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Buckley C, Lee MD, Zhang X, Wilson C, McCarron JG. Signalling switches maintain intercellular communication in the vascular endothelium. Br J Pharmacol 2024; 181:2810-2832. [PMID: 38651236 DOI: 10.1111/bph.16366] [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: 11/23/2023] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND AND PURPOSE The single layer of cells lining all blood vessels, the endothelium, is a sophisticated signal co-ordination centre that controls a wide range of vascular functions including the regulation of blood pressure and blood flow. To co-ordinate activities, communication among cells is required for tissue level responses to emerge. While a significant form of communication occurs by the propagation of signals between cells, the mechanism of propagation in the intact endothelium is unresolved. EXPERIMENTAL APPROACH Precision signal generation and targeted cellular manipulation was used in conjunction with high spatiotemporal mesoscale Ca2+ imaging in the endothelium of intact blood vessels. KEY RESULTS Multiple mechanisms maintain communication so that Ca2+ wave propagation occurs irrespective of the status of connectivity among cells. Between adjoining cells, regenerative IP3-induced IP3 production transmits Ca2+ signals and explains the propagated vasodilation that underlies the increased blood flow accompanying tissue activity. The inositide is itself sufficient to evoke regenerative phospholipase C-dependent Ca2+ waves across coupled cells. None of gap junctions, Ca2+ diffusion or the release of extracellular messengers is required to support this type of intercellular Ca2+ signalling. In contrast, when discontinuities exist between cells, ATP released as a diffusible extracellular messenger transmits Ca2+ signals across the discontinuity and drives propagated vasodilation. CONCLUSION AND IMPLICATIONS These results show that signalling switches underlie endothelial cell-to-cell signal transmission and reveal how communication is maintained in the face of endothelial damage. The findings provide a new framework for understanding wave propagation and cell signalling in the endothelium.
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Affiliation(s)
- Charlotte Buckley
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Matthew D Lee
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Xun Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Calum Wilson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - John G McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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2
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Bayraktar E, Lopez-Pigozzi D, Bortolozzi M. Calcium Regulation of Connexin Hemichannels. Int J Mol Sci 2024; 25:6594. [PMID: 38928300 PMCID: PMC11204158 DOI: 10.3390/ijms25126594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/07/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
Connexin hemichannels (HCs) expressed at the plasma membrane of mammalian cells are of paramount importance for intercellular communication. In physiological conditions, HCs can form gap junction (GJ) channels, providing a direct diffusive path between neighbouring cells. In addition, unpaired HCs provide conduits for the exchange of solutes between the cytoplasm and the extracellular milieu, including messenger molecules involved in paracrine signalling. The synergistic action of membrane potential and Ca2+ ions controls the gating of the large and relatively unselective pore of connexin HCs. The four orders of magnitude difference in gating sensitivity to the extracellular ([Ca2+]e) and the cytosolic ([Ca2+]c) Ca2+ concentrations suggests that at least two different Ca2+ sensors may exist. While [Ca2+]e acts as a spatial modulator of the HC opening, which is most likely dependent on the cell layer, compartment, and organ, [Ca2+]c triggers HC opening and the release of extracellular bursts of messenger molecules. Such molecules include ATP, cAMP, glutamate, NAD+, glutathione, D-serine, and prostaglandins. Lost or abnormal HC regulation by Ca2+ has been associated with several diseases, including deafness, keratitis ichthyosis, palmoplantar keratoderma, Charcot-Marie-Tooth neuropathy, oculodentodigital dysplasia, and congenital cataracts. The fact that both an increased and a decreased Ca2+ sensitivity has been linked to pathological conditions suggests that Ca2+ in healthy cells finely tunes the normal HC function. Overall, further investigation is needed to clarify the structural and chemical modifications of connexin HCs during [Ca2+]e and [Ca2+]c variations. A molecular model that accounts for changes in both Ca2+ and the transmembrane voltage will undoubtedly enhance our interpretation of the experimental results and pave the way for developing therapeutic compounds targeting specific HC dysfunctions.
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Affiliation(s)
- Erva Bayraktar
- Veneto Institute of Molecular Medicine (VIMM), Via Orus 2, 35129 Padova, Italy
- Department of Physics and Astronomy “G. Galilei”, University of Padua, Via Marzolo 8, 35131 Padova, Italy
| | - Diego Lopez-Pigozzi
- Veneto Institute of Molecular Medicine (VIMM), Via Orus 2, 35129 Padova, Italy
- Department of Physics and Astronomy “G. Galilei”, University of Padua, Via Marzolo 8, 35131 Padova, Italy
| | - Mario Bortolozzi
- Veneto Institute of Molecular Medicine (VIMM), Via Orus 2, 35129 Padova, Italy
- Department of Physics and Astronomy “G. Galilei”, University of Padua, Via Marzolo 8, 35131 Padova, Italy
- Institute of Endocrinology and Oncology “Gaetano Salvatore” (IEOS-CNR), Via Pietro Castellino 111, 80131 Napoli, Italy
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3
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Puebla M, Muñoz MF, Lillo MA, Contreras JE, Figueroa XF. Control of astrocytic Ca 2+ signaling by nitric oxide-dependent S-nitrosylation of Ca 2+ homeostasis modulator 1 channels. Biol Res 2024; 57:19. [PMID: 38689353 PMCID: PMC11059852 DOI: 10.1186/s40659-024-00503-3] [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: 08/31/2023] [Accepted: 04/18/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Astrocytes Ca2+ signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during an increase in synaptic activity triggers coordinated Ca2+ signals in astrocytes. Importantly, astrocytes express the Ca2+-dependent nitric oxide (NO)-synthetizing enzymes eNOS and nNOS, which might contribute to the Ca2+ signals by triggering Ca2+ influx or ATP release through the activation of connexin 43 (Cx43) hemichannels, pannexin-1 (Panx-1) channels or Ca2+ homeostasis modulator 1 (CALHM1) channels. Hence, we aim to evaluate the participation of NO in the astrocytic Ca2+ signaling initiated by stimulation of mGluR in primary cultures of astrocytes from rat brain cortex. RESULTS Astrocytes were stimulated with glutamate or t-ACPD and NO-dependent changes in [Ca2+]i and ATP release were evaluated. In addition, the activity of Cx43 hemichannels, Panx-1 channels and CALHM1 channels was also analyzed. The expression of Cx43, Panx-1 and CALHM1 in astrocytes was confirmed by immunofluorescence analysis and both glutamate and t-ACPD induced NO-mediated activation of CALHM1 channels via direct S-nitrosylation, which was further confirmed by assessing CALHM1-mediated current using the two-electrode voltage clamp technique in Xenopus oocytes. Pharmacological blockade or siRNA-mediated inhibition of CALHM1 expression revealed that the opening of these channels provides a pathway for ATP release and the subsequent purinergic receptor-dependent activation of Cx43 hemichannels and Panx-1 channels, which further contributes to the astrocytic Ca2+ signaling. CONCLUSIONS Our findings demonstrate that activation of CALHM1 channels through NO-mediated S-nitrosylation in astrocytes in vitro is critical for the generation of glutamate-initiated astrocytic Ca2+ signaling.
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Affiliation(s)
- Mariela Puebla
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile
| | - Manuel F Muñoz
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Mauricio A Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Jorge E Contreras
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile.
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Tao S, Hulpiau P, Wagner LE, Witschas K, Yule DI, Bultynck G, Leybaert L. IP3RPEP6, a novel peptide inhibitor of IP 3 receptor channels that does not affect connexin-43 hemichannels. Acta Physiol (Oxf) 2024; 240:e14086. [PMID: 38240350 DOI: 10.1111/apha.14086] [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: 07/20/2023] [Revised: 10/24/2023] [Accepted: 01/01/2024] [Indexed: 02/24/2024]
Abstract
AIM Inositol 1,4,5-trisphosphate receptors (IP3 Rs) are intracellular Ca2+ -release channels with crucial roles in cell function. Current IP3 R inhibitors suffer from off-target effects and poor selectivity towards the three distinct IP3 R subtypes. We developed a novel peptide inhibitor of IP3 Rs and determined its effect on connexin-43 (Cx43) hemichannels, which are co-activated by IP3 R stimulation. METHODS IP3RPEP6 was developed by in silico molecular docking studies and characterized by on-nucleus patch-clamp experiments of IP3 R2 channels and carbachol-induced IP3 -mediated Ca2+ responses in IP3 R1, 2 or 3 expressing cells, triple IP3 R KO cells and astrocytes. Cx43 hemichannels were studied by patch-clamp and ATP-release approaches, and by inhibition with Gap19 peptide. IP3RPEP6 interactions with IP3 Rs were verified by co-immunoprecipitation and affinity pull-down assays. RESULTS IP3RPEP6 concentration-dependently reduced the open probability of IP3 R2 channels and competitively inhibited IP3 Rs in an IC50 order of IP3 R2 (~3.9 μM) < IP3 R3 (~4.3 μM) < IP3 R1 (~9.0 μM), without affecting Cx43 hemichannels or ryanodine receptors. IP3RPEP6 co-immunoprecipitated with IP3 R2 but not with IP3 R1; interaction with IP3 R3 varied between cell types. The IC50 of IP3RPEP6 inhibition of carbachol-induced Ca2+ responses decreased with increasing cellular Cx43 expression. Moreover, Gap19-inhibition of Cx43 hemichannels significantly reduced the amplitude of the IP3 -Ca2+ responses and strongly increased the EC50 of these responses. Finally, we identified palmitoyl-8G-IP3RPEP6 as a membrane-permeable IP3RPEP6 version allowing extracellular application of the IP3 R-inhibiting peptide. CONCLUSION IP3RPEP6 inhibits IP3 R2/R3 at concentrations that have limited effects on IP3 R1. IP3 R activation triggers hemichannel opening, which strongly affects the amplitude and concentration-dependence of IP3 -triggered Ca2+ responses.
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Affiliation(s)
- Siyu Tao
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent, Belgium
| | - Paco Hulpiau
- Department of Bio-Medical Sciences, HOWEST University of Applied Sciences (Hogeschool West-Vlaanderen), Bruges, Belgium
| | - Larry E Wagner
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York, USA
| | - Katja Witschas
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent, Belgium
| | - David I Yule
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York, USA
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, KU Leuven, Leuven, Belgium
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent, Belgium
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5
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Peracchia C. Gap Junction Channel Regulation: A Tale of Two Gates-Voltage Sensitivity of the Chemical Gate and Chemical Sensitivity of the Fast Voltage Gate. Int J Mol Sci 2024; 25:982. [PMID: 38256055 PMCID: PMC10815820 DOI: 10.3390/ijms25020982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Gap junction channels are regulated by gates sensitive to cytosolic acidification and trans-junctional voltage (Vj). We propose that the chemical gate is a calmodulin (CaM) lobe. The fast-Vj gate is made primarily by the connexin's NH2-terminus domain (NT). The chemical gate closes the channel slowly and completely, while the fast-Vj gate closes the channel rapidly but incompletely. The chemical gate closes with increased cytosolic calcium concentration [Ca2+]i and with Vj gradients at Vj's negative side. In contrast, the fast-Vj gate closes at the positive or negative side of Vj depending on the connexin (Cx) type. Cxs with positively charged NT close at Vj's negative side, while those with negatively charged NT close at Vj's positive side. Cytosolic acidification alters in opposite ways the sensitivity of the fast-Vj gate: it increases the Vj sensitivity of negative gaters and decreases that of positive gaters. While the fast-Vj gate closes and opens instantaneously, the chemical gate often shows fluctuations, likely to reflect the shifting of the gate (CaM's N-lobe) in and out of the channel's pore.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University Rochester, Rochester, NY 14642-8711, USA
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6
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Bayraktar E, Bortolozzi M. Measuring Connexin Hemichannel Opening in Response to an InsP3-Mediated Cytosolic Ca 2+ Increase. Methods Mol Biol 2024; 2801:189-197. [PMID: 38578422 DOI: 10.1007/978-1-0716-3842-2_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
The opening of connexin hemichannels (HCs) expressed at the plasma membrane of mammalian cells is regulated by a number of physiological parameters, including extracellular and intracellular Ca2+ ions. Submicromolar variations of the cytosolic Ca2+ concentration ([Ca2+]c) are per se sufficient to trigger extracellular bursts of messenger molecules through connexin HCs, thus mediating paracrine signaling. In this chapter, we present a quantitative method to measure the opening dynamics of connexin HCs expressed in a single HeLa cell upon stimulation by a canonical InsP3-mediated [Ca2+]c transient. The protocol relies on a combination of Ca2+ imaging and patch-clamp techniques. The insights gained from our method are expected to make a significant contribution to understanding the structure-function relationship of connexin HCs. The protocol is also suitable to screen candidate therapeutic compounds to treat connexin-related diseases linked to HC dysfunction.
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Affiliation(s)
- Erva Bayraktar
- Department of Physics and Astronomy "G. Galilei", University of Padua, Padova, Italy
- Veneto Institute of Molecular Medicine (VIMM), Padova, Italy
| | - Mario Bortolozzi
- Department of Physics and Astronomy "G. Galilei", University of Padua, Padova, Italy.
- Veneto Institute of Molecular Medicine (VIMM), Padova, Italy.
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7
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León-Fuentes IM, Salgado-Gil MG, Novoa MS, Retamal MA. Connexins in Cancer, the Possible Role of Connexin46 as a Cancer Stem Cell-Determining Protein. Biomolecules 2023; 13:1460. [PMID: 37892142 PMCID: PMC10604234 DOI: 10.3390/biom13101460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/15/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
Cancer is a widespread and incurable disease caused by genetic mutations, leading to uncontrolled cell proliferation and metastasis. Connexins (Cx) are transmembrane proteins that facilitate intercellular communication via hemichannels and gap junction channels. Among them, Cx46 is found mostly in the eye lens. However, in pathological conditions, Cx46 has been observed in various types of cancers, such as glioblastoma, melanoma, and breast cancer. It has been demonstrated that elevated Cx46 levels in breast cancer contribute to cellular resistance to hypoxia, and it is an enhancer of cancer aggressiveness supporting a pro-tumoral role. Accordingly, Cx46 is associated with an increase in cancer stem cell phenotype. These cells display radio- and chemoresistance, high proliferative abilities, self-renewal, and differentiation capacities. This review aims to consolidate the knowledge of the relationship between Cx46, its role in forming hemichannels and gap junctions, and its connection with cancer and cancer stem cells.
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Affiliation(s)
| | | | | | - Mauricio A. Retamal
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, República de Honduras 12740, Las Condes, Santiago 7610496, Chile; (I.M.L.-F.); (M.G.S.-G.); (M.S.N.)
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8
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Cea LA, Vásquez W, Hernández-Salinas R, Vielma AZ, Castillo-Ruiz M, Velarde V, Salgado M, Sáez JC. Skeletal Muscle Atrophy Induced by Diabetes Is Mediated by Non-Selective Channels and Prevented by Boldine. Biomolecules 2023; 13:708. [PMID: 37189454 PMCID: PMC10136059 DOI: 10.3390/biom13040708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/23/2023] [Accepted: 04/04/2023] [Indexed: 05/17/2023] Open
Abstract
Individuals with diabetes mellitus present a skeletal muscle myopathy characterized by atrophy. However, the mechanism underlying this muscular alteration remains elusive, which makes it difficult to design a rational treatment that could avoid the negative consequences in muscles due to diabetes. In the present work, the atrophy of skeletal myofibers from streptozotocin-induced diabetic rats was prevented with boldine, suggesting that non-selective channels inhibited by this alkaloid are involved in this process, as has previously shown for other muscular pathologies. Accordingly, we found a relevant increase in sarcolemma permeability of skeletal myofibers of diabetic animals in vivo and in vitro due to de novo expression of functional connexin hemichannels (Cx HCs) containing connexins (Cxs) 39, 43, and 45. These cells also expressed P2X7 receptors, and their inhibition in vitro drastically reduced sarcolemma permeability, suggesting their participation in the activation of Cx HCs. Notably, sarcolemma permeability of skeletal myofibers was prevented by boldine treatment that blocks Cx43 and Cx45 HCs, and now we demonstrated that it also blocks P2X7 receptors. In addition, the skeletal muscle alterations described above were not observed in diabetic mice with myofibers deficient in Cx43/Cx45 expression. Moreover, murine myofibers cultured for 24 h in high glucose presented a drastic increase in sarcolemma permeability and levels of NLRP3, a molecular member of the inflammasome, a response that was also prevented by boldine, suggesting that, in addition to the systemic inflammatory response found in diabetes, high glucose can promote the expression of functional Cx HCs and activation of the inflammasome in skeletal myofibers. Therefore, Cx43 and Cx45 HCs play a critical role in myofiber degeneration, and boldine could be considered a potential therapeutic agent to treat muscular complications due to diabetes.
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Affiliation(s)
- Luis A. Cea
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Av. Llano Subercaseaux 2801, San Miguel, Santiago 8910060, Chile
| | - Walter Vásquez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Romina Hernández-Salinas
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Universidad del Desarrollo, Santiago 7610000, Chile
| | - Alejandra Z. Vielma
- Escuela de Odontología, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7610000, Chile
| | - Mario Castillo-Ruiz
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370149, Chile
- Departamento de Ciencias Químicas y Biológicas, Facultad de Ciencias de la Salud, Universidad Bernardo O’Higgins, Santiago 8370854, Chile
| | - Victoria Velarde
- Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Magdiel Salgado
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Pasaje Harrington 287, Playa Ancha, Valparaíso 2340000, Chile
| | - Juan C. Sáez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Pasaje Harrington 287, Playa Ancha, Valparaíso 2340000, Chile
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Mitochondrial connexin43 and mitochondrial K ATP channels modulate triggered arrhythmias in mouse ventricular muscle. Pflugers Arch 2023; 475:477-488. [PMID: 36707457 DOI: 10.1007/s00424-023-02789-w] [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: 09/07/2022] [Revised: 12/21/2022] [Accepted: 01/18/2023] [Indexed: 01/29/2023]
Abstract
Connexin43 (Cx43) exits as hemichannels in the inner mitochondrial membrane. We examined how mitochondrial Cx43 and mitochondrial KATP channels affect the occurrence of triggered arrhythmias. To generate cardiac-specific Cx43-deficient (cCx43-/-) mice, Cx43flox/flox mice were crossed with α-MHC (Myh6)-cre+/- mice. The resulting offspring, Cx43flox/flox/Myh6-cre+/- mice (cCx43-/- mice) and their littermates (cCx43+/+ mice), were used. Trabeculae were dissected from the right ventricles of mouse hearts. Cardiomyocytes were enzymatically isolated from the ventricles of mouse hearts. Force was measured with a strain gauge in trabeculae (22°C). To assess arrhythmia susceptibility, the minimal extracellular Ca2+ concentration ([Ca2+]o,min), at which arrhythmias were induced by electrical stimulation, was determined in trabeculae. ROS production was estimated with 2',7'-dichlorofluorescein (DCF), mitochondrial membrane potential with tetramethylrhodamine methyl ester (TMRM), and Ca2+ spark frequency with fluo-4 and confocal microscopy in cardiomyocytes. ROS production within the mitochondria was estimated with MitoSoxRed and mitochondrial Ca2+ with rhod-2 in trabeculae. Diazoxide was used to activate mitochondrial KATP. Most of cCx43-/- mice died suddenly within 8 weeks. Cx43 was present in the inner mitochondrial membrane in cCx43+/+ mice but not in cCx43-/- mice. In cCx43-/- mice, the [Ca2+]o,min was lower, and Ca2+ spark frequency, the slope of DCF fluorescence intensity, MitoSoxRed fluorescence, and rhod-2 fluorescence were higher. TMRM fluorescence was more decreased in cCx43-/- mice. Most of these changes were suppressed by diazoxide. In addition, in cCx43-/- mice, antioxidant peptide SS-31 and N-acetyl-L-cysteine increased the [Ca2+]o,min. These results suggest that Cx43 deficiency activates Ca2+ leak from the SR, probably due to depolarization of mitochondrial membrane potential, an increase in mitochondrial Ca2+, and an increase in ROS production, thereby causing triggered arrhythmias, and that Cx43 hemichannel deficiency may be compensated by activation of mitochondrial KATP channels in mouse hearts.
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10
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Dale N, Butler J, Dospinescu VM, Nijjar S. Channel-mediated ATP release in the nervous system. Neuropharmacology 2023; 227:109435. [PMID: 36690324 DOI: 10.1016/j.neuropharm.2023.109435] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
ATP is well established as a transmitter and modulator in the peripheral and central nervous system. While conventional exocytotic release of ATP at synapses occurs, this transmitter is unusual in also being released into the extracellular space via large-pored plasma membrane channels. This review considers the channels that are known to be permeable to ATP and some of the functions of channel-mediated ATP release. While the possibility of ATP release via channels mediating volume transmission has been known for some time, localised ATP release via channels at specialised synapses made by taste cells to the afferent nerve has recently been documented in taste buds. This raises the prospect that "channel synapses" may occur in other contexts. However, volume transmission and channel synapses are not necessarily mutually exclusive. We suggest that certain glial cells in the brain stem and hypothalamus, which possess long processes and are known to release ATP, may be candidates for both modes of ATP release -channel-mediated volume transmission in the region of their somata and more localised transmission possibly via either conventional or channel synapses from their processes at distal targets. Finally, we consider the different characteristics of vesicular and channel synapses and suggest that channel synapses may be advantageous in requiring less energy than their conventional vesicular counterparts. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Affiliation(s)
- Nicholas Dale
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK.
| | - Jack Butler
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK
| | | | - Sarbjit Nijjar
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK
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11
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Yang D, Chen M, Yang S, Deng F, Guo X. Connexin hemichannels and pannexin channels in toxicity: Recent advances and mechanistic insights. Toxicology 2023; 488:153488. [PMID: 36918108 DOI: 10.1016/j.tox.2023.153488] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/10/2023] [Accepted: 03/11/2023] [Indexed: 03/14/2023]
Abstract
Connexin hemichannels and pannexin channels are two types of transmembrane channels that allow autocrine/paracrine signalling through the exchange of ions and molecules between the intra- and extracellular compartments. However, owing to the poor selectivity of permeable ions and metabolites, the massive opening of these plasma membrane channels can lead to an excessive influx of toxic substances and an outflux of essential metabolites, such as adenosine triphosphate, glutathione, glutamate and ions, resulting in unbalanced cell homeostasis and impaired cell function. It is becoming increasingly clear that these channels can be activated in response to external stimuli and are involved in toxicity, yet their concrete mechanistic roles in the toxic effects induced by stress and various environmental changes remain poorly defined. This review provides an updated understanding of connexin hemichannels and pannexin channels in response to multiple extrinsic stressors and how these activated channels and their permeable messengers participate in toxicological pathways and processes, including inflammation, oxidative damage, intracellular calcium imbalance, bystander DNA damage and excitotoxicity.
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Affiliation(s)
- Di Yang
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China
| | - Mengyuan Chen
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China
| | - Sijia Yang
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China
| | - Furong Deng
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China
| | - Xinbiao Guo
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
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12
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Leybaert L, De Smet MA, Lissoni A, Allewaert R, Roderick HL, Bultynck G, Delmar M, Sipido KR, Witschas K. Connexin hemichannels as candidate targets for cardioprotective and anti-arrhythmic treatments. J Clin Invest 2023; 133:168117. [PMID: 36919695 PMCID: PMC10014111 DOI: 10.1172/jci168117] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
Abstract
Connexins are crucial cardiac proteins that form hemichannels and gap junctions. Gap junctions are responsible for the propagation of electrical and chemical signals between myocardial cells and cells of the specialized conduction system in order to synchronize the cardiac cycle and steer cardiac pump function. Gap junctions are normally open, while hemichannels are closed, but pathological circumstances may close gap junctions and open hemichannels, thereby perturbing cardiac function and homeostasis. Current evidence demonstrates an emerging role of hemichannels in myocardial ischemia and arrhythmia, and tools are now available to selectively inhibit hemichannels without inhibiting gap junctions as well as to stimulate hemichannel incorporation into gap junctions. We review available experimental evidence for hemichannel contributions to cellular pro-arrhythmic events in ventricular and atrial cardiomyocytes, and link these to insights at the level of molecular control of connexin-43-based hemichannel opening. We conclude that a double-edged approach of both preventing hemichannel opening and preserving gap junctional function will be key for further research and development of new connexin-based experimental approaches for treating heart disease.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Maarten Aj De Smet
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Alessio Lissoni
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Rosalie Allewaert
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, and
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Mario Delmar
- Leon H. Charney Division of Cardiology, School of Medicine, New York University, New York, USA
| | - Karin R Sipido
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, and
| | - Katja Witschas
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
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13
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Caruso G, Di Pietro L, Caraci F. Gap Junctions and Connexins in Microglia-Related Oxidative Stress and Neuroinflammation: Perspectives for Drug Discovery. Biomolecules 2023; 13:biom13030505. [PMID: 36979440 PMCID: PMC10046203 DOI: 10.3390/biom13030505] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/28/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
Microglia represent the immune system of the brain. Their role is central in two phenomena, neuroinflammation and oxidative stress, which are at the roots of different pathologies related to the central nervous system (CNS). In order to maintain the homeostasis of the brain and re-establish the equilibrium after a threatening imbalance, microglia communicate with each other and other cells within the CNS by receiving specific signals through membrane-bound receptors and then releasing neurotrophic factors into either the extracellular milieu or directly into the cytoplasm of nearby cells, such as astrocytes and neurons. These last two mechanisms rely on the activity of protein structures that enable the formation of channels in the membrane, namely, connexins and pannexins, that group and form gap junctions, hemichannels, and pannexons. These channels allow the release of gliotransmitters, such as adenosine triphosphate (ATP) and glutamate, together with calcium ion (Ca2+), that seem to play a pivotal role in inter-cellular communication. The aim of the present review is focused on the physiology of channel protein complexes and their contribution to neuroinflammatory and oxidative stress-related phenomena, which play a central role in neurodegenerative disorders. We will then discuss how pharmacological modulation of these channels can impact neuroinflammatory phenomena and hypothesize that currently available nutraceuticals, such as carnosine and N-acetylcysteine, can modulate the activity of connexins and pannexins in microglial cells and reduce oxidative stress in neurodegenerative disorders.
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Affiliation(s)
- Giuseppe Caruso
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
- Unit of Neuropharmacology and Translational Neurosciences, Oasi Research Institute-IRCCS, 94018 Troina, Italy
- Correspondence: ; Tel.: +39-0957385036
| | - Lucia Di Pietro
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
- Scuola Superiore di Catania, University of Catania, 95123 Catania, Italy
| | - Filippo Caraci
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
- Unit of Neuropharmacology and Translational Neurosciences, Oasi Research Institute-IRCCS, 94018 Troina, Italy
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14
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Zeng Y, Riquelme MA, Hua R, Zhang J, Acosta FM, Gu S, Jiang JX. Mechanosensitive piezo1 calcium channel activates connexin 43 hemichannels through PI3K signaling pathway in bone. Cell Biosci 2022; 12:191. [PMID: 36457052 PMCID: PMC9716748 DOI: 10.1186/s13578-022-00929-w] [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: 07/25/2022] [Accepted: 11/11/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Mechanical loading promotes bone formation and osteocytes are a major mechanosensory cell in the bone. Both Piezo1 channels and connexin 43 hemichannels (Cx43 HCs) in osteocytes are important players in mechanotransduction and anabolic function by mechanical loading. However, the mechanism underlying mechanotransduction involving Piezo1 channels and Cx43 HCs in osteocytes and bone remains unknown. RESULTS We showed that, like mechanical loading, Piezo1 specific agonist Yoda1 was able to increase intracellular Ca2+ signaling and activate Cx43 HCs, while Yoda1 antagonist Dooku1 inhibited Ca2+ and Cx43 HC activation induced by both mechanical loading and Yoda1. Moreover, the intracellular Ca2+ signal activated by Yoda1 was reduced by the inhibition of Cx43 HCs and pannexin1 (Panx1) channels, as well as ATP-P2X receptor signaling. Piezo1 and Cx43 HCs were co-localized on the osteocyte cell surface, and Yoda1-activated PI3K-Akt signaling regulated the opening of Cx43 HCs. Furthermore, Cx43 HCs opening by mechanical loading on tibias was ablated by inhibition of Piezo1 activation in vivo. CONCLUSION We demonstrated that upon mechanical stress, increased intracellular Ca2+ activated by Piezo1 regulates the opening of HCs through PI3K-Akt and opened Cx43 HCs, along with Panx1 channels, and ATP-P2X signaling sustain the intracellular Ca2+ signal, leading to bone anabolic function.
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Affiliation(s)
- Yan Zeng
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA ,grid.452708.c0000 0004 1803 0208The Second Xiangya Hospital, Central South University, Changsha, Hunan China
| | - Manuel A. Riquelme
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA
| | - Rui Hua
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA
| | - Jingruo Zhang
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA
| | - Francisca M. Acosta
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA
| | - Sumin Gu
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA
| | - Jean X. Jiang
- grid.267309.90000 0001 0629 5880Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX USA
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15
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Zlomuzica A, Plank L, Dere E. A new path to mental disorders: Through gap junction channels and hemichannels. Neurosci Biobehav Rev 2022; 142:104877. [PMID: 36116574 DOI: 10.1016/j.neubiorev.2022.104877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/20/2022] [Accepted: 09/13/2022] [Indexed: 11/18/2022]
Abstract
Behavioral disturbances related to emotional regulation, reward processing, cognition, sleep-wake regulation and activity/movement represent core symptoms of most common mental disorders. Increasing empirical and theoretical evidence suggests that normal functioning of these behavioral domains relies on fine graded coordination of neural and glial networks which are maintained and modulated by intercellular gap junction channels and unapposed pannexin or connexin hemichannels. Dysfunctions in these networks might contribute to the development and maintenance of psychopathological and neurobiological features associated with mental disorders. Here we review and discuss the evidence indicating a prominent role of gap junction channel and hemichannel dysfunction in core symptoms of mental disorders. We further discuss how the increasing knowledge on intercellular gap junction channels and unapposed pannexin or connexin hemichannels in the brain might lead to deeper mechanistic insight in common mental disorders and to the development of novel treatment approaches. We further attempt to exemplify what type of future research on this topic could be integrated into multidimensional approaches to understand and cure mental disorders.
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Affiliation(s)
- Armin Zlomuzica
- Department of Behavioral and Clinical Neuroscience, Ruhr-University Bochum (RUB), Massenbergstraße 9-13, D-44787 Bochum, Germany.
| | - Laurin Plank
- Department of Behavioral and Clinical Neuroscience, Ruhr-University Bochum (RUB), Massenbergstraße 9-13, D-44787 Bochum, Germany
| | - Ekrem Dere
- Department of Behavioral and Clinical Neuroscience, Ruhr-University Bochum (RUB), Massenbergstraße 9-13, D-44787 Bochum, Germany; Sorbonne Université. Institut de Biologie Paris-Seine, (IBPS), Département UMR 8256: Adaptation Biologique et Vieillissement, UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris, France.
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16
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Rieck J, Skatchkov SN, Derst C, Eaton MJ, Veh RW. Unique Chemistry, Intake, and Metabolism of Polyamines in the Central Nervous System (CNS) and Its Body. Biomolecules 2022; 12:biom12040501. [PMID: 35454090 PMCID: PMC9025450 DOI: 10.3390/biom12040501] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/04/2023] Open
Abstract
Polyamines (PAs) are small, versatile molecules with two or more nitrogen-containing positively charged groups and provide widespread biological functions. Most of these aspects are well known and covered by quite a number of excellent surveys. Here, the present review includes novel aspects and questions: (1) It summarizes the role of most natural and some important synthetic PAs. (2) It depicts PA uptake from nutrition and bacterial production in the intestinal system following loss of PAs via defecation. (3) It highlights the discrepancy between the high concentrations of PAs in the gut lumen and their low concentration in the blood plasma and cerebrospinal fluid, while concentrations in cellular cytoplasm are much higher. (4) The present review provides a novel and complete scheme for the biosynthesis of Pas, including glycine, glutamate, proline and others as PA precursors, and provides a hypothesis that the agmatine pathway may rescue putrescine production when ODC knockout seems to be lethal (solving the apparent contradiction in the literature). (5) It summarizes novel data on PA transport in brain glial cells explaining why these cells but not neurons preferentially accumulate PAs. (6) Finally, it provides a novel and complete scheme for PA interconversion, including hypusine, putreanine, and GABA (unique gliotransmitter) as end-products. Altogether, this review can serve as an updated contribution to understanding the PA mystery.
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Affiliation(s)
- Julian Rieck
- Institut für Zell- und Neurobiologie, Centrum 2, Charité—Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany;
| | - Serguei N. Skatchkov
- Department of Physiology, Universidad Central del Caribe, Bayamón, PR 00956, USA
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA;
- Correspondence: (S.N.S.); (R.W.V.)
| | - Christian Derst
- Institut für Integrative Neuroanatomie, Centrum 2, Charité—Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany;
| | - Misty J. Eaton
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA;
| | - Rüdiger W. Veh
- Institut für Zell- und Neurobiologie, Centrum 2, Charité—Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany;
- Correspondence: (S.N.S.); (R.W.V.)
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17
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Connexin 43 gap junction-mediated astrocytic network reconstruction attenuates isoflurane-induced cognitive dysfunction in mice. J Neuroinflammation 2022; 19:64. [PMID: 35255943 PMCID: PMC8903726 DOI: 10.1186/s12974-022-02424-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 02/23/2022] [Indexed: 01/18/2023] Open
Abstract
Background Postoperative cognitive dysfunction (POCD) is a common complication following anesthesia and surgery. General anesthetic isoflurane has potential neurotoxicity and induces cognitive impairments, but the exact mechanism remains unclear. Astrocytes form interconnected networks in the adult brain through gap junctions (GJs), which primarily comprise connexin 43 (Cx43), and play important roles in brain homeostasis and functions such as memory. However, the role of the GJ-Cx43-mediated astrocytic network in isoflurane-induced cognitive dysfunction has not been defined. Methods 4-month-old male C57BL/6 mice were exposure to long-term isoflurane to induce cognitive impairment. To simulate an in vitro isoflurane-induced cognitive dysfunction‐like condition, primary mouse astrocytes were subjected to long-term isoflurane exposure. Cognitive function was assessed by Y-maze and fear conditioning tests. Western blot was used to determine the expression levels of different functional configurations of Cx43. The morphology of the GJs-Cx43 was evaluated by immunofluorescence staining. Levels of IL-1β and IL-6 were examined by ELISA. The ability of GJs-Cx43-mediated intercellular communication was examined by lucifer yellow dye transfer assay. Ethidium bromide uptake assays were used to measure the activity of Cx43 hemichannels. The ultrastructural morphology of astrocyte gap junctions and tripartite synapse were observed by transmission electron microscopy. Results After long-term isoflurane anesthesia, the GJs formed by Cx43 in the mouse hippocampus and primary mouse astrocytes were significantly reduced, GJs function was impaired, hemichannel activity was enhanced, the levels of IL-1β and IL-6 were increased, and mice showed significant cognitive impairment. After treatment with the novel GJ-Cx43 enhancer ZP1609, GJ-Cx43-mediated astrocytic network function was enhanced, neuroinflammation was alleviated, and ameliorated cognition dysfunction induced by long-term isoflurane exposure. However, ZP1609 enhances the astrocytic network by promoting Cx43 to form GJs without affecting hemichannel activity. Additionally, our data showed that long-term isoflurane exposure does not alter the structure of tripartite synapse. Conclusion Our results reveal a novel mechanism of the GJ-Cx43-mediated astrocytic network involved in isoflurane-induced neuroinflammation and cognitive impairments, which provides new mechanistic insight into the pathogenesis of POCD and identifies potential targets for its treatment. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02424-y.
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18
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She J, Feng N, Zheng W, Zheng H, Cai P, Zou H, Yuan Y, Gu J, Liu Z, Bian J. Zearalenone Exposure Disrupts Blood-Testis Barrier Integrity through Excessive Ca 2+-Mediated Autophagy. Toxins (Basel) 2021; 13:toxins13120875. [PMID: 34941713 PMCID: PMC8703826 DOI: 10.3390/toxins13120875] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 12/24/2022] Open
Abstract
Zearalenone (ZEA), a common mycotoxin in grains and animal feeds, has been associated with male reproductive disorders. However, the potential toxicity mechanism of ZEA is not fully understood. In this study, in vivo and in vitro models were used to explore the effects of ZEA on the blood-testis barrier (BTB) and related molecular mechanisms. First, male BALB/C mice were administered ZEA orally (40 mg/kg·bw) for 5-7 d. Sperm motility, testicular morphology, and expressions of BTB junction proteins and autophagy-related proteins were evaluated. In addition, TM4 cells (mouse Sertoli cells line) were used to delineate the molecular mechanisms that mediate the effects of ZEA on BTB. Our results demonstrated that ZEA exposure induced severe testicular damage in histomorphology and an ultrastructural, time-dependent decrease in the expression of blood-testis barrier junction-related proteins, accompanied by an increase in the expression of autophagy-related proteins. Additionally, similar to the in vitro results, the dose-dependent treatment of ZEA increased the level of cytoplasmic Ca2+ and the levels of the autophagy markers LC3-II and p62, in conjunction with a decrease in the BTB junction proteins occludin, claudin-11, and Cx43, with the dislocation of the gap junction protein Cx43. Meanwhile, inhibition of autophagy by CQ and 3-MA or inhibition of cytoplasmic Ca2+ by BAPTA-AM was sufficient to reduce the effects of ZEA on the TM4 cell BTB. To summarize, this study emphasizes the role of Ca2+-mediated autophagy in ZEA-induced BTB destruction, which deepens our understanding of the molecular mechanism of ZEA-induced male reproductive disorders.
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Affiliation(s)
- Jinjin She
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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
| | - Nannan Feng
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Wanglong Zheng
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Hao Zheng
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Peirong Cai
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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
| | - Jianchun Bian
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China; (J.S.); (N.F.); (W.Z.); (H.Z.); (P.C.); (H.Z.); (Y.Y.); (J.G.); (Z.L.)
- 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:
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19
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Donati V, Peres C, Nardin C, Scavizzi F, Raspa M, Ciubotaru CD, Bortolozzi M, Pedersen MG, Mammano F. Calcium Signaling in the Photodamaged Skin: In Vivo Experiments and Mathematical Modeling. FUNCTION 2021; 3:zqab064. [PMID: 35330924 PMCID: PMC8788836 DOI: 10.1093/function/zqab064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 01/07/2023] Open
Abstract
The epidermis forms an essential barrier against a variety of insults. The overall goal of this study was to shed light not only on the effects of accidental epidermal injury, but also on the mechanisms that support laser skin resurfacing with intra-epidermal focal laser-induced photodamage, a widespread medical practice used to treat a range of skin conditions. To this end, we selectively photodamaged a single keratinocyte with intense, focused and pulsed laser radiation, triggering Ca2+ waves in the epidermis of live anesthetized mice with ubiquitous expression of a genetically encoded Ca2+ indicator. Waves expanded radially and rapidly, reaching up to eight orders of bystander cells that remained activated for tens of minutes, without displaying oscillations of the cytosolic free Ca2+ concentration ([Formula: see text]). By combining in vivo pharmacological dissection with mathematical modeling, we demonstrate that Ca2+ wave propagation depended primarily on the release of ATP, a prime damage-associated molecular patterns (DAMPs), from the hit cell. Increments of the [Formula: see text] in bystander cells were chiefly due to Ca2+ release from the endoplasmic reticulum (ER), downstream of ATP binding to P2Y purinoceptors. ATP-dependent ATP release though connexin hemichannels (HCs) affected wave propagation at larger distances, where the extracellular ATP concentration was reduced by the combined effect of passive diffusion and hydrolysis due to the action of ectonucleotidases, whereas pannexin channels had no role. Bifurcation analysis suggests basal keratinocytes have too few P2Y receptors (P2YRs) and/or phospholipase C (PLC) to transduce elevated extracellular ATP levels into inositol trisphosphate (IP3) production rates sufficiently large to sustain [Formula: see text] oscillations.
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Affiliation(s)
- Viola Donati
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Chiara Peres
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Chiara Nardin
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Ferdinando Scavizzi
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Marcello Raspa
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | | | - Mario Bortolozzi
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
- Foundation for Advanced Biomedical Research, Veneto Institute of Molecular Medicine (VIMM), 35129 Padova (PD), Italy
| | - Morten Gram Pedersen
- Department of Information Engineering, University of Padova, 35131 Padova (PD), Italy
- Department of Mathematics “Tullio Levi-Civita”, University of Padova, 35121 Padova (PD), Italy
| | - Fabio Mammano
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
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20
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Nardin C, Peres C, Putti S, Orsini T, Colussi C, Mazzarda F, Raspa M, Scavizzi F, Salvatore AM, Chiani F, Tettey-Matey A, Kuang Y, Yang G, Retamal MA, Mammano F. Connexin Hemichannel Activation by S-Nitrosoglutathione Synergizes Strongly with Photodynamic Therapy Potentiating Anti-Tumor Bystander Killing. Cancers (Basel) 2021; 13:cancers13205062. [PMID: 34680212 PMCID: PMC8533914 DOI: 10.3390/cancers13205062] [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: 09/28/2021] [Revised: 10/02/2021] [Accepted: 10/06/2021] [Indexed: 12/22/2022] Open
Abstract
Simple Summary Bystander effects depend on direct cell-cell communication and/or paracrine signaling mediated by the release of soluble factors into the extracellular environment and may greatly influence therapy outcome. Although the limited data available suggest a role for intercellular gap junction channels, far less is known about the role of connexin hemichannels. Here, we investigated bystander effects induced by photodynamic therapy in syngeneic murine melanoma models in vivo. We determined that (i) photoactivation of a photosensitizer triggered calcium-dependent cell death pathways in both irradiated and bystander tumor cells; (ii) hemichannel activity and adenosine triphosphate release were key factors for the induction of bystander cell death; and (iii) bystander cell killing and antitumor response elicited by photodynamic therapy were greatly enhanced by combination treatment with S-nitrosoglutathione, which promoted hemichannel opening in these experimental conditions. Therefore, these findings in a preclinical model have important translational potential. Abstract In this study, we used B16-F10 cells grown in the dorsal skinfold chamber (DSC) preparation that allowed us to gain optical access to the processes triggered by photodynamic therapy (PDT). Partial irradiation of a photosensitized melanoma triggered cell death in non-irradiated tumor cells. Multiphoton intravital microscopy with genetically encoded fluorescence indicators revealed that bystander cell death was mediated by paracrine signaling due to adenosine triphosphate (ATP) release from connexin (Cx) hemichannels (HCs). Intercellular calcium (Ca2+) waves propagated from irradiated to bystander cells promoting intracellular Ca2+ transfer from the endoplasmic reticulum (ER) to mitochondria and rapid activation of apoptotic pathways. Combination treatment with S-nitrosoglutathione (GSNO), an endogenous nitric oxide (NO) donor that biases HCs towards the open state, greatly potentiated anti-tumor bystander killing via enhanced Ca2+ signaling, leading to a significant reduction of post-irradiation tumor mass. Our results demonstrate that HCs can be exploited to dramatically increase cytotoxic bystander effects and reveal a previously unappreciated role for HCs in tumor eradication promoted by PDT.
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Affiliation(s)
- Chiara Nardin
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Chiara Peres
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Sabrina Putti
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Tiziana Orsini
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Claudia Colussi
- Institute for Systems Analysis and Computer Science “A. Ruberti” (IASI)-CNR, 00168 Rome, Italy;
- Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Catholic University of the Sacred Heart, 00168 Rome, Italy
| | - Flavia Mazzarda
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Marcello Raspa
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Ferdinando Scavizzi
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Anna Maria Salvatore
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Francesco Chiani
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Abraham Tettey-Matey
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
| | - Yuanyuan Kuang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China; (Y.K.); (G.Y.)
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China; (Y.K.); (G.Y.)
| | - Mauricio A. Retamal
- Universidad del Desarrollo, Centro de Fisiología Celular e Integrativa, Facultad de Medicina Clínica Alemana, Santiago 7780272, Chile;
| | - Fabio Mammano
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Rome, Italy; (C.N.); (C.P.); (S.P.); (T.O.); (F.M.); (M.R.); (F.S.); (A.M.S.); (F.C.); (A.T.-M.)
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Correspondence:
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21
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Ai X, Yan J, Pogwizd SM. Serine-threonine protein phosphatase regulation of Cx43 dephosphorylation in arrhythmogenic disorders. Cell Signal 2021; 86:110070. [PMID: 34217833 PMCID: PMC8963383 DOI: 10.1016/j.cellsig.2021.110070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/11/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
Regulation of cell-to-cell communication in the heart by the gap junction protein Connexin43 (Cx43) involves modulation of Cx43 phosphorylation state by protein kinases, and dephosphorylation by protein phosphatases. Dephosphorylation of Cx43 has been associated with impaired intercellular coupling and enhanced arrhythmogenesis in various pathologic states. While there has been extensive study of the protein kinases acting on Cx43, there has been limited studies of the protein phosphatases that may underlie Cx43 dephosphorylation. The focus of this review is to introduce serine-threonine protein phosphatase regulation of Cx43 phosphorylation state and cell-to-cell communication, and its impact on arrhythmogenesis in the setting of chronic heart failure and myocardial ischemia, as well as on atrial fibrillation. We also discuss the therapeutic potential of modulating protein phosphatases to treat arrhythmias in these clinical settings.
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Affiliation(s)
- Xun Ai
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Jiajie Yan
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Steven M Pogwizd
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America.
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22
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García-Rodríguez C, Bravo-Tobar ID, Duarte Y, Barrio LC, Sáez JC. Contribution of non-selective membrane channels and receptors in epilepsy. Pharmacol Ther 2021; 231:107980. [PMID: 34481811 DOI: 10.1016/j.pharmthera.2021.107980] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/14/2022]
Abstract
Overcoming refractory epilepsy's resistance to the combination of antiepileptic drugs (AED), mitigating side effects, and preventing sudden unexpected death in epilepsy are critical goals for therapy of this disorder. Current therapeutic strategies are based primarily on neurocentric mechanisms, overlooking the participation of astrocytes and microglia in the pathophysiology of epilepsy. This review is focused on a set of non-selective membrane channels (permeable to ions and small molecules), including channels and ionotropic receptors of neurons, astrocytes, and microglia, such as: the hemichannels formed by Cx43 and Panx1; the purinergic P2X7 receptors; the transient receptor potential vanilloid (TRPV1 and TRPV4) channels; calcium homeostasis modulators (CALHMs); transient receptor potential canonical (TRPC) channels; transient receptor potential melastatin (TRPM) channels; voltage-dependent anion channels (VDACs) and volume-regulated anion channels (VRACs), which all have in common being activated by epileptic activity and the capacity to exacerbate seizure intensity. Specifically, we highlight evidence for the activation of these channels/receptors during epilepsy including neuroinflammation and oxidative stress, discuss signaling pathways and feedback mechanisms, and propose the functions of each of them in acute and chronic epilepsy. Studying the role of these non-selective membrane channels in epilepsy and identifying appropriate blockers for one or more of them could provide complementary therapies to better alleviate the disease.
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Affiliation(s)
- Claudia García-Rodríguez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
| | - Iván D Bravo-Tobar
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile
| | - Yorley Duarte
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Luis C Barrio
- Hospital Ramon y Cajal-IRYCIS, Centro de Tecnología Biomédica de la Universidad Politécnica, Madrid, Spain
| | - Juan C Sáez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
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23
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Retamal MA, Fernandez-Olivares A, Stehberg J. Over-activated hemichannels: A possible therapeutic target for human diseases. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166232. [PMID: 34363932 DOI: 10.1016/j.bbadis.2021.166232] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/21/2021] [Accepted: 07/26/2021] [Indexed: 12/14/2022]
Abstract
In our body, all the cells are constantly sharing chemical and electrical information with other cells. This intercellular communication allows them to respond in a concerted way to changes in the extracellular milieu. Connexins are transmembrane proteins that have the particularity of forming two types of channels; hemichannels and gap junction channels. Under normal conditions, hemichannels allow the controlled release of signaling molecules to the extracellular milieu. However, under certain pathological conditions, over-activated hemichannels can induce and/or exacerbate symptoms. In the last decade, great efforts have been put into developing new tools that can modulate these over-activated hemichannels. Small molecules, antibodies and mimetic peptides have shown a potential for the treatment of human diseases. In this review, we summarize recent findings in the field of hemichannel modulation via specific tools, and how these tools could improve patient outcome in certain pathological conditions.
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Affiliation(s)
- Mauricio A Retamal
- Universidad del Desarrollo, Programa de Comunicación Celular en Cáncer, Santiago, Chile; Universidad del Desarrollo, Centro de Fisiología Celular e Integrativa, Santiago, Chile.
| | | | - Jimmy Stehberg
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
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24
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Rinaldi C, Donato L, Alibrandi S, Scimone C, D’Angelo R, Sidoti A. Oxidative Stress and the Neurovascular Unit. Life (Basel) 2021; 11:life11080767. [PMID: 34440511 PMCID: PMC8398978 DOI: 10.3390/life11080767] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/15/2022] Open
Abstract
The neurovascular unit (NVU) is a relatively recent concept that clearly describes the relationship between brain cells and their blood vessels. The components of the NVU, comprising different types of cells, are so interrelated and associated with each other that they are considered as a single functioning unit. For this reason, even slight disturbances in the NVU could severely affect brain homeostasis and health. In this review, we aim to describe the current state of knowledge concerning the role of oxidative stress on the neurovascular unit and the role of a single cell type in the NVU crosstalk.
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Affiliation(s)
- Carmela Rinaldi
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
| | - Luigi Donato
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics and Avant-Garde Therapies, Istituto Euro-Mediterraneo di Scienza e Tecnologia (I.E.ME.S.T.), Via Michele Miraglia, 90139 Palermo, Italy
| | - Simona Alibrandi
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 Messina, Italy
| | - Concetta Scimone
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics and Avant-Garde Therapies, Istituto Euro-Mediterraneo di Scienza e Tecnologia (I.E.ME.S.T.), Via Michele Miraglia, 90139 Palermo, Italy
- Correspondence:
| | - Rosalia D’Angelo
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
| | - Antonina Sidoti
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
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25
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Sherwood MW, Oliet SHR, Panatier A. NMDARs, Coincidence Detectors of Astrocytic and Neuronal Activities. Int J Mol Sci 2021; 22:7258. [PMID: 34298875 PMCID: PMC8307462 DOI: 10.3390/ijms22147258] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 12/18/2022] Open
Abstract
Synaptic plasticity is an extensively studied cellular correlate of learning and memory in which NMDARs play a starring role. One of the most interesting features of NMDARs is their ability to act as a co-incident detector. It is unique amongst neurotransmitter receptors in this respect. Co-incident detection is possible because the opening of NMDARs requires membrane depolarisation and the binding of glutamate. Opening of NMDARs also requires a co-agonist. Although the dynamic regulation of glutamate and membrane depolarization have been well studied in coincident detection, the role of the co-agonist site is unexplored. It turns out that non-neuronal glial cells, astrocytes, regulate co-agonist availability, giving them the ability to influence synaptic plasticity. The unique morphology and spatial arrangement of astrocytes at the synaptic level affords them the capacity to sample and integrate information originating from unrelated synapses, regardless of any pre-synaptic and post-synaptic commonality. As astrocytes are classically considered slow responders, their influence at the synapse is widely recognized as modulatory. The aim herein is to reconsider the potential of astrocytes to participate directly in ongoing synaptic NMDAR activity and co-incident detection.
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Affiliation(s)
- Mark W. Sherwood
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France;
| | | | - Aude Panatier
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France;
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26
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Huang X, Su Y, Wang N, Li H, Li Z, Yin G, Chen H, Niu J, Yi C. Astroglial Connexins in Neurodegenerative Diseases. Front Mol Neurosci 2021; 14:657514. [PMID: 34122008 PMCID: PMC8192976 DOI: 10.3389/fnmol.2021.657514] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 05/05/2021] [Indexed: 12/16/2022] Open
Abstract
Astrocytes play a crucial role in the maintenance of the normal functions of the Central Nervous System (CNS). During the pathogenesis of neurodegenerative diseases, astrocytes undergo morphological and functional remodeling, a process called reactive astrogliosis, in response to the insults to the CNS. One of the key aspects of the reactive astrocytes is the change in the expression and function of connexins. Connexins are channel proteins that highly expressed in astrocytes, forming gap junction channels and hemichannels, allowing diffusional trafficking of small molecules. Alterations of astrocytic connexin expression and function found in neurodegenerative diseases have been shown to affect the disease progression by changing neuronal function and survival. In this review, we will summarize the role of astroglial connexins in neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Also, we will discuss why targeting connexins can be a plausible therapeutic strategy to manage these neurodegenerative diseases.
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Affiliation(s)
- Xiaomin Huang
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Yixun Su
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Nan Wang
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Hui Li
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Zhigang Li
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Guowei Yin
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Hui Chen
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Jianqin Niu
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Chenju Yi
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
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27
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Qin Y, Jiang X, Yang Q, Zhao J, Zhou Q, Zhou Y. The Functions, Methods, and Mobility of Mitochondrial Transfer Between Cells. Front Oncol 2021; 11:672781. [PMID: 34041035 PMCID: PMC8141658 DOI: 10.3389/fonc.2021.672781] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/20/2021] [Indexed: 12/31/2022] Open
Abstract
Mitochondria are vital organelles in cells, regulating energy metabolism and apoptosis. Mitochondrial transcellular transfer plays a crucial role during physiological and pathological conditions, such as rescuing recipient cells from bioenergetic deficit and tumorigenesis. Studies have shown several structures that conduct transcellular transfer of mitochondria, including tunneling nanotubes (TNTs), extracellular vesicles (EVs), and Cx43 gap junctions (GJs). The intra- and intercellular transfer of mitochondria is driven by a transport complex. Mitochondrial Rho small GTPase (MIRO) may be the adaptor that connects the transport complex with mitochondria, and myosin XIX is the motor protein of the transport complex, which participates in the transcellular transport of mitochondria through TNTs. In this review, the roles of TNTs, EVs, GJs, and related transport complexes in mitochondrial transcellular transfer are discussed in detail, as well as the formation mechanisms of TNTs and EVs. This review provides the basis for the development of potential clinical therapies targeting the structures of mitochondrial transcellular transfer.
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Affiliation(s)
- Yiming Qin
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, China
| | - Xin Jiang
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, China
| | - Qi Yang
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, China
| | - Jiaqi Zhao
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, China
| | - Qiong Zhou
- Department of Neurology, Yiyang Central Hospital, Yiyang City, China
| | - Yanhong Zhou
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, China
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28
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Marsh SR, Williams ZJ, Pridham KJ, Gourdie RG. Peptidic Connexin43 Therapeutics in Cardiac Reparative Medicine. J Cardiovasc Dev Dis 2021; 8:52. [PMID: 34063001 PMCID: PMC8147937 DOI: 10.3390/jcdd8050052] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/19/2021] [Accepted: 05/01/2021] [Indexed: 12/12/2022] Open
Abstract
Connexin (Cx43)-formed channels have been linked to cardiac arrhythmias and diseases of the heart associated with myocardial tissue loss and fibrosis. These pathologies include ischemic heart disease, ischemia-reperfusion injury, heart failure, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and Duchenne muscular dystrophy. A number of Cx43 mimetic peptides have been reported as therapeutic candidates for targeting disease processes linked to Cx43, including some that have advanced to clinical testing in humans. These peptides include Cx43 sequences based on the extracellular loop domains (e.g., Gap26, Gap 27, and Peptide5), cytoplasmic-loop domain (Gap19 and L2), and cytoplasmic carboxyl-terminal domain (e.g., JM2, Cx43tat, CycliCX, and the alphaCT family of peptides) of this transmembrane protein. Additionally, RYYN peptides binding to the Cx43 carboxyl-terminus have been described. In this review, we survey preclinical and clinical data available on short mimetic peptides based on, or directly targeting, Cx43, with focus on their potential for treating heart disease. We also discuss problems that have caused reluctance within the pharmaceutical industry to translate peptidic therapeutics to the clinic, even when supporting preclinical data is strong. These issues include those associated with the administration, stability in vivo, and tissue penetration of peptide-based therapeutics. Finally, we discuss novel drug delivery technologies including nanoparticles, exosomes, and other nanovesicular carriers that could transform the clinical and commercial viability of Cx43-targeting peptides in treatment of heart disease, stroke, cancer, and other indications requiring oral or parenteral administration. Some of these newly emerging approaches to drug delivery may provide a path to overcoming pitfalls associated with the drugging of peptide therapeutics.
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Affiliation(s)
- Spencer R. Marsh
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
| | - Zachary J. Williams
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA 24016, USA
| | - Kevin J. Pridham
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
| | - Robert G. Gourdie
- Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, VA 24016, USA; (S.R.M.); (Z.J.W.); (K.J.P.)
- Center for Heart and Reparative Medicine Research, Virginia Tech, Roanoke, VA 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Emergency Medicine, Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA
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29
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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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30
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Broadhead MJ, Miles GB. A common role for astrocytes in rhythmic behaviours? Prog Neurobiol 2021; 202:102052. [PMID: 33894330 DOI: 10.1016/j.pneurobio.2021.102052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 03/03/2021] [Accepted: 04/13/2021] [Indexed: 01/16/2023]
Abstract
Astrocytes are a functionally diverse form of glial cell involved in various aspects of nervous system infrastructure, from the metabolic and structural support of neurons to direct neuromodulation of synaptic activity. Investigating how astrocytes behave in functionally related circuits may help us understand whether there is any conserved logic to the role of astrocytes within neuronal networks. Astrocytes are implicated as key neuromodulatory cells within neural circuits that control a number of rhythmic behaviours such as breathing, locomotion and circadian sleep-wake cycles. In this review, we examine the evidence that astrocytes are directly involved in the regulation of the neural circuits underlying six different rhythmic behaviours: locomotion, breathing, chewing, gastrointestinal motility, circadian sleep-wake cycles and oscillatory feeding behaviour. We discuss how astrocytes are integrated into the neuronal networks that regulate these behaviours, and identify the potential gliotransmission signalling mechanisms involved. From reviewing the evidence of astrocytic involvement in a range of rhythmic behaviours, we reveal a heterogenous array of gliotransmission mechanisms, which help to regulate neuronal networks. However, we also observe an intriguing thread of commonality, in the form of purinergic gliotransmission, which is frequently utilised to facilitate feedback inhibition within rhythmic networks to constrain a given behaviour within its operational range.
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Affiliation(s)
- Matthew J Broadhead
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
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31
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Wang Q, Liu S. Analysis of Hemichannels and Gap Junctions: Application and Extension of the Passive Transmembrane Ion Transport Model. Front Cell Neurosci 2021; 15:596953. [PMID: 33897368 PMCID: PMC8058385 DOI: 10.3389/fncel.2021.596953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/15/2021] [Indexed: 02/02/2023] Open
Abstract
Electrical synaptic transmission is an essential form of interneuronal communication which is mediated by gap junctions that permit ion flow. Three gene families (connexins, innexins, and pannexins) have evolved to form gap junctional channels. Each gap junctional channel is formed by the docking of the hemichannel of one cell with the corresponding hemichannel of an adjacent cell. To date, there has been a lack of study models to describe this structure in detail. In this study, we demonstrate that numerical simulations suggest that the passive transmembrane ion transport model, based on the generality of ion channels, also applies to hemichannels in non-junctional plasma membranes. On this basis, we established a gap junctional channel model, which describes hemichannels' docking. We simulated homotypic and heterotypic gap junctions formed by connexins, innexins, and pannexins. Based on the numerical results and our theoretical model, we discussed the physiology of hemichannels and gap junctions, including ion blockage of hemichannels, voltage gating of gap junctions, and asymmetry and delay of electrical synaptic transmission, for which the numerical simulations are first comprehensively realized.
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Affiliation(s)
- Qiqian Wang
- School of Mathematics, South China University of Technology, Guangzhou, China
| | - Shenquan Liu
- School of Mathematics, South China University of Technology, Guangzhou, China
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Van Campenhout R, Gomes AR, De Groof TW, Muyldermans S, Devoogdt N, Vinken M. Mechanisms Underlying Connexin Hemichannel Activation in Disease. Int J Mol Sci 2021; 22:ijms22073503. [PMID: 33800706 PMCID: PMC8036530 DOI: 10.3390/ijms22073503] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/22/2021] [Accepted: 03/26/2021] [Indexed: 02/07/2023] Open
Abstract
Gap junctions and connexin hemichannels mediate intercellular and extracellular communication, respectively. While gap junctions are seen as the “good guys” by controlling homeostasis, connexin hemichannels are considered as the “bad guys”, as their activation is associated with the onset and dissemination of disease. Open connexin hemichannels indeed mediate the transport of messengers between the cytosol and extracellular environment and, by doing so, fuel inflammation and cell death in a plethora of diseases. The present mini-review discusses the mechanisms involved in the activation of connexin hemichannels during pathology.
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Affiliation(s)
- Raf Van Campenhout
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (R.V.C.); (A.R.G.)
| | - Ana Rita Gomes
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (R.V.C.); (A.R.G.)
| | - Timo W.M. De Groof
- Department of Medical Imaging, In Vivo Cellular and Molecular Imaging Laboratory, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (T.W.M.D.G.); (N.D.)
| | - Serge Muyldermans
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium;
| | - Nick Devoogdt
- Department of Medical Imaging, In Vivo Cellular and Molecular Imaging Laboratory, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (T.W.M.D.G.); (N.D.)
| | - Mathieu Vinken
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (R.V.C.); (A.R.G.)
- Correspondence: ; Tel.: +32-2-4774587
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Pham C, Hérault K, Oheim M, Maldera S, Vialou V, Cauli B, Li D. Astrocytes respond to a neurotoxic Aβ fragment with state-dependent Ca 2+ alteration and multiphasic transmitter release. Acta Neuropathol Commun 2021; 9:44. [PMID: 33726852 PMCID: PMC7968286 DOI: 10.1186/s40478-021-01146-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/28/2021] [Indexed: 12/13/2022] Open
Abstract
Excessive amounts of amyloid β (Aβ) peptide have been suggested to dysregulate synaptic transmission in Alzheimer's disease (AD). As a major type of glial cell in the mammalian brain, astrocytes regulate neuronal function and undergo activity alterations upon Aβ exposure. Yet the mechanistic steps underlying astrocytic responses to Aβ peptide remain to be elucidated. Here by fluorescence imaging of signaling pathways, we dissected astrocytic responses to Aβ25-35 peptide, a neurotoxic Aβ fragment present in AD patients. In native health astrocytes, Aβ25-35 evoked Ca2+ elevations via purinergic receptors, being also dependent on the opening of connexin (CX) hemichannels. Aβ25-35, however, induced a Ca2+ diminution in Aβ-preconditioned astrocytes as a result of the potentiation of the plasma membrane Ca2+ ATPase (PMCA). The PMCA and CX protein expression was observed with immunostaining in the brain tissue of hAPPJ20 AD mouse model. We also observed both Ca2+-independent and Ca2+-dependent glutamate release upon astrocytic Aβ exposure, with the former mediated by CX hemichannel and the latter by both anion channels and lysosome exocytosis. Our results suggest that Aβ peptide causes state-dependent responses in astrocytes, in association with a multiphasic release of signaling molecules. This study therefore helps to understand astrocyte engagement in AD-related amyloidopathy.
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Natha CM, Vemulapalli V, Fiori MC, Chang CWT, Altenberg GA. Connexin hemichannel inhibitors with a focus on aminoglycosides. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166115. [PMID: 33711451 DOI: 10.1016/j.bbadis.2021.166115] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/06/2021] [Accepted: 02/22/2021] [Indexed: 12/31/2022]
Abstract
Connexins are membrane proteins involved directly in cell-to-cell communication through the formation of gap-junctional channels. These channels result from the head-to-head docking of two hemichannels, one from each of two adjacent cells. Undocked hemichannels are also present at the plasma membrane where they mediate the efflux of molecules that participate in autocrine and paracrine signaling, but abnormal increase in hemichannel activity can lead to cell damage in disorders such as cardiac infarct, stroke, deafness, cataracts, and skin diseases. For this reason, connexin hemichannels have emerged as a valid therapeutic target. Know small molecule hemichannel inhibitors are not ideal leads for the development of better drugs for clinical use because they are not specific and/or have toxic effects. Newer inhibitors are more selective and include connexin mimetic peptides, anti-connexin antibodies and drugs that reduce connexin expression such as antisense oligonucleotides. Re-purposed drugs and their derivatives are also promising because of the significant experience with their clinical use. Among these, aminoglycoside antibiotics have been identified as inhibitors of connexin hemichannels that do not inhibit gap-junctional channels. In this review, we discuss connexin hemichannels and their inhibitors, with a focus on aminoglycoside antibiotics and derivatives of kanamycin A that inhibit connexin hemichannels, but do not have antibiotic effect.
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Affiliation(s)
- Cristina M Natha
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Varun Vemulapalli
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Mariana C Fiori
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Cheng-Wei T Chang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
| | - Guillermo A Altenberg
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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Harnessing the therapeutic potential of antibodies targeting connexin hemichannels. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166047. [PMID: 33418036 DOI: 10.1016/j.bbadis.2020.166047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 11/17/2020] [Accepted: 12/03/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Connexin hemichannels have been implicated in pathology-promoting conditions, including inflammation, numerous widespread human diseases, including cancer and diabetes, and several rare diseases linked to pathological point mutations. METHODS We analysed the literature focusing on antibodies capable of modulating hemichannel function, highlighting generation methods, applications to basic biomedical research and translational potential. RESULTS Anti-hemichannel antibodies generated over the past 3 decades targeted mostly connexin 43, with a focus on cancer treatment. A slow transition from relatively unselective polyclonal antibodies to more selective monoclonal antibodies resulted in few products with interesting characteristics that are under evaluation for clinical trials. Selection of antibodies from combinatorial phage-display libraries, has permitted to engineer a monoclonal antibody that binds to and blocks pathological hemichannels formed by connexin 26, 30 and 32. CONCLUSIONS All known antibodies that modulate connexin hemichannels target the two small extracellular loops of the connexin proteins. The extracellular region of different connexins is highly conserved, and few residues of each connexins are exposed. The search for new antibodies may develop an unprecedented potential for therapeutic applications, as it may benefit tremendously from novel whole-cell screening platforms that permit in situ selection of antibodies against membrane proteins in native state. The demonstrated efficacy of mAbs in reaching and modulating hemichannels in vivo, together with their relative specificity for connexins overlapping epitopes, should hopefully stimulate an interest for widening the scope of anti-hemichannel antibodies. There is no shortage of currently incurable diseases for which therapeutic intervention may benefit from anti-hemichannel antibodies capable of modulating hemichannel function selectively and specifically.
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The role of connexin proteins and their channels in radiation-induced atherosclerosis. Cell Mol Life Sci 2021; 78:3087-3103. [PMID: 33388835 PMCID: PMC8038956 DOI: 10.1007/s00018-020-03716-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/29/2020] [Accepted: 11/17/2020] [Indexed: 02/08/2023]
Abstract
Radiotherapy is an effective treatment for breast cancer and other thoracic tumors. However, while high-energy radiotherapy treatment successfully kills cancer cells, radiation exposure of the heart and large arteries cannot always be avoided, resulting in secondary cardiovascular disease in cancer survivors. Radiation-induced changes in the cardiac vasculature may thereby lead to coronary artery atherosclerosis, which is a major cardiovascular complication nowadays in thoracic radiotherapy-treated patients. The underlying biological and molecular mechanisms of radiation-induced atherosclerosis are complex and still not fully understood, resulting in potentially improper radiation protection. Ionizing radiation (IR) exposure may damage the vascular endothelium by inducing DNA damage, oxidative stress, premature cellular senescence, cell death and inflammation, which act to promote the atherosclerotic process. Intercellular communication mediated by connexin (Cx)-based gap junctions and hemichannels may modulate IR-induced responses and thereby the atherosclerotic process. However, the role of endothelial Cxs and their channels in atherosclerotic development after IR exposure is still poorly defined. A better understanding of the underlying biological pathways involved in secondary cardiovascular toxicity after radiotherapy would facilitate the development of effective strategies that prevent or mitigate these adverse effects. Here, we review the possible roles of intercellular Cx driven signaling and communication in radiation-induced atherosclerosis.
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Andelova K, Egan Benova T, Szeiffova Bacova B, Sykora M, Prado NJ, Diez ER, Hlivak P, Tribulova N. Cardiac Connexin-43 Hemichannels and Pannexin1 Channels: Provocative Antiarrhythmic Targets. Int J Mol Sci 2020; 22:ijms22010260. [PMID: 33383853 PMCID: PMC7795512 DOI: 10.3390/ijms22010260] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiac connexin-43 (Cx43) creates gap junction channels (GJCs) at intercellular contacts and hemi-channels (HCs) at the peri-junctional plasma membrane and sarcolemmal caveolae/rafts compartments. GJCs are fundamental for the direct cardiac cell-to-cell transmission of electrical and molecular signals which ensures synchronous myocardial contraction. The HCs and structurally similar pannexin1 (Panx1) channels are active in stressful conditions. These channels are essential for paracrine and autocrine communication through the release of ions and signaling molecules to the extracellular environment, or for uptake from it. The HCs and Panx1 channel-opening profoundly affects intracellular ionic homeostasis and redox status and facilitates via purinergic signaling pro-inflammatory and pro-fibrotic processes. These conditions promote cardiac arrhythmogenesis due to the impairment of the GJCs and selective ion channel function. Crosstalk between GJCs and HCs/Panx1 channels could be crucial in the development of arrhythmogenic substrates, including fibrosis. Despite the knowledge gap in the regulation of these channels, current evidence indicates that HCs and Panx1 channel activation can enhance the risk of cardiac arrhythmias. It is extremely challenging to target HCs and Panx1 channels by inhibitory agents to hamper development of cardiac rhythm disorders. Progress in this field may contribute to novel therapeutic approaches for patients prone to develop atrial or ventricular fibrillation.
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Affiliation(s)
- Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Tamara Egan Benova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Natalia Jorgelina Prado
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Emiliano Raul Diez
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Peter Hlivak
- Department of Arrhythmias and Pacing, National Institute of Cardiovascular Diseases, Pod Krásnou Hôrkou 1, 83348 Bratislava, Slovakia;
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
- Correspondence: ; Tel.: +421-2-32295-423
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Radiation-Induced Salivary Gland Dysfunction: Mechanisms, Therapeutics and Future Directions. J Clin Med 2020; 9:jcm9124095. [PMID: 33353023 PMCID: PMC7767137 DOI: 10.3390/jcm9124095] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/14/2022] Open
Abstract
Salivary glands sustain collateral damage following radiotherapy (RT) to treat cancers of the head and neck, leading to complications, including mucositis, xerostomia and hyposalivation. Despite salivary gland-sparing techniques and modified dosing strategies, long-term hypofunction remains a significant problem. Current therapeutic interventions provide temporary symptom relief, but do not address irreversible glandular damage. In this review, we summarize the current understanding of mechanisms involved in RT-induced hyposalivation and provide a framework for future mechanistic studies. One glaring gap in published studies investigating RT-induced mechanisms of salivary gland dysfunction concerns the effect of irradiation on adjacent non-irradiated tissue via paracrine, autocrine and direct cell-cell interactions, coined the bystander effect in other models of RT-induced damage. We hypothesize that purinergic receptor signaling involving P2 nucleotide receptors may play a key role in mediating the bystander effect. We also discuss promising new therapeutic approaches to prevent salivary gland damage due to RT.
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Astrocytic Connexin43 Channels as Candidate Targets in Epilepsy Treatment. Biomolecules 2020; 10:biom10111578. [PMID: 33233647 PMCID: PMC7699773 DOI: 10.3390/biom10111578] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
In epilepsy research, emphasis is put on exploring non-neuronal targets such as astrocytic proteins, since many patients remain pharmacoresistant to current treatments, which almost all target neuronal mechanisms. This paper reviews available data on astrocytic connexin43 (Cx43) signaling in seizures and epilepsy. Cx43 is a widely expressed transmembrane protein and the constituent of gap junctions (GJs) and hemichannels (HCs), allowing intercellular and extracellular communication, respectively. A plethora of research papers show altered Cx43 mRNA levels, protein expression, phosphorylation state, distribution and/or functional coupling in human epileptic tissue and experimental models. Human Cx43 mutations are linked to seizures as well, as 30% of patients with oculodentodigital dysplasia (ODDD), a rare genetic condition caused by mutations in the GJA1 gene coding for Cx43 protein, exhibit neurological symptoms including seizures. Cx30/Cx43 double knock-out mice show increased susceptibility to evoked epileptiform events in brain slices due to impaired GJ-mediated redistribution of K+ and glutamate and display a higher frequency of spontaneous generalized chronic seizures in an epilepsy model. Contradictory, Cx30/Cx43 GJs can traffic nutrients to high-energy demanding neurons and initiate astrocytic Ca2+ waves and hyper synchronization, thereby supporting proconvulsant effects. The general connexin channel blocker carbenoxolone and blockers from the fenamate family diminish epileptiform activity in vitro and improve seizure outcome in vivo. In addition, interventions with more selective peptide inhibitors of HCs display anticonvulsant actions. To conclude, further studies aiming to disentangle distinct roles of HCs and GJs are necessary and tools specifically targeting Cx43 HCs may facilitate the search for novel epilepsy treatments.
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Lissoni A, Wang N, Nezlobinskii T, De Smet M, Panfilov AV, Vandersickel N, Leybaert L, Witschas K. Gap19, a Cx43 Hemichannel Inhibitor, Acts as a Gating Modifier That Decreases Main State Opening While Increasing Substate Gating. Int J Mol Sci 2020; 21:ijms21197340. [PMID: 33027889 PMCID: PMC7583728 DOI: 10.3390/ijms21197340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/12/2020] [Accepted: 09/25/2020] [Indexed: 02/05/2023] Open
Abstract
Cx43 hemichannels (HCs) are electrically and chemically gated transmembrane pores with low open probability and multiple conductance states, which makes kinetic studies of channel gating in large datasets challenging. Here, we developed open access software, named HemiGUI, to analyze HC gating transitions and investigated voltage-induced HC opening based on up to ≈4000 events recorded in HeLa-Cx43-overexpressing cells. We performed a detailed characterization of Cx43 HC gating profiles and specifically focused on the role of the C-terminal tail (CT) domain by recording the impact of adding an EGFP tag to the Cx43 CT end (Cx43-EGFP) or by supplying the Cx43 HC-inhibiting peptide Gap19 that interferes with CT interaction with the cytoplasmic loop (CL). We found that Gap19 not only decreased HC opening activity to the open state (≈217 pS) but also increased the propensity of subconductance (≈80 pS) transitions that additionally became slower as compared to the control. The work demonstrates that large sample transition analysis allows detailed investigations on Cx43 HC gating and shows that Gap19 acts as a HC gating modifier by interacting with the CT that forms a crucial gating element.
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Affiliation(s)
- Alessio Lissoni
- Department of Basic and Applied Medical Sciences—Physiology Group, Ghent University, 9000 Ghent, Belgium; (A.L.); (N.W.); (M.D.S.)
| | - Nan Wang
- Department of Basic and Applied Medical Sciences—Physiology Group, Ghent University, 9000 Ghent, Belgium; (A.L.); (N.W.); (M.D.S.)
| | - Timur Nezlobinskii
- Department of Physics and Astronomy, Ghent University, 9000 Ghent, Belgium; (T.N.); (A.V.P.); (N.V.)
| | - Maarten De Smet
- Department of Basic and Applied Medical Sciences—Physiology Group, Ghent University, 9000 Ghent, Belgium; (A.L.); (N.W.); (M.D.S.)
| | - Alexander V. Panfilov
- Department of Physics and Astronomy, Ghent University, 9000 Ghent, Belgium; (T.N.); (A.V.P.); (N.V.)
- Laboratory of Computational Biology and Medicine, Ural Federal University, 620075 Ekaterinburg, Russia
| | - Nele Vandersickel
- Department of Physics and Astronomy, Ghent University, 9000 Ghent, Belgium; (T.N.); (A.V.P.); (N.V.)
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences—Physiology Group, Ghent University, 9000 Ghent, Belgium; (A.L.); (N.W.); (M.D.S.)
- Correspondence: (L.L.); (K.W.); Tel.: +32-9-332-3366 (L.L.); +32-9-332-6944 (K.W.)
| | - Katja Witschas
- Department of Basic and Applied Medical Sciences—Physiology Group, Ghent University, 9000 Ghent, Belgium; (A.L.); (N.W.); (M.D.S.)
- Correspondence: (L.L.); (K.W.); Tel.: +32-9-332-3366 (L.L.); +32-9-332-6944 (K.W.)
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Dere D, Zlomuzica A, Dere E. Channels to consciousness: a possible role of gap junctions in consciousness. Rev Neurosci 2020; 32:/j/revneuro.ahead-of-print/revneuro-2020-0012/revneuro-2020-0012.xml. [PMID: 32853172 DOI: 10.1515/revneuro-2020-0012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/26/2020] [Indexed: 12/20/2022]
Abstract
The neurophysiological basis of consciousness is still unknown and one of the most challenging questions in the field of neuroscience and related disciplines. We propose that consciousness is characterized by the maintenance of mental representations of internal and external stimuli for the execution of cognitive operations. Consciousness cannot exist without working memory, and it is likely that consciousness and working memory share the same neural substrates. Here, we present a novel psychological and neurophysiological framework that explains the role of consciousness for cognition, adaptive behavior, and everyday life. A hypothetical architecture of consciousness is presented that is organized as a system of operation and storage units named platforms that are controlled by a consciousness center (central executive/online platform). Platforms maintain mental representations or contents, are entrusted with different executive functions, and operate at different levels of consciousness. The model includes conscious-mode central executive/online and mental time travel platforms and semiconscious steady-state and preconscious standby platforms. Mental representations or contents are represented by neural circuits and their support cells (astrocytes, oligodendrocytes, etc.) and become conscious when neural circuits reverberate, that is, fire sequentially and continuously with relative synchronicity. Reverberatory activity in neural circuits may be initiated and maintained by pacemaker cells/neural circuit pulsars, enhanced electronic coupling via gap junctions, and unapposed hemichannel opening. The central executive/online platform controls which mental representations or contents should become conscious by recruiting pacemaker cells/neural network pulsars, the opening of hemichannels, and promoting enhanced neural circuit coupling via gap junctions.
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Affiliation(s)
- Dorothea Dere
- Département UMR 8256 Adaptation Biologique et Vieillissement, Sorbonne Université, Institut de Biologie Paris-Seine, (IBPS), UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris Cedex, France
| | - Armin Zlomuzica
- Faculty of Psychology, Behavioral and Clinical Neuroscience, University of Bochum, Massenbergstraße 9-13, D-44787 Bochum, Germany
| | - Ekrem Dere
- Département UMR 8256 Adaptation Biologique et Vieillissement, Sorbonne Université, Institut de Biologie Paris-Seine, (IBPS), UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris Cedex, France
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Peracchia C. Calmodulin-Cork Model of Gap Junction Channel Gating-One Molecule, Two Mechanisms. Int J Mol Sci 2020; 21:E4938. [PMID: 32668628 PMCID: PMC7404200 DOI: 10.3390/ijms21144938] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/08/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022] Open
Abstract
The Calmodulin-Cork gating model is based on evidence for the direct role of calmodulin (CaM) in channel gating. Indeed, chemical gating of cell-to-cell channels is sensitive to nanomolar cytosolic calcium concentrations [Ca2+]i. Calmodulin inhibitors and inhibition of CaM expression prevent chemical gating. CaMCC, a CaM mutant with higher Ca2+-sensitivity greatly increases chemical gating sensitivity (in CaMCC the NH2-terminal EF-hand pair (res. 9-76) is replaced by the COOH-terminal pair (res. 82-148). Calmodulin colocalizes with connexins. Connexins have high-affinity CaM binding sites. Several connexin mutants paired to wild-type connexins have a high gating sensitivity that is eliminated by inhibition of CaM expression. Repeated transjunctional voltage (Vj) pulses slowly and progressively close a large number of channels by the chemical/slow gate (CaM lobe). At the single-channel level, the chemical/slow gate closes and opens slowly with on-off fluctuations. The model proposes two types of CaM-driven gating: "Ca-CaM-Cork" and "CaM-Cork". In the first, gating involves Ca2+-induced CaM-activation. In the second, gating takes place without [Ca2+]i rise. The Ca-CaM-Cork gating is only reversed by a return of [Ca2+]i to resting values, while the CaM-Cork gating is reversed by Vj positive at the gated side.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University Rochester, Rochester, NY 14642, USA
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Giaume C, Naus CC, Sáez JC, Leybaert L. Glial Connexins and Pannexins in the Healthy and Diseased Brain. Physiol Rev 2020; 101:93-145. [PMID: 32326824 DOI: 10.1152/physrev.00043.2018] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Over the past several decades a large amount of data have established that glial cells, the main cell population in the brain, dynamically interact with neurons and thus impact their activity and survival. One typical feature of glia is their marked expression of several connexins, the membrane proteins forming intercellular gap junction channels and hemichannels. Pannexins, which have a tetraspan membrane topology as connexins, are also detected in glial cells. Here, we review the evidence that connexin and pannexin channels are actively involved in dynamic and metabolic neuroglial interactions in physiological as well as in pathological situations. These features of neuroglial interactions open the way to identify novel non-neuronal aspects that allow for a better understanding of behavior and information processing performed by neurons. This will also complement the "neurocentric" view by facilitating the development of glia-targeted therapeutic strategies in brain disease.
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Affiliation(s)
- Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Christian C Naus
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Juan C Sáez
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Luc Leybaert
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Himelman E, Lillo MA, Nouet J, Gonzalez JP, Zhao Q, Xie LH, Li H, Liu T, Wehrens XH, Lampe PD, Fishman GI, Shirokova N, Contreras JE, Fraidenraich D. Prevention of connexin-43 remodeling protects against Duchenne muscular dystrophy cardiomyopathy. J Clin Invest 2020; 130:1713-1727. [PMID: 31910160 PMCID: PMC7108916 DOI: 10.1172/jci128190] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022] Open
Abstract
Aberrant expression of the cardiac gap junction protein connexin-43 (Cx43) has been suggested as playing a role in the development of cardiac disease in the mdx mouse model of Duchenne muscular dystrophy (DMD); however, a mechanistic understanding of this association is lacking. Here, we identified a reduction of phosphorylation of Cx43 serines S325/S328/S330 in human and mouse DMD hearts. We hypothesized that hypophosphorylation of Cx43 serine-triplet triggers pathological Cx43 redistribution to the lateral sides of cardiomyocytes (remodeling). Therefore, we generated knockin mdx mice in which the Cx43 serine-triplet was replaced with either phospho-mimicking glutamic acids (mdxS3E) or nonphosphorylatable alanines (mdxS3A). The mdxS3E, but not mdxS3A, mice were resistant to Cx43 remodeling, with a corresponding reduction of Cx43 hemichannel activity. MdxS3E cardiomyocytes displayed improved intracellular Ca2+ signaling and a reduction of NADPH oxidase 2 (NOX2)/ROS production. Furthermore, mdxS3E mice were protected against inducible arrhythmias, related lethality, and the development of cardiomyopathy. Inhibition of microtubule polymerization by colchicine reduced both NOX2/ROS and oxidized CaMKII, increased S325/S328/S330 phosphorylation, and prevented Cx43 remodeling in mdx hearts. Together, these results demonstrate a mechanism of dystrophic Cx43 remodeling and suggest that targeting Cx43 may be a therapeutic strategy for preventing heart dysfunction and arrhythmias in DMD patients.
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Affiliation(s)
| | | | - Julie Nouet
- Department of Cell Biology and Molecular Medicine
| | | | - Qingshi Zhao
- Department of Cell Biology and Molecular Medicine
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine
| | - Hong Li
- Center for Advanced Proteomics Research, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, USA
| | - Tong Liu
- Center for Advanced Proteomics Research, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, USA
| | - Xander H.T. Wehrens
- Department of Molecular Physiology and Biophysics, Medicine, Neuroscience, and Pediatrics, Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, USA
| | - Paul D. Lampe
- Fred Hutchinson Cancer Research Center, Translational Research Program, Public Health Sciences Division, Seattle, Washington, USA
| | - Glenn I. Fishman
- Leon H. Charney Division of Cardiology, New York University Langone Health, New York, New York, USA
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45
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Hoorelbeke D, Decrock E, De Smet M, De Bock M, Descamps B, Van Haver V, Delvaeye T, Krysko DV, Vanhove C, Bultynck G, Leybaert L. Cx43 channels and signaling via IP 3/Ca 2+, ATP, and ROS/NO propagate radiation-induced DNA damage to non-irradiated brain microvascular endothelial cells. Cell Death Dis 2020; 11:194. [PMID: 32188841 PMCID: PMC7080808 DOI: 10.1038/s41419-020-2392-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023]
Abstract
Radiotherapeutic treatment consists of targeted application of radiation beams to a tumor but exposure of surrounding healthy tissue is inevitable. In the brain, ionizing radiation induces breakdown of the blood-brain barrier by effects on brain microvascular endothelial cells. Damage from directly irradiated cells can be transferred to surrounding non-exposed bystander cells, known as the radiation-induced bystander effect. We investigated involvement of connexin channels and paracrine signaling in radiation-induced bystander DNA damage in brain microvascular endothelial cells exposed to focused X-rays. Irradiation caused DNA damage in the directly exposed area, which propagated over several millimeters in the bystander area. DNA damage was significantly reduced by the connexin channel-targeting peptide Gap26 and the Cx43 hemichannel blocker TAT-Gap19. ATP release, dye uptake, and patch clamp experiments showed that hemichannels opened within 5 min post irradiation in both irradiated and bystander areas. Bystander signaling involved cellular Ca2+ dynamics and IP3, ATP, ROS, and NO signaling, with Ca2+, IP3, and ROS as crucial propagators of DNA damage. We conclude that bystander effects are communicated by a concerted cascade involving connexin channels, and IP3/Ca2+, ATP, ROS, and NO as major contributors of regenerative signal expansion.
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Affiliation(s)
- Delphine Hoorelbeke
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Elke Decrock
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Maarten De Smet
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Marijke De Bock
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Benedicte Descamps
- Infinity Lab, IBiTech-MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Valérie Van Haver
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Tinneke Delvaeye
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Dmitri V Krysko
- Cell Death Investigation and Therapy Laboratory, Department of Human Structure and Repair, Ghent University, Ghent, Belgium.,Department of Physiology, Sechenov First Moscow State Medical University, Moskow, Russia
| | - Christian Vanhove
- Infinity Lab, IBiTech-MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Geert Bultynck
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Luc Leybaert
- Physiology group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium.
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46
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Ramadan R, Vromans E, Anang DC, Goetschalckx I, Hoorelbeke D, Decrock E, Baatout S, Leybaert L, Aerts A. Connexin43 Hemichannel Targeting With TAT-Gap19 Alleviates Radiation-Induced Endothelial Cell Damage. Front Pharmacol 2020; 11:212. [PMID: 32210810 PMCID: PMC7066501 DOI: 10.3389/fphar.2020.00212] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/14/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Emerging evidence indicates an excess risk of late occurring cardiovascular diseases, especially atherosclerosis, after thoracic cancer radiotherapy. Ionizing radiation (IR) induces cellular effects which may induce endothelial cell dysfunction, an early marker for atherosclerosis. In addition, intercellular communication through channels composed of transmembrane connexin proteins (Cxs), i.e. Gap junctions (direct cell-cell coupling) and hemichannels (paracrine release/uptake pathway) can modulate radiation-induced responses and therefore the atherosclerotic process. However, the role of endothelial hemichannel in IR-induced atherosclerosis has never been described before. MATERIALS AND METHODS Telomerase-immortalized human Coronary Artery/Microvascular Endothelial cells (TICAE/TIME) were exposed to X-rays (0.1 and 5 Gy). Production of reactive oxygen species (ROS), DNA damage, cell death, inflammatory responses, and senescence were assessed with or without applying a Cx43 hemichannel blocker (TAT-Gap19). RESULTS We report here that IR induces an increase in oxidative stress, cell death, inflammatory responses (IL-8, IL-1β, VCAM-1, MCP-1, and Endothelin-1) and premature cellular senescence in TICAE and TIME cells. These effects are significantly reduced in the presence of the Cx43 hemichannel-targeting peptide TAT-Gap19. CONCLUSION Our findings suggest that endothelial Cx43 hemichannels contribute to various IR-induced processes, such as ROS, cell death, inflammation, and senescence, resulting in an increase in endothelial cell damage, which could be protected by blocking these hemichannels. Thus, targeting Cx43 hemichannels may potentially exert radioprotective effects.
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Affiliation(s)
- Raghda Ramadan
- Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
- Department of Fundamental and Basic Medical Sciences, Physiology Group, Ghent University, Ghent, Belgium
| | - Els Vromans
- Centre for Environmental Health Sciences, Hasselt University, Hasselt, Belgium
| | - Dornatien Chuo Anang
- Biomedical Research Institute and Transnational University of Limburg, Hasselt University, Hasselt, Belgium
| | - Ines Goetschalckx
- Protein Chemistry, Proteomics and Epigenetic Signaling Group, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Delphine Hoorelbeke
- Department of Fundamental and Basic Medical Sciences, Physiology Group, Ghent University, Ghent, Belgium
| | - Elke Decrock
- Department of Fundamental and Basic Medical Sciences, Physiology Group, Ghent University, Ghent, Belgium
| | - Sarah Baatout
- Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
- Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
| | - Luc Leybaert
- Department of Fundamental and Basic Medical Sciences, Physiology Group, Ghent University, Ghent, Belgium
| | - An Aerts
- Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
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47
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Lagos-Cabré R, Burgos-Bravo F, Avalos AM, Leyton L. Connexins in Astrocyte Migration. Front Pharmacol 2020; 10:1546. [PMID: 32009957 PMCID: PMC6974553 DOI: 10.3389/fphar.2019.01546] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/29/2019] [Indexed: 12/18/2022] Open
Abstract
Astrocytes have long been considered the supportive cells of the central nervous system, but during the last decades, they have gained much more attention because of their active participation in the modulation of neuronal function. For example, after brain damage, astrocytes become reactive and undergo characteristic morphological and molecular changes, such as hypertrophy and increase in the expression of glial fibrillary acidic protein (GFAP), in a process known as astrogliosis. After severe damage, astrocytes migrate to the lesion site and proliferate, which leads to the formation of a glial scar. At this scar-forming stage, astrocytes secrete many factors, such as extracellular matrix proteins, cytokines, growth factors and chondroitin sulfate proteoglycans, stop migrating, and the process is irreversible. Although reactive gliosis is a normal physiological response that can protect brain cells from further damage, it also has detrimental effects on neuronal survival, by creating a hostile and non-permissive environment for axonal repair. The transformation of astrocytes from reactive to scar-forming astrocytes highlights migration as a relevant regulator of glial scar formation, and further emphasizes the importance of efficient communication between astrocytes in order to orchestrate cell migration. The coordination between astrocytes occurs mainly through Connexin (Cx) channels, in the form of direct cell-cell contact (gap junctions, GJs) or contact between the extracellular matrix and the astrocytes (hemichannels, HCs). Reactive astrocytes increase the expression levels of several proteins involved in astrocyte migration, such as αvβ3 Integrin, Syndecan-4 proteoglycan, the purinergic receptor P2X7, Pannexin1, and Cx43 HCs. Evidence has indicated that Cx43 HCs play a role in regulating astrocyte migration through the release of small molecules to the extracellular space, which then activate receptors in the same or adjacent cells to continue the signaling cascades required for astrocyte migration. In this review, we describe the communication of astrocytes through Cxs, the role of Cxs in inflammation and astrocyte migration, and discuss the molecular mechanisms that regulate Cx43 HCs, which may provide a therapeutic window of opportunity to control astrogliosis and the progression of neurodegenerative diseases.
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Affiliation(s)
- Raúl Lagos-Cabré
- Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Center for Studies on Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Instituto de Ciencias Biomédicas (ICBM), Universidad de Chile, Santiago, Chile
| | - Francesca Burgos-Bravo
- Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Center for Studies on Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Instituto de Ciencias Biomédicas (ICBM), Universidad de Chile, Santiago, Chile
| | - Ana María Avalos
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Lisette Leyton
- Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Center for Studies on Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Instituto de Ciencias Biomédicas (ICBM), Universidad de Chile, Santiago, Chile
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48
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Peracchia C. Calmodulin-Mediated Regulation of Gap Junction Channels. Int J Mol Sci 2020; 21:E485. [PMID: 31940951 PMCID: PMC7014422 DOI: 10.3390/ijms21020485] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 12/25/2022] Open
Abstract
Evidence that neighboring cells uncouple from each other as one dies surfaced in the late 19th century, but it took almost a century for scientists to start understanding the uncoupling mechanism (chemical gating). The role of cytosolic free calcium (Ca2+i) in cell-cell channel gating was first reported in the mid-sixties. In these studies, only micromolar [Ca2+]i were believed to affect gating-concentrations reachable only in cell death, which would discard Ca2+i as a fine modulator of cell coupling. More recently, however, numerous researchers, including us, have reported the effectiveness of nanomolar [Ca2+]i. Since connexins do not have high-affinity calcium sites, the effectiveness of nanomolar [Ca2+]i suggests the role of Ca-modulated proteins, with calmodulin (CaM) being most obvious. Indeed, in 1981 we first reported that a CaM-inhibitor prevents chemical gating. Since then, the CaM role in gating has been confirmed by studies that tested it with a variety of approaches such as treatments with CaM-inhibitors, inhibition of CaM expression, expression of CaM mutants, immunofluorescent co-localization of CaM and gap junctions, and binding of CaM to peptides mimicking connexin domains identified as CaM targets. Our gating model envisions Ca2+-CaM to directly gate the channels by acting as a plug ("Cork" gating model), and probably also by affecting connexin conformation.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
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49
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Lissoni A, Hulpiau P, Martins-Marques T, Wang N, Bultynck G, Schulz R, Witschas K, Girao H, De Smet M, Leybaert L. RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes. Cardiovasc Res 2019; 117:123-136. [PMID: 31841141 DOI: 10.1093/cvr/cvz340] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/14/2019] [Accepted: 12/11/2019] [Indexed: 12/16/2022] Open
Abstract
AIMS Connexin-based gap junctions are crucial for electrical communication in the heart; they are each composed of two docked hemichannels (HCs), supplied as unpaired channels via the sarcolemma. When open, an unpaired HC forms a large pore, high-conductance and Ca2+-permeable membrane shunt pathway that may disturb cardiomyocyte function. HCs composed of connexin 43 (Cx43), a major cardiac connexin, can be opened by electrical stimulation but only by very positive membrane potentials. Here, we investigated the activation of Cx43 HCs in murine ventricular cardiomyocytes voltage-clamped at -70 mV. METHODS AND RESULTS Using whole-cell patch-clamp, co-immunoprecipitation, western blot analysis, immunocytochemistry, proximity ligation assays, and protein docking studies, we found that stimulation of ryanodine receptors (RyRs) triggered unitary currents with a single-channel conductance of ∼220 pS, which were strongly reduced by Cx43 knockdown. Recordings under Ca2+-clamp conditions showed that both RyR activation and intracellular Ca2+ elevation were necessary for HC opening. Proximity ligation studies indicated close Cx43-RyR2 apposition (<40 nm), and both proteins co-immunoprecipitated indicating physical interaction. Molecular modelling suggested a strongly conserved RyR-mimicking peptide sequence (RyRHCIp), which inhibited RyR/Ca2+ HC activation but not voltage-triggered activation. The peptide also slowed down action potential repolarization. Interestingly, alterations in the concerned RyR sequence are known to be associated with primary familial hypertrophic cardiomyopathy. CONCLUSION Our results demonstrate that Cx43 HCs are intimately linked to RyRs, allowing them to open at negative diastolic membrane potential in response to RyR activation.
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Affiliation(s)
- Alessio Lissoni
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Paco Hulpiau
- Department of Bio-Medical Sciences, HOWEST University of Applied Sciences (Hogeschool West-Vlaanderen), Bruges, Belgium
| | - Tânia Martins-Marques
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
| | - Nan Wang
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Geert Bultynck
- Department of Molecular Cell Biology, Laboratory of Molecular and Cellular Signaling, KU Leuven, Leuven, Belgium
| | - Rainer Schulz
- Institut für Physiologie, JustusLiebig Universität Giessen, Giessen, Germany
| | - Katja Witschas
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
| | - Maarten De Smet
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
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50
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Delvaeye T, De Smet MAJ, Verwaerde S, Decrock E, Czekaj A, Vandenbroucke RE, Lemeire K, Gonçalves A, Declercq W, Vandenabeele P, Krysko DV, Leybaert L. Blocking connexin43 hemichannels protects mice against tumour necrosis factor-induced inflammatory shock. Sci Rep 2019; 9:16623. [PMID: 31719598 PMCID: PMC6851386 DOI: 10.1038/s41598-019-52900-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/22/2019] [Indexed: 02/07/2023] Open
Abstract
Upon intravenous injection of tumour necrosis factor (TNF) in mice, a systemic inflammatory response syndrome (SIRS) is initiated, characterized by an acute cytokine storm and induction of vascular hyperpermeability. Connexin43 hemichannels have been implicated in various pathological conditions, e.g. ischemia and inflammation, and can lead to detrimental cellular outcomes. Here, we explored whether targeting connexin43 hemichannels could alleviate TNF-induced endothelial barrier dysfunction and lethality in SIRS. Therefore, we verified whether administration of connexin43-targeting-peptides affected survival, body temperature and vascular permeability in vivo. In vitro, TNF-effects on connexin43 hemichannel function were investigated by single-channel studies and Ca2+-imaging. Blocking connexin43 hemichannels with TAT-Gap19 protected mice against TNF-induced mortality, hypothermia and vascular leakage, while enhancing connexin43 hemichannel function with TAT-CT9 provoked opposite sensitizing effects. In vitro patch-clamp studies revealed that TNF acutely activated connexin43 hemichannel opening in endothelial cells, which was promoted by CT9, and inhibited by Gap19 and intracellular Ca2+-buffering. In vivo experiments aimed at buffering intracellular Ca2+, and pharmacologically targeting Ca2+/calmodulin-dependent protein kinase-II, a known modulator of endothelial barrier integrity, demonstrated their involvement in permeability alterations. Our results demonstrate significant benefits of inhibiting connexin43 hemichannels to counteract TNF-induced SIRS-associated vascular permeability and lethality.
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Affiliation(s)
- Tinneke Delvaeye
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Maarten A J De Smet
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Stijn Verwaerde
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Elke Decrock
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Aleksandra Czekaj
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Roosmarijn E Vandenbroucke
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Kelly Lemeire
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Amanda Gonçalves
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,VIB BioImaging Core, Ghent, Belgium
| | - Wim Declercq
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Peter Vandenabeele
- VIB Center for Inflammation Research, Ghent, Belgium. .,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium. .,Methusalem Program, Ghent University, Ghent, Belgium.
| | - Dmitri V Krysko
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium.
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium.
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