1
|
Vagin O, Tokhtaeva E, Larauche M, Davood J, Marcus EA. Helicobacter pylori-Induced Decrease in Membrane Expression of Na,K-ATPase Leads to Gastric Injury. Biomolecules 2024; 14:772. [PMID: 39062486 PMCID: PMC11274427 DOI: 10.3390/biom14070772] [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: 05/01/2024] [Revised: 06/12/2024] [Accepted: 06/26/2024] [Indexed: 07/28/2024] Open
Abstract
Helicobacter pylori is a highly prevalent human gastric pathogen that causes gastritis, ulcer disease, and gastric cancer. It is not yet fully understood how H. pylori injures the gastric epithelium. The Na,K-ATPase, an essential transporter found in virtually all mammalian cells, has been shown to be important for maintaining the barrier function of lung and kidney epithelia. H. pylori decreases levels of Na,K-ATPase in the plasma membrane of gastric epithelial cells, and the aim of this study was to demonstrate that this reduction led to gastric injury by impairing the epithelial barrier. Similar to H. pylori infection, the inhibition of Na,K-ATPase with ouabain decreased transepithelial electrical resistance and increased paracellular permeability in cell monolayers of human gastric cultured cells, 2D human gastric organoids, and gastric epithelium isolated from gerbils. Similar effects were caused by a partial shRNA silencing of Na,K-ATPase in human gastric organoids. Both H. pylori infection and ouabain exposure disrupted organization of adherens junctions in human gastric epithelia as demonstrated by E-cadherin immunofluorescence. Functional and structural impairment of epithelial integrity with a decrease in Na,K-ATPase amount or activity provides evidence that the H. pylori-induced downregulation of Na,K-ATPase plays a role in the complex mechanism of gastric disease induced by the bacteria.
Collapse
Affiliation(s)
- Olga Vagin
- Department of Pediatrics, DGSOM at UCLA, 10833 LeConte Ave., 12-383 MDCC, Los Angeles, CA 90095, USA; (O.V.); (E.T.)
- VA GLAHS 11301 Wilshire Blvd, Bldg 113, Rm 324, Los Angeles, CA 90073, USA; (M.L.); (J.D.)
| | - Elmira Tokhtaeva
- Department of Pediatrics, DGSOM at UCLA, 10833 LeConte Ave., 12-383 MDCC, Los Angeles, CA 90095, USA; (O.V.); (E.T.)
- VA GLAHS 11301 Wilshire Blvd, Bldg 113, Rm 324, Los Angeles, CA 90073, USA; (M.L.); (J.D.)
| | - Muriel Larauche
- VA GLAHS 11301 Wilshire Blvd, Bldg 113, Rm 324, Los Angeles, CA 90073, USA; (M.L.); (J.D.)
- Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, DGSOM at UCLA, 650 Charles E Young Dr. S., CHS 43-276, Los Angeles, CA 90095, USA
| | - Joshua Davood
- VA GLAHS 11301 Wilshire Blvd, Bldg 113, Rm 324, Los Angeles, CA 90073, USA; (M.L.); (J.D.)
- Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, DGSOM at UCLA, 650 Charles E Young Dr. S., CHS 43-276, Los Angeles, CA 90095, USA
| | - Elizabeth A. Marcus
- Department of Pediatrics, DGSOM at UCLA, 10833 LeConte Ave., 12-383 MDCC, Los Angeles, CA 90095, USA; (O.V.); (E.T.)
- VA GLAHS 11301 Wilshire Blvd, Bldg 113, Rm 324, Los Angeles, CA 90073, USA; (M.L.); (J.D.)
| |
Collapse
|
2
|
Contreras RG, Torres-Carrillo A, Flores-Maldonado C, Shoshani L, Ponce A. Na +/K +-ATPase: More than an Electrogenic Pump. Int J Mol Sci 2024; 25:6122. [PMID: 38892309 PMCID: PMC11172918 DOI: 10.3390/ijms25116122] [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: 03/26/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
The sodium pump, or Na+/K+-ATPase (NKA), is an essential enzyme found in the plasma membrane of all animal cells. Its primary role is to transport sodium (Na+) and potassium (K+) ions across the cell membrane, using energy from ATP hydrolysis. This transport creates and maintains an electrochemical gradient, which is crucial for various cellular processes, including cell volume regulation, electrical excitability, and secondary active transport. Although the role of NKA as a pump was discovered and demonstrated several decades ago, it remains the subject of intense research. Current studies aim to delve deeper into several aspects of this molecular entity, such as describing its structure and mode of operation in atomic detail, understanding its molecular and functional diversity, and examining the consequences of its malfunction due to structural alterations. Additionally, researchers are investigating the effects of various substances that amplify or decrease its pumping activity. Beyond its role as a pump, growing evidence indicates that in various cell types, NKA also functions as a receptor for cardiac glycosides like ouabain. This receptor activity triggers the activation of various signaling pathways, producing significant morphological and physiological effects. In this report, we present the results of a comprehensive review of the most outstanding studies of the past five years. We highlight the progress made regarding this new concept of NKA and the various cardiac glycosides that influence it. Furthermore, we emphasize NKA's role in epithelial physiology, particularly its function as a receptor for cardiac glycosides that trigger intracellular signals regulating cell-cell contacts, proliferation, differentiation, and adhesion. We also analyze the role of NKA β-subunits as cell adhesion molecules in glia and epithelial cells.
Collapse
Affiliation(s)
| | | | | | | | - Arturo Ponce
- Department of Physiology, Biophysics and Neurosciences, CINVESTAV-IPN, Mexico City 07360, Mexico; (R.G.C.); (A.T.-C.); (C.F.-M.); (L.S.)
| |
Collapse
|
3
|
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
|
4
|
da Silva MI, Ott T. Effects of conceptus proteins on endometrium and blood leukocytes of dairy cattle using transcriptome and meta-analysis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591148. [PMID: 38712302 PMCID: PMC11071483 DOI: 10.1101/2024.04.25.591148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
This study investigates the short and long-term effects of IFNT and PAG on the transcriptome of endometrium and blood leukocytes. Holstein heifers received intrauterine infusions of one of the following treatments: 20 mL of a 200 μg/mL bovine serum albumin solution (BSA; vehicle) from day 14 to 16 of the estrous cycle (BSA), vehicle + 10 μg/mL of IFNT from day 14 to 16 (IFNT3), vehicle + 10 μg/mL of IFNT from day 14 to 19 (IFNT6), and vehicle + 10 μg/mL of IFNT from day 14 to 16 followed by vehicle + 10 μg/mL of IFNT + 5 μg/mL of PAG from day 17 to 19 (IFNT+PAG). RNA-seq analysis was performed in endometrial biopsies and blood leukocytes collected after treatments. Acute IFNT signaling in the endometrium (IFNT3 vs BSA), induced differentially expressed genes (DEG) associated with interferon activation, immune response, inflammation, cell death, and inhibited vesicle transport and extracellular matrix remodeling. Prolonged IFNT signaling (IFNT6 vs IFNT3) altered gene expression related to cell invasion, retinoic acid signaling, and embryo implantation. In contrast, PAG induced numerous DEG in blood leukocytes but only 4 DEG in the endometrium. In blood leukocytes, PAG stimulated genes involved in development and TGFB signaling while inhibiting interferon signaling and cell migration. Overall, IFNT is a primary regulator of endometrial gene expression, while PAG predominantly affected the transcriptome of circulating immune cells during early pregnancy. Further research is essential to fully grasp the roles of identified DEG in both the endometrium and blood leukocytes.
Collapse
Affiliation(s)
- Maria Isabel da Silva
- Department of Animal Science, Center for Reproductive Biology and Health, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Troy Ott
- Department of Animal Science, Center for Reproductive Biology and Health, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
5
|
Kim Y, Ko JY, Kong HK, Lee M, Chung W, Lim S, Son D, Oh S, Park JW, Kim DY, Lee M, Han W, Park WY, Yoo KH, Park JH. Hypomethylation of ATP1A1 Is Associated with Poor Prognosis and Cancer Progression in Triple-Negative Breast Cancer. Cancers (Basel) 2024; 16:1666. [PMID: 38730618 PMCID: PMC11083557 DOI: 10.3390/cancers16091666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Dysregulated DNA methylation in cancer is critical in the transcription machinery associated with cancer progression. Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, but no treatment targeting TNBC biomarkers has yet been developed. To identify specific DNA methylation patterns in TNBC, methyl-binding domain protein 2 (MBD) sequencing data were compared in TNBC and the three other major breast cancer subtypes. Integrated analysis of DNA methylation and gene expression identified a gene set showing a correlation between DNA methylation and gene expression. ATPase Na+/K+-transporting subunit alpha 1 (ATP1A1) was found to be specifically hypomethylated in the coding sequence (CDS) region and to show increased expression in TNBC. The Cancer Genome Atlas (TCGA) database also showed that hypomethylation and high expression of ATP1A1 were strongly associated with poor survival in patients with TNBC. Furthermore, ATP1A1 knockdown significantly reduced the viability and tumor-sphere formation of TNBC cells. These results suggest that the hypomethylation and overexpression of ATP1A1 could be a prognostic marker in TNBC and that the manipulation of ATP1A1 expression could be a therapeutic target in this disease.
Collapse
Affiliation(s)
- Yesol Kim
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Je Yeong Ko
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Hyun Kyung Kong
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Minyoung Lee
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Woosung Chung
- Samsung Genome Institute, Samsung Medical Center, Seoul 06351, Republic of Korea
| | - Sera Lim
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Dasom Son
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Sumin Oh
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Jee Won Park
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Do Yeon Kim
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Minju Lee
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Wonshik Han
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul 06351, Republic of Korea
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06355, Republic of Korea
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Kyung Hyun Yoo
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| | - Jong Hoon Park
- Department of Biological Science, Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Republic of Korea; (Y.K.); (J.Y.K.)
| |
Collapse
|
6
|
Raposo-Garcia S, Cao A, Costas C, Louzao MC, Vilariño N, Vale C, Botana LM. Mouse N2a Neuroblastoma Assay: Uncertainties and Comparison with Alternative Cell-Based Assays for Ciguatoxin Detection. Mar Drugs 2023; 21:590. [PMID: 37999414 PMCID: PMC10672529 DOI: 10.3390/md21110590] [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: 10/11/2023] [Revised: 10/25/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023] Open
Abstract
The growing concern about ciguatera fish poisoning (CF) due to the expansion of the microorganisms producing ciguatoxins (CTXs) increased the need to develop a reliable and fast method for ciguatoxin detection to guarantee food safety. Cytotoxicity assay on the N2a cells sensitized with ouabain (O) and veratridine (V) is routinely used in ciguatoxin detection; however, this method has not been standardized yet. This study demonstrated the low availability of sodium channels in the N2a cells, the great O/V damage to the cells and the cell detachment when the cell viability is evaluated by the classical cytotoxicity assay and confirmed the absence of toxic effects caused by CTXs alone when using the methods that do not require medium removal such as lactate dehydrogenase (LDH) and Alamar blue assays. Different cell lines were evaluated as alternatives, such as human neuroblastoma, which was not suitable for the CTX detection due to the greater sensitivity to O/V and low availability of sodium channels. However, the HEK293 Nav cell line expressing the α1.6 subunit of sodium channels was sensitive to the ciguatoxin without the sensitization with O/V due to its expression of sodium channels. In the case of sensitizing the cells with O/V, it was possible to detect the presence of the ciguatoxin by the classical cytotoxicity MTT method at concentrations as low as 0.0001 nM CTX3C, providing an alternative cell line for the detection of compounds that act on the sodium channels.
Collapse
Affiliation(s)
| | | | | | | | | | - Carmen Vale
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain; (S.R.-G.); (A.C.); (C.C.); (M.C.L.); (N.V.)
| | - Luis M. Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain; (S.R.-G.); (A.C.); (C.C.); (M.C.L.); (N.V.)
| |
Collapse
|
7
|
The Alpha-1 Subunit of the Na +/K +-ATPase (ATP1A1) Is a Host Factor Involved in the Attachment of Porcine Epidemic Diarrhea Virus. Int J Mol Sci 2023; 24:ijms24044000. [PMID: 36835408 PMCID: PMC9966514 DOI: 10.3390/ijms24044000] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/18/2023] Open
Abstract
Porcine epidemic diarrhea (PED) is an acute and severe atrophic enteritis caused by porcine epidemic diarrhea virus (PEDV) that infects pigs and makes huge economic losses to the global swine industry. Previously, researchers have believed that porcine aminopeptidase-N (pAPN) was the primary receptor for PEDV, but it has been found that PEDV can infect pAPN knockout pigs. Currently, the functional receptor for PEDV remains unspecified. In the present study, we performed virus overlay protein binding assay (VOPBA), found that ATP1A1 was the highest scoring protein in the mass spectrometry results, and confirmed that the CT structural domain of ATP1A1 interacts with PEDV S1. First, we investigated the effect of ATP1A1 on PEDV replication. Inhibition of hosts ATP1A1 protein expression using small interfering RNA (siRNAs) significantly reduced the cells susceptibility to PEDV. The ATP1A1-specific inhibitors Ouabain (a cardiac steroid) and PST2238 (a digitalis toxin derivative), which specifically bind ATP1A1, could block the ATP1A1 protein internalization and degradation, and consequently reduce the infection rate of host cells by PEDV significantly. Additionally, as expected, overexpression of ATP1A1 notably enhanced PEDV infection. Next, we observed that PEDV infection of target cells resulted in upregulation of ATP1A1 at the mRNA and protein levels. Furthermore, we found that the host protein ATP1A1 was involved in PEDV attachment and co-localized with PEDV S1 protein in the early stage of infection. In addition, pretreatment of IPEC-J2 and Vero-E6 cells with ATP1A1 mAb significantly reduced PEDV attachment. Our observations provided a perspective on identifying key factors in PEDV infection, and may provide valuable targets for PEDV infection, PEDV functional receptor, related pathogenesis, and the development of new antiviral drugs.
Collapse
|
8
|
Chen YI, Chang CC, Hsu MF, Jeng YM, Tien YW, Chang MC, Chang YT, Hu CM, Lee WH. Homophilic ATP1A1 binding induces activin A secretion to promote EMT of tumor cells and myofibroblast activation. Nat Commun 2022; 13:2945. [PMID: 35618735 PMCID: PMC9135720 DOI: 10.1038/s41467-022-30638-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 05/09/2022] [Indexed: 12/30/2022] Open
Abstract
Tumor cells with diverse phenotypes and biological behaviors are influenced by stromal cells through secretory factors or direct cell-cell contact. Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia with fibroblasts as the major cell type. In the present study, we observe enrichment of myofibroblasts in a juxta-tumoral position with tumor cells undergoing epithelial-mesenchymal transition (EMT) that facilitates invasion and correlates with a worse clinical prognosis in PDAC patients. Direct cell-cell contacts forming heterocellular aggregates between fibroblasts and tumor cells are detected in primary pancreatic tumors and circulating tumor microemboli (CTM). Mechanistically, ATP1A1 overexpressed in tumor cells binds to and reorganizes ATP1A1 of fibroblasts that induces calcium oscillations, NF-κB activation, and activin A secretion. Silencing ATP1A1 expression or neutralizing activin A secretion suppress tumor invasion and colonization. Taken together, these results elucidate the direct interplay between tumor cells and bound fibroblasts in PDAC progression, thereby providing potential therapeutic opportunities for inhibiting metastasis by interfering with these cell-cell interactions.
Collapse
Affiliation(s)
- Yi-Ing Chen
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Chin-Chun Chang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
- Master Program for Cancer Biology and Drug Discovery, China Medical University and Academia Sinica, Taichung, Taiwan
| | - Min-Fen Hsu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yung-Ming Jeng
- Department of Pathology, National Taiwan University Hospital, Graduate Institute of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yu-Wen Tien
- Department of Surgery, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Chu Chang
- Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Yu-Ting Chang
- Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chun-Mei Hu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.
| | - Wen-Hwa Lee
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.
- Drug Development Center, China Medical University, Taichung, Taiwan.
- Department of Biological Chemistry, University of California, Irvine, USA.
| |
Collapse
|
9
|
Nakamura K, Shiozaki A, Kosuga T, Shimizu H, Kudou M, Ohashi T, Arita T, Konishi H, Komatsu S, Kubota T, Fujiwara H, Okamoto K, Kishimoto M, Konishi E, Otsuji E. The expression of the alpha1 subunit of Na +/K +-ATPase is related to tumor development and clinical outcomes in gastric cancer. Gastric Cancer 2021; 24:1278-1292. [PMID: 34251542 DOI: 10.1007/s10120-021-01212-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND The Na+/K+-ATPase alpha1 subunit (ATP1A1) is a critical component of Na+/K+-ATPase (NKA), a membrane pump that maintains a low intracellular Na+/K+ ratio and retains cellular volume and osmolarity. ATP1A1 was recently implicated in tumor behavior. Therefore, the present study investigated the role of ATP1A1 in patients with gastric cancer (GC). METHODS Knockdown experiments were conducted on human GC cell lines using ATP1A1 siRNA, and its effects on proliferation, the cell cycle, apoptosis, and cellular movement were examined. Gene expression profiling was performed by a microarray analysis. Primary tumor samples from 192 GC patients who underwent gastrectomy were subjected to an immunohistochemical analysis. RESULTS High ATP1A1 expression levels were observed in NUGC4 and MKN74 cells. Cell proliferation was suppressed and apoptosis was induced by the siRNA-induced knockdown of ATP1A1. The microarray analysis showed that knockdown of ATP1A1 leads to the up-regulated expression of genes involved in the interferon (IFN) signaling pathway, such as STAT1, STAT2, IRF1, and IRF9. Furthermore, the depletion of ATP1A1 altered the phosphorylation of the MAPK pathway. The immunohistochemical analysis revealed that the expression of ATP1A1 was associated with the histological type, venous invasion, and the pathological T stage. Furthermore, the prognostic analysis showed a relationship between high ATP1A1 expression levels and poor postoperative survival. CONCLUSIONS ATP1A1 appears to regulate tumor progression by altering IFN signaling, and high ATP1A1 expression levels were associated with poor postoperative survival in GC patients. The present results provide novel insights into the function of ATP1A1 as a mediator and/or biomarker of GC.
Collapse
Affiliation(s)
- Kei Nakamura
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Atsushi Shiozaki
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan.
| | - Toshiyuki Kosuga
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Hiroki Shimizu
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Michihiro Kudou
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Takuma Ohashi
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Tomohiro Arita
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Hirotaka Konishi
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Shuhei Komatsu
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Takeshi Kubota
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Hitoshi Fujiwara
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Kazuma Okamoto
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Mitsuo Kishimoto
- Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.,Department of Pathology, Kyoto City Hospital, Kyoto, 604-8845, Japan
| | - Eiichi Konishi
- Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Eigo Otsuji
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| |
Collapse
|
10
|
de Oliveira GC, Rocha SC, da Silva Lopes MA, Paixão N, Alves SLG, Pessoa MTC, Noël F, Quintas LEM, Barbosa LA, Villar JAFP, Cortes VF. Implications of Synthetic Modifications of the Cardiotonic Steroid Lactone Ring on Cytotoxicity. J Membr Biol 2021; 254:487-497. [PMID: 34128090 DOI: 10.1007/s00232-021-00186-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/08/2021] [Indexed: 01/24/2023]
Abstract
Na,K-ATPase (NKA) and cardiotonic steroids (CTS) have shown potent cytotoxic and anticancer effects. Here, we have synthesized a series of CTS digoxin derivatives (γ-benzylidene) with substitutions in the lactone ring and evaluated the cytotoxicity caused by digoxin derivatives in tumor and non-tumor cells lines, as well as their effects on NKA. The cytotoxicity assay was determined in HeLa, A549, and WI-26 VA4 after they were treated for 48 h with increased concentrations of CTS. The effects of CTS on NKA activity and immunoblotting of α1 and β1 isoforms were evaluated at IC50 concentrations in A549 cell membrane. NKA activity from mouse brain cortex was also measured. The majority of CTS exhibited low cytotoxicity in tumor and non-tumor cells, presenting IC50 values at micromolar concentrations, while digoxin showed cytotoxicity at nanomolar concentrations. BD-15 presented the lowest IC50 value (8 µM) in A549 and reduced its NKA activity in 28%. In contrast, BD-7 was the compound that most inhibited NKA (56% inhibition) and presented high IC50 value for A549. In mouse cortex, only BD-15 modulated the enzyme activity in a concentration-dependent inhibition curve. These results demonstrate that the cytotoxicity of these compounds is not related to NKA inhibition. The substitutions in the lactone ring of digoxin led to an increase in the cytotoxic concentration in tumor cells, which may not be interesting for cancer, but it has the advantage of increasing the therapeutic margin of these molecules when compared to classic CTS, and can be used safely in research for other diseases.
Collapse
Affiliation(s)
- Gisele Capanema de Oliveira
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil
| | - Sayonarah Carvalho Rocha
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil
| | - Miliane Alves da Silva Lopes
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal Do Rio de Janeiro, Av Carlos Chagas, 373, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Natasha Paixão
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal Do Rio de Janeiro, Av Carlos Chagas, 373, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Silmara Lúcia Grego Alves
- Laboratório de Síntese Orgânica e Nanoestruturas, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil
| | - Marco Túlio Corrêa Pessoa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil.,Marshall Institute for Interdisciplinary Research, Huntington, WV, USA
| | - François Noël
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal Do Rio de Janeiro, Av Carlos Chagas, 373, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Luis Eduardo M Quintas
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal Do Rio de Janeiro, Av Carlos Chagas, 373, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Leandro Augusto Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil
| | - José Augusto Ferreira Perez Villar
- Laboratório de Síntese Orgânica e Nanoestruturas, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil.
| | - Vanessa Faria Cortes
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro Oeste Dona Lindu, Av Sebastião Gonçalves Coelho, 400, Bairro Chanadour, Divinópolis, MG, 35501-296, Brazil.
| |
Collapse
|
11
|
Silva CID, Gonçalves-de-Albuquerque CF, Moraes BPTD, Garcia DG, Burth P. Na/K-ATPase: Their role in cell adhesion and migration in cancer. Biochimie 2021; 185:1-8. [PMID: 33713729 DOI: 10.1016/j.biochi.2021.03.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/18/2022]
Abstract
Na/K-ATPase (NKA) is a p-type transmembrane enzyme formed by three different subunits (α, β, and γ gamma). Primarily responsible for transporting sodium and potassium through the cell membrane, it also plays a critical role in intracellular signaling. The activation of diverse intracellular pathways may trigger cell death, survival, or even cell proliferation. Changes in the NKA functions or expression in isoforms subunits impact pathological conditions, such as cancer. The NKA function affects cell adhesion, motility, and migration, which are different in the physiological and pathological states. All enzyme subunits take part in the cell adhesion process, with the β subunit being the most studied. Thus, herein we aim to highlight NKA' central role in cell adhesion, motility, and migration in cancer cells.
Collapse
Affiliation(s)
- Camila Ignácio da Silva
- Laboratório de Enzimologia e Sinalização Celular, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil; Pós-Graduação em Ciências e Biotecnologia Universidade Federal Fluminense, Niterói, Brazil
| | - Cassiano Felippe Gonçalves-de-Albuquerque
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil; Laboratorio de Imunofarmacologia, Departamento de Bioquímica, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Bianca Portugal Tavares de Moraes
- Laboratorio de Imunofarmacologia, Departamento de Bioquímica, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Diogo Gomes Garcia
- Laboratório de Neurociências Translacional, Programa de Pós-Graduação em Neurologia, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Patrícia Burth
- Laboratório de Enzimologia e Sinalização Celular, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil; Pós-Graduação em Ciências e Biotecnologia Universidade Federal Fluminense, Niterói, Brazil.
| |
Collapse
|
12
|
Ouabain Accelerates Collective Cell Migration Through a cSrc and ERK1/2 Sensitive Metalloproteinase Activity. J Membr Biol 2019; 252:549-559. [PMID: 31041466 DOI: 10.1007/s00232-019-00066-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 04/17/2019] [Indexed: 10/26/2022]
Abstract
Studies made in the Madin-Darby canine kidney (MDCK) epithelial cell line showed that ouabain regulates cell adhesion and cell-adhesion-related biological processes, such as migration. Here, we demonstrated that 10 nM ouabain accelerates collective cell migration and heals wounds in cultured MDCK cell monolayers. Ouabain-induced acceleration of cell migration depends on activation of the cSrc-ERK1/2 signaling cascade, as it was inhibited by the kinase inhibitors PP2 and PD98059. Activation of the cSrc-ERK1/2 signaling cascade increased expression and activation of the extracellular matrix metalloproteinase-2 (MMP-2). Inhibition of MMP activity using the generic inhibitor GM6001 or the potent iMMP-2 inhibitor prevented the accelerative effect of ouabain. Likewise, Focal Adhesion Kinase (FAK) inhibition with the transfection of dominant negative peptide FRNK impaired the effect of ouabain. These results suggest that ouabain binding to the Na+,K+-ATPase accelerates collective migration of MDCK cells through activation of the cSrc-ERK1/2-FAK signaling cascade and promoting secretion and MMP activity.
Collapse
|
13
|
Vilchis-Nestor CA, Roldán ML, Leonardi A, Navea JG, Padilla-Benavides T, Shoshani L. Ouabain Enhances Cell-Cell Adhesion Mediated by β 1 Subunits of the Na +,K +-ATPase in CHO Fibroblasts. Int J Mol Sci 2019; 20:E2111. [PMID: 31035668 PMCID: PMC6539428 DOI: 10.3390/ijms20092111] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 12/19/2022] Open
Abstract
Adhesion is a crucial characteristic of epithelial cells to form barriers to pathogens and toxic substances from the environment. Epithelial cells attach to each other using intercellular junctions on the lateral membrane, including tight and adherent junctions, as well as the Na+,K+-ATPase. Our group has shown that non-adherent chinese hamster ovary (CHO) cells transfected with the canine β1 subunit become adhesive, and those homotypic interactions amongst β1 subunits of the Na+,K+-ATPase occur between neighboring epithelial cells. Ouabain, a cardiotonic steroid, binds to the α subunit of the Na+,K+-ATPase, inhibits the pump activity and induces the detachment of epithelial cells when used at concentrations above 300 nM. At nanomolar non-inhibiting concentrations, ouabain affects the adhesive properties of epithelial cells by inducing the expression of cell adhesion molecules through the activation of signaling pathways associated with the α subunit. In this study, we investigated whether the adhesion between β1 subunits was also affected by ouabain. We used CHO fibroblasts stably expressing the β1 subunit of the Na+,K+-ATPase (CHO β1), and studied the effect of ouabain on cell adhesion. Aggregation assays showed that ouabain increased the adhesion between CHO β1 cells. Immunofluorescence and biotinylation assays showed that ouabain (50 nM) increases the expression of the β1 subunit of the Na+,K+-ATPase at the cell membrane. We also examined the effect of ouabain on the activation of signaling pathways in CHO β1 cells, and their subsequent effect on cell adhesion. We found that cSrc is activated by ouabain and, therefore, that it likely regulates the adhesive properties of CHO β1 cells. Collectively, our findings suggest that the β1 subunit adhesion is modulated by the expression levels of the Na+,K+-ATPase at the plasma membrane, which is regulated by ouabain.
Collapse
Affiliation(s)
- Claudia Andrea Vilchis-Nestor
- Department of Physiology Biophysics and Neurosciences, Center for Research and Advanced Studies, Cinvestav-Ipn, CDMX 07360, Mexico.
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - María Luisa Roldán
- Department of Physiology Biophysics and Neurosciences, Center for Research and Advanced Studies, Cinvestav-Ipn, CDMX 07360, Mexico.
| | - Angelina Leonardi
- Department of Chemistry, Skidmore College, 815 North Broadway, Saratoga Springs, NY 12866, USA.
| | - Juan G Navea
- Department of Chemistry, Skidmore College, 815 North Broadway, Saratoga Springs, NY 12866, USA.
| | - Teresita Padilla-Benavides
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Liora Shoshani
- Department of Physiology Biophysics and Neurosciences, Center for Research and Advanced Studies, Cinvestav-Ipn, CDMX 07360, Mexico.
| |
Collapse
|
14
|
In Vitro Cytotoxicity Induced by the Bufadienolides 1α,2α-Epoxyscillirosidine and Lanceotoxin B on Rat Myocardial and Mouse Neuroblastoma Cell Lines. Toxins (Basel) 2019; 11:toxins11010014. [PMID: 30609690 PMCID: PMC6356634 DOI: 10.3390/toxins11010014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/21/2018] [Accepted: 12/23/2018] [Indexed: 11/22/2022] Open
Abstract
Consumption of bufadienolide-containing plants are responsible for many livestock mortalities annually. Bufadienolides are divided into two groups; non-cumulative bufadienolides and cumulative bufadienolides. Cumulative bufadienolides are referred to as neurotoxic, as the chronic intoxication with this type of bufadienolide results in a paretic/paralytic syndrome known as ‘krimpsiekte’. The in vitro cytotoxicity of a non-cumulative bufadienolide, 1α,2α-epoxyscillirosidine, and a cumulative bufadienolide, lanceotoxin B, were compared using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction) assay after exposing rat myocardial (H9c2) and mouse neuroblastoma (Neuro-2a) cell lines. The effect of these two bufadienolides on cell ultrastructure was also investigated using transmission electron microscopy (TEM). H9c2 cells exhibited greater cytotoxicity when exposed to 1α,2α-epoxyscillirosidine, compared to lanceotoxin B. In contrast, Neuro-2a cells were more susceptible to lanceotoxin B. The EC50 (half maximal effective concentration) of lanceotoxin B exposure of Neuro-2a cells for 24–72 h ranged from 4.4–5.5 µM compared to EC50s of 35.7–37.6 µM for 1α,2α-epoxyscillirosidine exposure of Neuro-2a cells over the same period. 1α,2α-Epoxyscillirosidine induced extensive vacuolization in both cell types, with swollen RER (rough endoplasmic reticulum) and perinuclear spaces. Lanceotoxin B caused swelling of the mitochondria and sequestration of cytoplasmic material within autophagic vesicles. These results corroborate the notion that cumulative bufadienolides are neurotoxic.
Collapse
|
15
|
The Na/K-ATPase Signaling: From Specific Ligands to General Reactive Oxygen Species. Int J Mol Sci 2018; 19:ijms19092600. [PMID: 30200500 PMCID: PMC6163532 DOI: 10.3390/ijms19092600] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/10/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022] Open
Abstract
The signaling function of the Na/K-ATPase has been established for 20 years and is widely accepted in the field, with many excellent reports and reviews not cited here. Even though there is debate about the underlying mechanism, the signaling function is unquestioned. This short review looks back at the evolution of Na/K-ATPase signaling, from stimulation by cardiotonic steroids (also known as digitalis-like substances) as specific ligands to stimulation by reactive oxygen species (ROS) in general. The interplay of cardiotonic steroids and ROS in Na/K-ATPase signaling forms a positive-feedback oxidant amplification loop that has been implicated in some pathophysiological conditions.
Collapse
|
16
|
Zhang C, Wang H, Chen Z, Zhuang L, Xu L, Ning Z, Zhu Z, Wang P, Meng Z. Carbonic anhydrase 2 inhibits epithelial–mesenchymal transition and metastasis in hepatocellular carcinoma. Carcinogenesis 2018; 39:562-570. [DOI: 10.1093/carcin/bgx148] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Affiliation(s)
- Chenyue Zhang
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Haiyong Wang
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, China
| | - Zhiao Chen
- Fudan University Shanghai Cancer Center and Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Liping Zhuang
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Litao Xu
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhouyu Ning
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhenfeng Zhu
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Peng Wang
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhiqiang Meng
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| |
Collapse
|
17
|
Khajah MA, Mathew PM, Luqmani YA. Na+/K+ ATPase activity promotes invasion of endocrine resistant breast cancer cells. PLoS One 2018; 13:e0193779. [PMID: 29590154 PMCID: PMC5874017 DOI: 10.1371/journal.pone.0193779] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/17/2018] [Indexed: 01/27/2023] Open
Abstract
Background The Na+/K+-ATPase (NKP) is an important ion transporter also involved in signal transduction. Its expression profile is altered in various tumours including that of the breast. We studied the effect of inhibiting NKP activity in non-tumorigenic breast cell line and in estrogen receptor positive and negative breast cancer cells. Methods Expression and localization of NKP and downstream signaling molecules were determined by RT-PCR, western blotting and immunofluorescence. Cell proliferation, apoptosis and cell cycle stage were determined using MTT, annexin V and flow cytometry. Cell motility and invasion were determined using wound healing and matrigel assays. Total matrix metalloproteinase (MMP) was determined by a fluorescence-based assay. Results NKP was mainly localized on the cell membrane. Its baseline expression and activity were enhanced in breast cancer compared to the non-tumorigenic breast cell line. Ouabain and 3,4,5,6-tetrahydroxyxanthone (TTX) treatment significantly inhibited NKP activity, which significantly reduced cell proliferation, motility, invasion and pH-induced membrane blebbing. EGF stimulation induced internalization of NKP from the cell membrane to the cytoplasm. Ouabain inhibited EGF-induced phosphorylation of Rac/cdc42, profillin, ERK1/2 and P70S6K. Conclusions The NKP may offer a novel therapeutic target in breast cancer patients who have developed metastasis, aiming to improve therapeutic outcomes and enhance survival rate.
Collapse
|
18
|
Vegliante R, Ciriolo MR. Autophagy and Autophagic Cell Death: Uncovering New Mechanisms Whereby Dehydroepiandrosterone Promotes Beneficial Effects on Human Health. VITAMINS AND HORMONES 2018; 108:273-307. [PMID: 30029730 DOI: 10.1016/bs.vh.2018.01.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dehydroepiandrosterone (DHEA) is the most abundant steroid hormone in human serum and a precursor of sexual hormones. Its levels, which are maximum between the age of 20 and 30, dramatically decline with aging thus raising the question that many pathological conditions typical of the elderly might be associated with the decrement of circulating DHEA. Moreover, since its very early discovery, DHEA and its metabolites have been shown to be active in many pathophysiological contexts, including cardiovascular disease, brain disorders, and cancer. Indeed, treatment with DHEA has beneficial effects for the cure of these and many other pathologies in vitro, in vivo, and in patient studies. However, the molecular mechanisms underlying DHEA effects have been only partially elucidated. Autophagy is a self-digestive process, by which cell homeostasis is maintained, damaged organelles removed, and cell survival assured upon stress stimuli. However, high rate of autophagy is detrimental and leads to a form of programmed cell death known as autophagic cell death (ACD). In this chapter, we describe the process of autophagy and the morphological and biochemical features of ACD. Moreover, we analyze the beneficial effects of DHEA in several pathologies and the molecular mechanisms with particular emphasis on its regulation of cell death processes. Finally, we review data indicating DHEA and structurally related steroid hormones as modulators of both autophagy and ACD, a research field that opens new avenues in the therapeutic use of these compounds.
Collapse
Affiliation(s)
- Rolando Vegliante
- MN3T, The Microenvironmental Niche in Tumorigenesis and Targeted Therapy, Hopital Civil-Institut d'Hématologie et Immunologie, Strasbourg, France
| | - Maria R Ciriolo
- University of Rome 'Tor Vergata', Rome, Italy; IRCCS San Raffaele 'La Pisana', Rome, Italy.
| |
Collapse
|
19
|
Cui X, Xie Z. Protein Interaction and Na/K-ATPase-Mediated Signal Transduction. Molecules 2017; 22:molecules22060990. [PMID: 28613263 PMCID: PMC6152704 DOI: 10.3390/molecules22060990] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/01/2017] [Accepted: 06/02/2017] [Indexed: 02/05/2023] Open
Abstract
The Na/K-ATPase (NKA), or Na pump, is a member of the P-type ATPase superfamily. In addition to pumping ions across cell membrane, it is engaged in assembly of multiple protein complexes in the plasma membrane. This assembly allows NKA to perform many non-pumping functions including signal transduction that are important for animal physiology and disease progression. This article will focus on the role of protein interaction in NKA-mediated signal transduction, and its potential utility as target for developing new therapeutics.
Collapse
Affiliation(s)
- Xiaoyu Cui
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV 25703, USA.
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV 25703, USA.
| |
Collapse
|
20
|
On the Many Actions of Ouabain: Pro-Cystogenic Effects in Autosomal Dominant Polycystic Kidney Disease. Molecules 2017; 22:molecules22050729. [PMID: 28467389 PMCID: PMC5688955 DOI: 10.3390/molecules22050729] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/19/2017] [Accepted: 04/30/2017] [Indexed: 02/07/2023] Open
Abstract
Ouabain and other cardenolides are steroidal compounds originally discovered in plants. Cardenolides were first used as poisons, but after finding their beneficial cardiotonic effects, they were rapidly included in the medical pharmacopeia. The use of cardenolides to treat congestive heart failure remained empirical for centuries and only relatively recently, their mechanisms of action became better understood. A breakthrough came with the discovery that ouabain and other cardenolides exist as endogenous compounds that circulate in the bloodstream of mammals. This elevated these compounds to the category of hormones and opened new lines of investigation directed to further study their biological role. Another important discovery was the finding that the effect of ouabain was mediated not only by inhibition of the activity of the Na,K-ATPase (NKA), but by the unexpected role of NKA as a receptor and a signal transducer, which activates a complex cascade of intracellular second messengers in the cell. This broadened the interest for ouabain and showed that it exerts actions that go beyond its cardiotonic effect. It is now clear that ouabain regulates multiple cell functions, including cell proliferation and hypertrophy, apoptosis, cell adhesion, cell migration, and cell metabolism in a cell and tissue type specific manner. This review article focuses on the cardenolide ouabain and discusses its various in vitro and in vivo effects, its role as an endogenous compound, its mechanisms of action, and its potential use as a therapeutic agent; placing especial emphasis on our findings of ouabain as a pro-cystogenic agent in autosomal dominant polycystic kidney disease (ADPKD).
Collapse
|
21
|
Na⁺ i,K⁺ i-Dependent and -Independent Signaling Triggered by Cardiotonic Steroids: Facts and Artifacts. Molecules 2017; 22:molecules22040635. [PMID: 28420099 PMCID: PMC6153942 DOI: 10.3390/molecules22040635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/31/2017] [Accepted: 04/11/2017] [Indexed: 11/17/2022] Open
Abstract
Na⁺,K⁺-ATPase is the only known receptor of cardiotonic steroids (CTS) whose interaction with catalytic α-subunits leads to inhibition of this enzyme. As predicted, CTS affect numerous cellular functions related to the maintenance of the transmembrane gradient of monovalent cations, such as electrical membrane potential, cell volume, transepithelial movement of salt and osmotically-obliged water, symport of Na⁺ with inorganic phosphate, glucose, amino acids, nucleotides, etc. During the last two decades, it was shown that side-by-side with these canonical Na⁺i/K⁺i-dependent cellular responses, long-term exposure to CTS affects transcription, translation, tight junction, cell adhesion and exhibits tissue-specific impact on cell survival and death. It was also shown that CTS trigger diverse signaling cascades via conformational transitions of the Na⁺,K⁺-ATPase α-subunit that, in turn, results in the activation of membrane-associated non-receptor tyrosine kinase Src, phosphatidylinositol 3-kinase and the inositol 1,4,5-triphosphate receptor. These findings allowed researchers to propose that endogenous CTS might be considered as a novel class of steroid hormones. We focus our review on the analysis of the relative impact Na⁺i,K⁺i-mediated and -independent pathways in cellular responses evoked by CTS.
Collapse
|
22
|
Venugopal J, McDermott J, Sanchez G, Sharma M, Barbosa L, Reif GA, Wallace DP, Blanco G. Ouabain promotes partial epithelial to mesenchymal transition (EMT) changes in human autosomal dominant polycystic kidney disease (ADPKD) cells. Exp Cell Res 2017; 355:142-152. [PMID: 28385574 DOI: 10.1016/j.yexcr.2017.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/31/2017] [Accepted: 04/01/2017] [Indexed: 12/13/2022]
Abstract
The hormone ouabain has been shown to enhance the cystic phenotype of autosomal dominant polycystic kidney disease (ADPKD). Among other characteristics, the ADPKD phenotype includes cell de-differentiation and epithelial to mesenchymal transition (EMT). Here, we determined whether physiological concentrations of ouabain induces EMT in human renal epithelial cells from patients with ADPKD. We found that ADPKD cells respond to ouabain with a decrease in expression of the epithelial marker E-cadherin and increase in the expression of the mesenchymal markers N-cadherin, α smooth muscle actin (αSMA) and collagen-I; and the tight junction protein occludin and claudin-1. Other adhesion molecules, such as ZO-1, β-catenin and vinculin were not significantly modified by ouabain. At the cellular level, ouabain stimulated ADPKD cell migration, reduced cell-cell interaction, and the ability of ADPKD cells to form aggregates. Moreover, ouabain increased the transepithelial electrical resistance of ADPKD cell monolayers, suggesting that the paracellular transport pathway was preserved in the cells. These effects of ouabain were not observed in normal human kidney (NHK) cells. Altogether these results show a novel role for ouabain in ADPKD, inducing changes that lead to a partial EMT phenotype in the cells. These effects further support the key role that ouabain has as a factor that promotes the cystic characteristics of ADPKD cells.
Collapse
Affiliation(s)
- Jessica Venugopal
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Jeffrey McDermott
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Gladis Sanchez
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Madhulika Sharma
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Leandro Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Divinopolis, Brazil
| | - Gail A Reif
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Darren P Wallace
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Gustavo Blanco
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States.
| |
Collapse
|
23
|
Lopachev AV, Lopacheva OM, Osipova EA, Vladychenskaya EA, Smolyaninova LV, Fedorova TN, Koroleva OV, Akkuratov EE. Ouabain-induced changes in MAP kinase phosphorylation in primary culture of rat cerebellar cells. Cell Biochem Funct 2017; 34:367-77. [PMID: 27338714 DOI: 10.1002/cbf.3199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 02/06/2023]
Abstract
Cardiotonic steroid (CTS) ouabain is a well-established inhibitor of Na,K-ATPase capable of inducing signalling processes including changes in the activity of the mitogen activated protein kinases (MAPK) in various cell types. With increasing evidence of endogenous CTS in the blood and cerebrospinal fluid, it is of particular interest to study ouabain-induced signalling in neurons, especially the activation of MAPK, because they are the key kinases activated in response to extracellular signals and regulating cell survival, proliferation and apoptosis. In this study we investigated the effect of ouabain on the level of phosphorylation of three MAPK (ERK1/2, JNK and p38) and on cell survival in the primary culture of rat cerebellar cells. Using Western blotting we described the time course and concentration dependence of phosphorylation for ERK1/2, JNK and p38 in response to ouabain. We discovered that ouabain at a concentration of 1 μM does not cause cell death in cultured neurons while it changes the phosphorylation level of the three MAPK: ERK1/2 is phosphorylated transiently, p38 shows sustained phosphorylation, and JNK is dephosphorylated after a long-term incubation. We showed that ERK1/2 phosphorylation increase does not depend on ouabain-induced calcium increase and p38 activation. Changes in p38 phosphorylation, which is independent from ERK1/2 activation, are calcium dependent. Changes in JNK phosphorylation are calcium dependent and also depend on ERK1/2 and p38 activation. Ten-micromolar ouabain leads to cell death, and we conclude that different effects of 1-μM and 10-μM ouabain depend on different ERK1/2 and p38 phosphorylation profiles. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Alexander V Lopachev
- Research Center of Neurology, Moscow, Russia.,Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Olga M Lopacheva
- Research Center of Neurology, Moscow, Russia.,Lomonosov Moscow State University, International Biotechnological Center, Moscow, Russia
| | - Ekaterina A Osipova
- Lomonosov Moscow State University, International Biotechnological Center, Moscow, Russia.,Lomonosov Moscow State University, Faculty of Chemistry, Department of Chemical Enzymology, Moscow, Russia
| | | | - Larisa V Smolyaninova
- Lomonosov Moscow State University, International Biotechnological Center, Moscow, Russia.,Lomonosov Moscow State University, Faculty of Biology, Department of Biochemistry, Moscow, Russia
| | | | - Olga V Koroleva
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Evgeny E Akkuratov
- St. Petersburg State University, Institute of Translational Biomedicine, St. Petersburg, Russia
| |
Collapse
|
24
|
Tudpor K, Charoenphandhu N, Saengamnart W, Krishnamra N. Long-Term Prolactin Exposure Differentially Stimulated the Transcellular and Solvent Drag-Induced Calcium Transport in the Duodenum of Ovariectomized Rats. Exp Biol Med (Maywood) 2016; 230:836-44. [PMID: 16339748 DOI: 10.1177/153537020523001108] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Prolactin, having been shown to stimulate transcellular active and solvent drag-induced calcium transport in the duodenum of female rats, was postulated to improve duodenal calcium transport in estrogen-deficient rats. The aim of the present study was, therefore, to demonstrate the effects of long-term prolactin exposure produced by anterior pituitary (AP) transplantation on the duodenal calcium transport in young (9-week-old) and adult (22-week-old) ovariectomized rats. We found that ovariectomy did not alter the transcellular active duodenal calcium transport in young and adult rats fed normal calcium diet (1.0% w/w Ca) but decreased the solvent drag-induced duodenal calcium transport from 75.50 ± 10.12 to 55.75 ± 4.77 nmol·hr–1 cm–2 (P < 0.05) only in adult rats. Long-term prolactin exposure stimulated the transcellular active calcium transport in young and adult AP-grafted ovariectomized rats fed with normal calcium diet by more than 2-fold from 7.56 ± 0.79 to 16.54 ± 2.05 (P < 0.001) and 9.78 ± 0.72 to 15.99 ± 1.75 (P < 0.001) nmol·hr–1 cm–2, respectively. However, only the solvent drag-induced duodenal calcium transport in young rats was enhanced by prolactin from 95.51 ± 10.64 to 163.20 ± 18.03 nmol·hr–1 cm–2 (P < 0.001) whereas that in adult rats still showed a decreased flux from 75.50 ± 10.12 to 47.77 ± 5.42 nmol·hr–1 cm–2 (P < 0.05). Because oral calcium supplement has been widely used to improve calcium balance in estrogen-deficient animals, the effect of a high-calcium diet (2.0% w/w Ca) was also investigated. The results showed that stimulatory action of long-term prolactin on the transcellular active duodenal calcium transport in both young and adult rats was diminished after being fed a high-calcium diet. The same diet also abolished prolactin-enhanced solvent drag-induced duodenal calcium transport in young and further decreased that in adult AP-grafted ovariectomized rats. We concluded that the solvent drag-induced duodenal calcium transport in adult rats was decreased after ovariectomy. Long-term prolactin exposure stimulated the transcellular active duodenal calcium transport in both young and adult rats whereas enhancing the solvent drag-induced duodenal calcium transport only in young rats. Effects of prolactin were abolished by a high-calcium diet.
Collapse
Affiliation(s)
- Kukiat Tudpor
- Department of Physiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | | | | | | |
Collapse
|
25
|
Sahoo SS, Mishra C, Rout M, Nayak G, Mohanty ST, Panigrahy KK. Comparative in silico and protein-protein interaction network analysis of ATP1A1 gene. GENE REPORTS 2016. [DOI: 10.1016/j.genrep.2016.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
26
|
Na+/K+-ATPase α1 subunit, a novel therapeutic target for hepatocellular carcinoma. Oncotarget 2016; 6:28183-93. [PMID: 26334094 PMCID: PMC4695053 DOI: 10.18632/oncotarget.4726] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 08/07/2015] [Indexed: 01/13/2023] Open
Abstract
We aimed to identify the expression patterns of Na+/K+-ATPase (NKA) α subunits in human hepatocellular carcinoma (HCC) samples and evaluate these subunits as potential targets for HCC treatment. The mRNA expression profiles of NKA α subunits in human HCC samples were analyzed. We found that the mRNA expression for NKA α1 subunit (ATP1A1) was higher than that for other NKA α subunits. Also, ATP1A1 gene expression was markedly higher in HCC samples than in adjacent nontumor tissue samples. Western blotting data suggested that 6 of 14 (43%) HCC samples had elevated ATP1A1 protein expression. Furthermore, knockdown of ATP1A1 expression in human HCC HepG2 and MHCC97H cells markedly reduced their proliferation in vitro and suppressed the tumorigenicity of MHCC97H cells in vivo. Downregulation of ATP1A1 expression resulted in cell-cycle arrest at G2/M phase and apoptosis in HepG2 cells as well as decreased migration in Hep3B cells. We further validated that ATP1A1 downregulation caused intracellular accumulation of reactive oxygen species. Pretreatment with N-acetyl cysteine blocked cell-growth inhibition induced by ATP1A1 downregulation. Collectively, these data suggested that targeting ATP1A1 is a novel approach to the treatment of HCC.
Collapse
|
27
|
Proteasome Inhibition Contributed to the Cytotoxicity of Arenobufagin after Its Binding with Na, K-ATPase in Human Cervical Carcinoma HeLa Cells. PLoS One 2016; 11:e0159034. [PMID: 27428326 PMCID: PMC4948917 DOI: 10.1371/journal.pone.0159034] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 06/27/2016] [Indexed: 11/25/2022] Open
Abstract
Although the possibility of developing cardiac steroids/cardiac glycosides as novel cancer therapeutic agents has been recognized, the mechanism of their anticancer activity is still not clear enough. Toad venom extract containing bufadienolides, which belong to cardiac steroids, has actually long been used as traditional Chinese medicine in clinic for cancer therapy in China. The cytotoxicity of arenobufagin, a bufadienolide isolated from toad venom, on human cervical carcinoma HeLa cells was checked. And, the protein expression profile of control HeLa cells and HeLa cells treated with arenobufagin for 48 h was analyzed using two-dimensional electrophoresis, respectively. Differently expressed proteins in HeLa cells treated with arenobufagin were identified and the pathways related to these proteins were mapped from KEGG database. Computational molecular docking was performed to verify the binding of arenobufagin and Na, K-ATPase. The effects of arenobufagin on Na, K-ATPase activity and proteasome activity of HeLa cells were checked. The protein-protein interaction network between Na, K-ATPase and proteasome was constructed and the expression of possible intermediate proteins ataxin-1 and translationally-controlled tumor protein in HeLa cells treated with arenobufagin was then checked. Arenobufagin induced apoptosis and G2/M cell cycle arrest in HeLa cells. The cytotoxic effect of arenobufagin was associated with 25 differently expressed proteins including proteasome-related proteins, calcium ion binding-related proteins, oxidative stress-related proteins, metabolism-related enzymes and others. The results of computational molecular docking revealed that arenobufagin was bound in the cavity formed by the transmembrane alpha subunits of Na, K-ATPase, which blocked the pathway of extracellular Na+/K+ cation exchange and inhibited the function of ion exchange. Arenobufagin inhibited the activity of Na, K-ATPase and proteasome, decreased the expression of Na, K-ATPase α1 and α3 subunits and increased the expression of WEE1 in HeLa cells. Antibodies against Na, K-ATPase α1 and α3 subunits alone or combinated with arenobufagin also inhibited the activity of proteasome. Furthermore, the expression of the possible intermediate proteins ataxin-1 and translationally-controlled tumor protein was increased in HeLa cells treated with arenobufagin by flow cytometry analysis, respectively. These results indicated that arenobufagin might directly bind with Na, K-ATPase α1 and α3 subunits and the inhibitive effect of arenobufagin on proteasomal activity of HeLa cells might be related to its binding with Na, K-ATPase.
Collapse
|
28
|
Yan G, Wang Q, Hu S, Wang D, Qiao Y, Ma G, Tang C, Gu Y. Digoxin inhibits PDGF-BB-induced VSMC proliferation and migration through an increase in ILK signaling and attenuates neointima formation following carotid injury. Int J Mol Med 2015; 36:1001-11. [PMID: 26311435 PMCID: PMC4564091 DOI: 10.3892/ijmm.2015.2320] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 07/31/2015] [Indexed: 11/06/2022] Open
Abstract
The increased proliferation and migration of vascular smooth muscle cells (VSMCs) are key events in the development of artery restenosis following percutaneous coronary intervention. Digoxin has long been used in the treatment of heart failure and has been shown to inhibit the proliferation of cancer cells through multiple pathways. However, the potential role of digoxin in the regulation of VSMC proliferation and migration and its effectiveness in the treatment of cardiovascular diseases, such as restenosis, remains unexplored. In the present study, we demonstrate that digoxin-induced growth inhibition is associated with the downregulation of CDK activation and the restoration of p27Kip1 levels in platelet-derived growth factor (PDGF)-stimulated VSMCs. In addition, we found that digoxin restored the PDGF‑BB-induced inhibition of integrin linked kinase (ILK) expression and prevented the PDGF‑BB-induced activation of glycogen synthase kinase (GSK)-3β. Furthermore, digoxin inhibited adhesion molecule and extracellular matrix relative protein expression. Finally, we found that digoxin significantly inhibited neointima formation, accompanied by a decrease in cell proliferation following vascular injury in rats. These effects of digoxin were shown to be mediated, at least in part, through an increase in ILK/Akt signaling and a decrease in GSK-3β signaling in PDGF‑BB-stimulated VSMCs. In conclusion, our data demonstrate that digoxin exerts an inhibitory effect on the PDGF‑BB-induced proliferation, migration and phenotypic modulation of VSMCs, and prevents neointima formation in rats. These observations indicate the potential therapeutic application of digoxin in the treatment of cardiovascular diseases, such as restenosis.
Collapse
Affiliation(s)
- Gaoliang Yan
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Qingjie Wang
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Shengda Hu
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Dong Wang
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Yong Qiao
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Genshan Ma
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Chengchun Tang
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu 210009, P.R. China
| | - Yuchun Gu
- Institute of Molecular Medicine (IMM), Peking University, Beijing 100190, P.R. China
| |
Collapse
|
29
|
Balasubramaniam SL, Gopalakrishnapillai A, Barwe SP. Ion dependence of Na-K-ATPase-mediated epithelial cell adhesion and migration. Am J Physiol Cell Physiol 2015; 309:C437-41. [PMID: 26157008 DOI: 10.1152/ajpcell.00140.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Sona Lakshme Balasubramaniam
- Nemours Center for Childhood Cancer Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware; and Department of Biological Sciences, University of Delaware, Newark, Delaware
| | | | - Sonali P Barwe
- Nemours Center for Childhood Cancer Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware; and Department of Biological Sciences, University of Delaware, Newark, Delaware
| |
Collapse
|
30
|
Abstract
UNLABELLED In addition to transporting ions, the multisubunit Na(+),K(+)-ATPase also functions by relaying cardiotonic steroid (CTS)-binding-induced signals into cells. In this study, we analyzed the role of Na(+),K(+)-ATPase and, in particular, of its ATP1A1 α subunit during coronavirus (CoV) infection. As controls, the vesicular stomatitis virus (VSV) and influenza A virus (IAV) were included. Using gene silencing, the ATP1A1 protein was shown to be critical for infection of cells with murine hepatitis virus (MHV), feline infectious peritonitis virus (FIPV), and VSV but not with IAV. Lack of ATP1A1 did not affect virus binding to host cells but resulted in inhibited entry of MHV and VSV. Consistently, nanomolar concentrations of the cardiotonic steroids ouabain and bufalin, which are known not to affect the transport function of Na(+),K(+)-ATPase, inhibited infection of cells with MHV, FIPV, Middle East respiratory syndrome (MERS)-CoV, and VSV, but not IAV, when the compounds were present during virus inoculation. Cardiotonic steroids were shown to inhibit entry of MHV at an early stage, resulting in accumulation of virions close to the cell surface and, as a consequence, in reduced fusion. In agreement with an early block in infection, the inhibition of VSV by CTSs could be bypassed by low-pH shock. Viral RNA replication was not affected when these compounds were added after virus entry. The antiviral effect of ouabain could be relieved by the addition of different Src kinase inhibitors, indicating that Src signaling mediated via ATP1A1 plays a crucial role in the inhibition of CoV and VSV infections. IMPORTANCE Coronaviruses (CoVs) are important pathogens of animals and humans, as demonstrated by the recent emergence of new human CoVs of zoonotic origin. Antiviral drugs targeting CoV infections are lacking. In the present study, we show that the ATP1A1 subunit of Na(+),K(+)-ATPase, an ion transporter and signaling transducer, supports CoV infection. Targeting ATP1A1 either by gene silencing or by low concentrations of the ATP1A1-binding cardiotonic steroids ouabain and bufalin resulted in inhibition of infection with murine, feline, and MERS-CoVs at an early entry stage. Infection with the control virus VSV was also inhibited. Src signaling mediated by ATP1A1 was shown to play a crucial role in the inhibition of virus entry by ouabain and bufalin. These results suggest that targeting the Na(+),K(+)-ATPase using cardiotonic steroids, several of which are FDA-approved compounds, may be an attractive therapeutic approach against CoV and VSV infections.
Collapse
|
31
|
The influence of Ouabain on human dendritic cells maturation. Mediators Inflamm 2014; 2014:494956. [PMID: 25609892 PMCID: PMC4291013 DOI: 10.1155/2014/494956] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 12/01/2014] [Indexed: 11/17/2022] Open
Abstract
Although known as a Na,K-ATPase inhibitor, several other cellular and systemic actions have been ascribed to the steroid Ouabain (Oua). Particularly in the immune system, our group showed that Ouabain acts on decreasing lymphocyte proliferation, synergizing with glucocorticoids in spontaneous thymocyte apoptosis, and also lessening CD14 expression and blocking CD16 upregulation on human monocytes. However, Ouabain effects on dendritic cells (DCs) were not explored so far. Considering the peculiar plasticity and the importance of DCs in immune responses, the aim of our study was to investigate DC maturation under Ouabain influence. To generate immature DCs, human monocytes were cultured with IL-4 and GM-CSF (5 days). To investigate Ouabain role on DC activation, DCs were stimulated with TNF-α for 48 h in the presence or absence of Ouabain. TNF-induced CD83 expression and IL-12 production were abolished in DCs incubated with 100 nM Ouabain, though DC functional capacity concerning lymphocyte activation remained unaltered. Nevertheless, TNF-α-induced antigen capture downregulation, another maturation marker, occurred even in the presence of Ouabain. Besides, Ouabain increased HLA-DR and CD86 expression, whereas CD80 expression was maintained. Collectively, our results suggest that DCs respond to Ouabain maturating into a distinct category, possibly contributing to the balance between immunity and tolerance.
Collapse
|
32
|
Rocha SC, Pessoa MTC, Neves LDR, Alves SLG, Silva LM, Santos HL, Oliveira SMF, Taranto AG, Comar M, Gomes IV, Santos FV, Paixão N, Quintas LEM, Noël F, Pereira AF, Tessis ACSC, Gomes NLS, Moreira OC, Rincon-Heredia R, Varotti FP, Blanco G, Villar JAFP, Contreras RG, Barbosa LA. 21-Benzylidene digoxin: a proapoptotic cardenolide of cancer cells that up-regulates Na,K-ATPase and epithelial tight junctions. PLoS One 2014; 9:e108776. [PMID: 25290152 PMCID: PMC4188576 DOI: 10.1371/journal.pone.0108776] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 08/25/2014] [Indexed: 02/07/2023] Open
Abstract
Cardiotonic steroids are used to treat heart failure and arrhythmia and have promising anticancer effects. The prototypic cardiotonic steroid ouabain may also be a hormone that modulates epithelial cell adhesion. Cardiotonic steroids consist of a steroid nucleus and a lactone ring, and their biological effects depend on the binding to their receptor, Na,K-ATPase, through which, they inhibit Na+ and K+ ion transport and activate of several intracellular signaling pathways. In this study, we added a styrene group to the lactone ring of the cardiotonic steroid digoxin, to obtain 21-benzylidene digoxin (21-BD), and investigated the effects of this synthetic cardiotonic steroid in different cell models. Molecular modeling indicates that 21-BD binds to its target Na,K-ATPase with low affinity, adopting a different pharmacophoric conformation when bound to its receptor than digoxin. Accordingly, 21-DB, at relatively high µM amounts inhibits the activity of Na,K-ATPase α1, but not α2 and α3 isoforms. In addition, 21-BD targets other proteins outside the Na,K-ATPase, inhibiting the multidrug exporter Pdr5p. When used on whole cells at low µM concentrations, 21-BD produces several effects, including: 1) up-regulation of Na,K-ATPase expression and activity in HeLa and RKO cancer cells, which is not found for digoxin, 2) cell specific changes in cell viability, reducing it in HeLa and RKO cancer cells, but increasing it in normal epithelial MDCK cells, which is different from the response to digoxin, and 3) changes in cell-cell interaction, altering the molecular composition of tight junctions and elevating transepithelial electrical resistance of MDCK monolayers, an effect previously found for ouabain. These results indicate that modification of the lactone ring of digoxin provides new properties to the compound, and shows that the structural change introduced could be used for the design of cardiotonic steroid with novel functions.
Collapse
Affiliation(s)
- Sayonarah C. Rocha
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Marco T. C. Pessoa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Luiza D. R. Neves
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Silmara L. G. Alves
- Laboratório de Síntese Orgânica, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Luciana M. Silva
- Laboratório de Biologia Celular e Inovação Biotecnológica, Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil
| | - Herica L. Santos
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Soraya M. F. Oliveira
- Laboratório de Bioinformática, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Alex G. Taranto
- Laboratório de Bioinformática, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Moacyr Comar
- Laboratório de Bioinformática, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Isabella V. Gomes
- Laboratório de Biologia Celular e Mutagenicidade, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Fabio V. Santos
- Laboratório de Biologia Celular e Mutagenicidade, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Natasha Paixão
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Luis E. M. Quintas
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - François Noël
- Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Antonio F. Pereira
- Laboratório de Bioquímica Microbiana, Instituto de Microbiologia Paulo Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Ana C. S. C. Tessis
- Laboratório de Bioquímica Microbiana, Instituto de Microbiologia Paulo Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro (IFRJ), Rio de Janeiro, RJ, Brazil
| | - Natalia L. S. Gomes
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Otacilio C. Moreira
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Ruth Rincon-Heredia
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City, Mexico
| | - Fernando P. Varotti
- Laboratório de Bioquímica de Parasitos, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Gustavo Blanco
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Jose A. F. P. Villar
- Laboratório de Síntese Orgânica, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| | - Rubén G. Contreras
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City, Mexico
| | - Leandro A. Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Divinópolis, MG, Brazil
| |
Collapse
|
33
|
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: 527] [Impact Index Per Article: 52.7] [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
|
34
|
Larre I, Ponce A, Franco M, Cereijido M. The emergence of the concept of tight junctions and physiological regulation by ouabain. Semin Cell Dev Biol 2014; 36:149-56. [PMID: 25242280 DOI: 10.1016/j.semcdb.2014.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 09/09/2014] [Indexed: 02/01/2023]
Abstract
The exchange of substances between metazoan and the environment takes place across transporting epithelia that have two fundamental differentiated features: tight junctions (TJ) and apical/basolateral polarity. Usually, reviews of the structure and function of transporting epithelia follow a historical description of major biological findings, but seldom refer to the fact that it also required fundamental theoretical changes in the physics and chemistry involved. We make a brief description of the concatenation of both types of achievements, in which it becomes clear that the major source of conflicts was the enzyme Na(+),K(+)-ATPase (also referred to as "the pump"), because of its intrinsic mechanisms and its asymmetric expression on one side of epithelial cells only (polarity). This enzyme is also the receptor of the newly recognized hormone ouabain, whose chief function is to modulate cell contacts, such as TJs, several types of cell-cell contacts participating in polarization (as gauged through ciliogenesis).
Collapse
Affiliation(s)
- I Larre
- Department of Physiology, Biophysics and Neurosciences, Center for Research & Advanced Studies (Cinvestav), Mexico
| | - A Ponce
- Department of Physiology, Biophysics and Neurosciences, Center for Research & Advanced Studies (Cinvestav), Mexico
| | - M Franco
- National Institute of Cardiology "Ignacio Chavez", Mexico
| | - M Cereijido
- Department of Physiology, Biophysics and Neurosciences, Center for Research & Advanced Studies (Cinvestav), Mexico.
| |
Collapse
|
35
|
Khundmiri SJ. Advances in understanding the role of cardiac glycosides in control of sodium transport in renal tubules. J Endocrinol 2014; 222:R11-24. [PMID: 24781255 DOI: 10.1530/joe-13-0613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cardiotonic steroids have been used for the past 200 years in the treatment of congestive heart failure. As specific inhibitors of membrane-bound Na(+)/K(+) ATPase, they enhance cardiac contractility through increasing myocardial cell calcium concentration in response to the resulting increase in intracellular Na concentration. The half-minimal concentrations of cardiotonic steroids required to inhibit Na(+)/K(+) ATPase range from nanomolar to micromolar concentrations. In contrast, the circulating levels of cardiotonic steroids under physiological conditions are in the low picomolar concentration range in healthy subjects, increasing to high picomolar levels under pathophysiological conditions including chronic kidney disease and heart failure. Little is known about the physiological function of low picomolar concentrations of cardiotonic steroids. Recent studies have indicated that physiological concentrations of cardiotonic steroids acutely stimulate the activity of Na(+)/K(+) ATPase and activate an intracellular signaling pathway that regulates a variety of intracellular functions including cell growth and hypertrophy. The effects of circulating cardiotonic steroids on renal salt handling and total body sodium homeostasis are unknown. This review will focus on the role of low picomolar concentrations of cardiotonic steroids in renal Na(+)/K(+) ATPase activity, cell signaling, and blood pressure regulation.
Collapse
Affiliation(s)
- Syed Jalal Khundmiri
- Division of Nephrology and HypertensionDepartment of MedicineDepartment of Physiology and BiophysicsUniversity of Louisville, 570 S. Preston Street, Louisville, Kentucky 40202, USADivision of Nephrology and HypertensionDepartment of MedicineDepartment of Physiology and BiophysicsUniversity of Louisville, 570 S. Preston Street, Louisville, Kentucky 40202, USA
| |
Collapse
|
36
|
Effect of long intake of aspartame on ionic imbalance in immune organs of immunized wistar albino rats. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.biomag.2014.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
37
|
Aspartame induces alteration in electrolytes homeostasis of immune organs in wistar albino rats. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.bionut.2013.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
38
|
Ouabain induces endocytosis and degradation of tight junction proteins through ERK1/2-dependent pathways. Exp Cell Res 2014; 320:108-18. [DOI: 10.1016/j.yexcr.2013.10.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 10/07/2013] [Accepted: 10/09/2013] [Indexed: 11/20/2022]
|
39
|
Xie JX, Li X, Xie Z. Regulation of renal function and structure by the signaling Na/K-ATPase. IUBMB Life 2013; 65:991-8. [PMID: 24323927 PMCID: PMC5375025 DOI: 10.1002/iub.1229] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 11/08/2013] [Indexed: 12/23/2022]
Abstract
The Na/K-ATPase as an essential ion pump was discovered more than 50 years ago (Skou (1989) Biochim. Biophys. Acta 1000, 439-446; Feraille and Doucet (2001) Physiol. Rev. 81, 345-418). The signaling function of Na/K-ATPase has been gradually appreciated over the last 20 years, first from the studies of regulatory effects of ouabain on cardiac cell growth. Several reviews on this topic have been written during the last few years (Schoner and Scheiner-Bobis (2007) Am. J. Physiol. Cell. Physiol. 293, C509-C536; Xie and Cai (2003) Mol. Interv. 3, 157 - 168; Bagrov et al. (2009) Pharmacol. Rev. 61, 9-38; Tian and Xie (2008) Physiology 23, 205-211; Fontana et al. (2013) FEBS J. 280, 5450-5455; Blanco and Wallace (2013) Am. J. Physiol. Renal Physiol. 305, F797-F812). This article will focus on the molecular mechanism of Na/K-ATPase-mediated signal transduction and its potential regulatory role in renal physiology and diseases.
Collapse
Affiliation(s)
- Jeffrey X Xie
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, USA
| | | | | |
Collapse
|
40
|
Autosis is a Na+,K+-ATPase-regulated form of cell death triggered by autophagy-inducing peptides, starvation, and hypoxia-ischemia. Proc Natl Acad Sci U S A 2013; 110:20364-71. [PMID: 24277826 DOI: 10.1073/pnas.1319661110] [Citation(s) in RCA: 433] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A long-standing controversy is whether autophagy is a bona fide cause of mammalian cell death. We used a cell-penetrating autophagy-inducing peptide, Tat-Beclin 1, derived from the autophagy protein Beclin 1, to investigate whether high levels of autophagy result in cell death by autophagy. Here we show that Tat-Beclin 1 induces dose-dependent death that is blocked by pharmacological or genetic inhibition of autophagy, but not of apoptosis or necroptosis. This death, termed "autosis," has unique morphological features, including increased autophagosomes/autolysosomes and nuclear convolution at early stages, and focal swelling of the perinuclear space at late stages. We also observed autotic death in cells during stress conditions, including in a subpopulation of nutrient-starved cells in vitro and in hippocampal neurons of neonatal rats subjected to cerebral hypoxia-ischemia in vivo. A chemical screen of ~5,000 known bioactive compounds revealed that cardiac glycosides, antagonists of Na(+),K(+)-ATPase, inhibit autotic cell death in vitro and in vivo. Furthermore, genetic knockdown of the Na(+),K(+)-ATPase α1 subunit blocks peptide and starvation-induced autosis in vitro. Thus, we have identified a unique form of autophagy-dependent cell death, a Food and Drug Administration-approved class of compounds that inhibit such death, and a crucial role for Na(+),K(+)-ATPase in its regulation. These findings have implications for understanding how cells die during certain stress conditions and how such cell death might be prevented.
Collapse
|
41
|
Overexpression of FXYD-3 is involved in the tumorigenesis and development of esophageal squamous cell carcinoma. DISEASE MARKERS 2013; 35:195-202. [PMID: 24167366 PMCID: PMC3774971 DOI: 10.1155/2013/740201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 06/13/2013] [Accepted: 07/16/2013] [Indexed: 01/03/2023]
Abstract
Objective. To investigate the association of FXYD-3 expression with clinicopathological variables and PINCH in patients with ESCC. Patients and Methods. Expression of FXYD-3 protein was immunohistochemically examined in normal esophageal mucous (n = 20) and ESCC (n = 64). Results. Expression of FXYD-3 in the cytoplasm markedly increased from normal esophageal epithelial cells to primary ESCC (P = 0.001). The expression of FXYD-3 was correlated with TNM stages and depth of tumor invasion. Furthermore, the cases with lymph node metastasis tended to show a higher frequency of positive expression than those without metastasis (P = 0.086), and FXYD-3 expression tended to be positively related to the expression of PINCH (P = 0.063). Moreover, the cases positive for both proteins had the highest frequency of lymph node metastasis (P = 0.001). However, FXYD-3 expression was not correlated with patient's gender (P = 0.847), age (P = 0.876), tumor location (P = 0.279), size (P = 0.771), grade of differentiation (P = 0.279), and survival (P = 0.113). Conclusion. Overexpression of FXYD-3 in the cytoplasm may play an important role in the tumorigenesis and development in the human ESCC, particularly in combination with PINCH expression.
Collapse
|
42
|
Maturu P, Vaddi DR, Pannuru P, Nallanchakravarthula V. Modification of Erythrocyte Membrane Proteins, Enzymes and Transport Mechanisms in Chronic Alcoholics: An In vivo and In vitro Study. Alcohol Alcohol 2013; 48:679-86. [DOI: 10.1093/alcalc/agt071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
|
43
|
Mony S, Lee SJ, Harper JF, Barwe SP, Langhans SA. Regulation of Na,K-ATPase β1-subunit in TGF-β2-mediated epithelial-to-mesenchymal transition in human retinal pigmented epithelial cells. Exp Eye Res 2013; 115:113-22. [PMID: 23810808 DOI: 10.1016/j.exer.2013.06.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/15/2013] [Accepted: 06/07/2013] [Indexed: 12/14/2022]
Abstract
Proliferative vitreo retinopathy (PVR) is associated with extracellular matrix membrane (ECM) formation on the neural retina and disruption of the multilayered retinal architecture leading to distorted vision and blindness. During disease progression in PVR, retinal pigmented epithelial cells (RPE) lose cell-cell adhesion, undergo epithelial-to-mesenchymal transition (EMT), and deposit ECM leading to tissue fibrosis. The EMT process is mediated via exposure to vitreous cytokines and growth factors such as TGF-β2. Previous studies have shown that Na,K-ATPase is required for maintaining a normal polarized epithelial phenotype and that decreased Na,K-ATPase function and subunit levels are associated with TGF-β1-mediated EMT in kidney cells. In contrast to the basolateral localization of Na,K-ATPase in most epithelia, including kidney, Na,K-ATPase is found on the apical membrane in RPE cells. We now show that EMT is also associated with altered Na,K-ATPase expression in RPE cells. TGF-β2 treatment of ARPE-19 cells resulted in a time-dependent decrease in Na,K-ATPase β1 mRNA and protein levels while Na,K-ATPase α1 levels, Na,K-ATPase activity, and intracellular sodium levels remained largely unchanged. In TGF-β2-treated cells reduced Na,K-ATPase β1 mRNA inversely correlated with HIF-1α levels and analysis of the Na,K-ATPase β1 promoter revealed a putative hypoxia response element (HRE). HIF-1α bound to the Na,K-ATPase β1 promoter and inhibiting the activity of HIF-1α blocked the TGF-β2 mediated Na,K-ATPase β1 decrease suggesting that HIF-1α plays a potential role in Na,K-ATPase β1 regulation during EMT in RPE cells. Furthermore, knockdown of Na,K-ATPase β1 in ARPE-19 cells was associated with a change in cell morphology from epithelial to mesenchymal and induction of EMT markers such as α-smooth muscle actin and fibronectin, suggesting that loss of Na,K-ATPase β1 is a potential contributor to TGF-β2-mediated EMT in RPE cells.
Collapse
Affiliation(s)
- Sridevi Mony
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Rockland Center I, 1701 Rockland Road, Wilmington, DE 19803, USA.
| | | | | | | | | |
Collapse
|
44
|
Orlov SN, Platonova AA, Hamet P, Grygorczyk R. Cell volume and monovalent ion transporters: their role in cell death machinery triggering and progression. Am J Physiol Cell Physiol 2013; 305:C361-72. [PMID: 23615964 DOI: 10.1152/ajpcell.00040.2013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell death is accompanied by the dissipation of electrochemical gradients of monovalent ions across the plasma membrane that, in turn, affects cell volume via modulation of intracellular osmolyte content. In numerous cell types, apoptotic and necrotic stimuli caused cell shrinkage and swelling, respectively. Thermodynamics predicts a cell type-specific rather than an ubiquitous impact of monovalent ion transporters on volume perturbations in dying cells, suggesting their diverse roles in the cell death machinery. Indeed, recent data showed that apoptotic collapse may occur in the absence of cell volume changes and even follow cell swelling rather than shrinkage. Moreover, side-by-side with cell volume adjustment, monovalent ion transporters contribute to cell death machinery engagement independently of volume regulation via cell type-specific signaling pathways. Thus, inhibition of Na(+)-K(+)-ATPase by cardiotonic steroids (CTS) rescues rat vascular smooth muscle cells from apoptosis via a novel Na(+)i-K(+)i-mediated, Ca(2+)i-independent mechanism of excitation-transcription coupling. In contrast, CTS kill renal epithelial cells independently of Na(+)-K(+)-ATPase inhibition and increased [Na(+)]i/[K(+)]i ratio. The molecular origin of [Na(+)]i/[K(+)]i sensors involved in the inhibition of apoptosis as well as upstream intermediates of Na(+)i/K(+)i-independent death signaling triggered by CTS remain unknown.
Collapse
Affiliation(s)
- Sergei N Orlov
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada.
| | | | | | | |
Collapse
|
45
|
Cong X, Zhang Y, Yang NY, Li J, Ding C, Ding QW, Su YC, Mei M, Guo XH, Wu LL, Yu GY. Occludin is required for TRPV1-modulated paracellular permeability in the submandibular gland. J Cell Sci 2013; 126:1109-21. [PMID: 23345400 DOI: 10.1242/jcs.111781] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Occludin plays an important role in maintaining tight junction barrier function in many types of epithelia. We previously reported that activation of transient receptor potential vanilloid subtype 1 (TRPV1) in rabbit submandibular gland promoted salivary secretion, partly by an increase in paracellular permeability. We have now explored the role of occludin in TRPV1-modulated paracellular permeability in a rat submandibular gland cell line SMG-C6. Both TRPV1 and occludin were expressed in SMG-C6 cells, and capsaicin induced redistribution of occludin, but not claudin-3, claudin-4 or E-cadherin, from the cell membrane into the cytoplasm. Capsaicin also decreased transepithelial electrical resistance (TER) and increased the Trypan Blue and FITC-dextran flux. Capsazepine (CPZ), a TRPV1 antagonist, inhibited the capsaicin-induced occludin redistribution and TER decrease. Moreover, occludin knockdown by shRNA suppressed, whereas occludin re-expression restored, the TER response to capsaicin. Mechanistically, TRPV1 activation increased ERK1/2 and MLC2 phosphorylation. PD98059, an ERK1/2 kinase inhibitor, abolished the capsaicin-induced MLC2 phosphorylation, whereas ML-7, an MLC2 kinase inhibitor, did not affect ERK1/2 phosphorylation, suggesting that ERK1/2 is the upstream signaling molecule of MLC2. Capsaicin also induced F-actin reorganization, which was abolished by CPZ, PD98059 and ML-7, indicating that TRPV1 activation altered F-actin organization in an ERK1/2- and MLC2-dependent manner. Furthermore, either PD98059 or ML-7 could abolish the capsaicin-induced TER response and occludin redistribution, whereas knockdown of ERK1/2 further confirmed that the TRPV1-modulated paracellular permeability was ERK1/2 dependent. Taken together, these results identified a crucial role of occludin in submandibular epithelial cells, and more importantly, demonstrated that occludin was required to mediate TRPV1-modulated paracellular permeability.
Collapse
Affiliation(s)
- Xin Cong
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Jansson K, Nguyen ANT, Magenheimer BS, Reif GA, Aramadhaka LR, Bello-Reuss E, Wallace DP, Calvet JP, Blanco G. Endogenous concentrations of ouabain act as a cofactor to stimulate fluid secretion and cyst growth of in vitro ADPKD models via cAMP and EGFR-Src-MEK pathways. Am J Physiol Renal Physiol 2012; 303:F982-90. [PMID: 22859406 PMCID: PMC3469686 DOI: 10.1152/ajprenal.00677.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 07/26/2012] [Indexed: 01/26/2023] Open
Abstract
In autosomal-dominant polycystic kidney disease (ADPKD), renal cysts develop by aberrant epithelial cell proliferation and transepithelial fluid secretion. We previously showed that ouabain increases proliferation of cultured human ADPKD cells via stimulation of the EGF receptor (EGFR)-Src-MEK/ERK signaling pathway. We examined whether ouabain affects fluid secretion and in vitro cyst growth of human ADPKD cell monolayers, ADPKD cell microcysts cultured in a three-dimensional collagen matrix, and metanephric organ cultures from Pkd1(m1Bei) mice. Physiological concentrations of ouabain alone did not affect net transepithelial basal-to-apical fluid transport in ADPKD monolayers or growth of cultured ADPKD microcysts. In contrast, in the presence of forskolin or 8-bromo-cAMP, ouabain significantly enhanced ADPKD fluid secretion and microcyst expansion. Ouabain exerted this effect by enhancing cAMP-dependent Cl(-) secretion via the CFTR. Similarly, ouabain accelerated cAMP-dependent cyst enlargement in Pkd1(m1Bei) mice metanephroi, with a more prominent response in homozygous than heterozygous mice. Ouabain had no effect on fluid secretion and cystogenesis of normal human kidney cells and caused only slight cystic dilations in wild-type mouse kidneys. The effects of ouabain in ADPKD cells and Pkd1(m1Bei) metanephroi were prevented by inhibitors of EGFR (AG1478), Src (PP2), and MEK (U0126). Together, our results show that ouabain, used in physiological concentrations, has synergistic effects on cAMP-mediated fluid secretion and cyst growth, via activation of the EGFR-Src-MEK pathway. These data provide important evidence for the role of ouabain as an endogenous hormone that exacerbates ADPKD cyst progression.
Collapse
Affiliation(s)
- Kyle Jansson
- Dept. of Molecular and Integrative Physiology, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Vagin O, Dada LA, Tokhtaeva E, Sachs G. The Na-K-ATPase α₁β₁ heterodimer as a cell adhesion molecule in epithelia. Am J Physiol Cell Physiol 2012; 302:C1271-81. [PMID: 22277755 PMCID: PMC3361946 DOI: 10.1152/ajpcell.00456.2011] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Accepted: 01/24/2012] [Indexed: 11/22/2022]
Abstract
The ion gradients generated by the Na-K-ATPase play a critical role in epithelia by driving transepithelial transport of various solutes. The efficiency of this Na-K-ATPase-driven vectorial transport depends on the integrity of epithelial junctions that maintain polar distribution of membrane transporters, including the basolateral sodium pump, and restrict paracellular diffusion of solutes. The review summarizes the data showing that, in addition to pumping ions, the Na-K-ATPase located at the sites of cell-cell junction acts as a cell adhesion molecule by interacting with the Na-K-ATPase of the adjacent cell in the intercellular space accompanied by anchoring to the cytoskeleton in the cytoplasm. The review also discusses the experimental evidence on the importance of a specific amino acid region in the extracellular domain of the Na-K-ATPase β(1) subunit for the Na-K-ATPase trans-dimerization and intercellular adhesion. Furthermore, a possible role of N-glycans linked to the Na-K-ATPase β(1) subunit in regulation of epithelial junctions by modulating β(1)-β(1) interactions is discussed.
Collapse
Affiliation(s)
- Olga Vagin
- Department of Physiology, School of Medicine, University of California Los Angeles and Veterans Administration Greater Los Angeles Health Care System, Los Angeles, California, USA.
| | | | | | | |
Collapse
|
48
|
The plasma membrane potential and the organization of the actin cytoskeleton of epithelial cells. Int J Cell Biol 2012; 2012:121424. [PMID: 22315611 PMCID: PMC3272338 DOI: 10.1155/2012/121424] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Accepted: 10/08/2011] [Indexed: 12/22/2022] Open
Abstract
The establishment and maintenance of the polarized epithelial phenotype require a characteristic organization of the cytoskeletal components. There are many cellular effectors involved in the regulation of the cytoskeleton of epithelial cells. Recently, modifications in the plasma membrane potential (PMP) have been suggested to participate in the modulation of the cytoskeletal organization of epithelia. Here, we review evidence showing that changes in the PMP of diverse epithelial cells promote characteristic modifications in the cytoskeletal organization, with a focus on the actin cytoskeleton. The molecular paths mediating these effects may include voltage-sensitive integral membrane proteins and/or peripheral proteins sensitive to surface potentials. The voltage dependence of the cytoskeletal organization seems to have implications in several physiological processes, including epithelial wound healing and apoptosis.
Collapse
|
49
|
Modulation of tight junction structure and function by kinases and phosphatases targeting occludin. J Biomed Biotechnol 2012; 2012:807356. [PMID: 22315516 PMCID: PMC3270569 DOI: 10.1155/2012/807356] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 08/22/2011] [Indexed: 01/20/2023] Open
Abstract
Tight junctions (TJs) typically represent the most apical contacts in epithelial and endothelial cell layers where they play an essential role in the separation of extracellular or luminal spaces from underlying tissues in the body. Depending on the protein composition, TJs define the barrier characteristics and in addition maintain cell polarity. Two major families of integral membrane proteins form the typical TJ strand network, the tight junction-associated MARVEL protein (TAMP) family members occludin, tricellulin, and MarvelD3 as well as a specific set of claudins. Occludin was the first identified member of these tetraspanins and is now widely accepted as a regulator of TJ assembly and function. Therefore, occludin itself has to be tightly regulated. Phosphorylation of occludin appears to be of central importance in this context. Here we want to summarize current knowledge on the kinases and phosphatases directly modifying occludin, and their role in the regulation of TJ structure, function, and dynamics.
Collapse
|
50
|
Abstract
The exchange of substances between higher organisms and the environment occurs across transporting epithelia whose basic features are tight junctions (TJs) that seal the intercellular space, and polarity, which enables cells to transport substances vectorially. In a previous study, we demonstrated that 10 nM ouabain modulates TJs, and we now show that it controls polarity as well. We gauge polarity through the development of a cilium at the apical domain of Madin-Darby canine kidney cells (MDCK, epithelial dog kidney). Ouabain accelerates ciliogenesis in an ERK1/2-dependent manner. Claudin-2, a molecule responsible for the Na(+) and H(2)O permeability of the TJs, is also present at the cilium, as it colocalizes and coprecipitates with acetylated α-tubulin. Ouabain modulates claudin-2 localization at the cilium through ERK1/2. Comparing wild-type and ouabain-resistant MDCK cells, we show that ouabain acts through Na(+),K(+)-ATPase. Taken together, our previous and present results support the possibility that ouabain constitutes a hormone that modulates the transporting epithelial phenotype, thereby playing a crucial role in metazoan life.
Collapse
|