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Ali I, Jupp B, Hudson MR, Major B, Silva J, Yamakawa GR, Casillas-Espinosa PM, Braine E, Thergarajan P, Haskali MB, Vivash L, Brkljaca R, Shultz SR, Kwan P, Fukushima K, Sachdev P, Cheng JY, Mychasiuk R, Jones NC, Wright DK, OBrien TJ. In vivo biomarkers of GABAergic function in epileptic rats treated with the GAT-1 inhibitor E2730. Epilepsia 2024. [PMID: 39302665 DOI: 10.1111/epi.18119] [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: 05/21/2024] [Revised: 08/23/2024] [Accepted: 08/27/2024] [Indexed: 09/22/2024]
Abstract
OBJECTIVE E2730, an uncompetitive γ-aminobutyric acid (GABA) transporter-1 (GAT-1) inhibitor, has potent anti-seizure effects in a rodent model of chronic temporal lobe epilepsy, the kainic acid status epilepticus (KASE) rat model. In this study, we examined purported neuroimaging and physiological surrogate biomarkers of the effect of E2730 on brain GABAergic function. METHODS We conducted a randomized cross-over study, incorporating 1-week treatments with E2730 (100 mg/kg/day subcutaneous infusion) or vehicle in epileptic post-KASE rats. KASE rats underwent serial 9.4 T magnetic resonance spectroscopy (MRS) measuring GABA and other brain metabolites, [18F]Flumazenil positron emission tomography (PET) quantifying GABAA receptor availability, quantitative electroencephalography (qEEG) and transcranial magnetic stimulation (TMS)-mediated motor activity, as well as continuous video-EEG recording to measure spontaneous seizures during each treatment. Age-matched, healthy control animals treated with E2730 or vehicle were also studied. RESULTS E2730 treatment significantly reduced spontaneous seizures, with 8 of 11 animals becoming seizure-free. MRS revealed that E2730-treated animals had significantly reduced taurine levels. [18F]Flumazenil PET imaging revealed no changes in GABA receptor affinity or density during E2730 treatment. The power of gamma frequency oscillations in the EEG was decreased significantly in the auditory cortex and hippocampus of KASE and control rats during E2730 treatment. Auditory evoked gamma frequency power was enhanced by E2730 treatment in the auditory cortex of KASE and healthy controls, but only in the hippocampus of KASE rats. E2730 did not influence motor evoked potentials triggered by TMS. SIGNIFICANCE This study identified clinically relevant changes in multimodality imaging and functional purported biomarkers of GABAergic activity during E2730 treatment in epileptic and healthy control animals. These biomarkers could be utilized in clinical trials of E2730 and potentially other GABAergic drugs to provide surrogate endpoints, thereby reducing the cost of such trials.
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Affiliation(s)
- Idrish Ali
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, The University of Melbourne, Parkville, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Bianca Jupp
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | - Matthew R Hudson
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | - Brendan Major
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | - Juliana Silva
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | - Glenn R Yamakawa
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | - Pablo M Casillas-Espinosa
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, The University of Melbourne, Parkville, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Emma Braine
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | | | - Mohammad B Haskali
- Department of Radiopharmaceutical Sciences, Cancer Imaging, The Peter MacCallum Cancer Centre, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria, Australia
| | - Lucy Vivash
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, The University of Melbourne, Parkville, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | | | - Sandy R Shultz
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
- Centre for Trauma and Mental Health Research, Vancouver Island University, Nanaimo, Canada
| | - Patrick Kwan
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, The University of Melbourne, Parkville, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | | | - Pallavi Sachdev
- Clinical Evidence Generation, Translational Sciences, Eisai Inc., Bunkyo, Japan
| | - Jocelyn Y Cheng
- Clinical Evidence Generation, Translational Sciences, Eisai Inc., Bunkyo, Japan
| | | | - Nigel C Jones
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, The University of Melbourne, Parkville, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - David K Wright
- The Department of Neuroscience, Monash University, Melbourne, Australia
| | - Terence J OBrien
- The Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, The University of Melbourne, Parkville, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
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Stary D, Bajda M. Structural Studies of the Taurine Transporter: A Potential Biological Target from the GABA Transporter Subfamily in Cancer Therapy. Int J Mol Sci 2024; 25:7339. [PMID: 39000444 PMCID: PMC11242302 DOI: 10.3390/ijms25137339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/28/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024] Open
Abstract
The taurine transporter (TauT, SLC6A6) is a member of the solute carrier 6 (SLC6) family, which plays multiple physiological roles. The SLC6 family is divided into four subfamilies: GABA (γ-aminobutyric acid), monoamine, glycine and neutral amino acid transporters. Proteins from the GABA group, including the taurine transporter, are primarily considered therapeutic targets for treating central nervous system disorders. However, recent studies have suggested that inhibitors of SLC6A6 could also serve as anticancer agents. Overexpression of TauT has been associated with the progression of colon and gastric cancer. The pool of known ligands of this transporter is limited and the exact spatial structure of taurine transporter remains unsolved. Understanding its structure could aid in the development of novel inhibitors. Therefore, we utilized homology modelling techniques to create models of TauT. Docking studies and molecular dynamics simulations were conducted to describe protein-ligand interactions. We compared the obtained information for TauT with literature data on other members of the GABA transporter group. Our in silico analysis allowed us to characterize the transporter structure and point out amino acids crucial for ligand binding: Glu406, Gly62 and Tyr138. The significance of selected residues was confirmed through structural studies of mutants. These results will aid in the development of novel taurine transporter inhibitors, which can be explored as anticancer agents.
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Affiliation(s)
- Dorota Stary
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Cracow, Poland
- Doctoral School of Medical and Health Sciences, Jagiellonian University Medical College, św. Łazarza 16, 31-530 Cracow, Poland
| | - Marek Bajda
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Cracow, Poland
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Centeno D, Farsinejad S, Kochetkova E, Volpari T, Gladych-Macioszek A, Klupczynska-Gabryszak A, Polotaye T, Greenberg M, Kung D, Hyde E, Alshehri S, Pavlovic T, Sullivan W, Plewa S, Vakifahmetoglu-Norberg H, Monsma FJ, Muller PAJ, Matysiak J, Zaborowski MP, DiFeo A, Norberg E, Martin LA, Iwanicki M. Modeling of Intracellular Taurine Levels Associated with Ovarian Cancer Reveals Activation of p53, ERK, mTOR and DNA-Damage-Sensing-Dependent Cell Protection. Nutrients 2024; 16:1816. [PMID: 38931171 PMCID: PMC11206249 DOI: 10.3390/nu16121816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
Taurine, a non-proteogenic amino acid and commonly used nutritional supplement, can protect various tissues from degeneration associated with the action of the DNA-damaging chemotherapeutic agent cisplatin. Whether and how taurine protects human ovarian cancer (OC) cells from DNA damage caused by cisplatin is not well understood. We found that OC ascites-derived cells contained significantly more intracellular taurine than cell culture-modeled OC. In culture, elevation of intracellular taurine concentration to OC ascites-cell-associated levels suppressed proliferation of various OC cell lines and patient-derived organoids, reduced glycolysis, and induced cell protection from cisplatin. Taurine cell protection was associated with decreased DNA damage in response to cisplatin. A combination of RNA sequencing, reverse-phase protein arrays, live-cell microscopy, flow cytometry, and biochemical validation experiments provided evidence for taurine-mediated induction of mutant or wild-type p53 binding to DNA, activation of p53 effectors involved in negative regulation of the cell cycle (p21), and glycolysis (TIGAR). Paradoxically, taurine's suppression of cell proliferation was associated with activation of pro-mitogenic signal transduction including ERK, mTOR, and increased mRNA expression of major DNA damage-sensing molecules such as DNAPK, ATM and ATR. While inhibition of ERK or p53 did not interfere with taurine's ability to protect cells from cisplatin, suppression of mTOR with Torin2, a clinically relevant inhibitor that also targets DNAPK and ATM/ATR, broke taurine's cell protection. Our studies implicate that elevation of intracellular taurine could suppress cell growth and metabolism, and activate cell protective mechanisms involving mTOR and DNA damage-sensing signal transducti.
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Affiliation(s)
- Daniel Centeno
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Sadaf Farsinejad
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Elena Kochetkova
- Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; (E.K.); (H.V.-N.); (E.N.)
| | - Tatiana Volpari
- The New York Stem Cell Foundation Research Institute, New York, NY 10019, USA; (T.V.); (W.S.); (F.J.M.J.)
| | | | - Agnieszka Klupczynska-Gabryszak
- Department of Inorganic and Analytical Chemistry, Poznań University of Medical Sciences, 61-701 Poznań, Poland; (A.K.-G.); (S.P.); (J.M.)
| | - Teagan Polotaye
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Michael Greenberg
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Douglas Kung
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Emily Hyde
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Sarah Alshehri
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - Tonja Pavlovic
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
| | - William Sullivan
- The New York Stem Cell Foundation Research Institute, New York, NY 10019, USA; (T.V.); (W.S.); (F.J.M.J.)
| | - Szymon Plewa
- Department of Inorganic and Analytical Chemistry, Poznań University of Medical Sciences, 61-701 Poznań, Poland; (A.K.-G.); (S.P.); (J.M.)
| | - Helin Vakifahmetoglu-Norberg
- Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; (E.K.); (H.V.-N.); (E.N.)
| | - Frederick J. Monsma
- The New York Stem Cell Foundation Research Institute, New York, NY 10019, USA; (T.V.); (W.S.); (F.J.M.J.)
| | | | - Jan Matysiak
- Department of Inorganic and Analytical Chemistry, Poznań University of Medical Sciences, 61-701 Poznań, Poland; (A.K.-G.); (S.P.); (J.M.)
| | | | - Analisa DiFeo
- Departments of Obstetrics and Gynecology and Pathology, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Erik Norberg
- Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; (E.K.); (H.V.-N.); (E.N.)
| | - Laura A. Martin
- The New York Stem Cell Foundation Research Institute, New York, NY 10019, USA; (T.V.); (W.S.); (F.J.M.J.)
| | - Marcin Iwanicki
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, NJ 07030, USA; (D.C.); (S.F.); (T.P.); (M.G.); (D.K.); (E.H.); (S.A.); (T.P.)
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4
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Centeno D, Farsinejad S, Kochetkova E, Volpari T, Gladych-Macioszek A, Klupczynska-Gabryszak A, Polotaye T, Greenberg M, Kung D, Hyde E, Alshehri S, Pavlovic T, Sullivan W, Plewa S, Vakifahmetoglu-Norberg H, Monsma FJ, Muller PAJ, Matysiak J, Zaborowski M, DiFeo A, Norberg E, Martin LA, Iwanicki M. Modeling of Intracellular Taurine Levels Associated with Ovarian Cancer Reveals Activation of p53, ERK, mTOR and DNA-damage-sensing-dependent Cell Protection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.24.529893. [PMID: 36909636 PMCID: PMC10002676 DOI: 10.1101/2023.02.24.529893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Taurine, a non-proteogenic amino acid, and commonly used nutritional supplement can protect various tissues from degeneration associated with the action of the DNA-damaging chemotherapeutic agent cisplatin. Whether and how taurine protects human ovarian cancer (OC) cells from DNA damage caused by cisplatin is not well understood. We have found that OC ascites-derived cells contained significantly more intracellular taurine than cell cultures modeling OC. In culture, elevation of intracellular taurine concentration to OC ascites-cells-associated levels suppressed proliferation of various OC cell lines and patient-derived organoids, reduced glycolysis, and induced cell protection from cisplatin. Taurine cell protection was associated with decreased DNA damage in response to cisplatin. A combination of RNA sequencing, reverse phase protein arrays, live-cell microscopy, flow cytometry, and biochemical validation experiments provided evidence for taurine-mediated induction of mutant- or wild-type p53 binding to DNA, and activation of p53 effectors involved in negative regulation of the cell cycle (p21), and glycolysis (TIGAR). Paradoxically, taurine's suppression of cell proliferation was associated with activation of pro-mitogenic signal transduction including ERK, mTOR, and increased mRNA expression of major DNA damage sensing molecules such as DNAPK, ATM and ATR. While inhibition of ERK or p53 did not interfere with taurine's ability to protect cells from cisplatin, suppression of mTOR with Torin2, a clinically relevant inhibitor that also targets DNAPK and ATM/ATR, broke taurine's cell protection. Our studies implicate that elevation of intracellular taurine could suppress cell growth, metabolism, and activate cell protective mechanisms involving mTOR and DNA damage sensing signal transduction.
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5
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Dixon TAM, Rhyno ELM, El N, McGaw SP, Otley NA, Parker KS, Buldo EC, Pabody CM, Savoie M, Cockshutt A, Morash AJ, Lamarre SG, MacCormack TJ. Taurine depletion impairs cardiac function and affects tolerance to hypoxia and high temperatures in brook char (Salvelinus fontinalis). J Exp Biol 2023; 226:286891. [PMID: 36728502 DOI: 10.1242/jeb.245092] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/20/2023] [Indexed: 02/03/2023]
Abstract
Physiological and environmental stressors can cause osmotic stress in fish hearts, leading to a reduction in intracellular taurine concentration. Taurine is a β-amino acid known to regulate cardiac function in other animal models but its role in fish has not been well characterized. We generated a model of cardiac taurine deficiency (TD) by feeding brook char (Salvelinus fontinalis) a diet enriched in β-alanine, which inhibits cardiomyocyte taurine uptake. Cardiac taurine levels were reduced by 21% and stress-induced changes in normal taurine handling were observed in TD brook char. Responses to exhaustive exercise and acute thermal and hypoxia tolerance were then assessed using a combination of in vivo, in vitro and biochemical approaches. Critical thermal maximum was higher in TD brook char despite significant reductions in maximum heart rate. In vivo, TD brook char exhibited a lower resting heart rate, blunted hypoxic bradycardia and a severe reduction in time to loss of equilibrium under hypoxia. In vitro function was similar between control and TD hearts under oxygenated conditions, but stroke volume and cardiac output were severely compromised in TD hearts under severe hypoxia. Aspects of mitochondrial structure and function were also impacted in TD permeabilized cardiomyocytes, but overall effects were modest. High levels of intracellular taurine are required to achieve maximum cardiac function in brook char and cardiac taurine efflux may be necessary to support heart function under stress. Taurine appears to play a vital, previously unrecognized role in supporting cardiovascular function and stress tolerance in fish.
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Affiliation(s)
- Toni-Anne M Dixon
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Emma-Lee M Rhyno
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Nir El
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Samuel P McGaw
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Nathan A Otley
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Katya S Parker
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Elena C Buldo
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Claire M Pabody
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Mireille Savoie
- Department of Biology, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Amanda Cockshutt
- Department of Chemistry, Saint Francis Xavier University, Antigonish, NS, Canada, B2G 2W5
| | - Andrea J Morash
- Department of Biology, Mount Allison University, Sackville, NB, Canada, E4L 1E4
| | - Simon G Lamarre
- Departement de Biologie, Université de Moncton, Moncton, NB, Canada, E1A 3E9
| | - Tyson J MacCormack
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1E4
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Stary D, Bajda M. Taurine and Creatine Transporters as Potential Drug Targets in Cancer Therapy. Int J Mol Sci 2023; 24:ijms24043788. [PMID: 36835201 PMCID: PMC9964810 DOI: 10.3390/ijms24043788] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
Cancer cells are characterized by uncontrolled growth, proliferation, and impaired apoptosis. Tumour progression could be related to poor prognosis and due to this fact, researchers have been working on novel therapeutic strategies and antineoplastic agents. It is known that altered expression and function of solute carrier proteins from the SLC6 family could be associated with severe diseases, including cancers. These proteins were noticed to play important physiological roles through transferring nutrient amino acids, osmolytes, neurotransmitters, and ions, and many of them are necessary for survival of the cells. Herein, we present the potential role of taurine (SLC6A6) and creatine (SLC6A8) transporters in cancer development as well as therapeutic potential of their inhibitors. Experimental data indicate that overexpression of analyzed proteins could be connected with colon or breast cancers, which are the most common types of cancers. The pool of known inhibitors of these transporters is limited; however, one ligand of SLC6A8 protein is currently tested in the first phase of clinical trials. Therefore, we also highlight structural aspects useful for ligand development. In this review, we discuss SLC6A6 and SLC6A8 transporters as potential biological targets for anticancer agents.
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Affiliation(s)
- Dorota Stary
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688 Cracow, Poland
- Doctoral School of Medical and Health Sciences, Jagiellonian University Medical College, św. Łazarza 16 St., 31-530 Cracow, Poland
| | - Marek Bajda
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688 Cracow, Poland
- Correspondence:
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Kim HJ, Zhao J, Sparrow JR. Vitamin A aldehyde-taurine adducts function in photoreceptor cells. Redox Biol 2022; 54:102386. [PMID: 35809434 PMCID: PMC9287728 DOI: 10.1016/j.redox.2022.102386] [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: 05/18/2022] [Revised: 06/17/2022] [Accepted: 06/24/2022] [Indexed: 01/12/2023] Open
Abstract
To facilitate the movement of retinoids through the visual cycle and to limit nonspecific chemical reaction, multiple mechanisms are utilized to handle these molecules when not contained within the binding pocket of opsin. Vitamin A aldehyde is sequestered by reversible Schiff base formation with phosphatidylethanolamine (PE) and subsequently undergoes NADPH-dependent reduction. Otherwise inefficient handling of retinaldehyde can lead to the formation of fluorescent di-retinal compounds within the outer segments of photoreceptor cells. These bisretinoid fluorophores initiate photooxidative processes having adverse consequences for retina. Various carrier proteins confer water solubility and maintain the 11-cis-retinoid configuration. Mechanisms for sequestration of retinoid include the formation of a reversible Schiff base between retinaldehyde and taurine (A1-taurine, A1T), the most abundant amino acid in photoreceptor cells. Here we have undertaken to examine the effects of taurine depletion using the transport inhibitors guanidinoethyl sulfonate (GES) and β-alanine. Oral treatment of BALB/cJ mice with β-alanine reduced ocular A1T and the mice exhibited significantly lower scotopic and photopic a-wave amplitudes. As a secondary effect of retinal degeneration, A1T was not detected and taurine was significantly reduced in mice carrying a P23H opsin mutation. The thinning of ONL that is indicative of reduced photoreceptor cell viability in albino Abca4-/- mice was more pronounced in β-alanine treated mice. Treatment of agouti and albino Abca4-/- mice with β-alanine and GES was associated with reduced bisretinoid measured chromatographically. Consistent with a reduction in carbonyl scavenging activity by taurine, methylglyoxal-adducts were also increased in the presence of β-alanine. Taken together these findings support the postulate that A1T serves as a reservoir of vitamin A aldehyde, with diminished A1T explaining reduced photoreceptor light-sensitivity, accentuated ONL thinning in Abca4-/- mice and attenuated bisretinoid formation.
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Affiliation(s)
- Hye Jin Kim
- Departments of Ophthalmology and Columbia University Medical Center, New York, NY, 10032, USA
| | - Jin Zhao
- Departments of Ophthalmology and Columbia University Medical Center, New York, NY, 10032, USA
| | - Janet R. Sparrow
- Departments of Ophthalmology and Columbia University Medical Center, New York, NY, 10032, USA,Departments of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, 10032, USA,Corresponding author. Departments of Ophthalmology and Columbia University Medical Center, New York, NY, 10032, USA.
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Wu H, Zhang X, Yang J, Feng T, Chen Y, Feng R, Wang H, Qian Y. OUP accepted manuscript. Hum Reprod 2022; 37:1229-1243. [PMID: 35526154 PMCID: PMC9156853 DOI: 10.1093/humrep/deac089] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/02/2022] [Indexed: 11/13/2022] Open
Abstract
STUDY QUESTION Are taurine and its transporter TAUT associated with spermiogenesis and early embryo development? SUMMARY ANSWER Morphologically abnormal spermatozoa increased after local functional interference by intratesticular injection, and taurine depletion significantly reduced the normal embryo numbers in vivo and blastocyst formation rate in vitro. WHAT IS KNOWN ALREADY Taurine is one of the most abundant amino acids in the male reproductive system and it has been demonstrated that taurine can efficiently improve spermatogenic function in rat models of testicular injury. However, limited information is known about the role of taurine and its transporter TAUT in spermatogenesis and early embryo development. STUDY DESIGN, SIZE, DURATION Clinical characteristics from 110 couples who have experienced recurrent pregnancy loss (RPL) were collected from December 2014 to March 2018. According to whether a fetal heartbeat was seen in the previous pregnancy under ultrasonic monitoring, patients with RPL were divided into two groups: an RPL without heartbeat (pregnancy with no fetal heartbeat, ROH) group, and an RPL with heartbeat (one or more pregnancies with fetal heartbeat, RWH) group. Semen samples (21 ROH and 20 RWH) were finally used for metabolomic analysis. Furthermore, semen samples were obtained from 30 patients with teratozoospermia (normal sperm morphology <4%) seeking evaluation for infertility and 25 age-matched control subjects with normal semen quality for western blotting. Animal experiments were performed in CD-1/ICR mice. PARTICIPANTS/MATERIALS, SETTING, METHODS Metabolomics was performed to determine the metabolic changes between the ROH and RWH groups. Sperm proteins from patients with teratozoospermia and healthy controls were extracted for detecting TAUT expression using western blot analysis. Immunofluorescence was used to characterize the localization of TAUT in the testis and ejaculated spermatozoa. Functional analysis in mice was performed by intratesticular injection of siRNAs or antagonist (β-alanine) and 5% β-alanine was provided in drinking water to 3-week-old male mice for 5 weeks with the aim of depleting taurine. Murine epididymal spermatozoa were stained with hematoxylin and eosin for morphological assessment. IVF and mating tests were performed in mice for assessing fertility. MAIN RESULTS AND THE ROLE OF CHANCE Metabolomic analysis demonstrated that the taurine content was lower in spermatozoa but higher in seminal plasma from the ROH than the RWH group. TAUT expression was lower in spermatozoa from patients with teratozoospermia than controls. Immunofluorescence showed that TAUT was localized to the manchette in mouse elongated spermatids functional analysis showed that morphologically abnormal spermatozoa increased after interference, and this defect increased after supplementation with 5% β-alanine but was improved by 5% taurine supplementation. Supplementation with 5% β-alanine significantly reduced the normal embryo number in the mouse uterus as well as blastocyst formation rate in vitro. LARGE SCALE DATA N/A LIMITATIONS, REASONS FOR CAUTION The sample size was low and larger cohorts are needed to confirm the positive effect of taurine on human sperm quality. A comprehensive safety examination should be performed to evaluate whether taurine is a possible treatment for teratozoospermia. Furthermore, the specific molecular mechanism of TAUT involvement in spermiogenesis remains to be clarified. WIDER IMPLICATIONS OF THE FINDINGS The study provides new insights into the role of taurine and its transporter TAUT in male reproduction and embryo development. The results also indicate that TAUT is a promising molecular candidate for the assessment of sperm quality, which may contribute to the diagnosis and treatment for teratozoospermia. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by grants from the National Natural Science Foundation of China (no. 81774075, 31900605, 81971451), Jiangsu Science and Technology Program Grant (BK20190654) and Maternal and child health scientific research of Jiangsu Province (F202121). The authors declare no competing financial interests.
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Affiliation(s)
| | | | - Jihong Yang
- Reproductive Medical Center of Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ting Feng
- Reproductive Medical Center of Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yao Chen
- Reproductive Medical Center of Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ruizhi Feng
- State Key Laboratory of Reproductive Medicine, Second Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Hui Wang
- Correspondence address. Reproductive Medical Center of Second Affiliated Hospital of Nanjing Medical University, 121 Jiangjiayuan Road, Nanjing 210011, China. Tel: +86-025-58771027; E-mail: (Y.Q.); Department of Histology and Embryology, State Key Laboratory of Reproductive Medicine, Nanjing Medical University, 101 Longmian Avenue, Nanjing 211166, China. Tel: +86-025-86869380; E-mail: (H.W.)
| | - Yun Qian
- Correspondence address. Reproductive Medical Center of Second Affiliated Hospital of Nanjing Medical University, 121 Jiangjiayuan Road, Nanjing 210011, China. Tel: +86-025-58771027; E-mail: (Y.Q.); Department of Histology and Embryology, State Key Laboratory of Reproductive Medicine, Nanjing Medical University, 101 Longmian Avenue, Nanjing 211166, China. Tel: +86-025-86869380; E-mail: (H.W.)
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9
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Keenan BT, Galante RJ, Lian J, Zhang L, Guo X, Veatch OJ, Chesler EJ, O'Brien WT, Svenson KL, Churchill GA, Pack AI. The dihydropyrimidine dehydrogenase gene contributes to heritable differences in sleep in mice. Curr Biol 2021; 31:5238-5248.e7. [PMID: 34653361 DOI: 10.1016/j.cub.2021.09.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/25/2021] [Accepted: 09/17/2021] [Indexed: 12/27/2022]
Abstract
Many aspects of sleep are heritable, but only a few sleep-regulating genes have been reported. Here, we leverage mouse models to identify and confirm a previously unreported gene affecting sleep duration-dihydropyrimidine dehydrogenase (Dpyd). Using activity patterns to quantify sleep in 325 Diversity Outbred (DO) mice-a population with high genetic and phenotypic heterogeneity-a linkage peak for total sleep in the active lights off period was identified on chromosome 3 (LOD score = 7.14). Mice with the PWK/PhJ ancestral haplotype at this location demonstrated markedly reduced sleep. Among the genes within the linkage region, available RNA sequencing data in an independent sample of DO mice supported a highly significant expression quantitative trait locus for Dpyd, wherein reduced expression was associated with the PWK/PhJ allele. Validation studies were performed using activity monitoring and EEG/EMG recording in Collaborative Cross mouse strains with and without the PWK/PhJ haplotype at this location, as well as EEG and EMG recording of sleep and wake in Dpyd knockout mice and wild-type littermate controls. Mice lacking Dpyd had 78.4 min less sleep during the lights-off period than wild-type mice (p = 0.007; Cohen's d = -0.94). There was no difference in other measured behaviors in knockout mice, including assays evaluating cognitive-, social-, and affective-disorder-related behaviors. Dpyd encodes the rate-limiting enzyme in the metabolic pathway that catabolizes uracil and thymidine to β-alanine, an inhibitory neurotransmitter. Thus, data support β-alanine as a neurotransmitter that promotes sleep in mice.
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Affiliation(s)
- Brendan T Keenan
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Raymond J Galante
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Jie Lian
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Lin Zhang
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Xiaofeng Guo
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Olivia J Veatch
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
| | | | - W Timothy O'Brien
- Neurobehavior Testing Core, Institute for Translational and Therapeutic Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | | | - Allan I Pack
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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10
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Abstract
Taurine is a sulfur-containing amino acid that is not incorporated into protein but is abundant in retina. Schiff base adducts that form nonenzymatically and reversibly from reactions between taurine and vitamin A aldehyde (A1T) are increased under conditions in which the visual chromophore 11-cis-retinal is more abundant. These settings include black versus albino mice, dark-adapted versus light-adapted mice, and mice expressing the Rpe65-Leu450 versus Rpe65-Met450 variant. Conversely, A1T is less abundant in mouse models deficient in 11-cis-retinal. As an amphiphile, protonated A1T may serve to facilitate retinoid trafficking and could constitute a small-molecule reserve of mobilizable 11-cis-retinal in photoreceptor cells. Visual pigment consists of opsin covalently linked to the vitamin A-derived chromophore, 11-cis-retinaldehyde. Photon absorption causes the chromophore to isomerize from the 11-cis- to all-trans-retinal configuration. Continued light sensitivity necessitates the regeneration of 11-cis-retinal via a series of enzyme-catalyzed steps within the visual cycle. During this process, vitamin A aldehyde is shepherded within photoreceptors and retinal pigment epithelial cells to facilitate retinoid trafficking, to prevent nonspecific reactivity, and to conserve the 11-cis configuration. Here we show that redundancy in this system is provided by a protonated Schiff base adduct of retinaldehyde and taurine (A1-taurine, A1T) that forms reversibly by nonenzymatic reaction. A1T was present as 9-cis, 11-cis, 13-cis, and all-trans isomers, and the total levels were higher in neural retina than in retinal pigment epithelium (RPE). A1T was also more abundant under conditions in which 11-cis-retinaldehyde was higher; this included black versus albino mice, dark-adapted versus light-adapted mice, and mice carrying the Rpe65-Leu450 versus Rpe65-450Met variant. Taurine levels paralleled these differences in A1T. Moreover, A1T was substantially reduced in mice deficient in the Rpe65 isomerase and in mice deficient in cellular retinaldehyde-binding protein; in these models the production of 11-cis-retinal is compromised. A1T is an amphiphilic small molecule that may represent a mechanism for escorting retinaldehyde. The transient Schiff base conjugate that the primary amine of taurine forms with retinaldehyde would readily hydrolyze to release the retinoid and thus may embody a pool of 11-cis-retinal that can be marshalled in photoreceptor cells.
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11
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Police A, Shankar VK, Murthy SN. Role of Taurine Transporter in the Retinal Uptake of Vigabatrin. AAPS PharmSciTech 2020; 21:196. [PMID: 32666325 DOI: 10.1208/s12249-020-01736-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 06/20/2020] [Indexed: 12/18/2022] Open
Abstract
Vigabatrin (VGB) is a first-line drug used for treatment of infantile spasms. On therapeutic dose, VGB accumulates in the retina causing permanent peripheral visual field constriction. The mechanism involved in retinal accumulation of VGB is ambiguous. In the present study, mechanism of VGB transport into retina was evaluated. VGB uptake into retina was studied in vitro using human adult retinal pigment epithelial (ARPE-19) cells as a model for outer blood retinal barrier. The VGB cell uptake studies demonstrated saturation kinetics with Km value of 13.1 mM and uptake was significantly increased at pH 7.4 and hyperosmolar conditions indicating involvement of carrier-mediated Na+-Cl--dependent transporter. In the presence of taurine transporter (TauT) substrates (taurine and GABA) and inhibitor guanidinoethyl sulfonate (GES), the uptake of VGB decreased significantly demonstrating contribution of TauT. The VGB retinal levels in rats were decreased by 1.5- and 1.3-folds on chronic administration of GES and taurine, respectively. In conclusion, this study demonstrated the TauT involvement in VGB uptake and accumulation in retina.
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12
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Chen Y, Dinges MM, Green A, Cramer SE, Larive CK, Lytle C. Absorptive transport of amino acids by the rat colon. Am J Physiol Gastrointest Liver Physiol 2020; 318:G189-G202. [PMID: 31760764 PMCID: PMC6985843 DOI: 10.1152/ajpgi.00277.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The capacity of the colon to absorb microbially produced amino acids (AAs) and the underlying mechanisms of AA transport are incompletely defined. We measured the profile of 16 fecal AAs along the rat ceco-colonic axis and compared unidirectional absorptive AA fluxes across mucosal tissues isolated from the rat jejunum, cecum, and proximal colon using an Ussing chamber approach, in conjunction with 1H-NMR and ultra-performance liquid chromatography-mass spectrometry chemical analyses. Passage of stool from cecum to midcolon was associated with segment-specific changes in fecal AA composition and a decrease in total AA content. Simultaneous measurement of up to 16 AA fluxes under native luminal conditions, with correction for endogenous AA release, demonstrated absorptive transfer of AAs across the cecum and proximal colon at rates comparable (30-80%) to those across the jejunum, with significant Na+-dependent and H+-stimulated components. Expression profiling of 30 major AA transporter genes by quantitative PCR revealed comparatively high levels of transcripts for 20 AA transporters in the cecum and/or colon, with the levels of 12 exceeding those in the small intestine. Our results suggest a more detailed model of major apical and basolateral AA transporters in rat colonocytes and provide evidence for a previously unappreciated transfer of AAs across the colonic epithelium that could link the prodigious metabolic capacities of the luminal microbiota, the colonocytes, and the body tissues.NEW & NOTEWORTHY This study provides evidence for a previously unappreciated transfer of microbially generated amino acids across the colonic epithelium under physiological conditions that could link the prodigious metabolic capacities of the luminal microbiota, the colonocytes, and the body tissues. The segment-specific expression of at least 20 amino acid transporter genes along the colon provides a detailed mechanistic basis for uniport, heteroexchange, Na+-cotransport, and H+-cotransport components of colonic amino acid absorption.
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Affiliation(s)
- Yuxin Chen
- 1Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California
| | - Meredith M. Dinges
- 2Department of Chemistry, University of California, Riverside, California
| | - Andrew Green
- 2Department of Chemistry, University of California, Riverside, California
| | - Scott E. Cramer
- 1Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California
| | - Cynthia K. Larive
- 2Department of Chemistry, University of California, Riverside, California
| | - Christian Lytle
- 1Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California
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13
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Lai HW, Sasaki R, Usuki S, Nakajima M, Tanaka T, Ogura SI. Novel strategy to increase specificity of ALA-Induced PpIX accumulation through inhibition of transporters involved in ALA uptake. Photodiagnosis Photodyn Ther 2019; 27:327-335. [DOI: 10.1016/j.pdpdt.2019.06.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/20/2019] [Accepted: 06/24/2019] [Indexed: 01/10/2023]
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14
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García-Ayuso D, Di Pierdomenico J, Valiente-Soriano FJ, Martínez-Vacas A, Agudo-Barriuso M, Vidal-Sanz M, Picaud S, Villegas-Pérez MP. β-alanine supplementation induces taurine depletion and causes alterations of the retinal nerve fiber layer and axonal transport by retinal ganglion cells. Exp Eye Res 2019; 188:107781. [PMID: 31473259 DOI: 10.1016/j.exer.2019.107781] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/26/2019] [Accepted: 08/28/2019] [Indexed: 11/30/2022]
Abstract
To study the effect of taurine depletion induced by β-alanine supplementation in the retinal nerve fiber layer (RNFL), and retinal ganglion cell (RGC) survival and axonal transport. Albino Sprague-Dawley rats were divided into two groups: one group received β-alanine supplementation (3%) in the drinking water during 2 months to induce taurine depletion, and the other group received regular water. After one month, half of the rats from each group were exposed to light. Retinas were analyzed in-vivo using Spectral-Domain Optical Coherence Tomography (SD-OCT). Prior to processing, RGCs were retrogradely traced with fluorogold (FG) applied to both superior colliculi, to assess the state of their retrograde axonal transport. Retinas were dissected as wholemounts, surviving RGCs were immunoidentified with Brn3a, and the RNFL with phosphorylated high-molecular-weight subunit of the neurofilament triplet (pNFH) antibodies. β-alanine supplementation decreases significantly taurine plasma levels and causes a significant reduction of the RNFL thickness that is increased after light exposure. An abnormal pNFH immunoreactivity in some RGC bodies, their proximal dendrites and axons, and a further diminution of the mean number of FG-traced RGCs compared with Brn3a+RGCs, indicate that their retrograde axonal transport is affected. In conclusion, taurine depletion causes RGC loss and axonal transport impairment. Finally, our results suggest that care should be taken when ingesting β-alanine supplements due to the limited understanding of their potential adverse effects.
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Affiliation(s)
- Diego García-Ayuso
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.
| | - Johnny Di Pierdomenico
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Francisco J Valiente-Soriano
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Ana Martínez-Vacas
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Marta Agudo-Barriuso
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Manuel Vidal-Sanz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Serge Picaud
- INSERM U968, Institut de la Vision, Paris, France; Sorbonnes Universités, INSERM U968, CNRS UMR 7210, Institut de la Vision, 75012, Paris, France
| | - María P Villegas-Pérez
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.
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15
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Richter M, Moroniak SJ, Michel H. Identification of competitive inhibitors of the human taurine transporter TauT in a human kidney cell line. Pharmacol Rep 2019; 71:121-129. [PMID: 30612046 DOI: 10.1016/j.pharep.2018.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/24/2018] [Accepted: 10/10/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND The osmolyte and antioxidant taurine plays an important role in regulation of cellular volume, oxidative status and Ca2+-homeostasis. Taurine uptake in human cells is regulated by the Na+- and Cl--dependent taurine transporter TauT. In order to gain deeper structural insights about the substrate binding pocket of TauT, a HEK293 cell line producing a GFP-TauT fusion protein was generated. METHODS Transport activity was validated using cell-based [3H]-taurine transport assays. We determined the Km and IC50 values of taurine, β-alanine and γ-aminobutyrate. Additionally we were able to identify structurally similar compounds as potential new substrates or inhibitors of the TauT transporter. Substrate induced cytotoxicity was analyzed using a cell viability assay. RESULTS In this study we show competitive effects of the 3-pyridinesulfonate, 2-aminoethylhydrogen sulfate, 5-aminovalerate, β-aminobutyrate, piperidine-4-sulfonate, 2-aminoethylphosphate and homotaurine. We demonstrate that taurine uptake can be inhibited by a phosphate. Furthermore our studies revealed that piperidine-4-sulfonate interacts with TauT with a higher affinity than γ-aminobutyrate and imidazole-4-acetate. CONCLUSION We propose that piperidine-4-sulfonate may serve as a potential lead structure for the design of novel drug candidates required for specific modulation of the TauT transporter in therapy of neurodegenerative diseases.
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Affiliation(s)
- Michelle Richter
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Selina J Moroniak
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Hartmut Michel
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
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16
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Rasmussen RN, Christensen KV, Holm R, Nielsen CU. Transcriptome analysis identifies activated signaling pathways and regulated ABC transporters and solute carriers after hyperosmotic stress in renal MDCK I cells. Genomics 2018; 111:1557-1565. [PMID: 30389539 DOI: 10.1016/j.ygeno.2018.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/22/2018] [Accepted: 10/29/2018] [Indexed: 12/01/2022]
Abstract
Hyperosmolality is found under physiological conditions in the kidneys, whereas hyperosmolality in other tissues may be associated with pathological conditions. In such tissues an association between inflammation and hyperosmolality has been suggested. During hyperosmotic stress, an important phenomenon is upregulation of solute carriers (SLCs). We hypothesize that hyperosmolality affects the expression of many SLCs as well as ABC transporters. Through RNA-sequencing and topological pathway analysis, the cell cycle, the cytokine-cytokine receptor interaction pathway, and the chemokine-signaling pathway were significantly activated in MDCK I cells after hyperosmotic treatment (Δ200 mOsm) with raffinose or NaCl. 9065, 8052 and 5018 genes were significantly regulated by raffinose, NaCl or urea supplementation (500 mOsm), respectively, compared to control (300 mOsm). Cytokines, that have not previously been associated with hyperosmolality, were identified. We further provide an overview of transport proteins that could be of relevance in tissues exposed to hyperosmolality. Especially Slc5a8 was found highly up-regulated.
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Affiliation(s)
- Rune Nørgaard Rasmussen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark..
| | | | - René Holm
- Drug Product Development, Janssens Research and Development, Johnson & Johnson, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Carsten Uhd Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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17
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Valembois S, Krall J, Frølund B, Steffansen B. Imidazole-4-acetic acid, a new lead structure for interaction with the taurine transporter in outer blood-retinal barrier cells. Eur J Pharm Sci 2017; 103:77-84. [DOI: 10.1016/j.ejps.2017.02.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 10/20/2022]
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18
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Rasmussen RN, Holm R, Christensen KV, Nielsen CU. Ibuprofen transport in renal cell cultures: characterization of an ibuprofen transporter upregulated by hyperosmolarity. MEDCHEMCOMM 2016. [DOI: 10.1039/c6md00305b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An ibuprofen transporter localizes to the apical and basolateral membrane of MDCK I cells is upregulated by hyperosmotic exposure. Ibuprofen uptake is inhibited by other NSAIDs and ibuprofen metabolites.
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Affiliation(s)
- Rune Nørgaard Rasmussen
- Department of Physics, Chemistry and Pharmacy
- University of Southern Denmark
- DK-5230 Odense M
- Denmark
| | - René Holm
- Drug Product Development
- Janssens Research and Development
- Johnson & Johnson
- 2430 Beerse
- Belgium
| | | | - Carsten Uhd Nielsen
- Department of Physics, Chemistry and Pharmacy
- University of Southern Denmark
- DK-5230 Odense M
- Denmark
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