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Vitureira N, Rafael A, Abudara V. P2X7 receptors and pannexin1 hemichannels shape presynaptic transmission. Purinergic Signal 2024; 20:223-236. [PMID: 37713157 PMCID: PMC11189373 DOI: 10.1007/s11302-023-09965-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/06/2023] [Indexed: 09/16/2023] Open
Abstract
Over the last decades, since the discovery of ATP as a transmitter, accumulating evidence has been reported about the role of this nucleotide and purinergic receptors, in particular P2X7 receptors, in the modulation of synaptic strength and plasticity. Purinergic signaling has emerged as a crucial player in orchestrating the molecular interaction between the components of the tripartite synapse, and much progress has been made in how this neuron-glia interaction impacts neuronal physiology under basal and pathological conditions. On the other hand, pannexin1 hemichannels, which are functionally linked to P2X7 receptors, have appeared more recently as important modulators of excitatory synaptic function and plasticity under diverse contexts. In this review, we will discuss the contribution of ATP, P2X7 receptors, and pannexin hemichannels to the modulation of presynaptic strength and its impact on motor function, sensory processing, synaptic plasticity, and neuroglial communication, with special focus on the P2X7 receptor/pannexin hemichannel interplay. We also address major hypotheses about the role of this interaction in physiological and pathological circumstances.
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Affiliation(s)
- Nathalia Vitureira
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
| | - Alberto Rafael
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
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2
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Ryan AT, Kim M, Lim K. Immune Cell Migration to Cancer. Cells 2024; 13:844. [PMID: 38786066 PMCID: PMC11120175 DOI: 10.3390/cells13100844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 04/27/2024] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.
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Affiliation(s)
- Allison T. Ryan
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA; (A.T.R.); (M.K.)
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY 14642, USA
| | - Minsoo Kim
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA; (A.T.R.); (M.K.)
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY 14642, USA
| | - Kihong Lim
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA; (A.T.R.); (M.K.)
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, Rochester, NY 14642, USA
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Gómez GI, Alvear TF, Roa DA, Farias-Pasten A, Vergara SA, Mellado LA, Martinez-Araya CJ, Prieto-Villalobos J, García-Rodríguez C, Sánchez N, Sáez JC, Ortíz FC, Orellana JA. Cx43 hemichannels and panx1 channels contribute to ethanol-induced astrocyte dysfunction and damage. Biol Res 2024; 57:15. [PMID: 38576018 PMCID: PMC10996276 DOI: 10.1186/s40659-024-00493-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Alcohol, a widely abused drug, significantly diminishes life quality, causing chronic diseases and psychiatric issues, with severe health, societal, and economic repercussions. Previously, we demonstrated that non-voluntary alcohol consumption increases the opening of Cx43 hemichannels and Panx1 channels in astrocytes from adolescent rats. However, whether ethanol directly affects astroglial hemichannels and, if so, how this impacts the function and survival of astrocytes remains to be elucidated. RESULTS Clinically relevant concentrations of ethanol boost the opening of Cx43 hemichannels and Panx1 channels in mouse cortical astrocytes, resulting in the release of ATP and glutamate. The activation of these large-pore channels is dependent on Toll-like receptor 4, P2X7 receptors, IL-1β and TNF-α signaling, p38 mitogen-activated protein kinase, and inducible nitric oxide (NO) synthase. Notably, the ethanol-induced opening of Cx43 hemichannels and Panx1 channels leads to alterations in cytokine secretion, NO production, gliotransmitter release, and astrocyte reactivity, ultimately impacting survival. CONCLUSION Our study reveals a new mechanism by which ethanol impairs astrocyte function, involving the sequential stimulation of inflammatory pathways that further increase the opening of Cx43 hemichannels and Panx1 channels. We hypothesize that targeting astroglial hemichannels could be a promising pharmacological approach to preserve astrocyte function and synaptic plasticity during the progression of various alcohol use disorders.
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Affiliation(s)
- Gonzalo I Gómez
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Tanhia F Alvear
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Daniela A Roa
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Arantza Farias-Pasten
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Sergio A Vergara
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Luis A Mellado
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Claudio J Martinez-Araya
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Juan Prieto-Villalobos
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile
| | - Claudia García-Rodríguez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, 2360102, Chile
| | - Natalia Sánchez
- Department of Anatomy, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan C Sáez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, 2360102, Chile
| | - Fernando C Ortíz
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Mechanisms of Myelin Formation and Repair Laboratory, Chacabuco 675, of. 212, Santiago, 8350347, Chile.
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, 8330024, Chile.
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Fjærvoll HK, Fjærvoll KA, Yang M, Bair J, Utheim TP, Dartt DA. Purinergic 2X 4 (P2X4), but not P2X7, receptors increase cytosolic [Ca 2+] and stimulate mucin secretion in rat conjunctival goblet cells to maintain ocular surface health. Exp Eye Res 2023; 235:109614. [PMID: 37580003 DOI: 10.1016/j.exer.2023.109614] [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: 05/07/2023] [Revised: 07/14/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
Ionotropic purinergic receptors (P2XRs) are activated by ATP and ATP analogs. ATP can be released through ATP-permeable channels such as the pannexin hemichannels. Upon activation, the P2XRs become permeable to Ca2+, a potent stimulator of mucin secretion in conjunctival goblet cells (CGCs). The purpose of this study was to investigate the presence and function of P2XRs in CGCs. We also examined the presence of pannexin hemichannels. Rat first passage CGCs were stained with the goblet cell marker anti-cytokeratin 7 antibody and specific antibodies to P2X1-7 receptors and pannexin 1-3. mRNA expression was determined by RT-PCR using primers specific to P2XRs and pannexins. Proteins were identified with Western blotting (WB) using the same antibodies as for immunofluorescence (IF) microscopy. To study receptor function, CGCs were incubated with Fura 2-AM, exposed to agonists and antagonists, and intracellular [Ca2+] ([Ca2+]i) measured. [Ca2+]i was also measured after knock down of P2X4 and P2X7 receptor expression, and when exploiting P2XR specific characteristics. Lastly, mucin secretion was measured after the addition of several P2XR agonists. All P2XRs and pannexins were visualized with IF microscopy, and identified with RT-PCR and WB. [Ca2+]i was significantly increased when stimulated with ATP (10-7-10-4 M). Suramin, a non-selective P2XR antagonist at 10-4 M did not reduce ATP-induced peak [Ca2+]i. The potent P2X7 agonist, BzATP (10-7-10-4 M) increased the [Ca2+]i, although to a lesser extent than ATP. When measuring [Ca2+]i the effect of repeated applications of ATP at 10-5 or 10-6 M the response "desensitized" after 30-60 s. The P2X4 specific antagonist 5-BDBD decreased the P2X4 agonist, 2MeSATP,-induced [Ca2+]i increase. Furthermore, siRNA against the P2X4R, but not the P2X7R, decreased agonist-induced peak [Ca2+]i. ATP (10-5 M), BzATP (10-4 M) and 2MeSATP (10-5 M) induced mucin secretion. We conclude that all seven P2XRs are present in cultured rat CGCs. Of the P2XRs, only activation of the homotrimeric P2X4R appears to increase [Ca2+]i and induce mucin secretion. The P2X4R in CGCs offers a new therapeutic target for protective mucin secretion.
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Affiliation(s)
- Haakon K Fjærvoll
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States; Medical Student Research Program, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Ketil A Fjærvoll
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States; Medical Student Research Program, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Menglu Yang
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Jeffrey Bair
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Tor P Utheim
- Medical Student Research Program, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway; Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Darlene A Dartt
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
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Lissoni A, Tao S, Allewaert R, Witschas K, Leybaert L. Cx43 Hemichannel and Panx1 Channel Modulation by Gap19 and 10Panx1 Peptides. Int J Mol Sci 2023; 24:11612. [PMID: 37511370 PMCID: PMC10380488 DOI: 10.3390/ijms241411612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/14/2023] [Accepted: 07/16/2023] [Indexed: 07/30/2023] Open
Abstract
Cx43 hemichannels (HCs) and Panx1 channels are two genetically distant protein families. Despite the lack of sequence homology, Cx43 and Panx1 channels have been the subject of debate due to their overlapping expression and the fact that both channels present similarities in terms of their membrane topology and electrical properties. Using the mimetic peptides Gap19 and 10Panx1, this study aimed to investigate the cross-effects of these peptides on Cx43 HCs and Panx1 channels. The single-channel current activity from stably expressing HeLa-Cx43 and C6-Panx1 cells was recorded using patch-clamp experiments in whole-cell voltage-clamp mode, demonstrating 214 pS and 68 pS average unitary conductances for the respective channels. Gap19 was applied intracellularly while 10Panx1 was applied extracellularly at different concentrations (100, 200 and 500 μM) and the average nominal open probability (NPo) was determined for each testing condition. A concentration of 100 µM Gap19 more than halved the NPo of Cx43 HCs, while 200 µM 10Panx1 was necessary to obtain a half-maximal NPo reduction in the Panx1 channels. Gap19 started to significantly inhibit the Panx1 channels at 500 µM, reducing the NPo by 26% while reducing the NPo of the Cx43 HCs by 84%. In contrast 10Panx1 significantly reduced the NPo of the Cx43 HCs by 37% at 100 µM and by 83% at 200 µM, a concentration that caused the half-maximal inhibition of the Panx1 channels. These results demonstrate that 10Panx1 inhibits Cx43 HCs over the 100-500 µM concentration range while 500 µM intracellular Gap19 is necessary to observe some inhibition of Panx1 channels.
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6
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Mizdrak I, Mizdrak M, Racetin A, Bošković B, Benzon B, Durdov MG, Vukojević K, Filipović N. Expression of Connexins 37, 40 and 45, Pannexin 1 and Vimentin in Laryngeal Squamous Cell Carcinomas. Genes (Basel) 2023; 14:446. [PMID: 36833374 PMCID: PMC9956287 DOI: 10.3390/genes14020446] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
Approximately 60% of patients with squamous cell carcinoma (LSCC) have regional occult metastatic disease/distant metastases at the time of diagnosis, putting them at higher risk for disease progression. Therefore, biomarkers are needed for early prognostic purpose. The aim of this study was to analyze the expression pattern of connexins (Cx) 37, 40 and 45, pannexin1 (Panx1) and vimentin in LSCC and correlate with tumor grade (G) and outcome. METHODS Thirty-four patients who underwent (hemi-)laryngectomy and regional lymphadenectomy due to LSCC from 2017 to 2018 in University Hospital Split, Croatia, were studied. Samples of tumor tissue and adjacent normal mucosa embedded in paraffin blocks were stained using the immunofluorescence method and were semi-quantitatively analyzed. RESULTS The expression of Cx37, Cx40, and Panx1 differed between cancer and adjacent normal mucosa and between histological grades, being the highest in well-differentiated (G1) cancer and low/absent in poorly differentiated (G3) cancer (all p < 0.05). The expression of vimentin was the highest in G3 cancer. Expression of Cx45 was generally weak/absent, with no significant difference between cancer and the controls or between grades. Lower Panx1 and higher vimentin expression were found to be prognostic factors for regional metastatic disease. Lower Cx37 and 40 expressions were present in patients with disease recurrence after the three-year follow-up period. CONCLUSION Cx37 and Cx40, Panx1, and vimentin have the potential to be used as prognostic biomarkers for LSCC.
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Affiliation(s)
- Ivan Mizdrak
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia
| | - Maja Mizdrak
- Department of Nephrology and Hemodialysis, University Hospital of Split, Šoltanska 1, 21000 Split, Croatia
| | - Anita Racetin
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia
| | - Braco Bošković
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia
| | - Benjamin Benzon
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia
| | - Merica Glavina Durdov
- Department of Pathology, Forensic Medicine and Cytology, University Hospital of Split, University of Split School of Medicine, Spinčićeva 1, 21000 Split, Croatia
| | - Katarina Vukojević
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia
| | - Natalija Filipović
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia
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7
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Garré JM, Bukauskas FF, Bennett MVL. Single channel properties of pannexin-1 and connexin-43 hemichannels and P2X7 receptors in astrocytes cultured from rodent spinal cords. Glia 2022; 70:2260-2275. [PMID: 35915989 PMCID: PMC9560969 DOI: 10.1002/glia.24250] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 11/11/2022]
Abstract
Astrocytes express surface channels involved in purinergic signaling. Among these channels, pannexin-1 (Px1) and connexin-43 (Cx43) hemichannels (HCs) release ATP that acts directly, or through its derivatives, on neurons and glia via purinergic receptors. Although HCs are functional, that is, open and close under physiological and pathological conditions, single channel properties of Px1 HCs in astrocytes have not been defined. Here, we developed a dual voltage clamp technique in HeLa cells expressing human Px1-YFP, and then applied this system to rodent spinal astrocytes to compare their single channel properties with other surface channels, that is, Cx43 HCs and P2X7 receptors (P2X7Rs). Channels were recorded in cell attached patches and evoked with ramp cycles applied through another pipette in whole cell voltage clamp. The mean unitary conductances of Px1 HCs were comparable in HeLa Px1-YFP cells and spinal astrocytes, ~42 and ~48 pS, respectively. Based on their unitary conductance, voltage-dependence, and unitary activity after pharmacological and gene silencing, Px1 HCs in astrocytes could be distinguished from Cx43 HCs and P2X7Rs. Channel activity of Px1 HCs and P2X7Rs was greater than that of Cx43 HCs in control astrocytes during ramps. Unitary activity of Px1 HCs was decreased and that of Cx43 HCs and P2X7Rs increased in astrocytes treated with fibroblast growth factor 1 (FGF-1). In summary, we resolved single channel properties of three different surface channels involved in purinergic signaling in spinal astrocytes, which were differentially modulated by FGF-1, a growth factor involved in neurodevelopment, inflammation and repair.
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Affiliation(s)
- Juan Mauricio Garré
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Feliksas F Bukauskas
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Michael V L Bennett
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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8
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Li C, Zhang X, Yang B, Wei F, Ren Y, Mu W, Han X. Reversible Deformation of Artificial Cell Colonies Triggered by Actin Polymerization for Muscle Behavior Mimicry. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2204039. [PMID: 35765153 DOI: 10.1002/adma.202204039] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/23/2022] [Indexed: 06/15/2023]
Abstract
The use of artificial cells to mimic living tissues is beneficial for understanding the mechanism of interaction among cells. Artificial cells hold immense potential in the field of tissue engineering. Self-powered artificial cells capable of reversible deformation are developed by encapsulating living mitochondria, actins, and methylcellulose. Upon addition of pyruvate molecules, the mitochondria produce adenosine triphosphate (ATP), which acts as an energy source to trigger actin polymerization. The reversible deformation of artificial cells occurs with a spindle shape resulting from the polymerization of actins to form filaments adjacent to the lipid bilayer that subsequently returns to a spherical shape resulting from the depolymerization of actin filaments upon laser irradiation. The linear colonies composed of these artificial cells exhibit collective contraction and relaxation to mimic muscle tissues. At maximum contraction, the long axis of each giant unilamellar vesicle (GUV) is parallel to each other. All the colonies are synchronized in the contraction phase. The deformation of each GUV in the colonies is influenced by its adjacent GUVs. The muscle-like artificial cell colonies described here pave the way to develop sustainably self-powered artificial tissues.
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Affiliation(s)
- Chao Li
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
| | - Xiangxiang Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
| | - Boyu Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
| | - Feng Wei
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
| | - Yongshuo Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
| | - Wei Mu
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
| | - Xiaojun Han
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, China
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9
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Endogenous pannexin1 channels form functional intercellular cell-cell channels with characteristic voltage-dependent properties. Proc Natl Acad Sci U S A 2022; 119:e2202104119. [PMID: 35486697 PMCID: PMC9171361 DOI: 10.1073/pnas.2202104119] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Pannexin1 is a glycoprotein that has been shown to form functional plasma membrane channels and mediate many cellular signaling pathways. However, the formation and function of pannexin1-based intercellular cell–cell channels in mammalian cells and vertebrate tissue is a question of substantial debate. This work provides robust electrophysiological evidence to demonstrate that endogenously expressed human pannexin1 forms cell–cell channels and lays the groundwork for studying a potential new type of electrical synapses between many mammalian cell types that endogenously express pannexin1. The occurrence of intercellular channels formed by pannexin1 has been challenged for more than a decade. Here, we provide an electrophysiological characterization of exogenous human pannexin1 (hPanx1) cell–cell channels expressed in HeLa cells knocked out for connexin45. The observed hPanx1 cell–cell channels show two phenotypes: O-state and S-state. The former displayed low transjunctional voltage (Vj) sensitivity and single-channel conductance of ∼175 pS, with a substate of ∼35 pS; the latter showed a peculiar dynamic asymmetry in Vj dependence and single-channel conductance identical to the substate conductance of the O-state. S-state hPanx1 cell–cell channels were also identified between TC620 cells, a human oligodendroglioma cell line that endogenously expresses hPanx1. In these cells, dye and electrical coupling increased with temperature and were strongly reduced after hPanx1 expression was knocked down by small interfering RNA or inhibited with Panx1 mimetic inhibitory peptide. Moreover, cell–cell coupling was augmented when hPanx1 levels were increased with a doxycycline-inducible expression system. Application of octanol, a connexin gap junction (GJ) channel inhibitor, was not sufficient to block electrical coupling between HeLa KO Cx45-hPanx1 or TC620 cell pairs. In silico studies suggest that several arginine residues inside the channel pore may be neutralized by hydrophobic interactions, allowing the passage of DAPI, consistent with dye coupling observed between TC620 cells. These findings demonstrate that endogenously expressed hPanx1 forms intercellular cell–cell channels and their unique properties resemble those described in innexin-based GJ channels. Since Panx1 is ubiquitously expressed, finding conditions to recognize Panx1 cell–cell channels in different cell types might require special attention.
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10
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Harcha PA, López-López T, Palacios AG, Sáez PJ. Pannexin Channel Regulation of Cell Migration: Focus on Immune Cells. Front Immunol 2022; 12:750480. [PMID: 34975840 PMCID: PMC8716617 DOI: 10.3389/fimmu.2021.750480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/15/2021] [Indexed: 12/12/2022] Open
Abstract
The role of Pannexin (PANX) channels during collective and single cell migration is increasingly recognized. Amongst many functions that are relevant to cell migration, here we focus on the role of PANX-mediated adenine nucleotide release and associated autocrine and paracrine signaling. We also summarize the contribution of PANXs with the cytoskeleton, which is also key regulator of cell migration. PANXs, as mechanosensitive ATP releasing channels, provide a unique link between cell migration and purinergic communication. The functional association with several purinergic receptors, together with a plethora of signals that modulate their opening, allows PANX channels to integrate physical and chemical cues during inflammation. Ubiquitously expressed in almost all immune cells, PANX1 opening has been reported in different immunological contexts. Immune activation is the epitome coordination between cell communication and migration, as leukocytes (i.e., T cells, dendritic cells) exchange information while migrating towards the injury site. In the current review, we summarized the contribution of PANX channels during immune cell migration and recruitment; although we also compile the available evidence for non-immune cells (including fibroblasts, keratinocytes, astrocytes, and cancer cells). Finally, we discuss the current evidence of PANX1 and PANX3 channels as a both positive and/or negative regulator in different inflammatory conditions, proposing a general mechanism of these channels contribution during cell migration.
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Affiliation(s)
- Paloma A Harcha
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Tamara López-López
- Cell Communication and Migration Laboratory, Institute of Biochemistry and Molecular Cell Biology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Adrián G Palacios
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Pablo J Sáez
- Cell Communication and Migration Laboratory, Institute of Biochemistry and Molecular Cell Biology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Quercetin induces pannexin 1 expression via an alternative transcript with a translationally active 5' leader in rhabdomyosarcoma. Oncogenesis 2022; 11:9. [PMID: 35194046 PMCID: PMC8864035 DOI: 10.1038/s41389-022-00384-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 11/25/2022] Open
Abstract
Rhabdomyosarcoma (RMS) is a deadly cancer of skeletal muscle origin. Pannexin 1 (PANX1) is down-regulated in RMS and increasing its levels drastically inhibits RMS progression. PANX1 upregulation thus represents a prospective new treatment strategy for this malignancy. However, the mechanisms regulating PANX1 expression, in RMS and other contexts, remain largely unknown. Here we show that both RMS and normal skeletal muscle express a comparable amount of PANX1 mRNAs, but surprisingly the canonical 5′ untranslated region (5′ UTR) or 5′ leader of the transcript is completely lost in RMS. We uncover that quercetin, a natural plant flavonoid, increases PANX1 protein levels in RMS by inducing re-expression of a 5′ leader-containing PANX1 transcript variant that is efficiently translated. This particular PANX1 mRNA variant is also present in differentiated human skeletal muscle myoblasts (HSMM) that highly express PANX1. Mechanistically, abolishing ETV4 transcription factor binding sites in the PANX1 promoter significantly reduced the luciferase reporter activities and PANX1 5′ UTR levels, and both quercetin treatment in RMS cells and induction of differentiation in HSMM enriched the binding of ETV4 to its consensus element in the PANX1 promoter. Notably, quercetin treatment promoted RMS differentiation in a PANX1-dependent manner. Further showing its therapeutic potential, quercetin treatment prevented RMS in vitro tumor formation while inducing complete regression of established spheroids. Collectively, our results demonstrate the tumor-suppressive effects of quercetin in RMS and present a hitherto undescribed mechanism of PANX1 regulation via ETV4-mediated transcription of a translationally functional 5′ leader-containing PANX1 mRNA.
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12
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Wang Z, Chen X, Liang Q, An Y, Wei M, Shi W. Inhibiting of circ-TLK1 inhibits the progression of glioma through down-regulating PANX1 via targeting miR-17-5p. J Mol Histol 2021; 52:1007-1020. [PMID: 34181173 DOI: 10.1007/s10735-021-09993-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/03/2021] [Indexed: 10/21/2022]
Abstract
Glioma remains the most common malignant tumors in the central nervous system and often has poor prognosis. In recent years, it has been gradually revealed that non-coding RNA effects glioma progression. In this study, we aimed to investigate the significance of circular RNA TLK1 (Circ-TLK1) in predicting the survival of glioma patients as well as its role in glioma development via both in-vitro and in-vivo experiments. We found that Circ-TLK1 was conspicuously up-regulated in glioma tissues compared with adjacent normal tissues, and the up-regulated Circ-TLK1 was significantly correlated with glioma patients' larger tumor volume and higher grades. Functionally, Circ-TLK1 over-expression facilitated glioma growth, migration and invasion, inhibited cell apoptosis, and accelerated PANX1/MAPK/ERK expression, while Circ-TLK1 low expression had the opposite effects. In addition, bioinformatics analysis showed that miR-17-5p was a potential target of Circ-TLK1 and targeted at PANX1. Furthermore, through dual luciferase viability assay, Circ-TLK1 acted as a competing endogenous RNA by sponging miR-17-5p, which targeted and inhibited PANX1/MAPK/ERK expression. MiR-17-5p overexpression mitigated glioma progression, which was significantly inhibited with Circ-TLK1 upregulation. In conclusion, this study confirmed a novel axis of Circ-TLK1-miR-17-5p-PANX1 in modulating glioma development, providing more references for glioma diagnosis and targeted therapy.
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Affiliation(s)
- Zizhang Wang
- Department of Neurosurgery, Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Xu Chen
- Department of Internal Medicine 2, Shaanxi Provincial Tumor Hospital, The Affiliated Hospital of Xi'an Jiaotong Univesity, Xi'an, 710061, Shaanxi, China
| | - Qinlong Liang
- Department of Head and Neck Surgery, Shaanxi Provincial Tumor Hospital, The Affiliated Hospital of Xi'an Jiaotong Univesity, Xi'an, 710061, Shaanxi, China
| | - Yuan An
- Department of Head and Neck Surgery, Shaanxi Provincial Tumor Hospital, The Affiliated Hospital of Xi'an Jiaotong Univesity, Xi'an, 710061, Shaanxi, China
| | - Meng Wei
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Wei Shi
- Department of Neurosurgery, Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China.
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13
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Laird DW, Penuela S. Pannexin biology and emerging linkages to cancer. Trends Cancer 2021; 7:1119-1131. [PMID: 34389277 DOI: 10.1016/j.trecan.2021.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/20/2021] [Indexed: 12/18/2022]
Abstract
Pannexins are a family of glycoproteins that comprises three members, PANX1, PANX2, and PANX3. The widely expressed and interrogated PANX1 forms heptameric membrane channels that primarily serve to connect the cytoplasm to the extracellular milieu by being selectively permeable to small signaling molecules when activated. Apart from notable exceptions, PANX1 in many tumor cells appears to facilitate tumor growth and metastasis, suggesting that pannexin-blocking therapeutics may have utility in cancer. Attenuation of PANX1 function must also consider the fact that PANX1 is found in stromal cells of the tumor microenvironment (TME), including immune cells. This review highlights the key discoveries of the past 5 years that suggest pannexins facilitate, or in some cases inhibit, tumor cell growth and metastasis via direct protein interactions and through the regulated efflux of signaling molecules.
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Affiliation(s)
- Dale W Laird
- Department of Anatomy and Cell Biology, and Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada; Department of Oncology, Divisions of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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14
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Ying W, Zheng K, Wu Y, Wang O. Pannexin 1 Mediates Gastric Cancer Cell Epithelial-Mesenchymal Transition via Aquaporin 5. Biol Pharm Bull 2021; 44:1111-1119. [PMID: 34135208 DOI: 10.1248/bpb.b21-00292] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pannexin 1 (PANX1) has been implicated in cancer emergence and progression. However, its roles in gastric cancer remain unclear. In the present study, the function and molecular mechanisms of PANX1 in gastric cancer were investigated in vitro. Two gastric cancer cell lines exhibiting low and high PANX1 expression (SNU-16 and HCG-27, respectively) were transfected using a PANX1-containing plasmid or PANX1 transcript-targeting short hairpin (sh)RNA. In addition, HCG-27 cells and PANX1-overexpressing SNU-16 cells were subjected to short interfering (si)RNA-mediated aquaporin 5 (AQP5) knockdown. In vitro cell migration (scratch) and transwell invasion assays were performed to evaluate the cell migratory and invasive abilities. Real-time fluorescence quantitative PCR was used to detect transcripts encoding epithelial-mesenchymal transition markers. Immunofluorescence and Western blotting were conducted to quantify corresponding proteins. In SNU-16 cells, PANX1 overexpression induced conversion from round (cobblestone-like) to elongated (spindle-like) morphologies and enhanced the cell migratory and invasive abilities. PANX1 knockdown had the opposite effect in HGC-27 cells. In PANX1-overexpressing SNU-16 cells, expression of SLUG, vimentin, and AQP5 was significantly upregulated, whereas expression of E-cadherin was downregulated. In HGC-27 cells, PANX1 knockdown showed the opposite effect. In both PANX1-overexpressing SNU-16 cells and untransfected HGC-27 cells, silencing of AQP5 expression significantly inhibited PANX1-induced upregulation of SLUG and vimentin expression, as well as downregulation of E-cadherin expression and enhanced migratory and invasive abilities. In summary, elevated PANX1 expression induces gastric cancer cell epithelial-mesenchymal transition and the associated promotion of migratory and invasive abilities by inducing expression of AQP5, which facilitates SLUG-mediated regulation of vimentin and E-cadherin expression.
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Affiliation(s)
- Wenbing Ying
- Department of Oncology, Wenzhou People's Hospital, The Third Clinical Institute Affiliated to Wenzhou Medical University
| | - Kesi Zheng
- Department of Oncology, Wenzhou People's Hospital, The Third Clinical Institute Affiliated to Wenzhou Medical University
| | - Yuanzhao Wu
- Department of Oncology, Wenzhou People's Hospital, The Third Clinical Institute Affiliated to Wenzhou Medical University
| | - Ouchen Wang
- Department of Thyroid and Breast Surgery, The First Affiliated Hospital of Wenzhou Medical University
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Abstract
PANX2 forms large-pore channels mediating ATP release in response to physiological and pathological stimuli. Although PANX2 shows involvements in glioma genesis, the underlying mechanism remains unclear. PANX2 mRNA expression was analyzed via Oncomine and was confirmed via Gene Expression Profiling Interactive Analysis (GEPIA). The influence of PANX2 on overall survival (OS) of glioma was evaluated using LinkedOmics and further assessed through Cox regression analysis. The correlated genes with PANX2 acquired from LinkedOmics were validated through GEPIA and cBioPortal. Protein-protein interaction (PPI) of these genes was then obtained using Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape with MCODE plug-in. All the PANX2-related genes underwent Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The correlation between PANX2 and cancer immune infiltrates was evaluated via Tumor Immune Estimation Resource (TIMER). A higher expression of PANX2 only revealed a better OS in brain low grade glioma (LGG). PANX2-related genes in LGG functionally enriched in neuroactive ligand-receptor interaction, synaptic vesicle cycle, and calcium signaling. The hub genes from highest module of PPI were mainly linked to chemical synaptic transmission, plasma membrane, neuropeptide, and the pathway of neuroactive ligand-receptor interaction. Besides, PANX2 expression was negatively associated with infiltrating levels of macrophage, dendritic cells, and CD4+ T cells. This study demonstrated that PANX2 likely participated in LGG pathogenesis by affecting multiple molecular pathways and immune-related processes. PANX2 was associated with LGG prognosis and might become a promising therapeutic target of LGG.
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Affiliation(s)
- XiaoXue Xu
- Department of Neurology, The First
Hospital of China Medical University, Shenyang, China
- Key Laboratory of Neurological Disease
Big Data of Liaoning Province, Shenyang, China
| | - YueHan Hao
- Department of Neurology, The First
Hospital of China Medical University, Shenyang, China
- Key Laboratory of Neurological Disease
Big Data of Liaoning Province, Shenyang, China
| | - Shuang Xiong
- Liaoning Academy of Analytic Science,
Construction Engineering Center of Important Technology Innovation and Research and
Development Base in Liaoning Province, Shenyang, China
| | - ZhiYi He
- Department of Neurology, The First
Hospital of China Medical University, Shenyang, China
- Key Laboratory of Neurological Disease
Big Data of Liaoning Province, Shenyang, China
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16
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Purinergic signaling in nervous system health and disease: Focus on pannexin 1. Pharmacol Ther 2021; 225:107840. [PMID: 33753132 DOI: 10.1016/j.pharmthera.2021.107840] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2021] [Indexed: 02/06/2023]
Abstract
Purinergic signaling encompasses the cycle of adenosine 5' triphosphate (ATP) release and its metabolism into nucleotide and nucleoside derivatives, the direct release of nucleosides, and subsequent receptor-triggered downstream intracellular pathways. Since the discovery of nerve terminal and glial ATP release into the neuropil, purinergic signaling has been implicated in the modulation of nervous system development, function, and disease. In this review, we detail our current understanding of the roles of the pannexin 1 (PANX1) ATP-release channel in neuronal development and plasticity, glial signaling, and neuron-glial-immune interactions. We additionally provide an overview of PANX1 structure, activation, and permeability to orientate readers and highlight recent research developments. We identify areas of convergence between PANX1 and purinergic receptor actions. Additional highlights include data on PANX1's participation in the pathophysiology of nervous system developmental, degenerative, and inflammatory disorders. Our aim in combining this knowledge is to facilitate the movement of our current understanding of PANX1 in the context of other nervous system purinergic signaling mechanisms one step closer to clinical translation.
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17
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Xiang X, Langlois S, St-Pierre ME, Blinder A, Charron P, Graber TE, Fowler SL, Baird SD, Bennett SAL, Alain T, Cowan KN. Identification of pannexin 1-regulated genes, interactome, and pathways in rhabdomyosarcoma and its tumor inhibitory interaction with AHNAK. Oncogene 2021; 40:1868-1883. [PMID: 33564071 PMCID: PMC7946643 DOI: 10.1038/s41388-020-01623-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 01/31/2023]
Abstract
Rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, is an aggressive cancer with a poor prognosis. Despite current management, the 5-year survival rate for patients with metastatic RMS is ∼30%; underscoring the need to develop better treatment strategies. We have recently reported that pannexin 1 (PANX1) levels are downregulated in RMS and that restoring its expression inhibits RMS progression. Here, we have surveyed and characterized the molecular changes induced by PANX1 re-expression in RMS. We cataloged transcriptomic changes in this context by RNA sequencing. At the protein level, we unveiled PANX1 interactors using BioID, complemented by co-immunoprecipitation coupled to high-performance liquid chromatography/electrospray ionization tandem mass spectrometry performed in PANX1-enriched fractions. Using these data, we generated searchable public databases for the PANX1 interactome and changes to the RMS transcriptome occurring when PANX1 expression is restored. STRING network analyses revealed a PANX1 interactome involving plasma membrane and cytoskeleton-associated proteins including the previously undescribed interactor AHNAK. Indeed, AHNAK knockdown abrogated the PANX1-mediated reduction in RMS cell viability and migration. Using these unbiased approaches, we bring insight to the mechanisms by which PANX1 inhibits RMS progression, identifying the cell migration protein AHNAK as a key modifier of PANX1-mediated changes in RMS malignant properties.
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Affiliation(s)
- Xiao Xiang
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Stéphanie Langlois
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Marie-Eve St-Pierre
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Anna Blinder
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Philippe Charron
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Tyson E Graber
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Stephanie L Fowler
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
- Neural Regeneration Laboratory and Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
- UK Dementia Research Institute, University College London, London, UK
| | - Stephen D Baird
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Steffany A L Bennett
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
- Neural Regeneration Laboratory and Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Tommy Alain
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Kyle N Cowan
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada.
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada.
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18
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Ha NT, Lee CH. Roles of Farnesyl-Diphosphate Farnesyltransferase 1 in Tumour and Tumour Microenvironments. Cells 2020; 9:cells9112352. [PMID: 33113804 PMCID: PMC7693003 DOI: 10.3390/cells9112352] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/23/2020] [Accepted: 10/24/2020] [Indexed: 12/14/2022] Open
Abstract
Farnesyl-diphosphate farnesyltransferase 1 (FDFT1, squalene synthase), a membrane-associated enzyme, synthesizes squalene via condensation of two molecules of farnesyl pyrophosphate. Accumulating evidence has noted that FDFT1 plays a critical role in cancer, particularly in metabolic reprogramming, cell proliferation, and invasion. Based on these advances in our knowledge, FDFT1 could be a potential target for cancer treatment. This review focuses on the contribution of FDFT1 to the hallmarks of cancer, and further, we discuss the applicability of FDFT1 as a cancer prognostic marker and target for anticancer therapy.
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Yao Y, Dong S, Zhu C, Hu M, Du B, Tong X. [Down-regulation of pannexin 2 channel enhances cisplatin-induced apoptosis in testicular cancer I-10 cells]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2020; 40:1090-1096. [PMID: 32895173 DOI: 10.12122/j.issn.1673-4254.2020.08.04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the effect of down-regulation of pannexin 2 (Panx-2) channels on cisplatin-induced apoptosis in I-10 cells. METHODS The expression of Panx-2 protein in testicular cancer cells was detected with Western blotting. The testicular cancer cell line I-10 was transfected with two short hairpin RNA (shRNA1 and shRNA2) via Lipofectamine2000, the empty vector (NC group) or Lipofectamine2000 (blank control group), and the changes in the expression of Panx-2 was detected with Western blotting. The effects of transfection with a Panx-2 inhibitor on surviving fraction of the cells treated with cisplatin (16 μmol/L) for 24 h, 48 h and 72 h was assessed with MTT assay, and the clonogenic capacity of the cells was evaluated with colony-forming assay. At 8 h after incubation with 16 μmol/L cisplatin, AnnexinV/PI double staining was used to detect the early apoptosis of the cells. After 24 h of treatment with 16 μmol/L cisplatin, the cells were examined for expressions of caspase-3, Bcl-2 and Bax using Western blotting. RESULTS The expression of Panx-2 was significantly increased in cisplatin-resistant I-10/DDP (P < 0.001) cells and Tcam-2/DDP (P < 0.01) cells as compared with I-10 cells and Tcam-2 cells. Transfection of I-10 cells with shRNA1 and shRNA2 resulted in significantly decreased Panx-2 expression (P < 0.05) and significantly reduced cell surviving fraction (P < 0.001). In the presence of cisplatin, the cells in NC group showed a higher clonogenic efficiency than those in shRNA1 and shRNA2 groups (P < 0.001). The early-stage apoptosis rate of the cells in shRNA1 and shRNA2 groups were significantly higher than that in NC group (P < 0.01). Panx-2 knockdown in I-10 cells significantly increased caspase-3 and Bax expressions (P < 0.05) and significantly decreased the expression of Bcl-2 (P < 0.01). CONCLUSIONS Down-regulation of Panx-2 channel enhances cisplatin-induced apoptosis in cultured testicular cancer cells.
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Affiliation(s)
- Yanxue Yao
- School of Pharmacy, Bengbu Medical College, Bengbu 233030, China
| | - Shuying Dong
- School of Pharmacy, Bengbu Medical College, Bengbu 233030, China
| | - Chenlu Zhu
- School of Pharmacy, Bengbu Medical College, Bengbu 233030, China
| | - Miao Hu
- School of Pharmacy, Bengbu Medical College, Bengbu 233030, China
| | - Baolong Du
- School of Pharmacy, Bengbu Medical College, Bengbu 233030, China
| | - Xuhui Tong
- School of Pharmacy, Bengbu Medical College, Bengbu 233030, China
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20
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Navis KE, Fan CY, Trang T, Thompson RJ, Derksen DJ. Pannexin 1 Channels as a Therapeutic Target: Structure, Inhibition, and Outlook. ACS Chem Neurosci 2020; 11:2163-2172. [PMID: 32639715 DOI: 10.1021/acschemneuro.0c00333] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pannexin 1 (Panx1) channels are transmembrane proteins that release adenosine triphosphate and play an important role in intercellular communication. They are widely expressed in somatic and nervous system tissues, and their activity has been associated with many pathologies such as stroke, epilepsy, inflammation, and chronic pain. While there are a variety of small molecules known to inhibit Panx1, currently little is known about the mechanism of channel inhibition, and there is a dearth of sufficiently potent and selective drugs targeting Panx1. Herein we provide a review of the current literature on Panx1 structural biology and known pharmacological agents that will help provide a basis for rational development of Panx1 chemical modulators.
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Affiliation(s)
- Kathleen E. Navis
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Churmy Y. Fan
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Tuan Trang
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Roger J. Thompson
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Darren J. Derksen
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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21
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Caufriez A, Böck D, Martin C, Ballet S, Vinken M. Peptide-based targeting of connexins and pannexins for therapeutic purposes. Expert Opin Drug Discov 2020; 15:1213-1222. [PMID: 32539572 DOI: 10.1080/17460441.2020.1773787] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Connexin and pannexin (hemi)channels play an important role in paracrine and autocrine signaling pathways. The opening of these cellular pores is linked to a wide range of diseases. Therefore, pharmacological closing of connexin and pannexin (hemi)channels seems a promising therapeutic strategy. However, the currently available inhibitors cope with recurring problems concerning selectivity, specificity, stability and/or solubility. AREAS COVERED A number of peptides that mimic specific regions in the native sequence of connexins and pannexins have the potential to overcome some of these hurdles. In this paper, an overview is provided on these peptide-based inhibitors of connexin and pannexin (hemi)channels for therapeutic purposes. The authors also provide the reader with their expert perspectives on the future of these peptide-based inhibitors. EXPERT OPINION Peptide mimetics can become valuable tools in the treatment of connexin-related and pannexin-related diseases. This can be made possible provided that available peptides are optimized, and new peptide mimetics are designed based on knowledge of the mechanisms underlying the gating control of connexin and pannexin (hemi)channels.
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Affiliation(s)
- Anne Caufriez
- Department of in Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , 1090, Brussels, Belgium
| | - Denise Böck
- Department of in Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , 1090, Brussels, Belgium
| | - Charlotte Martin
- Department of Organic Chemistry, Vrije Universiteit Brussel , 1050, Brussels, Belgium
| | - Steven Ballet
- Department of Organic Chemistry, Vrije Universiteit Brussel , 1050, Brussels, Belgium
| | - Mathieu Vinken
- Department of in Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel , 1090, Brussels, Belgium
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Varela-Vázquez A, Guitián-Caamaño A, Carpintero-Fernandez P, Fonseca E, Sayedyahossein S, Aasen T, Penuela S, Mayán MD. Emerging functions and clinical prospects of connexins and pannexins in melanoma. Biochim Biophys Acta Rev Cancer 2020; 1874:188380. [PMID: 32461135 DOI: 10.1016/j.bbcan.2020.188380] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 05/16/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022]
Abstract
Cellular communication through gap junctions and hemichannels formed by connexins and through channels made by pannexins allows for metabolic cooperation and control of cellular activity and signalling. These channel proteins have been described to be tumour suppressors that regulate features such as cell death, proliferation and differentiation. However, they display cancer type-dependent and stage-dependent functions and may facilitate tumour progression through junctional and non-junctional pathways. The accumulated knowledge and emerging strategies to target connexins and pannexins are providing novel clinical opportunities for the treatment of cancer. Here, we provide an updated overview of the role of connexins and pannexins in malignant melanoma. We discuss how targeting of these channel proteins may be used to potentiate antitumour effects in therapeutic settings, including through improved immune-mediated tumour elimination.
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Affiliation(s)
- Adrián Varela-Vázquez
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Amanda Guitián-Caamaño
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Paula Carpintero-Fernandez
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Eduardo Fonseca
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain; Dermatology Deparment, University Hospital of A Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Samar Sayedyahossein
- Department of Anatomy & Cell Biology, and Oncology, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A5C1, Canada
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, Barcelona, Spain
| | - Silvia Penuela
- Department of Anatomy & Cell Biology, and Oncology, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A5C1, Canada
| | - María D Mayán
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain.
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Targeted Proteomics-Based Quantitative Protein Atlas of Pannexin and Connexin Subtypes in Mouse and Human Tissues and Cancer Cell Lines. J Pharm Sci 2020; 109:1161-1168. [DOI: 10.1016/j.xphs.2019.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 12/15/2022]
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Nielsen BS, Toft-Bertelsen TL, Lolansen SD, Anderson CL, Nielsen MS, Thompson RJ, MacAulay N. Pannexin 1 activation and inhibition is permeant-selective. J Physiol 2020; 598:361-379. [PMID: 31698505 DOI: 10.1113/jp278759] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/05/2019] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS The large-pore channel pannexin 1 (Panx1) is expressed in many cell types and can open upon different, yet not fully established, stimuli. Panx1 permeability is often inferred from channel permeability to fluorescent dyes, but it is currently unknown whether dye permeability translates to permeability to other molecules. Cell shrinkage and C-terminal cleavage led to a Panx1 open-state with increased permeability to atomic ions (current), but did not alter ethidium uptake. Panx1 inhibitors affected Panx1-mediated ion conduction differently from ethidium permeability, and inhibitor efficiency towards a given molecule therefore cannot be extrapolated to its effects on the permeability of another. We conclude that ethidium permeability does not reflect equal permeation of other molecules and thus is no measure of general Panx1 activity. ABSTRACT Pannexin 1 (Panx1) is a large-pore membrane channel connecting the extracellular milieu with the cell interior. While several activation regimes activate Panx1 in a variety of cell types, the selective permeability of an open Panx1 channel remains unresolved: does a given activation paradigm increase Panx1's permeability towards all permeants equally and does fluorescent dye flux serve as a proxy for biological permeation through an open channel? To explore permeant-selectivity of Panx1 activation and inhibition, we employed Panx1-expressing Xenopus laevis oocytes and HEK293T cells. We report that different mechanisms of activation of Panx1 differentially affected ethidium and atomic ion permeation. Most notably, C-terminal truncation or cell shrinkage elevated Panx1-mediated ion conductance, but had no effect on ethidium permeability. In contrast, extracellular pH changes predominantly affected ethidium permeability but not ionic conductance. High [K+ ]o did not increase the flux of either of the two permeants. Once open, Panx1 demonstrated preference for anionic permeants, such as Cl- , lactate and glutamate, while not supporting osmotic water flow. Panx1 inhibitors displayed enhanced potency towards Panx1-mediated currents compared to that of ethidium uptake. We conclude that activation or inhibition of Panx1 display permeant-selectivity and that permeation of ethidium does not necessarily reflect an equal permeation of smaller biological molecules and atomic ions.
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Affiliation(s)
- Brian Skriver Nielsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Trine Lisberg Toft-Bertelsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sara Diana Lolansen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Connor L Anderson
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Morten Schak Nielsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Roger J Thompson
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Nanna MacAulay
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Jalaleddine N, El-Hajjar L, Dakik H, Shaito A, Saliba J, Safi R, Zibara K, El-Sabban M. Pannexin1 Is Associated with Enhanced Epithelial-To-Mesenchymal Transition in Human Patient Breast Cancer Tissues and in Breast Cancer Cell Lines. Cancers (Basel) 2019; 11:cancers11121967. [PMID: 31817827 PMCID: PMC6966616 DOI: 10.3390/cancers11121967] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/30/2019] [Accepted: 11/05/2019] [Indexed: 12/21/2022] Open
Abstract
Loss of connexin-mediated cell-cell communication is a hallmark of breast cancer progression. Pannexin1 (PANX1), a glycoprotein that shares structural and functional features with connexins and engages in cell communication with its environment, is highly expressed in breast cancer metastatic foci; however, PANX1 contribution to metastatic progression is still obscure. Here we report elevated expression of PANX1 in different breast cancer (BRCA) subtypes using RNA-seq data from The Cancer Genome Atlas (TCGA). The elevated PANX1 expression correlated with poorer outcomes in TCGA BRCA patients. In addition, gene set enrichment analysis (GSEA) revealed that epithelial-to-mesenchymal transition (EMT) pathway genes correlated positively with PANX1 expression. Pharmacological inhibition of PANX1, in MDA-MB-231 and MCF-7 breast cancer cells, or genetic ablation of PANX1, in MDA-MB-231 cells, reverted the EMT phenotype, as evidenced by decreased expression of EMT markers. In addition, PANX1 inhibition or genetic ablation decreased the invasiveness of MDA-MB-231 cells. Our results suggest PANX1 overexpression in breast cancer is associated with a shift towards an EMT phenotype, in silico and in vitro, attributing to it a tumor-promoting effect, with poorer clinical outcomes in breast cancer patients. This association offers a novel target for breast cancer therapy.
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Affiliation(s)
- Nour Jalaleddine
- Department of Biological and Environmental Sciences, Faculty of Science, Beirut Arab University, Beirut 1107-2809, Lebanon;
| | - Layal El-Hajjar
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut 1107-2020, Lebanon;
| | - Hassan Dakik
- University of Tours, EA 7501 GICC, CNRS ERL 7001 LNOx, CEDEX 01, 37032 Tours, France;
| | - Abdullah Shaito
- Department of Biological and Chemical Sciences, Faculty of Arts and Sciences, Lebanese International University, Beirut 1105, Lebanon;
| | - Jessica Saliba
- Department of Biology, Faculty of Sciences, Lebanese University, Hadath, Beirut 1003, Lebanon;
| | - Rémi Safi
- Department of Dermatology, Faculty of Medicine, American University of Beirut, Beirut 1107-2020, Lebanon;
| | - Kazem Zibara
- ER045-Laboratory of Stem Cells, PRASE, Department of Biology, Faculty of Sciences, Lebanese University, Hadath, Beirut 1003, Lebanon;
| | - Marwan El-Sabban
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut 1107-2020, Lebanon;
- Correspondence: ; Tel.: +961-1-350000 (ext. 4765-4766)
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26
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Brocardo L, Acosta LE, Piantanida AP, Rela L. Beneficial and Detrimental Remodeling of Glial Connexin and Pannexin Functions in Rodent Models of Nervous System Diseases. Front Cell Neurosci 2019; 13:491. [PMID: 31780897 PMCID: PMC6851021 DOI: 10.3389/fncel.2019.00491] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/17/2019] [Indexed: 01/30/2023] Open
Abstract
A variety of glial cell functions are supported by connexin and pannexin proteins. These functions include the modulation of synaptic gain, the control of excitability through regulation of the ion and neurotransmitter composition of the extracellular milieu and the promotion of neuronal survival. Connexins and pannexins support these functions through diverse molecular mechanisms, including channel and non-channel functions. The former comprise the formation of gap junction-mediated networks supported by connexin intercellular channels and the formation of pore-like membrane structures or hemichannels formed by both connexins and pannexins. Non-channel functions involve adhesion properties and the participation in signaling intracellular cascades. Pathological conditions of the nervous system such as ischemia, neurodegeneration, pathogen infection, trauma and tumors are characterized by distinctive remodeling of connexin expression and function. However, whether these changes can be interpreted as part of the pathogenesis, or as beneficial compensatory effects, remains under debate. Here we review the available evidence addressing this matter with a special emphasis in mouse models with selective manipulation of glial connexin and pannexin proteins in vivo. We postulate that the beneficial vs. detrimental effects of glial connexin remodeling in pathological conditions depend on the impact of remodeling on the different connexin and pannexin channel and non-channel functions, on the characteristics of the inflammatory environment and on the type of interaction among glial cells types.
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Affiliation(s)
- Lucila Brocardo
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Luis Ernesto Acosta
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ana Paula Piantanida
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lorena Rela
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
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27
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Shi G, Liu C, Yang Y, Song L, Liu X, Wang C, Peng Z, Li H, Zhong L. Panx1 promotes invasion-metastasis cascade in hepatocellular carcinoma. J Cancer 2019; 10:5681-5688. [PMID: 31737105 PMCID: PMC6843873 DOI: 10.7150/jca.32986] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 08/03/2019] [Indexed: 01/14/2023] Open
Abstract
Background: The molecular function of pannexin1 (Panx1) in different tumor types has been remained equivocal. Until now, there is no study focused on the function of panx1 in hepatocellular carcinoma (HCC). This study aimed to explore the role of Panx1 in the invasion and metastasis of HCC. Methods: The expressions of Panx1 in 126 cases of HCC were analyzed by immunohistochemistry (IHC). The effects of Panx1 on HCC cell metastasis and invasion were observed by transwell. The expression levels of Panx1 and epithelial-mesenchymal transition (EMT) related proteins in HCC cells and tissues were detected by western blot and IHC. The tumor metastatic abilities were compared between Panx1 knockout mice and nude mice. Results: The higher expression of Panx1 in HCC was positively correlated with tumor lymph node metastasis, TNM (tumor, node, metastasis) classification and poor prognosis (overall survival, hazard ratio [HR] 2.769, 95% confidence interval [95%CI] 1.528-5.017, P=0.001; disease-free survival, HR=2.344, 95%CI 1.473-3.730, P<0.001). Overexpression of Panx1 promoted invasion and migration of HCC cells through modulation of EMT in vitro and in vivo. Conclusions: Our results suggest that the high expression of Panx1 is associated with poor HCC prognosis, providing a new clue for effective intervention for HCC metastasis.
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Affiliation(s)
- Guangjun Shi
- Department of Hepatobiliary Surgery, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Chuanliang Liu
- Department of General Surgery, The Third People's Hospital of LinYi, Linyi, China
| | - Yiming Yang
- School of Life Science, Shanghai University, Shanghai, China
| | - Liwei Song
- Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xueni Liu
- Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chuanxu Wang
- Department of Hepatobiliary Surgery, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Zhihai Peng
- Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hao Li
- Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin Zhong
- Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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28
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Epp AL, Ebert SN, Sanchez-Arias JC, Wicki-Stordeur LE, Boyce AKJ, Swayne LA. A novel motif in the proximal C-terminus of Pannexin 1 regulates cell surface localization. Sci Rep 2019; 9:9721. [PMID: 31278290 PMCID: PMC6611761 DOI: 10.1038/s41598-019-46144-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/24/2019] [Indexed: 12/11/2022] Open
Abstract
The Pannexin 1 (Panx1) ion and metabolite channel is expressed in a wide variety of cells where it regulates a number of cell behaviours including proliferation and differentiation. Panx1 is expressed on the cell surface as well as intracellular membranes. Previous work suggests that a region within the proximal Panx1 C-terminus (Panx1CT) regulates cell surface localization. Here we report the discovery of a putative leucine-rich repeat (LRR) motif in the proximal Panx1CT necessary for Panx1 cell surface expression in HEK293T cells. Deletion of the putative LRR motif results in significant loss of Panx1 cell surface distribution. Outcomes of complementary cell surface oligomerization and glycosylation state analyses were consistent with reduced cell surface expression of Panx1 LRR deletion mutants. Of note, the oligomerization analysis revealed the presence of putative dimers and trimers of Panx1 at the cell surface. Expression of Panx1 increased HEK293T cell growth and reduced doubling time, while expression of a Panx1 LRR deletion mutant (highly conserved segment) did not reproduce this effect. In summary, here we discovered the presence of a putative LRR motif in the Panx1CT that impacts on Panx1 cell surface localization. Overall these findings provide new insights into the molecular mechanisms underlying C-terminal regulation of Panx1 trafficking and raise potential new lines of investigation with respect to Panx1 oligomerization and glycosylation.
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Affiliation(s)
- Anna L Epp
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Sarah N Ebert
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Juan C Sanchez-Arias
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Leigh E Wicki-Stordeur
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Andrew K J Boyce
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada.
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29
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Liu H, Yuan M, Yao Y, Wu D, Dong S, Tong X. In vitro effect of Pannexin 1 channel on the invasion and migration of I-10 testicular cancer cells via ERK1/2 signaling pathway. Biomed Pharmacother 2019; 117:109090. [PMID: 31202174 DOI: 10.1016/j.biopha.2019.109090] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/30/2019] [Accepted: 06/04/2019] [Indexed: 12/14/2022] Open
Abstract
Pannexin (Panx) plays a crucial role in several cellular processes such as immune cell death, cell proliferation, invasion, and migration, apoptosis, and autophagy. However, the role of Panx in regulating cell migration and invasion in testicular cancer remains to be elucidated. In the present study, we determined the correlation between Panx-1 channel function and migration and invasion in I-10 testicular cancer cells. Transwell and wound healing assays showed that inhibition of Panx-1 by carbenoxolone (CBX) and probenecid (PBN) attenuated the migration and invasion of testicular cancer cells in vitro. Moreover, knockdown of Panx-1 with short hairpin RNA (shRNA) remarkably decreased the migration and invasion ability of I-10 cells. In shRNA-transfected cells, extracellular ATP (released through Panx channel) was also found to be decreased. Similarly, overexpression of Panx-1 with mPanx-1 increased the migration and invasion ability of I-10 cells. Moreover, we found that in mPanx-1-transfected cells treated with U0126 (inhibitor of p-ERK1/2), the migration and invasion of I-10 cells were remarkably attenuated. Overall, increased Panx-1 promotes migration and invasion in testicular cancer cells, and the effect is probably be related with ERK1/2 kinase activity. Thus, Panx-1 can serve as a potential therapeutic target for the treatment of testicular cancer.
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Affiliation(s)
- Haofeng Liu
- School of Pharmacy, Bengbu Medical College, Anhui, Bengbu, 233030, PR China
| | - Min Yuan
- School of Pharmacy, Bengbu Medical College, Anhui, Bengbu, 233030, PR China
| | - Yanxue Yao
- School of Pharmacy, Bengbu Medical College, Anhui, Bengbu, 233030, PR China
| | - Dandan Wu
- College of Life Sciences, Nanjing University, Jiangsu, Nanjing, 210093, PR China
| | - Shuying Dong
- School of Pharmacy, Bengbu Medical College, Anhui, Bengbu, 233030, PR China
| | - Xuhui Tong
- School of Pharmacy, Bengbu Medical College, Anhui, Bengbu, 233030, PR China.
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30
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Role of pannexin-1 in the cellular uptake, release and hydrolysis of anandamide by T84 colon cancer cells. Sci Rep 2019; 9:7622. [PMID: 31110238 PMCID: PMC6527687 DOI: 10.1038/s41598-019-44057-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/02/2019] [Indexed: 12/24/2022] Open
Abstract
The large pore ion channel pannexin-1 (Panx1) has been reported to play a role in the cellular uptake and release of anandamide (AEA) in the hippocampus. It is not known whether this is a general mechanism or limited to the hippocampus. We have investigated this pharmacologically using T84 colon cancer cells. The cells expressed Panx1 at the mRNA level, and released ATP in a manner that could be reduced by treatment with the Panx1 inhibitors carbenoxolone and mefloquine and the Panx1 substrate SR101. However, no significant effects of these compounds upon the uptake or hydrolysis of exogenously applied AEA was seen. Uptake by T84 cells of the other main endocannabinoid 2-arachidonoylglycerol and the AEA homologue palmitoylethanolamide was similarly not affected by carbenoxolone or mefloquine. Total release of tritium from [3H]AEA-prelabelled T84 cells over 10 min was increased, rather than inhibited by carbenoxolone and mefloquine. Finally, AEA uptake by PC3 prostate cancer and SH-SY5Y neuroblastoma cells, which express functional Panx1 channels, was not inhibited by carbenoxolone. Thus, in contrast to the hippocampus, Panx1 does not appear to play a role in AEA uptake and release from the cells studied under the conditions used.
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31
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O’Hare EA, Antin PB, Delany ME. Two Proximally Close Priority Candidate Genes for diplopodia-1, an Autosomal Inherited Craniofacial-Limb Syndrome in the Chicken: MRE11 and GPR83. J Hered 2019; 110:194-210. [PMID: 30597046 PMCID: PMC6399517 DOI: 10.1093/jhered/esy071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 12/29/2018] [Indexed: 11/12/2022] Open
Abstract
Next-generation sequencing (NGS) and expression technologies were utilized to investigate the genes and sequence elements in a 586 kb region of chicken chromosome 1 associated with the autosomal recessive diplopodia-1 (dp-1) mutation. This mutation shows a syndromic phenotype similar to known human developmental abnormalities (e.g., cleft palate, polydactyly, omphalocele [exposed viscera]). Toward our goal to ascertain the variant responsible, the entire 586 kb region was sequenced following utilization of a specifically designed capture array and to confirm/validate fine-mapping results. Bioinformatic analyses identified a total of 6142 sequence variants, which included SNPs, indels, and gaps. Of these, 778 SNPs, 146 micro-indels, and 581 gaps were unique to the UCD-Dp-1.003 inbred congenic line; those found within exons and splice sites were studied for contribution to the mutant phenotype. Upon further validation with additional mutant samples, a smaller subset (of variants [51]) remains linked to the mutation. Additionally, utilization of specific samples in the NGS technology was advantageous in that fine-mapping methodologies eliminated an additional 326 kb of sequence information on chromosome 1. Predicted and confirmed protein-coding genes within the smaller 260 kb region were assessed for their developmental expression patterns over several stages of early embryogenesis in regions/tissues of interest (e.g., digits, craniofacial region). Based on these results and known function in other vertebrates, 2 genes within 5 kb of each other, MRE11 and GPR83, are proposed as high-priority candidates for the dp-1 mutation.
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Affiliation(s)
- Elizabeth A O’Hare
- Department of Animal Science, University of California, Davis, CA
- Elizabeth A. O’Hare is now at the Department of Biological Sciences, Towson University, Towson, MD
| | - Parker B Antin
- Department of Molecular and Cellular Medicine, University of Arizona, Tucson, AZ
| | - Mary E Delany
- Department of Animal Science, University of California, Davis, CA
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Beckmann A, Hainz N, Tschernig T, Meier C. Facets of Communication: Gap Junction Ultrastructure and Function in Cancer Stem Cells and Tumor Cells. Cancers (Basel) 2019; 11:cancers11030288. [PMID: 30823688 PMCID: PMC6468480 DOI: 10.3390/cancers11030288] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 12/28/2022] Open
Abstract
Gap junction proteins are expressed in cancer stem cells and non-stem cancer cells of many tumors. As the morphology and assembly of gap junction channels are crucial for their function in intercellular communication, one focus of our review is to outline the data on gap junction plaque morphology available for cancer cells. Electron microscopic studies and freeze-fracture analyses on gap junction ultrastructure in cancer are summarized. As the presence of gap junctions is relevant in solid tumors, we exemplarily outline their role in glioblastomas and in breast cancer. These were also shown to contain cancer stem cells, which are an essential cause of tumor onset and of tumor transmission into metastases. For these processes, gap junctional communication was shown to be important and thus we summarize, how the expression of gap junction proteins and the resulting communication between cancer stem cells and their surrounding cells contributes to the dissemination of cancer stem cells via blood or lymphatic vessels. Based on their importance for tumors and metastases, future cancer-specific therapies are expected to address gap junction proteins. In turn, gap junctions also seem to contribute to the unattainability of cancer stem cells by certain treatments and might thus contribute to therapeutic resistance.
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Affiliation(s)
- Anja Beckmann
- Department of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany.
| | - Nadine Hainz
- Department of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany.
| | - Thomas Tschernig
- Department of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany.
| | - Carola Meier
- Department of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany.
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33
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Inhibition of Pannexin 1 Reduces the Tumorigenic Properties of Human Melanoma Cells. Cancers (Basel) 2019; 11:cancers11010102. [PMID: 30654593 PMCID: PMC6356688 DOI: 10.3390/cancers11010102] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 01/19/2023] Open
Abstract
Pannexin 1 (PANX1) is a channel-forming glycoprotein expressed in many tissues including the skin. PANX1 channels allow the passage of ions and molecules up to 1 kDa, including ATP and other metabolites. In this study, we show that PANX1 is highly expressed in human melanoma tumors at all stages of disease progression, as well as in patient-derived cells and established melanoma cell lines. Reducing PANX1 protein levels using shRNA or inhibiting channel function with the channel blockers, carbenoxolone (CBX) and probenecid (PBN), significantly decreased cell growth and migration, and increased melanin production in A375-P and A375-MA2 cell lines. Further, treatment of A375-MA2 tumors in chicken embryo xenografts with CBX or PBN significantly reduced melanoma tumor weight and invasiveness. Blocking PANX1 channels with PBN reduced ATP release in A375-P cells, suggesting a potential role for PANX1 in purinergic signaling of melanoma cells. In addition, cell-surface biotinylation assays indicate that there is an intracellular pool of PANX1 in melanoma cells. PANX1 likely modulates signaling through the Wnt/β-catenin pathway, because β-catenin levels were significantly decreased upon PANX1 silencing. Collectively, our findings identify a role for PANX1 in controlling growth and tumorigenic properties of melanoma cells contributing to signaling pathways that modulate melanoma progression.
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34
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Abudara V, Retamal MA, Del Rio R, Orellana JA. Synaptic Functions of Hemichannels and Pannexons: A Double-Edged Sword. Front Mol Neurosci 2018; 11:435. [PMID: 30564096 PMCID: PMC6288452 DOI: 10.3389/fnmol.2018.00435] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/08/2018] [Indexed: 01/18/2023] Open
Abstract
The classical view of synapses as the functional contact between presynaptic and postsynaptic neurons has been challenged in recent years by the emerging regulatory role of glial cells. Astrocytes, traditionally considered merely supportive elements are now recognized as active modulators of synaptic transmission and plasticity at the now so-called "tripartite synapse." In addition, an increasing body of evidence indicates that beyond immune functions microglia also participate in various processes aimed to shape synaptic plasticity. Release of neuroactive compounds of glial origin, -process known as gliotransmission-, constitute a widespread mechanism through which glial cells can either potentiate or reduce the synaptic strength. The prevailing vision states that gliotransmission depends on an intracellular Ca2+/exocytotic-mediated release; notwithstanding, growing evidence is pointing at hemichannels (connexons) and pannexin channels (pannexons) as alternative non-vesicular routes for gliotransmitters efflux. In concurrence with this novel concept, both hemichannels and pannexons are known to mediate the transfer of ions and signaling molecules -such as ATP and glutamate- between the cytoplasm and the extracellular milieu. Importantly, recent reports show that glial hemichannels and pannexons are capable to perceive synaptic activity and to respond to it through changes in their functional state. In this article, we will review the current information supporting the "double edge sword" role of hemichannels and pannexons in the function of central and peripheral synapses. At one end, available data support the idea that these channels are chief components of a feedback control mechanism through which gliotransmitters adjust the synaptic gain in either resting or stimulated conditions. At the other end, we will discuss how the excitotoxic release of gliotransmitters and [Ca2+]i overload linked to the opening of hemichannels/pannexons might impact cell function and survival in the nervous system.
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Affiliation(s)
- Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile.,Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, United States.,Programa de Comunicación Celular en Cáncer, Instituto de Ciencias e Innovación en Medicina, Santiago, Chile
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
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Pannexin 1 inhibits rhabdomyosarcoma progression through a mechanism independent of its canonical channel function. Oncogenesis 2018; 7:89. [PMID: 30459312 PMCID: PMC6246549 DOI: 10.1038/s41389-018-0100-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 11/05/2018] [Indexed: 01/22/2023] Open
Abstract
Rhabdomyosarcoma (RMS) is an aggressive soft tissue sarcoma of childhood thought to arise from impaired differentiation of skeletal muscle progenitors. We have recently identified Pannexin 1 (PANX1) channels as a novel regulator of skeletal myogenesis. In the present study, we determined that PANX1 transcript and protein levels are down-regulated in embryonal (eRMS) and alveolar RMS (aRMS) patient-derived cell lines and primary tumor specimens as compared to differentiated skeletal muscle myoblasts and tissue, respectively. While not sufficient to overcome the inability of RMS to reach terminal differentiation, ectopic expression of PANX1 in eRMS (Rh18) and aRMS (Rh30) cells significantly decreased their proliferative and migratory potential. Furthermore, ectopic PANX1 abolished 3D spheroid formation in eRMS and aRMS cells and induced regression of established spheroids through induction of apoptosis. Notably, PANX1 expression also significantly reduced the growth of human eRMS and aRMS tumor xenografts in vivo. Interestingly, PANX1 does not form active channels when expressed in eRMS (Rh18) and aRMS (Rh30) cells and the addition of PANX1 channel inhibitors did not alter or reverse the PANX1-mediated reduction of cell proliferation and migration. Moreover, expression of channel-defective PANX1 mutants not only disrupted eRMS and aRMS 3D spheroids, but also inhibited in vivo RMS tumor growth. Altogether our findings suggest that PANX1 alleviates RMS malignant properties in vitro and in vivo through a process that is independent of its canonical channel function.
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Dong A, Liu S, Li Y. Gap Junctions in the Nervous System: Probing Functional Connections Using New Imaging Approaches. Front Cell Neurosci 2018; 12:320. [PMID: 30283305 PMCID: PMC6156252 DOI: 10.3389/fncel.2018.00320] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 09/03/2018] [Indexed: 11/13/2022] Open
Abstract
Gap junctions are channels that physically connect adjacent cells, mediating the rapid exchange of small molecules, and playing an essential role in a wide range of physiological processes in nearly every system in the body, including the nervous system. Thus, altered function of gap junctions has been linked with a plethora of diseases and pathological conditions. Being able to measure and characterize the distribution, function, and regulation of gap junctions in intact tissue is therefore essential for understanding the physiological and pathophysiological roles that gap junctions play. In recent decades, several robust in vitro and in vivo methods have been developed for detecting and characterizing gap junctions. Here, we review the currently available methods with respect to invasiveness, signal-to-noise ratio, temporal resolution and others, highlighting the recently developed chemical tracers and hybrid imaging systems that use novel chemical compounds and/or genetically encoded enzymes, transporters, channels, and fluorescent proteins in order to map gap junctions. Finally, we discuss possible avenues for further improving existing techniques in order to achieve highly sensitive, cell type-specific, non-invasive measures of in vivo gap junction function with high throughput and high spatiotemporal resolution.
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Affiliation(s)
- Ao Dong
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Simin Liu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
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37
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Zhang W, Liu MW, Li M, Xiao W, Zhang XW, He HJ, Chen YB, Ding L, Luo KJ. Unexpected link between insect innexins and apoptosis of HeLa cells. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2018; 99:e21473. [PMID: 29862562 DOI: 10.1002/arch.21473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Little is known about how mammalian cells respond to the expression of innexins (Inxs), which are known to mediate cell-to-cell communication that causes apoptosis in the cells of the insect Spodoptera litura. The mammalian expression system, p3xFLAG tag protein, containing the CMV promoter, allowed us to construct two C-terminally elongated innexins (Cte-Inxs), SpliInx2 (Inx2-FLAG), and SpliInx3 (Inx3-FLAG), which were predicted to have the same secondary topological structures as the native SpliInx2 and SpliInx3. Here, we found that only the mRNAs of the two Cte-Inxs were expressed under the control of the CMV promoter in HeLa cells. Unexpectedly, mRNA expression of the two Cte-Inxs enhanced apoptosis of HeLa cells. The two Cte-Inx mRNAs were associated with a significant decrease in Akt phosphorylation in HeLa cells undergoing apoptosis. Furthermore, Inx3-FLAG mRNA expression in nonapoptotic HCT116 cells was also associated with a significant decrease in the levels of phosphorylated Akt. Intriguingly, expression of the mRNAs of the two Cte-Inxs did not activate caspase 3, but it markedly reduced Bid levels in HeLa cells undergoing apoptosis. These results suggest that mRNA expression of the two Cte-Inxs may activate a Bid-dependent apoptotic pathway in HeLa cells. Our study demonstrates that invertebrate gap junction mRNAs can function in vertebrate cancer cells as tumor suppressors.
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Affiliation(s)
- Wei Zhang
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
- Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Meng-Wei Liu
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Ming Li
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
- Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Wei Xiao
- School of Life Sciences, Yunnan University, Kunming, P.R. China
| | - Xue-Wen Zhang
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
- Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Hao-Juan He
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
- Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Ya-Bin Chen
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Lei Ding
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
| | - Kai-Jun Luo
- School of Life Sciences, Yunnan University, Kunming, P.R. China
- Key Laboratory for Biochemistry and Molecular Biology of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
- Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P.R. China
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Makarenkova HP, Shah SB, Shestopalov VI. The two faces of pannexins: new roles in inflammation and repair. J Inflamm Res 2018; 11:273-288. [PMID: 29950881 PMCID: PMC6016592 DOI: 10.2147/jir.s128401] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Pannexins belong to a family of ATP-release channels expressed in almost all cell types. An increasing body of literature on pannexins suggests that these channels play dual and sometimes contradictory roles, contributing to normal cell function, as well as to the pathological progression of disease. In this review, we summarize our understanding of pannexin "protective" and "harmful" functions in inflammation, regeneration and mechanical signaling. We also suggest a possible basis for pannexin's dual roles, related to extracellular ATP and K+ levels and the activation of various types of P2 receptors that are associated with pannexin. Finally, we speculate upon therapeutic strategies related to pannexin using eyes, lacrimal glands, and peripheral nerves as examples of interesting therapeutic targets.
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Affiliation(s)
| | - Sameer B Shah
- Departments of Orthopaedic Surgery and Bioengineering, University of California.,Research Division, Veterans Affairs San Diego Healthcare System, San Diego, CA
| | - Valery I Shestopalov
- Bascom Eye Institute, Department of Ophthalmology, University of Miami, Miami, FL, USA.,Vavilov Institute for General Genetics, Russian Academy of Sciences.,Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
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39
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Connexins and Pannexins: Important Players in Tumorigenesis, Metastasis and Potential Therapeutics. Int J Mol Sci 2018; 19:ijms19061645. [PMID: 29865195 PMCID: PMC6032133 DOI: 10.3390/ijms19061645] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022] Open
Abstract
Since their characterization more than five decades ago, gap junctions and their structural proteins-the connexins-have been associated with cancer cell growth. During that period, the accumulation of data and molecular knowledge about this association revealed an apparent contradictory relationship between them and cancer. It appeared that if gap junctions or connexins can down regulate cancer cell growth they can be also implied in the migration, invasion and metastatic dissemination of cancer cells. Interestingly, in all these situations, connexins seem to be involved through various mechanisms in which they can act either as gap-junctional intercellular communication mediators, modulators of signalling pathways through their interactome, or as hemichannels, which mediate autocrine/paracrine communication. This complex involvement of connexins in cancer progression is even more complicated by the fact that their hemichannel function may overlap with other gap junction-related proteins, the pannexins. Despite this complexity, the possible involvements of connexins and pannexins in cancer progression and the elucidation of the mechanisms they control may lead to use them as new targets to control cancer progression. In this review, the involvements of connexins and pannexins in these different topics (cancer cell growth, invasion/metastasis process, possible cancer therapeutic targets) are discussed.
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40
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Xiong Y, Teng S, Zheng L, Sun S, Li J, Guo N, Li M, Wang L, Zhu F, Wang C, Rao Z, Zhou Z. Stretch-induced Ca 2+ independent ATP release in hippocampal astrocytes. J Physiol 2018; 596:1931-1947. [PMID: 29488635 DOI: 10.1113/jp275805] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 02/21/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Similar to neurons, astrocytes actively participate in synaptic transmission via releasing gliotransmitters. The Ca2+ -dependent release of gliotransmitters includes glutamate and ATP. Following an 'on-cell-like' mechanical stimulus to a single astrocyte, Ca2+ independent single, large, non-quantal, ATP release occurs. Astrocytic ATP release is inhibited by either selective antagonist treatment or genetic knockdown of P2X7 receptor channels. Our work suggests that ATP can be released from astrocytes via two independent pathways in hippocampal astrocytes; in addition to the known Ca2+ -dependent vesicular release, larger non-quantal ATP release depends on P2X7 channels following mechanical stretch. ABSTRACT Astrocytic ATP release is essential for brain functions such as synaptic long-term potentiation for learning and memory. However, whether and how ATP is released via exocytosis remains hotly debated. All previous studies of non-vesicular ATP release have used indirect assays. By contrast, two recent studies report vesicular ATP release using more direct assays. In the present study, using patch clamped 'ATP-sniffer cells', we re-investigated astrocytic ATP release at single-vesicle resolution in hippocampal astrocytes. Following an 'on-cell-like' mechanical stimulus of a single astrocyte, a Ca2+ independent single large non-quantal ATP release occurred, in contrast to the Ca2+ -dependent multiple small quantal ATP release in a chromaffin cell. The mechanical stimulation-induced ATP release from an astrocyte was inhibited by either exposure to a selective antagonist or genetic knockdown of P2X7 receptor channels. Functional P2X7 channels were expressed in astrocytes in hippocampal brain slices. Thus, in addition to small quantal ATP release, larger non-quantal ATP release depends on P2X7 channels in astrocytes.
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Affiliation(s)
- Yingfei Xiong
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China.,Institute of Neurosciences, Fourth Military Medical University, Xi'an, China.,Department of Neurosurgery, Affiliated Hospital of Air Force Institute of Aeromedicine, Beijing, China
| | - Sasa Teng
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Lianghong Zheng
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Suhua Sun
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Jie Li
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Ning Guo
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Mingli Li
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Li Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Feipeng Zhu
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Changhe Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Zhiren Rao
- Institute of Neurosciences, Fourth Military Medical University, Xi'an, China
| | - Zhuan Zhou
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Institute of Molecular Medicine, Peking University, Beijing, China
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41
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Li S, Bjelobaba I, Stojilkovic SS. Interactions of Pannexin1 channels with purinergic and NMDA receptor channels. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:166-173. [PMID: 28389204 PMCID: PMC5628093 DOI: 10.1016/j.bbamem.2017.03.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 12/31/2022]
Abstract
Pannexins are a three-member family of vertebrate plasma membrane spanning molecules that have homology to the invertebrate gap junction forming proteins, the innexins. However, pannexins do not form gap junctions but operate as plasma membrane channels. The best-characterized member of these proteins, Pannexin1 (Panx1) was suggested to be functionally associated with purinergic P2X and N-methyl-D-aspartate (NMDA) receptor channels. Activation of these receptor channels by their endogenous ligands leads to cross-activation of Panx1 channels. This in turn potentiates P2X and NMDA receptor channel signaling. Two potentiation concepts have been suggested: enhancement of the current responses and/or sustained receptor channel activation by ATP released through Panx1 pore and adenosine generated by ectonucleotidase-dependent dephosphorylation of ATP. Here we summarize the current knowledge and hypotheses about interactions of Panx1 channels with P2X and NMDA receptor channels. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Shuo Li
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Ivana Bjelobaba
- Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 11000 Belgrade, Serbia
| | - Stanko S Stojilkovic
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
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42
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Regulation of Skeletal Muscle Myoblast Differentiation and Proliferation by Pannexins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 925:57-73. [PMID: 27518505 DOI: 10.1007/5584_2016_53] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Pannexins are newly discovered channels that are now recognized as mediators of adenosine triphosphate release from several cell types allowing communication with the extracellular environment. Pannexins have been associated with various physiological and pathological processes including apoptosis, inflammation, and cancer. However, it is only recently that our work has unveiled a role for Pannexin 1 and Pannexin 3 as novel regulators of skeletal muscle myoblast proliferation and differentiation. Myoblast differentiation is an ordered multistep process that includes withdrawal from the cell cycle and the expression of key myogenic factors leading to myoblast differentiation and fusion into multinucleated myotubes. Eventually, myotubes will give rise to the diverse muscle fiber types that build the complex skeletal muscle architecture essential for body movement, postural behavior, and breathing. Skeletal muscle cell proliferation and differentiation are crucial processes required for proper skeletal muscle development during embryogenesis, as well as for the postnatal skeletal muscle regeneration that is necessary for muscle repair after injury or exercise. However, defects in skeletal muscle cell differentiation and/or deregulation of cell proliferation are involved in various skeletal muscle pathologies. In this review, we will discuss the expression of pannexins and their post-translational modifications in skeletal muscle, their known functions in various steps of myogenesis, including myoblast proliferation and differentiation, as well as their possible roles in skeletal muscle development, regeneration, and diseases such as Duchenne muscular dystrophy.
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43
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Voigt A, Nowick K, Almaas E. A composite network of conserved and tissue specific gene interactions reveals possible genetic interactions in glioma. PLoS Comput Biol 2017; 13:e1005739. [PMID: 28957313 PMCID: PMC5634634 DOI: 10.1371/journal.pcbi.1005739] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 10/10/2017] [Accepted: 08/24/2017] [Indexed: 02/08/2023] Open
Abstract
Differential co-expression network analyses have recently become an important step in the investigation of cellular differentiation and dysfunctional gene-regulation in cell and tissue disease-states. The resulting networks have been analyzed to identify and understand pathways associated with disorders, or to infer molecular interactions. However, existing methods for differential co-expression network analysis are unable to distinguish between various forms of differential co-expression. To close this gap, here we define the three different kinds (conserved, specific, and differentiated) of differential co-expression and present a systematic framework, CSD, for differential co-expression network analysis that incorporates these interactions on an equal footing. In addition, our method includes a subsampling strategy to estimate the variance of co-expressions. Our framework is applicable to a wide variety of cases, such as the study of differential co-expression networks between healthy and disease states, before and after treatments, or between species. Applying the CSD approach to a published gene-expression data set of cerebral cortex and basal ganglia samples from healthy individuals, we find that the resulting CSD network is enriched in genes associated with cognitive function, signaling pathways involving compounds with well-known roles in the central nervous system, as well as certain neurological diseases. From the CSD analysis, we identify a set of prominent hubs of differential co-expression, whose neighborhood contains a substantial number of genes associated with glioblastoma. The resulting gene-sets identified by our CSD analysis also contain many genes that so far have not been recognized as having a role in glioblastoma, but are good candidates for further studies. CSD may thus aid in hypothesis-generation for functional disease-associations.
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Affiliation(s)
- André Voigt
- Network Systems Biology Group, Department of Biotechnology, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Katja Nowick
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany
- Bioinformatics, Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
- Human Biology, Institute for Biology, Free University Berlin, Berlin, Germany
| | - Eivind Almaas
- Network Systems Biology Group, Department of Biotechnology, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and General Practice, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
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44
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Role of Pannexin1 channels in the resistance of I-10 testicular cancer cells to cisplatin mediated by ATP/IP 3 pathway. Biomed Pharmacother 2017; 94:514-522. [PMID: 28780469 DOI: 10.1016/j.biopha.2017.07.144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 07/26/2017] [Accepted: 07/27/2017] [Indexed: 12/15/2022] Open
Abstract
Cisplatin (DDP) is the most commonly used drug in testicular cancer. However, drug resistance severely limits its clinical use and the underlying mechanisms need to be further clarified. The aim of present study was to investigate the role of ATP/IP3 pathway mediated by pannexin1 (Panx-1) channels on DDP-induced apoptosis and to reveal the potential mechanisms of DDP-resistance in testicular cancer. We found that the expression of Panx-1 in I-10/DDP cells (DDP-resistance) was decreased compared with parental I-10 cells determined by western blotting and immunofluorescence assay. To further clarify the role of Panx-1 in DDP resistance, Panx-1 function was modulated by overexpression and knockdown of Panx-1 expression. Panx-1 overexpression increased DDP-induced apoptosis, ATP release and IP3 levels. On the contrary, Panx-1 silencing decreased DDP-induced apoptosis, ATP release and IP3 levels. Apyrase (hydrolyzing extracellular ATP) or xestospongin C (antagonizing IP3 receptor) also decreased DDP-induced apoptosis. Our findings demonstrate that Panx-1 is involved in DDP-resistance and ATP/IP3 pathway mediated by Panx-1 channels participates in DDP-induced apoptosis in testicular cancer. Panx-1 modulation may be interesting to amplify the clinical effect of DDP and reverse the resistance of testicular cancer cells to DDP.
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45
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FGF-1 Triggers Pannexin-1 Hemichannel Opening in Spinal Astrocytes of Rodents and Promotes Inflammatory Responses in Acute Spinal Cord Slices. J Neurosci 2017; 36:4785-801. [PMID: 27122036 DOI: 10.1523/jneurosci.4195-15.2016] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/16/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED We show here that the growth factor FGF-1 is proinflammatory in the spinal cord and explore the inflammatory mechanisms. FGF-1 applied to rat spinal astrocytes in culture initiates calcium signaling and induces secretion of ATP that within minutes increases membrane permeability to ethidium (Etd(+)) and Ca(2+) by activating P2X7 receptors (P2X7Rs) that open pannexin hemichannels (Px1 HCs) that release further ATP; by 7 h treatment, connexin 43 hemichannels (Cx43 HCs) are also opened. In acute mouse spinal cord slices ex vivo, we found that FGF-1 treatment for 1 h increases the percentage of GFAP-positive astrocytes that show enhanced Px1 HC-mediated Etd(+) uptake. This response to FGF-1 was not observed in astrocytes in slices of cerebral cortex. FGF-1-induced dye uptake by astrocytes is prevented by BAPTA-AM or a phospholipase C (PLC) inhibitor. Furthermore, in spinal cord slices, P2X7R antagonists (BBG and A740003) and Px1 HC blockers ((10)Panx1 and carbenoxolone) prevent the increase in Etd(+) uptake by astrocytes, whereas Gap19, a selective Cx43 HC blocker, has no effect on dye uptake at this time. Microglia are not required for the increase in Etd(+) uptake by astrocytes induced by FGF-1, although they are activated by FGF-1 treatment. The morphological signs of microglia activation are inhibited by P2X7R antagonists and (10)Panx1 and are associated with elevated levels of proinflammatory cytokines in cord slices treated with FGF-1. The FGF-1 initiated cascade may play an important role in spinal cord inflammation in vivo SIGNIFICANCE STATEMENT We find that FGF-1 elevates [Ca(2+)]i in spinal astrocytes, which causes vesicular release of ATP and activation of P2X7Rs to trigger opening of Px1 HCs, which release further ATP. This regenerative response occurs in astrocyte cultures and in acute spinal cord slices. In the latter, FGF-1 application promotes the activation of microglia and increases the production of proinflammatory cytokines through mechanisms depending on P2X7 receptors and Px1 HCs. This proinflammatory microenvironment may favor recruitment of leukocytes into the spinal cord and impacts negatively on neuronal structure and function in vivo Any step in these processes provides a potential therapeutic target for treatment of secondary damage in various spinal cord pathologies.
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Xu J, Chen L, Li L. Pannexin hemichannels: A novel promising therapy target for oxidative stress related diseases. J Cell Physiol 2017; 233:2075-2090. [PMID: 28295275 DOI: 10.1002/jcp.25906] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 12/16/2022]
Abstract
Pannexins, which contain three subtypes: pannexin-1, -2, and -3, are vertebrate glycoproteins that form non-junctional plasma membrane intracellular hemichannels via oligomerization. Oxidative stress refers to an imbalance of the generation and elimination of reactive oxygen species (ROS). Studies have shown that elevated ROS levels are pivotal in the development of a variety of diseases. Recent studies indicate that the occurrence of these oxidative stress related diseases is associated with pannexin hemichannels. It is also reported that pannexins regulate the production of ROS which in turn may increase the opening of pannexin hemichannels. In this paper, we review recent researches about the important role of pannexin hemichannels in oxidative stress related diseases. Thus, pannexin hemichannels, novel therapeutic targets, hold promise in managing oxidative stress related diseases such as the tumor, inflammatory bowel diseases (IBD), pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), cardiovascular disease, insulin resistance (IR), and neural degeneration diseases.
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Affiliation(s)
- Jin Xu
- Learning Key Laboratory for Pharmacoproteomics, Institute of Pharmacy and Pharmacology, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, P. R. China
| | - Linxi Chen
- Learning Key Laboratory for Pharmacoproteomics, Institute of Pharmacy and Pharmacology, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, P. R. China
| | - Lanfang Li
- Learning Key Laboratory for Pharmacoproteomics, Institute of Pharmacy and Pharmacology, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, P. R. China
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Kim Y, Davidson JO, Green CR, Nicholson LFB, O'Carroll SJ, Zhang J. Connexins and Pannexins in cerebral ischemia. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:224-236. [PMID: 28347700 DOI: 10.1016/j.bbamem.2017.03.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/24/2017] [Accepted: 03/22/2017] [Indexed: 12/12/2022]
Abstract
A common cause of mortality and long-term adult disability, cerebral ischemia or brain ischemia imposes a significant health and financial burden on communities worldwide. Cerebral ischemia is a condition that arises from a sudden loss of blood flow and consequent failure to meet the high metabolic demands of the brain. The lack of blood flow initiates a sequelae of cell death mechanisms, including the activation of the inflammatory pathway, which can ultimately result in irreversible brain tissue damage. In particular, Connexins and Pannexins are non-selective channels with a large pore that have shown to play time-dependent roles in the perpetuation of ischaemic injury. This review highlights the roles of Connexin and Pannexin channels in cell death mechanisms as a promising therapeutic target in cerebral ischemia, and in particular connexin hemichannels which may contribute most of the ATP release as a result of ischemia as well as during reperfusion. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Yeri Kim
- Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland
| | - Joanne O Davidson
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland
| | - Colin R Green
- Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland
| | - Louise F B Nicholson
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland
| | - Simon J O'Carroll
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland
| | - Jie Zhang
- Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland.
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48
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Boyce AKJ, Epp AL, Nagarajan A, Swayne LA. Transcriptional and post-translational regulation of pannexins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:72-82. [PMID: 28279657 DOI: 10.1016/j.bbamem.2017.03.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 12/21/2022]
Abstract
Pannexins are a 3-membered family of proteins that form large pore ion and metabolite channels in vertebrates. The impact of pannexins on vertebrate biology is intricately tied to where and when they are expressed, and how they are modified, once produced. The purpose of this review is therefore to outline our current understanding of transcriptional and post-translational regulation of pannexins. First, we briefly summarize their discovery and characteristics. Next, we describe several aspects of transcriptional regulation, including cell and tissue-specific expression, dynamic expression over development and disease, as well as new insights into the underlying molecular machinery involved. Following this, we delve into the role of post-translational modifications in the regulation of trafficking and channel properties, highlighting important work on glycosylation, phosphorylation, S-nitrosylation and proteolytic cleavage. Embedded throughout, we also highlight important knowledge gaps and avenues of future research. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Andrew K J Boyce
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada
| | - Anna L Epp
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada
| | - Archana Nagarajan
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver V6T 1Z3, Canada.
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49
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Abstract
Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. Although many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field.
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Affiliation(s)
- Trond Aasen
- (Co-corresponding authors) Correspondence to
T.A. () and D.W.L.
()
| | - Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences
Fondamentales et Appliquées, Université de Poitiers, Poitiers,
France
| | - Christian C. Naus
- Department of Cellular and Physiological Sciences, The Life
Sciences Institute, University of British Columbia, Vancouver, British
Columbia, Canada
| | - Paul D. Lampe
- Translational Research Program, Fred Hutchinson Cancer Research
Center, Seattle, United States
| | - Dale W. Laird
- (Co-corresponding authors) Correspondence to
T.A. () and D.W.L.
()
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50
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Crespo Yanguas S, Willebrords J, Johnstone SR, Maes M, Decrock E, De Bock M, Leybaert L, Cogliati B, Vinken M. Pannexin1 as mediator of inflammation and cell death. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:51-61. [PMID: 27741412 DOI: 10.1016/j.bbamcr.2016.10.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 10/07/2016] [Accepted: 10/08/2016] [Indexed: 02/06/2023]
Abstract
Pannexins form channels at the plasma membrane surface that establish a pathway for communication between the cytosol of individual cells and their extracellular environment. By doing so, pannexin signaling dictates several physiological functions, but equally underlies a number of pathological processes. Indeed, pannexin channels drive inflammation by assisting in the activation of inflammasomes, the release of pro-inflammatory cytokines, and the activation and migration of leukocytes. Furthermore, these cellular pores facilitate cell death, including apoptosis, pyroptosis and autophagy. The present paper reviews the roles of pannexin channels in inflammation and cell death. In a first part, a state-of-the-art overview of pannexin channel structure, regulation and function is provided. In a second part, the mechanisms behind their involvement in inflammation and cell death are discussed.
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Affiliation(s)
- Sara Crespo Yanguas
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Joost Willebrords
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Scott R Johnstone
- College of Medical, Veterinary and Life Sciences, British Heart Foundation Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Michaël Maes
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Elke Decrock
- Department of Basic Medical Sciences, Physiology group, Ghent University, Gent, Belgium
| | - Marijke De Bock
- Department of Basic Medical Sciences, Physiology group, Ghent University, Gent, Belgium
| | - Luc Leybaert
- Department of Basic Medical Sciences, Physiology group, Ghent University, Gent, Belgium
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium.
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