1
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Takayama Y, Tominaga M. Interaction between TRP channels and anoctamins. Cell Calcium 2024; 121:102912. [PMID: 38823351 DOI: 10.1016/j.ceca.2024.102912] [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: 02/28/2024] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 06/03/2024]
Abstract
Anoctamin 1 (ANO1) binds to transient receptor potential (TRP) channels (protein-protein interaction) and then is activated by TRP channels (functional interaction). TRP channels are non-selective cation channels that are expressed throughout the body and play roles in multiple physiological functions. Studies on TRP channels increased after the identification of TRP vanilloid 1 (TRPV1) in 1997. Calcium-activated chloride channel anoctamin 1 (ANO1, also called TMEM16A and DOG1) was identified in 2008. ANO1 plays a major role in TRP channel-mediated functions, as first shown in 2014 with the demonstration of a protein-protein interaction between TRPV4 and ANO1. In cells that co-express TRP channels and ANO1, calcium entering cells through activated TRP channels causes ANO1 activation. Therefore, in many tissues, the physiological functions related to TRP channels are modulated through chloride flux associated with ANO1 activation. In this review, we summarize the latest understanding of TRP-ANO1 interactions, particularly interaction of ANO1 with TRPV4, TRP canonical 6 (TRPC6), TRPV3, TRPV1, and TRPC2 in the salivary glands, blood vessels, skin keratinocytes, primary sensory neurons, and vomeronasal organs, respectively.
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Affiliation(s)
- Yasunori Takayama
- Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo, Japan.
| | - Makoto Tominaga
- Division of Cell Signaling, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Aza-Higashiyama, Myodaiji, Okazaki, Aichi, Japan; Thermal Biology Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, 5-1 Aza-Higashiyama, Myodaiji, Okazaki, Aichi, Japan; Thermal Biology Research Group, Nagoya Advanced Research and Development Center, Nagoya City University, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, Japan.
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2
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Kunzelmann K, Ousingsawat J, Schreiber R. VSI: The anoctamins: Structure and function: "Intracellular" anoctamins. Cell Calcium 2024; 120:102888. [PMID: 38657371 DOI: 10.1016/j.ceca.2024.102888] [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: 02/20/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/26/2024]
Abstract
Plasma membrane localized anoctamin 1, 2 and 6 (TMEM16A, B, F) have been examined in great detail with respect to structure and function, but much less is known about the other seven intracellular members of this exciting family of proteins. This is probably due to their limited accessibility in intracellular membranous compartments, such as the endoplasmic reticulum (ER) or endosomes. However, these so-called intracellular anoctamins are also found in the plasma membrane (PM) which adds to the confusion regarding their cellular role. Probably all intracellular anoctamins except of ANO8 operate as intracellular phospholipid (PL) scramblases, allowing for Ca2+-activated, passive transport of phospholipids like phosphatidylserine between both membrane leaflets. Probably all of them also conduct ions, which is probably part of their physiological function. In this brief overview, we summarize key findings on the biological functions of ANO3, 4, 5, 7, 8, 9 and 10 (TMEM16C, D, E, G, H, J, K) that are gradually coming to light. Compartmentalized regulation of intracellular Ca2+ signals, tethering of the ER to specific PM contact sites, and control of intracellular vesicular trafficking appear to be some of the functions of intracellular anoctamins, while loss of function and abnormal expression are the cause for various diseases.
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Affiliation(s)
- Karl Kunzelmann
- Physiological Institute, University of Regensburg, University street 31, D-93053, Regensburg, Germany.
| | - Jiraporn Ousingsawat
- Physiological Institute, University of Regensburg, University street 31, D-93053, Regensburg, Germany
| | - Rainer Schreiber
- Physiological Institute, University of Regensburg, University street 31, D-93053, Regensburg, Germany
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3
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Okada Y. Physiology of the volume-sensitive/regulatory anion channel VSOR/VRAC. Part 1: from its discovery and phenotype characterization to the molecular entity identification. J Physiol Sci 2024; 74:3. [PMID: 38238667 PMCID: PMC10795261 DOI: 10.1186/s12576-023-00897-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/27/2023] [Indexed: 01/22/2024]
Abstract
The volume-sensitive outwardly rectifying or volume-regulated anion channel, VSOR/VRAC, which was discovered in 1988, is expressed in most vertebrate cell types and is essentially involved in cell volume regulation after swelling and in the induction of cell death. This series of review articles describes what is already known and what remains to be uncovered about the functional and molecular properties as well as the physiological and pathophysiological roles of VSOR/VRAC. This Part 1 review article describes, from the physiological standpoint, first its discovery and significance in cell volume regulation, second its phenotypical properties, and third its molecular identification. Although the pore-forming core molecules and the volume-sensing subcomponent of VSOR/VRAC were identified as LRRC8 members and TRPM7 in 2014 and 2021, respectively, it is stressed that the identification of the molecular entity of VSOR/VRAC is still not complete enough to explain the full set of phenotypical properties.
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Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan.
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan.
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan.
- Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.
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4
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Kolesnikov DO, Grigorieva ER, Nomerovskaya MA, Reshetin DS, Shalygin AV, Kaznacheyeva E. The Effect of Calcium Ions on the Electrophysiological Properties of Single ANO6 Channels. Acta Naturae 2024; 16:40-47. [PMID: 38698960 PMCID: PMC11062105 DOI: 10.32607/actanaturae.27338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 12/23/2024] [Indexed: 05/05/2024] Open
Abstract
Proteins belonging to the anoctamin (ANO) family form calcium-activated chloride channels (CaCCs). The most unusual member of this family, ANO6 (TMEM16F), simultaneously exhibits the functions of calcium-dependent scramblase and the ion channel. ANO6 affects the plasma membrane dynamics and phosphatidylserine transport; it is also involved in programmed cell death. The properties of ANO6 channels remain the subject of debate. In this study, we investigated the effect of variations in the intracellular and extracellular concentrations of calcium ions on the electrophysiological properties of endogenous ANO6 channels by recording single ANO6 channels. It has been demonstrated that (1) a high calcium concentration in an extracellular solution increases the activity of endogenous ANO6 channels, (2) the permeability of endogenous ANO6 channels for chloride ions is independent of the extracellular concentration of calcium ions, (3) that an increase in the intracellular calcium concentration leads to the activation of endogenous ANO6 channels with double amplitude, and (4) that the kinetics of the channel depend on the plasma membrane potential rather than the intracellular concentration of calcium ions. Our findings give grounds for proposing new mechanisms for the regulation of the ANO6 channel activity by calcium ions both at the inner and outer sides of the membrane.
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Affiliation(s)
- D. O. Kolesnikov
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064 Russian Federation
| | - E. R. Grigorieva
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064 Russian Federation
| | - M. A. Nomerovskaya
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064 Russian Federation
| | - D. S. Reshetin
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064 Russian Federation
| | - A. V. Shalygin
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064 Russian Federation
| | - E.V. Kaznacheyeva
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064 Russian Federation
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5
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Kunzelmann K, Ousingsawat J, Kraus A, Park JH, Marquardt T, Schreiber R, Buchholz B. Pathogenic Relationships in Cystic Fibrosis and Renal Diseases: CFTR, SLC26A9 and Anoctamins. Int J Mol Sci 2023; 24:13278. [PMID: 37686084 PMCID: PMC10487509 DOI: 10.3390/ijms241713278] [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: 06/28/2023] [Revised: 07/31/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
The Cl--transporting proteins CFTR, SLC26A9, and anoctamin (ANO1; ANO6) appear to have more in common than initially suspected, as they all participate in the pathogenic process and clinical outcomes of airway and renal diseases. In the present review, we will therefore concentrate on recent findings concerning electrolyte transport in the airways and kidneys, and the role of CFTR, SLC26A9, and the anoctamins ANO1 and ANO6. Special emphasis will be placed on cystic fibrosis and asthma, as well as renal alkalosis and polycystic kidney disease. In essence, we will summarize recent evidence indicating that CFTR is the only relevant secretory Cl- channel in airways under basal (nonstimulated) conditions and after stimulation by secretagogues. Information is provided on the expressions of ANO1 and ANO6, which are important for the correct expression and function of CFTR. In addition, there is evidence that the Cl- transporter SLC26A9 expressed in the airways may have a reabsorptive rather than a Cl--secretory function. In the renal collecting ducts, bicarbonate secretion occurs through a synergistic action of CFTR and the Cl-/HCO3- transporter SLC26A4 (pendrin), which is probably supported by ANO1. Finally, in autosomal dominant polycystic kidney disease (ADPKD), the secretory function of CFTR in renal cyst formation may have been overestimated, whereas ANO1 and ANO6 have now been shown to be crucial in ADPKD and therefore represent new pharmacological targets for the treatment of polycystic kidney disease.
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Affiliation(s)
- Karl Kunzelmann
- Physiological Institute, University of Regensburg, University Street 31, 93053 Regensburg, Germany; (J.O.); (R.S.)
| | - Jiraporn Ousingsawat
- Physiological Institute, University of Regensburg, University Street 31, 93053 Regensburg, Germany; (J.O.); (R.S.)
| | - Andre Kraus
- Department of Nephrology and Hypertension, Friedrich Alexander University Erlangen Nuremberg, 91054 Erlangen, Germany; (A.K.); (B.B.)
| | - Julien H. Park
- Department of Pediatrics, University Hospital Münster, 48149 Münster, Germany; (J.H.P.); (T.M.)
| | - Thorsten Marquardt
- Department of Pediatrics, University Hospital Münster, 48149 Münster, Germany; (J.H.P.); (T.M.)
| | - Rainer Schreiber
- Physiological Institute, University of Regensburg, University Street 31, 93053 Regensburg, Germany; (J.O.); (R.S.)
| | - Björn Buchholz
- Department of Nephrology and Hypertension, Friedrich Alexander University Erlangen Nuremberg, 91054 Erlangen, Germany; (A.K.); (B.B.)
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6
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Li X, Zhong Z, Zhang R, Zhang J, Zhang Y, Zeng S, Du Q, Wang H, Zhang S, Lu L, Li M, Long K. Decoding the transcriptome of muscular dystrophy due to Ptrf deficiency using single-nucleus RNA sequencing. FASEB J 2023; 37:e22993. [PMID: 37235502 DOI: 10.1096/fj.202201949rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 04/20/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023]
Abstract
Lacking PTRF (polymerase I and transcript release factor), an essential caveolae component, causes a secondary deficiency of caveolins resulting in muscular dystrophy. The transcriptome responses of different types of muscle fibers and mononuclear cells in skeletal muscle to muscular dystrophy caused by Ptrf deletion have not been explored. Here, we created muscular dystrophy mice by Ptrf knockout and applied single-nucleus RNA sequencing (snRNA-seq) to unveil the transcriptional changes of the skeletal muscle at single-nucleus resolution. 11 613 muscle nuclei (WT, 5838; Ptrf KO, 5775) were classified into 12 clusters corresponding to 11 nuclear types. Trajectory analysis revealed the potential transition between type IIb_1 and IIb_2 myonuclei upon muscular dystrophy. Functional enrichment analysis indicated that apoptotic signaling and enzyme-linked receptor protein signaling pathway were significantly enriched in type IIb_1 and IIb_2 myonuclei of Ptrf KO, respectively. The muscle structure development and the PI3K-AKT signaling pathway were significantly enriched in type IIa and IIx myonuclei of Ptrf KO. Meanwhile, metabolic pathway analysis showed a decrease in overall metabolic pathway activity of myonuclei subtypes upon muscular dystrophy, with the most decrease in type IIb_1 myonuclei. Gene regulatory network analysis found that the activity of Mef2c, Mef2d, Myf5, and Pax3 regulons was enhanced in type II myonuclei of Ptrf KO, especially in type IIb_2 myonuclei. In addition, we investigated the transcriptome changes in adipocytes and found that muscular dystrophy enhanced the lipid metabolic capacity of adipocytes. Our findings provide a valuable resource for exploring the molecular mechanism of muscular dystrophy due to Ptrf deficiency.
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Affiliation(s)
- Xiaokai Li
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Zhining Zhong
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Ruowei Zhang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jiaman Zhang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yu Zhang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Sha Zeng
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Qinjiao Du
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Haoming Wang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Songling Zhang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Lu Lu
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Mingzhou Li
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Keren Long
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
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7
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Schmaier AA, Anderson PF, Chen SM, El-Darzi E, Aivasovsky I, Kaushik MP, Sack KD, Hartzell HC, Parikh SM, Flaumenhaft R, Schulman S. TMEM16E regulates endothelial cell procoagulant activity and thrombosis. J Clin Invest 2023; 133:e163808. [PMID: 36951953 PMCID: PMC10231993 DOI: 10.1172/jci163808] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/22/2023] [Indexed: 03/24/2023] Open
Abstract
Endothelial cells (ECs) normally form an anticoagulant surface under physiological conditions, but switch to support coagulation following pathogenic stimuli. This switch promotes thrombotic cardiovascular disease. To generate thrombin at physiologic rates, coagulation proteins assemble on a membrane containing anionic phospholipid, most notably phosphatidylserine (PS). PS can be rapidly externalized to the outer cell membrane leaflet by phospholipid "scramblases," such as TMEM16F. TMEM16F-dependent PS externalization is well characterized in platelets. In contrast, how ECs externalize phospholipids to support coagulation is not understood. We employed a focused genetic screen to evaluate the contribution of transmembrane phospholipid transport on EC procoagulant activity. We identified 2 TMEM16 family members, TMEM16F and its closest paralog, TMEM16E, which were both required to support coagulation on ECs via PS externalization. Applying an intravital laser-injury model of thrombosis, we observed, unexpectedly, that PS externalization was concentrated at the vessel wall, not on platelets. TMEM16E-null mice demonstrated reduced vessel-wall-dependent fibrin formation. The TMEM16 inhibitor benzbromarone prevented PS externalization and EC procoagulant activity and protected mice from thrombosis without increasing bleeding following tail transection. These findings indicate the activated endothelial surface is a source of procoagulant phospholipid contributing to thrombus formation. TMEM16 phospholipid scramblases may be a therapeutic target for thrombotic cardiovascular disease.
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Affiliation(s)
- Alec A. Schmaier
- Division of Cardiovascular Medicine and
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | | | | | - Emale El-Darzi
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | | | | | - Kelsey D. Sack
- Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - H. Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Samir M. Parikh
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
- Division of Nephrology and Departments of Internal Medicine and Pharmacology, University of Texas Southwestern Medical School, Dallas, Texas, USA
| | - Robert Flaumenhaft
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
- Division of Hematology and Hematologic Malignancies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Sol Schulman
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
- Division of Hematology and Hematologic Malignancies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
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8
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Sakuragi T, Nagata S. Regulation of phospholipid distribution in the lipid bilayer by flippases and scramblases. Nat Rev Mol Cell Biol 2023:10.1038/s41580-023-00604-z. [PMID: 37106071 PMCID: PMC10134735 DOI: 10.1038/s41580-023-00604-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2023] [Indexed: 04/29/2023]
Abstract
Cellular membranes function as permeability barriers that separate cells from the external environment or partition cells into distinct compartments. These membranes are lipid bilayers composed of glycerophospholipids, sphingolipids and cholesterol, in which proteins are embedded. Glycerophospholipids and sphingolipids freely move laterally, whereas transverse movement between lipid bilayers is limited. Phospholipids are asymmetrically distributed between membrane leaflets but change their location in biological processes, serving as signalling molecules or enzyme activators. Designated proteins - flippases and scramblases - mediate this lipid movement between the bilayers. Flippases mediate the confined localization of specific phospholipids (phosphatidylserine (PtdSer) and phosphatidylethanolamine) to the cytoplasmic leaflet. Scramblases randomly scramble phospholipids between leaflets and facilitate the exposure of PtdSer on the cell surface, which serves as an important signalling molecule and as an 'eat me' signal for phagocytes. Defects in flippases and scramblases cause various human diseases. We herein review the recent research on the structure of flippases and scramblases and their physiological roles. Although still poorly understood, we address the mechanisms by which they translocate phospholipids between lipid bilayers and how defects cause human diseases.
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Affiliation(s)
- Takaharu Sakuragi
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Shigekazu Nagata
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
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9
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Dewdney B, Ursich L, Fletcher EV, Johns TG. Anoctamins and Calcium Signalling: An Obstacle to EGFR Targeted Therapy in Glioblastoma? Cancers (Basel) 2022; 14:cancers14235932. [PMID: 36497413 PMCID: PMC9740065 DOI: 10.3390/cancers14235932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Glioblastoma is the most common form of high-grade glioma in adults and has a poor survival rate with very limited treatment options. There have been no significant advancements in glioblastoma treatment in over 30 years. Epidermal growth factor receptor is upregulated in most glioblastoma tumours and, therefore, has been a drug target in recent targeted therapy clinical trials. However, while many inhibitors and antibodies for epidermal growth factor receptor have demonstrated promising anti-tumour effects in preclinical models, they have failed to improve outcomes for glioblastoma patients in clinical trials. This is likely due to the highly plastic nature of glioblastoma tumours, which results in therapeutic resistance. Ion channels are instrumental in the development of many cancers and may regulate cellular plasticity in glioblastoma. This review will explore the potential involvement of a class of calcium-activated chloride channels called anoctamins in brain cancer. We will also discuss the integrated role of calcium channels and anoctamins in regulating calcium-mediated signalling pathways, such as epidermal growth factor signalling, to promote brain cancer cell growth and migration.
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Affiliation(s)
- Brittany Dewdney
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Centre for Child Health Research, University of Western Australia, Perth, WA 6009, Australia
- Correspondence: ; Tel.: +61-8-6319-1023
| | - Lauren Ursich
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- School of Biomedical Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Emily V. Fletcher
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Centre for Child Health Research, University of Western Australia, Perth, WA 6009, Australia
| | - Terrance G. Johns
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Centre for Child Health Research, University of Western Australia, Perth, WA 6009, Australia
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10
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Boekell KL, Brown BJ, Talbot BE, Schlondorff JS. Trpc6 gain-of-function disease mutation enhances phosphatidylserine exposure in murine platelets. PLoS One 2022; 17:e0270431. [PMID: 35749414 PMCID: PMC9231752 DOI: 10.1371/journal.pone.0270431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/09/2022] [Indexed: 01/28/2023] Open
Abstract
Platelets enhance coagulation by exposing phosphatidylserine (PS) on their cell surface in response to strong agonist activation. Transient receptor potential channels, including TRPC6, have been implicated in the calcium influx central to this process. Here, we characterize the effect of a Trpc6 gain-of-function (GOF) disease-associated, and a dominant negative (DN), mutation on murine platelet activation. Platelets from mice harboring Trpc6E896K/E896K (GOF) and Trpc6DN/DN mutations were subject to in vitro analysis. Trpc6E896K/E896K and Trpc6DN/DN mutant platelets show enhanced and absent calcium influx, respectively, upon addition of the TRPC3/6 agonist GSK1702934A (GSK). GSK was sufficient to induce integrin αIIbβ3 activation, P-selection and PS exposure, talin cleavage, and MLC2 phosphorylation in Trpc6E896K/E896K, but not in wild-type, platelets. Thrombin-induced calcium influx and PS exposure were enhanced, and clot retraction delayed, by GOF TRPC6, while no differences were noted between wild-type and Trpc6DN/DN platelets. In contrast, Erk activation upon GSK treatment was absent in Trpc6DN/DN, and enhanced in Trpc6E896K/E896K, platelets, compared to wild-type. The positive allosteric modulator, TRPC6-PAM-C20, and fluoxetine maintained their ability to enhance and inhibit, respectively, GSK-mediated calcium influx in Trpc6E896K/E896K platelets. The data demonstrate that gain-of-function mutant TRPC6 channel can enhance platelet activation, including PS exposure, while confirming that TRPC6 is not necessary for this process. Furthermore, the results suggest that Trpc6 GOF disease mutants do not simply increase wild-type TRPC6 responses, but can affect pathways not usually modulated by TRPC6 channel activity, displaying a true gain-of-function phenotype.
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Affiliation(s)
- Kimber L. Boekell
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brittney J. Brown
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brianna E. Talbot
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Johannes S. Schlondorff
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
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11
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Roufayel R, Younes K, Al-Sabi A, Murshid N. BH3-Only Proteins Noxa and Puma Are Key Regulators of Induced Apoptosis. Life (Basel) 2022; 12:life12020256. [PMID: 35207544 PMCID: PMC8875537 DOI: 10.3390/life12020256] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/04/2022] [Accepted: 02/06/2022] [Indexed: 12/29/2022] Open
Abstract
Apoptosis is an evolutionarily conserved and tightly regulated cell death pathway. Physiological cell death is important for maintaining homeostasis and optimal biological conditions by continuous elimination of undesired or superfluous cells. The BH3-only pro-apoptotic members are strong inducers of apoptosis. The pro-apoptotic BH3-only protein Noxa activates multiple death pathways by inhibiting the anti-apoptotic Bcl-2 family protein, Mcl-1, and other protein members leading to Bax and Bak activation and MOMP. On the other hand, Puma is induced by p53-dependent and p53-independent apoptotic stimuli in several cancer cell lines. Moreover, this protein is involved in several physiological and pathological processes, such as immunity, cancer, and neurodegenerative diseases. Future heat shock research could disclose the effect of hyperthermia on both Noxa and BH3-only proteins. This suggests post-transcriptional mechanisms controlling the translation of both Puma and Noxa mRNA in heat-shocked cells. This study was also the chance to recapitulate the different reactional mechanisms investigated for caspases.
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12
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Polymodal Control of TMEM16x Channels and Scramblases. Int J Mol Sci 2022; 23:ijms23031580. [PMID: 35163502 PMCID: PMC8835819 DOI: 10.3390/ijms23031580] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 02/01/2023] Open
Abstract
The TMEM16A/anoctamin-1 calcium-activated chloride channel (CaCC) contributes to a range of vital functions, such as the control of vascular tone and epithelial ion transport. The channel is a founding member of a family of 10 proteins (TMEM16x) with varied functions; some members (i.e., TMEM16A and TMEM16B) serve as CaCCs, while others are lipid scramblases, combine channel and scramblase function, or perform additional cellular roles. TMEM16x proteins are typically activated by agonist-induced Ca2+ release evoked by Gq-protein-coupled receptor (GqPCR) activation; thus, TMEM16x proteins link Ca2+-signalling with cell electrical activity and/or lipid transport. Recent studies demonstrate that a range of other cellular factors—including plasmalemmal lipids, pH, hypoxia, ATP and auxiliary proteins—also control the activity of the TMEM16A channel and its paralogues, suggesting that the TMEM16x proteins are effectively polymodal sensors of cellular homeostasis. Here, we review the molecular pathophysiology, structural biology, and mechanisms of regulation of TMEM16x proteins by multiple cellular factors.
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Hawn MB, Akin E, Hartzell H, Greenwood IA, Leblanc N. Molecular mechanisms of activation and regulation of ANO1-Encoded Ca 2+-Activated Cl - channels. Channels (Austin) 2021; 15:569-603. [PMID: 34488544 PMCID: PMC8480199 DOI: 10.1080/19336950.2021.1975411] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 08/29/2021] [Indexed: 01/13/2023] Open
Abstract
Ca2+-activated Cl- channels (CaCCs) perform a multitude of functions including the control of cell excitability, regulation of cell volume and ionic homeostasis, exocrine and endocrine secretion, fertilization, amplification of olfactory sensory function, and control of smooth muscle cell contractility. CaCCs are the translated products of two members (ANO1 and ANO2, also known as TMEM16A and TMEM16B) of the Anoctamin family of genes comprising ten paralogs. This review focuses on recent progress in understanding the molecular mechanisms involved in the regulation of ANO1 by cytoplasmic Ca2+, post-translational modifications, and how the channel protein interacts with membrane lipids and protein partners. After first reviewing the basic properties of native CaCCs, we then present a brief historical perspective highlighting controversies about their molecular identity in native cells. This is followed by a summary of the fundamental biophysical and structural properties of ANO1. We specifically address whether the channel is directly activated by internal Ca2+ or indirectly through the intervention of the Ca2+-binding protein Calmodulin (CaM), and the structural domains responsible for Ca2+- and voltage-dependent gating. We then review the regulation of ANO1 by internal ATP, Calmodulin-dependent protein kinase II-(CaMKII)-mediated phosphorylation and phosphatase activity, membrane lipids such as the phospholipid phosphatidyl-(4,5)-bisphosphate (PIP2), free fatty acids and cholesterol, and the cytoskeleton. The article ends with a survey of physical and functional interactions of ANO1 with other membrane proteins such as CLCA1/2, inositol trisphosphate and ryanodine receptors in the endoplasmic reticulum, several members of the TRP channel family, and the ancillary Κ+ channel β subunits KCNE1/5.
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Affiliation(s)
- M. B. Hawn
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - E. Akin
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - H.C. Hartzell
- Department of Cell Biology, Emory University School of Medicine, USA
| | - I. A. Greenwood
- Department of Vascular Pharmacology, St. George’s University of London, UK
| | - N. Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
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Calmodulin-Dependent Regulation of Overexpressed but Not Endogenous TMEM16A Expressed in Airway Epithelial Cells. MEMBRANES 2021; 11:membranes11090723. [PMID: 34564540 PMCID: PMC8471323 DOI: 10.3390/membranes11090723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 11/30/2022]
Abstract
Regulation of the Ca2+-activated Cl− channel TMEM16A by Ca2+/calmodulin (CAM) is discussed controversially. In the present study, we compared regulation of TMEM16A by Ca2+/calmodulin (holo-CAM), CAM-dependent kinase (CAMKII), and CAM-dependent phosphatase calcineurin in TMEM16A-overexpressing HEK293 cells and TMEM16A expressed endogenously in airway and colonic epithelial cells. The activator of the Ca2+/CAM-regulated K+ channel KCNN4, 1-EBIO, activated TMEM16A in overexpressing cells, but not in cells with endogenous expression of TMEM16A. Evidence is provided that CAM-interaction with TMEM16A modulates the Ca2+ sensitivity of the Cl− channel. Enhanced Ca2+ sensitivity of overexpressed TMEM16A explains its activity at basal (non-elevated) intracellular Ca2+ levels. The present results correspond well to a recent report that demonstrates a Ca2+-unbound form of CAM (apo-CAM) that is pre-associated with TMEM16A and mediates a Ca2+-dependent sensitization of activation (and inactivation). However, when using activators or inhibitors for holo-CAM, CAMKII, or calcineurin, we were unable to detect a significant impact of CAM, and limit evidence for regulation by CAM-dependent regulatory proteins on receptor-mediated activation of endogenous TMEM16A in airway or colonic epithelial cells. We propose that regulatory properties of TMEM16A and and other members of the TMEM16 family as detected in overexpression studies, should be validated for endogenous TMEM16A and physiological stimuli such as activation of phospholipase C (PLC)-coupled receptors.
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Yu H, Wang Z, Li Z, An Y, Yan M, Ji S, Xu M, Wang L, Dong W, Shi J, Gao C. Hyperuricemia enhances procoagulant activity of vascular endothelial cells through TMEM16F regulated phosphatidylserine exposure and microparticle release. FASEB J 2021; 35:e21808. [PMID: 34390515 DOI: 10.1096/fj.202100426r] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/12/2021] [Accepted: 07/06/2021] [Indexed: 12/15/2022]
Abstract
The link between serum uric acid (SUA) and the risk of venous thromboembolism (VTE) is well established. Recent data suggested a causative role of UA in endothelial cells (ECs) dysfunction. However, the molecular mechanism of high UA on thrombogenesis is unknown. We investigate whether high UA induce phosphatidylserine (PS) externalization and microparticle (MP) shedding in cultured EC, and contribute to UA-induced hypercoagulable state. In the present study, we demonstrate that UA induces PS exposure and EMP release of EC in a concentration- and time-dependent manner, which enhances the procoagulant activity (PCA) of EC and inhibited over 90% by lactadherin in vitro. Furthermore, hyperuricemic rat model was used to evaluate the development of thrombi following by flow stasis in the inferior vena cava (IVC). Hyperuricemia group is more likely to form large and hard thrombi compared with control. Importantly, we found that TMEM16F expression is significantly upregulated in UA-treated EC, which is crucial for UA-induced PS exposure and MP formation. Additionally, UA increases the generation of reactive oxygen species (ROS), lipid peroxidation, and cytosolic Ca2+ concentration in EC, which might contribute to increased TMEM16F expression. Using confocal microscopy, we also observed disruption of the actin cytoskeleton, suggesting that depolymerization of actin filaments might be required for TMEM16F activation and followed by PS exposure and membrane blebbing in UA-treated EC. Our results demonstrate a thrombotic role of EC in hyperuricemia through TMEM16F-mediated PS exposure and MPs release.
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Affiliation(s)
- Hongyin Yu
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Zelong Wang
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Zhanni Li
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Yao An
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Meishan Yan
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Shuting Ji
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Minghui Xu
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
| | - Liqiu Wang
- Department of Clinical Laboratory, The Fifth Hospital, Harbin Medical University, Daqing, China
| | - Weijun Dong
- Department of General Surgery, The Fifth Hospital, Harbin Medical University, Daqing, China
| | - Jialan Shi
- Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Chunyan Gao
- Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China
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Zhang X, Zhang G, Zhao Z, Xiu R, Jia J, Chen P, Liu Y, Wang Y, Yi J. Cepharanthine, a novel selective ANO1 inhibitor with potential for lung adenocarcinoma therapy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119132. [PMID: 34450215 DOI: 10.1016/j.bbamcr.2021.119132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 10/20/2022]
Abstract
Anoctamin-1 (ANO1), also known as transmembrane protein 16A (TMEM16A), is identified as a Ca2+-activated Cl- channel that is expressed in many organs and tissues. It is involved in numerous major physiological functions and especially in tumor growth. By screening 530 natural compounds, we identified cepharanthine as a potent blocker of ANO1 channels with an IC50 of 11.2 ± 0.9 μM and Emax of 92.7 ± 1.7%. The Lys384, Arg535, Thr539, and Glu624 in ANO1 are critical for the inhibitory effect of cepharanthine. Similar to its effect on ANO1, cepharanthine inhibits ANO2, the closest analog of TMEM16A. In contrast, up to 30 μM of cepharanthine showed limited inhibitory effects on recombinant ANO6 and bestrophin-1-encoded Ca2+-activated Cl- currents, but it showed no effects on endogenous volume-regulated anion currents (VRAC). Cepharanthine could also potently suppress endogenous ANO1 currents, significantly inhibit cell proliferation and migration, and induce apoptosis in LA795 lung adenocarcinoma cells. Moreover, animal experiments have shown that cepharanthine can dramatically inhibit the growth of xenograft tumors in mice. The high specificity provided by cepharanthine could be an important foundation for future studies of the physiological role of ANO1 channels, and these findings may reveal a new mechanism of its anticancer effect.
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Affiliation(s)
- Xuan Zhang
- Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun, China.; Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Gaohua Zhang
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Zhijun Zhao
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Ruilian Xiu
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Jie Jia
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Pingping Chen
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Yanshuang Liu
- Department of Diagnostics, School of Integrated Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Yuanyuan Wang
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Jianfeng Yi
- Research Center for Differentiation and Development of Traditional Chinese Medicine Basic Theory, Jiangxi University of Traditional Chinese Medicine, Nanchang, China; Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun, China..
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Mucus Release and Airway Constriction by TMEM16A May Worsen Pathology in Inflammatory Lung Disease. Int J Mol Sci 2021; 22:ijms22157852. [PMID: 34360618 PMCID: PMC8346050 DOI: 10.3390/ijms22157852] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022] Open
Abstract
Activation of the Ca2+ activated Cl− channel TMEM16A is proposed as a treatment in inflammatory airway disease. It is assumed that activation of TMEM16A will induce electrolyte secretion, and thus reduce airway mucus plugging and improve mucociliary clearance. A benefit of activation of TMEM16A was shown in vitro and in studies in sheep, but others reported an increase in mucus production and airway contraction by activation of TMEM16A. We analyzed expression of TMEM16A in healthy and inflamed human and mouse airways and examined the consequences of activation or inhibition of TMEM16A in asthmatic mice. TMEM16A was found to be upregulated in the lungs of patients with asthma or cystic fibrosis, as well as in the airways of asthmatic mice. Activation or potentiation of TMEM16A by the compounds Eact or brevenal, respectively, induced acute mucus release from airway goblet cells and induced bronchoconstriction in mice in vivo. In contrast, niclosamide, an inhibitor of TMEM16A, blocked mucus production and mucus secretion in vivo and in vitro. Treatment of airway epithelial cells with niclosamide strongly inhibited expression of the essential transcription factor of Th2-dependent inflammation and goblet cell differentiation, SAM pointed domain-containing ETS-like factor (SPDEF). Activation of TMEM16A in people with inflammatory airway diseases is likely to induce mucus secretion along with airway constriction. In contrast, inhibitors of TMEM16A may suppress pulmonary Th2 inflammation, goblet cell metaplasia, mucus production, and bronchoconstriction, partially by inhibiting expression of SPDEF.
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The role of pulmonary ORCC and CLC-2 channels in the response to oxidative stress. Mol Cell Toxicol 2021. [DOI: 10.1007/s13273-021-00137-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
Background
Exposure of human lung epithelial cells to the oxidant pollutant ozone (O3) alters cell Cl− currents inducing an outward rectifier effect. Among the various Cl− channels, ClC-2 and ORCC seemed to be involved in this response.
Objectives
To identify the channel related to O3 induced current changes.
Results
Down regulating the expression of ORCC and ClC-2 genes and analyzing the membrane current show that the enhancement of the current disappeared when ORCC was silenced. The contribution of ORCC and ClC-2 channels in control and O3 treated cells was obtained by a mathematical approach.
Conclusion
We suggest that O3 activates ORCC channels and slightly inhibited ClC-2 channels in the negative voltage range. These findings open the possibility of identifying the biomolecular changes induced by O3 allowing a possible pharmacological intervention towards chloride current due to oxidative stress.
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Kostritskii AY, Machtens JP. Molecular mechanisms of ion conduction and ion selectivity in TMEM16 lipid scramblases. Nat Commun 2021; 12:2826. [PMID: 33990555 PMCID: PMC8121942 DOI: 10.1038/s41467-021-22724-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 03/23/2021] [Indexed: 02/03/2023] Open
Abstract
TMEM16 lipid scramblases transport lipids and also operate as ion channels with highly variable ion selectivities and various physiological functions. However, their molecular mechanisms of ion conduction and selectivity remain largely unknown. Using computational electrophysiology simulations at atomistic resolution, we identified the main ion-conductive state of TMEM16 lipid scramblases, in which an ion permeation pathway is lined by lipid headgroups that directly interact with permeating ions in a voltage polarity-dependent manner. We found that lipid headgroups modulate the ion-permeability state and regulate ion selectivity to varying degrees in different scramblase isoforms, depending on the amino-acid composition of the pores. Our work has defined the structural basis of ion conduction and selectivity in TMEM16 lipid scramblases and uncovered the mechanisms responsible for the direct effects of membrane lipids on the conduction properties of ion channels.
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Affiliation(s)
- Andrei Y. Kostritskii
- grid.8385.60000 0001 2297 375XInstitute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, Jülich, Germany ,grid.1957.a0000 0001 0728 696XInstitute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany ,grid.1957.a0000 0001 0728 696XDepartment of Physics, RWTH Aachen University, Aachen, Germany
| | - Jan-Philipp Machtens
- grid.8385.60000 0001 2297 375XInstitute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, Jülich, Germany ,grid.1957.a0000 0001 0728 696XInstitute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
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20
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Kolesnikov D, Perevoznikova A, Gusev K, Glushankova L, Kaznacheyeva E, Shalygin A. Electrophysiological Properties of Endogenous Single Ca 2+ Activated Cl - Channels Induced by Local Ca 2+ Entry in HEK293. Int J Mol Sci 2021; 22:4767. [PMID: 33946319 PMCID: PMC8124839 DOI: 10.3390/ijms22094767] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 12/19/2022] Open
Abstract
Microdomains formed by proteins of endoplasmic reticulum and plasma membrane play a key role in store-operated Ca2+ entry (SOCE). Ca2+ release through inositol 1,4,5-trisphosphate receptor (IP3R) and subsequent Ca2+ store depletion activate STIM (stromal interaction molecules) proteins, sensors of intraluminal Ca2+, which, in turn, open the Orai channels in plasma membrane. Downstream to this process could be activated TRPC (transient receptor potential-canonical) calcium permeable channels. Using single channel patch-clamp technique we found that a local Ca2+ entry through TRPC1 channels activated endogenous Ca2+-activated chloride channels (CaCCs) with properties similar to Anoctamin6 (TMEM16F). Our data suggest that their outward rectification is based on the dependence from membrane potential of both the channel conductance and the channel activity: (1) The conductance of active CaCCs highly depends on the transmembrane potential (from 3 pS at negative potentials till 60 pS at positive potentials); (2) their activity (NPo) is enhanced with increasing Ca2+ concentration and/or transmembrane potential, conversely lowering of intracellular Ca2+ concentration reduced the open state dwell time; (3) CaCC amplitude is only slightly increased by intracellular Ca2+ concentration. Experiments with Ca2+ buffering by EGTA or BAPTA suggest close local arrangement of functional CaCCs and TRPC1 channels. It is supposed that Ca2+-activated chloride channels are involved in Ca2+ entry microdomains.
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Affiliation(s)
| | | | | | | | - Elena Kaznacheyeva
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, 194064 St. Petersburg, Russia; (D.K.); (A.P.); (K.G.); (L.G.)
| | - Alexey Shalygin
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, 194064 St. Petersburg, Russia; (D.K.); (A.P.); (K.G.); (L.G.)
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21
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ANO7: Insights into topology, function, and potential applications as a biomarker and immunotherapy target. Tissue Cell 2021; 72:101546. [PMID: 33940566 DOI: 10.1016/j.tice.2021.101546] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 03/21/2021] [Accepted: 04/11/2021] [Indexed: 01/01/2023]
Abstract
Anoctamin 7 (ANO7) is a member of the transmembrane protein TMEM16 family. It has a conservative topology similar to other members in this family, such as the typical eight-transmembrane domain, but it also has unique features. Although the ion channel role of ANO7 has been well accepted, evolutionary analyses and relevant studies suggest that ANO7 may be a multi-facet protein in function. Studies have shown that ANO7 may also function as a scramblase. ANO7 is highly expressed in prostate cancer as well as normal prostate tissues. A considerable amount of evidence has confirmed that ANO7 is associated with human physiology and pathology, particularly with the development of prostate cancer, which makes ANO7 a good candidate as a diagnostic and prognostic biomarker. In addition, ANO7 may be a potential target for prostate cancer immunotherapy. Antibody-based or T cell-mediated immunotherapies against prostate cancer by targeting ANO7 have been highly anticipated. ANO7 may also correlate with several other types of cancers or diseases, where further studies are warranted.
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22
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Le SC, Yang H. Structure-Function of TMEM16 Ion Channels and Lipid Scramblases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:87-109. [PMID: 35138612 PMCID: PMC11020148 DOI: 10.1007/978-981-16-4254-8_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The TMEM16 protein family comprises two novel classes of structurally conserved but functionally distinct membrane transporters that function as Ca2+-dependent Cl- channels (CaCCs) or dual functional Ca2+-dependent ion channels and phospholipid scramblases. Extensive functional and structural studies have advanced our understanding of TMEM16 molecular mechanisms and physiological functions. TMEM16A and TMEM16B CaCCs control transepithelial fluid transport, smooth muscle contraction, and neuronal excitability, whereas TMEM16 phospholipid scramblases mediate the flip-flop of phospholipids across the membrane to allow phosphatidylserine externalization, which is essential in a plethora of important processes such as blood coagulation, bone development, and viral and cell fusion. In this chapter, we summarize the major methods in studying TMEM16 ion channels and scramblases and then focus on the current mechanistic understanding of TMEM16 Ca2+- and voltage-dependent channel gating as well as their ion and phospholipid permeation.
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Affiliation(s)
- Son C Le
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Huanghe Yang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA.
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23
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Öhlinger T, Müllner EW, Fritz M, Sauer T, Werning M, Baron DM, Salzer U. Lysophosphatidic acid-induced pro-thrombotic phosphatidylserine exposure and ionophore-induced microvesiculation is mediated by the scramblase TMEM16F in erythrocytes. Blood Cells Mol Dis 2020; 83:102426. [PMID: 32222693 DOI: 10.1016/j.bcmd.2020.102426] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/12/2020] [Accepted: 03/12/2020] [Indexed: 12/31/2022]
Abstract
Recent studies indicate that erythrocytes actively modulate blood clotting and thrombus formation. The lipid mediator lysophosphatidic acid (LPA) is produced by activated platelets, and triggers a signaling process in erythrocytes. This results in cellular calcium uptake and exposure of phosphatidylserine (PS) at the cell surface, thereby generating activated membrane binding sites for factors of the clotting cascade. Moreover, erythrocytes of patients with a bleeding disorder and mutations in the scramblase TMEM16F show impaired PS exposure and microvesiculation upon treatment with calcium ionophore. We report that TMEM16F inhibitors tannic acid (TA) and epigallocatechin-3-gallate (EGCG) inhibit LPA-induced PS exposure and calcium uptake at low micromolar concentrations; fluoxetine, an antidepressant and a known activator of TMEM16F, enhances these processes. These effectors likewise modulate erythrocyte PS exposure and microvesicle shedding induced by calcium ionophore treatment. Further, LPA-treated erythrocytes triggered thrombin generation in platelet-free plasma which was partially impaired in the presence of TA and EGCG. Thus, this study suggests that LPA activates the scramblase TMEM16F in erythrocytes, thereby possibly mediating a pro-thrombotic function in these cells. EGCG as well as fluoxetine, substances with potentially high plasma concentrations due to alimentation or medical treatment, should be considered as potential effectors of systemic hemostatic regulation.
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Affiliation(s)
- Thomas Öhlinger
- Center for Medical Biochemistry, Max Perutz Laboratories, Medical University of Vienna, Vienna, Austria; Department of Anaesthesia, Intensive Care Medicine and Pain Medicine, Medical University of Vienna, Vienna, Austria
| | - Ernst W Müllner
- Center for Medical Biochemistry, Max Perutz Laboratories, Medical University of Vienna, Vienna, Austria
| | - Magdalena Fritz
- Center for Medical Biochemistry, Max Perutz Laboratories, Medical University of Vienna, Vienna, Austria
| | - Thomas Sauer
- Center for Medical Biochemistry, Max Perutz Laboratories, Medical University of Vienna, Vienna, Austria
| | - Maike Werning
- Center for Medical Biochemistry, Max Perutz Laboratories, Medical University of Vienna, Vienna, Austria
| | - David M Baron
- Department of Anaesthesia, Intensive Care Medicine and Pain Medicine, Medical University of Vienna, Vienna, Austria
| | - Ulrich Salzer
- Center for Medical Biochemistry, Max Perutz Laboratories, Medical University of Vienna, Vienna, Austria.
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Buchholz B, Eckardt KU. Role of oxygen and the HIF-pathway in polycystic kidney disease. Cell Signal 2020; 69:109524. [PMID: 31904413 DOI: 10.1016/j.cellsig.2020.109524] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/01/2020] [Accepted: 01/01/2020] [Indexed: 12/16/2022]
Abstract
Kidney cyst growth in ADPKD is associated with regional hypoxia, presumably due to a mismatch between enlarged cysts and the peritubular capillary blood supply and compression of peritubular capillaries in cyst walls. Regional hypoxia leads to activation of hypoxia-inducible transcription factors, with the two main HIF isoforms, HIF-1 and HIF-2 expressed in cyst epithelia and pericystic interstitial cells, respectively. While HIF-2 activation is linked to EPO production, mitigating the anemia that normally accompanies chronic kidney disease, HIF-1 promotes cyst growth. HIF-dependent cyst growth is primarily due to an increase in chloride-dependent fluid secretion into the cyst lumen. However, given the broad spectrum of HIF-target genes, additional HIF-mediated pathways may also contribute to cyst progression. Furthermore, hypoxia can influence cyst growth through the generation of reactive oxygen species. Since cyst expansion aggravates regional hypoxia, a feedforward loop is established that accelerates cyst expansion and disease progression. Inhibiting the HIF pathway and/or HIF target genes that are of particular relevance for HIF-dependent cyst fluid secretion may therefore represent novel therapeutic approaches to retard the progression of APDKD.
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Affiliation(s)
- Bjoern Buchholz
- Department of Nephrology and Hypertension, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| | - Kai-Uwe Eckardt
- Department of Nephrology and Medical Intensive Care, Charité, Universitätsmedizin Berlin, Berlin, Germany
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25
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Song HY, Zhou L, Hou XF, Lian H. Anoctamin 5 regulates cell proliferation and migration in pancreatic cancer. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:4263-4270. [PMID: 31933826 PMCID: PMC6949878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Pancreatic cancer (PC) has one of the worst survival rates of all cancers. Anoctamin (ANO) inlcudes a family of Ca2+-activated Cl- channels (CaCCs) that participate in tumorigenesis and progression. However, the exact role of ANO5 in PC has not yet been clarified. Our previous study showed that ANO5 is highly expressed in the epithelial cells of the digestive tract, but there have been no reports of ANO5 expression in normal pancreatic tissue and in PC tissue. In the present study, we investigated the expression of ANO5 in normal pancreatic tissues and PC tissues using immunohistochemistry. The results indicated that ANO5 expression was significantly elevated in PC tissues compared with normal pancreatic tissues. Next, we investigated the expression of ANO5 in pancreatic ductal epithelial cells and PC cells using western blotting and quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR). The results indicated that ANO5 expression was significantly elevated in PC cells compared with pancreatic ductal epithelial cells. The impact of siRNA-mediated ANO5 knockdown on PC cell proliferation and migration was detected using CCK-8 assays and scratch experiments. The results indicated that ANO5 siRNA reduced the proliferation and migration of PC cells. Collectively, the results suggest that downregulation of ANO5 inhibits the proliferation and migration of PC cells. Therefore, ANO5 is potentially a novel therapeutic target for PC treatment.
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Affiliation(s)
- Hai-Yan Song
- School of Basic Medical Sciences, Xinxiang Medical UniversityXinxiang 453003, Henan Province, China
- Xinxiang Key Laboratory of Molecular NeurologyXinxiang 453003, Henan Province, China
- Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory MedicineXinxiang 453003, Henan Province, China
| | - Li Zhou
- School of Basic Medical Sciences, Xinxiang Medical UniversityXinxiang 453003, Henan Province, China
- Xinxiang Key Laboratory of Molecular NeurologyXinxiang 453003, Henan Province, China
- Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory MedicineXinxiang 453003, Henan Province, China
| | - Xin-Fang Hou
- Department of Medical Oncology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer HospitalZhengzhou 450008, Henan Province, China
| | - Hui Lian
- School of Basic Medical Sciences, Xinxiang Medical UniversityXinxiang 453003, Henan Province, China
- Xinxiang Key Laboratory of Molecular NeurologyXinxiang 453003, Henan Province, China
- Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory MedicineXinxiang 453003, Henan Province, China
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Ousingsawat J, Schreiber R, Kunzelmann K. TMEM16F/Anoctamin 6 in Ferroptotic Cell Death. Cancers (Basel) 2019; 11:E625. [PMID: 31060306 PMCID: PMC6562394 DOI: 10.3390/cancers11050625] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/01/2019] [Accepted: 05/03/2019] [Indexed: 12/21/2022] Open
Abstract
Ca2+ activated Cl- channels (TMEM16A; ANO1) support cell proliferation and cancer growth. Expression of TMEM16A is strongly enhanced in different types of malignomas. In contrast, TMEM16F (ANO6) operates as a Ca2+ activated chloride/nonselective ion channel and scrambles membrane phospholipids to expose phosphatidylserine at the cell surface. Both phospholipid scrambling and cell swelling induced through activation of nonselective ion currents appear to destabilize the plasma membrane thereby causing cell death. There is growing evidence that activation of TMEM16F contributes to various forms of regulated cell death. In the present study, we demonstrate that ferroptotic cell death, occurring during peroxidation of plasma membrane phospholipids activates TMEM16F. Ferroptosis was induced by erastin, an inhibitor of the cystine-glutamate antiporter and RSL3, an inhibitor of glutathione peroxidase 4 (GPX4). Cell death was largely reduced in the intestinal epithelium, and in peritoneal macrophages isolated from mice with tissue-specific knockout of TMEM16F. We show that TMEM16F is activated during erastin and RSL3-induced ferroptosis. In contrast, inhibition of ferroptosis by ferrostatin-1 and by inhibitors of TMEM16F block TMEM16F currents and inhibit cell death. We conclude that activation of TMEM16F is a crucial component during ferroptotic cell death, a finding that may be useful to induce cell death in cancer cells.
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Affiliation(s)
- Jiraporn Ousingsawat
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
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Lin H, Jun I, Woo JH, Lee MG, Kim SJ, Nam JH. Temperature-dependent increase in the calcium sensitivity and acceleration of activation of ANO6 chloride channel variants. Sci Rep 2019; 9:6706. [PMID: 31040335 PMCID: PMC6491614 DOI: 10.1038/s41598-019-43162-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/12/2019] [Indexed: 02/08/2023] Open
Abstract
Anoctamin-6 (ANO6) belongs to a family of calcium (Ca2+)-activated chloride channels (CaCCs), with three splicing variants (V1, V2, and V5) showing plasma membrane expression. Unlike other CaCCs, ANO6 requires a non-physiological intracellular free calcium concentration ([Ca2+]i > 1 μM) and several minutes for full activation under a whole-cell patch clamp. Therefore, its physiological role as an ion channel is uncertain and it is more commonly considered a Ca2+-dependent phospholipid scramblase. Here, we demonstrate that physiological temperature (37 °C) increases ANO6 Ca2+ sensitivity under a whole-cell patch clamp; V1 was activated by 1 μM [Ca2+]i, whereas V2 and V5 were activated by 300 nM [Ca2+]i. Increasing the temperature to 42 °C led to activation of all ANO6 variants by 100 nM [Ca2+]i. The delay time for activation of the three variants was significantly shortened at 37 °C. Notably, the temperature-dependent Ca2+-sensitisation of ANO6 became insignificant under inside-out patch clamp, suggesting critical roles of unknown cytosolic factors. Unlike channel activity, 27 °C but not 37 °C (physiological temperature) induced the scramblase activity of ANO6 at submicromolar [Ca2+]i (300 nM), irrespective of variant type. Our results reveal a physiological ion conducting property of ANO6 at 37 °C and suggest that ANO6 channel function acts separately from its scramblase activity.
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Affiliation(s)
- Haiyue Lin
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Ikhyun Jun
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Department of Pharmacology and Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Joo Han Woo
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju, 38066, Republic of Korea
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang, Gyeonggi-do, 10326, Republic of Korea
| | - Min Goo Lee
- Department of Pharmacology and Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju, 38066, Republic of Korea.
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang, Gyeonggi-do, 10326, Republic of Korea.
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28
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Taylor KA, Mahaut-Smith MP. A major interspecies difference in the ionic selectivity of megakaryocyte Ca 2+-activated channels sensitive to the TMEM16F inhibitor CaCCinh-A01. Platelets 2019; 30:962-966. [PMID: 31008669 PMCID: PMC6816474 DOI: 10.1080/09537104.2019.1595560] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 02/12/2019] [Accepted: 03/04/2019] [Indexed: 12/15/2022]
Abstract
TMEM16F is a surface membrane protein critical for platelet procoagulant activity, which exhibits both phospholipid scramblase and ion channel activities following sustained elevation of cytosolic Ca2+. The extent to which the ionic permeability of TMEM16F is important for platelet scramblase responses remains controversial. To date, only one study has reported the electrophysiological properties of TMEM16F in cells of platelet/megakaryocyte lineage, which observed cation-selectivity within excised patch recordings from murine marrow-derived megakaryocytes. This contrasts with reports using whole-cell recordings that describe this channel as displaying either selectivity for anions or being relatively non-selective amongst the major physiological monovalent ions. We have studied TMEM16F expression and channel activity in primary rat and mouse megakaryocytes and the human erythroleukemic (HEL) cell line that exhibits megakaryocytic surface markers. Immunocytochemical analysis was consistent with surface TMEM16F expression in cells from all three species. Whole-cell recordings in the absence of K+-selective currents revealed an outwardly rectifying conductance activated by a high intracellular Ca2+ concentration in all three species. These currents appeared after 5-6 minutes and were blocked by CaCCinh-A01, properties typical of TMEM16F. Ion substitution experiments showed that the underlying conductance was predominantly Cl--permeable in rat megakaryocytes and HEL cells, yet non-selective between monovalent anions and cations in mouse megakaryocytes. In conclusion, the present study further highlights the difference in ionic selectivity of TMEM16F in platelet lineage cells of the mouse compared to other mammalian species. This provides additional support for the ionic "leak" hypothesis that the scramblase activity of TMEM16F does not rely upon its ability to conduct ions of a specific type.
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Affiliation(s)
- Kirk A. Taylor
- Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- National Heart and Lung Institute, Cardio-respiratory Section, Imperial College London, London, UK
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Kunzelmann K, Ousingsawat J, Benedetto R, Cabrita I, Schreiber R. Contribution of Anoctamins to Cell Survival and Cell Death. Cancers (Basel) 2019; 11:E382. [PMID: 30893776 PMCID: PMC6468699 DOI: 10.3390/cancers11030382] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/13/2019] [Accepted: 03/16/2019] [Indexed: 02/07/2023] Open
Abstract
Before anoctamins (TMEM16 proteins) were identified as a family of Ca2+-activated chloride channels and phospholipid scramblases, the founding member anoctamin 1 (ANO1, TMEM16A) was known as DOG1, a marker protein for gastrointestinal stromal tumors (GIST). Meanwhile, ANO1 has been examined in more detail, and the role of ANO1 in cell proliferation and the development of different types of malignomas is now well established. While ANO5, ANO7, and ANO9 may also be relevant for growth of cancers, evidence has been provided for a role of ANO6 (TMEM16F) in regulated cell death. The cellular mechanisms by which anoctamins control cell proliferation and cell death, respectively, are just emerging; however, the pronounced effects of anoctamins on intracellular Ca2+ levels are likely to play a significant role. Recent results suggest that some anoctamins control membrane exocytosis by setting Ca2+i levels near the plasma membrane, and/or by controlling the intracellular Cl- concentration. Exocytosis and increased membrane trafficking induced by ANO1 and ANO6 may enhance membrane expression of other chloride channels, such as CFTR and volume activated chloride channels (VRAC). Notably, ANO6-induced phospholipid scrambling with exposure of phosphatidylserine is pivotal for the sheddase function of disintegrin and metalloproteinase (ADAM). This may support cell death and tumorigenic activity of IL-6 by inducing IL-6 trans-signaling. The reported anticancer effects of the anthelminthic drug niclosamide are probably related to the potent inhibitory effect on ANO1, apart from inducing cell cycle arrest through the Let-7d/CDC34 axis. On the contrary, pronounced activation of ANO6 due to a large increase in intracellular calcium, activation of phospholipase A2 or lipid peroxidation, can lead to ferroptotic death of cancer cells. It therefore appears reasonable to search for both inhibitors and potent activators of TMEM16 in order to interfere with cancer growth and metastasis.
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Affiliation(s)
- Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Jiraporn Ousingsawat
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Roberta Benedetto
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Ines Cabrita
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
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30
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Canella R, Martini M, Cavicchio C, Cervellati F, Benedusi M, Valacchi G. Involvement of the TREK-1 channel in human alveolar cell membrane potential and its regulation by inhibitors of the chloride current. J Cell Physiol 2019; 234:17704-17713. [PMID: 30805940 DOI: 10.1002/jcp.28396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 01/03/2019] [Accepted: 01/10/2019] [Indexed: 12/14/2022]
Abstract
K+ channels of the alveolar epithelium control the driving force acting on the ionic and solvent flow through the cell membrane contributing to the maintenance of cell volume and the constitution of epithelial lining fluid. In the present work, we analyze the effect of the Cl- channel inhibitors: (4-[(2-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-inden-5-yl)oxy] butanoic acid (DCPIB) and 9-anthracenecarboxylic acid (9-AC) on the total current in a type II pneumocytes (A549 cell line) model by patch clamp, immunocytochemical, and gene knockdown techniques. We noted that DCPIB and 9-AC promote the activation of K conductance. In fact, they significantly increase the intensity of the current and shift its reversal potential to values more negative than the control. By silencing outward rectifier channel in its anoctamin 6 portion, we excluded a direct involvement of Cl- ions in modulation of IK and, by means of functional tests with its specific inhibitor spadin, we identified the TREK-1 channel as the presumable target of both drugs. As the activity of TREK-1 has a key role for the correct functioning of the alveolar epithelium, the identification of DCPIB and 9-AC molecules as its activators suggests their possible use to build new pharmacological tools for the modulation of this channel.
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Affiliation(s)
- Rita Canella
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marta Martini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Carlotta Cavicchio
- Animal Science Department, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
| | - Franco Cervellati
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mascia Benedusi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Animal Science Department, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
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31
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Schreiber R, Buchholz B, Kraus A, Schley G, Scholz J, Ousingsawat J, Kunzelmann K. Lipid Peroxidation Drives Renal Cyst Growth In Vitro through Activation of TMEM16A. J Am Soc Nephrol 2019; 30:228-242. [PMID: 30606785 DOI: 10.1681/asn.2018010039] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 11/19/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Transepithelial chloride- secretion, through the chloride channels cystic fibrosis transmembrane conductance regulator (CFTR) and TMEM16A (anoctamin 1), drives cyst enlargement in polycystic kidney disease (PKD). Polycystic kidneys are hypoxic, and oxidative stress activates TMEM16A. However, mechanisms for channel activation in PKD remain obscure. METHODS Using tissue samples from patients with autosomal dominant PKD, embryonic kidney cultures, and an MDCK in vitro cyst model, we assessed peroxidation of plasma membrane phospholipids in human and mouse polycystic kidneys. We also used electrophysiologic Ussing chamber and patch clamp experiments to analyze activation of TMEM16A and growth of renal cysts. RESULTS Peroxidation of phospholipids in human and mouse kidneys as well as MDCK cysts in vitro is probably due to enhanced levels of reactive oxygen species. Lipid peroxidation correlated with increased cyst volume as shown in renal cultures and MDCK cysts in three-dimensional cultures. Reactive oxygen species and lipid peroxidation strongly activated TMEM16A, leading to depletion of calcium ion stores and store-operated calcium influx. Activation of TMEM16A- and CFTR-dependent chloride secretion strongly augmented cyst growth. Exposure to scavengers of reactive oxygen species, such as glutathione, coenzyme Q10, or idebenone (a synthetic coenzyme Q10 homolog), as well as inhibition of oxidative lipid damage by ferrostatin-1 largely reduced activation of TMEM16A. Inhibition of TMEM16A reduced proliferation and fluid secretion in vitro. CONCLUSIONS These findings indicate that activation of TMEM16A by lipid peroxidation drives growth of renal cysts. We propose direct inhibition of TMEM16A or inhibition of lipid peroxidation as potentially powerful therapeutic approaches to delay cyst development in PKD.
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Affiliation(s)
- Rainer Schreiber
- Department of Physiology, University of Regensburg, Regensburg, Germany; and
| | - Björn Buchholz
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Andre Kraus
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Gunnar Schley
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Julia Scholz
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | | | - Karl Kunzelmann
- Department of Physiology, University of Regensburg, Regensburg, Germany; and
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32
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Delpire E, Gagnon KB. Water Homeostasis and Cell Volume Maintenance and Regulation. CURRENT TOPICS IN MEMBRANES 2018; 81:3-52. [PMID: 30243436 PMCID: PMC6457474 DOI: 10.1016/bs.ctm.2018.08.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
From early unicellular organisms that formed in salty water environments to complex organisms that live on land away from water, cells have had to protect a homeostatic internal environment favorable to the biochemical reactions necessary for life. In this chapter, we will outline what steps were necessary to conserve the water within our cells and how mechanisms have evolved to maintain and regulate our cellular and organismal volume. We will first examine whole body water homeostasis and the relationship between kidney function, regulation of blood pressure, and blood filtration in the process of producing urine. We will then discuss how the composition of the lipid-rich bilayer affects its permeability to water and salts, and how the cell uses this differential to drive physiological and biochemical cellular functions. The capacity to maintain cell volume is vital to epithelial transport, neurotransmission, cell cycle, apoptosis, and cell migration. Finally, we will wrap up the chapter by discussing in some detail specific channels, cotransporters, and exchangers that have evolved to facilitate the movement of cations and anions otherwise unable to cross the lipid-rich bilayer and that are involved in maintaining or regulating cell volume.
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Affiliation(s)
- Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine
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33
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Molecular Identities and ATP Release Activities of Two Types of Volume-Regulatory Anion Channels, VSOR and Maxi-Cl. CURRENT TOPICS IN MEMBRANES 2018; 81:125-176. [PMID: 30243431 DOI: 10.1016/bs.ctm.2018.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An elaborate volume regulation system based on interplay of ion channels and transporters was evolved to cope with constant osmotic challenges caused by intensive metabolism, transport and other physiological/pathophysiological events. In animal cells, two types of anion channels are directly activated by cell swelling and involved in the regulatory volume decrease (RVD): volume-sensitive outwardly rectifying anion channel (VSOR), also called volume-regulated anion channel (VRAC), and Maxi-Cl which is the most major type of maxi-anion channel (MAC). These two channels have very different biophysical profiles and exhibit opposite dependence on intracellular ATP. After several decades of verifying many false-positive candidates for VSOR and Maxi-Cl, LRRC8 family proteins emerged as major VSOR components, and SLCO2A1 protein as a core of Maxi-Cl. Still, neither of these proteins alone can fully reproduce the native channel phenotypes suggesting existence of missing components. Although both VSOR and Maxi-Cl have pores wide enough to accommodate bulky ATP4- and MgATP2- anions, evidence accumulated hitherto, based on pharmacological and gene silencing experiments, suggests that Maxi-Cl, but not VSOR, serves as one of the major pathways for the release of ATP from swollen and ischemic/hypoxic cells. Relations of VSOR and Maxi-Cl with diseases and their selective pharmacology are the topics promoted by recent advance in molecular identification of the two volume-activated, volume-regulatory anion channels.
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34
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Schenk LK, Ousingsawat J, Skryabin BV, Schreiber R, Pavenstädt H, Kunzelmann K. Regulation and Function of TMEM16F in Renal Podocytes. Int J Mol Sci 2018; 19:ijms19061798. [PMID: 29912162 PMCID: PMC6032267 DOI: 10.3390/ijms19061798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 06/12/2018] [Accepted: 06/14/2018] [Indexed: 12/13/2022] Open
Abstract
The Ca2+-activated phospholipid scramblase and ion channel TMEM16F is expressed in podocytes of renal glomeruli. Podocytes are specialized cells that form interdigitating foot processes as an essential component of the glomerular filter. These cells, which participate in generation of the primary urine, are often affected during primary glomerular diseases, such as glomerulonephritis and secondary hypertensive or diabetic nephropathy, which always leads to proteinuria. Because the function of podocytes is known to be controlled by intracellular Ca2+ signaling, it is important to know about the role of Ca2+-activated TMEM16F in these cells. To that end, we generated an inducible TMEM16F knockdown in the podocyte cell line AB8, and produced a conditional mouse model with knockout of TMEM16F in podocytes and renal epithelial cells of the nephron. We found that knockdown of TMEM16F did not produce proteinuria or any obvious phenotypic changes. Knockdown of TMEM16F affected cell death of tubular epithelial cells but not of glomerular podocytes when analyzed in TUNEL assays. Surprisingly, and in contrast to other cell types, TMEM16F did not control intracellular Ca2+ signaling and was not responsible for Ca2+-activated whole cell currents in podocytes. TMEM16F levels in podocytes were enhanced after inhibition of the endolysosomal pathway and after treatment with angiotensin II. Renal knockout of TMEM16F did not compromise renal morphology and serum electrolytes. Taken together, in contrast to other cell types, such as platelets, bone cells, and immune cells, TMEM16F shows little effect on basal properties of podocytes and does not appear to be essential for renal function.
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Affiliation(s)
- Laura K Schenk
- Department of Nephrology, Hypertension and Rheumatology, University Hospital Muenster, 48149 Muenster, Germany.
| | - Jiraporn Ousingsawat
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Boris V Skryabin
- Transgenic Animal and Genetic Engineering Models (TRAM), Department of Medicine, Westfälischen, Wilhelms⁻Universität Münster, 48149 Münster, Germany.
| | - Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Hermann Pavenstädt
- Department of Nephrology, Hypertension and Rheumatology, University Hospital Muenster, 48149 Muenster, Germany.
| | - Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
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35
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Falzone ME, Malvezzi M, Lee BC, Accardi A. Known structures and unknown mechanisms of TMEM16 scramblases and channels. J Gen Physiol 2018; 150:933-947. [PMID: 29915161 PMCID: PMC6028493 DOI: 10.1085/jgp.201711957] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/29/2018] [Indexed: 12/25/2022] Open
Abstract
Falzone et al. interpret the mechanisms underlying the activity of TMEM16 family members from recent structural and functional work. The TMEM16 family of membrane proteins is composed of both Ca2+-gated Cl− channels and Ca2+-dependent phospholipid scramblases. The functional diversity of TMEM16s underlies their involvement in numerous signal transduction pathways that connect changes in cytosolic Ca2+ levels to cellular signaling networks. Indeed, defects in the function of several TMEM16s cause a variety of genetic disorders, highlighting their fundamental pathophysiological importance. Here, we review how our mechanistic understanding of TMEM16 function has been shaped by recent functional and structural work. Remarkably, the recent determination of near-atomic-resolution structures of TMEM16 proteins of both functional persuasions has revealed how relatively minimal rearrangements in the substrate translocation pathway are sufficient to precipitate the dramatic functional differences that characterize the family. These structures, when interpreted in the light of extensive functional analysis, point to an unusual mechanism for Ca2+-dependent activation of TMEM16 proteins in which substrate permeation is regulated by a combination of conformational rearrangements and electrostatics. These breakthroughs pave the way to elucidate the mechanistic bases of ion and lipid transport by the TMEM16 proteins and unravel the molecular links between these transport activities and their function in human pathophysiology.
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Affiliation(s)
- Maria E Falzone
- Department of Biochemistry, Weill Cornell Medical School, New York, NY
| | - Mattia Malvezzi
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY
| | - Byoung-Cheol Lee
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY
| | - Alessio Accardi
- Department of Biochemistry, Weill Cornell Medical School, New York, NY .,Department of Anesthesiology, Weill Cornell Medical School, New York, NY.,Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medical School, New York, NY
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36
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Canella R, Benedusi M, Martini M, Cervellati F, Cavicchio C, Valacchi G. Role of Nrf2 in preventing oxidative stress induced chloride current alteration in human lung cells. J Cell Physiol 2018; 233:6018-6027. [PMID: 29271475 DOI: 10.1002/jcp.26416] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/19/2017] [Indexed: 12/24/2022]
Abstract
The lung tissue is one of the main targets of oxidative stress due to external sources and respiratory activity. In our previous work, we have demonstrated in that O3 exposure alters the Cl- current-voltage relationship, with the appearance of a large outward rectifier component mainly sustained by outward rectifier chloride channels (ORCCs) in human lung epithelial cells (A549 line). In the present study, we have performed patch clamp experiments, in order to identify which one of the O3 byproducts (4hydroxynonenal (HNE) and/or H2 O2 ) was responsible for chloride current change. While 4HNE exposition (up to 25 μM for 30' before electrophysiological analysis) did not reproduce O3 effect, H2 O2 produced by glucose oxidase 10 mU for 24 hr before electrophysiological analysis mimicked O3 response. This result was confirmed treating the cell with catalase (CAT) before O3 exposure (1,000 U/ml for 2 hr): CAT was able to rescue Cl- current alteration. Since CAT is regulated by Nrf2 transcription factor, we pre-treated the cells with the Nrf2 activators, resveratrol and tBHQ. Immunochemical and immunocytochemical results showed Nrf2 activation with both substances that lead to prevent OS effect on Cl- current. These data bring new insights into the mechanisms involved in OS-induced lung tissue damage, pointing out the role of H2 O2 in chloride current alteration and the ability of Nfr2 activation in preventing this effect.
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Affiliation(s)
- Rita Canella
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mascia Benedusi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marta Martini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Franco Cervellati
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Carlotta Cavicchio
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Department of Animal Science, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
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37
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Contribution of TMEM16F to pyroptotic cell death. Cell Death Dis 2018; 9:300. [PMID: 29463790 PMCID: PMC5833444 DOI: 10.1038/s41419-018-0373-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 02/02/2018] [Accepted: 02/05/2018] [Indexed: 02/08/2023]
Abstract
Pyroptosis is a highly inflammatory form of programmed cell death that is caused by infection with intracellular pathogens and activation of canonical or noncanonical inflammasomes. The purinergic receptor P2X7 is activated by the noncanonical inflammasome and contributes essentially to pyroptotic cell death. The Ca2+ activated phospholipid scramblase and ion channel TMEM16F has been shown earlier to control cellular effects downstream of purinergic P2X7 receptors that ultimately lead to cell death. As pyroptotic cell death is accompanied by an increases in intracellular Ca2+, we asked whether TMEM16F is activated during pyroptosis. The N-terminal cleavage product of gasdermin D (GD-N) is an executioner of pyroptosis by forming large plasma membrane pores. Expression of GD-N enhanced basal Ca2+ levels and induced cell death. We observed that GD-N induced cell death in HEK293 and HAP1 cells, which was depending on expression of endogenous TMEM16F. GD-N activated large whole cell currents that were suppressed by knockdown or inhibition of TMEM16F. The results suggest that whole cell currents induced by the pore forming domain of gasdermin-D, are at least in part due to activation of TMEM16F. Knockdown of other TMEM16 paralogues expressed in HAP1 cells suggest TMEM16F as a crucial element during pyroptosis and excluded a role of other TMEM16 proteins. Thus TMEM16F supports pyroptosis and other forms of inflammatory cell death such as ferroptosis. Its potent inhibition by tannic acid may be part of the anti-inflammatory effects of flavonoids.
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38
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Pelz T, Drose DR, Fleck D, Henkel B, Ackels T, Spehr M, Neuhaus EM. An ancestral TMEM16 homolog from Dictyostelium discoideum forms a scramblase. PLoS One 2018; 13:e0191219. [PMID: 29444117 PMCID: PMC5812556 DOI: 10.1371/journal.pone.0191219] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 12/29/2017] [Indexed: 01/11/2023] Open
Abstract
TMEM16 proteins are a recently identified protein family comprising Ca2+-activated Cl- channels that generate outwardly rectifying ionic currents in response to intracellular Ca2+ elevations. Some TMEM16 family members, such as TMEM16F/ANO6 are also essential for Ca2+-dependent phospholipid scrambling. TMEM16-like genes are present in the genomes of most eukaryotic species, the function(s) of TMEM16 family members from evolutionary ancient eukaryotes is not completely clear. Here, we provide insight into the evolution of these TMEM16 proteins by similarity searches for ancestral sequences. All eukaryotic genomes contain TMEM16 homologs, but only vertebrates have the full repertoire of ten distinct subtypes. TMEM16 homologs studied so far belong to the opisthokont branch of the phylogenetic tree, which includes the animal and fungal kingdoms. An organism outside this group is Dictyostelium discoideum, a representative of the amoebozoa group that diverged from the metazoa before fungi. We here functionally investigated the TMEM16 family member from Dictyostelium discoideum. When recombinantly expressed in HEK293 cells, DdTMEM16 induces phospholipid scrambling. However, in several electrophysiological experiments we did not find evidence for a Ca2+-activated Cl- channel function of DdTMEM16.
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Affiliation(s)
- Thomas Pelz
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Daniela R. Drose
- Department of Chemosensation, Institute for Biology II, RWTH-Aachen University, Aachen, Germany
| | - David Fleck
- Department of Chemosensation, Institute for Biology II, RWTH-Aachen University, Aachen, Germany
| | - Bastian Henkel
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Tobias Ackels
- Department of Chemosensation, Institute for Biology II, RWTH-Aachen University, Aachen, Germany
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH-Aachen University, Aachen, Germany
| | - Eva M. Neuhaus
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
- * E-mail:
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Schreiber R, Ousingsawat J, Wanitchakool P, Sirianant L, Benedetto R, Reiss K, Kunzelmann K. Regulation of TMEM16A/ANO1 and TMEM16F/ANO6 ion currents and phospholipid scrambling by Ca 2+ and plasma membrane lipid. J Physiol 2018; 596:217-229. [PMID: 29134661 PMCID: PMC5767690 DOI: 10.1113/jp275175] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/08/2017] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS TMEM16 proteins can operate as Ca2+ -activated Cl- channels or scramble membrane phospholipids, which are both highly relevant mechanisms during disease. Overexpression of TMEM16A and TMEM16F were found to be partially active at 37°C and at resting intracellular Ca2+ concentrations. We show that TMEM16 Cl- currents and phospholipid scrambling can be activated by modification of plasma membrane phospholipids, through reactive oxygen species and phospholipase A2. While phospholipids and Cl- ions are likely to use the same pore within TMEM16F, TMEM16A only conducts Cl- ions. Lipid regulation of TMEM16 proteins is highly relevant during inflammation and regulated cell death such as apoptosis and ferroptosis. ABSTRACT TMEM16/anoctamin (ANO) proteins form Ca2+ -activated ion channels or phospholipid scramblases. We found that both TMEM16A/ANO1 and TMEM16F/ANO6 produced Cl- currents when activated by intracellular Ca2+ , but only TMEM16F was able to expose phosphatidylserine to the outer leaflet of the plasma membrane. Mutations within TMEM16F or TMEM16A/F chimeras similarly changed Cl- currents and phospholipid scrambling, suggesting the same intramolecular pathway for Cl- and phospholipids. When overexpressed, TMEM16A and TMEM16F produced spontaneous Cl- currents at 37°C even at resting intracellular Ca2+ levels, which was abolished by inhibition of phospholipase A2 (PLA2 ). Connversely, activation of PLA2 or application of active PLA2 , as well as lipid peroxidation induced by reactive oxygen species (ROS) using staurosporine or tert-butyl hydroperoxide, enhanced ion currents by TMEM16A/F and in addition activated phospholipid scrambling by TMEM16F. Thus, TMEM16 proteins are activated by an increase in intracellular Ca2+ , or independent of intracellular Ca2+ , by modifications occurring in plasma and intracellular membrane phospholipids. These results may help to explain why regions distant to the TMEM16 pore and the Ca2+ binding sites control Cl- currents and phospholipid scrambling. Regulation of TMEM16 proteins through modification of membrane phospholipids occurs during regulated cell death such as apoptosis and ferroptosis. It contributes to inflammatory and nerve injury-induced hypersensitivity and generation of pain and therefore provides a regulatory mechanism that is particularly relevant during disease.
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Affiliation(s)
- Rainer Schreiber
- Institut für PhysiologieUniversität RegensburgUniversitätsstraße 31D‐93053RegensburgGermany
| | - Jiraporn Ousingsawat
- Institut für PhysiologieUniversität RegensburgUniversitätsstraße 31D‐93053RegensburgGermany
| | | | - Lalida Sirianant
- Institut für PhysiologieUniversität RegensburgUniversitätsstraße 31D‐93053RegensburgGermany
| | - Roberta Benedetto
- Institut für PhysiologieUniversität RegensburgUniversitätsstraße 31D‐93053RegensburgGermany
| | - Karina Reiss
- Department of DermatologyUniversity of KielSchittenhelmstrasse 7Kiel24105Germany
| | - Karl Kunzelmann
- Institut für PhysiologieUniversität RegensburgUniversitätsstraße 31D‐93053RegensburgGermany
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40
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Lérias J, Pinto M, Benedetto R, Schreiber R, Amaral M, Aureli M, Kunzelmann K. Compartmentalized crosstalk of CFTR and TMEM16A (ANO1) through EPAC1 and ADCY1. Cell Signal 2018; 44:10-19. [PMID: 29331508 DOI: 10.1016/j.cellsig.2018.01.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 12/11/2017] [Accepted: 01/08/2018] [Indexed: 02/08/2023]
Abstract
Airway epithelial cells express both Ca2+ activated TMEM16A/ANO1 and cAMP activated CFTR anion channels. Previous work suggested a significant crosstalk of intracellular Ca2+ and cAMP signaling pathways, leading to activation of both chloride channels. We demonstrate that in airway epithelial cells, stimulation of purinergic or muscarinic G-protein coupled receptors (GPCRs) activates TMEM16A and CFTR. Additional expression of Gq/11 and phospholipase C coupled GPCRs strongly enhanced the crosstalk between Ca2+- and cAMP-dependent signaling. Knockdown of endogenous GRCRs attenuated crosstalk and functional coupling between TMEM16A and CFTR. The number of receptors did not affect expression or membrane localization of TMEM16A or CFTR, but controlled assembly of the local signalosome. GPCRs translocate Ca2+-sensitive adenylate cyclase type 1 (ADCY1) and exchange protein directly activated by cAMP (EPAC1) to particular plasma membrane domains containing GPCRs, CFTR and TMEM16A, thereby producing compartmentalized Ca2+ and cAMP signals and significant crosstalk. While biosynthesis and membrane trafficking of CFTR requires a functional Golgi apparatus, maturation and membrane trafficking of TMEM16A may occur independent of the Golgi. Because Ca2+ activated TMEM16A currents are only transient, continuous Cl- secretion by airway epithelial cells requires CFTR. The present data also explain why receptor-dependent activation of TMEM16A is more efficient than direct stimulation by Ca2+.
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Affiliation(s)
- Joana Lérias
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Madalena Pinto
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Roberta Benedetto
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Margarida Amaral
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Massimo Aureli
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Milano, Italy
| | - Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
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41
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Muratori C, Pakhomov AG, Gianulis E, Meads J, Casciola M, Mollica PA, Pakhomova ON. Activation of the phospholipid scramblase TMEM16F by nanosecond pulsed electric fields (nsPEF) facilitates its diverse cytophysiological effects. J Biol Chem 2017; 292:19381-19391. [PMID: 28982976 PMCID: PMC5702676 DOI: 10.1074/jbc.m117.803049] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/20/2017] [Indexed: 12/17/2022] Open
Abstract
Nanosecond pulsed electric fields (nsPEF) are emerging as a novel modality for cell stimulation and tissue ablation. However, the downstream protein effectors responsible for nsPEF bioeffects remain to be established. Here we demonstrate that nsPEF activate TMEM16F (or Anoctamin 6), a protein functioning as a Ca2+-dependent phospholipid scramblase and Ca2+-activated chloride channel. Using confocal microscopy and patch clamp recordings, we investigated the relevance of TMEM16F activation for several bioeffects triggered by nsPEF, including phosphatidylserine (PS) externalization, nanopore-conducted currents, membrane blebbing, and cell death. In HEK 293 cells treated with a single 300-ns pulse of 25.5 kV/cm, Tmem16f expression knockdown and TMEM16F-specific inhibition decreased nsPEF-induced PS exposure by 49 and 42%, respectively. Moreover, the Tmem16f silencing significantly decreased Ca2+-dependent chloride channel currents activated in response to the nanoporation. Tmem16f expression also affected nsPEF-induced cell blebbing, with only 20% of the silenced cells developing blebs compared with 53% of the control cells. This inhibition of cellular blebbing correlated with a 25% decrease in cytosolic free Ca2+ transient at 30 s after nanoporation. Finally, in TMEM16F-overexpressing cells, a train of 120 pulses (300 ns, 20 Hz, 6 kV/cm) decreased cell survival to 34% compared with 51% in control cells (*, p < 0.01). Taken together, these results indicate that TMEM16F activation by nanoporation mediates and enhances the diverse cellular effects of nsPEF.
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Affiliation(s)
| | | | - Elena Gianulis
- From the Frank Reidy Research Center for Bioelectrics, and
| | - Jade Meads
- From the Frank Reidy Research Center for Bioelectrics, and
| | - Maura Casciola
- From the Frank Reidy Research Center for Bioelectrics, and
| | - Peter A Mollica
- the Department of Medical Diagnostics and Translational Sciences, Old Dominion University, Norfolk, Virginia 23508
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42
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Lérias JR, Pinto MC, Botelho HM, Awatade NT, Quaresma MC, Silva IAL, Wanitchakool P, Schreiber R, Pepperkok R, Kunzelmann K, Amaral MD. A novel microscopy-based assay identifies extended synaptotagmin-1 (ESYT1) as a positive regulator of anoctamin 1 traffic. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1865:421-431. [PMID: 29154949 DOI: 10.1016/j.bbamcr.2017.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/02/2017] [Accepted: 11/14/2017] [Indexed: 01/14/2023]
Abstract
An attractive possibility to treat Cystic Fibrosis (CF), a severe condition caused by dysfunctional CFTR, an epithelial anion channel, is through the activation of alternative (non-CFTR) anion channels. Anoctamin 1 (ANO1) was demonstrated to be a Ca2+-activated chloride channel (CaCC) and thus of high potential to replace CFTR. Despite that ANO1 is expressed in human lung CF tissue, it is present at the cell surface at very low levels. In addition, little is known about regulation of ANO1 traffic, namely which factors promote its plasma membrane (PM) localization. Here, we generated a novel cellular model, expressing an inducible 3HA-ANO1-eGFP construct, and validated its usage as a microscopy tool to monitor for ANO1 traffic. We demonstrate the robustness and specificity of this cell-based assay, by the identification of siRNAs acting both as ANO1 traffic enhancer and inhibitor, targeting respectively COPB1 and ESYT1 (extended synaptotagmin-1), the latter involved in coupling of the endoplasmic reticulum to the PM at specific microdomains. We further show that knockdown of ESYT1 (and family members ESYT2 and ESYT3) significantly decreased ANO1 current density. This ANO1 cell-based assay constitutes an important tool to be further used in high-throughput screens and drug discovery of high relevance for CF and cancer.
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Affiliation(s)
- Joana R Lérias
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Department of Physiology, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Madalena C Pinto
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Department of Physiology, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany; Cell Biology and Biophysics Unit and Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Hugo M Botelho
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Nikhil T Awatade
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Margarida C Quaresma
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Iris A L Silva
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Podchanart Wanitchakool
- Department of Physiology, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Rainer Schreiber
- Department of Physiology, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Rainer Pepperkok
- Cell Biology and Biophysics Unit and Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Karl Kunzelmann
- Department of Physiology, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Margarida D Amaral
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Cell Biology and Biophysics Unit and Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany.
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43
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Batti L, Sundukova M, Murana E, Pimpinella S, De Castro Reis F, Pagani F, Wang H, Pellegrino E, Perlas E, Di Angelantonio S, Ragozzino D, Heppenstall PA. TMEM16F Regulates Spinal Microglial Function in Neuropathic Pain States. Cell Rep 2017; 15:2608-15. [PMID: 27332874 PMCID: PMC4921873 DOI: 10.1016/j.celrep.2016.05.039] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 12/10/2015] [Accepted: 05/07/2016] [Indexed: 12/31/2022] Open
Abstract
Neuropathic pain is a widespread chronic pain state that results from injury to the nervous system. Spinal microglia play a causative role in the pathogenesis of neuropathic pain through secretion of growth factors and cytokines. Here, we investigated the contribution of TMEM16F, a protein that functions as a Ca2+-dependent ion channel and a phospholipid scramblase, to microglial activity during neuropathic pain. We demonstrate that mice with a conditional ablation of TMEM16F in microglia do not develop mechanical hypersensitivity upon nerve injury. In the absence of TMEM16F, microglia display deficits in process motility and phagocytosis. Moreover, loss of GABA immunoreactivity upon injury is spared in TMEM16F conditional knockout mice. Collectively, these data indicate that TMEM16F is an essential component of the microglial response to injury and suggest the importance of microglial phagocytosis in the pathogenesis of neuropathic pain. Microglial TMEM16F channels are required for neuropathic pain development in mice TMEM16F-deficient microglia display deficits in process motility and phagocytosis Deleting TMEM16F spares injury-induced loss of spinal cord GABA immunoreactivity Microglial phagocytosis may contribute to neuropathic pain development
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Affiliation(s)
- Laura Batti
- EMBL Mouse Biology Unit, Via Ramarini 32, Monterotondo 00015, Italy.
| | - Mayya Sundukova
- EMBL Mouse Biology Unit, Via Ramarini 32, Monterotondo 00015, Italy
| | - Emanuele Murana
- Istituto Pasteur-Fondazione Cenci Bolognetti and Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5 00185 Rome, Italy
| | - Sofia Pimpinella
- EMBL Mouse Biology Unit, Via Ramarini 32, Monterotondo 00015, Italy
| | | | - Francesca Pagani
- Center for Life Nanoscience, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Hong Wang
- Pharmacology Institute, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg
| | - Eloisa Pellegrino
- Istituto Pasteur-Fondazione Cenci Bolognetti and Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5 00185 Rome, Italy
| | - Emerald Perlas
- EMBL Mouse Biology Unit, Via Ramarini 32, Monterotondo 00015, Italy
| | - Silvia Di Angelantonio
- Center for Life Nanoscience, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy; Istituto Pasteur-Fondazione Cenci Bolognetti and Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5 00185 Rome, Italy
| | - Davide Ragozzino
- Istituto Pasteur-Fondazione Cenci Bolognetti and Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5 00185 Rome, Italy; IRCCS Neuromed, Via Atinese, Pozzilli 86077, Italy
| | - Paul A Heppenstall
- EMBL Mouse Biology Unit, Via Ramarini 32, Monterotondo 00015, Italy; Molecular Medicine Partnership Unit (MMPU), 69117 Heidelberg, Germany.
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44
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Jiang T, Yu K, Hartzell HC, Tajkhorshid E. Lipids and ions traverse the membrane by the same physical pathway in the nhTMEM16 scramblase. eLife 2017; 6:28671. [PMID: 28917060 PMCID: PMC5628016 DOI: 10.7554/elife.28671] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/08/2017] [Indexed: 12/21/2022] Open
Abstract
From bacteria to mammals, different phospholipid species are segregated between the inner and outer leaflets of the plasma membrane by ATP-dependent lipid transporters. Disruption of this asymmetry by ATP-independent phospholipid scrambling is important in cellular signaling, but its mechanism remains incompletely understood. Using MD simulations coupled with experimental assays, we show that the surface hydrophilic transmembrane cavity exposed to the lipid bilayer on the fungal scramblase nhTMEM16 serves as the pathway for both lipid translocation and ion conduction across the membrane. Ca2+ binding stimulates its open conformation by altering the structure of transmembrane helices that line the cavity. We have identified key amino acids necessary for phospholipid scrambling and validated the idea that ions permeate TMEM16 Cl- channels via a structurally homologous pathway by showing that mutation of two residues in the pore region of the TMEM16A Ca2+-activated Cl- channel convert it into a robust scramblase.
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Affiliation(s)
- Tao Jiang
- Department of Biochemistry, Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Kuai Yu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, United States
| | - H Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States
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45
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Simões F, Ousingsawat J, Wanitchakool P, Fonseca A, Cabrita I, Benedetto R, Schreiber R, Kunzelmann K. CFTR supports cell death through ROS-dependent activation of TMEM16F (anoctamin 6). Pflugers Arch 2017; 470:305-314. [DOI: 10.1007/s00424-017-2065-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/25/2017] [Accepted: 08/28/2017] [Indexed: 12/11/2022]
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46
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Fedigan S, Bradley E, Webb T, Large RJ, Hollywood MA, Thornbury KD, McHale NG, Sergeant GP. Effects of new-generation TMEM16A inhibitors on calcium-activated chloride currents in rabbit urethral interstitial cells of Cajal. Pflugers Arch 2017; 469:1443-1455. [PMID: 28733893 DOI: 10.1007/s00424-017-2028-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 06/21/2017] [Accepted: 07/03/2017] [Indexed: 12/18/2022]
Abstract
Interstitial cells of Cajal (ICC) isolated from the rabbit urethra exhibit Ca2+-activated Cl- currents (I ClCa) that are important for the development of urethral tone. Here, we examined if TMEM16A (ANO1) contributed to this activity by examining the effect of "new-generation" TMEM16A inhibitors, CACCinh-A01 and T16Ainh-A01, on I ClCa recorded from freshly isolated rabbit urethral ICC (RUICC) and on contractions of intact strips of rabbit urethra smooth muscle. Real-time quantitative PCR experiments demonstrated that TMEM16A was highly expressed in rabbit urethra smooth muscle, in comparison to TMEM16B and TMEM16F. Single-cell RT-PCR experiments revealed that only TMEM16A was expressed in freshly isolated RUICC. Depolarization-evoked I ClCa in isolated RUICC, recorded using voltage clamp, were inhibited by CACCinh-A01 and T16Ainh-A01 with IC50 values of 1.2 and 3.4 μM, respectively. Similarly, spontaneous transient inward currents (STICs) recorded from RUICC voltage clamped at -60 mV and spontaneous transient depolarizations (STDs), recorded in current clamp, were also inhibited by CACCinh-A01 and T16Ainh-A01. In contrast, spontaneous Ca2+ waves in isolated RUICC were only partially reduced by CACCinh-A01 and T16Ainh-A01. Finally, neurogenic contractions of strips of rabbit urethra smooth muscle (RUSM), evoked by electric field stimulation (EFS), were also significantly reduced by CACCinh-A01 and T16Ainh-A01. These data are consistent with the idea that TMEM16A is involved with CACCs in RUICC and in contraction of rabbit urethral smooth muscle.
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Affiliation(s)
- Stephen Fedigan
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Eamonn Bradley
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Timothy Webb
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Roddy J Large
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Mark A Hollywood
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Keith D Thornbury
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Noel G McHale
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Gerard P Sergeant
- The Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland.
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Scoville DK, Botta D, Galdanes K, Schmuck SC, White CC, Stapleton PL, Bammler TK, MacDonald JW, Altemeier WA, Hernandez M, Kleeberger SR, Chen LC, Gordon T, Kavanagh TJ. Genetic determinants of susceptibility to silver nanoparticle-induced acute lung inflammation in mice. FASEB J 2017; 31:4600-4611. [PMID: 28716969 DOI: 10.1096/fj.201700187r] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/19/2017] [Indexed: 12/12/2022]
Abstract
Silver nanoparticles (AgNPs) are employed in a variety of consumer products; however, in vivo rodent studies indicate that AgNPs can cause lung inflammation and toxicity in a strain- and particle type-dependent manner, but mechanisms of susceptibility remain unclear. The aim of this study was to assess the variation in AgNP-induced lung inflammation and toxicity across multiple inbred mouse strains and to use genome-wide association (GWA) mapping to identify potential candidate susceptibility genes. Mice received doses of 0.25 mg/kg of either 20-nm citrate-coated AgNPs or citrate buffer using oropharyngeal aspiration. Neutrophils in bronchoalveolar lavage fluid (BALF) served as markers of inflammation. We found significant strain- and treatment-dependent variation in neutrophils in BALF. GWA mapping identified 10 significant single-nucleotide polymorphisms (false discovery rate, 15%) in 4 quantitative trait loci on mouse chromosomes 1, 4, 15, and 18, and Nedd4l (neural precursor cell expressed developmentally downregulated gene 4-like; chromosome 18), Ano6 (anocatmin 6; chromosome 15), and Rnf220 (Ring finger protein 220; chromosome 4) were considered candidate genes. Quantitative RT-PCR revealed significant inverse associations between mRNA levels of these genes and neutrophil influx. Nedd4l, Ano6, and Rnf220 are candidate susceptibility genes for AgNP-induced lung inflammation that warrant additional exploration in future studies.-Scoville, D. K., Botta, D., Galdanes, K., Schmuck, S. C., White, C. C., Stapleton, P. L., Bammler, T. K., MacDonald, J. W., Altemeier, W. A., Hernandez, M., Kleeberger, S. R., Chen, L.-C., Gordon, T., Kavanagh, T. J. Genetic determinants of susceptibility to silver nanoparticle-induced acute lung inflammation in mice.
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Affiliation(s)
- David K Scoville
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Dianne Botta
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Karen Galdanes
- Department of Environmental Medicine, New York University, Tuxedo, New York, USA
| | - Stefanie C Schmuck
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Collin C White
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Patricia L Stapleton
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - James W MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | | | - Michelle Hernandez
- Department of Environmental Medicine, New York University, Tuxedo, New York, USA
| | - Steven R Kleeberger
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Lung-Chi Chen
- Department of Environmental Medicine, New York University, Tuxedo, New York, USA
| | - Terry Gordon
- Department of Environmental Medicine, New York University, Tuxedo, New York, USA
| | - Terrance J Kavanagh
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA;
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48
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Canella R, Martini M, Borriello R, Cavicchio C, Muresan XM, Benedusi M, Cervellati F, Valacchi G. Modulation of Chloride Currents in Human Lung Epithelial Cells Exposed to Exogenous Oxidative Stress. J Cell Physiol 2017; 232:1817-1825. [DOI: 10.1002/jcp.25705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/22/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Rita Canella
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Marta Martini
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Roberta Borriello
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Carlotta Cavicchio
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Ximena M. Muresan
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Mascia Benedusi
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Franco Cervellati
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
- Department of Animal Science; North Carolina State University; PHHI NC Research Campus; Kannapolis North Carolina
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49
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Banerjee J, Leung CT, Li A, Peterson-Yantorno K, Ouyang H, Stamer WD, Civan MM. Regulatory Roles of Anoctamin-6 in Human Trabecular Meshwork Cells. Invest Ophthalmol Vis Sci 2017; 58:492-501. [PMID: 28125837 PMCID: PMC5283088 DOI: 10.1167/iovs.16-20188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 12/07/2016] [Indexed: 12/19/2022] Open
Abstract
Purpose Trabecular meshwork (TM) cell volume is a determinant of aqueous humor outflow resistance, and thereby IOP. Regulation of TM cell volume depends on chloride ion (Cl-) release through swelling-activated channels (ICl,Swell), whose pore is formed by LRRC8 proteins. Chloride ion release through swelling-activated channels has been reported to be regulated by calcium-activated anoctamins, but this finding is controversial. Particularly uncertain has been the effect of anoctamin Ano6, reported as a Ca2+-activated Cl- (CaCC) or cation channel in other cells. The current study tested whether anoctamin activity modifies volume regulation of primary TM cell cultures and cell lines. Methods Gene expression was studied with quantitative PCR, supplemented by reverse-transcriptase PCR and Western immunoblots. Currents were measured by ruptured whole-cell patch clamping and volume by electronic cell sizing. Results Primary TM cell cultures and the TM5 and GTM3 cell lines expressed Ano6 3 to 4 orders of magnitude higher than the other anoctamin CaCCs (Ano1 and Ano2). Ionomycin increased cell Ca2+ and activated macroscopic currents conforming to CaCCs in other cells, but displayed significantly more positive mean reversal potentials (+5 to +12 mV) than those displayed by ICl,Swell (-14 to -21 mV) in the same cells. Nonselective CaCC inhibitors (tannic acid>CaCCinh-A01) and transient Ano6 knockdown strongly inhibited ionomycin-activated currents, ICl,Swell and the regulatory volume response to hyposmotic swelling. Conclusions Ionomycin activates CaCCs associated with net cation movement in TM cells. These currents, ICl,Swell, and cell volume are regulated by Ano6. The findings suggest a novel clinically-relevant approach for altering cell volume, and thereby outflow resistance, by targeting Ano6.
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Affiliation(s)
- Juni Banerjee
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Chi-Ting Leung
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Ang Li
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
- Guangdong-Hong Kong - Macau Institute of CNS Regeneration, Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, China
| | - Kim Peterson-Yantorno
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Huan Ouyang
- Guangdong-Hong Kong - Macau Institute of CNS Regeneration, Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, China
| | - W. Daniel Stamer
- Departments of Ophthalmology and Biomedical Engineering, Duke University, DUMC 3802, Durham, North Carolina, United States
| | - Mortimer M. Civan
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
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50
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Schreiber R, Kunzelmann K. Expression of anoctamins in retinal pigment epithelium (RPE). Pflugers Arch 2016; 468:1921-1929. [PMID: 27822608 DOI: 10.1007/s00424-016-1898-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/17/2016] [Accepted: 10/19/2016] [Indexed: 01/24/2023]
Abstract
The anoctamin (ANO, TMEM16) family of Ca2+-activated Cl- channels consists of ten members with different cellular functions (ANO1-10). ANO1 is a Ca2+-activated Cl- channel in secretory epithelial cells of exocrine pancreas, salivary glands, or enterocytes. Expression of ANO1 also promotes cell proliferation and migration of tumor cells. ANO6 is essential for Ca2+-dependent scrambling of membrane phospholipids in platelets, red blood cells, and lymphocytes. ANO10 modulates Ca2+ signals in macrophages and has a role in cerebellar ataxia and other neurological disorders. All three anoctamins have been proposed to control intracellular Ca2+ signals. Anoctamins may also form the basolateral Ca2+-activated Cl- channel in the retinal pigment epithelium (RPE). We show that native human, bovine, porcine, and mouse RPEs express ANO1, ANO6, and ANO10. Growth arrested and confluent RPR cells expressed ANO1 in the plasma membrane, whereas ANO6 and ANO10 were found in the primary cilium. Ussing chamber experiments showed that the application of ATP to the apical (retinal) side of porcine RPE induced a Ca2+-activated Cl- secretion. Activation was inhibited by basolateral (choroidal) administration of the ANO inhibitors AO1, niflumic acid (NFA), and 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS). The results suggest that ANO1 is responsible for basolateral Ca2+-dependent Cl- secretion in RPE, whereas ANO6 and ANO10 may have different functions, such as modulating Ca2+ signals.
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Affiliation(s)
- Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
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