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Hau RK, Wright SH, Cherrington NJ. Addressing the Clinical Importance of Equilibrative Nucleoside Transporters in Drug Discovery and Development. Clin Pharmacol Ther 2023; 114:780-794. [PMID: 37404197 DOI: 10.1002/cpt.2984] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 05/30/2023] [Indexed: 07/06/2023]
Abstract
The US Food and Drug Administration (FDA), European Medicines Agency (EMA), and Pharmaceuticals and Medical Devices Agency (PMDA) guidances on small-molecule drug-drug interactions (DDIs), with input from the International Transporter Consortium (ITC), recommend the evaluation of nine drug transporters. Although other clinically relevant drug uptake and efflux transporters have been discussed in ITC white papers, they have been excluded from further recommendation by the ITC and are not included in current regulatory guidances. These include the ubiquitously expressed equilibrative nucleoside transporters (ENT) 1 and ENT2, which have been recognized by the ITC for their potential role in clinically relevant nucleoside analog drug interactions for patients with cancer. Although there is comparatively limited clinical evidence supporting their role in DDI risk or other adverse drug reactions (ADRs) compared with the nine highlighted transporters, several in vitro and in vivo studies have identified ENT interactions with non-nucleoside/non-nucleotide drugs, in addition to nucleoside/nucleotide analogs. Some noteworthy examples of compounds that interact with ENTs include cannabidiol and selected protein kinase inhibitors, as well as the nucleoside analogs remdesivir, EIDD-1931, gemcitabine, and fialuridine. Consequently, DDIs involving the ENTs may be responsible for therapeutic inefficacy or off-target toxicity. Evidence suggests that ENT1 and ENT2 should be considered as transporters potentially involved in clinically relevant DDIs and ADRs, thereby warranting further investigation and regulatory consideration.
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Affiliation(s)
- Raymond K Hau
- Department of Pharmacology & Toxicology, College of Pharmacy, The University of Arizona, Tucson, Arizona, USA
| | - Stephen H Wright
- Department of Physiology, College of Medicine, The University of Arizona, Tucson, Arizona, USA
| | - Nathan J Cherrington
- Department of Pharmacology & Toxicology, College of Pharmacy, The University of Arizona, Tucson, Arizona, USA
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2
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Pinto-Cardoso R, Bessa-Andrês C, Correia-de-Sá P, Bernardo Noronha-Matos J. Could hypoxia rehabilitate the osteochondral diseased interface? Lessons from the interplay of hypoxia and purinergic signals elsewhere. Biochem Pharmacol 2023:115646. [PMID: 37321413 DOI: 10.1016/j.bcp.2023.115646] [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: 04/07/2023] [Revised: 06/03/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023]
Abstract
The osteochondral unit comprises the articular cartilage (90%), subchondral bone (5%) and calcified cartilage (5%). All cells present at the osteochondral unit that is ultimately responsible for matrix production and osteochondral homeostasis, such as chondrocytes, osteoblasts, osteoclasts and osteocytes, can release adenine and/or uracil nucleotides to the local microenvironment. Nucleotides are released by these cells either constitutively or upon plasma membrane damage, mechanical stress or hypoxia conditions. Once in the extracellular space, endogenously released nucleotides can activate membrane-bound purinoceptors. Activation of these receptors is fine-tuning regulated by nucleotides' breakdown by enzymes of the ecto-nucleotidase cascade. Depending on the pathophysiological conditions, both the avascular cartilage and the subchondral bone subsist to significant changes in oxygen tension, which has a tremendous impact on tissue homeostasis. Cell stress due to hypoxic conditions directly influences the expression and activity of several purinergic signalling players, namely nucleotide release channels (e.g. Cx43), NTPDase enzymes and purinoceptors. This review gathers experimental evidence concerning the interplay between hypoxia and the purinergic signalling cascade contributing to osteochondral unit homeostasis. Reporting deviations to this relationship resulting from pathological alterations of articular joints may ultimately unravel novel therapeutic targets for osteochondral rehabilitation. At this point, one can only hypothesize how hypoxia mimetic conditions can be beneficial to the ex vivo expansion and differentiation of osteo- and chondro-progenitors for auto-transplantation and tissue regenerative purposes.
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Affiliation(s)
- Rui Pinto-Cardoso
- Laboratório de Farmacologia e Neurobiologia; Center for Drug Discovery and Innovative Medicines (MedInUP), Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP)
| | - Catarina Bessa-Andrês
- Laboratório de Farmacologia e Neurobiologia; Center for Drug Discovery and Innovative Medicines (MedInUP), Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP)
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia; Center for Drug Discovery and Innovative Medicines (MedInUP), Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP)
| | - José Bernardo Noronha-Matos
- Laboratório de Farmacologia e Neurobiologia; Center for Drug Discovery and Innovative Medicines (MedInUP), Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP).
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3
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Couto AR, Parreira B, Power DM, Pinheiro L, Madruga Dias J, Novofastovski I, Eshed I, Sarzi-Puttini P, Pappone N, Atzeni F, Verlaan JJ, Kuperus J, Bieber A, Ambrosino P, Kiefer D, Khan MA, Mader R, Baraliakos X, Bruges-Armas J. Evidence for a genetic contribution to the ossification of spinal ligaments in Ossification of Posterior Longitudinal Ligament and Diffuse idiopathic skeletal hyperostosis: A narrative review. Front Genet 2022; 13:987867. [PMID: 36276944 PMCID: PMC9586552 DOI: 10.3389/fgene.2022.987867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/16/2022] [Indexed: 11/25/2022] Open
Abstract
Diffuse Idiopathic Skeletal Hyperostosis (DISH) and Ossification of the Posterior Longitudinal Ligament (OPLL) are common disorders characterized by the ossification of spinal ligaments. The cause for this ossification is currently unknown but a genetic contribution has been hypothesized. Over the last decade, many studies on the genetics of ectopic calcification disorders have been performed, mainly on OPLL. Most of these studies were based on linkage analysis and case control association studies. Animal models have provided some clues but so far, the involvement of the identified genes has not been confirmed in human cases. In the last few years, many common variants in several genes have been associated with OPLL. However, these associations have not been at definitive levels of significance and evidence of functional significance is generally modest. The current evidence suggests a multifactorial aetiopathogenesis for DISH and OPLL with a subset of cases showing a stronger genetic component.
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Affiliation(s)
- Ana Rita Couto
- Hospital de Santo Espirito da Ilha Terceira EPER, SEEBMO, Angra do Heroísmo, Portugal
- CHRC Campus Nova Medical School, Lisboa, Portugal
| | - Bruna Parreira
- Hospital de Santo Espirito da Ilha Terceira EPER, SEEBMO, Angra do Heroísmo, Portugal
- CHRC Campus Nova Medical School, Lisboa, Portugal
| | - Deborah M. Power
- University of Algarve, Center of Marine Science (CCMAR), Faro, Portugal
| | - Luís Pinheiro
- Hospital de Santo Espirito da Ilha Terceira EPER, Orthopedics Service, Angra do Heroísmo, Portugal
| | - João Madruga Dias
- Centro Hospitalar Do Medio Tejo EPE Unidade de Torres Novas, Rheumatology Department, Santarém, Portugal
- CHRC Campus Nova Medical School, EpiDoc Research Unit, CEDOC, Lisboa, Portugal
| | | | | | | | - Nicola Pappone
- Istituti Clinici Scientifici Maugeri IRCCS, Neuromotor Rehabilitation Unit of Telese Terme Institute, Pavia, Italy
| | - Fabiola Atzeni
- Universita Degli Studi di Messina, Rheumatology Unit, Clinical and Experimental Medicine, Messina, Italy
| | - Jorrit-Jan Verlaan
- University Medical Centre, Department of Orthopedics, Utrecht, Netherlands
| | | | - Amir Bieber
- Emek Medical Center, Rheumatology Unit, Afula, Israel
| | - Pasquale Ambrosino
- Istituti Clinici Scientifici Maugeri IRCCS, Cardiac Rehabilitation Unit of Telese Terme Institute, Pavia, Italy
| | - David Kiefer
- Ruhr-Universitat Bochum, Rheumazentrum Ruhrgebiet, Bochum, Germany
| | | | - Reuven Mader
- Emek Medical Center, Rheumatology Unit, Afula, Israel
- Rappaport Faculty of Medicine, Technion, Haifa, Israel
- Ruhr University Bochum, Rheumazentrum Ruhrgebiet, Herne, Germany
| | | | - Jácome Bruges-Armas
- Hospital de Santo Espirito da Ilha Terceira EPER, SEEBMO, Angra do Heroísmo, Portugal
- CHRC Campus Nova Medical School, Lisboa, Portugal
- *Correspondence: Jácome Bruges-Armas,
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Boneski PK, Madhu V, Tomlinson RE, Shapiro IM, van de Wetering K, Risbud MV. Abcc6 Null Mice—a Model for Mineralization Disorder PXE Shows Vertebral Osteopenia Without Enhanced Intervertebral Disc Calcification With Aging. Front Cell Dev Biol 2022; 10:823249. [PMID: 35186933 PMCID: PMC8850990 DOI: 10.3389/fcell.2022.823249] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 01/03/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic low back pain is a highly prevalent health condition intricately linked to intervertebral disc degeneration. One of the prominent features of disc degeneration that is commonly observed with aging is dystrophic calcification. ATP-binding cassette sub-family C member 6 (ABCC6), a presumed ATP efflux transporter, is a key regulator of systemic levels of the mineralization inhibitor pyrophosphate (PPi). Mutations in ABCC6 result in pseudoxanthoma elasticum (PXE), a progressive human metabolic disorder characterized by mineralization of the skin and elastic tissues. The implications of ABCC6 loss-of-function on pathological mineralization of structures in the spine, however, are unknown. Using the Abcc6−/− mouse model of PXE, we investigated age-dependent changes in the vertebral bone and intervertebral disc. Abcc6−/− mice exhibited diminished trabecular bone quality parameters at 7 months, which remained significantly lower than the wild-type mice at 18 months of age. Abcc6−/− vertebrae showed increased TRAP staining along with decreased TNAP staining, suggesting an enhanced bone resorption as well as decreased bone formation. Surprisingly, however, loss of ABCC6 resulted only in a mild, aging disc phenotype without evidence of dystrophic mineralization. Finally, we tested the utility of oral K3Citrate to treat the vertebral phenotype since it is shown to regulate hydroxyapatite mechanical behavior. The treatment resulted in inhibition of the osteoclastic response and an early improvement in mechanical properties of the bone underscoring the promise of potassium citrate as a therapeutic agent. Our data suggest that although ectopic mineralization is tightly regulated in the disc, loss of ABCC6 compromises vertebral bone quality and dysregulates osteoblast-osteoclast coupling.
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Affiliation(s)
- Paige K. Boneski
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Vedavathi Madhu
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ryan E. Tomlinson
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Irving M. Shapiro
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Makarand V. Risbud
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
- *Correspondence: Makarand V. Risbud,
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Daniels G. Augustine Blood Group System and Equilibrative Nucleoside Transporter 1. Transfus Med Hemother 2022; 49:25-29. [PMID: 35221865 PMCID: PMC8832251 DOI: 10.1159/000520596] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 10/27/2021] [Indexed: 10/02/2023] Open
Abstract
Augustine (AUG) is a blood group system comprising four antigens: AUG1, AUG2 (Ata), and AUG4 are of very high frequency; AUG3 is of very low frequency. These antigens are located on ENT1, an equilibrative nucleoside transporter encoded by SLC19A1. AUG antibodies are of clinical relevance in blood transfusion and pregnancy: anti-AUG2 have caused haemolytic transfusion reactions; the only anti-AUG3 was associated with severe haemolytic disease of the fetus and newborn. ENT1 is present in almost all human tissues. It facilitates the transfer of purine and pyrimidine nucleosides and is responsible for the majority of adenosine transport across plasma membranes. Adenosine transport appears to be an important factor in the regulation of bone metabolism. The AUGnull phenotype (AUG:-1,-2,-3,-4) has been found in three siblings, who are homozygous for an inactivating splice-site mutation in SLC29A1. Although ENT1 is very likely to be absent from all cells in these three individuals, they were apparently healthy with normal lifestyles. However, they suffered frequent attacks of pseudogout, a form of arthritis, in various joints with multiple calcifications around their hand joints. Ectopic calcification in the hips, pubic symphysis, and lumbar discs was present in the propositus. The three AUGnull individuals had misshapen red cells with deregulated protein phosphorylation, but no anaemia or shortening of red cell lifespan. Defective in vitro erythropoiesis in the absence of ENT1 was confirmed by shRNA-mediated knockdown of ENT1 during in vitro erythropoiesis of CD34+ progenitor cells from individuals with normal ENT1. Nucleoside transporters, such as ENT1, are vital in the uptake of synthetic nucleoside analogue drugs, used in cancer and viral chemotherapy. It is feasible that the efficacy of these drugs would be compromised in patients with the extremely rare AUGnull phenotype.
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Shi SL, Fukuda H, Chujo T, Kouwaki T, Oshiumi H, Tomizawa K, Wei FY. Export of RNA-derived modified nucleosides by equilibrative nucleoside transporters defines the magnitude of autophagy response and Zika virus replication. RNA Biol 2021; 18:478-495. [PMID: 34382915 PMCID: PMC8677048 DOI: 10.1080/15476286.2021.1960689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/14/2021] [Accepted: 07/23/2021] [Indexed: 11/25/2022] Open
Abstract
RNA contains a wide variety of posttranscriptional modifications covalently attached to its base or sugar group. These modified nucleosides are liberated from RNA molecules as the consequence of RNA catabolism and released into extracellular space, but the molecular mechanism of extracellular transport and its pathophysiological implications have been unclear. In the present study, we discovered that RNA-derived modified nucleosides are exported to extracellular space through equilibrative nucleoside transporters 1 and 2 (ENT1 and ENT2), with ENT1 showing higher preference for modified nucleosides than ENT2. Pharmacological inhibition or genetic deletion of ENT1 and ENT2 significantly attenuated export of modified nucleosides thereby resulting in their accumulation in cytosol. Using mutagenesis strategy, we identified an amino acid residue in ENT1 that is involved in the discrimination of unmodified and modified nucleosides. In ENTs-deficient cells, the elevated levels of intracellular modified nucleosides were closely associated with an induction of autophagy response as evidenced by increased LC3-II level. Importantly, we performed a screening of modified nucleosides capable of inducing autophagy and found that 1-methylguanosine (m1G) was sufficient to induce LC3-II levels. Pathophysiologically, defective export of modified nucleosides drastically induced Zika virus replication in an autophagy-dependent manner. In addition, we also found that pharmacological inhibition of ENTs by dilazep significantly induced Zika virus replication. Collectively, our findings highlight RNA-derived modified nucleosides as important signaling modulators that activate autophagy response and indicate that defective export of these modified nucleoside can have profound consequences for pathophysiology.
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Affiliation(s)
- Sheng-Lan Shi
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hiroyuki Fukuda
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takeshi Chujo
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takahisa Kouwaki
- Department of Immunology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hiroyuki Oshiumi
- Department of Immunology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kazuhito Tomizawa
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Fan-Yan Wei
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Miyagi, Japan
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7
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Fournier DE, Beaucage KL, Beach RJ, Kiser PK, Séguin CA, Dixon SJ. Ectopic mineralisation of the mandibular symphysis in ENT1 knockout mice: A model of dystrophic calcification. Bone Rep 2021; 15:101100. [PMID: 34258331 PMCID: PMC8253951 DOI: 10.1016/j.bonr.2021.101100] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 05/07/2021] [Accepted: 06/15/2021] [Indexed: 02/06/2023] Open
Abstract
Equilibrative nucleoside transporter 1 (ENT1) transfers nucleosides, such as adenosine, across plasma membranes. We reported previously that mice lacking ENT1 (ENT1 -/- ) exhibit progressive ectopic calcification of spinal tissues-a phenotype resembling diffuse idiopathic skeletal hyperostosis (DISH) in humans. Our objective was to investigate potential calcification of orofacial tissues in ENT1 -/- mice. Heads of wild-type mice and ENT1 -/- mice from 3 to 17 months were evaluated using microcomputed tomography (μCT). Some heads were decalcified and processed for histological assessment. Other heads were examined using energy dispersive X-ray spectroscopy and micro X-ray diffraction. Using μCT, ENT1 -/- mice showed extensive radiopaque lesions within the mandibular symphysis, the severity of which increased with advancing age. Histologically, at 6 months these ectopic radiopacities were found to correspond to acellular, amorphous, eosinophilic material, with no evidence of inflammatory cells. Because lesions were localised to the symphysis, we identified early pathological changes at 3 months and observed that lesions initiated specifically within the fibrocartilage pad. Energy-dispersive X-ray spectroscopy of ectopic lesions revealed large amounts of calcium and phosphorous in a molar ratio of ~1.59, and X-ray diffraction profiles matched that of calcium-deficient hydroxyapatite. This is the first characterisation of ectopic calcifications within the mandibular symphysis of ENT1 -/- mice, indicating a role for ENT1 and adenosine metabolism in regulating calcification of fibrocartilaginous tissues. Moreover, these murine lesions resemble areas of dystrophic calcification in the spinal tissues of humans with DISH. Importantly, ectopic calcifications develop in a reproducible temporal pattern within a well-defined anatomical region and, thus, provide a model for determining the cellular and molecular pathways underlying ectopic calcification in DISH and related disorders.
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Affiliation(s)
- Dale E Fournier
- Health and Rehabilitation Sciences, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada.,Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada
| | - Kim L Beaucage
- Dentistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Ryan J Beach
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Patti K Kiser
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Cheryle A Séguin
- Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - S Jeffrey Dixon
- Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada.,Dentistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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Cao LB, Leung CK, Law PWN, Lv Y, Ng CH, Liu HB, Lu G, Ma JL, Chan WY. Systemic changes in a mouse model of VCD-induced premature ovarian failure. Life Sci 2020; 262:118543. [PMID: 33038381 DOI: 10.1016/j.lfs.2020.118543] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 09/29/2020] [Indexed: 02/07/2023]
Abstract
AIMS Premature ovarian failure (POF) is a phenomenon in which the ovaries fail before the age of 40 years. Prior research has used a wide range of mouse models designed to reflect different causes of POF, including genetic factors, iatrogenic factors, and immune factors. The current study employed a mouse model of POF induced by 4-vinylcyclohexene diepoxide (VCD). VCD can specifically kill primordial and primary ovarian follicles, which destroys the follicular reserve and causes POF. The current study sought to specify and extend the applications of this model by examining the effect of timing and VCD dose and by exploring the effect of the model on systems outside of the ovaries. MATERIALS AND METHODS A VCD-induced mouse model of POF was constructed using established methods (VCD injected continuously at a concentration of 160 mg/kg for 15 days). Evidence for a graded effect of VCD was observed using a range of concentrations, and the best windows for examining VCD's effects on follicles and associated tissues were identified. KEY FINDINGS The mouse model used here successfully simulated two common complications of POF - emotional changes and decreased bone density. The model's application was then extended to examine the links between disease and intestinal microorganisms, and evidence was found linking POF to the reproductively relevant composition of the gut microbiota. SIGNIFICANCE These findings provide novel methodological guidance for future research, and they significantly extend the applications and scope of VCD-induced POF mouse models.
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Affiliation(s)
- Lian Bao Cao
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250001, China; CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China
| | - Chi Kwan Leung
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250001, China; CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China; SDIVF R&D Centre, Hong Kong Science and Technology Parks, Shatin, Hong Kong, China
| | - Patrick Wai-Nok Law
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China
| | - Yue Lv
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250001, China; CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China
| | - Cheuk-Hei Ng
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250001, China; CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China; SDIVF R&D Centre, Hong Kong Science and Technology Parks, Shatin, Hong Kong, China
| | - Hong Bin Liu
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250001, China; CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China; SDIVF R&D Centre, Hong Kong Science and Technology Parks, Shatin, Hong Kong, China
| | - Gang Lu
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China.
| | - Jin Long Ma
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250001, China; CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China; SDIVF R&D Centre, Hong Kong Science and Technology Parks, Shatin, Hong Kong, China
| | - Wai Yee Chan
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong 250001, China.
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9
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Local delivery of adenosine receptor agonists to promote bone regeneration and defect healing. Adv Drug Deliv Rev 2019; 146:240-247. [PMID: 29913176 DOI: 10.1016/j.addr.2018.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 05/08/2018] [Accepted: 06/12/2018] [Indexed: 01/07/2023]
Abstract
Adenosine receptor activation has been investigated as a potential therapeutic approach to heal bone. Bone has enhanced regenerative potential when influenced by either direct or indirect adenosine receptor agonism. As investigators continue to elucidate how adenosine influences bone cell homeostasis at the cellular and molecular levels, a small but growing body of literature has reported successful in vivo applications of adenosine delivery. This review summarizes the role adenosine receptor ligation plays in osteoblast and osteoclast biology and remodeling/regeneration. It also reports on all the modalities described in the literature at this point for delivery of adenosine through in vivo models for bone healing and regeneration.
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10
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Best KA, Bone DB, Vilas G, Gros R, Hammond JR. Changes in aortic reactivity associated with the loss of equilibrative nucleoside transporter 1 (ENT1) in mice. PLoS One 2018; 13:e0207198. [PMID: 30408123 PMCID: PMC6224178 DOI: 10.1371/journal.pone.0207198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 10/26/2018] [Indexed: 01/23/2023] Open
Abstract
Slc29a1 encodes for equilibrative nucleoside transporter subtype 1 (ENT1), the primary mechanism of adenosine transfer across cell membranes. Previous studies showed that tissues isolated from Slc29a1-null mice are relatively resistant to injury caused by vascular ischemia-reperfusion. To determine if there are similar changes in the microvasculature, and investigate underlying mechanism, we examined aortas isolated from wildtype and Slc29a1-null mice. Aorta macrostructure and gene expression were examined histologically and by qPCR, respectively. Wire myography was used to assess the contractile properties of isolated thoracic aortic rings and their response to adenosine under both normoxic and hypoxic conditions. In vivo haemodynamic parameters were assessed using the tail-cuff method. Slc29a1-null mice had significantly (P<0.05) increased plasma adenosine (2.75-fold) and lower blood pressure (~15% ↓) than wild-type mice. Aortas from Slc29a1-null mice were stiffer with a smaller circumference (11% ↓), and had an enhanced contractile response to KCl and receptor-mediated stimuli. Blockade of ENT1 with nitrobenzylthioinosine significantly enhanced (by ~3.5-fold) the response of aorta from wild-type mice to phenylephrine, but had minimal effect on aortas from Slc29a1-null mice. Adenosine enhanced phenylephrine-mediated constriction in the wild-type tissue under both normoxic (11.7-fold) and hypoxic (3.6-fold) conditions, but had no effect on the Slc29a1-null aortic aorta. In conclusion, aortas from Slc29a1-null mice respond to hypoxic insult in a manner comparable to wild-type tissues that have been pharmacologically preconditioned with adenosine. These data also support a role for ENT1 in the regulation of the protective effects of adenosine on contractile function in elastic conduit arteries such as thoracic aorta.
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Affiliation(s)
- K. Arielle Best
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Derek B. Bone
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Gonzalo Vilas
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - Robert Gros
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
- Molecular Medicine Research Group, Robarts Research Institute, London, Ontario, Canada
| | - James R. Hammond
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
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Abstract
PURPOSE OF REVIEW To summarize and discuss recent progress and novel signaling mechanisms relevant to bone marrow adipocyte formation and its physiological/pathophysiological implications for bone remodeling. RECENT FINDINGS Skeletal remodeling is a coordinated process entailing removal of old bone and formation of new bone. Several bone loss disorders such as osteoporosis are commonly associated with increased bone marrow adipose tissue. Experimental and clinical evidence supports that a reduction in osteoblastogenesis from mesenchymal stem cells at the expense of adipogenesis, as well as the deleterious effects of adipocyte-derived signaling, contributes to the etiology of osteoporosis as well as bone loss associated with aging, diabetes mellitus, post-menopause, and chronic drug therapy. However, this view is challenged by findings indicating that, in some contexts, bone marrow adipose tissue may have a beneficial impact on skeletal health. Further research is needed to better define the role of marrow adipocytes in bone physiology/pathophysiology and to determine the therapeutic potential of manipulating mesenchymal stem cell differentiation.
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Affiliation(s)
- Shanmugam Muruganandan
- Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA
| | - Rajgopal Govindarajan
- Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA
| | - Christopher J Sinal
- Department of Pharmacology, Dalhousie University, 5850 College Street, Box 15000, Halifax, Nova Scotia, B3H4R2, Canada.
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Pastor-Anglada M, Pérez-Torras S. Emerging Roles of Nucleoside Transporters. Front Pharmacol 2018; 9:606. [PMID: 29928232 PMCID: PMC5997781 DOI: 10.3389/fphar.2018.00606] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/21/2018] [Indexed: 01/02/2023] Open
Abstract
Since human Nucleoside Transporters (hNTs) were identified by their activity as transport systems, extensive work has been done to fully characterize them at the molecular and physiological level. Many efforts have been addressed to the identification of their selectivity for natural substrates and nucleoside analogs used to treat several diseases. hNTs belong to two different gene families, SLC28 and SLC29, encoding human Concentrative Nucleoside Transporters (hCNTs) and human Equilibrative Nucleoside Transporters (hENTs), respectively. hCNTs and hENTs are integral membrane proteins, albeit structurally unrelated. Both families share common features as substrate selectivity and often tissue localization. This apparent biological redundancy may anticipate some different roles for hCNTs and hENTs in cell physiology. Thus, hENTs may have a major role in maintaining nucleoside homeostasis, whereas hCNTs could contribute to nucleoside sensing and signal transduction. In this sense, the ascription of hCNT1 to a transceptor reinforces this hypothesis. Moreover, some evidences could suggest a putative role of hCNT2 and hCNT3 as transceptors. The interacting proteins identified for hCNT2 suggest a link to energy metabolism. Moreover, the ability of hCNT2 and hCNT3 to transport adenosine links both proteins to purinergic signaling. On the other hand, the broad selectivity transporters hENTs have a crucial role in salvage pathways and purinergic signaling by means of nucleoside pools regulation. In particular, the two new hENT2 isoforms recently described together with hENT2 seem to be key elements controlling nucleoside and nucleotide pools for DNA synthesis. This review focuses on all these NTs functions beyond their mere translocation ability.
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Affiliation(s)
- Marçal Pastor-Anglada
- Biochemistry and Molecular Pharmacology Section, Department of Biochemistry and Molecular Biomedicine, Institute of Biomedicine (IBUB), University of Barcelona, Barcelona, Spain
| | - Sandra Pérez-Torras
- Biochemistry and Molecular Pharmacology Section, Department of Biochemistry and Molecular Biomedicine, Institute of Biomedicine (IBUB), University of Barcelona, Barcelona, Spain
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Ye Q, Li G, Liu S, Guan Y, Li Y, Li J, Jia H, Li X, Li Q, Huang R, Wang H, Zhang Y. Targeted disruption of adenosine kinase in myeloid monocyte cells increases osteoclastogenesis and bone resorption in mice. Int J Mol Med 2018; 41:2177-2184. [PMID: 29344645 DOI: 10.3892/ijmm.2018.3394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/05/2018] [Indexed: 11/05/2022] Open
Abstract
Adenosine kinase (ADK) serves an important role in intracellular adenosine clearance via phosphorylating adenosine to AMP. The role of adenosine and its receptors in the maintenance of bone homeostasis is well studied, particularly in osteoclastogenesis and bone resorption; however, the function of ADK in bone metabolism is still unclear. In the present study, utilizing the cre/floxp recombination system, mice with conditional loss of ADK function in myeloid monocyte cells were used to assess the effect of ADK deficiency on bone metabolism. Mice were evaluated by means of gross observation and bone histomorphometric analysis. Ex vivo osteoclast differentiation and bone resorption were also examined using genetic deletion and pharmacologic inhibition of ADK in osteoclasts. Compared with control mice, the results of the present study demonstrate that adult mice lacking ADK in the myeloid monocyte cells had reduced body weight and nasoanal length. The results of bone histomorphometric analysis revealed that bone mass was significantly decreased and osteoclastic parameters were increased in the study mice. Furthermore, in vitro cell culture revealed that inhibition of ADK function promoted osteoclast differentiation and bone resorption. Osteoclast‑associated gene expression, including tartrate‑resistant acid phosphatase, nuclear factor of activated T‑cells, cytoplasmic 1, matrix metalloproteinase 9, Cathepsin K and calcitonin receptor, was also significantly increased. These results suggest that mice with ADK deficiency have reduced bone formation due to increased osteoclastogenesis and bone resorption. The present study provides further insight into the mechanism by which ADK serves a key role in bone metabolism.
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Affiliation(s)
- Qiuying Ye
- Department of Food and Drugs, Qingyuan Polytechnic, Qingyuan, Guangdong 511510, P.R. China
| | - Ge Li
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Shuhua Liu
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Yalun Guan
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Yunfeng Li
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Jinling Li
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Huanhuan Jia
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Xuejiao Li
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Qingnan Li
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Ren Huang
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
| | - Hui Wang
- Department of Food and Drugs, Qingyuan Polytechnic, Qingyuan, Guangdong 511510, P.R. China
| | - Yu Zhang
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou, Guangdong 510663, P.R. China
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15
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Oliveros A, Starski P, Lindberg D, Choi S, Heppelmann CJ, Dasari S, Choi DS. Label-Free Neuroproteomics of the Hippocampal-Accumbal Circuit Reveals Deficits in Neurotransmitter and Neuropeptide Signaling in Mice Lacking Ethanol-Sensitive Adenosine Transporter. J Proteome Res 2017; 16:1445-1459. [PMID: 27998058 DOI: 10.1021/acs.jproteome.6b00830] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The neural circuit of the dorsal hippocampus (dHip) and nucleus accumbens (NAc) contributes to cue-induced learning and addictive behaviors, as demonstrated by the escalation of ethanol-seeking behaviors observed following deletion of the adenosine equilibrative nucleoside transporter 1 (ENT1-/-) in mice. Here we perform quantitative LC-MS/MS neuroproteomics in the dHip and NAc of ENT1-/- mice. Using Ingenuity Pathway Analysis, we identified proteins associated with increased long-term potentiation, ARP2/3-mediated actin cytoskeleton signaling and protein expression patterns suggesting deficits in glutamate degradation, GABAergic signaling, as well as significant changes in bioenergetics and energy homeostasis (oxidative phosphorylation, TCA cycle, and glycolysis). These pathways are consistent with previously reported behavioral and biochemical phenotypes that typify mice lacking ENT1. Moreover, we validated decreased expression of the SNARE complex protein VAMP1 (synaptobrevin-1) in the dHip as well as decreased expression of pro-dynorphin (PDYN), neuroendocrine convertase (PCSK1), and Leu-Enkephalin (dynorphin-A) in the NAc. Taken together, our proteomic approach provides novel pathways indicating that ENT1-regulated signaling is essential for neurotransmitter release and neuropeptide processing, both of which underlie learning and reward-seeking behaviors.
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Affiliation(s)
- Alfredo Oliveros
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Phillip Starski
- Neurobiology of Disease Program, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Daniel Lindberg
- Neurobiology of Disease Program, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Sun Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Carrie J Heppelmann
- Proteomics Research Center, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Surendra Dasari
- Division of Biomedical Statistics and Informatics, Mayo Clinic , Rochester, Minnesota 55905, United States
| | - Doo-Sup Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic , Rochester, Minnesota 55905, United States.,Neurobiology of Disease Program, Mayo Clinic , Rochester, Minnesota 55905, United States.,Department of Psychiatry and Psychology, Mayo Clinic , Rochester, Minnesota 55905, United States
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16
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Strazzulla LC, Cronstein BN. Regulation of bone and cartilage by adenosine signaling. Purinergic Signal 2016; 12:583-593. [PMID: 27473363 PMCID: PMC5124004 DOI: 10.1007/s11302-016-9527-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 07/14/2016] [Indexed: 12/28/2022] Open
Abstract
There is growing recognition that bone serves important endocrine and immunologic functions that are compromised in several disease states. While many factors are known to affect bone metabolism, recent attention has focused on investigating the role of purinergic signaling in bone formation and regulation. Adenosine is a purine nucleoside produced intracellularly and extracellularly in response to stimuli such as hypoxia and inflammation, which then interacts with P1 receptors. Numerous studies have suggested that these receptors play a pivotal role in osteoblast, osteoclast, and chondrocyte differentiation and function. This review discusses the various ways by which adenosine signaling contributes to bone and cartilage homeostasis, while incorporating potential therapeutic applications of these signaling pathways.
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Affiliation(s)
- Lauren C Strazzulla
- Department of Medicine, School of Medicine, New York University , New York, NY, 10016, USA
| | - Bruce N Cronstein
- Divisions of Rheumatology and Translational Medicine, Department of Medicine, School of Medicine, New York University, 550 First Avenue, MSB251, New York, NY, 10016, USA.
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Boswell-Casteel RC, Hays FA. Equilibrative nucleoside transporters-A review. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2016; 36:7-30. [PMID: 27759477 DOI: 10.1080/15257770.2016.1210805] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Equilibrative nucleoside transporters (ENTs) are polytopic integral membrane proteins that mediate the transport of nucleosides, nucleobases, and therapeutic analogs. The best-characterized ENTs are the human transporters hENT1 and hENT2. However, non-mammalian eukaryotic ENTs have also been studied (e.g., yeast, parasitic protozoa). ENTs are major pharmaceutical targets responsible for modulating the efficacy of more than 30 approved drugs. However, the molecular mechanisms and chemical determinants of ENT-mediated substrate recognition, binding, inhibition, and transport are poorly understood. This review highlights findings on the characterization of ENTs by surveying studies on genetics, permeant and inhibitor interactions, mutagenesis, and structural models of ENT function.
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Affiliation(s)
- Rebba C Boswell-Casteel
- a Department of Biochemistry and Molecular Biology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Franklin A Hays
- a Department of Biochemistry and Molecular Biology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA.,b Stephenson Cancer Center , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA.,c Harold Hamm Diabetes Center , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
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18
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Ii H, Warraich S, Tenn N, Quinonez D, Holdsworth DW, Hammond JR, Dixon SJ, Séguin CA. Disruption of biomineralization pathways in spinal tissues of a mouse model of diffuse idiopathic skeletal hyperostosis. Bone 2016; 90:37-49. [PMID: 27237608 DOI: 10.1016/j.bone.2016.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 01/06/2023]
Abstract
Equilibrative nucleoside transporter 1 (ENT1) mediates passage of adenosine across the plasma membrane. We reported previously that mice lacking ENT1 (ENT1(-/-)) exhibit progressive ectopic mineralization of spinal tissues resembling diffuse idiopathic skeletal hyperostosis (DISH) in humans. Here, we investigated mechanisms underlying aberrant mineralization in ENT1(-/-) mice. Micro-CT revealed ectopic mineralization of spinal tissues in both male and female ENT1(-/-) mice, involving the annulus fibrosus of the intervertebral discs (IVDs) of older mice. IVDs were isolated from wild-type and ENT1(-/-) mice at 2months of age (prior to disc mineralization), 4, and 6months of age (disc mineralization present) and processed for real-time PCR, cell isolation, or histology. Relative to the expression of ENTs in other tissues, ENT1 was the primary nucleoside transporter expressed in wild-type IVDs and mediated the functional uptake of [(3)H]2-chloroadenosine by annulus fibrosus cells. No differences in candidate gene expression were detected in IVDs from ENT1(-/-) and wild-type mice at 2 or 4months of age. However, at 6months of age, expression of genes that inhibit biomineralization Mgp, Enpp1, Ank, and Spp1 were reduced in IVDs from ENT1(-/-) mice. To assess whether changes detected in ENT1(-/-) mice were cell autonomous, annulus fibrosus cell cultures were established. Compared to wild-type cells, cells isolated from ENT1(-/-) IVDs at 2 or 6months of age demonstrated greater activity of alkaline phosphatase, a promoter of biomineralization. Cells from 2-month-old ENT1(-/-) mice also showed greater mineralization than wild-type. Interestingly, altered localization of alkaline phosphatase activity was detected in the inner annulus fibrosus of ENT1(-/-) mice in vivo. Alkaline phosphatase activity, together with the marked reduction in mineralization inhibitors, is consistent with the mineralization of IVDs seen in ENT1(-/-) mice at older ages. These findings establish that both cell-autonomous and systemic mechanisms contribute to ectopic mineralization in ENT1(-/-) mice.
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Affiliation(s)
- Hisataka Ii
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada; Department of Oral Health School of Life Dentistry at Tokyo, The Nippon Dental University, 1-9-20 Fujimi, Chiyoda-ku, Tokyo 102-8159, Japan
| | - Sumeeta Warraich
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada
| | - Neil Tenn
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada
| | - Diana Quinonez
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada
| | - David W Holdsworth
- Imaging Research Laboratories, Robarts Research Institute, Department of Surgery, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada
| | - James R Hammond
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - S Jeffrey Dixon
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada
| | - Cheryle A Séguin
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, and Bone and Joint Institute, The University of Western Ontario, London, Ontario, Canada.
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Lack of the nucleoside transporter ENT1 results in the Augustine-null blood type and ectopic mineralization. Blood 2015; 125:3651-4. [PMID: 25896650 DOI: 10.1182/blood-2015-03-631598] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/12/2015] [Indexed: 01/26/2023] Open
Abstract
The Augustine-negative alias At(a-) blood type, which seems to be restricted to people of African ancestry, was identified half a century ago but remains one of the last blood types with no known genetic basis. Here we report that a nonsynonymous single nucleotide polymorphism in SLC29A1 (rs45458701) is responsible for the At(a-) blood type. The resulting p.Glu391Lys variation in the last extracellular loop of the equilibrative nucleoside transporter 1 (ENT1; also called SLC29a1) is known not to alter its ability to transport nucleosides and nucleoside analog drugs. Furthermore, we identified 3 individuals of European ancestry who are homozygous for a null mutation in SLC29A1 (c.589+1G>C) and thus have the Augustine-null blood type. These individuals lacking ENT1 exhibit periarticular and ectopic mineralization, which confirms an important role for ENT1/SLC29A1 in human bone homeostasis as recently suggested by the skeletal phenotype of aging Slc29a1(-/-) mice. Our results establish Augustine as a new blood group system and place SLC29A1 as a new candidate gene for idiopathic disorders characterized with ectopic calcification/mineralization.
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Hinton DJ, Lee MR, Jang JS, Choi DS. Type 1 equilibrative nucleoside transporter regulates astrocyte-specific glial fibrillary acidic protein expression in the striatum. Brain Behav 2014; 4:903-14. [PMID: 25365803 PMCID: PMC4178301 DOI: 10.1002/brb3.283] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 06/30/2014] [Accepted: 08/26/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Adenosine signaling has been implicated in several neurological and psychiatric disorders. Previously, we found that astrocytic excitatory amino acid transporter 2 (EAAT2) and aquaporin 4 (AQP4) are downregulated in the striatum of mice lacking type 1 equilibrative nucleoside transporter (ENT1). METHODS To further investigate the gene expression profile in the striatum, we preformed Illumina Mouse Whole Genome BeadChip microarray analysis of the caudate-putamen (CPu) and nucleus accumbens (NAc) in ENT1 null mice. Gene expression was validated by RT-PCR, Western blot, and immunofluorescence. Using transgenic mice expressing enhanced green fluorescence protein (EGFP) under the control of the glial fibrillary acidic protein (GFAP) promoter, we examined EGFP expression in an ENT1 null background. RESULTS Glial fibrillary acidic protein was identified as a top candidate gene that was reduced in ENT1 null mice compared to wild-type littermates. Furthermore, EGFP expression was significantly reduced in GFAP-EGFP transgenic mice in an ENT1 null background in both the CPu and NAc. Finally, pharmacological inhibition or siRNA knockdown of ENT1 in cultured astrocytes also reduced GFAP mRNA levels. CONCLUSIONS Overall, our findings demonstrate that ENT1 regulates GFAP expression and possibly astrocyte function.
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Affiliation(s)
- David J Hinton
- Department of Psychiatry and Psychology, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905 ; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905 ; Neurobiology of Disease Program, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905
| | - Moonnoh R Lee
- Department of Biochemistry and Molecular Biology, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905
| | - Jin Sung Jang
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905
| | - Doo-Sup Choi
- Department of Psychiatry and Psychology, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905 ; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905 ; Neurobiology of Disease Program, Mayo Clinic, College of Medicine Rochester, Minnesota, 55905
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