1
|
Khan N, Kurnik-Łucka M, Latacz G, Gil K. Systematic-Narrative Hybrid Literature Review: Crosstalk between Gastrointestinal Renin-Angiotensin and Dopaminergic Systems in the Regulation of Intestinal Permeability by Tight Junctions. Int J Mol Sci 2024; 25:5566. [PMID: 38791603 PMCID: PMC11122119 DOI: 10.3390/ijms25105566] [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: 04/17/2024] [Revised: 05/12/2024] [Accepted: 05/18/2024] [Indexed: 05/26/2024] Open
Abstract
In the first part of this article, the role of intestinal epithelial tight junctions (TJs), together with gastrointestinal dopaminergic and renin-angiotensin systems, are narratively reviewed to provide sufficient background. In the second part, the current experimental data on the interplay between gastrointestinal (GI) dopaminergic and renin-angiotensin systems in the regulation of intestinal epithelial permeability are reviewed in a systematic manner using the PRISMA methodology. Experimental data confirmed the copresence of DOPA decarboxylase (DDC) and angiotensin converting enzyme 2 (ACE2) in human and rodent enterocytes. The intestinal barrier structure and integrity can be altered by angiotensin (1-7) and dopamine (DA). Both renin-angiotensin and dopaminergic systems influence intestinal Na+/K+-ATPase activity, thus maintaining electrolyte and nutritional homeostasis. The colocalization of B0AT1 and ACE2 indicates the direct role of the renin-angiotensin system in amino acid absorption. Yet, more studies are needed to thoroughly define the structural and functional interaction between TJ-associated proteins and GI renin-angiotensin and dopaminergic systems.
Collapse
Affiliation(s)
- Nadia Khan
- Faculty of Medicine, Department of Pathophysiology, Jagiellonian University Medical College, Czysta 18, 31-121 Krakow, Poland
- Faculty of Pharmacy, Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 31-008 Krakow, Poland
| | - Magdalena Kurnik-Łucka
- Faculty of Medicine, Department of Pathophysiology, Jagiellonian University Medical College, Czysta 18, 31-121 Krakow, Poland
| | - Gniewomir Latacz
- Faculty of Pharmacy, Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 31-008 Krakow, Poland
| | - Krzysztof Gil
- Faculty of Medicine, Department of Pathophysiology, Jagiellonian University Medical College, Czysta 18, 31-121 Krakow, Poland
| |
Collapse
|
2
|
McKenna MJ, Renaud JM, Ørtenblad N, Overgaard K. A century of exercise physiology: effects of muscle contraction and exercise on skeletal muscle Na +,K +-ATPase, Na + and K + ions, and on plasma K + concentration-historical developments. Eur J Appl Physiol 2024; 124:681-751. [PMID: 38206444 PMCID: PMC10879387 DOI: 10.1007/s00421-023-05335-9] [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: 02/02/2023] [Accepted: 09/27/2023] [Indexed: 01/12/2024]
Abstract
This historical review traces key discoveries regarding K+ and Na+ ions in skeletal muscle at rest and with exercise, including contents and concentrations, Na+,K+-ATPase (NKA) and exercise effects on plasma [K+] in humans. Following initial measures in 1896 of muscle contents in various species, including humans, electrical stimulation of animal muscle showed K+ loss and gains in Na+, Cl- and H20, then subsequently bidirectional muscle K+ and Na+ fluxes. After NKA discovery in 1957, methods were developed to quantify muscle NKA activity via rates of ATP hydrolysis, Na+/K+ radioisotope fluxes, [3H]-ouabain binding and phosphatase activity. Since then, it became clear that NKA plays a central role in Na+/K+ homeostasis and that NKA content and activity are regulated by muscle contractions and numerous hormones. During intense exercise in humans, muscle intracellular [K+] falls by 21 mM (range - 13 to - 39 mM), interstitial [K+] increases to 12-13 mM, and plasma [K+] rises to 6-8 mM, whilst post-exercise plasma [K+] falls rapidly, reflecting increased muscle NKA activity. Contractions were shown to increase NKA activity in proportion to activation frequency in animal intact muscle preparations. In human muscle, [3H]-ouabain-binding content fully quantifies NKA content, whilst the method mainly detects α2 isoforms in rats. Acute or chronic exercise affects human muscle K+, NKA content, activity, isoforms and phospholemman (FXYD1). Numerous hormones, pharmacological and dietary interventions, altered acid-base or redox states, exercise training and physical inactivity modulate plasma [K+] during exercise. Finally, historical research approaches largely excluded female participants and typically used very small sample sizes.
Collapse
Affiliation(s)
- Michael J McKenna
- Institute for Health and Sport, Victoria University, Melbourne, VIC, 8001, Australia.
- College of Physical Education, Southwest University, Chongqing, China.
- College of Sport Science, Zhuhai College of Science and Technology, Zhuhai, China.
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, Neuromuscular Research Center, University of Ottawa, Ottawa, ON, Canada
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Kristian Overgaard
- Exercise Biology, Department of Public Health, Aarhus University, Aarhus, Denmark
| |
Collapse
|
3
|
Gonçalves-de-Albuquerque CF, Cunha CMCD, Castro LVGD, Martins CDA, Barnese MRC, Burth P, Younes-Ibrahim M. Cellular Pathophysiology of Leptospirosis: Role of Na/K-ATPase. Microorganisms 2023; 11:1695. [PMID: 37512868 PMCID: PMC10383190 DOI: 10.3390/microorganisms11071695] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/04/2023] [Accepted: 06/19/2023] [Indexed: 07/30/2023] Open
Abstract
Inada and Ido identified Leptospira sp. as the pathogen responsible for Weil's Disease in 1915. Later, it was confirmed that Leptospira causes leptospirosis. The host microorganism's interaction at the cellular level remained misunderstood for many years. Although different bacterial components have been isolated and purified, the complexity of the molecular interactions between these components and the host and the molecular mechanisms responsible for the systemic dysfunctions still needs to be fully unveiled. Leptospirosis affects virtually all animal species. Its cellular pathophysiology must involve a ubiquitous cellular mechanism in all eukaryotes. Na/K-ATPase is the molecular target of the leptospiral endotoxin (glycolipoprotein-GLP). Na/K-ATPase dysfunctions on different types of cells give rise to the organ disorders manifested in leptospirosis. Concomitantly, the development of a peculiar metabolic disorder characterized by dyslipidemia, with increased levels of circulating free fatty acids and an imbalance in the fatty acid/albumin molar ratio, triggers events of cellular lipotoxicity. Synergistically, multiple molecular stimuli are prompted during the infection, activating inflammasomes and Na/K-ATPase signalosome, leading to pro-inflammatory and metabolic alterations during leptospirosis. Leptospirosis involves diverse molecular mechanisms and alteration in patient inflammatory and metabolic status. Nonetheless, Na/K-ATPase is critical in the disease, and it is targeted by GLP, its components, and other molecules, such as fatty acids, that inhibit or trigger intracellular signaling through this enzyme. Herein, we overview the role of Na/K-ATPase during leptospirosis infection as a potential therapeutic target or an indicator of disease severity.
Collapse
Affiliation(s)
| | - Carolina Medina Coeli da Cunha
- Laboratory of Immunopharmacology, Department of Physiology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro 20211-030, Brazil
- Neuroscience Graduate Program, Federal Fluminense University (UFF), Niteroi 24000-000, Brazil
| | | | - Caroline de Azevedo Martins
- School of Medicine and Surgery, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro 20270-901, Brazil
| | | | - Patrícia Burth
- Laboratory of Enzymology and Cellular Signaling, Department of Cellular and Molecular Biology, Federal Fluminense University (UFF), Niteroi 24000-000, Brazil
| | - Mauricio Younes-Ibrahim
- FISCLINEX Postgraduate Program, State University of Rio de Janeiro (UERJ), Rio de Janeiro 20550-900, Brazil
- Department of Medicine, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22453-900, Brazil
- State University of Rio de Janeiro (UERJ), Rio de Janeiro 20550-900, Brazil
| |
Collapse
|
4
|
Na/K-ATPase Ion Transport and Receptor-Mediated Signaling Pathways. J Membr Biol 2021; 254:443-446. [PMID: 34724099 DOI: 10.1007/s00232-021-00207-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 10/19/2022]
|
5
|
Jiao S, Johnson K, Moreno C, Yano S, Holmgren M. Comparative description of the mRNA expression profile of Na + /K + -ATPase isoforms in adult mouse nervous system. J Comp Neurol 2021; 530:627-647. [PMID: 34415061 PMCID: PMC8716420 DOI: 10.1002/cne.25234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 06/16/2021] [Accepted: 08/16/2021] [Indexed: 11/09/2022]
Abstract
Mutations in genes encoding Na+ /K+ -ATPase α1, α2, and α3 subunits cause a wide range of disabling neurological disorders, and dysfunction of Na+ /K+ -ATPase may contribute to neuronal injury in stroke and dementia. To better understand the pathogenesis of these diseases, it is important to determine the expression patterns of the different Na+ /K+ -ATPase subunits within the brain and among specific cell types. Using two available scRNA-Seq databases from the adult mouse nervous system, we examined the mRNA expression patterns of the different isoforms of the Na+ /K+ -ATPase α, β and Fxyd subunits at the single-cell level among brain regions and various neuronal populations. We subsequently identified specific types of neurons enriched with transcripts for α1 and α3 isoforms and elaborated how α3-expressing neuronal populations govern cerebellar neuronal circuits. We further analyzed the co-expression network for α1 and α3 isoforms, highlighting the genes that positively correlated with α1 and α3 expression. The top 10 genes for α1 were Chn2, Hpcal1, Nrgn, Neurod1, Selm, Kcnc1, Snrk, Snap25, Ckb and Ccndbp1 and for α3 were Sorcs3, Eml5, Neurod2, Ckb, Tbc1d4, Ptprz1, Pvrl1, Kirrel3, Pvalb, and Asic2.
Collapse
Affiliation(s)
- Song Jiao
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Kory Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Cristina Moreno
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Sho Yano
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Miguel Holmgren
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
6
|
Shahnazari M, Alemzadeh A, Zakipour Z, Razi H. Evolution and classification of Na/K ATPase α-subunit in Arthropoda and Nematoda. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2020.101015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
7
|
Shen X, Wang C, Zhu H, Wang Y, Wang X, Cheng X, Ge W, Lu W. Exosome-mediated transfer of CD44 from high-metastatic ovarian cancer cells promotes migration and invasion of low-metastatic ovarian cancer cells. J Ovarian Res 2021; 14:38. [PMID: 33627162 PMCID: PMC7905574 DOI: 10.1186/s13048-021-00776-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/25/2021] [Indexed: 01/18/2023] Open
Abstract
Objective To investigate the detailed roles and mechanisms of tumor-derived exosomes in progression and metastasis of ovarian cancer in vitro. Methods Exosomes were isolated by differential centrifugation method; the morphology, size and biological markers of exosomes were separately defined by transmission electron microscopy, nanoS90 and Western blotting; Trans-well chambers assay was used to assess the ability of migration and invasion of recipient cells uptaking the exosomes from HO8910PM cells. The downstream molecule was screened by mass spectrometry.CD44 was identified by western blotting and the function of CD44 was identified by trans-well chambers assay and CCK8 assay. Results Exosomes derived from HO8910PM cells could be transferred to HO8910 cells and promote cell migration and invasion in the recipient cells of ovarian cancer. And CD44 could be transferred to the HO8910 cells through exosomes from HO8910PM cells and influence the migration and invasion ability of HO8910 cells. Conclusion The more aggressive subpopulation can transfer a metastatic phenotype to the less one via secreting exosomes within a heterogeneous tumor. CD44 may be a potential therapeutic approach for ovarian cancer.
Collapse
Affiliation(s)
- Xiameng Shen
- Department of Gynecologic Oncology, Women's Hospital School of Medicine Zhejiang University, No. 1 Xueshi Road, Hangzhou, 310006, China
| | - Conghui Wang
- Women's Reproductive Health Research Laboratory of Zhejiang Province, Women's Hospital School of Medicine Zhejiang University, Hangzhou, China
| | - Huihui Zhu
- Department of Gynecologic Oncology, Women's Hospital School of Medicine Zhejiang University, No. 1 Xueshi Road, Hangzhou, 310006, China
| | - Yaping Wang
- Department of Gynecologic Oncology, Women's Hospital School of Medicine Zhejiang University, No. 1 Xueshi Road, Hangzhou, 310006, China
| | - Xinyu Wang
- Department of Gynecologic Oncology, Women's Hospital School of Medicine Zhejiang University, No. 1 Xueshi Road, Hangzhou, 310006, China.,Women's Reproductive Health Research Laboratory of Zhejiang Province, Women's Hospital School of Medicine Zhejiang University, Hangzhou, China.,Zhejiang University Cancer Center, Hangzhou, China
| | - Xiaodong Cheng
- Department of Gynecologic Oncology, Women's Hospital School of Medicine Zhejiang University, No. 1 Xueshi Road, Hangzhou, 310006, China.,Women's Reproductive Health Research Laboratory of Zhejiang Province, Women's Hospital School of Medicine Zhejiang University, Hangzhou, China.,Zhejiang University Cancer Center, Hangzhou, China
| | - Wanzhong Ge
- Women's Reproductive Health Research Laboratory of Zhejiang Province, Women's Hospital School of Medicine Zhejiang University, Hangzhou, China.,Zhejiang University Cancer Center, Hangzhou, China
| | - Weiguo Lu
- Department of Gynecologic Oncology, Women's Hospital School of Medicine Zhejiang University, No. 1 Xueshi Road, Hangzhou, 310006, China. .,Women's Reproductive Health Research Laboratory of Zhejiang Province, Women's Hospital School of Medicine Zhejiang University, Hangzhou, China. .,Zhejiang University Cancer Center, Hangzhou, China.
| |
Collapse
|
8
|
Syeda SS, Sánchez G, McDermott JP, Hong KH, Blanco G, Georg GI. The Na+ and K+ transport system of sperm (ATP1A4) is essential for male fertility and an attractive target for male contraception†. Biol Reprod 2020; 103:343-356. [PMID: 32588885 PMCID: PMC7401355 DOI: 10.1093/biolre/ioaa093] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/19/2020] [Indexed: 01/07/2023] Open
Abstract
One of the mechanisms that cells have developed to fulfil their specialized tasks is to express different molecular variants of a particular protein that has unique functional properties. Na,K-ATPase (NKA), the ion transport mechanism that maintains the transmembrane Na+ and K+ concentrations across the plasma membrane of cells, is one of such protein systems that shows high molecular and functional heterogeneity. Four different isoforms of the NKA catalytic subunit are expressed in mammalian cells (NKAα1, NKAα2, NKAα3, and NKAα4). NKAα4 (ATP1A4) is the isoform with the most restricted pattern of expression, being solely produced in male germ cells of the testis. NKAα4 is abundant in spermatozoa, where it is required for sperm motility and hyperactivation. This review discusses the expression, functional properties, mechanism of action of NKAα4 in sperm physiology, and its role in male fertility. In addition, we describe the use of NKAα4 as a target for male contraception and a potential approach to pharmacologically block its ion transport function to interfere with male fertility.
Collapse
Affiliation(s)
- Shameem Sultana Syeda
- Department of Medicinal Chemistry, College of Pharmacy, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA
| | - Gladis Sánchez
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jeffrey P McDermott
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Kwon Ho Hong
- Department of Medicinal Chemistry, College of Pharmacy, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA
| | - Gustavo Blanco
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Gunda I Georg
- Department of Medicinal Chemistry, College of Pharmacy, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA
| |
Collapse
|
9
|
Blaustein MP, Hamlyn JM. Ouabain, endogenous ouabain and ouabain-like factors: The Na + pump/ouabain receptor, its linkage to NCX, and its myriad functions. Cell Calcium 2020; 86:102159. [PMID: 31986323 DOI: 10.1016/j.ceca.2020.102159] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/01/2020] [Accepted: 01/03/2020] [Indexed: 12/12/2022]
Abstract
In this brief review we discuss some aspects of the Na+ pump and its roles in mediating the effects of ouabain and endogenous ouabain (EO): i) in regulating the cytosolic Ca2+ concentration ([Ca2+]CYT) via Na/Ca exchange (NCX), and ii) in activating a number of protein kinase (PK) signaling cascades that control a myriad of cell functions. Importantly, [Ca2+]CYT and the other signaling pathways intersect at numerous points because of the influence of Ca2+ and calmodulin in modulating some steps in those other pathways. While both mechanisms operate in virtually all cells and tissues, this article focuses primarily on their functions in the cardiovascular system, the central nervous system (CNS) and the kidneys.
Collapse
Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| |
Collapse
|
10
|
Ding T, Wang S, Gao Y, Li C, Wan F, Zhang B. Toxicity and effects of four insecticides on Na +, K +-ATPase of western flower thrips, Frankliniella occidentalis. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:58-64. [PMID: 31784922 DOI: 10.1007/s10646-019-02139-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/12/2019] [Indexed: 06/10/2023]
Abstract
Western flower thrips (WFT), Frankliniella occidentalis, has become an important pest of vegetables worldwide, due to its economic damage to crop production. In order to control WFT, chemical insecticides are widely used. However, WFT has developed a high resistance against many kinds of insecticides. Na+, K+-ATPase, playing an important role in the ionic transmission across the membrane, is commonly considered to be the target of several xenobiotic compounds. However, whether the Na+, K+-ATPase can be used as one of the target sites for controlling WFT is still unknown. In this study, resistance levels of WFT to four insecticides (chlorpyrifos, beta cypermethrin, abamectin, and thiamethoxam) were measured. It was found that all four insecticides exhibited significant inhibitory effects on WFT, especially on nymphs. The activity of Na+, K+-ATPase was estimated after the treatment of four insecticides. Additionally, mRNA expression levels of three Na+, K+-ATPase α-subunit isoforms (X1, X2 and X3) were detected using RT-qPCR. The transcription profile of three Na+, K+-ATPase α-subunit isoforms were diverse after treatment by these four insecticides, which indicated that these isoforms might play different roles in the tolerance to insecticides. The results suggested that Na+, K+-ATPase can obviously be inhibited by these four classes of insecticide, and may serve as the new target for controlling WFT.
Collapse
Affiliation(s)
- Tianbo Ding
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
| | - Sifang Wang
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
| | - Yulin Gao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, PR China
| | - Changyou Li
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
| | - Fanghao Wan
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, PR China
| | - Bin Zhang
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China.
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China.
| |
Collapse
|
11
|
Meinzer F, Dobler S, Donath A, Lohr JN. Robust reference gene design and validation for expression studies in the large milkweed bug, Oncopeltus fasciatus, upon cardiac glycoside stress. Gene 2019; 710:66-75. [PMID: 31108166 DOI: 10.1016/j.gene.2019.05.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 04/06/2019] [Accepted: 05/13/2019] [Indexed: 11/18/2022]
Abstract
Despite its history as a developmental and evolutionary model organism, gene expression analysis in the large milkweed bug, Oncopeltus fasciatus, has rarely been explored using quantitative real-time PCR. The strength of this method depends greatly on the endogenous controls used for normalization, which are lacking for the milkweed bug system. Here, to fill in this gap in our knowledge, we validated the stability of a set of ten candidate reference genes identified from the O. fasciatus transcriptome, and did so upon exposure to a dietary toxin, a cardiac glycoside, and across four different exposure periods. To increase robustness against gDNA contaminants, genome resources were used to design intron-bridging primers. A comprehensive stability validation by the Bestkeeper, Normfinder, geNorm and comparative ΔCt methods identified ef1a and tubulin as the most stable genes across treatments and time points, whereas 18S rRNA was the most unstable. However, accounting for the temporal scale indicated that time point confined normalizers might enable higher quantification accuracy for treatment comparison. Overall this study demonstrates: (i) a robust RT-qPCR primer design approach is possible for non-model organisms where genome annotation is often incomplete, and (ii) the importance of detailed reference gene stability exploration in multifactorial experimental designs.
Collapse
Affiliation(s)
- Fee Meinzer
- Molekulare Evolutionsbiologie, Institut für Zoologie, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany.
| | - Susanne Dobler
- Molekulare Evolutionsbiologie, Institut für Zoologie, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Alexander Donath
- Zentrum für Molekulare Biodiversitätsforschung, Zoologisches Forschungsmuseum Alexander Koenig, 53113 Bonn, Germany
| | - Jennifer N Lohr
- Molekulare Evolutionsbiologie, Institut für Zoologie, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| |
Collapse
|
12
|
Dobretsov M, Hayar A, Kockara NT, Kozhemyakin M, Light KE, Patyal P, Pierce DR, Wight PA. A Transgenic Mouse Model to Selectively Identify α 3 Na,K-ATPase Expressing Cells in the Nervous System. Neuroscience 2018; 398:274-294. [PMID: 30031123 DOI: 10.1016/j.neuroscience.2018.07.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/06/2018] [Accepted: 07/11/2018] [Indexed: 10/28/2022]
Abstract
The α3 Na+,K+-ATPase (α3NKA) is one of four known α isoforms of the mammalian transporter. A deficiency in α3NKA is linked to severe movement control disorders. Understanding the pathogenesis of these disorders is limited by an incomplete knowledge of α3NKA expression in the brain as well as the challenges associated with identifying living cells that express the isoform for subsequent electrophysiological studies. To address this problem, transgenic mice were generated on the C57BL/6 genetic background, which utilize the mouse α3 subunit gene (Atp1a3) promoter to drive the expression of ZsGreen1 fluorescent protein. Consistent with published results on α3NKA distribution, a ZsGreen1 signal was detected in the brain, but not in the liver, with Atp1a3-ZsGreen1 transgenic mice. The intensity of ZsGreen1 fluorescence in neuronal cell bodies varied considerably in the brain, being highest in the brainstem, deep cerebellar and select thalamic nuclei, and relatively weak in cortical regions. Fluorescence was not detected in astrocytes or white matter areas. ZsGreen1-positive neurons were readily observed in fresh (unfixed) brain sections, which were amenable to patch-clamp recordings. Thus, the α3NKA-ZsGreen1 mouse model provides a powerful tool for studying the distribution and functional properties of α3NKA-expressing neurons in the brain.
Collapse
Affiliation(s)
- Maxim Dobretsov
- Department of Anesthesiology, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States.
| | - Abdallah Hayar
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States
| | - Neriman T Kockara
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States
| | - Maxim Kozhemyakin
- Department of Neurology, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States
| | - Kim E Light
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States
| | - Pankaj Patyal
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States
| | - Dwight R Pierce
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States
| | - Patricia A Wight
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR, United States.
| |
Collapse
|
13
|
Taub M. Gene Level Regulation of Na,K-ATPase in the Renal Proximal Tubule Is Controlled by Two Independent but Interacting Regulatory Mechanisms Involving Salt Inducible Kinase 1 and CREB-Regulated Transcriptional Coactivators. Int J Mol Sci 2018; 19:E2086. [PMID: 30021947 PMCID: PMC6073390 DOI: 10.3390/ijms19072086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 12/26/2022] Open
Abstract
For many years, studies concerning the regulation of Na,K-ATPase were restricted to acute regulatory mechanisms, which affected the phosphorylation of Na,K-ATPase, and thus its retention on the plasma membrane. However, in recent years, this focus has changed. Na,K-ATPase has been established as a signal transducer, which becomes part of a signaling complex as a consequence of ouabain binding. Na,K-ATPase within this signaling complex is localized in caveolae, where Na,K-ATPase has also been observed to regulate Inositol 1,4,5-Trisphosphate Receptor (IP3R)-mediated calcium release. This latter association has been implicated as playing a role in signaling by G Protein Coupled Receptors (GPCRs). Here, the consequences of signaling by renal effectors that act via such GPCRs are reviewed, including their regulatory effects on Na,K-ATPase gene expression in the renal proximal tubule (RPT). Two major types of gene regulation entail signaling by Salt Inducible Kinase 1 (SIK1). On one hand, SIK1 acts so as to block signaling via cAMP Response Element (CRE) Binding Protein (CREB) Regulated Transcriptional Coactivators (CRTCs) and on the other hand, SIK1 acts so as to stimulate signaling via the Myocyte Enhancer Factor 2 (MEF2)/nuclear factor of activated T cell (NFAT) regulated genes. Ultimate consequences of these pathways include regulatory effects which alter the rate of transcription of the Na,K-ATPase β1 subunit gene atp1b1 by CREB, as well as by MEF2/NFAT.
Collapse
Affiliation(s)
- Mary Taub
- Biochemistry Dept., Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main Street, Suite 4902, Buffalo, NY 14203, USA.
| |
Collapse
|
14
|
Floyd RV, Mobasheri A, Wray S. Gestation changes sodium pump isoform expression, leading to changes in ouabain sensitivity, contractility, and intracellular calcium in rat uterus. Physiol Rep 2018; 5. [PMID: 29208689 PMCID: PMC5727280 DOI: 10.14814/phy2.13527] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 11/24/2022] Open
Abstract
Developmental and tissue‐specific differences in isoforms allow Na+, K+‐ATPase function to be tightly regulated, as they control sensitivity to ions and inhibitors. Uterine contraction relies on the activity of the Na+, K+ATPase, which creates ionic gradients that drive excitation‐contraction coupling. It is unknown whether Na+, K+ATPase isoforms are regulated throughout pregnancy or whether they have a direct role in modulating uterine contractility. We hypothesized that gestation‐dependent differential expression of isoforms would affect contractile responses to Na+, K+ATPase α subunit inhibition with ouabain. Our aims were therefore: (1) to determine the gestation‐dependent expression of mRNA transcripts, protein abundance and tissue distribution of Na+, K+ATPase isoforms in myometrium; (2) to investigate the functional effects of differential isoform expression via ouabain sensitivity; and (3) if changes in contractile responses can be explained by changes in intracellular [Ca2+]. Changes in abundance and distribution of the Na+, K+ATPase α, β and FXYD1 and 2 isoforms, were studied in rat uterus from nonpregnant, and early, mid‐, and term gestation. All α, β subunit isoforms (1,2,3) and FXYD1 were detected but FXYD2 was absent. The α1 and β1 isoforms were unchanged throughout pregnancy, whereas α2 and α3 significant decreased at term while β2 and FXYD1 significantly increased from mid‐term onwards. These changes in expression correlated with increased functional sensitivity to ouabain, and parallel changes in intracellular Ca2+, measured with Indo‐1. In conclusion, gestation induces specific regulatory changes in expression of Na+, K+ATPase isoforms in the uterus which influence contractility and may be related to the physiological requirements for successful pregnancy and delivery.
Collapse
Affiliation(s)
- Rachel V Floyd
- The Department of Molecular and Cellular Physiology, University of Liverpool, Liverpool, United Kingdom
| | - Ali Mobasheri
- Department of Veterinary Preclinical Sciences, School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Susan Wray
- The Department of Molecular and Cellular Physiology, University of Liverpool, Liverpool, United Kingdom
| |
Collapse
|
15
|
Lohr JN, Meinzer F, Dalla S, Romey-Glüsing R, Dobler S. The function and evolutionary significance of a triplicated Na,K-ATPase gene in a toxin-specialized insect. BMC Evol Biol 2017; 17:256. [PMID: 29246105 PMCID: PMC5732401 DOI: 10.1186/s12862-017-1097-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/27/2017] [Indexed: 01/27/2023] Open
Abstract
Background The Na,K-ATPase is a vital animal cell-membrane protein that maintains the cell’s resting potential, among other functions. Cardenolides, a group of potent plant toxins, bind to and inhibit this pump. The gene encoding the α-subunit of the pump has undergone duplication events in some insect species known to feed on plants containing cardenolides. Here we test the function of these duplicated gene copies in the cardenolide-adapted milkweed bug, Oncopeltus fasciatus, which has three known copies of the gene: α1A, α1B and α1C. Results Using RT-qPCR analyses we demonstrate that the α1C is highly expressed in neural tissue, where the pump is generally thought to be most important for neuron excitability. With the use of in vivo RNAi in adult bugs we found that α1C knockdowns suffered high mortality, where as α1A and α1B did not, supporting that α1C is most important for effective ion pumping. Next we show a role for α1A and α1B in the handling of cardenolides: expression results find that both copies are primarily expressed in the Malpighian tubules, the primary insect organ responsible for excretion, and when we injected either α1A or α1B knockdowns with cardenolides this proved fatal (whereas not in controls). Conclusions These results show that the Na,K-ATPα gene-copies have taken on diverse functions. Having multiple copies of this gene appears to have allowed the newly arisen duplicates to specialize on resistance to cardenolides, whereas the ancestral copy of the pump remains comparatively sensitive, but acts as a more efficient ion carrier. Interestingly both the α1A and α1B were required for cardenolide handling, suggesting that these two copies have separate and vital functions. Gene duplications of the Na,K-ATPase thus represent an excellent example of subfunctionalization in response to a new environmental challenge. Electronic supplementary material The online version of this article (10.1186/s12862-017-1097-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jennifer N Lohr
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany. .,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, WC1E 6BT, London, UK.
| | - Fee Meinzer
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| | - Safaa Dalla
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| | - Renja Romey-Glüsing
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| | - Susanne Dobler
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| |
Collapse
|
16
|
Blaustein MP. The pump, the exchanger, and the holy spirit: origins and 40-year evolution of ideas about the ouabain-Na + pump endocrine system. Am J Physiol Cell Physiol 2017; 314:C3-C26. [PMID: 28971835 DOI: 10.1152/ajpcell.00196.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Two prescient 1953 publications set the stage for the elucidation of a novel endocrine system: Schatzmann's report that cardiotonic steroids (CTSs) are all Na+ pump inhibitors, and Szent-Gyorgi's suggestion that there is an endogenous "missing screw" in heart failure that CTSs like digoxin may replace. In 1977 I postulated that an endogenous Na+ pump inhibitor acts as a natriuretic hormone and simultaneously elevates blood pressure (BP) in salt-dependent hypertension. This hypothesis was based on the idea that excess renal salt retention promoted the secretion of a CTS-like hormone that inhibits renal Na+ pumps and salt reabsorption. The hormone also inhibits arterial Na+ pumps, elevates myocyte Na+ and promotes Na/Ca exchanger-mediated Ca2+ gain. This enhances vasoconstriction and arterial tone-the hallmark of hypertension. Here I describe how those ideas led to the discovery that the CTS-like hormone is endogenous ouabain (EO), a key factor in the pathogenesis of hypertension and heart failure. Seminal observations that underlie the still-emerging picture of the EO-Na+ pump endocrine system in the physiology and pathophysiology of multiple organ systems are summarized. Milestones include: 1) cloning the Na+ pump isoforms and physiological studies of mutated pumps in mice; 2) discovery that Na+ pumps are also EO-triggered signaling molecules; 3) demonstration that ouabain, but not digoxin, is hypertensinogenic; 4) elucidation of EO's roles in kidney development and cardiovascular and renal physiology and pathophysiology; 5) discovery of "brain ouabain", a component of a novel hypothalamic neuromodulatory pathway; and 6) finding that EO and its brain receptors modulate behavior and learning.
Collapse
Affiliation(s)
- Mordecai P Blaustein
- Departments of Physiology and Medicine, University of Maryland School of Medicine , Baltimore, Maryland
| |
Collapse
|
17
|
Amar M, Singh A, Mallick BN. Noradrenergic β-Adrenoceptor-Mediated Intracellular Molecular Mechanism of Na-K ATPase Subunit Expression in C6 Cells. Cell Mol Neurobiol 2017; 38:441-457. [PMID: 28353187 DOI: 10.1007/s10571-017-0488-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/23/2017] [Indexed: 11/26/2022]
Abstract
Rapid eye movement sleep deprivation-associated elevated noradrenaline increases and decreases neuronal and glial Na-K ATPase activity, respectively. In this study, using C6 cell-line as a model, we investigated the possible intracellular molecular mechanism of noradrenaline-induced decreased glial Na-K ATPase activity. The cells were treated with noradrenaline in the presence or absence of adrenoceptor antagonists, modulators of extra- and intracellular Ca++ and modulators of intracellular signalling pathways. We observed that noradrenaline acting on β-adrenoceptor decreased Na-K ATPase activity and mRNA expression of the catalytic α2-Na-K ATPase subunit in the C6 cells. Further, cAMP and protein kinase-A mediated release of intracellular Ca++ played a critical role in such decreased α2-Na-K ATPase expression. In contrast, noradrenaline acting on β-adrenoceptor up-regulated the expression of regulatory β2-Na-K ATPase subunit, which although was cAMP and Ca++ dependent, was independent of protein kinase-A and protein kinase-C. Combining these with previous findings (including ours) we have proposed a working model for noradrenaline-induced suppression of glial Na-K ATPase activity and alteration in its subunit expression. The findings help understanding noradrenaline-associated maintenance of brain excitability during health and altered states, particularly in relation to rapid eye movement sleep and its deprivation when the noradrenaline level is naturally altered.
Collapse
Affiliation(s)
- Megha Amar
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Abhishek Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | | |
Collapse
|
18
|
Vertacnik KL, Linnen CR. Evolutionary genetics of host shifts in herbivorous insects: insights from the age of genomics. Ann N Y Acad Sci 2017; 1389:186-212. [DOI: 10.1111/nyas.13311] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/16/2016] [Accepted: 12/22/2016] [Indexed: 12/25/2022]
|
19
|
Dalla S, Dobler S. Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants. Evolution 2016; 70:2767-2777. [DOI: 10.1111/evo.13077] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 01/20/2023]
Affiliation(s)
- Safaa Dalla
- Molecular Evolutionary Biology, Zoological Institute, Biocenter Grindel; University of Hamburg; 20146 Hamburg Germany
| | - Susanne Dobler
- Molecular Evolutionary Biology, Zoological Institute, Biocenter Grindel; University of Hamburg; 20146 Hamburg Germany
| |
Collapse
|
20
|
Thabet R, Rouault JD, Ayadi H, Leignel V. Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates. Comp Biochem Physiol B Biochem Mol Biol 2016; 196-197:11-18. [PMID: 26812300 DOI: 10.1016/j.cbpb.2016.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 01/18/2023]
Abstract
The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates.
Collapse
Affiliation(s)
- Rahma Thabet
- University of Sfax, Laboratory of Biodiversity and Aquatic Ecosystems UR/11ES72, Ecology and Planktonology, Department of Life Sciences, Road Soukra Km 3.5, BP1171, 3000, Sfax, Tunisia
| | - J-D Rouault
- Laboratoire Evolution, Genomes et Speciation, UPR9034, CNRS, 91198 Gif-sur-Yvette, France
| | - Habib Ayadi
- University of Sfax, Laboratory of Biodiversity and Aquatic Ecosystems UR/11ES72, Ecology and Planktonology, Department of Life Sciences, Road Soukra Km 3.5, BP1171, 3000, Sfax, Tunisia
| | - Vincent Leignel
- Université du Maine, Laboratoire Mer Molecule Sante EA 2160 FR-CNRS 3473 IUML, 72085 Le Mans, France.
| |
Collapse
|
21
|
Chen Y, Kennedy DJ, Ramakrishnan DP, Yang M, Huang W, Li Z, Xie Z, Chadwick AC, Sahoo D, Silverstein RL. Oxidized LDL-bound CD36 recruits an Na⁺/K⁺-ATPase-Lyn complex in macrophages that promotes atherosclerosis. Sci Signal 2015; 8:ra91. [PMID: 26350901 DOI: 10.1126/scisignal.aaa9623] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
One characteristic of atherosclerosis is the accumulation of lipid-laden macrophage foam cells in the arterial wall. We have previously shown that the binding of oxidized low-density lipoprotein (oxLDL) to the scavenger receptor CD36 activates the kinase Lyn, initiating a cascade that inhibits macrophage migration and is necessary for foam cell generation. We identified the plasma membrane ion transporter Na(+)/K(+)-ATPase as a key component in the macrophage oxLDL-CD36 signaling axis. Using peritoneal macrophages isolated from Atp1a1 heterozygous or Cd36-null mice, we demonstrated that CD36 recruited an Na(+)/K(+)-ATPase-Lyn complex for Lyn activation in response to oxLDL. Macrophages deficient in the α1 Na(+)/K(+)-ATPase catalytic subunit did not respond to activation of CD36, showing attenuated oxLDL uptake and foam cell formation, and oxLDL failed to inhibit migration of these macrophages. Furthermore, Apoe-null mice, which are a model of atherosclerosis, were protected from diet-induced atherosclerosis by global deletion of a single allele encoding the α1 Na(+)/K(+)-ATPase subunit or reconstitution with macrophages that lacked an allele encoding the α1 Na(+)/K(+)-ATPase subunit. These findings identify Na(+)/K(+)-ATPase as a potential target for preventing or treating atherosclerosis.
Collapse
Affiliation(s)
- Yiliang Chen
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
| | - David J Kennedy
- Department of Medicine, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
| | - Devi Prasadh Ramakrishnan
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA. Department of Molecular Medicine, Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA
| | - Moua Yang
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA. Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Wenxin Huang
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
| | - Zhichuan Li
- Department of Physiology and Pharmacology, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
| | - Zijian Xie
- Department of Physiology and Pharmacology, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
| | - Alexandra C Chadwick
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daisy Sahoo
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA. Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA. Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Roy L Silverstein
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA. Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| |
Collapse
|
22
|
Rapid Eye Movement Sleep Deprivation Associated Increase in Na-K ATPase Activity in the Rat Brain is Due to Noradrenaline Induced α1-Adrenoceptor Mediated Increased α-Subunit of the Enzyme. Neurochem Res 2015; 40:1747-57. [DOI: 10.1007/s11064-015-1660-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/29/2015] [Accepted: 07/01/2015] [Indexed: 10/23/2022]
|
23
|
Scherzer P, Gal-Moscovici A, Sheikh-Hamad D, Popovtzer MM. Sodium-pump gene-expression, protein abundance and enzyme activity in isolated nephron segments of the aging rat kidney. Physiol Rep 2015; 3:3/6/e12369. [PMID: 26056060 PMCID: PMC4510615 DOI: 10.14814/phy2.12369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aging is associated with alteration in renal tubular functions, including sodium handling and concentrating ability. Na-K-ATPase plays a key role in driving tubular transport, and we hypothesized that decreased concentrating ability of the aging kidney is due in part to downregulation of Na-K-ATPase. In this study, we evaluated Na and K balance, aldosterone levels, and Na-K-ATPase gene expression, protein abundance, and activity in aging rat kidney. Na-K-ATPase activity (assayed microfluorometrically), mRNA (RT-PCR), and protein abundance (immunoblotting) were quantitated in the following isolated nephron segments: PCT, PST, MTAL, DCT, and CCD from 2, 8, 15, and 24 month-old-rats. In the course of aging, creatinine clearance decreased from 0.48 ± 0.02 mL/min/100 g BW to 0.28 ± 0.06 (P < 0.001) and aldosterone decreased from 23.6 ± 0.8 ng/dL to 13.2 ± 0.6 (P < 0.001). Serum Na+ and K+ increased by 4.0% and 22.5%, respectively. Na-K-ATPase activity, mRNA, and protein abundance of the α1 subunit displayed similar trends in all assayed segments; increasing in PCT and PST; decreasing in MTAL and DCT; increasing in CCD: in PCT they increased by 40%, 75%, and 250%, respectively; while in PST they increased by 80%, 50%, and 100%, respectively (P < 0.001). In MTAL they declined by 36%, 24%, and 34%, respectively, and in DCT by 38%, 59%, and 60%, respectively (P < 0.001). They were higher in CCD by 110%, 115%, and 246%, respectively (P < 0.001). Rats maintained Na/K balance; however with a steady state elevated serum K+. These results reveal quantitative changes in axial distribution of Na-K-ATPase at the level of gene expression, protein abundance, and activity in the nephrons of aging animals and may explain, in part, the pathophysiology of the senescent kidney.
Collapse
Affiliation(s)
- Pnina Scherzer
- Nephrology and Hypertension Services, Hadassah University Hospital, Jerusalem, Israel
| | - Anca Gal-Moscovici
- Nephrology and Hypertension Services, Hadassah University Hospital, Jerusalem, Israel
| | - David Sheikh-Hamad
- Nephrology and Hypertension Services, Hadassah University Hospital, Jerusalem, Israel Nephrology Division, Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Mordecai M Popovtzer
- Nephrology and Hypertension Services, Hadassah University Hospital, Jerusalem, Israel South Arizona VA Health Care System and University of Arizona, Tucson, Arizona
| |
Collapse
|
24
|
Manoharan P, Gayam S, Arthur S, Palaniappan B, Singh S, Dick GM, Sundaram U. Chronic and selective inhibition of basolateral membrane Na-K-ATPase uniquely regulates brush border membrane Na absorption in intestinal epithelial cells. Am J Physiol Cell Physiol 2015; 308:C650-6. [PMID: 25652450 DOI: 10.1152/ajpcell.00355.2014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/30/2015] [Indexed: 11/22/2022]
Abstract
Na-K-ATPase, an integral membrane protein in mammalian cells, is responsible for maintaining the favorable intracellular Na gradient necessary to promote Na-coupled solute cotransport processes [e.g., Na-glucose cotransport (SGLT1)]. Inhibition of brush border membrane (BBM) SGLT1 is, at least in part, due to the diminished Na-K-ATPase in villus cells from chronically inflamed rabbit intestine. The aim of the present study was to determine the effect of Na-K-ATPase inhibition on the two major BBM Na absorptive pathways, specifically Na-glucose cotransport and Na/H exchange (NHE), in intestinal epithelial (IEC-18) cells. Na-K-ATPase was inhibited using 1 mM ouabain or siRNA for Na-K-ATPase-α1 in IEC-18 cells. SGLT1 activity was determined as 3-O-methyl-D-[(3)H]glucose uptake. Na-K-ATPase activity was measured as the amount of inorganic phosphate released. Treatment with ouabain resulted in SGLT1 inhibition at 1 h but stimulation at 24 h. To further characterize this unexpected stimulation of SGLT1, siRNA silencing was utilized to inhibit Na-K-ATPase-α1. SGLT1 activity was significantly upregulated by Na-K-ATPase silencing, while NHE3 activity remained unaltered. Kinetics showed that the mechanism of stimulation of SGLT1 activity was secondary to an increase in affinity of the cotransporter for glucose without a change in the number of cotransporters. Molecular studies demonstrated that the mechanism of stimulation was not secondary to altered BBM SGLT1 protein levels. Chronic and direct silencing of basolateral Na-K-ATPase uniquely regulates BBM Na absorptive pathways in intestinal epithelial cells. Specifically, while BBM NHE3 is unaffected, SGLT1 is stimulated secondary to enhanced affinity of the cotransporter.
Collapse
Affiliation(s)
- Palanikumar Manoharan
- Department of Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio
| | - Swapna Gayam
- Section of Digestive Diseases, West Virginia University, Morgantown, West Virginia
| | - Subha Arthur
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Balasubramanian Palaniappan
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Soudamani Singh
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Gregory M Dick
- Center for Cardiovascular and Respiratory Sciences, West Virginia University, Morgantown, West Virginia
| | - Uma Sundaram
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| |
Collapse
|
25
|
P2C-Type ATPases and Their Regulation. Mol Neurobiol 2015; 53:1343-1354. [DOI: 10.1007/s12035-014-9076-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 12/29/2014] [Indexed: 12/12/2022]
|
26
|
Molecular mechanism of regulation of villus cell Na-K-ATPase in the chronically inflamed mammalian small intestine. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:702-11. [PMID: 25462166 DOI: 10.1016/j.bbamem.2014.11.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 11/03/2014] [Accepted: 11/06/2014] [Indexed: 11/24/2022]
Abstract
Na-K-ATPase located on the basolateral membrane (BLM) of intestinal epithelial cells provides a favorable intracellular Na+ gradient to promote all Na dependent co-transport processes across the brush border membrane (BBM). Down-regulation of Na-K-ATPase activity has been postulated to alter the absorption via Na-solute co-transporters in human inflammatory bowel disease (IBD). Further, the altered activity of a variety of Na-solute co-transporters in intact villus cells has been reported in animal models of chronic enteritis. But the molecular mechanism of down-regulation of Na-K-ATPase is not known. In the present study, using a rabbit model of chronic intestinal inflammation, which resembles human IBD, Na-K-ATPase in villus cells was shown to decrease. The relative mRNA abundance of α-1 and β-1 subunits was not altered in villus cells during chronic intestinal inflammation. Similarly, the protein levels of these subunits were also not altered in villus cells during chronic enteritis. However, the BLM concentration of α-1 and β-1 subunits was diminished in the chronically inflamed intestinal villus cells. An ankyrin-spectrin skeleton is necessary for the proper trafficking of Na-K-ATPase to the BLM of the cell. In the present study, ankyrin expression was markedly diminished in villus cells from the chronically inflamed intestine resulting in depolarization of ankyrin-G protein. The decrease of Na-K-ATPase activity was comparable to that seen in ankyrin knockdown IEC-18 cells. Therefore, altered localization of Na-K-ATPase as a result of transcriptional down-regulation of ankyrin-G mediates the down-regulation of Na-K-ATPase activity during chronic intestinal inflammation.
Collapse
|
27
|
Autosis and autophagic cell death: the dark side of autophagy. Cell Death Differ 2014; 22:367-76. [PMID: 25257169 PMCID: PMC4326571 DOI: 10.1038/cdd.2014.143] [Citation(s) in RCA: 526] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/03/2014] [Accepted: 08/04/2014] [Indexed: 12/31/2022] Open
Abstract
It is controversial whether cells truly die via autophagy or whether — in dying cells — autophagy is merely an innocent bystander or a well-intentioned ‘Good Samaritan' trying to prevent inevitable cellular demise. However, there is increasing evidence that the genetic machinery of autophagy may be essential for cell death in certain settings. We recently identified a novel form of autophagy gene-dependent cell death, termed autosis, which is mediated by the Na+,K+-ATPase pump and has unique morphological features. High levels of cellular autophagy, as occurs with treatment with autophagy-inducing peptides, starvation, or in vivo during certain types of ischemia, can trigger autosis. These findings provide insights into the mechanisms and strategies for prevention of cell death during extreme stress conditions.
Collapse
|
28
|
Affiliation(s)
- Mordecai P Blaustein
- Departments of Physiology and Medicine and the Center for Heart, Hypertension and Kidney Disease, University of Maryland School of Medicine, Baltimore, Maryland
| |
Collapse
|
29
|
Amphibian myiasis. Blowfly larvae (Lucilia bufonivora, Diptera: Calliphoridae) coping with the poisonous skin secretion of the common toad (Bufo bufo). CHEMOECOLOGY 2014. [DOI: 10.1007/s00049-014-0157-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
30
|
Holzinger F, Wink M. Mediation of cardiac glycoside insensitivity in the monarch butterfly (Danaus plexippus): Role of an amino acid substitution in the ouabain binding site of Na(+),K (+)-ATPase. J Chem Ecol 2013; 22:1921-37. [PMID: 24227116 DOI: 10.1007/bf02028512] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/1996] [Accepted: 05/16/1996] [Indexed: 12/01/2022]
Abstract
The Monarch butterfly (Danaus plexippus) sequesters cardiac glycosides (CG) for its chemical defense against predators. Larvae and adults of this butterfly are insensitive towards dietary cardiac glycosides, whereas other Lepidoptera are sensitive and intoxicated by ouabain. Ouabain inhibits Na(+),K(+)-ATPase by binding to its α-subunit. We have amplified and cloned the DNA-sequence encoding the respective ouabain binding site. Instead of the amino acid asparagine at position 122 in ouabain-sensitive insects, the Monarch has a histidine in the putative ouabain binding site, which consists of 12 amino acids. Starting with the CG-sensitive Na(+),K(+)-ATPase gene fromDrosophila, we converted pos. 122 to a histidine residue as inDanaus plexippus by site-directed mutagenesis. Human embryonic kidney cells (HEK) (which are sensitive to ouabain) were transfected with the mutated Na(+),K(+)-ATPase gene in a pSVDF-expression vector and showed a transient expression of the mutatedDrosophila Na(+),K(+)-ATPase. When treated with ouabain, the transfected cells tolerated ouabain at a concentration of 50 mM, whereas untransformed controls or controls transfected with the unmutatedDrosophila gene, showed a substantial mortality. This result implies that the asparagine to histidine exchange contributes to ouabain insensitivity in the Monarch. In two other CG-sequestering insects, e.g.,Danaus gilippus andSyntomeida epilais, the pattern of amino acid substitution differed, indicating that the Monarch has acquired this mutation independently during evolution.
Collapse
Affiliation(s)
- F Holzinger
- Institut für Pharmazeutische Biologie, Universität Heidelberg, Im Neuenheimer Feld 364, D-69120, Heidelberg, Germany
| | | |
Collapse
|
31
|
Górska-Andrzejak J. Glia-related circadian plasticity in the visual system of Diptera. Front Physiol 2013; 4:36. [PMID: 23986707 PMCID: PMC3750947 DOI: 10.3389/fphys.2013.00036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/13/2013] [Indexed: 11/28/2022] Open
Abstract
The circadian changes in morphology of the first visual neuropil or lamina of Diptera represent an example of the neuronal plasticity controlled by the circadian clock (circadian plasticity). It is observed in terminals of the compound eye photoreceptor cells, the peripheral oscillators expressing the clock genes. However, it has been found also in their postsynaptic partners, the L1 and L2 monopolar cells, in which the activity of the clock genes have not yet been detected. The circadian input that the L1 and L2 receive seems to originate not only from the retina photoreceptors and from the circadian pacemaker neurons located in the brain, but also from the glial cells that express the clock genes and thus contain circadian oscillators. This paper summarizes the morphological and biochemical rhythms in glia of the optic lobe, shows how they contribute to circadian plasticity, and discusses how glial clocks may modulate circadian rhythms in the lamina.
Collapse
Affiliation(s)
- Jolanta Górska-Andrzejak
- Department of Cell Biology and Imaging, Institute of Zoology, Jagiellonian University Kraków, Poland
| |
Collapse
|
32
|
Irles P, Silva-Torres FA, Piulachs MD. RNAi reveals the key role of Nervana 1 in cockroach oogenesis and embryo development. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:178-188. [PMID: 23262289 DOI: 10.1016/j.ibmb.2012.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 12/07/2012] [Accepted: 12/11/2012] [Indexed: 06/01/2023]
Abstract
Na(+), K(+)-ATPases is a heterodimer protein consisting of α- and β-subunits that control the ion transport through cell membranes. In insects the β-subunit of the Na(+), K(+)-ATPase, known as Nervana, was characterized as a nervous system-specific glycoprotein antigen from adult Drosophila melanogaster heads. Nervana is expressed ubiquitously in all insect tissues, and in epithelial cells appeared located in a basolateral position as part of the septate junctions. Herein we study two Nervana isoforms from Blattella germanica, a cockroach species with panoistic ovaries. The sequencing and the phylogenetic analysis results suggest that these two isoforms are orthologs of D. melanogaster Nervana 1 and Nervana 2, respectively. Nervana 1 is highly expressed in the ovary of B. germanica, and depleting its expression results in changes in oocyte shape that do not impair oviposition. However, the resulting embryos show different defects and never hatch. These findings highlight the importance of this type of membrane pump in insect oogenesis as well as in embryo development, and its possible regulation by juvenile hormone.
Collapse
Affiliation(s)
- Paula Irles
- Institut de Biologia Evolutiva (Universitat Pompeu Fabra-CSIC), Passeig Marítim de la Barceloneta, 37, 08003 Barcelona, Spain.
| | | | | |
Collapse
|
33
|
Abstract
The Na,K-ATPase is the only established receptor for cardiac glycosides like digoxin or ouabain. There are now known to be three different isoforms of its principal subunit. These isoforms can differ from one another in their intrinsic affinity for cardiac glycosides. Recent work examines the molecular structure of the binding site. The relative level of expression of the isoforms in cardiac tissue is modified in several developmental, hormonal, and pathological states, contributing to alterations in the digitalis sensitivity of the tissue.
Collapse
Affiliation(s)
- K J Sweadner
- Neurosurgical Research, Massachusetts General Hospital; and the Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, MA 02114, USA
| |
Collapse
|
34
|
Elucidation of ameliorative effect of Co-enzyme Q10 in streptozotocin-induced diabetic neuropathic perturbation by modulation of electrophysiological, biochemical and behavioral markers. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.biomag.2012.10.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
35
|
Zhen Y, Aardema ML, Medina EM, Schumer M, Andolfatto P. Parallel molecular evolution in an herbivore community. Science 2012; 337:1634-7. [PMID: 23019645 PMCID: PMC3770729 DOI: 10.1126/science.1226630] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Numerous insects have independently evolved the ability to feed on plants that produce toxic secondary compounds called cardenolides and can sequester these compounds for use in their defense. We surveyed the protein target for cardenolides, the alpha subunit of the sodium pump, Na(+),K(+)-ATPase (ATPα), in 14 species that feed on cardenolide-producing plants and 15 outgroups spanning three insect orders. Despite the large number of potential targets for modulating cardenolide sensitivity, amino acid substitutions associated with host-plant specialization are highly clustered, with many parallel substitutions. Additionally, we document four independent duplications of ATPα with convergent tissue-specific expression patterns. We find that unique substitutions are disproportionately associated with recent duplications relative to parallel substitutions. Together, these findings support the hypothesis that adaptation tends to take evolutionary paths that minimize negative pleiotropy.
Collapse
Affiliation(s)
- Ying Zhen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Matthew L. Aardema
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Edgar M. Medina
- Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá 11001, Colombia
| | - Molly Schumer
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Peter Andolfatto
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| |
Collapse
|
36
|
Harper ME, Patrick J, Himms-Hagen J. Altered Brown Adipose Tissue and Na,K Pump Activities During Diet-Induced Obesity and Weight Loss in Rats. ACTA ACUST UNITED AC 2012; 1:106-17. [PMID: 16350567 DOI: 10.1002/j.1550-8528.1993.tb00599.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Brown adipose tissue (BAT) thermogenesis is an uncoupled ATPase-independent thermogenic mechanism. Ion transport by the Na,K pump is an ATPase-dependent thermogenic mechanism. Both have been proposed as mechanisms of altered energy expenditure during states of dietary energy surfeit and deficit. Our aim was to study these mechanisms during diet-induced obesity and weight loss. Over 36 weeks rats were fed lard- or tallow-based diets (63% energy as fat), or a control diet (12% energy as fat). During periods of restriction rats were fed 50% of the energy intake of controls in the form of a control diet. Several components of thermogenic response increased in rats eating high fat diets and decreased following dietary restriction. BAT activation occurred, particularly with a lard-based diet, as indicated by increased GDP binding and uncoupling protein (UCP) content. Na,K pump activity in thymocytes increased with the feeding of both high fat diets at some time points. Plasma T3 level increased in rats eating the lard-based diet and decreased with dietary restriction regardless of previous diet. Resting metabolic rate (RMR) of the animals was unchanged despite increases in these thermogenic components and was decreased in all groups following dietary restriction. Our results indicate a lack of any major role for activated BAT thermogenesis in mitigating the extent of the obesity induced by the high fat diets. The reasons for the differences in response to the two different sources of saturated fat, lard, and tallow, are not clear.
Collapse
Affiliation(s)
- M E Harper
- Dept. of Biochemistry, Univ. of Cambridge, Tennis Court Road, Cambridge, England, UK CB2 1QW
| | | | | |
Collapse
|
37
|
Community-wide convergent evolution in insect adaptation to toxic cardenolides by substitutions in the Na,K-ATPase. Proc Natl Acad Sci U S A 2012; 109:13040-5. [PMID: 22826239 DOI: 10.1073/pnas.1202111109] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The extent of convergent molecular evolution is largely unknown, yet is critical to understanding the genetics of adaptation. Target site insensitivity to cardenolides is a prime candidate for studying molecular convergence because herbivores in six orders of insects have specialized on these plant poisons, which gain their toxicity by blocking an essential transmembrane carrier, the sodium pump (Na,K-ATPase). We investigated gene sequences of the Na,K-ATPase α-subunit in 18 insects feeding on cardenolide-containing plants (spanning 15 genera and four orders) to screen for amino acid substitutions that might lower sensitivity to cardenolides. The replacement N122H that was previously shown to confer resistance in the monarch butterfly (Danaus plexippus) and Chrysochus leaf beetles was found in four additional species, Oncopeltus fasciatus and Lygaeus kalmii (Heteroptera, Lygaeidae), Labidomera clivicollis (Coleoptera, Chrysomelidae), and Liriomyza asclepiadis (Diptera, Agromyzidae). Thus, across 300 Myr of insect divergence, specialization on cardenolide-containing plants resulted in molecular convergence for an adaptation likely involved in coevolution. Our screen revealed a number of other substitutions connected to cardenolide binding in mammals. We confirmed that some of the particular substitutions provide resistance to cardenolides by introducing five distinct constructs of the Drosophila melanogaster gene into susceptible eucaryotic cells under an ouabain selection regime. These functional assays demonstrate that combined substitutions of Q(111) and N(122) are synergistic, with greater than twofold higher resistance than either substitution alone and >12-fold resistance over the wild type. Thus, even across deep phylogenetic branches, evolutionary degrees of freedom seem to be limited by physiological constraints, such that the same molecular substitutions confer adaptation.
Collapse
|
38
|
Qiu R, Croom J, Ali RA, Ballou AL, Smith CD, Ashwell CM, Hassan HM, Chiang CC, Koci MD. Direct fed microbial supplementation repartitions host energy to the immune system. J Anim Sci 2012; 90:2639-51. [PMID: 22367073 DOI: 10.2527/jas.2011-4611] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Direct fed microbials and probiotics are used to promote health in livestock and poultry; however, their mechanism of action is still poorly understood. We previously reported that direct fed microbial supplementation in young broilers reduced ileal respiration without changing whole-body energy expenditure. The current studies were conducted to further investigate the effects of a direct fed microbial on energy metabolism in different tissues of broilers. One hundred ninety-two 1-d-old broiler chicks (16 chicks/pen) were randomly assigned to 2 dietary groups: standard control starter diet (CSD) and CSD plus direct fed microbial (DFMD; 0.3%) with 6 pens/treatment. Body weight, feed consumption, whole-body energy expenditure, organ mass, tissue respiration rates, and peripheral blood mononuclear cell (PBMC) ATP concentrations were measured to estimate changes in energy metabolism. No differences in whole body energy expenditure or BW gain were observed; however, decreased ileal O(2) respiration (P < 0.05) was measured in DFMD fed broilers. In contrast, the respiration rate of the thymus in those broilers was increased (P < 0.05). The PBMC from DFMD fed broilers had increased ATP concentrations and exhibited increased ATP turnover (P < 0.01). To determine if the increased energy consumption by PBMC corresponded with an altered immune response, broilers were immunized with sheep red blood cells (SRBC) and assayed for differences in their humoral response. The DFMD-fed broilers had a faster rate of antigen specific IgG production (P < 0.05) and an increase in total IgA (P < 0.05). Collectively, these data indicate that supplementation with the direct fed microbial used in this study resulted in energy re-partitioning to the immune system and an increase in antibody production independent of changes in whole body metabolism or growth performance.
Collapse
Affiliation(s)
- R Qiu
- Department of Poultry Science, North Carolina State University, Raleigh, NC 27695-7608, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Cui X, Sun ZR, Ren GW, Wang GL, Qi Y, Ma YP, Ruan Q. Interaction between human cytomegalovirus UL136 protein and ATP1B1 protein. Braz J Med Biol Res 2011; 44:1251-5. [DOI: 10.1590/s0100-879x2011007500144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 10/13/2011] [Indexed: 11/21/2022] Open
Affiliation(s)
- Xin Cui
- China Medical University, China
| | | | | | | | - Ying Qi
- China Medical University, China
| | | | | |
Collapse
|
40
|
Blaustein MP, Leenen FHH, Chen L, Golovina VA, Hamlyn JM, Pallone TL, Van Huysse JW, Zhang J, Wier WG. How NaCl raises blood pressure: a new paradigm for the pathogenesis of salt-dependent hypertension. Am J Physiol Heart Circ Physiol 2011; 302:H1031-49. [PMID: 22058154 DOI: 10.1152/ajpheart.00899.2011] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Excess dietary salt is a major cause of hypertension. Nevertheless, the specific mechanisms by which salt increases arterial constriction and peripheral vascular resistance, and thereby raises blood pressure (BP), are poorly understood. Here we summarize recent evidence that defines specific molecular links between Na(+) and the elevated vascular resistance that directly produces high BP. In this new paradigm, high dietary salt raises cerebrospinal fluid [Na(+)]. This leads, via the Na(+)-sensing circumventricular organs of the brain, to increased sympathetic nerve activity (SNA), a major trigger of vasoconstriction. Plasma levels of endogenous ouabain (EO), the Na(+) pump ligand, also become elevated. Remarkably, high cerebrospinal fluid [Na(+)]-evoked, locally secreted (hypothalamic) EO participates in a pathway that mediates the sustained increase in SNA. This hypothalamic signaling chain includes aldosterone, epithelial Na(+) channels, EO, ouabain-sensitive α(2) Na(+) pumps, and angiotensin II (ANG II). The EO increases (e.g.) hypothalamic ANG-II type-1 receptor and NADPH oxidase and decreases neuronal nitric oxide synthase protein expression. The aldosterone-epithelial Na(+) channel-EO-α(2) Na(+) pump-ANG-II pathway modulates the activity of brain cardiovascular control centers that regulate the BP set point and induce sustained changes in SNA. In the periphery, the EO secreted by the adrenal cortex directly enhances vasoconstriction via an EO-α(2) Na(+) pump-Na(+)/Ca(2+) exchanger-Ca(2+) signaling pathway. Circulating EO also activates an EO-α(2) Na(+) pump-Src kinase signaling cascade. This increases the expression of the Na(+)/Ca(2+) exchanger-transient receptor potential cation channel Ca(2+) signaling pathway in arterial smooth muscle but decreases the expression of endothelial vasodilator mechanisms. Additionally, EO is a growth factor and may directly participate in the arterial structural remodeling and lumen narrowing that is frequently observed in established hypertension. These several central and peripheral mechanisms are coordinated, in part by EO, to effect and maintain the salt-induced elevation of BP.
Collapse
Affiliation(s)
- Mordecai P Blaustein
- Dept. of Physiology, Univ. of Maryland School of Medicine, 655 W. Baltimore St., Baltimore, MD, 21201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Dobler S, Petschenka G, Pankoke H. Coping with toxic plant compounds--the insect's perspective on iridoid glycosides and cardenolides. PHYTOCHEMISTRY 2011; 72:1593-1604. [PMID: 21620425 DOI: 10.1016/j.phytochem.2011.04.015] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 03/30/2011] [Accepted: 04/20/2011] [Indexed: 05/27/2023]
Abstract
Specializing on host plants with toxic secondary compounds enforces specific adaptation in insect herbivores. In this review, we focus on two compound classes, iridoid glycosides and cardenolides, which can be found in the food plants of a large number of insect species that display various degrees of adaptation to them. These secondary compounds have very different modes of action: Iridoid glycosides are usually activated in the gut of the herbivores by β-glucosidases that may either stem from the food plant or be present in the gut as standard digestive enzymes. Upon cleaving, the unstable aglycone is released that unspecifically acts by crosslinking proteins and inhibiting enzymes. Cardenolides, on the other hand, are highly specific inhibitors of an essential ion carrier, the sodium pump. In insects exposed to both kinds of toxins, carriers either enabling the safe storage of the compounds away from the activating enzymes or excluding the toxins from sensitive tissues, play an important role that deserves further analysis. To avoid toxicity of iridoid glycosides, repression of activating enzymes emerges as a possible alternative strategy. Cardenolides, on the other hand, may lose their toxicity if their target site is modified and this strategy has evolved multiple times independently in cardenolide-adapted insects.
Collapse
Affiliation(s)
- Susanne Dobler
- Biocenter Grindel, Hamburg University, Martin-Luther-King Platz 3, 20146 Hamburg, Germany.
| | | | | |
Collapse
|
42
|
Rindler TN, Dostanic I, Lasko VM, Nieman ML, Neumann JC, Lorenz JN, Lingrel JB. Knockout of the Na,K-ATPase α₂-isoform in the cardiovascular system does not alter basal blood pressure but prevents ACTH-induced hypertension. Am J Physiol Heart Circ Physiol 2011; 301:H1396-404. [PMID: 21856916 DOI: 10.1152/ajpheart.00121.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The α(2)-isoform of Na,K-ATPase (α(2)) is thought to play a role in blood pressure regulation, but the specific cell type(s) involved have not been identified. Therefore, it is important to study the role of the α(2) in individual cell types in the cardiovascular system. The present study demonstrates the role of vascular smooth muscle α(2) in the regulation of cardiovascular hemodynamics. To accomplish this, we developed a mouse model utilizing the Cre/LoxP system to generate a cell type-specific knockout of the α(2) in vascular smooth muscle cells using the SM22α Cre. We achieved a 90% reduction in the α(2)-expression in heart and vascular smooth muscle in the knockout mice. Interestingly, tail-cuff blood pressure analysis reveals that basal systolic blood pressure is unaffected by the knockout of α(2) in the knockout mice. However, knockout mice do fail to develop ACTH-induced hypertension, as seen in wild-type mice, following 5 days of treatment with ACTH (Cortrosyn; wild type = 119.0 ± 6.8 mmHg; knockout = 103.0 ± 2.0 mmHg). These results demonstrate that α(2)-expression in heart and vascular smooth muscle is not essential for regulation of basal systolic blood pressure, but α(2) is critical for blood pressure regulation under chronic stress such as ACTH-induced hypertension.
Collapse
Affiliation(s)
- Tara N Rindler
- Department of Molecular Genetics, Biochemistry, and Microbiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Scapin S, Leoni S, Spagnuolo S, Gnocchi D, De Vito P, Luly P, Pedersen JZ, Incerpi S. Short-term effects of thyroid hormones during development: Focus on signal transduction. Steroids 2010; 75:576-84. [PMID: 19900468 DOI: 10.1016/j.steroids.2009.10.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 10/21/2009] [Accepted: 10/28/2009] [Indexed: 12/27/2022]
Abstract
Extranuclear or nongenomic effects of thyroid hormones are mediated by receptors located at the plasma membrane or inside cells, and are independent of protein synthesis. Recently the alphaVbeta3 integrin was identified as a cell membrane receptor for thyroid hormones, and a wide variety of nongenomic effects have now been shown to be induced through binding of thyroid hormones to this receptor. However, also other thyroid hormone receptors can produce nongenomic effects, including the cytoplasmic TRalpha and TRbeta receptors and probably also a G protein-coupled membrane receptor, and increasing importance is now given to thyroid hormone metabolites like 3,5-diiodothyronine and reverse T(3) that can mimick some nongenomic effects of T(3) and T(4). Signal transduction from the alphaVbeta3 integrin may proceed through at least three independent pathways (protein kinase C, Src or mitogen-activated kinases) but the details are still unknown. Thyroid hormones induce nongenomic effects on at least three important Na(+)-dependent transport systems, the Na(+)/K(+)-ATPase, the Na(+)/H(+) exchanger, and amino acid transport System A, leading to a mitogenic response in embryo cells; but modulation of the same transport systems may have different roles in other cells and at different developmental stages. It seems that thyroid hormones in many cases can modulate nongenomically the same targets affected by the nuclear receptors through long-term mechanisms. Recent results on nongenomic effects confirm the old theory that the primary role of thyroid hormones is to keep the steady-state level of functioning of the cell, but more and more mechanisms are discovered by which this goal can be achieved.
Collapse
Affiliation(s)
- Sergio Scapin
- Department of Cellular and Developmental Biology, Sapienza University, 00185 Rome, Italy
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Signaling mechanisms that link salt retention to hypertension: endogenous ouabain, the Na(+) pump, the Na(+)/Ca(2+) exchanger and TRPC proteins. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1219-29. [PMID: 20211726 DOI: 10.1016/j.bbadis.2010.02.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 02/26/2010] [Accepted: 02/27/2010] [Indexed: 12/26/2022]
Abstract
Salt retention as a result of chronic, excessive dietary salt intake, is widely accepted as one of the most common causes of hypertension. In a small minority of cases, enhanced Na(+) reabsorption by the kidney can be traced to specific genetic defects of salt transport, or pathological conditions of the kidney, adrenal cortex, or pituitary. Far more frequently, however, salt retention may be the result of minor renal injury or small genetic variation in renal salt transport mechanisms. How salt retention actually leads to the increase in peripheral vascular resistance (the hallmark of hypertension) and the elevation of blood pressure remains an enigma. Here we review the evidence that endogenous ouabain (an adrenocortical hormone), arterial smooth muscle α2 Na(+) pumps, type-1 Na/Ca exchangers, and receptor- and store-operated Ca(2+) channels play key roles in the pathway that links salt to hypertension. We discuss cardenolide structure-function relationships in an effort to understand why prolonged administration of ouabain, but not digoxin, induces hypertension, and why digoxin is actually anti-hypertensive. Finally, we summarize recent observations which indicate that ouabain upregulates arterial myocyte Ca(2+) signaling mechanisms that promote vasoconstriction, while simultaneously downregulating endothelial vasodilator mechanisms. In sum, the reports reviewed here provide novel insight into the molecular mechanisms by which salt retention leads to hypertension.
Collapse
|
45
|
Taub M, Springate JE, Cutuli F. Targeting of renal proximal tubule Na,K-ATPase by salt-inducible kinase. Biochem Biophys Res Commun 2010; 393:339-44. [PMID: 20152810 DOI: 10.1016/j.bbrc.2010.02.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 02/06/2010] [Indexed: 11/20/2022]
Abstract
The renal proximal tubule (RPT) is a central locale for Na+ reabsorption, and blood pressure regulation. Na+ reabsorption in the RPT depends upon the Na,K-ATPase, which is controlled by a complex regulatory network, including Salt-Inducible Protein Kinase (SIK). SIKs are recently discovered members of the AMP-activated Protein Kinase (AMPK) family, which regulate salt homeostasis and metabolism in a number of tissues. In the RPT, SIK interacts with the Na,K-ATPase in the basolateral membrane (BM), regulating both the activity and level of Na,K-ATPase in the BM. Thus, Na,K-ATPase activity can be rapidly adjusted in response to changes in Na+ balance. Long-term changes in Na+ intake affect the state of SIK phosphorylation, and as a consequence the phosphorylation of TORCs, Transducers of Regulated CREB (cAMP Regulatory Element Binding Protein). Once phosphorylated, TORCs enter the nucleus, and activate transcription of the ATP1B1 gene encoding for the Na,K-ATPase beta subunit.
Collapse
Affiliation(s)
- Mary Taub
- Department of Biochemistry, University at Buffalo, 140 Farber Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | | | | |
Collapse
|
46
|
Tian J, Li X, Liang M, Liu L, Xie JX, Ye Q, Kometiani P, Tillekeratne M, Jin R, Xie Z. Changes in sodium pump expression dictate the effects of ouabain on cell growth. J Biol Chem 2009; 284:14921-9. [PMID: 19329430 PMCID: PMC2685674 DOI: 10.1074/jbc.m808355200] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 03/27/2009] [Indexed: 11/06/2022] Open
Abstract
Here we show that ouabain-induced cell growth regulation is intrinsically coupled to changes in the cellular amount of Na/K-ATPase via the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway. Ouabain increases the endocytosis and degradation of Na/K-ATPase in LLC-PK1, human breast (BT20), and prostate (DU145) cancer cells. However, ouabain stimulates the PI3K/Akt/mTOR pathway and consequently up-regulates the expression of Na/K-ATPase in LLC-PK1 but not BT20 and DU145 cells. This up-regulation is sufficient to replete the plasma membrane pool of Na/K-ATPase and to stimulate cell proliferation in LLC-PK1 cells. On the other hand, ouabain causes a gradual depletion of Na/K-ATPase and an increased expression of cell cycle inhibitor p21(cip), which consequently inhibits cell proliferation in BT20 and DU145 cells. Consistently, we observe that small interfering RNA-mediated knockdown of Na/K-ATPase is sufficient to induce the expression of p21(cip) and slow the proliferation of LLC-PK1 cells. Moreover, this knockdown converts the growth stimulatory effect of ouabain to growth inhibition in LLC-PK1 cells. Mechanistically, both Src and caveolin-1 are required for ouabain-induced activation of Akt and up-regulation of Na/K-ATPase. Furthermore, inhibition of the PI3K/Akt/mTOR pathway by rapamycin completely blocks ouabain-induced expression of Na/K-ATPase and converts ouabain-induced growth stimulation to growth inhibition in LLC-PK1 cells. Taken together, we conclude that changes in the expression of Na/K-ATPase dictate the growth regulatory effects of ouabain on cells.
Collapse
Affiliation(s)
- Jiang Tian
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Górska-Andrzejak J, Salvaterra PM, Meinertzhagen IA, Krzeptowski W, Görlich A, Pyza E. Cyclical expression of Na+/K+-ATPase in the visual system of Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:459-468. [PMID: 19428365 PMCID: PMC2721802 DOI: 10.1016/j.jinsphys.2009.02.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 02/13/2009] [Accepted: 02/16/2009] [Indexed: 05/27/2023]
Abstract
In the first (lamina) and second (medulla) optic neuropils of Drosophila melanogaster, sodium pump subunit expression changes during the day and night, controlled by a circadian clock. We examined alpha-subunit expression from the intensity of immunolabeling. For the beta-subunit, encoded by Nervana 2 (Nrv2), we used Nrv2-GAL4 to drive expression of GFP, and measured the resultant fluorescence in whole heads and specific optic lobe cells. All optic neuropils express the alpha-subunit, highest at the beginning of night in both lamina and medulla in day/night condition and the oscillation was maintained in constant darkness. This rhythm was lacking in the clock arrhythmic per(0) mutant. GFP driven by Nrv2 was mostly detected in glial cells, mainly in the medulla. There, GFP expression occurs in medulla neuropil glia (MNGl), which express the clock gene per, and which closely contact the terminals of clock neurons immunoreactive to pigment dispersing factor. GFP fluorescence exhibited circadian oscillation in whole heads from Nrv2-GAL4+UAS-S65T-GFP flies, although significant GFP oscillations were lacking in MNGl, as they were for both subunit mRNAs in whole-head homogenates. In the dissected brain tissues, however, the mRNA of the alpha-subunit showed a robust daily rhythm in concentration changes while changes in the beta-subunit mRNA were weaker and not statistically significant. Thus in the brain, the genes for the sodium pump subunits, at least the one encoding the alpha-subunit, seem to be clock-controlled and the abundance of their corresponding proteins mirrors daily changes in mRNA, showing cyclical accumulation in cells.
Collapse
Affiliation(s)
- Jolanta Górska-Andrzejak
- Department of Cytology and Histology, Institute of Zoology, Jagiellonian University, Ingardena 6, Kraków 30-060, Poland
| | | | | | | | | | | |
Collapse
|
48
|
Chen Y, Cai T, Wang H, Li Z, Loreaux E, Lingrel JB, Xie Z. Regulation of intracellular cholesterol distribution by Na/K-ATPase. J Biol Chem 2009; 284:14881-90. [PMID: 19363037 DOI: 10.1074/jbc.m109.003574] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Recent studies have ascribed many non-pumping functions to the Na/K-ATPase. We show here that graded knockdown of cellular Na/K-ATPase alpha1 subunit produces a parallel decrease in both caveolin-1 and cholesterol in light fractions of LLC-PK1 cell lysates. This observation is further substantiated by imaging analyses, showing redistribution of cholesterol from the plasma membrane to intracellular compartments in the knockdown cells. Moreover, this regulation is confirmed in alpha1(+/-) mouse liver. Functionally, the knockdown-induced redistribution appears to affect the cholesterol sensing in the endoplasmic reticulum, because it activates the sterol regulatory element-binding protein pathway and increases expression of hydroxymethylglutaryl-CoA reductase and low density lipoprotein receptor in the liver. Consistently, we detect a modest increase in hepatic cholesterol as well as a reduction in the plasma cholesterol. Mechanistically, alpha1(+/-) livers show increases in cellular Src and ERK activity and redistribution of caveolin-1. Although activation of Src is not required in Na/K-ATPase-mediated regulation of cholesterol distribution, the interaction between the Na/K-ATPase and caveolin-1 is important for this regulation. Taken together, our new findings demonstrate a novel function of the Na/K-ATPase in control of the plasma membrane cholesterol distribution. Moreover, the data also suggest that the plasma membrane Na/K-ATPase-caveolin-1 interaction may represent an important sensing mechanism by which the cells regulate the sterol regulatory element-binding protein pathway.
Collapse
Affiliation(s)
- Yiliang Chen
- Department of Physiology and Pharmacology, College of Medicine, University of Toledo, Toledo, Ohio 43614-2598, USA
| | | | | | | | | | | | | |
Collapse
|
49
|
Yakushev SS, Kumskova EM, Rubtsov AM, Lopina OD. Effect of colchicine on sensitivity of duck salt gland Na,K-ATPase to Na+. BIOCHEMISTRY (MOSCOW) 2008; 73:990-4. [PMID: 18976215 DOI: 10.1134/s0006297908090058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Low molecular mass proteins of the FXYD family that affect the sensitivity of Na,K-ATPase to Na+ and K+ are known to be present in Na,K-ATPases in various tissues. In particular, in Na,K-ATPase from kidney a gamma-subunit (with electrophoretic mobility corresponding to molecular mass of about 10 kD) is present, and Na,K-ATPase preparations from heart contain phospholemman (electrophoretic mobility of this protein corresponds to molecular mass of 13-14 kD), which provides for the interaction of heart Na,K-ATPase with cytoskeletal microtubules. Disruption of microtubules by colchicine removes phospholemman from heart Na,K-ATPase preparations. The goal of the present study was to reveal a low molecular mass protein (probably a member of FXYD family) in preparation of Na,K-ATPase from duck salt glands. Immunoprecipitation of solubilized duck salt gland Na,K-ATPase using antibodies against alpha1-subunit results in the coprecipitation of a 13 kD protein with the Na,K-ATPase complex. Treatment of homogenate from duck salt glands with colchicine removes this protein from the purified preparation of Na,K-ATPase. Simultaneously, we observed a decrease in the sensitivity of Na,K-ATPase to Na+ at pH 6.5. However, colchicine treatment of homogenate from rabbit kidney does not affect either the sensitivity of Na,K-ATPase obtained from this homogenate to Na+ or the content of 10 kD protein (presumably gamma-subunit). The data suggest that phospholemman (or a similar member of the FXYD family) tightly interacts with Na,K-ATPase from duck salt glands and binds it to microtubules, simultaneously participating in the regulation of the sensitivity of Na,K-ATPase to Na+.
Collapse
Affiliation(s)
- S S Yakushev
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | | | | | | |
Collapse
|
50
|
Na⁺,K⁺-ATPase as the Target Enzyme for Organic and Inorganic Compounds. SENSORS 2008; 8:8321-8360. [PMID: 27873990 PMCID: PMC3791021 DOI: 10.3390/s8128321] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 11/09/2008] [Accepted: 12/11/2008] [Indexed: 01/16/2023]
Abstract
This paper gives an overview of the literature data concerning specific and non specific inhibitors of Na+,K+-ATPase receptor. The immobilization approaches developed to improve the rather low time and temperature stability of Na+,K+-ATPase, as well to preserve the enzyme properties were overviewed. The functional immobilization of Na+,K+-ATPase receptor as the target, with preservation of the full functional protein activity and access of various substances to an optimum number of binding sites under controlled conditions in the combination with high sensitive technology for the detection of enzyme activity is the basis for application of this enzyme in medical, pharmaceutical and environmental research.
Collapse
|