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Rozas-Villanueva FM, Orellana VP, Alarcón R, Maripillan J, Martinez AD, Alfaro IE, Retamal MA. Cx40 Levels Regulate Hypoxia-Induced Changes in the Migration, Proliferation, and Formation of Gap Junction Plaques in an Extravillous Trophoblast Cell Model. Cells 2024; 13:1150. [PMID: 38995001 PMCID: PMC11240472 DOI: 10.3390/cells13131150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/19/2024] [Accepted: 03/24/2024] [Indexed: 07/13/2024] Open
Abstract
BACKGROUND Extravillous trophoblasts (EVTs) form stratified columns at the placenta-uterus interface. In the closest part to fetal structures, EVTs have a proliferative phenotype, whereas in the closest part to maternal structures, they present a migratory phenotype. During the placentation process, Connexin 40 (Cx40) participates in both the proliferation and migration of EVTs, which occurs under hypoxia. However, a possible interaction between hypoxia and Cx40 has not yet been established. METHODS We developed two cellular models, one with "low Cx40" (Jeg-3), which reflected the expression of this protein found in migratory EVTs, and one with "high Cx40" (Jeg-3/hCx40), which reflected the expression of this protein in proliferative cells. We analyzed the migration and proliferation of these cells under normoxic and hypoxic conditions for 24 h. Jeg-3 cells under hypoxia increased their migratory capacity over their proliferative capacity. However, in Jeg-3/hCx40, the opposite effect was induced. On the other hand, hypoxia promoted gap junction (GJ) plaque formation between neighboring Jeg-3 cells. Similarly, the activation of a nitro oxide (NO)/cGMP/PKG-dependent pathway induced an increase in GJ-plaque formation in Jeg-3 cells. CONCLUSIONS The expression patterns of Cx40 play a crucial role in shaping the responses of EVTs to hypoxia, thereby influencing their migratory or proliferative phenotype. Simultaneously, hypoxia triggers an increase in Cx40 gap junction (GJ) plaque formation through a pathway dependent on NO.
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Affiliation(s)
- Fernanda M Rozas-Villanueva
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7550000, Chile
| | - Viviana P Orellana
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7550000, Chile
| | - Rodrigo Alarcón
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7550000, Chile
| | - Jaime Maripillan
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Agustin D Martinez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Ivan E Alfaro
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7550000, Chile
| | - Mauricio A Retamal
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7550000, Chile
- Center for Membrane Protein Research, Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
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2
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Wingrove JS, Wimmer J, Saba Echezarreta VE, Piazza A, Spencer GE. Retinoic acid reduces the formation of, and acutely modulates, invertebrate electrical synapses. J Neurophysiol 2024; 131:965-981. [PMID: 38568843 DOI: 10.1152/jn.00057.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/05/2024] Open
Abstract
Communication between cells in the nervous system is dependent on both chemical and electrical synapses. Factors that can affect chemical synapses have been well studied, but less is known about factors that influence electrical synapses. Retinoic acid, the vitamin A metabolite, is a known regulator of chemical synapses, but few studies have examined its capacity to regulate electrical synapses. In this study, we determine that retinoic acid is capable of rapidly altering the strength of electrical synapses in an isomer- and cell-dependent manner. Furthermore, we provide evidence that this acute effect might be independent of either the retinoid receptors or the activation of a protein kinase. In addition to the rapid modulatory effects of retinoic acid, we provide data to suggest that retinoic acid is also capable of regulating the formation of electrical synapses. Long-term exposure to both all-trans-retinoic acid or 9-cis-retinoic acid reduced the proportion of cell pairs forming electrical synapses, as well as reduced the strength of electrical synapses that did form. In summary, this study provides insights into the role that retinoids might play in both the formation and modulation of electrical synapses in the central nervous system.NEW & NOTEWORTHY Retinoids are known modulators of chemical synapses and mediate synaptic plasticity in the nervous system, but little is known of their effects on electrical synapses. Here, we show that retinoids selectively reduce electrical synapses in a cell- and isomer-dependent manner. This modulatory action on existing electrical synapses was rapid and nongenomic in nature. We also showed for the first time that longer retinoid exposures inhibit the formation of electrical synapses.
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Affiliation(s)
- Joel S Wingrove
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Justin Wimmer
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | | | - Alicia Piazza
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Gaynor E Spencer
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
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3
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Tseng CC, Woolley TE, Jiang TX, Wu P, Maini PK, Widelitz RB, Chuong CM. Gap junctions in Turing-type periodic feather pattern formation. PLoS Biol 2024; 22:e3002636. [PMID: 38743770 PMCID: PMC11161087 DOI: 10.1371/journal.pbio.3002636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/07/2024] [Accepted: 04/22/2024] [Indexed: 05/16/2024] Open
Abstract
Periodic patterning requires coordinated cell-cell interactions at the tissue level. Turing showed, using mathematical modeling, how spatial patterns could arise from the reactions of a diffusive activator-inhibitor pair in an initially homogeneous 2D field. Most activators and inhibitors studied in biological systems are proteins, and the roles of cell-cell interaction, ions, bioelectricity, etc. are only now being identified. Gap junctions (GJs) mediate direct exchanges of ions or small molecules between cells, enabling rapid long-distance communications in a cell collective. They are therefore good candidates for propagating nonprotein-based patterning signals that may act according to the Turing principles. Here, we explore the possible roles of GJs in Turing-type patterning using feather pattern formation as a model. We found 7 of the 12 investigated GJ isoforms are highly dynamically expressed in the developing chicken skin. In ovo functional perturbations of the GJ isoform, connexin 30, by siRNA and the dominant-negative mutant applied before placode development led to disrupted primary feather bud formation. Interestingly, inhibition of gap junctional intercellular communication (GJIC) in the ex vivo skin explant culture allowed the sequential emergence of new feather buds at specific spatial locations relative to the existing primary buds. The results suggest that GJIC may facilitate the propagation of long-distance inhibitory signals. Thus, inhibition of GJs may stimulate Turing-type periodic feather pattern formation during chick skin development, and the removal of GJ activity would enable the emergence of new feather buds if the local environment were competent and the threshold to form buds was reached. We further propose Turing-based computational simulations that can predict the sequential appearance of these ectopic buds. Our models demonstrate how a Turing activator-inhibitor system can continue to generate patterns in the competent morphogenetic field when the level of intercellular communication at the tissue scale is modulated.
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Affiliation(s)
- Chun-Chih Tseng
- Department of Biochemistry and Molecular Medicine, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | | | - Ting-Xin Jiang
- Department of Pathology, University of Southern California, Los Angeles, California, United States of America
| | - Ping Wu
- Department of Pathology, University of Southern California, Los Angeles, California, United States of America
| | - Philip K. Maini
- Wolfson Centre for Mathematical Biology, Mathematical Institute, Andrew Wiles Building, University of Oxford, Radcliffe Observatory Quarter, Oxford, United Kingdom
| | - Randall B. Widelitz
- Department of Pathology, University of Southern California, Los Angeles, California, United States of America
| | - Cheng-Ming Chuong
- Department of Pathology, University of Southern California, Los Angeles, California, United States of America
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4
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Okolo CA, Maran JJ, Watts A, Maripillan J, Harkiolaki M, Martínez AD, Green CR, Mugisho OO. Correlative light and X-ray tomography jointly unveil the critical role of connexin43 channels on inflammation-induced cellular ultrastructural alterations. Heliyon 2024; 10:e27888. [PMID: 38560181 PMCID: PMC10979075 DOI: 10.1016/j.heliyon.2024.e27888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
Non-junctional connexin43 (Cx43) plasma membrane hemichannels have been implicated in several inflammatory diseases, particularly playing a role in ATP release that triggers activation of the inflammasome. Therapies targeting the blocking of the hemichannels to prevent the pathological release or uptake of ions and signalling molecules through its pores are of therapeutic interest. To date, there is no close-to-native, high-definition documentation of the impact of Cx43 hemichannel-mediated inflammation on cellular ultrastructure, neither is there a robust account of the ultrastructural changes that occur following treatment with selective Cx43 hemichannel blockers such as Xentry-Gap19 (XG19). A combination of same-sample correlative high-resolution three-dimensional fluorescence microscopy and soft X-ray tomography at cryogenic temperatures, enabled in the identification of novel 3D molecular interactions within the cellular milieu when comparing behaviour in healthy states and during the early onset or late stages under inflammatory conditions. Notably, our findings suggest that XG19 blockage of connexin hemichannels under pro-inflammatory conditions may be crucial in preventing the direct degradation of connexosomes by lysosomes, without affecting connexin protein translation and trafficking. We also delineated fine and gross cellular phenotypes, characteristic of inflammatory insult or road-to-recovery from inflammation, where XG19 could indirectly prevent and reverse inflammatory cytokine-induced mitochondrial swelling and cellular hypertrophy through its action on Cx43 hemichannels. Our findings suggest that XG19 might have prophylactic and therapeutic effects on the inflammatory response, in line with functional studies.
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Affiliation(s)
- Chidinma Adanna Okolo
- Beamline B24, Life Sciences Division, Diamond Light Source, Didcot, Oxfordshire, United Kingdom
| | - Jack Jonathan Maran
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Amy Watts
- Beamline B24, Life Sciences Division, Diamond Light Source, Didcot, Oxfordshire, United Kingdom
| | - Jaime Maripillan
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
| | - Maria Harkiolaki
- Beamline B24, Life Sciences Division, Diamond Light Source, Didcot, Oxfordshire, United Kingdom
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
| | - Colin R. Green
- Department of Ophthalmology, University of Auckland, New Zealand
| | - Odunayo Omolola Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, New Zealand
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5
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Totland MZ, Knudsen LM, Rasmussen NL, Omori Y, Sørensen V, Elster VCW, Stenersen JM, Larsen M, Jensen CL, Zickfeldt Lade AA, Bruusgaard E, Basing S, Kryeziu K, Brech A, Aasen T, Lothe RA, Leithe E. The E3 ubiquitin ligase ITCH negatively regulates intercellular communication via gap junctions by targeting connexin43 for lysosomal degradation. Cell Mol Life Sci 2024; 81:171. [PMID: 38597989 PMCID: PMC11006747 DOI: 10.1007/s00018-024-05165-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 01/27/2024] [Accepted: 02/05/2024] [Indexed: 04/11/2024]
Abstract
Intercellular communication via gap junctions has a fundamental role in regulating cell growth and tissue homeostasis, and its dysregulation may be involved in cancer development and radio- and chemotherapy resistance. Connexin43 (Cx43) is the most ubiquitously expressed gap junction channel protein in human tissues. Emerging evidence indicates that dysregulation of the sorting of Cx43 to lysosomes is important in mediating the loss of Cx43-based gap junctions in cancer cells. However, the molecular basis underlying this process is currently poorly understood. Here, we identified the E3 ubiquitin ligase ITCH as a novel regulator of intercellular communication via gap junctions. We demonstrate that ITCH promotes loss of gap junctions in cervical cancer cells, which is associated with increased degradation of Cx43 in lysosomes. The data further indicate that ITCH interacts with and regulates Cx43 ubiquitination and that the ITCH-induced loss of Cx43-based gap junctions requires its catalytic HECT (homologous to E6-AP C-terminus) domain. The data also suggest that the ability of ITCH to efficiently promote loss of Cx43-based gap junctions and degradation of Cx43 depends on a functional PY (PPXY) motif in the C-terminal tail of Cx43. Together, these data provide new insights into the molecular basis underlying the degradation of Cx43 and have implications for the understanding of how intercellular communication via gap junctions is lost during cancer development.
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Affiliation(s)
- Max Zachrisson Totland
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Lars Mørland Knudsen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Nikoline Lander Rasmussen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Centre for Molecular Medicine Norway, Faculty of Medicine, Oslo, Norway
| | - Yasufumi Omori
- Department of Molecular and Tumour Pathology, Akita University Graduate School of Medicine, Akita, 010-8543, Japan
| | - Vigdis Sørensen
- Department of Core Facilities, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Oslo, 0379, Norway
| | - Vilde C Wivestad Elster
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Jakob Mørkved Stenersen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Mathias Larsen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Caroline Lunder Jensen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Anna A Zickfeldt Lade
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Emilie Bruusgaard
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Sebastian Basing
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Kushtrim Kryeziu
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Andreas Brech
- Department of Core Facilities, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, 0379, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, Oslo, 0316, Norway
| | - Trond Aasen
- Patologia Molecular Translacional, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119-129, Barcelona, 08035, Spain
| | - Ragnhild A Lothe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, Oslo, 0316, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, 0317, Norway
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
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6
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Al-attar R, Jargstorf J, Romagnuolo R, Jouni M, Alibhai FJ, Lampe PD, Solan JL, Laflamme MA. Casein Kinase 1 Phosphomimetic Mutations Negatively Impact Connexin-43 Gap Junctions in Human Pluripotent Stem Cell-Derived Cardiomyocytes. Biomolecules 2024; 14:61. [PMID: 38254663 PMCID: PMC10813327 DOI: 10.3390/biom14010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/14/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
The transplantation of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) has shown promise in preclinical models of myocardial infarction, but graft myocardium exhibits incomplete host-graft electromechanical integration and a propensity for pro-arrhythmic behavior. Perhaps contributing to this situation, hPSC-CM grafts show low expression of connexin 43 (Cx43), the major gap junction (GJ) protein, in ventricular myocardia. We hypothesized that Cx43 expression and function could be rescued by engineering Cx43 in hPSC-CMs with a series of phosphatase-resistant mutations at three casein kinase 1 phosphorylation sites (Cx43-S3E) that have been previously reported to stabilize Cx43 GJs and reduce arrhythmias in transgenic mice. However, contrary to our predictions, transgenic Cx43-S3E hPSC-CMs exhibited reduced Cx43 expression relative to wild-type cells, both at baseline and following ischemic challenge. Cx43-S3E hPSC-CMs showed correspondingly slower conduction velocities, increased automaticity, and differential expression of other connexin isoforms and various genes involved in cardiac excitation-contraction coupling. Cx43-S3E hPSC-CMs also had phosphorylation marks associated with Cx43 GJ internalization, a finding that may account for their impaired GJ localization. Taken collectively, our data indicate that the Cx43-S3E mutation behaves differently in hPSC-CMs than in adult mouse ventricular myocytes and that multiple biological factors likely need to be addressed synchronously to ensure proper Cx43 expression, localization, and function.
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Affiliation(s)
- Rasha Al-attar
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Joseph Jargstorf
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Rocco Romagnuolo
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Mariam Jouni
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Faisal J. Alibhai
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Paul D. Lampe
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Joell L. Solan
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Michael A. Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON M5G 1L7, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5G 1L7, Canada
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7
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Xu K, Chen S, Bai X, Xie L, Qiu Y, Liu X, Wang X, Kong W, Sun Y. Degradation of cochlear Connexin26 accelerate the development of age-related hearing loss. Aging Cell 2023; 22:e13973. [PMID: 37681746 PMCID: PMC10652327 DOI: 10.1111/acel.13973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/03/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
The GJB2 gene, encoding Connexin26 (Cx26), is one of the most common causes of inherited deafness. Clinically, mutations in GJB2 cause congenital deafness or late-onset progressive hearing loss. Recently, it has been reported that Cx26 haploid deficiency accelerates the development of age-related hearing loss (ARHL). However, the roles of cochlear Cx26 in the hearing function of aged animals remain unclear. In this study, we revealed that the Cx26 expression was significantly reduced in the cochleae of aged mice, and further explored the underlying molecular mechanism for Cx26 degradation. Immunofluorescence co-localization results showed that Cx26 was internalized and degraded by lysosomes, which might be one of the important ways for Cx26 degradation in the cochlea of aged mice. Currently, whether the degradation of Cx26 in the cochlea leads directly to ARHL, as well as the mechanism of Cx26 degradation-related hearing loss are still unclear. To address these questions, we generated mice with Cx26 knockout in the adult cochlea as a model for the natural degradation of Cx26. Auditory brainstem response (ABR) results showed that Cx26 knockout mice exhibited high-frequency hearing loss, which gradually progressed over time. Pathological examination also revealed the degeneration of hair cells and spiral ganglions, which is similar to the phenotype of ARHL. In summary, our findings suggest that degradation of Cx26 in the cochlea accelerates the occurrence of ARHL, which may be a novel mechanism of ARHL.
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Affiliation(s)
- Kai Xu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Sen Chen
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xue Bai
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Le Xie
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Yue Qiu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xiao‐zhou Liu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xiao‐hui Wang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Wei‐jia Kong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and RegenerationWuhanChina
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8
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Ye Q, Chen W, Fu H, Ding Y, Jing Y, Shen J, Yuan Z, Zha K. Targeting Autophagy in Atrial Fibrillation. Rev Cardiovasc Med 2023; 24:288. [PMID: 39077569 PMCID: PMC11273128 DOI: 10.31083/j.rcm2410288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 05/04/2023] [Accepted: 05/19/2023] [Indexed: 07/31/2024] Open
Abstract
Atrial fibrillation (AF) is the most common type of arrhythmia in clinical practice, and its incidence is positively correlated with risk factors that include advanced age, hypertension, diabetes, and heart failure. Although our understanding of the mechanisms that govern the occurrence and persistence of AF has been increasing rapidly, the exact mechanism of AF is still not fully understood. Autophagy is an evolutionarily highly conserved and specific physiological process in cells that has been suggested as a potential therapeutic target for several cardiovascular diseases including the pathophysiology of AF. The present article provides an updated review of the fast-progressing field of research surrounding autophagy in AF, and how regulating autophagy might be a therapeutic target to reduce the incidence of AF.
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Affiliation(s)
- Qiang Ye
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Wen Chen
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Hengsong Fu
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Yanling Ding
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Yuling Jing
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Jingsong Shen
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Ziyang Yuan
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
| | - Kelan Zha
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, 646000 Luzhou, Sichuan, China
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9
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Totland MZ, Omori Y, Sørensen V, Kryeziu K, Aasen T, Brech A, Leithe E. Endocytic trafficking of connexins in cancer pathogenesis. Biochim Biophys Acta Mol Basis Dis 2023:166812. [PMID: 37454772 DOI: 10.1016/j.bbadis.2023.166812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/26/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Gap junctions are specialized regions of the plasma membrane containing clusters of channels that provide for the diffusion of ions and small molecules between adjacent cells. A fundamental role of gap junctions is to coordinate the functions of cells in tissues. Cancer pathogenesis is usually associated with loss of intercellular communication mediated by gap junctions, which may affect tumor growth and the response to radio- and chemotherapy. Gap junction channels consist of integral membrane proteins termed connexins. In addition to their canonical roles in cell-cell communication, connexins modulate a range of signal transduction pathways via interactions with proteins such as β-catenin, c-Src, and PTEN. Consequently, connexins can regulate cellular processes such as cell growth, migration, and differentiation through both channel-dependent and independent mechanisms. Gap junctions are dynamic plasma membrane entities, and by modulating the rate at which connexins undergo endocytosis and sorting to lysosomes for degradation, cells rapidly adjust the level of gap junctions in response to alterations in the intracellular or extracellular milieu. Current experimental evidence indicates that aberrant trafficking of connexins in the endocytic system is intrinsically involved in mediating the loss of gap junctions during carcinogenesis. This review highlights the role played by the endocytic system in controlling connexin degradation, and consequently gap junction levels, and discusses how dysregulation of these processes contributes to the loss of gap junctions during cancer development. We also discuss the therapeutic implications of aberrant endocytic trafficking of connexins in cancer cells.
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Affiliation(s)
| | - Yasufumi Omori
- Department of Molecular and Tumour Pathology, Akita University Graduate School of Medicine, Akita, Japan
| | | | | | - Trond Aasen
- Patologia Molecular Translacional, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron, Barcelona, Spain
| | - Andreas Brech
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Oslo, Norway; Section for Physiology and Cell Biology, Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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10
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Scott H, Dong L, Stevenson A, MacDonald AI, Srinivasan S, Massimi P, Banks L, Martin PE, Johnstone SR, Graham SV. The human discs large protein 1 interacts with and maintains connexin 43 at the plasma membrane in keratinocytes. J Cell Sci 2023; 136:jcs259984. [PMID: 37288673 PMCID: PMC10309592 DOI: 10.1242/jcs.259984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
Gap junction channels, composed of connexins, allow direct cell-to-cell communication. Connexin 43 (Cx43; also known as GJA1) is widely expressed in tissues, including the epidermis. In a previous study of human papillomavirus-positive cervical epithelial tumour cells, we identified Cx43 as a binding partner of the human homologue of Drosophila Discs large (Dlg1; also known as SAP97). Dlg1 is a member of the membrane associated-guanylate kinase (MAGUK) scaffolding protein family, which is known to control cell shape and polarity. Here, we show that Cx43 also interacts with Dlg1 in uninfected keratinocytes in vitro and in keratinocytes, dermal cells and adipocytes in normal human epidermis in vivo. Depletion of Dlg1 in keratinocytes did not alter Cx43 transcription but was associated with a reduction in Cx43 protein levels. Reduced Dlg1 levels in keratinocytes resulted in a reduction in Cx43 at the plasma membrane with a concomitant reduction in gap junctional intercellular communication and relocation of Cx43 to the Golgi compartment. Our data suggest a key role for Dlg1 in maintaining Cx43 at the plasma membrane in keratinocytes.
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Affiliation(s)
- Harry Scott
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Li Dong
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Andrew Stevenson
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Alasdair I. MacDonald
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Sharmila Srinivasan
- Translation Research Platform for Veterinary Biologicals, Chennai, Tamil Nadu, India
| | - Paola Massimi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Lawrence Banks
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Patricia E. Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK
| | - Scott R. Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke VA 24016, USA
| | - Sheila V. Graham
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
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11
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Tseng CC, Woolley TE, Jiang TX, Wu P, Maini PK, Widelitz RB, Chuong CM. Gap junctions in Turing-type periodic feather pattern formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.15.537019. [PMID: 37090608 PMCID: PMC10120740 DOI: 10.1101/2023.04.15.537019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Periodic patterning requires coordinated cell-cell interactions at the tissue level. Turing showed, using mathematical modeling, how spatial patterns could arise from the reactions of a diffusive activator-inhibitor pair in an initially homogenous two-dimensional field. Most activators and inhibitors studied in biological systems are proteins, and the roles of cell-cell interaction, ions, bioelectricity, etc. are only now being identified. Gap junctions (GJs) mediate direct exchanges of ions or small molecules between cells, enabling rapid long-distance communications in a cell collective. They are therefore good candidates for propagating non-protein-based patterning signals that may act according to the Turing principles. Here, we explore the possible roles of GJs in Turing-type patterning using feather pattern formation as a model. We found seven of the twelve investigated GJ isoforms are highly dynamically expressed in the developing chicken skin. In ovo functional perturbations of the GJ isoform, connexin 30, by siRNA and the dominant-negative mutant applied before placode development led to disrupted primary feather bud formation, including patches of smooth skin and buds of irregular sizes. Later, after the primary feather arrays were laid out, inhibition of gap junctional intercellular communication in the ex vivo skin explant culture allowed the emergence of new feather buds in temporal waves at specific spatial locations relative to the existing primary buds. The results suggest that gap junctional communication may facilitate the propagation of long-distance inhibitory signals. Thus, the removal of GJ activity would enable the emergence of new feather buds if the local environment is competent and the threshold to form buds is reached. We propose Turing-based computational simulations that can predict the appearance of these ectopic bud waves. Our models demonstrate how a Turing activator-inhibitor system can continue to generate patterns in the competent morphogenetic field when the level of intercellular communication at the tissue scale is modulated.
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Affiliation(s)
- Chun-Chih Tseng
- Department of Biochemistry and Molecular Medicine, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, U.S.A
- Current address: Department of Molecular Biology, Princeton University, Princeton, NJ 08540, U.S.A
| | - Thomas E. Woolley
- School of Mathematics, Cardiff University, Senghennydd Road, Cardiff, CF24 4AG, U.K
| | - Ting-Xin Jiang
- Department of Pathology, University of Southern California, Los Angeles, CA 90033, U.S.A
| | - Ping Wu
- Department of Pathology, University of Southern California, Los Angeles, CA 90033, U.S.A
| | - Philip K. Maini
- Wolfson Centre for Mathematical Biology, Mathematical Institute, Andrew Wiles Building, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, U.K
| | - Randall B. Widelitz
- Department of Pathology, University of Southern California, Los Angeles, CA 90033, U.S.A
| | - Cheng-Ming Chuong
- Department of Pathology, University of Southern California, Los Angeles, CA 90033, U.S.A
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12
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Basu I, Li H, Trease AJ, Sorgen PL. Regulation of Cx43 Gap Junction Intercellular Communication by Bruton's Tyrosine Kinase and Interleukin-2-Inducible T-Cell Kinase. Biomolecules 2023; 13:biom13040660. [PMID: 37189407 DOI: 10.3390/biom13040660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/30/2023] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
T and B cell receptor signaling involves the activation of Akt, MAPKs, and PKC as well as an increase in intracellular Ca2+ and calmodulin activation. While these coordinate the rapid turnover of gap junctions, also implicated in this process is Src, which is not activated as part of T and B cell receptor signaling. An in vitro kinase screen identified that Bruton's tyrosine kinase (BTK) and interleukin-2-inducible T-cell kinase (ITK) phosphorylate Cx43. Mass spectroscopy revealed that BTK and ITK phosphorylate Cx43 residues Y247, Y265, and Y313, which are identical to the residues phosphorylated by Src. Overexpression of BTK or ITK in the HEK-293T cells led to increased Cx43 tyrosine phosphorylation as well as decreased gap junction intercellular communication (GJIC) and Cx43 membrane localization. In the lymphocytes, activation of the B cell receptor (Daudi cells) or T cell receptor (Jurkat cells) increased the BTK and ITK activity, respectively. While this led to increased tyrosine phosphorylation of Cx43 and decreased GJIC, the cellular localization of Cx43 changed little. We have previously identified that Pyk2 and Tyk2 also phosphorylate Cx43 at residues Y247, Y265, and Y313 with a similar cellular fate to that of Src. With phosphorylation critical to Cx43 assembly and turnover, and kinase expression varying between different cell types, there would be a need for different kinases to achieve the same regulation of Cx43. The work presented herein suggests that in the immune system, ITK and BTK have the capacity for the tyrosine phosphorylation of Cx43 to alter the gap junction function in a similar manner as Pyk2, Tyk2, and Src.
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Affiliation(s)
- Ishika Basu
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Hanjun Li
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Andrew J Trease
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Paul L Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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13
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Zhou Y, Bennett TM, White TW, Shiels A. Charged multivesicular body protein 4b forms complexes with gap junction proteins during lens fiber cell differentiation. FASEB J 2023; 37:e22801. [PMID: 36880430 PMCID: PMC10101236 DOI: 10.1096/fj.202201368rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 03/08/2023]
Abstract
Charged multivesicular body protein 4b (CHMP4B) is a core sub-unit of the endosomal sorting complex required for transport III (ESCRT-III) machinery that serves myriad remodeling and scission processes of biological membranes. Mutation of the human CHMP4B gene underlies rare forms of early-onset lens opacities or cataracts, and CHMP4B is required for lens growth and differentiation in mice. Here, we determine the sub-cellular distribution of CHMP4B in the lens and uncover a novel association with gap junction alpha-3 protein (GJA3) or connexin 46 (Cx46) and GJA8 or Cx50. Immunofluorescence confocal microscopy revealed that CHMP4B localized to cell membranes of elongated fiber cells in the outer cortex of the lens-where large gap junction plaques begin to form-particularly, on the broad faces of these flattened hexagon-like cells in cross-section. Dual immunofluorescence imaging showed that CHMP4B co-localized with gap junction plaques containing Cx46 and/or Cx50. When combined with the in situ proximity ligation assay, immunofluorescence confocal imaging indicated that CHMP4B lay in close physical proximity to Cx46 and Cx50. In Cx46-knockout (Cx46-KO) lenses, CHMP4B-membrane distribution was similar to that of wild-type, whereas, in Cx50-KO lenses, CHMP4B localization to fiber cell membranes was lost. Immunoprecipitation and immunoblotting analyses revealed that CHMP4B formed complexes with Cx46 and Cx50 in vitro. Collectively, our data suggest that CHMP4B forms plasma membrane complexes, either directly and/or indirectly, with gap junction proteins Cx46 and Cx50 that are often associated with "ball-and-socket" double-membrane junctions during lens fiber cell differentiation.
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Affiliation(s)
- Yuefang Zhou
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas W. White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
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14
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Zhou M, Zheng M, Zhou X, Tian S, Yang X, Ning Y, Li Y, Zhang S. The roles of connexins and gap junctions in the progression of cancer. Cell Commun Signal 2023; 21:8. [PMID: 36639804 PMCID: PMC9837928 DOI: 10.1186/s12964-022-01009-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/03/2022] [Indexed: 01/15/2023] Open
Abstract
Gap junctions (GJs), which are composed of connexins (Cxs), provide channels for direct information exchange between cells. Cx expression has a strong spatial specificity; however, its influence on cell behavior and information exchange between cells cannot be ignored. A variety of factors in organisms can modulate Cxs and subsequently trigger a series of responses that have important effects on cellular behavior. The expression and function of Cxs and the number and function of GJs are in dynamic change. Cxs have been characterized as tumor suppressors in the past, but recent studies have highlighted the critical roles of Cxs and GJs in cancer pathogenesis. The complex mechanism underlying Cx and GJ involvement in cancer development is a major obstacle to the evolution of therapy targeting Cxs. In this paper, we review the post-translational modifications of Cxs, the interactions of Cxs with several chaperone proteins, and the effects of Cxs and GJs on cancer. Video Abstract.
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Affiliation(s)
- Mingming Zhou
- grid.265021.20000 0000 9792 1228Graduate School, Tianjin Medical University, Tianjin, 300070 People’s Republic of China
| | - Minying Zheng
- Department of Pathology, Tianjin Union Medical Center, Nankai University, Tianjin, 300121 People’s Republic of China
| | - Xinyue Zhou
- grid.265021.20000 0000 9792 1228Graduate School, Tianjin Medical University, Tianjin, 300070 People’s Republic of China
| | - Shifeng Tian
- grid.265021.20000 0000 9792 1228Graduate School, Tianjin Medical University, Tianjin, 300070 People’s Republic of China
| | - Xiaohui Yang
- grid.216938.70000 0000 9878 7032Nankai University School of Medicine, Nankai University, Tianjin, 300071 People’s Republic of China
| | - Yidi Ning
- grid.216938.70000 0000 9878 7032Nankai University School of Medicine, Nankai University, Tianjin, 300071 People’s Republic of China
| | - Yuwei Li
- grid.417031.00000 0004 1799 2675Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, 300121 People’s Republic of China
| | - Shiwu Zhang
- Department of Pathology, Tianjin Union Medical Center, Nankai University, Tianjin, 300121 People’s Republic of China
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15
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Yuan J, Huang X, Zhao Y, Gu J, Yuan Y, Liu Z, Zou H, Bian J. Rat Hepatocytes Mitigate Cadmium Toxicity by Forming Annular Gap Junctions and Degrading Them via Endosome-Lysosome Pathway. Int J Mol Sci 2022; 23:ijms232415607. [PMID: 36555247 PMCID: PMC9778680 DOI: 10.3390/ijms232415607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Gap junction protein connexin 43 (Cx43) plays a critical role in gap junction communication in rat hepatocytes. However, those located between hepatocytes are easily internalized following exposure to poisons. Herein, we investigated the potential of buffalo rat liver 3A (BRL 3A) cells to generate annular gap junctions (AGJs) proficient at alleviating cadmium (Cd) cytotoxic injury through degradation via an endosome-lysosome pathway. Our results showed that Cd-induced damage of liver microtubules promoted Cx43 internalization and increased Cx43 phosphorylation at Ser373 site. Furthermore, we established that Cd induced AGJs generation in BRL 3A cells, and AGJs were subsequently degraded through the endosome-lysosome pathway. Overall, our results suggested that Cx43 internalization and the generation of AGJs were cellular protective mechanisms to alleviate Cd toxicity in rat hepatocytes.
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Affiliation(s)
- Junzhao Yuan
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaoqian Huang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yumeng Zhao
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Jianhong Gu
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yan Yuan
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Zongping Liu
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Hui Zou
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- Correspondence: (H.Z.); (J.B.)
| | - Jianchun Bian
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- Correspondence: (H.Z.); (J.B.)
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16
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Falck AT, Lund BA, Johansen D, Lund T, Ytrehus K. The Ambivalence of Connexin43 Gap Peptides in Cardioprotection of the Isolated Heart against Ischemic Injury. Int J Mol Sci 2022; 23:ijms231710197. [PMID: 36077595 PMCID: PMC9456187 DOI: 10.3390/ijms231710197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 11/16/2022] Open
Abstract
The present study investigates infarct-reducing effects of blocking ischemia-induced opening of connexin43 hemichannels using peptides Gap19, Gap26 or Gap27. Cardioprotection by ischemic preconditioning (IPC) and Gap peptides was compared, and combined treatment was tested in isolated, perfused male rat hearts using function and infarct size after global ischemia, high-resolution respirometry of isolated mitochondrial and peptide binding kinetics as endpoints. The Gap peptides reduced infarct size significantly when given prior to ischemia plus at reperfusion (Gap19 76.2 ± 2.7, Gap26 72.9 ± 5.8 and Gap27 71.9 ± 5.8% of untreated control infarcts, mean ± SEM). Cardioprotection was lost when Gap26, but not Gap27 or Gap19, was combined with triggering IPC (IPC 73.4 ± 5.5, Gap19-IPC 60.9 ± 5.1, Gap26-IPC 109.6 ± 7.8, Gap27-IPC 56.3 ± 8.0% of untreated control infarct). Binding stability of peptide Gap26 to its specific extracellular loop sequence (EL2) of connexin43 was stronger than Gap27 to its corresponding loop EL1 (dissociation rate constant Kd 0.061 ± 0.004 vs. 0.0043 ± 0.0001 s-1, mean ± SD). Mitochondria from IPC hearts showed slightly but significantly reduced respiratory control ratio (RCR). In vitro addition of Gap peptides did not significantly alter respiration. If transient hemichannel activity is part of the IPC triggering event, inhibition of IPC triggering stimuli might limit the use of cardioprotective Gap peptides.
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Affiliation(s)
- Aleksander Tank Falck
- Cardiovascular Research Group, Department of Medical Biology, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | - Bjarte Aarmo Lund
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, Faculty of Science and Technology, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | - David Johansen
- Department of Internal Medicine, University Hospital of North Norway, 9019 Tromsø, Norway
| | - Trine Lund
- Cardiovascular Research Group, Department of Medical Biology, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | - Kirsti Ytrehus
- Cardiovascular Research Group, Department of Medical Biology, UiT The Arctic University of Norway, 9037 Tromsø, Norway
- Correspondence:
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17
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Van Campenhout R, Leroy K, Cooreman A, Tabernilla A, Cogliati B, Kadam P, Vinken M. Connexin-Based Channels in the Liver. Compr Physiol 2022; 12:4147-4163. [PMID: 35950654 DOI: 10.1002/cphy.c220007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Connexin proteins oligomerize in hexameric structures called connexin hemichannels, which then dock to form gap junctions. Gap junctions direct cell-cell communication by allowing the exchange of small molecules and ions between neighboring cells. In this way, hepatic gap junctions support liver homeostasis. Besides serving as building blocks for gap junctions, connexin hemichannels provide a pathway between the intracellular and the extracellular environment. The activation of connexin hemichannels is associated with acute and chronic liver pathologies. This article discusses the role of gap junctions and connexin hemichannels in the liver. © 2022 American Physiological Society. Compr Physiol 12:1-17, 2022.
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Affiliation(s)
- Raf Van Campenhout
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Kaat Leroy
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Axelle Cooreman
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Andrés Tabernilla
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Bruno Cogliati
- School of Veterinary Medicine and Animal Science, Department of Pathology, University of São Paulo, São Paulo, Brazil
| | - Prashant Kadam
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Mathieu Vinken
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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18
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Zhao H, Kong H, Wang W, Chen T, Zhang Y, Zhu J, Feng D, Cui Y. High Glucose Aggravates Retinal Endothelial Cell Dysfunction by Activating the RhoA/ROCK1/pMLC/Connexin43 Signaling Pathway. Invest Ophthalmol Vis Sci 2022; 63:22. [PMID: 35881407 PMCID: PMC9339693 DOI: 10.1167/iovs.63.8.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This research aims to explore the mechanism underlying the relationship between RhoA/ROCK signaling and Connexin43 (Cx43) in retinal endothelial cell dysfunction and to evaluate the protective effect of ROCK inhibitors against retinal endothelial cell dysfunction in diabetic retinopathy (DR) models. Methods TUNEL staining, hematoxylin and eosin staining, a retinal digestion assay, and Evans blue assay were conducted to explore the effect of fasudil in alleviating retinal dysfunction induced by DR. ELISA, the CCK-8 assay, and flow cytometry were conducted to study inflammation, viability, and apoptosis of mouse retinal microvascular endothelial cells treated with high glucose and ROCK inhibitors. The qRT–PCR and Western blotting were used to evaluate the expression of RhoA, ROCK1, ROCK2, MLC, pMLC, and Cx43. Co-immunoprecipitation was used to verify the interaction between pMLC and Cx43. Immunofluorescence and scrape-loading and dye transfer were used to evaluate the expression and function of Cx43. Results Marked endothelial cell dysfunction resulting from the activation of RhoA/ROCK1 signaling was found in in vivo and in vitro models of DR. Via interaction with pMLC, which is downstream of RhoA/ROCK1, a significant downregulation of Cx43 was observed in retinal endothelial cells. Treatment with ROCK inhibitors ameliorated retinal endothelial dysfunction in vitro. The ROCK inhibitor, fasudil, significantly alleviated retinal dysfunction as shown by a decrease of retinal acellular capillaries, an improvement of vascular permeability, and a reduction of cell apoptosis in vivo. Conclusions Our study highlights a novel mechanism that high glucose could activate RhoA/ROCK1/pMLC signaling, which targets the expression and localization of Cx43 and is responsible for cell viability, apoptosis, and inflammation, resulting in retinal endothelial cell injury. ROCK inhibitors markedly ameliorate endothelial cell dysfunction, suggesting their therapeutic potential for diabetic retinopathy.
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Affiliation(s)
- Hongran Zhao
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China.,School of Medicine, Shandong University, Jinan, Shandong Province, China.,NHC Key Laboratory of Otorhinolaryngology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China.,Laboratory of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Hui Kong
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China.,Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China.,NHC Key Laboratory of Otorhinolaryngology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Wenjuan Wang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
| | - Tianran Chen
- School of Medicine, Shandong University, Jinan, Shandong Province, China
| | - Yuting Zhang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
| | - Jing Zhu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
| | - Dandan Feng
- Department of Cardiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, China
| | - Yan Cui
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
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19
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Cross-talk between mutant p53 and p62/SQSTM1 augments cancer cell migration by promoting the degradation of cell adhesion proteins. Proc Natl Acad Sci U S A 2022; 119:e2119644119. [PMID: 35439056 PMCID: PMC9173583 DOI: 10.1073/pnas.2119644119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Missense mutations in the TP53 gene, encoding the p53 tumor suppressor, are very frequent in human cancer. Some of those mutations, particularly the more common (“hotspot”) ones, not only abrogate p53’s tumor suppressor activities but also endow the mutant protein with oncogenic gain of function (GOF). We report that p53R273H, the most common p53 mutant in pancreatic cancer, interacts with the SQSTM1/p62 protein to accelerate the degradation of cell adhesion proteins. This enables pancreatic cancer cells to detach from the epithelial sheet and engage in individualized cell migration, probably augmenting metastatic spread. By providing insights into mechanisms that underpin mutant p53 GOF, this study may suggest ways to interfere with the progression of cancers bearing particular p53 mutants. Missense mutations in the p53 tumor suppressor abound in human cancer. Common (“hotspot”) mutations endow mutant p53 (mutp53) proteins with oncogenic gain of function (GOF), including enhanced cell migration and invasiveness, favoring cancer progression. GOF is usually attributed to transcriptional effects of mutp53. To elucidate transcription-independent effects of mutp53, we characterized the protein interactome of the p53R273H mutant in cells derived from pancreatic ductal adenocarcinoma (PDAC), where p53R273H is the most frequent p53 mutant. We now report that p53R273H, but not the p53R175H hotspot mutant, interacts with SQSTM1/p62 and promotes cancer cell migration and invasion in a p62-dependent manner. Mechanistically, the p53R273H-p62 axis drives the proteasomal degradation of several cell junction–associated proteins, including the gap junction protein Connexin 43, facilitating scattered cell migration. Concordantly, down-regulation of Connexin 43 augments PDAC cell migration, while its forced overexpression blunts the promigratory effect of the p53R273H-p62 axis. These findings define a mechanism of mutp53 GOF.
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20
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Yawer A, Sychrová E, Raška J, Babica P, Sovadinová I. Endocrine-disrupting chemicals affect sertoli TM4 cell functionality through dysregulation of gap junctional intercellular communication in vitro. Food Chem Toxicol 2022; 164:113004. [PMID: 35413382 DOI: 10.1016/j.fct.2022.113004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/20/2022] [Accepted: 04/06/2022] [Indexed: 01/10/2023]
Abstract
The frequencies of adverse outcomes associated with male reproductive health, including infertility and testicular cancer, are increasing. These adverse trends are partially attributed to increased exposure to environmental agents such as endocrine-disrupting chemicals (EDCs). This study addresses effects on EDCs on adjacent prepubertal Sertoli TM4 cells, specifically on 1) testicular gap junctional intercellular communication (GJIC), one of the hallmarks of non-genotoxic carcinogenicity, 2) GJIC building blocks connexins (Cx), and 3) mitogen-activated protein kinases MAPKs. We selected eight representatives of EDCs: bisphenol A and organochlorine chemicals such as pesticides dichlorodiphenyltrichloroethane, lindane, methoxychlor, and vinclozolin, industrial chemical 2,2',4,4',5,5'-hexachlorobiphenyl, and components of personal care products, triclocarban and triclosan. EDCs rapidly dysregulated GJIC in Sertoli TM4 cells mainly via MAPK p38 and/or Erk1/2/pathways by the intermediate hyper- or de-phosphorylation of Cx43 (Ser368, Ser282) and translocalization of Cx43 from the plasma membrane, suggesting disturbed intracellular trafficking of Cx43 protein. Surprisingly, EDCs did not rapidly activate MAPK Erk1/2 or p38; on the contrary, TCC and TCS decreased their activity (phosphorylation). Our results indicate that EDCs might disrupt testicular homeostasis and development via testicular GJIC, junctional and non-junctional functions of Cx43 and MAPK-signalling pathways in Sertoli cells.
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Affiliation(s)
- Affiefa Yawer
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Eliška Sychrová
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Jan Raška
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Iva Sovadinová
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
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21
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Fadjukov J, Wienbar S, Hakanen S, Aho V, Vihinen-Ranta M, Ihalainen TO, Schwartz GW, Nymark S. Gap junctions and connexin hemichannels both contribute to the electrical properties of retinal pigment epithelium. J Gen Physiol 2022; 154:213064. [PMID: 35275193 PMCID: PMC8922333 DOI: 10.1085/jgp.202112916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 02/17/2022] [Indexed: 12/13/2022] Open
Abstract
Gap junctions are intercellular channels that permit the transfer of ions and small molecules between adjacent cells. These cellular junctions are particularly dense in the retinal pigment epithelium (RPE), and their contribution to many retinal diseases has been recognized. While gap junctions have been implicated in several aspects of RPE physiology, their role in shaping the electrical properties of these cells has not been characterized in mammals. The role of gap junctions in the electrical properties of the RPE is particularly important considering the growing appreciation of RPE as excitable cells containing various voltage-gated channels. We used a whole-cell patch clamp to measure the electrical characteristics and connectivity between RPE cells, both in cultures derived from human embryonic stem cells and in the intact RPE monolayers from mouse eyes. We found that the pharmacological blockade of gap junctions eliminated electrical coupling between RPE cells, and that the blockade of gap junctions or Cx43 hemichannels significantly increased their input resistance. These results demonstrate that gap junctions function in the RPE not only as a means of molecular transport but also as a regulator of electrical excitability.
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Affiliation(s)
- Julia Fadjukov
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Sophia Wienbar
- Department of Ophthalmology, Northwestern University, Chicago, IL.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL.,Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL
| | - Satu Hakanen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Vesa Aho
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Maija Vihinen-Ranta
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Teemu O Ihalainen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Gregory W Schwartz
- Department of Ophthalmology, Northwestern University, Chicago, IL.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL.,Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL
| | - Soile Nymark
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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22
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Zhou X, Li M, Cheng Q, Shao Y, Wang W, Du Q, Liu J, Yang Y. Methylselenocysteine Potentiates Etoposide-Induced Cytotoxicity by Enhancing Gap Junction Activity. Biol Pharm Bull 2022; 45:467-476. [DOI: 10.1248/bpb.b21-00893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Xueli Zhou
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Man Li
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Qianqian Cheng
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Yu Shao
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Wei Wang
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Qianyu Du
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Jing Liu
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
| | - Yan Yang
- Department of Medical Oncology, The First Affiliated Hospital of Bengbu Medical College
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23
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The Effect of the NFκB-USP9X-Cx43 Axis on the Dynamic Balance of Bone Formation/Degradation during Ossification of the Posterior Longitudinal Ligament of the Cervical Spine. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1604932. [PMID: 35391932 PMCID: PMC8983240 DOI: 10.1155/2022/1604932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 01/23/2022] [Accepted: 02/08/2022] [Indexed: 12/17/2022]
Abstract
Connexin 43- (Cx43-) mediated nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling has been found involved in the ossification of the posterior longitudinal ligament (OPLL). However, the underlying mechanism how OPLL is regulated has not been elucidated. In the present study, primary ligament fibroblast were isolated; immunoprecipitation (IP) and liquid chromatography-mass spectrometry (LC-MS) assays were applied to identify potential binding proteins of Cx43. Protein interaction was then confirmed by co-IP assay. Alkaline phosphatase (ALP) activity and alizarin red staining were used to evaluate ossification. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were employed to assess the binding between NF-κB p65 and target gene. Lipoxygenase inhibitor (5,8,11-eicosatriynoic acid, EPA) was applied to induce endoplasmic reticulum (ER) stress, and 4-phenylbutyrate (4-PBA) was used as an ER-stress inhibitor. Expression of USP9X, Cx43, and nuclei p65 in ligaments from patients and controls was detected by Western blotting. The results showed that ubiquitin-specific protease 9 X-chromosome (USP9X), a deubiquitylating enzyme, was a candidate of Cx43 binding proteins, and USP9X inhibited Cx43 ubiquitination. In vitro experiments showed that USP9X promoted ossification of primary ligament fibroblasts and nuclear translocation of NF-κB p65 by regulating Cx43 expression. Moreover, NF-κB can bind to the USP9X promoter to promote its transcription. When ER stress was inhibited by 4-PBA, USP9X levels, NF-κB nuclei translocation, and ALP activity were decreased. Reverse results were obtained when ER stress was induced by EPA. PDTC, an NF-κB inhibitor, could abolish the effects of EPA. Furthermore, USP9X, Cx43, and nuclei p65 were significantly upregulated in ligaments from OPLL patients than non-OPLL controls. USP9X was positively correlated with CX43 and nuclei p65 in OPLL samples. Overall, the findings suggest that the ER stress–NFκB-USP9X-Cx43 signaling pathway plays an important role in OPLL progression.
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24
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Minogue PJ, Tong JJ, Wichmann K, Mysliwiec H, Ebihara L, Beyer EC, Berthoud VM. Cataract-linked serine mutations in the gap junction protein connexin50 expose a sorting signal that promotes its lysosomal degradation. J Biol Chem 2022; 298:101673. [PMID: 35120923 PMCID: PMC8927986 DOI: 10.1016/j.jbc.2022.101673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/24/2023] Open
Abstract
Many human connexin50 (Cx50) mutants have been linked to cataracts including two carboxyl terminus serine mutants that are known phosphorylation sites in the lens (Cx50S258F and Cx50S259Y). To examine the behavior of these mutants and the role of phosphorylation at these positions, we stably transfected HeLa cells with cataract-linked and phosphorylation-mimicking (Cx50S258D and Cx50S259D) Cx50 mutants. We observed that gap junctional plaques were rarely detected in Cx50S258F- and Cx50S259Y-expressing cells compared with wild-type cells. In addition, gap junction abundance and size were greatly increased for Cx50S258D and Cx50S259D mutants. Cx50S258F and Cx50S259Y supported very low levels of gap junctional coupling, whereas Cx50S258D and Cx50S259D supported extensive intercellular communication. Furthermore, Cx50 levels as detected by immunoblotting were lower in Cx50S258F and Cx50S259Y mutants than in the wild type or the aspartate substitution mutants, and chloroquine or ammonium chloride treatment significantly increased Cx50S258F and Cx50S259Y protein levels, implying participation of the lysosome in their increased degradation. Alanine substitution of amino acids within a predicted tyrosine-based sorting signal in Cx50S258F and Cx50S259Y increased levels of gap junctional plaques and intercellular transfer of Neurobiotin. These results suggest that absence of phosphorylatable serines at these positions exposes a sorting signal leading to lysosomal degradation of Cx50, whereas phosphorylation at these sites conceals this signal and allows targeting of Cx50 to the plasma membrane and stabilization of gap junction plaques. We propose that in the lens degradation of Cx50S258F and Cx50S259Y decreases Cx50 levels at the plasma membrane and consequently Cx50 function, leading to cataracts.
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Affiliation(s)
- Peter J Minogue
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Jun-Jie Tong
- Center of Proteomics and Molecular Therapeutics, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Kelly Wichmann
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Hubert Mysliwiec
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Lisa Ebihara
- Center of Proteomics and Molecular Therapeutics/Discipline of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Eric C Beyer
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Viviana M Berthoud
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA.
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25
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Viheriälä T, Hongisto H, Sorvari J, Skottman H, Nymark S, Ilmarinen T. Cell maturation influences the ability of hESC-RPE to tolerate cellular stress. Stem Cell Res Ther 2022; 13:30. [PMID: 35073969 PMCID: PMC8785579 DOI: 10.1186/s13287-022-02712-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/10/2022] [Indexed: 11/15/2022] Open
Abstract
Background Transplantation of human pluripotent stem cell-derived retinal pigment epithelium (RPE) is an urgently needed treatment for the cure of degenerative diseases of the retina. The transplanted cells must tolerate cellular stress caused by various sources such as retinal inflammation and regain their functions rapidly after the transplantation. We have previously shown the maturation level of the cultured human embryonic stem cell-derived RPE (hESC-RPE) cells to influence for example their calcium (Ca2+) signaling properties. Yet, no comparison of the ability of hESC-RPE at different maturity levels to tolerate cellular stress has been reported. Methods Here, we analyzed the ability of the hESC-RPE populations with early (3 weeks) and late (12 weeks) maturation status to tolerate cellular stress caused by chemical cell stressors protease inhibitor (MG132) or hydrogen peroxide (H2O2). After the treatments, the functionality of the RPE cells was studied by transepithelial resistance, immunostainings of key RPE proteins, phagocytosis, mitochondrial membrane potential, Ca2+ signaling, and cytokine secretion. Results The hESC-RPE population with late maturation status consistently showed improved tolerance to cellular stress in comparison to the population with early maturity. After the treatments, the early maturation status of hESC-RPE monolayer showed impaired barrier properties. The hESC-RPE with early maturity status also exhibited reduced phagocytic and Ca2+ signaling properties, especially after MG132 treatment. Conclusions Our results suggest that due to better tolerance to cellular stress, the late maturation status of hESC-RPE population is superior compared to monolayers with early maturation status in the transplantation therapy settings. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02712-7.
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Affiliation(s)
- Taina Viheriälä
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Heidi Hongisto
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Juhana Sorvari
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Heli Skottman
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Soile Nymark
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Tanja Ilmarinen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland. .,BioMediTech, Faculty of Medicine and Life Sciences, Tampere University, Arvo Ylpön katu 34, 33520, Tampere, Finland.
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26
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Subcellular Localization of Connexin 26 in Cardiomyocytes and in Cardiomyocyte-Derived Extracellular Vesicles. Molecules 2021; 26:molecules26216726. [PMID: 34771134 PMCID: PMC8587102 DOI: 10.3390/molecules26216726] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 12/13/2022] Open
Abstract
Connexins (Cxs) are a family of membrane-spanning proteins, expressed in vertebrates and named according to their molecular weight. They are involved in tissue homeostasis, and they function by acting at several communication levels. Cardiac Cxs are responsible for regular heart function and, among them, Cx26 and Cx43 are widely expressed throughout the heart. Cx26 is present in vessels, as well as in cardiomyocytes, and its localization is scattered all over the cell aside from at the intercalated discs as is the case for the other cardiac Cxs. However, having been found in cardiomyocytes only recently, both its subcellular localization and its functional characterization in cardiomyocytes remain poorly understood. Therefore, in this study we aimed to obtain further data on the localization of Cx26 at the subcellular level. Our TEM immunogold analyses were performed on rat heart ventricles and differentiated H9c2 cardiac cell sections as well as on differentiated H9c2 derived extracellular vesicles. The results confirmed the absence of Cx26 at intercalated discs and showed the presence of Cx26 at the level of different subcellular compartments. The peculiar localization at the level of extracellular vesicles suggested a specific role for cardiac Cx26 in inter-cellular communication in an independent gap junction manner.
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27
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Leroy K, Pieters A, Cooreman A, Van Campenhout R, Cogliati B, Vinken M. Connexin-Based Channel Activity Is Not Specifically Altered by Hepatocarcinogenic Chemicals. Int J Mol Sci 2021; 22:11724. [PMID: 34769157 PMCID: PMC8584159 DOI: 10.3390/ijms222111724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/24/2021] [Accepted: 10/27/2021] [Indexed: 12/21/2022] Open
Abstract
Connexin-based channels play key roles in cellular communication and can be affected by deleterious chemicals. In this study, the effects of various genotoxic carcinogenic compounds, non-genotoxic carcinogenic compounds and non-carcinogenic compounds on the expression and functionality of connexin-based channels, both gap junctions and connexin hemichannels, were investigated in human hepatoma HepaRG cell cultures. Expression of connexin26, connexin32, and connexin43 was evaluated by means of real-time reverse transcription quantitative polymerase chain reaction analysis, immunoblot analysis and in situ immunostaining. Gap junction functionality was assessed via a scrape loading/dye transfer assay. Opening of connexin hemichannels was monitored by measuring extracellular release of adenosine triphosphate. It was found that both genotoxic and non-genotoxic carcinogenic compounds negatively affect connexin32 expression. However, no specific effects related to chemical type were observed at gap junction or connexin hemichannel functionality level.
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Affiliation(s)
- Kaat Leroy
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (K.L.); (A.P.); (A.C.); (R.V.C.)
| | - Alanah Pieters
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (K.L.); (A.P.); (A.C.); (R.V.C.)
| | - Axelle Cooreman
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (K.L.); (A.P.); (A.C.); (R.V.C.)
| | - Raf Van Campenhout
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (K.L.); (A.P.); (A.C.); (R.V.C.)
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, Brazil;
| | - Mathieu Vinken
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (K.L.); (A.P.); (A.C.); (R.V.C.)
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28
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Kirichenko EY, Skatchkov SN, Ermakov AM. Structure and Functions of Gap Junctions and Their Constituent Connexins in the Mammalian CNS. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 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] [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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29
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Grodstein J, Levin M. Stability and robustness properties of bioelectric networks: A computational approach. BIOPHYSICS REVIEWS 2021; 2:031305. [PMID: 38505634 PMCID: PMC10903393 DOI: 10.1063/5.0062442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/07/2021] [Indexed: 03/21/2024]
Abstract
Morphogenesis during development and regeneration requires cells to communicate and cooperate toward the construction of complex anatomical structures. One important set of mechanisms for coordinating growth and form occurs via developmental bioelectricity-the dynamics of cellular networks driving changes of resting membrane potential which interface with transcriptional and biomechanical downstream cascades. While many molecular details have been elucidated about the instructive processes mediated by ion channel-dependent signaling outside of the nervous system, future advances in regenerative medicine and bioengineering require the understanding of tissue, organ, or whole body-level properties. A key aspect of bioelectric networks is their robustness, which can drive correct, invariant patterning cues despite changing cell number and anatomical configuration of the underlying tissue network. Here, we computationally analyze the minimal models of bioelectric networks and use the example of the regenerating planarian flatworm, to reveal important system-level aspects of bioelectrically derived patterns. These analyses promote an understanding of the robustness of circuits controlling regeneration and suggest design properties that can be exploited for synthetic bioengineering.
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Affiliation(s)
- Joel Grodstein
- Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155, USA
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30
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Defourny J, Audouard C, Davy A, Thiry M. Efnb2 haploinsufficiency induces early gap junction plaque disassembly and endocytosis in the cochlea. Brain Res Bull 2021; 174:153-160. [PMID: 34139316 DOI: 10.1016/j.brainresbull.2021.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/07/2021] [Accepted: 06/11/2021] [Indexed: 11/15/2022]
Abstract
Chromosome 13q deletions encompassing EFNB2, which encodes the transmembrane protein ephrin-B2, are likely to cause syndromic forms of sensorineural hearing loss of unclear origin. Thus, unravelling the pathogenic mechanisms could help to improve therapeutic strategies. In the cochlea, adjacent non-sensory epithelial cells are connected via gap junction channels, the activity of which is critical to maintain cochlear homeostasis. Here we show that ephrin-B2 promotes the assembly of connexin 30 (Cx30) gap junction plaques (GJPs) between adjacent non-sensory Deiters' cells. An in situ proximity ligation assay revealed that ephrin-B2 preferentially interacts with Cx30 in the periphery of the GJPs, i.e. where newly synthesized connexin hemichannels accrue to the GJP. Moreover, we observed that heterozygous mice encoding an Efnb2 null allele display excessive clathrin-mediated internalization of Cx30 GJPs in early postnatal stages. Finally, an in vitro organotypic assay revealed that ectopic activation of ephrin-B2 reverse signalling promotes the internalization of Cx30 GJPs. These data argue in favor of a cell-autonomous, Eph receptor-independent role of ephrin-B2 in the assembly of Cx30 GJPs. According to recent observations, early GJP degradation could certainly play a role in the pathogenic process leading to progressive sensorineural hearing loss due to Efnb2/EFNB2 haploinsufficiency.
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Affiliation(s)
- Jean Defourny
- GIGA-Neurosciences, Unit of Cell and Tissue Biology, University of Liège, CHU B36, 4000, Liège, Belgium.
| | - Christophe Audouard
- Center for Developmental Biology, Center for Integrative Biology, University of Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse, France
| | - Alice Davy
- Center for Developmental Biology, Center for Integrative Biology, University of Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse, France
| | - Marc Thiry
- GIGA-Neurosciences, Unit of Cell and Tissue Biology, University of Liège, CHU B36, 4000, Liège, Belgium
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Connexins in the Heart: Regulation, Function and Involvement in Cardiac Disease. Int J Mol Sci 2021; 22:ijms22094413. [PMID: 33922534 PMCID: PMC8122935 DOI: 10.3390/ijms22094413] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Gap junctional channels put into contact the cytoplasms of connected cardiomyocytes, allowing the existence of electrical coupling. However, in addition to this fundamental role, connexins are also involved in cardiomyocyte death and survival. Thus, chemical coupling through gap junctions plays a key role in the spreading of injury between connected cells. Moreover, in addition to their involvement in cell-to-cell communication, mounting evidence indicates that connexins have additional gap junction-independent functions. Opening of unopposed hemichannels, located at the lateral surface of cardiomyocytes, may compromise cell homeostasis and may be involved in ischemia/reperfusion injury. In addition, connexins located at non-canonical cell structures, including mitochondria and the nucleus, have been demonstrated to be involved in cardioprotection and in regulation of cell growth and differentiation. In this review, we will provide, first, an overview on connexin biology, including their synthesis and degradation, their regulation and their interactions. Then, we will conduct an in-depth examination of the role of connexins in cardiac pathophysiology, including new findings regarding their involvement in myocardial ischemia/reperfusion injury, cardiac fibrosis, gene transcription or signaling regulation.
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Richard C, Ruiz A, Cavagna S, Bigotte M, Vukusic S, Masaki K, Suenaga T, Kira JI, Giraudon P, Marignier R. Connexins in neuromyelitis optica: a link between astrocytopathy and demyelination. Brain 2021; 143:2721-2732. [PMID: 32889550 DOI: 10.1093/brain/awaa227] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 04/01/2020] [Accepted: 05/06/2020] [Indexed: 01/26/2023] Open
Abstract
Neuromyelitis optica, a rare neuroinflammatory demyelinating disease of the CNS, is characterized by the presence of specific pathogenic autoantibodies directed against the astrocytic water channel aquaporin 4 (AQP4) and is now considered as an astrocytopathy associated either with complement-dependent astrocyte death or with astrocyte dysfunction. However, the link between astrocyte dysfunction and demyelination remains unclear. We propose glial intercellular communication, supported by connexin hemichannels and gap junctions, to be involved in demyelination process in neuromyelitis optica. Using mature myelinated cultures, we demonstrate that a treatment of 1 h to 48 h with immunoglobulins purified from patients with neuromyelitis optica (NMO-IgG) is responsible for a complement independent demyelination, compared to healthy donors' immunoglobulins (P < 0.001). In parallel, patients' immunoglobulins induce an alteration of connexin expression characterized by a rapid loss of astrocytic connexins at the membrane followed by an increased size of gap junction plaques (+60%; P < 0.01). This was co-observed with connexin dysfunction with gap junction disruption (-57%; P < 0.001) and increased hemichannel opening (+17%; P < 0.001), associated with glutamate release. Blocking connexin 43 hemichannels with a specific peptide was able to prevent demyelination in co-treatment with patients compared to healthy donors' immunoglobulins. By contrast, the blockade of connexin 43 gap junctions with another peptide was detrimental for myelin (myelin density -48%; P < 0.001). Overall, our results suggest that dysregulation of connexins would play a pathogenetic role in neuromyelitis optica. The further identification of mechanisms leading to connexin dysfunction and soluble factors implicated, would provide interesting therapeutic strategies for demyelinating disorders.
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Affiliation(s)
- Chloé Richard
- INSERM U1028, CNRS UMR 5292, Lyon1 University, Center for Research in Neuroscience of Lyon, Lyon, France
| | - Anne Ruiz
- INSERM U1028, CNRS UMR 5292, Lyon1 University, Center for Research in Neuroscience of Lyon, Lyon, France
| | - Sylvie Cavagna
- INSERM U1028, CNRS UMR 5292, Lyon1 University, Center for Research in Neuroscience of Lyon, Lyon, France
| | - Maxime Bigotte
- INSERM U1028, CNRS UMR 5292, Lyon1 University, Center for Research in Neuroscience of Lyon, Lyon, France
| | - Sandra Vukusic
- Service de neurologie, sclérose en plaques, pathologies de la myéline et neuro-inflammation, Hôpital Neurologique Pierre Wertheimer Hospices Civils de Lyon, Lyon, France.,Centre de référence des maladies inflammatoires rares du cerveau et de la moelle, Lyon, France
| | - Katsuhisa Masaki
- Department of Neurology, Neurological institute, Graduate School of Medical Sciences, Kyushu University
| | | | - Jun-Ichi Kira
- Department of Neurology, Neurological institute, Graduate School of Medical Sciences, Kyushu University
| | - Pascale Giraudon
- INSERM U1028, CNRS UMR 5292, Lyon1 University, Center for Research in Neuroscience of Lyon, Lyon, France
| | - Romain Marignier
- INSERM U1028, CNRS UMR 5292, Lyon1 University, Center for Research in Neuroscience of Lyon, Lyon, France.,Service de neurologie, sclérose en plaques, pathologies de la myéline et neuro-inflammation, Hôpital Neurologique Pierre Wertheimer Hospices Civils de Lyon, Lyon, France.,Centre de référence des maladies inflammatoires rares du cerveau et de la moelle, Lyon, France
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Norris RP, Terasaki M. Gap junction internalization and processing in vivo: a 3D immuno-electron microscopy study. J Cell Sci 2021; 134:jcs252726. [PMID: 33277382 DOI: 10.1242/jcs.252726] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/26/2020] [Indexed: 12/15/2022] Open
Abstract
Gap junctions have well-established roles in cell-cell communication by way of forming permeable intercellular channels. Less is understood about their internalization, which forms double membrane vesicles containing cytosol and membranes from another cell called connexosomes or annular gap junctions. Here, we systematically investigated the fate of connexosomes in intact ovarian follicles. High-pressure frozen, serial-sectioned tissue was immunogold labeled for connexin 43 (Cx43, also known as GJA1). Within a volume corresponding to ∼35 cells, every labeled structure was categorized and had its surface area measured. Measurements support the concept that multiple connexosomes form from larger invaginated gap junctions. Subsequently, the inner and outer membranes separate, Cx43 immunogenicity is lost from the outer membrane, and the inner membrane appears to undergo fission. One pathway for processing involves lysosomes, based on localization of cathepsin B to some processed connexosomes. In summary, this study demonstrates new technology for high-resolution analyses of gap junction processing.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Rachael P Norris
- Department of Cell Biology, UConn Health, 263 Farmington Ave, Farmington, CT 06030, USA
| | - Mark Terasaki
- Department of Cell Biology, UConn Health, 263 Farmington Ave, Farmington, CT 06030, USA
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Hong J, Won M, Ro H. The Molecular and Pathophysiological Functions of Members of the LNX/PDZRN E3 Ubiquitin Ligase Family. Molecules 2020; 25:E5938. [PMID: 33333989 PMCID: PMC7765395 DOI: 10.3390/molecules25245938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 12/27/2022] Open
Abstract
The ligand of Numb protein-X (LNX) family, also known as the PDZRN family, is composed of four discrete RING-type E3 ubiquitin ligases (LNX1, LNX2, LNX3, and LNX4), and LNX5 which may not act as an E3 ubiquitin ligase owing to the lack of the RING domain. As the name implies, LNX1 and LNX2 were initially studied for exerting E3 ubiquitin ligase activity on their substrate Numb protein, whose stability was negatively regulated by LNX1 and LNX2 via the ubiquitin-proteasome pathway. LNX proteins may have versatile molecular, cellular, and developmental functions, considering the fact that besides these proteins, none of the E3 ubiquitin ligases have multiple PDZ (PSD95, DLGA, ZO-1) domains, which are regarded as important protein-interacting modules. Thus far, various proteins have been isolated as LNX-interacting proteins. Evidence from studies performed over the last two decades have suggested that members of the LNX family play various pathophysiological roles primarily by modulating the function of substrate proteins involved in several different intracellular or intercellular signaling cascades. As the binding partners of RING-type E3s, a large number of substrates of LNX proteins undergo degradation through ubiquitin-proteasome system (UPS) dependent or lysosomal pathways, potentially altering key signaling pathways. In this review, we highlight recent and relevant findings on the molecular and cellular functions of the members of the LNX family and discuss the role of the erroneous regulation of these proteins in disease progression.
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Affiliation(s)
- Jeongkwan Hong
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 305-764, Korea;
| | - Minho Won
- Biotechnology Process Engineering Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), 30 Yeongudanji-ro, Cheongwon-gu, Cheongju 28116, Korea
| | - Hyunju Ro
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 305-764, Korea;
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Meng L, Yan D. NLR-1/CASPR Anchors F-Actin to Promote Gap Junction Formation. Dev Cell 2020; 55:574-587.e3. [PMID: 33238150 DOI: 10.1016/j.devcel.2020.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 08/05/2020] [Accepted: 10/28/2020] [Indexed: 12/31/2022]
Abstract
Gap junctions are present in most tissues and play essential roles in various biological processes. However, we know surprisingly little about the molecular mechanisms underlying gap junction formation. Here, we uncover the essential role of a conserved EGF- and laminin-G-domain-containing protein nlr-1/CASPR in the regulation of gap junction formation in multiple tissues across different developmental stages in C. elegans. NLR-1 is located in the gap junction perinexus, a region adjacent to but not overlapping with gap junctions, and forms puncta before the clusters of gap junction channels appear on the membrane. We show that NLR-1 can directly bind to actin to recruit F-actin networks at the gap junction formation plaque, and the formation of F-actin patches plays a critical role in the assembly of gap junction channels. Our findings demonstrate that nlr-1/CASPR acts as an early stage signal for gap junction formation through anchoring of F-actin networks.
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Affiliation(s)
- Lingfeng Meng
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Dong Yan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Regeneration Next, and Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27710, USA.
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36
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Solan JL, Lampe PD. Src Regulation of Cx43 Phosphorylation and Gap Junction Turnover. Biomolecules 2020; 10:biom10121596. [PMID: 33255329 PMCID: PMC7759836 DOI: 10.3390/biom10121596] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/19/2020] [Accepted: 11/22/2020] [Indexed: 12/18/2022] Open
Abstract
The gap junction protein Connexin43 (Cx43) is highly regulated by phosphorylation at over a dozen sites by probably at least as many kinases. This Cx43 “kinome” plays an important role in gap junction assembly and turnover. We sought to gain a better understanding of the interrelationship of these phosphorylation events particularly related to src activation and Cx43 turnover. Using state-of-the-art live imaging methods, specific inhibitors and many phosphorylation-status specific antibodies, we found phospho-specific domains in gap junction plaques and show evidence that multiple pathways of disassembly exist and can be regulated at the cellular and subcellular level. We found Src activation promotes formation of connexisomes (internalized gap junctions) in a process involving ERK-mediated phosphorylation of S279/282. Proteasome inhibition dramatically and rapidly restored gap junctions in the presence of Src and led to dramatic changes in the Cx43 phospho-profile including to increased Y247, Y265, S279/282, S365, and S373 phosphorylation. Lysosomal inhibition, on the other hand, nearly eliminated phosphorylation on Y247 and Y265 and reduced S368 and S373 while increasing S279/282 phosphorylation levels. We present a model of gap junction disassembly where multiple modes of disassembly are regulated by phosphorylation and can have differential effects on cellular signaling.
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Affiliation(s)
- Joell L. Solan
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA;
| | - Paul D. Lampe
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA;
- Department of Global Health, Pathobiology Program, University of Washington, Seattle, WA 98109, USA
- Correspondence:
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Zheng L, Chenavas S, Kieken F, Trease A, Brownell S, Anbanandam A, Sorgen PL, Spagnol G. Calmodulin Directly Interacts with the Cx43 Carboxyl-Terminus and Cytoplasmic Loop Containing Three ODDD-Linked Mutants (M147T, R148Q, and T154A) that Retain α-Helical Structure, but Exhibit Loss-of-Function and Cellular Trafficking Defects. Biomolecules 2020; 10:biom10101452. [PMID: 33080786 PMCID: PMC7602980 DOI: 10.3390/biom10101452] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/14/2022] Open
Abstract
The autosomal-dominant pleiotropic disorder called oculodentodigital dysplasia (ODDD) is caused by mutations in the gap junction protein Cx43. Of the 73 mutations identified to date, over one-third are localized in the cytoplasmic loop (Cx43CL) domain. Here, we determined the mechanism by which three ODDD mutations (M147T, R148Q, and T154A), all of which localize within the predicted 1-5-10 calmodulin-binding motif of the Cx43CL, manifest the disease. Nuclear magnetic resonance (NMR) and circular dichroism revealed that the three ODDD mutations had little-to-no effect on the ability of the Cx43CL to form α-helical structure as well as bind calmodulin. Combination of microscopy and a dye-transfer assay uncovered these mutations increased the intracellular level of Cx43 and those that trafficked to the plasma membrane did not form functional channels. NMR also identify that CaM can directly interact with the Cx43CT domain. The Cx43CT residues involved in the CaM interaction overlap with tyrosines phosphorylated by Pyk2 and Src. In vitro and in cyto data provide evidence that the importance of the CaM interaction with the Cx43CT may lie in restricting Pyk2 and Src phosphorylation, and their subsequent downstream effects.
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Affiliation(s)
- Li Zheng
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
| | - Sylvie Chenavas
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
| | - Fabien Kieken
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
| | - Andrew Trease
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
| | - Sarah Brownell
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
| | - Asokan Anbanandam
- Biomolecular NMR Core Facility, University of Kansas, Lawrence, KS 66045, USA;
| | - Paul L. Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
- Correspondence: (P.L.S.); (G.S.)
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (L.Z.); (S.C.); (F.K.); (A.T.); (S.B.)
- Correspondence: (P.L.S.); (G.S.)
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Park S, Shi Y, Kim BC, Jo MH, Cruz LO, Gou Z, Ha T, Lu LF, Reich DH, Chen Y. Force-dependent trans-endocytosis by breast cancer cells depletes costimulatory receptor CD80 and attenuates T cell activation. Biosens Bioelectron 2020; 165:112389. [PMID: 32729511 DOI: 10.1016/j.bios.2020.112389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022]
Abstract
In this study, we investigated the biophysical interaction between cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and CD80. CTLA-4 is a key molecule in immunosuppression, and CD80 is a costimulatory receptor promoting T cell activation. We observed that after cell-cell contact was established between breast cancer cells and antigen presenting cells (APCs), CTLA-4 expressed on the breast cancer cells bind to CD80 expressed on the APCs, and underwent trans-endocytosis to deplete CD80. Force measurement and live cell imaging revealed that upon binding to CD80, forces generated by breast cancer cells and transmitted via CTLA-4 were sufficiently strong to displace CD80 from the surface of APCs to be internalized by breast cancer cells. We further demonstrated that because of the force-dependent trans-endocytosis of CD80, the capacity of APCs to activate T cells was significantly attenuated. Furthermore, inhibiting force generation in cancer cells would increase the T cell activating capacity of APCs. Our results provide a possible mechanism behind the immunosuppression commonly seen in breast cancer patients, and may lead to a new strategy to restore anti-tumor immunity by inhibiting pathways of force-generation.
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Affiliation(s)
- Seungman Park
- Department of Mechanical Engineering, Johns Hopkins University, MD, 21218, USA; Center for Cell Dynamics, Johns Hopkins University, MD, 21218, USA; Institute for NanoBioTechnology, Johns Hopkins University, MD, 21218, USA
| | - Yu Shi
- Department of Physics & Astronomy, Johns Hopkins University, MD, 21218, USA
| | - Byoung Choul Kim
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA; Howard Hughes Medical Institute, Baltimore, MD, 21205, USA; Division of Nano-Bioengineering, Incheon National University, Incheon, 22012, South Korea
| | - Myung Hyun Jo
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Leilani O Cruz
- Division of Biological Science, University of California, San Diego, CA, 92093, USA
| | - Zheming Gou
- Department of Mechanical Engineering, Johns Hopkins University, MD, 21218, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA; Howard Hughes Medical Institute, Baltimore, MD, 21205, USA
| | - Li-Fan Lu
- Division of Biological Science, University of California, San Diego, CA, 92093, USA
| | - Daniel H Reich
- Department of Physics & Astronomy, Johns Hopkins University, MD, 21218, USA
| | - Yun Chen
- Department of Mechanical Engineering, Johns Hopkins University, MD, 21218, USA; Center for Cell Dynamics, Johns Hopkins University, MD, 21218, USA; Institute for NanoBioTechnology, Johns Hopkins University, MD, 21218, USA.
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Pelletier RM, Layeghkhavidaki H, Kumar NM, Vitale ML. Cx30.2 deletion causes imbalances in testicular Cx43, Cx46, and Cx50 and insulin receptors. Reciprocally, diabetes/obesity alters Cx30.2 in mouse testis. Am J Physiol Regul Integr Comp Physiol 2020; 318:R1078-R1090. [PMID: 32348681 PMCID: PMC7311678 DOI: 10.1152/ajpregu.00044.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/28/2020] [Accepted: 04/28/2020] [Indexed: 11/22/2022]
Abstract
Cx30.2 protein content and localization were assessed during development. An account of Cx30.2, Cx43, Cx46, and Cx50, and insulin receptor (IR) responses to Cx30.2, Cx46, or Cx50 deficiency in mouse interstitial tissue (ITf)- and seminiferous tubule-enriched fractions (STf) is given. The impact of high glucose/insulin on Cx30.2 was investigated in spontaneously diabetic and obese db/db and ob/ob mouse testis and anterior pituitary (AP). Cx30.2 labeled contacts in vascular endothelial and Leydig cells and Sertoli cell junctions in stage V-VII. Cx30.2 expression is regulated differently in the interstitium and tubules. Cx30.2 at 30-kDa levels peaked by 28 days in ITf and by 14 days in STf. In STf, deleting Cx30.2 decreased Cx43 and Cx50, whereas deleting Cx50 downregulated Cx30.2. The opposite occurred in ITf. In STf, deleting Cx30.2 upregulated Cx46 except the full-length reciprocally, deleting Cx46 upregulated Cx30.2. In ITf, Cx30.2 deficiency upregulated full-length and phosphorylated Cx46, whereas deleting Cx46 downregulated 48- to 50-kDa Cx30.2. The db/db and ob/ob mouse ITf, STf, and AP showed imbalanced Cx30.2 levels. IRα levels at 135 kDa declined in Cx30.2-/- and Cx50-/- mouse ITf and Cx46-/- and Cx50-/- STf. IRβ at 98 to 110 kDa dropped in Cx30.2-/- and Cx46-/- mice STf suggesting that Cx30.2 deficiency decreases active IR sites. The results show the connexins interdependence and interaction and that altering a single connexin changes the remaining connexins expression, which can modify gap junction-mediated glucose exchanges in contacting cells. Data suggest that glucose/insulin influences Cx30.2 turnover in testis and AP and, reciprocally, that connexins modulate testis glucose uptake and response to insulin.
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Affiliation(s)
- R-Marc Pelletier
- Department of Pathology and Cell Biology, Université de Montréal, Québec, Canada
| | | | - Nalin M Kumar
- Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago, Illinois
| | - María Leiza Vitale
- Department of Pathology and Cell Biology, Université de Montréal, Québec, Canada
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Ghézali G, Vasile F, Curry N, Fantham M, Cheung G, Ezan P, Cohen-Salmon M, Kaminski C, Rouach N. Neuronal Activity Drives Astroglial Connexin 30 in Perisynaptic Processes and Shapes Its Functions. Cereb Cortex 2020; 30:753-766. [PMID: 31271200 PMCID: PMC7086174 DOI: 10.1093/cercor/bhz123] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 04/22/2019] [Accepted: 05/17/2019] [Indexed: 12/17/2022] Open
Abstract
Astrocytes play key roles in brain functions through dynamic interactions with neurons. One of their typical features is to express high levels of connexins (Cxs), Cx43 and Cx30, the gap junction (GJ)-forming proteins. Cx30 is involved in basic cognitive processes and shapes synaptic and network activities, as shown by recent studies in transgenic animals. Yet it remains unknown whether astroglial Cx30 expression, localization, and functions are endogenously and dynamically regulated by neuronal activity and could therefore play physiological roles in neurotransmission. We here show that neuronal activity increased hippocampal Cx30 protein levels via a posttranslational mechanism regulating lysosomal degradation. Neuronal activity also increased Cx30 protein levels at membranes and perisynaptic processes, as revealed by superresolution imaging. This translated at the functional level in the activation of Cx30 hemichannels and in Cx30-mediated remodeling of astrocyte morphology independently of GJ biochemical coupling. Altogether, these data show activity-dependent dynamics of Cx30 expression, perisynaptic localization, and functions.
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Affiliation(s)
- Grégory Ghézali
- Neuroglial Interactions in Cerebral Physiology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
- Doctoral School N° 158, Pierre and Marie Curie University, 75006 Paris, France
| | - Flora Vasile
- Neuroglial Interactions in Cerebral Physiology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
- Doctoral School N°474, Rene Descartes University, 75006 Paris, France
| | - Nathan Curry
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Marcus Fantham
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Giselle Cheung
- Neuroglial Interactions in Cerebral Physiology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Pascal Ezan
- Neuroglial Interactions in Cerebral Physiology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Martine Cohen-Salmon
- Neuroglial Interactions in Cerebral Physiology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Clemens Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, 75005 Paris, France
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Totland MZ, Rasmussen NL, Knudsen LM, Leithe E. Regulation of gap junction intercellular communication by connexin ubiquitination: physiological and pathophysiological implications. Cell Mol Life Sci 2020; 77:573-591. [PMID: 31501970 PMCID: PMC7040059 DOI: 10.1007/s00018-019-03285-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 08/10/2019] [Accepted: 08/16/2019] [Indexed: 12/15/2022]
Abstract
Gap junctions consist of arrays of intercellular channels that enable adjacent cells to communicate both electrically and metabolically. Gap junctions have a wide diversity of physiological functions, playing critical roles in both excitable and non-excitable tissues. Gap junction channels are formed by integral membrane proteins called connexins. Inherited or acquired alterations in connexins are associated with numerous diseases, including heart failure, neuropathologies, deafness, skin disorders, cataracts and cancer. Gap junctions are highly dynamic structures and by modulating the turnover rate of connexins, cells can rapidly alter the number of gap junction channels at the plasma membrane in response to extracellular or intracellular cues. Increasing evidence suggests that ubiquitination has important roles in the regulation of endoplasmic reticulum-associated degradation of connexins as well as in the modulation of gap junction endocytosis and post-endocytic sorting of connexins to lysosomes. In recent years, researchers have also started to provide insights into the physiological roles of connexin ubiquitination in specific tissue types. This review provides an overview of the advances made in understanding the roles of connexin ubiquitination in the regulation of gap junction intercellular communication and discusses the emerging physiological and pathophysiological implications of these processes.
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Affiliation(s)
- Max Zachrisson Totland
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Nikoline Lander Rasmussen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
- Department of Medical Biology, University of Tromsø, Tromsø, Norway
| | - Lars Mørland Knudsen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, 0424, Oslo, Norway.
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway.
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42
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Zhang Q, Tsuji-Hosokawa A, Willson C, Watanabe M, Si R, Lai N, Wang Z, Yuan JXJ, Wang J, Makino A. Chloroquine differentially modulates coronary vasodilation in control and diabetic mice. Br J Pharmacol 2020; 177:314-327. [PMID: 31503328 DOI: 10.1111/bph.14864] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND AND PURPOSE Chloroquine is a traditional medicine to treat malaria. There is increasing evidence that chloroquine not only induces phagocytosis but regulates vascular tone. Few reports investigating the effect of chloroquine on vascular responsiveness of coronary arteries have been made. In this study, we examined how chloroquine affected endothelium-dependent relaxation in coronary arteries under normal and diabetic conditions. EXPERIMENTAL APPROACH We isolated coronary arteries from mice and examined endothelium-dependent relaxation (EDR). Human coronary endothelial cells and mouse coronary endothelial cells isolated from control and diabetic mouse (TALLYHO/Jng [TH] mice, a spontaneous type 2 diabetic mouse model) were used for the molecular biological or cytosolic NO and Ca2+ measurements. KEY RESULTS Chloroquine inhibited endothelium-derived NO-dependent relaxation but had negligible effect on endothelium-derived hyperpolarization (EDH)-dependent relaxation in coronary arteries of control mice. Chloroquine significantly decreased NO production in control human coronary endothelial cells partly by phosphorylating eNOSThr495 (an inhibitory phosphorylation site of eNOS) and attenuating the rise of cytosolic Ca2+ concentration after stimulation. EDR was significantly inhibited in diabetic mice in comparison to control mice. Interestingly, chloroquine enhanced EDR in diabetic coronary arteries by, specifically, increasing EDH-dependent relaxation due partly to its augmenting effect on gap junction activity in diabetic mouse coronary endothelial cells. CONCLUSIONS AND IMPLICATIONS These data indicate that chloroquine affects vascular relaxation differently under normal and diabetic conditions. Therefore, the patients' health condition such as coronary macrovascular or microvascular disease, with or without diabetes, must be taken account into the consideration when selecting chloroquine for the treatment of malaria.
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Affiliation(s)
- Qian Zhang
- Department of Medicine, University of California, San Diego, La Jolla, California.,Department of Physiology, The University of Arizona, Tucson, Arizona.,State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | | | - Conor Willson
- Department of Physiology, The University of Arizona, Tucson, Arizona
| | - Makiko Watanabe
- Department of Physiology, The University of Arizona, Tucson, Arizona
| | - Rui Si
- Department of Physiology, The University of Arizona, Tucson, Arizona
| | - Ning Lai
- Department of Medicine, University of California, San Diego, La Jolla, California.,State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Ziyi Wang
- Department of Medicine, University of California, San Diego, La Jolla, California.,Department of Medicine, The University of Arizona, Tucson, Arizona.,State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jason X-J Yuan
- Department of Medicine, University of California, San Diego, La Jolla, California.,Department of Medicine, The University of Arizona, Tucson, Arizona
| | - Jian Wang
- Department of Medicine, The University of Arizona, Tucson, Arizona.,State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Ayako Makino
- Department of Medicine, University of California, San Diego, La Jolla, California.,Department of Physiology, The University of Arizona, Tucson, Arizona.,Department of Medicine, The University of Arizona, Tucson, Arizona
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43
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Zeng SG, Lin X, Liu JC, Zhou J. Hypoxia‑induced internalization of connexin 26 and connexin 43 in pulmonary epithelial cells is involved in the occurrence of non‑small cell lung cancer via the P53/MDM2 signaling pathway. Int J Oncol 2019; 55:845-859. [PMID: 31485592 PMCID: PMC6741836 DOI: 10.3892/ijo.2019.4867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 04/16/2019] [Indexed: 12/18/2022] Open
Abstract
Reports have highlighted an association between connexins (CXs) or gap junction proteins and non-small cell lung cancer (NSCLC). In the present study, it was aimed to elucidate the regulatory mechanism of CX26 and CX43 under hypoxic conditions in NSCLC. Clinical samples were collected for analysis of CX26 and CX43 expression and clinical cancerization followed by quantification of CX26 and CX43 expression. Following the establishment of an in vitro hypoxia model, P53/murine double minute-2 (MDM2) signaling pathway-, proliferation- and epithelial-mesenchymal transition (EMT)-related genes were quantified to evaluate the influence of CX26 and CX43 on the biological functions of pulmonary epithelial cells in NSCLC. In addition, the proliferation and tumorigenicity of cancer cells were assessed by EdU staining and xenograft tumors, respectively. Decreased expression of CX26 and CX43 was found in cancer tissues compared with surrounding normal tissue. Hypoxia was shown to activate the P53/MDM2 axis and stimulate the downregulation, ubiquitination and degradation of CX26 and CX43, which were translocated from the membrane to the cytoplasm. Low levels of CX26 and CX43 were demonstrated to further promote EMT and the induction of the proliferation and tumorigenicity of cancer cells. These results were reflected by decreased E-cadherin expression and increased N-cadherin expression, along with increased cell migration, promoted cell proliferation ability and elevated relative protein expression of Oct4 and Nanog, and accelerated tumor growth, accompanied by a higher number of metastatic nodes. Taken together, the key observations of the present study demonstrate that the internalization of CX26 and CX43 promoted proliferation, EMT and migration and thus induced NSCLC via aberrant activation of the P53/MDM2 signaling pathway under hypoxic conditions.
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Affiliation(s)
- Shang-Gan Zeng
- Department of Thoracic Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Xiang Lin
- Department of Thoracic Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Ji-Chun Liu
- Departments of Cardio‑Thoracic Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Jin Zhou
- Department of Respiratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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44
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Pogoda K, Kameritsch P, Mannell H, Pohl U. Connexins in the control of vasomotor function. Acta Physiol (Oxf) 2019; 225:e13108. [PMID: 29858558 DOI: 10.1111/apha.13108] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 12/13/2022]
Abstract
Vascular endothelial cells, as well as smooth muscle cells, show heterogeneity with regard to their receptor expression and reactivity. For the vascular wall to act as a functional unit, the various cells' responses require integration. Such an integration is not only required for a homogeneous response of the vascular wall, but also for the vasomotor behaviour of consecutive segments of the microvascular arteriolar tree. As flow resistances of individual sections are connected in series, sections require synchronization and coordination to allow effective changes of conductivity and blood flow. A prerequisite for the local coordination of individual vascular cells and different sections of an arteriolar tree is intercellular communication. Connexins are involved in a dual manner in this coordination. (i) By forming gap junctions between cells, they allow an intercellular exchange of signalling molecules and electrical currents. In particular, the spread of electrical currents allows for coordination of cell responses over longer distances. (ii) Connexins are able to interact with other proteins to form signalling complexes. In this way, they can modulate and integrate individual cells' responses also in a channel-independent manner. This review outlines mechanisms allowing the vascular connexins to exert their coordinating function and to regulate the vasomotor reactions of blood vessels both locally, and in vascular networks. Wherever possible, we focus on the vasomotor behaviour of small vessels and arterioles which are the main vessels determining vascular resistance, blood pressure and local blood flow.
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Affiliation(s)
- K. Pogoda
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
| | - P. Kameritsch
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
| | - H. Mannell
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
| | - U. Pohl
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich Germany
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45
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Araldi RP, Sant’Ana TA, Módolo DG, de Melo TC, Spadacci-Morena DD, de Cassia Stocco R, Cerutti JM, de Souza EB. The human papillomavirus (HPV)-related cancer biology: An overview. Biomed Pharmacother 2018; 106:1537-1556. [DOI: 10.1016/j.biopha.2018.06.149] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/24/2018] [Accepted: 06/27/2018] [Indexed: 02/07/2023] Open
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46
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Hughes JW, Ustione A, Lavagnino Z, Piston DW. Regulation of islet glucagon secretion: Beyond calcium. Diabetes Obes Metab 2018; 20 Suppl 2:127-136. [PMID: 30230183 PMCID: PMC6148361 DOI: 10.1111/dom.13381] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 05/03/2018] [Accepted: 05/23/2018] [Indexed: 12/19/2022]
Abstract
The islet of Langerhans plays a key role in glucose homeostasis through regulated secretion of the hormones insulin and glucagon. Islet research has focused on the insulin-secreting β-cells, even though aberrant glucagon secretion from α-cells also contributes to the aetiology of diabetes. Despite its importance, the mechanisms controlling glucagon secretion remain controversial. Proper α-cell function requires the islet milieu, where β- and δ-cells drive and constrain α-cell dynamics. The response of glucagon to glucose is similar between isolated islets and that measured in vivo, so it appears that the glucose dependence requires only islet-intrinsic factors and not input from blood flow or the nervous system. Elevated intracellular free Ca2+ is needed for α-cell exocytosis, but interpreting Ca2+ data is tricky since it is heterogeneous among α-cells at all physiological glucose levels. Total Ca2+ activity in α-cells increases slightly with glucose, so Ca2+ may serve a permissive, rather than regulatory, role in glucagon secretion. On the other hand, cAMP is a more promising candidate for controlling glucagon secretion and is itself driven by paracrine signalling from β- and δ-cells. Another pathway, juxtacrine signalling through the α-cell EphA receptors, stimulated by β-cell ephrin ligands, leads to a tonic inhibition of glucagon secretion. We discuss potential combinations of Ca2+ , cAMP, paracrine and juxtacrine factors in the regulation of glucagon secretion, focusing on recent data in the literature that might unify the field towards a quantitative understanding of α-cell function.
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Affiliation(s)
- Jing W. Hughes
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Alessandro Ustione
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Zeno Lavagnino
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - David W. Piston
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
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47
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Cyr DG, Dufresne J, Gregory M. Cellular junctions in the epididymis, a critical parameter for understanding male reproductive toxicology. Reprod Toxicol 2018; 81:207-219. [PMID: 30130578 DOI: 10.1016/j.reprotox.2018.08.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/14/2018] [Accepted: 08/16/2018] [Indexed: 12/28/2022]
Abstract
Epididymal sperm maturation is a critical aspect of male reproduction in which sperm acquire motility and the ability to fertilize an ovum. Sperm maturation is dependent on the creation of a specific environment that changes along the epididymis and which enables the maturation process. The blood-epididymis barrier creates a unique luminal micro-environment, different from blood, by limiting paracellular transport and forcing receptor-mediated transport of macromolecules across the epididymal epithelium. Direct cellular communication between cells allows coordinated function of the epithelium. A limited number of studies have directly examined the effects of toxicants on junctional proteins and barrier function in the epididymis. Effects on the integrity of the blood-epididymis barrier have resulted in decreased fertility and, in some cases, the development of sperm granulomas. Studies have shown that in addition to tight junctions, proteins implicated in the maintenance of adherens junctions and gap junctions alter epididymal functions. This review will provide an overview of the types and roles of cellular junctions in the epididymis, and how these are targeted by different toxicants.
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Affiliation(s)
- Daniel G Cyr
- Laboratory for Reproductive Toxicology, INRS-Institut Armand-Frappier, Université du Québec, 531 boul. des Prairies, Laval, Québec, H7V 1B7, Canada.
| | - Julie Dufresne
- Laboratory for Reproductive Toxicology, INRS-Institut Armand-Frappier, Université du Québec, 531 boul. des Prairies, Laval, Québec, H7V 1B7, Canada
| | - Mary Gregory
- Laboratory for Reproductive Toxicology, INRS-Institut Armand-Frappier, Université du Québec, 531 boul. des Prairies, Laval, Québec, H7V 1B7, Canada
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48
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Kells-Andrews RM, Margraf RA, Fisher CG, Falk MM. Connexin-43 K63-polyubiquitylation on lysines 264 and 303 regulates gap junction internalization. J Cell Sci 2018; 131:jcs.204321. [PMID: 30054380 DOI: 10.1242/jcs.204321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 06/22/2018] [Indexed: 12/20/2022] Open
Abstract
Gap junctions (GJs) assembled from connexin (Cx) proteins allow direct cell-cell communication. While phosphorylation is known to regulate multiple GJ functions, much less is known about the role of ubiquitin in these processes. Using ubiquitylation-type-specific antibodies and Cx43 lysine-to-arginine mutants we show that ∼8% of a GJ, localized in central plaque domains, is K63-polyubiquitylated on K264 and K303. Levels and localization of ubiquitylation correlated well with: (1) the short turnover rate of Cxs and GJs; (2) removal of older channels from the plaque center; and (3) the fact that not all Cxs in an internalizing GJ channel need to be ubiquitylated. Connexins mutated at these two sites assembled significantly larger GJs, exhibited much longer protein half-lives and were internalization impaired. Interestingly, these ubiquitin-deficient Cx43 mutants accumulated as hyper-phosphorylated polypeptides in the plasma membrane, suggesting that K63-polyubiquitylation is triggered by phosphorylation. Phospho-specific anti-Cx43 antibodies revealed that upregulated phosphorylation affected serines 368, 279/282 and 255, which are well-known regulatory PKC and MAPK sites. Together, these novel findings suggest that the internalizing portion of channels in a GJ is K63-polyubiquitylated, ubiquitylation is critical for GJ internalization and that phosphorylation induces Cx K63-polyubiquitylation.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Rachael M Kells-Andrews
- Department of Biological Sciences, Lehigh University, 111 Research Drive, Iacocca Hall, Bethlehem, PA 18015, USA
| | - Rachel A Margraf
- Department of Biological Sciences, Lehigh University, 111 Research Drive, Iacocca Hall, Bethlehem, PA 18015, USA
| | - Charles G Fisher
- Department of Biological Sciences, Lehigh University, 111 Research Drive, Iacocca Hall, Bethlehem, PA 18015, USA
| | - Matthias M Falk
- Department of Biological Sciences, Lehigh University, 111 Research Drive, Iacocca Hall, Bethlehem, PA 18015, USA
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49
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Sun J, Hu Q, Peng H, Peng C, Zhou L, Lu J, Huang C. The ubiquitin-specific protease USP8 deubiquitinates and stabilizes Cx43. J Biol Chem 2018; 293:8275-8284. [PMID: 29626091 DOI: 10.1074/jbc.ra117.001315] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 03/26/2018] [Indexed: 11/06/2022] Open
Abstract
Connexin-43 (Cx43, also known as GJA1) is the most ubiquitously expressed connexin isoform in mammalian tissues. It forms intercellular gap junction (GJ) channels, enabling adjacent cells to communicate both electrically and metabolically. Cx43 is a short-lived protein which can be quickly degraded by the ubiquitin-dependent proteasomal, endolysosomal, and autophagosomal pathways. Here, we report that the ubiquitin-specific peptidase 8 (USP8) interacts with and deubiquitinates Cx43. USP8 reduces both multiple monoubiquitination and polyubiquitination of Cx43 to prevent autophagy-mediated degradation. Consistently, knockdown of USP8 results in decreased Cx43 protein levels in cultured cells and suppresses intercellular communication, revealed by the dye transfer assay. In human breast cancer specimens, the expression levels of USP8 and Cx43 proteins are positively correlated. Taken together, these results identified USP8 as a crucial and bona fide deubiquitinating enzyme involved in autophagy-mediated degradation of Cx43.
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Affiliation(s)
- Jian Sun
- Department of Breast Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025
| | - Qianwen Hu
- Shanghai Institute of Immunology & Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hong Peng
- Shanghai Institute of Immunology & Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Cheng Peng
- Shanghai Institute of Immunology & Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Liheng Zhou
- Department of Breast Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025
| | - Jinsong Lu
- Department of Breast Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025.
| | - Chuanxin Huang
- Shanghai Institute of Immunology & Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
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50
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Corticosterone impairs gap junctions in the prefrontal cortical and hippocampal astrocytes via different mechanisms. Neuropharmacology 2018; 131:20-30. [DOI: 10.1016/j.neuropharm.2017.12.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 11/28/2017] [Accepted: 12/03/2017] [Indexed: 01/20/2023]
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