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Jiang J, Tang Y, Cao Z, Zhou C, Yu Z. Effects of hypo-osmotic stress on osmoregulation, antioxidant response, and energy metabolism in sea cucumber Holothuria moebii under desalination environment. ENVIRONMENTAL RESEARCH 2024; 252:118800. [PMID: 38555088 DOI: 10.1016/j.envres.2024.118800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/15/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
With global climate changing, hypo-salinity events are increasing in frequency and duration because of continuous rainfall and freshwater inflow, which causes reduced cytosolic osmolarity and cellular stress responses in aquatic animals. Sea cucumbers are considered stenohaline because they lack osmoregulatory organs and are vulnerable to salinity fluctuations. In this study, we performed multiple biochemical assays, de novo transcriptomics, and widely targeted metabolomics to comprehensively explore the osmoregulatory mechanisms and physiological responses of sea cucumber Holothuria moebii to hypo-osmotic stress, which is a representative specie that is frequently exposed to hypo-saline intertidal zones. Our results found that H. moebii contracted their ambulacral feet and oral tentacles, and the coelomic fluid ion concentrations were reduced to be consistent with the environment. The microvilli of intestines and respiratory trees underwent degeneration, and the cytoplasm exhibited swelling and vacuolation. Moreover, the Na+, K+, and Cl- concentrations and Na+/K+-ATPase activity were significantly reduced under hypo-osmotic stress. The decrease in protein kinase A activity and increase in 5'-AMP level indicated a significant inhibition of the cAMP signaling pathway to regulate ion concentrations. And small intracellular organic molecules (amino acids, nucleotides and their derivatives) also play crucial roles in osmoregulation through oxidative deamination of glutamate, nucleotide catabolism, and nucleic acid synthesis. Moreover, lysosomes and peroxisomes removed oxidative damage, whereas antioxidant metabolites, such as N-acetyl amino acids and glutathione, were increased to resist oxidative stress. With prolonged hypo-osmotic stress, glycerophospholipid metabolism was enhanced to maintain membrane stability. Furthermore, acyl-CoA-binding protein activity was significantly inhibited, and only a small amount of acylcarnitine was significantly accumulated, which indicated a disruption in energy metabolism. PPAR signaling pathway and choline content were up-regulated to promote fatty acid metabolism under hypo-osmotic stress. Overall, our results provide new insights into the osmoregulatory mechanisms and physiological responses of sea cucumbers to hypo-osmotic stress.
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Affiliation(s)
- Junyang Jiang
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Yanna Tang
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Zhaozhao Cao
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Cong Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Zonghe Yu
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China.
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Meera P, Uusi-Oukari M, Lipshutz GS, Wallner M. GABA A receptors as plausible molecular targets and mediators for taurine and homotaurine actions. Front Pharmacol 2023; 14:1271203. [PMID: 38155909 PMCID: PMC10752957 DOI: 10.3389/fphar.2023.1271203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/20/2023] [Indexed: 12/30/2023] Open
Abstract
Dementia and autoimmune diseases are prevalent conditions with limited treatment options. Taurine and homotaurine (HT) are naturally occurring sulfonate amino acids, with taurine being highly abundant in animal tissues, but declining with age in the blood. HT is a blood-brain barrier permeable drug under investigation for Alzheimer's disease. HT also has beneficial effects in a mouse model of multiple sclerosis likely through an anti-inflammatory mechanism mediated by GABAA receptor (GABAAR) agonism in immune cells. While both taurine and HT are structural GABA analogs and thought to be GABA mimetics at GABAARs, there is uncertainty concerning their potency as GABA mimetics on native GABAARs. We show that HT is a very potent GABA mimetic, as it evokes GABAAR-mediated currents with an EC50 of 0.4 μM (vs. 3.7 μM for GABA and 116 µM for taurine) in murine cerebellar granule cells in brain slices, with both taurine and HT having similar efficacy in activating native GABAARs. Furthermore, HT displaces the high affinity GABAAR ligand [3H]muscimol at similarly low concentrations (HT IC50 of 0.16 μM vs. 125 μM for taurine) in mouse brain homogenates. The potency of taurine and HT as GABAAR agonists aligns with endogenous concentrations of taurine in the blood and with HT concentrations achieved in the brain following oral administration of HT or the HT pro-drug ALZ-801. Consequently, we discuss that GABAARs subtypes, similar to the ones we studied here in neurons, are plausible targets for mediating the potential beneficial effects of taurine in health and life-span extension and the beneficial HT effects in dementia and autoimmune conditions.
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Affiliation(s)
- Pratap Meera
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Mikko Uusi-Oukari
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Gerald S. Lipshutz
- Department of Surgery, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, United States
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA, United States
- Semel Institute for Neuroscience, University of California, Los Angeles, Los Angeles, CA, United States
| | - Martin Wallner
- Department of Surgery, University of California, Los Angeles, Los Angeles, CA, United States
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Song W, Li X, Cao H, Wang T, Sun Y, Fan Q, Zahid D, Li M, Li W. Taurine promotes B-cell activation by interaction with the V H /V L framework regions of B-cell receptor. Immunology 2023; 169:141-156. [PMID: 36510675 DOI: 10.1111/imm.13617] [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: 12/18/2021] [Accepted: 11/17/2022] [Indexed: 12/14/2022] Open
Abstract
Taurine (Tau) is a special sulphur-containing amino acid and has been widely used as a dietary supplement. Although Tau exists in lymphocytes in large quantities, the physiological significance of Tau to modulate human immunity is unknown. In the present study, we first found that Tau regulates the B-cell receptor (BCR)-mediated signal transduction and induces the B cells activation. The IgG production of mice after ovalbumin immunization was also increased by Tau administration. Moreover, the isothermal titration calorimetry and surface plasmon resonance analysis have shown that Tau specifically bound to the IgG2a-BCR. The Tau could bind to IgG F(ab')2 regions via fluorescence spectroscopy analysis. In the molecular docking analysis, Tau bound to the framework regions (FRs) of variable region of the heavy chains (VH ) and in the light chains (VL ) of IgG2a-BCR. Our results suggested that Tau could improve the activation of B cells by interaction with the VH /VL FRs of BCR.
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Affiliation(s)
- Wanli Song
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou, Guangdong, China
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Xueying Li
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Hongyu Cao
- School of Life Science and Biotechnology, Liaoning Key Lab of Bio-Organic Chemistry, Dalian University, Dalian, Liaoning, China
| | - Tiantong Wang
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Yuhan Sun
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Qingjie Fan
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Danish Zahid
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Ming Li
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Wenzhe Li
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou, Guangdong, China
- College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
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Ding L, Yang Z, Liu G, Ran N, Yi M, Li H, Zhao H, Tang L, Cheng H, Zhao J, Zhang Y, Ji X, Liu S. Safety and efficacy of taurine as an add-on treatment for tics in youngsters. Eur J Neurol 2019; 27:490-497. [PMID: 31618495 DOI: 10.1111/ene.14107] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 10/14/2019] [Indexed: 01/19/2023]
Abstract
BACKGROUND AND PURPOSE The pathophysiological model of tics generally describes disruption of γ-aminobutyric acid transmission, and taurine is found to be an agonist of γ-aminobutyric acid receptors. The study aimed to evaluate the safety and efficacy of taurine as an add-on treatment for tics. METHODS Four hundred and four youngsters with tic disorders were randomly assigned to 12 weeks of either oral taurine or placebo. The Yale Global Tic Severity Scale was used to measure tic severity. The primary outcome measure was global severity scores reduced by more than 60% compared with baseline scores. RESULTS Three hundred and eighty-two patients were successfully treated. At week 4, no significant differences were found in the treatment effect and the total occurrence of adverse drug reactions between the taurine and placebo groups. At week 12, the proportion of significant improvement in tics was significantly higher in the taurine group than the placebo group (53.4% with taurine versus 34.5% without taurine; relative risk 1.546; P < 0.001), and no group differences were found in the total occurrence of adverse drug reactions. CONCLUSIONS Taurine is safe and effective for tics.
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Affiliation(s)
- L Ding
- Department of Epidemiology and Health Statistics, The Affiliated Hospital of Qingdao University, Qingdao, China.,Department of Medical Management, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Z Yang
- Department of Child Health Care, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - G Liu
- Department of Epidemiology and Health Statistics, The Affiliated Hospital of Qingdao University, Qingdao, China.,Department of Outpatient Administration, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - N Ran
- Department of Child Health Care, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - M Yi
- Department of Child Health Care, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - H Li
- Department of Neurosurgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - H Zhao
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - L Tang
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - H Cheng
- Department of Customer Service, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - J Zhao
- Department of Pharmacology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Y Zhang
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - X Ji
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - S Liu
- Department of Prenatal Diagnosis, The Affiliated Hospital of Qingdao University, Qingdao, China
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Pierce SR, Senneff TC, Germann AL, Akk G. Steady-state activation of the high-affinity isoform of the α4β2δ GABA A receptor. Sci Rep 2019; 9:15997. [PMID: 31690811 PMCID: PMC6831628 DOI: 10.1038/s41598-019-52573-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/18/2019] [Indexed: 12/18/2022] Open
Abstract
Activation of GABAA receptors consisting of α4, β2 (or β3), and δ subunits is a major contributor to tonic inhibition in several brain regions. The goal of this study was to analyze the function of the α4β2δ receptor in the presence of GABA and other endogenous and clinical activators and modulators under steady-state conditions. We show that the receptor has a high constitutive open probability (~0.1), but is only weakly activated by GABA that has a maximal peak open probability (POpen,peak) of 0.4, taurine (maximal POpen,peak = 0.4), or the endogenous steroid allopregnanolone (maximal POpen,peak = 0.2). The intravenous anesthetic propofol is a full agonist (maximal POpen,peak = 0.99). Analysis of currents using a cyclic three-state Resting-Active-Desensitized model indicates that the maximal steady-state open probability of the α4β2δ receptor is ~0.45. Steady-state open probability in the presence of combinations of GABA, taurine, propofol, allopregnanolone and/or the inhibitory steroid pregnenolone sulfate closely matched predicted open probability calculated assuming energetic additivity. The results suggest that the receptor is active in the presence of physiological concentrations of GABA and taurine, but, surprisingly, that receptor activity is only weakly potentiated by propofol.
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Affiliation(s)
- Spencer R Pierce
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Thomas C Senneff
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Allison L Germann
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gustav Akk
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, 63110, USA. .,The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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