1
|
Lee CE, Charmantier G, Lorin-Nebel C. Mechanisms of Na + uptake from freshwater habitats in animals. Front Physiol 2022; 13:1006113. [PMID: 36388090 PMCID: PMC9644288 DOI: 10.3389/fphys.2022.1006113] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/28/2022] [Indexed: 07/20/2023] Open
Abstract
Life in fresh water is osmotically and energetically challenging for living organisms, requiring increases in ion uptake from dilute environments. However, mechanisms of ion uptake from freshwater environments are still poorly understood and controversial, especially in arthropods, for which several hypothetical models have been proposed based on incomplete data. One compelling model involves the proton pump V-type H+ ATPase (VHA), which energizes the apical membrane, enabling the uptake of Na+ (and other cations) via an unknown Na+ transporter (referred to as the "Wieczorek Exchanger" in insects). What evidence exists for this model of ion uptake and what is this mystery exchanger or channel that cooperates with VHA? We present results from studies that explore this question in crustaceans, insects, and teleost fish. We argue that the Na+/H+ antiporter (NHA) is a likely candidate for the Wieczorek Exchanger in many crustaceans and insects; although, there is no evidence that this is the case for fish. NHA was discovered relatively recently in animals and its functions have not been well characterized. Teleost fish exhibit redundancy of Na+ uptake pathways at the gill level, performed by different ion transporter paralogs in diverse cell types, apparently enabling tolerance of low environmental salinity and various pH levels. We argue that much more research is needed on overall mechanisms of ion uptake from freshwater habitats, especially on NHA and other potential Wieczorek Exchangers. Such insights gained would contribute greatly to our general understanding of ionic regulation in diverse species across habitats.
Collapse
Affiliation(s)
- Carol Eunmi Lee
- Department of Integrative Biology, University of Wisconsin, Madison, WI, United States
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Guy Charmantier
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | | |
Collapse
|
2
|
Su M, Liu N, Zhang Z, Zhang J. Osmoregulatory strategies of estuarine fish Scatophagus argus in response to environmental salinity changes. BMC Genomics 2022; 23:545. [PMID: 35907798 PMCID: PMC9339187 DOI: 10.1186/s12864-022-08784-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/20/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Scatophagus argus, an estuarine inhabitant, can rapidly adapt to different salinity environments. However, the knowledge of the molecular mechanisms underlying its strong salinity tolerance remains unclear. The gill, as the main osmoregulatory organ, plays a vital role in the salinity adaptation of the fish, and thus relative studies are constructive to reveal unique osmoregulatory mechanisms in S. argus. RESULTS In the present study, iTRAQ coupled with nanoLC-MS/MS techniques were employed to explore branchial osmoregulatory mechanisms in S. argus acclimated to different salinities. Among 1,604 identified proteins, 796 differentially expressed proteins (DEPs) were detected. To further assess osmoregulatory strategies in the gills under different salinities, DEPs related to osmoregulatory (22), non-directional (18), hypo- (52), and hypersaline (40) stress responses were selected. Functional annotation analysis of these selected DEPs indicated that the cellular ion regulation (e.g. Na+-K+-ATPase [NKA] and Na+-K+-2Cl- cotransporter 1 [NKCC1]) and ATP synthesis were deeply involved in the osmoregulatory process. As an osmoregulatory protein, NKCC1 expression was inhibited under hyposaline stress but showed the opposite trend in hypersaline conditions. The expression levels of NKA α1 and β1 were only increased under hypersaline challenge. However, hyposaline treatments could enhance branchial NKA activity, which was inhibited under hypersaline environments, and correspondingly, reduced ATP content was observed in gill tissues exposed to hyposaline conditions, while its contents were increased in hypersaline groups. In vitro experiments indicated that Na+, K+, and Cl- ions were pumped out of branchial cells under hypoosmotic stress, whereas they were absorbed into cells under hyperosmotic conditions. Based on our results, we speculated that NKCC1-mediated Na+ influx was inhibited, and proper Na+ efflux was maintained by improving NKA activity under hyposaline stress, promoting the rapid adaptation of branchial cells to the hyposaline condition. Meanwhile, branchial cells prevented excessive loss of ions by increasing NKA internalization and reducing ATP synthesis. In contrast, excess ions in cells exposed to the hyperosmotic medium were excreted with sufficient energy supply, and reduced NKA activity and enhanced NKCC1-mediated Na+ influx were considered a compensatory regulation. CONCLUSIONS S. argus exhibited divergent osmoregulatory strategies in the gills when encountering hypoosmotic and hyperosmotic stresses, facilitating effective adaptabilities to a wide range of environmental salinity fluctuation.
Collapse
Affiliation(s)
- Maoliang Su
- Shenzhen Key Laboratory of Marine Bioresource & Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Nanxi Liu
- Shenzhen Key Laboratory of Marine Bioresource & Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Zhengqi Zhang
- Shenzhen Key Laboratory of Marine Bioresource & Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Junbin Zhang
- Shenzhen Key Laboratory of Marine Bioresource & Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
| |
Collapse
|
3
|
Vargas-Chacoff L, Dann F, Paschke K, Oyarzún-Salazar R, Nualart D, Martínez D, Wilson JM, Guerreiro PM, Navarro JM. Freshening effect on the osmotic response of the Antarctic spiny plunderfish Harpagifer antarcticus. JOURNAL OF FISH BIOLOGY 2021; 98:1558-1571. [PMID: 33452810 DOI: 10.1111/jfb.14676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/05/2021] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Global warming is having a significant impact around the world, modifying environmental conditions in many areas, including in zones that have been thermally stable for thousands of years, such as Antarctica. Stenothermal sedentary intertidal fish species may suffer due to warming, notably if this causes water freshening from increased freshwater inputs. Acute decreases in salinity, from 33 down to 5, were used to assess osmotic responses to environmental salinity fluctuations in Antarctic spiny plunderfish Harpagifer antarcticus, in particular to evaluate if H. antarcticus is able to cope with freshening and to describe osmoregulatory responses at different levels (haematological variables, muscle water content, gene expression, NKA activity). H. antarcticus were acclimated to a range of salinities (33 as control, 20, 15, 10 and 5) for 1 week. At 5, plasma osmolality and calcium concentration were both at their lowest, while plasma cortisol and percentage muscle water content were at their highest. At the same salinity, gill and intestine Na+ -K+ -ATPase (NKA) activities were at their lowest and highest, respectively. In kidney, NKA activity was highest at intermediate salinities (15 and 10). The salinity-dependent NKA mRNA expression patterns differed depending on the tissue. Marked changes were also observed in the expression of genes coding membrane proteins associated with ion and water transport, such as NKCC2, CFTR and AQP8, and in the expression of mRNA for the regulatory hormone prolactin (PRL) and its receptor (PRLr). Our results demonstrate that freshening causes osmotic imbalances in H. antarcticus, apparently due to reduced capacity of both transport and regulatory mechanisms of key organs to maintain homeostasis. This has implications for fish species that have evolved in stable environmental conditions in the Antarctic, now threatened by climate change.
Collapse
Affiliation(s)
- Luis Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes, Universidad Austral de Chile, Valdivia, Chile
| | - Francisco Dann
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes, Universidad Austral de Chile, Valdivia, Chile
| | - Kurt Paschke
- Centro Fondap de Investigación de Altas Latitudes, Universidad Austral de Chile, Valdivia, Chile
- Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Ricardo Oyarzún-Salazar
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes, Universidad Austral de Chile, Valdivia, Chile
- Escuela de Graduados Programa de Doctorado en Ciencias de la Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Daniela Nualart
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - Danixa Martínez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - Jonathan M Wilson
- Wilfrid Laurier University, Waterloo, Ontario, Canada
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Matosinhos, Portugal
| | | | - Jorge M Navarro
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes, Universidad Austral de Chile, Valdivia, Chile
| |
Collapse
|
4
|
Immunohistochemical characterization and change in location of branchial ionocytes after transfer from freshwater to seawater in the euryhaline obscure puffer, Takifugu obscurus. J Comp Physiol B 2020; 190:585-596. [PMID: 32715333 DOI: 10.1007/s00360-020-01298-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/21/2020] [Accepted: 07/10/2020] [Indexed: 10/24/2022]
Abstract
The obscure puffer Takifugu obscurus is a euryhaline fish species suitable for studying the molecular mechanism of osmoregulation. The distributional changes of branchial ionocytes were detected following the transfer from freshwater (FW) to seawater (SW) based on two main ion transporters, Na+/K+-ATPase (NKA) and Na+/K+/ 2Cl- cotransporter 1 (NKCC1). The mRNA and protein expression levels of NKA and NKCC1 in the gills all increased rapidly in the first four days after transfer to SW. Double immunofluorescence staining showed that NKCC1 and NKA were colocalized in the branchial ionocytes and the immunoreaction of NKCC1 was stronger after transfer. Moreover, following transfer to SW, the number of lamellar ionocytes in the gills is reduced and the number of filament ionocytes is increased significantly. Taken together, these findings indicated that SW transfer of obscure puffer promotes the changes of distribution, function and size of branchial ionocytes.
Collapse
|
5
|
Capacity of Caulerpa lentillifera in the Removal of Fish Culture Effluent in a Recirculating Aquaculture System. Processes (Basel) 2019. [DOI: 10.3390/pr7070440] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aquaculture is one of the fastest growing food producing industries in the world. Aquaculture effluent contains high concentrations of inorganic nutrients. Reduction of these inorganic nutrients in aquaculture effluent is crucial for fulfilling the effluent standards or reuse of aquaculture effluent. This study investigated the effective use of green macroalga Caulerpa lentillifera as a bioremediatory species for nutrient removal from aquaculture effluent by conducting an on-station experiment and measurements. The effluent of a fish culture unit was circulated through a macroalgal culture unit every four days for a total of 60 days, allowing 15 circulations. Concentrations of inorganic nutrients (NO2−-N, NO3−-N, NH3-N, and PO43−) were measured in the integrated system consisting of a fish unit, settling unit, macroalgal unit and extra tank for water circulation in triplicates. Multiple linear regression analysis revealed that the application of the bioremediation system led to a significant reduction in nutrient concentrations within one day, and slightly further in the following two days. On average over the 15 circulations, the first one day of application decreased the concentrations of NO2−-N, NO3−-N, NH3-N, and PO43− by 0.247 mg/L, 81.6 mg/L, 0.682 mg/L, and 0.352 mg/L, respectively. Furthermore, the C:N ratio of macroalgae decreased during the 60-day application period, providing evidence of the nutrient uptake by macroalgae. Based on the European Union (EU) standard and quality criteria of France and the Joint FAO/WHO Expert Committee (JFWEC), the macroalgae grown in the integrated system were at the safe level for human consumption in terms of contents of Cd, Pb, and As. The results of our study imply that recirculating aquaculture systems utilizing C. lentillifera for biofiltration have the potential for effective treatment of aquaculture effluent integrating fish and macroalgae production.
Collapse
|
6
|
Optimization of Macroalgal Density and Salinity for Nutrient Removal by Caulerpa lentillifera from Aquaculture Effluent. Processes (Basel) 2019. [DOI: 10.3390/pr7050303] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Determining the optimum levels of macroalgal density and salinity for removing aquaculture effluent has gained increasing research interest in recent years because of the growing concerns over environmental sustainability. Here, we determined the effects of macroalgal density and salinity on the uptake of NO2−, NO3−, NH3, and PO43− by Caulerpa lentillifera from the effluent of Poecilia latipinna using spectrophotometry. Laboratory experiments were conducted to measure nutrient uptake at five different macroalgal density levels (10, 20, 30, 40, and 50 g/L) and three salinity levels (20, 30, and 40 ppt) with and without aeration. Quadratic regression analysis revealed significant nonlinear and linear effects of macroalgal density on the uptake of NO2−, NO3−, NH3, and PO43−, where the maximum uptake was predicted to occur at the macroalgal densities of 31.6, 33.3, 50.0, and 20.0 g/L, respectively. Likewise, the effects of salinity on the uptake of NO2−, NO3−, NH3, and PO43− were significant and nonlinear where the maximum uptake was predicted to occur at the salinity levels of 29.1, 30.7, 29.5, and 29.5 ppt, respectively. The result of the effects of aeration was mixed but somewhat indicated a positive effect on the nutrient uptake within the 24 h period. Our results could help aquaculturists to minimize the excessive nutrients by C. lentillifera from aquaculture effluent while achieving long-term sustainable aquaculture production.
Collapse
|
7
|
Yang WK, Yang IC, Chuang HJ, Chao TL, Hu YC, Wu WY, Wang YC, Tang CH, Lee TH. Positive correlation of gene expression between branchial FXYD proteins and Na +/K +-ATPase of euryhaline milkfish in response to hypoosmotic challenges. Comp Biochem Physiol A Mol Integr Physiol 2019; 231:177-187. [PMID: 30818021 DOI: 10.1016/j.cbpa.2019.02.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 11/17/2022]
Abstract
FXYD proteins are crucial regulators of Na+/K+-ATPase (NKA), which plays an important role in ion exchange by providing the driving force for other ion-transporting systems in the osmoregulatory organs, including the gills. In milkfish (Chanos chanos), gill NKA has been widely investigated and found to alter its expression (both mRNA and protein) and activity in response to environmental salinity changes. However, the expression and roles of the regulatory proteins of NKA, the FXYD proteins, in milkfish gills upon salinity challenge is not yet clear. Hence, this study illustrated the potential roles of milkfish branchial FXYD proteins in modulating NKA expression via identification and tissue distributions of FXYD proteins, as well as the effects of salinity on expression of gill fxyd and nka mRNA. Six milkfish FXYD proteins (CcFXYD) were identified. In milkfish gill, gill-specific Ccfxyd11 was the predominant member, followed by Ccfxyd9 and Ccfxyd8. Upon hypoosmotic challenges, increases in gill Ccfxyd11, Ccfxyd8, Ccnka α1, and Ccnka β1 mRNA as well as significantly positive correlations were observed. Moreover, after acute salinity changes, expression of gill Ccfxyd11 and Ccnka was found to change with ambient salinity, and significant positive correlations were also exhibited between Ccfxyd11 and Ccnka α1. Overall, these results revealed close relationships between CcFXYD11 and CcNKA α1 in milkfish gills, highlighting the potential roles of CcFXYD11 in osmoregulation.
Collapse
Affiliation(s)
- Wen-Kai Yang
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan; Bachelor Degree Program in Animal Healthcare, Hungkuang University, Taichung 43302, Taiwan
| | - I-Chan Yang
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Hsin-Ju Chuang
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Tse-Lih Chao
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Yau-Chung Hu
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Wen-Yi Wu
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Yu-Chun Wang
- Planning and Information Division, Fisheries Research Institute, Keelung 20246, Taiwan
| | - Cheng-Hao Tang
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan; Department of Oceanography, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
| | - Tsung-Han Lee
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
| |
Collapse
|
8
|
Lai JC, Kam YC, Lin HC, Wu CS. Enhanced salt tolerance of euryhaline tadpoles depends on increased Na+, K+-ATPase expression after salinity acclimation. Comp Biochem Physiol A Mol Integr Physiol 2019; 227:84-91. [DOI: 10.1016/j.cbpa.2018.09.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/24/2018] [Indexed: 12/18/2022]
|
9
|
Molecular characterization of Na+/K+/2Cl− cotransporter 1 alpha from Trachinotus ovatus (Linnaeus, 1758) and its expression responses to acute salinity stress. Comp Biochem Physiol B Biochem Mol Biol 2018; 223:29-38. [DOI: 10.1016/j.cbpb.2018.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 11/23/2022]
|
10
|
Brix KV, Brauner CJ, Schluter D, Wood CM. Pharmacological evidence that DAPI inhibits NHE2 in Fundulus heteroclitus acclimated to freshwater. Comp Biochem Physiol C Toxicol Pharmacol 2018; 211:1-6. [PMID: 29763692 DOI: 10.1016/j.cbpc.2018.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 11/21/2022]
Abstract
Ionoregulation in the euryhaline killifish Fundulus heteroclitus has been intensively studied over the last two decades using a variety of techniques. However, there has been limited use of pharmacological inhibitors to identify proteins involved in ion transport for this species. In this study, we used a range of pharmacological inhibitors (EIPA, DAPI, ethoxzolamide, bumetanide, bafilomycin, phenamil, hydrochlorothiazide) to investigate the proteins involved in Na+ transport in freshwater (1 mM Na+) acclimated F. heteroclitus. Our results indicate that Na+ uptake under these conditions is sensitive to both EIPA (NHE-specific inhibitor) and DAPI (putative ASIC-specific inhibitor), but not to any of the other inhibitors. Results for EIPA are consistent with previous studies indicating F. heteroclitus relies solely on NHE2 for Na+ transport across the apical membrane of ionocytes. In contrast, results for DAPI are surprising given previous studies that have indicated the H+-ATPase is basolaterally located in F. heteroclitus and so cannot contribute to Na+ uptake via ASIC. The lack of bafilomycin sensitivity in the current study is consistent with a basolaterally located H+-ATPase. This suggests that DAPI is not an ASIC-specific inhibitor as has been previously assumed, and that it may also inhibit NHE2. Finally, we did not observe Na+ uptake to be sensitive to ethoxzolamide, suggesting that carbonic anhydrase may not be involved in generating the H+ needed to maintain NHE activity in freshwater as has been previously proposed.
Collapse
Affiliation(s)
- Kevin V Brix
- EcoTox, Miami, FL, United States; University of Miami, RSMAS, Miami, FL, United States.
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Dolph Schluter
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
11
|
Yang WK, Hsu AD, Kang CK, Lai IP, Liao PS, Lee TH. Intestinal FXYD12 and sodium-potassium ATPase: A comparative study on two euryhaline medakas in response to salinity changes. PLoS One 2018; 13:e0201252. [PMID: 30052675 PMCID: PMC6063443 DOI: 10.1371/journal.pone.0201252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 07/11/2018] [Indexed: 11/18/2022] Open
Abstract
FXYD proteins are the regulators of sodium-potassium ATPase (Na+/K+-ATPase, NKA). In teleosts, NKA is a primary driving force for the operation of many ion transport systems in the osmoregulatory organs (e.g. intestines). Hence, the purpose of this study was to determine the expression of FXYD proteins and NKA α-subunit in the intestines of two closely related medakas (Oryzias dancena and O. latipes), which came from different salinity habitats and have diverse osmoregulatory capabilities, to illustrate the association between NKA and FXYD proteins of two medaka species in response to salinity changes. The results showed that the fxyd12 mRNA was the most predominant in the intestines of both medakas. The association of FXYD12 and NKA in the intestines of the two medaka species was demonstrated via double immunofluorescent staining and co-immunoprecipitation. Upon salinity challenge, the localization of FXYD12 and NKA was similar in the intestines of the two medaka species. However, the expression profiles of intestinal FXYD12 and NKA (mRNA and protein levels), as well as NKA activity differed between the medakas. These results showed that FXYD12 may play a role in modulating NKA activity in the intestines of the two medakas following salinity changes in the maintenance of internal homeostasis. These findings contributed to knowledge of the expression and potential role of vertebrate FXYD12, the regulators of NKA, upon salinity challenge.
Collapse
Affiliation(s)
- Wen-Kai Yang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
- The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Bachelor Degree Program in Animal Healthcare, Hungkuang University, Taichung, Taiwan
| | - An-Di Hsu
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Chao-Kai Kang
- Tainan Hydraulics Laboratory, National Cheng Kung University, Tainan, Taiwan
| | - Ivan Pochou Lai
- National Taichung First Senior High School, Taichung, Taiwan
| | - Pei-Shao Liao
- National Taichung First Senior High School, Taichung, Taiwan
| | - Tsung-Han Lee
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
- The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- * E-mail:
| |
Collapse
|
12
|
Wang PJ, Yang WK, Lin CH, Hwang HH, Lee TH. FXYD8, a Novel Regulator of Renal Na +/K +-ATPase in the Euryhaline Teleost, Tetraodon nigroviridis. Front Physiol 2017; 8:576. [PMID: 28848450 PMCID: PMC5550679 DOI: 10.3389/fphys.2017.00576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/25/2017] [Indexed: 11/19/2022] Open
Abstract
FXYD proteins are important regulators of Na+/K+-ATPase (NKA) activity in mammals. As an inhabitant of estuaries, the pufferfish (Tetraodon nigroviridis) responds to ambient salinity changes with efficient osmoregulation, including alterations in branchial, and renal NKA activities. Previous studies on teleostean FXYDs have mainly focused on the expression and potential functions of FXYD proteins in gills. The goal of the present study was to elucidate the potential role of FXYD8, a member of the fish FXYD protein family, in the modulation of NKA activity in the kidneys of this euryhaline pufferfish by using molecular, biochemical, and physiological approaches. The results demonstrate that T. nigroviridis FXYD8 (TnFXYD8) interacts with NKA in renal tubules. Meanwhile, the protein expression of renal TnFXYD8 was found to be significantly upregulated in hyperosmotic seawater-acclimated pufferfish. Moreover, overexpression of TnFXYD8 in Xenopus oocytes decreased NKA activity. Our results suggest the FXYD8 is able to modulate NKA activity through inhibitory effects upon salinity challenge. The present study further extends our understanding of the functions of FXYD proteins, the regulators of NKA, in vertebrates.
Collapse
Affiliation(s)
- Pei-Jen Wang
- Department of Life Sciences, National Chung Hsing UniversityTaichung, Taiwan
- Department of Public Affairs and Civic Education, National Changhua University of EducationChanghua, Taiwan
| | - Wen-Kai Yang
- Department of Life Sciences, National Chung Hsing UniversityTaichung, Taiwan
- Bachelor Degree Program in Animal Healthcare, Hungkuang UniversityTaichung, Taiwan
| | - Chia-Hao Lin
- National Institute for Basic Biology, National Institutes of Natural SciencesOkazaki, Japan
| | - Hau-Hsuan Hwang
- Department of Life Sciences, National Chung Hsing UniversityTaichung, Taiwan
| | - Tsung-Han Lee
- Department of Life Sciences, National Chung Hsing UniversityTaichung, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing UniversityTaichung, Taiwan
| |
Collapse
|
13
|
Juo JJ, Kang CK, Yang WK, Yang SY, Lee TH. A Stenohaline Medaka, Oryzias woworae, Increases Expression of Gill Na(+), K(+)-ATPase and Na(+), K(+), 2Cl(-) Cotransporter 1 to Tolerate Osmotic Stress. Zoolog Sci 2017; 33:414-25. [PMID: 27498801 DOI: 10.2108/zs150157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The present study aimed to evaluate the osmoregulatory mechanism of Daisy's medaka, O. woworae,as well as demonstrate the major factors affecting the hypo-osmoregulatory characteristics of euryhaline and stenohaline medaka. The medaka phylogenetic tree indicates that Daisy's medaka belongs to the celebensis species group. The salinity tolerance of Daisy's medaka was assessed. Our findings revealed that 20‰ (hypertonic) saltwater (SW) was lethal to Daisy's medaka. However, 62.5% of individuals survived 10‰ (isotonic) SW with pre-acclimation to 5‰ SW for one week. This transfer regime, "Experimental (Exp.) 10‰ SW", was used in the following experiments. After 10‰ SW-transfer, the plasma osmolality of Daisy's medaka significantly increased. The protein abundance and distribution of branchial Na(+), K(+)-ATPase (NKA) and Na(+), K(+), 2Cl(-) cotransporter 1 (NKCC1) were also examined after transfer to 10‰ SW for one week. Gill NKA activity increased significantly after transfer to 10‰ SW. Meanwhile, elevation of gill NKA αα-subunit protein-abundance was found in the 10‰ SW-acclimated fish. In gill cross-sections, more and larger NKA-immunoreactive (NKA-IR) cells were observed in the Exp. 10‰ SW medaka. The relative abundance of branchial NKCC1 protein increased significantly after transfer to 10‰ SW. NKCC1 was distributed in the basolateral membrane of NKA-IR cells of the Exp. 10‰ SW group. Furthermore, a higher abundance of NKCC1 protein was found in the gill homogenates of the euryhaline medaka, O. dancena, than in that of the stenohaline medaka, O. woworae.
Collapse
Affiliation(s)
- Jiun-Jang Juo
- 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.,† JJJ, CKK, and WKY contributed equally to this paper
| | - Chao-Kai Kang
- 2 Tainan Hydraulics Laboratory, National Cheng Kung University, Tainan 709, Taiwan.,† JJJ, CKK, and WKY contributed equally to this paper
| | - Wen-Kai Yang
- 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.,† JJJ, CKK, and WKY contributed equally to this paper
| | - Shu-Yuan Yang
- 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan
| | - Tsung-Han Lee
- 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.,3 Department of Biological Science and Technology, China Medical University,Taichung 404, Taiwan
| |
Collapse
|
14
|
Yang WK, Chung CH, Cheng HC, Tang CH, Lee TH. Different expression patterns of renal Na +/K +-ATPase α-isoform-like proteins between tilapia and milkfish following salinity challenges. Comp Biochem Physiol B Biochem Mol Biol 2016; 202:23-30. [PMID: 27497666 DOI: 10.1016/j.cbpb.2016.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/28/2016] [Accepted: 07/30/2016] [Indexed: 01/13/2023]
Abstract
Euryhaline teleosts can survive in a broad range of salinity via alteration of the molecular mechanisms in certain osmoregulatory organs, including in the gill and kidney. Among these mechanisms, Na+/K+-ATPase (NKA) plays a crucial role in triggering ion-transporting systems. The switch of NKA isoforms in euryhaline fish gills substantially contributes to salinity adaptation. However, there is little information about switches in the kidneys of euryhaline teleosts. Therefore, the responses of the renal NKA α-isoform protein switch to salinity challenge in euryhaline tilapia (Oreochromis mossambicus) and milkfish (Chanos chanos) with different salinity preferences were examined and compared in this study. Immunohistochemical staining in tilapia kidneys revealed the localization of NKA in renal tubules rather than in the glomeruli, similar to our previous findings in milkfish kidneys. Protein abundance in the renal NKA pan α-subunit-like, α1-, and α3-isoform-like proteins in seawater-acclimated tilapia was significantly higher than in the freshwater group, whereas the α2-isoform-like protein exhibited the opposite pattern of expression. In the milkfish, higher protein abundance in the renal NKA pan α-subunit-like and α1-isoform-like proteins was found in freshwater-acclimated fish, whereas no difference was found in the protein abundance of α2- and α3-isoform-like proteins between groups. These findings suggested that switches for renal NKA α-isoforms, especially the α1-isoform, were involved in renal osmoregulatory mechanisms of euryhaline teleosts. Moreover, differences in regulatory responses of the renal NKA α-subunit to salinity acclimation between tilapia and milkfish revealed that divergent mechanisms for maintaining osmotic balance might be employed by euryhaline teleosts with different salinity preferences.
Collapse
Affiliation(s)
- Wen-Kai Yang
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chang-Hung Chung
- Graduate Institute of Science Education, National Changhua University of Education, Changhua 50007, Taiwan; Taichung Municipal Kuang Rong Junior High School, Taichung 41265, Taiwan
| | - Hui Chen Cheng
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Cheng-Hao Tang
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
| | - Tsung-Han Lee
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
| |
Collapse
|
15
|
Takahashi H, Sato T, Ikeuchi T, Saito K, Sakaizumi M, Sakamoto T. High levels of plasma cortisol and impaired hypoosmoregulation in a mutant medaka deficient in P450c17I. Mol Cell Endocrinol 2016; 430:25-32. [PMID: 27107936 DOI: 10.1016/j.mce.2016.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/12/2016] [Accepted: 04/19/2016] [Indexed: 11/25/2022]
Abstract
scl is a spontaneous medaka mutant deficient in P450c17I, which is required for production of sex steroids, but not of cortisol, the major role of which is osmoregulation in teleost fish. The scl mutant provides a new model to study the functions of these hormones. We first found that fish homozygous for this mutation have plasma cortisol constitutively at a high physiological level (1000 nM). Since we previously showed that this level reversed the seawater-type differentiation of the medaka gastrointestinal tract, hypoosmoregulation of the scl mutant was analyzed. Muscle water contents in freshwater were normal in scl homozygotes, but the contents were lower than those of the wild type (WT) after seawater transfer. There were no differences in gill mRNA levels of corticosteroid receptors or ion transporters between scl homozygotes and WT. In the intestine, expression of glucocorticoid receptors and Na(+)/K(+)/2Cl(-) cotransporter were induced in WT during seawater acclimation, but not in scl homozygotes. The high plasma cortisol may prevent hypoosmoregulation by inhibition of increased intestinal water absorption, essentially by the Na(+)/K(+)/2Cl(-) cotransporter, in seawater.
Collapse
Affiliation(s)
- Hideya Takahashi
- Department of Environmental Science, Faculty of Science, Niigata University, Ikarashi, Niigata, 950-2181, Japan; Ushimado Marine Institute, Faculty of Science, Okayama University, Ushimado, Setouchi, 701-4303, Japan
| | - Tadashi Sato
- Department of Environmental Science, Faculty of Science, Niigata University, Ikarashi, Niigata, 950-2181, Japan
| | - Toshitaka Ikeuchi
- Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga, 526-0829, Japan
| | - Kazuhiro Saito
- Ushimado Marine Institute, Faculty of Science, Okayama University, Ushimado, Setouchi, 701-4303, Japan
| | - Mitsuru Sakaizumi
- Department of Environmental Science, Faculty of Science, Niigata University, Ikarashi, Niigata, 950-2181, Japan
| | - Tatsuya Sakamoto
- Ushimado Marine Institute, Faculty of Science, Okayama University, Ushimado, Setouchi, 701-4303, Japan.
| |
Collapse
|
16
|
Yang WK, Wu YC, Tang CH, Lee TH. Microtubule-dependent changes in morphology and localization of chloride transport proteins in gill mitochondria-rich cells of the tilapia, Oreochromis mossambicus. J Morphol 2016; 277:1113-22. [PMID: 27239784 DOI: 10.1002/jmor.20561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/29/2016] [Accepted: 04/27/2016] [Indexed: 11/11/2022]
Abstract
The tilapia (Oreochromis mossambicus) is a euryhaline fish exhibiting adaptive changes in cell size, phenotype, and ionoregulatory functions upon salinity challenge. Na(+) /Cl(-) cotransporter (NCC) and Na(+) /K(+) /2Cl(-) cotransporter (NKCC) are localized in the apical and basolateral membranes of mitochondria-rich (MR) cells of the gills. These cells are responsible for chloride absorption (NCC) and secretion (NKCC), respectively, thus, the switch of gill NCC and NKCC expression is a crucial regulatory mechanism for salinity adaptation in tilapia. However, little is known about the interaction of cytoskeleton and these adaptive changes. In this study, we examined the time-course of changes in the localization of NKCC/NCC in the gills of tilapia transferred from fresh water (FW) to brackish water (20‰) and from seawater (SW; 35‰) to FW. The results showed that basolateral NKCC disappeared and NCC was expressed in the apical membrane of MR cells. To further clarify the process of these adaptive changes, colchicine, a specific inhibitor of microtubule-dependent cellular regulating processes was used. SW-acclimated tilapia were transferred to SW, FW, and FW with colchicine (colchicine-FW) for 96 h. Compared with the FW-treatment group, in the MR cells of colchicine-FW-treatment group, (1) the average size was significantly larger, (2) only wavy-convex-subtype apical surfaces were found, and (3) the basolateral (cytoplasmic) NKCC signals were still exhibited. Taken together, our results suggest that changes in size, phenotype, as well as the expression of NCC and NKCC cotransporters of MR cells in the tilapia are microtubule-dependent. J. Morphol. 277:1113-1122, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Wen-Kai Yang
- Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
| | - Yu-Ching Wu
- Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
| | - Cheng-Hao Tang
- Graduate Institute of Marine Biology, National Dong Hwa University, Pingtung, 944, Taiwan.,National Museum of Marine Biology and Aquarium, Pingtung, 944, Taiwan
| | - Tsung-Han Lee
- Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan.,Department of Biological Science and Technology, China Medical University, Taichung, 404, Taiwan
| |
Collapse
|
17
|
Yang WK, Kang CK, Hsu AD, Lin CH, Lee TH. Different Modulatory Mechanisms of Renal FXYD12 for Na(+)-K(+)-ATPase between Two Closely Related Medakas upon Salinity Challenge. Int J Biol Sci 2016; 12:730-45. [PMID: 27194950 PMCID: PMC4870716 DOI: 10.7150/ijbs.15066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 03/21/2016] [Indexed: 12/02/2022] Open
Abstract
Upon salinity challenge, the Na+-K+-ATPase (NKA) of fish kidney plays a crucial role in maintaining ion and water balance. Moreover, the FXYD protein family was found to be a regulator of NKA. Our preliminary results revealed that fxyd12 was highly expressed in the kidneys of the two closely related euryhaline medaka species (Oryzias dancena and O. latipes) from different natural habitats (brackish water and fresh water). In this study, we investigated the expression and association of renal FXYD12 and NKA α-subunit as well as potential functions of FXYD12 in the two medakas. These findings illustrated and compared the regulatory roles of FXYD12 for NKA in kidneys of the two medakas in response to salinity changes. In this study, at the mRNA and/or protein level, the expression patterns were similar for renal FXYD12 and NKA in the two medakas. However, different patterns of NKA activities and different interaction levels between FXYD12 and NKA were found in the kidneys of these two medakas. The results revealed that different strategies were used in the kidneys of the two medaka species upon salinity challenge. On the other hand, gene knockdown experiments demonstrated that the function of O. dancena FXYD12 allowed maintenance of a high level of NKA activity. The results of the present study indicated that the kidneys of the examined euryhaline medakas originating from brackish water and fresh water exhibited different modulatory mechanisms through which renal FXYD12 enhanced NKA activity to maintain internal homeostasis. Our findings broadened the knowledge of expression and functions of FXYD proteins, the modulators of NKA, in vertebrates.
Collapse
Affiliation(s)
- Wen-Kai Yang
- 1. Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan
| | - Chao-Kai Kang
- 2. Tainan Hydraulics Laboratory, National Cheng Kung University, Tainan 709, Taiwan
| | - An-Di Hsu
- 1. Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan
| | - Chia-Hao Lin
- 3. National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Tsung-Han Lee
- 1. Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.; 4. Department of Biological Science and Technology, China Medical University, Taichung 404, Taiwan
| |
Collapse
|
18
|
Lee JD, Yang WK, Lee MH. Impaired Na(+)/K(+)-ATPase Function in Patients with Interstitial Cystitis/Painful Bladder Syndrome. J Korean Med Sci 2016; 31:280-5. [PMID: 26839484 PMCID: PMC4729510 DOI: 10.3346/jkms.2016.31.2.280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 09/02/2015] [Indexed: 12/29/2022] Open
Abstract
Na(+)/K(+)-ATPase (NKA) is abundantly expressed in the basolateral membrane of epithelial cells, which is necessary for tight junction formation. The tight junction is an urothelial barrier between urine and the underlying bladder. Impairment of tight junctions allows migration of urinary solutes in patients with interstitial cystitis/painful bladder syndrome (IC/PBS). We evaluated NKA expression and activity in bladder samples from patients with IC/PBS. The study group consisted of 85 patients with IC/PBS, and the control group consisted of 20 volunteers. Bladder biopsies were taken from both groups. We determined the expression and distribution of NKA using NKA activity assays, immunoblotting, immunohistochemical staining, and immunofluorescent staining. The protein levels and activity of NKA in the study group were significantly lower than the control group (1.08 ± 0.06 vs. 2.39 ± 0.29 and 0.60 ± 0.04 vs. 1.81 ± 0.18 µmol ADP/mg protein/hour, respectively; P < 0.05). Additionally, immunofluorescent staining for detection of CK7, a marker of the bladder urothelium, predominantly colocalized with NKA in patients in the study group. Our results demonstrated the expression and activity of NKA were decreased in bladder biopsies of patients with IC/PBS. These findings suggest that NKA function is impaired in the bladders from patients with IC/PBS.
Collapse
Affiliation(s)
- Jane-Dar Lee
- Division of Urology, Department of Surgery, Taichung Armed Forces General Hospital, Taichung, Taiwan, Republic of China
- Central Taiwan University of Science and Technology, Taichung, Taiwan, Republic of China
- National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Wen-Kai Yang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China
| | - Ming-Huei Lee
- Department of Urology, Feng-Yuan Hospital, Ministry of Health and Welfare, Taichung, Taiwan, Republic of China
| |
Collapse
|
19
|
Thanh NM, Jung H, Lyons RE, Njaci I, Yoon BH, Chand V, Tuan NV, Thu VTM, Mather P. Optimizing de novo transcriptome assembly and extending genomic resources for striped catfish (Pangasianodon hypophthalmus). Mar Genomics 2015; 23:87-97. [PMID: 25979246 DOI: 10.1016/j.margen.2015.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 05/03/2015] [Accepted: 05/03/2015] [Indexed: 12/17/2022]
Abstract
Striped catfish (Pangasianodon hypophthalmus) is a commercially important freshwater fish used in inland aquaculture in the Mekong Delta, Vietnam. The culture industry is facing a significant challenge however from saltwater intrusion into many low topographical coastal provinces across the Mekong Delta as a result of predicted climate change impacts. Developing genomic resources for this species can facilitate the production of improved culture lines that can withstand raised salinity conditions, and so we have applied high-throughput Ion Torrent sequencing of transcriptome libraries from six target osmoregulatory organs from striped catfish as a genomic resource for use in future selection strategies. We obtained 12,177,770 reads after trimming and processing with an average length of 97bp. De novo assemblies were generated using CLC Genomic Workbench, Trinity and Velvet/Oases with the best overall contig performance resulting from the CLC assembly. De novo assembly using CLC yielded 66,451 contigs with an average length of 478bp and N50 length of 506bp. A total of 37,969 contigs (57%) possessed significant similarity with proteins in the non-redundant database. Comparative analyses revealed that a significant number of contigs matched sequences reported in other teleost fishes, ranging in similarity from 45.2% with Atlantic cod to 52% with zebrafish. In addition, 28,879 simple sequence repeats (SSRs) and 55,721 single nucleotide polymorphisms (SNPs) were detected in the striped catfish transcriptome. The sequence collection generated in the current study represents the most comprehensive genomic resource for P. hypophthalmus available to date. Our results illustrate the utility of next-generation sequencing as an efficient tool for constructing a large genomic database for marker development in non-model species.
Collapse
Affiliation(s)
- Nguyen Minh Thanh
- International University - VNU HCMC, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Viet Nam.
| | - Hyungtaek Jung
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia; Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia.
| | - Russell E Lyons
- Animal Genetics Laboratory, School of Veterinary Science, University of Queensland, Gatton, QLD 4343, Australia.
| | - Isaac Njaci
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia.
| | - Byoung-Ha Yoon
- Medical Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Functional Genomics, Korea University of Science and Technology, Daejoen 305-333, Republic of Korea.
| | - Vincent Chand
- Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia.
| | - Nguyen Viet Tuan
- Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia.
| | - Vo Thi Minh Thu
- International University - VNU HCMC, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Viet Nam.
| | - Peter Mather
- Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia.
| |
Collapse
|
20
|
Tang CH, Leu MY, Yang WK, Tsai SC. Exploration of the mechanisms of protein quality control and osmoregulation in gills of Chromis viridis in response to reduced salinity. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:1533-1546. [PMID: 24805086 DOI: 10.1007/s10695-014-9946-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/28/2014] [Indexed: 06/03/2023]
Abstract
Fish gills are the vital multifunctional organ in direct contact with external environment. Therefore, activation of the cytoprotective mechanisms to maintain branchial cell viability is important for fish upon stresses. Salinity is one of the major factors strongly affecting cellular and organismal functions. Reduction of ambient salinity may occur in coral reef and leads to osmotic stress for reef-associated stenohaline fish. However, the physiological responses to salinity stress in reef-associated fish were not examined substantially. With this regard, the physiological parameters and the responses of protein quality control (PQC) and osmoregulatory mechanisms in gills of seawater (SW; 33-35 ‰)- and brackish water (BW; 20 ‰)-acclimated blue-green damselfish (Chromis viridis) were explored. The results showed that the examined physiological parameters were maintained within certain physiological ranges in C. viridis acclimated to different salinities. In PQC mechanism, expression of heat-shock protein (HSP) 90, 70, and 60 elevated in response to BW acclimation while the levels of ubiquitin-conjugated proteins were similar between the two groups. Thus, it was presumed that upregulation of HSPs was sufficient to prevent the accumulation of aggregated proteins for maintaining the protein quality and viability of gill cells when C. viridis were acclimated to BW. Moreover, gill Na(+)/K(+)-ATPase expression and protein amounts of basolaterally located Na(+)/K(+)/2Cl(-) cotransporter were higher in SW fish than in BW fish. Taken together, this study showed that the cytoprotective and osmoregulatory mechanisms of blue-green damselfish were functionally activated and modulated to withstand the challenge of reduction in salinity for maintaining physiological homeostasis.
Collapse
Affiliation(s)
- Cheng-Hao Tang
- Institute of Marine Biotechnology, National Dong Hwa University, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan,
| | | | | | | |
Collapse
|
21
|
Takei Y, Hiroi J, Takahashi H, Sakamoto T. Diverse mechanisms for body fluid regulation in teleost fishes. Am J Physiol Regul Integr Comp Physiol 2014; 307:R778-92. [PMID: 24965789 DOI: 10.1152/ajpregu.00104.2014] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Teleost fishes are the major group of ray-finned fishes and represent more than one-half of the total number of vertebrate species. They have experienced in their evolution an additional third-round whole genome duplication just after the divergence of their lineage, which endowed them with an extra adaptability to invade various aquatic habitats. Thus their physiology is also extremely diverse compared with other vertebrate groups as exemplified by the many patterns of body fluid regulation or osmoregulation. The key osmoregulatory organ for teleosts, whose body fluid composition is similar to mammals, is the gill, where ions are absorbed from or excreted into surrounding waters of various salinities against concentration gradients. It has been shown that the underlying molecular physiology of gill ionocytes responsible for ion regulation is highly variable among species. This variability is also seen in the endocrine control of osmoregulation where some hormones have distinct effects on body fluid regulation in different teleost species. A typical example is atrial natriuretic peptide (ANP); ANP is secreted in response to increased blood volume and acts on various osmoregulatory organs to restore volume in rainbow trout as it does in mammals, but it is secreted in response to increased plasma osmolality, and specifically decreases NaCl, and not water, in the body of eels. The distinct actions of other osmoregulatory hormones such as growth hormone, prolactin, angiotensin II, and vasotocin among teleost species are also evident. We hypothesized that such diversity of ionocytes and hormone actions among species stems from their intrinsic differences in body fluid regulation that originated from their native habitats, either fresh water or seawater. In this review, we summarized remarkable differences in body fluid regulation and its endocrine control among teleost species, although the number of species is still limited to substantiate the hypothesis.
Collapse
Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan;
| | - Junya Hiroi
- Department of Anatomy, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan; and
| | - Hideya Takahashi
- Ushimado Marine Institute (UMI), Faculty of Science, Okayama University, Setouchi, Okayama, Japan
| | - Tatsuya Sakamoto
- Ushimado Marine Institute (UMI), Faculty of Science, Okayama University, Setouchi, Okayama, Japan
| |
Collapse
|
22
|
Chandrasekar S, Nich T, Tripathi G, Sahu NP, Pal AK, Dasgupta S. Acclimation of brackish water pearl spot (Etroplus suratensis) to various salinities: relative changes in abundance of branchial Na(+)/K (+)-ATPase and Na (+)/K (+)/2Cl (-) co-transporter in relation to osmoregulatory parameters. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:983-996. [PMID: 24482094 DOI: 10.1007/s10695-013-9899-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
The present study was conducted to elucidate the osmoregulatory ability of the fish pearl spot (Etroplus suratensis) to know the scope of this species for aquaculture under various salinities. Juvenile pearl spot were divided into three groups and acclimated to freshwater (FW), brackish water (BW) or seawater (SW) for 15 days. The fish exhibited effective salinity tolerance under osmotic challenges. Although the plasma osmolality and Na(+), K(+) and Cl(-) levels increased with the increasing salinities, the parameters remained within the physiological range. The muscle water contents were constant among FW-, BW- and SW-acclimated fish. Two Na+/K+-ATPase α-isoforms (NKA α) were expressed in gills during acclimation in FW, BW and SW. Abundance of one isoform was up-regulated in response to seawater acclimation, suggesting its role in ion secretion similar to NKA α1b, while expression of another isoform was simultaneously up-regulated in response to both FW and SW acclimation, suggesting the presence of isoforms switching phenomenon during acclimation to different salinities. Nevertheless, NKA enzyme activities in the gills of the SW and FW individuals were higher (p < 0.05) than in BW counterparts. Immunohistochemistry revealed that Na(+)/K(+)-ATPase immunoreactive (NKA-IR) cells were mainly distributed in the interlamellar region of the gill filaments in FW groups and in the apical portion of the filaments in BW and SW groups. The number of NKA-IR cells in the gills of the FW-acclimated fish was almost similar to that of SW individuals, which exceeded that of the BW individuals. The NKA-IR cells of BW and SW were bigger in size than their FW counterparts. Besides, the relative abundance of branchial Na(+)/K(+)/2Cl(-) co-transporter showed stronger evidence in favor of involvement of this protein in hypo-osmoregulation, requiring ion secretion by the chloride cells. To the best of our knowledge, this is the first study reporting the wide salinity tolerance of E. suratensis involving differential activation of ion transporters and thereby suggesting its potential as candidate for fish farming under different external salinities.
Collapse
Affiliation(s)
- S Chandrasekar
- Central Institute of Fisheries Education (Indian Council of Agricultural Research), Versova, Mumbai, 400061, India
| | | | | | | | | | | |
Collapse
|
23
|
Expression profiles of branchial FXYD proteins in the brackish medaka Oryzias dancena: a potential saltwater fish model for studies of osmoregulation. PLoS One 2013; 8:e55470. [PMID: 23383199 PMCID: PMC3561181 DOI: 10.1371/journal.pone.0055470] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 12/23/2012] [Indexed: 12/03/2022] Open
Abstract
FXYD proteins are novel regulators of Na+-K+-ATPase (NKA). In fish subjected to salinity challenges, NKA activity in osmoregulatory organs (e.g., gills) is a primary driving force for the many ion transport systems that act in concert to maintain a stable internal environment. Although teleostean FXYD proteins have been identified and investigated, previous studies focused on only a limited group of species. The purposes of the present study were to establish the brackish medaka (Oryzias dancena) as a potential saltwater fish model for osmoregulatory studies and to investigate the diversity of teleostean FXYD expression profiles by comparing two closely related euryhaline model teleosts, brackish medaka and Japanese medaka (O. latipes), upon exposure to salinity changes. Seven members of the FXYD protein family were identified in each medaka species, and the expression of most branchial fxyd genes was salinity-dependent. Among the cloned genes, fxyd11 was expressed specifically in the gills and at a significantly higher level than the other fxyd genes. In the brackish medaka, branchial fxyd11 expression was localized to the NKA-immunoreactive cells in gill epithelia. Furthermore, the FXYD11 protein interacted with the NKA α-subunit and was expressed at a higher level in freshwater-acclimated individuals relative to fish in other salinity groups. The protein sequences and tissue distributions of the FXYD proteins were very similar between the two medaka species, but different expression profiles were observed upon salinity challenge for most branchial fxyd genes. Salinity changes produced different effects on the FXYD11 and NKA α-subunit expression patterns in the gills of the brackish medaka. To our knowledge, this report is the first to focus on FXYD expression in the gills of closely related euryhaline teleosts. Given the advantages conferred by the well-developed Japanese medaka system, we propose the brackish medaka as a saltwater fish model for osmoregulatory studies.
Collapse
|
24
|
Brix KV, Grosell M. Characterization of Na(+) uptake in the endangered desert pupfish, Cyprinodon macularius (Baird and Girard). CONSERVATION PHYSIOLOGY 2013; 1:cot005. [PMID: 27293589 PMCID: PMC4806610 DOI: 10.1093/conphys/cot005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 03/14/2013] [Indexed: 05/03/2023]
Abstract
This study provided an initial characterization of Na(+) uptake in saline freshwater by the endangered pupfish, Cyprinodon macularius. This species occurs only in several saline water systems in the southwestern USA and northern Mexico, where salinity is largely controlled by water-management practices. Consequently, understanding the osmoregulatory capacity of this species is important for their conservation. The lower acclimation limit of C. macularius in freshwater was found to be 2 mM Na(+). Fish acclimated to 2 or 7 mM Na(+) displayed similar Na(+) uptake kinetics, with K m values of 4321 and 3672 μM and V max values of 4771 and 3602 nmol g(-1) h(-1), respectively. A series of experiments using pharmacological inhibitors indicated that Na(+) uptake in C. macularius was not sensitive to bumetanide, metolazone, or phenamil. These results indicate the Na(+)-K(+)-2Cl(-) cotransporter, Na(+)-Cl(-) cotransporter, and the Na(+) channel-H(+)-ATPase system are likely not to be involved in Na(+) uptake at the apical membrane of fish gill ionocytes in fish acclimated to 2 or 7 mM Na(+). However, Na(+) uptake was sensitive to 1 × 10(-3) M amiloride (not 1 × 10(-4) or 1 × 10(-5) M), 5-(N-ethyl-N-isopropyl)-amiloride (EIPA), and ethoxzolamide. These data suggest that C. macularius relies on a low-affinity Na(+)-H(+) exchanger for apical Na(+) uptake and that H(+) ions generated via carbonic anhydrase-mediated CO2 hydration are important for the function of this protein.
Collapse
Affiliation(s)
- Kevin V. Brix
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1
- The Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
- Corresponding author: Tel: +1 905 979 0836.
| | - Martin Grosell
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1
| |
Collapse
|
25
|
Kang CK, Yang WK, Lin ST, Liu CC, Lin HM, Chen HH, Cheng CW, Lee TH, Hwang PP. The acute and regulatory phases of time-course changes in gill mitochondrion-rich cells of seawater-acclimated medaka (Oryzias dancena) when exposed to hypoosmotic environments. Comp Biochem Physiol A Mol Integr Physiol 2012; 164:181-91. [PMID: 22960413 DOI: 10.1016/j.cbpa.2012.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 10/27/2022]
Abstract
The recent model showed that seawater (SW) mitochondrion-rich (MR) cells with hole-type apical openings secrete Cl(-) through the transporters including the Na(+), K(+)-ATPase (NKA), Na(+), K(+), 2Cl(-) cotransporter (NKCC), and cystic fibrosis transmembrane conductance regulator (CFTR). The present study focused on the dynamic elimination of the Cl(-) secretory capacity and illustrated different phases (i.e., acute and regulatory phases) of branchial MR cells in response to hypoosmotic challenge. Time-course remodeling of the cell surfaces and the altered expressions of typical ion transporters were observed in the branchial MR cells of SW-acclimated brackish medaka (Oryzias dancena) when exposed to fresh water (FW). On the 1st day post-transfer, rapid changes were shown in the acute phase: the flat-type MR cells with large apical surfaces replaced the hole-type cells, the gene expression of both Odnkcc1a and Odcftr decreased, and the apical immunostaining signals of CFTR protein disappeared. The basolateral immunostaining signals of NKCC1a protein decreased throughout the regulatory phase (>1day post-transfer). During this period, the size and number of NKA-immunoreactive MR cells were significantly reduced and elevated, respectively. Branchial NKA expression and activity were maintained at constant levels in both phases. The results revealed that when SW-acclimated brackish medaka were transferred to hypoosmotic FW for 24h, the Cl(-) secretory capacity of MR cells was eliminated, whereas NKCC1a protein was retained to maintain the hypoosmoregulatory endurance of the gills. The time-course acute and regulatory phases of gill MR cells showed different strategies of the euryhaline medaka when subjected to hypoosmotic environments.
Collapse
Affiliation(s)
- Chao-Kai Kang
- Department of Life Sciences, National Chung-Hsing University, Taichung 402, Taiwan
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Adaptation of teleosts to very high salinity. Comp Biochem Physiol A Mol Integr Physiol 2012; 163:1-6. [DOI: 10.1016/j.cbpa.2012.05.203] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 12/21/2022]
|
27
|
Hiroi J, McCormick SD. New insights into gill ionocyte and ion transporter function in euryhaline and diadromous fish. Respir Physiol Neurobiol 2012; 184:257-68. [PMID: 22850177 DOI: 10.1016/j.resp.2012.07.019] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 07/19/2012] [Accepted: 07/20/2012] [Indexed: 11/29/2022]
Abstract
Teleost fishes are able to acclimatize to seawater by secreting excess NaCl by means of specialized "ionocytes" in the gill epithelium. Antibodies against Na(+)/K(+)-ATPase (NKA) have been used since 1996 as a marker for identifying branchial ionocytes. Immunohistochemistry of NKA by itself and in combination with Na(+)/K(+)/2Cl(-) cotransporter and CFTR Cl(-) channel provided convincing evidence that ionocytes are functional during seawater acclimation, and also revealed morphological variations in ionocytes among teleost species. Recent development of antibodies to freshwater- and seawater-specific isoforms of the NKA alpha-subunit has allowed functional distinction of ion absorptive and secretory ionocytes in Atlantic salmon. Cutaneous ionocytes of tilapia embryos serve as a model for branchial ionocytes, allowing identification of 4 types: two involved in ion uptake, one responsible for salt secretion and one with unknown function. Combining molecular genetics, advanced imaging techniques and immunohistochemistry will rapidly advance our understanding of both the unity and diversity of ionocyte function and regulation in fish osmoregulation.
Collapse
Affiliation(s)
- Junya Hiroi
- Department of Anatomy, St. Marianna University School of Medicine, 2-16-1 Sugao, Kawasaki 216-8511, Japan.
| | | |
Collapse
|
28
|
McNamara JC, Faria SC. Evolution of osmoregulatory patterns and gill ion transport mechanisms in the decapod Crustacea: a review. J Comp Physiol B 2012; 182:997-1014. [DOI: 10.1007/s00360-012-0665-8] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 04/02/2012] [Accepted: 04/04/2012] [Indexed: 10/28/2022]
|