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Mogilnicka I, Jaworska K, Koper M, Maksymiuk K, Szudzik M, Radkiewicz M, Chabowski D, Ufnal M. Hypertensive rats show increased renal excretion and decreased tissue concentrations of glycine betaine, a protective osmolyte with diuretic properties. PLoS One 2024; 19:e0294926. [PMID: 38166023 PMCID: PMC10760924 DOI: 10.1371/journal.pone.0294926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 11/10/2023] [Indexed: 01/04/2024] Open
Abstract
Hypertension leads to water-electrolyte disturbances and end-organ damage. Betaine is an osmolyte protecting cells against electrolyte imbalance and osmotic stress, particularly in the kidneys. This study aimed to evaluate tissue levels and hemodynamic and renal effects of betaine in normotensive and hypertensive rats. Betaine levels were assessed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) in normotensive rats (Wistar-Kyoto, WKYs) and Spontaneously Hypertensive rats (SHRs), a model of genetic hypertension. Acute effects of IV betaine on blood pressure, heart rate, and minute diuresis were evaluated. Gene and protein expression of chosen kidney betaine transporters (SLC6a12 and SLC6a20) were assessed using real-time PCR and Western blot. Compared to normotensive rats, SHRs showed significantly lower concentration of betaine in blood serum, the lungs, liver, and renal medulla. These changes were associated with higher urinary excretion of betaine in SHRs (0.20 ± 0.04 vs. 0.09 ± 0.02 mg/ 24h/ 100g b.w., p = 0.036). In acute experiments, betaine increased diuresis without significantly affecting arterial blood pressure. The diuretic response was greater in SHRs than in WKYs. There were no significant differences in renal expression of betaine transporters between WKYs and SHRs. Increased renal excretion of betaine contributes to decreased concentration of the protective osmolyte in tissues of hypertensive rats. These findings pave the way for studies evaluating a causal relation between depleted betaine and hypertensive organ damage, including kidney injury.
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Affiliation(s)
- Izabella Mogilnicka
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Kinga Jaworska
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Mateusz Koper
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Klaudia Maksymiuk
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Mateusz Szudzik
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Mariusz Radkiewicz
- Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Dawid Chabowski
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Marcin Ufnal
- Department of Experimental Physiology and Pathophysiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
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Lum GR, Ha SM, Olson CA, Blencowe M, Paramo J, Reyes B, Matsumoto JH, Yang X, Hsiao EY. Ketogenic diet therapy for pediatric epilepsy is associated with alterations in the human gut microbiome that confer seizure resistance in mice. Cell Rep 2023; 42:113521. [PMID: 38070135 PMCID: PMC10769314 DOI: 10.1016/j.celrep.2023.113521] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 07/13/2023] [Accepted: 11/14/2023] [Indexed: 12/30/2023] Open
Abstract
The gut microbiome modulates seizure susceptibility and the anti-seizure effects of the ketogenic diet (KD) in animal models, but whether these relationships translate to KD therapies for human epilepsy is unclear. We find that the clinical KD alters gut microbial function in children with refractory epilepsy. Colonizing mice with KD-associated microbes promotes seizure resistance relative to matched pre-treatment controls. Select metagenomic and metabolomic features, including those related to anaplerosis, fatty acid β-oxidation, and amino acid metabolism, are seen with human KD therapy and preserved upon microbiome transfer to mice. Mice colonized with KD-associated gut microbes exhibit altered hippocampal transcriptomes, including pathways related to ATP synthesis, glutathione metabolism, and oxidative phosphorylation, and are linked to susceptibility genes identified in human epilepsy. Our findings reveal key microbial functions that are altered by KD therapies for pediatric epilepsy and linked to microbiome-induced alterations in brain gene expression and seizure protection in mice.
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Affiliation(s)
- Gregory R Lum
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Sung Min Ha
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christine A Olson
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Montgomery Blencowe
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jorge Paramo
- UCLA Goodman-Luskin Microbiome Center, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Beck Reyes
- Department of Pediatrics, Division of Pediatric Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Joyce H Matsumoto
- Department of Pediatrics, Division of Pediatric Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xia Yang
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elaine Y Hsiao
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA; UCLA Goodman-Luskin Microbiome Center, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, Los Angeles, CA 90095, USA.
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Zaręba P, Łątka K, Mazur G, Gryzło B, Pasieka A, Godyń J, Panek D, Skrzypczak-Wiercioch A, Höfner GC, Latacz G, Maj M, Espargaró A, Sabaté R, Jóźwiak K, Wanner KT, Sałat K, Malawska B, Kulig K, Bajda M. Discovery of novel multifunctional ligands targeting GABA transporters, butyrylcholinesterase, β-secretase, and amyloid β aggregation as potential treatment of Alzheimer's disease. Eur J Med Chem 2023; 261:115832. [PMID: 37837674 DOI: 10.1016/j.ejmech.2023.115832] [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: 07/28/2023] [Revised: 09/12/2023] [Accepted: 09/23/2023] [Indexed: 10/16/2023]
Abstract
Alzheimer's disease (AD) is a global health problem in the medical sector that will increase over time. The limited treatment of AD leads to the search for a new clinical candidate. Considering the multifactorial nature of AD, a strategy targeting number of regulatory proteins involved in the development of the disease is an effective approach. Here, we present a discovery of new multi-target-directed ligands (MTDLs), purposely designed as GABA transporter (GAT) inhibitors, that successfully provide the inhibitory activity against butyrylcholinesterase (BuChE), β-secretase (BACE1), amyloid β aggregation and calcium channel blockade activity. The selected GAT inhibitors, 19c and 22a - N-benzylamide derivatives of 4-aminobutyric acid, displayed the most prominent multifunctional profile. Compound 19c (mGAT1 IC50 = 10 μM, mGAT4 IC50 = 12 μM and BuChE IC50 = 559 nM) possessed the highest hBACE1 and Aβ40 aggregation inhibitory activity (IC50 = 1.57 μM and 99 % at 10 μM, respectively). Additionally, it showed a decrease in both the elongation and nucleation constants of the amyloid aggregation process. In contrast compound 22a represented the highest activity and a mixed-type of eqBuChE inhibition (IC50 = 173 nM) with hBACE1 (IC50 = 9.42 μM), Aβ aggregation (79 % at 10 μM) and mGATs (mGAT1 IC50 = 30 μM, mGAT4 IC50 = 25 μM) inhibitory activity. Performed molecular docking studies described the mode of interactions with GATs and enzymatic targets. In ADMET in vitro studies both compounds showed acceptable metabolic stability and low neurotoxicity. Successfully, compounds 19c and 22a at the dose of 30 mg/kg possessed statistically significant antiamnesic properties in a mouse model of amnesia caused by scopolamine and assessed in the novel object recognition (NOR) task or the passive avoidance (PA) task.
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Affiliation(s)
- Paula Zaręba
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Kamil Łątka
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Gabriela Mazur
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Beata Gryzło
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Anna Pasieka
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Justyna Godyń
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Dawid Panek
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Anna Skrzypczak-Wiercioch
- Department of Animal Anatomy and Preclinical Sciences, University Centre of Veterinary Medicine JU-UA, University of Agriculture in Kraków, Mickiewicz 24/28 St., 30-059, Kraków, Poland
| | - Georg C Höfner
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München Butenandtstr., 5-13, 81377, Munich, Germany
| | - Gniewomir Latacz
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Maciej Maj
- Department of Biopharmacy, Medical University of Lublin, W. Chodzki 4a St., 20-093, Lublin, Poland
| | - Alba Espargaró
- Department of Pharmacy and Pharmaceutical Technology and Physical-Chemistry, School of Pharmacy and Food Sciences, University of Barcelona, Av Joan XXIII 27-31, 08028, Barcelona, Spain; Institute of Nanoscience and Nanotechnology (IN2UB), Av Joan XXIII, S/N, 08028, Barcelona, Spain
| | - Raimon Sabaté
- Department of Pharmacy and Pharmaceutical Technology and Physical-Chemistry, School of Pharmacy and Food Sciences, University of Barcelona, Av Joan XXIII 27-31, 08028, Barcelona, Spain; Institute of Nanoscience and Nanotechnology (IN2UB), Av Joan XXIII, S/N, 08028, Barcelona, Spain
| | - Krzysztof Jóźwiak
- Department of Biopharmacy, Medical University of Lublin, W. Chodzki 4a St., 20-093, Lublin, Poland
| | - Klaus T Wanner
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München Butenandtstr., 5-13, 81377, Munich, Germany
| | - Kinga Sałat
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Barbara Malawska
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Katarzyna Kulig
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland
| | - Marek Bajda
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9 St., 30-688, Kraków, Poland.
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Sziraki A, Zhong Y, Neltner AM, Niedowicz D, Rogers CB, Wilcock DM, Nehra G, Neltner JH, Smith RR, Hartz AM, Cao J, Nelson PT. A high-throughput single-cell RNA expression profiling method identifies human pericyte markers. Neuropathol Appl Neurobiol 2023; 49:e12942. [PMID: 37812061 PMCID: PMC10842535 DOI: 10.1111/nan.12942] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 09/19/2023] [Accepted: 10/02/2023] [Indexed: 10/10/2023]
Abstract
AIMS We sought to identify and optimise a universally available histological marker for pericytes in the human brain. Such a marker could be a useful tool for researchers. Further, identifying a gene expressed relatively specifically in human pericytes could provide new insights into the biological functions of this fascinating cell type. METHODS We analysed single-cell RNA expression profiles derived from different human and mouse brain regions using a high-throughput and low-cost single-cell transcriptome sequencing method called EasySci. Through this analysis, we were able to identify specific gene markers for pericytes, some of which had not been previously characterised. We then used commercially (and therefore universally) available antibodies to immunolabel the pericyte-specific gene products in formalin-fixed paraffin-embedded (FFPE) human brains and also performed immunoblots to determine whether appropriately sized proteins were recognised. RESULTS In the EasySci data sets, highly pericyte-enriched expression was notable for SLC6A12 and SLC19A1. Antibodies against these proteins recognised bands of approximately the correct size in immunoblots of human brain extracts. Following optimisation of the immunohistochemical technique, staining for both antibodies was strongly positive in small blood vessels and was far more effective than a PDGFRB antibody at staining pericyte-like cells in FFPE human brain sections. In an exploratory sample of other human organs (kidney, lung, liver, muscle), immunohistochemistry did not show the same pericyte-like pattern of staining. CONCLUSIONS The SLC6A12 antibody was well suited for labelling pericytes in human FFPE brain sections, based on the combined results of single-cell RNA-seq analyses, immunoblots and immunohistochemical studies.
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Affiliation(s)
- Andras Sziraki
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA
- The David Rockefeller Graduate Program in Bioscience, The Rockefeller University, New York, NY, USA
| | - Yu Zhong
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Allison M. Neltner
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Dana Niedowicz
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Colin B. Rogers
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Donna M. Wilcock
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky, USA
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Geetika Nehra
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Janna H. Neltner
- Department of Pathology and Laboratory Science, University of Kentucky, Lexington, Kentucky, USA
| | - Rebecca R. Smith
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Anika M. Hartz
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Junyue Cao
- Laboratory of Single Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY, USA
| | - Peter T. Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
- Department of Pathology and Laboratory Science, University of Kentucky, Lexington, Kentucky, USA
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Wang K, Zhao B, Ao Y, Zhu J, Zhao C, Wang W, Zou Y, Huang D, Zhong Y, Chen W, Qian H. Super-small zwitterionic micelles enable the improvement of blood-brain barrier crossing for efficient orthotopic glioblastoma combinational therapy. J Control Release 2023; 364:261-271. [PMID: 37839641 DOI: 10.1016/j.jconrel.2023.10.019] [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: 06/17/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 10/17/2023]
Abstract
Glioblastoma multiforme (GBM) remains incurable in clinical, nanotechnology-based drug delivery strategies show promising perspective in alleviating GBM, while limited blood-brain-barrier (BBB) permeation, short blood half-live accompanied by the poor tumor accumulation and penetration, significantly restrict the therapeutic outcomes. Herein, a versatile super-small zwitterionic nano-system (MCB(S)) based on carboxybetaine (CB) zwitterion functionalized hyperbranched polycarbonate (HPCB) is developed to overcome the brain delivery challenges. After grafting with amino-functionalized IR780 (free IR780), the ultimate paclitaxel (PTX)-encapsulated micelles (MCB(S)-IR@PTX) are precisely activated by near-infrared (NIR) for accelerated drug release and effective combinational GBM therapy. Importantly, MCB(S)-IR@PTX with the crosslinked structure and CB zwitterion prolongs blood-circulation, and CB-zwitterion further facilitates BBB-traversing through betaine/γ-aminobutyric acid (GABA) transporter-1 (BGT-1) pathway. Combined with the benefit of super small-size, MCB(S)-IR@PTX highly accumulates at tumor sites and penetrates deeply, thus efficiently inhibiting tumor growth and strikingly improving survival time in U87MG orthotopic GBM-bearing mouse model. The ingenious nanoplatform furnishes a versatile strategy for delivering therapeutics into the brain and realizing efficient brain cancer therapy.
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Affiliation(s)
- Ke Wang
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Bingbing Zhao
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Yuli Ao
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Jinyu Zhu
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Changshun Zhao
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Wei Wang
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Yan Zou
- Henan-Macquarie Uni Joint Centre for Biomedical Innovation, Academy for Advanced Interdisciplinary Studies, Henan Key Laboratory of Brain Targeted Bio-nanomedicine, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
| | - Dechun Huang
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China.
| | - Yinan Zhong
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China
| | - Wei Chen
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China.
| | - Hongliang Qian
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China.
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Bhatt M, Di Iacovo A, Romanazzi T, Roseti C, Bossi E. Betaine-The dark knight of the brain. Basic Clin Pharmacol Toxicol 2023; 133:485-495. [PMID: 36735640 DOI: 10.1111/bcpt.13839] [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: 11/15/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023]
Abstract
The role of betaine in the liver and kidney has been well documented, even from the cellular and molecular point of view. Despite literature reporting positive effects of betaine supplementation in Alzheimer's, Parkinson's and schizophrenia, the role and function of betaine in the brain are little studied and reviewed. Beneficial effects of betaine in neurodegeneration, excitatory and inhibitory imbalance and against oxidative stress in the central nervous system (CNS) have been collected and analysed to understand the main role of betaine in the brain. There are many 'dark' aspects needed to complete the picture. The understanding of how this osmolyte is transported across neuron and glial cells is also controversial, as the expression levels and functioning of the known protein capable to transport betaine expressed in the brain, betaine-GABA transporter 1 (BGT-1), is itself not well clarified. The reported actions of betaine beyond BGT-1 related to neuronal degeneration and memory impairment are the focus of this work. With this review, we underline the scarcity of detailed molecular and cellular information about betaine action. Consequently, the requirement of detailed focus on and study of the interaction of this molecule with CNS components to sustain the therapeutic use of betaine.
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Affiliation(s)
- Manan Bhatt
- Department of Biotechnology and Life Sciences, Laboratory of Cellular and Molecular Physiology, University of Insubria, Varese, Italy
- School of Experimental and Translational Medicine, University of Insubria, Varese, Italy
| | - Angela Di Iacovo
- Department of Biotechnology and Life Sciences, Laboratory of Cellular and Molecular Physiology, University of Insubria, Varese, Italy
- School of Experimental and Translational Medicine, University of Insubria, Varese, Italy
| | - Tiziana Romanazzi
- Department of Biotechnology and Life Sciences, Laboratory of Cellular and Molecular Physiology, University of Insubria, Varese, Italy
- School of Experimental and Translational Medicine, University of Insubria, Varese, Italy
| | - Cristina Roseti
- Department of Biotechnology and Life Sciences, Laboratory of Cellular and Molecular Physiology, University of Insubria, Varese, Italy
- Centre for Neuroscience, University of Insubria, Varese, Italy
| | - Elena Bossi
- Department of Biotechnology and Life Sciences, Laboratory of Cellular and Molecular Physiology, University of Insubria, Varese, Italy
- Centre for Neuroscience, University of Insubria, Varese, Italy
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7
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Astrocytes regulate inhibitory neurotransmission through GABA uptake, metabolism, and recycling. Essays Biochem 2023; 67:77-91. [PMID: 36806927 DOI: 10.1042/ebc20220208] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 02/23/2023]
Abstract
Synaptic regulation of the primary inhibitory neurotransmitter γ-aminobutyric acid (GABA) is essential for brain function. Cerebral GABA homeostasis is tightly regulated through multiple mechanisms and is directly coupled to the metabolic collaboration between neurons and astrocytes. In this essay, we outline and discuss the fundamental roles of astrocytes in regulating synaptic GABA signaling. A major fraction of synaptic GABA is removed from the synapse by astrocytic uptake. Astrocytes utilize GABA as a metabolic substrate to support glutamine synthesis. The astrocyte-derived glutamine is subsequently transferred to neurons where it serves as the primary precursor of neuronal GABA synthesis. The flow of GABA and glutamine between neurons and astrocytes is collectively termed the GABA-glutamine cycle and is essential to sustain GABA synthesis and inhibitory signaling. In certain brain areas, astrocytes are even capable of synthesizing and releasing GABA to modulate inhibitory transmission. The majority of oxidative GABA metabolism in the brain takes place in astrocytes, which also leads to synthesis of the GABA-related metabolite γ-hydroxybutyric acid (GHB). The physiological roles of endogenous GHB remain unclear, but may be related to regulation of tonic inhibition and synaptic plasticity. Disrupted inhibitory signaling and dysfunctional astrocyte GABA handling are implicated in several diseases including epilepsy and Alzheimer's disease. Synaptic GABA homeostasis is under astrocytic control and astrocyte GABA uptake, metabolism, and recycling may therefore serve as relevant targets to ameliorate pathological inhibitory signaling.
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Pukale DD, Lazarenko D, Aryal SR, Khabaz F, Shriver LP, Leipzig ND. Osmotic Contribution of Synthesized Betaine by Choline Dehydrogenase Using In Vivo and In Vitro Models of Post-traumatic Syringomyelia. Cell Mol Bioeng 2023; 16:41-54. [PMID: 36660584 PMCID: PMC9842837 DOI: 10.1007/s12195-022-00749-5] [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: 02/09/2022] [Accepted: 10/27/2022] [Indexed: 11/28/2022] Open
Abstract
Introduction Syringomyelia (SM) is a debilitating spinal cord disorder in which a cyst, or syrinx, forms in the spinal cord parenchyma due to congenital and acquired causes. Over time syrinxes expand and elongate, which leads to compressing the neural tissues and a mild to severe range of symptoms. In prior omics studies, significant upregulation of betaine and its synthesis enzyme choline dehydrogenase (CHDH) were reported during syrinx formation/expansion in SM injured spinal cords, but the role of betaine regulation in SM etiology remains unclear. Considering betaine's known osmoprotectant role in biological systems, along with antioxidant and methyl donor activities, this study aimed to better understand osmotic contributions of synthesized betaine by CHDH in response to SM injuries in the spinal cord. Methods A post-traumatic SM (PTSM) rat model and in vitro cellular models using rat astrocytes and HepG2 liver cells were utilized to investigate the role of betaine synthesis by CHDH. Additionally, the osmotic contributions of betaine were evaluated using a combination of experimental as well as simulation approaches. Results In the PTSM injured spinal cord CHDH expression was observed in cells surrounding syrinxes. We next found that rat astrocytes and HepG2 cells were capable of synthesizing betaine via CHDH under osmotic stress in vitro to maintain osmoregulation. Finally, our experimental and simulation approaches showed that betaine was capable of directly increasing meaningful osmotic pressure. Conclusions The findings from this study demonstrate new evidence that CHDH activity in the spinal cord provides locally synthesized betaine for osmoregulation in SM pathophysiology. Supplementary Information The online version of this article contains supplementary material available 10.1007/s12195-022-00749-5.
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Affiliation(s)
- Dipak D. Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, OH 44325 USA
| | - Daria Lazarenko
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH 44325 USA
| | - Siddhartha R. Aryal
- Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA
| | - Fardin Khabaz
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, OH 44325 USA
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH 44325 USA
| | - Leah P. Shriver
- Department of Chemistry, Washington University, Saint Louis, MO 63130 USA
- Department of Medicine, Washington University, Saint Louis, MO 63130 USA
- Center for Metabolomics and Isotope Tracing, Washington University, Saint Louis, MO 63130 USA
| | - Nic D. Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, OH 44325 USA
- Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA
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9
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Li Q, Wen C, Yang J, Zhou X, Zhu Y, Zheng J, Cheng G, Bai J, Xu T, Ji J, Jiang S, Zhang L, Zhang P. Zwitterionic Biomaterials. Chem Rev 2022; 122:17073-17154. [PMID: 36201481 DOI: 10.1021/acs.chemrev.2c00344] [Citation(s) in RCA: 98] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The term "zwitterionic polymers" refers to polymers that bear a pair of oppositely charged groups in their repeating units. When these oppositely charged groups are equally distributed at the molecular level, the molecules exhibit an overall neutral charge with a strong hydration effect via ionic solvation. The strong hydration effect constitutes the foundation of a series of exceptional properties of zwitterionic materials, including resistance to protein adsorption, lubrication at interfaces, promotion of protein stabilities, antifreezing in solutions, etc. As a result, zwitterionic materials have drawn great attention in biomedical and engineering applications in recent years. In this review, we give a comprehensive and panoramic overview of zwitterionic materials, covering the fundamentals of hydration and nonfouling behaviors, different types of zwitterionic surfaces and polymers, and their biomedical applications.
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Affiliation(s)
- Qingsi Li
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Chiyu Wen
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Jing Yang
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Xianchi Zhou
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yingnan Zhu
- Institute of Drug Discovery and Development, School of Pharmaceutical Sciences, Center for Drug Safety Evaluation and Research, Zhengzhou University, Zhengzhou 450001, China
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Gang Cheng
- Department of Chemical Engineering, The University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Jie Bai
- College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051, China
| | - Tong Xu
- College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051, China
| | - Jian Ji
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Shaoyi Jiang
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Lei Zhang
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Peng Zhang
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
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10
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Ilyas A, Wijayasinghe YS, Khan I, El Samaloty NM, Adnan M, Dar TA, Poddar NK, Singh LR, Sharma H, Khan S. Implications of trimethylamine N-oxide (TMAO) and Betaine in Human Health: Beyond Being Osmoprotective Compounds. Front Mol Biosci 2022; 9:964624. [PMID: 36310589 PMCID: PMC9601739 DOI: 10.3389/fmolb.2022.964624] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Osmolytes are naturally occurring small molecular weight organic molecules, which are accumulated in large amounts in all life forms to maintain the stability of cellular proteins and hence preserve their functions during adverse environmental conditions. Trimethylamine N-oxide (TMAO) and N,N,N-trimethylglycine (betaine) are methylamine osmolytes that have been extensively studied for their diverse roles in humans and have demonstrated opposing relations with human health. These osmolytes are obtained from food and synthesized endogenously using dietary constituents like choline and carnitine. Especially, gut microbiota plays a vital role in TMAO synthesis and contributes significantly to plasma TMAO levels. The elevated plasma TMAO has been reported to be correlated with the pathogenesis of numerous human diseases, including cardiovascular disease, heart failure, kidney diseases, metabolic syndrome, etc.; Hence, TMAO has been recognized as a novel biomarker for the detection/prediction of several human diseases. In contrast, betaine acts as a methyl donor in one-carbon metabolism, maintains cellular S-adenosylmethionine levels, and protects the cells from the harmful effects of increased plasma homocysteine. Betaine also demonstrates antioxidant and anti-inflammatory activities and has a promising therapeutic value in several human diseases, including homocystinuria and fatty liver disease. The present review examines the multifarious functions of TMAO and betaine with possible molecular mechanisms towards a better understanding of their emerging and diverging functions with probable implications in the prevention, diagnosis, and treatment of human diseases.
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Affiliation(s)
- Ashal Ilyas
- Department of Biotechnology, Invertis University, Bareilly, Uttar Pradesh, India
| | - Yasanandana Supunsiri Wijayasinghe
- Department of Biochemistry and Clinical Chemistry, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka,*Correspondence: Yasanandana Supunsiri Wijayasinghe, , Nitesh Kumar Poddar, , , Shahanavaj Khan,
| | - Ilyas Khan
- Department of Mathematics, College of Science Al-Zulfi, Majmaah University, Al-Majmaah, Saudi Arabia
| | - Nourhan M. El Samaloty
- Department of Pharmacology, Toxicology and Biochemistry, Faculty of Pharmacy, Future University in Egypt, Cairo, Egypt
| | - Mohd Adnan
- Department of Biology, College of Science, University of Hail, Hail, Saudi Arabia
| | - Tanveer Ali Dar
- Department of Clinical Biochemistry, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | - Nitesh Kumar Poddar
- Department of Biosciences, Manipal University Jaipur, Jaipur, Rajasthan, India,*Correspondence: Yasanandana Supunsiri Wijayasinghe, , Nitesh Kumar Poddar, , , Shahanavaj Khan,
| | - Laishram R. Singh
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | - Hemlata Sharma
- Department of Biosciences, Manipal University Jaipur, Jaipur, Rajasthan, India
| | - Shahanavaj Khan
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia,Department of Medical Lab Technology, Indian Institute of Health and Technology (IIHT), Saharanpur, Uttar Pradesh, India,*Correspondence: Yasanandana Supunsiri Wijayasinghe, , Nitesh Kumar Poddar, , , Shahanavaj Khan,
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11
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Wang R, Yang S, Xiao P, Sun Y, Li J, Jiang X, Wu W. Fluorination and Betaine Modification Augment the Blood-Brain Barrier-Crossing Ability of Cylindrical Polymer Brushes. Angew Chem Int Ed Engl 2022; 61:e202201390. [PMID: 35143085 DOI: 10.1002/anie.202201390] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Indexed: 12/25/2022]
Abstract
Blood-brain barrier (BBB)-crossing ability of drugs is of paramount importance for the treatments of central nervous system diseases. However, the known methods for drug transport across the BBB are generally complicated and inefficient, and exhibit serious side effects in some cases. Herein, we report an exciting finding that fluorination and betaine modification can significantly augment the BBB-crossing ability of cylindrical polymer brushes (CPBs), which was demonstrated by the comparison with the CPBs modified with alkyl and poly(ethylene glycol) chains, respectively. We surmise that fluorination enhances the BBB penetration of the CPBs by increasing the hydrophobicity and reducing the surface energy, and betaine medication achieves this function via a betaine transporter BGT1 expressed on brain capillaries. By means of an in vitro BBB model, we demonstrated that the CPBs penetrated the BBB through transendothelial transport. This work provides a novel strategy for enhancing the BBB-crossing ability of nanomaterials.
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Affiliation(s)
- Ruonan Wang
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Shuo Yang
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Panpan Xiao
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Ying Sun
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Jia Li
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Xiqun Jiang
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Wei Wu
- Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
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12
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Li A, Gu Y, Zhang X, Yu H, Liu D, Pang Q. Betaine Regulates the Production of Reactive Oxygen Species Through Wnt10b Signaling in the Liver of Zebrafish. Front Physiol 2022; 13:877178. [PMID: 35574489 PMCID: PMC9096094 DOI: 10.3389/fphys.2022.877178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/17/2022] [Indexed: 11/26/2022] Open
Abstract
When fish are under oxidative stress, levels of reactive oxygen species (ROS) are chronically elevated, which play a crucial role in fish innate immunity. In the present study, the mechanism by which betaine regulates ROS production via Wnt10b/β-catenin signaling was investigated in zebrafish liver. Our results showed that betaine enrichment of diet at 0.1, 0.2 and 0.4 g/kg induced Wnt10b and β-catenin gene expression, but suppressed GSK-3β expression in zebrafish liver. In addition, the content of superoxide anion (O2·−), hydrogen peroxide (H2O2) and hydroxyl radical (·OH) was decreased by all of the experimental betaine treatments. However, betaine enrichment of diet at 0.1, 0.2 and 0.4 g/kg enhanced gene expression and activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and catalase (CAT) in zebrafish liver. In addition, Wnt10b RNA was further interfered in zebrafish, and the results of Wnt10b RNAi indicated that Wnt10b plays a key role in regulating ROS production and antioxidant enzyme activity. In conclusion, betaine can inhibit ROS production in zebrafish liver through the Wnt10b/β-catenin signaling pathway.
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Affiliation(s)
- Ao Li
- Anti-Aging & Regenerative Medicine Research Institution, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Yaqi Gu
- Anti-Aging & Regenerative Medicine Research Institution, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Xiuzhen Zhang
- Anti-Aging & Regenerative Medicine Research Institution, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Hairui Yu
- College of Biological and Agricultural Engineering, Weifang Bioengineering Technology Research Center, Weifang University, Weifang, China
| | - Dongwu Liu
- Anti-Aging & Regenerative Medicine Research Institution, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
- *Correspondence: Dongwu Liu, ; Qiuxiang Pang,
| | - Qiuxiang Pang
- Anti-Aging & Regenerative Medicine Research Institution, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
- *Correspondence: Dongwu Liu, ; Qiuxiang Pang,
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13
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Fischer FP, Kasture AS, Hummel T, Sucic S. Molecular and Clinical Repercussions of GABA Transporter 1 Variants Gone Amiss: Links to Epilepsy and Developmental Spectrum Disorders. Front Mol Biosci 2022; 9:834498. [PMID: 35295842 PMCID: PMC7612498 DOI: 10.3389/fmolb.2022.834498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/01/2022] [Indexed: 12/15/2022] Open
Abstract
The human γ-aminobutyric acid (GABA) transporter 1 (hGAT-1) is the first member of the solute carrier 6 (SLC6) protein superfamily. GAT-1 (SLC6A1) is one of the main GABA transporters in the central nervous system. Its principal physiological role is retrieving GABA from the synapse into neurons and astrocytes, thus swiftly terminating neurotransmission. GABA is a key inhibitory neurotransmitter and shifts in GABAergic signaling can lead to pathological conditions, from anxiety and epileptic seizures to schizophrenia. Point mutations in the SLC6A1 gene frequently give rise to epilepsy, intellectual disability or autism spectrum disorders in the afflicted individuals. The mechanistic routes underlying these are still fairly unclear. Some loss-of-function variants impair the folding and intracellular trafficking of the protein (thus retaining the transporter in the endoplasmic reticulum compartment), whereas others, despite managing to reach their bona fide site of action at the cell surface, nonetheless abolish GABA transport activity (plausibly owing to structural/conformational defects). Whatever the molecular culprit(s), the physiological aftermath transpires into the absence of functional transporters, which in turn perturbs GABAergic actions. Dozens of mutations in the kin SLC6 family members are known to exhort protein misfolding. Such events typically elicit severe ailments in people, e.g., infantile parkinsonism-dystonia or X-linked intellectual disability, in the case of dopamine and creatine transporters, respectively. Flaws in protein folding can be rectified by small molecules known as pharmacological and/or chemical chaperones. The search for such apt remedies calls for a systematic investigation and categorization of the numerous disease-linked variants, by biochemical and pharmacological means in vitro (in cell lines and primary neuronal cultures) and in vivo (in animal models). We here give special emphasis to the utilization of the fruit fly Drosophila melanogaster as a versatile model in GAT-1-related studies. Jointly, these approaches can portray indispensable insights into the molecular factors underlying epilepsy, and ultimately pave the way for contriving efficacious therapeutic options for patients harboring pathogenic mutations in hGAT-1.
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Affiliation(s)
- Florian P. Fischer
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
- Department of Epileptology and Neurology, University of Aachen, Aachen, Germany
| | - Ameya S. Kasture
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Thomas Hummel
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
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14
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Wang R, Yang S, Xiao P, Sun Y, Li J, Jiang X, Wu W. Fluorination and Betaine Modification Augment the Blood‐Brain Barrier‐Crossing Ability of Cylindrical Polymer Brushes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ruonan Wang
- Nanjing University Department of Polymer Science & Engineering CHINA
| | - Shuo Yang
- Nanjing University Department of Polymer Science & Engineering CHINA
| | - Panpan Xiao
- Nanjing University Department of Polymer Science & Engineering CHINA
| | - Ying Sun
- Nanjing University Department of Polymer Science & Engineering CHINA
| | - Jia Li
- Nanjing University Department of Polymer Science & Engineering CHINA
| | - Xiqun Jiang
- Nanjing University Department of Polymer Science & Engineering CHINA
| | - Wei Wu
- Nanjing University Department of Polymer Science & Engineering 163 Xianlin Road, Qixia District, Nanjing, Jiangsu Province, 210023 CHINA
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15
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Bukina ES, Kondratyev NV, Kozin SV, Golimbet VE, Artyuhov AS, Dashinimaev EB. SLC6A1 and Neuropsychiatric Diseases: The Role of Mutations and Prospects for Treatment with Genome Editing Systems. NEUROCHEM J+ 2021. [DOI: 10.1134/s1819712421040048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Pukale DD, Farrag M, Gudneppanavar R, Baumann HJ, Konopka M, Shriver LP, Leipzig ND. Osmoregulatory Role of Betaine and Betaine/γ-Aminobutyric Acid Transporter 1 in Post-Traumatic Syringomyelia. ACS Chem Neurosci 2021; 12:3567-3578. [PMID: 34550670 DOI: 10.1021/acschemneuro.1c00056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Syringomyelia (SM) is primarily characterized by the formation of a fluid-filled cyst that forms in the parenchyma of the spinal cord following injury or other pathology. Recent omics studies in animal models have identified dysregulation of solute carriers, channels, transporters, and small molecules associated with osmolyte regulation during syrinx formation/expansion in the spinal cord. However, their connections to syringomyelia etiology are poorly understood. In this study, the biological functions of the potent osmolyte betaine and its associated solute carrier betaine/γ-aminobutyric acid (GABA) transporter 1 (BGT1) were studied in SM. First, a rat post-traumatic SM model was used to demonstrate that the BGT1 was primarily expressed in astrocytes in the vicinity of syrinxes. In an in vitro system, we found that astrocytes uptake betaine through BGT1 to regulate cell size under hypertonic conditions. Treatment with BGT1 inhibitors, especially NNC 05-2090, demonstrated midhigh micromolar range potency in vitro that reversed the osmoprotective effects of betaine. Finally, the specificity of these BGT1 inhibitors in the CNS was demonstrated in vivo, suggesting feasibility for targeting betaine transport in SM. In summary, these data provide an enhanced understanding of the role of betaine and its associated solute carrier BGT1 in cell osmoregulation and implicates the active role of betaine and BGT1 in syringomyelia progression.
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Affiliation(s)
- Dipak D. Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Mahmoud Farrag
- Integrated Biosciences Program, University of Akron, Akron, Ohio 44325, United States
| | | | - Hannah J. Baumann
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Michael Konopka
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Leah P. Shriver
- Integrated Biosciences Program, University of Akron, Akron, Ohio 44325, United States
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Nic D. Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, Ohio 44325, United States
- Integrated Biosciences Program, University of Akron, Akron, Ohio 44325, United States
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17
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Kickinger S, Lie MEK, Suemasa A, Al-Khawaja A, Fujiwara K, Watanabe M, Wilhelmsen KS, Falk-Petersen CB, Frølund B, Shuto S, Ecker GF, Wellendorph P. Molecular Determinants and Pharmacological Analysis for a Class of Competitive Non-transported Bicyclic Inhibitors of the Betaine/GABA Transporter BGT1. Front Chem 2021; 9:736457. [PMID: 34595152 PMCID: PMC8476755 DOI: 10.3389/fchem.2021.736457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
The betaine/GABA transporter 1 (BGT1) is a member of the GABA transporter (GAT) family with still elusive function, largely due to a lack of potent and selective tool compounds. Based on modeling, we here present the design, synthesis and pharmacological evaluation of five novel conformationally restricted cyclic GABA analogs related to the previously reported highly potent and selective BGT1 inhibitor (1S,2S,5R)-5-aminobicyclo[3.1.0]hexane-2-carboxylic acid (bicyclo-GABA). Using [3H]GABA radioligand uptake assays at the four human GATs recombinantly expressed in mammalian cell lines, we identified bicyclo-GABA and its N-methylated analog (2) as the most potent and selective BGT1 inhibitors. Additional pharmacological characterization in a fluorescence-based membrane potential assay showed that bicyclo-GABA and 2 are competitive inhibitors, not substrates, at BGT1, which was validated by a Schild analysis for bicyclo-GABA (pKB value of 6.4). To further elaborate on the selectivity profile both compounds were tested at recombinant α1β2γ2 GABAA receptors. Whereas bicyclo-GABA showed low micromolar agonistic activity, the N-methylated 2 was completely devoid of activity at GABAA receptors. To further reveal the binding mode of bicyclo-GABA and 2 binding hypotheses of the compounds were obtained from in silico-guided mutagenesis studies followed by pharmacological evaluation at selected BGT1 mutants. This identified the non-conserved BGT1 residues Q299 and E52 as the molecular determinants driving BGT1 activity and selectivity. The binding mode of bicyclo-GABA was further validated by the introduction of activity into the corresponding GAT3 mutant L314Q (38 times potency increase cf. wildtype). Altogether, our data reveal the molecular determinants for the activity of bicyclic GABA analogs, that despite their small size act as competitive inhibitors of BGT1. These compounds may serve as valuable tools to selectively and potently target BGT1 in order to decipher its elusive pharmacological role in the brain and periphery such as the liver and kidneys.
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Affiliation(s)
- Stefanie Kickinger
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Pharmaceutical Science, University of Vienna, Vienna, Austria
| | - Maria E K Lie
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Akihiro Suemasa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Anas Al-Khawaja
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Koichi Fujiwara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Mizuki Watanabe
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Kristine S Wilhelmsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina B Falk-Petersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bente Frølund
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Satoshi Shuto
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Gerhard F Ecker
- Department of Pharmaceutical Science, University of Vienna, Vienna, Austria
| | - Petrine Wellendorph
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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18
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Liu D, Gu Y, Pang Q, Yu H, Zhang J. Dietary betaine regulates the synthesis of fatty acids through mTOR signaling in the muscle of zebrafish. J Funct Foods 2021. [DOI: 10.1016/j.jff.2021.104610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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19
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Fu J, Zhang Q, Wu Z, Hong C, Zhu C. Transcriptomic Analysis Reveals a Sex-Dimorphic Influence of GAT-2 on Murine Liver Function. Front Nutr 2021; 8:751388. [PMID: 34604287 PMCID: PMC8481587 DOI: 10.3389/fnut.2021.751388] [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: 08/01/2021] [Accepted: 08/17/2021] [Indexed: 11/15/2022] Open
Abstract
Accumulating evidence shows that the γ-amino butyric acid (GABA)ergic system affects the functions of different organs, and liver is one of the most sex-dimorphic organs in animals. However, whether and how the GABAergic system influences liver function in a sex-specific manner at the intrinsic molecular level remains elusive. In this study, firstly, we find that the levels of GABA are significantly increased in the livers of female mice with GABA transporter (GAT)-2 deficiency (KO) whereas it only slightly increased in male GAT-2 KO mice. Apart from the amino acid profiles, the expressions of toll-like receptors (TLRs) also differ in the livers of female and male KO mice. Moreover, RNA-seq results show 2,227 differentially expressed genes (DEGs) in which 1,030 are upregulated whereas 1,197 that are downregulated in the livers of female KO mice. Notably, oxidative phosphorylation, non-alcoholic fatty liver disease, Huntington's disease, and peroxisome proliferator-activated receptor (PPAR) signaling pathways are highly enriched by GAT-2 deficiency, indicating that these pathways probably meditate the effects of GAT-2 on female liver functions, on the other hand, only 1,233 DEGs, including 474 are upregulated and 759 are downregulated in the livers of male KO mice. Interestingly, retinol metabolism, PPAR signaling pathway, and tuberculosis pathways are substantially enriched by GAT-2 deficiency, suggesting that these pathways may be responsible for the effects of GAT-2 on male liver functions. Collectively, our results reveal the sex-dimorphic effects of GAT-2 in guiding liver functions, and we propose that targeting the GABAergic system (e.g., GATs) in a sex-specific manner could provide previously unidentified therapeutic opportunities for liver diseases.
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Affiliation(s)
- Jian Fu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Qingzhuo Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zebiao Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Changming Hong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory of Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Congrui Zhu
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
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20
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Gryzło B, Zaręba P, Malawska K, Mazur G, Rapacz A, Ła̧tka K, Höfner GC, Latacz G, Bajda M, Sałat K, Wanner KT, Malawska B, Kulig K. Novel Functionalized Amino Acids as Inhibitors of GABA Transporters with Analgesic Activity. ACS Chem Neurosci 2021; 12:3073-3100. [PMID: 34347423 PMCID: PMC8397297 DOI: 10.1021/acschemneuro.1c00351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
![]()
Neuropathic pain
resistance to pharmacotherapy has encouraged researchers
to develop effective therapies for its treatment. γ-Aminobutyric
acid (GABA) transporters 1 and 4 (mGAT1 and mGAT4) have been increasingly
recognized as promising drug targets for neuropathic pain (NP) associated
with imbalances in inhibitory neurotransmission. In this context,
we designed and synthesized new functionalized amino acids as inhibitors
of GABA uptake and assessed their activities toward all four mouse
GAT subtypes (mGAT1–4). According to the obtained results,
compounds 2RS,4RS-39c (pIC50 (mGAT4) = 5.36), 50a (pIC50 (mGAT2) = 5.43), and 56a (with moderate subtype selectivity
that favored mGAT4, pIC50 (mGAT4) = 5.04) were of particular
interest and were therefore evaluated for their cytotoxic and hepatotoxic
effects. In a set of in vivo experiments, both compounds 50a and 56a showed antinociceptive properties
in three rodent models of NP, namely, chemotherapy-induced neuropathic
pain models (the oxaliplatin model and the paclitaxel model) and the
diabetic neuropathic pain model induced by streptozotocin; however
compound 56a demonstrated predominant activity. Since
impaired motor coordination is also observed in neuropathic pain conditions,
we have pointed out that none of the test compounds induced motor
deficits in the rotarod test.
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Affiliation(s)
- Beata Gryzło
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Paula Zaręba
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Katarzyna Malawska
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Gabriela Mazur
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Anna Rapacz
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Kamil Ła̧tka
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Georg C. Höfner
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München Butenandtstraße 5-13, 81377 Munich, Germany
| | - Gniewomir Latacz
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Marek Bajda
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Kinga Sałat
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Klaus T. Wanner
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München Butenandtstraße 5-13, 81377 Munich, Germany
| | - Barbara Malawska
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
| | - Katarzyna Kulig
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Kraków, Poland
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21
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Sharma S, Kaur T, Sharma AK, Singh B, Pathak D, Yadav HN, Singh AP. Betaine attenuates sodium arsenite-induced renal dysfunction in rats. Drug Chem Toxicol 2021; 45:2488-2495. [PMID: 34380335 DOI: 10.1080/01480545.2021.1959699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Exposure to higher levels of arsenic is a serious threat affecting human health worldwide. We investigated the protective role of betaine (N,N,N-trimethylglycine) against sodium arsenite-induced renal dysfunction in rats. Sodium arsenite (5 mg/kg, oral) was given to rats for 4 weeks to induce nephrotoxicity. Betaine (125 and 250 mg/kg, oral) was administered in rats for 4 weeks along with sodium-arsenite feeding. Arsenic-induced renal dysfunction was demonstrated by measuring serum creatinine, creatinine clearance, urea, uric acid, potassium, fractional excretion of sodium, and microproteinuria. Oxidative stress in rat kidneys was determined by assaying thiobarbituric acid reactive substances, superoxide anion generation, and reduced glutathione levels. Furthermore, hydroxyproline assay was done to assess renal fibrosis in arsenic intoxicated rats. Hematoxylin-eosin and picrosirius red staining revealed pathological alterations in rat kidneys. Renal endothelial nitric oxide synthase (eNOS) expression was determined by immuno-histochemistry. Concurrent administration of betaine abrogated arsenic-induced renal biochemical and histological changes in rats. Betaine treatment significantly attenuated arsenic-induced decrease in renal eNOS expression. In conclusion, betaine is protective against sodium arsenite-induced renal dysfunction, which may be attributed to its anti-oxidant activity and modulation of renal eNOS expression in rat kidneys.
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Affiliation(s)
- Sumedha Sharma
- Department of Pharmaceutical Sciences, Faculty of Life Sciences, Guru Nanak Dev University, Amritsar, India
| | - Tajpreet Kaur
- Department of Pharmaceutical Sciences, Faculty of Life Sciences, Guru Nanak Dev University, Amritsar, India.,Department of Pharmacology, Khalsa College of Pharmacy, Amritsar, India
| | - Ashwani Kumar Sharma
- Department of Pharmaceutical Sciences, Faculty of Life Sciences, Guru Nanak Dev University, Amritsar, India
| | - Balbir Singh
- Department of Pharmaceutical Sciences, Faculty of Life Sciences, Guru Nanak Dev University, Amritsar, India
| | - Devendra Pathak
- Department of Veterinary Anatomy, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, India
| | | | - Amrit Pal Singh
- Department of Pharmaceutical Sciences, Faculty of Life Sciences, Guru Nanak Dev University, Amritsar, India
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22
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Zaręba P, Sałat K, Höfner GC, Łątka K, Bajda M, Latacz G, Kotniewicz K, Rapacz A, Podkowa A, Maj M, Jóźwiak K, Filipek B, Wanner KT, Malawska B, Kulig K. Development of tricyclic N-benzyl-4-hydroxybutanamide derivatives as inhibitors of GABA transporters mGAT1-4 with anticonvulsant, antinociceptive, and antidepressant activity. Eur J Med Chem 2021; 221:113512. [PMID: 34015586 DOI: 10.1016/j.ejmech.2021.113512] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 01/04/2023]
Abstract
γ-Aminobutyric acid (GABA) neurotransmission has a significant impact on the proper functioning of the central nervous system. Numerous studies have indicated that inhibitors of the GABA transporters mGAT1-4 offer a promising strategy for the treatment of several neurological disorders, including epilepsy, neuropathic pain, and depression. Following our previous results, herein, we report the synthesis, biological evaluation, and structure-activity relationship studies supported by molecular docking and molecular dynamics of a new series of N-benzyl-4-hydroxybutanamide derivatives regarding their inhibitory potency toward mGAT1-4. This study allowed us to identify compound 23a (N-benzyl-4-hydroxybutanamide bearing a dibenzocycloheptatriene moiety), a nonselective GAT inhibitor with a slight preference toward mGAT4 (pIC50 = 5.02 ± 0.11), and compound 24e (4-hydroxy-N-[(4-methylphenyl)-methyl]butanamide bearing a dibenzocycloheptadiene moiety) with relatively high inhibitory activity toward mGAT2 (pIC50 = 5.34 ± 0.09). In a set of in vivo experiments, compound 24e successively showed predominant anticonvulsant activity and antinociception in the formalin model of tonic pain. In contrast, compound 23a showed significant antidepressant-like properties in mice. These results were consistent with the available literature data, which indicates that, apart from seizure control, GABAergic neurotransmission is also involved in the pathophysiology of several psychiatric diseases, however alternative mechanisms underlying this action cannot be excluded. Finally, it is worth noting that the selected compounds showed unimpaired locomotor skills that have been indicated to give reliable results in behavioral assays.
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Affiliation(s)
- Paula Zaręba
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland.
| | - Kinga Sałat
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Georg C Höfner
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München Butenandtstr, 5-13, 81377, Munich, Germany
| | - Kamil Łątka
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Marek Bajda
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Gniewomir Latacz
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Krzysztof Kotniewicz
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Anna Rapacz
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Adrian Podkowa
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Maciej Maj
- Department of Biopharmacy, Medical University of Lublin, ul. W. Chodzki 4a, 20-093, Lublin, Poland
| | - Krzysztof Jóźwiak
- Department of Biopharmacy, Medical University of Lublin, ul. W. Chodzki 4a, 20-093, Lublin, Poland
| | - Barbara Filipek
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Klaus T Wanner
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München Butenandtstr, 5-13, 81377, Munich, Germany
| | - Barbara Malawska
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
| | - Katarzyna Kulig
- Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Kraków, Poland
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23
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Danbolt NC, López-Corcuera B, Zhou Y. Reconstitution of GABA, Glycine and Glutamate Transporters. Neurochem Res 2021; 47:85-110. [PMID: 33905037 PMCID: PMC8763731 DOI: 10.1007/s11064-021-03331-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 10/25/2022]
Abstract
In contrast to water soluble enzymes which can be purified and studied while in solution, studies of solute carrier (transporter) proteins require both that the protein of interest is situated in a phospholipid membrane and that this membrane forms a closed compartment. An additional challenge to the study of transporter proteins has been that the transport depends on the transmembrane electrochemical gradients. Baruch I. Kanner understood this early on and first developed techniques for studying plasma membrane vesicles. This advanced the field in that the experimenter could control the electrochemical gradients. Kanner, however, did not stop there, but started to solubilize the membranes so that the transporter proteins were taken out of their natural environment. In order to study them, Kanner then had to find a way to reconstitute them (reinsert them into phospholipid membranes). The scope of the present review is both to describe the reconstitution method in full detail as that has never been done, and also to reveal the scientific impact that this method has had. Kanner's later work is not reviewed here although that also deserves a review because it too has had a huge impact.
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Affiliation(s)
- Niels Christian Danbolt
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317, Oslo, Norway.
| | - Beatriz López-Corcuera
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Madrid, Spain.,Centro de Biología Molecular "Severo Ochoa" Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Hospital Universitario La Paz, Madrid, Spain
| | - Yun Zhou
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317, Oslo, Norway
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24
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Sears SM, Hewett SJ. Influence of glutamate and GABA transport on brain excitatory/inhibitory balance. Exp Biol Med (Maywood) 2021; 246:1069-1083. [PMID: 33554649 DOI: 10.1177/1535370221989263] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
An optimally functional brain requires both excitatory and inhibitory inputs that are regulated and balanced. A perturbation in the excitatory/inhibitory balance-as is the case in some neurological disorders/diseases (e.g. traumatic brain injury Alzheimer's disease, stroke, epilepsy and substance abuse) and disorders of development (e.g. schizophrenia, Rhett syndrome and autism spectrum disorder)-leads to dysfunctional signaling, which can result in impaired cognitive and motor function, if not frank neuronal injury. At the cellular level, transmission of glutamate and GABA, the principle excitatory and inhibitory neurotransmitters in the central nervous system control excitatory/inhibitory balance. Herein, we review the synthesis, release, and signaling of GABA and glutamate followed by a focused discussion on the importance of their transport systems to the maintenance of excitatory/inhibitory balance.
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Affiliation(s)
- Sheila Ms Sears
- Department of Biology, Program in Neuroscience, 2029Syracuse University, Syracuse, NY 13244, USA
| | - Sandra J Hewett
- Department of Biology, Program in Neuroscience, 2029Syracuse University, Syracuse, NY 13244, USA
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25
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Synthesis and biological evaluation of novel N-substituted nipecotic acid derivatives with tricyclic cage structures in the lipophilic domain as GABA uptake inhibitors. Med Chem Res 2020. [DOI: 10.1007/s00044-020-02647-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractA new class of GABA reuptake inhibitors with sterically demanding, highly rigid tricyclic cage structures as the lipophilic domain was synthesized and investigated in regard to their biological activity at the murine GABA transporters (mGAT1–mGAT4). The construction of these compounds, consisting of nipecotic acid, a symmetric tricyclic amine, and a plain hydrocarbon linker connecting the two subunits via their amino nitrogens, was accomplished via reductive amination of a nipecotic acid derivative with an N-alkyl substituent displaying a terminal aldehyde function with tricyclic secondary amines. The target compounds varied with regard to spacer length, the bridge size of one of the bridges, and the substituents of the tricyclic skeleton to study the impact of these changes on their potency. Among the tested compounds nipecotic acid ethyl ester derivates with phenyl residues attached to the cage subunit showed reasonable inhibitory potency and subtype selectivity in favor of mGAT3 and mGAT4, respectively.
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26
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Hu QX, Klatt GM, Gudmundsrud R, Ottestad-Hansen S, Verbruggen L, Massie A, Danbolt NC, Zhou Y. Semi-quantitative distribution of excitatory amino acid (glutamate) transporters 1–3 (EAAT1-3) and the cystine-glutamate exchanger (xCT) in the adult murine spinal cord. Neurochem Int 2020; 140:104811. [DOI: 10.1016/j.neuint.2020.104811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/21/2020] [Accepted: 07/09/2020] [Indexed: 01/01/2023]
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27
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Exploring the molecular determinants for subtype-selectivity of 2-amino-1,4,5,6-tetrahydropyrimidine-5-carboxylic acid analogs as betaine/GABA transporter 1 (BGT1) substrate-inhibitors. Sci Rep 2020; 10:12992. [PMID: 32747622 PMCID: PMC7400577 DOI: 10.1038/s41598-020-69908-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/17/2020] [Indexed: 12/13/2022] Open
Abstract
We have previously identified 2-amino-1,4,5,6-tetrahydropyrimidine-5-carboxylic acid (ATPCA) as the most potent substrate-inhibitor of the betaine/GABA transporter 1 (BGT1) (IC50 2.5 µM) reported to date. Herein, we characterize the binding mode of 20 novel analogs and propose the molecular determinants driving BGT1-selectivity. A series of N1-, exocyclic-N-, and C4-substituted analogs was synthesized and pharmacologically characterized in radioligand-based uptake assays at the four human GABA transporters (hGATs) recombinantly expressed in mammalian cells. Overall, the analogs retained subtype-selectivity for hBGT1, though with lower inhibitory activities (mid to high micromolar IC50 values) compared to ATPCA. Further characterization of five of these BGT1-active analogs in a fluorescence-based FMP assay revealed that the compounds are substrates for hBGT1, suggesting they interact with the orthosteric site of the transporter. In silico-guided mutagenesis experiments showed that the non-conserved residues Q299 and E52 in hBGT1 as well as the conformational flexibility of the compounds potentially contribute to the subtype-selectivity of ATPCA and its analogs. Overall, this study provides new insights into the molecular interactions governing the subtype-selectivity of BGT1 substrate-inhibitors. The findings may guide the rational design of BGT1-selective pharmacological tool compounds for future drug discovery.
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28
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Cells grown in three-dimensional spheroids mirror in vivo metabolic response of epithelial cells. Commun Biol 2020; 3:246. [PMID: 32427948 PMCID: PMC7237469 DOI: 10.1038/s42003-020-0973-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 04/29/2020] [Indexed: 02/07/2023] Open
Abstract
Metabolism in cells adapts quickly to changes in nutrient availability and cellular differentiation status, including growth conditions in cell culture settings. The last decade saw a vast increase in three-dimensional (3D) cell culture techniques, engendering spheroids and organoids. These methods were established to improve comparability to in vivo situations, differentiation processes and growth modalities. How far spheroids mimic in vivo metabolism, however, remains enigmatic. Here, to our knowledge, we compare for the first time metabolic fingerprints between cells grown as a single layer or as spheroids with freshly isolated in situ tissue. While conventionally grown cells express elevated levels of glycolysis intermediates, amino acids and lipids, these levels were significantly lower in spheroids and freshly isolated primary tissues. Furthermore, spheroids differentiate and start to produce metabolites typical for their tissue of origin. 3D grown cells bear many metabolic similarities to the original tissue, recommending animal testing to be replaced by 3D culture techniques.
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29
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Andreß JC, Böck MC, Höfner G, Wanner KT. Synthesis and biological evaluation of α- and β-hydroxy substituted amino acid derivatives as potential mGAT1–4 inhibitors. Med Chem Res 2020. [DOI: 10.1007/s00044-020-02548-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractIn this study, we report the synthesis and biological evaluation of a variety of α- and β-hydroxy substituted amino acid derivatives as potential amino acid subunits in inhibitors of GABA uptake transporters (GATs). In order to ensure that the test compounds adopt a binding pose similar to that presumed for related larger GAT inhibitors, lipophilic residues were introduced either at the amino nitrogen atom or at the alcohol function. Several of the synthesized compounds were found to exhibit similar inhibitory activity at the GAT subtypes mGAT2, mGAT3, and mGAT4, respectively, as compared with the reference N-butylnipecotic acid. Hence, these compounds might serve as starting point for future developments of more complex GAT inhibitors.
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30
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Łątka K, Jończyk J, Bajda M. γ-Aminobutyric acid transporters as relevant biological target: Their function, structure, inhibitors and role in the therapy of different diseases. Int J Biol Macromol 2020; 158:S0141-8130(20)32987-1. [PMID: 32360967 DOI: 10.1016/j.ijbiomac.2020.04.126] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 12/13/2022]
Abstract
γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the nervous system. It plays a crucial role in many physiological processes. Upon release from the presynaptic element, it is removed from the synaptic cleft by reuptake due to the action of GABA transporters (GATs). GATs belong to a large SLC6 protein family whose characteristic feature is sodium-dependent relocation of neurotransmitters through the cell membrane. GABA transporters are characterized in many contexts, but their spatial structure is not fully known. They are divided into four types, which differ in occurrence and role. Herein, the special attention was paid to these transporting proteins. This comprehensive review presents the current knowledge about GABA transporters. Their distribution in the body, physiological functions and possible utilization in the therapy of different diseases were fully discussed. The important structural features were described based on published data, including sequence analysis, mutagenesis studies, and comparison with known SLC6 transporters for leucine (LeuT), dopamine (DAT) and serotonin (SERT). Moreover, the most important inhibitors of GABA transporters of various basic scaffolds, diverse selectivity and potency were presented.
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Affiliation(s)
- Kamil Łątka
- Jagiellonian University Medical College, Faculty of Pharmacy, Department of Physicochemical Drug Analysis, 30-688 Cracow, Medyczna 9, Poland
| | - Jakub Jończyk
- Jagiellonian University Medical College, Faculty of Pharmacy, Department of Physicochemical Drug Analysis, 30-688 Cracow, Medyczna 9, Poland
| | - Marek Bajda
- Jagiellonian University Medical College, Faculty of Pharmacy, Department of Physicochemical Drug Analysis, 30-688 Cracow, Medyczna 9, Poland.
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31
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McFadden JW, Girard CL, Tao S, Zhou Z, Bernard JK, Duplessis M, White HM. Symposium review: One-carbon metabolism and methyl donor nutrition in the dairy cow. J Dairy Sci 2020; 103:5668-5683. [PMID: 32278559 DOI: 10.3168/jds.2019-17319] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 02/10/2020] [Indexed: 12/17/2022]
Abstract
The present review focuses on methyl donor metabolism and nutrition in the periparturient and lactating dairy cow. Methyl donors are involved in one-carbon metabolism, which includes the folate and Met cycles. These cycles work in unison to support lipid, nucleotide, and protein synthesis, as well as methylation reactions and the maintenance of redox status. A key feature of one-carbon metabolism is the multi-step conversion of tetrahydrofolate to 5-methyltetrahyrofolate. Homocysteine and 5-methyltetrahyrofolate are utilized by vitamin B12-dependent Met synthase to couple the folate and Met cycles and generate Met. Methionine may also be remethylated from choline-derived betaine under the action of betaine hydroxymethyltransferase. Regardless, Met is converted within the Met cycle to S-adenosylmethionine, which is universally utilized in methyl-group transfer reactions including the synthesis of phosphatidylcholine. Homocysteine may also enter the transsulfuration pathway to generate glutathione or taurine for scavenging of reactive oxygen metabolites. In the transition cow, a high demand exists for compounds with a labile methyl group. Limited methyl group supply may contribute to inadequate hepatic phosphatidylcholine synthesis and hepatic triglyceride export, systemic oxidative stress, and compromised milk production. To minimize the perils associated with methyl donor deficiency, the peripartum cow relies on de novo methylneogenesis from tetrahydrofolate. In addition, dietary supplementation of rumen-protected folic acid, vitamin B12, Met, choline, and betaine are potential nutritional approaches to target one-carbon pools and improve methyl donor balance in transition cows. Such strategies have merit considering research demonstrating their ability to improve milk production efficiency, milk protein synthesis, hepatic health, and immune response. This review aims to summarize the current understanding of folic acid, vitamin B12, Met, choline, and betaine utilization in the dairy cow. Methyl donor co-supplementation, fatty acid feeding strategies that may optimize methyl donor supplementation efficacy, and potential epigenetic mechanisms are also considered.
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Affiliation(s)
- J W McFadden
- Department of Animal Science, Cornell University, Ithaca, NY 14853.
| | - C L Girard
- Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada J1M 0C8
| | - S Tao
- Department of Animal and Dairy Science, University of Georgia, Tifton 31793
| | - Z Zhou
- Department of Animal Science, Michigan State University, East Lansing 48824
| | - J K Bernard
- Department of Animal and Dairy Science, University of Georgia, Tifton 31793
| | - M Duplessis
- Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada J1M 0C8
| | - H M White
- Department of Dairy Science, University of Wisconsin, Madison 53706
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32
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Synthesis and biological evaluation of fluorescent GAT-ligands based on asymmetric substituted BODIPY dyes. Med Chem Res 2020. [DOI: 10.1007/s00044-020-02521-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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33
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The Vitamin D Receptor Regulates Glycerolipid and Phospholipid Metabolism in Human Hepatocytes. Biomolecules 2020; 10:biom10030493. [PMID: 32213983 PMCID: PMC7175212 DOI: 10.3390/biom10030493] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 12/13/2022] Open
Abstract
The vitamin D receptor (VDR) must be relevant to liver lipid metabolism because VDR deficient mice are protected from hepatosteatosis. Therefore, our objective was to define the role of VDR on the overall lipid metabolism in human hepatocytes. We developed an adenoviral vector for human VDR and performed transcriptomic and metabolomic analyses of cultured human hepatocytes upon VDR activation by vitamin D (VitD). Twenty percent of the VDR responsive genes were related to lipid metabolism, including MOGAT1, LPGAT1, AGPAT2, and DGAT1 (glycerolipid metabolism); CDS1, PCTP, and MAT1A (phospholipid metabolism); and FATP2, SLC6A12, and AQP3 (uptake of fatty acids, betaine, and glycerol, respectively). They were rapidly induced (4–6 h) upon VDR activation by 10 nM VitD or 100 µM lithocholic acid (LCA). Most of these genes were also upregulated by VDR/VitD in mouse livers in vivo. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) metabolomics demonstrated intracellular accumulation of triglycerides, with concomitant decreases in diglycerides and phosphatidates, at 8 and 24 h upon VDR activation. Significant alterations in phosphatidylcholines, increases in lyso-phosphatidylcholines and decreases in phosphatidylethanolamines and phosphatidylethanolamine plasmalogens were also observed. In conclusion, active VitD/VDR signaling in hepatocytes triggers an unanticipated coordinated gene response leading to triglyceride synthesis and to important perturbations in glycerolipids and phospholipids.
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34
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Yi Z, Waseem Ghani M, Ghani H, Jiang W, Waseem Birmani M, Ye L, Bin L, Cun LG, Lilong A, Mei X. Gimmicks of gamma-aminobutyric acid (GABA) in pancreatic β-cell regeneration through transdifferentiation of pancreatic α- to β-cells. Cell Biol Int 2020; 44:926-936. [PMID: 31903671 DOI: 10.1002/cbin.11302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/04/2020] [Indexed: 02/06/2023]
Abstract
In vivo regeneration of lost or dysfunctional islet β cells can fulfill the promise of improved therapy for diabetic patients. To achieve this, many mitogenic factors have been attempted, including gamma-aminobutyric acid (GABA). GABA remarkably affects pancreatic islet cells' (α cells and β cells) function through paracrine and/or autocrine binding to its membrane receptors on these cells. GABA has also been studied for promoting the transformation of α cells to β cells. Nonetheless, the gimmickry of GABA-induced α-cell transformation to β cells has two different perspectives. On the one hand, GABA was found to induce α-cell transformation to β cells in vivo and insulin-secreting β-like cells in vitro. On the other hand, GABA treatment showed that it has no α- to β-cell transformation response. Here, we will summarize the physiological effects of GABA on pancreatic islet β cells with an emphasis on its regenerative effects for transdifferentiation of islet α cells to β cells. We will also critically discuss the controversial results about GABA-mediated transdifferentiation of α cells to β cells.
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Affiliation(s)
- Zhao Yi
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Muhammad Waseem Ghani
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Hammad Ghani
- Nawaz Sharif Medical College, University of Gujrat, Punjab, 50180, Pakistan
| | - Wu Jiang
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Muhammad Waseem Birmani
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Li Ye
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Liu Bin
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Lang Guan Cun
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - An Lilong
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Xiao Mei
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
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Valmiki RR, Venkatesalu S, Chacko AG, Prabhu K, Thomas MM, Mathew V, Yoganathan S, Muthusamy K, Chacko G, Vanjare HA, Krothapalli SB. Phosphoproteomic analysis reveals Akt isoform-specific regulation of cytoskeleton proteins in human temporal lobe epilepsy with hippocampal sclerosis. Neurochem Int 2019; 134:104654. [PMID: 31884041 DOI: 10.1016/j.neuint.2019.104654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/03/2019] [Accepted: 12/23/2019] [Indexed: 01/04/2023]
Abstract
Akt is one of the most important downstream effectors of phosphatidylinositol 3-kinase/mTOR pathway. Hyperactivation and expression of this pathway are seen in a variety of neurological disorders including human temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Nevertheless, the expression and activation profiles of the Akt isoforms, Akt1, Akt2, and Akt3 and their functional roles in human TLE-HS have not been studied. We examined the protein expression and activation (phosphorylation) patterns of Akt and its isoforms in human hippocampal tissue from TLE and non-TLE patients. A phosphoproteomic approach followed by interactome analysis of each Akt isoform was used to understand protein-protein interactions and their role in TLE-HS pathology. Our results demonstrated activation of the Akt/mTOR pathway as well as activation of Akt downstream substrates like GSK3β, mTOR, and S6 in TLE-HS samples. Akt1 isoform levels were significantly increased in the TLE-HS samples as compared to the non-TLE samples. Most importantly, different isoforms were activated in different TLE-HS samples, Akt2 was activated in three samples, Akt2 and Akt1 were simultaneously activated in one sample and Akt3 was activated in two samples. Our phosphoproteomic screen across six TLE-HS samples identified 183 proteins phosphorylated by Akt isoforms, 29 of these proteins belong to cytoskeletal modification. Also, we were able to identify proteins of several other classes involved in glycolysis, neuronal development, protein folding and excitatory amino acid transport functions as Akt substrates. Taken together, our data offer clues to understand the role of Akt and its isoforms in underlying the pathology of TLE-HS and further, modulation of Akt/mTOR pathway using Akt isoforms specific inhibitors may offer a new therapeutic window for treatment of human TLE-HS.
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Affiliation(s)
- Rajesh Ramanna Valmiki
- Neurophysiology Laboratory, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India.
| | - Subhashini Venkatesalu
- Neurophysiology Laboratory, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Ari George Chacko
- Neurosurgery, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Krishna Prabhu
- Neurosurgery, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Maya Mary Thomas
- Department of Pediatric Neurology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Vivek Mathew
- Neurology, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Sangeetha Yoganathan
- Department of Pediatric Neurology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Karthik Muthusamy
- Department of Pediatric Neurology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Geeta Chacko
- Neuropathology, Department of General Pathology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | | | - Srinivasa Babu Krothapalli
- Neurophysiology Laboratory, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
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Liu Z, Li Q, Shen R, Ci L, Wan Z, Shi J, Huang Q, Yang X, Zhang M, Yang H, Sun R, Wang Z, Huang F, Lu T, Fei J. Betaine/GABA transporter-1 (BGT-1) deficiency in mouse prevents acute liver failure in vivo and hepatocytes apoptosis in vitro. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165634. [PMID: 31830527 DOI: 10.1016/j.bbadis.2019.165634] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/06/2019] [Accepted: 12/04/2019] [Indexed: 01/13/2023]
Abstract
Betaine/γ-aminobutyric acid (GABA) transporter 1 (BGT-1 or Slc6a12) is a transporter for the neurotransmitter GABA and osmolyte betaine. To date, most studies on BGT-1 have focused on its functions in the nervous system and renal osmotic homeostasis. Despite its dominant distribution in the liver, the function of BGT-1 in hepatic physiology or disease remains unknown. Here, we report that BGT-1 was significantly downregulated in patients with liver failure as well as in mice with experimental acute liver failure (ALF). Furthermore, mice deficient in BGT-1 showed significant resistance to ALF compared with wild type (WT) mice, manifesting as improved survival rate, reduced alanine transaminase/aspartate aminotransferase levels, better histopathological symptoms and fewer apoptotic cells in the liver. Similarly, in primary hepatocytes, BGT-1 deficiency or treatment with a BGT-1 inhibitor, NNC 05-2090, attenuated TNF-α mediated apoptosis. In addition, BGT-1 deficiency or dosing with NNC 05-2090 stimulated the expression of the anti-apoptotic gene, c-Met in the liver, suggesting the involvement of c-Met in the function on hepatocytes of BGT-1 apoptosis. Our findings suggest BGT-1 is a promising candidate drug target to prevent and treat hepatocyte apoptosis related diseases, such as ALF.
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Affiliation(s)
- Zhenze Liu
- School of Life Science and Technology, Tongji University. Shanghai, China
| | - Qing Li
- School of Life Science and Technology, Tongji University. Shanghai, China; Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, State Key Laboratory of Medical Neurobiology & Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ruling Shen
- Shanghai Laboratory Animal Research Center, Shanghai, China; Joint Laboratory for Model Organism, Shanghai Laboratory Animal Research Center and School of Life Science and Technology, Tongji University
| | - Lei Ci
- Shanghai Engineering Research Center for Model Organisms, SMOC, Shanghai, China
| | - Zhipeng Wan
- School of Life Science and Technology, Tongji University. Shanghai, China
| | - Jiahao Shi
- School of Life Science and Technology, Tongji University. Shanghai, China
| | - Qin Huang
- Shanghai Engineering Research Center for Model Organisms, SMOC, Shanghai, China
| | - Xu Yang
- School of Life Science and Technology, Tongji University. Shanghai, China
| | - Mengjie Zhang
- School of Life Science and Technology, Tongji University. Shanghai, China
| | - Hua Yang
- School of Life Science and Technology, Tongji University. Shanghai, China
| | - Ruilin Sun
- Shanghai Engineering Research Center for Model Organisms, SMOC, Shanghai, China
| | - Zhugang Wang
- Shanghai Engineering Research Center for Model Organisms, SMOC, Shanghai, China
| | - Fang Huang
- Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, State Key Laboratory of Medical Neurobiology & Institutes of Brain Science, Fudan University, Shanghai, China
| | - Tianfei Lu
- Department of Liver Surgery and Liver Transplantation Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
| | - Jian Fei
- School of Life Science and Technology, Tongji University. Shanghai, China; Shanghai Engineering Research Center for Model Organisms, SMOC, Shanghai, China; Joint Laboratory for Model Organism, Shanghai Laboratory Animal Research Center and School of Life Science and Technology, Tongji University.
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37
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Synthesis and biological evaluation of fluorescent GAT-ligands based on meso-substituted BODIPY dyes. Med Chem Res 2019. [DOI: 10.1007/s00044-019-02483-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Application of the concept of oxime library screening by mass spectrometry (MS) binding assays to pyrrolidine-3-carboxylic acid derivatives as potential inhibitors of γ-aminobutyric acid transporter 1 (GAT1). Bioorg Med Chem 2019; 27:2753-2763. [PMID: 31097402 DOI: 10.1016/j.bmc.2019.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/15/2019] [Accepted: 05/01/2019] [Indexed: 11/20/2022]
Abstract
In the present study, the concept of oxime library screening by MS Binding Assays was successfully extended to N-substituted lipophilic pyrrolidine-3-carboxylic acid derivatives in the pursuit of varying the amino acid motif in order to identify new inhibitors for GAT1 and to broaden structure-activity-relationships for this target, the most abundant GABA transporter in the central nervous system. For the screening, 28 different oxime sub-libraries were employed that were generated by simple condensation reaction of an excess of pyrrolidine-3-carboxylic acid derivatives carrying a hydroxylamine functionality with various sub-libraries each assembled of eight aldehydes with broadly varying chemical structures and functionalities. The compounds responsible for the activity of an oxime sub-library were identified by deconvolution experiments performed by employing single oximes. Binding affinities of the oxime hits were confirmed in full-scale competitive MS Binding Assays. Thereby, oxime derivatives with a 1,1'-biphenyl moiety were found as the first inhibitors of mGAT1 comprising a pyrrolidine-3-carboxylic acid motif with affinities in the submicromolar range.
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Kickinger S, Hellsberg E, Frølund B, Schousboe A, Ecker GF, Wellendorph P. Structural and molecular aspects of betaine-GABA transporter 1 (BGT1) and its relation to brain function. Neuropharmacology 2019; 161:107644. [PMID: 31108110 DOI: 10.1016/j.neuropharm.2019.05.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/14/2019] [Accepted: 05/16/2019] [Indexed: 01/09/2023]
Abstract
ɣ-aminobutyric-acid (GABA) functions as the principal inhibitory neurotransmitter in the central nervous system. Imbalances in GABAergic neurotransmission are involved in the pathophysiology of various neurological diseases such as epilepsy, Alzheimer's disease and stroke. GABA transporters (GATs) facilitate the termination of GABAergic signaling by transporting GABA together with sodium and chloride from the synaptic cleft into presynaptic neurons and surrounding glial cells. Four different GATs have been identified that all belong to the solute carrier 6 (SLC6) transporter family: GAT1-3 (SLC6A1, SLC6A13, SLC6A11) and betaine/GABA transporter 1 (BGT1, SLC6A12). BGT1 has emerged as an interesting target for treating epilepsy due to animal studies that reported anticonvulsant effects for the GAT1/BGT1 selective inhibitor EF1502 and the BGT1 selective inhibitor RPC-425. However, the precise involvement of BGT1 in epilepsy remains elusive because of its controversial expression levels in the brain and the lack of highly selective and potent tool compounds. This review gathers the current structural and functional knowledge on BGT1 with emphasis on brain relevance, discusses all available compounds, and tries to shed light on the molecular determinants driving BGT1 selectivity. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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Affiliation(s)
- Stefanie Kickinger
- University of Vienna, Department of Pharmaceutical Chemistry, Althanstrasse 14, 1090, Vienna, Austria
| | - Eva Hellsberg
- University of Vienna, Department of Pharmaceutical Chemistry, Althanstrasse 14, 1090, Vienna, Austria
| | - Bente Frølund
- University of Copenhagen, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, 2 Universitetsparken, 2100, Copenhagen, Denmark
| | - Arne Schousboe
- University of Copenhagen, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, 2 Universitetsparken, 2100, Copenhagen, Denmark
| | - Gerhard F Ecker
- University of Vienna, Department of Pharmaceutical Chemistry, Althanstrasse 14, 1090, Vienna, Austria
| | - Petrine Wellendorph
- University of Copenhagen, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, 2 Universitetsparken, 2100, Copenhagen, Denmark.
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Schaarschmidt M, Höfner G, Wanner KT. Synthesis and Biological Evaluation of Nipecotic Acid and Guvacine Derived 1,3-Disubstituted Allenes as Inhibitors of Murine GABA Transporter mGAT1. ChemMedChem 2019; 14:1135-1151. [PMID: 30957949 DOI: 10.1002/cmdc.201900170] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Indexed: 12/18/2022]
Abstract
A new class of nipecotic acid and guvacine derivatives has been synthesized and characterized for their inhibitory potency at mGAT1-4 and binding affinity for mGAT1. Compounds of the described class are defined by a four-carbon-atom allenyl spacer connecting the nitrogen atom of the nipecotic acid or guvacine head with an aromatic residue. Among the compounds investigated, the mixture of nipecotic acid derivatives rac-{(Ra )-1-[4-([1,1':2',1''-terphenyl]-2-yl)buta-2,3-dien-1-yl](3R)-piperidine-3-carboxylic acid} and rac-{(Sa )-1-[4-([1,1':2',1''-terphenyl]-2-yl)buta-2,3-dien-1-yl](3R)-piperidine-3-carboxylic acid} (21 p), possessing an o-terphenyl residue, was identified as highly selective and the most potent mGAT1 inhibitor in this study. For the (R)-nipecotic acid derived form of 21 p, the inhibitory potency in [3 H]GABA uptake assays was determined as pIC50 =6.78±0.08, and the binding affinity in MS Binding Assays as pKi =7.10±0.12. The synthesis of the designed compounds was carried out by a two-step procedure, generating the allene moiety via allenylation of terminal alkynes which allows broad variation of the terminal phenyl and biphenyl subunit.
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Affiliation(s)
- Maren Schaarschmidt
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr. 7-13, 81377, Munich, Germany
| | - Georg Höfner
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr. 7-13, 81377, Munich, Germany
| | - Klaus T Wanner
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr. 7-13, 81377, Munich, Germany
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Maeoka Y, Okamoto T, Wu Y, Saito A, Asada R, Matsuhisa K, Terao M, Takada S, Masaki T, Imaizumi K, Kaneko M. Renal medullary tonicity regulates RNF183 expression in the collecting ducts via NFAT5. Biochem Biophys Res Commun 2019; 514:436-442. [PMID: 31053298 DOI: 10.1016/j.bbrc.2019.04.168] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 04/24/2019] [Indexed: 01/06/2023]
Abstract
Nuclear factor of activated T-cells 5 (NFAT5) directly binds to the promoter of the RING finger protein 183 (RNF183) gene and induces its transcription under hypertonic conditions in mouse inner-medullary collecting duct (mIMCD-3) cells. However, there is no specific anti-RNF183 antibody for immunostaining; therefore, it is unclear whether NFAT5 regulates RNF183 expression in vivo and where RNF183 is localized in the kidney. This study investigated NFAT5-regulated in vivo RNF183 expression and localization using CRISPR/Cas9-mediated RNF183-green fluorescent protein (RNF183-GFP) knock-in mice. GFP with linker sequences was introduced upstream of an RNF183 open reading frame in exon 3 by homologous recombination through a donor plasmid. Immunofluorescence staining using GFP antibody revealed that GFP signals gradually increase from the outer medulla down to the inner medulla and colocalize with aquaporin-2. Furosemide treatment dramatically decreased RNF183 expression in the renal medulla, consistent with the decrease in NFAT5 protein and target gene mRNA expression. Furosemide treatment of mIMCD-3 cells did not affect mRNA expression and RNF183 promoter activities. These results indicated that RNF183 is predominantly expressed in the renal medullary collecting ducts, and that decreased renal medullary tonicity by furosemide treatment decreases RNF183 expression by NFAT5 downregulation.
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Affiliation(s)
- Yujiro Maeoka
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan
| | - Takumi Okamoto
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yan Wu
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Atsushi Saito
- Department of Stress Protein Processing, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Rie Asada
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, MO, USA
| | - Koji Matsuhisa
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Miho Terao
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Shuji Takada
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Takao Masaki
- Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
| | - Masayuki Kaneko
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
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42
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Kinetic and structural analysis of human ALDH9A1. Biosci Rep 2019; 39:BSR20190558. [PMID: 30914451 PMCID: PMC6487263 DOI: 10.1042/bsr20190558] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 01/27/2023] Open
Abstract
Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes, which detoxify aldehydes produced in various metabolic pathways to the corresponding carboxylic acids. Among the 19 human ALDHs, the cytosolic ALDH9A1 has so far never been fully enzymatically characterized and its structure is still unknown. Here, we report complete molecular and kinetic properties of human ALDH9A1 as well as three crystal forms at 2.3, 2.9, and 2.5 Å resolution. We show that ALDH9A1 exhibits wide substrate specificity to aminoaldehydes, aliphatic and aromatic aldehydes with a clear preference for γ-trimethylaminobutyraldehyde (TMABAL). The structure of ALDH9A1 reveals that the enzyme assembles as a tetramer. Each ALDH monomer displays a typical ALDHs fold composed of an oligomerization domain, a coenzyme domain, a catalytic domain, and an inter-domain linker highly conserved in amino-acid sequence and folding. Nonetheless, structural comparison reveals a position and a fold of the inter-domain linker of ALDH9A1 never observed in any other ALDH so far. This unique difference is not compatible with the presence of a bound substrate and a large conformational rearrangement of the linker up to 30 Å has to occur to allow the access of the substrate channel. Moreover, the αβE region consisting of an α-helix and a β-strand of the coenzyme domain at the dimer interface are disordered, likely due to the loss of interactions with the inter-domain linker, which leads to incomplete β-nicotinamide adenine dinucleotide (NAD+) binding pocket.
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Li C, Wang Y, Li L, Han Z, Mao S, Wang G. Betaine protects against heat exposure-induced oxidative stress and apoptosis in bovine mammary epithelial cells via regulation of ROS production. Cell Stress Chaperones 2019; 24:453-460. [PMID: 30805833 PMCID: PMC6439124 DOI: 10.1007/s12192-019-00982-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/11/2019] [Accepted: 01/30/2019] [Indexed: 12/15/2022] Open
Abstract
Heat stress is one of the wide varieties of factors which cause oxidative stress in vivo; elevated temperature can lead to oxidative stress of dairy cows that affects milk production. The aim of this study was to determine the capacity of the betaine to act as an antioxidant against oxidative stress induced by heat exposure and apoptosis in mammary epithelial cells (mammary alveolar cells, MAC-T). The MAC-T were divided into four treatment groups: control (37 °C), heat stress (HS, 42 °C), betaine (37 °C), and HS + betaine. MAC-T under heat stress (HS) showed increased ROS accumulation, malondialdehyde (MDA) content, superoxide dismutase (SOD) concentration, and catalase (CAT) activity. During heat stress, betaine decreased the mRNA expression level of HSP70 and HSP27 in MAC-T. Bax/Bcl-2 ratio and caspase-3, the markers of apoptosis, were also elevated in MAC-T under heat stress. The markers of oxidative stress Nrf-2/HO-1 genes were also elevated in MAC-T under heat stress. Pretreatment of betaine reversed the heat-induced depletion in total antioxidant status, ROS accumulation, and SOD and CAT contents in MAC-T. Bax/Bcl-2 ratio and Nrf-2/HO-1 expression of heat-exposed MAC-T were also reduced with betaine supplementation. In conclusion, betaine alleviated oxidative stress and apoptosis of MAC-T by inhibiting ROS accumulation.
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Affiliation(s)
- Chengmin Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Yiru Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Lian Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
| | - Zhaoyu Han
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Shengyong Mao
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Genlin Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
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Tóth K, Höfner G, Wanner KT. Synthesis and biological evaluation of novel N-substituted nipecotic acid derivatives with a cis-alkene spacer as GABA uptake inhibitors. Bioorg Med Chem 2019; 27:822-831. [DOI: 10.1016/j.bmc.2019.01.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/15/2019] [Accepted: 01/23/2019] [Indexed: 10/27/2022]
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Kern F, Wanner KT. Screening oxime libraries by means of mass spectrometry (MS) binding assays: Identification of new highly potent inhibitors to optimized inhibitors γ-aminobutyric acid transporter 1. Bioorg Med Chem 2019; 27:1232-1245. [PMID: 30777661 DOI: 10.1016/j.bmc.2019.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/07/2019] [Indexed: 11/26/2022]
Abstract
Generation and screening of oxime libraries by competitive MS Binding Assays represents a powerful tool for the identification of new compounds, with affinity to mGAT1, the most abundant plasma membrane bound GABA transporter in the CNS. By screening a guvacine derived oxime library, new potent inhibitors of mGAT1 had been revealed. In the present study, oxime libraries generated by reaction of a large excess of a rac-nipecotic acid derivative displaying a hydroxylamine functionality in which various aldehydes under suitable conditions, were examined for new potent inhibitors of mGAT1. The pKi values obtained of the best hits were compared with those of related compounds displaying a guvacine instead of a nipecotic acid subunit as hydrophilic moiety. Amongst the new compounds one of the most affine ligands of mGAT1 known so far (pKi = 8.55 ± 0.04) was found.
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Affiliation(s)
- Felix Kern
- Department Pharmacy - Center for Drug Research, Ludwig-Maximilians-University München, Butenandtstr. 7, 81377 Munich, Germany
| | - Klaus T Wanner
- Department Pharmacy - Center for Drug Research, Ludwig-Maximilians-University München, Butenandtstr. 7, 81377 Munich, Germany.
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46
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Tóth K, Höfner G, Wanner KT. Synthesis and biological evaluation of novel N-substituted nipecotic acid derivatives with a trans-alkene spacer as potent GABA uptake inhibitors. Bioorg Med Chem 2018; 26:5944-5961. [DOI: 10.1016/j.bmc.2018.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/31/2018] [Accepted: 11/02/2018] [Indexed: 12/13/2022]
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47
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Huber SK, Höfner G, Wanner KT. Identification of Pyrrolidine‐3‐acetic Acid Derived Oximes as Potent Inhibitors of γ‐Aminobutyric Acid Transporter 1 through Library Screening with MS Binding Assays. ChemMedChem 2018; 13:2488-2503. [DOI: 10.1002/cmdc.201800556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Simone K. Huber
- Department of Pharmacy, Center of Drug ResearchLudwig Maximilians University of Munich Butenandtstr. 7 81377 Munich Germany
| | - Georg Höfner
- Department of Pharmacy, Center of Drug ResearchLudwig Maximilians University of Munich Butenandtstr. 7 81377 Munich Germany
| | - Klaus T. Wanner
- Department of Pharmacy, Center of Drug ResearchLudwig Maximilians University of Munich Butenandtstr. 7 81377 Munich Germany
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48
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AMP-Activated Protein Kinase (AMPK)-Dependent Regulation of Renal Transport. Int J Mol Sci 2018; 19:ijms19113481. [PMID: 30404151 PMCID: PMC6274953 DOI: 10.3390/ijms19113481] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/26/2018] [Accepted: 10/30/2018] [Indexed: 02/06/2023] Open
Abstract
AMP-activated kinase (AMPK) is a serine/threonine kinase that is expressed in most cells and activated by a high cellular AMP/ATP ratio (indicating energy deficiency) or by Ca2+. In general, AMPK turns on energy-generating pathways (e.g., glucose uptake, glycolysis, fatty acid oxidation) and stops energy-consuming processes (e.g., lipogenesis, glycogenesis), thereby helping cells survive low energy states. The functional element of the kidney, the nephron, consists of the glomerulus, where the primary urine is filtered, and the proximal tubule, Henle's loop, the distal tubule, and the collecting duct. In the tubular system of the kidney, the composition of primary urine is modified by the reabsorption and secretion of ions and molecules to yield final excreted urine. The underlying membrane transport processes are mainly energy-consuming (active transport) and in some cases passive. Since active transport accounts for a large part of the cell's ATP demands, it is an important target for AMPK. Here, we review the AMPK-dependent regulation of membrane transport along nephron segments and discuss physiological and pathophysiological implications.
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49
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Zhou Y, Dhaher R, Parent M, Hu QX, Hassel B, Yee SP, Hyder F, Gruenbaum SE, Eid T, Danbolt NC. Selective deletion of glutamine synthetase in the mouse cerebral cortex induces glial dysfunction and vascular impairment that precede epilepsy and neurodegeneration. Neurochem Int 2018; 123:22-33. [PMID: 30053506 DOI: 10.1016/j.neuint.2018.07.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/22/2018] [Accepted: 07/23/2018] [Indexed: 12/31/2022]
Abstract
Glutamate-ammonia ligase (glutamine synthetase; Glul) is enriched in astrocytes and serves as the primary enzyme for ammonia detoxification and glutamate inactivation in the brain. Loss of astroglial Glul is reported in hippocampi of epileptic patients, but the mechanism by which Glul deficiency might cause disease remains elusive. Here we created a novel mouse model by selectively deleting Glul in the hippocampus and neocortex. The Glul deficient mice were born without any apparent malformations and behaved unremarkably until postnatal week three. There were reductions in tissue levels of aspartate, glutamate, glutamine and GABA and in mRNA encoding glutamate receptor subunits GRIA1 and GRIN2A as well as in the glutamate transporter proteins EAAT1 and EAAT2. Adult Glul-deficient mice developed progressive neurodegeneration and spontaneous seizures which increased in frequency with age. Importantly, progressive astrogliosis occurred before neurodegeneration and was first noted in astrocytes along cerebral blood vessels. The responses to CO2-provocation were attenuated at four weeks of age and dilated microvessels were observed histologically in sclerotic areas of cKO. Thus, the abnormal glutamate metabolism observed in this model appeared to cause epilepsy by first inducing gliopathy and disrupting the neurovascular coupling.
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Affiliation(s)
- Yun Zhou
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317, Oslo, Norway.
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Maxime Parent
- Magnetic Resonance Research Center, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Qiu-Xiang Hu
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317, Oslo, Norway
| | - Bjørnar Hassel
- Department of Complex Neurology and Neurohabilitation, Oslo University Hospital, University of Oslo, N-0450, Oslo, Norway
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, 06030, USA
| | - Fahmeed Hyder
- Magnetic Resonance Research Center, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Shaun E Gruenbaum
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Tore Eid
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317, Oslo, Norway; Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, 06520, USA.
| | - Niels Christian Danbolt
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317, Oslo, Norway.
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Tóth K, Höfner G, Wanner KT. Synthesis and biological evaluation of novel N-substituted nipecotic acid derivatives with an alkyne spacer as GABA uptake inhibitors. Bioorg Med Chem 2018; 26:3668-3687. [DOI: 10.1016/j.bmc.2018.05.049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/25/2018] [Accepted: 05/30/2018] [Indexed: 12/14/2022]
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