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Hu CQ, Hou T, Xiang R, Li X, Li J, Wang TT, Liu WJ, Hou S, Wang D, Zhao QH, Yu XX, Xu M, Liu XK, Chi YJ, Yang JC. PANX1-mediated ATP release confers FAM3A's suppression effects on hepatic gluconeogenesis and lipogenesis. Mil Med Res 2024; 11:41. [PMID: 38937853 PMCID: PMC11210080 DOI: 10.1186/s40779-024-00543-6] [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: 12/01/2023] [Accepted: 06/10/2024] [Indexed: 06/29/2024] Open
Abstract
BACKGROUND Extracellular adenosine triphosphate (ATP) is an important signal molecule. In previous studies, intensive research had revealed the crucial roles of family with sequence similarity 3 member A (FAM3A) in controlling hepatic glucolipid metabolism, islet β cell function, adipocyte differentiation, blood pressure, and other biological and pathophysiological processes. Although mitochondrial protein FAM3A plays crucial roles in the regulation of glucolipid metabolism via stimulating ATP release to activate P2 receptor pathways, its mechanism in promoting ATP release in hepatocytes remains unrevealed. METHODS db/db, high-fat diet (HFD)-fed, and global pannexin 1 (PANX1) knockout mice, as well as liver sections of individuals, were used in this study. Adenoviruses and adeno-associated viruses were utilized for in vivo gene overexpression or inhibition. To evaluate the metabolic status in mice, oral glucose tolerance test (OGTT), pyruvate tolerance test (PTT), insulin tolerance test (ITT), and magnetic resonance imaging (MRI) were conducted. Protein-protein interactions were determined by coimmunoprecipitation with mass spectrometry (MS) assays. RESULTS In livers of individuals and mice with steatosis, the expression of ATP-permeable channel PANX1 was increased (P < 0.01). Hepatic PANX1 overexpression ameliorated the dysregulated glucolipid metabolism in obese mice. Mice with hepatic PANX1 knockdown or global PANX1 knockout exhibited disturbed glucolipid metabolism. Restoration of hepatic PANX1 rescued the metabolic disorders of PANX1-deficient mice (P < 0.05). Mechanistically, ATP release is mediated by the PANX1-activated protein kinase B-forkhead box protein O1 (Akt-FOXO1) pathway to inhibit gluconeogenesis via P2Y receptors in hepatocytes. PANX1-mediated ATP release also activated calmodulin (CaM) (P < 0.01), which interacted with c-Jun N-terminal kinase (JNK) to inhibit its activity, thereby deactivating the transcription factor activator protein-1 (AP1) and repressing fatty acid synthase (FAS) expression and lipid synthesis (P < 0.05). FAM3A stimulated the expression of PANX1 via heat shock factor 1 (HSF1) in hepatocytes (P < 0.05). Notably, FAM3A overexpression failed to promote ATP release, inhibit the expression of gluconeogenic and lipogenic genes, and suppress gluconeogenesis and lipid deposition in PANX1-deficient hepatocytes and livers. CONCLUSIONS PANX1-mediated release of ATP plays a crucial role in maintaining hepatic glucolipid homeostasis, and it confers FAM3A's suppressive effects on hepatic gluconeogenesis and lipogenesis.
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Affiliation(s)
- Cheng-Qing Hu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
- Department of Obstetrics and Gynecology, Peking University Third Hospital/National Clinical Research Center for Obstetrics and Gynecology, Beijing, 100191, China
| | - Tao Hou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Rui Xiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Xin Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Jing Li
- Department of Endocrinology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Tian-Tian Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Wen-Jun Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Song Hou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Di Wang
- Department of Central Laboratory and Institute of Clinical Molecular Biology, Peking University People's Hospital, Beijing, 100044, China
| | - Qing-He Zhao
- Department of Gastroenterology, Peking University People's Hospital, Beijing, 100044, China
| | - Xiao-Xing Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China
| | - Ming Xu
- Department of Cardiology, Institute of Vascular Medicine, Peking University Third Hospital/Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Beijing, 100191, China
| | - Xing-Kai Liu
- Department of Hepatobiliary and Pancreatic Surgery, General Surgery Centre, the First Hospital of Jilin University, Changchun, 130061, China.
| | - Yu-Jing Chi
- Department of Central Laboratory and Institute of Clinical Molecular Biology, Peking University People's Hospital, Beijing, 100044, China.
- Department of Gastroenterology, Peking University People's Hospital, Beijing, 100044, China.
| | - Ji-Chun Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences/State Key Laboratory of Vascular Homeostasis and Remodeling/Center for Non-Coding RNA Medicine, Peking University Health Science Center, Beijing, 100191, China.
- Department of Cardiology, Peking University Third Hospital, Beijing, 100191, China.
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2
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Freeman E, Langlois S, Leyba MF, Ammar T, Léger Z, McMillan HJ, Renaud JM, Jasmin BJ, Cowan KN. Pannexin 1 dysregulation in Duchenne muscular dystrophy and its exacerbation of dystrophic features in mdx mice. Skelet Muscle 2024; 14:8. [PMID: 38671506 PMCID: PMC11046831 DOI: 10.1186/s13395-024-00340-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is associated with impaired muscle regeneration, progressive muscle weakness, damage, and wasting. While the cause of DMD is an X-linked loss of function mutation in the gene encoding dystrophin, the exact mechanisms that perpetuate the disease progression are unknown. Our laboratory has demonstrated that pannexin 1 (Panx1 in rodents; PANX1 in humans) is critical for the development, strength, and regeneration of male skeletal muscle. In normal skeletal muscle, Panx1 is part of a multiprotein complex with dystrophin. We and others have previously shown that Panx1 levels and channel activity are dysregulated in various mouse models of DMD. METHODS We utilized myoblast cell lines derived from DMD patients to assess PANX1 expression and function. To investigate how Panx1 dysregulation contributes to DMD, we generated a dystrophic (mdx) mouse model that lacks Panx1 (Panx1-/-/mdx). In depth characterization of this model included histological analysis, as well as locomotor, and physiological tests such as muscle force and grip strength assessments. RESULTS Here, we demonstrate that PANX1 levels and channel function are reduced in patient-derived DMD myoblast cell lines. Panx1-/-/mdx mice have a significantly reduced lifespan, and decreased body weight due to lean mass loss. Their tibialis anterior were more affected than their soleus muscles and displayed reduced mass, myofiber loss, increased centrally nucleated myofibers, and a lower number of muscle stem cells compared to that of Panx1+/+/mdx mice. These detrimental effects were associated with muscle and locomotor functional impairments. In vitro, PANX1 overexpression in patient-derived DMD myoblasts improved their differentiation and fusion. CONCLUSIONS Collectively, our findings suggest that PANX1/Panx1 dysregulation in DMD exacerbates several aspects of the disease. Moreover, our results suggest a potential therapeutic benefit to increasing PANX1 levels in dystrophic muscles.
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MESH Headings
- Animals
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Connexins/genetics
- Connexins/metabolism
- Mice, Inbred mdx
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Male
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Humans
- Mice
- Myoblasts/metabolism
- Cell Line
- Muscle Strength
- Disease Models, Animal
- Mice, Inbred C57BL
- Mice, Knockout
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Affiliation(s)
- Emily Freeman
- Children's Hospital of Eastern Ontario Research Institute, Pediatric General Surgery, 401 Smyth Rd, Room 3360, Ottawa, ON, K1H 8L1, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Stéphanie Langlois
- Department of Surgery, Division of Pediatric Surgery, University of Ottawa, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
- Children's Hospital of Eastern Ontario Research Institute, Pediatric General Surgery, 401 Smyth Rd, Room 3360, Ottawa, ON, K1H 8L1, Canada
| | - Marcos F Leyba
- Department of Surgery, Division of Pediatric Surgery, University of Ottawa, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
- Children's Hospital of Eastern Ontario Research Institute, Pediatric General Surgery, 401 Smyth Rd, Room 3360, Ottawa, ON, K1H 8L1, Canada
| | - Tarek Ammar
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Centre for Neuromuscular Disease, Ottawa, ON, Canada
| | - Zacharie Léger
- Children's Hospital of Eastern Ontario Research Institute, Pediatric General Surgery, 401 Smyth Rd, Room 3360, Ottawa, ON, K1H 8L1, Canada
| | - Hugh J McMillan
- Children's Hospital of Eastern Ontario Research Institute, Pediatric General Surgery, 401 Smyth Rd, Room 3360, Ottawa, ON, K1H 8L1, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Centre for Neuromuscular Disease, Ottawa, ON, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Centre for Neuromuscular Disease, Ottawa, ON, Canada
| | - Kyle N Cowan
- Department of Surgery, Division of Pediatric Surgery, University of Ottawa, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada.
- Children's Hospital of Eastern Ontario Research Institute, Pediatric General Surgery, 401 Smyth Rd, Room 3360, Ottawa, ON, K1H 8L1, Canada.
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.
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3
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Pavelec CM, Young AP, Luviano HL, Orrell EE, Szagdaj A, Poudel N, Wolpe AG, Thomas SH, Yeudall S, Upchurch CM, Okusa MD, Isakson BE, Wolf MJ, Leitinger N. Pannexin 1 Channels Control Cardiomyocyte Metabolism and Neutrophil Recruitment During Non-Ischemic Heart Failure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.29.573679. [PMID: 38234768 PMCID: PMC10793433 DOI: 10.1101/2023.12.29.573679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Pannexin 1 (PANX1), a ubiquitously expressed ATP release membrane channel, has been shown to play a role in inflammation, blood pressure regulation, and myocardial infarction. However, a possible role of PANX1 in cardiomyocytes in the progression of heart failure has not yet been investigated. We generated a novel mouse line with constitutive deletion of PANX1 in cardiomyocytes (Panx1 MyHC6 ). PANX1 deletion in cardiomyocytes had no effect on unstressed heart function but increased the glycolytic metabolism both in vivo and in vitro . In vitro , treatment of H9c2 cardiomyocytes with isoproterenol led to PANX1-dependent release of ATP and Yo-Pro-1 uptake, as assessed by pharmacological blockade with spironolactone and siRNA-mediated knock-down of PANX1. To investigate non-ischemic heart failure and the preceding cardiac hypertrophy we administered isoproterenol, and we demonstrate that Panx1 MyHC6 mice were protected from systolic and diastolic left ventricle volume increases and cardiomyocyte hypertrophy. Moreover, we found that Panx1 MyHC6 mice showed decreased isoproterenol-induced recruitment of immune cells (CD45 + ), particularly neutrophils (CD11b + , Ly6g + ), to the myocardium. Together these data demonstrate that PANX1 deficiency in cardiomyocytes impacts glycolytic metabolism and protects against cardiac hypertrophy in non-ischemic heart failure at least in part by reducing immune cell recruitment. Our study implies PANX1 channel inhibition as a therapeutic approach to ameliorate cardiac dysfunction in heart failure patients.
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4
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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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5
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El-Lakany MA, Haghbin N, Arora N, Hashad AM, Mironova GY, Sancho M, Gros R, Welsh DG. Ca V3.1 channels facilitate calcium wave generation and myogenic tone development in mouse mesenteric arteries. Sci Rep 2023; 13:20407. [PMID: 37989780 PMCID: PMC10663617 DOI: 10.1038/s41598-023-47715-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
The arterial myogenic response to intraluminal pressure elicits constriction to maintain tissue perfusion. Smooth muscle [Ca2+] is a key determinant of constriction, tied to L-type (CaV1.2) Ca2+ channels. While important, other Ca2+ channels, particularly T-type could contribute to pressure regulation within defined voltage ranges. This study examined the role of one T-type Ca2+ channel (CaV3.1) using C57BL/6 wild type and CaV3.1-/- mice. Patch-clamp electrophysiology, pressure myography, blood pressure and Ca2+ imaging defined the CaV3.1-/- phenotype relative to C57BL/6. CaV3.1-/- mice had absent CaV3.1 expression and whole-cell current, coinciding with lower blood pressure and reduced mesenteric artery myogenic tone, particularly at lower pressures (20-60 mmHg) where membrane potential is hyperpolarized. This reduction coincided with diminished Ca2+ wave generation, asynchronous events of Ca2+ release from the sarcoplasmic reticulum, insensitive to L-type Ca2+ channel blockade (Nifedipine, 0.3 µM). Proximity ligation assay (PLA) confirmed IP3R1/CaV3.1 close physical association. IP3R blockade (2-APB, 50 µM or xestospongin C, 3 µM) in nifedipine-treated C57BL/6 arteries rendered a CaV3.1-/- contractile phenotype. Findings indicate that Ca2+ influx through CaV3.1 contributes to myogenic tone at hyperpolarized voltages through Ca2+-induced Ca2+ release tied to the sarcoplasmic reticulum. This study helps establish CaV3.1 as a potential therapeutic target to control blood pressure.
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Affiliation(s)
- Mohammed A El-Lakany
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada.
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
| | - Nadia Haghbin
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Naman Arora
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Ahmed M Hashad
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Galina Yu Mironova
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Maria Sancho
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Robert Gros
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Donald G Welsh
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada.
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6
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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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7
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Wakefield B, Penuela S. Potential Implications of Exercise Training on Pannexin Expression and Function. J Vasc Res 2022; 60:114-124. [PMID: 36366809 DOI: 10.1159/000527240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/14/2022] [Indexed: 09/05/2023] Open
Abstract
Pannexins (PANX1, 2, 3) are channel-forming glycoproteins that are expressed throughout the cardiovascular and musculoskeletal system. The canonical function of these proteins is to release nucleotides that act as purinergic signalling at the cell membrane or Ca2+ channels at the endoplasmic reticulum membrane. These two forms of signalling are essential for autocrine and paracrine signalling in health, and alterations in this signalling have been implicated in the pathogenesis of many diseases. Many musculoskeletal and cardiovascular diseases are largely the result of a lack of physical activity which causes altered gene expression. Considering exercise training has been shown to alter a wide array of gene expression in musculoskeletal tissues, understanding the interaction between exercise training, gene function and expression in relevant diseases is warranted. With regards to pannexins, multiple publications have shown that exercise training can influence pannexin expression and may influence the significance of its function in certain diseases. This review further discusses the potential interaction between exercise training and pannexin biology in relevant tissues and disease models. We propose that exercise training in relevant animal and human models will provide a more comprehensive understanding of the implications of pannexin biology in disease.
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Affiliation(s)
- Brent Wakefield
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
- Department of Oncology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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8
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Rusiecka OM, Tournier M, Molica F, Kwak BR. Pannexin1 channels-a potential therapeutic target in inflammation. Front Cell Dev Biol 2022; 10:1020826. [PMID: 36438559 PMCID: PMC9682086 DOI: 10.3389/fcell.2022.1020826] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 10/20/2022] [Indexed: 08/11/2023] Open
Abstract
An exaggerated inflammatory response is the hallmark of a plethora of disorders. ATP is a central signaling molecule that orchestrates the initiation and resolution of the inflammatory response by enhancing activation of the inflammasome, leukocyte recruitment and activation of T cells. ATP can be released from cells through pannexin (Panx) channels, a family of glycoproteins consisting of three members, Panx1, Panx2, and Panx3. Panx1 is ubiquitously expressed and forms heptameric channels in the plasma membrane mediating paracrine and autocrine signaling. Besides their involvement in the inflammatory response, Panx1 channels have been shown to contribute to different modes of cell death (i.e., pyroptosis, necrosis and apoptosis). Both genetic ablation and pharmacological inhibition of Panx1 channels decrease inflammation in vivo and contribute to a better outcome in several animal models of inflammatory disease involving various organs, including the brain, lung, kidney and heart. Up to date, several molecules have been identified to inhibit Panx1 channels, for instance probenecid (Pbn), mefloquine (Mfq), flufenamic acid (FFA), carbenoxolone (Cbx) or mimetic peptides like 10Panx1. Unfortunately, the vast majority of these compounds lack specificity and/or serum stability, which limits their application. The recent availability of detailed structural information on the Panx1 channel from cryo-electron microscopy studies may open up innovative approaches to acquire new classes of synthetic Panx1 channel blockers with high target specificity. Selective inhibition of Panx1 channels may not only limit acute inflammatory responses but may also prove useful in chronic inflammatory diseases, thereby improving human health. Here, we reviewed the current knowledge on the role of Panx1 in the initiation and resolution of the inflammatory response, we summarized the effects of Panx1 inhibition in inflammatory pathologies and recapitulate current Panx1 channel pharmacology with an outlook towards future approaches.
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Affiliation(s)
- Olga M. Rusiecka
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Geneva Centre for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Malaury Tournier
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Geneva Centre for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Filippo Molica
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Geneva Centre for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Brenda R. Kwak
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Geneva Centre for Inflammation Research, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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9
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Freeman E, Langlois S, Scott K, Ravel-Chapuis A, Jasmin BJ, Cowan KN. Sex-dependent role of Pannexin 1 in regulating skeletal muscle and satellite cell function. J Cell Physiol 2022; 237:3944-3959. [PMID: 35938715 DOI: 10.1002/jcp.30850] [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: 03/13/2022] [Revised: 07/06/2022] [Accepted: 07/25/2022] [Indexed: 11/05/2022]
Abstract
The development and regeneration of skeletal muscle are mediated by satellite cells (SCs), which ensure the efficient formation of myofibers while repopulating the niche that allows muscle repair following injuries. Pannexin 1 (Panx1) channels are expressed in SCs and their levels increase during differentiation in vitro, as well as during skeletal muscle development and regeneration in vivo. Panx1 has recently been shown to regulate muscle regeneration by promoting bleb-based myoblast migration and fusion. While skeletal muscle is largely influenced in a sex-specific way, the sex-dependent roles of Panx1 in regulating skeletal muscle and SC function remain to be investigated. Here, using global Panx1 knockout (KO) mice, we demonstrate that Panx1 loss reduces muscle fiber size and strength, decreases SC number, and alters early SC differentiation and myoblast fusion in male, but not in female mice. Interestingly, while both male and female Panx1 KO mice display an increase in the number of regenerating fibers following acute injury, the newly formed fibers in male Panx1 KO mice are smaller. Overall, our results demonstrate that Panx1 plays a significant role in regulating muscle development, regeneration, and SC number and function in male mice and reveal distinct sex-dependent functions of Panx1 in skeletal muscle.
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Affiliation(s)
- 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
| | - 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
| | - Kaylee Scott
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Centre for Neuromuscular Disease, Ottawa, Ontario, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Centre for Neuromuscular Disease, 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
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10
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Wakefield CB, Lee VR, Johnston D, Boroumand P, Pillon NJ, Sayedyahossein S, O'Donnell BL, Tang J, Sanchez-Pupo RE, Barr KJ, Gros R, Flynn L, Borradaile NM, Klip A, Beier F, Penuela S. Pannexin 3 deletion reduces fat accumulation and inflammation in a sex-specific manner. Int J Obes (Lond) 2022; 46:726-738. [PMID: 34897286 DOI: 10.1038/s41366-021-01037-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/16/2021] [Accepted: 11/23/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND Pannexin 3 (PANX3) is a channel-forming glycoprotein that enables nutrient-induced inflammation in vitro, and genetic linkage data suggest that it regulates body mass index. Here, we characterized inflammatory and metabolic parameters in global Panx3 knockout (KO) mice in the context of forced treadmill running (FEX) and high-fat diet (HFD). METHODS C57BL/6N (WT) and KO mice were randomized to either a FEX running protocol or no running (SED) from 24 until 30 weeks of age. Body weight was measured biweekly, and body composition was measured at 24 and 30 weeks of age. Male WT and KO mice were fed a HFD from 12 to 28 weeks of age. Metabolic organs were analyzed for a panel of inflammatory markers and PANX3 expression. RESULTS In females there were no significant differences in body composition between genotypes, which could be due to the lack of PANX3 expression in female white adipose tissue, while male KOs fed a chow diet had lower body weight and lower fat mass at 24 and 30 weeks of age, which was reduced to the same extent as 6 weeks of FEX in WT mice. In addition, male KO mice exhibited significantly lower expression of multiple pro-inflammatory genes in white adipose tissue compared to WT mice. While on a HFD body weight differences were insignificant, multiple inflammatory genes were significantly different in quadriceps muscle and white adipose tissue resulting in a more anti-inflammatory phenotype in KO mice compared to WT. The lower fat mass in male KO mice may be due to significantly fewer adipocytes in their subcutaneous fat compared to WT mice. Mechanistically, adipose stromal cells (ASCs) cultured from KO mice grow significantly slower than WT ASCs. CONCLUSION PANX3 is expressed in male adult mouse adipose tissue and may regulate adipocyte numbers, influencing fat accumulation and inflammation.
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Affiliation(s)
- C Brent Wakefield
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, ON, N6G 2V4, Canada
| | - Vanessa R Lee
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Danielle Johnston
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Parastoo Boroumand
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Nicolas J Pillon
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Samar Sayedyahossein
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Brooke L O'Donnell
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Justin Tang
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Rafael E Sanchez-Pupo
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Kevin J Barr
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Robert Gros
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Lauren Flynn
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, ON, N6G 2V4, Canada
- Department of Chemical and Biomedical Engineering, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Nica M Borradaile
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Frank Beier
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, ON, N6G 2V4, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada.
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, ON, N6G 2V4, Canada.
- Department of Oncology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada.
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11
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BMP2 increases hyperplasia and hypertrophy of bovine subcutaneous preadipocytes via BMP/SMAD signaling. In Vitro Cell Dev Biol Anim 2022; 58:210-219. [PMID: 35275330 DOI: 10.1007/s11626-022-00661-2] [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: 12/28/2021] [Accepted: 02/20/2022] [Indexed: 11/05/2022]
Abstract
The study aims to characterize functions of bone morphogenetic protein 2 (BMP2) gene in the process of subcutaneous (SQ) fat deposition of bovine, thereby providing insights into mechanisms for the use of BMP2 in fat management. Our results show that BMP2 was extensively expressed in bovine and relatively rich in adipose tissue. Exogenous BMP2 significantly enhanced proliferation of bovine preadipocytes. Consistently, si-BMP2 apparently induced cell cycle arrest at G0/G1 phase and decreased proliferation of preadipocytes. Meanwhile, exogenous BMP2 mildly enhanced preadipocyte differentiation at day 3 of differentiation, as evidenced by accelerated lipid accumulation, as well as increased mRNA and protein expressions of adipogenic key transcription factor PPARγ; contrary results about lipids were found by BMP2 interference treatment. No difference was observed concerning BMP2 or si-BMP2 treatment at day - 2 and day 0 of differentiation. Additionally, LDN-193189 (inhibitor of BMP type I receptor) pretreatment diminished the enhancement of preadipocyte proliferation and differentiation induced by BMP2, as evidenced by constant proliferation rate and PPARγ expressions. Furthermore, BMP2 markedly enhanced phosphorylation level of SMAD1/5/9, and LDN-193189 could diminish the difference caused by BMP2. Thus, our results suggest that BMP2 triggers BMP/SMAD signaling pathway, promoting both hyperplasia and hypertrophy of bovine preadipocytes.
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12
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Quercetin induces pannexin 1 expression via an alternative transcript with a translationally active 5' leader in rhabdomyosarcoma. Oncogenesis 2022; 11:9. [PMID: 35194046 PMCID: PMC8864035 DOI: 10.1038/s41389-022-00384-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 11/25/2022] Open
Abstract
Rhabdomyosarcoma (RMS) is a deadly cancer of skeletal muscle origin. Pannexin 1 (PANX1) is down-regulated in RMS and increasing its levels drastically inhibits RMS progression. PANX1 upregulation thus represents a prospective new treatment strategy for this malignancy. However, the mechanisms regulating PANX1 expression, in RMS and other contexts, remain largely unknown. Here we show that both RMS and normal skeletal muscle express a comparable amount of PANX1 mRNAs, but surprisingly the canonical 5′ untranslated region (5′ UTR) or 5′ leader of the transcript is completely lost in RMS. We uncover that quercetin, a natural plant flavonoid, increases PANX1 protein levels in RMS by inducing re-expression of a 5′ leader-containing PANX1 transcript variant that is efficiently translated. This particular PANX1 mRNA variant is also present in differentiated human skeletal muscle myoblasts (HSMM) that highly express PANX1. Mechanistically, abolishing ETV4 transcription factor binding sites in the PANX1 promoter significantly reduced the luciferase reporter activities and PANX1 5′ UTR levels, and both quercetin treatment in RMS cells and induction of differentiation in HSMM enriched the binding of ETV4 to its consensus element in the PANX1 promoter. Notably, quercetin treatment promoted RMS differentiation in a PANX1-dependent manner. Further showing its therapeutic potential, quercetin treatment prevented RMS in vitro tumor formation while inducing complete regression of established spheroids. Collectively, our results demonstrate the tumor-suppressive effects of quercetin in RMS and present a hitherto undescribed mechanism of PANX1 regulation via ETV4-mediated transcription of a translationally functional 5′ leader-containing PANX1 mRNA.
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Kordowitzki P, Sokołowska G, Wasielak-Politowska M, Skowronska A, Skowronski MT. Pannexins and Connexins: Their Relevance for Oocyte Developmental Competence. Int J Mol Sci 2021; 22:ijms22115918. [PMID: 34072911 PMCID: PMC8199496 DOI: 10.3390/ijms22115918] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/23/2021] [Accepted: 05/28/2021] [Indexed: 12/29/2022] Open
Abstract
The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways, which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possibly due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore they do play a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed and, at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.
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Affiliation(s)
- Paweł Kordowitzki
- Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Bydgoska Street 7, 10-243 Olsztyn, Poland;
- Department of Basic and Preclinical Sciences, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Gagarina Street 7, 87-100 Torun, Poland
| | - Gabriela Sokołowska
- Department of Reproduction and Gynecological Endocrinology, Medical University of Bialystok, Jana Kilińskiego Street 1, 15-089 Białystok, Poland;
| | - Marta Wasielak-Politowska
- Center of Gynecology, Endocrinology and Reproductive Medicine—Artemida, Jagiellońska Street 78, 10-357 Olsztyn, Poland;
| | - Agnieszka Skowronska
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, Warszawska Street 30, 10-357 Olsztyn, Poland;
| | - Mariusz T. Skowronski
- Department of Basic and Preclinical Sciences, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Gagarina Street 7, 87-100 Torun, Poland
- Correspondence: ; Tel.: +48-566-112-231
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14
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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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15
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Senthivinayagam S, Serbulea V, Upchurch CM, Polanowska-Grabowska R, Mendu SK, Sahu S, Jayaguru P, Aylor KW, Chordia MD, Steinberg L, Oberholtzer N, Uchiyama S, Inada N, Lorenz UM, Harris TE, Keller SR, Meher AK, Kadl A, Desai BN, Kundu BK, Leitinger N. Adaptive thermogenesis in brown adipose tissue involves activation of pannexin-1 channels. Mol Metab 2021; 44:101130. [PMID: 33248294 PMCID: PMC7779784 DOI: 10.1016/j.molmet.2020.101130] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 11/06/2020] [Accepted: 11/21/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Brown adipose tissue (BAT) is specialized in thermogenesis. The conversion of energy into heat in brown adipocytes proceeds via stimulation of β-adrenergic receptor (βAR)-dependent signaling and activation of mitochondrial uncoupling protein 1 (UCP1). We have previously demonstrated a functional role for pannexin-1 (Panx1) channels in white adipose tissue; however, it is not known whether Panx1 channels play a role in the regulation of brown adipocyte function. Here, we tested the hypothesis that Panx1 channels are involved in brown adipocyte activation and thermogenesis. METHODS In an immortalized brown pre-adipocytes cell line, Panx1 currents were measured using patch-clamp electrophysiology. Flow cytometry was used for assessment of dye uptake and luminescence assays for adenosine triphosphate (ATP) release, and cellular temperature measurement was performed using a ratiometric fluorescence thermometer. We used RNA interference and expression plasmids to manipulate expression of wild-type and mutant Panx1. We used previously described adipocyte-specific Panx1 knockout mice (Panx1Adip-/-) and generated brown adipocyte-specific Panx1 knockout mice (Panx1BAT-/-) to study pharmacological or cold-induced thermogenesis. Glucose uptake into brown adipose tissue was quantified by positron emission tomography (PET) analysis of 18F-fluorodeoxyglucose (18F-FDG) content. BAT temperature was measured using an implantable telemetric temperature probe. RESULTS In brown adipocytes, Panx1 channel activity was induced either by apoptosis-dependent caspase activation or by β3AR stimulation via a novel mechanism that involves Gβγ subunit binding to Panx1. Inactivation of Panx1 channels in cultured brown adipocytes resulted in inhibition of β3AR-induced lipolysis, UCP-1 expression, and cellular thermogenesis. In mice, adiponectin-Cre-dependent genetic deletion of Panx1 in all adipose tissue depots resulted in defective β3AR agonist- or cold-induced thermogenesis in BAT and suppressed beigeing of white adipose tissue. UCP1-Cre-dependent Panx1 deletion specifically in brown adipocytes reduced the capacity for adaptive thermogenesis without affecting beigeing of white adipose tissue and aggravated diet-induced obesity and insulin resistance. CONCLUSIONS These data demonstrate that Gβγ-dependent Panx1 channel activation is involved in β3AR-induced thermogenic regulation in brown adipocytes. Identification of Panx1 channels in BAT as novel thermo-regulatory elements downstream of β3AR activation may have therapeutic implications.
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Affiliation(s)
| | - Vlad Serbulea
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Clint M Upchurch
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | | | - Suresh K Mendu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Srabani Sahu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Prathiba Jayaguru
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Kevin W Aylor
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Mahendra D Chordia
- Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Limor Steinberg
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Nathaniel Oberholtzer
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Seichii Uchiyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Noriko Inada
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Ulrike M Lorenz
- Department of Microbiology, Immunology and Cancer Biology, Center for Cell Clearance, the Beirne B. Carter Center for Immunology Research, USA
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Susanna R Keller
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Akshaya K Meher
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Alexandra Kadl
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Bimal N Desai
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Bijoy K Kundu
- Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA; Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Norbert Leitinger
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA; Robert M Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, 22908, USA.
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16
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Varela-Vázquez A, Guitián-Caamaño A, Carpintero-Fernandez P, Fonseca E, Sayedyahossein S, Aasen T, Penuela S, Mayán MD. Emerging functions and clinical prospects of connexins and pannexins in melanoma. Biochim Biophys Acta Rev Cancer 2020; 1874:188380. [PMID: 32461135 DOI: 10.1016/j.bbcan.2020.188380] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 05/16/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022]
Abstract
Cellular communication through gap junctions and hemichannels formed by connexins and through channels made by pannexins allows for metabolic cooperation and control of cellular activity and signalling. These channel proteins have been described to be tumour suppressors that regulate features such as cell death, proliferation and differentiation. However, they display cancer type-dependent and stage-dependent functions and may facilitate tumour progression through junctional and non-junctional pathways. The accumulated knowledge and emerging strategies to target connexins and pannexins are providing novel clinical opportunities for the treatment of cancer. Here, we provide an updated overview of the role of connexins and pannexins in malignant melanoma. We discuss how targeting of these channel proteins may be used to potentiate antitumour effects in therapeutic settings, including through improved immune-mediated tumour elimination.
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Affiliation(s)
- Adrián Varela-Vázquez
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Amanda Guitián-Caamaño
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Paula Carpintero-Fernandez
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Eduardo Fonseca
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain; Dermatology Deparment, University Hospital of A Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Samar Sayedyahossein
- Department of Anatomy & Cell Biology, and Oncology, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A5C1, Canada
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, Barcelona, Spain
| | - Silvia Penuela
- Department of Anatomy & Cell Biology, and Oncology, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A5C1, Canada
| | - María D Mayán
- CellCOM Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain.
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17
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Sang Q, Zhang Z, Shi J, Sun X, Li B, Yan Z, Xue S, Ai A, Lyu Q, Li W, Zhang J, Wu L, Mao X, Chen B, Mu J, Li Q, Du J, Sun Q, Jin L, He L, Zhu S, Kuang Y, Wang L. A pannexin 1 channelopathy causes human oocyte death. Sci Transl Med 2020; 11:11/485/eaav8731. [PMID: 30918116 DOI: 10.1126/scitranslmed.aav8731] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 01/14/2019] [Accepted: 03/06/2019] [Indexed: 12/13/2022]
Abstract
Connexins and pannexins are two protein families that play an important role in cellular communication. Pannexin 1 (PANX1), one of the members of pannexin family, is a channel protein. It is glycosylated and forms three species, GLY0, GLY1, and GLY2. Here, we describe four independent families in which mutations in PANX1 cause familial or sporadic female infertility via a phenotype that we term "oocyte death." The mutations, which are associated with oocyte death, alter the PANX1 glycosylation pattern, influence the subcellular localization of PANX1 in cultured cells, and result in aberrant PANX1 channel activity, ATP release in oocytes, and mutant PANX1 GLY1. Overexpression of a patient-derived mutation in mice causes infertility, recapitulating the human oocyte death phenotype. Our findings demonstrate the critical role of PANX1 in human oocyte development, provide a genetic explanation for a subtype of infertility, and suggest a potential target for therapeutic intervention for this disease.
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Affiliation(s)
- Qing Sang
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China.
| | - Zhihua Zhang
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Juanzi Shi
- Reproductive Medicine Center, Shaanxi Maternal and Child Care Service Center, Shaanxi 710069, China
| | - Xiaoxi Sun
- Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China
| | - Bin Li
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Zheng Yan
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Songguo Xue
- Reproductive Medicine Center, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 2000120, China
| | - Ai Ai
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Qifeng Lyu
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Wei Li
- Institute of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jilin Zhang
- Institute of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ling Wu
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Xiaoyan Mao
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Biaobang Chen
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Jian Mu
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Qiaoli Li
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Jing Du
- Shanghai Institute of Planned Parenthood Research, Shanghai 200011, China
| | - Qiang Sun
- Institute of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Li Jin
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Lin He
- Bio-X Center, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Shujia Zhu
- Institute of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yanping Kuang
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China.
| | - Lei Wang
- Zhongshan Hospital, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China. .,Shanghai Center for Women and Children's Health, Shanghai 200062, China
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Tam TH, Chan KL, Boroumand P, Liu Z, Brozinick JT, Bui HH, Roth K, Wakefield CB, Penuela S, Bilan PJ, Klip A. Nucleotides released from palmitate-activated murine macrophages attract neutrophils. J Biol Chem 2020; 295:4902-4911. [PMID: 32132172 DOI: 10.1074/jbc.ra119.010868] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/27/2020] [Indexed: 01/11/2023] Open
Abstract
Obesity and elevation of circulating free fatty acids are associated with an accumulation and proinflammatory polarization of macrophages within metabolically active tissues, such as adipose tissue, muscle, liver, and pancreas. Beyond macrophages, neutrophils also accumulate in adipose and muscle tissues during high-fat diets and contribute to a state of local inflammation and insulin resistance. However, the mechanisms by which neutrophils are recruited to these tissues are largely unknown. Here we used a cell culture system as proof of concept to show that, upon exposure to a saturated fatty acid, palmitate, macrophages release nucleotides that attract neutrophils. Moreover, we found that palmitate up-regulates pannexin-1 channels in macrophages that mediate the attraction of neutrophils, shown previously to allow transfer of nucleotides across membranes. These findings suggest that proinflammatory macrophages release nucleotides through pannexin-1, a process that may facilitate neutrophil recruitment into metabolic tissues during obesity.
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Affiliation(s)
- Theresa H Tam
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Kenny L Chan
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Parastoo Boroumand
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Zhi Liu
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | | | | | - Kenneth Roth
- Eli Lilly and Company, Indianapolis, Indiana 46285
| | - C Brent Wakefield
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada.,Department of Oncology, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Philip J Bilan
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada .,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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19
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Sato T, Vargas D, Miyazaki K, Uchida K, Ariyani W, Miyazaki M, Okada J, Lizcano F, Koibuchi N, Shimokawa N. EID1 suppresses lipid accumulation by inhibiting the expression of GPDH in 3T3-L1 preadipocytes. J Cell Physiol 2020; 235:6725-6735. [PMID: 32056205 DOI: 10.1002/jcp.29567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 01/13/2020] [Indexed: 01/23/2023]
Abstract
The imbalance between food intake and energy expenditure causes high accumulation of triglycerides in adipocytes. Obesity is related with the increased lipid accumulation in white adipose tissue, which is a major risk factor for the development of metabolic disorders, such as type 2 diabetes and cardiovascular disease. This study highlights the role of E1A-like inhibitor of differentiation 1 (EID1) in the modulation of adipogenesis through the downregulation of glycerol-3-phosphate dehydrogenase (GPDH), which is a key enzyme in the synthesis of triglycerides and is considered to be a marker of adipogenesis. By analyzing DNA microarray data, we found that when EID1 is overexpressed in preadipocytes (3T3-L1 cells) during adipocyte differentiation, EID1 inhibits lipid accumulation through the downregulation of GPDH. In contrast, EID1 is not involved in the regulation of intracellular glucose via the translocation of glucose transporter. A confocal image analysis showed that EID1 is located in the nucleus of preadipocytes in the form of speckles, which could be involved as a regulator of the transcriptional process. We further confirmed that EID1 is able to bind to the promoter sequence of GPDH in the nucleus. These findings provide a molecular explanation for the inhibitory effect of EID1 on lipid accumulation in adipocytes.
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Affiliation(s)
- Tomohiko Sato
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.,Department of Nutrition, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan.,Department of Physical Therapy, Ota College of Medical Technology, Ota, Gunma, Japan
| | - Diana Vargas
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.,Department of Nutrition, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan.,Center of Biomedical Research, Universidad de La Sabana, Chia, Colombia
| | - Kakushin Miyazaki
- Department of Nutrition, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan
| | - Kaoru Uchida
- Department of Nutrition, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan
| | - Winda Ariyani
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Mitsue Miyazaki
- Department of Nutrition, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan
| | - Junichi Okada
- Department of Physical Therapy, Ota College of Medical Technology, Ota, Gunma, Japan
| | - Fernando Lizcano
- Center of Biomedical Research, Universidad de La Sabana, Chia, Colombia
| | - Noriyuki Koibuchi
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Noriaki Shimokawa
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.,Department of Nutrition, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan
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20
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A Genetic Polymorphism in the Pannexin1 Gene Predisposes for The Development of Endothelial Dysfunction with Increasing BMI. Biomolecules 2020; 10:biom10020208. [PMID: 32023876 PMCID: PMC7072696 DOI: 10.3390/biom10020208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/16/2020] [Accepted: 01/26/2020] [Indexed: 01/07/2023] Open
Abstract
Endothelial dysfunction worsens when body mass index (BMI) increases. Pannexin1 (Panx1) ATP release channels regulate endothelial function and lipid homeostasis in mice. We investigated whether the Panx1-400A>C single nucleotide polymorphism (SNP), encoding for a gain-of-function channel, associates with endothelial dysfunction in non-obese and obese individuals. Myocardial blood flow (MBF) was measured by 13N-ammonia positron emission/computed tomography at rest, during cold pressor test (CPT) or dipyridamole-induced hyperemia. Myocardial flow reserve (MFR) and endothelial function were compared in 43 non-obese (BMI < 30 kg/m2) vs. 29 obese (BMI 30 kg/m2) participants and genotyping for the Panx1-400A>C SNP was performed. Groups comprised subjects homozygous for the C allele (n = 40) vs. subjects with at least one A allele (n = 32). MBF (during CPT or hyperemia), MFR and endothelial function correlated negatively with BMI in the full cohort. BMI correlated negatively with MFR and endothelial function in non-obese Panx1-400C subjects, but not in Panx1-400A individuals nor in obese groups. BMI correlated positively with serum triglycerides, insulin or HOMA. MFR correlated negatively with these factors in non-obese Panx1-400C but not in Panx1-400A individuals. Here, we demonstrated that Panx1-400C SNP predisposes to BMI-dependent endothelial dysfunction in non-obese subjects. This effect may be masked by excessive dysregulation of metabolic factors in obese individuals.
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21
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Destination and consequences of Panx1 and mutant expression in polarized MDCK cells. Exp Cell Res 2019; 381:235-247. [PMID: 31102595 DOI: 10.1016/j.yexcr.2019.05.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/09/2019] [Accepted: 05/11/2019] [Indexed: 12/12/2022]
Abstract
The channel-forming membrane glycoprotein pannexin 1 (Panx1) is best characterized as an ATP release channel. To investigate the trafficking and sorting of Panx1, we used polarized MDCK cells and non-polarized BICR-M1Rk cells to track the fate of GFP-tagged Panx1. In non-polarized cells, Panx1 was found throughout the plasma membrane, including the lamellipodia of the tumor cells and the cell surface-targeting domain was mapped to residues 307-379. Panx1 was preferentially enriched at the apical membrane domain of polarized MDCK cells grown as monolayer sheets or as spheroids. Residual Panx1 localized within basolateral membranes of polarized MDCK cells was independent of a putative dileucine sorting motif LL365/6 found within the C-terminal of Panx1. Unexpectedly, stable expression of a Panx1 mutant, where a putative tyrosine-based basolateral sorting motif (YxxØ) was mutated (Y308F), or a truncated Δ379 Panx1 mutant, caused MDCK cells to lose cell-cell contacts and their ability to polarize as they underwent a switch to a more fibroblast-like phenotype. We conclude that Panx1 is preferentially delivered to the apical domain of polarized epithelial cells, and Panx1 mutants drive phenotypic changes to MDCK cells preventing their polarization.
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22
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Double deletion of Panx1 and Panx3 affects skin and bone but not hearing. J Mol Med (Berl) 2019; 97:723-736. [PMID: 30918989 DOI: 10.1007/s00109-019-01779-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 12/15/2022]
Abstract
Pannexins (Panxs), large-pore channel forming glycoproteins, are expressed in a wide variety of tissues including the skin, bone, and cochlea. To date, the use of single knock-out mouse models of both Panx1 and Panx3 have demonstrated their roles in skin development, bone formation, and auditory phenotypes. Due to sequence homology between Panx1 and Panx3, when one Panx is ablated from germline, the other may be upregulated in a compensatory mechanism to maintain tissue homeostasis and function. To evaluate the roles of Panx1 and Panx3 in the skin, bone, and cochlea, we created the first Panx1/Panx3 double knock-out mouse model (dKO). These mice had smaller litters and reduced body weight compared to wildtype controls. The dKO dorsal skin had decreased epidermal and dermal area as well as decreased hypodermal area in neonatal but not in older mice. In addition, mouse skull shape and size were altered, and long bone length was decreased in neonatal dKO mice. Finally, auditory tests revealed that dKO mice did not exhibit hearing loss and were even slightly protected against noise-induced hearing damage at mid-frequency regions. Taken together, our findings suggest that Panx1 and Panx3 are important at early stages of development in the skin and bone but may be redundant in the auditory system. KEY MESSAGES: Panx double KO mice had smaller litters and reduced body weight. dKO skin had decreased epidermal and dermal area in neonatal mice. Skull shape and size changed plus long bone length decreased in neonatal dKO mice. dKO had no hearing loss and were slightly protected against noise-induced damage.
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