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Casillas Martinez A, Wicki-Stordeur LE, Ariano AV, Swayne LA. Dual role for pannexin 1 at synapses: regulating functional and morphological plasticity. J Physiol 2024. [PMID: 39264228 DOI: 10.1113/jp285228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 07/29/2024] [Indexed: 09/13/2024] Open
Abstract
Pannexin 1 (PANX1) is an ion and metabolite membrane channel and scaffold protein enriched in synaptic compartments of neurons in the central nervous system. In addition to a well-established link between PANX1 and synaptic plasticity, we recently identified a role for PANX1 in the regulation of dendritic spine stability. Notably, PANX1 and its interacting proteins are linked to neurological conditions involving dendritic spine loss. Understanding the dual role of PANX1 in synaptic function and morphology may help to shed light on these links. We explore potential mechanisms, including PANX1's interactions with postsynaptic receptors and cytoskeleton regulating proteins. Finally, we contextualize PANX1's dual role within neurological diseases involving dendritic spine and synapse dysfunction.
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Affiliation(s)
| | - Leigh E Wicki-Stordeur
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Annika V Ariano
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
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2
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Ahn Y, Park JH. Novel Potential Therapeutic Targets in Autosomal Dominant Polycystic Kidney Disease from the Perspective of Cell Polarity and Fibrosis. Biomol Ther (Seoul) 2024; 32:291-300. [PMID: 38589290 PMCID: PMC11063481 DOI: 10.4062/biomolther.2023.207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/18/2023] [Accepted: 12/26/2023] [Indexed: 04/10/2024] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), a congenital genetic disorder, is a notable contributor to the prevalence of chronic kidney disease worldwide. Despite the absence of a complete cure, ongoing research aims for early diagnosis and treatment. Although agents such as tolvaptan and mTOR inhibitors have been utilized, their effectiveness in managing the disease during its initial phase has certain limitations. This review aimed to explore new targets for the early diagnosis and treatment of ADPKD, considering ongoing developments. We particularly focus on cell polarity, which is a key factor that influences the process and pace of cyst formation. In addition, we aimed to identify agents or treatments that can prevent or impede the progression of renal fibrosis, ultimately slowing its trajectory toward end-stage renal disease. Recent advances in slowing ADPKD progression have been examined, and potential therapeutic approaches targeting multiple pathways have been introduced. This comprehensive review discusses innovative strategies to address the challenges of ADPKD and provides valuable insights into potential avenues for its prevention and treatment.
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Affiliation(s)
- Yejin Ahn
- Department of Biological Sciences, Sookmyung Women’s University, Seoul, 04310, 04310, Republic of Korea
| | - Jong Hoon Park
- Department of Biological Sciences, Sookmyung Women’s University, Seoul, 04310, 04310, Republic of Korea
- Research Institute of Women’s Health, Sookmyung Women’s University, Seoul, 04310, Republic of Korea
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3
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Xing Q, Cibelli A, Yang GL, Dohare P, Li QH, Scemes E, Guan FX, Spray DC. Neuronal Panx1 drives peripheral sensitization in experimental plantar inflammatory pain. Mil Med Res 2024; 11:27. [PMID: 38685116 PMCID: PMC11057180 DOI: 10.1186/s40779-024-00525-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 03/25/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND The channel-forming protein Pannexin1 (Panx1) has been implicated in both human studies and animal models of chronic pain, but the underlying mechanisms remain incompletely understood. METHODS Wild-type (WT, n = 24), global Panx1 KO (n = 24), neuron-specific Panx1 KO (n = 20), and glia-specific Panx1 KO (n = 20) mice were used in this study at Albert Einstein College of Medicine. The von Frey test was used to quantify pain sensitivity in these mice following complete Freund's adjuvant (CFA) injection (7, 14, and 21 d). The qRT-PCR was employed to measure mRNA levels of Panx1, Panx2, Panx3, Cx43, Calhm1, and β-catenin. Laser scanning confocal microscopy imaging, Sholl analysis, and electrophysiology were utilized to evaluate the impact of Panx1 on neuronal excitability and morphology in Neuro2a and dorsal root ganglion neurons (DRGNs) in which Panx1 expression or function was manipulated. Ethidium bromide (EtBr) dye uptake assay and calcium imaging were employed to investigate the role of Panx1 in adenosine triphosphate (ATP) sensitivity. β-galactosidase (β-gal) staining was applied to determine the relative cellular expression levels of Panx1 in trigeminal ganglia (TG) and DRG of transgenic mice. RESULTS Global or neuron-specific Panx1 deletion markedly decreased pain thresholds after CFA stimuli (7, 14, and 21 d; P < 0.01 vs. WT group), indicating that Panx1 was positively correlated with pain sensitivity. In Neuro2a, global Panx1 deletion dramatically reduced neurite extension and inward currents compared to the WT group (P < 0.05), revealing that Panx1 enhanced neurogenesis and excitability. Similarly, global Panx1 deletion significantly suppressed Wnt/β-catenin dependent DRG neurogenesis following 5 d of nerve growth factor (NGF) treatment (P < 0.01 vs. WT group). Moreover, Panx1 channels enhanced DRG neuron response to ATP after CFA injection (P < 0.01 vs. Panx1 KO group). Furthermore, ATP release increased Ca2+ responses in DRGNs and satellite glial cells surrounding them following 7 d of CFA treatment (P < 0.01 vs. Panx1 KO group), suggesting that Panx1 in glia also impacts exaggerated neuronal excitability. Interestingly, neuron-specific Panx1 deletion was found to markedly reduce differentiation in cultured DRGNs, as evidenced by stunted neurite outgrowth (P < 0.05 vs. Panx1 KO group; P < 0.01 vs. WT group or GFAP-Cre group), blunted activation of Wnt/β-catenin signaling (P < 0.01 vs. WT, Panx1 KO and GFAP-Cre groups), and diminished cell excitability (P < 0.01 vs. GFAP-Cre group) and response to ATP stimulation (P < 0.01 vs. WT group). Analysis of β-gal staining showed that cellular expression levels of Panx1 in neurons are significantly higher (2.5-fold increase) in the DRG than in the TG. CONCLUSIONS The present study revealed that neuronal Panx1 is a prominent driver of peripheral sensitivity in the setting of inflammatory pain through cell-autonomous effects on neuronal excitability. This hyperexcitability dependence on neuronal Panx1 contrasts with inflammatory orofacial pain, where similar studies revealed a prominent role for glial Panx1. The apparent differences in Panx1 expression in neuronal and non-neuronal TG and DRG cells are likely responsible for the distinct impact of these cell types in the two pain models.
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Affiliation(s)
- Qu Xing
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Antonio Cibelli
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, Bari, 70125, Italy
| | - Greta Luyuan Yang
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT, 06459, USA
| | - Preeti Dohare
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Qing-Hua Li
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Eliana Scemes
- Department of Anatomy and Cell Biology, New York Medical College, Valhalla, NY, 10595, USA
| | - Fang-Xia Guan
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China.
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, 450001, China.
| | - David C Spray
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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4
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Noort RJ, Zhu H, Flemmer RT, Moore CS, Belbin TJ, Esseltine JL. Apically localized PANX1 impacts neuroepithelial expansion in human cerebral organoids. Cell Death Discov 2024; 10:22. [PMID: 38212304 PMCID: PMC10784521 DOI: 10.1038/s41420-023-01774-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/01/2023] [Accepted: 12/11/2023] [Indexed: 01/13/2024] Open
Abstract
Dysfunctional paracrine signaling through Pannexin 1 (PANX1) channels is linked to several adult neurological pathologies and emerging evidence suggests that PANX1 plays an important role in human brain development. It remains unclear how early PANX1 influences brain development, or how loss of PANX1 alters the developing human brain. Using a cerebral organoid model of early human brain development, we find that PANX1 is expressed at all stages of organoid development from neural induction through to neuroepithelial expansion and maturation. Interestingly, PANX1 cellular distribution and subcellular localization changes dramatically throughout cerebral organoid development. During neural induction, PANX1 becomes concentrated at the apical membrane domain of neural rosettes where it co-localizes with several apical membrane adhesion molecules. During neuroepithelial expansion, PANX1-/- organoids are significantly smaller than control and exhibit significant gene expression changes related to cell adhesion, WNT signaling and non-coding RNAs. As cerebral organoids mature, PANX1 expression is significantly upregulated and is primarily localized to neuronal populations outside of the ventricular-like zones. Ultimately, PANX1 protein can be detected in all layers of a 21-22 post conception week human fetal cerebral cortex. Together, these results show that PANX1 is dynamically expressed by numerous cell types throughout embryonic and early fetal stages of human corticogenesis and loss of PANX1 compromises neuroepithelial expansion due to dysregulation of cell-cell and cell-matrix adhesion, perturbed intracellular signaling, and changes to gene regulation.
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Affiliation(s)
- Rebecca J Noort
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada
| | - Hanrui Zhu
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada
| | - Robert T Flemmer
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada
| | - Craig S Moore
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada
| | - Thomas J Belbin
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada
- Discipline of Oncology, Faculty of sp. Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada
| | - Jessica L Esseltine
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, A1B 3V6, NL, Canada.
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5
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O'Donnell BL, Penuela S. Skin in the game: pannexin channels in healthy and cancerous skin. Biochem J 2023; 480:1929-1949. [PMID: 38038973 DOI: 10.1042/bcj20230176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/15/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
The skin is a highly organized tissue composed of multiple layers and cell types that require coordinated cell to cell communication to maintain tissue homeostasis. In skin cancer, this organized structure and communication is disrupted, prompting the malignant transformation of healthy cells into melanoma, basal cell carcinoma or squamous cell carcinoma tumours. One such family of channel proteins critical for cellular communication is pannexins (PANX1, PANX2, PANX3), all of which are present in the skin. These heptameric single-membrane channels act as conduits for small molecules and ions like ATP and Ca2+ but have also been shown to have channel-independent functions through their interacting partners or action in signalling pathways. Pannexins have diverse roles in the skin such as in skin development, aging, barrier function, keratinocyte differentiation, inflammation, and wound healing, which were discovered through work with pannexin knockout mice, organotypic epidermis models, primary cells, and immortalized cell lines. In the context of cutaneous cancer, PANX1 is present at high levels in melanoma tumours and functions in melanoma carcinogenesis, and both PANX1 and PANX3 expression is altered in non-melanoma skin cancer. PANX2 has thus far not been implicated in any skin cancer. This review will discuss pannexin isoforms, structure, trafficking, post-translational modifications, interactome, and channel activity. We will also outline the expression, localization, and function of pannexin channels within the diverse cell types of the epidermis, dermis, hypodermis, and adnexal structures of the skin, and how these properties are exploited or abrogated in instances of skin cancer.
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Affiliation(s)
- Brooke L O'Donnell
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
- Department of Oncology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
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Frederiksen SD, Wicki-Stordeur LE, Swayne LA. Overlap in synaptic neurological condition susceptibility pathways and the neural pannexin 1 interactome revealed by bioinformatics analyses. Channels (Austin) 2023; 17:2253102. [PMID: 37807670 PMCID: PMC10563626 DOI: 10.1080/19336950.2023.2253102] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 08/22/2023] [Indexed: 10/10/2023] Open
Abstract
Many neurological conditions exhibit synaptic impairments, suggesting mechanistic convergence. Additionally, the pannexin 1 (PANX1) channel and signaling scaffold is linked to several of these neurological conditions and is an emerging regulator of synaptic development and plasticity; however, its synaptic pathogenic contributions are relatively unexplored. To this end, we explored connections between synaptic neurodevelopmental disorder and neurodegenerative disease susceptibility genes discovered by genome-wide association studies (GWASs), and the neural PANX1 interactome (483 proteins) identified from mouse Neuro2a (N2a) cells. To identify shared susceptibility genes, we compared synaptic suggestive GWAS candidate genes amongst autism spectrum disorders, schizophrenia, Parkinson's disease, and Alzheimer's disease. To further probe PANX1 signaling pathways at the synapse, we used bioinformatics tools to identify PANX1 interactome signaling pathways and protein-protein interaction clusters. To shed light on synaptic disease mechanisms potentially linking PANX1 and these four neurological conditions, we performed additional cross-analyses between gene ontologies enriched for the PANX1 synaptic and disease-susceptibility gene sets. Finally, to explore the regional specificity of synaptic PANX1-neurological condition connections, we identified brain region-specific elevations of synaptic PANX1 interactome and GWAS candidate gene set transcripts. Our results confirm considerable overlap in risk genes for autism spectrum disorders and schizophrenia and identify potential commonalities in genetic susceptibility for neurodevelopmental disorders and neurodegenerative diseases. Our findings also pinpointed novel putative PANX1 links to synaptic disease-associated pathways, such as regulation of vesicular trafficking and proteostasis, warranting further validation.
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Affiliation(s)
| | | | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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7
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Badaoui M, Chanson M. Intercellular Communication in Airway Epithelial Cell Regeneration: Potential Roles of Connexins and Pannexins. Int J Mol Sci 2023; 24:16160. [PMID: 38003349 PMCID: PMC10671439 DOI: 10.3390/ijms242216160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/19/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Connexins and pannexins are transmembrane proteins that can form direct (gap junctions) or indirect (connexons, pannexons) intercellular communication channels. By propagating ions, metabolites, sugars, nucleotides, miRNAs, and/or second messengers, they participate in a variety of physiological functions, such as tissue homeostasis and host defense. There is solid evidence supporting a role for intercellular signaling in various pulmonary inflammatory diseases where alteration of connexin/pannexin channel functional expression occurs, thus leading to abnormal intercellular communication pathways and contributing to pathophysiological aspects, such as innate immune defense and remodeling. The integrity of the airway epithelium, which is the first line of defense against invading microbes, is established and maintained by a repair mechanism that involves processes such as proliferation, migration, and differentiation. Here, we briefly summarize current knowledge on the contribution of connexins and pannexins to necessary processes of tissue repair and speculate on their possible involvement in the shaping of the airway epithelium integrity.
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Affiliation(s)
| | - Marc Chanson
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland;
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8
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Wu YL, Yang AH, Chiu YH. Recent advances in the structure and activation mechanisms of metabolite-releasing Pannexin 1 channels. Biochem Soc Trans 2023; 51:1687-1699. [PMID: 37622532 DOI: 10.1042/bst20230038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/13/2023] [Accepted: 08/15/2023] [Indexed: 08/26/2023]
Abstract
Pannexin 1 (PANX1) is a widely expressed large-pore ion channel located in the plasma membrane of almost all vertebrate cells. It possesses a unique ability to act as a conduit for both inorganic ions (e.g. potassium or chloride) and bioactive metabolites (e.g. ATP or glutamate), thereby activating varying signaling pathways in an autocrine or paracrine manner. Given its crucial role in cell-cell interactions, the activity of PANX1 has been implicated in maintaining homeostasis of cardiovascular, immune, and nervous systems. Dysregulation of PANX1 has also been linked to numerous diseases, such as ischemic stroke, seizure, and inflammatory disorders. Therefore, the mechanisms underlying different modes of PANX1 activation and its context-specific channel properties have gathered significant attention. In this review, we summarize the roles of PANX1 in various physiological processes and diseases, and analyze the accumulated lines of evidence supporting diverse molecular mechanisms associated with different PANX1 activation modalities. We focus on examining recent discoveries regarding PANX1 regulations by reversible post-translational modifications, elevated intracellular calcium concentration, and protein-protein interactions, as well as by irreversible cleavage of its C-terminal tail. Additionally, we delve into the caveats in the proposed PANX1 gating mechanisms and channel open-closed configurations by critically analyzing the structural insights derived from cryo-EM studies and the unitary properties of PANX1 channels. By doing so, we aim to identify potential research directions for a better understanding of the functions and regulations of PANX1 channels.
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Affiliation(s)
- Yi-Ling Wu
- Department of Life Science, National Tsing Hua University, No. 101, Sec. 2, Kuang Fu Rd., Hsinchu 300044, Taiwan
| | - Ai-Hsing Yang
- Department of Life Science, National Tsing Hua University, No. 101, Sec. 2, Kuang Fu Rd., Hsinchu 300044, Taiwan
| | - Yu-Hsin Chiu
- Department of Life Science, National Tsing Hua University, No. 101, Sec. 2, Kuang Fu Rd., Hsinchu 300044, Taiwan
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, No. 101, Sec. 2, Kuang Fu Rd., Hsinchu 300044, Taiwan
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9
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Langlois S, St-Pierre ME, Holland SH, Xiang X, Freeman E, Mohamed H, Dural AC, Hammad A, Karami S, van de Panne C, Cowan KN. Inhibition of PANX1 Channels Reduces the Malignant Properties of Human High-Risk Neuroblastoma. J Cancer 2023; 14:689-706. [PMID: 37056395 PMCID: PMC10088893 DOI: 10.7150/jca.79552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 03/03/2023] [Indexed: 04/15/2023] Open
Abstract
Pannexin 1 (PANX1) is expressed in many tissue types including tissues of neural origin. Neuroblastoma (NB) is a neural crest-derived malignancy mainly occurring in children. The majority of NB patients present with high-risk disease for which current therapies are ineffective. Here, we show that while PANX1 is expressed in NB of all stages, high PANX1 expression in high-risk NB is associated with a reduced survival probability. PANX1 channel inhibition using probenecid (PBN) or carbenoxolone (CBX) reduced the proliferation of our panel of high-risk NB cell lines. We show that expression of the Y10F PANX1 mutant, which cannot be phosphorylated on tyrosine 10 and acts in a dominant-negative manner, curtailed NB cell proliferation. Furthermore, PBN and CBX treatment halted the growth of NB spheroids and in some cases triggered the regression of established NB spheroids. Finally, both drugs reduced the progression of high-risk NB in vivo. Together our data indicate that PANX1 channels regulate human NB malignant properties and that the use of PBN or CBX may provide a new therapeutic approach for high-risk NB.
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Affiliation(s)
- Stéphanie Langlois
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - Marie-Eve St-Pierre
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Stephen H. Holland
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Xiao Xiang
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Emily Freeman
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Hisham Mohamed
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - Ahmet Cem Dural
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - Ahmed Hammad
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - Sanaz Karami
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Chloé van de Panne
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Kyle N. Cowan
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
- ✉ Corresponding author: Dr. Kyle N. Cowan, Children's Hospital of Eastern Ontario, Pediatric General Surgery, 401 Smyth Rd, Room 3370, Ottawa, Ontario, K1H 8L1, Canada; E-mail: ; Phone: +1 613-737-7600 (ext. 2675); Fax: 613-738-4849
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10
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Flores-Muñoz C, García-Rojas F, Pérez MA, Santander O, Mery E, Ordenes S, Illanes-González J, López-Espíndola D, González-Jamett AM, Fuenzalida M, Martínez AD, Ardiles ÁO. The Long-Term Pannexin 1 Ablation Produces Structural and Functional Modifications in Hippocampal Neurons. Cells 2022; 11:cells11223646. [PMID: 36429074 PMCID: PMC9688914 DOI: 10.3390/cells11223646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/29/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022] Open
Abstract
Enhanced activity and overexpression of Pannexin 1 (Panx1) channels contribute to neuronal pathologies such as epilepsy and Alzheimer's disease (AD). The Panx1 channel ablation alters the hippocampus's glutamatergic neurotransmission, synaptic plasticity, and memory flexibility. Nevertheless, Panx1-knockout (Panx1-KO) mice still retain the ability to learn, suggesting that compensatory mechanisms stabilize their neuronal activity. Here, we show that the absence of Panx1 in the adult brain promotes a series of structural and functional modifications in the Panx1-KO hippocampal synapses, preserving spontaneous activity. Compared to the wild-type (WT) condition, the adult hippocampal neurons of Panx1-KO mice exhibit enhanced excitability, a more complex dendritic branching, enhanced spine maturation, and an increased proportion of multiple synaptic contacts. These modifications seem to rely on the actin-cytoskeleton dynamics as an increase in the actin polymerization and an imbalance between the Rac1 and the RhoA GTPase activities were observed in Panx1-KO brain tissues. Our findings highlight a novel interaction between Panx1 channels, actin, and Rho GTPases, which appear to be relevant for synapse stability.
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Affiliation(s)
- Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Francisca García-Rojas
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Miguel A. Pérez
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Escuela de Ciencias de la Salud, Universidad de Viña del Mar, Viña del Mar 2572007, Chile
| | - Odra Santander
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Elena Mery
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
| | - Stefany Ordenes
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Javiera Illanes-González
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Daniela López-Espíndola
- Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2529002, Chile
- Centro de Investigaciones Biomédicas, Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar 2529002, Chile
| | - Arlek M. González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Marco Fuenzalida
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Correspondence: (M.F.); (A.D.M.); (Á.O.A.)
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Correspondence: (M.F.); (A.D.M.); (Á.O.A.)
| | - Álvaro O. Ardiles
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Centro Interdisciplinario de estudios en salud, Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar 2572007, Chile
- Correspondence: (M.F.); (A.D.M.); (Á.O.A.)
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11
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Abstract
Pannexin-1 (Panx1) channels contribute to neurological disorders, including stroke and epilepsy, where their function has been linked to N-methyl D-aspartate (NMDA) receptors (NMDARs). We discovered that Ca2+ entry via NMDARs recruits endoplasmic reticulum–resident STIM proteins to activate Panx1 by binding to a hydrophobic region localized to the Panx1 N terminus. Using loss-of-function approaches, combined with molecular replacement and use of a STIM/Panx1 function–blocking antibody, we demonstrate that disrupting the STIM/Panx1 interaction prevents Panx1 activation by NMDARs, but not by hypotonic stimuli. Thus, our findings serve as a basis for the design of modality-specific inhibitors against STIM-dependent Panx1 activation that will aid in understanding the multimodal functions of Panx1 and their contribution to physiology and pathology. Pannexin-1 (Panx1) is a large-pore ion and solute permeable channel highly expressed in the nervous system, where it subserves diverse processes, including neurite outgrowth, dendritic spine formation, and N-methyl D-aspartate (NMDA) receptor (NMDAR)-dependent plasticity. Moreover, Panx1 dysregulation contributes to neurological disorders, including neuropathic pain, epilepsy, and excitotoxicity. Despite progress in understanding physiological and pathological functions of Panx1, the mechanisms that regulate its activity, including its ion and solute permeability, remain poorly understood. In this study, we identify endoplasmic reticulum (ER)-resident stromal interaction molecules (STIM1/2), which are Ca2+ sensors that communicate events within the ER to plasma membrane channels, as binding and signaling partners of Panx1. We demonstrate that Panx1 is activated to its large-pore configuration in response to stimuli that recruit STIM1/2 and map the interaction interface to a hydrophobic region within the N terminus of Panx1. We further characterize a Panx1 N terminus–recognizing antibody as a function-blocking tool able to prevent large-pore Panx1 activation by STIM1/2. Using either the function-blocking antibody or re-expression of Panx1 deletion mutants in Panx1 knockout (KO) neurons, we show that STIM recruitment couples Ca2+ entry via NMDARs to Panx1 activation, thereby identifying a model of NMDAR-STIM-Panx1 signaling in neurons. Our study highlights a previously unrecognized and important role of the Panx1 N terminus in regulating channel activation and membrane localization. Considering past work demonstrating an intimate functional relation between NMDARs and Panx1, our study opens avenues for understanding activation modality and context-specific functions of Panx1, including functions linked to diverse STIM-regulated cellular responses.
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12
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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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13
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Mechanisms of Pannexin 1 (PANX1) Channel Mechanosensitivity and Its Pathological Roles. Int J Mol Sci 2022; 23:ijms23031523. [PMID: 35163442 PMCID: PMC8836264 DOI: 10.3390/ijms23031523] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/21/2022] [Accepted: 01/27/2022] [Indexed: 02/01/2023] Open
Abstract
Pannexins (PANX) were cloned based on their sequence homology to innexins (Inx), invertebrate gap junction proteins. Although there is no sequence homology between PANX and connexins (Cx), these proteins exhibit similar configurations. The PANX family has three members, PANX1, PANX2 and PANX3. Among them, PANX1 has been the most extensively studied. The PANX1 channels are activated by many factors, including high extracellular K+ ([K+]e), high intracellular Ca2+ ([Ca2+]i), Src family kinase (SFK)-mediated phosphorylation, caspase cleavage and mechanical stimuli. However, the mechanisms mediating this mechanosensitivity of PANX1 remain unknown. Both force-from-lipids and force-from-filaments models are proposed to explain the gating mechanisms of PANX1 channel mechanosensitivity. Finally, both the physiological and pathological roles of mechanosensitive PANX1 are discussed.
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14
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Suarez-Berumen K, Collins-Hooper H, Gromova A, Meech R, Sacco A, Dash PR, Mitchell R, Shestopalov VI, Woolley TE, Vaiyapuri S, Patel K, Makarenkova HP. Pannexin 1 Regulates Skeletal Muscle Regeneration by Promoting Bleb-Based Myoblast Migration and Fusion Through a Novel Lipid Based Signaling Mechanism. Front Cell Dev Biol 2021; 9:736813. [PMID: 34676213 PMCID: PMC8523994 DOI: 10.3389/fcell.2021.736813] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Adult skeletal muscle has robust regenerative capabilities due to the presence of a resident stem cell population called satellite cells. Muscle injury leads to these normally quiescent cells becoming molecularly and metabolically activated and embarking on a program of proliferation, migration, differentiation, and fusion culminating in the repair of damaged tissue. These processes are highly coordinated by paracrine signaling events that drive cytoskeletal rearrangement and cell-cell communication. Pannexins are a family of transmembrane channel proteins that mediate paracrine signaling by ATP release. It is known that Pannexin1 (Panx1) is expressed in skeletal muscle, however, the role of Panx1 during skeletal muscle development and regeneration remains poorly understood. Here we show that Panx1 is expressed on the surface of myoblasts and its expression is rapidly increased upon induction of differentiation and that Panx1-/- mice exhibit impaired muscle regeneration after injury. Panx1-/- myoblasts activate the myogenic differentiation program normally, but display marked deficits in migration and fusion. Mechanistically, we show that Panx1 activates P2 class purinergic receptors, which in turn mediate a lipid signaling cascade in myoblasts. This signaling induces bleb-driven amoeboid movement that in turn supports myoblast migration and fusion. Finally, we show that Panx1 is involved in the regulation of cell-matrix interaction through the induction of ADAMTS (Disintegrin-like and Metalloprotease domain with Thrombospondin-type 5) proteins that help remodel the extracellular matrix. These studies reveal a novel role for lipid-based signaling pathways activated by Panx1 in the coordination of myoblast activities essential for skeletal muscle regeneration.
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Affiliation(s)
- Katia Suarez-Berumen
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.,West Anaheim Medical Center, Anaheim, CA, United States
| | | | - Anastasia Gromova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.,Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Robyn Meech
- Department of Clinical Pharmacology, Flinders University, Adelaide, SA, Australia
| | - Alessandra Sacco
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Phil R Dash
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Robert Mitchell
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Valery I Shestopalov
- Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, FL, United States.,Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Thomas E Woolley
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | | | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
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15
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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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16
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Noort RJ, Christopher GA, Esseltine JL. Pannexin 1 Influences Lineage Specification of Human iPSCs. Front Cell Dev Biol 2021; 9:659397. [PMID: 33937260 PMCID: PMC8086557 DOI: 10.3389/fcell.2021.659397] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Every single cell in the body communicates with nearby cells to locally organize activities with their neighbors and dysfunctional cell-cell communication can be detrimental during cell lineage commitment, tissue patterning and organ development. Pannexin channels (PANX1, PANX2, and PANX3) facilitate purinergic paracrine signaling through the passage of messenger molecules out of cells. PANX1 is widely expressed throughout the body and has recently been identified in human oocytes as well as 2 and 4-cell stage human embryos. Given its abundance across multiple adult tissues and its expression at the earliest stages of human development, we sought to understand whether PANX1 impacts human induced pluripotent stem cells (iPSCs) or plays a role in cell fate decisions. Western blot, immunofluorescence and flow cytometry reveal that PANX1 is expressed in iPSCs as well as all three germ lineages derived from these cells: ectoderm, endoderm, and mesoderm. PANX1 demonstrates differential glycosylation patterns and subcellular localization across the germ lineages. Using CRISPR-Cas9 gene ablation, we find that loss of PANX1 has no obvious impact on iPSC morphology, survival, or pluripotency gene expression. However, PANX1 gene knockout iPSCs exhibit apparent lineage specification bias under 3-dimensional spontaneous differentiation into the three germ lineages. Indeed, loss of PANX1 increases representation of endodermal and mesodermal populations in PANX1 knockout cells. Importantly, PANX1 knockout iPSCs are fully capable of differentiating toward each specific lineage when exposed to the appropriate external signaling pressures, suggesting that although PANX1 influences germ lineage specification, it is not essential to this process.
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Affiliation(s)
- Rebecca J Noort
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Grace A Christopher
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jessica L Esseltine
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
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17
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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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18
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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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19
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Flores-Muñoz C, Maripillán J, Vásquez-Navarrete J, Novoa-Molina J, Ceriani R, Sánchez HA, Abbott AC, Weinstein-Oppenheimer C, Brown DI, Cárdenas AM, García IE, Martínez AD. Restraint of Human Skin Fibroblast Motility, Migration, and Cell Surface Actin Dynamics, by Pannexin 1 and P2X7 Receptor Signaling. Int J Mol Sci 2021; 22:1069. [PMID: 33499026 PMCID: PMC7865282 DOI: 10.3390/ijms22031069] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 01/01/2023] Open
Abstract
Wound healing is a dynamic process required to maintain skin integrity and which relies on the precise migration of different cell types. A key molecule that regulates this process is ATP. However, the mechanisms involved in extracellular ATP management are poorly understood, particularly in the human dermis. Here, we explore the role, in human fibroblast migration during wound healing, of Pannexin 1 channels and their relationship with purinergic signals and in vivo cell surface filamentous actin dynamics. Using siRNA against Panx isoforms and different Panx1 channel inhibitors, we demonstrate in cultured human dermal fibroblasts that the absence or inhibition of Panx1 channels accelerates cell migration, increases single-cell motility, and promotes actin redistribution. These changes occur through a mechanism that involves the release of ATP to the extracellular space through a Panx1-dependent mechanism and the activation of the purinergic receptor P2X7. Together, these findings point to a pivotal role of Panx1 channels in skin fibroblast migration and suggest that these channels could be a useful pharmacological target to promote damaged skin healing.
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Affiliation(s)
- Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Joel Novoa-Molina
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Ricardo Ceriani
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Helmuth A. Sánchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Ana C. Abbott
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Caroline Weinstein-Oppenheimer
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile;
- Centro de Investigación Farmacopea Chilena, Valparaíso 2360102, Chile
| | - Donald I. Brown
- Laboratorio de Biología de la Reproducción y del Desarrollo, Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile;
| | - Ana María Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Isaac E. García
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
- Laboratorio de Fisiología Molecular y Biofísica, Facultad de Odontología, Universidad de Valparaíso, Valparaíso 2360004, Chile
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
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20
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Bhat EA, Sajjad N. Human Pannexin 1 channel: Insight in structure-function mechanism and its potential physiological roles. Mol Cell Biochem 2021; 476:1529-1540. [PMID: 33394272 DOI: 10.1007/s11010-020-04002-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/21/2020] [Indexed: 12/15/2022]
Abstract
Pannexins, large non-gap junction super family exists in vertebrates, play multiple roles in different cellular functions through their ATP release. Panx1-mediated adenosine 5'-triphosphate (ATP) release plays a vital role in physiological and pathophysiological conditions and is known major extracellular molecule in purinergic signaling. To modulate their function in vivo, a proper regulation of channel is necessary. Post-translational modifications are considered to be some regulating mechanisms for PANX1, while PANX2, PANX3 have been uncharacterized to date. Through their significant evidences, PANXs exclude from gap junction and conduits ATP release and other cellular molecules from cells by various mechanisms. PANX1 is most extensive characterized and implicated in ATP signaling and inflammatory processes. Despite the constant advances, much significance of PANX1 in physiological processes remains elusive. Recently, various research groups along with our group have reported the Cryo-EM structure of Panx1 channel and uncovered the hidden functions in structure-function mechanism as well as to provide the clear understanding in physiological and pathophysiological roles. These research groups reported the novel heptameric structure with contains 4 transmembrane helices (TM), two extracellular loops and one intracellular loop with N and C terminus located at the intracellular side. In addition, the structure contains a large pore of which an inhibitor CBX act as a plug that blocking the passage of substrate. In this context, this review will present current mechanistic understanding in structure and function together with significant physiological roles particularly ATP release in health and disease. As such, this review emphasizes on recent functional properties associated with novel heptameric channel and demystifies channel-mediated ATP release function.
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Affiliation(s)
- Eijaz Ahmed Bhat
- Life Science Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, People's Republic of China.
| | - Nasreena Sajjad
- Department of Biochemistry, University of Kashmir, Hazratbal, Jammu and Kashmir, India
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21
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Menéndez Méndez A, Smith J, Engel T. Neonatal Seizures and Purinergic Signalling. Int J Mol Sci 2020; 21:ijms21217832. [PMID: 33105750 PMCID: PMC7660091 DOI: 10.3390/ijms21217832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023] Open
Abstract
Neonatal seizures are one of the most common comorbidities of neonatal encephalopathy, with seizures aggravating acute injury and clinical outcomes. Current treatment can control early life seizures; however, a high level of pharmacoresistance remains among infants, with increasing evidence suggesting current anti-seizure medication potentiating brain damage. This emphasises the need to develop safer therapeutic strategies with a different mechanism of action. The purinergic system, characterised by the use of adenosine triphosphate and its metabolites as signalling molecules, consists of the membrane-bound P1 and P2 purinoreceptors and proteins to modulate extracellular purine nucleotides and nucleoside levels. Targeting this system is proving successful at treating many disorders and diseases of the central nervous system, including epilepsy. Mounting evidence demonstrates that drugs targeting the purinergic system provide both convulsive and anticonvulsive effects. With components of the purinergic signalling system being widely expressed during brain development, emerging evidence suggests that purinergic signalling contributes to neonatal seizures. In this review, we first provide an overview on neonatal seizure pathology and purinergic signalling during brain development. We then describe in detail recent evidence demonstrating a role for purinergic signalling during neonatal seizures and discuss possible purine-based avenues for seizure suppression in neonates.
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Affiliation(s)
- Aida Menéndez Méndez
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
| | - Jonathon Smith
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Tobias Engel
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
- Correspondence: ; Tel.: +35-314-025-199
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22
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Pannexin 1 Regulates Dendritic Protrusion Dynamics in Immature Cortical Neurons. eNeuro 2020; 7:ENEURO.0079-20.2020. [PMID: 32737184 PMCID: PMC7544189 DOI: 10.1523/eneuro.0079-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 07/16/2020] [Accepted: 07/21/2020] [Indexed: 11/21/2022] Open
Abstract
The integration of neurons into networks relies on the formation of dendritic spines. These specialized structures arise from dynamic filopodia-like dendritic protrusions. It was recently reported that cortical neurons lacking the channel protein pannexin 1 (PANX1) exhibited higher dendritic spine densities. Here, we expanded on those findings to investigate, at an earlier developmental time point (with more abundant dendritic protrusions), whether differences in the properties of dendritic protrusion dynamics could contribute to this previously discovered phenomenon. Using a fluorescent membrane tag (mCherry-CD9-10) to visualize dendritic protrusions in developing neurons [at 10 d in vitro (DIV10)], we confirmed that lack of PANX1 led to higher protrusion density, while transient transfection of Panx1 led to decreased protrusion density. To quantify the impact of PANX1 expression on protrusion formation, elimination, and motility, we used live cell imaging in DIV10 neurons (one frame every 5 s for 10 min). We discovered that at DIV10, loss of PANX1 stabilized protrusions. Notably, re-expression of PANX1 in Panx1 knock-out (KO) neurons resulted in a significant increase in protrusion motility and turnover. In summary, these new data revealed that PANX1 could regulate the development of dendritic spines, in part, by controlling dendritic protrusion dynamics.
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23
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Muñoz P, Ardiles ÁO, Pérez-Espinosa B, Núñez-Espinosa C, Paula-Lima A, González-Billault C, Espinosa-Parrilla Y. Redox modifications in synaptic components as biomarkers of cognitive status, in brain aging and disease. Mech Ageing Dev 2020; 189:111250. [PMID: 32433996 DOI: 10.1016/j.mad.2020.111250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/05/2020] [Accepted: 04/10/2020] [Indexed: 02/06/2023]
Abstract
Aging is a natural process that includes several changes that gradually make organisms degenerate and die. Harman's theory proposes that aging is a consequence of the progressive accumulation of oxidative modifications mediated by reactive oxygen/nitrogen species, which plays an essential role in the development and progression of many neurodegenerative diseases. This review will focus on how abnormal redox modifications induced by age impair the functionality of neuronal redox-sensitive proteins involved in axonal elongation and guidance, synaptic plasticity, and intercellular communication. We will discuss post-transcriptional regulation of gene expression by microRNAs as a mechanism that controls the neuronal redox state. Finally, we will discuss how some brain-permeant antioxidants from the diet have a beneficial effect on cognition. Taken together, the evidence revised here indicates that oxidative-driven modifications of specific proteins and changes in microRNA expression may be useful biomarkers for aging and neurodegenerative diseases. Also, some specific antioxidant therapies have undoubtedly beneficial neuroprotective effects when administered in the correct doses, in the ideal formulation combination, and during the appropriate therapeutic window. The use of some antioxidants is, therefore, still poorly explored for the treatment of neurodegenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- Pablo Muñoz
- Department of Pathology and Physiology, Medical School, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Translational Neurology Center, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Biomedical Research Center, Universidad de Valparaíso, Valparaíso, Chile; Thematic Task Force on Healthy Aging, CUECH Research Network.
| | - Álvaro O Ardiles
- Department of Pathology and Physiology, Medical School, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Translational Neurology Center, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Thematic Task Force on Healthy Aging, CUECH Research Network; Interdisciplinary Center of Neuroscience of Valparaíso, Universidad de Valparaíso, Valparaíso, Chile; Interdisciplinary Center for Health Studies, Universidad de Valparaíso, Valparaíso, Chile
| | - Boris Pérez-Espinosa
- Thematic Task Force on Healthy Aging, CUECH Research Network; Laboratorio biología de la Reproduccion, Departamento Biomédico, Facultad Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristian Núñez-Espinosa
- Thematic Task Force on Healthy Aging, CUECH Research Network; School of Medicine, Universidad de Magallanes, Punta Arenas, Chile
| | - Andrea Paula-Lima
- Thematic Task Force on Healthy Aging, CUECH Research Network; Institute for Research in Dental Sciences, Faculty of Dentistry; Universidad de Chile, Santiago, Chile; Biomedical Neuroscience Institute (BNI) and Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Christian González-Billault
- Thematic Task Force on Healthy Aging, CUECH Research Network; Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA, USA.
| | - Yolanda Espinosa-Parrilla
- Thematic Task Force on Healthy Aging, CUECH Research Network; School of Medicine, Universidad de Magallanes, Punta Arenas, Chile; Laboratory of Molecular Medicine - LMM, Center for Education, Healthcare and Investigation - CADI, University of Magallanes, Punta Arenas, Chile.
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24
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Glial ATP and Large Pore Channels Modulate Synaptic Strength in Response to Chronic Inactivity. Mol Neurobiol 2020; 57:2856-2869. [PMID: 32388797 DOI: 10.1007/s12035-020-01919-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 04/14/2020] [Indexed: 01/08/2023]
Abstract
A key feature of neurotransmission is its ability to adapt to changes in neuronal environment, which is essential for many brain functions. Homeostatic synaptic plasticity (HSP) emerges as a compensatory mechanism used by neurons to adjust their excitability in response to changes in synaptic activity. Recently, glial cells emerged as modulators for neurotransmission by releasing gliotransmitters into the synaptic cleft through pathways that include P2X7 receptors (P2X7R), connexons, and pannexons. However, the role of gliotransmission in the activity-dependent adjustment of presynaptic strength is still an open question. Here, we investigated whether glial cells participate in HSP upon chronic inactivity and the role of adenosine triphosphate (ATP), connexin43 hemichannels (Cx43HCs), and pannexin1 (Panx1) channels in this process. We used immunocytochemistry against vesicular glutamate transporter 1 (vGlut1) to estimate changes in synaptic strength in hippocampal dissociated cultures. Pharmacological manipulations indicate that glial-derived ATP and P2X7R are required for HSP. In addition, inhibition of Cx43 and Panx1 channels reveals a pivotal role for these channels in the compensatory adjustment of synaptic strength, emerging as new pathways for ATP release upon inactivity. The involvement of Panx1 channels was confirmed by using Panx1-deficient animals. Lacking Panx1 in neurons is sufficient to prevent the P2X7R-dependent upregulation of presynaptic strength; however, the P2X7R-dependent compensatory adjustment of synapse density requires both neuronal and glial Panx1. Together, our data supports an essential role for glial ATP signaling and Cx43HCs and Panx1 channels in the homeostatic adjustment of synaptic strength in hippocampal cultures upon chronic inactivity.
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25
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Yeung AK, Patil CS, Jackson MF. Pannexin‐1 in the CNS: Emerging concepts in health and disease. J Neurochem 2020; 154:468-485. [DOI: 10.1111/jnc.15004] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/26/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Albert K. Yeung
- Department of Pharmacology and Therapeutics Max Rady College of Medicine Rady Faculty of Health Sciences University of Manitoba Winnipeg Manitoba Canada
- Neuroscience Research Program Kleysen Institute for Advanced Medicine University of Manitoba Winnipeg Manitoba Canada
| | - Chetan S. Patil
- Department of Pharmacology and Therapeutics Max Rady College of Medicine Rady Faculty of Health Sciences University of Manitoba Winnipeg Manitoba Canada
- Neuroscience Research Program Kleysen Institute for Advanced Medicine University of Manitoba Winnipeg Manitoba Canada
| | - Michael F. Jackson
- Department of Pharmacology and Therapeutics Max Rady College of Medicine Rady Faculty of Health Sciences University of Manitoba Winnipeg Manitoba Canada
- Neuroscience Research Program Kleysen Institute for Advanced Medicine University of Manitoba Winnipeg Manitoba Canada
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26
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Flores-Muñoz C, Gómez B, Mery E, Mujica P, Gajardo I, Córdova C, Lopez-Espíndola D, Durán-Aniotz C, Hetz C, Muñoz P, Gonzalez-Jamett AM, Ardiles ÁO. Acute Pannexin 1 Blockade Mitigates Early Synaptic Plasticity Defects in a Mouse Model of Alzheimer's Disease. Front Cell Neurosci 2020; 14:46. [PMID: 32265655 PMCID: PMC7103637 DOI: 10.3389/fncel.2020.00046] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 02/18/2020] [Indexed: 12/11/2022] Open
Abstract
Synaptic loss induced by soluble oligomeric forms of the amyloid β peptide (sAβos) is one of the earliest events in Alzheimer’s disease (AD) and is thought to be the major cause of the cognitive deficits. These abnormalities rely on defects in synaptic plasticity, a series of events manifested as activity-dependent modifications in synaptic structure and function. It has been reported that pannexin 1 (Panx1), a nonselective channel implicated in cell communication and intracellular signaling, modulates the induction of excitatory synaptic plasticity under physiological contexts and contributes to neuronal death under inflammatory conditions. Here, we decided to study the involvement of Panx1 in functional and structural defects observed in excitatory synapses of the amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic (Tg) mice, an animal model of AD. We found an age-dependent increase in the Panx1 expression that correlates with increased Aβ levels in hippocampal tissue from Tg mice. Congruently, we also observed an exacerbated Panx1 activity upon basal conditions and in response to glutamate receptor activation. The acute inhibition of Panx1 activity with the drug probenecid (PBN) did not change neurodegenerative parameters such as amyloid deposition or astrogliosis, but it significantly reduced excitatory synaptic defects in the AD model by normalizing long-term potentiation (LTP) and depression and improving dendritic arborization and spine density in hippocampal neurons of the Tg mice. These results suggest a major contribution of Panx1 in the early mechanisms leading to the synaptopathy in AD. Indeed, PBN induced a reduction in the activation of p38 mitogen-activated protein kinase (MAPK), a kinase widely implicated in the early neurotoxic signaling in AD. Our data strongly suggest that an enhanced expression and activation of Panx1 channels contribute to the Aβ-induced cascades leading to synaptic dysfunction in AD.
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Affiliation(s)
- Carolina Flores-Muñoz
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Bárbara Gómez
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Elena Mery
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Paula Mujica
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Ivana Gajardo
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Claudio Córdova
- Laboratorio de Estructura y Función Celular, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Daniela Lopez-Espíndola
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile.,Centro de Investigaciones Biomédicas, Escuela de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Claudia Durán-Aniotz
- Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibáñez, Santiago de Chile, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Pablo Muñoz
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro de Investigaciones Biomédicas, Escuela de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Arlek M Gonzalez-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Álvaro O Ardiles
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Estudios en Salud, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar, Chile
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27
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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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28
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Pannexin 1 Regulates Network Ensembles and Dendritic Spine Development in Cortical Neurons. eNeuro 2019; 6:ENEURO.0503-18.2019. [PMID: 31118206 PMCID: PMC6557035 DOI: 10.1523/eneuro.0503-18.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 01/22/2023] Open
Abstract
Dendritic spines are the postsynaptic targets of excitatory synaptic inputs that undergo extensive proliferation and maturation during the first postnatal month in mice. However, our understanding of the molecular mechanisms that regulate spines during this critical period is limited. Previous work has shown that pannexin 1 (Panx1) regulates neurite growth and synaptic plasticity. We therefore investigated the impact of global Panx1 KO on spontaneous cortical neuron activity using Ca2+ imaging and in silico network analysis. Panx1 KO increased both the number and size of spontaneous co-active cortical neuron network ensembles. To understand the basis for these findings, we investigated Panx1 expression in postnatal synaptosome preparations from early postnatal mouse cortex. Between 2 and 4 postnatal weeks, we observed a precipitous drop in cortical synaptosome protein levels of Panx1, suggesting it regulates synapse proliferation and/or maturation. At the same time points, we observed significant enrichment of the excitatory postsynaptic density proteins PSD-95, GluA1, and GluN2a in cortical synaptosomes from global Panx1 knock-out mice. Ex vivo analysis of pyramidal neuron structure in somatosensory cortex revealed a consistent increase in dendritic spine densities in both male and female Panx1 KO mice. Similar findings were observed in an excitatory neuron-specific Panx1 KO line (Emx1-Cre driven; Panx1 cKOE) and in primary Panx1 KO cortical neurons cultured in vitro. Altogether, our study suggests that Panx1 negatively regulates cortical dendritic spine development.
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29
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DeLalio LJ, Keller AS, Chen J, Boyce AK, Artamonov M, Askew-Page HR, Keller TS, Johnstone SR, Weaver RB, Good ME, Murphy S, Best AK, Mintz EL, Penuela S, Greenwood I, Machado RF, Somlyo AV, Swayne LA, Minshall R, Isakson BE. Interaction Between Pannexin 1 and Caveolin-1 in Smooth Muscle Can Regulate Blood Pressure. Arterioscler Thromb Vasc Biol 2018; 38:2065-2078. [PMID: 30026274 PMCID: PMC6202122 DOI: 10.1161/atvbaha.118.311290] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 06/19/2018] [Indexed: 12/31/2022]
Abstract
Objective- Sympathetic nerve innervation of vascular smooth muscle cells (VSMCs) is a major regulator of arteriolar vasoconstriction, vascular resistance, and blood pressure. Importantly, α-adrenergic receptor stimulation, which uniquely couples with Panx1 (pannexin 1) channel-mediated ATP release in resistance arteries, also requires localization to membrane caveolae. Here, we test whether localization of Panx1 to Cav1 (caveolin-1) promotes channel function (stimulus-dependent ATP release and adrenergic vasoconstriction) and is important for blood pressure homeostasis. Approach and Results- We use in vitro VSMC culture models, ex vivo resistance arteries, and a novel inducible VSMC-specific Cav1 knockout mouse to probe interactions between Panx1 and Cav1. We report that Panx1 and Cav1 colocalized on the VSMC plasma membrane of resistance arteries near sympathetic nerves in an adrenergic stimulus-dependent manner. Genetic deletion of Cav1 significantly blunts adrenergic-stimulated ATP release and vasoconstriction, with no direct influence on endothelium-dependent vasodilation or cardiac function. A significant reduction in mean arterial pressure (total=4 mm Hg; night=7 mm Hg) occurred in mice deficient for VSMC Cav1. These animals were resistant to further blood pressure lowering using a Panx1 peptide inhibitor Px1IL2P, which targets an intracellular loop region necessary for channel function. Conclusions- Translocalization of Panx1 to Cav1-enriched caveolae in VSMCs augments the release of purinergic stimuli necessary for proper adrenergic-mediated vasoconstriction and blood pressure homeostasis.
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Affiliation(s)
- Leon J. DeLalio
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
| | - Alexander S. Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
| | - Jiwang Chen
- Department of Medicine, The University of Illinois at Chicago, Chicago, IL
| | - Andrew K.J. Boyce
- Division of Medical Sciences, Centre for Biomedical Research, University of Victoria, Victoria, BC Canada
| | - Mykhaylo Artamonov
- Department of Molecular Physiology and Biophysics, University of Virginia, Charlottesville, VA
| | - Henry R. Askew-Page
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - T.C. Stevenson Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
- Department of Molecular Physiology and Biophysics, University of Virginia, Charlottesville, VA
| | - Scott R. Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Rachel B. Weaver
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Miranda E. Good
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Sara Murphy
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Angela K. Best
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Ellen L. Mintz
- Department of Biomedical Engineering, University of Virginia School of Engineering, Charlottesville, VA
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich Scholl of Medicine and Dentistry, University of Western Ontario, London ON, Canada
| | - Iain Greenwood
- Molecular and Clinical Sciences Research Institute, St. George’s University London UK
| | - Roberto F. Machado
- Division of Pulmonary, Critical Care, Sleep, & Occupational Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Avril V. Somlyo
- Department of Molecular Physiology and Biophysics, University of Virginia, Charlottesville, VA
| | - Leigh Anne Swayne
- Division of Medical Sciences, Centre for Biomedical Research, University of Victoria, Victoria, BC Canada
| | - Richard Minshall
- Department of Pharmacology and Department of Anesthesiology, The University of Illinois at Chicago, Chicago, IL
| | - Brant E. Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
- Department of Molecular Physiology and Biophysics, University of Virginia, Charlottesville, VA
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30
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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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31
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Xu X, Wicki-Stordeur LE, Sanchez-Arias JC, Liu M, Weaver MS, Choi CSW, Swayne LA. Probenecid Disrupts a Novel Pannexin 1-Collapsin Response Mediator Protein 2 Interaction and Increases Microtubule Stability. Front Cell Neurosci 2018; 12:124. [PMID: 29867357 PMCID: PMC5958195 DOI: 10.3389/fncel.2018.00124] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 04/17/2018] [Indexed: 12/25/2022] Open
Abstract
Neurite formation relies on finely-tuned control of the cytoskeleton. Here we identified a novel protein-protein interaction between the ion and metabolite channel protein Pannexin 1 (Panx1) and collapsin response mediator protein 2 (Crmp2), a positive regulator of microtubule polymerization and stabilization. Panx1 and Crmp2 co-precipitated from both Neuro-2a (N2a) cells and mouse ventricular zone (VZ) tissue. In vitro binding assays between purified proteins revealed the interaction occurs directly between the Panx1 C-terminus (Panx1 CT) and Crmp2. Because Crmp2 is a well-established microtubule-stabilizing protein, and we previously observed a marked increase in neurite formation following treatment with the Panx1 blocker, probenecid, in N2a cells and VZ neural precursor cells (NPCs), we investigated the impact of probenecid on the Panx1-Crmp2 interaction. Probenecid treatment significantly disrupted the Panx1-Crmp2 interaction by both immunoprecipitation (IP) and proximity ligation analysis, without altering overall Crmp2 protein expression levels. In the presence of probenecid, Crmp2 was concentrated at the distal ends of growing neurites. Moreover, probenecid treatment increased tubulin polymerization and microtubule stability in N2a cells. These results reveal that probenecid disrupts a novel interaction between Panx1 and the microtubule stabilizer, Crmp2, and also increases microtubule stability.
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Affiliation(s)
- Xiaoxue Xu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | | | | | - Mei Liu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nanjing, China
| | - Maria S Weaver
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Catherine S W Choi
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Leigh A Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biology, University of Victoria, Victoria, BC, Canada.,Island Medical Program and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
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Horton SM, Luna Lopez C, Blevins E, Howarth H, Weisberg J, Shestopalov VI, Makarenkova HP, Shah SB. Pannexin 1 Modulates Axonal Growth in Mouse Peripheral Nerves. Front Cell Neurosci 2017; 11:365. [PMID: 29213230 PMCID: PMC5702652 DOI: 10.3389/fncel.2017.00365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/06/2017] [Indexed: 01/29/2023] Open
Abstract
The pannexin family of channels consists of three members—pannexin-1 (Panx1), pannexin-2 (Panx2), and pannexin-3 (Panx3) that enable the exchange of metabolites and signaling molecules between intracellular and extracellular compartments. Pannexin-mediated release of intracellular ATP into the extracellular space has been tied to a number of cellular activities, primarily through the activity of type P2 purinergic receptors. Previous work indicates that the opening of Panx1 channels and activation of purinergic receptors by extracellular ATP may cause inflammation and apoptosis. In the CNS (central nervous system) and PNS (peripheral nervous system), coupled pannexin, and P2 functions have been linked to peripheral sensitization (pain) pathways. Purinergic pathways are also essential for other critical processes in the PNS, including myelination and neurite outgrowth. However, whether such pathways are pannexin-dependent remains to be determined. In this study, we use a Panx1 knockout mouse model and pharmacological inhibitors of the Panx1 and the ATP-mediated signaling pathway to fill gaps in our understanding of Panx1 localization in peripheral nerves, roles for Panx1 in axonal outgrowth and myelination, and neurite extension. Our data show that Panx1 is localized to axonal, myelin, and vascular compartments of the peripheral nerves. Knockout of Panx1 gene significantly increased axonal caliber in vivo and axonal growth rate in cultured dorsal root ganglia (DRG) neurons. Furthermore, genetic knockout of Panx1 or inhibition of components of purinergic signaling, by treatment with probenecid and apyrase, resulted in denser axonal outgrowth from cultured DRG explants compared to untreated wild-types. Our findings suggest that Panx1 regulates axonal growth in the peripheral nervous system.
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Affiliation(s)
- Steven M Horton
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | - Carlos Luna Lopez
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | - Elisabeth Blevins
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, United States
| | - Holly Howarth
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
| | - Jake Weisberg
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | | | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Sameer B Shah
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, United States.,Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
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Sáez PJ, Vargas P, Shoji KF, Harcha PA, Lennon-Duménil AM, Sáez JC. ATP promotes the fast migration of dendritic cells through the activity of pannexin 1 channels and P2X 7 receptors. Sci Signal 2017; 10:10/506/eaah7107. [PMID: 29162744 DOI: 10.1126/scisignal.aah7107] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Upon its release from injured cells, such as infected, transformed, inflamed, or necrotic cells, extracellular adenosine-5'-triphosphate (ATP) acts as a danger signal that recruits phagocytes, such as neutrophils, macrophages, and dendritic cells (DCs), to the site of injury. The sensing of extracellular ATP occurs through purinergic (P2) receptors. We investigated the cellular mechanisms linking purinergic signaling to DC motility. We found that ATP stimulated fast DC motility through an autocrine signaling loop, which was initiated by the activation of P2X7 receptors and further amplified by pannexin 1 (Panx1) channels. Upon stimulation of the P2X7 receptor by ATP, Panx1 contributed to fast DC motility by increasing the permeability of the plasma membrane, which resulted in supplementary ATP release. In the absence of Panx1, DCs failed to increase their speed of migration in response to ATP, despite exhibiting a normal P2X7 receptor-mediated Ca2+ response. In addition to DC migration, Panx1 channel- and P2X7 receptor-dependent signaling was further required to stimulate the reorganization of the actin cytoskeleton. In vivo, functional Panx1 channels were required for the homing of DCs to lymph nodes, although they were dispensable for DC maturation. These data suggest that P2X7 receptors and Panx1 channels are crucial players in the regulation of DC migration to endogenous danger signals.
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Affiliation(s)
- Pablo J Sáez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile. .,INSERM U932 Immunité et Cancer, Institut Curie, Paris Sciences et Lettres (PSL) Research University, 12 Rue Lhomond, Paris 75005, France
| | - Pablo Vargas
- INSERM U932 Immunité et Cancer, Institut Curie, Paris Sciences et Lettres (PSL) Research University, 12 Rue Lhomond, Paris 75005, France.,CNRS UMR144, Institut Curie, PSL Research University, 12 Rue Lhomond, Paris 75005, France
| | - Kenji F Shoji
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
| | - Paloma A Harcha
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile.,Instituto Milenio, Centro Interdisciplinario de Neurociencias de Valparaíso, Valparaíso 2360103, Chile
| | - Ana-María Lennon-Duménil
- INSERM U932 Immunité et Cancer, Institut Curie, Paris Sciences et Lettres (PSL) Research University, 12 Rue Lhomond, Paris 75005, France.
| | - Juan C Sáez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile. .,Instituto Milenio, Centro Interdisciplinario de Neurociencias de Valparaíso, Valparaíso 2360103, Chile
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Basova LV, Tang X, Umasume T, Gromova A, Zyrianova T, Shmushkovich T, Wolfson A, Hawley D, Zoukhri D, Shestopalov VI, Makarenkova HP. Manipulation of Panx1 Activity Increases the Engraftment of Transplanted Lacrimal Gland Epithelial Progenitor Cells. Invest Ophthalmol Vis Sci 2017; 58:5654-5665. [PMID: 29098296 PMCID: PMC5678547 DOI: 10.1167/iovs.17-22071] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose Sjögren's syndrome is a systemic chronic autoimmune inflammatory disease that primarily targets the salivary and lacrimal glands (LGs). Currently there is no cure; therefore, cell-based regenerative therapy may be a viable option. LG inflammation is facilitated by extracellular ATP and mediated by the Pannexin-1 (Panx1) membrane channel glycoprotein. We propose that suppression of inflammation through manipulation of Panx1 activity can stimulate epithelial cell progenitor (EPCP) engraftment. Methods The expression of pannexins in the mouse and human LG was assayed by qRT-PCR and immunostaining. Acute LG inflammation was induced by interleukin-1α (IL1α) injection. Prior to EPCP transplantation, IL1α-injured or chronically inflamed LGs of thrombospondin-1–null mice (TSP-1−/−) were treated with the Panx1-specific blocking peptide (10panx) or the self-deliverable RNAi (sdRNAi). The efficacy of cell engraftment and the area of inflammation were analyzed by microscopy. Results Panx1 and Panx2 were detected in the mouse and human LGs. Panx1 and proinflammatory factors were upregulated during acute inflammation at days 1 to 3 after the IL1α injection. The analysis of EPCP engraftment demonstrated a significant and reproducible positive correlation between the 10panx peptide or Panx1 sdRNAi treatment and the number of engrafted cells. Similarly, treatment of the LG of the TSP-1−/− mouse (mouse model of chronic LG inflammation) by either Panx1 or Caspase-4 (also known as Casp11) sdRNAi showed a significant decrease in expression of proinflammatory markers and the lymphocyte infiltration. Conclusions Our results suggest that blocking Panx1 and/or Casp4 activities is a beneficial strategy to enhance donor cell engraftment and LG regeneration through the reduction of inflammation.
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Affiliation(s)
- Liana V Basova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
| | - Xin Tang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
| | - Takeshi Umasume
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
| | - Anastasia Gromova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
| | - Tatiana Zyrianova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
| | | | | | - Dillon Hawley
- Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, Massachusetts, United States
| | - Driss Zoukhri
- Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, Massachusetts, United States.,Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - Valery I Shestopalov
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami School of Medicine, Miami, Florida, United States.,Department of Cell Biology, University of Miami School of Medicine, Miami, Florida, United States
| | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
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35
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Swayne LA, Murphy NP, Asuri S, Chen L, Xu X, McIntosh S, Wang C, Lancione PJ, Roberts JD, Kerr C, Sanatani S, Sherwin E, Kline CF, Zhang M, Mohler PJ, Arbour LT. Novel Variant in the ANK2 Membrane-Binding Domain Is Associated With Ankyrin-B Syndrome and Structural Heart Disease in a First Nations Population With a High Rate of Long QT Syndrome. ACTA ACUST UNITED AC 2017; 10:CIRCGENETICS.116.001537. [PMID: 28196901 DOI: 10.1161/circgenetics.116.001537] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 11/21/2016] [Indexed: 01/15/2023]
Abstract
BACKGROUND Long QT syndrome confers susceptibility to ventricular arrhythmia, predisposing to syncope, seizures, and sudden death. While rare globally, long QT syndrome is ≈15× more common in First Nations of Northern British Columbia largely because of a known mutation in KCNQ1. However, 2 large multigenerational families were affected, but negative for the known mutation. METHODS AND RESULTS Long QT syndrome panel testing was carried out in the index case of each family, and clinical information was collected. Cascade genotyping was performed. Biochemical and myocyte-based assays were performed to evaluate the identified gene variant for loss-of-function activity. Index cases in these 2 families harbored a novel ANK2 c.1937C>T variant (p.S646F). An additional 16 carriers were identified, including 2 with structural heart disease: one with cardiomyopathy resulting in sudden death and the other with congenital heart disease. For all carriers of this variant, the average QTc was 475 ms (±40). Although ankyrin-B p.S646F is appropriately folded and expressed in bacteria, the mutant polypeptide displays reduced expression in cultured H9c2 cells and aberrant localization in primary cardiomyocytes. Furthermore, myocytes expressing ankyrin-B p.S646F lack normal membrane targeting of the ankyrin-binding partner, the Na/Ca exchanger. Thus, ankyrin-B p.S646F is a loss-of-function variant. CONCLUSIONS We identify the first disease-causing ANK2 variant localized to the membrane-binding domain resulting in reduced ankyrin-B expression and abnormal localization. Further study is warranted on the potential association of this variant with structural heart disease given the role of ANK2 in targeting and stabilization of key structural and signaling molecules in cardiac cells.
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Affiliation(s)
- Leigh Anne Swayne
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Nathaniel P Murphy
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Sirisha Asuri
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Lena Chen
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Xiaoxue Xu
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Sarah McIntosh
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Chao Wang
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Peter J Lancione
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Jason D Roberts
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Charles Kerr
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Shubhayan Sanatani
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Elizabeth Sherwin
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Crystal F Kline
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Mingjie Zhang
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Peter J Mohler
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.)
| | - Laura T Arbour
- From the Division of Medical Sciences, University of Victoria, BC, Canada (L.A.S., L.C., X.X., L.T.A.); University of British Columbia Island Medical Program, Victoria, BC, Canada (L.A.S., L.T.A.); Department of Medical Genetics (S.A., S.M., L.T.A.), Division of Cardiology (C.K.), and Division of Cardiology, Department of Pediatrics, BC Children's Hospital (S.S., E.S.), University of British Columbia, Vancouver, BC, Canada; Division of Cardiovascular Medicine, Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute (N.P.M., P.J.L., C.F.K., P.J.M.) and Department of Physiology and Cell Biology (N.P.M., P.J.L., C.F.K., P.J.M.), The Ohio State University Wexner Medical Center, Columbus, OH; Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China (C.W., M.Z.); and Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (J.D.R.).
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Swayne LA, Boyce AKJ. Regulation of Pannexin 1 Surface Expression by Extracellular ATP: Potential Implications for Nervous System Function in Health and Disease. Front Cell Neurosci 2017; 11:230. [PMID: 28848396 PMCID: PMC5550711 DOI: 10.3389/fncel.2017.00230] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/24/2017] [Indexed: 02/02/2023] Open
Abstract
Pannexin 1 (Panx1) channels are widely recognized for their role in ATP release, and as follows, their function is closely tied to that of ATP-activated P2X7 purinergic receptors (P2X7Rs). Our recent work has shown that extracellular ATP induces clustering of Panx1 with P2X7Rs and their subsequent internalization through a non-canonical cholesterol-dependent mechanism. In other words, we have demonstrated that extracellular ATP levels can regulate the cell surface expression of Panx1. Here we discuss two situations in which we hypothesize that ATP modulation of Panx1 surface expression could be relevant for central nervous system function. The first scenario involves the development of new neurons in the ventricular zone. We propose that ATP-induced Panx1 endocytosis could play an important role in regulating the balance of cell proliferation, survival, and differentiation within this neurogenic niche in the healthy brain. The second scenario relates to the spinal cord, in which we posit that an impairment of ATP-induced Panx1 endocytosis could contribute to pathological neuroplasticity. Together, the discussion of these hypotheses serves to highlight important outstanding questions regarding the interplay between extracellular ATP, Panx1, and P2X7Rs in the nervous system in health and disease.
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Affiliation(s)
- Leigh A Swayne
- Division of Medical Sciences and Island Medical Program, University of Victoria, VictoriaBC, Canada.,Department of Cellular and Physiological Sciences, University of British Columbia, VancouverBC, Canada
| | - Andrew K J Boyce
- Division of Medical Sciences and Island Medical Program, University of Victoria, VictoriaBC, Canada
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P2X7 receptor cross-talk regulates ATP-induced pannexin 1 internalization. Biochem J 2017; 474:2133-2144. [PMID: 28495860 DOI: 10.1042/bcj20170257] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/04/2017] [Accepted: 05/10/2017] [Indexed: 12/12/2022]
Abstract
In the nervous system, extracellular ATP levels transiently increase in physiological and pathophysiological circumstances, effecting key signalling pathways in plasticity and inflammation through purinergic receptors. Pannexin 1 (Panx1) forms ion- and metabolite-permeable channels that mediate ATP release and are particularly enriched in the nervous system. Our recent study demonstrated that elevation of extracellular ATP triggers Panx1 internalization in a concentration- and time-dependent manner. Notably, this effect was sensitive to inhibition of ionotropic P2X7 purinergic receptors (P2X7Rs). Here, we report our novel findings from the detailed investigation of the mechanism underlying P2X7R-Panx1 cross-talk in ATP-stimulated internalization. We demonstrate that extracellular ATP triggers and is required for the clustering of P2X7Rs and Panx1 on Neuro2a cells through an extracellular physical interaction with the Panx1 first extracellular loop (EL1). Importantly, disruption of P2X7R-Panx1 clustering by mutation of tryptophan 74 within the Panx1 EL1 inhibits Panx1 internalization. Notably, P2X7R-Panx1 clustering and internalization are independent of P2X7R-associated intracellular signalling pathways (Ca2+ influx and Src activation). Further analysis revealed that cholesterol is required for ATP-stimulated P2X7R-Panx1 clustering at the cell periphery. Taken together, our data suggest that extracellular ATP induces and is required for Panx1 EL1-mediated, cholesterol-dependent P2X7R-Panx1 clustering and endocytosis. These findings have important implications for understanding the role of Panx1 in the nervous system and provide important new insights into Panx1-P2X7R cross-talk.
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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: 45] [Impact Index Per Article: 6.4] [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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Pannexin 1 Differentially Affects Neural Precursor Cell Maintenance in the Ventricular Zone and Peri-Infarct Cortex. J Neurosci 2016; 36:1203-10. [PMID: 26818508 DOI: 10.1523/jneurosci.0436-15.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED We demonstrated previously that Pannexin 1 (Panx1), an ion and metabolite channel, promotes the growth and proliferation of ventricular zone (VZ) neural precursor cells (NPCs) in vitro. To investigate its role in vivo, we used floxed Panx1 mice in combination with viruses to delete Panx1 in VZ NPCs and to track numbers of Panx1-null and Panx1-expressing VZ NPCs over time. Two days after virus injection, Panx1-null cells were less abundant than Panx1-expressing cells, suggesting that Panx1 is required for the maintenance of VZ NPCs. We also investigated the effect of Panx1 deletion in VZ NPCs after focal cortical stroke via photothrombosis. Panx1 is essential for maintaining elevated VZ NPC numbers after stroke. In contrast, Panx1-null NPCs were more abundant than Panx1-expressing NPCs in the peri-infarct cortex. Together, these findings suggest that Panx1 plays an important role in NPC maintenance in the VZ niche in the naive and stroke brain and could be a key target for improving NPC survival in the peri-infarct cortex. SIGNIFICANCE STATEMENT Here, we demonstrate that Pannexin 1 (Panx1) maintains a consistent population size of neural precursor cells in the ventricular zone, both in the healthy brain and in the context of stroke. In contrast, Panx1 appears to be detrimental to the survival of neural precursor cells that surround damaged cortical tissue in the stroke brain. This suggests that targeting Panx1 in the peri-infarct cortex, in combination with other therapies, could improve cell survival around the injury site.
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Abstract
Connexins and pannexins share very similar structures and functions; they also exhibit overlapping expression in many stages of neuronal development. Here, we review evidence implicating connexin- and pannexin-mediated communication in the regulation of the birth and development of neurons, specifically Cx26, Cx30, Cx32, Cx36, Cx43, Cx45, Panx1, and Panx2. We begin by dissecting the involvement of these proteins in the generation and development of new neurons in the embryonic, postnatal, and adult brain. Next we briefly outline common mechanisms employed by both pannexins and connexins in these roles, including modulation of purinergic receptor signalling and signalling nexus functions. Throughout this review we highlight developing themes as well as important gaps in knowledge to be bridged.
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Affiliation(s)
- Leigh Anne Swayne
- />Division of Medical Sciences, University of Victoria, Medical Sciences Building Rm 224, 3800 Finnerty Rd, Victoria, BC V8P5C2 Canada
| | - Steffany A. L. Bennett
- />Department of Biochemistry, Microbiology and Immunology, Neural Regeneration Laboratory, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON Canada
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Abstract
Pannexin-1 (Panx1) forms anion-selective channels with a permeability up to 1 kDa and represents a pathway for the release of cytosolic ATP. Several structurally similar connexin (Cx) proteins have been identified in platelets and shown to play roles in haemostasis and thrombosis. More recently, functional Panx1 channels have been demonstrated on the surface of human platelets [Taylor et al. (2014) J. Thromb. Haemost. 12, 987-998]. Since their identification in the year 2000, several mechanisms have been reported to activate Panx1 channels, including mechanical stimulation, oxygen-glucose deprivation, a rise of [Ca2+]i, caspase cleavage and phosphorylation. Within this review, the regulation of Panx1 channels is discussed, with a focus on how they may contribute to platelet function.
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Sanchez-Arias JC, Wicki-Stordeur LE, Swayne LA. Perspectives on the role of Pannexin 1 in neural precursor cell biology. Neural Regen Res 2016; 11:1540-1544. [PMID: 27904473 PMCID: PMC5116821 DOI: 10.4103/1673-5374.193221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
We recently reported that targeted deletion of Pannexin 1 in neural precursor cells of the ventricular zone impairs the maintenance of these cells in healthy and stroke-injured brain. Here we frame this exciting new finding in the context of our previous studies on Pannexin 1 in neural precursors as well as the close relationship between Pannexin 1 and purinergic receptors established by other groups. Moreover, we identify important gaps in our understanding of Pannexin 1 in neural precursor cell biology in terms of the underlying molecular mechanisms and functional/behavioural outcomes.
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Affiliation(s)
- Juan C Sanchez-Arias
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Leigh E Wicki-Stordeur
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada; Island Medical Program and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Raslan A, Hainz N, Beckmann A, Tschernig T, Meier C. Pannexin-1 expression in developing mouse nervous system: new evidence for expression in sensory ganglia. Cell Tissue Res 2015; 364:29-41. [PMID: 26453396 DOI: 10.1007/s00441-015-2294-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 09/07/2015] [Indexed: 12/14/2022]
Abstract
Pannexin1 (Panx1) is one of three members of the pannexin protein family. The expression of Panx1 mRNA has been extensively investigated from late embryonic to adult stages. In contrast, expression during early embryonic development is largely unknown. Our aim is to examine the temporal and spatial expression of Panx1 in mouse embryonic development by focusing on embryonic days (E) 9.5 to 12.5. Whole embryos are investigated in order to provide a comprehensive survey. Analyses were performed at the mRNA level by using reverse transcription plus the polymerase chain reaction and whole-mount in situ hybridization. Panx1 mRNA was detected in the heads and bodies of embryos at all developmental stages investigated (E9.5, E10.5, E11.5, E12.5). In particular, the nervous system expressed Panx1 at an early time point. Interestingly, Panx1 expression was found in afferent ganglia of the cranial nerves and spinal cord. This finding is of particular interest in the context of neuropathic pain and other Panx1-related neurological disorders. Our study shows, for the first time, that Panx1 is expressed in the central and peripheral nervous system during early developmental stages. The consequences of Panx1 deficiency or inhibition in a number of experimental paradigms might therefore be predicated on changes during early development.
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Affiliation(s)
- Abdulrahman Raslan
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Nadine Hainz
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Anja Beckmann
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Thomas Tschernig
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Carola Meier
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany.
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Decrock E, De Bock M, Wang N, Bultynck G, Giaume C, Naus CC, Green CR, Leybaert L. Connexin and pannexin signaling pathways, an architectural blueprint for CNS physiology and pathology? Cell Mol Life Sci 2015; 72:2823-51. [PMID: 26118660 PMCID: PMC11113968 DOI: 10.1007/s00018-015-1962-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 02/06/2023]
Abstract
The central nervous system (CNS) is composed of a highly heterogeneous population of cells. Dynamic interactions between different compartments (neuronal, glial, and vascular systems) drive CNS function and allow to integrate and process information as well as to respond accordingly. Communication within this functional unit, coined the neuro-glio-vascular unit (NGVU), typically relies on two main mechanisms: direct cell-cell coupling via gap junction channels (GJCs) and paracrine communication via the extracellular compartment, two routes to which channels composed of transmembrane connexin (Cx) or pannexin (Panx) proteins can contribute. Multiple isoforms of both protein families are present in the CNS and each CNS cell type is characterized by a unique Cx/Panx portfolio. Over the last two decades, research has uncovered a multilevel platform via which Cxs and Panxs can influence different cellular functions within a tissue: (1) Cx GJCs enable a direct cell-cell communication of small molecules, (2) Cx hemichannels and Panx channels can contribute to autocrine/paracrine signaling pathways, and (3) different structural domains of these proteins allow for channel-independent functions, such as cell-cell adhesion, interactions with the cytoskeleton, and the activation of intracellular signaling pathways. In this paper, we discuss current knowledge on their multifaceted contribution to brain development and to specific processes in the NGVU, including synaptic transmission and plasticity, glial signaling, vasomotor control, and blood-brain barrier integrity in the mature CNS. By highlighting both physiological and pathological conditions, it becomes evident that Cxs and Panxs can play a dual role in the CNS and that an accurate fine-tuning of each signaling mechanism is crucial for normal CNS physiology.
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Affiliation(s)
- Elke Decrock
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Marijke De Bock
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Nan Wang
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, KU Leuven, Louvain, Belgium
| | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, 75231 Paris Cedex 05, France
- University Pierre et Marie
Curie, ED, N°158, 75005 Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France
| | - Christian C. Naus
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3 Canada
| | - Colin R. Green
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
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Abstract
The ubiquitous pannexin 1 (Panx1) ion- and metabolite-permeable channel mediates the release of ATP, a potent signalling molecule. In the present study, we provide striking evidence that ATP, in turn, stimulates internalization of Panx1 to intracellular membranes. These findings hold important implications for understanding the regulation of Panx1 when extracellular ATP is elevated. In the nervous system, this includes phenomena such as synaptic plasticity, pain, precursor cell development and stroke; outside of the nervous system, this includes things like skeletal and smooth muscle activity and inflammation. Within 15 min, ATP led to significant Panx1-EGFP internalization. In a series of experiments, we determined that hydrolysable ATP is the most potent stimulator of Panx1 internalization. We identified two possible mechanisms for Panx1 internalization, including activation of ionotropic purinergic (P2X) receptors and involvement of a putative ATP-sensitive residue in the first extracellular loop of Panx1 (Trp(74)). Internalization was cholesterol-dependent, but clathrin, caveolin and dynamin independent. Detailed analysis of Panx1 at specific endosome sub-compartments confirmed that Panx1 is expressed in endosome membranes of the classical degradation pathway under basal conditions and that elevation of ATP levels diverts a sub-population to recycling endosomes. This is the first report detailing endosome localization of Panx1 under basal conditions and the potential for ATP regulation of its surface expression. Given the ubiquitous expression profile of Panx1 and the importance of ATP signalling, these findings are of critical importance for understanding the role of Panx1 in health and disease.
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46
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Swayne LA, Altier C, Zamponi GW. The truth in complexes: perspectives on ion channel signaling nexuses in the nervous system. Front Cell Neurosci 2014; 8:406. [PMID: 25505383 PMCID: PMC4244691 DOI: 10.3389/fncel.2014.00406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/10/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
- Leigh A Swayne
- Island Medical Program, Division of Medical Sciences, University of Victoria Victoria, BC, Canada ; Department of Biology, University of Victoria Victoria, BC, Canada ; Department of Cellular and Physiological Sciences, University of British Columbia Vancouver, BC, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, University of Calgary Calgary, AB, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, University of Calgary Calgary, AB, Canada
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47
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Cheung G, Chever O, Rouach N. Connexons and pannexons: newcomers in neurophysiology. Front Cell Neurosci 2014; 8:348. [PMID: 25408635 PMCID: PMC4219455 DOI: 10.3389/fncel.2014.00348] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/06/2014] [Indexed: 11/14/2022] Open
Abstract
Connexin hemichannels are single membrane channels which have been traditionally thought to work in pairs to form gap junction channels across two opposing cells. In astrocytes, gap junction channels allow direct intercellular communication and greatly facilitate the transmission of signals. Recently, there has been growing evidence demonstrating that connexin hemichannels, as well as pannexin channels, on their own are open in various conditions. They allow bidirectional flow of ions and signaling molecules and act as release sites for transmitters like ATP and glutamate into the extracellular space. While much attention has focused on the function of connexin hemichannels and pannexons during pathological situations like epilepsy, inflammation, neurodegeneration or ischemia, their potential roles in physiology is often ignored. In order to fully understand the dynamic properties and roles of connexin hemichannels and pannexons in the brain, it is essential to decipher whether they also have some physiological functions and contribute to normal cerebral processes. Here, we present recent studies in the CNS suggesting emerging physiological functions of connexin hemichannels and pannexons in normal neuronal activity and behavior. We also discuss how these pioneer studies pave the way for future research to extend the physiological relevance of connexons and pannexons, and some fundamental issues yet to be addressed.
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Affiliation(s)
- Giselle Cheung
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University Paris, France
| | - Oana Chever
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University Paris, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University Paris, France
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48
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Abstract
In less than a decade, a small family of channel-forming glycoproteins, named pannexins, have captured the interest of many biologists, in large part due to their association with common diseases, ranging from cancers to neuropathies to infectious diseases. Although the pannexin family consists of only three members (Panx1, Panx2 and Panx3), one or more of these pannexins are expressed in virtually every mammalian organ, implicating their potential role in a diverse array of pathophysiologies. Panx1 is the most extensively studied, but features of this pannexin must be cautiously extrapolated to the other pannexins, as for example we now know that Panx2, unlike Panx1, exhibits unique properties such as a tendency to be retained within intracellular compartments. In the present review, we assess the biochemical and channel features of pannexins focusing on the literature which links these unique molecules to over a dozen diseases and syndromes. Although no germ-line mutations in genes encoding pannexins have been linked to any diseases, many cases have shown that high pannexin expression is associated with disease onset and/or progression. Disease may also occur, however, when pannexins are underexpressed, highlighting that pannexin expression must be exquisitely regulated. Finally, we discuss some of the most pressing questions and controversies in the pannexin field as the community seeks to uncover the full biological relevance of pannexins in healthy organs and during disease.
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49
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Makarenkova HP, Shestopalov VI. The role of pannexin hemichannels in inflammation and regeneration. Front Physiol 2014; 5:63. [PMID: 24616702 PMCID: PMC3933922 DOI: 10.3389/fphys.2014.00063] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 02/02/2014] [Indexed: 12/19/2022] Open
Abstract
Tissue injury involves coordinated systemic responses including inflammatory response, targeted cell migration, cell-cell communication, stem cell activation and proliferation, and tissue inflammation and regeneration. The inflammatory response is an important prerequisite for regeneration. Multiple studies suggest that extensive cell-cell communication during tissue regeneration is coordinated by purinergic signaling via extracellular adenosine triphosphate (ATP). Most recent data indicates that ATP release for such communication is mediated by hemichannels formed by connexins and pannexins. The Pannexin family consists of three vertebrate proteins (Panx 1, 2, and 3) that have low sequence homology with other gap junction proteins and were shown to form predominantly non-junctional plasma membrane hemichannels. Pannexin-1 (Panx1) channels function as an integral component of the P2X/P2Y purinergic signaling pathway and is arguably the major contributor to pathophysiological ATP release. Panx1 is expressed in many tissues, with highest levels detected in developing brain, retina and skeletal muscles. Panx1 channel expression and activity is reported to increase significantly following injury/inflammation and during regeneration and differentiation. Recent studies also report that pharmacological blockade of the Panx1 channel or genetic ablation of the Panx1 gene cause significant disruption of progenitor cell migration, proliferation, and tissue regeneration. These findings suggest that pannexins play important roles in activation of both post-injury inflammatory response and the subsequent process of tissue regeneration. Due to wide expression in multiple tissues and involvement in diverse signaling pathways, pannexins and connexins are currently being considered as therapeutic targets for traumatic brain or spinal cord injuries, ischemic stroke and cancer. The precise role of pannexins and connexins in the balance between tissue inflammation and regeneration needs to be further understood.
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Affiliation(s)
- Helen P Makarenkova
- Department of Cell and Molecular Biology, The Scripps Research Institute La Jolla, CA, USA
| | - Valery I Shestopalov
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine Miami, FL, USA ; Department of Cell Biology and Anatomy, Vavilov Institute for General Genetics Moscow, Russia
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Abstract
The pannexins (Panxs) are a family of chordate proteins homologous to the invertebrate gap junction forming proteins named innexins. Three distinct Panx paralogs (Panx1, Panx2, and Panx3) are shared among the major vertebrate phyla, but they appear to have suppressed (or even lost) their ability to directly couple adjacent cells. Connecting the intracellular and extracellular compartments is now widely accepted as Panx's primary function, facilitating the passive movement of ions and small molecules along electrochemical gradients. The tissue distribution of the Panxs ranges from pervasive to very restricted, depending on the paralog, and are often cell type-specific and/or developmentally regulated within any given tissue. In recent years, Panxs have been implicated in an assortment of physiological and pathophysiological processes, particularly with respect to ATP signaling and inflammation, and they are now considered to be a major player in extracellular purinergic communication. The following is a comprehensive review of the Panx literature, exploring the historical events leading up to their discovery, outlining our current understanding of their biochemistry, and describing the importance of these proteins in health and disease.
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Affiliation(s)
- Stephen R Bond
- Genome Technology Branch, Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health Bethesda, MD, USA ; Department of Cellular and Physiological Science, Life Sciences Institute, University of British Columbia Vancouver, BC, Canada
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Sciences Institute, University of British Columbia Vancouver, BC, Canada
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