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Papadakos SP, Chatzikalil E, Arvanitakis K, Vakadaris G, Stergiou IE, Koutsompina ML, Argyrou A, Lekakis V, Konstantinidis I, Germanidis G, Theocharis S. Understanding the Role of Connexins in Hepatocellular Carcinoma: Molecular and Prognostic Implications. Cancers (Basel) 2024; 16:1533. [PMID: 38672615 PMCID: PMC11048329 DOI: 10.3390/cancers16081533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Connexins, a family of tetraspan membrane proteins forming intercellular channels localized in gap junctions, play a pivotal role at the different stages of tumor progression presenting both pro- and anti-tumorigenic effects. Considering the potential role of connexins as tumor suppressors through multiple channel-independent mechanisms, their loss of expression may be associated with tumorigenic activity, while it is hypothesized that connexins favor the clonal expansion of tumor cells and promote cell migration, invasion, and proliferation, affecting metastasis and chemoresistance in some cases. Hepatocellular carcinoma (HCC), characterized by unfavorable prognosis and limited responsiveness to current therapeutic strategies, has been linked to gap junction proteins as tumorigenic factors with prognostic value. Notably, several members of connexins have emerged as promising markers for assessing the progression and aggressiveness of HCC, as well as the chemosensitivity and radiosensitivity of hepatocellular tumor cells. Our review sheds light on the multifaceted role of connexins in HCC pathogenesis, offering valuable insights on recent advances in determining their prognostic and therapeutic potential.
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Affiliation(s)
- Stavros P. Papadakos
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (S.P.P.); (E.C.)
| | - Elena Chatzikalil
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (S.P.P.); (E.C.)
| | - Konstantinos Arvanitakis
- Division of Gastroenterology and Hepatology, First Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (K.A.); (G.V.)
- Basic and Translational Research Unit, Special Unit for Biomedical Research and Education, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece
| | - Georgios Vakadaris
- Division of Gastroenterology and Hepatology, First Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (K.A.); (G.V.)
| | - Ioanna E. Stergiou
- Pathophysiology Department, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece; (I.E.S.); (M.-L.K.)
| | - Maria-Loukia Koutsompina
- Pathophysiology Department, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece; (I.E.S.); (M.-L.K.)
| | - Alexandra Argyrou
- Academic Department of Gastroenterology, Laikon General Hospital, Athens University Medical School, 11527 Athens, Greece; (A.A.); (V.L.)
| | - Vasileios Lekakis
- Academic Department of Gastroenterology, Laikon General Hospital, Athens University Medical School, 11527 Athens, Greece; (A.A.); (V.L.)
| | | | - Georgios Germanidis
- Division of Gastroenterology and Hepatology, First Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (K.A.); (G.V.)
- Basic and Translational Research Unit, Special Unit for Biomedical Research and Education, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece
| | - Stamatios Theocharis
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (S.P.P.); (E.C.)
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Zhu Y, Zhu H, Wu P. Gap junctions in polycystic ovary syndrome: Implications for follicular arrest. Dev Dyn 2024. [PMID: 38501340 DOI: 10.1002/dvdy.706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 02/24/2024] [Accepted: 02/28/2024] [Indexed: 03/20/2024] Open
Abstract
Gap junctions are specialized intercellular conduits that provide a direct pathway between neighboring cells, which are involved in numerous physiological processes, such as cellular differentiation, cell growth, and metabolic coordination. The effect of gap junctional hemichannels in folliculogenesis is particularly obvious, and the down-regulation of connexins is related to abnormal follicle growth. Polycystic ovary syndrome (PCOS) is a ubiquitous endocrine disorder of the reproductive system, affecting the fertility of adult women due to anovulation. Exciting evidence shows that gap junction is involved in the pathological process related to PCOS and affects the development of follicles in women with PCOS. In this review, we examine the expression of connexins in follicular cells of PCOS and figure out whether such communication could have consequences for PCOS women. While along with results from clinical and related animal studies, we summarize the mechanism of connexins involved in the pathogenesis of PCOS.
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Affiliation(s)
- Ying Zhu
- Department of Gynaecology, School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Hongqiu Zhu
- Department of Gynaecology, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Peijuan Wu
- Department of Gynaecology, School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
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Peracchia C. Gap Junction Channel Regulation: A Tale of Two Gates-Voltage Sensitivity of the Chemical Gate and Chemical Sensitivity of the Fast Voltage Gate. Int J Mol Sci 2024; 25:982. [PMID: 38256055 PMCID: PMC10815820 DOI: 10.3390/ijms25020982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Gap junction channels are regulated by gates sensitive to cytosolic acidification and trans-junctional voltage (Vj). We propose that the chemical gate is a calmodulin (CaM) lobe. The fast-Vj gate is made primarily by the connexin's NH2-terminus domain (NT). The chemical gate closes the channel slowly and completely, while the fast-Vj gate closes the channel rapidly but incompletely. The chemical gate closes with increased cytosolic calcium concentration [Ca2+]i and with Vj gradients at Vj's negative side. In contrast, the fast-Vj gate closes at the positive or negative side of Vj depending on the connexin (Cx) type. Cxs with positively charged NT close at Vj's negative side, while those with negatively charged NT close at Vj's positive side. Cytosolic acidification alters in opposite ways the sensitivity of the fast-Vj gate: it increases the Vj sensitivity of negative gaters and decreases that of positive gaters. While the fast-Vj gate closes and opens instantaneously, the chemical gate often shows fluctuations, likely to reflect the shifting of the gate (CaM's N-lobe) in and out of the channel's pore.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University Rochester, Rochester, NY 14642-8711, USA
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Li Y, Acosta FM, Jiang JX. Gap Junctions or Hemichannel-Dependent and Independent Roles of Connexins in Fibrosis, Epithelial-Mesenchymal Transitions, and Wound Healing. Biomolecules 2023; 13:1796. [PMID: 38136665 PMCID: PMC10742173 DOI: 10.3390/biom13121796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Fibrosis initially appears as a normal response to damage, where activated fibroblasts produce large amounts of the extracellular matrix (ECM) during the wound healing process to assist in the repair of injured tissue. However, the excessive accumulation of the ECM, unresolved by remodeling mechanisms, leads to organ dysfunction. Connexins, a family of transmembrane channel proteins, are widely recognized for their major roles in fibrosis, the epithelial-mesenchymal transition (EMT), and wound healing. Efforts have been made in recent years to identify novel mediators and targets for this regulation. Connexins form gap junctions and hemichannels, mediating communications between neighboring cells and inside and outside of cells, respectively. Recent evidence suggests that connexins, beyond forming channels, possess channel-independent functions in fibrosis, the EMT, and wound healing. One crucial channel-independent function is their role as the primary functional component for cell adhesion. Other channel-independent functions of connexins involve their roles in mitochondria and exosomes. This review summarizes the latest advances in the channel-dependent and independent roles of connexins in fibrosis, the EMT, and wound healing, with a particular focus on eye diseases, emphasizing their potential as novel, promising therapeutic targets.
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Affiliation(s)
- Yuting Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
- Department of Pathology, Basic Medical School, Ningxia Medical University, Yinchuan 750004, China
| | - Francisca M. Acosta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
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Badaoui M, Chanson M. Intercellular Communication in Airway Epithelial Cell Regeneration: Potential Roles of Connexins and Pannexins. Int J Mol Sci 2023; 24:16160. [PMID: 38003349 PMCID: PMC10671439 DOI: 10.3390/ijms242216160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/19/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Connexins and pannexins are transmembrane proteins that can form direct (gap junctions) or indirect (connexons, pannexons) intercellular communication channels. By propagating ions, metabolites, sugars, nucleotides, miRNAs, and/or second messengers, they participate in a variety of physiological functions, such as tissue homeostasis and host defense. There is solid evidence supporting a role for intercellular signaling in various pulmonary inflammatory diseases where alteration of connexin/pannexin channel functional expression occurs, thus leading to abnormal intercellular communication pathways and contributing to pathophysiological aspects, such as innate immune defense and remodeling. The integrity of the airway epithelium, which is the first line of defense against invading microbes, is established and maintained by a repair mechanism that involves processes such as proliferation, migration, and differentiation. Here, we briefly summarize current knowledge on the contribution of connexins and pannexins to necessary processes of tissue repair and speculate on their possible involvement in the shaping of the airway epithelium integrity.
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Affiliation(s)
| | - Marc Chanson
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland;
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Jiménez-Madrona E, Morado-Díaz CJ, Talaverón R, Tabernero A, Pastor AM, Sáez JC, Matarredona ER. Antiproliferative effect of boldine on neural progenitor cells and on glioblastoma cells. Front Neurosci 2023; 17:1211467. [PMID: 37655012 PMCID: PMC10467274 DOI: 10.3389/fnins.2023.1211467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/02/2023] [Indexed: 09/02/2023] Open
Abstract
Introduction The subventricular zone (SVZ) is a brain region that contains neural stem cells and progenitor cells (NSCs/NPCs) from which new neurons and glial cells are formed during adulthood in mammals. Recent data indicate that SVZ NSCs are the cell type that acquires the initial tumorigenic mutation in glioblastoma (GBM), the most aggressive form of malignant glioma. NSCs/NPCs of the SVZ present hemichannel activity whose function has not yet been fully elucidated. In this work, we aimed to analyze whether hemichannel-mediated communication affects proliferation of SVZ NPCs and GBM cells. Methods and Results For that purpose, we used boldine, an alkaloid derived from the boldo tree (Peumus boldus), that inhibits connexin and pannexin hemichannels, but without affecting gap junctional communication. Boldine treatment (50 μM) of rat SVZ NPCs grown as neurospheres effectively inhibited dye uptake through hemichannels and induced a significant reduction in neurosphere diameter and in bromodeoxyuridine (BrdU) incorporation. However, the differentiation pattern was not modified by the treatment. Experiments with specific blockers for hemichannels formed by connexin subunits (D4) or pannexin 1 (probenecid) revealed that probenecid, but not D4, produced a decrease in BrdU incorporation similar to that obtained with boldine. These results suggest that inhibition of pannexin 1 hemichannels could be partially responsible for the antiproliferative effect of boldine on SVZ NPCs. Analysis of the effect of boldine (25-600 μM) on different types of primary human GBM cells (GBM59, GBM96, and U87-MG) showed a concentration-dependent decrease in GBM cell growth. Boldine treatment also induced a significant inhibition of hemichannel activity in GBM cells. Discussion Altogether, we provide evidence of an antimitotic action of boldine in SVZ NPCs and in GBM cells which may be due, at least in part, to its hemichannel blocking function. These results could be of relevance for future possible strategies in GBM aimed to suppress the proliferation of mutated NSCs or glioma stem cells that might remain in the brain after tumor resection.
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Affiliation(s)
- Enrique Jiménez-Madrona
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Camilo J. Morado-Díaz
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Rocío Talaverón
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Angel M. Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Juan C. Sáez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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Fisher CG, Falk MM. Endocytosis and Endocytic Motifs across the Connexin Gene Family. Int J Mol Sci 2023; 24:12851. [PMID: 37629031 PMCID: PMC10454166 DOI: 10.3390/ijms241612851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023] Open
Abstract
Proteins fated to be internalized by clathrin-mediated endocytosis require an endocytic motif, where AP-2 or another adaptor protein can bind and recruit clathrin. Tyrosine and di-leucine-based sorting signals are such canonical motifs. Connexin 43 (Cx43) has three canonical tyrosine-based endocytic motifs, two of which have been previously shown to recruit clathrin and mediate its endocytosis. In addition, di-leucine-based motifs have been characterized in the Cx32 C-terminal domain and shown to mediate its endocytosis. Here, we examined the amino acid sequences of all 21 human connexins to identify endocytic motifs across the connexin gene family. We find that although there is limited conservation of endocytic motifs between connexins, 14 of the 21 human connexins contain one or more canonical tyrosine or di-leucine-based endocytic motif in their C-terminal or intracellular loop domain. Three connexins contain non-canonical (modified) di-leucine motifs. However, four connexins (Cx25, Cx26, Cx31, and Cx40.1) do not harbor any recognizable endocytic motif. Interestingly, live cell time-lapse imaging of different GFP-tagged connexins that either contain or do not contain recognizable endocytic motifs readily undergo endocytosis, forming clearly identifiable annular gap junctions when expressed in HeLa cells. How connexins without defined endocytic motifs are endocytosed is currently not known. Our results demonstrate that an array of endocytic motifs exists in the connexin gene family. Further analysis will establish whether the sites we identified in this in silico analysis are legitimate endocytic motifs.
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Affiliation(s)
| | - Matthias M. Falk
- Department of Biological Sciences, Lehigh University, 111 Research Drive, Bethlehem, PA 18015, USA
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Skieresz-Szewczyk K, Jackowiak H. Pattern Distribution of Connexins in the Ortho- and Parakeratinized Epithelium of the Lingual Mucosa in Birds. Cells 2023; 12:1776. [PMID: 37443811 PMCID: PMC10341081 DOI: 10.3390/cells12131776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Connexins are important proteins involved in cell-to-cell communication and cytodifferentiation during renewal and cornification of the multilayered epithelia. So far, there is a lack of reports on this subject in birds' structurally different ortho- and parakeratinized epithelium of the tongue. The study aims to describe the distribution and expression profiles of the α-connexins (Cx40 and 43) and β-connexins (Cx26, 30, and 31) in those epithelia in duck, goose, and domestic turkey. Research revealed the presence of the mentioned connexins and the occurrence of interspecies differences. Connexins form gap junctions in the cell membrane or are in the cytoplasm of keratinocytes. Differences in connexin expression were noted between the basal and intermediate layers, which may determine the proliferation of keratinocytes. Cx40, 43, and Cx30 in the gap junction of the keratinocytes of the intermediate layer are related to the synchronization of the cornification process. Because of the exfoliation of cornified plaques, a lack of connexins was observed in the cornified layer of orthokeratinized epithelium. However, in parakeratinized epithelium, connexins were present in the cell membrane of keratinocytes and thus maintained cellular integrity in gradually desquamating cells. The current studies will be useful in further comparative analyses of normal and pathological epithelia of the oral cavity in birds.
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Affiliation(s)
- Kinga Skieresz-Szewczyk
- Department of Histology and Embryology, Faculty of Veterinary Medicine and Animal Science, Poznan University of Life Sciences, Wojska Polskiego 71C, 60-625 Poznan, Poland;
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Toro CA, Johnson K, Hansen J, Siddiq MM, Vásquez W, Zhao W, Graham ZA, Sáez JC, Iyengar R, Cardozo CP. Boldine modulates glial transcription and functional recovery in a murine model of contusion spinal cord injury. Front Cell Neurosci 2023; 17:1163436. [PMID: 37416508 PMCID: PMC10321410 DOI: 10.3389/fncel.2023.1163436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/01/2023] [Indexed: 07/08/2023] Open
Abstract
Membrane channels such as those formed by connexins (Cx) and P2X7 receptors (P2X7R) are permeable to calcium ions and other small molecules such as adenosine triphosphate (ATP) and glutamate. Release of ATP and glutamate through these channels is a key mechanism driving tissue response to traumas such as spinal cord injury (SCI). Boldine, an alkaloid isolated from the Chilean boldo tree, blocks both Cx and Panx1 hemichannels (HCs). To test if boldine could improve function after SCI, boldine or vehicle was administered to treat mice with a moderate severity contusion-induced SCI. Boldine led to greater spared white matter and increased locomotor function as determined by the Basso Mouse Scale and horizontal ladder rung walk tests. Boldine treatment reduced immunostaining for markers of activated microglia (Iba1) and astrocytic (GFAP) markers while increasing that for axon growth and neuroplasticity (GAP-43). Cell culture studies demonstrated that boldine blocked glial HC, specifically Cx26 and Cx30, in cultured astrocytes and blocked calcium entry through activated P2X7R. RT-qPCR studies showed that boldine treatment reduced expression of the chemokine Ccl2, cytokine IL-6 and microglial gene CD68, while increasing expression of the neurotransmission genes Snap25 and Grin2b, and Gap-43. Bulk RNA sequencing revealed that boldine modulated a large number of genes involved in neurotransmission in spinal cord tissue just caudal from the lesion epicenter at 14 days after SCI. Numbers of genes regulated by boldine was much lower at 28 days after injury. These results indicate that boldine treatment ameliorates injury and spares tissue to increase locomotor function.
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Affiliation(s)
- Carlos A. Toro
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, NY, United States
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kaitlin Johnson
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, NY, United States
| | - Jens Hansen
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Mustafa M. Siddiq
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Walter Vásquez
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile
- Instituto de Neurociencias, Centro Interdisciplinario De Neurociencia De Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Wei Zhao
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, NY, United States
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Zachary A. Graham
- Florida Institute for Human and Machine Cognition, Pensacola, FL, United States
- Department of Cell, Developmental, and Integrative Biology, University of Alabama, Birmingham, AL, United States
- Research Service, Birmingham Veterans Affairs Health Care System, Birmingham, AL, United States
| | - Juan C. Sáez
- Instituto de Neurociencias, Centro Interdisciplinario De Neurociencia De Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Ravi Iyengar
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Christopher P. Cardozo
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, NY, United States
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Rehabilitative Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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López-Gálvez R, Rivera-Caravaca JM, Mandaglio-Collados D, Orenes-Piñero E, Lahoz Á, Hernández-Romero D, Martínez CM, Carpes M, Arribas JM, Cánovas S, Lip GYH, Marín F. Molecular mechanisms of postoperative atrial fibrillation in patients with obstructive sleep apnea. FASEB J 2023; 37:e22941. [PMID: 37115741 DOI: 10.1096/fj.202201965rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/31/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023]
Abstract
Obstructive sleep apnea (OSA) promotes atrial remodeling and fibrosis, providing a substrate for atrial fibrillation (AF). Herein, we investigate the pathophysiological mechanisms of AF in association with OSA in a cohort of cardiac surgery patients. A prospective study including patients undergoing cardiac surgery. Biomarkers reflective of AF pathophysiology (interleukin [IL-6], C-reactive protein [CRP], von Willebrand factor [vWF], N-terminal pro-brain natriuretic peptide [NT-proBNP], high-sensitivity Troponin T [hs-TnT], and Galectin-3 [Gal-3]) was assessed by functional or immunological assays. miRNAs involved in AF were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Using atrial tissue samples, fibrosis was assessed by Masson's trichrome. Connexin 40 and 43 (Cx40; Cx43) were evaluated by immunolabeling. Fifty-six patients (15 with OSA and 41 non-OSA) were included in this hypothesis-generating pilot study. OSA group had a higher incidence of postoperative AF (POAF) (46.7% vs. 19.5%; p = .042), presented an increased risk of POAF (OR 3.61, 95% CI 1.01-12.92), and had significantly higher baseline levels of NT-proBNP (p = .044), vWF (p = .049), Gal-3 (p = .009), IL-6 (p = .002), and CRP (p = .003). This group presented lower levels of miR-21 and miR-208 (both p < .05). Also, lower Cx40 levels in POAF and/or OSA patients (50.0% vs. 81.8%, p = .033) were found. The presence of interstitial fibrosis (according to myocardial collagen by Masson's trichrome) was raised in OSA patients (86.7% vs. 53.7%, p = .024). Several biomarkers and miRNAs involved in inflammation and fibrosis were dysregulated in OSA patients, which together with a higher degree of interstitial fibrosis, altered miRNA, and Cxs expression predisposes to the development of a substrate that increases the AF risk.
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Affiliation(s)
- Raquel López-Gálvez
- Department of Cardiology, Hospital Clínico Universitario Virgen de la Arrixaca, University of Murcia, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), CIBERCV, Murcia, Spain
| | - José Miguel Rivera-Caravaca
- Department of Cardiology, Hospital Clínico Universitario Virgen de la Arrixaca, University of Murcia, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), CIBERCV, Murcia, Spain
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart & Chest Hospital, Liverpool, UK
| | - Darío Mandaglio-Collados
- Department of Cardiology, Hospital Clínico Universitario Virgen de la Arrixaca, University of Murcia, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), CIBERCV, Murcia, Spain
| | - Esteban Orenes-Piñero
- Proteomic Unit, Instituto Murciano de Investigaciones Biosanitarias (IMIB-Arrixaca), Murcia, Spain
| | - Álvaro Lahoz
- Department of Cardiovascular Surgery, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Murcia, Spain
| | - Diana Hernández-Romero
- Department of Legal and Forensic Medicine, Faculty of Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), University of Murcia, Murcia, Spain
| | - Carlos M Martínez
- Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Marina Carpes
- Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - José María Arribas
- Department of Cardiovascular Surgery, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Murcia, Spain
| | - Sergio Cánovas
- Department of Cardiovascular Surgery, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Murcia, Spain
| | - Gregory Y H Lip
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart & Chest Hospital, Liverpool, UK
- Department of Clinical Medicine, Aalborg Thrombosis Research Unit, Aalborg University, Aalborg, Denmark
| | - Francisco Marín
- Department of Cardiology, Hospital Clínico Universitario Virgen de la Arrixaca, University of Murcia, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), CIBERCV, Murcia, Spain
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11
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Cea LA, Vásquez W, Hernández-Salinas R, Vielma AZ, Castillo-Ruiz M, Velarde V, Salgado M, Sáez JC. Skeletal Muscle Atrophy Induced by Diabetes Is Mediated by Non-Selective Channels and Prevented by Boldine. Biomolecules 2023; 13:708. [PMID: 37189454 PMCID: PMC10136059 DOI: 10.3390/biom13040708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/23/2023] [Accepted: 04/04/2023] [Indexed: 05/17/2023] Open
Abstract
Individuals with diabetes mellitus present a skeletal muscle myopathy characterized by atrophy. However, the mechanism underlying this muscular alteration remains elusive, which makes it difficult to design a rational treatment that could avoid the negative consequences in muscles due to diabetes. In the present work, the atrophy of skeletal myofibers from streptozotocin-induced diabetic rats was prevented with boldine, suggesting that non-selective channels inhibited by this alkaloid are involved in this process, as has previously shown for other muscular pathologies. Accordingly, we found a relevant increase in sarcolemma permeability of skeletal myofibers of diabetic animals in vivo and in vitro due to de novo expression of functional connexin hemichannels (Cx HCs) containing connexins (Cxs) 39, 43, and 45. These cells also expressed P2X7 receptors, and their inhibition in vitro drastically reduced sarcolemma permeability, suggesting their participation in the activation of Cx HCs. Notably, sarcolemma permeability of skeletal myofibers was prevented by boldine treatment that blocks Cx43 and Cx45 HCs, and now we demonstrated that it also blocks P2X7 receptors. In addition, the skeletal muscle alterations described above were not observed in diabetic mice with myofibers deficient in Cx43/Cx45 expression. Moreover, murine myofibers cultured for 24 h in high glucose presented a drastic increase in sarcolemma permeability and levels of NLRP3, a molecular member of the inflammasome, a response that was also prevented by boldine, suggesting that, in addition to the systemic inflammatory response found in diabetes, high glucose can promote the expression of functional Cx HCs and activation of the inflammasome in skeletal myofibers. Therefore, Cx43 and Cx45 HCs play a critical role in myofiber degeneration, and boldine could be considered a potential therapeutic agent to treat muscular complications due to diabetes.
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Affiliation(s)
- Luis A. Cea
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Av. Llano Subercaseaux 2801, San Miguel, Santiago 8910060, Chile
| | - Walter Vásquez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Romina Hernández-Salinas
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Universidad del Desarrollo, Santiago 7610000, Chile
| | - Alejandra Z. Vielma
- Escuela de Odontología, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7610000, Chile
| | - Mario Castillo-Ruiz
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370149, Chile
- Departamento de Ciencias Químicas y Biológicas, Facultad de Ciencias de la Salud, Universidad Bernardo O’Higgins, Santiago 8370854, Chile
| | - Victoria Velarde
- Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Magdiel Salgado
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Pasaje Harrington 287, Playa Ancha, Valparaíso 2340000, Chile
| | - Juan C. Sáez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Pasaje Harrington 287, Playa Ancha, Valparaíso 2340000, Chile
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12
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Chang CWT, Poudyal N, Verdugo DA, Peña F, Stehberg J, Retamal MA. KI04 an Aminoglycosides-Derived Molecule Acts as an Inhibitor of Human Connexin46 Hemichannels Expressed in HeLa Cells. Biomolecules 2023; 13:411. [PMID: 36979346 PMCID: PMC10046693 DOI: 10.3390/biom13030411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Connexins (Cxs) are proteins that help cells to communicate with the extracellular media and with the cytoplasm of neighboring cells. Despite their importance in several human physiological and pathological conditions, their pharmacology is very poor. In the last decade, some molecules derived from aminoglycosides have been developed as inhibitors of Cxs hemichannels. However, these studies have been performed in E. coli, which is a very simple model. Therefore, our main goal is to test whether these molecules have similar effects in mammalian cells. METHODS We transfected HeLa cells with the human Cx46tGFP and characterized the effect of a kanamycin-derived molecule (KI04) on Cx46 hemichannel activity by time-lapse recordings, changes in phosphorylation by Western blot, localization by epifluorescence, and possible binding sites by molecular dynamics (MD). RESULTS We observed that kanamycin and KI04 were the most potent inhibitors of Cx46 hemichannels among several aminoglycosides, presenting an IC50 close to 10 μM. The inhibitory effect was not associated with changes in Cx46 electrophoretic mobility or its intracellular localization. Interestingly, 5 mM DTT did not reverse KI04 inhibition, but the KI04 effect completely disappeared after washing out KI04 from the recording media. MD analysis revealed two putative binding sites of KI04 in the Cx46 hemichannel. RESULTS These results demonstrate that KI04 could be used as a Cx46 inhibitor and could help to develop future selective Cx46 inhibitors.
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Affiliation(s)
- Cheng-Wei T. Chang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
| | - Naveena Poudyal
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
| | - Daniel A. Verdugo
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Francisca Peña
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Mauricio A. Retamal
- Center for Membrane Protein Research, Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7610496, Chile
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13
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Zappalà A, Romano IR, D’Angeli F, Musumeci G, Lo Furno D, Giuffrida R, Mannino G. Functional Roles of Connexins and Gap Junctions in Osteo-Chondral Cellular Components. Int J Mol Sci 2023; 24:ijms24044156. [PMID: 36835567 PMCID: PMC9967557 DOI: 10.3390/ijms24044156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
Gap junctions (GJs) formed by connexins (Cxs) play an important role in the intercellular communication within most body tissues. In this paper, we focus on GJs and Cxs present in skeletal tissues. Cx43 is the most expressed connexin, participating in the formation of both GJs for intercellular communication and hemichannels (HCs) for communication with the external environment. Through GJs in long dendritic-like cytoplasmic processes, osteocytes embedded in deep lacunae are able to form a functional syncytium not only with neighboring osteocytes but also with bone cells located at the bone surface, despite the surrounding mineralized matrix. The functional syncytium allows a coordinated cell activity through the wide propagation of calcium waves, nutrients and anabolic and/or catabolic factors. Acting as mechanosensors, osteocytes are able to transduce mechanical stimuli into biological signals that spread through the syncytium to orchestrate bone remodeling. The fundamental role of Cxs and GJs is confirmed by a plethora of investigations that have highlighted how up- and downregulation of Cxs and GJs critically influence skeletal development and cartilage functions. A better knowledge of GJ and Cx mechanisms in physiological and pathological conditions might help in developing therapeutic approaches aimed at the treatment of human skeletal system disorders.
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Affiliation(s)
- Agata Zappalà
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Ivana Roberta Romano
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Floriana D’Angeli
- Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University, 00166 Rome, Italy
| | - Giuseppe Musumeci
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Debora Lo Furno
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Correspondence: (D.L.F.); (R.G.)
| | - Rosario Giuffrida
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Correspondence: (D.L.F.); (R.G.)
| | - Giuliana Mannino
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, 98122 Messina, Italy
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14
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Kutova OM, Pospelov AD, Balalaeva IV. The Multifaceted Role of Connexins in Tumor Microenvironment Initiation and Maintenance. Biology (Basel) 2023; 12. [PMID: 36829482 DOI: 10.3390/biology12020204] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/19/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023]
Abstract
Today's research on the processes of carcinogenesis and the vital activity of tumor tissues implies more attention be paid to constituents of the tumor microenvironment and their interactions. These interactions between cells in the tumor microenvironment can be mediated via different types of protein junctions. Connexins are one of the major contributors to intercellular communication. They form the gap junctions responsible for the transfer of ions, metabolites, peptides, miRNA, etc., between neighboring tumor cells as well as between tumor and stromal cells. Connexin hemichannels mediate purinergic signaling and bidirectional molecular transport with the extracellular environment. Additionally, connexins have been reported to localize in tumor-derived exosomes and facilitate the release of their cargo. A large body of evidence implies that the role of connexins in cancer is multifaceted. The pro- or anti-tumorigenic properties of connexins are determined by their abundance, localization, and functionality as well as their channel assembly and non-channel functions. In this review, we have summarized the data on the contribution of connexins to the formation of the tumor microenvironment and to cancer initiation and progression.
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15
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Madonna R, Moscato S, Cufaro MC, Pieragostino D, Mattii L, Del Boccio P, Ghelardoni S, Zucchi R, De Caterina R. Empagliflozin inhibits excessive autophagy through the AMPK/GSK3β signaling pathway in diabetic cardiomyopathy. Cardiovasc Res 2023; 119:1175-1189. [PMID: 36627733 DOI: 10.1093/cvr/cvad009] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/23/2022] [Accepted: 12/09/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND AIMS Sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial effects on heart failure and cardiovascular mortality in diabetic and nondiabetic patients, with unclear mechanisms. Autophagy is a cardioprotective mechanism under acute stress conditions, but excessive autophagy accelerates myocardial cell death leading to autosis. We evaluated the protective role of empagliflozin (EMPA) against cardiac injury in murine diabetic cardiomyopathy. METHODS AND RESULTS Male mice, rendered diabetics by one single intraperitoneal injection of streptozotocin and treated with EMPA (30 mg/kg/day) had fewer apoptotic cells (4.9 ± 2.1 vs 1 ± 0.5 TUNEL-positive cells %, p < 0.05), less senescence (10.1 ± 2 vs 7.9 ± 1.2 β-gal positivity/tissue area, p < 0.05), fibrosis (0.2 ± 0.05 vs 0.15 ± 0.06, p < 0.05 fibrotic area/tissue area), autophagy (7.9 ± 0.05 vs 2.3 ± 0.6 fluorescence intensity/total area, p < 0.01), and connexin (Cx)-43 lateralization compared with diabetic mice. Proteomic analysis showed a downregulation of the 5' adenosine monophosphate-activated protein kinase (AMPK) pathway and upstream activation of sirtuins in the heart of diabetic mice treated with EMPA compared with diabetic mice. Because sirtuin activation leads to modulation of cardiomyogenic transcription factors, we analyzed the DNA binding activity to serum response elements (SRE) of serum response factor (SRF) by electromobility shift assay. Compared with diabetic mice (0.5 ± 0.01 densitometric units, DU), nondiabetic mice treated with EMPA (2.2 ± 0.01 DU, p < 0.01) and diabetic mice treated with EMPA (2.0 ± 0.1 DU, p < 0.01) significantly increased SRF binding activity to SRE, paralleled by increased cardiac actin expression (4.1 ± 0.1 vs 2.2 ± 0.01 target protein/β-actin ratio, p < 0.01). EMPA significantly reversed cardiac dysfunction on echocardiography in diabetic mice and inhibited excessive autophagy in high-glucose-treated cardiomyocytes by inhibiting the autophagy inducer GSK3β, leading to reactivation of cardiomyogenic transcription factors. CONCLUSIONS Taken together, our results describe a novel paradigm in which EMPA inhibits hyperactivation of autophagy through the AMPK/GSK3β signaling pathway in the context of diabetes.
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Affiliation(s)
- Rosalinda Madonna
- Department of Pathology, Cardiology Division, University of Pisa, Pisa, Italy
| | - Stefania Moscato
- Department of Clinical and Experimental Medicine, Histology Division, University of Pisa, Pisa, Italy
| | - Maria Concetta Cufaro
- Department of Pharmacy, ''G. d'Annunzio'' University of Chieti-Pescara, Chieti, Italy.,Analytical Biochemistry and Proteomics Laboratory, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Italy
| | - Damiana Pieragostino
- Department of Innovative Technologies in Medicine and Dentistry, ''G. d'Annunzio'' University of Chieti-Pescara, Chieti, Italy.,Analytical Biochemistry and Proteomics Laboratory, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Italy
| | - Letizia Mattii
- Department of Clinical and Experimental Medicine, Histology Division, University of Pisa, Pisa, Italy
| | - Piero Del Boccio
- Department of Pharmacy, ''G. d'Annunzio'' University of Chieti-Pescara, Chieti, Italy.,Analytical Biochemistry and Proteomics Laboratory, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Italy
| | - Sandra Ghelardoni
- Department of Pathology, Laboratory of Biochemistry, University of Pisa, Italy
| | - Riccardo Zucchi
- Department of Pathology, Laboratory of Biochemistry, University of Pisa, Italy
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16
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Garré JM, Bukauskas FF, Bennett MVL. Single channel properties of pannexin-1 and connexin-43 hemichannels and P2X7 receptors in astrocytes cultured from rodent spinal cords. Glia 2022; 70:2260-2275. [PMID: 35915989 PMCID: PMC9560969 DOI: 10.1002/glia.24250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 11/11/2022]
Abstract
Astrocytes express surface channels involved in purinergic signaling. Among these channels, pannexin-1 (Px1) and connexin-43 (Cx43) hemichannels (HCs) release ATP that acts directly, or through its derivatives, on neurons and glia via purinergic receptors. Although HCs are functional, that is, open and close under physiological and pathological conditions, single channel properties of Px1 HCs in astrocytes have not been defined. Here, we developed a dual voltage clamp technique in HeLa cells expressing human Px1-YFP, and then applied this system to rodent spinal astrocytes to compare their single channel properties with other surface channels, that is, Cx43 HCs and P2X7 receptors (P2X7Rs). Channels were recorded in cell attached patches and evoked with ramp cycles applied through another pipette in whole cell voltage clamp. The mean unitary conductances of Px1 HCs were comparable in HeLa Px1-YFP cells and spinal astrocytes, ~42 and ~48 pS, respectively. Based on their unitary conductance, voltage-dependence, and unitary activity after pharmacological and gene silencing, Px1 HCs in astrocytes could be distinguished from Cx43 HCs and P2X7Rs. Channel activity of Px1 HCs and P2X7Rs was greater than that of Cx43 HCs in control astrocytes during ramps. Unitary activity of Px1 HCs was decreased and that of Cx43 HCs and P2X7Rs increased in astrocytes treated with fibroblast growth factor 1 (FGF-1). In summary, we resolved single channel properties of three different surface channels involved in purinergic signaling in spinal astrocytes, which were differentially modulated by FGF-1, a growth factor involved in neurodevelopment, inflammation and repair.
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Affiliation(s)
- Juan Mauricio Garré
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Feliksas F Bukauskas
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Michael V L Bennett
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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17
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Portal B, Vasile F, Zapata J, Lejards C, Ait Tayeb AEK, Colle R, Verstuyft C, Corruble E, Rouach N, Guiard BP. Astroglial Connexins Inactivation Increases Relapse of Depressive-like Phenotype after Antidepressant Withdrawal. Int J Mol Sci 2022; 23:13227. [PMID: 36362016 PMCID: PMC9656718 DOI: 10.3390/ijms232113227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 09/11/2023] Open
Abstract
Studies suggest that astrocytic connexins (Cx) have an important role in the regulation of high brain functions through their ability to establish fine-tuned communication with neurons within the tripartite synapse. In light of these properties, growing evidence suggests a role of Cx in psychiatric disorders such as major depression but also in the therapeutic activity of antidepressant drugs. However, the real impact of Cx on treatment response and the underlying neurobiological mechanisms remain yet to be clarified. On this ground, the present study was designed to evaluate the functional activity of Cx in a mouse model of depression based on chronic corticosterone exposure and to determine to which extent their pharmacological inactivation influences the antidepressant-like activity of venlafaxine (VENLA). On the one hand, our results indicate that depressed mice have impaired Cx-based gap-junction and hemichannel activities. On the other hand, while VENLA exerts robust antidepressant-like activity in depressed mice; this effect is abolished by the pharmacological inhibition of Cx with carbenoxolone (CBX). Interestingly, the combination of VENLA and CBX is also associated with a higher rate of relapse after treatment withdrawal. To our knowledge, this study is one of the first to develop a model of relapse, and our results reveal that Cx-mediated dynamic neuroglial interactions play a critical role in the efficacy of monoaminergic antidepressant drugs, thus providing new targets for the treatment of depression.
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Affiliation(s)
- Benjamin Portal
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Flora Vasile
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Jonathan Zapata
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Camille Lejards
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Abd El Kader Ait Tayeb
- CESP, MOODS Team, INSERM, Faculté de Médecine, University of Paris-Saclay, 94275 Le Kremlin Bicêtre, France
- Service Hospitalo-Universitaire de Psychiatrie de Bicêtre, Hôpitaux Universitaires Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, 94275 Le Kremlin Bicêtre, France
| | - Romain Colle
- CESP, MOODS Team, INSERM, Faculté de Médecine, University of Paris-Saclay, 94275 Le Kremlin Bicêtre, France
- Service Hospitalo-Universitaire de Psychiatrie de Bicêtre, Hôpitaux Universitaires Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, 94275 Le Kremlin Bicêtre, France
| | - Céline Verstuyft
- CESP, MOODS Team, INSERM, Faculté de Médecine, University of Paris-Saclay, 94275 Le Kremlin Bicêtre, France
- Service de Génétique Moléculaire, Pharmacogénétique et Hormonologie de Bicêtre, Hôpitaux Universitaires Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, 94275 Le Kremlin Bicêtre, France
| | - Emmanuelle Corruble
- CESP, MOODS Team, INSERM, Faculté de Médecine, University of Paris-Saclay, 94275 Le Kremlin Bicêtre, France
- Service Hospitalo-Universitaire de Psychiatrie de Bicêtre, Hôpitaux Universitaires Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, 94275 Le Kremlin Bicêtre, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Bruno P. Guiard
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, 31062 Toulouse, France
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18
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Baracaldo-Santamaría D, Corrales-Hernández MG, Ortiz-Vergara MC, Cormane-Alfaro V, Luque-Bernal RM, Calderon-Ospina CA, Cediel-Becerra JF. Connexins and Pannexins: Important Players in Neurodevelopment, Neurological Diseases, and Potential Therapeutics. Biomedicines 2022; 10:2237. [PMID: 36140338 PMCID: PMC9496069 DOI: 10.3390/biomedicines10092237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Cell-to-cell communication is essential for proper embryonic development and its dysfunction may lead to disease. Recent research has drawn attention to a new group of molecules called connexins (Cxs) and pannexins (Panxs). Cxs have been described for more than forty years as pivotal regulators of embryogenesis; however, the exact mechanism by which they provide this regulation has not been clearly elucidated. Consequently, Cxs and Panxs have been linked to congenital neurodegenerative diseases such as Charcot-Marie-Tooth disease and, more recently, chronic hemichannel opening has been associated with adult neurodegenerative diseases (e.g., Alzheimer's disease). Cell-to-cell communication via gap junctions formed by hexameric assemblies of Cxs, known as connexons, is believed to be a crucial component in developmental regulation. As for Panxs, despite being topologically similar to Cxs, they predominantly seem to form channels connecting the cytoplasm to the extracellular space and, despite recent research into Panx1 (Pannexin 1) expression in different regions of the brain during the embryonic phase, it has been studied to a lesser degree. When it comes to the nervous system, Cxs and Panxs play an important role in early stages of neuronal development with a wide span of action ranging from cellular migration during early stages to neuronal differentiation and system circuitry formation. In this review, we describe the most recent available evidence regarding the molecular and structural aspects of Cx and Panx channels, their role in neurodevelopment, congenital and adult neurological diseases, and finally propose how pharmacological modulation of these channels could modify the pathogenesis of some diseases.
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Affiliation(s)
- Daniela Baracaldo-Santamaría
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - María Gabriela Corrales-Hernández
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Maria Camila Ortiz-Vergara
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Valeria Cormane-Alfaro
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Ricardo-Miguel Luque-Bernal
- Anatomy and Embriology Units, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Carlos-Alberto Calderon-Ospina
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
- GENIUROS Research Group, Center for Research in Genetics and Genomics (CIGGUR), School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Juan-Fernando Cediel-Becerra
- Histology and Embryology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
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19
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Peracchia C. Anesthetics and Cell-Cell Communication: Potential Ca 2+-Calmodulin Role in Gap Junction Channel Gating by Heptanol, Halothane and Isoflurane. Int J Mol Sci 2022; 23:9017. [PMID: 36012286 DOI: 10.3390/ijms23169017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/08/2022] [Accepted: 08/11/2022] [Indexed: 11/17/2022] Open
Abstract
Cell–cell communication via gap junction channels is known to be inhibited by the anesthetics heptanol, halothane and isoflurane; however, despite numerous studies, the mechanism of gap junction channel gating by anesthetics is still poorly understood. In the early nineties, we reported that gating by anesthetics is strongly potentiated by caffeine and theophylline and inhibited by 4-Aminopyridine. Neither Ca2+ channel blockers nor 3-isobutyl-1-methylxanthine (IBMX), forskolin, CPT-cAMP, 8Br-cGMP, adenosine, phorbol ester or H7 had significant effects on gating by anesthetics. In our publication, we concluded that neither cytosolic Ca2+i nor pHi were involved, and suggested a direct effect of anesthetics on gap junction channel proteins. However, while a direct effect cannot be excluded, based on the potentiating effect of caffeine and theophylline added to anesthetics and data published over the past three decades, we are now reconsidering our earlier interpretation and propose an alternative hypothesis that uncoupling by heptanol, halothane and isoflurane may actually result from a rise in cytosolic Ca2+ concentration ([Ca2+]i) and consequential activation of calmodulin linked to gap junction proteins.
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Durkina AV, Bernikova OG, Gonotkov MA, Mikhaleva NJ, Sedova KA, Malykhina IA, Kuzmin VS, Velegzhaninov IO, Azarov JE. Melatonin treatment improves ventricular conduction via upregulation of Nav1.5 channel proteins and sodium current in the normal rat heart. J Pineal Res 2022; 73:e12798. [PMID: 35384053 DOI: 10.1111/jpi.12798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/31/2022] [Accepted: 04/02/2022] [Indexed: 11/29/2022]
Abstract
Melatonin treatment was reported to reduce the risk of cardiac arrhythmias, and crucial for this antiarrhythmic action was the effect of melatonin on activation spread. The aim of the present study was evaluation of the mechanisms of this activation enhancement. Experiments were performed in a total of 123 control and melatonin-treated (10 mg/kg, daily, for 7 days) male Wistar rats. In epicardial mapping studies (64 leads, interlead distance 0.5 mm) in the anesthetized animals, activation times (ATs) were determined in each lead as dV/dt minimum during QRS complex under sinus rhythm. Epicardial pacing was performed to measure conduction velocity (CV) across the mapped area. Average left ventricular ATs were shorter in the treated animals as compared to the controls, whereas the minimal epicardial ATs indicating the duration of activation propagation via the ventricular conduction system did not differ between the groups. CV was higher in the treated groups indicating that melatonin affected conduction via contractile myocardium The area of Cx43-derived fluorescence, as well as the expression of Cx43 protein, was similar in ventricles in the control and melatonin-treated groups. Expression of Gja1 gene transcripts encoding Cx43, was increased in the last group. An uncoupling agent octanol modified myocardial conduction properties (time of activation, action potential upstroke velocity, passive electrotonic phase duration) similarly in both groups. On the other hand, the expression of both Scn5a gene transcripts encoding Nav1.5 proteins, as well as peak density of transmembrane sodium current were increased in the ventricular myocytes from the melatonin-treated animals. Thus, a week-long melatonin treatment caused the increase of conduction velocity via enhancement of sodium channel proteins expression and increase of sodium current in the ventricular myocytes.
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Affiliation(s)
- Aleksandra V Durkina
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Olesya G Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Mikhail A Gonotkov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Natalia J Mikhaleva
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ksenia A Sedova
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Inna A Malykhina
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Vladislav S Kuzmin
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Ilya O Velegzhaninov
- Department of Radioecology, Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Jan E Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
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Zhou Z, Chai W, Liu Y, Zhou M, Zhang X. Connexins and angiogenesis: Functional aspects, pathogenesis, and emerging therapies (Review). Int J Mol Med 2022; 50:110. [PMID: 35762312 PMCID: PMC9256078 DOI: 10.3892/ijmm.2022.5166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/08/2022] [Indexed: 11/20/2022] Open
Abstract
Connexins (Cxs) play key roles in cellular communication. By facilitating metabolite exchange or interfering with distinct signaling pathways, Cxs affect cell homeostasis, proliferation, and differentiation. Variations in the activity and expression of Cxs have been linked to numerous clinical conditions including carcinomas, cardiac disorders, and wound healing. Recent discoveries on the association between Cxs and angiogenesis have sparked interest in Cx-mediated angiogenesis due to its essential functions in tissue formation, wound repair, tumor growth, and metastasis. It is now widely recognized that understanding the association between Cxs and angiogenesis may aid in the development of new targeted therapies for angiogenic diseases. The aim of the present review was to provide a comprehensive overview of Cxs and Cx-mediated angiogenesis, with a focus on therapeutic implications.
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Affiliation(s)
- Zizi Zhou
- Department of Cardio‑Thoracic Surgery, Shenzhen University General Hospital, Shenzhen, Guangdong 518055, P.R. China
| | - Wenxiang Chai
- Department of Cardio‑Thoracic Surgery, Shenzhen University General Hospital, Shenzhen, Guangdong 518055, P.R. China
| | - Yi Liu
- Department of Cardio‑Thoracic Surgery, Shenzhen University General Hospital, Shenzhen, Guangdong 518055, P.R. China
| | - Meng Zhou
- Department of Cardio‑Thoracic Surgery, Shenzhen University General Hospital, Shenzhen, Guangdong 518055, P.R. China
| | - Xiaoming Zhang
- Department of Cardio‑Thoracic Surgery, Shenzhen University General Hospital, Shenzhen, Guangdong 518055, P.R. China
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22
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Fernández-Olivares A, Durán-Jara E, Verdugo DA, Fiori MC, Altenberg GA, Stehberg J, Alfaro I, Calderón JF, Retamal MA. Extracellular Cysteines Are Critical to Form Functional Cx46 Hemichannels. Int J Mol Sci 2022; 23:7252. [PMID: 35806258 PMCID: PMC9266770 DOI: 10.3390/ijms23137252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/16/2022] [Accepted: 06/18/2022] [Indexed: 12/10/2022] Open
Abstract
Connexin (Cxs) hemichannels participate in several physiological and pathological processes, but the molecular mechanisms that control their gating remain elusive. We aimed at determining the role of extracellular cysteines (Cys) in the gating and function of Cx46 hemichannels. We studied Cx46 and mutated all of its extracellular Cys to alanine (Ala) (one at a time) and studied the effects of the Cys mutations on Cx46 expression, localization, and hemichannel activity. Wild-type Cx46 and Cys mutants were expressed at comparable levels, with similar cellular localization. However, functional experiments showed that hemichannels formed by the Cys mutants did not open either in response to membrane depolarization or removal of extracellular divalent cations. Molecular-dynamics simulations showed that Cys mutants may show a possible alteration in the electrostatic potential of the hemichannel pore and an altered disposition of important residues that could contribute to the selectivity and voltage dependency in the hemichannels. Replacement of extracellular Cys resulted in "permanently closed hemichannels", which is congruent with the inhibition of the Cx46 hemichannel by lipid peroxides, through the oxidation of extracellular Cys. These results point to the modification of extracellular Cys as potential targets for the treatment of Cx46-hemichannel associated pathologies, such as cataracts and cancer, and may shed light into the gating mechanisms of other Cx hemichannels.
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Affiliation(s)
- Ainoa Fernández-Olivares
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile; (A.F.-O.); (I.A.)
| | - Eduardo Durán-Jara
- Centro de Medicina Regenerativa, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile;
| | - Daniel A. Verdugo
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 7780272, Chile; (D.A.V.); (J.S.)
| | - Mariana C. Fiori
- Department of Cell Physiology and Molecular Biophysics and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA; (M.C.F.); (G.A.A.)
| | - Guillermo A. Altenberg
- Department of Cell Physiology and Molecular Biophysics and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA; (M.C.F.); (G.A.A.)
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 7780272, Chile; (D.A.V.); (J.S.)
| | - Iván Alfaro
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile; (A.F.-O.); (I.A.)
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Santiago 7690000, Chile
| | - Juan Francisco Calderón
- Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile
| | - Mauricio A. Retamal
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile; (A.F.-O.); (I.A.)
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Santiago 7690000, Chile
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7690000, Chile
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Meter D, Racetin A, Vukojević K, Balog M, Ivić V, Zjalić M, Heffer M, Filipović N. A Lack of GD3 Synthase Leads to Impaired Renal Expression of Connexins and Pannexin1 in St8sia1 Knockout Mice. Int J Mol Sci 2022; 23:ijms23116237. [PMID: 35682927 PMCID: PMC9181035 DOI: 10.3390/ijms23116237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 02/01/2023] Open
Abstract
The aim of this study was to determine the effects of altered ganglioside composition on the expression of Cx37, Cx40, Cx43, Cx45, and Panx1 in different kidney regions of St8sia1 gene knockout mice (St8sia1 KO) lacking the GD3 synthase enzyme. Experiments were performed in twelve male 6-month-old mice: four wild-type (C57BL/6-type, WT) and eight St8sia1 KO mice. After euthanasia, kidney tissue was harvested, embedded in paraffin wax, and processed for immunohistochemistry. The expression of connexins and Panx1 was determined in different regions of the kidney: cortex (CTX.), outer stripe of outer medulla (O.S.), inner stripe of outer medulla (IN.S.), and inner medulla (IN.MED.). We determined significantly lower expression of Cx37, Cx40, Cx45, and Panx1 in different parts of the kidneys of St8sia1 KO mice compared with WT. The most consistent decrease was found in the O.S. where all markers (Cx 37, 40, 45 and Panx1) were disrupted in St8si1 KO mice. In the CTX. region, we observed decrease in the expression of Cx37, Cx45, and Panx1, while reduced expression of Cx37 and Panx1 was more specific to IN.S. The results of the present study suggest that deficiency of GD3 synthase in St8sia1 KO mice leads to disruption of renal Cx expression, which is probably related to alteration of ganglioside composition.
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Affiliation(s)
- Diana Meter
- Department of Rheumatology and Clinical Immunology, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia;
| | - Anita Racetin
- Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (A.R.); (K.V.)
| | - Katarina Vukojević
- Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (A.R.); (K.V.)
- Laboratory for Neurocardiology, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia
| | - Marta Balog
- Department of Medical Biology and Genetics, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia; (M.B.); (V.I.); (M.H.)
| | - Vedrana Ivić
- Department of Medical Biology and Genetics, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia; (M.B.); (V.I.); (M.H.)
| | - Milorad Zjalić
- Department of Molecular Medicine and Biotechnology, Faculty of Medicine Rijeka, University of Rijeka, Branchetta brothers 20, 51000 Rijeka, Croatia;
| | - Marija Heffer
- Department of Medical Biology and Genetics, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia; (M.B.); (V.I.); (M.H.)
| | - Natalija Filipović
- Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (A.R.); (K.V.)
- Correspondence:
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Abstract
Cellular delivery of therapeutic macromolecules such as proteins, peptides, and nucleic acids remains limited due to inefficient transport across the cellular plasma membrane. Gap junction channels, composed of connexin proteins, provide a mechanism for direct transfer of small molecules across membranes, and recent evidence suggests that the transfer of larger, polymer-like molecules such as microRNAs may be possible. Here, we report direct evidence of gap junction-mediated transfer of polymeric macromolecules. Specifically, we examined the transport of dextran chains with molecular weights ranging from 10 to 70 kDa. We found that dextran chains of up to 40 kDa can diffuse through at least five cell layers in a gap junction-dependent manner within a 30 min time frame. Further, we evaluated the ability of connectosomes, cell-derived vesicles containing functional connexin proteins, to be loaded with dextran chains. By opening connexon hemichannel pores within the membranes of connectosomes, we found that 10 kDa dextran was loaded into more than 90% of vesicles, with reduced levels of loading for dextran chains of larger molecular weight. Upon delivering 10 kDa dextran-loaded connectosomes to cells, we further found that connectosomes transferred these membrane-impermeable molecules to the cellular cytosol with dramatically improved efficiency in comparison to the delivery of free, unencapsulated dextran. Collectively, these results reveal that polymeric macromolecules can be delivered to cells via gap junctions, suggesting that the gap junction route may be useful for the delivery of polymeric therapeutic molecules, such as nucleic acids and peptides.
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Affiliation(s)
- Andrea N Trementozzi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Chi Zhao
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Hugh Smyth
- College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Zhengrong Cui
- College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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25
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Guo YH, Yang YQ. Atrial Fibrillation: Focus on Myocardial Connexins and Gap Junctions. Biology (Basel) 2022; 11:489. [PMID: 35453689 PMCID: PMC9029470 DOI: 10.3390/biology11040489] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Atrial fibrillation (AF) represents the most common type of clinical cardiac arrhythmia worldwide and contributes to substantial morbidity, mortality and socioeconomic burden. Aggregating evidence highlights the strong genetic basis of AF. In addition to chromosomal abnormalities, pathogenic mutations in over 50 genes have been causally linked to AF, of which the majority encode ion channels, cardiac structural proteins, transcription factors and gap junction channels. In the heart, gap junctions comprised of connexins (Cxs) form intercellular pathways responsible for electrical coupling and rapid coordinated action potential propagation between adjacent cardiomyocytes. Among the 21 isoforms of connexins already identified in the mammal genomes, 5 isoforms (Cx37, Cx40, Cx43, Cx45 and Cx46) are expressed in human heart. Abnormal electrical coupling between cardiomyocytes caused by structural remodeling of gap junction channels (alterations in connexin distribution and protein levels) has been associated with enhanced susceptibility to AF and recent studies have revealed multiple causative mutations or polymorphisms in 4 isoforms of connexins predisposing to AF. In this review, an overview of the genetics of AF is made, with a focus on the roles of mutant myocardial connexins and gap junctions in the pathogenesis of AF, to underscore the hypothesis that cardiac connexins are a major molecular target in the management of AF.
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Affiliation(s)
- Yu-Han Guo
- Department of Cardiology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China;
| | - Yi-Qing Yang
- Department of Cardiology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China;
- Cardiovascular Research Laboratory, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China
- Center Laboratory, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China
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26
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Sathiyanadan K, Alonso F, Domingos-Pereira S, Santoro T, Hamard L, Cesson V, Meda P, Nardelli-Haefliger D, Haefliger JA. Targeting Endothelial Connexin37 Reduces Angiogenesis and Decreases Tumor Growth. Int J Mol Sci 2022; 23:2930. [PMID: 35328350 DOI: 10.3390/ijms23062930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/28/2022] [Accepted: 03/03/2022] [Indexed: 12/13/2022] Open
Abstract
Connexin37 (Cx37) and Cx40 form intercellular channels between endothelial cells (EC), which contribute to the regulation of the functions of vessels. We previously documented the participation of both Cx in developmental angiogenesis and have further shown that loss of Cx40 decreases the growth of different tumors. Here, we report that loss of Cx37 reduces (1) the in vitro proliferation of primary human EC; (2) the vascularization of subcutaneously implanted matrigel plugs in Cx37−/− mice or in WT using matrigel plugs supplemented with a peptide targeting Cx37 channels; (3) tumor angiogenesis; and (4) the growth of TC-1 and B16 tumors, resulting in a longer mice survival. We further document that Cx37 and Cx40 function in a collaborative manner to promote tumor growth, inasmuch as the injection of a peptide targeting Cx40 into Cx37−/− mice decreased the growth of TC-1 tumors to a larger extent than after loss of Cx37. This loss did not alter vessel perfusion, mural cells coverage and tumor hypoxia compared to tumors grown in WT mice. The data show that Cx37 is relevant for the control of EC proliferation and growth in different tumor models, suggesting that it may be a target, alone or in combination with Cx40, in the development of anti-tumoral treatments.
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27
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Brotherton DH, Savva CG, Ragan TJ, Dale N, Cameron AD. Conformational changes and CO 2-induced channel gating in connexin26. Structure 2022; 30:697-706.e4. [PMID: 35276081 PMCID: PMC9592558 DOI: 10.1016/j.str.2022.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 12/22/2022]
Abstract
Connexins form large-pore channels that function either as dodecameric gap junctions or hexameric hemichannels to allow the regulated movement of small molecules and ions across cell membranes. Opening or closing of the channels is controlled by a variety of stimuli, and dysregulation leads to multiple diseases. An increase in the partial pressure of carbon dioxide (PCO2) has been shown to cause connexin26 (Cx26) gap junctions to close. Here, we use cryoelectron microscopy (cryo-EM) to determine the structure of human Cx26 gap junctions under increasing levels of PCO2. We show a correlation between the level of PCO2 and the size of the aperture of the pore, governed by the N-terminal helices that line the pore. This indicates that CO2 alone is sufficient to cause conformational changes in the protein. Analysis of the conformational states shows that movements at the N terminus are linked to both subunit rotation and flexing of the transmembrane helices. High-resolution cryo-EM structures of connexin26 at varying levels of PCO2 CO2 alone causes conformational changes in the protein under stable pH conditions The N-terminal helices regulate the aperture of the pore KID syndrome mutations affecting CO2 sensitivity map to flexion points of structure
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Affiliation(s)
- Deborah H Brotherton
- School of Life Sciences, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK
| | - Christos G Savva
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, LE1 7HB Leicester, UK
| | - Timothy J Ragan
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, LE1 7HB Leicester, UK
| | - Nicholas Dale
- School of Life Sciences, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK.
| | - Alexander D Cameron
- School of Life Sciences, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK.
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28
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Zhao D, Riquelme MA, Guda T, Tu C, Xu H, Gu S, Jiang JX. Connexin hemichannels with prostaglandin release in anabolic function of bone to mechanical loading. eLife 2022; 11:74365. [PMID: 35132953 PMCID: PMC8824479 DOI: 10.7554/elife.74365] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/10/2022] [Indexed: 01/18/2023] Open
Abstract
Mechanical stimulation, such as physical exercise, is essential for bone formation and health. Here, we demonstrate the critical role of osteocytic Cx43 hemichannels in anabolic function of bone in response to mechanical loading. Two transgenic mouse models, R76W and Δ130–136, expressing dominant-negative Cx43 mutants in osteocytes were adopted. Mechanical loading of tibial bone increased cortical bone mass and mechanical properties in wild-type and gap junction-impaired R76W mice through increased PGE2, endosteal osteoblast activity, and decreased sclerostin. These anabolic responses were impeded in gap junction/hemichannel-impaired Δ130–136 mice and accompanied by increased endosteal osteoclast activity. Specific inhibition of Cx43 hemichannels by Cx43(M1) antibody suppressed PGE2 secretion and impeded loading-induced endosteal osteoblast activity, bone formation and anabolic gene expression. PGE2 administration rescued the osteogenic response to mechanical loading impeded by impaired hemichannels. Together, osteocytic Cx43 hemichannels could be a potential new therapeutic target for treating bone loss and osteoporosis.
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Affiliation(s)
- Dezhi Zhao
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, United States.,School of Life Sciences, Northwestern Polytechnical University, Xian, China
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, United States
| | - Teja Guda
- Department of Biomedical Engineering and Chemical Engineering, University of Texas at San Antonio, San Antonio, United States
| | - Chao Tu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, United States.,Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Huiyun Xu
- School of Life Sciences, Northwestern Polytechnical University, Xian, China
| | - Sumin Gu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, United States
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, United States
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29
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Curti S, Davoine F, Dapino A. Function and Plasticity of Electrical Synapses in the Mammalian Brain: Role of Non-Junctional Mechanisms. Biology (Basel) 2022; 11:81. [PMID: 35053079 DOI: 10.3390/biology11010081] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 01/27/2023]
Abstract
Simple Summary Relevant brain functions, such as perception, organization of behavior, and cognitive processes, are the outcome of information processing by neural circuits. Within these circuits, communication between neurons mainly relies on two modalities of synaptic transmission: chemical and electrical. Moreover, changes in the strength of these connections, aka synaptic plasticity, are believed to underlie processes of learning and memory, and its dysfunction has been suggested to underlie a variety of neurological disorders. While the relevance of chemical transmission and its plastic changes are known in great detail, analogous mechanisms and functional impact of their electrical counterparts were only recently acknowledged. In this article, we review the basic physical principles behind electrical transmission between neurons, the plethora of functional operations supported by this modality of neuron-to-neuron communication, as well as the basic principles of plasticity at these synapses. Abstract Electrical transmission between neurons is largely mediated by gap junctions. These junctions allow the direct flow of electric current between neurons, and in mammals, they are mostly composed of the protein connexin36. Circuits of electrically coupled neurons are widespread in these animals. Plus, experimental and theoretical evidence supports the notion that, beyond synchronicity, these circuits are able to perform sophisticated operations such as lateral excitation and inhibition, noise reduction, as well as the ability to selectively respond upon coincident excitatory inputs. Although once considered stereotyped and unmodifiable, we now know that electrical synapses are subject to modulation and, by reconfiguring neural circuits, these modulations can alter relevant operations. The strength of electrical synapses depends on the gap junction resistance, as well as on its functional interaction with the electrophysiological properties of coupled neurons. In particular, voltage and ligand gated channels of the non-synaptic membrane critically determine the efficacy of transmission at these contacts. Consistently, modulatory actions on these channels have been shown to represent relevant mechanisms of plasticity of electrical synaptic transmission. Here, we review recent evidence on the regulation of electrical synapses of mammals, the underlying molecular mechanisms, and the possible ways in which they affect circuit function.
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Laird DW, Lampe PD. Cellular mechanisms of connexin-based inherited diseases. Trends Cell Biol 2022; 32:58-69. [PMID: 34429228 PMCID: PMC8688313 DOI: 10.1016/j.tcb.2021.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 01/03/2023]
Abstract
The 21-member connexin gene family exhibits distinct tissue expression patterns that can cause a diverse array of over 30 inherited connexin-linked diseases ranging from deafness to skin defects and blindness. Intriguingly, germline mutations can cause disease in one tissue while other tissues that abundantly express the mutant connexin remain disease free, highlighting the importance of the cellular context of mutant expression. Modeling connexin pathologies in genetically modified mice and tissue-relevant cells has informed extensively on no less than a dozen gain- and loss-of-function mechanisms that underpin disease. This review focuses on how a deeper molecular understanding of the over 930 mutations in 11 connexin-encoding genes is foundational for creating a framework for therapeutic interventions.
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Affiliation(s)
- Dale W. Laird
- Departments of Anatomy and Cell Biology, and Physiology and Pharmacology, University of Western Ontario, London, ON, CANADA
| | - Paul D. Lampe
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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Peracchia C, Leverone Peracchia LM. Calmodulin-Connexin Partnership in Gap Junction Channel Regulation-Calmodulin-Cork Gating Model. Int J Mol Sci 2021; 22:ijms222313055. [PMID: 34884859 PMCID: PMC8658047 DOI: 10.3390/ijms222313055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 01/19/2023] Open
Abstract
In the past four decades numerous findings have indicated that gap junction channel gating is mediated by intracellular calcium concentrations ([Ca2+i]) in the high nanomolar range via calmodulin (CaM). We have proposed a CaM-based gating model based on evidence for a direct CaM role in gating. This model is based on the following: CaM inhibitors and the inhibition of CaM expression to prevent chemical gating. A CaM mutant with higher Ca2+ sensitivity greatly increases gating sensitivity. CaM co-localizes with connexins. Connexins have high-affinity CaM-binding sites. Connexin mutants paired to wild type connexins have a higher gating sensitivity, which is eliminated by the inhibition of CaM expression. Repeated trans-junctional voltage (Vj) pulses progressively close channels by the chemical/slow gate (CaM’s N-lobe). At the single channel level, the gate closes and opens slowly with on-off fluctuations. Internally perfused crayfish axons lose gating competency but recover it by the addition of Ca-CaM to the internal perfusion solution. X-ray diffraction data demonstrate that isolated gap junctions are gated at the cytoplasmic end by a particle of the size of a CaM lobe. We have proposed two types of CaM-driven gating: “Ca-CaM-Cork” and “CaM-Cork”. In the first, the gating involves Ca2+-induced CaM activation. In the second, the gating occurs without a [Ca2+]i rise.
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Donati V, Peres C, Nardin C, Scavizzi F, Raspa M, Ciubotaru CD, Bortolozzi M, Pedersen MG, Mammano F. Calcium Signaling in the Photodamaged Skin: In Vivo Experiments and Mathematical Modeling. Function (Oxf) 2021; 3:zqab064. [PMID: 35330924 PMCID: PMC8788836 DOI: 10.1093/function/zqab064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 01/07/2023] Open
Abstract
The epidermis forms an essential barrier against a variety of insults. The overall goal of this study was to shed light not only on the effects of accidental epidermal injury, but also on the mechanisms that support laser skin resurfacing with intra-epidermal focal laser-induced photodamage, a widespread medical practice used to treat a range of skin conditions. To this end, we selectively photodamaged a single keratinocyte with intense, focused and pulsed laser radiation, triggering Ca2+ waves in the epidermis of live anesthetized mice with ubiquitous expression of a genetically encoded Ca2+ indicator. Waves expanded radially and rapidly, reaching up to eight orders of bystander cells that remained activated for tens of minutes, without displaying oscillations of the cytosolic free Ca2+ concentration ([Formula: see text]). By combining in vivo pharmacological dissection with mathematical modeling, we demonstrate that Ca2+ wave propagation depended primarily on the release of ATP, a prime damage-associated molecular patterns (DAMPs), from the hit cell. Increments of the [Formula: see text] in bystander cells were chiefly due to Ca2+ release from the endoplasmic reticulum (ER), downstream of ATP binding to P2Y purinoceptors. ATP-dependent ATP release though connexin hemichannels (HCs) affected wave propagation at larger distances, where the extracellular ATP concentration was reduced by the combined effect of passive diffusion and hydrolysis due to the action of ectonucleotidases, whereas pannexin channels had no role. Bifurcation analysis suggests basal keratinocytes have too few P2Y receptors (P2YRs) and/or phospholipase C (PLC) to transduce elevated extracellular ATP levels into inositol trisphosphate (IP3) production rates sufficiently large to sustain [Formula: see text] oscillations.
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Affiliation(s)
- Viola Donati
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Chiara Peres
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Chiara Nardin
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Ferdinando Scavizzi
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Marcello Raspa
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | | | - Mario Bortolozzi
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
- Foundation for Advanced Biomedical Research, Veneto Institute of Molecular Medicine (VIMM), 35129 Padova (PD), Italy
| | - Morten Gram Pedersen
- Department of Information Engineering, University of Padova, 35131 Padova (PD), Italy
- Department of Mathematics “Tullio Levi-Civita”, University of Padova, 35121 Padova (PD), Italy
| | - Fabio Mammano
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
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Theotokis P, Kesidou E, Mitsiadou D, Petratos S, Damianidou O, Boziki M, Chatzidimitriou A, Grigoriadis N. Lumbar spine intrathecal transplantation of neural precursor cells promotes oligodendrocyte proliferation in hot spots of chronic demyelination. Brain Pathol 2021; 32:e13040. [PMID: 34845781 PMCID: PMC9245942 DOI: 10.1111/bpa.13040] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023] Open
Abstract
Experimental autoimmune encephalomyelitis (EAE) is a basic and reliable model used to study clinical and pathological hallmarks of multiple sclerosis (MS) in rodents. Several studies suggest neural precursor cells (NPCs) as a significant research tool while reporting that transplanted NPCs are a promising therapeutic approach to treating neurological disorders, such as MS. The main objective was to approach a preclinical, in vivo scenario of oligodendrogenesis with NPCs, targeting the main chronic demyelinated lumbosacral milieu of EAE, via the least invasive delivery method which is lumbar puncture. We utilized MOG35‐55 peptide to induce EAE in C57BL/6 mice and prior to the acute relapse, we intervened with either the traceable GFP+ cellular therapy or saline solution in the intrathecal space of their lumbar spine. A BrdU injection, which enabled us to monitor endogenous proliferation, marked the endpoint 50 days post‐induction (50 dpi). Neuropathology with high‐throughput, triple immunofluorescent, and transmission electron microscopy (TEM) data were extracted and analyzed. The experimental treatment attenuated the chronic phase of EAE (50 dpi; score <1) following an acute, clinical relapse. Myelination and axonal integrity were rescued in the NPC‐treated animals along with suppressed immune populations. The differentiation profile of the exogenous NPCs and endogenous BrdU+ cells was location‐dependent where GFP+‐rich areas drove undifferentiated phenotypes toward the oligodendrocyte lineage. In situ oligodendrocyte enrichment was demonstrated through increased (p < 0.001) gap junction channels of Cx32 and Cx47, reliable markers for proliferative oligodendroglia syncytium. TEM morphometric analysis ultimately manifested an increased g‐ratio in lumbosacral fibers of the recovered animals (p < 0.001). Herein, we suggest that a single, lumbar intrathecal administration of NPCs capacitated a viable cellular load and resulted in clinical and pathological amelioration, stimulating resident OPCs to overcome the remyelination failure in EAE demyelinating locale.
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Affiliation(s)
- Paschalis Theotokis
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Evangelia Kesidou
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Dimitra Mitsiadou
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, Victoria, Australia
| | - Olympia Damianidou
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Marina Boziki
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | | | - Nikolaos Grigoriadis
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece.,Institute of Applied Biosciences, Centre for Research and Technology Hellas, Thessaloniki, Greece
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González-Casanova JE, Durán-Agüero S, Caro-Fuentes NJ, Gamboa-Arancibia ME, Bruna T, Bermúdez V, Rojas-Gómez DM. New Insights on the Role of Connexins and Gap Junctions Channels in Adipose Tissue and Obesity. Int J Mol Sci 2021; 22:ijms222212145. [PMID: 34830025 PMCID: PMC8619175 DOI: 10.3390/ijms222212145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/05/2021] [Accepted: 11/05/2021] [Indexed: 12/20/2022] Open
Abstract
Due to the inability to curb the excessive increase in the prevalence of obesity and overweight, it is necessary to comprehend in more detail the factors involved in the pathophysiology and to appreciate more clearly the biochemical and molecular mechanisms of obesity. Thus, understanding the biological regulation of adipose tissue is of fundamental relevance. Connexin, a protein that forms intercellular membrane channels of gap junctions and unopposed hemichannels, plays a key role in adipogenesis and in the maintenance of adipose tissue homeostasis. The expression and function of Connexin 43 (Cx43) during the different stages of the adipogenesis are differentially regulated. Moreover, it has been shown that cell–cell communication decreases dramatically upon differentiation into adipocytes. Furthermore, inhibition of Cx43 degradation or constitutive overexpression of Cx43 blocks adipocyte differentiation. In the first events of adipogenesis, the connexin is highly phosphorylated, which is likely associated with enhanced Gap Junction (GJ) communication. In an intermediate state of adipocyte differentiation, Cx43 phosphorylation decreases, as it is displaced from the membrane and degraded through the proteasome; thus, Cx43 total protein is reduced. Cx is involved in cardiac disease as well as in obesity-related cardiovascular diseases. Different studies suggest that obesity together with a high-fat diet are related to the production of remodeling factors associated with expression and distribution of Cx43 in the atrium.
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Affiliation(s)
- Jorge Enrique González-Casanova
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8910060, Chile; (J.E.G.-C.); (N.J.C.-F.)
| | - Samuel Durán-Agüero
- Facultad de Ciencias Para el Cuidado de la Salud, Universidad San Sebastián, Sede Los Leones, Lota 2465, Providencia, Santiago 7500000, Chile;
| | - Nelson Javier Caro-Fuentes
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8910060, Chile; (J.E.G.-C.); (N.J.C.-F.)
| | - Maria Elena Gamboa-Arancibia
- Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O’higgins 3363, Estación Central, Santiago 9170022, Chile;
| | - Tamara Bruna
- Centro de Investigación Austral Biotech, Facultad de Ciencias, Universidad Santo Tomás, Avenida Ejercito 146, Santiago 8320000, Chile;
| | - Valmore Bermúdez
- Facultad de Ciencias de la Salud, Universidad Simón Bolívar, Barranquilla 080002, Colombia;
| | - Diana Marcela Rojas-Gómez
- Escuela de Nutrición y Dietética, Facultad de Medicina, Universidad Andres Bello, Santiago 8370321, Chile
- Correspondence: ; Tel.: +56-226618559
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Arulkandarajah KH, Osterstock G, Lafont A, Le Corronc H, Escalas N, Corsini S, Le Bras B, Chenane L, Boeri J, Czarnecki A, Mouffle C, Bullier E, Hong E, Soula C, Legendre P, Mangin JM. Neuroepithelial progenitors generate and propagate non-neuronal action potentials across the spinal cord. Curr Biol 2021; 31:4584-4595.e4. [PMID: 34478646 DOI: 10.1016/j.cub.2021.08.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/29/2021] [Accepted: 08/05/2021] [Indexed: 11/30/2022]
Abstract
In the developing central nervous system, electrical signaling is thought to rely exclusively on differentiating neurons as they acquire the ability to generate and propagate action potentials. Accordingly, neuroepithelial progenitors (NEPs), which give rise to all neurons and glial cells during development, have been reported to remain electrically passive. Here, we investigated the physiological properties of NEPs at the onset of spontaneous neural activity (SNA) initiating motor behavior in mouse embryonic spinal cord. Using patch-clamp recordings, we discovered that spinal NEPs exhibit spontaneous membrane depolarizations during episodes of SNA. These rhythmic depolarizations exhibited a ventral-to-dorsal gradient with the highest amplitude located in the floor plate, the ventral-most part of the neuroepithelium. Paired recordings revealed that NEPs are coupled via gap junctions and form an electrical syncytium. Although other NEPs were electrically passive, we discovered that floor-plate NEPs generated large Na+/Ca2+ action potentials. Unlike in neurons, floor-plate action potentials relied primarily on the activation of voltage-gated T-type calcium channels (TTCCs). In situ hybridization showed that all 3 known subtypes of TTCCs are predominantly expressed in the floor plate. During SNA, we found that acetylcholine released by motoneurons rhythmically triggers floor-plate action potentials by acting through nicotinic acetylcholine receptors. Finally, by expressing the genetically encoded calcium indicator GCaMP6f in the floor plate, we demonstrated that neuroepithelial action potentials are associated with calcium waves and propagate along the entire length of the spinal cord. Our work reveals a novel physiological mechanism to generate and propagate electrical signals across a neural structure independently from neurons.
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Affiliation(s)
- Kalaimakan Hervé Arulkandarajah
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Guillaume Osterstock
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Agathe Lafont
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Hervé Le Corronc
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France; Université d'Angers, 49000 Angers, France
| | - Nathalie Escalas
- Centre de Biologie du Développement (CBD) CNRS/UPS, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31000 Toulouse, France
| | - Silvia Corsini
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Barbara Le Bras
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Linda Chenane
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Juliette Boeri
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Antonny Czarnecki
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Christine Mouffle
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Erika Bullier
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Elim Hong
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Cathy Soula
- Centre de Biologie du Développement (CBD) CNRS/UPS, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31000 Toulouse, France
| | - Pascal Legendre
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Jean-Marie Mangin
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France.
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36
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Kirichenko EY, Skatchkov SN, Ermakov AM. Structure and Functions of Gap Junctions and Their Constituent Connexins in the Mammalian CNS. Biochem (Mosc) Suppl Ser A Membr Cell Biol 2021; 15:107-119. [PMID: 34512926 PMCID: PMC8432592 DOI: 10.1134/s1990747821020069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Numerous data obtained in the last 20 years indicate that all parts of the mature central nervous system, from the retina and olfactory bulb to the spinal cord and brain, contain cells connected by gap junctions (GJs). The morphological basis of the GJs is a group of joined membrane hemichannels called connexons, the subunit of each connexon is the protein connexin. In the central nervous system, connexins show specificity and certain types of them are expressed either in neurons or in glial cells. Connexins and GJs of neurons, combining certain types of inhibitory hippocampal and neocortical neuronal ensembles, provide synchronization of local impulse and rhythmic activity, thalamocortical conduction, control of excitatory connections, which reflects their important role in the processes of perception, concentration of attention and consolidation of memory, both on the cellular and at the system level. Connexins of glial cells are ubiquitously expressed in the brain, and the GJs formed by them provide molecular signaling and metabolic cooperation and play a certain role in the processes of neuronal migration during brain development, myelination, tissue homeostasis, and apoptosis. At the same time, mutations in the genes of glial connexins, as well as a deficiency of these proteins, are associated with such diseases as congenital neuropathies, hearing loss, skin diseases, and brain tumors. This review summarizes the existing data of numerous molecular, electrophysiological, pharmacological, and morphological studies aimed at progress in the study of the physiological and pathophysiological significance of glial and neuronal connexins and GJs for the central nervous system.
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Affiliation(s)
- E Yu Kirichenko
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, 344090 Russia
| | - S N Skatchkov
- Department of Biochemistry, School of Medicine, P.O. Box 60327, Universidad Central del Caribe, Bayamón, PR, 00960-6032 USA.,Department of Physiology, School of Medicine, P.O. Box 60327, Universidad Central del Caribe, Bayamón, PR, 00960-6032 USA
| | - A M Ermakov
- Faculty of Bioengineering and Veterinary Medicine, Don State Technical University, Rostov-on-Don, 344003 Russia
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Khan AK, Jagielnicki M, Bennett BC, Purdy MD, Yeager M. Cryo-EM structure of an open conformation of a gap junction hemichannel in lipid bilayer nanodiscs. Structure 2021; 29:1040-1047.e3. [PMID: 34129834 PMCID: PMC9616683 DOI: 10.1016/j.str.2021.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 02/26/2021] [Accepted: 05/14/2021] [Indexed: 12/30/2022]
Abstract
To mediate cell-to-cell communication via gap junction channels (GJCs), connexins (Cx) traffic as hexameric hemichannels to the plasma membrane, which dock end-to-end between adjacent cell membranes, thereby forming a dodecameric intercellular conduit. Hemichannels also function independently to mediate the passage of contents between the cytoplasm and extracellular space. To generate hemichannels, the mutation N176Y was introduced into the second extracellular loop of Cx26. The electron cryomicroscopy structure of the hexameric hemichannel in lipid bilayer nanodiscs displays an open pore and a 4-helix bundle transmembrane design that is nearly identical to dodecameric GJCs. In contrast to the high resolution of the transmembrane α-helices, the extracellular loops are less well resolved. The conformational flexibility of the extracellular loops may be essential to facilitate surveillance of hemichannels in apposed cells to identify compatible Cx isoforms that enable intercellular docking. Our results also provide a structural foundation for previous electrophysiologic and permeation studies of Cx hemichannels.
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Affiliation(s)
- Ali K Khan
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Sheridan G. Snyder Translational Research Building, Rm 320, 480 Ray C. Hunt Drive, Charlottesville, VA 22908, USA
| | - Maciej Jagielnicki
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Sheridan G. Snyder Translational Research Building, Rm 320, 480 Ray C. Hunt Drive, Charlottesville, VA 22908, USA
| | - Brad C Bennett
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Sheridan G. Snyder Translational Research Building, Rm 320, 480 Ray C. Hunt Drive, Charlottesville, VA 22908, USA
| | - Michael D Purdy
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Sheridan G. Snyder Translational Research Building, Rm 320, 480 Ray C. Hunt Drive, Charlottesville, VA 22908, USA
| | - Mark Yeager
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Sheridan G. Snyder Translational Research Building, Rm 320, 480 Ray C. Hunt Drive, Charlottesville, VA 22908, USA; Center for Membrane Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Medicine, Division of Cardiovascular Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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Prieto-Villalobos J, Alvear TF, Liberona A, Lucero CM, Martínez-Araya CJ, Balmazabal J, Inostroza CA, Ramírez G, Gómez GI, Orellana JA. Astroglial Hemichannels and Pannexons: The Hidden Link between Maternal Inflammation and Neurological Disorders. Int J Mol Sci 2021; 22:ijms22179503. [PMID: 34502412 PMCID: PMC8430734 DOI: 10.3390/ijms22179503] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 08/30/2021] [Accepted: 08/30/2021] [Indexed: 12/11/2022] Open
Abstract
Maternal inflammation during pregnancy causes later-in-life alterations of the offspring’s brain structure and function. These abnormalities increase the risk of developing several psychiatric and neurological disorders, including schizophrenia, intellectual disability, bipolar disorder, autism spectrum disorder, microcephaly, and cerebral palsy. Here, we discuss how astrocytes might contribute to postnatal brain dysfunction following maternal inflammation, focusing on the signaling mediated by two families of plasma membrane channels: hemi-channels and pannexons. [Ca2+]i imbalance linked to the opening of astrocytic hemichannels and pannexons could disturb essential functions that sustain astrocytic survival and astrocyte-to-neuron support, including energy and redox homeostasis, uptake of K+ and glutamate, and the delivery of neurotrophic factors and energy-rich metabolites. Both phenomena could make neurons more susceptible to the harmful effect of prenatal inflammation and the experience of a second immune challenge during adulthood. On the other hand, maternal inflammation could cause excitotoxicity by producing the release of high amounts of gliotransmitters via astrocytic hemichannels/pannexons, eliciting further neuronal damage. Understanding how hemichannels and pannexons participate in maternal inflammation-induced brain abnormalities could be critical for developing pharmacological therapies against neurological disorders observed in the offspring.
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Affiliation(s)
- Juan Prieto-Villalobos
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Tanhia F. Alvear
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Andrés Liberona
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Claudia M. Lucero
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago 8910060, Chile; (C.M.L.); (G.I.G.)
| | - Claudio J. Martínez-Araya
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Javiera Balmazabal
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Carla A. Inostroza
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Gigliola Ramírez
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
| | - Gonzalo I. Gómez
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago 8910060, Chile; (C.M.L.); (G.I.G.)
| | - Juan A. Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.P.-V.); (T.F.A.); (A.L.); (C.J.M.-A.); (J.B.); (C.A.I.); (G.R.)
- Correspondence: ; Tel.: +56-23548105
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Orellana VP, Tittarelli A, Retamal MA. Connexins in melanoma: Potential role of Cx46 in its aggressiveness. Pigment Cell Melanoma Res 2021; 34:853-868. [PMID: 33140904 DOI: 10.1111/pcmr.12945] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/20/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022]
Abstract
Melanoma is the most aggressive skin cancer, and in metastatic advanced states, it is completely refractory to chemotherapy. Therefore, it is relevant to understand the molecular bases that rule their aggressiveness. Connexins (Cxs) are proteins that under normal physiological conditions participate in intercellular communication, via the exchange of signaling molecules between the cytoplasm and extracellular milieu and the exchange of ions/second messengers between the cytoplasm of contacting cells. These proteins have shown important roles in cancer progression, chemo- and radiotherapy resistance, and metastasis. Accordingly, Cx26 and Cx43 seem to play important roles in melanoma progression and metastasis. On the other hand, Cx46 is typically expressed in the eye lens, where it seems to be associated with oxidative stress protection in fiber lens cells. However, in the last decade, Cx46 expression has been associated with breast and brain cancers, due to its role in potentiation of both extracellular vesicle release and cancer stem cell-like properties. In this review, we analyzed a potential role of Cx46 as a new biomarker and therapeutic target in melanoma.
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Affiliation(s)
- Viviana P Orellana
- Universidad del Desarrollo. Centro de Fisiología Celular e Integrativa, Clinica Alemana Facultad de Medicina, Santiago, Chile
- Universidad del Desarrollo. Programa de Comunicación Celular en Cáncer, Clínica Alemana Facultad de Medicina, Santiago, Chile
| | - Andrés Tittarelli
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana (UTEM), Santiago, Chile
| | - Mauricio A Retamal
- Universidad del Desarrollo. Centro de Fisiología Celular e Integrativa, Clinica Alemana Facultad de Medicina, Santiago, Chile
- Universidad del Desarrollo. Programa de Comunicación Celular en Cáncer, Clínica Alemana Facultad de Medicina, Santiago, Chile
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Papathanasiou KA, Giotaki SG, Vrachatis DA, Siasos G, Lambadiari V, Iliodromitis KE, Kossyvakis C, Kaoukis A, Raisakis K, Deftereos G, Papaioannou TG, Giannopoulos G, Avramides D, Deftereos SG. Molecular Insights in Atrial Fibrillation Pathogenesis and Therapeutics: A Narrative Review. Diagnostics (Basel) 2021; 11:diagnostics11091584. [PMID: 34573926 PMCID: PMC8470040 DOI: 10.3390/diagnostics11091584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 12/15/2022] Open
Abstract
The prevalence of atrial fibrillation (AF) is bound to increase globally in the following years, affecting the quality of life of millions of people, increasing mortality and morbidity, and beleaguering health care systems. Increasingly effective therapeutic options against AF are the constantly evolving electroanatomic substrate mapping systems of the left atrium (LA) and ablation catheter technologies. Yet, a prerequisite for better long-term success rates is the understanding of AF pathogenesis and maintenance. LA electrical and anatomical remodeling remains in the epicenter of current research for novel diagnostic and treatment modalities. On a molecular level, electrical remodeling lies on impaired calcium handling, enhanced inwardly rectifying potassium currents, and gap junction perturbations. In addition, a wide array of profibrotic stimuli activates fibroblast to an increased extracellular matrix turnover via various intermediaries. Concomitant dysregulation of the autonomic nervous system and the humoral function of increased epicardial adipose tissue (EAT) are established mediators in the pathophysiology of AF. Local atrial lymphomononuclear cells infiltrate and increased inflammasome activity accelerate and perpetuate arrhythmia substrate. Finally, impaired intracellular protein metabolism, excessive oxidative stress, and mitochondrial dysfunction deplete atrial cardiomyocyte ATP and promote arrhythmogenesis. These overlapping cellular and molecular alterations hinder us from distinguishing the cause from the effect in AF pathogenesis. Yet, a plethora of therapeutic modalities target these molecular perturbations and hold promise in combating the AF burden. Namely, atrial selective ion channel inhibitors, AF gene therapy, anti-fibrotic agents, AF drug repurposing, immunomodulators, and indirect cardiac neuromodulation are discussed here.
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Affiliation(s)
- Konstantinos A. Papathanasiou
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Sotiria G. Giotaki
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Dimitrios A. Vrachatis
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Gerasimos Siasos
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Vaia Lambadiari
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | | | - Charalampos Kossyvakis
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Andreas Kaoukis
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Konstantinos Raisakis
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Gerasimos Deftereos
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Theodore G. Papaioannou
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | | | - Dimitrios Avramides
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Spyridon G. Deftereos
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
- Correspondence: ; Tel.: +30-21-0583-2355
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Peracchia C. Gap Junction Channelopathies and Calmodulinopathies. Do Disease-Causing Calmodulin Mutants Affect Direct Cell-Cell Communication? Int J Mol Sci 2021; 22:9169. [PMID: 34502077 DOI: 10.3390/ijms22179169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/19/2021] [Accepted: 08/21/2021] [Indexed: 11/24/2022] Open
Abstract
The cloning of connexins cDNA opened the way to the field of gap junction channelopathies. Thus far, at least 35 genetic diseases, resulting from mutations of 11 different connexin genes, are known to cause numerous structural and functional defects in the central and peripheral nervous system as well as in the heart, skin, eyes, teeth, ears, bone, hair, nails and lymphatic system. While all of these diseases are due to connexin mutations, minimal attention has been paid to the potential diseases of cell–cell communication caused by mutations of Cx-associated molecules. An important Cx accessory protein is calmodulin (CaM), which is the major regulator of gap junction channel gating and a molecule relevant to gap junction formation. Recently, diseases caused by CaM mutations (calmodulinopathies) have been identified, but thus far calmodulinopathy studies have not considered the potential effect of CaM mutations on gap junction function. The major goal of this review is to raise awareness on the likely role of CaM mutations in defects of gap junction mediated cell communication. Our studies have demonstrated that certain CaM mutants affect gap junction channel gating or expression, so it would not be surprising to learn that CaM mutations known to cause diseases also affect cell communication mediated by gap junction channels.
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Turovsky EA, Varlamova EG. Mechanism of Ca 2+-Dependent Pro-Apoptotic Action of Selenium Nanoparticles, Mediated by Activation of Cx43 Hemichannels. Biology (Basel) 2021; 10:biology10080743. [PMID: 34439975 PMCID: PMC8389560 DOI: 10.3390/biology10080743] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/31/2022]
Abstract
To date, there are practically no data on the mechanisms of the selenium nanoparticles action on calcium homeostasis, intracellular signaling in cancer cells, and on the relationship of signaling pathways activated by an increase in Ca2+ in the cytosol with the induction of apoptosis, which is of great importance. The study of these mechanisms is important for understanding the cytotoxic effect of selenium nanoparticles and the role of this microelement in the regulation of carcinogenesis. The work is devoted to the study of the role of selenium nanoparticles obtained by laser ablation in the activation of the calcium signaling system and the induction of apoptosis in human glioblastoma cells (A-172 cell line). In this work, it was shown for the first time that the generation of Ca2+ signals in A-172 cells occurs in response to the application of various concentrations of selenium nanoparticles. The intracellular mechanism responsible for the generation of these Ca2+ signals has also been established. It was found that nanoparticles promote the mobilization of Ca2+ ions from the endoplasmic reticulum through the IP3-receptor. This leads to the activation of vesicular release of ATP through connexin hemichannels (Cx43) and paracrine cell activation through purinergic receptors (mainly P2Y). In addition, it was shown that the activation of this signaling pathway is accompanied by an increase in the expression of pro-apoptotic genes and the induction of apoptosis. For the first time, the role of Cx43 in the regulation of apoptosis caused by selenium nanoparticles in glioblastoma cells has been shown. It was found that inhibition of Cx43 leads to a significant suppression of the induction of apoptosis in these cells after 24 h treatment of cells with selenium nanoparticles at a concentration of 5 µg/mL.
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Koepple C, Zhou Z, Huber L, Schulte M, Schmidt K, Gloe T, Kneser U, Schmidt VJ, de Wit C. Expression of Connexin43 Stimulates Endothelial Angiogenesis Independently of Gap Junctional Communication In Vitro. Int J Mol Sci 2021; 22:ijms22147400. [PMID: 34299018 PMCID: PMC8306600 DOI: 10.3390/ijms22147400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 12/14/2022] Open
Abstract
Connexins (Cx) form gap junctions (GJ) and allow for intercellular communication. However, these proteins also modulate gene expression, growth, and cell migration. The downregulation of Cx43 impairs endothelial cell migration and angiogenetic potential. Conversely, endothelial Cx43 expression is upregulated in an in vivo angiogenesis model relying on hemodynamic forces. We studied the effects of Cx43 expression on tube formation and proliferation in HUVECs and examined its dependency on GJ communication. Expectedly, intercellular communication assessed by dye transfer was linked to Cx43 expression levels in HUVECs and was sensitive to a GJ blockade by the Cx43 mimetic peptide Gap27. The proliferation of HUVECs was not affected by Cx43 overexpression using Cx43 cDNA transfection, siRNA-mediated knockdown of Cx43, or the inhibition of GJ compared to the controls (transfection of an empty vector, scrambled siRNA, and the solvent). In contrast, endothelial tube and sprout formation in HUVECs was minimized after Cx43 knockdown and significantly enhanced after Cx43 overexpression. This was not affected by a GJ blockade (Gap27). We conclude that Cx43 expression positively modulates the angiogenic potential of endothelial cells independent of GJ communication. Since proliferation remained unaffected, we suggest that Cx43 protein may modulate endothelial cell migration, thereby supporting angiogenesis. The modulation of Cx43 expression may represent an exploitable principle for angiogenesis induction in clinical therapy.
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Affiliation(s)
- Christoph Koepple
- Department for Hand Surgery, Plastic Surgery and Reconstructive Surgery, BG Trauma Center Ludwigshafen, Heidelberg University, 67071 Ludwigshafen, Germany; (Z.Z.); (L.H.); (M.S.); (U.K.)
- Correspondence: (C.K.); (V.J.S.); (C.d.W.)
| | - Zizi Zhou
- Department for Hand Surgery, Plastic Surgery and Reconstructive Surgery, BG Trauma Center Ludwigshafen, Heidelberg University, 67071 Ludwigshafen, Germany; (Z.Z.); (L.H.); (M.S.); (U.K.)
| | - Lena Huber
- Department for Hand Surgery, Plastic Surgery and Reconstructive Surgery, BG Trauma Center Ludwigshafen, Heidelberg University, 67071 Ludwigshafen, Germany; (Z.Z.); (L.H.); (M.S.); (U.K.)
| | - Matthias Schulte
- Department for Hand Surgery, Plastic Surgery and Reconstructive Surgery, BG Trauma Center Ludwigshafen, Heidelberg University, 67071 Ludwigshafen, Germany; (Z.Z.); (L.H.); (M.S.); (U.K.)
| | - Kjestine Schmidt
- Institut für Physiologie, Universität zu Lübeck, 23562 Lübeck, Germany;
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), 23562 Lübeck, Germany
| | - Torsten Gloe
- Physiology, Institute of Theoretical Medicine, Universität Augsburg, 86159 Augsburg, Germany;
| | - Ulrich Kneser
- Department for Hand Surgery, Plastic Surgery and Reconstructive Surgery, BG Trauma Center Ludwigshafen, Heidelberg University, 67071 Ludwigshafen, Germany; (Z.Z.); (L.H.); (M.S.); (U.K.)
| | - Volker Jürgen Schmidt
- Department for Plastic Surgery and Breast Surgery, Zealand University Hospital (SUH) Roskilde, Copenhagen University, 4000 Roskilde, Denmark
- Correspondence: (C.K.); (V.J.S.); (C.d.W.)
| | - Cor de Wit
- Institut für Physiologie, Universität zu Lübeck, 23562 Lübeck, Germany;
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), 23562 Lübeck, Germany
- Correspondence: (C.K.); (V.J.S.); (C.d.W.)
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Gong XD, Wang Y, Hu XB, Zheng SY, Fu JL, Nie Q, Wang L, Hou M, Xiang JW, Xiao Y, Gao Q, Bai YY, Liu YZ, Li DWC. Aging-dependent loss of GAP junction proteins Cx46 and Cx50 in the fiber cells of human and mouse lenses accounts for the diminished coupling conductance. Aging (Albany NY) 2021; 13:17568-17591. [PMID: 34226295 PMCID: PMC8312418 DOI: 10.18632/aging.203247] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 06/12/2021] [Indexed: 06/13/2023]
Abstract
The homeostasis of the ocular lens is maintained by a microcirculation system propagated through gap junction channels. It is well established that the intercellular communications of the lens become deteriorative during aging. However, the molecular basis for this change in human lenses has not been well defined. Here, we present evidence to show that over 90% of Cx46 and Cx50 are lost in the fiber cells of normal human lenses aged 50 and above. From transparent to cataractous lenses, while Cx43 was upregulated, both Cx46 and Cx50 were significantly down-regulated in the lens epithelia. During aging of mouse lenses, Cx43 remained unchanged, but both Cx46 and Cx50 were significantly downregulated. Under oxidative stress treatment, mouse lenses develop in vitro cataractogenesis. Associated with this process, Cx43 was significantly upregulated, in contrast, Cx46 and Cx50 were sharply downregulated. Together, our results for the first time reveal that downregulation in Cx46 and Cx50 levels appears to be the major reason for the diminished coupling conductance, and the aging-dependent loss of Cx46 and Cx50 promotes senile cataractogenesis.
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Affiliation(s)
- Xiao-Dong Gong
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Yan Wang
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Xue-Bin Hu
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Shu-Yu Zheng
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Jia-Ling Fu
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Qian Nie
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Ling Wang
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Min Hou
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Jia-Wen Xiang
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Yuan Xiao
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Qian Gao
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Yue-Yue Bai
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - Yi-Zhi Liu
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
| | - David Wan-Cheng Li
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510230, China
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Gorska AM, Donoso M, Valdebenito S, Prideaux B, Queen S, Scemes E, Clements J, Eugenin E. Human immunodeficiency virus-1/simian immunodeficiency virus infection induces opening of pannexin-1 channels resulting in neuronal synaptic compromise: A novel therapeutic opportunity to prevent NeuroHIV. J Neurochem 2021; 158:500-521. [PMID: 33899944 DOI: 10.1111/jnc.15374] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/27/2021] [Accepted: 04/21/2021] [Indexed: 01/16/2023]
Abstract
In healthy conditions, pannexin-1 (Panx-1) channels are in a close state, but in several pathological conditions, including human immunodeficiency virus-1 (HIV) and NeuroHIV, the channel becomes open. However, the mechanism or contribution of Panx-1 channels to the HIV pathogenesis and NeuroHIV is unknown. To determine the contribution of Panx-1 channels to the pathogenesis of NeuroHIV, we used a well-established model of simian immunodeficiency virus (SIV) infection in macaques (Macaca mulatta) in the presence of and absence of a Panx-1 blocker to later examine the synaptic/axonal compromise induced for the virus. Using Golgi's staining, we demonstrated that SIV infection compromised synaptic and axonal structures, especially in the white matter. Blocking Panx-1 channels after SIV infection prevented the synaptic and axonal compromise induced by the virus, especially by maintaining the more complex synapses. Our data demonstrated that targeting Panx-1 channels can prevent and maybe revert brain synaptic compromise induced by SIV infection.
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Affiliation(s)
- Anna Maria Gorska
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Maribel Donoso
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Silvana Valdebenito
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Brendan Prideaux
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Suzanne Queen
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Janice Clements
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliseo Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
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Stavropoulos F, Georgiou E, Sargiannidou I, Kleopa KA. Dysregulation of Blood-Brain Barrier and Exacerbated Inflammatory Response in Cx47-Deficient Mice after Induction of EAE. Pharmaceuticals (Basel) 2021; 14:ph14070621. [PMID: 34203192 PMCID: PMC8308522 DOI: 10.3390/ph14070621] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/18/2022] Open
Abstract
Induction of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), in connexin 32 (Cx32) or Cx47 knockout (KO) mice with deficiency in oligodendrocyte gap junctions (GJs) results in a more severe disease course. In particular, Cx47 KO EAE mice experience an earlier EAE onset and more pronounced disease severity, accompanied by dysregulated pro-inflammatory responses preceding the disease manifestations. In this study, analysis of relevant pro-inflammatory cytokines in wild type EAE, Cx32 KO EAE, and Cx47 KO EAE mice revealed altered expression of Vcam-1 preceding EAE [7 days post injection (dpi)], of Ccl2 at the onset of EAE (12 dpi), and of Gm-csf at the peak of EAE (24 dpi) in Cx47 KO EAE mice. Moreover, Cx47 KO EAE mice exhibited more severe blood-spinal cord barrier (BSCB) disruption, enhanced astrogliosis with defects in tight junction formation at the glia limitans, and increased T-cell infiltration prior to disease onset. Thus, Cx47 deficiency appears to cause dysregulation of the inflammatory profile and BSCB integrity, promoting early astrocyte responses in Cx47 KO EAE mice that lead to a more severe EAE outcome. Further investigation into the role of oligodendrocytic Cx47 in EAE and multiple sclerosis pathology is warranted.
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Affiliation(s)
- Filippos Stavropoulos
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (F.S.); (E.G.); (I.S.)
| | - Elena Georgiou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (F.S.); (E.G.); (I.S.)
| | - Irene Sargiannidou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (F.S.); (E.G.); (I.S.)
| | - Kleopas A. Kleopa
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (F.S.); (E.G.); (I.S.)
- Center for Multiple Sclerosis and Related Disorders, The Cyprus Institute of Neurology and Genetics and Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus
- Correspondence: ; Tel.: +357-22-358600; Fax: +357-22-392786
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Mazaud D, Capano A, Rouach N. The many ways astroglial connexins regulate neurotransmission and behavior. Glia 2021; 69:2527-2545. [PMID: 34101261 DOI: 10.1002/glia.24040] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 05/17/2021] [Accepted: 05/21/2021] [Indexed: 12/18/2022]
Abstract
Astrocytes have emerged as major players in the brain, contributing to many functions such as energy supply, neurotransmission, and behavior. They accomplish these functions in part via their capacity to form widespread intercellular networks and to release neuroactive factors, which can modulate neurotransmission at different levels, from individual synapses to neuronal networks. The extensive network communication of astrocytes is primarily mediated by gap junction channels composed of two connexins, Cx30 and Cx43, which present distinct temporal and spatial expression patterns. Yet, astroglial connexins are also involved in direct exchange with the extracellular space via hemichannels, as well as in adhesion and signaling processes via unconventional nonchannel functions. Accumulating evidence indicate that astrocytes modulate neurotransmission and behavior through these diverse connexin functions. We here review the many ways astroglial connexins regulate neuronal activity from the molecular level to behavior.
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Affiliation(s)
- David Mazaud
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
| | - Anna Capano
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.,Doctoral School N°158, Sorbonne University, Paris, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
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Wang F, Zhang LL, Meng W, Bin Z, Li SF, Wu QW, Zhang S. Recognition of the atrioventricular node anatomical structure: Connection between the retroaortic node and the compact node. J Cardiovasc Electrophysiol 2021; 32:1896-1906. [PMID: 34053145 DOI: 10.1111/jce.15117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The complex electrophysiological phenomena related to the atrioventricular node (AVN) are due to its complex anatomical structures. Aside from the inferior nodal extension (INE), other node-like tissues, such as the retroaortic node (RN), have been described less extensively and may also share the mechanism of normal conduction and abnormal conduction in AVN re-entrant tachycardia. METHODS High-density sections of the entire AVN were obtained from rats and rabbits. Fibrosis was analyzed by Masson's trichrome staining. Connexin (Cx43, Cx40, and Cx45) and ion channel (Nav 1.5, Cav 3.1, and HCN4) proteins were immunohistochemically labeled for the analysis of tissue features. Three-dimensional (3D) reconstruction of the AV junction was performed to clarify the relationships among different structures. RESULTS The RN expressed the same connexin isoforms as the compact node (CN) and INE. Nav 1.5 labeling was observed at low levels in the CN, RN, and INE, where Cav 3.1 and HCN4 were expressed. The CN connected with the RN in a narrow strip pattern at the start of the CN. The RN presented as a shuttle shape and was the only tissue directly connected with the atrium in the anterior septum. CONCLUSION The RN connects with the AVN anatomically, suggesting that direct electrical conduction occurs between them. The entrance of the atria into the AVN is distal to the RN, which may form the fast AVN pathway.
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Affiliation(s)
- Fan Wang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, Harbin, China
| | - Lu Lu Zhang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Wei Meng
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zhu Bin
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shu Feng Li
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Qiu Wen Wu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shuo Zhang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, Harbin, China
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49
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Jang MW, Oh DY, Yi E, Liu X, Ling J, Kim N, Sharma K, Kim TY, Lee S, Kim AR, Kim MY, Kim MA, Lee M, Han JH, Han JJ, Park HR, Kim BJ, Lee SY, Woo DH, Oh J, Oh SJ, Du T, Koo JW, Oh SH, Shin HW, Seong MW, Lee KY, Kim UK, Shin JB, Sang S, Cai X, Mei L, He C, Blanton SH, Chen ZY, Chen H, Liu X, Nourbakhsh A, Huang Z, Kang KW, Park WY, Feng Y, Lee CJ, Choi BY. A nonsense TMEM43 variant leads to disruption of connexin-linked function and autosomal dominant auditory neuropathy spectrum disorder. Proc Natl Acad Sci U S A 2021; 118:e2019681118. [PMID: 34050020 DOI: 10.1073/pnas.2019681118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Genes that are primarily expressed in cochlear glia-like supporting cells (GLSs) have not been clearly associated with progressive deafness. Herein, we present a deafness locus mapped to chromosome 3p25.1 and an auditory neuropathy spectrum disorder (ANSD) gene, TMEM43, mainly expressed in GLSs. We identify p.(Arg372Ter) of TMEM43 by linkage analysis and exome sequencing in two large Asian families segregating ANSD, which is characterized by inability to discriminate speech despite preserved sensitivity to sound. The knock-in mouse with the p.(Arg372Ter) variant recapitulates a progressive hearing loss with histological abnormalities in GLSs. Mechanistically, TMEM43 interacts with the Connexin26 and Connexin30 gap junction channels, disrupting the passive conductance current in GLSs in a dominant-negative fashion when the p.(Arg372Ter) variant is introduced. Based on these mechanistic insights, cochlear implant was performed on three subjects, and speech discrimination was successfully restored. Our study highlights a pathological role of cochlear GLSs by identifying a deafness gene and its causal relationship with ANSD.
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50
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Lasseigne AM, Echeverry FA, Ijaz S, Michel JC, Martin EA, Marsh AJ, Trujillo E, Marsden KC, Pereda AE, Miller AC. Electrical synaptic transmission requires a postsynaptic scaffolding protein. eLife 2021; 10:e66898. [PMID: 33908867 PMCID: PMC8081524 DOI: 10.7554/elife.66898] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/30/2021] [Indexed: 02/06/2023] Open
Abstract
Electrical synaptic transmission relies on neuronal gap junctions containing channels constructed by Connexins. While at chemical synapses neurotransmitter-gated ion channels are critically supported by scaffolding proteins, it is unknown if channels at electrical synapses require similar scaffold support. Here, we investigated the functional relationship between neuronal Connexins and Zonula Occludens 1 (ZO1), an intracellular scaffolding protein localized to electrical synapses. Using model electrical synapses in zebrafish Mauthner cells, we demonstrated that ZO1 is required for robust synaptic Connexin localization, but Connexins are dispensable for ZO1 localization. Disrupting this hierarchical ZO1/Connexin relationship abolishes electrical transmission and disrupts Mauthner cell-initiated escape responses. We found that ZO1 is asymmetrically localized exclusively postsynaptically at neuronal contacts where it functions to assemble intercellular channels. Thus, forming functional neuronal gap junctions requires a postsynaptic scaffolding protein. The critical function of a scaffolding molecule reveals an unanticipated complexity of molecular and functional organization at electrical synapses.
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Affiliation(s)
| | - Fabio A Echeverry
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Sundas Ijaz
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | | | - E Anne Martin
- Institute of Neuroscience, University of OregonEugeneUnited States
| | - Audrey J Marsh
- Institute of Neuroscience, University of OregonEugeneUnited States
| | - Elisa Trujillo
- Institute of Neuroscience, University of OregonEugeneUnited States
| | - Kurt C Marsden
- Department of Biological Sciences, NC State UniversityRaleighUnited States
| | - Alberto E Pereda
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Adam C Miller
- Institute of Neuroscience, University of OregonEugeneUnited States
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