood.
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Affiliation(s)
- Sloane K. Tilley
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Robert M. Joseph
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Karl C. K. Kuban
- Department of Pediatrics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Olaf U. Dammann
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - T. Michael O’Shea
- Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Rebecca C. Fry
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
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40
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Whyte-Fagundes P, Siu R, Brown C, Zoidl G. Pannexins in vision, hearing, olfaction and taste. Neurosci Lett 2017; 695:32-39. [PMID: 28495272 DOI: 10.1016/j.neulet.2017.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/06/2017] [Accepted: 05/05/2017] [Indexed: 12/25/2022]
Abstract
In mammals, the pannexin gene family consists of three members (Panx1, 2, 3), which represent a class of integral membrane channel proteins sharing some structural features with chordate gap junction proteins, the connexins. Since their discovery in the early 21st century, pannexin expression has been detected throughout the vertebrate body including eye, ear, nose and tongue, making the investigation of the roles of this new class of channel protein in health and disease very appealing. The localization in sensory organs, coupled with unique channel properties and associations with major signaling pathways make Panx1, and its relative's, significant contributors for fundamental functions in sensory perception. Until recently, cell-based studies were at the forefront of pannexin research. Lately, the availability of mice with genetic ablation of pannexins opened new avenues for testing pannexin functions and behavioural phenotyping. Although we are only at the beginning of understanding the roles of pannexins in health and disease, this review summarizes recent advances in elucidating the various emerging roles pannexins play in sensory systems, with an emphasis on unresolved conflicts.
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Affiliation(s)
- Paige Whyte-Fagundes
- Graduate Program In Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Ryan Siu
- Graduate Program In Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Cherie Brown
- Graduate Program In Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Georg Zoidl
- Department of Biology, Faculty of Science, York University, Toronto, ON, Canada; Center for Vision Research, York University, Toronto, ON, Canada.
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41
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Mittal R, Debs LH, Nguyen D, Patel AP, Grati M, Mittal J, Yan D, Eshraghi AA, Liu XZ. Signaling in the Auditory System: Implications in Hair Cell Regeneration and Hearing Function. J Cell Physiol 2017; 232:2710-2721. [DOI: 10.1002/jcp.25695] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 11/18/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Luca H. Debs
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Desiree Nguyen
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Amit P. Patel
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - M'hamed Grati
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Jeenu Mittal
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Denise Yan
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Adrien A. Eshraghi
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Xue Zhong Liu
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
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