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Martínez-Burguete T, Peña-Marín ES, Llera-Herrera RA, Jiménez-Martínez LD, Martínez-García R, Alvarez-Villagomez CS, Alvarez-González CA. Identification and expression analysis of transcripts involved in taurine biosynthesis during early ontogeny of tropical gar Atractosteus tropicus. Comp Biochem Physiol A Mol Integr Physiol 2023; 285:111501. [PMID: 37562582 DOI: 10.1016/j.cbpa.2023.111501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/12/2023]
Abstract
In fishes, the availability of taurine is regulated during ontogenetic development, where its endogenous synthesis capacity is species dependent. Thus, different pathways and involved enzymes have been described: pathway I (cysteine sulfinate-dependent pathway), cysteine dioxygenase type 1 (cdo1) and cysteine sulfinic acid decarboxylase (csad); pathway II (cysteic acid pathway), cdo1 and glutamic acid decarboxylase (gad); and pathway III (cysteamine pathway), 2-aminoethanethiol dioxygenase (ado); whereas taurine transporter (taut) is responsible for taurine entry into cells on the cell membrane and the mitochondria. This study determined if the tropical gar (Atractosteus tropicus), an ancient holostean fish model, has the molecular mechanism to synthesize taurine through the identification and analysis expression of transcripts coding for proteins involved in its biosynthesis and transportation, at different embryo-larvae stages and in different organs of juveniles (31 dah). We observed a fluctuating expression of all transcripts involved in the three pathways at all analyzed stages. All transcripts are expressed during the beginning of larval development; however, ado and taut show a peak expression at 9 dah, and all transcripts but csad decreased at 23 dah, when the organism ended the larval period. Furthermore, at 31 dah, we observed taut expression in all examined organs. The transcripts involved in pathways I and III are expressed differently across all organs, whereas pathway II was only observed in the brain, eye, and skin. The results suggested that taurine biosynthesis in tropical gar is regulated during its early development before first feeding, and the pathway might also be organ-type dependent.
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Affiliation(s)
- Talhia Martínez-Burguete
- Laboratorio de Fisiología en Recursos Acuáticos, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Carretera Villahermosa-Cárdenas Km. 0.5, CP.86139 Villahermosa, Tabasco, Mexico.
| | - Emyr Saúl Peña-Marín
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California (UABC), Ensenada 21100, Baja California, Mexico.
| | - Raúl Antonio Llera-Herrera
- Instituto de Ciencias del Mar y Limnología - Unidad Académica Mazatlán, Universidad Nacional Autónoma de México, Joel Montes Camarena S/N, PO Box 811, Mazatlán, Sinaloa, Mexico.
| | - Luis Daniel Jiménez-Martínez
- División Académica Multidisciplinaria de Jalpa de Méndez, Universidad Juárez Autónoma de Tabasco, Carretera Nacajuca-Jalpa de Méndez R7a Rivera Alta, C.P. 86200 Jalpa de Méndez, Tabasco, Mexico.
| | - Rafael Martínez-García
- Laboratorio de Fisiología en Recursos Acuáticos, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Carretera Villahermosa-Cárdenas Km. 0.5, CP.86139 Villahermosa, Tabasco, Mexico.
| | - Carina Shianya Alvarez-Villagomez
- Laboratorio de Fisiología en Recursos Acuáticos, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Carretera Villahermosa-Cárdenas Km. 0.5, CP.86139 Villahermosa, Tabasco, Mexico.
| | - Carlos Alfonso Alvarez-González
- Laboratorio de Fisiología en Recursos Acuáticos, División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Carretera Villahermosa-Cárdenas Km. 0.5, CP.86139 Villahermosa, Tabasco, Mexico.
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2
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Aragão C, Teodósio R, Colen R, Richard N, Rønnestad I, Dias J, Conceição LEC, Ribeiro L. Taurine Supplementation to Plant-Based Diets Improves Lipid Metabolism in Senegalese Sole. Animals (Basel) 2023; 13:ani13091501. [PMID: 37174538 PMCID: PMC10177204 DOI: 10.3390/ani13091501] [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: 03/28/2023] [Revised: 04/14/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Taurine is a sulphur-containing amino acid with important physiological roles and a key compound for the synthesis of bile salts, which are essential for the emulsion and absorption of dietary lipids. This study aimed to evaluate the effects of taurine supplementation to low-fishmeal diets on the metabolism of taurine, bile acids, and lipids of Senegalese sole. A fishmeal (FM) and a plant-protein-based (PP0) diet were formulated, and the latter was supplemented with taurine at 0.5 and 1.5% (diets PP0.5 and PP1.5). Diets were assigned to triplicate tanks containing 35 fish (initial weight ~14 g) for 6 weeks. Fish from the PP0 treatment presented lower taurine and bile-acid concentrations compared with the FM treatment, and a downregulation of cyp7a1 and abcb11 was observed. Triolein catabolism decreased in PP0-fed fish, resulting in increased hepatic fat content and plasma triglycerides, while no effects on plasma cholesterol were observed. Taurine supplementation to plant-based diets resulted in a higher taurine accumulation in fish tissues, increased bile-acid concentration, and upregulation of cyp7a1 and abcb11. Hepatic fat content and plasma triglycerides decreased with increasing dietary taurine supplementation. Taurine supplementation mitigated part of the negative effects of plant-based diets, leading to better lipid utilisation.
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Affiliation(s)
- Cláudia Aragão
- Centre of Marine Sciences (CCMAR), 8005-139 Faro, Portugal
- Universidade do Algarve, 8005-139 Faro, Portugal
| | - Rita Teodósio
- Centre of Marine Sciences (CCMAR), 8005-139 Faro, Portugal
| | - Rita Colen
- Centre of Marine Sciences (CCMAR), 8005-139 Faro, Portugal
| | - Nadège Richard
- Centre of Marine Sciences (CCMAR), 8005-139 Faro, Portugal
- Phileo by Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Ivar Rønnestad
- Department of Biological Sciences, University of Bergen, 5020 Bergen, Norway
| | | | | | - Laura Ribeiro
- IPMA-Portuguese Institute for the Ocean and Atmosphere/EPPO-Aquaculture Research Station, 8700-194 Olhão, Portugal
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Gates MA, Morash AJ, Lamarre SG, MacCormack TJ. Intracellular taurine deficiency impairs cardiac contractility in rainbow trout (Oncorhynchus mykiss) without affecting aerobic performance. J Comp Physiol B 2021; 192:49-60. [PMID: 34581858 DOI: 10.1007/s00360-021-01407-4] [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: 08/09/2021] [Revised: 09/03/2021] [Accepted: 09/16/2021] [Indexed: 01/07/2023]
Abstract
Taurine is a non-proteinogenic sulfonic acid found in high concentrations inside vertebrate cardiomyocytes and its movement across the sarcolemmal membrane is critical for cell volume regulation. Taurine deficiency is rare in mammals, where it impairs cardiac contractility and leads to congestive heart failure. In fish, cardiac taurine levels vary substantially between species and can decrease by up to 60% in response to environmental change but its contribution to cardiac function is understudied. We addressed this gap in knowledge by generating a taurine-deficient rainbow trout (Oncorhynchus mykiss) model using a feed enriched with 3% β-alanine to inhibit cellular taurine uptake. Cardiac taurine was reduced by 17% after 4 weeks with no effect on growth or condition factor. Taurine deficiency did not affect routine or maximum rates of O2 consumption, aerobic scope, or critical swimming speed in whole animals but cardiac contractility was significantly impaired. In isometrically contracting ventricular strip preparations, the force-frequency and extracellular Ca2+-sensitivity relationships were both shifted downward and maximum pacing frequency was significantly lower in β-alanine fed trout. Cardiac taurine deficiency reduces sarcoplasmic reticular Ca2+-ATPase activity in mammals and our results are consistent with such an effect in rainbow trout. Our data indicate that intracellular taurine contributes to the regulation of cardiac contractility in rainbow trout. Aerobic performance was unaffected in β-alanine-fed animals, but further study is needed to determine if more significant natural reductions in taurine may constrain performance under certain environmental conditions.
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Affiliation(s)
- M A Gates
- Department of Chemistry and Biochemistry, Mount Allison University, 63C York St., Sackville, NB, E4L1G8, Canada.,Department of Biology, Mount Allison University, Sackville, NB, Canada.,Department of Biology, Université de Moncton, Moncton, NB, Canada
| | - A J Morash
- Department of Chemistry and Biochemistry, Mount Allison University, 63C York St., Sackville, NB, E4L1G8, Canada.,Department of Biology, Mount Allison University, Sackville, NB, Canada.,Department of Biology, Université de Moncton, Moncton, NB, Canada
| | - S G Lamarre
- Department of Chemistry and Biochemistry, Mount Allison University, 63C York St., Sackville, NB, E4L1G8, Canada.,Department of Biology, Mount Allison University, Sackville, NB, Canada.,Department of Biology, Université de Moncton, Moncton, NB, Canada
| | - T J MacCormack
- Department of Chemistry and Biochemistry, Mount Allison University, 63C York St., Sackville, NB, E4L1G8, Canada. .,Department of Biology, Mount Allison University, Sackville, NB, Canada. .,Department of Biology, Université de Moncton, Moncton, NB, Canada.
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Jiang W, Tian X, Fang Z, Li L, Dong S, Li H, Zhao K. Metabolic responses in the gills of tongue sole (Cynoglossus semilaevis) exposed to salinity stress using NMR-based metabolomics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 653:465-474. [PMID: 30412891 DOI: 10.1016/j.scitotenv.2018.10.404] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 06/08/2023]
Abstract
Salinity is an important environmental factor affecting fish physiology. Tongue sole (Cynoglossus semilaevis) is a euryhaline species that can survive in a wide range of salinity, and might be used as a promising model animal for environmental science. In this study, by using the nuclear magnetic resonance (1H NMR)-based metabolomics, amino acids analysis and real-time quantitative PCR assay, we investigated the metabolic responses in the gills and plasma of tongue sole subjected to hypo- (0 ppt, S0) and hyper-osmotic stress (50 ppt, S50) from isosmotic environment (30 ppt, S30). The results showed that the metabolic profiles of S50 were significantly different from those of S0 and S30 groups, and a clear overlap was found between the latter two groups. Ten metabolites were significantly different between the salt stress groups and the isosmotic group. Taurine and creatine elevated in both S0 and S50 groups. Choline decreased in S50 group while increased in S0 group. Amino acids and energy compounds were higher in the gills of S50 group. The metabolic network showed that ten metabolic pathways were all found in S50 group, while seven pathways were observed in S0 group. Meanwhile, the transcript levels of the Tau-T and ATP synthase in the gills increased with increasing salinity. Aspartate and methionine exhibited significant differences in the plasma among the groups, but did not show differences in the gills. Comparatively, glutamate exhibited significant differences both in the plasma and the gills. Overall, these findings provide a preliminary profile of osmotic regulation in euryhaline fish.
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Affiliation(s)
- Wenwen Jiang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China
| | - Xiangli Tian
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, People's Republic of China.
| | - Ziheng Fang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China
| | - Li Li
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, People's Republic of China
| | - Shuanglin Dong
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, People's Republic of China
| | - Haidong Li
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China
| | - Kun Zhao
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, Shandong Province, People's Republic of China
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Yasuike M, Iwasaki Y, Nishiki I, Nakamura Y, Matsuura A, Yoshida K, Noda T, Andoh T, Fujiwara A. The yellowtail (Seriola quinqueradiata) genome and transcriptome atlas of the digestive tract. DNA Res 2018; 25:547-560. [PMID: 30329019 PMCID: PMC6191305 DOI: 10.1093/dnares/dsy024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 06/28/2018] [Indexed: 12/30/2022] Open
Abstract
Seriola quinqueradiata (yellowtail) is the most widely farmed and economically important fish in aquaculture in Japan. In this study, we used the genome of haploid yellowtail fish larvae for de novo assembly of whole-genome sequences, and built a high-quality draft genome for the yellowtail. The total length of the assembled sequences was 627.3 Mb, consisting of 1,394 scaffold sequences (>2 kb) with an N50 length of 1.43 Mb. A total of 27,693 protein-coding genes were predicted for the draft genome, and among these, 25,832 predicted genes (93.3%) were functionally annotated. Given our lack of knowledge of the yellowtail digestive system, and using the annotated draft genome as a reference, we conducted an RNA-Seq analysis of its three digestive organs (stomach, intestine and rectum). The RNA-Seq results highlighted the importance of certain genes in encoding proteolytic enzymes necessary for digestion and absorption in the yellowtail gastrointestinal tract, and this finding will accelerate development of formulated feeds for this species. Since this study offers comprehensive annotation of predicted protein-coding genes, it has potential broad application to our understanding of yellowtail biology and aquaculture.
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Affiliation(s)
- Motoshige Yasuike
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Yuki Iwasaki
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Issei Nishiki
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Yoji Nakamura
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Aiko Matsuura
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Kazunori Yoshida
- Goto Laboratory, Stock Enhancement and Aquaculture Division, Seikai National Fisheries Research Institute Japan Fisheries Research and Education Agency, Tamanoura-cho, Goto, Nagasaki, Japan
| | - Tsutomu Noda
- Goto Laboratory, Stock Enhancement and Aquaculture Division, Seikai National Fisheries Research Institute Japan Fisheries Research and Education Agency, Tamanoura-cho, Goto, Nagasaki, Japan
| | - Tadashi Andoh
- Stock Enhancement and Aquaculture Division, Seikai National Fisheries Research Institute, Japan Fisheries Research and Education Agency, Nagasaki, Japan
| | - Atushi Fujiwara
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
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Liu CL, Watson AM, Place AR, Jagus R. Taurine Biosynthesis in a Fish Liver Cell Line (ZFL) Adapted to a Serum-Free Medium. Mar Drugs 2017; 15:md15060147. [PMID: 28587087 PMCID: PMC5484097 DOI: 10.3390/md15060147] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 05/18/2017] [Accepted: 05/22/2017] [Indexed: 12/22/2022] Open
Abstract
Although taurine has been shown to play multiple important physiological roles in teleosts, little is known about the molecular mechanisms underlying dietary requirements. Cell lines can provide useful tools for deciphering biosynthetic pathways and their regulation. However, culture media and sera contain variable taurine levels. To provide a useful cell line for the investigation of taurine homeostasis, an adult zebrafish liver cell line (ZFL) has been adapted to a taurine-free medium by gradual accommodation to a commercially available synthetic medium, UltraMEM™-ITES. Here we show that ZFL cells are able to synthesize taurine and be maintained in medium without taurine. This has allowed for the investigation of the effects of taurine supplementation on cell growth, cellular amino acid pools, as well as the expression of the taurine biosynthetic pathway and taurine transporter genes in a defined fish cell type. After taurine supplementation, cellular taurine levels increase but hypotaurine levels stay constant, suggesting little suppression of taurine biosynthesis. Cellular methionine levels do not change after taurine addition, consistent with maintenance of taurine biosynthesis. The addition of taurine to cells grown in taurine-free medium has little effect on transcript levels of the biosynthetic pathway genes for cysteine dioxygenase (CDO), cysteine sulfinate decarboxylase (CSAD), or cysteamine dioxygenase (ADO). In contrast, supplementation with taurine causes a 30% reduction in transcript levels of the taurine transporter, TauT. This experimental approach can be tailored for the development of cell lines from aquaculture species for the elucidation of their taurine biosynthetic capacity.
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Affiliation(s)
- Chieh-Lun Liu
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.
| | - Aaron M Watson
- Marine Resources Research Institute, South Carolina Department of Natural Resources, 217 Fort Johnson Rd, Charleston, SC 29412, USA.
| | - Allen R Place
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.
| | - Rosemary Jagus
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.
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Karlsen Ø, van der Meeren T, Rønnestad I, Mangor-Jensen A, Galloway TF, Kjørsvik E, Hamre K. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae - can we identify the underlying factors? PeerJ 2015; 3:e902. [PMID: 26038712 PMCID: PMC4451035 DOI: 10.7717/peerj.902] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemia (the intensive group). In the second experiment (Exp-2), two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers) throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5) after the fish had been fed the same formulated diet for approximately 2 weeks.
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Affiliation(s)
- Ørjan Karlsen
- Institute of Marine Research, Austevoll Research Station , Storebø , Norway ; Hjort Centre for Marine Ecosystem Dynamics, Institute of Marine Research , Bergen , Norway
| | - Terje van der Meeren
- Institute of Marine Research, Austevoll Research Station , Storebø , Norway ; Hjort Centre for Marine Ecosystem Dynamics, Institute of Marine Research , Bergen , Norway
| | - Ivar Rønnestad
- Department of Biology, University of Bergen , Bergen , Norway
| | | | | | - Elin Kjørsvik
- Department of Biology, Norwegian University of Science and Technology , Trondheim , Norway
| | - Kristin Hamre
- National Institute of Nutrition and Seafood Research , Nordnes, Bergen , Norway
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Lambert IH, Jensen JV, Pedersen PA. mTOR ensures increased release and reduced uptake of the organic osmolyte taurine under hypoosmotic conditions in mouse fibroblasts. Am J Physiol Cell Physiol 2014; 306:C1028-40. [DOI: 10.1152/ajpcell.00005.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that modulates translation in response to growth factors and alterations in nutrient availability following hypoxia and DNA damage. Here we demonstrate that mTOR activity in Ehrlich Lettré ascites (ELA) cells is transiently increased within minutes following osmotic cell swelling and that inhibition of phosphatidylinositol-3-phosphatase (PTEN) counteracts the upstream phosphatidylinositol kinase and potentiates mTOR activity. PTEN inhibition concomitantly potentiates swelling-induced taurine release via the volume-sensitive transporter for organic osmolytes and anion channels (VSOAC) and enhances swelling-induced inhibition of taurine uptake via the taurine-specific transporter (TauT). Chronic osmotic stress, i.e., exposure to hypotonic or hypertonic media for 24 h, reduces and increases mTOR activity in ELA cells, respectively. Using rapamycin, we demonstrate that mTOR inhibition is accompanied by reduction in TauT activity and increase in VSOAC activity in cells expressing high (NIH3T3 fibroblasts) or low (ELA) amounts of mTOR protein. The effect of mTOR inhibition on TauT activity reflects reduced TauT mRNA, TauT protein abundance, and an overall reduction in protein synthesis, whereas the effect on VSOAC is mimicked by catalase inhibition and correlates with reduced catalase mRNA abundance. Hence, mTOR activity favors loss of taurine following hypoosmotic cell swelling, i.e., release via VSOAC and uptake via TauT during acute hypotonic exposure is potentiated and reduced, respectively, by phosphorylation involving mTOR and/or the kinases upstream to mTOR. Decrease in TauT activity during chronic hypotonic exposure, on the other hand, involves reduction in expression/activity of TauT and enzymes in antioxidative defense.
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Affiliation(s)
- Ian Henry Lambert
- Department of Biology, Section of Cellular and Developmental Biology, University of Copenhagen, Copenhagen, Denmark; and
| | - Jane Vendelbo Jensen
- Department of Biology, Section of Cellular and Developmental Biology, University of Copenhagen, Copenhagen, Denmark; and
| | - Per Amstrup Pedersen
- Department of Biology, Section for Molecular Integrative Physiology, University of Copenhagen, Copenhagen, Denmark
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Pinto W, Rønnestad I, Dinis MT, Aragão C. Taurine and Fish Development: Insights for the Aquaculture Industry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 776:329-34. [DOI: 10.1007/978-1-4614-6093-0_30] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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10
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Taurine homeostasis requires de novo synthesis via cysteine sulfinic acid decarboxylase during zebrafish early embryogenesis. Amino Acids 2012; 44:615-29. [DOI: 10.1007/s00726-012-1386-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 08/06/2012] [Indexed: 10/28/2022]
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