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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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2
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Henze E, Ehrlich JJ, Burkhardt RN, Fox BW, Michalski K, Kramer L, Lenfest M, Boesch JM, Schroeder FC, Kawate T. ATP-release pannexin channels are gated by lysophospholipids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563601. [PMID: 37961151 PMCID: PMC10634739 DOI: 10.1101/2023.10.23.563601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Adenosine triphosphate (ATP) serves as an extracellular messenger that mediates diverse cell-to-cell communication. Compelling evidence supports that ATP is released from cells through pannexins, a family of heptameric large pore-forming channels. However, the activation mechanisms that trigger ATP release by pannexins remain poorly understood. Here, we discover lysophospholipids as endogenous pannexin activators, using activity-guided fractionation of mouse tissue extracts combined with untargeted metabolomics and electrophysiology. We show that lysophospholipids directly and reversibly activate pannexins in the absence of other proteins. Molecular docking, mutagenesis, and single-particle cryo-EM reconstructions suggest that lysophospholipids open pannexin channels by altering the conformation of the N-terminal domain. Our results provide a connection between lipid metabolism and ATP signaling, both of which play major roles in inflammation and neurotransmission. One-Sentence Summary Untargeted metabolomics discovers a class of messenger lipids as endogenous activators of membrane channels important for inflammation and neurotransmission.
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Aldous N, Moin ASM, Abdelalim EM. Pancreatic β-cell heterogeneity in adult human islets and stem cell-derived islets. Cell Mol Life Sci 2023; 80:176. [PMID: 37270452 DOI: 10.1007/s00018-023-04815-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/27/2023] [Accepted: 05/19/2023] [Indexed: 06/05/2023]
Abstract
Recent studies reported that pancreatic β-cells are heterogeneous in terms of their transcriptional profiles and their abilities for insulin secretion. Sub-populations of pancreatic β-cells have been identified based on the functionality and expression of specific surface markers. Under diabetes condition, β-cell identity is altered leading to different β-cell sub-populations. Furthermore, cell-cell contact between β-cells and other endocrine cells within the islet play an important role in regulating insulin secretion. This highlights the significance of generating a cell product derived from stem cells containing β-cells along with other major islet cells for treating patients with diabetes, instead of transplanting a purified population of β-cells. Another key question is how close in terms of heterogeneity are the islet cells derived from stem cells? In this review, we summarize the heterogeneity in islet cells of the adult pancreas and those generated from stem cells. In addition, we highlight the significance of this heterogeneity in health and disease conditions and how this can be used to design a stem cell-derived product for diabetes cell therapy.
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Affiliation(s)
- Noura Aldous
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, Doha, Qatar
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, PO Box 34110, Doha, Qatar
| | - Abu Saleh Md Moin
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, PO Box 34110, Doha, Qatar
- Research Department, Royal College of Surgeons in Ireland Bahrain, Adliya, Kingdom of Bahrain
| | - Essam M Abdelalim
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, Doha, Qatar.
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, PO Box 34110, Doha, Qatar.
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Mori C, Lee JY, Tokumoto M, Satoh M. Cadmium Toxicity Is Regulated by Peroxisome Proliferator-Activated Receptor δ in Human Proximal Tubular Cells. Int J Mol Sci 2022; 23:ijms23158652. [PMID: 35955783 PMCID: PMC9369238 DOI: 10.3390/ijms23158652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/26/2022] [Accepted: 08/02/2022] [Indexed: 12/13/2022] Open
Abstract
Cadmium (Cd) is a toxic heavy metal that is widely present in the environment. Renal proximal tubule disorder is the main symptom of Cd chronic poisoning. Our previous study demonstrated that Cd inhibits the total activities of peroxisome proliferator-activated receptor (PPAR) transcription factors in human and rat proximal tubular cells. In this study, we investigated the involvement of PPAR in Cd renal toxicity using the HK-2 human proximal tubular cell line. Among PPAR isoform genes, only PPARD knockdown significantly showed resistance to Cd toxicity in HK-2 cells. The transcriptional activity of PPARδ was decreased not only by PPARD knockdown but also by Cd treatment. DNA microarray analysis showed that PPARD knockdown changed the expression of apoptosis-related genes in HK-2 cells. PPARD knockdown decreased apoptosis signals and caspase-3 activity induced by Cd treatment. PPARD knockdown did not affect the intracellular Cd level after Cd treatment. These results suggest that PPARδ plays a critical role in the modification of susceptibility to Cd renal toxicity and that the apoptosis pathway may be involved in PPARδ-related Cd toxicity.
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Sanchez-Pupo RE, O'Donnell BL, Johnston D, Gyenis L, Litchfield DW, Penuela S. Pannexin 2 is expressed in murine skin and promotes UVB-induced apoptosis of keratinocytes. Mol Biol Cell 2022; 33:ar24. [PMID: 34985913 PMCID: PMC9250380 DOI: 10.1091/mbc.e21-08-0387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pannexins (PANX) are a family of three channel-forming membrane glycoproteins expressed in the skin. Previous studies have focused on the role of PANX1 and PANX3 in the regulation of cellular functions in skin cells while PANX2, the largest member of this protein family, has not been investigated. In the current study, we explored the temporal PANX2 expression in murine skin and found that one Panx2 splice variant (Panx2-202) tends to be more abundant at the protein level and is continuously expressed in developed skin. PANX2 was detected in the suprabasal layers of the mouse epidermis and up-regulated in an in vitro model of rat epidermal keratinocyte differentiation. Furthermore, we show that in apoptotic rat keratinocytes, upon UV light B (UVB)-induced caspase-3/7 activation, ectopically overexpressed PANX2 is cleaved in its C-terminal domain at the D416 residue without increasing the apoptotic rate measured by caspase-3/7 activation. Notably, CRISPR-Cas9 mediated genetic deletion of rat Panx2 delays but does not impair caspase-3/7 activation and cytotoxicity in UVB-irradiated keratinocytes. We propose that endogenous PANX2 expression in keratinocytes promotes cell death after UVB insult and may contribute to skin homeostasis.
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Affiliation(s)
- Rafael E Sanchez-Pupo
- Department of Anatomy and Cell Biology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Brooke L O'Donnell
- Department of Anatomy and Cell Biology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Danielle Johnston
- Department of Anatomy and Cell Biology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Laszlo Gyenis
- Department of Biochemistry, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - David W Litchfield
- Department of Biochemistry, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada.,Department of Oncology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada.,Department of Oncology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
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Syrjanen J, Michalski K, Kawate T, Furukawa H. On the molecular nature of large-pore channels. J Mol Biol 2021; 433:166994. [PMID: 33865869 PMCID: PMC8409005 DOI: 10.1016/j.jmb.2021.166994] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 12/25/2022]
Abstract
Membrane transport is a fundamental means to control basic cellular processes such as apoptosis, inflammation, and neurodegeneration and is mediated by a number of transporters, pumps, and channels. Accumulating evidence over the last half century has shown that a type of so-called "large-pore channel" exists in various tissues and organs in gap-junctional and non-gap-junctional forms in order to flow not only ions but also metabolites such as ATP. They are formed by a number of protein families with little or no evolutionary linkages including connexin, innexin, pannexin, leucine-rich repeat-containing 8 (LRRC8), and calcium homeostasis modulator (CALHM). This review summarizes the history and concept of large-pore channels starting from connexin gap junction channels to the more recent developments in innexin, pannexin, LRRC8, and CALHM. We describe structural and functional features of large-pore channels that are crucial for their diverse functions on the basis of available structures.
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Affiliation(s)
- Johanna Syrjanen
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Kevin Michalski
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Toshimitsu Kawate
- Department of Molecular Medicine, Fields of Biochemistry, Molecular, and Cell Biology (BMCB), and Biophysics, Cornell University, Ithaca, NY 14853, USA
| | - Hiro Furukawa
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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Fløyel T, Meyerovich K, Prause MC, Kaur S, Frørup C, Mortensen HB, Nielsen LB, Pociot F, Cardozo AK, Størling J. SKAP2, a Candidate Gene for Type 1 Diabetes, Regulates β-Cell Apoptosis and Glycemic Control in Newly Diagnosed Patients. Diabetes 2021; 70:464-476. [PMID: 33203694 PMCID: PMC7881866 DOI: 10.2337/db20-0092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 11/10/2020] [Indexed: 01/27/2023]
Abstract
The single nucleotide polymorphism rs7804356 located in the Src kinase-associated phosphoprotein 2 (SKAP2) gene is associated with type 1 diabetes (T1D), suggesting SKAP2 as a causal candidate gene. The objective of the study was to investigate if SKAP2 has a functional role in the β-cells in relation to T1D. In a cohort of children with newly diagnosed T1D, rs7804356 predicted glycemic control and residual β-cell function during the 1st year after diagnosis. In INS-1E cells and rat and human islets, proinflammatory cytokines reduced the content of SKAP2. Functional studies revealed that knockdown of SKAP2 aggravated cytokine-induced apoptosis in INS-1E cells and primary rat β-cells, suggesting an antiapoptotic function of SKAP2. In support of this, overexpression of SKAP2 afforded protection against cytokine-induced apoptosis, which correlated with reduced nuclear content of S536-phosphorylated nuclear factor-κB (NF-κB) subunit p65, lower nitric oxide production, and diminished CHOP expression indicative of decreased endoplasmic reticulum stress. Knockdown of CHOP partially counteracted the increase in cytokine-induced apoptosis caused by SKAP2 knockdown. In conclusion, our results suggest that SKAP2 controls β-cell sensitivity to cytokines possibly by affecting the NF-κB-inducible nitric oxide synthase-endoplasmic reticulum stress pathway.
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Affiliation(s)
- Tina Fløyel
- Translational Type 1 Diabetes Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Kira Meyerovich
- ULB Center for Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - Michala C Prause
- Translational Type 1 Diabetes Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simranjeet Kaur
- Translational Type 1 Diabetes Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Caroline Frørup
- Translational Type 1 Diabetes Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Henrik B Mortensen
- Department of Pediatrics E, Herlev and Gentofte Hospital, Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lotte B Nielsen
- Department of Pediatrics E, Herlev and Gentofte Hospital, Herlev, Denmark
| | - Flemming Pociot
- Translational Type 1 Diabetes Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Alessandra K Cardozo
- ULB Center for Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - Joachim Størling
- Translational Type 1 Diabetes Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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8
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Ray SL, Coulson DJ, Yeoh MLY, Tamara A, Latief JS, Bakhashab S, Weaver JU. The Role of miR-342 in Vascular Health. Study in Subclinical Cardiovascular Disease in Mononuclear Cells, Plasma, Inflammatory Cytokines and PANX2. Int J Mol Sci 2020; 21:ijms21197217. [PMID: 33003647 PMCID: PMC7582278 DOI: 10.3390/ijms21197217] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/06/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular disease (CVD) correlates with inflammation and a reduction in circulating endothelial progenitor cells (cEPCs). Recently, CVD was shown to be the main cause of mortality in individuals with type 1 diabetes (T1DM). In animals, miR-342 was shown to exert an anti-inflammatory effect in CVD. Hypothesis: miR-342-3p/-5p are downregulated in subclinical CVD (T1DM), whereas inflammatory cytokines are upregulated. We studied miR -342 -3p/5p in plasma/peripheral blood mononuclear cells (PBMCs) in 29 T1DM and 20 controls (HC). Vascular health was measured by fibronectin adhesion assay (FAA), cEPCs (CD45dimCD34+133+ cells) and by assessing inflammation and tissue inhibition of metalloproteases (TIMP-1). In T1DM IL-7, IL-8, TNFα and VEGF-C were increased in plasma. MiR-342-3p/-5p were downregulated in PBMCs in T1DM, but not in plasma. PANX2, chemokine receptors CXCR1/2 mRNAs, were increased in PBMCs in T1DM. MiR-342-3p was negatively correlated with TIMP-1, IL-6, IL-8, TNF-α, HbA1c and CXCR2, whilst miR-342-5p was negatively correlated with TIMP-1, IL-6, IL-8 and HbA1c. There was a positive correlation among miR-342-3p, FAA and cEPCs, and between miR-342-5p and cEPCs. ROC curve analyses showed significant downregulation of miR-342-3p/-5p at HbA1c > 46.45 mmol/mol, indicating their potential as biomarkers for subclinical CVD. Our findings validated animal studies and confirmed the proangiogenic properties of miR-342-3p/-5p. MiR-342-3p/-5p-based intervention or monitoring may prove to be beneficial in managing CVD.
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Affiliation(s)
- Sabina L. Ray
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
| | - David J. Coulson
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
| | - Megan Li Yuen Yeoh
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
| | - Alice Tamara
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
| | - Jevi Septyani Latief
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
| | - Sherin Bakhashab
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
- Biochemistry Department, King Abdulaziz University, P.O. Box 80218, Jeddah 21589, Saudi Arabia
| | - Jolanta U. Weaver
- Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; (S.L.R.); (D.J.C.); (M.L.Y.Y.); (A.T.); (J.S.L.); (S.B.)
- Department of Diabetes, Queen Elizabeth Hospital, Gateshead, Newcastle Upon Tyne NE9 6SH, UK
- Vascular Biology and Medicine Theme, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK
- Correspondence: ; Tel.: +44-(191)-445-2181
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Bartley C, Brun T, Oberhauser L, Grimaldi M, Molica F, Kwak BR, Bosco D, Chanson M, Maechler P. Chronic fructose renders pancreatic β-cells hyper-responsive to glucose-stimulated insulin secretion through extracellular ATP signaling. Am J Physiol Endocrinol Metab 2019; 317:E25-E41. [PMID: 30912960 DOI: 10.1152/ajpendo.00456.2018] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Fructose is widely used as a sweetener in processed food and is also associated with metabolic disorders, such as obesity. However, the underlying cellular mechanisms remain unclear, in particular, regarding the pancreatic β-cell. Here, we investigated the effects of chronic exposure to fructose on the function of insulinoma cells and isolated mouse and human pancreatic islets. Although fructose per se did not acutely stimulate insulin exocytosis, our data show that chronic fructose rendered rodent and human β-cells hyper-responsive to intermediate physiological glucose concentrations. Fructose exposure reduced intracellular ATP levels without affecting mitochondrial function, induced AMP-activated protein kinase activation, and favored ATP release from the β-cells upon acute glucose stimulation. The resulting increase in extracellular ATP, mediated by pannexin1 (Panx1) channels, activated the calcium-mobilizer P2Y purinergic receptors. Immunodetection revealed the presence of both Panx1 channels and P2Y1 receptors in β-cells. Addition of an ectonucleotidase inhibitor or P2Y1 agonists to naïve β-cells potentiated insulin secretion stimulated by intermediate glucose, mimicking the fructose treatment. Conversely, the P2Y1 antagonist and Panx1 inhibitor reversed the effects of fructose, as confirmed using Panx1-null islets and by the clearance of extracellular ATP by apyrase. These results reveal an important function of ATP signaling in pancreatic β-cells mediating fructose-induced hyper-responsiveness.
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Affiliation(s)
- Clarissa Bartley
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Thierry Brun
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Lucie Oberhauser
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Mariagrazia Grimaldi
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Filippo Molica
- Department of Pathology and Immunology, University of Geneva Medical Center , Geneva , Switzerland
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva Medical Center , Geneva , Switzerland
- Division of Cardiology, University of Geneva Medical Center , Geneva , Switzerland
| | - Domenico Bosco
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
- Department of Surgery, Cell Isolation and Transplantation Center, Geneva University Hospital , Geneva , Switzerland
| | - Marc Chanson
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Department of Pediatrics, Geneva University Hospital , Geneva , Switzerland
| | - Pierre Maechler
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
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Pannexin 2 Localizes at ER-Mitochondria Contact Sites. Cancers (Basel) 2019; 11:cancers11030343. [PMID: 30862038 PMCID: PMC6468579 DOI: 10.3390/cancers11030343] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/22/2019] [Accepted: 02/27/2019] [Indexed: 01/02/2023] Open
Abstract
Endomembrane specialization allows functional compartmentalization but imposes physical constraints to information flow within the cell. However, the evolution of an endomembrane system was associated with the emergence of contact sites facilitating communication between membrane-bound organelles. Contact sites between the endoplasmic reticulum (ER) and mitochondria are highly conserved in terms of their morphological features but show surprising molecular diversity within and across eukaryote species. ER-mitochondria contact sites are thought to regulate key processes in oncogenesis but their molecular composition remains poorly characterized in mammalian cells. In this study, we investigate the localization of pannexin 2 (Panx2), a membrane channel protein showing tumor-suppressing properties in cancer cells. Using a combination of subcellular fractionation, particle tracking in live-cell, and immunogold electron microscopy, we show that Panx2 localizes at ER-mitochondria contact sites in mammalian cells and sensitizes cells to apoptotic stimuli.
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